ALBERT

Description: Introduction: Adeno-associated virus (AAV)-based factor IX (FIX) gene therapy has the potential to provide clinical benefit in patients with hemophilia B. TAK-748 is a novel next-generation AAV vector for FIX gene therapy. The vector design includes the insertion of 3 hepatocyte-specific cis-regulatory elements to increase the strength of the liver-specific transthyretin promoter driving expression of a human FIX transgene. Aims: The objectives of this study were to investigate the TAK-748 dose-response relationship for FIX activity, and evaluate its efficacy, in FIX knockout (KO) mice and rhesus monkeys. Methods: Male FIX KO mice (N=12/group) received single intravenous doses of TAK-748 (7.4×1010, 1.5×1011, 7.4×1011, or 1.5×1012 vector genomes [vg]/kg) or buffer. Blood samples were taken on days 7, 14, 28, 42, and 56 for the analysis of plasma FIX activity. At the end of the observation period, the bleeding phenotype was assessed by a tail-tip bleeding assay. The viral transduction efficiency of TAK-748 in liver tissue was analyzed by quantitative real-time polymerase chain reaction. Safety assessments included monitoring for clinical signs, and histopathological analysis of selected organs (liver, spleen, kidney, and heart). Male rhesus monkeys (N=3/group) were administered single TAK-748 intravenous bolus injections (3.8×1011, 9.5×1011, or 1.9×1012 vg/kg). Blood samples were collected before dosing and weekly after dosing up to week 18. Plasma FIX activity, human (hu)FIX antigen, and anti-hu-Padua FIX neutralizing antibodies were analyzed. Results: No clinical signs or deaths were recorded in animals treated with TAK-748, and there were no TAK-748-related histopathological findings in the tissues collected from the mice. FIX activity levels in plasma from FIX KO mice treated with buffer were below the lower limit of quantification. Administration of TAK-748 resulted in a dose-dependent increase in mean plasma FIX activity, and supraphysiologic mean FIX levels up to 41.0 IU/mL (1.5×1012 vg/kg). In the tail-tip bleeding assay, blood loss was significantly reduced in the TAK-748 groups at dose levels above 7.4×1010 vg/kg (P

Description: Introduction Monoclonal gammopathy of undetermined significance (MGUS) is a clinically asymptomatic premalignant plasma cell disorder. Previous studies in Western countries have described the prevalence of MGUS in Caucasians. However, data is limited in Chinese population. We therefore performed this study to ascertain the prevalence and characteristics of MGUS among Chinese population. Methods A total of 154597 consecutive healthy participants from Beijing who underwent annual physical examination between December 2013 and April 2019 at Peking Union Medical College Hospital were enrolled. Serum M protein was evaluated by capillary electrophoresis. Patients with a positive or suspicious serum M protein were suggested to be referred to the hematological clinic for immunofixation electrophoresis (IFE) and free light chain (FLC) assays. MGUS was defined in accordance with previous definitions. We calculated age-specific and sex-specific prevalence and described laboratory characteristics of patients with MGUS among those participants. Results MGUS were diagnosed in 843 patients (0.55%, 95%CI 0.51% to 0.59%). The median age at presentation was 58 years, with a range of 25-96 years. The overall prevalence of MGUS was 1.14% among participants aged 50 years or older and 2.6% among those aged 70 years or older. In both sexes, the prevalence increased with age: 0.1% (

Description: BACKGROUND: In multiple myeloma (MM), deletion of TP53/17p (del17p), present in around 10% of patients, is associated with shortened survival. Lower incidence of del17p is reported in African Americans (AA) compared to European Americans (EA), alluding to possible contribution of disease biology to racial differences in outcome among AA and EA patients with MM. Our recent report of a significantly superior age-adjusted risk of death in AA compared to EA patients in the younger (

Description: The advent of therapeutic monoclonal antibodies (elotuzumab, daratumumab) for multiple myeloma (MM) heralded a new era of immunologic therapy for this disease. Laboratory and clinical data suggest that immune checkpoint inhibitors (ICI) targeting the PD-1/PD-L1 axis are a promising novel strategy, as PD-L1 is commonly expressed on MM cells and a phase 2 clinical trial demonstrated encouraging responses to pembrolizumab (anti-PD-1) in combination with pomalidomide and dexamethasone. However, two late stage MM clinical trials of ICI combined with either lenalidomide or pomalidomide were halted due to safety concerns and lack of efficacy, although subgroup analysis suggested that the overall response rate in subjects with immune related adverse events was higher in subjects who received pembrolizumab + pomalidomide and dexamethasone vs the control group. As a result, further investigation of ICI in MM has largely discontinued. This discrepancy with the positive findings in the early phase trial suggests that genetic or immunologic features of the tumors or immune microenvironment of the patients may influence outcome to ICI, but these factors are as yet undefined. In solid tumors, high mutation burden as assessed by microsatellite sequence instability-high (MSI-high) or mismatch repair genes deficiency (dMMR) was correlated to response to anti-PD-1 ICI, and is now an indication for these agents. Newly diagnosed MM is considered an intermediate-low mutation burden disease (

Description: Elevated plasma levels of the nucleoside diphosphate kinase (NDPK) NM23-H1 are associated with poorer prognosis in acute myeloid leukemia (AML). We previously demonstrated that leukemic blasts release NM23-H1, which binds to more differentiated myeloid cells inducing their secretion of inflammatory cytokines, including IL-1β, that promote survival and proliferation of leukemic blasts1. Both AML and myelodysplastic syndrome (MDS) patients are prone to infections due to impaired hematopoiesis that is worsened by treatment. NDPKs are highly evolutionarily conserved raising the possibility that bacterial/fungal NDPKs could mediate the same survival effect on malignant AML/MDS blasts and exacerbate disease progression. To test this, we generated recombinant NDPKs (rNDPKs) from bacteria and fungi associated with common infections in these patients (E. coli, S. aureus, S. pneumoniae, K. pneumoniae, C. albicans). Cytokine production and survival responses of primary AMLs to these proteins were indistinguishable from their response to rNM23-H1. This activity was independent of NDPK enzyme activity since mutant rNM23-H1 and bacterial and fungal rNDPKs with impaired oligomerization, kinase or exonuclease activity elicited the same cytokine and survival response. Toll like receptors (TLRs) are the major family of human DAMP/PAMP receptors and IL-1β secretion is closely associated with TLR-4 mediated activation of the NLRP3 inflammasome in monocytes. We therefore postulated that NM23-H1 and pathogen derived NDPKs act as novel damage- and pathogen- associated molecular pattern (DAMP, PAMP) molecules. We confirmed that fluorescently labelled rNM23-H1 and S. pneumoniae rNDPK bound selectively to monocytes in peripheral blood. Using in vitro generated monocytes (vitamin D3 differentiated THP-1 cells) we demonstrated that both wild type and mutant rNM23-H1 and bacterial/fungal rNDPKs induced activation of caspase-1 and cleavage of pro-IL-1β into its active form. Secretion of IL-1β was inhibited by antagonists/inhibitors of TLR4, NLRP3 and caspase-1 indicating the involvement of the TLR4-NLRP3 inflammasome axis is mediating the NDPK response. Unlike the canonical NLRP3-inflammasome pathway that leads to monocyte cell death by pyroptosis, rNM23-H1 and rNDPKs did not lead to cell death indicating that rNDPKs are responsible for the activation of the alternative inflammasome. In our earlier studies, and those of others, we demonstrated that not all AML primary samples responsed to NM23-H1 in vitro. We have observed that non responders to NM23-H1 also do not respond to pathogen derived rNDPKs. In contrast, we have observed uniform responses in terms of cytokine release in all normal peripheral blood. We hence hypothesized that the non-rNDPK-responding AML samples may reflect the absence of monocytes in culture. To test this, we generated conditioned media using normal donor leukocytes, in presence or absence of a TLR-4 antagonist to inhibit the IL-1β production. The conditioned media was then used to culture primary AML samples, in parallel with rNDPK in unconditioned media. All the samples analyzed showed increased survival in rNDPK conditioned media even whilst some did not respond to rNDPK in unconditioned media. In summary, our data demonstrate for the first time that NM23-H1 and bacterial/fungal NDPKs are novel DAMPs/PAMPS that signal via TLR4 in monocytes. We further demonstrate that this interaction results in activation of the alternative NLRP3 inflammasome and subsequent cleavage and secretion of IL-1β without death by pyroptosis. Our data showing that bacterial/fungal NDPKs can promote survival of AML blasts indicates that rather than just being a consequence of AML associated immunosuppression, infections may drive the progression and AML. These findings have important implications in the clinical management of AML and its precursor myelodysplastic syndromes (MDS). Lilly AJ, et al.Cancer Res. 2011;71(3):1177-86.Gaidt MM, et al. Immunity. 2016;44(4):833-46 Disclosures Drayson: Abingdon Health: Consultancy, Equity Ownership.

Description: Cancer cells have altered energy demand due to their increased proliferative capacity. In Waldenstrom Macroglobulinemia (WM), an indolent yet incurable B-cell lymphoma, the homeostasis of the bone marrow (BM) environment is disturbed due to the infiltration of the lymphoplamacytic cells that continuously produce monoclonal IgM. An alteration in energy demand could skew the balance of key proteins and metabolites towards a permissive niche for WM tumor cells growth, and unfavorably effect on the immune response against tumor cells. Therefore, the aim of our study was to identify how changes in certain metabolites and/or proteins could contribute to the pathobiology of WM and whether the cytokine and chemokine composition of the BM microenvironment play a role in such changes. WM patient's samples including BM plasma, peripheral blood serum and BM cells (n=101) as well as equivalent normal counterparts (n=86) were collected and used for metabolomics analysis. Comprehensive targeted metabolomics analysis was performed using Capillary Electrophoresis Time-of-Flight Mass spectrometry (CE-TOFMS), CE-triple quadrupole mass spectrometry (CE-qQqMS) and Liquid Chromatography (LC-TOFMS). Normal and WM peripheral blood serums samples were also used for untargeted proteomics analysis using a fully automated proteomic technology platform that includes an Agilent 1200 Series Quaternary HPLC system connected to a Q Exactive Plus mass spectrometer. Real-time PCR analysis was performed to detect the gene expression of the relevant metabolite transporters located on the cell membrane. BM cells from control and WM patients' samples were used for flow cytometry analysis. IHC was used to detect the proteins on the BM tissues. Principal Component Analysis (PCA) and Hierarchal Clustering Analysis (HCA) on both metabolomics and proteomics data identified two distinct clusters for disease and normal samples, indicating that there are differentially expressed proteins and metabolites in WM versus normal samples. Furthermore, pathway analysis showed that the majority of the altered metabolites were the members of the glutathione (GSH) metabolism pathway. This finding was further validated not only by data obtained from metabolomics analysis of BM cells and BM plasma, but also by proteomic data WM patients serum, implying that GSH metabolism is key to the biology of WM. Moreover, stimulation of WM cell lines by IL-6 and IL-21, cytokines involved in inducing WM cell proliferation and IgM secretion, resulted in increased gene expression of the transporters mediating uptake of metabolites required for GSH synthesis, including SLC7A11, 4F2HC and LAT1, indicating that cytokines in the WM BM could modulate GSH metabolism. In addition, IHC staining of the BM tissues as well as flow cytometry analysis of patients' lymphoplasmacytic cells identified glutathione peroxidase as one of the major proteins modulating GSH metabolism in WM. In summary, our data highlight a central role for GSH metabolism in WM disease biology and indicate that intervening with the metabolic processes could be a potential therapeutic strategy for patients with WM. Disclosures Ansell: AI Therapeutics: Other: research funding for clinical trials; Seattle Genetics: Other: research funding for clinical trials; Regeneron: Other: research funding for clinical trials; Affimed: Other: research funding for clinical trials; Bristol Myers Squibb: Other: research funding for clinical trials; Pfizer: Other: research funding for clinical trials; Merck: Other: research funding for clinical trials; Takeda: Other: research funding for clinical trials.

Description: Background and Aims Venous thromboembolism (VTE) is considered as a preventable cause of death for hospitalized patients. Current guidelines recommend pharmacologic prophylaxis for medical patients considered high risk for VTE, despite failure of studies to show reduction in mortality. We aimed to assess the benefit and safety of VTE prophylaxis in acutely ill medical patients hospitalized in internal medicine wards. Methods Retrospective cohort study of all patients admitted to the internal medicine and acute geriatric departments, with an admission lasting more than 48 hours, during 2012-2018. Patients who received pharmacologic prophylaxis were compared to those who did not. The primary outcome was 30-day mortality. Secondary outcomes were the 90 day incidence of pulmonary embolism (PE), symptomatic deep vein thrombosis (DVT), and major bleeding. Propensity-weighted logistic multivariable analysis was performed. Results A total of 18890 patient-unique episodes were included in the analysis. Of them 3206 (17%) received prophylaxis. A total of 1309 (6.9%) died. 540/1309 (41.3%) of those who received VTE prophylaxis died and 769/1309 (58.7%) of those who did not receive prophylaxis died. VTE Prophylaxis was not associated with a reduction in mortality, multivariate-adjusted OR 0.99 (95% CI 0.84-1.14). One hundred and forty two patients (0.7%) developed VTE. The frequency of VTE among patients who received VTE prophylaxis was 31% (44/142) compared with 69% (98/142) in patients who did not receive prophylaxis. The frequency of VTE in patients who had a Padua score ≥4 and received VTE prophylaxis, was 1.9% (30/1573) compared with 1.6% (44/2797) in those with a Padua score ≥4 who did not receive prophylaxis. 74/142 (52.1%) of patients with VTE had a Padua score ≥4, 44/1309 (1.4%) of those who received VTE prophylaxis and 98/15864 (0.6%) of those who did not. VTE Prophylaxis was not associated with reduction in VTE in the whole cohort, multivariable-adjusted OR 1.09 (95% CI 0.52-2.29). VTE prophylaxis was associated with an increase in major bleeding (multivariable-adjusted OR 1.24, 95% CI 1.04-1.48) Conclusion The current practice of routinely administering VTE prophylaxis to medically ill patients considered at high risk for VTE, resulted in a high risk for bleeding a without clear clinical benefit, and should be reassessed. Disclosures No relevant conflicts of interest to declare.

Description: Background: Prophylactic transfusion of platelets provides a good protection for the implementation of invasive procedures and the prevention of bleeding events during chemotherapy and hematopoietic stem cell transplantation in patients who are suffering from hematological diseases. The issues that what is the optimal dose of platelet transfusion and how to monitor platelet transfusion efficiency are important due to the short storage time of platelet products, rising clinical demands, and decreasing donors. It is worthy that there are amount of studies have been conducted in the past to explore factors that may affect the clinical efficacy of platelet transfusion and characteristics of patients under these different transfusion effects. While, previous studies failed to exactly address the problems of clinical needs for platelet transfusion. Methods: The aim of our study is to develop a model to evaluate the efficacy of platelet transfusion and the statistic method of machine learning algorithm (ML) was involved. The differences between this algorithm and traditional methods are that the former one can continuously be learning from the data and form a self-training model, therefore ML is more accurate than traditional artificial models and generally independent of the model and parameters themselves. We further take the multi-layer fully connected layer neural network model (MLNN) into our consideration because it simulates the multi-layer interconnection of human nervous systems, which is suitable for processing inaccurate and fuzzy information. In our study, the establishment of a neural network model was used to make a multiple-dimension analysis between factors affecting platelet transfusion efficacy and platelet count added value correction index (aCCI), and explore the correlation among these influencing factors as well. Results: The study utilized the data relative to 1840 platelet transfusions performed in 460 patients with hematological diseases. The participants ranged in age from 16 to 92, and the median age was 59.5. There were 199 females and 261 men. The whole data was divided to 2 parts, 2/3 of them were analyzed as a training set and the others were used for validating. We selected 30 factors (including patient-related factors and transfusion product-related characteristics) that may affect the efficacy of platelet transfusion except the storage time of platelet (all data 〈 2 days), and established a model for predicting platelet transfusion efficacy based on the volume of platelet transfusion. After the model was established, it was tested for goodness of fit, and the results showed that the LOSS value tended to be stable. Conclusions: The establishment of this model may not only be used for predicting the platelet count after platelet transfusions in patients and the amount of platelets that need to be transfused, but also provide supports for the solution of related problems. Disclosures No relevant conflicts of interest to declare.

Description: Patients with Sickle Cell Disease (SCD) frequently present for emergency care with pain or fever. The rate of emergency visits/year is between 2-4 per patient every year with 12% of patients visiting the emergency 4 or more times/year1. National medical organizations in Canada and the United States recommend pain therapy within 30 minutes of arriving to the emergency department2,3. Feedback from patients in Canada reflected a lack of awareness of the medical community regarding the disease and optimal management. As a response Canadian Haemoglobinopathy Association2 (CanHaem), created the "Sickle Cell Disease Emergency Wallet Cards" which were inspired from the successful Hemophilia "Factor First Card4". The goal of the cards was to provide simple care instructions to an emergency responder and facilitate timely care for patients in crisis. These wallet cards have recommendations for treatment of pain and fever within 30 minutes, patient's diagnosis, program contact details, and patient's individual pain plan. The cards have been in circulation for 4 years. The purpose of this study was to determine if the cards are used by parents and patients as intended. Research Questions: 1.Are the CanHaem Cards used by patients and families? 2. Do patients find the card helpful in facilitating their care delivery? Methods: The surveys were administered to patients and/or proxies. Prior to survey distribution three parents/patients have verified the utility of the questions, the content and the readability of the survey. The survey was translated into French/Arabic by two independent translators per language. It was distributed in Alberta and British Columbia, Canada in specialty clinics known to use the cards. The University of Alberta Ethics Board deemed the project a quality improvement initiative and the ARECCI tool: A pRoject Ethics Community Consensus Initiative was completed prior to quality improvement project start. Results: 140/184 participants completed the survey. The response rate: 76%. Demographics: 91% province of Alberta. Proxy: 49%; Patients: 51%. The majority of respondents were female: 54%, median age: 37 years (range 16-84 years). See graphs 1-4 below: 72.3% felt the card was helpful in their care. 78.6% carry the physical card (purse, wallet, and diaper bag), while 10.7% have a picture on their phone, 9.3% don't carry the card, 7.1% state they never received a card. The majority (63.6%) show the card at first contact in emergency, 48.9% felt staff read the card. Total of 68 comments. 67.6% of comments were positive: "Sense of security"; "Get us in to see the doctor faster..." Neutral comments (22%) ranged from requests for lamination to provider response to the card being variable "sometimes it is faster and sometime(s) doesn't really change anything". Finally, 10% were negative reflecting long wait times "Good concept, the idea itself is great. Execution... could be improved greatly", and requests for more information on the card. Conclusion: In Canada, SCD is an uncommon disease and many healthcare providers may not be aware of national and international guidelines regarding acute presentations. To help facilitate knowledge transfer and to aid communication with emergency services, CanHaem created wallet cards as a Canada-wide initiative. This survey demonstrates the patient/parent perspective of the emergency cards. Eighty-nine percent of patients/proxies carried the card (either digitally or physically) and 63% showed the card in the acute care setting. The discrepancy between those who carry the card and those who show it may reflect that numerous respondents stated they had not required emergency care since receiving the card as well some respondents were "carried away by the pain and forget to use the card". Comments revealed a sense of security and patient's appreciation for having the card available to them indicating the value of card to patients. The card demonstrates a simple and low cost intervention to facilitate emergency care for hemoglobinopathy patients. References: 1. Paulukonis ST et al. Emergency department utilization by Californians with sickle cell disease. Ped Blood and Ca 2017. doi: 1002/pbc.26390 2. CanHaem https://www.canhaem.org/healthcare-professionals/ 3. Evidence-Based Management of Sickle Cell Disease: Expert Panel, 2014. 4. Canadian Hemophilia Society. Stop the Bleeding. https://www.hemophilia.ca/files/ER%20CARD%20E_%20Jan%2009.pdf Figure Disclosures Ezzat: Novartis: Honoraria, Speakers Bureau; ApoPharma: Research Funding.

Description: Background Circular RNAs (circRNAs), a novel family of non-coding RNAs, have crucial roles in cancer progression. Conventional research is mainly focus on nuclear genome derived circRNAs (nu-circRNAs). The biological and clinical characteristics of mitochondrial genome derived-circRNAs (mt-circRNA) remains largely unknown, especially in chronic lymphocytic leukemia (CLL), the most prevalent incurable B-cell neoplasm in western countries. Lack of convenient and reliable clinical biomarkers is a hindrance in monitoring the progression of CLL. It is in urgent need of screening effective new biomarkers and exploring potential therapeutic targets associated with CLL initiation and progression. Recent studies have shown that circRNAs are enriched and stable in serum exosomes. However, the biological mechanisms of exosomal circRNAs remain unclear. In this study, we attempted to identify the novel characteristics of a mt-circRNA mc-COX2, which was abundant in plasma exosomes and could be involved in the progression of CLL. Since CLL patients have specific expression features of exosomal circRNAs in plasma, the function of the circRNAs and their clinical significance is urged to be explored. Methods Firstly, to unveil circRNAs expression profiles in CLL, plasma samples from five treatment-naive CLL patients and five age-/sex-matched healthy donors (HDs) were collected for circRNA microarray analyses. Northern blot and RNA- FISH were conducted to verify the existence of circRNAs in mitochondria. qPCR and other functional analysis such as RNase R, actinomycin D and RIP experiments were carried out to demonstrated the clinical and biological characteristics of mc-COX2, one of the mt-circRNAs. Cell apoptosis ability was determined by FCM. Moreover, electron microscope, partical size analysis, FCM and Western blot were used to explore the existence of exosomes and q-PCR analysis was performed to detect the expression of mc-COX2. Results Mt-circRNAs were highly expressed in CLL patients plasma (Figure A, B). Herein, we reported a novel circRNA named as mc-COX2 which was generated from the COX2 gene on mitochondrial genome by back-splicing and closely related to prognosis of CLL patients (Figure C). The enrichment of mc-COX2 in the mitochondria was further confirmed by RNA-FISH (Figure D). Northern blot was performed using head-to-tail probe of mc-COX2 and the results showed that mc-COX2 was detectable within the splice sites (Figure E). Notably, obviously different from nu-circRNAs, mc-COX2 showed lower stability with lower tolerance to RNase R and actinomycin D, but it was much more stable compared with linear RNAs (Figure G, F). And mc-COX2 cannot bind to AGO2 protein, suggesting that it probably function via other mechanisms instead of acting as ceRNA (Figure H). Furthermore, the up-regulated expression of mc-COX2 was positively associated with leukemogenesis and worse survival of CLL patients (Figure I, J). CLL patients with TP53 deletion rather than mutation displayed higher expression of mc-COX2 (Figure K). The endogenous reduction of mc-COX2 could induce cell apoptosis (Figure L). In addition, we indicated that mc-COX2 was highly enriched in exosomes, by which circRNAs could enter the circulation and be readily measured in the serum (Figure M). Moreover, the existence of mc-COX2 in plasma suggests that mc-COX2 may serve as a potentially novel prognosis biomarker for CLL patients, guiding targeted therapy in clinic. Conclusions In summary, we demonstrated the existence and clinical significance of mc-COX2, a novel class of circRNA species abundant in CLL plasma exosomes for the first time, which was distinct from nu-circRNAs. Furthermore, the specific high expression of mc-COX2 in CLL plasma which was strongly correlated with P53 deletion, can indicate worse prognosis of CLL patients. Taken together, our study not only identifies a novel circRNA which may serve as a new "liquid biopsy" biomarker for CLL prognosis but also expands the current knowledge regarding molecular mechanisms of circRNAs, providing potential diagnostic and therapeutic implications for CLL. It would be of great interest to explore the biogenesis of mt-circRNAs and their impact on mitochondrial function in future studies. Figure Disclosures No relevant conflicts of interest to declare.

Description: Brain death is a permanent loss of all brain function [1]. Current clinical organ transplantations mostly depend on the organs from brain-dead patients [2]. And of note, a lot of blood deases are easy to cause cerebral haemorrhage, which is quite of danger and usually induce brain death if not detected and treated in time. Thus prompt evaluation of brain death is of great significance for saving medical resources and reducing economic burden of the patients' families. Current guide for diagnosing brain death required to perform a list of 〉30 hours neurological examninations, some of which are even invasive, not in time and easily hampered by many confounding factors. An ideal ancillary test to assess brain death is highlighted to be noninvasive, sensitive, universally available, timely, and easy to perform at the bedside. Near infrared spectroscopy ( NIRS ) is capable of monitoring hemodynamics in response to brain activity noninvasively, conveniently, continually, and relatively inexpensively, evidented by a series of clinical cerebral studies recently. Weigl et al newly reported to use a time resolved NIRS to detect the fluorescence photons excited in the indocyanine green ( ICG ) for cerebral perfusion detection. It provided a novel optical ancillary tool to assess brain death, while its accuracy was only 69.2%, which did not reach the level of brain death confirmation. Plus, it was invasive, requiring injection of optical contrast agent. We attempted to assess brain death completely in nonivasive way with just a custom wearable NIRS device developed in our lab [3] ( fig.1 a ). We novelly incororate a protocol at markedly but safely varied fractions of oxygen respiration. Firstly, Monte Carlo modeling were carried out to test the difference in photon transport within human brain at different oxygen concentrations induced by varied fractions of oxygen respiration ( FIO2 ) [4]. 18 healthy subjects ( 41 ± 11 years old ) and 17 brain dead patients were recruited from the intensive care unit (ICU) in Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital. No significant difference in age was found between patients and healthy groups ( p 〉0.413 ). These patients were finally clinically diagnosed by the international standards of brain death. Two protocols were used ( fig.1 b). One is consisted of 1 hour resting, 3-minute baseline measure, half-hour measurement at 60% FIO2 ( phase I, high oxygen ),a half hour measure at 40% FIO2 ( phase II, low oxygen ), and a half hour measure at 60% FIO2 ( phase III, high oxygen ). The other is low, high, and low. The Δ[Hb] and Δ[HbO2] time courses were recorded by NIRS in real time with related signal processing ( fig.1 c ). Statistical analysis were focus on the sensitivity and specificiy of our proposed methodology at combination of NIRS and above protocol, as well as which protocol act better. Fig.1 ( c right ) showed that the detected light signal profile dramatically differed among varied oxygen concentrations in human brain. Plus the hemodynamic responses varied clearly between two subject groups among varied FIO2 in both protocols ( fig1. d ). The ' II-III ' phase act more distinct in differing two groups than ' I-II ' phase. And the low-high-low protocol acted almost perfect in accessing brain death with highest sensitivity and specificity. Over all, the novel incorporation of NIRS and a low-high-low varied FIO2 protocol was shown to a be most sensitive, highly specific, noninvasive and real time way to assess brain death and promptly offer quality assured donor organs. [1] E. F. M. Wijdicks, P. N. Varelas, G. S. Gronseth, D. M. Greer, Evidence-based guideline update: Determining brain death in adults report of the quality standards subcommittee of the American Academy of Neurology, Neurology, vol. 74, no. 23, pp. 1911-1918, 2010 [2] K. Singbartl, R. Murugan, A. M. Kaynar, D. W. Crippen, S. A. Tisherman, K. Shutterly, S. A. Stuart, R. Simmons, Intensivist-led management of brain-dead donors is associated with an increase in organ recovery for transplantation, J. M. Darby, Am. J. Transplant., vol. 11, no. 7, pp. 1517-1521, 2011 [3] T. Li, M. Duan, Y. Zhao, G. Yu, Z. Ruan. Bedside monitoring of patients with shock using a portable spatially-resolved near-infrared spectroscopy. Biomed. Opt. Express, vol. 6, no. 9, pp. 3431-3436, 2015 [4] B. Pan, C. Huang, X. Fang, X. Huang, T. Li*, Noninvasive and Sensitive Optical Assessment of Brain Death, J. Biophotonics, vol. 12, no. 3, pp. e201800240, 2018 Disclosures No relevant conflicts of interest to declare.

Description: Background Leg ulcerations are a serious and debilitating complication of sickle cell disease (SCD). Patients with SCD and leg ulcers have biomarkers of severe hemolytic anemia, a state associated with low bioavailability of nitric oxide (NO). Therapies directed at restoring NO bioavailability might prove beneficial. We selected topical sodium nitrite for clinical development due to its safety profile and vascular, anti-microbial, antiplatelet, and pro-keratinocyte functions. The nitrite anion is a vasodilator in vivo by generating NO in tissues with low oxygen tension and pH, conditions that are likely present in chronic wounds. Data from our successful phase 1 study showed improved regional blood flow, decreased ulcer pain, and appeared to improve ulcer healing. The dosing data informed the concentration of active ingredient to be used and suggested sodium nitrite efficacy in SCD patients with leg ulcers (Minniti, CP et al, Lancet Haematol 1, e95-e103). Study Design and Methods This is a multicenter, phase 2, prospective, randomized, placebo-controlled study of topical sodium nitrite in patients with SCD and leg ulcers. Primary aim is to determine the safety, tolerability, and effectiveness of twice a week topical application of study ointment for 10 weeks. We hypothesize that sodium nitrite will 1) accelerate wound healing (〉25% improvement over placebo arm); and/or 2) decrease pain at the wound site (〉20% over placebo). Ulcers measured by ImageJ planimetry software to increase accuracy. The secondary aims are to: a) evaluate the effect of hydroxyurea (HU) on leg ulcer healing in combination with topical sodium nitrite or placebo; b) assess changes in ulcer microbiome after application of sodium nitrite or placebo and how these changes may relate to healing; c) evaluate the dermal composition and microvascular structure in the ulcer beds. We plan to enroll 50 adults with all SCD genotypes and leg ulcers not individually 〉100 cm2, such that, after an expected 20% dropout, 40 subjects will complete 〉 8 weeks of treatment. Exclusion criteria: use of PDE5 inhibitors, NO, L-arginine, nitroprusside, nitroglycerine; acute bacterial infection; pre-existing methemoglobinemia (〉3.5% on two different occasions); G6PD deficiency. Randomization is stratified by HU use to minimize potential confounding effects on study outcomes. Funded by the Food and Drug Administration (FDA) Division of Orphan Drug Development (# FD-R-0005729); active at two sites (ClinicalTrials.gov NCT02863068). Results We have screened 68 subjects with known history of leg ulcer: 46% were not eligible as the ulcer was closed at the time of screening. Of the 30 eligible, 13 subjects enrolled (12 at Montefiore Medical Center, 1 at the University of Pittsburgh), with 9 subjects randomized. Reasons for screen failure, other than ulcer closed, are depicted in fig 1. Three subjects experienced ulcer decrease 〉25% in the run-in period and did not have ointment application as per protocol. One subject withdrew due to lack of adherence. Therefore the overall dropout rate at this time is 33%, higher than the 20% anticipated. No study ointment SAEs have been noted, AEs have been minor and non-ointment related. Most SAEs have been VOCs, expected in this patient population and wound infections. Discussion As expected, enrollment of subjects with a rare complication of a rare disease is challenging. The recurrent pattern of ulcers in SCD was the reason why the majority of patients were not able to enroll, as the ulcer was closed at the time of screening. We monitor them closely for possible re-opening. Simplification of protocol-related procedures, such as decrease in number of required visits from twice to once a week by packaging dose-specific blister packs that the patient takes home for self-administration of ointment, has facilitated enrollment. Travel to the center is being addressed. A close relationship between the subjects and study team is essential. Co-location of the wound specialist in the sickle cell clinic and training the research nurse for wound care has helped with recruitment. Disclosures Ogu: Vertex Pharmaceuticals: Consultancy. Kato:Novartis, Global Blood Therapeutics: Consultancy, Research Funding; Bayer: Research Funding. Minniti:Doris Duke Foundation: Research Funding.

Description: Introduction Cutaneous T-cell lymphomas (CTCLs) are characterized by dermal and epidermal infiltration of skin homing clonal CD4+ memory T-cells. Little is known about the oncogenic events driving either the progression of skin-limited disease such as Mycosis Fungoides (MF) to a leukemic form or Sézary Syndrome (SS), and there are no histologic means to predict evolution. Genetic instability is a hallmark of malignancy progression and telomere remodeling has been shown to play a role in the progression of hematological malignancies. Thus, the aim of this study is to characterize the three-dimensional (3D) telomeric organization in early and advanced CTCLs. Methods We performed 3D telomeric quantitative fluorescent in situ hybridization (3D Telo-Q-FISH) of 5mm skin tissue slides of 10 patients with MF and SS and of CD4+ lymphocytes of 3 healthy controls (Figure 1). Using the program TeloView (Vermolen et al., 2005), the proportion of telomeres of low intensity (TLI) (

Description: Background: FLT3-internal tandem duplication (FLT3-ITD) mutation is a poor prognostic factor for acute myeloid leukemia (AML). Several second-generation FLT3-targeted tyrosine kinase inhibitors with high selectivity and potency have been developed to date. Recently, gilteritinib was approved for the FLT3 mutation-positive relapsed or refractory AML patients. However, acquired mutations at the F691 residue in FLT3 kinase domain were identified in the patients who had disease progression after the treatment with gilteritinib, as with quizartinib treatment that caused resistant mutations at F691 and D835 residues. Therefore, it is very important to clarify the potencies of each FLT3 inhibitors against acquired FLT3 mutations for clinically selecting an appropriate FLT3 inhibitor according to the mutation type. In this study, we explored the resistant mutations against FLT3 inhibitors by random mutagenesis analysis and evaluated the cross-reactivity of FLT3 inhibitors against each resistant mutation. Methods: For random mutagenesis assay, 32D cells were infected with retroviruses encoding randomly mutagenized human FLT3-ITD. FLT3-ITD dependent 32D cells were established without an addition of IL-3, and then treated with FLT3 inhibitors, gilteritinib, FF-10101 and quizartinib, at concentrations of GI95 and 3 x GI95. Two weeks after treatment, full length FLT3-ITD sequences of viable clones were analyzed. The identified mutated FLT3-ITDs were introduced into 32D cells to confirm the resistance to FLT3 inhibitors. For cell growth assay, 32D transfectants were incubated with 5 FLT3 inhibitors (gilteritinib, FF-10101, quizartinib, crenolanib and midostaurin) for 3 days followed by determination of cell viability. Results: We identified the gilteritinib-resistant mutation (FLT3-ITD+D698N), quizartinib-resitant mutation (FLT3-ITD+N676T), and FF-10101-resistant mutation (FLT3-ITD+C695W) (Table). Inhibitory activity of gilteritinib against FLT3-ITD+D698N-expressing 32D cells (GI50, 27 nM) was decreased by 12-fold as compared with that against original FLT3-ITD-expressing 32D cells (GI50, 2.3nM). FF-10101 (GI50, 0.73 nM), quizartinib (GI50, 0.99 nM) and crenolanib (GI50, 19 nM) retained potency against FLT3-ITD+D698N, while midostaurin (GI50, 47 nM) did not have a potency. In FLT3-ITD+N676T-expressing 32D cells, inhibitory activities of quizartinib and midostaurin were decreased by 11 and 15-fold (GI50, 6.6 nM and 83 nM, respectively), while FF-10101 (GI50, 0.73 nM), gilteritinib (GI50, 6.6 nM) and crenolanib (GI50, 19 nM) retained potency. In FF-10101-resistant mutation (FLT3-ITD+C695W)-expressing 32D cells, the other inhibitors retained growth inhibitory activity. Conclusions: Resistant mutations to gilteritinib and quizartinib were newly identified in FLT3 kinase domain by random mutagenesis analysis. FF-10101 retained potent inhibitory activities against FLT3-ITD+N676T conferring resistance to quizartinib and midostaurin, and FLT3-ITD+D698N resistant to gilteritinib and midostaurin, although FF-10101 was vulnerable to FLT3-ITD+C695W substituted for C695 residue which forms covalent bond with FF-10101. These results indicated that FF-10101 was a promising agent for the treatment of patients with AML with FLT3 inhibitor-resistant mutations newly identified in this study. Disclosures Ishikawa: Bristol-Myers Squibb: Honoraria; Abbvie GK.: Honoraria; Celgene Co., Ltd.: Honoraria; Kyowa Hakko Kirin Co., Ltd.: Honoraria. Saito:FUJIFILM Corporation: Employment. Morimoto:FUJIFILM Corporation: Employment. Murao:FUJIFILM Corporation: Employment. Terada:FUJIFILM Corporation: Employment. Yamaura:FUJIFILM Corporation: Employment. Hagiwara:FUJIFILM Coporation: Employment. Kiyoi:Daiichi Sankyo Co., Ltd: Research Funding; Takeda Pharmaceutical Co., Ltd.: Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; FUJIFILM Corporation: Research Funding; Pfizer Japan Inc.: Honoraria; Bristol-Myers Squibb: Research Funding; Perseus Proteomics Inc.: Research Funding; Otsuka Pharmaceutical Co.,Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Astellas Pharma Inc.: Honoraria, Research Funding; Nippon Shinyaku Co., Ltd.: Research Funding.

Description: Classic Hodgkin Lymphoma (cHL) is a germinal center derived lymphoma with 8,500-9,000 new cases/year diagnosed in the US. Despite 90% stage I cHL patients can respond to current systemic therapy, this drops to 60%, when diagnosed in advanced stages. Furthermore, 20-30% of diagnosed patients, would be refractory or would relapse and have a poor prognosis. Refractory and relapsed disease (RRD) is currently the challenge when treating cHL patients. There is no specific therapy to offer rather than rescue chemotherapy schemes, which fails in 50% of the cases and associates with high risk severe toxicity. This highlights the need to deeper understand the cHL molecular biology, the screening for molecular markers suitable to identify the risk of refractory and relapse disease and specific therapeutic directed-targets. We have previously reported that the alternative NFkB pathway, mediated by Rel-B and NIK (NFkB Inducing Kinase), plays an important role in cHL survival. Its constitutive activation sustains high BCL2 expression levels and seems to be involved in the RRD. BCL2 was found as a specific Rel-B target gene in cHL cells by ChIP-Seq (Chromatin Immunoprecipitation sequencing) and expression arrays. BCL2 exogenous expression was enough to partially rescue the death induce in cHL cells, which highlight the relevance of this alternative NFkB pathway target gene. Since the BCL2 data was obtained in human cHL cell lines established from patients with refractory and relapsed disease, we decided to analyze whether mediators of this pathway and BCL2 could be useful as prognosis markers and would represent potential targetable factors in both refractory and relapsed disease. We analyzed NIK and BCL2 citoplasm expression in Hodgkin Reed-Sternberg cells (HRS) in the lymph node biopsies of 113 cHL naïve of therapy patients by inmunohistochemistry [52 female Md age and (range) 36 (6-88), 61 male 40.7 (9-78)]. The follow-up period range from 6 to 136 months. The univariate analysis showed no correlation between NIK or BCL2 expression and the prognosis clinical and pathological parameters, including the PET Scan indicated at the end of the first line treatment, neither the molecular markers routinely assayed. The statistical significance was maintained in multivariate analysis (Logistic and Cox Regression p=0.01). NIK expression did not associate with prognosis but the BCL2 expression level correlated with lack of response to conventional therapy and both early and late disease progression. The survival analysis, using the Kaplan-Meir curves, showed that patients with ≥60% positive HRS cells had a shorter disease-free survival (DFS) [Log Rank Test (Mantel Cox) p=0.002] and a reduced overall survival (OS) [Log Rank Test (Mantel Cox) p=0.02]. L1236, U-H01, KM-H2, SUPDH1 and L540, human cHL cell lines that express BCL2 protein, were sensitive to venetoclax, a specific BCL2 inhibitor. The drug induced a cell cycle arrest in S-Phase when treated with 1uM each 24 hours during 10 days, as compared to wild type cells and cells treated with the vehicle. In summary, we found that the alternative NFkB pathway plays a role in the refractory and relapsed classic Hodgkin Lymphoma disease, being BCL2 one of its key downstream target genes. BCL2 can be used as a prognosis marker determined by routine immunohistochemistry at diagnosis of the primary disease. BCL2 expression correlated with refractory disease to first line conventional therapy and disease progression. Based on the venetoclax effect in cHL cell lines we believe BCL2 directed-therapy in cHL should be considered in the subgroup of cHL patients that express this protein in ≥60% HRS cells in the lymph node biopsy performed at diagnosis. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: venetoclax used to specifically block BCL2.

Description: Introduction Diagnosis and follow-up monitoring of Multiple Myeloma (MM) requires documentation of (clonal) plasma cells using morphological bone marrow assessment and other ancillary studies including CD138 immunohistochemistry (IHC), flow cytometry (FC), and myeloma-specific fluorescence in situ hybridization (FISH). While IHC and FC have traditionally been shown to be the more sensitive methods for the assessment of residual disease, the detection rates of FISH have markedly increased with the recent use of magnetic cell sorting for CD138 cell enrichment. We, therefore, aimed to revisit the clinical utility of these ancillary studies in the diagnosis and follow-up of MM. Methods We retrospectively reviewed the reports of bone marrow biopsy specimens received for the initial diagnosis or follow-up assessment of MM from October 2015 to January 2019. All cases that had both FC and FISH performed were included in the analysis. Patient demographics, treatment history and the results of bone marrow evaluation were recorded. Results During the study period, we evaluated a total of 1,712 biopsy specimens from 464 MM patients (mean±SD age: 64.0±9.4 years; females 41.4%). Of these, 87 cases were submitted for initial diagnosis and 1,625 cases had already established MM and were being evaluated for post-treatment residual disease. For both initial diagnosis and follow-up cases, CD138+ IHC demonstrated highest plasma cell burden (mean: 49.1% and 4.6%, respectively) followed by morphological aspirate count (mean: 29.6% and 2.3%, respectively) and FC (mean: 10.9% and 1.8%, respectively). Both FC and FISH had comparable detection rates at the time of initial diagnosis (95.4% versus 97.7%, respectively) and for follow-up cases (28.6% versus 28.2%, respectively). The FC and FISH results were concordant in 97.7% of the initial diagnosis cases and 89.7% of follow-up cases. Discordant cases with positive FISH results and negative FC results included 2 (2.3%) initial diagnosis cases and 81 (5.0%) follow-up cases whereas those with negative FISH and positive FC results included 87 (5.3%) follow-up cases. In comparison with all concordant cases, the FISH positive, FC negative discordant cases were older in age, more likely to have received treatment with Daratumumab, and less likely to have received stem cell transplantation (p

Description: Background: Hematopoietic stem cell transplantation (HSCT) is still the only curative therapy for β-thalassemia major (BTM). Several new approaches have been applied to reduce the toxicity of conditioning regimens, improve strategies for the prevention of graft-versus-host disease (GVHD), and optimize supportive care. Objectives: This study aimed to evaluate the thalassemia-free survival and outcome of HSCT in the Egyptian experience and to analyze patients and donors' characteristics as well transplantation related factors that could affect the graft success rate. Methods: We report the results of 174 consecutive first related allogeneic stem cell transplants for children with β‐thalassaemia major performed between January 1997 and December 2014. Patients and methods: the study included 174 consecutive patients with β-thalassaemia major received allogenic hematopoietic stem cell transplant (HSCT) from HLA fully matched sibling (n=153) or parent (n=10) donners. Patients mean age was 6.1±4.2 (range: 0.7 to 23.7 yrs.), the median follow up was 34 months (range 1 to 134 months). The Pesaro risk class I, II, and III categories were 21.8, 63.2% and 14.9%, respectively. Bone marrow was the source of stem cells in 26 (14.9%) and peripheral blood(PBSC) in 148 (85.1%)cases. One hundred fifty-seven patients (90.2%) received conditioning with Busulphan(BU) followed by cyclophosphamide. ATG was added in 155/157 patients at a total dose of 110 mg/kg divided into 10 doses (5 pre and 5 post-transplant). Whereas 17 (9.8%) patients received long duration conditioning with Fludarabine, Busulphan followed by cyclophosphamide in 5 patients and ATG was added in 12/17 patients at a total dose of 60 mg/kg. Regarding Graft versus Host Disease GVHD prophylaxis; all patients received cyclosporine (CsA) at a dose of 3 mg/kg/day IV from day -1 until oral intake was possible then shifted to oral dose 5 mg/kg/day divided to 2 daily doses and maintained till day 270, then gradually tapered off. CSA was combined with methotrexate (MTX) in 79 patients (51.3%); at a dose of 15 mg/m2 IV on day +1, then 10 mg/m2 on days +3, +6, and +11. While 75 patients (48.7%) received CSA and methylprednisone 2 mg/kg starting from day -7 till day +4 then tapered gradually over two weeks. Results: The median time to achieve neutrophil recovery was 18 days (range 8-60 days) and for platelet recovery was 20.5 days (range 7-60 days). Graft failure rate was 12.6% (n=22); 12 (6.9%) as primary and 10 (5.7%) as secondary. The risk of GF was investigated in relation to risk class, serum ferritin level, stem cell source and use of ATG in conditioning regimen. Bone marrow as a source of stem cell was related to a higher graft failure rate (p=0.018) Five-year. Probabilities of overall-, disease-free and event-free survival in all patients were 74.9%, 61% and 55.8%, respectively. Five years overall survival was higher in patients with Pesaro risk class II (p=0.001). Moreover, DFS and EFS were significantly higher in patients with serum ferritin ≤2000 ng/ml (p =0.012, and 0.021 respectively). Transplant related mortality (TRM) was 18.4%, the leading causes of death were infection ( 40.5%), GVHD (16.7%)and respiratory failure(14.3%). Conclusion: Patients with low serum ferritin , Pesaro Risk Class I &I I and PBSC transplant have a more favorable outcome .Infection was the leading cause of mortality among our patients. Figure Disclosures No relevant conflicts of interest to declare.

Description: Background Duvelisib, an oral dual PI3K-δ and PI3K-γ inhibitor, is approved by the US Food and Drug Administration for the treatment of adult patients with relapsed or refractory (R/R) follicular lymphoma (FL) after ≥ 2 prior systemic therapies. In multiple phase 1-3 studies that included patients with iNHL, duvelisib was shown to be efficacious, with a favorable risk-benefit profile. This study will evaluate whether duvelisib efficacy at the approved 25 mg twice daily (BID) dose can be achieved and maintained with an acceptable or improved safety profile by the inclusion of prespecified 2-week drug holidays in patients with R/R iNHL. Study Design and Methods TEMPO is a randomized, open-label, multicenter, international, phase 2 study of duvelisib in adult patients with R/R iNHL in whom ≥ 1 line of prior therapy has failed. The primary objective is to evaluate the efficacy of duvelisib administered with prescribed drug holidays, with the primary endpoint of overall response rate (ORR) by the 2007 revised International Working Group criteria. Key secondary endpoints include ORR by the 2014 Lugano criteria, progression-free survival, overall survival, time to treatment failure, duration of response, lymph node response rate, time to the first response, adverse event profile, and determination of pharmacokinetics parameters. Exploratory objectives include assessment of quality of life and biomarkers of treatment response and toxicity. Key inclusion criteria include histologically confirmed FL grades 1 to 3a, marginal zone lymphoma (splenic, nodal, or extranodal) or small lymphocytic lymphoma, radiological evidence of disease progression and ≥ 1 bidimensionally measurable lesion ≥ 1.5 cm, adequate organ function, and Eastern Cooperative Oncology Group performance status ≤ 2. Key exclusion criteria include prior allogeneic hematopoietic stem cell transplant; previous treatment with a PI3K inhibitor; history of drug-induced colitis or drug-induced pneumonitis; ongoing treatment for systemic infection; central nervous system NHL; prolonged QT interval; history of tuberculosis treatment within the 2 past years; history of stroke, unstable angina, myocardial infarction, or ventricular arrhythmia requiring medication or mechanical control within the past 6 months; history of or concurrent interstitial lung disease of any severity and/or severely impaired lung function; ongoing treatment with chronic immunosuppressants; and any unstable or severe uncontrolled medical condition. A total of 102 patients are planned to be enrolled. Patients will be randomized 1:1 to 2 arms and stratified by number of prior therapies (1 or 〉 1), bulky disease status (longest diameter of baseline lesion 〈 5 cm or ≥ 5 cm), and time since last recurrence (≥ 24 months or 〈 24 months). In arm 1, patients will receive duvelisib 25 mg BID for one 10-week (W) cycle followed by 25 mg BID on W3 and W4 of each subsequent 4-week cycle. In arm 2, patients will receive duvelisib 25 mg BID on W1, W2, W5, W6, W9, and W10 of one 10-week cycle and then on W3 and W4 of each subsequent 4-week cycle. Patients will be treated until disease progression, unacceptable toxicity, or withdrawal. This study will test the null hypothesis that the ORR in each arm is ≤ 30% against the alternative that the ORR is ≥ 55%. The study has a 2-stage design. In stage 1, 15 patients will be enrolled in each arm, with response assessment after ≥ 3 cycles. If there are fewer than 6 partial or complete responses, consideration may be given to terminating the arm. Otherwise, in stage 2, 36 additional patients will be enrolled, for a total of 51 per arm. Enrollment is planned to be initiated in August 2019. Approximately 50 sites will be open for enrollment across the United States, Europe, and Asia. Disclosures Karmali: Takeda, BMS: Other: Research Funding to Institution; Gilead/Kite; Juno/Celgene: Consultancy, Speakers Bureau; Astrazeneca: Speakers Bureau. Youssoufian:Verastem Oncology: Consultancy, Equity Ownership. Sprott:SMOC Therapeutics: Employment, Equity Ownership; Verastem Oncology: Employment, Equity Ownership. Weaver:FemtoDx: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Inventor; Verastem Oncology: Employment, Equity Ownership, Patents & Royalties: Inventor; Hillstream Biopharma: Consultancy, Equity Ownership. Narasimhan:Verastem: Employment, Equity Ownership. Lustgarten:Verastem: Employment. Patrick:Verastem Oncology: Employment. Zalutskaya:Verastem Inc: Employment, Equity Ownership. Gordon:Gilead: Other: Advisory Board; Juno/Celgene: Other: Advisory Board, Research Funding; Zylem LLC: Other: co-founder; research in nanoparticles in cancer; Bayer: Other: Advisory Board. OffLabel Disclosure: Duvelisib (DUV), a dual PI3K-delta,gamma inhibitor, is US FDA approved at 25 mg twice daily (BID) for the treatment of R/R chronic lymphocytic leukemia or small lymphocytic lymphoma after at least 2 lines of prior therapy and R/R follicular lymphoma after at least two prior systemic therapies.

Description: Introduction The treatment landscape of Hodgkin Lymphoma (HL) has undergone a revolution in recent years, providing multiple options for providers and patients in their shared goal for disease control. However, these successful treatment options (e.g. multi-agent chemotherapy, radiotherapy, or combined modality) come at a high cost in the form of late effects, with little known about long-term toxicity of novel agents (e.g., Brentuximab vedotin, immunotherapy). As part of an international effort to develop tools to enhance treatment decision-making for providers and patients, we developed a survey to learn about what role HL survivors played in their initial treatment decision(s) as well as to understand survivors' knowledge and experience of late effects. Methods The survey titled Understanding of Decision-Making among HL Survivors included three themes: 1) initial treatment plan; 2) role in decision-making about the plan and factors important to the treatment selection; and 3) understanding of late effects. The survey was initially piloted at a cancer conference in Spring 2019 after which modest revisions were made to improve clarity. The revised survey was then distributed nationally in a single push through the Leukemia & Lymphoma Society's voluntary email listserv (Summer 2019). Responses were captured in the HIPAA complaint, web-based application, REDCap®, and then analyzed with descriptive statistics. Results A total of 129 HL survivors responded to the survey. The majority of respondents (n=98, 76%) identified as female. While nearly half (46%) were between 1-5 years from treatment, 27% were 5 years ago. Age distribution at diagnosis ranged from 26 years (n=91, 71%). Two-thirds (n=83, 64%) of patients were treated with chemotherapy alone. Overall, 90% of survivors reported receiving ABVD or a close variant (e.g., AVD). The majority of survivors (n=88, 68%) reported only receiving one treatment option by their oncologist. Half (n=69, 54%) engaged in shared decision-making with their physician, with or without family/friends, 24% (n=31) deferred to their physician, 20% (n=26) decided on their own or with family/friend, and 2% (n=3) followed the plan determined by their physician and family on their behalf. Most respondents were treated in the community (n=77, 60%) with an additional 34% (n=44) reporting having been treated at an academic medical center. For 8 respondents (6%) the treatment site was categorized as other. Survivors were asked to rate the importance of factors in their initial treatment decision-making on a 3-point scale. Results were then dichotomized to important or not important. Health systems factors (e.g., cost, distance) were deemed less important, while patient-level factors (e.g., side effects, late effects) were widely endorsed (Table 1). The majority of survivors (n=107, 83%) were aware they are/may be at risk for late effects. Seventy percent (n=68 of 97) had been told at the time of discussion of treatment option(s) with their oncologist. The remainder (n=29 of 97, 30%) learned after completion of treatment or when transitioning care from their treating oncologist to survivorship or primary care. One third of respondents (n=46, 36%) reported they have been diagnosed with a late effect, which included substantial late effects of secondary malignancy (n=5, 11%) and cardiac toxicity (n=4, 9%). Discussion We report the results of a recent national survey of HL survivors, represented by an activated cohort that elects to participate in cancer advocacy groups. While two-thirds of respondents had little choice in initial treatment options, the majority endorsed the importance of side effects and late effects in treatment selection. Only half of survivors engaged in shared decision-making with their physician, indicating ample room for improvement and the development of tools to facilitate this process. Disclosures No relevant conflicts of interest to declare.

Description: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment strategy for patients with acute leukemia. The ATG-based transplantation system initiated by Peking University people's hospital, known as the Peking regimen, has become a mainstream transplant system worldwide. Here, based on the Peking regimen, we report a modified protocol:(1)add Fludarabine and replace ATG with ATG-F in the conditioning regimen; (2)transfuse higher-dose cell collections from granulocyte-colony stimulating factor(G-CSF) primed bone marrow and peripheral blood samples; (3) add Basiliximab (a CD25-antibody) on day +3 for acute GVHD prophylaxis. In this study, 265 patients (158 patients with haplo-SCT and 107 patients with sibling-SCT) underwent allo-HSCT with our modified protocols. All patients achieved sustained full-donor chimerism. The incidence of grade II-IV and III-IV acute GVHD in haplo-SCT comparing with sibling-SCT was 36.1%(57/158) vs 17.8%(19/107)(P=0.001) and 13.3% (21/158) vs 9.3%(10/107)(P〉0.05) respectively. The 2-year cumulative incidence of total chronic GVHD and extensive chronic GVHD in haplo-SCT was 41% (65/158) and 15% (24/158) respectively. The 3-year cumulative incidence of non-relapse mortality (NRM) in haplo-SCT and sibling-SCT was 6.3% (10/158) and 4.7%(5/107) respectively(P〉0.05). The 100-day cumulative incidence of CMV viremia in haplo-SCT and sibling-SCT was 35.5% (56/158) and 23.4%(25/107) respectively(P=0.036). A total of 36 patients in haplo-SCT group and 24 patients in haplo-SCT group had recurrent disease, reaching a cumulative incidence of relapse of 20.8% in haplo-SCT and 23.4% in sibling-SCT at 3 years respectively(P〉0.05). The relapse ratio of haplo-SCT and sibing-SCT in the 1st year, between the 1st and the 2nd year and after 2 years was 21.5% vs 14.1%(P〉0.05), 1.3%(2/158) vs 0%(P〉0.05) and 0% vs 6.5%(P=0.009) respectively. The 3-year overall survival(OS) and leukemia-free survival(LFS) rates in haplo-SCT and sibling-SCT was 78.8% vs 74.2% and 76.8% vs 75.04% respectively(P〉0.05) by the Kaplan-Meier estimate. The 3-year GVHD-free and leukemia-free survival rates (GRFS) in haplo-SCT and sibling-SCT were 43.4% vs 69.5%(P=0.045) respectively. Lower OS in haplo-SCT was associated with III-IV aucte GVHD and lower MNC(

Description: Introduction T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive T-lymphoid malignancy with poor response to current treatment strategies. We recently demonstrated single agent activity of venetoclax in relapsed/refractory (r/r) T-PLL, however resistance developed on mono-therapy. We here set out to identify partners for an effective combinatorial treatment concept. Methods To overcome bcl-2 inhibitor resistance we utilized primary T-PLL patient samples and applied a combinatorial next-generation functional drug screen for venetoclax and 25 additional therapeutic agents (Fig.1a). Molecular mechanisms of drug combinations were evaluated by BH3-family member profiling and mass spectrometry. Protein expression was assessed by Western Blot and viability by AnnexinV/Hoechst staining. The best scoring combination was evaluated in two late stage r/r T-PLL patients. Results Pairwise combinations screen of venetoclax with candidate small molecule inhibitors and chemotherapeutic drugs on primary T-PLL cells revealed synergistic action of venetoclax with ibrutinib, idelalisib, and 5-azacytidine, and to lower extents Olaparib, Temsirolimus, Ruxolitinib and Belinostat whereas cisplatin antagonized the effect of venetoclax across all patient samples tested (Fig 1b). The combination of venetoclax and ibrutinib resulted in substantial reduction of viability in primary T-PLL cells (Fig 1c). BH3-profiling on primary T-PLL samples with and without ibrutinib treatment demonstrated enhanced overall priming with predominant increase of bcl-2 dependency upon ibrutinib treatment (Fig 1d). Addition of ibrutinib to venetoclax led to decreased phosphorylation of ITK in vivo (Fig 1e). Two patients suffering from r/r T-PLL after failing at least two treatment lines including alemtuzumab were treated with the combination of venetoclax and ibrutinib resulting in significant clinical responses with substantial drops in leukocytosis and LDH as well as substantial clinical improvement (Fig 2a, b). The dynamic BH3 profiling in samples taken from these patients confirmed that the addition of ibrutinib is indeed increasing overall priming and Bcl-2 dependency (Fig 2c, d). Conclusion Our findings suggest efficacy of combinatorial treatment of venetoclax with ibrutinib in T-PLL. Mechanistically, ibrutinib dephosphorylated ITK in T-PLL cells and, furthermore, enhanced BCL2 dependency, both, in-vivo and in-vitro. Patients treated with the combination venetoclax and ibrutinib experienced profound clinical responses which needs further evaluation in an prospective clinical study on a larger cohort of r/r T-PLL patients. Disclosures Herbaux: Abbvie: Honoraria; Janssen: Honoraria; Takeda: Honoraria; BMS: Honoraria; Gilead: Honoraria. Mayerhoefer:Siemens: Research Funding, Speakers Bureau; BMS: Speakers Bureau. Jaeger:Novartis, Roche, Sandoz: Consultancy; AbbVie, Celgene, Gilead, Novartis, Roche, Takeda Millennium: Research Funding; Amgen, AbbVie, Celgene, Eisai, Gilead, Janssen, Novartis, Roche, Takeda Millennium, MSD, BMS, Sanofi: Honoraria; Celgene, Roche, Janssen, Gilead, Novartis, MSD, AbbVie, Sanofi: Membership on an entity's Board of Directors or advisory committees. Davids:AbbVie, Acerta Pharma, Adaptive, Biotechnologies, Astra-Zeneca, Genentech, Gilead Sciences, Janssen, Pharmacyclics, TG therapeutics: Membership on an entity's Board of Directors or advisory committees; AbbVie, Astra-Zeneca, Genentech, Janssen, MEI, Pharmacyclics, Syros Pharmaceuticals, Verastem: Consultancy; Acerta Pharma, Ascentage Pharma, Genentech, MEI pharma, Pharmacyclics, Surface Oncology, TG Therapeutics, Verastem: Research Funding; Research to Practice: Honoraria. Staber:Takeda-Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; MSD: Honoraria, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. OffLabel Disclosure: Ibrutinib - BTK inhibitor Venetoclax - bcl2 inhibitor

Description: Childhood Leukemia treatment is one of the most common malignancies seen across the globe in the pediatric age group. Severe Hemophilia A is still considered a rare bleeding disorder. Only 13 patients with hemophilia A or B have been reported in literature to also be diagnosed with acute leukemia in childhood . This rarity appeared again in a 13 year boy with severe hemophilia A who presented with worsening bone pain and joint swelling, weight loss and leukocytosis. Morphology and molecular diagnostics confirmed Acute Pre B Lymphoblastic Leukemia . The patient happens to be the first case of Acute Lymphoblastic Leukemia in a patient with severe Hemophilia with Inhibitors. Severe hemophilia with inhibitors pose challenge in clinical management given their propensity of bleeding and poor response to traditional therapies due to a neutralizing antibody as is. Treatment of acute lymphoblastic leukemia requires an intensive treatment with systemic and intrathecal chemotherapy. Medications are commonly administered through a central line, in many cases an implantable catheter. Coexistence of both these life threatening disorders posed a unique practical challenge in providing standard care and our discussion aims at highlighting strategies in management of Severe Hemophilia in challenging clinical scenarios. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: While children diagnosed with acute lymphoblastic leukemia (ALL) experience close to a 90% likelihood of cure, the outcome for certain high-risk pediatric ALL subtypes as well as adult ALL remains poor. Several standard-of-care drugs used in multi-agent treatment protocols for ALL (including vincristine, daunorubicin and methotrexate) are substrates for the ATP-dependent drug efflux pump P-glycoprotein (P-gp), encoded by the ABCB1 gene, although there are limited reports of ABCB1 gene expression being associated with poor outcome in ALL (Carrillo et al, Hematol. 22:286-91, 2017). A previously identified high-risk subtype of T-ALL (early T-cell precursor ALL, ETP-ALL) characterized by poor early response to conventional induction treatment, expresses significantly higher levels of the ABCB1 gene compared with typical T-ALL (1.97-fold; false discovery rate=0.0026; P=0.00029; Zhang et al, Nature 481:157-63, 2012). E7130 is a novel anti-microtubule drug that is a less potent substrate for P-gp compared with other anti-microtubule drugs such as vincristine, and it has shown significant preclinical activity against patient-derived xenograft (PDX) models of adult malignancies. Therefore, it was of interest for the Pediatric Preclinical Testing Consortium (PPTC) to test the in vivo activity of E7130 against its PDX models of pediatric ETP-ALL. Methods: ABCB1 mRNA expression in ALL PDXs was quantified by RNAseq (https://pedcbioportal.org) and qRT-PCR. P-gp protein expression was assessed by immunoblotting, while its activity was measured by the Rhodamine-123 efflux assay in the absence or presence of the P-gp inhibitor tariquidar. E7130 and vincristine were evaluated in vivo against 6 ETP-ALL PDXs. Each PDX was inoculated into 6-8 immune-deficient (NSG) mice per treatment group (2-5 x 106 cells/mouse). Engraftment and drug responses were evaluated by enumerating the proportion of human CD45+ cells in the peripheral blood (%huCD45+) at weekly intervals. E7130 was tested at 2 dose levels (0.09 and 0.135 mg/kg IV), while vincristine was evaluated at 1 mg/kg IP. Both drugs were administered weekly x 3. Events were defined as the %huCD45+ ≥25%. Drug efficacy was assessed by event-free survival of treated (T) and control (C) groups by T-C, T/C and stringent objective response criteria (Houghton et al, Pediatr Blood Cancer 49:928-40, 2007). Results: RNAseq analysis of the 6 ETP-ALL PDXs in the PPTC panel of 90 pediatric ALL PDXs revealed 3 with high ABCB1 expression (FPKM 7.1-13.6; ETP-2, -3 and -6) and 3 with low expression (FPKM 0-0.15; ETP-1, -4 and -5), which was confirmed by qRT-PCR and immunoblotting. Moreover, high levels of tariquidar-sensitive Rhodamine-123 efflux activity were confirmed in the 2 high ABCB1 expressing PDXs tested (ETP-2 and -3). E7130 was generally well tolerated in NSG mice, with maximum average weight loss of 2.7-17.6% in the groups treated with the highest dose compared with 3.2-12.7% in the vincristine treated groups. E7130 (0.09 mg/kg) significantly (P

Description: Introduction: Two surveys were conducted to understand the rationale for hematologists/oncologists (hem/oncs) to seek continuing medical education (CME) as well as how the information is applied to clinical practice. Additionally, we studied the clinical decision making of hem/oncs who treat patients with multiple myeloma (MM) in order to understand the areas to focus for future CME activities. Methods: We conducted two incentivized surveys where only hem/oncs in the US who treat patients were eligible: 1) MM decision-making survey (MM survey) in November 2018 where they were asked case-based questions to assess practice patterns and they were asked to rate their level of confidence in their decisions for the cases; and 2) Information seeking behaviors and preferences survey (behavior survey) in May and June 2019 where they responded to questions about what information informs practice and how often they need new information. Physicians were paid for their participation in the surveys. Results: 93 hem/oncs participated in the behavior survey with 56% from the community setting and 44% practicing exclusively in an academic setting. Community hem/oncs visit online CME more frequently than academic hem/oncs (daily or at least once a week: 67 vs 51%, respectively). The primary factors driving hem/oncs to access online CME include the need to learn about the latest developments (45%) and looking for an answer to a specific question (25%). Community hem/oncs are 2x more likely than academic hem/oncs to access online CME in order to earn credits. All of the hem/oncs surveyed have modified or implemented a new clinical practice in the last year, with the majority of the modified or new practices related to treatment (69%). Community hem/oncs are 174% more likely than academic hem/oncs to use CME as the source of the information leading to modified/new practice (27% vs 10%). The influence of CME on clinical practices is especially striking among hem/oncs practicing in a community vs academic setting on both gaining more confidence in their current practices (71% vs 59%) and modifying treatment practices (64% vs 54%). There were 101 hem/oncs who participated in the MM survey with 51% practicing in the community setting and 55% seeing between 1 to 10 patients with MM per month, whereas 22% saw more than 20 patients with MM per month. Case 1 highlights the lack of confidence among hem/oncs in making treatment decisions for patients with relapsed/refractory MM, with the majority, between 55% to 72%, only somewhat or not confident in their clinical decision. Although various options would be acceptable and not harmful, ideally treatment decisions would be made with a sense of confidence. In case 2, a striking 48% of hem/oncs would use a bortezomib-based regimen in a patient who has severe peripheral neuropathy, despite bortezomib's known side effect of peripheral neuropathy. For those who would use carfilzomib (52%) or a non-bortezomib regimen (13%), less than half (42% and 46%, respectively) were confident in their decision. Case 3 highlights the complexity of tailoring therapy for patients with MM as any of the answers could be appropriate, but between 37% and 67% of hem/oncs were only somewhat or not confident in their choices, indicating a need for additional education. Conclusions: Large Impact of CME on Community Hem/Oncs: A majority of hem/oncs access online CME at least once a week in order to learn about the latest developments and to find answers to specific questions, with the need for CME credits being a minor driver of CME consumption. The data show that CME has a high impact on clinical practices as the majority of hem/oncs surveyed modified or implemented new clinical practices in the last year as a result of what was learned in CME activities. The impact of CME on clinical practices is particularly striking among hem/oncs who practice in community-based settings. Additional Multiple Myeloma-Focused CME is Needed:The treatment paradigm for MM is rapidly evolving and this analysis shows that in order to improve the skills of hem/oncs as well as their confidence in their clinical decision making, additional CME is needed in the areas of (1) individualizing treatment for R/R MM, (2) managing adverse events, and (3) selecting maintenance therapy for high-risk MM. Table Disclosures No relevant conflicts of interest to declare.

Description: Background: Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms that can progress to post-PV (PPV) myelofibrosis (MF) and post-ET (PET) MF, also known as secondary myelofibrosis (SMF). The 2009 International Working Group for Myelofibrosis Research and Treatment group (IWG-MRT) diagnostic criteria for SMF require the presence of grade 2 or 3 bone marrow fibrosis (BMF) according to the European classification. The prognostic value of BMF in primary MF has been recently explored. Aim of this study is to describe the relevance of BMF grading in terms of presentation and outcome in SMF. Methods: The MYSEC (Myelofibrosis Secondary to PV and ET Collaboration) project is an international retrospective collaboration that collected 805 SMF cases. BMF grade at time of SMF evolution was defined as grade 2 (BMF2) in case of a diffuse increase in reticulin with extensive intersections, occasional bundles of collagen and/or osteosclerosis, or as grade 3 (BMF3) if presenting with coarse bundles of collagen, often associated with osteosclerosis. Chi-square or Fisher exact test for categorical variables, Wilcoxon rank-sum test for continuous ones and multiple logistic regression analysis were applied in order to explore pattern of association between BMF grading and patients' characteristics. A Poisson regression model was applied to estimate incidence rate of events, together with 95% Confidence Interval (CI). Survival was estimated using the Kaplan-Meier method. Differences between BMF groups were compared by a Log-rank test. The MYSEC study was approved by the Review Board of each Institution and conducted in accordance with the Declaration of Helsinki. Results: Detailed information about BMF grade was available in 675 patients: BMF2 was reported in 443 (65.6%) and BMF3 in 232 (34.4%). We did not find any correlation between BMF grade and advanced age, marrow blasts percentage, spleen and liver size, presence of constitutional symptoms, abnormal karyotype at the time of SMF diagnosis. No imbalance was evident for gender and for time to progression from PV/ET to SMF. Looking at genotype, BMF grading was not differently distributed among the 3 phenotypic driver mutations as well as the "triple negative" cases. On the contrary, in univariate analysis we found a significant association between BMF3 and previous diagnosis of ET vs. PV, decreased hemoglobin levels, reduced platelet and leukocyte counts, higher percentage of circulating blast cells and higher LDH value (Table 1). In a multivariate analysis that took into consideration SMF subtypes, complete blood count and circulating blast cells in 437 SMF patients, PET-MF, lower hemoglobin levels and reduced platelet count maintained their association with BMF3 (Table 2). The cumulative incidence of thrombosis after SMF was 3.2% (CI 95%: 2.4-4.2) person-year of follow up (PYFU) in BMF2, equivalent to BMF3 (2.7% PYFU, CI 95%: 1.2-5.7) (P = 0.44). Besides, BMF grade did not impact on the cumulative incidence of post-SMF blast phase, which resulted 2.4% (CI 95%: 1.8-3.3) PYFU in case of BMF2 and 3% (CI 95%: 1.3-6.9) PYFU in the BMF3 cohort (P = 0.68). Overall, MYSEC-PM (MYSEC-Prognostic Model) risk categories were differently distributed between BMF grades: patients with BMF2 were more frequently included in lower risk groups, while those with BMF3 were enriched in the higher categories (Table 1). Finally, we found a significantly higher mortality in patients with BMF3 vs. BMF2, mainly due to SMF progression (Table 1). Figure 1 shows the Kaplan-Meier estimate of survival in the 2 populations, resulting significantly different. Nevertheless, when considering the MYSEC-PM score in a multivariate analysis, BMF grade lost its prognostic impact on survival. Conclusions: This study provides evidence that BMF grade does correlate with specific clinical phenotype in SMF. BMF3 was associated with a more "cytopenic" phenotype (lower hemoglobin levels and reduced platelet count) and clustered with higher MYSEC-PM scores. Survival is significantly reduced in patients with BMF3. In conclusion, irrespectively of the PV/ET duration, progressive anemia and thrombocytopenia imply more frequently BMF3, finally resulting in a worse survival. This highlights the need of performing bone marrow biopsy earlier in disease evolution. Disclosures Rumi: novartis: Honoraria, Research Funding. Rambaldi:Omeros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau, travel support; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Italfarmaco: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau. Komrokji:Incyte: Consultancy; pfizer: Consultancy; JAZZ: Speakers Bureau; celgene: Consultancy; JAZZ: Consultancy; Novartis: Speakers Bureau; Agios: Consultancy; DSI: Consultancy. Gotlib:Deceiphera: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Research Funding; Promedior: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Blueprint Medicines: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Allakos: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Honoraria, Research Funding; Celgene: Consultancy. Cervantes:Novartis: Honoraria, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Palandri:Novartis: Consultancy, Honoraria. Silver:PharmEssentia: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Benevolo:Novartis Pharmaceuticals: Consultancy. Albano:Incyte: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Iurlo:Novartis: Other: Speaker Honoraria; Incyte: Other: Speaker Honoraria; Pfizer: Other: Speaker Honoraria. Vannucchi:Incyte: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Italfarmaco: Membership on an entity's Board of Directors or advisory committees; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Passamonti:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Celgene Corporation: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau.

Description: Background: Calreticulin (CALR) mutations are one of the major driver mutations in BCL-ABL1-negative myeloproliferative neoplasm (MPN) and are frequently detected in JAK2/MPL-unmutated essential thrombocythemia and primary myelofibrosis. Mutant CALR activates JAK-STAT signaling through an MPL-dependent mechanism to mediate pathogenic thrombopoiesis in MPNs. Although JAK inhibitors such as ruxolitinib can provide important clinical benefits to MPN patients including those harboring CALR mutations, JAK inhibition does not preferentially target the MPN clone and acquired resistance develops over time. We aimed to characterize the mechanisms of acquired resistance to JAK inhibitors in CALR-mutated hematopoietic cells and to screen for novel therapeutic approaches specifically target CALR-mutant cells in this study. Methods: UT-7/TPO-derived cell lines expressing wild-type and type 1 and type 2 mutant CALR (CALRdel52 and CALRins5) were kindly provided by Drs. Komatsu and Araki. JAK2-inhibitor-resistant cells were generated by co-cultured with ruxolitinib and fedratinib (TG101348, a JAK2-selective inhibitor). JAK-STAT signaling was evaluated by Western blot on CALR-wild-type and mutated cells exposed to JAK2 inhibitor compared to untreated cells. For the detection of acquired secondary mutations in CALR-mutated cells exposed to JAK2 inhibitor, whole exome sequencing (WES) was performed using the BGISEQ-500 Sequencing platform (BGI, Shenzhen, China) with the 2 x 100 bp paired-end protocol. Genome Analysis Toolkit was used for variation detection. Reads were aligned to human reference genome hg19 using BWA version 0.7.15. Targeted resequencing was performed on leukocytes from patients with MPN who had been treated with ruxolitinib. Screening with chemical libraries/novel compounds will be conducted on UT7/TPO-CALR cell lines. Results: Compared to the parental cells, ruxolitinib-resistant UT7/TPO-CALR mutant cell lines have developed significant cross resistance to other JAK inhibitor as shown in the cell viability study. Signalling downstream of JAK2 in all 3 inhibitor-naïve UT-7/TPO/CALR parental cell lines was inhibited by acute treatment of ruxolitinib as shown on Western blot. Whereas, constitutive JAK2 activation was observed in all 3 inhibitor-resistant UT-7/TPO/CALR cell lines. No change in the expression of Epo and MPL receptors in these cell lines was found. Interestingly, constitutive JAK3 activation was also seen in inhibitor-resistant UT-7/TPO/CALR cells in comparison with parental cells. These findings indicated the presence of transphosphorylation by JAK3 in inhibitor-resistant UT-7/TPO/CALR cell lines. In addition, the results of WES identified several acquired secondary mutations in 3 inhibitor-resistant UT-7/TPO/CALR cell lines including SH2B1, ABCC1, HOXB3 and KRTAP4-5. No acquired secondary mutation was identified in CALR and other genes involved in JAK-STAT signaling. Acquired secondary mutation will be screened in primary MPN patients' samples treated with JAK inhibitor. Type II JAK inhibitor such as BBT-594 has been shown to inhibit JAK activation and signaling in JAK-persistent/resistant cells. Conclusions: Our results confirmed that the in vitro efficacy of JAK2 inhibition on CALR-mutant cells. Our data also suggested that JAK2 transphosphorylation and acquired secondary mutations could be underlying mechanisms for acquired resistance to JAK inhibitors in CALR-mutated cells. Novel therapeutics approaches should be developed to overcome acquired resistance in CALR-mutated cells. Disclosures No relevant conflicts of interest to declare.

Description: Chimeric antigen receptor (CAR) T-cell therapy represents a major advancement in personalized cancer treatment. Generating robust and well characterized manufacturing processes for cell therapy has become crucial. Traditional manufacturing processes activate and expand T cells in media containing human serum, which supports cell growth and viability. However, serum batches vary significantly from lot to lot and require frequent screening for contaminants that can be detrimental to patients. T cell manufacturing processes independent of human serum will render adoptive T cell therapy less expensive, more consistent, and safer for patients. In order to create a best-in class serum-free medium that is even more robust than serum-containing media, we need to gain a better understanding of the metabolic requirements of T cells during expansion. For this purpose, we have utilized a multi-omics approach to fully characterize the proteomic and metabolomic signatures of T cells expanded in a serum free, xeno free medium at different phases of growth. We sampled cells at days 3, 5, and 7 for label-free proteomics and untargeted extra- and intracellular metabolomics analysis in order to identify metabolic patterns that could be corrected with media supplementation. We identified over 6,043 proteins and 900 metabolites from 4 donors and detected 1,200 significantly different proteins and 312 metabolites. Using an in-house bioinformatics strategy to analyze the multi-omics data, we focused on several metabolic and signaling pathways that were significantly different at days 5 and 7 compared to day 3. The "corrective" media supplementation that we added based on these results demonstrated a tremendous increase in cell growth and viability yielding a 2.6- and 3.2-fold increase in cell growth on days 5 and 7, respectively, and an increase in viability of 15-20% and 11-15% on days 5 and 7, respectively, compared to the un-supplemented prototype. In addition, cells maintained high viability throughout the whole culture and phenotype was not affected. These data demonstrate that multi-omics is a powerful tool for understanding T cell metabolism and identifying components to develop robust and reproducible serum-free media that produces high quality T cells. Disclosures No relevant conflicts of interest to declare.

Description: Background: Azacitidine (AZA) therapy is the standard of care for higher-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) patients not eligible for intensive treatment. Although nearly 50% of patients respond to AZA treatment, most of them experience disease progression within 2 years of remission. The prognosis of patients after AZA failure is dismal with a median overall survival (OS) reaching 3-6 months. Interestingly, recent studies have demonstrated clinical efficacy of cladribine combined with cytarabine in newly diagnosed AML patients. In view of epigenetic properties of cladribine and known synergy with cytarabine, it may be speculated that combination of cladribine and low-dose cytarabine (LD-AraC) exerts some clinical activity also in the setting of relapsed/refractory AML/MDS. Aim: The aim our study was to assess activity and toxicity of combination of cladribine and LD-AraC in patients with MDS/AML after AZA failure. Methods: This retrospective analysis included patients with AML with 20% to 30% blasts, high and intermediate-2 risk MDS and CMML patients with AZA failure who were treated with combination of cladribine and LD-AraC in centers of the Polish Adult Leukemia Group (PALG). Therapy started with induction phase consisting of 2 cycles of cladribine 5 mg/m2 iv on days 1-5 (cycle 1) and on days 1-3 (cycle 2) in combination with LD-AraC 40 mg/m2 sc (days 1-10). Patients who achieved remission moved on to maintenance therapy with LD-AraC 40 mg/m2 sc, days 1-10), every 4 weeks. The treatment was continued for as long as tolerated and there was a clinical benefit. Treatment response was determined in accordance with the 2017 European Leukemia Net (ELN) and the 2006 International Working Group (IWG) criteria after each cycle. Results: Overall, 16 patients (8 patients with diagnosis of AML, 7 with diagnosis of MDS, and 1 with diagnosis of CMML myelodysplastic subtype at AZA therapy initiation) who had been treated with combination of cladribine and LD-AraC at AZA failure in 3 centers of PALG between 2014 and 2019 were identified. There were 9 males and 7 females, with median age of 72 years (range 64 - 78). The patients had previously received a median of 15 cycles of AZA (range 4 - 33). At the initiation of cladribine and LD-AraC therapy the median number of blasts was 27,5% (range 15,5 - 77) with 13 patients fulfilling the criteria of AML. At the data cut-off the median of administered chemotherapy cycles reached 4 (range 1-14), with 4 patients continuing treatment. The regimen was relatively well tolerated with no treatment related deaths and the most common non-hematological adverse events of grade 3 or worse being neutropenic fever and pneumonia. Response assessment revealed that nine patients (56%) achieved a remission, including 6 complete remissions (CR) and 3 complete remissions with incomplete recovery (CRi). The median time to response was 1 cycle. Median progression-free survival was 8 months, and the median OS reached 10.6 months. The estimated 6-months and 12-months OS probability were 79.3% and 44.6%, respectively. Conclusions: The combination of cladribine and LD-AraC appears to be an attractive option in the therapy of AML/MDS patients after AZA failure. Although prospective studies are needed to confirm these findings such treatment seems to be associated with an improvement in OS compared to the historical data. Disclosures Gora Tybor: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: Background:Light-chain amyloidosis (AL) is a clonal plasma cell disorder in which Ig light chains cause organ-specific disease due to toxic misfolded light-chain aggregates and extracellular deposition of amyloid fibrils derived from light chain proteins. The majority of amyloid patients present in various stages of heart failure and survival is largely driven by the extent of cardiac involvement. In the general heart failure population, overweight and mild/moderate obesity is associated with lower mortality, termed the obesity survival paradox. Conversely for patients with multiple myeloma, a disease similar in pathophysiology to AL, obesity is a risk factor for hematological progression. Hypothesis:We hypothesized that patients with cardiac amyloidosis would exhibit an obesity survival paradox and sought to determine the impact of BMI on hematological and cardiac responses to anti-plasma cell treatment. Methods:We conducted a single tertiary center retrospective study of consecutive patients with cardiac AL amyloidosis, referred between 1/1/2009 and 09/30/2018. We collected demographics and BMI prior to treatment. We recorded the date of diagnosis and subsequent dates of hematological and/or cardiac response, mortality or end of follow-up. We constructed a Cox proportional hazards model examining the association between BMI and mortality with a restricted cubic spline function curve. Three logistic regression models were constructed to examine the association between high BMI (〉/=25 kg/m2) and cardiac or hematological response, and mortality. Models were adjusted for age, sex and cardiac stage at the time of diagnosis. Results:Of 79 patients, 17 patients had BMI of 17-22.5, 19 a BMI of 22.6-25, 23 a BMI of 25.1-29.7, and 20 a BMI of 〉/=30 kg/m2. Crude mortality was 31/79 (39%). There was no relationship between BMI as a continuous variable and mortality (HR 0.98, 95% CI 0.91-1.06, p=0.625, adjusted for age and sex), although a survival paradox trend was suggested by the spline curve. While there was no relationship between high BMI and hematological response (adjusted OR 1.00, 0.37-2.75, p=0.996), there was a relationship between high BMI and lower likelihood of achieving cardiac response (adjusted OR 0.23, 0.07-0.71, p=0.011). Conclusions:In this small cohort of patients with AL cardiac amyloidosis, there was no significant relationship between BMI and mortality. Hematological response was unrelated to BMI, but patients with a higher BMI were significantly less likely to achieve a cardiac response. These findings suggest that obesity might be associated with poorer cardiac outcomes in AL amyloidosis, highlighting the importance of a multidisciplinary approach involving oncologists, cardiologists, and nutritionists in the treatment of this complex multi-organ disease. Disclosures Comenzo: Caelum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Prothena Biosciences: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Takeda: Research Funding; Unum: Membership on an entity's Board of Directors or advisory committees, Research Funding; Myself: Patents & Royalties: Patent 9593332, Pending 20170008966; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Research Funding.

Description: Adult hematopoietic stem cells (HSCs) are a rare and unique population of stem cells that reside in the bone marrow, where they undergo self-renewal and differentiation to maintain the blood system. The maintenance of a proper balance between HSC self-renewal and differentiation requires growth factors, cytokines, and chemokines, most of which activate the phosphoinositide 3-kinase/Protein Kinase B (PI3K/AKT) signaling pathway. Pathologic activation of the AKT pathway is frequently observed in tumors, making it a desirable target for cancer treatment. Since several PI3K inhibitors are now in clinical use, it is critical to determine the roles of PI3K in adult HSCs. However, the specific roles of PI3K in HSC function are poorly understood. Hematopoietic cells express three Class IA catalytic PI3K isoforms (P110α, β, and δ), which can all transduce growth factor and cytokine signals, and can compensate for one another in some cell types. Individual Class 1A PI3K isoforms have unique functions in mature hematopoietic lineages, but are dispensable for HSC function. To uncover the potentially redundant roles of PI3K isoforms in HSCs, we have generated a triple knockout (TKO) mouse model with conditional deletion of p110α and p110β in hematopoietic cells using MX1-Cre, and germline deletion of p110δ. TKO mice develop pancytopenia, which is also observed upon transplantation of TKO bone marrow. Competitive repopulation assays reveal a defect in long-term multi-lineage chimerism. Surprisingly, loss of Class 1A PI3K causes significant expansion of donor-derived long-term (Lin-cKit+Flk2-CD150+CD48-) and short-term (Lin-cKit+Flk2-CD150-CD48-) HSCs in the bone marrow, but not committed progenitors. This phenotype could not be explained by alterations in HSC cell cycling or apoptosis in TKO HSCs. TKO transplant recipients also have dysplastic features in the bone marrow. Methylcellulose plating assays of TKO bone marrow revealed a relative increase in granulocyte erythroid macrophage megakaryocyte (GEMM) colonies and extended serial replating, suggesting increased self-renewal. Thus, our data are consistent with impaired HSC differentiation upon deletion of all Class IA PI3K isoforms, which leads to dysplastic changes. RNA sequencing of sorted long-term HSCs from the bone marrow of TKO transplant recipients revealed the enrichment of human and mouse HSC signatures, and the downregulation of DNA repair gene sets and RNA splicing gene sets in TKO HSCs. Interestingly, we also observed downregulation of autophagy gene sets in TKO HSCs. Macroautophagy has been shown to be essential for the maintenance of HSC metabolism and self-renewal. Analysis of the autophagosomal marker LC3-II in TKO HSCs revealed a decrease in autophagy upon growth factor deprivation. Surprisingly, we observed an increase in MTOR activation in TKO cKit+ bone marrow cells via compensatory signaling through the MAPK pathway. Given that MTOR is a known negative regulator of autophagy, this is consistent with the observed autophagy decrease in TKO HSCs. Additionally, we found that autophagy can still be induced in TKO HSCs with the MTOR inhibitor rapamycin. Furthermore, rapamycin treatment impairs serial replating of TKO bone marrow cells. In conclusion, we found that inactivation of all Class 1A PI3 kinases leads to impaired HSC differentiation, likely due to a defect in autophagy induction in response to growth factor deprivation. Disclosures No relevant conflicts of interest to declare.

Description: Background Binding of E-selectin (E-sel) to sialyl Lex, the E-sel ligand, on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. Higher expression of E-sel ligand is associated with relapse and poor survival. Uproleselan (GMI-1271), a novel E-selectin antagonist, disrupts cell survival pathway activation, enhances chemotherapy response and protects from toxicity such as mucositis with improved survival in vivo. Preclinical data support combination of uproleselan with chemotherapy improves response without additional toxicity. A phase 1/2 study (NCT02306291) of uproleselan added to chemotherapy (mitoxantrone, etoposide, cytarabine, MEC) in R/R AML showed promising outcomes at the recommended phase 2 dose (RP2D), including a CR/CRi rate of 41% and median OS of 8.8 m (95% CI 5.7-11.4). 11/16 (69%) evaluable patients were MRD negative (DeAngelo et al ASH 2018). Patients with sufficient expression of the appropriate E-selectin ligand (the target of the E-selectin inhibitor) exhibited higher CR/CRi rate and longer survival. Median OS for Leukemic blasts/E-sel ligand ≥10% vs leukemic blasts/E-sel ligand

Description: Background: Iron deficiency, even without a diagnosis of anemia, can be neurodevelopmentally dangerous in pediatric populations. Oral iron supplementation has been the treatment of choice but is associated with poor adherence for several reasons including metallic taste of the tablets, gastric irritation, severe constipation, and daily dosing for several weeks. Intravenous iron has been safely used in adult populations for iron supplementation, but has less commonly been used in pediatric populations. It is hypothesized that pediatric patients with iron deficiency anemia (IDA) who receive intravenous iron infusions will show normalization of hematologic parameters. Methods: EMR of patients aged 1-21 who received at least one intravenous iron infusion at Cooper University Hospital between 2016 and January 2019 were reviewed for retrospective data collection. Pre-infusion lab values including Hgb, MCV, RBCs and RDW were compared to post-infusion values to determine if values normalized after intravenous iron infusion. Patient demographics including ethnicity, cause of IDA, prior oral iron treatments, and adverse effects of oral and IV iron were analyzed. Results: There were 33 subjects in this study. The average age of the subjects was 12.8 (+/- 5.1) years of age and 79% were female. The most prevalent indication for IV iron was menorrhagia (55%), while GI issues were 18% and insufficient diet accounted for 27%. The mean baseline HGB was 8.3 (+/- 1.7) while the mean final HGB increased to 11.5 (+/- 1.4) (p

Description: Acute myeloid leukemia (AML) develops in a step-wise manner from pre-leukemic clonal expansion to full-blown disease driven by aberrant epigenetic changes. Indeed, regulators of the epigenome such as DNMT3A, TET2, IDH1/2, EZH2 and ASXL1 are often mutated in pre-leukemia and myeloid malignancies. We and others identified K27M/I mutations in histone H3 in AML (Boileau et al. Nat Commun, 2019; Lehnertz et al. Blood, 2017). We demonstrated that K27 mutations are found in pre-leukemic hematopoietic stem cells (HSCs), are enriched in secondary AML, expand the functional human HSC pool and increase leukemic aggressiveness. Transcriptomic and epigenomic analysis determined that K27 mutations alter gene expression through a global decrease in promoter H3K27 tri-methylation and a gene-specific increase in H3K27 acetylation in leukemic cells (Boileau et al. Nat Commun, 2019). Here, we have analyzed the effects of the K27M mutation on HSCs at the single-cell level to understand its role in pre-leukemic clonal expansion. Healthy CD34+CD38- human cord blood cells were transduced with HIST1H3H WT or K27M and injected intrafemorally into sub-lethally irradiated NSG mice. After 14 weeks, bone marrow cells from the femur were collected and sorted for CD34+ transduced (GFP+) cells. Single-cell transcriptomics were performed by generating gene expression libraries from ~8,000 CD34+ cells using the 10X Genomics technology and sequenced using HiSeq4000. We have performed initial clustering and dimensionality reduction (t-SNE and UMAP) and identified 10 and 11 distinct clusters in the WT and K27M samples, respectively. Gene sets distinguishing the individual clusters have been determined. Using published gene lists for primitive hematopoietic cell types, the clusters have been assigned to specific cell types such as HSC, granulocyte-monocyte progenitors (GMP), common myeloid progenitors (CMP), multi-lymphoid progenitors (MLP) and megakaryocyte-erythroid progenitors (MEP) (Laurenti et al. Nat Immunol, 2013). Preliminary joint clustering analysis indicates the presence of two distinct clusters for the WT and K27M samples that were both assigned as "HSCs" in individual clustering. Further analysis to identify the differences in the clusters and cell populations between WT and K27M samples is being performed and will be presented at this meeting. Overall, this single-cell transcriptomic analysis will aid in determining the mechanism of action of the K27M mutant histone in pre-leukemic HSC clonal expansion. In addition, we will be performing similar single-cell analysis on HSCs expressing mutant ASXL1 as a comparison. Further understanding of the role of mutations in epigenetic regulators, such as histone H3 and ASXL1, in pre-leukemic clonal hematopoiesis will provide valuable insight on how to better prevent and treat AML and other myeloid malignancies. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: CD20-TCB (RG6026) is a novel T-cell-engaging bispecific (TCB) antibody with a '2:1' molecular format that comprises two fragment antigen binding regions that bind CD20 (on the surface of B cells) and one that binds CD3 (on the surface of T cells). CD20-TCB offers the potential for increased tumor antigen avidity, rapid T-cell activation, and enhanced tumor cell killing versus other bispecific formats. An ongoing Phase I dose-escalation study (NP30179; NCT03075696) has shown promising antitumor activity and acceptable safety in relapsed or refractory (R/R) non-Hodgkin lymphoma (NHL) patients (pts) (Dickinson et al. ICML 2019). We investigated population pharmacokinetics (popPK) and exposure-response (E-R) relationships for CD20-TCB in NP30179. Methods: Indolent (i) and aggressive (a) R/R NHL pts received CD20-TCB doses of 0.005 to 25mg every 2 or 3 weeks following single 1000mg obinutuzumab (G) pre-treatment (Gpt) on Cycle 1 Day −7 to mitigate for cytokine release syndrome (CRS). Serial and spare PK data collected from pts were used to develop a popPK model in NONMEM v7.4. Physiologically relevant covariates were investigated for their potential influence on CD20-TCB PK variability. Using the previously established G popPK model (Gibiansky et al. CPT Pharmacometrics Syst Pharmacol 2014;3:e144), full G concentration-time profiles were constructed in order to estimate CD20-TCB receptor occupancy (RO%) in the presence of G concentrations competing for CD20 receptors over time. E-R relationships between CD20-TCB time-averaged RO% (AvgRO%) up to Cycle 3 Day 1 and objective response rate (ORR) and complete response rate (CRR) were investigated in aNHL pts who reached Cycle 3 Day 1, and the relationship between CD20-TCB AvgRO% over the first 24 hours (as the majority of events occurred within the first 24 hours) and CRS, the most common safety event, as defined by Lee et al. (Blood 2014;124:188-95), was investigated in iNHL and aNHL pts combined using logistic regression. Results: The popPK analysis included 139 iNHL and aNHL pts with at least one PK sample. The E-R analysis for efficacy included 76 aNHL pts with PK and efficacy data at Cycle 3 Day 1. The E-R analysis for safety included 121 iNHL and aNHL pts with PK and safety data. CD20-TCB PK was best described using a two-compartment PK model with linear clearance. Body weight had a statistically significant influence on PK and was retained using theory-based allometric scaling. There were no obvious differences in PK between iNHL and aNHL pts. In aNHL pts, logistic regression analyses demonstrated a significant positive E-R relationship between AvgRO% up to Cycle 3 Day 1 and efficacy (ORR and CRR, p=0.007; Figure 1 for CRR). In the highest tertile of AvgRO% (≥0.48%), the observed ORR was 76% versus 38.5% (

Description: Background: Hypomethylating agents (HMA), azacitidine (AZA) and decitabine (DEC), are the current standard of care in patients with intermediate-2 and high risk myelodysplastic syndromes (MDS) by IPSS prognostic category (higher-risk MDS) based on clinical trials showing increased response rates and overall survival with these agents. However, the outcomes of patients with MDS treated with HMAs have not been comprehensively assessed in real-world practice. This study describes real-world treatment patterns and outcomes among patients with MDS treated with HMAs. Methods: Adult patients with a confirmed MDS diagnosis between 01/2009-12/2015 treated with HMA were identified in the SEER-Medicare database (01/2006-12/2016). The index date was the date of HMA initiation; the first HMA was defined as the index HMA. Patients were required to have Medicare Parts A and B coverage for ≥12 months pre-index and ≥1 month post-index date. Patients with evidence of stem cell transplant (SCT) or acute myeloid leukemia (AML) pre-index, or enrollment in a clinical trial at any time were excluded. Patients meeting the aforementioned criteria formed the study population. An algorithm, based on timing of HMA initiation, timing of diagnosis of pancytopenia (low counts for red blood cells, white blood cells, and platelets), and diagnosis of refractory anemia with excess of blasts (RAEB)-1 and RAEB-2, was developed to categorize patients into specific MDS risk groups using claims data (Figure A). Patients with RAEB-1/2 diagnosis who initiated HMA within 1 month prior to or 4 months post-RAEB diagnosis, or pancytopenia diagnosis within 3 months prior to HMA initiation (regardless of types of MDS diagnosis) were classified into the higher-risk MDS group. Patients with non-RAEB MDS diagnosis and HMA initiation within 1 month prior to or 4 months post-MDS diagnosis were classified into the intermediate-1-risk MDS group; remaining, unclassified patients from the study population were assigned into the unknown-risk MDS group. OS and time to AML transformation (determined by a diagnosis of AML in claims) were assessed for each risk stratum post-index using Kaplan-Meier (KM) analyses. HMA treatment patterns were measured up to 12 months post-index or until the first event among the following: SCT, AML-like intensive chemotherapy use, AML, or end of data/Medicare Parts A and B coverage (follow-up period). Results: A total of 3,046 patients with MDS treated with HMA were included. On average, patients were aged 77.4 years, and 36.8% were female. The majority of patients were classified in the higher-risk MDS group (70.9%), 8.0% in the intermediate-1-risk MDS group, and 21.1% in the unknown-risk MDS group. Median OS was 11.6 months among patients in the higher-risk MDS group, whereas median OS was 18.4 and 19.1 months for patients in the intermediate-1 and unknown-risk MDS groups, respectively (Figure B). Median time to AML transformation was 19.3 months in the higher-risk MDS group, 50.4 months in the intermediate-1-risk MDS group, and was not reached for the unknown-risk MDS group (Figure C). Overall, patients received an average of 5.1 HMA cycles (median = 4.0 cycles) and the majority were complete cycles (90.9%; as indicated per label or, for AZA, also including the commonly used alternative regimens of 5-day 5-0-0 or 7-day with a weekend break 5-2-2). The mean duration of HMA cycles was 32.6 days (median = 28.0 days). As many as 45.3% of patients received

Description: Introduction. Diffuse large B cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphomas (NHL). The use of chemoimmunotherapy (R-CHOP) in DLBCL has improved Overall Survival (OS). However, there are among 45-55% of patients who will die due to relapse, progression (refractoriness) or toxicity to treatment. Genomic classifications are difficult to use in clinical practice, especially in lain America, due to the need of trained personnel and cost. So, we continue using the International Prognostic Index (IPI) and its variations (e.g. revised-IPI, NCCN-IPI) for prognostic purposes. However, other biological variables have been reported to be prognostic, such as serum beta-2-microglobulin (B2M), lymphocyte/monocyte ratio (LMR), neutrophil/lymphocyte ratio (NLR), platelets/lymphocyte ratio (PLR) and serum albumin (SA). These factors have been associated with burden of disease, inflammation and nutritional status. Aim. Therefore, we performed a retrospective analysis of the databases of two Latin American groups to determine which biological variable is the most powerful factor prognostic of OS. Methods. A total of 1,250 patients were analyzed from two databases [(Grupo de Estudio para el Linfoma Mexicano (GELMEX) and the Grupo de Estudio para el Linfoma Latino Americano (GELL)], where 525 patients met the following inclusion criteria: DLBCL diagnosis by immunochemistry; complete data on absolute lymphocyte, absolute monocyte, absolute neutrophil and absolute platelet count, serum B2M and SA; and complete data on traditional variables for calculating risk groups for IPI, NCCN-IPI & R-IPI. The LMR, NLR and PLR was obtained. We evaluated the AUC of the biological variables and the differences among each one of them (including cut-off). Kaplan-Meier curves (KMC) were estimated and subsequently, the inference of OS was evaluated by Hazard Ratio (HR) Cox-regression in univariate/multivariate analyses by forward model. All variables with p3.2 mg/dL vs. ≤3.2 mg/dL) were 72% vs 34% (Log Rank p

Description: BCL-2 inhibition exerts effective pro-apoptotic activities in acute myeloid leukemia (AML) but clinical efficacy as a monotherapy was limited in part due to the treatment-induced MCL-1 increase. Triptolide (TPL) exhibits anti-tumor activities in part by upregulating pro-apoptotic BCL-2 proteins and decreasing MCL-1 expression in various malignant cells. We hypothesized that combined BCL-2 inhibition and TPL exert synergistic anti-leukemia activities and prevent the resistance to BCL-2 inhibition in AML. We here report that TPL combined with BCL-2 inhibitor ABT-199 synergistically induced apoptosis in leukemic cells regardless of p53 status through activating the intrinsic mitochondrial apoptotic pathway in vitro. Although ABT-199 or TPL alone inhibited AML growth in vivo, the combination therapy demonstrated a significantly stronger anti-leukemic effect. Mechanistically, TPL significantly upregulated BH3 only proteins including PUMA, NOXA, BID and BIM and decreased MCL-1 but upregulated BCL-2 expression in both p53 wild type and p53 mutant AML cell lines, while the combination decreased both BCL-2 and MCL-1 and further increased BH3 only BCL-2 proteins. MCL-1 and BCL-2 increases associated with respective ABT-199 and TPL treatment and resistance were also observed in vivo. Significantly downregulating MCL-1 and elevating BH3 only proteins by TPL could not only potentially block MCL-1-mediated resistance but also enhance anti-leukemic efficacy of ABT-199. Conversely, BCL-2 inhibition counteracted the potential resistance of TPL mediated by upregulation of BCL-2. The combination further amplified the effect, which likely contributed to the synthetic lethality. This mutual blockade of potential resistance provides a rational basis for the promising clinical application of TPL and BCL-2 inhibition in AML independent of p53 status. Disclosures Carter: Amgen: Research Funding; AstraZeneca: Research Funding; Ascentage: Research Funding.

Description: Background Persons with multiple sclerosis (MS) are sometimes treated with high-dose immune suppressive or cytotoxic drugs and an autotransplant. Use of autotransplants may be substantially more common as many cases are not reported. Therapy-related mortality (TRM) has decreased to 70%, extended Disability Status Scale (EDSS ≤8 in the 2 w pretransplant), CNS magnetic resonance image (MRI) ≤3 mo pretransplant, no prior bone marrow toxic drugs, normal heart, liver, lung and kidney function, ≥6 mo since exposure to immune suppressive drugs. Results 495 females and 244 males were included; median age was 47 years. 310 patients presented with relapsing remitting MS (RRMS), 273 with secondary progressive (SPMS) and 156 with primary progressive (PPMS). All procedures were started on an outpatient basis and only 31 persons needed to be admitted to the hospital during the procedure. In order to obtain at least 1x106/Kg viable CD34 cells, one to three apheresis were performed (median 1). Total number of viable CD34+ cells infused ranged between 1 and 37.83 x106 / Kg (median 5.62). Patients recovered above 0.5 x109/L absolute granulocytes on day 8 (median, range 2-13), whereas platelet recovery above 20 x109/L on day 4 (median, range 0-10). Seven individuals required red blood cells and eight needed platelet transfusions. There was one transplant related death and the 30-month overall survival of the patients is 99.9%. Patients with RRMS or PPMS had a significant drop in the EDSS before and 15-mo after the transplant, whereas patients with SPMS remained stable (A). The response rate (either drop or stabilization of the EDSS score) at 12 months was 78% for RRMS, 81% for PPMS and 73% for SPMS (B), whereas the relapse-free survival was 84% for all patients (92% for PPMS, 83% for RRMS and 81% for SPMS). Conclusions Changes in the EDSS score consonant with neurological improvement were observed in persons with all types of MS after HSCT employing the "Mexican method". Figure 1 Disclosures Gomez-Almaguer: Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Teva: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau.

Description: Background: L-asparaginase, an important component of ALL therapy, hydrolyzes the nonessential amino acid asparagine, depleting plasma levels and selectively killing leukemic lymphoblasts that are asparagine autotrophs. L-asparaginases are immunogenic and can induce hypersensitivity reactions; high neutralizing antibody titers may limit their therapeutic effect. The inability to receive asparaginase secondary to hypersensitivity has prognostic implications for patients with ALL and has been associated with significantly worse outcomes (Silverman LB, et al. Blood 2001;97:1211-1218; Gupta S, et al. J Clin Oncol. 2019;37[suppl]: Abstract 10005). Alternative preparations are needed to ensure that all patients unable to receive E. coli-derived asparaginase due to hypersensitivity are able to receive adequate treatment. RC-P is a recombinant crisantaspase. Due to the use of a novel Pseudomonas fluorescens technology expression platform, RC-P has no immunologic cross-reactivity to E. coli-derived asparaginases. In a study of RC-P administration in healthy adults (JZP458-101), the enzyme was well tolerated and maintained adequate (≥0.1 IU/mL) serum asparaginase activity (SAA), a surrogate marker for asparagine depletion, for up to 72 hours. Study Design and Methods: This is an open-label, multicenter, dose confirmation and pharmacokinetic (PK) study (JZP458-201) of RC-P in patients with ALL or LBL who develop allergic reactions to an E. coli-derived asparaginase and have ≥1 dose of E. coli-derived asparaginase remaining in their treatment plan (Table). For these patients, 6 doses of RC-P will be substituted for each dose of long-acting E. coli-derived asparaginase. Individual patient treatment duration will vary depending on the number of E. coli-derived asparaginase doses that remain in the patient's original treatment plan. The study will consist of 2 sequential parts: Part A will determine the dose of RC-P for intramuscular (IM) administration and confirm safety and efficacy; Part B will define the optimal dose and schedule of intravenous (IV) RC-P. Blood samples will be collected at prespecified time points to determine SAA levels, and patients will be monitored for adverse events. Immunogenicity of RC-P treatment will also be assessed. The primary objectives are to (1) determine the efficacy of IM RC-P administration measured by the last 72-hour nadir SAA (NSAA) level being ≥0.1 IU/mL during the first course of treatment, and (2) assess the safety and tolerability of IM RC-P in patients with ALL/LBL who are hypersensitive to E. coli-derived asparaginases. Secondary objectives include determination of the efficacy of IM RC-P measured by the last 48-hour and last 72-hour NSAA levels being ≥0.4 IU/mL during the first course, characterization of PK of IM RC-P using a population PK approach, and assessment of immunogenicity following repeat administration of RC-P. Exploratory objectives include determination of the efficacy, safety, PK, and immunogenicity of IV RC-P. Disclosures Raetz: Pfizer: Research Funding. Lin:Jazz Pharmaceuticals: Employment, Equity Ownership. Zhu:Jazz Pharmaceuticals: Employment, Equity Ownership. Kim:Jazz Pharmaceuticals: Employment, Equity Ownership. Chandula:Jazz Pharmaceuticals: Employment, Equity Ownership. McClung:Jazz Pharmaceuticals: Employment, Equity Ownership. Gray:Jazz Pharmaceuticals: Employment, Equity Ownership. Choi:Jazz Pharmaceuticals: Employment, Equity Ownership. Loh:Medisix Therapeutics, Inc.: Membership on an entity's Board of Directors or advisory committees. Adamson:Pfizer: Research Funding; Celgene: Research Funding; Bristol-Myers Squibb: Research Funding; Adaptive Biotechnologies: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amneal Pharmaceuticals: Equity Ownership; Allergan: Equity Ownership; Gilad Sciences: Equity Ownership; Medtronic: Equity Ownership; Merck: Equity Ownership, Research Funding; Genentech/Roche: Research Funding; Novartis: Research Funding; Eisa: Research Funding; Celator: Research Funding; Seattle Genetics: Research Funding; United Therapeutics: Research Funding; Sanofi/Aventis: Research Funding; Jubilant Pharmaceuticals: Research Funding; Jazz Pharmaceuticals: Research Funding; Incyte: Research Funding; Bayer: Research Funding; Amgen: Research Funding; AstraZeneca: Research Funding; Cancer Prevention Pharmaceuticals: Research Funding; Astellas Pharma: Research Funding; Lilly: Research Funding; Springworks: Research Funding; Millennium: Research Funding. OffLabel Disclosure: The abstract presents data from an investigational agent.

Description: BACKGROUND Multiple Myeloma (MM) is an incurable malignancy heralded by an immunosuppressive tumor microenvironment (TME). Therapeutic efforts to reprogram the TME and release innate and adaptive immunity may synergize with current anti-MM drugs, deepen responses and ultimately prolong long-term survival. We have developed an ex vivo gene therapy approach that locally delivers interferon-alpha (IFNa) into the TME through the Tie2+ myeloid progeny of transplanted gene-modified hematopoietic stem and progenitor cells (HSPCs). Preclinical studies in the immunocompetent Vk*Myc murine model as well as in the hematochimeric xenotransplantation setting demonstrate that IFNa gene therapy has anti-MM effect and may subvert the immunosuppressive MM TME, acting both on myeloma cells as well as on the immune infiltrate. Additional toxicology data, demonstrates that a mixture of genetically modified and unmodified CD34+ cells can be transplanted safely. We have therefore progressed into the clinic at Ospedale San Raffaele in Milan, Italy, with our gene therapy approach (Temferon). METHODS The TEM-MM-101 study recruits patients with MM in early relapse (within 18 months) after intensive front line therapy defined as triplet induction (at least 3 cycles including a proteasome inhibitor and/or immunomodulatory drug [IMID]) followed by single or double autologous stem cell transplantation, or, triplet or quadruplet induction including at least a proteasome inhibitor and an IMID, followed by consolidation/maintenance treatment. Three cohorts of 3 patients will be included in the study. Patients will be dosed sequentially in each cohort with data review by an independent data monitoring committee before dose escalation to the next cohort. Key eligibility criteria include achieving at least a VGPR after second line salvage therapy, age 18-70 years, ECOG 70%, adequate cardiac, renal, hepatic and pulmonary function, and willingness to use appropriate contraception if relevant. Important exclusion criteria include the presence of active autoimmune disease or ineligibility for autologous bone marrow transplant. After confirmation of eligibility, patients undergo autologous peripheral blood HSPC mobilization with lenograstim and plerixafor, before undergoing apheresis. After purification, CD34+ cells undergo transduction with a third-generation, vesicular stomatitis virus-G pseudo-typed lentiviral vector driving myeloid-specific IFNa2 expression. Patients will be offered maintenance treatment from successful HSPC collection until Temferon release. A reduced intensity conditioning regimen is administered at Day -2 followed by ASCT and administration of Temferon at Day 0. Following hematological recovery, patients will be discharged from the Transplant Unit with regular outpatient follow up. After Day +100 from Temferon infusion, patients will resume anti-myeloma consolidation/maintenance treatment according to best clinical practice, unless there is Temferon engraftment and absence of disease on Day +100 evaluations, documented by stringent complete response (sCR) according to the IMWG response criteria, imaging (PET, MRI) negativity, and bone marrow minimal residual disease 〈 10-4 by multi-parameter flow cytometry, to be confirmed by next generation sequencing. If these response criteria are met on Day +100, patients may stay off maintenance treatment, as long as MRD≤10-5 documented on bone marrow aspirates performed every 3 months, starting from the Day +180 visit. The primary endpoints for this study are: Engraftment of Temferon between Day +30 and Day +100The proportion of patients achieving hematologic recovery by Day +30 from ASCTSafety of Temferon (short-term tolerability of Temferon; stable blood counts and absence of cytopenias 〉 grade 2, unless related to myeloma progression or concomitant medications; absence of systemic IFNa toxicity; absence of Replication Competent Lentivirus; absence of hematologic malignancy that is distinct from progression of the primary neoplasm) The study is actively recruiting patients in Italy. In parallel, a study using Temferon in patients with glioblastoma multiforme with a similar study design and approach (TEM-GBM-001) is also in progress with the first cohort fully recruited. Disclosures Gentner: Genenta Science: Consultancy, Equity Ownership, Research Funding. Mazzoleni:Genenta Science: Employment, Equity Ownership. Russo:Genenta Science: Consultancy, Equity Ownership. Naldini:Genenta Science: Consultancy, Equity Ownership; Magenta Therapeutics: Equity Ownership; San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), a joint venture between Fondazione Telethon and Ospedale San Raffaele (OSR): Other: Wiskott-Aldrich Syndrome (WAS) gene therapy was licensed to GlaxoSmithKline (GSK) in 2014. It was then licensed to Orchard Therapeutics (OTL) in April 2018. OTL is the current sponsor of the clinical trial..

Description: Introduction: Defibrotide is approved for adult and pediatric patients with hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) with renal or pulmonary dysfunction after hematopoietic cell transplantation (HCT) in the United States and Canada and for patients aged 〉1 month with severe hepatic VOD/SOS post-HCT in the European Union. The recommended dose is 6.25 mg/kg every 6 hours given as a 2-hour intravenous (IV) infusion. Defibrotide has been shown in vitro to reduce endothelial cell (EC) activation and promote EC-mediated fibrinolysis. Post-HCT patients with VOD/SOS are often at a high risk for bleeding events. In a phase 3 study of patients with VOD/SOS post-HCT, rates of bleeding-related adverse events (AEs) with defibrotide were generally similar to matched historic controls (Richardson PG, et al. Blood. 2016;127[13]:1656-1665). To broaden our understanding of the risk of bleeding events associated with defibrotide treatment, this meta-analysis assessed the incidence and risk of bleeding-related AEs with defibrotide treatment in studies outside of the VOD/SOS and HCT setting, using published literature. Methods: PubMed and Embase were searched from database inception through July 24, 2018 for studies using defibrotide (controlled trials with ≥1 arm assessing an intervention of interest, observational/retrospective studies, retrospective or post hoc analyses, and case series with ≥10 patients). Studies of patients with VOD/SOS or HCT, case reports with 1,000 patients. An IV defibrotide formulation was used in 12 studies; the other 7 used intramuscular or oral delivery or more than one method of defibrotide administration. The most common indications were prevention of deep vein thrombosis (11 of 19) and treatment of thrombosis (3 of 19). Most studies (14 of 19) had 2 treatment arms; among these studies, heparin was the most common comparator (11 of 14). For the other 5 of 19 studies, 4 studies were single-arm and 1 study had 3 arms. The majority of studies (16 of 19) were conducted in adults; the other 3 studies did not specify patients' age. The most commonly administered defibrotide dose was 800 mg daily (14 of 19 studies). Bleeding rate and risk ratio of bleeding were calculated based upon data from the 12 studies that used IV defibrotide. Rates of bleeding events reported in the 12 studies with IV defibrotide ranged from 0% to 10% in individual studies and the estimated overall bleeding rate was 1% (95% confidence interval [CI]: 0.00-0.03). In 10 studies with control treatments (9 calcium heparin, 1 urokinase), rates of bleeding events ranged from 1% to 37%, with 7 studies having rates ≥10%. Across the 10 control studies, the estimated overall bleeding rate for controls was 11% (95% CI: 0.05-0.20). Among the 8 studies with available data on IV defibrotide and controls (7 calcium heparin, 1 urokinase), the risk ratio for bleeding events with IV defibrotide versus controls was 0.36 (95% CI: 0.24-0.52; P

Description: Background: Diffuse large B-cell lymphoma (DLBCL) is a genetically heterogeneous disease of malignant B cells most often classified by tumor gene expression and/or mutations. DLBCL is also characterized by a tumor microenvironmental influence that has not been well described. Immuno-oncology-targeting agents such as immune checkpoint inhibitors have limited clinical activity in DLBCL, highlighting the need for a better understanding of the DLBCL tumor microenvironment for rational drug development, combinations, and disease stratification. Here, we systematically characterize the immune composition of more than 100 DLBCL tumors using 2 imaging technologies and provide insight into the complexity of DLBCL disease biology. Methods: A total of 110 cases of newly diagnosed DLBCL were analyzed by multiplex immunohistochemistry (IHC; n=70) and multiplexed ion beam imaging (MIBI) (n=40), each with 10 common markers (CD20, CD3, CD8, Foxp3, CD56, CD163, CD11c, CD56, PD-1, PD-L1) and a few platform-specific markers. Both IHC and MIBI images were digitalized to generate marker-positive cell counts (including single, double, or triple positivity), cell density (cell count/mm2), and population fraction (% of total nucleated cells). Marker density was analyzed for the major components of tumor-infiltrating cell types and correlation between any pair of markers. In addition, RNAseq data and fluorescence in situ hybridization (FISH) data on MYC, BCL-2, and BCL-6 translocation were generated. Results: In the IHC cohort, T cells (CD3+), dendritic cells (DCs; by CD11c+), and macrophages (CD163+)were the major immune components, with median population fractions of 22%, 16%, and 2.7%, respectively. Natural killer cells (CD56+CD20−) were a minor component at a median of 0.1%. A significant negative correlation was observed between tumor cells (CD20+) and CD4+ (Spearman ρ = −0.47; P = 1.3 × 10−04), and CD8+ T cells (Spearman ρ = −0.42; P = 1.4 × 10−03) cells, and an unexpectedly negative correlation between DCs (CD11c+) and macrophages (CD163+, r = −0.63; P = 9.8 × 10−06) was found. Similar to follicular lymphoma, 2 PD-1+ T-cell populations were identified: PD-1bright and PD-1dim. The PD-1bright cells co-stained with CXCR5, indicating T follicular helper cells (Tfh). The PD-1dim were expressed on exhausted effector cells that co-stained with Tim3 or Lag3. The median population fraction of Tim3+ or Lag3+ among T cells was 25%, whereas that of PD-1dim among T cells was 0.2%, indicating that PD-1 was not a useful marker for exhausted T cells. PD-L1 was predominantly found on DCs and macrophages, and the median population fraction of PD-L1+ among tumor cells was only 6.2%. By unsupervised hierarchical clustering on marker density, 3 major immune-infiltration patterns (P1, P2, and P3) were identified. The first 2 segments (P1 and P2) were 20% and 25% of the total cases, respectively. Both were characterized by high T-cell, macrophage, and DC infiltration. P1 was enriched for PD-1+ T cells, whereas P2 was void of any PD-1+ cells. The third segment (P3) that comprised 55% of the cases was predominantly tumor cells with low T-cell, macrophage, and DC infiltration. PD-L1+ cells were primarily found in segments P1 and P2 but rare in segment P3. Additional analysis on the associations between the 3 immune-infiltration patterns and prognostic DLBCL molecular features such as cell-of-origin, double-hit gene signature, and double-hit FISH will also be presented. Conclusions: These data show the complexity of DLBCL disease biology and show classification of DLBCL at the immune-infiltration level as 3 distinct patterns. The overall low expression of PD-1+ T cells and the restricted pattern of PD-L1+ tumor cells provide a possible explanation for the lack of clinical activity of PD-1/PD-L1 blockade in DLBCL. We also observed other exhausted T cells expressing Lag3 and Tim3, suggesting alternative therapeutic opportunities in stratified populations. These data also highlight the opportunity to develop rational immuno-oncology-targeted agents based on the immune infiltration pattern of DLBCL and selection of patients who may respond more favorably to particular agents. Disclosures Huang: Celgene Corporation: Employment, Equity Ownership. Nakayama:Celgene Corporation: Employment, Equity Ownership. Stokes:Celgene Corporation: Employment, Equity Ownership. Towfic:Celgene Corporation: Employment, Equity Ownership. Lee:Celgene Corporation: Employment, Equity Ownership. Ren:Celgene Corporation: Employment, Equity Ownership. Marella:Celgene Corporation: Employment, Equity Ownership. Wang:Celgene Corporation: Employment, Equity Ownership. Hagner:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Couto:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Newhall:Celgene Corporation: Employment, Equity Ownership. Gandhi:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties.

Description: Background: Next-generation sequencing (NGS) technologies have led to the discovery of recurrently-mutated genes in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). These mutations have proven useful in diagnosis, prognostication, and prediction of treatment response when used in conjunction with cytogenetics and other clinical characteristics known to influence patient outcome. NGS platforms that test for the presence of genetic mutations associated with myeloid malignancies are now widely available in clinical practice and are often utilized during initial diagnostic evaluation. However, there is considerable variability among hematologists in the use of such data, and it is still unclear whether physicians are using molecular data to properly prognosticate or make treatment decisions for their patients. Thus, the purpose of this study is to assess real-world practices of physicians caring for patients with AML or MDS at a large National Comprehensive Cancer Network (NCCN) Member Institution and to determine the degree to which molecular data is being utilized to prognosticate or alter clinical management. Methods: Patients presenting to the University of Wisconsin-Madison Hospital and Clinics with newly-diagnosed AML or MDS from 1/1/2014 through 12/31/2018 were included in the study. Data was collected retrospectively, including patient demographics, clinical characteristics, cytogenetic and mutational data, and treatment. The medical record was scrutinized for documentation regarding impact of molecular data on physician prognostication and decision-making. Results and Discussion: 102 patients were included in the analysis, including 54 patients with AML and 48 patients with MDS. For AML patients, 36% were classified as adverse risk, 34% as intermediate risk, and 30% as favorable risk based on ELN criteria. For MDS patients, 50% were classified as very high or high risk, 27% as intermediate risk, and 23% as low or very low risk by IPSS-R criteria. The proportion of AML and MDS patients having normal cytogenetics were comparable (37% versus 29% respectively, p=0.40). The type and frequency of molecular data utilized differed significantly according to diagnosis (p

Description: Elevated circulating levels of NM23-H1 have been associated with poor prognosis in haematological malignancies including AML and non-Hodgkin's lymphomas. In diffuse large B-cell lymphoma (DLBCL), several studies have demonstrated that both elevated circulating plasma levels and intra-tumoural levels of NM23-H1 correlate with poorer prognosis. These observations bring into question whether the mechanistic link of NM23-H1 expression with DLBCL prognosis depends an intrinsic intracellular mechanisms or is mediated by release of NM23-H1. We have shown that DLBCL lymphoma cell lines (Farage, HT, OCI-LY1, OCI-LY3, OCI-LY7, SUDHL4, SUDHL5 SUDHL6, U2932) express both NM23-H1 protein and the highly related protein NM23-H2. We also demonstrated that DLBCL cell lines release significant levels of NM23-H1 into their extracellular environment but not NM23-H2. Release of NM23-H1 was highly variable between cell lines with some releasing very high levels and some releasing much lower levels. Thus, DLBCL cell lines represent appropriate models to investigate the role of high and low levels of NM23-H1 on prognosis. The DLBCL cell lines HT and OCI-LY1 where selected for further study as representative of high and low level releasers of NM23-H1, respectively. CRISPR-Cas9 knockout of NM23-H1 (KO-NM23-H1) in HT and OCI-LY1 DLBCL cells had no impact on cell growth, viability or immuno-phenotype either in normoxic or hypoxic cultures. Thus NM23-H1 appears to not be required intrinsically by DLBCL cell lines. We therefore considered that the link between higher expression and release of NM23-H1 with prognosis is mediated via tumour-host environment interactions. We used an NSG mouse model transplanted subcutaneously with 1x106 CRISPR control (CTRL)-HT, CTRL-OCIL-Y1, KO-NM23-H1-HT or KO-NM23-H1-OCI-LY1 cell lines. We did not observe significant differences in tumour growth between CTRL and KO-NM23-H1 cells in the low NM23-H1 expressing OCI-LY1 DLBCL cell line. However, the high-expressing KO-NM23-H1-HT cells had significantly slower tumour progression and increased host survival when compared to CTRL-HT cells. We interpret to indicate that NM23-H1 release above a certain threshold provides a tumour growth advantage. Reduced lymphocyte:monocyte ratios (LMR) are also associated with poor prognosis in DLBCL. To investigate a potential functional link between NM23-H1 release and monocyte behaviour we first exposed peripheral blood leucocytes to Alexa 647 labelled fluorescent recombinant-NM23-H1 and found that monocytes but not neutrophils, T-cells or B-cells bound NM23-H1. We also observed that monocyte viability and survival were elevated in serum free cultures when supplemented with rNM23-H1, an observation that might indicate that elevated circulating NM23-H1 and reduced LMR in poor prognosis DLBCL may be mechanistically linked. We next co- cultured CTRL-HT or koNM23-H1-HT in a 1:1 ratios with purified monocytes from healthy human donors. Principle component analyses of 27 cytokines simultaneously measured by luminex assays identified that IL-1β, IL-6, IL-8, MIP-1α, MIP-1β and TNF-α were elevated when monocytes were co-cultured with CTRL-HT cells compared to co-culture with koNm23-H1-HT cells. In contrast, IP-10 was found elevated in the co-culture with koNm23-H1-HT cells. These observations indicate potentially important cross talk between the malignant DLBCL cells and innate immune cells of the host. Consistent with this, IL-6 and IL-8 serum levels have been shown to be elevated in pretreatment DLBCL patients compared to control subjects and MIP-1α, IL-6, and IL-8 serum levels have a greater association with DLBCL than follicular lymphoma. In conclusion ours is the first study to investigate potential mechanistic links between the associations of elevated NM23-H1 and poor prognosis in DLBCL and indicate a role for cross-talk between tumour cells and innate immune cells. Our data also indicate that NM23-H1 release from DLBCL cells may be a driving component in driving reduced LMRs that are also associated with poor prognosis. Whether reduced LMR and NM23-H1 release are casually related or not, the possibility that patients with both elevated monocytes and elevated circulating NM23-H1 levels are likely to represent a group with particularly poor prognosis requires urgent investigation. Disclosures Drayson: Abingdon Health: Consultancy, Equity Ownership. Rushworth:Abbvie: Research Funding; Janssen: Research Funding.

Description: Background: The treatment of multiple myeloma (MM) is optimized by use of combination regimens consisting of agents with different mechanisms of action. Panobinostat is a pan-inhibitor of histone deacetylases types I,II, and IV. Panobinostat, bortezomib, dexamethasone was shown to be an effective regimen (San Miguel et al Lancet Hematol 2016; Richardson et al Blood 2016), leading to the FDA approval of panobinostat for patients with relapsed/refractory MM. Carfilzomib is a proteasome inhibitor that was FDA approved in relapsed/refractory MM with the advantage of minimal neuropathy. Panobinostat and carfilzomib has also been shown to be a highly active regimen in relapsed/refractory MM with an overall response rate of up to 75% (Berdeja et al, Haematologica, 2015). With the heterogeneity of MM, individual patients exhibit wide variability in responses to drug combinations. A test that could predict patient responses to specific agents might enable clinicians to optimize therapy for patients, improving outcomes. We developed an in vitro high throughput drug sensitivity assay with formal synergy testing to predict response. In this ongoing trial, Panobinostat with Carfilzomib and Dexamethasone for Relapsed/Refractory Multiple Myeloma: Correlation with In Vitro Chemosensitivity Testing (NCT03256045), we will correlate individual patient in vitro sensitivity assay results with individual clinical response to the same triple drug regimen. Study Design and Methods: This study's objective is to directly demonstrate the utility of a high throughput drug sensitivity assay in determining biomarkers (e.g. individual IC50s, AUCs and/or synergy scores) to accurately predict response to combination therapy that was given prospectively to all enrolled patients. We are enrolling patients with relapsed/refractory MM by IMWG criteria with measurable disease defined by the detection of a quantifiable monoclonal protein in the urine or serum or an abnormal serum free light chain ratio. Additionally, patients must have adequate blood counts and organ function. Patients who have had prior autologous or allogeneic transplants or CAR-T cell therapy are eligible. The regimen consists of panobinostat 20 mg orally on days 1,3,5,15,17,19; carfilzomib 20 mg/m2/dose IV on days 1,2 of cycle 1, then dose escalation up to 45 mg/m2/dose days 8,9,15,16 and all days for subsequent cycles; and dexamethasone 20 mg orally on days of carfilzomib. Dose reductions of all three drugs are permitted per patient tolerance to allow continuation on study treatment. Up to 12 cycles of treatment are permitted. Patients are monitored by serial electrocardiograms and assessments of cardiac function. Safety parameters including adverse events are recorded. CD138+ plasma cells are procured from the patient bone marrow (aspiration and biopsy) and blood (when present) by magnetic bead separation. Cells are then added to 384-well plates and incubated overnight before the drugs are added. Cells are exposed to 8 concentrations (spanning 4 logs) of panobinostat, carfilzomib, or dexamethasone as singlet, doublet and triplet combinations for 72 hours. Cell viability is determined using CellTiter-Glo and IC50 and AUC values are are calculated by fitting data using least squares method to the standard four-parameter logistic model. Curve fitting is performed using IDBS XLFit software. The combination index is calculated by the method described by Chou and Talalay, Trends Pharmacol Sci 1983;4:450-4. Concentrations of Drug1 and Drug2 (that is, panobinostat and dexamethasone or panobinostat and carfilzomib) alone or in combinations are determined that give rise to 90% growth inhibition. At 90% Growth Inhibition, the Combination Index or CI = ([D1] in the combination / [D1] alone) + ([D2] in the combination / [D2] alone). All patients are treated with panobinostat, carfilzomib, and dexamethasone and evaluated for response using the IMWG response criteria. At the completion of enrollment at 35 patients, we plan to correlate the in vitro testing data with in vivo clinical response to determine appropriate biomarkers. This will be done by correlating the IC50s and AUCs for the individual drugs for responders vs. non-responders (including degree of response VGPR vs PR vs SD), as well as correlations of the synergy scores for each of the pairs of drugs in the responders vs. non-responders. Enrollment was initiated in April 2018. Disclosures Becker: Accordant Health Services/Caremark: Consultancy; AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding; The France Foundation: Honoraria. Libby:Abbvie: Consultancy; Pharmacyclics and Janssen: Consultancy; Akcea: Consultancy; Alnylam: Consultancy. Cowan:Juno: Research Funding; Abbvie: Research Funding; Sanofi: Consultancy; Janssen: Consultancy, Research Funding; Cellectar: Consultancy; Celgene: Consultancy, Research Funding. Hammer:Glycomimetics: Consultancy.

Description: Acute systemic painful vaso-occlusive crisis (VOC) often serves as an antecedent to acute chest syndrome (ACS), which is a type of acute lung injury and the leading cause of mortality among sickle cell disease (SCD) patients. Thrombocytopenia secondary to pulmonary thrombosis is major risk factor for ACS, however, only 20% of ACS patients are diagnosed with pulmonary thrombosis as an underlying cause of ACS. Although clinical evidence supports the presence of prothrombotic state in subset of SCD patients, the molecular, cellular and genetic mechanisms that selectively render subset of SCD patients at either higher or lower risk of developing pulmonary thrombosis remains elusive. Adenosine diphosphate (ADP) released from lysed erythrocytes can activate platelets by stimulating their purinergic P2Y1 and P2Y12 receptors, however, P2Y12 receptor antagonists have not shown any benefit in clinical trials, justifying the need for better understanding of purinergic signaling in SCD. Here, we use intravital lung microscopy in transgenic humanized SCD mice to show that intravenous administration of ADP triggered pulmonary thrombosis in control mice but failed to trigger pulmonary thrombosis in SCD mice. In contrast, collagen evoked pulmonary thrombosis identically in both control and SCD mice. Identical to intravital findings, IV ADP administration also evoked transient thrombocytopenia in control but not SCD mice, while, IV collagen led to comparable drop in platelet count in both SCD and control mice. ADP is metabolized by the ecto-nucleoside-tri-phosphate-diphosphohydrolase-1 (E-NTPDase1) CD39. IV administration of fluorescent analogue of ADP, N⁶- ethenoadenosine- 5'- O- diphosphate (ε-ADP) followed by invivo microdialysis and HPLC analysis revealed impaired ε-ADP degradation in SCD mice, suggestive of decreased CD39 activity. Our current findings suggest that loss of CD39 activity in SCD possibly prevents ADP-mediated pulmonary thrombosis. Currently, experiments are underway to identify pathways contributing to loss of CD39 activity in SCD, how that affects purinergic signaling and whether selective activation vs deactivation of this pathway is responsible for risk of pulmonary thrombosis in only 20% of ACS patients. Disclosures Gladwin: Globin Solutions, Inc: Patents & Royalties: Provisional patents for the use of recombinant neuroglobin and heme-based molecules as antidotes for CO poisoning; United Therapeutics: Patents & Royalties: Co-inventor on an NIH government patent for the use of nitrite salts in cardiovascular diseases ; Bayer Pharmaceuticals: Other: Co-investigator.

Description: Background: Thrombin generation and other clotting assays suffer from a wide variation of pre-analytical variables. One of those pre-analytical variables is contact activation through blood withdrawal methods, different syringes, differences in blood coagulation tubes, blood transport and sample handling. It has been shown that the addition of contact activation inhibitors in low tissue factor activated thrombin generation leads to a correction of the, in these circumstances significant, increase in thrombin generation due to contact activation. We compare the novel 'thermostable inhibitor of contact activation' (TICA) to the current standard 'corn trypsin inhibitor' (CTI). Aim: Comparing the effectiveness of novel contact activation inhibitor TICA to the current standard CTI in low tissue factor-induced thrombin generation and recalcification in sodium citrate anticoagulated platelet poor plasma (PPP) and platelet rich plasma (PRP). Methods: We compared TICA, Corn trypsin inhibitor and plasma without contact activation inhibitors in low tissue factor PPP thrombin generation and in PRP recalcification thrombin generation, the latter the most sensitive condition for contact activation. In addition, we compared low tissue factor activated thrombin generation in plasma from severe hemophilia A patients with and without TICA during and after blood drawing. Thermostability - as a measure of shelf life - was measured and compared to CTI. Results: TICA is able to fully block contact activation in PRP recalcification experiments and is comparable to CTI in doing so. TICA significantly lowers low tissue factor induced thrombin generation by blocking contact activation. Pre-loading vacuum blood collection tubes with contact activation inhibitors is superior in inhibiting contact activation compared to addition of the inhibitor during the thrombin generation assay itself. TICA did not alter coagulation activity when added to FXIIa deficient plasma in thrombin generation. In contrast to CTI TICA is heat stable which will be of benefit to shelf life of pre-loaded blood drawing tubes. Conclusion: TICA is able to fully block contact activation and has several advantages over CTI. Disclosures No relevant conflicts of interest to declare.

Description: Acute myeloid leukemia (AML) has remained one of the most treatment resistant and deadliest cancers. The survival of AML blast cells is controlled by the balance of anti- and pro-apoptotic proteins. Recently approved Bcl-2 targeted therapy of AML with the Bcl-2 specific inhibitor Venetoclax in combinations has improved patients outcomes. However, a priori and developing resistance to venetoclax combinations with hypomethylating agents (HMA) azacitidine and decitabine challenge this treatment. As such, novel therapies to overcome venetoclax-HMA resistance are urgently needed. We have identified a combination of DNA damage repair interference by WEE1 inhibition with AZD1775, combined with low dose cytarabine (AraC) as an effective strategy to overcome combined venetoclax-azacitidine resistance (VAR). AZD1775 with low dose AraC induced massive apoptosis (by Annexin V and cleaved caspase-3) and almost completely reduced viability and clonogenic growth of primary AML cells. To delineate the molecular mechanism of the synergistic effect of AZD1775/AraC we performed RNAseq analysis of single agent or the combination of AZD1775+AraC in AML cell lines and primary CD34+ selected AML patient cells with the goal to identify deferentially regulated genes indicating a mechanistic underpinning of the potent activity. Only 2 genes were deferentially regulated across cell lines and CD34+ selected cells under AZD1775+AraC treatment: one of these is NR4A1, an orphan nuclear receptor, which we went on to validate as a potential downstream target of Wee1 inhibition. The inactivation of NR4A1 in mice was previously shown to induce AML and to maintain leukemia stem cells. Using qPCR we confirmed that the expression of NR4A1 is upregulated after AZD1775/AraC combo treatment in human leukemic cells. We then demonstrated that activators of NR4A1 (cytosporone B and pPhOCH3) reduce viability of leukemic cells, while NR4A1 inhibitor pPhOH was able to abolish the effect of AZD1775/AraC combo treatment increasing leukemic cell viability]. To investigate the involvement of mitochondria in the effect of AZD1775/AraC treatment we performed the expression of mitochondrial genes and pathway analyses in RNAseq data and found that mitochondrial gene expression, including many genes involved in apoptosis, has most dramatic changes in the combo treatment if compared to the single agents. Subsequently, we have examined the expression of the main BCL-2 family apoptotic genes by qPCR and western blot analysis. We found that AZD1775/AraC induces the expression of Bim isoforms, whereas Bcl-2, Mcl-1 and Bcl-Xl were largely unaffected. NR4A1 was previously shown to translocate to mitochondria, release Bim from Bcl-2 protein binding, as well as convert Bcl-2 to an extreme potent pro-apoptotic form. Finally, we generated several additional VAR cell lines and cells with subclones and demonstrated that AZD1775/AraC combination treatment is able to overcome VAR in almost every clone. Our results show that DNA damage repair interference with Wee1 inhibition has the potential to overcome VAR through a novel mechanisms of AZD1775 increasing NR4A1, freeing pro-apoptotic Bim irrespective of anti-apoptotic Bcl-2 proteins leading to massive apoptotic cell death in AML cells. The precise molecular mechanisms and the involvement of NR4A1 in this phenomenon will be presented at the meeting. Our findings will help to develop new therapeutic strategies in AML treatment and a trial of AZD1775 + AraC in AML is currently ongoing. Disclosures No relevant conflicts of interest to declare.

Description: I NTRODUCTION: Acute painful vaso-occlusive crises (VOC) in sickle cell disease (SCD) are the leading cause of emergency department (ED) encounters and frequent hospital admissions. For patients presenting with an uncomplicated VOC, acute care observation units (ACOU) have previously been shown to reduce admission rates and length of stay. We wished to evaluate if implementing a standardized acute care order set (ACOS) at the University of Illinois Hospital Sickle Cell ACOU would decrease the time to first dose of analgesic medication, inpatient hospital stays, and subsequent admissions to the ACOU. METHODS: The ACOS includes standard orders for laboratory tests to monitor severity of sickle cell hemolysis, intravenous fluids, and analgesic medications including opioids. We conducted a retrospective analysis to evaluate if the ACOS enhanced workflow and improved the timeliness of treatment in patients experiencing a VOC. The ACOS was created in April 2017 and we compiled data from the three months before (January-March 2017) and after (May-July 2017) ACOS creation. We collected data on the time it took to administer the first opioid dose, admission rate, length of stay, number of acute care visits, ED visits, and inpatient hospitalizations in a three-month span, and demographics including variations in age, gender, and sickle cell disease genotype. Patient data was collected from a pharmacy-generated list of patients who received narcotics in the ACOU during the aforementioned time period. We analyzed the effect of the ACOS on the aforementioned variables. A mixed effects linear model was used to compare time to first dose of opioids and length of stay between data sets. A mixed effects logistic model was used for binary outcomes. Covariates of age (years), gender, and severity of sickle cell hemoglobin genotype (severe: HbSS, HbS beta0 thalassemia; mild: HbSC, HbS beta+ thalassemia) were included in the models. Statistical analyses were carried out in R version 3.4.3. DISCUSSION: The pre-ACOS data set contains 291 patient encounters for 76 patients with a median age of 37 years (interquartile range [IQR], 30-47 years), 66% female, and 71% with severe genotypes. The post-ACOS data set contained 289 patient encounters for 80 patients with a median age of 32 years (IQR, 27-45 years), 80% female, and 73% with severe genotypes. Implementation of an ACOS was associated with decreased time to pain management by 3.7 minutes (p=0.077) in patients presenting with uncomplicated VOC and with fewer repeat visits to the ACOU in the studied 3-month period [OR 0.35 (95% CI 0.13-1.00), p=0.049]. The median number of opiate doses received by patients in both data sets was 3. Using 3 as a cutoff, the implementation of the ACOS was also associated with more patients receiving 〉3 doses of opiates [OR=1.84 (95% CI 1.05-3.19), p = 0.033]. We demonstrate that in SCD patients experiencing VOC, a standardized ACOS was associated with a trend to reducing time to receiving pain management, with increased total opioid doses during the ACOU admission (suggesting better pain control), and subsequently with a statistically significant reduction in the number of repeat ACOU visits in the studied 3-month period. We have shown that a standardized ACOS that streamlines workflow in an ACOU may play an important role in delivering timely and quality care to patients with SCD. Disclosures Gordeuk: Pfizer: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Global Blood Therapeutics: Consultancy, Honoraria, Research Funding; Modus Therapeutics: Consultancy, Honoraria; Ironwood: Research Funding; CSL Behring: Consultancy, Honoraria, Research Funding; Imara: Research Funding; Inctye: Research Funding; Inctye: Research Funding; Pfizer: Research Funding; Emmaus: Consultancy, Honoraria; CSL Behring: Consultancy, Honoraria, Research Funding; Ironwood: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Imara: Research Funding; Modus Therapeutics: Consultancy, Honoraria.

Description: Allogeneic stem cell transplantation (SCT) is a potentially curative treatment for MDS. Besides the innate heterogeneity of MDS, intensity of the conditioning regimen (myeloablative (MAC) versus reduced intensity/non-myeloablative (RIC)), specific agents used in conditioning, donor and source of stem cells and GVHD prevention regimens further influence outcomes. We sought to determine how conditioning regimens influenced MDS subgroup cohort outcomes. We retrospectively analyzed outcomes of 107 MDS patients (63 male and 44 females) with median age 61.8 (17-73 years) who underwent allogeneic SCT at our institution between 2008 and 2017. For the purposes of this report, patients were grouped according to WHO classification into non-RAEB (RCMD, RA, RARS RCUD or 5q deletion, n=49) and RAEB (RAEB1 and RAEB2, n=58) categories. Median time from MDS diagnosis to transplantation was 139 days (20-3175). No patients were in complete remission (CR) at time of SCT. Allogeneic donor types were matched related, matched unrelated, haplo-identical and cord blood in 30, 65, 10 and 2 patients, respectively. Stem cell source was peripheral blood (91 patients) and bone marrow in 14. Forty patients (median age 52.2 (17-61) years) underwent MAC and 67 (median age 63.7 (23-73) years) RIC. Twelve patients died within 100 days of transplantation, 3 due to disease progression, 5 to acute GVHD, and 4 to other transplant-related causes. Median overall survival (OS) for all 107 patients was 1.3 years with 54%, 47% and 40% alive at 1, 2 and at 5 years. OS was slightly higher in patients undergoing RIC with OS of 57%, 48% and 40% (median 1.532 years) versus 50%, 40% and 38% with MAC (median 0.92 years) at the same time points (p〉0.1). Median OS of the 49 patients with non-RAEB and 58 patients with RAEB MDS was 3.01 years versus 0.92 years (p〉0.1). GVHD was the most frequent cause of death (46%), followed by relapse/progression (28%), infection (14%) and other (12%). Of 29 patients undergoing RIC with non-RAEB MDS, median OS was 3.78 years while for 38 RAEB patients it was 1.17 years (p〉0.1). See table for OS according to conditioning regimen and WHO classification. For MAC, in 20 non-RAEB patients median OS was 2.2 years while the median OS was 0.69 years for 20 RAEB patients (p〉0.1). CR after SCT was achieved in 57 patients (53%), 33 receiving RIC (CR 49.2%) and 24 receiving MAC (CR 60%). Seven patients subsequently relapsed, 4 RIC and 3 MAC. Of the non-RAEB patients achieving CR, median OS in the 16 patients treated with 111 RIC was not reached and in 14 patients receiving MAC, median OS was 3.75 years (p〉0.1). For the 27 RAEB patients achieving CR, median OS was 4.4 years in 17 patients treated with RIC versus not reached in 10 patients treated with MAC. Overall, death in non-RAEB patients occurred in 26/49 (53%) compared to 38/58 (66%) RAEB patients and in 40/67 (59%) patients undergoing RIC versus 25/40 (63%) MAC patients (p〉0.5). The hematopoietic transplant comorbidity index did not predict OS outcomes in these MDS patients (p〉0.1) and the cytogenetic score according to the IPSS-R "very good -very poor" groups indicated no differences in OS in the non-RAEB patients but in RAEB patients significant differences according to the cytogenetic score was evident (P

Description: Background: Of the several drugs and drug combinations approved for treatment of relapsed and refractory chronic lymphocytic leukemia (CLL), the reported complete response rates are no greater than 30%. Obinutuzumab is a glycoengineered, humanized type 2 anti-CD20 monoclonal antibody thought to engage the immune system by directly activating antibody- dependent, cell-mediated cytotoxicity (ADCC); it is approved for treatment of chronic lymphocytic leukemia in combination with chlorambucil. The key mediators of ADCC are polymorphonuclear neutrophils, monocytes, and natural killer (NK) cells. Recombinant human Interleukin-15 (rhIL-15) is a stimulatory cytokine that promotes the differentiation and activation of NK cells, monocytes, and long-term CD8+ memory T-cells. In a Phase I trial, administration of rhIL-15 as a 5-day continuous intravenous infusion (civ) was associated with up to 45-fold increase in the number of NK cells at well- tolerated dose levels. Preclinical murine lymphoid malignancy models have shown increased efficacy of monoclonal antibodies when administered together with rhIL-15; BL/6 mice inoculated with EL4-CD20 cells (a syngeneic lymphoma line); including significant prolongation of survival with the IL-15/Rituximab combination compared to either drug given as single agent (90% v. 30% alive at 75 days). We hypothesized that rhIL-15-associated increase in NK cell number and activity would improve efficacy of obinutuzumab in treatment of relapsed and refractory CLL, and would increase the duration and depth of response; this phase I trial is testing the safety of the combination. Primary objective: determine the safety, toxicity profile, dose-limiting toxicity (DLT) and the maximum tolerated dose (MTD) of civ rhIL-15 administration in combination with obinutuzumab treatment Secondary objectives: 1) evaluate the potential antitumor activity of the combination of rhIL-15 and obinutuzumab by assessing the clinical response rate, minimal residual disease (MRD) status, progression-free survival, and overall survival in patients with relapsed and refractory CLL; 2) define the effects of rhIL-15 on the ADCC mediated by obinutuzumab using ex vivo peripheral blood mononuclear cells (PBMCs); 3) characterize the biological effects of rhIL-15 administered with obinutuzumab on the percentages and absolute numbers of circulating lymphocytes (T and NK cells) and the T- cell subsets (including naïve, central, and effector memory subsets) by flow cytometry Exploratory objectives: identify biomarkers predictive of response to rhIL-15 and obinutuzumab treatment, such as circulating tumor DNA (ctDNA) and baseline cytokine levels Eligibility criteria: 1) age ≥ 18 years; 2) ECOG ≤ 1; 3) Diagnosis of CLL or small lymphocytic lymphoma (SLL) with ≥ 50% of B cells expressing CD20; 4) measurable or evaluable disease that is refractory or relapsed following therapy with a BTK inhibitor OR have relapsed/refractory CLL and are intolerant to BTK inhibitor therapy; patients with del(17p) must also be refractory or relapsed after, or intolerant to, therapy with venetoclax; 5) adequate organ function parameters as defined within the protocol; 6) active disease requiring treatment, as defined within the protocol. Study design: a single institution non-randomized phase I dose escalation study evaluating increasing doses of civ rhIL-15 in combination with obinutuzumab using a 3 + 3 dose escalation design. On days 1-5 of each 4-week cycle, rhIL-15 will be administered by civ at dose levels 0.5, 1, and 2 mcg/kg/day. During the first cycle, obinutuzumab will be administered at a dose of 100 mg by IV on day 4, 900 mg on day 5, 1,000 mg on day 11, and 1,000 mg on day 18; then 1,000 mg on day 4 of each subsequent cycle. Infusion reaction, antimicrobial, and tumor lysis syndrome prophylaxis will be administered per manufacturer's recommendations. Treatment will continue up to 6 cycles, or until unacceptable toxicity or progressive disease. Up to 24 patients will be enrolled in the study. Correlative studies: 1) optional lymph node biopsy at baseline and after the first week of treatment (C1D8) for tissue immune cell subsets and quantifying antibody penetration; 2) lymphocyte subset testing, ctDNA, and cell and plasma banking on days 1, 4, 8, and 11 of cycle 1, and days 1 and 8 of cycles 2-6; 3) ADCC capacity of ex vivo NK cells on C1D1, 4, and 8. One patient has started treatment to date. Enrollment is ongoing. Figure Disclosures Wiestner: Acerta: Research Funding; Pharmayclics: Research Funding; Merck: Research Funding; Nurix: Research Funding. Waldmann:Bioniz: Membership on an entity's Board of Directors or advisory committees.

Description: Background: Because infections are a major cause of morbidity and mortality after AML induction chemotherapy, patients typically remain hospitalized for monitoring and rapid antimicrobial therapy until hematopoietic recovery. With declining early mortality and improved oral antimicrobials, interest in moving post-induction care to the outpatient setting has emerged. In the 5-year period since completing a prospective phase 2 trial evaluating an Early Hospital Discharge (EHD) strategy, EHD following AML-like induction chemotherapy has become routine at our institution. In recent retrospective analyses, we found 〉80% of EHD patients required hospital readmission, primarily for neutropenic fever. Still, the EHD strategy was safe and reduced healthcare resource utilization, and EHD patients spent 〉70% of their post-chemotherapy time as outpatients. Here, we investigated differences in the pattern of infectious complications between patients managed as outpatients following induction chemotherapy and those who remain hospitalized until hematopoietic recovery. Methods: We retrospectively identified all adults ≥18 years with untreated AML/high-grade myeloid neoplasms (≥10% blasts in blood/ bone marrow) who started intensive induction chemotherapy ("7+3" or a regimen of similar/higher intensity) at our institution from 8/1/2014-7/31/2018. Patients were considered "EHD" if they were discharged from the hospital

Description: Introduction: Sickle cell anemia (SCA) is caused by mutations in β-globin that result in the production of the abnormal hemoglobin, HbS, with deleterious effects on erythrocyte shape and life span. Because the propensity of erythrocytes to sickle is inversely proportional to the concentration of HbS in the cell, decreasing the mean cellular hemoglobin concentration (MCHC) represents a potential therapeutic approach. Whereas iron restriction in healthy individuals does not alter MCHC, concomitant iron deficiency has been associated with decreased MCHC in SCA patients. Isolated case reports have linked iron restricted erythropoiesis with decreased hemolysis, increased red cell lifespan, and improvement in certain outcomes in SCA patients. We systematically examined the effects of iron restriction on erythropoietic outcomes in SCA utilizing the Townes murine model to investigate the hypothesis that mice with dietary iron deficiency will demonstrate a decreased MCHC, decreased erythrocyte sickling propensity, and improved anemia compared with mice on an iron sufficient diet. Methods: Townes SCA mice were weaned to diets containing either 20 ppm iron (low) or 48 ppm iron (sufficient) and maintained on those diets until sacrifice at 2 months of age. Blood was collected for complete blood count by submandibular or cardiac puncture. Spleen weight was normalized to body weight for calculation of the splenic index. Red cell deformability, defined by the elongation index (EI), and the oxygen pressure at which sickling occurs (point of sickling) during deoxygenation were characterized by oxygenscan ektacytometry using a laser optical rotational red cell analyzer (Mechatronics, The Netherlands). Results: SCA mice fed a 20 ppm low iron diet demonstrate a significant decrease in MCHC compared to SCA mice fed a 48 ppm iron sufficient diet (17.7+1.1 vs 22.7+5.5 g/dL; p

Description: Introduction Monitoring BCR-ABL transcript levels in peripheral blood of patients using real-time quantitative PCR is standard of care in the management of Chronic Myeloid Leukemia. Xpert BCR-ABL Ultra is an automated cartridge-based assay developed by Cepheid for sensitive assessment of BCR-ABL transcript levels. However, in clinical situations the total RNA isolated from white blood cell (WBC) in the patient's blood is insufficient to ensure assay LoD of 0.003% (IS)/MR4.52, or high WBCC in specimen can overload the Ultra cartridge, resulting in inaccurate test results. Therefore, it is necessary to determine proper WBCC input, to ensure accurate assay quantification results. Objectives The objective of this study was to determine the correlation between ABL copy number input and Ct value, determine lower and upper WBCC input limits for the Xpert BCR-ABL Ultra assay and establish the ABL Ct cut-offs. Methods To establish an upper ABL Ct limit that corresponds to a minimal ABL CN input of 32,000 for supporting LoD, a BCR-ABL plasmid DNA (pDNA, ERM-AD623) was serially diluted and tested in an EDTA whole blood background to make a calibration panel. A standard curve was generated against which the ABL Ct could be estimated as a function of ABL copy number. To estimate the lower WBCC limit, CML negative EDTA lysate with normal WBCC was serially diluted with WBC depleted EDTA lysate. To estimate the upper WBCC limit, EDTA lysate from a specimen with high WBCC (69.9×106cells/mL) was diluted with CML negative lysate with normal WBCC (3.5×106 cells/mL). To validate the WBCC limit, CML positive lysate with high WBCC (40×106cells/mL) was diluted with high WBCC (40×106cells/mL) CML negative lysate to produce five BCR-ABL levels within 0.03% (IS)/MR3.52 to 65% (IS)/MR0.19. Each level was further diluted with PBS lysate to achieve 8 levels of WBCC from 40×106 to 0.04×106 cells/mL. Results ABL Ct value of ~19 corresponding to a minimum ABL copy number input of 32,000 was established to support assay LoD of 0.003% (IS)/MR4.52 (Figure.1). To allow for a one Ct buffer, the upper ABL Ct cut-off was set at 18. The lower WBCC input limit, corresponding to the upper ABL Ct limit of ~18 with estimated ABL copy number greater than 64,000, was established to be 0.15×106 cells/mL (Figure.2) The upper WBCC input limit was established to be 30×106 cells/mL. This corresponds approximately to a Ct value of 10 (Figure.3). The Xpert BCR-ABL Ultra test monitors RNA expression levels of the BCR-ABL fusion transcript and the ABL transcript. Unlike a gene DNA marker, RNA expression levels are variable and can fluctuate. To accommodate for the variability in RNA expression levels and based on results from this study, the upper ABL Ct cut-off was lowered to 8. The lower and upper WBCC input limit, together with ABL Ct cut-off, were validated with CML patient specimens with WBCC input ranging from 0.04 to 40 × 106 /ml within IS% range of 0.03% to 65% (Table.1). The normal WBCC of 4 to 10 × 106/mL across all tested concentrations yielded ABL Ct range from 13.2 to 11.7 with estimated ABL copy number of 2.5×106 to 7.8×106. Conclusions A correlation between ABL copy number input and ABL Ct value was established with the standard curve generated from a pDNA calibration panel. The lower WBCC limit was set at 1.5×105 cells/mL and upper WBCC limit was set at 3.0×107 cells/mL, together with ABL Ct cut-offs of 18 and 8 and ABL copy number of 6.4×104 to 1.4×108, to support Xpert BCR-ABL Ultra assay performance. The normal WBCC of 4 to10×106/mL across all tested concentrations yielded an ABL Ct range from 13.2 to 11.7 with estimated ABL copy number of 2.5×106 to 7.8×106, indicating Xpert BCR-ABL Ultra assay normally provided more than 10 times the required minimum ABL Copy number to support the assay LoD claim at 0.003% (IS). *Product in development. Not for use in diagnostic procedures. Not reviewed by any regulatory body. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Risk stratification in acute myeloid leukemia (AML) is continually being refined as we learn more about the molecular pathophysiology of this heterogeneous disease. European LeukemiaNet (ELN) 2017 used widely to stratify the 'genetic' risk of AML, but there are considerable challenges in its application, particularly in centres where molecular genetic testing either not available, or not sufficiently timely for clinical decision making. Up to a third of the study subjects cannot be stratified using a full cytogenetic-molecular model in real-time, real-life setting. There are few attempts to combine clinical features and genetic factors aiming to find a scoring system to improve AML survival prediction. There is only one to our knowledge (Sorror ML et al. 2017). This study has generated an Adapted Genetic Risk (AGR) assessment, and used it in combination with clinical risk parameters to create a novel scoring system which has now been validated using two independent cohorts. Methods: A training cohort from São Paulo (FMUSP, n = 167) of intensively treated AML patients (18-65 years) was assessed using ELN2017 genetic criteria. A comparative validation with our AGR which permits missing cytogenetic or molecular data (Figure 1) split these patients into favorable-risk (FR), intermediate-risk (IR), and adverse-risk (AR). This cohort was also used for Cox Proportional-Hazard Model (CPHM) univariate and multivariate analysis to find clinical parameters that would inform a novel Survival AML Score (SAMLS). Variables which are included in SAMLS had to be either significant in both CPHM models or significant in univariate and crucial for multivariate fitness as measured for the Akaike Information Criterion (AIC). We then applied the AGR strategy and SAMLS to 2 independent test cohorts of intensively treated adult AML patients : Riberao Preto (FMRP, n=145) and Oxford (OUH, n=157). The study was approved by the institutional review boards of the 3 participating centers. Informed consent was obtained from all patients according to the Declaration of Helsinki. Results: Table 1 shows the clinical characteristics for all the 3 cohorts. The median follow-up (FUP) was 72.3, 44.4, and 70.5 months for FMUSP, FMRP, and OUH, respectively. The median Overall Survival (OS) was 12.4, 12.5, and 56.4 months and the 5-year OS were 29.6%, 29.7%, and 49.7% respectively. Both ELN2017 and AGR correlated with significant differences in OS (p-value

Description: Background: Transfusion is a major therapeutic of sickle cell disease (SCD); however, DHTR is one of the most feared complications . Prevention of allo immunization, by extended RBC matching is insufficient to prevent all cases of DHTR. Therefore, B cell depletion therapy should be also useful, especially in previously immunized patients to avoid the emergence of new allo-antibodies. Rituximab (RTX) is used for preventing alloimmunization for patients with a history of DHTR. Therefore, secondary prevention with rituximab prior a new exposure to transfused RBCs could be a relevant option. Here, we will report our experiences of RTX use in SCD adult patients with a previous history of DHTR. Methods: In this retrospective observational study, the data from 58 consecutive RTX infusion in 44 SCD patients with history of DHTR in our French referral center for SCD were analysed. Medical, biological and blood bank records of patients, clinical signs, rate of hemoglobin A (HbA) after transfusion (TF) were collected. To evaluate the persistence of transfused RBCs, the DHTR risk probability on days 15 and 30 after TF was evaluated according to Mekontso Dessaps nomogram. We also reported serious adverse events like infections in the year after RTX infusion. In cases of programmed surgery, 1 gramme of RTX was administred at day 1 and 15 few weeks before or one injection in emergency situation, with low dose of steroides. Adjuvant measure to avoid transfusion like EPO, Iron injection and hydroxyurea was decided in some cases. Results: We analyzed 58 cases of RTX administered to 44 adult patients with SCD, 10 of whom received two or more times this drug. A transfusion (TF) was required in 33/58 cases (56%). We distinguished three groups of patients. In the first group of 21 cases (36%), rituximab was used preventively before planned surgery at risk of bleeding, only 8 cases were transfused. In the second group of 30 cases (53%) during an acute event, in 19 cases patients received a transfusion. The third group of 7 patients received RTX during an active DHTR with hyperhemolysis requiring transfusion to protect an imminent transfusion and finally 6 of them was transfused. To evaluate the efficacy of transfusion we analyzed group 1 and 2 together and separately the third group with active DHTR and hyperhemolysis. In the first and second groups, HbA measurements was not available or interpretable in 11,1% of cases. On day 15 after TF, 77,8% of cases were classified as having a low probability of hemolysis, 7.4 % as intermediate probability and 3.7% as high probability. On day 30 after TF: 55,6% were into the low probability of hemolysis subgroup, 11,1% in the intermediate probability and 22,2% in the high probability group. (Figure 1) In group 3, HbA measurement wasn't available in 2 cases. On day 15 after TF, no cases were classified as having a low probability of hemolysis, 33,3 % as intermediate probability and 33.3% as high probability. On day 30 after TF: 33,3% were in the intermediate probability and 50 % in the high probability group. (Figure 2) Infection requiring intravenous antibiotic were observed in 19 cases/58 (32.7%) with a bacterial documentation in 73,7 %. In 63% of these cases, patients have been hospitalized in intensive care unit for acute events before RTX administration and had other risk factors of infection. The median time of apparition of infection was 28 days [11.5-46.5]. We report 4 deaths (6,8%), two patient died due to a hyperhemolysis syndrome with multiorgan failure that started before RTX administration, two other were due to an end stage cancer. These deaths are not related to the use of RTX. Conclusion: This study suggests that RTX can be safely used for preventing DHTR in patients with a previous history of DHTR and detected antibodies. We show that transfusion efficiency at day 15 post TF is better than days 30 postTF. The effectiveness of TF in active DHTR with h yperhemolysis is much lower, as most patients lose the transfused units at day 30 post TF.Beyond the use of RTX, the use of other measures such as hydroxyurea and erythropoietin to avoid the need of transfusion in these patients must be emphasized. Infection risk after RTX therapy is difficult to assess. In most cases an active inflammatory event was in process. Additional prospective studies are needed to improve the management of this challenging clinical situation. Disclosures Michel: Novartis: Consultancy; Amgen: Consultancy; Rigel: Consultancy. Galactéros:Addmedica: Membership on an entity's Board of Directors or advisory committees. Bartolucci:Novartis: Membership on an entity's Board of Directors or advisory committees; AddMedica: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; HEMANEXT: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees.

Description: Introduction: Acute Myeloid Leukemia (AML) is a biologically heterogeneous disease with poor outcomes despite aggressive induction chemotherapy (IC). Cytogenetics and mutational profile are used to inform subgroups of patients who are at high risk of relapse. Mutations in the fms-related tyrosine kinase 3 gene (FLT3) are detected in 30% of adults with newly diagnosed AML. The predominant (75%) FLT3 mutation, is an internal tandem duplication mutation (FLT3-ITD), which confers poor prognosis due to a high relapse rate. The addition of the multitargeted kinase inhibitor midostaurin to standard IC significantly prolonged overall survival (hazard ratio for death 0.77, p=0.016) among patients with AML and a FLT3 mutation. Midostaurin was approved by the United States Food and Drug Administration (FDA) in April 2017 for the treatment of adult patients with newly diagnosed FLT3+ AML, as detected by an FDA-approved test, in combination with standard cytarabine and daunorubicin IC and cytarabine consolidation. The recommended dose of midostaurin in AML is 50 mg twice daily with food on days 8 to 21 of each cycle of induction and consolidation chemotherapy followed by 50 mg with food as a single agent for up to 12 months. The objective of this study was to evaluate the utilization of midostaurin in AML in the real-world setting in the first year after its US approval and marketing. Methods: Patients with at least 1 claim for midostaurin (index date) between April 1, 2017 and October 31, 2018 and who had at least 1 claim with a diagnosis of AML in the 6-month pre-index period were identified from Symphony Health's Integrated Dataverse (IDV), a large US claims database containing linked longitudinal prescription, medical, and hospital claims. The IDV contains claims for 280 million active unique patients representing over 73% of specialty prescriptions, 58% of medical claims, and 30% of hospital claims volume in the US. Patients included in the study cohort had a 6-month pre-index period with no claims with a diagnosis of AML, were at least 18 years old at initiation of midostaurin, and no evidence of participation in a clinical trial. Patient characteristics and treatment patterns were summarized using descriptive statistics. Median and 95% confidence interval (CI) for duration of midostaurin were calculated using Kaplan-Meier estimates. Results: There were 708 patients with AML treated with midostaurin who met all study selection criteria. Median age at midostaurin initiation was 60 years (range 20-80), and 49% of patients were male. The majority (61%) had commercial insurance, and patients resided in all 4 US regions (43% West, 22% South, 18% Northeast, 16% Midwest). Midostaurin was given as first line therapy in 583 (82%) patients, as second line in 95 (13%) patients, and as third line or later in 30 (4%) patients (see Table). Among the 95 patients who received midostaurin as second line therapy, hydroxyurea monotherapy (n=24, 25%) and sorafenib monotherapy (n=23, 24%) were most common first line therapies. With a median follow-up of 5.9 months from initiation of midostaurin, the median duration of midostaurin treatment was 2.3 months (95% CI 1.9-2.6). Over half (51%) had an average daily dose of 100mg on their first fill, 25% had 50mg, 9% had 67mg, 5% had 25mg, and 10% had other doses. Conclusions: In this retrospective claims-based study, there is evidence of early uptake of midostaurin use in AML. However, majority of patients receive midostaurin as a single agent contrary to the approved schedule of initiating midostaurin concurrently with IC and with consolidation cytarabine. The median duration of midostaurin treatment was short at 2.3 months given that the recommendation is to continue it for 12 months after IC. Almost half the patients are started at a dose that is lower than the recommended dose, which may impact efficacy. Potential limitations of this dataset include a relatively short period of follow-up, retrospective design and low uptake post-marketing as some patients may have completed IC or missing data from midostaurin administered in the hospital. Barriers to the appropriate use of midostaurin in AML, if any, will need further exploration. Universal and timely testing for the FLT3 mutation is the essential first step to allow for including midostaurin as a part of IC for the appropriate utilization of this agent in FLT3 + AML. Disclosures Gajra: Cardinal Health: Employment. Klink:Cardinal Health: Employment. Kish:Cardinal Health: Employment. Chopra:Cardinal Health: Employment. Feinberg:Cardinal Health: Employment.

Description: Introduction: We have previously reported underrepresentation of female faculty at senior academic ranks in hematology/oncology (H/O). In this analysis we aimed to investigate the influence of sex in attaining leadership positions amongst academic hematologists/oncologists in United States. Methods: Faculty members were identified at 146 H/O fellowship programs listed on fellowship and residency electronic interactive database (FREIDA.) Data was collected on demographics, academic rank and research output using Doximity and Scopus databases. We compared the unadjusted characteristics of men and women by using two-sided t-tests and χ2 tests where appropriate. In primary analysis, logistic regression models were used to evaluate sex differences on probability of having full professorship (versus assistant and associate professorship) and of achieving leadership positions including division chief, Program Director (PD) and Associate Program Director (APD). Adjusted models included the following variables: clinical experience in years, number of publications, h-index, appointment at top 20 hospital, clinical trial investigator status and National Institutes of Health funding. Stratified analysis was performed adjusting for duration of clinical experience (≤15 vs 〉15 years) Results: Fewer women were full Professors (21.9% vs 78.1%), division chiefs (16.7% vs 83.3%), and PDs (30.5% vs 69.5) but the number was similar for Associate Program Directors (47.1% vs 52.9%). In a univariate unadjusted model, women were less likely to be full professors compared to men (OR 0.39; 95% confidence interval [CI], 0.31-0.48; P15 years) found no significant sex differences in attaining leadership position (Table) Conclusion: We found that women are underrepresented at higher academic ranks and in leadership positions in hematology/oncology, but that sex is not a significant negative predictor to women obtaining leadership positions after correcting for traditional predictors of academic success. However, "non-traditional" and therefore less measurable and analyzable factors such as networking, mentorship, sponsorship, gender bias, balancing work and home responsibilities and many others may contribute and should be further investigated. Disclosures No relevant conflicts of interest to declare.

Description: BACKGROUND: Regulatory T cells (Tregs) are non-redundant mediators of immunity and tolerance. Adoptive transfer of CD4+Foxp3+ Tregs has emerged as a promising therapy for graft-versus-host disease (GVHD) following allogeneic HSCT (aHSCT), solid organ transplantation and autoimmune diseases (Hanash AM, Blood 2005; Copsel S, Wolf D, Haematologica 2019; Marek-Trzonkowska N, Diabetes Care 2012; Tang Q, J Mol Cell Biol 2012). Our prior work was the first to demonstrate a two-pathway in vivo strategy targeting TNFRSF25 (with TL1A-Ig fusion protein) and CD25 (with low dose IL-2, IL-2LD) receptors can elicit a rapid and strong increase in Treg numbers and function (Wolf D, BBMT 2017). In fact, very low numbers of these in vivo expanded donor Tregs exhibited effective GVHD suppression in recipients following aHSCT (Copsel S, BBMT 2018). Based on these findings and the success of IL-2LD in pre-clinical and clinical studies, we asked: are there phenotypic/functional differences between Tregs expanded via IL-2LD, TL1A-Ig or their combined application (TL1A-Ig+IL-2LD)? METHODS: Mice were administered IL-2LD, TL1A-Ig or TL1A-Ig+IL-2LD over 6 days. Splenic and lymph node (LN) Treg phenotype was determined by flow cytometry. Treg functionality was assessed with sorted populations using an in vivo MHC-mismatched aHSCT. RESULTS: Treatment of C57BL/6-FoxP3RFP mice with TL1A-Ig+IL-2 LD versus IL-2LD only treatment resulted in significantly higher levels of activation/differentiation and functional markers on Tregs including KLRG1, CD103, Nrp1, ICOS (Fig. 1A). Ki67 expression was higher in two-pathway versus IL-2LD stimulation alone (Fig.1B). These data suggested a key role for TNFRSF25 stimulation. Notably, Treg stimulation with TL1A-Ig alone drove the above phenotype indicating a pathway difference between the TNFRSF25 and IL-2 receptors. This difference was further apparent as high affinity IL-2 receptor (CD25) expression was reduced after TL1A-Ig +/- IL-2LD -mediated expansion compared with IL-2 LD alone stimulated Tregs (Fig. 1A). Results were corroborated using a second independent mouse strain, BALB/c, following use of these protocols. To begin addressing if the observed phenotypic differences between CD25 vs. TNFRSF25 + CD25 expanded Tregs could be related to a more potent Treg in vivo suppressive activity, an initial MHC-mismatched aHSCT (donor/recipient = C57BL/6-BALB/c) was performed. We employed 200,000 sorted Tregs (〉98% purity by CD4+FoxP3+ selection from C57BL/6-FoxP3RFP reporter mice) from donor unexpanded, IL-2LD, or TL1A-Ig+IL-2LD treated mice combined with 1.0 x106 T cells. As anticipated, transfer 200,000 TL1A-Ig+IL-2LD stimulated Tregs ameliorated acute GVHD (Fig. 1C). Remarkably, lower GVHD clinical scores were obtained using the same number of IL-2LD only expanded Tregs compared with TL1A-Ig+IL-2LD stimulated Tregs (Fig. 1C). Moreover, early post-transplant, higher LN and splenic CD4/CD8 ratios were detected in aHSCT recipients treated with IL-2LD expanded Tregs vs. TL1A-Ig+IL-2LD (Fig. 1D). CONCLUSION: Our donor TL1A-Ig+IL-2LD Treg expansion protocol promotes a more activated/differentiated and proliferative phenotype versus IL-2LD stimulation alone. This finding may have accounted for their initial effectiveness - but less efficient long-term GVHD amelioration compared to IL-2LD only stimulated Tregs. Multiple variables are associated with the application of Tregs for therapy including numbers, persistence, and suppressive capacity. Our findings suggest a rationale that one-pathway and / or two-pathway stimulated Tregs may be beneficial for use in aHSCT recipients dependent on whether there is a perceived need for prolonged Treg presence and the stage of GVHD. Disclosures Levy: Heat Biologics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pelican Therapeutics: Consultancy, Research Funding.

Description: Anaplastic large cell lymphoma (ALCL) is an aggressive type of non-Hodgkin's lymphoma (NHL) comprising 2-8% of adult and 10-20% of pediatric and adolescent NHL. More than three-fourths of anaplastic lymphoma kinase (ALK)-positive ALCL express (nucleophosmin1) NPM1-ALK fusion gene as a result of t(2;5) chromosomal translocation. The self-dimerization of fusion kinase NPM1-ALK mediates constitutive activation of the chimeric tyrosine kinase activity leading to downstream signaling pathways responsible for lymphoma cell proliferation and survival. The current standard treatment regimen for ALK+ ALCL is CHOP (cyclophosphamide, hydroxy doxorubicin, vincristine, prednisone) chemotherapy. Oftentimes, resistance and failure of remission occur with CHOP therapy, making it a suboptimal treatment regimen for many patients. Therefore, an alternative therapeutic approach is warranted to better address the needs of the ALK+ ALCL population. Gilteritinib is a recently FDA approved tyrosine kinase inhibitor for the treatment of FMS-like tyrosine kinase (FLT3) mutation-positive acute myeloid leukemia. Along with inhibition of FLT3, gilteritinib also inhibits other tyrosine kinases such as AXL and ALK. In this study, for the first time, we demonstrated gilteritinib mediated growth inhibitory effects on NPM1-ALK driven ALCL cells. We have used a total of five cell lines in our study: NPM1-ALK endogenously expressing human ALCL cell lines (SUDHL-1, SUP-M2, SR-786, and DEL), and our laboratory generated ectopically overexpressing Ba/F3-FG-NPM1-ALK, a murine cell line. Gilteritinib treatment (5-20 nM) inhibited NPM1-ALK fusion kinase phosphorylation, which resulted in downregulation of downstream survival signaling pathways including AKT, ERK1/2, and STAT3 leading to induced apoptosis and decreased clonogenic survival. Gilteritinib mediated apoptosis was associated with caspase 3/9 and poly (ADP-ribose) polymerase cleavage with increased pro-apoptotic protein BAD and decreased anti-apoptotic protein MCL-1. Increased expression of c-Myc is associated with ALK-positive ALCL and gilteritinib treatment decreased c-Myc levels in a dose dependent manner. Cell cycle analysis demonstrated gilteritinib treatment induced cell cycle arrest at the G0/G1 phase with a concomitant decrease in G2/M and S phases. In summary, our preclinical results suggest gilteritinib has therapeutic potential for the treatment of ALCL cells expressing NPM1-ALK and other ALK /ALK-fusion driven hematologic or solid malignancies. Disclosures Lin: Jazz Pharmaceuticals: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees. Ganguly:Daiichi Sankyo: Research Funding; Seattle Genetics: Speakers Bureau; Janssen: Honoraria, Other: Advisory Board; Kite Pharma: Honoraria, Other: Advisory Board. McGuirk:ArticulateScience LLC: Other: Assistance with manuscript preparation; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bellicum Pharmaceuticals: Research Funding; Astellas: Research Funding; Novartis: Research Funding; Fresenius Biotech: Research Funding; Pluristem Ltd: Research Funding; Gamida Cell: Research Funding; Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Description: Background The acute leukemia of ambiguous lineage (ALAL) is high risk and uncommon in acute leukemia, including acute undifferentiated leukemia (AUL) and mixed phenotype acute leukemia (MPAL). On account of the rareness and age-influenced genome landscape, the genetic characterization was always limited and showed discrepancy among different cooperative groups. Methods By integrating the immunophenotype, cytogenetics, and molecular biology of ALAL patients, we found that the molecular profile played an important role in the diagnosis, treatment, and prognosis of ALAL patients. Through an in-depth analysis of the molecular features, we found the genetic differences between different subtypes of ALAL, and studied the unique gene mutation patterns and synergy of genomic abnormalities in different subtypes. Results Most patients in the cohort were children and young adults, and among B/myeloid and T/myeloid MPAL, while rare in AUL. Here we showed that ALAL patients show both genetic commonality and discrepancy among subtypes. Except for the BCR-ABL1 and KMT2A-r, which were mainly in B/myeloid MPAL, we reported that SET-NUP214 was recurrent in T/myeloid MPAL and AUL patients. The PHF6 were also frequently mutated in T/myeloid MPAL with most loss of function and significantly associated with SET-NUP214. Otherwise, there was a big difference between B/myeloid and T/myeloid MPAL in genetic profile. The most mutated genes in B/myeloid MPAL were CEBPA, RUNX1, NRAS, TET2, WT1, PTPN11, and FLT3, while NOTCH1, WT1, RUNX1, FLT3, PHF6, ETV6, and EZH2 were frequently in T/myeloid MPAL. Moreover, the alterations in the genes encoding transcriptional regulation were both recurrently mutated in B/myeloid and T/myeloid MPAL, especially WT1 and RUNX1, which were the most mutated genes and mutually exclusive with each other. Alterations in the genes involved in JAK_STAT signaling, RAS signaling, and epigenetic regulation were also recurrently mutated in B/myeloid and T/myeloid MPAL, despite some differences in incidence rate. However, the deletion of IKZF1 exclusively occurred in B/myeloid MPAL, while genes involved in NOTCH signaling were mainly altered in T/myeloid MPAL. When analyzing the synergy among genetic abnormalities, we found that SET-NUP214 and PHF6 (p = 0.00002), FLT3 and RUNX1 (p = 0.009), BCR-ABL1 and RUNX1 (p = 0.02) were the most significantly co-occurred genes (Figure 1-A, B). Although the association between NRAS and WT1 were not significantly (p = 0.11), they co-occurred in five patients (Figure 1-C). Since this was the first time to report that SET-NUP214 was recurrent in ALAL patients, we retrospectively review the therapy of patients with the aberration. According to the treatment of these ALAL patients, we confirmed that even with transplantation therapy the prognosis of SET-NUP214-positive ALAL patients was still very poor with a high risk of relapse. Discussion We charted the genomic landscape of ALAL to comprehensively reveal the commonality and discrepancy among subtypes of ALAL patients. The founding lesion of SET-NUP214 in early primitive hematopoietic cells was showed to be involved in the block of differentiation. Together with the loss of function in PHF6, which was showed a contribution to the lineage promiscuity and enhance the proliferation of hematopoietic cells, the combination event could make leukemia with ambiguous lineage. After deciphering the molecular characterization of ALAL patients, we proposed several candidate updates to WHO 2016 (Table 1), as these molecular features may help the diagnosis, therapy, and prognosis of the ALAL patients. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Autologous stem cell transplant (ASCT) followed by maintenance is the standard of care for eligible patients with multiple myeloma (MM). For patients that relapse, a second ASCT remains a viable option. However, the maintenance regimen to use for such patients remains an unanswered question, particularly in those with prior lenalidomide exposure. We retrospectively analyzed patients receiving two autologous transplants for a diagnosis of MM at our institution from 2008 to 2018 to determine maintenance strategies and outcomes upon completion of a second transplant. Methods: A total of 189 patients received two or more autologous transplants for MM at our institution from 2008 to 2018. Patients with planned tandem transplants, or those that proceeded directly to another transplant without interval progression were excluded. The remaining 135 patients were analyzed. Results: Patient characteristics are shown in Table 1. After first ASCT, 94 out of 135 patients (69.6 %) started maintenance therapy. The most commonly used maintenance regimen was lenalidomide in 63 patients, followed by bortezomib in 12 patients and thalidomide in 10 patients. Median time to initiation of maintenance from the date of transplant was 3.9 months. Overall median progression free survival (PFS) from transplant was 24.7 months with no significant difference between groups that received lenalidomide (median PFS: 21.2 months) or bortezomib (median PFS: 19.2 months, p:0.12). 10 (15.8%) patients discontinued lenalidomide due to toxicity, and 1 patient (8.3%) discontinued bortezomib due to toxicity. The median time from the onset of disease progression post first ASCT to time of second ASCT was 5.8 months. Strategies used post second ASCT includedconsolidation with triplet regimens followed by de-escalation (n=11) versus monotherapy (n=100). Table 2 highlights differing maintenance regimens used after the second ASCT. Median time from second ASCT to initiation of maintenance was 4.0 months. Median PFS post ASCT was 20.7 months. There was no statistically significant difference in PFS between the different regimens used (p=0.26), although there was a numerically higher discontinuation rate due to toxicity with older agents such as lenalidomide and bortezomib compared with newer agents such as daratumumab and pomalidomide. There was no statistically significant difference in the cytogenetic risk profile (p=0.21) or stage at diagnosis (p=0.36) between the groups that received different types of maintenance agents. However, patients receiving daratumumab as maintenance were more likely to have received more lines of therapy (median 5 for Daratumumab vs 3 for Lenalidomide, p=0.0001), and more likely to have previous exposure to daratumumab prior to second ASCT (92% vs 0% for other agents p=0.0001). Patients receiving daratumumab, carfilzomib or triple therapy were more likely to have been refractory to both a proteasome inhibitor (PI) and an immunomodulatory drug (IMiD) (p=0.0001). Despite stratifying for use of newer novel drugs (FDA approval after 2010- pomalidomide, daratumumab, carfilzomib) vs older novel drugs (FDA approval before 2010- lenalidomide, bortezomib, thalidomide), there was no difference in PFS ( 21.2 months vs 20.4 months, p= 0.92), between these groups when used as part of a maintenance strategy. Conclusions: Our data show a variety of maintenance and consolidation regimens are used for patients with MM after their second ASCT. In this single-center, retrospective analysis, there was no clear superiority of a consolidative strategy using triplet over monotherapy, and no superiority of newer agents compared to older agents. This suggests that toxicity, prior therapies and their tolerance may be the more important patient-related factors for consideration when selecting an agent/agents. Randomized, prospective data will be important to ascertain the standard of care in this situation. Disclosures Ganguly: Daiichi Sankyo: Research Funding; Seattle Genetics: Speakers Bureau; Kite Pharma: Honoraria, Other: Advisory Board; Janssen: Honoraria, Other: Advisory Board. McGuirk:Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bellicum Pharmaceuticals: Research Funding; Astellas: Research Funding; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Fresenius Biotech: Research Funding; Gamida Cell: Research Funding; Pluristem Ltd: Research Funding; ArticulateScience LLC: Other: Assistance with manuscript preparation.

Description: Precise regulation of transcription and RNA splicing is critical for controlling hematopoietic cell fate determination and lineage differentiation. Alteration of expression of lineage-specific transcription factors and several core spliceosome components in hematopoietic malignancies highlight the significance of abnormal transcription and RNA splicing as disease-causing factors. Our group previously demonstrated that SON, a large nuclear speckle protein possessing dual abilities to bind both DNA and RNA, functions as a splicing factor as well as a transcriptional repressor. We recently identified heterozygous loss-of-function mutations in the SON gene from children with intellectual disability and developmental delay often with a broad spectrum of other congenital anomalies. The disorder caused by SON haploinsufficiency has been designated as ZTTK syndrome (Zhu-Tokita-Takenouchi-Kim syndrome; OMIM #617140). The majority of the mutations found in these patients are frameshift or nonsense mutations which cause degradation of the mutation-bearing transcript. While the most prominent features of these patients are brain malformations and musculoskeletal abnormalities, we identified various hematological disorders from children with ZTTK syndrome. Notable symptoms include bone marrow failure, severe anemia, immunoglobulin deficiency, thalassemia, polycythemia, polycythemia vera, stroke due to blood clots, and leukocytopenia. Apart from the ZTTK syndrome, SON is known to be upregulated in acute myeloid leukemia (AML) patients and is correlated to altered hematopoietic differentiation. To investigate how altered SON expression affects hematopoiesis, we generated a mouse line with the Son gene deleted specifically in the hematopoietic lineage. Homozygous deletion of Son in hematopoietic lineage led to embryonic lethality, indicating that SON expression in blood cells is indispensable during development. Mice with heterozygous deletion of Son in the hematopoietic lineage were viable and born without notable defects or sign of diseases. However, there is a significant decrease in bone marrow cellularity in the mice with heterozygous deletion of Son. Furthermore, Son haploinsufficiency decreased the size of the lineage negative (Lin-) cell population and short-term hematopoietic stem cell (ST-HSC) population with a concurrent increase in megakaryocyte/erythrocyte lineage-biased multipotent progenitors (MPP2) within hematopoietic stem/progenitor cells. These findings suggest that the level of Son expression potentially affects stem cell maintenance and MPP lineage bias, and the distortion of the subpopulation balance within hematopoietic stem/progenitors is possibly linked to multiple hematological disorders. Our ongoing analyses of hematopoiesis and gene expression changes using this mouse model will expand our knowledge about the role of SON in several hematological disorders and benefit clinical practice for ZTTK syndrome patients. Disclosures No relevant conflicts of interest to declare.

Description: Background: Patients with cancer are at elevated risk for venous thromboembolism (VTE). Active cancer contributes a 4-7 fold increased risk for VTE; however, the incidence of VTE stratified by subpopulations of patients diagnosed with cancer, especially race/ethnicity, is uncertain. Objective: Describe the incidence of VTE among adult patients (age ≥ 18 years) with a cancer diagnosis in Oklahoma County, OK according to age, gender, race, and cancer type. Methods: In collaboration with the Centers for Disease Control and Prevention, we established a population-based surveillance system for VTE in Oklahoma County, OK between April 1, 2012-March 31, 2014 to estimate the incidences of first-time and recurrent VTE events. The Commissioner of Health made VTE a reportable condition and delegated surveillance-related responsibilities to the University of Oklahoma, College of Public Health. Active surveillance involved reviewing imaging studies (e.g., chest computed tomography and compression ultrasounds of the extremities) from all inpatient and outpatient facilities in the county and collecting demographic, treatment and risk factor data on all VTE case-patients. Patients were linked to the Oklahoma Central Cancer Registry. Any patient with a cancer diagnosis since 1997, excluding basal or squamous cell carcinoma, were included in the population-at-risk. Active cancer was defined as metastatic or a diagnosis ≤6 months before their VTE diagnosis. Poisson regression was used to estimate incidence rates (IRs) and 95% confidence intervals (CIs), which are reported per 1,000 person years (PY). Estimates with

Description: Factors associated with complete remission and durable remission after CD19 chimeric antigen receptor (CAR)-modified T-cell immunotherapy for aggressive B-cell non-Hodgkin lymphoma (NHL) have not been identified. We report multivariable analyses of factors affecting response and progression-free survival (PFS) in patients with aggressive NHL treated with CD19 CAR T cells. The best overall response rate was 71%, with 32% of patients achieving complete remission. The median PFS and OS of patients with aggressive NHL who achieved complete remission were 11 months and 12 months. The median PFS and OS of patients with bone and bone marrow involvement without soft tissue involvement were 14 months and 18 months. The median PFS and OS of patients with soft tissue involvement were 1 months and 4 months. We report complete remission rates and long-term survival rates in patients with bone and bone marrow involvement were significantly higher than those in patients with soft tissue involvement. Figure Disclosures No relevant conflicts of interest to declare.

Description: Interferon gamma (IFNy) is a pro-inflammatory cytokine that is upregulated during chronic infections and chronic diseases, such as aplastic anemia, and has been associated with pancytopenia and diminished hematopoiesis. Studies have shown that IFNy negatively regulates hematopoietic stem cell (HSC) homeostasis by decreasing self-renewal and promoting terminal differentiation. The tight regulation of HSC homeostasis is dependent upon the bone marrow (BM) microenvironment, or BM niche. The BM niche is composed of a network of cell types that provide elaborate cell-cell interactions, cellular metabolites, transcriptional regulators, and local and distant humoral and neural signals that allow for hematopoietic homeostasis. In particular, CXCL12-abundant reticular (CAR) cells are vital to HSC maintenance, as depletion of CXCL12, or its receptor, leads to HSC depletion. However, the mechanism which IFNy activates HSCs and influences its interaction with the BM niche is unknown. We hypothesize that IFNy promotes HSC terminal differentiation and loss of quiescence by altering HSC interactions with the BM niche. To assess changes in HSC interactions with the BM niche upon IFNy stimulation, we performed intravital imaging using CXCL12 GFP reporter mice before and after administration of recombinant IFNy. We found that HSCs stimulated with IFNy were significantly distanced from CAR cells compared to pre-treated controls. There was no change in distance with IFNy-receptor deficient HSCs, suggesting that movement away from the CAR cells was due to a cell autonomous IFNy-dependent mechanism. We performed gene expression analysis and transwell migration assays on HSCs from IFNy treated mice, and determined that there was no change in CXCL12 receptor (CXCR4) expression upon IFNy treatment, and IFNy did not alter migration towards CXCL12. These results suggest that HSC re-localization upon IFNy is independent of CXCL12 signaling. To explore the mechanism by which IFNy induces re-localization of HSCs, we first performed microarray analysis on HSCs from IFNy stimulated mice to assess what surface proteins were changed upon IFNy treatment. While there was no change in common HSC receptors thought to influence HSC homeostasis (cKit, Cdh2, Mpl, Itgb1, Itbg2, Itga4, and Itga1), we observed an increase in expression of bone marrow stromal antigen 2 (BST2). To explore the impact of BST2 on HSC homeostasis, quantification and proliferation analysis was performed on HSCs from Bst2-/- mice. Interestingly, Bst2-/- HSCs were significantly less proliferative and more abundant compared to controls. These studies suggest that BST2 may play a role in maintaining HSC homeostasis. The functional role of BST2 in cellular movement and adhesion has been studied in cancer. Increased BST2 expression has been associated with promoting the migration, adhesion and metastasis of various cancer cells. Since migration and adhesion is important for HSC homing, we assessed the effects of IFNy on HSC homing. Hematopoietic progenitors from IFNy-treated mice homed to the bone marrow with greater efficiency than PBS-treated controls, whereas progenitors from IFNy-receptor-deficientmice showed a decrease in homing. Additionally, WBM from IFNyR-/- had reduced engraftment than wildtype, consistent with a role for IFNy signaling in promoting HSC homing. The impact of BST2 on homing is currently being explored. In summary, we show that IFNy induces re-localization of HSCs away from quiescence-promoting CAR cells within the bone marrow niche via a mechanism that is independent of CXCL12 signaling. We further show that IFNy promotes HSC homing. The increased expression of BST2 on IFNy-stimulated HSCs appears to impact HSC proliferation and abundance in the bone marrow. Thus, BST2 may play a role in HSC activation and exit from quiescence. Expanding our understanding of the mechanism that drives HSC activation and terminal differentiation has important implications for patients who develop pancytopenia or bone marrow failure due to chronic inflammation. Disclosures No relevant conflicts of interest to declare.

Description: Background: Geriatric deficits in patients with malignancy are predictive of morbidity and mortality. Measuring geriatric deficits provides additional prognostic information not otherwise captured in routine oncology care. Currently, the gap in geriatric-care delivery is the paucity of data demonstrating effective interventions once geriatric deficits are identified. Older adults with hematologic malignancy are understudied and evaluating both the impact of geriatric factors and interventions to improve upon geriatric deficits are warranted. Here we demonstrate the impact of identifying functional impairment and an exercise program among older adults with hematologic malignancy. Methods: This was a single center prospective study of older patients (≥60 years) with hematologic malignancy. Patients actively receiving any therapeutic treatment (chemotherapy, immunotherapy, targeted agents) were enrolled in a six-month exercise program to attenuate functional decline. The Otago Exercise Program (OEP) has been found to be an effective exercise regimen to improve functional balance, muscle strength, and prevent fall-related injury and mortality.1 The OEP is a structured combination of physical therapist prescribed individualized exercise plans with home-based exercise targeted to improve balance and functional decline. Patients enrolled had mild or moderate impairments in physical function, as defined by a score ≤9 on the Short Physical Performance Battery (SPPB). Patients were evaluated at baseline for geriatric deficits (Visit 1), after four months of OEP training (Visit 2), and following two months of self-directed exercise (Visit 3 - end of study) using a standardized Geriatric Assessmpent (GA) tool (CARG GA). The relationship between geriatric deficits and mortality and hospital utilization were analyzed. The change in GA factors over 3 visits were evaluated through a linear mixed model. The proportional hazards model was built to assess the association between Visit 1 GA and overall survival (OS), where OS was defined as time from date of V1 to death, censoring patients who were still alive at time of last follow-up. The generalized linear models were used to link Visit 1 GA with other clinical outcomes such as hospital length of stay (LOS) and the probability of emergency room (ER) visit. Results: Older adults (median age: 75.5; range 62-83) actively receiving chemotherapy for hematologic malignancy were enrolled (n=30). Physical health scores as measured by the MOS-PFS increased significantly at the second visit. [Median MOS-PFS: V1=55 (0-100); V2=70 (30-100), p

Description: Background: AML is driven by a small subpopulation of leukemia stem cells (LSCs), which possess stem-cell properties such as quiescence and self-renewal that are linked to therapy resistance and relapse. The LSC17 score was derived from genes differentially expressed between functionally validated LSC+ and LSC- cell fractions from 78 AML patients. The LSC17 score was strongly associated with survival in 4 independent cohorts of AML patients treated with curative intent (n = 908), and accurately predicted initial response. Patients with high LSC17 scores had poor outcomes with standard treatment strategies. The LSC17 score remained highly significant in multivariate analyses, independent of commonly used prognostic factors. A critical advantage of the LSC17 test over cytogenetic analysis is its rapid turnaround time (24-48h on a NanoString platform), providing clinicians with a powerful tool for upfront risk stratification. To date, no RNA-based, stem cell-derived score has been transitioned into a Clinical Laboratory Improvement Amendments (CLIA) certified laboratory. Study design and methods: The study consists of 2 phases. Phase 1 aims to validate the assay in a CLIA certified laboratory setting. Phase 2 aims to determine prospectively the feasibility and prognostic power of LSC17 score testing in newly diagnosed AML patients in the real-world setting. Clinical endpoints include primary induction failure rate, relapse free survival and overall survival. All patients with a suspected diagnosis of de novo or secondary AML, who are deemed fit and appropriate by their treating physician to undergo intensive induction chemotherapy, are considered for this study. Patients who received any prior anti-leukemia treatments (except hydroxyurea) and patients with a confirmed diagnosis of acute promyelocytic leukemia are excluded. Current participating centres include Princess Margaret Cancer Centre (Toronto), Juravinski Cancer Centre (Hamilton), and The Ottawa Hospital Cancer Centre (Ottawa). Pre-study sample size analysis suggests that 150 patients will be required to demonstrate a hazard ratio for death of 2.3 between patients with a high and low LSC17 score (α = 0.05, power = 0.8). The survival for the high and low LSC17 score groups will be compared using the Cox proportional hazards model. Traditional risk stratification will also be tested within a Cox proportional hazards model. Phase 1 of the study has been completed and several key quality control measures have been created. Initial derivation and validation of the LSC17 score was performed using standard chemistry on the NanoString platform; for CLIA lab validation, the assay was transitioned to Elements© chemistry, which does not require custom codeset manufacture by NanoString. The original AML reference cohort was retested using Elements© chemistry to derive an absolute median threshold for prospective LSC17 score determination in individual patients. The lab validation process compared and found no difference in LSC17 scores between samples processed by Ficoll or collected in Paxgene for ease of processing. A standardised quality assurance (QA) process was completed to identify optimal sample requirements as well as specimen storage conditions, score stability during sample storage and turnaround time for testing. An algorithm has been created using the laboratory information system to allow standardised and rapid calculation of the LSC17 score from NanoString nCounter output data. The LSC17 score can be tested on peripheral blood or bone marrow, although bone marrow samples are preferred for patients with very low peripheral blast counts. Samples are ideally stored in RNA Paxgene tubes for RNA stability and to maximize RNA yield. The prospective phase of the study (Phase 2) opened in April 2018 and as of June 2019, 233 patients have been enrolled, of which 120 received induction chemotherapy. 54 patients were excluded due to an alternative diagnosis or failed QA. The remaining patients had non-intensive therapy based on patient choice. Standard prognostic markers including cytogenetics, molecular studies and targeted sequencing using a 49-gene AML panel are performed in parallel to the LSC17 score. Treatment was administered according to physician preference, based on patient history and results of standard prognostic assays, when available. The study continues to recruit and is open to collaborations in other centres. Disclosures Ng: Celgene: Research Funding. Leber:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Sabloff:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas Pharma Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTX: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi Canada: Research Funding. Minden:Trillium Therapetuics: Other: licensing agreement. Wang:NanoString: Other: Travel and accommodation; Trilium therapeutics: Other: licensing agreement, Research Funding; Pfizer AG Switzerland: Honoraria, Other: Travel and accommodation; Pfizer International: Honoraria, Other: Travel and accommodation.

Description: Background: Pyruvate kinase (PK) deficiency is a congenital hemolytic anemia caused by mutations in the PKLR gene, leading to a deficiency of the glycolytic enzyme red cell PK (PK-R). Current treatments for PK deficiency are supportive only. Mitapivat (AG-348) is an oral, small-molecule, allosteric PK-R activator in clinical trials for PK deficiency. We previously described results from DRIVE PK, a phase 2, randomized, open-label, dose-ranging study in adults with PK deficiency (N=52) treated with mitapivat for a median of 6 months. Aim: To report long-term safety and efficacy of mitapivat in patients who continue treatment in the ongoing Extension period of the DRIVE PK study (ClinicalTrials.gov NCT02476916). Methods: Patients were eligible to participate if ≥18 years of age with a confirmed diagnosis of PK deficiency (enzyme and molecular testing); baseline hemoglobin (Hb) levels ≤12.0 g/dL (males) or ≤11.0 g/dL (females); and if they had not received more than 3 units of red blood cells in the prior 12 months, with no transfusions in the prior 4 months. Patients were initially randomized 1:1 to receive mitapivat 50 mg twice daily (BID) or 300 mg BID for a 6-month Core period. Dose adjustment was allowed during the Core period based on safety and efficacy. Patients experiencing clinical benefit without concerning safety issues related to mitapivat (investigator discretion) could opt to enter the Extension period, with follow-up visits every 3 months. Safety (adverse events [AEs]) and efficacy (hematologic parameters including Hb) were assessed. Protocol amendments during the Extension period required that (1) patients who did not have an increase from baseline Hb of ≥1.0 g/dL for ≥3 of the prior 4 measurements withdraw from the study, and (2) patients treated with mitapivat doses 〉25 mg BID undergo a dose taper and continue on the dose that maintained their Hb level no lower than 1.0 g/dL below their pre-taper Hb level. Results: Fifty-two patients enrolled in this study and were treated in the 24-week Core period; 43 (83%) patients completed the Core period and 36 (69%) entered the Extension period. Eighteen patients discontinued from the Extension period: investigator decision (n=8), AEs (n=1), consent withdrawal (n=1), noncompliance (n=1), or other (n=7). Thus, 18 patients, all of whom received ≥29 months of treatment with mitapivat (median 35.6, range 28.7-41.9) have continued treatment. Ten of these 18 patients were male, 11 had a prior splenectomy, and 5 had a history of iron chelation. Median age was 33.5 (range 19-61) years; mean baseline Hb was 9.7 (range 7.9-12.0) g/dL. All patients had ≥1 missense PKLR mutation. The doses (post-taper) at which treatment was continued were (BID): ≤25 mg (n=12), 50 mg (n=5), and 200 mg (n=1). Improvements in Hb levels and markers of hemolysis (reticulocytes, indirect bilirubin, haptoglobin) were sustained (Figure). Among the 18 patients, headache was the most commonly reported AE during both the Extension (n=7, 38.9%) and Core (n=10, 55.6%) periods. Reports of insomnia and fatigue during the Extension period (n=5, 27.8% each) were the same as or similar to those during the Core period. There were fewer reports of nausea (2 vs 6) and hot flush (0 vs 5) in the Extension period. Nasopharyngitis was reported in 5 patients in the Extension period vs 1 patient in the Core period. These data are consistent with the AE profile for the 52 patients treated overall in the Core period, in that headache (44%), insomnia (40%), and nausea (38%) were the most commonly reported AEs and were transient (generally resolved within 7 days without intervention). Conclusion: Chronic daily dosing with mitapivat for a median of 3 years was well tolerated, with no new safety signals reported. Increased Hb levels and improvements in hemolysis markers were sustained at the optimized individual doses. These long-term data support the potential of mitapivat as the first disease-altering therapy for PK deficiency. Two phase 3 trials are underway to further study the effect of mitapivat in patients with PK deficiency. Disclosures Grace: Novartis: Research Funding; Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Layton:Novartis: Membership on an entity's Board of Directors or advisory committees; Cerus Corporation: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees. Galactéros:Addmedica: Membership on an entity's Board of Directors or advisory committees. Barcellini:Novartis: Research Funding, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau; Apellis: Consultancy; Incyte: Consultancy, Other: Advisory board; Agios: Consultancy, Other: Advisory board; Bioverativ: Consultancy, Other: Advisory board. van Beers:Agios Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Research Funding; RR Mechatronics: Research Funding. Ravindranath:Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Kuo:Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy; Celgene: Consultancy; Novartis: Consultancy, Honoraria; Pfizer: Consultancy. Sheth:Apopharma: Other: Clinical trial DSMB; CRSPR/Vertex: Other: Clinical Trial Steering committee; Celgene: Consultancy. Kwiatkowski:bluebird bio, Inc.: Consultancy, Research Funding; Apopharma: Research Funding; Novartis: Research Funding; Terumo: Research Funding; Celgene: Consultancy; Imara: Consultancy; Agios: Consultancy. Hua:Agios Pharmaceuticals, Inc.: Employment, Equity Ownership. Hawkins:Bristol Myers Squibb: Equity Ownership; Infinity Pharma: Equity Ownership; Agios: Employment, Equity Ownership; Jazz Pharmaceuticals: Equity Ownership. Mix:Agios: Employment, Equity Ownership. Glader:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: Introduction: The standard first line treatment for diffuse large B-cell lymphoma (DLBCL) is rituximab (R) plus CHOP (R-CHOP). However, approximately 35-40% of patients (pts) relapse following such treatment, and outcomes with salvage therapy remain poor. Obinutuzumab (GA101; G) is a fully humanized, glycoengineered, type II anti-CD20 monoclonal antibody. It has demonstrated greater direct cell death induction and antibody-dependent cellular cytotoxicity/phagocytosis activity than R, and has shown activity and an acceptable safety profile when combined with CHOP (G-CHOP) in first-line treatment of pts with advanced DLBCL (Sharman et al. Leuk Lymphoma 2019). GOYA (NCT01287741) was a randomized, open-label, multicenter Phase III study that compared the efficacy and safety of G-CHOP with R-CHOP in pts with previously untreated DLBCL. In the primary analysis (median observation period: 29 months), G-CHOP did not significantly improve investigator (INV)-assessed progression-free survival (PFS) compared with R-CHOP (Vitolo et al. J Clin Oncol 2017). Here, we present results from the final analysis of GOYA. Methods: Pts were aged ≥18 years, had histologically documented, previously untreated, CD20-positive DLBCL, with adequate hematologic function, ≥1 bi-dimensionally measurable lesion, an ECOG performance status of ≤2, and were classified as being in an International Prognostic Index (IPI) risk group of high, high-intermediate, or low-intermediate risk. Low-risk pts with an IPI score of 1 (not due to age alone) or 0 with bulky disease (1 lesion ≥7.5cm) were also eligible. Pts were randomized (1:1) to 8 (21-day) cycles of G (1000mg i.v. on Days [D]1, 8 and 15, Cycle [C]1 and D1, C2-8) or R (375mg/m2 i.v. on D1, C1-8) in combination with 6 or 8 cycles of CHOP. Preplanned radiotherapy was allowed for bulky or extranodal disease. The primary endpoint was INV-assessed PFS. Secondary endpoints included independent review committee-assessed PFS (primary analysis only); overall survival (OS); complete response (CR) and overall response rate (ORR) with or without PET (according to modified Cheson 2007 criteria); event-free survival; disease-free survival; duration of response; time to next anti-lymphoma treatment; PFS according to cell of origin (COO; germinal center B cell [GCB] or activated B cell [ABC]), as an exploratory endpoint; and safety. Results: In total, 1418 pts were randomized in GOYA; of these, 704 pts who received G-CHOP and 710 who received R-CHOP were included in this final analysis (clinical cut-off date: January 31, 2018). Overall median follow-up was 47.7 months. Baseline characteristics were well balanced between the G-CHOP and R-CHOP arms. INV-assessed PFS was similar between G-CHOP and R-CHOP (5-year PFS, 63.8% vs 62.6%; stratified HR, 0.94; 95% CI: 0.78, 1.12; p=0.48; Table). There was no significant difference in 5-year OS between the G-CHOP and R-CHOP groups (77.0% vs 77.7%) or in CR or ORR (Table). In the subgroup analysis of pts with ABC, GCB and unclassified DLBCL, no significant reductions in risk of disease progression were observed (stratified HR for INV-PFS, 0.91 [95% CI: 0.61, 1.36], 0.80 [95% CI: 0.58, 1.12] and 1.10 [95% CI: 0.65, 1.88], respectively). No new safety signals were identified. Grade ≥3 adverse events (AEs; 75% vs 66%) and serious AEs (44% vs 38%) were more common with G-CHOP than R-CHOP. Grade ≥3 AEs of particular interest (≥2% of pts in either treatment arm) were more frequent in the G-CHOP arm: infusion-related reactions (10% vs 3%), neutropenia (57% vs 47%), infections (20% vs 16%), cardiac events (5% vs 3%), thrombocytopenia (6% vs 2%), and hemorrhagic events (3% vs 1%); secondary malignancies occurred in 3% and 2% of the R-CHOP and G-CHOP arms, respectively. AEs resulting in treatment withdrawal (12% [87/702] G-CHOP; 8% [58/701] R-CHOP) and AEs with fatal outcome (6% [43/702] G-CHOP; 4% [31/701] R-CHOP) were slightly more common with G-CHOP. The most common grade 5 AEs were pneumonia (n=5 both arms) and sepsis/septic shock (G-CHOP, n=7; R-CHOP, n=3). Conclusions: Consistent with the primary analysis, G-CHOP did not significantly improve INV-assessed PFS compared with R-CHOP in previously untreated pts with DLBCL. Furthermore, there was no significant difference in 5-year OS between the treatment arms. No unexpected safety signals were identified. Further investigation of outcomes is ongoing, including the prognostic value of COO and BCL2 positivity. Disclosures Sehn: F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Lundbeck: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Apobiologix: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Verastem: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Janssen-Ortho: Consultancy, Honoraria; Janssen-Ortho: Honoraria; Kite Pharma: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria. Martelli:F. Hoffman-La Roche, Celgene, Janssen, Sandoz, Novartis, Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Honoraria; F. Hoffman-La Roche, Celgene, Janssen, Sandoz, Novartis, Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Honoraria. Trněný:Gilead Sciences: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria; Celgene: Consultancy; Incyte: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Liu:Roche Pharma Development, Shanghai, China: Employment. Bolen:Genentech, Inc.: Employment; F. Hoffmann-La Roche: Equity Ownership. Knapp:F. Hoffmann-La Roche Ltd: Employment. Sahin:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Sellam:Roche: Employment, Equity Ownership. Vitolo:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. OffLabel Disclosure: GAZYVA (obinutuzumab) is a CD20-directed cytolytic antibody and is indicated for the following: in combination with chlorambucil, for the treatment of patients with previously untreated CLL; in combination with bendamustine followed by GAZYVA monotherapy, for the treatment of patients with FL who relapsed after, or are refractory to, a rituximab-containing regimen; in combination with chemotherapy followed by GAZYVA monotherapy in patients achieving at least a partial remission, for the treatment of adult patients with previously untreated stage II bulky, III or IV FL.

Description: Background: Intensive care unit (ICU) patients undergo frequent blood sampling for laboratory testing resulting in blood loss that contributes to anemia and red blood cell (RBC) transfusion. Only 10% of the blood collected is used for testing suggesting that lower sample volumes may reduce the incidence/severity of anemia and use of RBC transfusion without compromising care. Small-volume (soft-draw) Vacutainer® tubes for blood collection (2-3 mL) have the same cost, physical dimensions, and blood draw technique as standard-volume tubes (4-10 mL) and are compatible with laboratory analyzers. We previously conducted a mixed-methods pilot study (n=369) in which small-volume tubes were implemented in the ICU resulting in a 45% reduction in blood loss with acceptability to end-users and no increased frequency of inadequate samples. We are currently conducting the STRATUS trial, a multi-center stepped wedge cluster randomized trial to determine whether a policy of using small-volume blood collection tubes reduces RBC transfusion compared to standard-volume tubes in adult ICU patients. Using this design an intervention can be incorporated into everyday practice at a site of care (such as an ICU) where individual randomization is not feasible. It is ideal for studying the effectiveness and implementation of interventions that have a high likelihood of benefit and low risk of harm. Study Design and Methods: STRATUS is a pragmatic stepped wedge cluster randomized trial being conducted at 25 ICUs (clusters) in Canada over 18 months. At 6-week intervals (steps), 2 ICUs are randomly selected to switch from standard-volume tubes (control) to small-volume tubes (intervention) for blood sampling. All patients admitted to the ICU during the study period are enrolled with waived consent and undergo blood sampling using the allocated tubes. To be eligible for STRATUS, ICUs met the following criteria: (i) adult care only (≥18 years), (ii) unit size ≥14 beds, (iii) capacity for mechanical ventilation; (iv) use of standard-volume Vacutainer® blood collection tubes at baseline; and (v) availability of electronic administrative and laboratory information. The primary outcome is the number of RBC units transfused per patient during their ICU stay in patients admitted to ICU for ≥48 hours. Secondary outcomes include (i) number of RBC units transfused per patient for the entire cohort, (ii) percentage change in estimated blood loss; (iii) change in hemoglobin concentration from ICU admission to discharge adjusted for RBC transfusion; (iv) number of samples with inadequate volume for testing; (v) ICU and hospital mortality; and (vi) ICU and hospital length of stay. The study is approved by local and provincial research ethics boards. Data are collected from electronic administrative and health record sources. Assuming a power of 90% with a type I error of 5% (2-sided) and intra-cluster correlation coefficient (ICC) of 0.01, 25 sites with 729 patients per site (total 18,240 ICU patients) are required to detect a minimum difference of 5 units per 100 patients (or 2.5% reduction). As the interventions are applied in hospital, we expect minimal loss to follow-up. From trial initiation January 2, 2019 to August 1, 2019, 6 sites have been switched to small-volume blood collection tubes on schedule. Up to May 2, 2019 enrolment was 4,186 patients. Significance: STRATUS will determine whether the use of small-volume blood collection tubes reduces RBC transfusion in ICU patients using an innovative cluster trial design that incorporates the intervention into routine ICU practice. With electronic administrative and health record data collection and a clinically relevant primary outcome, this pragmatic trial has the potential to change blood collection practices widely. Disclosures Siegal: Portola: Honoraria; BMS-Pfizer: Honoraria; Novartis: Honoraria; Bayer: Honoraria; Leo Pharma: Honoraria; Aspen Pharma: Honoraria. Arnold:Novartis: Honoraria, Research Funding; Rigel: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding; Principia: Consultancy. Connolly:Bayer Healthcare: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Portola Pharmaceuticals: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding. Crowther:Octapharma: Membership on an entity's Board of Directors or advisory committees; Shionogi: Membership on an entity's Board of Directors or advisory committees; Alexion: Speakers Bureau; Asahi Kasei: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Other: preparing educational material and/or providing educational presentations; Pfizer: Other: preparing educational material and/or providing educational presentations; Servier Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Other: Data and Safety Monitoring Board, Research Funding, Speakers Bureau; Diagnostica Stago: Other: preparing educational material and/or providing educational presentations, Research Funding; Alnylam: Equity Ownership.

Description: Background: Minimal/measurable residual disease (MRD) correlates with outcome in acute myeloid leukemia (AML). Flow cytometry (FC) and quantitative PCR (QPCR) both are recommended by ELN (Schuurhuis et al., Blood 2018) and NCCN guidelines. Comparative MRD data on FC and QPCR are limited. Aim: To assess the relative contribution of FC and QPCR in generating prognostically relevant MRD data in AML. Methods: 936 bone marrow samples of 305 AML patients in cytomorphologic CR were analyzed for MRD by both FC and QPCR (mainly fusion transcripts and NPM1 mutations) in parallel applying ELN guidelines. Patients´ages at diagnosis ranged from 20 to 89 years (median 57), sex ratio (f/m) was 155/150. As anticipated due to selection for MRD assessment risk according to ELN was favorable in 191 (63%), intermediate in 92 (30%) and poor in 18 (6%). Accordingly, 5 year event-free survival (EFS) was 68% and 5 year overall survival (OS) 68% at 2.4 years median follow-up. Samples for MRD assessment were drawn between 7 days and 8.5 years after diagnosis (median 5.8 months). MRD samples were categorized into 5 intervals: I1, 2 years, 148 (16%). Results: First, we focused on the percentages of MRD as determined by FC (%FC). %FC ranged from 0% to 5% (median, 0.003%). Overall, %FC strongly correlated with EFS (p

Description: Background: The International Society of Amyloidosis validated the criteria of hematologic response to therapy in AL amyloidosis, based on the reduction of free light chain (FLC) concentration and serum and urine immunofixation. Complete response (CR) predicted the longest survival and was defined by negative serum and urine immunofixation (s&u-IFE) with a normal FLC ratio (FLCR). Subsequently, we and others showed that, in patients with a difference between involved and uninvolved FLC (dFLC) between 20 and 49 mg/L, achieving a dFLC

Description: Introduction: Smoking is a potential risk factor for the development of non-Hodgkin lymphoma (NHL), and prior studies have reported inferior survival in tobacco users with certain subtypes of the disease (Taborelli et al, BMC Cancer, 2017; Ollberding et al, Br J Haematol, 2013). For instance, tobacco smokers with NHL had an inferior overall survival (OS) compared to non-smokers in a series of 471 patients who were managed up front with either chemotherapy (68%), radiation (27%), or observation, and this appeared to be most pronounced in patients with follicular lymphoma and in those with a 20+ pack year smoking history (Geyer et al, Cancer, 2010). The impact of tobacco use on survival specifically in patients with mantle cell lymphoma (MCL) has not been well studied. We conducted a multicenter study in MCL and evaluated the prognostic impact of tobacco use. Methods: We included patients with MCL from 12 sites who were ≥18 years old and for whom smoking status was known at the time of diagnosis. Cases were evaluated for reported smoking status at the time of diagnosis (active smoker, prior smoker, or never smoker) and standard baseline clinical prognostic data were obtained for each patient. Descriptive statistics were generated for these characteristics and were then compared across smoking status using chi-squared tests, Fisher's exact tests, or ANOVA, where appropriate. Overall survival (OS) and progression free survival (PFS) were estimated using the Kaplan-Meier method, and were compared using log-rank tests. Results: Of 946 included patients, 456 (48.2%) reported never using tobacco, 360 (38.7%) reported prior tobacco use, and 130 (13.7%) reported active tobacco use at the time of diagnosis. Median age was 59 in the active smoker group, 65 in prior smokers, and 61 in never smokers (p 〈 0.001). Any major medical comorbidity (defined as the presence of CAD, CHF, diabetes, CKD, ESRD, COPD, DVT, prior malignancy, or cirrhosis) was present in 59 (45.4%) of the active smokers, 143 (39.7%) of the prior smokers, and 140 (30.7%) of the never smokers (p = 0.002). Intensive induction regimens were used in 58.2% of active smokers, 47.2% of prior smokers, and 58.4% of never smokers (p=0.007). There were no significant differences between groups in regards to sex, race, ECOG performance status, Ann Arbor stage, time to first treatment, and use of auto transplant in first remission. Patients with no prior history of tobacco use were less likely to have a high risk MIPI score at diagnosis (26% high risk) compared to prior smokers (39.5%) and active smokers (32.5%, p=0.019). With a median follow up of 3.5 years after diagnosis, there was no significant difference between the 3 groups with regards to PFS or OS (Figure 1). Five-year OS in the never smoker group was 79.8% (95% CI: 74.8%, 83.9%) vs 75.1% (64.5%, 82.9%) in the active smoker group, and 80.6% (74.6%, 85.3%) in the prior smoker group (log rank p = 0.4079). Five- year progression free survival was 50.4% (44.6%, 56.0%) in the never smoker group, 42.5% (32.2%, 52.5%) in the active smoker group, and 50.2% (43.5%, 56.6%) in the prior smoker group (log rank p= 0.3595). Conclusions: Our data suggest that active or prior smoking does not significantly impact OS or PFS in patients with MCL. This study is limited by the fact that amount of current or former tobacco use was not available and it is not known how many current tobacco users ultimately stopped smoking during the course of their treatment. Future studies should incorporate more specific information regarding smoking history including pack-years and time between discontinuation of tobacco use and date of diagnosis. While tobacco use and other modifiable cardiovascular risk factors should be addressed as appropriate for all patients with MCL, current and former tobacco users can still achieve prolonged PFS and OS and may be candidates for intensive treatments after consideration of their other comorbidities and disease-specific risk factors. Disclosures Calzada: Seattle Genetics: Research Funding. Kolla:Amgen: Equity Ownership. Bachanova:Gamida Cell: Research Funding; GT Biopharma: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding; Celgene: Research Funding; Novartis: Research Funding; Kite: Membership on an entity's Board of Directors or advisory committees. Gerson:Seattle Genetics: Consultancy; Abbvie: Consultancy; Pharmacyclics: Consultancy. Barta:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Mundipharma: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Research Funding; Merck: Research Funding; Mundipharma: Honoraria; Bayer: Consultancy, Research Funding; Seattle Genetics: Honoraria, Research Funding. Danilov:Celgene: Consultancy; Abbvie: Consultancy; TG Therapeutics: Consultancy; Bayer Oncology: Consultancy, Research Funding; Gilead Sciences: Consultancy, Research Funding; Janssen: Consultancy; AstraZeneca: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Aptose Biosciences: Research Funding; Bristol-Meyers Squibb: Research Funding; MEI: Research Funding; Pharmacyclics: Consultancy; Verastem Oncology: Consultancy, Other: Travel Reimbursement , Research Funding; Curis: Consultancy; Takeda Oncology: Research Funding; Seattle Genetics: Consultancy. Grover:Seattle Genetics: Consultancy. Karmali:Astrazeneca: Speakers Bureau; Takeda, BMS: Other: Research Funding to Institution; Gilead/Kite; Juno/Celgene: Consultancy, Speakers Bureau. Hill:Seattle Genetics: Consultancy, Honoraria; Takeda: Research Funding; Amgen: Research Funding; TG therapeutics: Research Funding; AstraZeneca: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celegene: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Research Funding; Kite: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghosh:Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Speakers Bureau; Genentech: Research Funding; Celgene: Consultancy, Research Funding, Speakers Bureau; Forty Seven Inc: Research Funding; Gilead/Kite: Consultancy, Speakers Bureau; Spectrum: Consultancy, Speakers Bureau; AbbVie: Consultancy, Speakers Bureau; T G Therapeutics: Consultancy, Research Funding; Astra Zeneca: Speakers Bureau. Park:BMS: Consultancy, Research Funding; Rafael Pharma: Membership on an entity's Board of Directors or advisory committees; G1 Therapeutics: Consultancy; Teva: Consultancy, Research Funding; Gilead: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau. Epperla:Pharmacyclics: Honoraria; Verastem Oncology: Speakers Bureau. Hamadani:Pharmacyclics: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Merck: Research Funding; Celgene: Consultancy; Janssen: Consultancy; Medimmune: Consultancy, Research Funding; Sanofi Genzyme: Research Funding, Speakers Bureau; Otsuka: Research Funding; Takeda: Research Funding. Kahl:TG Therapeutics: Consultancy; BeiGene: Consultancy; Seattle Genetics: Consultancy; ADC Therapeutics: Consultancy, Research Funding. Martin:Janssen: Consultancy; Sandoz: Consultancy; I-MAB: Consultancy; Teneobio: Consultancy; Celgene: Consultancy; Karyopharm: Consultancy. Flowers:Karyopharm: Consultancy; Denovo Biopharma: Consultancy; Burroughs Wellcome Fund: Research Funding; AbbVie: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Spectrum: Consultancy; AstraZeneca: Consultancy; Pharmacyclics/Janssen: Consultancy, Research Funding; Bayer: Consultancy; Acerta: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Optimum Rx: Consultancy; Millenium/Takeda: Research Funding; Eastern Cooperative Oncology Group: Research Funding; National Cancer Institute: Research Funding; V Foundation: Research Funding; BeiGene: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; TG Therapeutics: Research Funding. Cohen:Genentech, Inc.: Consultancy, Research Funding; Janssen Pharmaceuticals: Consultancy; Takeda Pharmaceuticals North America, Inc.: Research Funding; Gilead/Kite: Consultancy; LAM Therapeutics: Research Funding; UNUM: Research Funding; Hutchison: Research Funding; Astra Zeneca: Research Funding; Lymphoma Research Foundation: Research Funding; ASH: Research Funding; Seattle Genetics, Inc.: Consultancy, Research Funding; Bristol-Meyers Squibb Company: Research Funding.

Description: BACKGROUND: Despite recent advances, outcomes remain poor in secondary and relapsed/refractory (R/R) acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We previously demonstrated that combination thioguanine (6TG) and decitabine restores therapeutic efficacy in vitro in R/R AML (O'Dwyer K et al. Blood 2010;114:2657). Based on these data, we completed a Phase I dose-escalation study of 6TG with decitabine in advanced myeloid malignancies with an overall response rate (ORR) of 67% and median progression-free survival (PFS) of 42 weeks in responding patients (Lee DJ, et al. Blood 2016;128:2816). Moreover, 5 of the 6 study participants who had previously received a hypomethylating agent (HMA) responded, suggesting that 6TG in combination with decitabine can overcome HMA resistance. Because of these results, a cohort of patients with high-risk and R/R AML and MDS were treated with combination 6TG and decitabine at Columbia University Irving Medical Center, and we now report our clinical experience with this regimen. METHODS: A retrospective chart review was performed of all adult patients at our institution with advanced myeloid malignancies who had received at least one cycle of 6TG and decitabine between 2013-2017. The treatment regimen utilized the maximum tolerated dose of 6TG identified in the phase I trial. Up to 2 cycles of induction with 6TG 80 mg/m2/day PO in 2 divided doses was given on Days 1-12. Decitabine 20 mg/m2 IV was given on Days 3-12. Following this, maintenance cycles consisted of 6TG on Days 1-7 and decitabine on Days 3-7 at the same doses. Treatment was continued until the time of hematopoietic stem cell transplant (HSCT), disease progression, or toxicity. The primary objective of this retrospective analysis was to determine the ORR. Secondary objectives were to evaluate PFS and overall survival (OS) in this population. RESULTS: Forty-two patients were identified, 55% of whom were female, with a median age of 68 years (range, 23-83 years). Thirty-three percent of the patients had secondary AML; 62% had R/R AML; 2% had R/R MDS; and 2% had chronic myelomonocytic leukemia. By ELN genetic risk stratification, 38% were adverse-risk, 43% were intermediate, and 17% were favorable, while 2% were unknown. However, 36 (86%) patients failed prior therapy, suggesting that nearly all of the treated patients were poor-risk. Nineteen (45%) patients had received prior HMA therapy, and 6 (14%) had undergone previous HSCT. Patients received a median of 2 cycles of therapy (range, 1-10). Five (12%) patients achieved complete remission (CR), 7 (16%) obtained a CR with incomplete count recovery (CRi/p), and 2 (5%) had morphologic leukemia-free state (MLFS), for an ORR of 33% (CR+CRi/p+MLFS). One notable patient who achieved CR was a 73-year-old with secondary AML, complex cytogenetics, and a TP53 mutation who subsequently went on to HSCT. Another 5 (36%) responders had complex karyotypes or poor-risk genetics. Ten of the 14 responders (71%) failed prior therapy. Of the 19 who had received prior HMA therapy, 6 (32%) responded. Six of 14 (43%) responders proceeded to HSCT. Two additional patients had significant blast reduction and underwent HSCT. Responses and maximum blast reduction were obtained after two cycles of therapy. For the responders, the median PFS was 38 weeks (range, 11-not reached), while the median OS was 43 weeks (range, 11-not reached). CONCLUSIONS: Combined 6TG and decitabine is a highly active regimen in advanced myeloid malignancies, with an ORR of 33% in this cohort, and median PFS and OS of 38 and 43 weeks, respectively, in responding patients. This compares favorably to the expected response rate of 10-20% with decitabine monotherapy in this poor-risk population consisting of mostly secondary and R/R AML. These data also confirm our prior phase I study findings that the addition of 6TG to decitabine can overcome prior HMA resistance, with 32% of those who had previously failed HMA therapy responding. This combination remains a viable therapeutic option for elderly and unfit patients with high-risk and R/R AML who cannot tolerate intensive chemotherapy. Disclosures Heaney: BMS: Research Funding; Partner Therapeutics: Consultancy; Roche: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Celgene: Research Funding; Novartis: Consultancy; AbbVie: Consultancy; Deciphera: Research Funding; Constellation: Research Funding; Blueprint: Research Funding; CTI: Research Funding. Lamanna:Ming: Research Funding; Celgene: Consultancy; Oncternal: Research Funding; TG Therapeutics: Research Funding; Infinity/ Verastem: Research Funding. Jurcic:Syros Pharmaceuticals: Research Funding; Astellas: Research Funding; AbbVie Inc: Consultancy; Daiichi Sankyo: Research Funding; Celgene: Consultancy, Research Funding; Incyte: Consultancy; Kura Oncology: Research Funding; Forma Therapeutics: Research Funding; Genentech: Research Funding; Novartis: Consultancy; Actinium Pharmaceuticals: Research Funding. Frattini:Celgene: Employment, Equity Ownership; Lin Bioscience: Consultancy. Lee:Abbvie: Research Funding; Roche: Research Funding; Tolero: Research Funding; Forty Seven, Inc.: Research Funding; Bayer: Research Funding.

Description: Background Protein arginine methyltransferase 5 (PRMT5) is the primary enzyme responsible for symmetric arginine dimethylation of multiple proteins that impact cell proliferation. Its substrates include proteins involved in mRNA splicing, signal transduction, gene transcription, and DNA repair. PRMT5 overexpression occurs in many cancers and correlates with poor prognosis. GSK3326595 is a potent, specific, and reversible inhibitor of PRMT5 that inhibits proliferation and induces cell death in a broad range of solid and hematologic tumor cell lines. It also exhibits potent anti-tumor activity in vivo in animal models, including in preclinical models of myeloid malignancies. One mechanism of action of GSK3326595 is via inhibition of cellular mRNA splicing and upregulation of tumor suppressor function. Mutations in splicing factors are frequent in myeloid malignancies (including approximately 40% of patients with myelodysplastic syndrome [MDS], and over 60% of patients with chronic myelomonocytic leukemia [CMML]), and further inhibition of mRNA splicing via GSK3326595 may lead to a synthetic lethal phenotype specifically in splicing mutant disease. Study 208809 is the first trial of a PRMT5 inhibitor in participants with myeloid malignancies. Methods Study 208809 is a Phase I/II study to evaluate the safety, tolerability, and clinical activity of GSK3326595 monotherapy in participants with relapsed and refractory MDS, CMML, and hypoproliferative acute myeloid leukemia (AML) that has evolved from an antecedent MDS. Part 1 will identify a tolerated dose and establish preliminary evidence of efficacy in this population. At the end of Part 1, if pre-specified criteria are met, then the study will be expanded with three additional Parts that will be opened in parallel. Part 2A is a Phase II randomized comparison of monotherapy GSK3326595 versus investigator's choice of best available care in participants with relapsed and refractory MDS, CMML, and hypoproliferative AML. Part 2B is a single-arm investigation of safety and efficacy of GSK3326595 plus 5-azacitidine in participants with newly diagnosed high-risk MDS. Part 2C is a single-arm investigation of the safety and efficacy of monotherapy GSK3326595 in participants with relapsed or refractory AML whose tumors harbor mutations in components of the pre-mRNA splicing machinery. All participants enrolled in this study have a diagnosis of MDS, CMML, or AML, with enrollment into each cohort as defined above. Participants are adults with adequate organ function as defined in the protocol. Prior allogeneic transplant is permitted. There are no required biomarkers for enrollment to Parts 1, 2A, and 2B, though central confirmation of pre-mRNA splicing factor mutations will be performed to stratify participants for overall analysis. Enrollment to Part 2C is limited to participants with splicing factor mutations. It is estimated that a maximum of 302 participants will be enrolled in the study, divided as follows: Approximately 41 participants in Part 1, approximately 192 participants in Part 2A, approximately 41 participants in Part 2B, and approximately 28 participants in Part 2C. In Part 1, the primary endpoint is clinical benefit rate, as defined as the percentage of participants achieving a complete remission, complete marrow remission, partial remission (PR), stable disease lasting at least 8 weeks, or hematologic improvement, as per standard criteria. In Part 2A, the primary endpoint is overall survival. In Part 2B and Part 2C, the primary endpoint is overall response rate (ORR), defined as the percentage of participants achieving a PR or better. Samples are collected to evaluate symmetric dimethylated arginine (SDMA), the enzymatic product of PRMT5. This has been demonstrated to be a pharmacodynamic marker of PRMT5 inhibition in plasma and tumor tissue. In addition, participants will be stratified based on the presence or absence of spliceosome mutations and analyzed separately to evaluate the effect of these mutations on clinical activity. As of 1 August 2019, recruitment is ongoing across six centers in the United States and Canada; ten participants have been enrolled, all into Part 1. ClinicalTrials.gov identifier: NCT03614728 Study is funded by GlaxoSmithKline Disclosures Watts: Takeda: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Bradley:AbbVie: Other: Advisory Board. Brunner:Novartis: Research Funding; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Forty Seven Inc: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Minden:Trillium Therapetuics: Other: licensing agreement. Papadantonakis:Agios: Consultancy, Honoraria. Abedin:Actinium Pharmaceuticals: Research Funding; Pfizer Inc: Research Funding; Helsinn Healthcare: Research Funding; Agios: Honoraria; Jazz Pharmaceuticals: Honoraria. Baines:GlaxoSmithKline: Employment, Equity Ownership. Barbash:GlaxoSmithKline: Employment, Equity Ownership, Patents & Royalties, Research Funding. Gorman:GlaxoSmithKline: Employment, Equity Ownership. Kremer:GlaxoSmithKline: Employment, Equity Ownership. Borthakur:Cantargia AB: Research Funding; Eisai: Research Funding; Tetralogic Pharmaceuticals: Research Funding; Argenx: Membership on an entity's Board of Directors or advisory committees; FTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; BioTheryX: Membership on an entity's Board of Directors or advisory committees; Xbiotech USA: Research Funding; Novartis: Research Funding; Oncoceutics: Research Funding; Oncoceutics, Inc.: Research Funding; PTC Therapeutics: Consultancy; BioLine Rx: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agensys: Research Funding; AstraZeneca: Research Funding; Bayer Healthcare AG: Research Funding; BMS: Research Funding; Eli Lilly and Co.: Research Funding; NKarta: Consultancy; Cyclacel: Research Funding; GSK: Research Funding; Janssen: Research Funding; Incyte: Research Funding; AbbVie: Research Funding; Merck: Research Funding; Arvinas: Research Funding; Polaris: Research Funding; Strategia Therapeutics: Research Funding.

Description: Among transplant related complications, graft versus host disease (GvHD) significantly affects survival among patients undergoing allogeneic hematopoietic stem cell transplantation (aHSCT). There is limited data on GvHD and its impact on outcomes of aHSCT in patients with thalassemia major (TM). We have reviewed the incidence and outcome of GVHD among patients with TM who underwent aHSCT at our center. All patients with TM undergoing their first aHSCT between January 2007 and December 2017 were included in this analysis. Till 2009, all patients received conditioning with busulfan (16mg/kg over 4 days) with cyclophosphamide (200mg/kg over 4 days). From 2010, most patients received treosulfan (42 G/m2 over 3 days) with thiotepa (8mg/Kg for one day) and fludarabine (160mg/m2over 4 days) based conditioning regimen. All patients receiving busulfan conditioning received bone marrow (BM) as the graft while most patients receiving treosulfan conditioning received mobilized peripheral blood stem cells (PBSC). GvHD prophylaxis was with short-course methotrexate (10mg/m2 on day +1, and 7mg/m2 on days 3, 6 and 11) with cyclosporine. Thymoglobulin was added for matched unrelated donors (MUD). GvHD was prospectively recorded and graded according to the Glucksberg classification. Between January 2007 and December 2017, 363 first transplants were done for patients with TM with HLA identical donors. There were 12(3.3%) class 1, 105(28.9%) class 2 and 246(67.8%) class 3 (Pesaro risk stratification), with 115(46.7%) of the latter being high risk (Vellore risk stratification - BBMT, 2007; 13: 889). The median age was 8 years (range: 1-25) with a male predominance (60%). 331 (91.2%) patients had matched related donors (MRD) and 32 (8.8%) had MUDs. Donor gender was mismatched in 207 (57%) of which 129 (35.5%) were female to male transplants. The graft was obtained from the bone marrow in 137 (37.7%) of whom 53 (38.7%) were class III, and from mobilized peripheral blood in 226 (62.3%) of whom 193 (85.4% were class III. 149 (41%) patients developed GvHD - acute GvHD (aGvHD) in 115 (31.7%) and chronic GvHD (cGvHD) in 80 (22%). aGvHD was grade I in 32 patients (27.8%), grade II in 36patients (31.3%), grade III in 16 patients (13.9%) and grade IV in 25 patients (21.7%), while 6 patients (5.2%) had features of overlap GvHD only (oral lichen planus). First line treatment was with steroids in all patients with grade II and above aGvHD (n=83) with 43 (51.8%) of them responding adequately. There were 37 patients (44.5%) who required various second line agents for aGvHD with 20 (24%) receiving more than one immunosuppressive agent. 20 patients (24%) with persistent aGvHD went on to develop cGvHD. Out of the total of 80 patients with cGvHD, 13 (16.3%) had limited and 67 (83.7%) had extensive cGvHD. 26 patients (32.5%) developed de novo cGvHD, 8 (10%) of them after donor lymphocyte infusion (DLI) for potential rejection. The other 46 patients (57.5%) had chronic overlap GvHD following previous aGvHD. Among the different variables evaluated for association with aGvHD (patient/donor age, gender mismatch, MUD vs MRD), none were significant. Among those with MRD, aGVHd occurred in 36/135 patients (26.7%) of patients receiving BM grafts compared to 65/196 patients (33.2%) who received PBSC grafts (p=ns). cGvHD occurred in 23/106 patients (21.7%) in those receiving BM grafts vs 52/171 patients (30.4%) receiving PBSC (p=ns). 30 patients (8.3%) persisted to have cGvHD at last follow-up but only 20 (5.2%) required treatment. Mortality of the whole cohort was 66 (18.2%), out of which 32 (8.8%) were related to GvHD - 24 (6.6%) due to aGvHD and 8 (2.2%) due to cGvHD. At a median follow up of 41 months (range: 0-148), the 5-year and 10-year overall survival (OS) was 81.1±2.1% each for the whole cohort. The 5-year OS of those with grade 2-4 aGvHD was significantly lower than those with grade 0/1 aGvHD (65.7±5.3% vs 85.7±2.2%, p=0.000) [figure 1]. The 5 year OS of those with cGvHD was 88.9% ± 3.8% as compared to those without cGVHD was 96.9% ± 1.2% (P=0.009) [figure 2]. There was no significant difference in OS among those with limited and extensive cGvHD (90.9±3.6% vs 88.4±4.2% (p=ns). Our data shows that, as expected, severe aGvHD and extensive cGvHD significantly lowers survival in patients with TM undergoing aHSCT. However, PBSC graft did not result in higher acute or chronic GVHD compared to BM. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: ALK+ anaplastic large cell lymphoma (ALCL) frequently carries the t(2;5) resulting in overexpression of NPM-ALK oncoprotein, which activates many oncogenic pathways. The Jab1 (c-Jun activation domain-binding protein-1), initially discovered as a c-Jun co-activator, represents the fifth component of an evolutionary highly conserved 8-subunit protein complex, named COP9 signalosome (CSN). The Jab1/Csn5 gene operates as an oncogene in cancer through multiple mechanisms including cell cycle control via the CDK inhibitor p27. Recent evidence suggests that Jab1/Csn5 is also involved in immune checkpoint regulation through PD-L1 stabilization by inhibition of PD-L1 proteasomal degradation. Recently, we reported that the protein levels of Jab1/Csn5 are the highest in ALCL as compared to other peripheral T-cell lymphomas (PTCL) and significantly correlate with PD-L1 levels in PTCLs (Drakos et al, HemaSphere 2019; (3):p596, EHA abstract). In this study, we hypothesized that NPM-ALK may regulate Jab1/Csn5 expression and thus contributes to cell proliferation as well as PD-L1/PD1 immune checkpoint regulation. Methods: The in vitro system included 4 ALK+ (Karpas 299, DEL, SUPM2, SUDHL1) and 2 ALK- (Mac1, Mac2a) ALCL cell lines as well as murine Ba/F3 parental and Ba/F3 clones stably transfected with NPM-ALK (Ba/F3-NPM-ALK), EEF1G (Ba/F3-EEF1G-ALK) or control plasmid (Ba/F3-MIG). Transient transfections with Jab1/CSN si-RNAs and STAT3 si-RNAs were also performed in ALCL cells. In addition, ALCL cells were treated with ALK (Crizotonib) or STAT3 (XIII) inhibitors. Two animal models were used in the study: 1) in the ex vivo model, Karpas-299 clones stably transfected with Jab1/CSN5 shRNA constructs were generated and injected in both thighs of SCID-beige immunocompromised mice. The Jab1/CSN5 shRNA and the control mice were followed for tumor development and their tumors were measured and analysed by immunohistochemistry. 2) in the patient derived xenograft (PDX) model of ALK+ ALCL, the mice were treated with the ALK inhibitor Ceritinib or control vehicle and were monitored for changes in tumor characteristics over two weeks. Tumor specimens were taken at early time points (24, 48, and 72 hrs) following treatment in order to obtain viable tumor cells for protein analysis. Results: Jab1/Csn5 was substantially upregulated in the Ba/F3-NPM-ALK and Ba/F3-EEF1G-ALK stable clones as compared to paternal or control Ba/F3-MIG clones. Jab1/Csn5 upregulation was associated with high STAT3 activation (Tyr705-phosphorylation) and increased PD-L1 gene expression in this system. Inversely, inhibition of ALK activity was associated with STAT3 de-activation and decreased protein levels of Jab1/Csn5 and PD-L1 in ALK+ ALCL cells. Knocking down STAT3 by siRNA or inhibition of its activity by the XIII inhibitor resulted in decreased levels of Jab1/Csn5 protein in both ALK+ and ALK- ALCL cell lines. The SCID-beige mice that received Jab1/CSN5-shRNA clones showed significant delay in tumor development and longer survival as compared to control mice, which was associated with significantly decreased PD-L1 protein levels and p27 upregulation in the tumor cells (xenografts). Treatment of the PDX mice with Ceritinib, a potent next generation ALK inhibitor, resulted in substantial tumor necrosis after 72 hrs and decreased tumor size at day 7 post-treatment. At earlier time points, de-activation (de-phosphorylation) of ALK kinase and STAT3 was observed in the Ceritinib-treated mice, which was linked to variably lower levels of Jab1/CSN5 and PD-L1 proteins as compared to control mice. Conclusion: Jab1/CSN5 is a novel downstream target of the NPM-ALK oncogenic kinase that regulates its expression, at least in part, through STAT3 activation. The Jab1/CSN5-mediated stabilization of PD-L1 can be efficiently inhibited by Ceritinib in preclinical animal models of ALK+ ALCL. Disclosures Österborg: BeiGene: Research Funding; Janssen: Research Funding; Abbvie: Research Funding; Kancera AB: Research Funding; Gilead: Research Funding. Vega:National Cancer Institute, national Institutes of Health: Other: Grant Funding-R01CA222918.

Description: Introduction Previous research from the Europe and Canada has identified several areas of unmet clinical and support need for cancer patients diagnosed with venous thromboembolism (VTE). It is not known whether such experiences are restricted to those particular countries healthcare systems and/ or cultures. We sought to evaluate patients' experience of cancer-associated thrombosis (CAT) within France. Methods Purposive sampling of twenty three patients with CAT were recruited from a thrombosis service in a general hospital in Colombes, France, Semi structured interviews were audio recorded and transcribed. Transcripts were coded using Invivo software. Analysis was undertaken using an applied framework matrix with an inductive approach to identify any new themes. This was in order to explicate potential cultural and operational differences that were not apparent in the previous datasets. Results Twenty three patients (11 male, 13 female) aged 51-83 (mean 69) participated. The main commonality observed between French patients and those interviewed in the United Kingdom, Spain and Canada was the lack of information regarding the risks of CAT or signs and symptoms, which would necessitate medical attention. In addition patients reported a similar lack of verbal and written information regarding treatment choices and how to administer low molecular weight heparin (LMWH). However, French patients were not concerned by this since they perceived the doctor knew best and did not see information giving as a necessary aspect of their healthcare. They adopted a passive unquestioning role whereby the doctor was always right. This lack of desire to understand about their condition and in particular CAT, resulted in two major themes which are , thus far, have only been observed in this cohort of patients. 1. Lack of understanding and desire to know about CAT meant that patients knew less about their condition than other patients. Whereas patients from other countries were significantly distressed by knowing the potentially fatal nature of CAT, French patients were not distressed by their diagnosis, its implications on their cancer journey or the future. 2. Patients did not appreciate the utility of shared decision making and relied on the doctor to decide on the drug of choice. They did not wish to understand the rationale for this and thereby did not view the LMWH as a necessary inconvenience. Consequently they were very resistant to LMWH. Conclusion The dynamics of the doctor patient relationship in French patients differed from other countries, with patients adopting a passive role with respect to information requirements and their role in shared decision making. This dynamic appears to be a "two edged sword" whereby distress around CAT was minimal, in contrast to all other countries interviewed, yet a lack of knowledge impacted on acceptability of LMWH patient groups. This data has implications for the choice of anticoagulant in the treatment of CAT, particularly now that several DOACS have been evaluated for this indication. Disclosures Mahe: Leo Pharma: Research Funding, Speakers Bureau; BMS: Research Funding, Speakers Bureau; Bayer: Speakers Bureau; Pfizer: Speakers Bureau. Noble:Leo Pharma: Research Funding; Daiichi Sankyo: Speakers Bureau; Bayer: Speakers Bureau; Pfizer: Speakers Bureau.

Description: Introduction A novel approach that can cover the therapeutic gap in NHL treatment are the autologous T cells, expressing Chimeric Antigen Receptors (CAR-T cells) against tumor markers. Such clinical-grade products based on Lenti (LV) or Retro- vectors have hit the market. An alternative vector system for CAR gene transfer in T-cells are Foamy Viruses (FV). To evaluate the potential of FV vectors in CAR-T cell development, we synthesized an antiCD19 scFv cDNA and cloned it in both an FV and an LV backbone; both vectors were tested in paired experiments Material and Methods The anti-CD19 CAR was under the control of the EF1a promoter; EGFP expression was under the control of an IRES2 element. The anti-CD19 CAR sequence was deduced from published data. FV vectors were made with a 4-plasmid vector system in 293T cells. 2nd generation LV vectors were purchased from Addgene. Cord blood (CB), healthy donor peripheral blood (PB) and CLL patients' PB was used as a source for CD3+ cells using immunomagnetic enrichment. Informed consent has been obtained in all cases of human sample use. T cells were activated by antiCD3/CD28 beads and transduced with antiCD19 LV or FV vectors. Transduction efficiency was assayed by flow cytometry (FCM) using a PE-conjugated anti-mouse Fab antibody. FV and LV CAR-T cells were expanded with Rapid Expansion Protocol (REP) and their cytotoxicity assays was evaluated against the CD19+ cell lines Raji and Daudi. The CLL patient derived CAR-Ts were evaluated against autologous B cells. Cytotoxicity was evaluated with an FCM protocol using CFSE-stained target cells vs unstained effector CARTs in different ratios. At the end of the incubation cells were stained with 7AAD to discriminate against live/dead cells. CAR-T cell activation was also assayed by INF-γ ELISA, following cocultures with target cells at a ratio of 1:1 for 24h. Results Vector titers: LV vector titers were between 3-5x10^5 TU/ml for both LV vectors (with or without EGFP cassette). FV vector titers were between 2-4x10^5 TU/ml regardless of the presence of the EGFP cassette. Tx efficiency: FV can mediate efficient gene transfer on T cells in the presence of heparin at an effective dose of 20-40 U/ml using a spinoculation technique. Transduction efficiency ranged from 40-65% at MOI=3-5, and was comparable to the transduction efficiency of LV vectors at a much higher MOI (10 to 30). Cytotoxicity data on lines: Following REP, the cell population consisted mostly (close to 96% purity) of CAR-T cells regardless of the vector used or of the T cell source. Effector cells were cocultured with the CD19+ cell lines, Daudi and Raji at varying ratios. With cord blood derived FV-CAR-T cells, at 4h post coculture we observed a 39.4% cell lysis at a ratio of 10:1 effector to target (n=1). Similar results were obtained for LV vectors. Peripheral blood derived CAR-T cells at THE same ratio (10:1), demonstrated 83.9% and 93.1% cell lysis for FV-CART and LV-CART cells respectively (n=2). Cytotoxicity data on CLL cells: T-cells from peripheral blood of CLL patients were used to generate LV- and FV-CAR-T cells. At the ratio of 10:1, we observed 73.1% and 69,8% cytotoxicity for FV-CAR-Ts and 70.1% and 70.7% with LV-CAR-Ts, in 2 independent paired experiments. IFN as activation marker: In two paired activation experiments, CB-derived FV-CAR-T cells secrete 560 and 437pg/ml of IFN-γ; similarly, LV-CAR-Ts secrete 534 and 554pg/ml IFN-γ. Untransduced control cells, produced 68pg/ml and 12pg/ml for FV-CAR-T and LV-CAR-T experimental arm respectively. Conclusion In the current work, we developed and tested FV vectors for anti- CD19 CAR-T cell production. We proved that FV viral vectors are capable of mediating efficient gene transfer to human T cells. We developed a method to efficiently transfer FV vectors into T-cells, using a clinically relevant protocol with heparin. The FV-derived CAR T cells demonstrate the same cytotoxic properties in vitro as their LV-derived counterpart and the same activation levels in the presence of CD19 expressing target cells as measured by IFN-γ secretion. FV CARTs derived from PB of CLL patients were capable of mediating comparable cytotoxicity levels as their LV-derived counterparts. Overall, we provide a proof of concept that FVs could be a safe and efficient alternative to LV derived vectors for CAR-T cells. Disclosures No relevant conflicts of interest to declare.

Description: Care of infants (

Description: Background Acute promyelocytic leukemia (APL) in the elderly has a favourable outcome in a significant proportion of patients (pts). Elderly and frail pts are usually treated with attenuated treatment schedules, mostly "according to medical judgment". The combination of all-trans retinoic (ATRA) and anthracycline-based chemotherapy (CT) has been the mainstay of treatment for many years. Alternative approaches, such as arsenic trioxide (ATO) and gentuzumab ozogamicin (GO) have recently been tested with success in this setting, even though no large series of elderly pts treated with CT-free first-line treatment have been published yet. Moreover, neither a "standard of care approach" nor a specific prognostic score system have been developed to guide physician in choosing the most adequate treatment schedule in this setting. Objective Aim of the present preliminary survey was to assess genetic and clinical features of APL in pts over 60 yrs. This cut off reflects the definition of "elderly patient" in most Italian APL GIMEMA trials. Moreover, both the real life outcome and safety data after either conventional anthracycline-based CT or alternative CT-free approaches were analysed. OS, response rate to either regimens and adverse event occurrence were collected. Methods This retrospective multicenter REL (Rete Ematologica Lombarda) survey, enrolled a total of 101 consecutive APL pts aged ≥60, treated between 2000-2018. Demographics, clinical data and therapy outcome data were recorded in a dedicated patient's report form. Statistical analysis was performed using the Kaplan Maier method, Log-rank test and Cox regression. Results For analysis, pts were grouped into different categories according to age and fitness. Tables 1 and 2 summarise clinical charcteristics and treatment administered. Performance status (PS) and number of comorbidities increase with age. Twentynine of 102 (28,4%) and 9/102 (8,8%) pts had a history of or subsequently developed a solid tumor respectively. High frequency of additive cytogenetic abnormalities was observed as well. CT+ATRA was preferentially administered, mostly with attenuated intensity, to younger pts with better PS, while ATO+ATRA was preferred in pts with reduced cardiac function and ATRA monotherapy was reserved to frail or over 80 yrs old pts. Rates of differentiation syndrome or infections or cardiac events were similar in the different treatment groups. Overall, complete remission (CR) rate after induction therapy was 94.16% [CI95%: 87,5%-97,8% ]. At a median follow-up of 40 mos (range 0-199), the overall relapse rate was 24%. Median time to relapse was 7 mos in 1/8 (12,5%) ATRA monotherapy treated pts and 13 mos (range 5-66) in the 23/68 (33,8%) pts receiving CT+ATRA. No relapse occurred among the 22 pts treated with ATO+ATRA (p 0.005). OS and EFS were significantly associated with pts' age (HR 9% and 7.6%; p

Description: Introduction Ibrutinib is an oral irreversible inhibitor of Bruton's tyrosine kinase for treatment of chronic lymphocytic leukemia (CLL). Ibrutinib has demonstrated superior efficacy for patients with TP53 aberration or relapsed/refractory (R/R) CLL; and more recently superior progression free survival (PFS) has been demonstrated compared to chemoimmunotherapy as first line therapy. However, knowledge about the outcomes and adverse events (AE) upon ibrutinib among patients at a population-based level are still limited. The aim of the here presented study is to explore outcomes of ibrutinib treatment in a population-based cohort of patients with CLL treated with ibrutinib in Denmark. Methods In this retrospective study, patients from 8 hospitals in Denmark, who were diagnosed with CLL and treated with ibrutinib from April 2014 until February 2019 were included. Medical records were retrospectively reviewed to obtain information. Patients receiving ibrutinib within clinical trials were excluded. Overall survival (OS) was defined as time from ibrutinib start to death from any cause while PFS was defined as time from ibrutinib start to progression or death from any cause. PFS and OS were analyzed with the Kaplan-Meier method while cumulative incidence was calculated with the Aalen-Johansen estimator. Results In total, 205 patients with CLL receiving ibrutinib treatment were identified from hospital records and registries. The median follow-up was 21.4 months (IQR, 11.9-32.8) and the median time on ibrutinib was 16.8 months (IQR, 6.0-28.1). The median age at treatment initiation was 72.8 years (IQR, 65.7-77.8), 128 (62.4%) were male, and 111 (63.4%) were Binet stage B/C at treatment initiation out of 175 with available information regarding clinical stage. Thirty-nine (19.0%) received ibrutinib as first-line, and 166 for R/R CLL with a median of 2 (range, 1-8) prior treatment regimens. Information on TP53 aberration was available for 149 and regarding IGHV mutation for 147 patients, 111 (74.5%) had TP53 aberration and 107 (72.8%) were IGHV unmutated. Eighty-six patients (42.0%) discontinued ibrutinib during follow-up with a median time until discontinuation of 9.3 months (IQR, 3.0-23.2). Forty-seven (54.7%) discontinued due to AEs, 19 (22.1%) due to progression (12 had progression of CLL and 7 had Richter's transformation) while the remaining 20 (23.2%) discontinued due to other reasons. The estimated cumulative incidence of discontinuation at 12 months was 24.8% (95% CI: 18.6-30.9). The estimated OS after 12 and 24 months was 88.8% (95%CI: 84.3-93.3) and 76.8% (95%CI: 70.4-83.2) and the estimated PFS after 12 and 24 months was 87.3% (95%CI: 82.5-92.1) and 72.4% (95%CI: 65.5-79.2). One hundred and eighty-eight (91.7%) experienced at least one AE, among these 45 (23.9%) experienced a grade 3+. The most common AEs were hemorrhage (tendency to bruise, epistaxis etc.) which occurred in 86 (42.0%) of all and musculoskeletal and connective tissue disorders (arthralgia, myalgia etc.) which occurred in 82 (40.0%). Thirty-one (15.1%) patients experienced atrial fibrillation while on ibrutinib and 14 (6.8%) developed hypertension. One hundred and thirty-seven patients (66.8%) had at least one infection and among these 80 (58.4%) were hospitalized with an infection. The most common infections were lower respiratory tract infections and urinary tract infections that occurred for 88 (42.9%) and 41 (20.0%). The estimated cumulative incidence for any infection was 58.9% (95%CI: 52.0-65.9) at 12 months. Conclusion This is the first study describing outcomes for a population-based cohort of CLL patients treated with ibrutinib in Denmark. Real-world studies are warranted, to confirm the results from clinical trials. In this study, patients appear to have comparable OS and types of AE compared with the RESONATE trial. Differences in frequency of AEs compared to the clinical trial may reflect the focus of clinicians in routine practice. Discontinuation in this cohort was higher compared to clinical trials but comparable to previously reported real-world studies. While ibrutinib can be safely managed in routine clinical practice, this study demonstrates that a quarter of patients discontinue treatment due to mainly AEs. Further patient training and information, and in some instances personalized treatment with other targeted agents based on adverse event profile, may improve treatment adherence. Disclosures Aarup: Research Committee, Rigshospitalet: Research Funding. Enggaard:Abbie: Other: Advisory board; Gilead: Other: Advisory board; Janssen: Other: Advisory board. Frederiksen:Gilead: Research Funding; Abbvie: Research Funding; Janssen Pharmaceuticals: Research Funding; Novartis: Research Funding; Alexion: Research Funding. Niemann:Novo Nordisk Foundation: Research Funding; AstraZeneca: Consultancy, Other: Travel Grant, Research Funding; Sunesis: Consultancy; Acerta: Consultancy; CSL Behring: Consultancy; Roche: Other: Travel Grant; Janssen: Consultancy, Other: Travel Grant, Research Funding; Gilead: Other: Travel Grant; Abbvie: Consultancy, Other: Travel Grant, Research Funding.

Description: Special thanks to Marcella Origgi, Selene Vasco & Andrea Emancipato from Janssen Cilag S.p.a. Introduction: Onco-hematological diseases are ones of the most widespread worldwide types of cancer. Affected people usually manifest different forms of distress, such as the physical, psychological, spiritual and existential ones. So, a strategic way to fully take care onco-hematological patients is to identify their unmet needs in all their quality of life dimensions and to target them with adequate interventions. In the last years, Internet has represented a revolution respect to health because it has become the principal tool used by patients to research information. Furthermore, through the Social Network, it represents a powerful communication tool, through which users can interact each other. Being online on Facebook patients can play an active role in their care process, researching information, sharing own needs, and interacting each other. Especially in the oncological field, E-health represents an opportunity for patients to narrate their illness stories and experiences in a virtual context of emotional acceptance and sharing. At the same time, E-health could be used as a precious instrument to target a wide range of patients' unmet needs and improving the quality of their care and life. Objective: To analyze the contents of a social network page dedicated to the onco-hematological diseases, developed by Insight Generation Project, and its users' utilization, in order to evaluate their unmet needs and approach to the page. Materials and Methods: The page contents, such as users' responses to the posts published on the page, were analyzed. Contents of the page, from its opening in January 2016 to June 2019, were considered. Descriptive statistics and content analysis were performed. Users' comments were clustered and categorical variables were created, according to the emerging themes. Statistical analysis was executed with software SPSS Statistics Version 24.0. Results: A total of 348 comments to posts were analyzed. 117 users were identified as patients, who were most affected by multiple myeloma and acute myeloid leukemia in acute phase. Seventy-two users were caregivers, and 43 of them were caregivers of deceased patients. The most emergent unmet needs were relational (n=234), psychological (n=232) and informative/communicative (n=113). The most affected quality of life spheres were the psychological (n=237), the relational (n=228) and the physical one (n=100). Users expressed most angry, sadness and concern. They tended to address most other users with motivational messages of support, encouragement and relief. So, most were comments of sharing and support, while others were informative/communicative. The most required information regarded the course of the disease, the treatments and the lifestyles. Posts most liked, shared and commented were on chronic lymphatic leukemia, on acute myeloid leukemia, on hematological cancer diagnosis and therapies, but also on patients needs and on the management of negative emotions. Conclusions: The social network page represents a virtual place for sharing experiences, emotions and psychological suffering, creating interpersonal relationships and group interchanges and providing reciprocal emotive support in a commonality context. Respect to palliative care, it could be also a useful resource for bereaved caregivers. Moreover, users benefited from the page to obtain medical/assistance information, playing an active role in their care process. So, the page resulted a powerful communicative tool offering opportunities of learning, interaction, and sharing of experiences and feelings. It well represents the E-health contribute to patients with life-threatening diseases and their caregivers. Finally, the analysis of the contents of virtual communities could contribute to the process of care through targeting patients' unmet needs and satisfying them with the promotion of adequate interventions. Disclosures Vitolo: Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: In mammals, either enhancer of zeste homologue 2 (EZH2) or its homolog EZH1 functions as the catalytic subunit of polycomb repressive complex 2 (PRC2), and plays an essential role for the maintenance of transcriptional repression by the trimethylation of histone H3 lysine 27 (H3K27me3). Hyperinduction of H3K27me3 mediated by EZH2 overexpression or EZH2 gain-of-function (GOF) mutation (e.g. Y641, A677 and A687) has been associated with lymphoma and myeloma progression. Many publications suggest that suppressing PRC2 activity by EZH2 inhibition is a potential therapeutic target for hematological malignancies. Up to date, there are known a few EZH2 selective inhibitors with showing anti-tumor activity in some preclinical and clinical studies. However, the inhibition of EZH2 can complementarily induce EZH1 activation, which reactivates PRC2 function in turn. Therefore, dual inhibition of EZH1 and EZH2 could give more effective than EZH2 inhibition alone in blocking PRC2 function as an anti-cancer therapy. Herein, we introduce a novel EZH1/2 dual inhibitor, HM97594, which simultaneously inhibits the methyltransferase activity of wild-type EZH1 as well as wild-type and GOF mutant EZH2 at nanomolar concentrations. HM97594 potently repressed trimethylation of H3K27 in lymphoma and myeloma cell lines. As a result, HM97594 showed broader and stronger activities than EZH2 selective inhibitors in in vitro studies of inhibiting the proliferation of various hematological cancer cell lines. HM97594 induced the differentiation of DLBCL to plasma cells with an increment of cell lineage specific markers (e.g. PRDM1, IRF4 and CD38) and decreased the colony forming ability. Also, HM97594 caused cell cycle G0/1 arrest and apoptosis in KARPAS-422 cells harboring EZH2 Y641 GOF mutation. In addition, HM97594 showed potent antitumor activity in KARPAS-422 lymphoma cell xenograft mouse model. Once daily orally administered HM97594 greatly inhibited tumor growth in a dose-dependent manner without body weight loss compared to the known EZH2 inhibitor. Collectively, it was demonstrated in the present studies that HM97594, EZH1/2 dual inhibitor, has promising potential as an anticancer drug for patients with subtypes of hematological malignancies. Further preclinical studies will be performed and reported soon after the establishment of a preclinical candidate. Disclosures No relevant conflicts of interest to declare.

Description: The introduction of disease specific therapy for patients with type 1 Gaucher disease (GD) was a revolution in the management of patients, but not without significant cost to the patient and to society. The management of mildly effected patients is still debated, and reviews about GD as well as chapters in textbooks fail to emphasize the fact that some patients may remain untreated for many years without any GD-related complications. Patient reported outcome measures (PROMs) were developed as a way to ascertain patients' views of their symptoms, their functional status, and their health-related quality-of-life (HRQoL). In this study, we evaluated the responses to a GD -specific PROM of untreated patients with GD1 and compared them to patients on GD-specific therapy. Methods: A PROM survey was developed for GD including 15 questions; six Point Verbal Response Scale regarding the last month and nine Visual Analogue Scales (VAS) from 0-10 regarding the last week (Elstein D, et al. Molecular Genetics and Metabolism 2019;126:S52). The PROM survey was proven to be accurate in encompassing disease-specific patient concerns. A Hebrew translated version of the GD-PROM was sent via mobile phone survey to 400 adult patients with type 1 GD followed in our Gaucher Unit. Clinical data and treatment status were extracted from the clinical charts. T-test and Mann-Whitney U test were used to compare normally and non-normally distributed data in independent samples, respectively. IBM SPSS version 25 was used for analysis. Results were considered to be statistically significant when two-tailed P-values were ≤0.01. Results: A total of 181 patients responded (45% response rate) of whom 65 (36%) were followed for at least 5 years in our unit without receiving GD specific therapy, i.e. enzyme replacement therapy (ERT) and/or substrate reduction therapy (SRT). The median (range) age of patients, 49 (20-91) years, was not significantly different between treated and untreated patients. The percentage of patients with the N370S/N370S genotype was significantly higher in untreated patients [55/65 (85%)] compared to treated patients [67/116 (57%)]. Significantly more treated patients reported that GD had restricted their education/job (38, 34%) and fun activities (29,25%) compared to untreated patients, (4, 6.5%) and (2, 3%), respectively. Compared to untreated patients, treated patients were more worried to be an emotional burden on others [27 (23%) vs. 3 (5%)], of being financial burden on others [57 (50%) vs. 16 (25%)] and more concerned regarding the risk of bone disease [82 (74%) vs. 26 (40%)], and the risk of Parkinson disease [72 (64%) vs. 27 (42%)]. Treated patients had a significantly higher score on VAS for questions on swollen abdomen, fatigue, physical weakness, severity of bone pain and worry regarding the future over the past week compared to untreated patients (Table 1). Patients concern regarding the risk for cancer (32%) and VAS score for a question on depression were similar between groups. Conclusion:The GD-specific PROM survey shows that asymptomatic or mildly affected untreated patients with GD1 have good functional status and HRQoL, supporting our practice that not all patients with GD1 require disease-specific therapy. Still, we advise a periodic (annual or bi-annual) follow-up, preferably at a referral center. Inclusion of GD-specific PROMs in the periodic assessments is important for better understanding patients' perspectives. It is important to note that mildly affected and asymptomatic patients are mainly found among Ashkenazi Jews and from this aspect our cohort reflects patients' populations in Israel, USA, UK, etc. but less relevant to non-Jewish and particularly to Asian cohorts. With the expected increase in early diagnosis via parental and/or newborn screening the understanding that not all subjects diagnosed with GD needs disease-specific therapy is all the more important. Despite the expected differences between the more severely affected treated patients and the by definition milder untreated ones, still a high percentage of the treated patients show good HRQoL parameters, reflecting the overall success of ERT/SRT. Larger cohorts and further analysis will evaluate potential predictors for differences in PROMs within the treatment group. Disclosures Revel-Vilk: Sanofi: Honoraria, Other: Travel, Research Funding; Pfizer: Honoraria, Other: Travel, Research Funding; Takeda: Honoraria, Other: Travel, Research Funding; Prevail therapeutics: Honoraria, Other: Travel, Research Funding. Zimran:Prevail Therapeutics: Consultancy; TAKEDA: Honoraria; Centogene: Other: research grant; Targeted Cell Therapies: Consultancy; Pfize: Honoraria, Research Funding; Shire: Consultancy, Honoraria, Research Funding; Bio-events: Honoraria.

Description: Hematopoiesis, especially the early events of blood cell formation, has been mainly studied in bulk populations of cells and using progenitor colony formation assays; the familiar hierarchy of cell lineage differentiation and maturation, and associated regulatory factors have been inferred from these methods. However, these techniques often require extensive manipulation of cells, the exposure of cells to unphysiological conditions, aggregation of heterogeneous populations, and prior assumptions concerning cell function and gene expression. New single cell methodology avoids many of these potential experimental deficiencies. Here we have applied single-cell RNA-sequencing(scRNA-seq)to fresh human bone marrow CD34+cells: we profiled 391 single hematopoietic stem/progenitor cells (HSPCs) from four healthy donors by deep sequencing of individual cell transcriptomes. An average of 4560 protein-coding genes were detected per cell. Cells clustered into six distinct groups, which could be assigned to known HSPC subpopulations (Fig 1A), based on expression of lineage-specific genes. Lin-CD34+CD38+cells emerged as locally clustered cell populations (Clusters 2-6, including MEP, GMP, ETP and ProB), while Lin-CD34+CD38-cells formed a single cluster (HSC/MLP). Reconstruction of differentiation trajectories by transcription in single cells revealed four committed lineages derived from stem cell compartment. The earliest fate split separates MEPs from MLPs, which partition further into lymphoid, and granulocyte-monocyte progenitors (Fig 1B). The overall pattern differs from the classical hematopoietic model describing a single binary split between myeloid and lymphoid differentiation immediately downstream of multipotent cells. However, our data align well to recently published scRNA-seq data showing sequential commitment of stem cells to the lymphoid, erythroid/megakaryocytic, and finally myeloid lineages (Setty M, Nat Biotechnol2019; Pellin D, Nat Commun2019). We further examined trends in gene expression in each of the branches and found dynamic expression changes underlying cell fate during early lineage differentiation (Fig 1C). As confirmation, PCA plot of published single-cell assay for transposase-accessible chromatin (scATAC-seq) shows similar differentiation pattern. After projecting scATAC-seq data to our transcriptomic clusters' specific genes, MEP-dependent and myeloid/lymphoid-dependent genes were located on opposing sides of the PC1 with same direction (Fig 1D), indicating transcriptome and epigenome work on differentiation in concerted effort. scRNA-seq provides opportunities for discovery and characterization at the molecular levels of early HSC differentiation and developmental intermediates, retrospectively, without the need to isolate purified populations. However, information inferred from scRNA-seq may be obscured due to missing reads and limited cell numbers. More cells would provide greater detail and higher resolution mapping.Given the low frequency of megakaryocyte progenitors within the CD34+cells as well as the neglected Lin-CD34-BM compartment, we could not fully resolve the separation and maturation of all lineages. Nonetheless, we found good coverage of cell types and a similar HSPC Atlas as other published studies (Velten L, Nat Cell Biol2017; Pellin D, Nat Commun2019)despite our limited numbers of starting cells. Our data accurately reflect the pattern of normal hematopoiesis, which may help to revise and refine characterization of hematopoiesis and provide a general reference framework to investigate the complexities of blood cell production at single-cell resolution - especially when cell numbers are limited, as from patient samples and in marrow failure syndromes. Fig. 1scRNA-seq of human hematopoietic stem and progenitor cells. (A) Unsupervised hierarchical clustering of gene expression data for all cells. C1, HSC/MLP; C2, MEP; C3, GMP; C4, ProB; C5-C6, ETP. (B)Visualization of the HSPC continuum. Each ball represents one cell.(C) Large-scale shifts in gene expression during development of hematopoietic cells.Bars on top indicate locations of individual cells, colored by stages of development, along this developmental trajectory. (D) Projections of five transcriptomic gene modules onto PCA of scATAC-seq data (Buenrostro JD,Cell 2018). Each dot represents a transcriptional factor. Figure 1 Disclosures No relevant conflicts of interest to declare.

Description: Background: triplet combinations comprising a proteasome inhibitor (PI) and an immunomodulatory drug (IMiD) are current standard induction and consolidation regimens in NDMM. The all-oral combination of weekly ixazomib plus lenalidomide-dexamethasone (IRd) has been evaluated by several groups in NDMM and is approved in relapsed-refractory MM. The IFM 2014-01 phase 2 trial previously studied the weekly IRd regimen as induction and extended consolidation followed by single-agent ixazomib maintenance in frontline transplant eligible patients (Moreau et al ASH meeting 2016): IRd was well tolerated and overall response rate was 81%, including 38% very good partial response or better (≥VGPR) at the completion of induction (3 cycles). Responses further increased at each step of the program and 76% of patients (per protocole analysis) achieved ≥VGPR before maintenance with 6% CR and 38% sCR. To stay in line with current RVd regimen, and to increase dose intensity, we examined the efficacy and safety of twice-weekly ixazomib +Rd as induction prior to transplant, followed by weekly IRd consolidation and single-agent lenalidomide maintenance (NCT02897830). Methods: This is a phase II, single-arm, open-label, multicenter study. During induction, patients received three 21-day cycles of twice-weekly oral IRd: ixazomib (3 mg on days 1, 4, 8 and 11), lenalidomide (25 mg daily, days 1-14), and dexamethasone (40 mg on days 1, 4, 8 and 11) followed by transplant. Patients then received two 28-day cycles of weekly IRd early consolidation followed by 6 additional cycles of IR (no dexamethasone) as late consolidation (ixazomib 4mg on days 1-8 and 15; lenalidomide 25mg daily, days 1-21). Single-agent lenalidomide maintenance was administered for up to 1 year (10 mg daily, days 1-21). The primary endpoint was the stringent complete response (sCR) rate at the completion of consolidation. The secondary endpoints included assessments of overall response rate (ORR) and rates of response categories at each step of the program, progression-free survival (PFS), feasibility and safety. Responses were assessed in accordance with the IMWG uniform criteria. Toxicity was evaluated according to NCI CTCAE, version 4.03. Results Between 07/2016 and 08/2017, 50 patients with NDMM were screened at 10 IFM centers, 46 were enrolled with a median age of 59 years, and 59% were male. The percentages of patients with ISS stage I, II, and III were 41.5%, 41.5%, and 17%, respectively. High-risk cytogenetics, defined as t (4; 14), or del17p (central Lab, H. Avet-Loiseau), was observed in 9% of patients (6.5% FISH failure). As of July 1st 2019 (data cut-off), 10 patients prematurely discontinued therapy. Considering efficacy, 43/46 patients (94%) completed consolidation and 9 achieved sCR (20.9%; 90% CI [11.4 to 33.7]). This result did not meet the minimum efficacy threshold (40%) for the primary efficacy endpoint (p=0.998). Overall, at the completion of consolidation, ORR was 91% including 21% sCR, 30% ≥CR and 58%≥VGPR. Responses at each step of the program are described in the table 1. If we focus on twice-weekly IRd induction, at the completion of 3 cycles, ORR was 74%, including 33% ≥VGPR. The feasibility of the program was good and overall, 39/46 patients (85%) were able to receive maintenance therapy with single-agent lenalidomide. After a median follow-up of 22 months, 7 patients progressed and 3 patients died. Concerning safety: 31 serious treatment emergent AEs were reported in 20 patients (43.5%) comprising infections (8 patients), cardiac disorders (2 patients: ischemic heart disease and aortic valve incompetence), psychiatric, renal and respiratory disorders (2 cases each). No grade 3-4 peripheral neuropathy was described. Conclusions The all-oral Ixazomib-Lenalidomide-Dexamethasone (IRd) induction/consolidation regimen in the transplant setting is convenient, well tolerated, leading to 21% sCR before maintenance. Twice-weekly IRd induction does not seem superior to weekly IRd induction Results on response rates following maintenance and MRD data will be presented during the meeting. Table Disclosures Roussel: Celgene Corporation: Consultancy, Other: travel fees, lecture fees, Research Funding; takeda: Other: travel fees, lecture fees, Research Funding; Amgen: Other: travel fees, lecture fees, Research Funding; Janssen: Honoraria, Other: travel fees, lecture fees, Research Funding. Hebraud:celgene: Other: travel fees, lecture fees; takeda: Other: travel fees, lecture fees. Hulin:Janssen, AbbVie, Celgene, Amgen: Honoraria; celgene: Consultancy, Honoraria. Leleu:Oncopeptide: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; Karyopharm: Honoraria; Amgen: Honoraria; Carsgen: Honoraria; Incyte: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Janssen: Honoraria; BMS: Honoraria; Merck: Honoraria. Facon:Amgen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Touzeau:celgene: Other: travel fees, lecture fees, Research Funding; takeda: Other: travel fees, lecture fees. Perrot:jannsen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; takeda: Honoraria. Stoppa:celgene: Other: travel fees, lecture fees; takeda: Other: travel fees. Moreau:Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Avet-Loiseau:takeda: Consultancy, Other: travel fees, lecture fees, Research Funding; celgene: Consultancy, Other: travel fees, lecture fees, Research Funding. Attal:celgene: Consultancy, Other: travel fees, lecture fees, Research Funding; takeda: Consultancy, Other: travel fees, lecture fees, Research Funding. OffLabel Disclosure: Ixazomib is indicated in RRMM in association with Rd

Description: Introduction. Chronic lymphocytic leukemia (CLL) has typically an indolent course but can undergo transformation into a more aggressive lymphoma so called Richter's syndrome. While the advent of novel targeted therapies is transforming the management of patients with CLL, these drugs failed to prevent the risk of RS. RS is associated with a very poor outcome and is thus becoming the main obstacle to long term CLL control. Autologous (auto-) and allogeneic (allo-) hematopoietic stem-cell transplantation (-SCT) have been recommended as the treatment of choice in eligible patients with clonally related RS (Rossi Blood 2018) but previous experience is still limited to less than 50 cases. We here aimed to investigate the safety and efficacy of both auto- and allo-SCT for patients with RS in a large cohort in a period overlapping the advent of novel agents. Methods. We report on a retrospective study of consecutive adult patients with RS who underwent auto- or allo-SCT between 2008 and 2018 in EBMT centers. Results. A total of 197 patients (M/F= 133/64) were included in the present study; 125 patients received allo-SCT and 72 auto-SCT. The main difference between these 2 cohorts was the median age at transplant that was lower in the allo- than in the auto-SCT group (median age 57 [18-71] vs 61 [39-74] years, p = 0.006). Regarding the allo-SCT cohort, median time from RS diagnosis to SCT was 10 months [1.1-322.8] and 54.2% had received 〉2 therapeutic lines for RS. At allo-SCT, 60 (48.4%) were in CR and 53 (42.7%) in PR or SD. Most patients received reduced intensity conditioning (RIC) regimen (n= 90, 72.6%) and peripheral blood (89.6%) as stem cell source. Donors were related (matched, n=40 (33%) or mismatched, n=4 (3%)) or unrelated (matched, n= 76 (61%) and mismatched, n=4 (3%). A total of 41 patients (33.6%) received total body irradiation (TBI). With a median follow-up of 48 months, 2-year OS was 46% (36-55%) and 2-year PFS 38% (28-48%). Two-year cumulative incidence of relapse (CIR) was 31% (22-40%) as was the 2-year NRM (Figure 1). Two-year CIR was significantly reduced in patients with ≤2 therapeutic lines for RS (12% (1-22%) vs 41% (26-55%); p=0.005). Performance status affected 2-y PFS (24% (7-42%) if Karnofsky index