ALBERT

Description: Background: Patients with acute spinal cord injury (SCI) have a high risk of venous thromboembolism despite thromboprophylaxis. Low molecular weight heparin (LMWH), the current standard of care, is inconvenient for long term thromboprophylaxis, costly, and partially effective. Direct oral anticoagulants (DOACs) have been shown to be at least as effective and as safe as LMWH in other thromboprophylaxis settings but there is no randomized evaluation of DOACs in this population. Aim: By conducting a feasibility randomized trial, we aimed to determine the likely recruitment rate of eligible patients into an RCT in which patients with acute SCI were randomized to a prophylactic dose of LMWH or apixaban. Methods: A pilot study was performed at Hamilton General Hospital (HGH). Adult patients with an acute traumatic SCI presenting to the hospital within 1 week of SCI and at least 36 h after the injury were included. Exclusion criteria were the need for therapeutic oral anticoagulation prior to enrolment; active bleeding, intracranial or peri-spinal hematoma, or a bleeding disorder; pregnancy or breastfeeding; severe renal failure (creatinine clearance ≤30 ml/min); severe cirrhosis (Child-Pugh class C); severe thrombocytopenia (platelets 1 week from SCI (n=2), indication for therapeutic anticoagulation (n=2), active bleeding (n=1), and minor injury with an expected short hospital admission (n=1). Four patients were randomized to each drug. Median age was 61 (range 51 to 70) and 7 (87.5%) were males. There were no symptomatic VTE or sudden deaths. One patient randomized to apixaban had major bleeding. There were no serious adverse events. Conclusions: Our pilot study is the first randomized trial to examine the role of a DOAC compared with LMWH for thromboprophylaxis in this high-risk group. The primary feasibility outcome was not met, and therefore a multicenter RCT is unlikely to be feasible. The efficacy and safety of DOACs on this indication should be evaluated in registry- or health care database studies. Disclosures Eikelboom: Heart and Stroke Foundation: Research Funding; Sanofi Aventis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Glaxo Smith Kline: Honoraria, Research Funding; Eli Lilly: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Boehringer Ingelheim: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding.

Description: Background Immune Thrombocytopenia (ITP) is an autoimmune disorder caused by immunologic destruction of otherwise normal platelets, most commonly occurring in response to an unknown stimulus. ITP is diagnosed after excluding other possible causes of disease, and symptoms can present across varying severities and treatments. The poor understanding of the symptoms and cause can result in both misdiagnosis and complex treatment patterns, which may significantly affect health related quality of life (HRQoL) in this patient population. There is currently no disease specific prospective tool in routine clinical practice to capture HRQoL in the adult ITP population. To help assess the impact of this condition on HRQOL, the ITP Life Quality Index (ILQI), a 10-item patient-reported outcome (PRO) measure was developed as a tool for clinical practice to aid discussions between patients and physicians about disease experience so to inform patient-centric treatment decisions. The ILQI was originally developed by clinical experts in the field of ITP and content validity was confirmed by conducting qualitative interviews with 15 adult patients with ITP. The ILQI was then cognitively debriefed patients with ITP and items refined following qualitative analysis and additional clinical input. The ILQI was included in the ITP World Impact Survey (I-WISh), a global observational study which collected data on the impact of ITP on patients' HRQoL. This large study provided an opportunity to assess the psychometric properties of the ILQI and confirm the scoring cut-offs. Methods The I-WISh survey resulted in data from 1,507 patients with ITP across 12 countries worldwide and was used to assess the structure, reliability and validity of the ILQI. The structure of the ILQI, how the items fit into total scores and subscales, was assessed by splitting the data into two datasets. One dataset was used for identifying the structure using exploratory factor analysis and one was used for checking the structure using confirmatory factor analysis. Validity, the ability of the ILQI to measure the correct construct, was assessed through known groups and convergent validity methods. Reliability, the consistency of the ILQI items and their ability to create reproducible scores, was assessed via internal consistency methods. To understand whether each ILQI item measured ITP in a similar way across countries, differential item functioning (DIF) was assessed using Cochran-Mantel-Haenszel test and Logistic regression. Finally, existing score cut-offs (20-"significantly impaired QoL"; 30 - "severely impaired QoL") were assessed using receiver operating characteristic (ROC) curves and a simulation study was conducted to develop rules for missing data. Results Results indicated that the ILQI has an essentially unidimensional structure, supporting the creation of a total score including all 10 items. The ILQI items work together to create a reproducible total score, usable for making judgements on an individual patient basis (Omega total and Cronbach's alpha coefficients ≥ 0.90). Known groups methods showed that ILQI monotonically increased with ITP severity (linear trends p's

Description: SF3B1 mutations disrupt normal pre-mRNA splicing to cause disease. Drugs inhibiting the interaction between the SF3b complex and RNA or agents degrading auxiliary splicing factors are being tested as new avenues for targeted therapy in myeloid neoplasia (MN) with SF3B1 mutations. Here we describe the ability of small molecules to restore altered RNA processes in SF3B1MT MN. We previously reported (Visconte, ASH 2018) the identification of the small molecule 4-pyridyl-2-anilinothiazole (PAT) which showed growth inhibition of CRISPR/Cas9 SF3B1+/K700E cells and primary SF3B1MT cells. PAT did not influence the growth of other cell models without (THP1, MOLM13FLT3, OCIAML3DNMT3A, SIGM5TET2/DNMT3A, K562PHF6) and with other splicing factor mutations (K562U2AF1, K562LUC7L2). We now describe data from medicinal chemistry, transcriptome, and in vivo studies to advance drug development for SF3B1MT MN. SAR studies focused on logical and systematic modifications of PAT, e.g., i) replacement of the 2,4-disubstituted thiazole spacer ring with other heteroatom containing rings (5,6,7 membered aromatic or aliphatic ring structures); ii) alternative linking groups for the NH linker of the aniline of the tail region (sulfonamide, amide, substituted amine linkers); iii) alternative substituted aromatic and aliphatic ring structures for the phenyl head region substituent, led us to identify permissive sites for further chemical optimization. For example, a 4-chlorophenyl analog demonstrated activity [IC50, 3μM] similar to PAT. Competitive repopulation assays of bone marrow (BM) cells from dual reporters (ACTBtdTomato; EGFP) B6.GtROSA26 mixed with BM cells from conditional knock-in Sf3b1+/K700E mice injected in pre-lethally irradiated B6.SJL-PtprcaPepcb/BoyJ (CD45.1) recipients (n=18) were used as a preclinical murine model. This model then allowed i) demonstration of drug efficacy in reducing the competitiveness of SF3B1MT cells and ii) evaluation of therapeutic index in normal hematopoiesis. Post-transplant recovery, recipients of B6.GtROSA26 cells underwent PAT treatment (10 mg/Kg/IP/5 days weekly) for a period of 6 weeks without showing any signs of distress or drug intolerance (drop in blood count, weight loss, abdominal swelling, liver or kidney toxicity). Two weeks after transplantation, donor Sf3b1+/K700E cells had an engraftment capability similar to that of donor B6.GtROSA26 cells (83.6 ± 4 vs. 86.4 ± 2.4) when transplanted as a sole graft in CD45.1 recipients. PAT reduced almost half the percentage of Sf3b1+/K700E donor cells at 6 weeks of treatment (47.4%) vs. pre-treatment (83.6%). In mixed (1:1) BM transplants, Sf3b1+/K700E cellshad a repopulative disadvantage against competitors B6.GtROSA26 contributing for 16% of the marrow reconstitution. Similar to single graft transplants, PAT decreased the percentage of Sf3b1+/K700E cells at 6 weeks vs. pre-treatment (average, 6% vs. 16%) in chimeras. Consistent with the lack of toxicity of PAT treatment B6.GtROSA26 cells in chimeras were not affected by PAT and gradually repopulated the host (post-treatment, 80% vs. pre-treatment, 64%). Subsequently, we focused our efforts identifying important genes known to be dysregulated in MDS that were mostly influenced by drug treatment and minimally affected in normal cells. Our approach was based on the analyses of genes linked to erythropoiesis (a key hallmark of low-risk MDS). In normal hematopoiesis TGF-β signaling inhibits terminal erythroid maturation. Out of 13,775 genes, 5% (664/13,775) were found differentially expressed between CRISPR/Cas9 SF3B1+/K700E and parental cells of which 60% of these genes were significantly up-regulated and 40% down-regulated. Pathway analysis showed that the expression levels of SMAD family of genes and GDF factors changed significantly upon drug treatment. SMAD7 mRNA levels are 3-fold lower in MDS CD34+ cells (n=159) compared to the ones of healthy subjects (n=17) (GEO accession GSE58831) leading to TGF-β over activation. PAT treatment normalized SMAD7 expression levels in CRISPR/Cas9 SF3B1+/K700E cells by 3-fold while reducing the levels of GDF11. In summary, we have identified new drug entities that are modulators of transcriptomic changes which decrease the competitiveness of SF3B1MT cells. These results suggest combination therapies with current TGF-β pathway inhibitors. Disclosures Advani: Glycomimetics: Consultancy, Research Funding; Kite Pharmaceuticals: Consultancy; Amgen: Research Funding; Pfizer: Honoraria, Research Funding; Macrogenics: Research Funding; Abbvie: Research Funding. Kelly:Novartis, Bayer, Janssen, Pharmacyclics, Celgene, Astrazeneca, Seattle Genetics: Honoraria, Speakers Bureau; Takeda: Research Funding; Genentech, Verastem: Consultancy. Sekeres:Syros: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Maciejewski:Novartis: Consultancy; Alexion: Consultancy.

Description: Of 400 female and 58 normal nonommunized male sera approximately 10% were cytotoxic for a panel of allogeneic granulocytes. Sera with strong alloreactivity were also autoreactive, which emphasized the large autoimmune component of most alloantisera against granulocytes. The cytotoxic granulocyte autoantibodies were complement dependent, of the IgM class, and exhibited optimum cytotoxic activity in vitro at 5 degrees C precomplement incubation temperatures with papain-treated cells. The sera were unreactive with autologous or allogeneic B and T lymphocytes, monocytes, and red blood cells but were cytotoxic for adult and cord granulocytes, eosinophils, and chronic myeloid leukemia cells. Granulocyte autoantibodies were present in 53% of sera from 57 patients with systemic lupus erythematosus (p less than 0.00002) but were not found in increased frequency in the sera of patients with 28 other diseases. We conclude that a single tissue-specific antigenic determinant(s) called “G” may be present on granulocytes and is the target of naturally occurring autoantibodies.

Description: Abstract 1402 Poster Board I-424 Introduction: Anatomic imaging using contrast-enhanced computed tomography (CT) is essential for management of lymphomas. Functional imaging using 18FDG-PET (PET) improves detection of certain lymphomas, specifically, diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). Currently, PET imaging is performed with co-registration of low-dose non-contrast enhanced CT images used for anatomic correlation and attenuation correction of PET images (PET/CT). It has been suggested that the low-dose non-enhanced CT cannot substitute for diagnostic contrast-enhanced CT imaging since the arterial and venous phases of contrast enhancement improve detection of lesions. Given the differential sensitivity for detection of specific lymphomas by PET imaging, we hypothesized that FDG could substitute for intravenous contrast in imaging of certain lymphomas, and that PET/CT or PET imaging could potentially obviate the need for contrast-enhanced CT. To test this hypothesis, we performed an independent and blinded radiology review of these imaging studies in patients (pts) with DLBCL, FL, small lymphocytic lymphoma/chronic lymphocytic leukemia (CLL/SLL) or marginal zone lymphoma (MZL) who had contrast-enhanced CT, PET, PET/CT, and low-dose non-enhanced CT available for retrospective review. Patients and Methods: Pts with a diagnosis of DLBCL, FL, CLL/SLL, or MZL with PET/CT and contrast-enhanced CT studies performed at the Hospital of the University of Pennsylvania within 6 weeks of each other without intervening therapy were studied. Pts with clinically suspected progression of lymphoma between studies were excluded. Radiologists, blinded to clinical information or other imaging results, separately interpreted image sets of low-dose non-enhanced CT, PET, fusion PET/CT, and contrast-enhanced CT studies. The presence or absence of disease at 44 nodal and 48 (female) or 49 (male) extranodal sites was recorded for each site for each imaging modality. Concordant findings across imaging modalities were defined as positive for involvement by lymphoma; discordant findings were reconciled using all available clinical and radiologic information with follow-up for progression or regression of abnormality, or by biopsy. Results: Between May 2006 and January 2008, 55 pts with either DLBCL (n=31), FL (n=13), CLL/SLL (n=5), or MZL (n=6) had complete images sets available for review. All patients had at least 18 months of clinical follow-up after imaging. A total of 282 sites met criteria for involvement by lymphoma. The rates of detection for specific lymphomas by each imaging modality are shown below: Conclusions: Our results suggest that combined PET/CT imaging is more sensitive than contrast-enhanced CT imaging for detection of DLBCL and at least as sensitive as contrast-enhanced CT imaging for detection of FL. In comparison, contrast-enhanced CT imaging appears superior to PET/CT imaging for CLL/SLL; while further studies are needed to confirm superiority of contrast-enhanced CT imaging in MZL. The routine use of both contrast enhanced CT and PET/CT modalities for staging of lymphoma may be unnecessary, potentially increasing both the cost of medical care and radiation exposure. Additional studies are needed to determine which imaging modality is optimal for each type of lymphoma. Disclosures: No relevant conflicts of interest to declare.

Description: Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease characterised by elevated peripheral platelet destruction and inadequate platelet production. Little published epidemiological data exists concerning the risk of thromboembolic events (TE) among adult patients with ITP. The objective of our investigation was to estimate the risk of TE among adult patients with and without ITP in the United Kingdom (UK) General Practice Research Database (GPRD), which contains patient data from 6.4 million patients from more than 480 representative medical practices across the UK. Using read [2871C] or Oxford Medical Information System (OXMIS) [D3130000, D313012, 42P2.11, D313.12] codes to define cases, incidence rates (IRs) per 10,000 patient-years of observation (PYO) with 95% confidence intervals (CIs) were estimated. Hazard ratios (HRs) of venous, arterial, and combined (venous and arterial) TE were modelled using Cox proportional hazards regression adjusting for history of prior TE, hypertension, splenectomy status, oral corticosteroids and intravenous immunoglobulin exposure. 840 adults (≥ 18 years) with codes for ITP first referenced between January 1, 1992 and September 30, 2005 and having at least one year pre-diagnosis and three months of post-diagnosis medical history were matched with 3,360 non-ITP patients by age, gender, primary care practice and pre-study follow-up time. Over a median 52 months of follow-up (range: 3–182 months), the cumulative incidence of TE among thromboembolic-free patients at baseline was higher within the ITP cohort [47 (6.7%) v. 172 (5.7%)]. As shown in the table below, the IRs of venous, arterial, and combined TE were additionally elevated among patients with ITP. Outcome Incidence Rate/10,000 PYO 95% CI Adult Patients with ITP Adult Patients without ITP Venous TE 70.83 (46.67–103.05) 47.53 (37.39–59.58) Arterial TE 82.02 (55.73–116.42) 71.50 (58.87–86.04) Combined TE 134.74 (99–179.18) 116.32 (99.59–135.06) Adjusted HRs of 1.58 (95% CI, 0.98–2.53), 1.02 (95% CI, 0.65–1.59), and 1.17 (95% CI, 0.82–1.66) were found for venous, arterial, and combined TE respectively. Further event categorisation revealed elevated HRs for each venous thromboembolic subtype [deep vein thrombosis 1.49 (95% CI, 0.62–3.61), pulmonary embolism 3.52 (95% CI, 1.23–10.04), and other TE 1.17 (95% CI, 0.64– 2.16)]. This study provides evidence of an increased risk in venous TE in adult patients with ITP relative to the general adult non-ITP population.

Description: Idiopathic thrombocytopenic purpura (ITP) is an autoimmune condition characterized by autoantibody-mediated platelet destruction and suboptimal megakaryocytic production. Primarily acute (〈 6 months) in duration among children, ITP manifests predominantly chronically among adults, increasing susceptibility to bleeding events. Despite recent growth, published literature on health-related quality of life in ITP remains limited. The objective of our investigation was to identify lifestyle concerns associated with ITP among adult and pediatric patients in the United Kingdom. In collaboration with ITP specialists, a 43 question, closed-field lifestyle survey was developed, addressing social engagement, work and school performance, sports and activities, treatment, and travel. Patient members of the United Kingdom ITP Support Association (N = 1,767) were asked to complete and return mailed surveys. Pearson’s chi-square and Fisher’s exact tests were used to evaluate differences in dichotomized variables between groups. 790 (45%) completed surveys were returned. As illustrated in the table below, roughly one-quarter of adults (≥ 16 years) and one-fifth of children reported ‘always’, ‘sometimes’, or ‘often’ missing school or work owing to fatigue and having encountered difficulty obtaining insurance. Nearly one-third of adults further revealed having an elective surgery delayed owing to a low platelet count. Disparities were noted across gender with regard to bruise concealment (adults: p 〈 0.01; children: p = 0.03) and suspicions of subjection to violence (adults: p 〈 0.01; children: p = 0.49). In contrast with adults, pediatric patients reported being more likely to having requests for referral denied (p = 0.03). This study represents the largest quality of life investigation of ITP to date. Although the survey utilized remains to be validated, its findings nonetheless successfully highlight avenues for future investigation. Subgroups: ‘Yes’ % Adults Children Question Total ‘Yes’ % N = 790 Male N = 199 Female N = 497 Male N = 51 Female N = 43 [1] Total number of responses recorded for the given question. Have you ever been unable to go to work or school because of tiredness and fatigue? 29% 
 710[1] 26%
 186 31%
 435 20%
 49 30%
 40 Have you had difficulty obtaining or been refused travel and life insurance? 29%
 611 30%
 540 18%
 71 Have you ever had surgery (other than splenectomy for ITP) postponed or delayed because of a low platelet count? 30%
 620 34%
 158 30%
 391 13%
 39 19%
 32 Do you try to hide your bruises? 29%
 756 10%
 190 37%
 475 20%
 50 42%
 41 Are people ever suspicious that the bruises are a result of physical violence? 17%
 750 5%
 193 19%
 468 31%
 49 38%
 40 Have you ever been refused a referral to an ITP specialist or hospital of 5%
 574 3%
 144 4%
 358 10%
 41 10%
 31

Description: Eltrombopag is an oral, non-peptide, platelet growth factor that increases platelet counts in a dose-dependent manner in adult subjects with chronic idiopathic thrombocytopenic purpura (ITP) and Hepatitis C virus (HCV)-associated thrombocytopenia. Safety results from four completed randomized, double-blind, placebo-controlled studies are presented here. In two 6-week studies of subjects with ITP, 231 subjects were analyzed for safety following administration of eltrombopag once daily. In the first study, 117 patients were randomized to eltrombopag 30 mg, 50 mg or 75 mg or placebo. In the second study, 114 patients were administered 50 mg eltrombopag with increases to 75 mg after 3 weeks, if necessary. In the third study, which investigated the effect of eltrombpag 50 mg, 75 mg or 100 mg in subjects with chemotherapy-induced thrombocytopenia (CIT), 180 subjects were included in the safety analysis; subjects were administered up to 8 cycles of carboplatin/paclitaxel plus once daily eltrombopag for 10 days per cycle. In a fourth study, 74 subjects with HCV-associated thrombocytopenia were analyzed for safety; eltrombopag was administered once-dailyat doses of 30 mg, 50 mg and 75 mg for 4 weeks until a target platelet count was reached; after which interferon/ribavirin therapy commenced. During this phase, eltrombopag was administered for up to 12 weeks. Adverse events (AEs), ophthalmologic exams results, clinical laboratory data, physical exams, vital signs and ECGs were frequently assessed during the aforementioned studies. Collectively, 485 subjects were evaluated, including 354 on eltrombopag (in doses ranging from 30–100 mg for up to 16 weeks) and 131 on placebo. Overall, the proportion of subjects reporting AEs was generally comparable across all groups within the study including placebo (Table). For the ITP and HCV trials, mild headache was the most commonly occurring AE for all study groups including placebo. For the CIT trial, nausea was the most commonly reported AE and was reported related to the administration of chemotherapy. There was no apparent association between the administration of different doses of eltrombopag and clinically significant changes in data generated from AE reports, ophthalmologic evaluations, clinical laboratory data, physical exams, vital signs and ECGs. In conclusion, safety data from these four completed, randomized, placebo-controlled trials support further development of eltrombopag for thrombocytopenia of various etiologies. Ongoing safety monitoring will further characterize the safety profile of eltrombopag. Patients Reporting Adverse Events PBO n (%) 30 mg n (%) 50 mg n (%) 75 mg n (%) 100 mg n (%) * reporting AEs ≥5%. † Reporting AEs in the eltrombopag only phase. Adverse Events Phase 2 ITP* 17 (59) 14 (47) 14 (47) 17 (61) Phase 3 ITP 14 (37) 45 (59) Phase 2 HCV† 10 (56) 11 (79) 10 (53) 13 (57) Phase 2 CIT 38 (83) 33 (75) 30 (68) 40 (87) Serious AEs Phase 3 ITP 8 7 Phase 2 HCV 1 3 1 2 Phase 2 CIT 9 4 8 10 Deaths Phase 2 ITP 0 0 1 0 Phase 3 ITP 0 0 Phase 2 HCV 1 0 0 0 Phase 2 CIT 3 0 3 3

Description: NK cell alloreactivity in HLA-identical sibling stem cell transplantation (SCT) is not well understood. We previously showed that higher (greater than the median of 150/ ul) NK30 (absolute NK count on day 30 post transplant in recipient) correlated with a particular “favorable” KIR combination (2DL5A, 2DS1, 3DS1) in the donor. Both high NK30 and “favorable” KIR correlated with improved transplant outcome after T-depleted myeloablative sibling donor SCT for myeloid malignancies. We therefore studied the readout of NK cell subset ratio, CD107a degranulation level and different KIR receptor expression level within each NK subset among these patients. Cryopreserved mononuclear cell from 16 pairs of donor pre-transplant sample with his/her corresponding recipient day 30 post-transplant sample were thawed, recovered overnight and incubated with K562 cells at an E:T ratio of 5:1 togather with CD107a-FITC. The incubation product was stained with multicolor fluorochrome antibody cocktails. Events were acquired on an LSR-II flow cytometer. Data was analysed by Flowjo software and Student t-test was performed on those readouts previously mentioned within donor and recipient samples, each is further grouped by high versus low NK30, favorable vs unfavorable KIR and mild (grade 0, 1) versus severe (grade 2 and above) acute GVHD (aGVHD). In recipient day 30 post-transplant samples, the high NK30 group had significantly higher CD56+CD16+ NK subset ratio (p

Description: Growing evidence from several murine models suggests that STAT3 signaling in CD4+ T-cells plays a pivotal role in the pathogenesis of autoimmunity. We herein tested the hypothesis that the same pathway plays a critical role in the induction of GVHD in murine models of allogeneic BMT. To test our hypothesis and to compare the differential ability of STAT3 signaling in CD4+ T-cells to mediate GVHD in MHC-mismatched and-matched murine models of alloBMT, CD4-Cre × STAT3flox/flox (STAT3KOCD4+), or corresponding wild-type control mice were used as donors of CD4+ T-cells. In an MHC-mismatched model, groups of lethally irradiated (775 cGy) BALB/c (H-2d) mice received T-cell depleted (TCD) bone marrow (BM) from wild-type C57BL/6 (H-2b) mice alone, TCD B6 BM plus 4 × 105wild-type, or STAT3KOCD4+ T-cells, all on a C57BL/6 background. In repeated experiments we observed significantly decreased clinical signs of GVHD in animals receiving STAT3KOCD4+ in comparison to those receiving wild-type CD4+ T-cells (median GVHD score of 2.25 vs. 5.29; P