ALBERT

Description: Key Points L5 is elevated in ischemic stroke patients, and its receptor, LOX-1, plays a critical role in increasing stroke size. L5 induces platelet secretion of Aβ to potentiate platelet activation and aggregation via LOX-1 and IKK2.

Description: Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL), accounting for roughly 30% of newly diagnosed cases in the United States (US). DLBCL is a heterogeneous lymphoma, including the activated B cell-like (ABC) and germinal center B cell-like (GCB) subtypes, which have different gene expression profiles, oncogenic aberrations, and clinical outcomes (Alizadeh, Nature 2000; Staudt, Adv Immunol 2005). ABC-DLBCL is characterized by chronic active B-cell receptor (BCR) signaling (Davis, Nature 2010), which is required for cell survival. Thus, the BCR signaling pathway is an attractive therapeutic target in this type of B-cell malignancy. Bruton's tyrosine kinase (BTK), which plays a pivotal role in BCR signaling, is covalently bound with high affinity by ibrutinib, a first-in-class BTK inhibitor approved in the US for mantle cell lymphoma and chronic lymphocytic leukemia (CLL) patients (pts) who have received at least one prior treatment, CLL with del17p, and WaldenstršmÕs macroglobulinemia. A recent phase 2 clinical trial of single-agent ibrutinib in DLBCL pts revealed an overall response rate of 40% for ABC-DLBCL (Wilson, Nat. Med 2015); however, responses to single kinase-targeted cancer therapies are often limited by the cellÕs ability to bypass the target via alternative pathways or acquired mutations in the target or its pathway (Nardi, Curr Opin Hematol 2004; Gazdar, Oncogene 2009). The serine/threonine-protein kinase PIM1 is one of several genes exhibiting differential expression in ibrutinib-resistant ABC-DLBCL cells compared with wild-type (WT) cells. We identified and report herein the role of PIM1 in ABC-DLBCL ibrutinib-resistant cells. Methods: PIM1 gene expression was analyzed by RT-qPCR. In vitro, cell viability was assessed in the human ABC-DLBCL cell line HBL-1 after treatment with ibrutinib and/or a pan-PIM inhibitor for 3 days, and the effect on colony formation was determined 7 days post-treatment. PIM1 mutational analysis was performed with clinical tumor biopsy samples from 2 studies, PCYC-04753 (NCT00849654) and PCYC-1106-CA (NCT01325701). PIM1 protein stability was analyzed by treating cells with cycloheximide and examining protein levels at different time points up to 8 hours. Results: Gene expression profiling of ibrutinib-resistant ABC-DLBCL cells revealed an upregulation of PIM1 (15-fold increase compared with WT cells) as well as PIM2 and PIM3. We also found that, compared with single-drug treatment, in vitro cell growth could be synergistically suppressed with a combination of ibrutinib and a pan-PIM inhibitor. This effect was observed in both WT (combination index (C.I.) = 0.25; synergy score = 3.18) and ibrutinib-resistant HBL-1 cells (C.I. = 0.18; synergy score = 4.98). In HBL-1 cells, this drug combination reduced colony formation and suppressed tumor growth in a xenograft model (Figure 1). In 48 DLBCL patient samples with available genomic profiling, PIM1 mutations appeared more frequently in pts diagnosed with ABC-DLBCL compared with GCB-DLBCL (5 out of 6 DLBCL pts with PIM1 mutations were ABC-subtype). 4 of these 5 pts exhibited a poor clinical response to ibrutinib, ie, 80% of ABC-DLBCL pts with PIM1 mutations had progressive disease, compared with only 13 of 26 (ie, 50%) ABC-DLBCL pts without PIM1 mutations. Subsequent characterization of the mutant PIM1 proteins (L2V, P81S, and S97N) confirmed that they were more stable than WT PIM1, suggesting increased protein levels by 2 potential mechanisms (WT PIM1 gene up-regulation or increased mutant PIM1 protein half-life). The impact of these mutations on PIM1 function and ibrutinib sensitivity is under investigation. Conclusions: Ibrutinib-resistant ABC-DLBCL cells have increased PIM1 expression, and synergistic growth suppression was observed when ibrutinib was combined with a pan-PIM inhibitor. PIM1 mutations identified in ABC-DLBCL pts with poor responses to ibrutinib contributed to increased PIM1 protein stability. A better understanding of the role of PIM1 in ibrutinib-resistant ABC-DLBCL tumors could provide a rationale for the design of combination therapies. Figure 1. Combination of ibrutinib and a pan-PIM inhibitor in the HBL-1 xenograft model. Ibrutinib and PIM inhibitor treatment suppressed tumor growth by 62% compared with the vehicle-treated group (*p 〈 0.01, repeated measures MANOVA adjusted univariate F-test). Figure 1. Combination of ibrutinib and a pan-PIM inhibitor in the HBL-1 xenograft model. Ibrutinib and PIM inhibitor treatment suppressed tumor growth by 62% compared with the vehicle-treated group (*p 〈 0.01, repeated measures MANOVA adjusted univariate F-test). Disclosures Kuo: Pharmacyclics LLC, an AbbVie Company: Employment. Hsieh:pharmacyclics LLC, an AbbVie Company: Employment. Schweighofer:Pharmacyclics LLC, an AbbVie Company: Employment. Cheung:Pharmacyclics LLC, an AbbVie Company: Employment. Wu:Pharmacyclics LLC, an AbbVie Company: Employment. Apatira:Pharmacyclics LLC, an AbbVie Company: Employment. Sirisawad:Pharmacyclics LLC, an AbbVie Company: Employment. Eckert:Pharmacyclics LLC, an AbbVie Company: Employment. Liang:Pharmacyclics LLC, an AbbVie Company: Employment. Hsu:Pharmacyclics LLC, an AbbVie Company: Employment. Chang:Pharmacyclics LLC, an AbbVie Company: Employment.

Description: Introduction: CAR T therapy has improved overall survival for patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) who otherwise have poor outcomes with traditional chemoimmunotherapy. Cytokine release syndrome (CRS) and neurotoxicity are well known side effect from CAR T therapy. Cytopenia has been reported as well. However, to our knowledge, transfusion requirements during the first 30 days post-CAR T treatment have not been reported. Here we report the cytopenia characteristics and transfusion requirements in 15 patients who received commercial Axicabtagene ciloleucel (Yescarta) CAR-T cell therapy. Methods: We retrospectively reviewed all DLBCL patients who received Yescarta between July 2018 through May 2019 at Weill Cornell Medical Center. All patients received cyclophosphamide (500mg/m2) and fludarabine (30mg/m2) lymphodepleting regimen from days -5 to -3 before the CAR T cell infusion. Cytopenia, granulocyte-colony stimulating factor (G-CSF) use, packed red blood cell (RBC) and platelet transfusion requirements during 30 days after CAR T infusion were examined. Cytopenia was defined according to CTCAE criteria. Grade 3 cytopenia was white blood cell (WBC)

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: TG-0054 (burixafor) is a potent and selective antagonist of human chemokine receptor CXCR4 that inhibits the binding of stromal-derived factor 1 (SDF-1). Interruption of the CXCR4/SDF-1 interaction prevents sequestration of CD34+ stem cells to the bone marrow and subsequently mobilizes these cells into the peripheral blood within 1 to 3 hours of drug administration. Materials and Methods: An open-label, phase II pilot trial was conducted in patients with multiple myeloma (MM), non-Hodgkin's lymphoma (NHL), or Hodgkin's lymphoma (HL) to evaluate the safety and stem cell mobilization of TG-0054 in combination with G-CSF. We planned to treat twelve patients with subcutaneous injections of 10 µg/kg/day G-CSF in the afternoon for 4 days. On the morning of Day 5, patients received 3.14 mg/kg TG-0054 and underwent large volume (18-24L) leukapheresis approximately 2 hours post-drug infusion. Patients were allowed by protocol to undergo leukapheresis for 1-5 days to obtain the predetermined target of ≥5.0 x 106 CD34+ cells/kg. 9 of 12 patients have been treated thus far with a plan to treat 3 additional patients. Results: A planned interim analysis revealed that6 of the 9 patients treated thus far collected more than 10 x 106 CD34+ cells/kg in 1 leukapheresis session. 2 patients required 2 days to achieve the study endpoint, and 1 outlier patient who had received Revlimid only 1 week prior to peripheral blood CD34 analysis failed to mobilize stem cells until he was allowed 2 more weeks to recover from his Revlimid treatment. Burixafor was well tolerated, and there were no adverse events that were attributed to the drug. All of the patients engrafted promptly after melphalan (7 patients) or BEAM (2 patients) conditioning regimens. Conclusion: Burixafor in combination with G-CSF is a potent and well-tolerated mobilizer of stem cells into the peripheral blood, and with the exception of 1 outlier, was able to mobilize 〉5.0 x 106 CD34+ cells/kg in 1-2 leukapheresis sessions in all patients treated thus far (median 1 day). This contrasts with our historical controls that required a median of 2-3 days to achieve a collection of ≥5.0 x 106 CD34+ cells/kg. A total of 12 patients will be treated on this pilot study. These encouraging results warrant the further testing of this drug in a larger randomized clinical trial. Disclosures Hsu: Taigen Biotechnology: Employment. Chang:Taigen Biotechnology: Employment. Schuster:Taigen Biotechnology: Research Funding.

Description: Background: Activating mutations of NRAS and KRAS genes are common in newly diagnosed acute myeloid leukemia (AML), occurring in 11-16% and 4-5% of patients, respectively. RAS mutations are frequently acquired at time of progression from MDS to AML and are associated with poor survival. Next generation sequencing (NGS) at diagnosis and during complete remission has shown that RAS mutations have high clearance rates with induction chemotherapy. In the CALGB 8525 study, RAS-mutant younger patients (age

Description: During adulthood and embryogenesis, fate decisions of hematopoietic stem and progenitor cells (HSPCs), such as specification, self-renewal, and differentiation are tightly regulated by their neighboring niche cells. Moreover, distinct types of niches supply differential cues to direct alternative cell fates for HSPCs. Yet, currently the intrinsic mechanisms balancing HSPC response obliqueness to microenvironmental signals are unknown. Friend Leukemia integration-1 (Fli-1), is an ETS transcription factor expressed by vascular beds and hematopoietic lineages. Fli-1 belongs to the "heptad factors" which are hypothesized to specify and sustain a hematopoietic cell fate. While Fli-1 overexpression is linked to leukemia, the functional role Fli-1 plays in HSPC specification and maintenance remains undefined. We show that inducible deletion of Fli-1 using a Rosa-CreERT2 transgenic adult mice (Fli-1ROSAΔ), results in a rapid thrombocytopenia-associated mortality. Transplantation of Fli-1ROSAΔ bone marrow (BM) cells into WT recipients, to exclude vascular-mediated defects, followed by induction of Fli-1 deletion, resulted with the same phenotype. In a set of modulated competitive transplantation experiments (differential induction time points pre- or post-transplant), we observed defective ability of Fli-1ROSAΔ HSPCs to lodge, engraft, and to sustain hematopoiesis post repopulation. Fli-1 deficient HSPCs exhibited reduced quiescent cell cycling status, a hallmark of stemness, and displayed enhanced apoptosis. Thus, Fli-1 is essential for previously unrecognized cell-autonomous HSPC functions. To determine whether Fli-1 modulates HSPC specification, Fli-1 was conditionally deleted using a developmental VE-cadherin (CDH5)-Cre transgenic model (Fli-1CDH5Δ). This resulted with premature mortality of Fli-1CDH5Δ embryos, accompanied with a hemorrhagic phenotype. Reduced numbers of hematopoietic cells were still detected in the AGM of e10.5 Fli-1CDH5Δ embryos. Conditional Fli-1 deletion using a developmental hematopoietic Vav-1 Cre transgenic model (Fli-1Vav-1Δ) resulted again with premature mortality. Reduced presence of embryonic Fli-1Vav-1Δ liver HSPCs was observed at e12.5. We also applied two in vitro co-culture systems, to study Fli-1 in endothelial to hematopoietic transition (EHT). First, isolated hemogenic endothelial cells (HEC) from WT and Fli-1ROSAΔ embryos were co-cultured with AGM-derived vascular niche. HECs isolated from Fli-1ROSAΔ AGM were still able to convert to CD45+ cells, however these cells did not expand on a vascular niche. Secondly, we have applied an endothelial to hematopoietic reprogramming system in which isolated lung ECs are virally introduced with DOX inducible FosB, Gfi1, Runx1, and Spi1 (FGRS) factors and co-cultured with vascular niche cells. Both WT and Fli-1ROSAΔ ECs were able to acquire a hemogenic like state resulting with a final capacity to convert into hematopoietic cells. Again, Fli-1ROSAΔ cells displayed lesser numbers of CD45+ cells at the end point, presumably due to impaired interaction with the vascular niche. Indeed, reduced expansion capacity was observed both for mature CD45+ and for HSPC derived from Fli-1CDH5Δ AGM region. Adult Fli-1ROSAΔ HSPCs exhibited the same niche-dependent expansion defect. Induction of Fli-1 deletion in vitro in adult HSPCs revealed loss of dependency on vascular niche inductive signals, as no additive expansion effect was observed for Fli-1ROSAΔ HSPCs in the presence of a vascular niche. Hence, Fli-1 is essential for HSPC expansion rather than hematopoietic specification. Differential RNA-seq analysis combined with epigenetic studies of expanding WT and Fli-1ROSAΔ HSPCs, revealed dysregulation of Fli-1-controlled pathways involved in transduction of microenvironmental signals for self-renewal. Unexpectedly, H3K27Ac analysis, a marker for transcriptional priming, revealed increased global acetylation of Fli-1ROSAΔ HSPCs' chromatin. Therefor, Fli-1 may not only perform as transcription activator, but foremostly as a genomic suppressor via modulation of histone acetylation status. Decrypting the mechanism(s) by which Fli-1 orchestrates HSPC self-renewal, may promote an improved expansion protocol of human HSPC pre-transplantation, and provide additional insights for microenvironmental sensing by Fli-1-dependent leukemic cells. Disclosures No relevant conflicts of interest to declare.

Description: Background: Autologous stem cell transplantation (ASCT) performed early in the disease course or at first relapse leads to improved progression-free and overall survival in transplant-eligible patients with multiple myeloma (MM). Filgrastim, a recombinant granulocyte colony-stimulating factor (G-CSF), when used after ASCT has been shown to accelerate time to neutrophil engraftment (TNE), and in some studies, it has been associated with reduced length of hospitalization, infectious complications, and antibiotic use. Strategies that reserve G-CSF administration to when neutrophil recovery is delayed, have attempted to show that there is no difference in infectious complications, length of hospitalization or TNE when compared to early administration of G-CSF on the day after stem cell infusion (DOT). However, the optimal timing for administering G-CSF has not yet been determined in patients with MM undergoing ASCT. Methods: This is a retrospective, single-center analysis of patients with MM undergoing ASCT from mobilized peripheral blood stem cells. Patients enrolled in a clinical trial of high-dose lenalidomide and melphalan as conditioning therapy which mandated the administration of filgrastim from day +1 after DOT (Lenalidomide Plus Melphalan as a Preparative Regimen for Autologous Stem Cell Transplantation in Relapsed Multiple Myeloma, NCT01054196) were assigned to the early strategy group (ES). Patients receiving filgrastim as per our institutional guideline (starting on day +12 if ANC 〈 1000 cells/uL, or at the physician's discretion) were included in the delayed strategy group (DS). Patients were excluded from the analysis if their conditioning regimen included a different agent other than melphalan or lenalidomide. DOT was defined as the day of stem cell infusion. Date of neutrophil engraftment was defined as the first of three consecutive days with an ANC ≥ 500 cells/uL. TNE was calculated as the time from DOT to the date neutrophil engraftment. Total duration of neutropenia was defined as the time from onset of neutropenia (ANC 〈 500 cells/uL) to date of neutrophil engraftment. Length of hospitalization was defined as the time from DOT to the day of discharge. Results: We identified 59 patients in the ES group and 39 patients in the DS group from 08-16-2010 to 05-22-2019, for a total of 98 included in this analysis. Median age was 60 and 65 years in the ES and DS groups, respectively. Patients received a comparable dose of CD34+ cells, 5.05x106/kg in the ES group vs 4.66x106/kg in the DS group (p = 0.48). The ES group started filgrastim administration earlier (day +1 vs +9, p 〈 0.001) and received a greater median number of doses (10 vs 4, p 〈 0.001) as compared to patients in the DS group. Median time to neutrophil engraftment was shorter in the ES group compared to the DS group (10 vs 12 days, p 〈 0.001), as was the total duration of neutropenia (5 vs 6 days, p 〈 0.001). Documented infections were just as likely in both groups, 37% in the ES group and 39% in the DS group (p = 1). Length of hospitalization was shorter in the ES group as compared to the DS group (15 vs 17 days, p = 0.01). Discussion: Filgrastim use guided by an ES decreased the time to neutrophil engraftment, the duration of neutropenia and the length of hospitalization compared to a DS. Further analyses to identify predictive factors associated with a reduction in infectious complications and length of stay are underway, with the aim of developing a risk-adapted strategy for the use of filgrastim in patients with MM undergoing ASCT. Disclosures Van Besien: Miltenyi Biotec: Research Funding. Coleman:Kite Pharmaceuticals: Equity Ownership; Merck: Research Funding; Pharmacyclics: Speakers Bureau; Gilead, Bayer, Celgene: Consultancy, Research Funding, Speakers Bureau. Rosenbaum:Janssen: Research Funding; Honoraria Akcea: Other: Accordant Health. Rossi:Janssen, Celgene, Amgen: Consultancy; BMS: Research Funding. Niesvizky:Takeda, Amgen, BMS, Janssen, Celgene: Consultancy, Research Funding.

Description: Background: Hypomethylating agents (HMAs) (e.g., azacitidine (aza), decitabine (dec)) and lenalidomide (len) are approved agents and used in the treatment of patients with myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML). Despite their widespread use, HMAs fail in the majority of MDS and AML patients, and len fails in 75% of non-del(5q) MDS. Unfortunately, no method exists to predict disease response, thus the management of MDS and AML patients is challenging. Predicting treatment response would improve treatment effectiveness, restrict treatment-related adverse events to those who would benefit, and reduce health care costs. Ideally, patient prediction would be based on disease biology. Aim: To determine the biological and clinical predictive values of a genomics-informed computational biology method in patients with AML and MDS who are treated with aza, dec or len. Methods: Patients with AML or MDS were recruited in a prospective clinical trial (NCT02435550) designed to assess predictive values by comparing computer predictions of treatment response to actual clinical response. Genomic profiling was conducted by conventional cytogenetics, whole exome sequencing (SureSelectXT Clinical Research Exome, Agilent), and array CGH (Agilent). These genomic results were inputted into computational biology software (Cellworks Group), which generates disease-specific protein network maps using PubMed and other online resources. Digital drug simulations were conducted by quantitatively measuring drug effect on a cell growth score, which is a composite of cell proliferation, viability and apoptosis. Each patient-specific protein network map was digitally screened for the extent by which aza, dec or len reduced simulated disease growth in a dose-respondent manner. Treatment was physician's choice based on SOC. Before initiating treatment, treating physicians were masked to the results of whole exome sequencing and computational predictions. Clinical outcomes were prospectively recorded. To be eligible for efficacy assessment, patients must have had at least 4 cycles of HMA treatment or 2 cycles of len treatment. For AML, CR+PR was used to define response (IWG 2003). For MDS, CR+PR+HI was used to define response (IWG 2006). To validate the predicted protein network perturbations, Western blot assays were performed on pertinent pathway proteins. Comparisons of computer-predicted versus actual responses were performed using 2x2 tables, from which prediction values were calculated. Fisher's exact test was used to compare prediction values of the genomics-informed computer method versus empiric drug administration. Results: Between June 2015 and June 2016, 80 patients were recruited. 40/80 (50%) had AML and 40/80 had MDS (50%). The median age was 66 (range 24-91). 44/80 (55%) were treatment-naïve and 36/80 (45%) were treatment-refractory. 99% completed all planned molecular tests and computational analyses. Laboratory validation study of computer-predicted, activated protein networks in 19 samples from 13 different patients showed correct prediction of 5 activated networks (Akt2, Akt3, PIK3CA, p38, Erk1/2) in 17 samples, exhibiting 89% accuracy. At the time of this report, 20/80 patients were eligible for efficacy evaluation. 6/20 patients showed clinical response to SOC therapy, while 14/20 did not achieve clinical response. 18 patients' outcome predictions were correctly matched to their actual clinical outcomes, and 2/20 were incorrectly matched, resulting in 90% prediction accuracy, 75% positive predictive value (PPV), 100% negative predictive value (NPV), 100% sensitivity, and 86% specificity. The accuracy of the genomics-informed computer method was significantly greater than empiric drug administration (p=1.664e-05). New genomic signature rules were discovered to correlate with clinical response after aza, dec or len. Conclusions: A computational method that models multiple genomic abnormalities simultaneously showed high predictive value of protein network perturbations and clinical outcomes after standard of care treatments. The network method uncovered molecular reasons for drug failure and highlighted resistance pathways that could be targeted to recover chemosensitivity. This technology could also be used to establish eligibility criteria for precision enrollment in drug development trials. Disclosures Vali: Cellworks Group: Employment. Abbasi:Cellworks: Employment. Kumar:Cellworks group: Employment. Kumar Singh:Cellworks group: Employment. Basu:Cellworks Group: Employment. Kumar:Cellworks Group: Employment. Husain:Cellworks Group: Employment. Wingard:Ansun: Consultancy; Merck: Consultancy; Fate Therapeutics: Consultancy; Astellas: Consultancy; Gilead: Consultancy.

Description: Introduction. There is little information on the effect of donor body mass index (BMI) on mobilization response to Filgrastim (G-CSF), especially in the unrelated donor setting. Obesity has been associated with chronic low-grade inflammation due to chronic activation of the innate immune system. Obesity-induced pro-inflammatory cytokines can interfere with bone marrow SDF1/CXCR4 axis and promote mobilization of progenitor cells leading to persistent leukocytosis and an increase in number of circulating progenitor cells. Given a higher number of circulatory progenitor cells in obese individuals compared to non-obese, a reduced G-CSF dose in obese donors may elicit adequate response, thus reducing the adverse events associated with peripheral blood stem cell (PBSC) collection. The aim of this study is to evaluate the impact of donor BMI on G-CSF mobilized peripheral blood progenitor cell yield in healthy donors. This study also examines whether there is a G-CSF dose threshold above which there is a significant increase in skeletal pain and other acute toxicities from mobilization without an appreciable increase in progenitor cell yield. Methods. The primary outcome was examination of CD34+ per liter of blood processed (x106/L) on Day 5 of G-CSF administration as a measure of collection yield. The secondary outcomes were the incidence of skeletal pain and highest toxicity level across selected body symptoms (fatigue, nausea, anorexia, insomnia, dizziness) at 24 hours after first G-CSF dose, day 1 to 5 of G-CSF administration, 2 days and 1-week post collection. The population studied was domestic unrelated G-CSF mobilized PBSC donors reported to the NMDP/CIBMTR between 2006 and 2016. G-CSF dosing was based on the NMDP weight-based dosing schema rounded to the nearest vial content. Donors were divided into normal, overweight, obese, and morbidly obese categories based on BMI. Multivariate analysis of collection yields between cohorts were done using linear regression analysis. Stepwise variable selection was used to add variables to the model: BMI group and G-CSF dose was forced into the final model as the variables of interest. Pain and acute toxicities at each time point were described using frequencies and compared between groups using chi-squared test or Fisher's exact test after adjusting for donor and baseline characteristics. Results. Examination of 20, 884 PBSC donors mobilized by G-CSF revealed a significant increase in collection yield in obese and morbidly obese compared to normal and overweight donors. Median CD34+ per liter of blood processed (x106/L) on Day 5 of G-CSF was 29.6, 36.4, 40.8 and 42.9 in normal, overweight, obese and morbidly obese donors, respectively (p