Gamida Cell Research Articles

Phase I Study of FT516, an Off-the-Shelf iPSC-Derived NK Cell Therapy, in Combination with Rituximab in Patients with Relapsed/Refractory B-Cell Lymphoma

Phase I Study of FT516, an Off-the-Shelf iPSC-Derived NK Cell Therapy, in Combination with Rituximab in Patients with Relapsed/Refractory B-Cell Lymphoma

Anakinra Targeting Cytokine Release Syndrome Associated with Chimeric Antigen Receptor T-Cell Therapies

Introduction: Cytokine release syndrome (CRS) is a common toxicity associated with chimeric antigen receptor (CAR) T-cell therapies. Corticosteroids and steroid-sparing therapies such as tocilizumab, an interleukin-6 receptor antagonist, and anakinra, an interleukin-1 receptor antagonist, have been used to reduce the incidence and severity of these toxicities. Preclinical and clinical case studies of anakinra, administered subcutaneously or intravenously at various doses, have shown promising results in the management of CRS and systemic inflammatory responses resembling hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS). In CARTITUDE-1, CRS occurred in 95% of heavily pretreated patients with relapsed/refractory multiple myeloma (RRMM) receiving ciltacabtagene autoleucel (cilta-cel), a CAR T-cell therapy with 2 B-cell maturation antigen-targeting single-domain antibodies (Berdeja et al. Lancet 2021). Per protocol, tocilizumab was required to manage CRS with option to give steroids and/or anakinra per investigator discretion. Here, we report the institutional experiences of anakinra use in the management of CRS in patients who have received cilta-cel as part of the CARTITUDE-1 study.Methods: Eligible patients had MM and received ≥3 prior therapies or were refractory to a proteasome inhibitor (PI) and immunomodulatory drug (IMiD), and had received a PI, IMiD, and anti-CD38 antibody (Berdeja et al. Lancet 2021). After apheresis, bridging therapy was permitted. Patients received a single cilta-cel infusion (target dose: 0.75×10 6 CAR+ viable T cells/kg; range 0.5-1.0×10 6) 5-7 days after lymphodepletion (300 mg/m 2 cyclophosphamide, 30 mg/m 2 fludarabine daily for 3 days). Lee et al (Blood 2014) grading criteria for CRS were mapped to the ASTCT criteria for CRS. Post-hoc analysis of data revealed use of anakinra at some sites in patients who failed to respond to the initial management of CRS with tocilizumab +/- dexamethasone or in clinical settings where rise of ferritin and/or liver function tests were indicative for continued HLH/MAS-like manifestations (Kennedy et al. ASH 2020).Results: Of 97 patients in CARTITUDE-1, CRS occurred in 92 (95%) patients; 4% were grade 3/4. The median time to onset was 7 days (range 1-12) and median duration was 4 days (range 1-14). Supportive measures to treat CRS were administered to 91% of patients, most commonly tocilizumab (69%; 4 patients received ≥3 doses), corticosteroids (22%), and anakinra (18 patients, 19%). CRS resolved in 99% of patients. Anakinra was administered after initial tocilizumab and within the first 48 hours (range 0-6 days) of CRS onset for the majority of patients as part of effective management of CRS. Anakinra was administered at a dose of 100-200 mg every 8-12 hours over a median of 2.5 days (range 1-15 days). CRS uniformly resolved following anakinra use in CARTITUDE-1, apart from one patient who died from sepsis (grade 5 outcome) due to HLH/MAS considered related to treatment (Table).Conclusions: CRS events in cilta-cel-treated patients in CARTITUDE-1 were common, generally low-grade, and successfully managed with standard tocilizumab +/- dexamethasone. The use of anakinra should be considered in patients with persistent CRS/inflammatory symptoms despite tocilizumab use, and in particular in patients with HLH/MAS-like symptoms/phenotype occurring following CRS or in the absence of prior CRS. [Display omitted] DisclosuresWong: Amgen: Consultancy; Genentech: Research Funding; Fortis: Research Funding; Janssen: Research Funding; GloxoSmithKlein: Research Funding; Dren Biosciences: Consultancy; Caelum: Research Funding; BMS: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees. Richard: Karyopharm, Janssen: Honoraria. Lin: Juno: Consultancy; Legend: Consultancy; Merck: Research Funding; Bluebird Bio: Consultancy, Research Funding; Sorrento: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Takeda: Research Funding; Gamida Cell: Consultancy; Vineti: Consultancy. Madduri: Janssen: Current Employment. Jackson: Janssen: Current Employment; Memorial Sloan Kettering Cancer Center: Consultancy. Zudaire: Janssen: Current Employment. Romanov: Janssen: Current Employment. Trigg: Janssen: Current Employment. Vogel: Janssen Global Services, LLC: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Divested equity in a private or publicly-traded company in the past 24 months. Garrett: Legend Biotech USA: Current Employment. Nesheiwat: Legend Biotech USA: Current Employment. Martin: Oncopeptides: Consultancy; Sanofi: Research Funding; Janssen: Research Funding; GlaxoSmithKline: Consultancy; Amgen: Research Funding. Jagannath: Bristol Myers Squibb: Consultancy; Legend Biotech: Consultancy; Karyopharm Therapeutics: Consultancy; Janssen Pharmaceuticals: Consultancy; Takeda: Consultancy; Sanofi: Consultancy. OffLabel Disclosure:At the time of abstract submission, cilta-cel is being investigated for the treatment of multiple myeloma but is not yet approved

Outcomes with “Off the Shelf” Allogeneic CD19 Chimeric Antigen Receptor T Cell Therapy for Hematological Malignancies: A Systematic Review and Meta-Analysis

Background:Chimeric antigen receptor T cell (CAR-T) therapy is an adoptive T cell immunotherapy that employs the genetically modified T cell to attack the cancer cell. It is widely studied across various hematological and solid organ malignancies. Several autologous CD19 CAR-T cell therapy constructs are now approved for various B cell lymphomas, including aggressive B cell lymphomas, indolent follicular lymphoma and mantle cell lymphoma, and acute lymphoblastic leukemia (ALL). Autologous CD19 CAR-T cell therapy has unprecedented success in relapsed and refractory disease. Long time to manufacture (2-5 weeks) and manufacture failure are challenges associated with risk of interim death and deterioration of CAR-T candidates with rapidly progressive disease. T cell fitness of the autologous product in heavily pretreated patients is also potentially compromised. To overcome these shortcomings, universal “off the shelf” allogeneic CAR-T cell therapy constructs are being developed and studied. Donor sources include healthy donors and cord or induced pluripotent stem cells (iPSCs). These CAR-T constructs have additional gene modifications to mitigate the risk of rejection and graft versus host disease (GVHD). We performed a systematic review and meta-analysis to assess the safety and efficacy of allogeneic CD19 CAR-T cell therapy.Methods:Four databases (Web of Science/MEDLINE/PubMed, Embase, and Cochrane Registry of Controlled Trials) were searched for this systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using MeSH terms and keywords for “Receptors, Chimeric antigen” OR “Artificial-T-cell receptor” OR “immunotherapy, adoptive” OR “CD-19”. Our search produced 3506 articles and after removing duplicates, 2243 records were screened. After excluding reviews and irrelevant articles, we included 8 prospective trials of allogeneic CD-19 CAR-T cell therapy enrolling two or more than two patients from Jan 2013 to Nov 2020. We also searched ASH 2020 abstracts to include any additional trials. The methodological quality of the included studies was evaluated using NIH quality assessment tool. Inter-study variance was calculated using the Der Simonian-Laird Estimator. Proportions along with 95% confidence Interval (CI) were extracted to compute pooled analysis using the ‘meta’ package by Schwarzer et al. in the R programming language (version 4.16-2).Results:A total of 68 patients from 8 studies were evaluated. Median age was 22.5 (4.8-64) years. (Table 1) The median follow-up time was 10 (2-18) months with median number of prior therapies of 3.2 (2-11) as reported by 5 studies. Underlying diagnosis was acute lymphocytic lymphoma (n=49, 72%), chronic lymphocytic leukemia (n=6, 9%), and non-Hodgkin lymphoma (n=13, 19%). The pooled overall response rate (ORR) was 77% (95% CI 0.63-0.89, I 2 =22%, n=68) with a complete response (CR) of 75% (95% CI 0.57-0.90, I 2 =48%, n=65). The pooled incidence of cytokine release syndrome grade I/II and grade III/IV was 53% (95% CI 0.16-0.89, I 2 =89%, n=65) and 10% (95% CI 0.01-0.25, I 2 =50%, n=65) respectively. Neurotoxicity grade I/II was 12% (95%CI 0.01-0.30, I 2 =47%, p=0.09, n=47) and GVHD grade I/II was 8% (95%CI 0.01-0.19, I 2 =0%, p=0.57 n=53). None of the clinical trials reported the duration of response.Conclusion:“Off the shelf” universal CAR-T therapy is early in development. Our available data suggest that allogeneic CD19 CAR-T constructs offer high ORR and CR rates with acceptable safety profiles. GVHD was mainly low grade (grade I-II). Given these findings, allogeneic CAR-T cell therapy is an attractive option to improve timely access compared to available autologous therapy. Extensive preclinical research to develop novel constructs and several phase I/II clinical trials are ongoing to shape the future of “off the shelf” CAR-T cell therapy. [Display omitted] DisclosuresHoffmann: Pharmcyclics: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; celgene: Consultancy, Honoraria. Abhyankar: Incyte/Therakos: Consultancy, Research Funding, Speakers Bureau. McGuirk: Fresenius Biotech: Research Funding; Gamida Cell: Research Funding; Pluristem Therapeutics: Research Funding; EcoR1 Capital: Consultancy; Novartis: Research Funding; Astelllas Pharma: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Bellicum Pharmaceuticals: Research Funding; Allovir: Consultancy, Honoraria, Research Funding.

Response to Bridging Therapy As a Predictor of Outcomes for Chimeric Antigen Receptor Therapy in Large B-Cell Lymphoma

Background: Bridging therapy (BT) was not allowed in the ZUMA-1 pivotal trial for axicabtagene ciloleucel (axi-cel) chimeric antigen receptor T-cell therapy (CAR-T) . Since then, several real-world studies have shown the use of bridging therapy to be associated with worse overall survival, duration of response, and complete remission rates. In addition, patients requiring BT during CAR-T manufacturing have a more aggressive and higher tumor burden of disease, also factors associated with poor outcomes. Therefore, factors that can predict outcomes in this high-risk patient cohort are required. We herein examine the impact of response to BT on CAR-T outcomes in large B-cell lymphoma (LBCL).Methods: A retrospective review of patients who received axi-cel for NHL from June 2016 - July 2020 at Mayo Clinic, Rochester, was performed. BT was defined as any lymphoma-directed therapy given between leukapheresis and CAR-T infusion. Patients received BT if there were concerns for symptomatic progression of disease during CAR-T manufacturing, reducing the likelihood of eligibility to receive CAR-T. The decision and choice of BT were at the discretion of the treating physician. Response to all lymphoma-directed therapy was evaluated using the 2014 Lugano criteria. Response to BT included patients with a partial response (PR) or stable disease (SD) on PET-CT before initiating lymphodepletion chemotherapy. Event-free survival (EFS) was defined as the time from axi-cel infusion to progression, next treatment, or death. Overall survival (OS) was defined as the time from axi-cel infusion to death. Survival curves were calculated using Kaplan-Meier estimates and were compared between subgroups using the log-rank test. Cox regression was used for univariate and multivariate analysis (MVA).Results: A total of 73 patients underwent car T therapy during this period. Of these, 67% (49/73) received BT therapy. Table 1 shows baseline characteristics of the total BT cohort (n = 49). The median age at CAR-T infusion was 59 years (IQR 46-64); 57% were males and comprised of 47% (23/49) DLBCL followed by 31% (15/49) high-grade B-cell lymphoma types. Based on the Lugano criteria on PET-CT, 22/49 (45%) patients responded to BT. The baseline characteristics were comparable between the responders and non-responders to BT except for a higher proportion (73%) of patients receiving systemic chemotherapy as BT in the responders (Table 1). At a median follow-up of 24 months, 75% had either progressed, died, or started the next treatment (event), and 59% (29/49) had died. The median EFS was significantly longer in the responders as compared to the non-responders to BT, figure 1 (13.04 months (95%CI, 3.54-not reached [NR]) vs. 2.56 months (95%CI, 1.18-3.02), p = 0.002). The OS also trended in favor of the responders (median OS 18.4 months (95% CI, 13.44-NR) vs. 11.84 months (95% CI, 5.05-NR), p = 0.092). The responder group also had a higher 6-month CR rate of 50% than 11.1% in the non-responder group (p = 0.004). There were no differences in any grade or grade ≥ 3 cytokine release syndrome and neurotoxicity rates in the two groups. On univariate analysis within the bridging group (n = 49), type of bridge (non-chemo) and response to bridge (PR+SD) were associated with a better EFS. In the MVA, only response to BT maintained significance for EFS (HR 0.34, p = 0.025).Conclusions: Having some control of lymphoma after BT was associated with better EFS and 6-month CR rate. Future studies need to prospectively evaluate the type and response to BT as a prognostic factor for improving outcomes in patients receiving CAR-T. [Display omitted] DisclosuresWang: InnoCare: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Genentech: Research Funding; MorphoSys: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Paludo: Karyopharm: Research Funding. Bennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Kite, a Gilead Company: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Bluebird Bio: Consultancy, Research Funding; Juno: Consultancy; Legend: Consultancy; Sorrento: Consultancy; Gamida Cell: Consultancy; Vineti: Consultancy; Merck: Research Funding; Takeda: Research Funding.

Clinical Experience in the Randomized Phase 3 Sierra Trial: Anti-CD45 Iodine (131I) Apamistamab [Iomab-B] Conditioning Enables Hematopoietic Cell Transplantation with Successful Engraftment and Acceptable Safety in Patients with Active, Relapsed/Refractory AML Not Responding to Targeted Therapies

Clinical Experience in the Randomized Phase 3 Sierra Trial: Anti-CD45 Iodine (131I) Apamistamab [Iomab-B] Conditioning Enables Hematopoietic Cell Transplantation with Successful Engraftment and Acceptable Safety in Patients with Active, Relapsed/Refractory AML Not Responding to Targeted Therapies

Peak Absolute Lymphocyte Count Post CAR-T Is Associated with Clinical Response and Survival Outcome in Aggressive Lymphoma

IntroductionChimeric antigen receptor T cell (CAR-T) expansion has been consistently identified as a predictor of clinical response. However, there are no clinically available test to measure CAR-T presence after infusion for the FDA approved CAR-T therapy. We hypothesize that the lymphocyte expansion which can be readily measured as absolute lymphocyte count (ALC) in blood count differential could be a clinically accessible surrogate for CAR-T expansion in patients who receive FDA approved CD19 CAR-T to treat aggressive B-cell non-Hodgkin lymphoma (NHL). We examined the ALC levels in the first 2 weeks after CAR-T infusion and correlation with clinical outcomes in NHL patients who received CAR-T at our institution.MethodsRecords were reviewed for patients who received CAR-T between 6/2016 and 1/2021 at Mayo Clinic, Rochester. CAR+ T cells were identified by flow cytometry using an anti-FMC63 antibody. Receiver operator curve was generated using nominal logistic regression to predict complete response (CR) as best response. Progression-free survival and overall survival were calculated using Kaplan-Meier method and between-group differences were assessed using log-rank test. Continuous variables were compared using wilcoxon text and categorical variables were compared using chi-square test.ResultsAmong the 87 patients who received CAR-T for NHL, majority of the pts received axicabtagene ciloleucel (86, 99%). The highest ALC level (ALC peak) in the first 15 days were identified for all patients and median ALC peak was 0.44 X10 9/L (range, 0 - 2.55x10 9/L). The median time to ALC peak was 10 ±3 days. Increasing ALC peak levels correlated with increased CAR+ T cells in blood measured by flow cytometry (n=16, R=0.63, p=0.0008). Using ROC analysis, an ALC peak level of 0.67 was identified as the cut point for best association with CR (AUC=0.68, p=0.0004). Baseline demographics were similar between the high ALC peak (N=35) and low ALC peak (N=52) groups, as shown in Table 1. There was no difference in the incidence, high grade, or duration of cytokine release syndrome (CRS) and immune effector associated neurotoxicity syndrome (ICANS) between the two groups (Table 2). Patients who received a higher cumulative dose of steroid for management of CRS and ICANS had lower ALC peak. A higher ALC peak was associated with an increased CR rate and durable CR at month 6. Similarly, a higher ALC peak was associated with increased progression-free survival (PFS, 6.4 months vs. 2.7 months, p=0.004) and overall survival (OS, 31 months vs. 12 months, p=0.04), as shown in figure 1.ConclusionGiven the typical CAR-T expansion seen in the first 2 weeks post infusion, ALC peak in the first 15 days is a clinically accessible, reliable surrogate for CAR-T expansion and predicts durable CR and longer PFS, OS.This study was supported in part by the Mayo Clinic Center for Individualized Medicine, Bernard E. and Edith B. Waterman, Henry J. Predolin Foundation and other generous benefactors of Mayo Clinic. [Display omitted] DisclosuresBennani: Verastem: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Vividion: Other: Advisory Board; Kymera: Other: Advisory Board. Paludo: Karyopharm: Research Funding. Wang: Genentech: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding; InnoCare: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Janssen: Consultancy, Research Funding; Legend: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Vineti: Consultancy; Gamida Cell: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Novartis: Consultancy; Takeda: Research Funding; Merck: Research Funding; Sorrento: Consultancy; Juno: Consultancy.

Outcomes with Natural Killer Cells Infusion after Allogeneic Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Background:Natural killer cells (NK) are known to be the first cells that recover after allogeneic hematopoietic stem cell transplant (HCT). NK cells have anti-leukemic and anti-viral properties and are also implicated in the graft versus leukemia (GVL) effect without causing graft versus host disease (GVHD). There is emerging evidence supporting the use of NK cells post-transplant as adoptive immunotherapy to prevent or treat the relapse of hematologic malignancies. Here, we present a systematic review and meta-analysis aimed to investigate the outcomes with NK cells infusion after HCT.Methods:A detailed literature search was conducted for the systematic review and meta-analysis according to the guidelines mentioned in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Population, intervention, comparison, and outcome (PICO) table was developed and three electronic databases (PubMed, Cochrane Library, and ClinicalTrials.gov) were searched through January 2021 using MeSH terms and keywords for “hematologic malignancy and natural killer cells” and “hematopoietic stem cell transplantation and natural killer cells”. No filters or publication time limits were applied for the search. A total of 988 records were identified through database searching. After excluding duplicates, review, and non-relevant articles, we selected 9 studies that reported outcomes with NK cells infusion after HCT. Quality evaluation was done using the NIH quality assessment tool and Inter-study variance was calculated using the Der Simonian-Laird Estimator. Pooled analysis was done using the ‘meta’ package (Schwarzer et al, R programming language) and proportions with 95% confidence intervals (CI) were computed.Results:We identified 9 studies with a total of 149 participants. Out of these, 53 patients were from 4 studies using NK cells for the treatment of relapsed disease after HCT (therapeutic studies) and 96 patients were from 5 studies using NK cells to prevent relapse after HCT (pre-emptive studies).Therapeutic use of NK cells for relapsed disease after HCT: A total of 53 patients from 4 studies were evaluated. The median age of patients was 44.5 (1.9-69) years, and 40% patients were male. The median follow-up was 20 (1-69) months. Overall survival (OS) was reported by two studies at 2 years and was 36.3% and 55%. The pooled complete response (CR) was 18% (95% CI 0.06-0.33, I 2 =0%, n=37) and overall response rate (ORR) was 45% (95% CI 0.20-0.71, I 2 =71%, n=53). The pooled relapse rate was 65% (95% CI 0.32-0.92, I 2 =75%, n=42). The pooled incidence of acute GVHD and chronic GVHD was 15% (95% CI 0.03-0.31, I 2 =41%, n=53) and 8% (95% CI 0.01-0.18, I 2 =0%, n=53) respectively.Pre-emptive use of NK cells to prevent relapse after HCT: A total of 96 patients from 5 studies were evaluated. The median age of patients was 33.5 (2-75) years, and 48% patients were males. The median follow-up was 23.1 (8-81.6) months. The median OS was 1 (0.63-5) years. The pooled CR was 45% (95% CI 0.21-0.70, I 2 =76%, n=83) and ORR was 89% (95% CI 0.57-1.00, I 2 =77%, n=42). The pooled relapse rate was 35% (95% CI 0.20-0.52, I 2 =55%, n=96). The pooled incidence of acute GVHD and chronic GVHD was 30% (95%CI 0.14-0.48, I 2 =61%, n=96) and 8% (95%CI 0.00-0.24, I 2 =73%, n=96) respectively.Conclusion:Infusion of NK cells after HCT to prevent relapsed disease results in favorable outcomes with an acceptable toxicity profile. Optimal use of NK cells infusions after HCT is in a pre-emptive fashion to prevent relapsed disease and the efficacy of NK cells infusions after HCT in the setting of overt hematologic relapse is modest. Our findings suggest the need for large prospective clinical trials to establish the potential benefit of NK cells infusion after HCT to prevent relapse of hematologic malignancies without increased non-relapse mortality. [Display omitted] DisclosuresAbhyankar: Incyte/Therakos: Consultancy, Research Funding, Speakers Bureau. McGuirk: Bellicum Pharmaceuticals: Research Funding; Gamida Cell: Research Funding; Novartis: Research Funding; Novartis: Research Funding; EcoR1 Capital: Consultancy; Fresenius Biotech: Research Funding; Astelllas Pharma: Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Pluristem Therapeutics: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau.

Lesion Characteristics and Patterns of Failure in Diffuse Large B Cell Lymphoma Patients Treated with Bridging Radiotherapy Prior to Chimeric Antigen Receptor T Cell Therapy

Lesion Characteristics and Patterns of Failure in Diffuse Large B Cell Lymphoma Patients Treated with Bridging Radiotherapy Prior to Chimeric Antigen Receptor T Cell Therapy

Response to COVID-19 Vaccination Post-CAR T Therapy in Patients with Non-Hodgkin Lymphoma and Multiple Myeloma

Response to COVID-19 Vaccination Post-CAR T Therapy in Patients with Non-Hodgkin Lymphoma and Multiple Myeloma

Meta-Analysis of Ciltacabtagene Autoleucel Versus Physician's Choice in the Treatment of Patients with Relapsed or Refractory Multiple Myeloma

Meta-Analysis of Ciltacabtagene Autoleucel Versus Physician's Choice in the Treatment of Patients with Relapsed or Refractory Multiple Myeloma

Large-Scale, Bioreactor-Generated Expansion of Umbilical Cord Blood Tissue-Derived Mesenchymal Stromal Cells for Clinical Use

Background: Over the past decade, bone marrow-derived mesenchymal stromal cells (BM-MSCs) have been used therapeutically in a variety of clinical settings including graft versus host disease, ischemic/non-ischemic cardiovascular disease, ischemic stroke and as gene-delivery vehicles. Limitations with BM-MSCs include the declining number and differentiation potential of the cells with increasing donor age, the inconsistent quality of BM-MSC products and the invasiveness of the requisite BM aspiration procedure. Following a normal infant birth, the cord blood tissue (CBt) is typically discarded, thus collection of the starting material is non-invasive. CBt-MSCs can expand to higher numbers more rapidly than BM-MSCs, and have similar immunosuppressive properties. We therefore chose to develop a GMP-compliant procedure to generate large numbers of CBt-MSCs for clinical use.Methods. CBt was obtained from consented healthy mothers of full term neonates following elective cesarean section. The CBt was transported in plasmalyte with penicillin/streptomycin. The CBt was cut into 7 equal fractions and incubated for 76 minutes in 370C in C-Tubes (Miltenyi) with various enzyme combinations including collagenase-NB4/6(Serva) and hyaluronidase (Sigma Aldrich) with or without DNase (Genentech) in the GentleMACS Octo Dissociator (Miltenyi). The cell suspension was filtered, washed and resuspended in alpha-MEM media containing 10% Platelet lysate, L-glutamine, heparin (complete media) with pen-strep and seeded into T175 flasks, then cultured until the MSCs were 80% confluent. The cells were harvested and expanded to P1 in T175 flasks to 80% confluence using complete media without antibiotics. After harvest of P1, the MSCs were analyzed for the expression of the typical MSC surface markers by flow cytometry and cryopreserved. Expansion was subsequently performed in a Quantum Bioreactor (Terumo) for 5-6 days. Immunosuppressive potential of CBt-MSCs was tested in vitro by CD4+ T cell proliferation assay (CFSE) and CD4+ T cell cytokine secretion assay. Half of the CBt-MSCs were preactivated with Interferon Gamma, then seeded into a 96 well plate and the others were seeded untreated. The following day, the MSCs were incubated with 10⁵ isolated CD4+ T cells at ratios of 1:1, 1:2, 1:10 and 1:20. CD3/28 beads (ThermoFisher Scientific) were added to all wells except the negative control. Isolated T cells were stained with CFSE for 10 minutes then incubated with 10% Fetal Bovine Serum (FBS) prior to co-culture with MSCs. After 72 hours, the wells were treated with BFA (10X), PMA (100X) and ionomycin (10X). Half of the wells were harvested, washed and stained with anti-CD4 (Biolegend) and Live-Dead dye (ThermoFisher Scientific). After Cytofix/Cytoperm Fixation and Permeabilization Solution (BD Biosciences), then 1X buffer were added, cells were stained for IL-2 (BD), TNF-alpha (BD) and Interferon gamma (BD Biosciences). On day 5, the remaining wells were harvested and stained with anti- CD4-APC (Biolegend) and Live-Dead (ThermoFisher Scientific). Flow cytometry was performed on all samples using the Fortessa X20 (BD Biosciences), then analyzed with FlowJo software.ResultsFollowing enzymatic digestion, the samples without DNase had poor P0 to P1 growth (less than 80% confluent by day 10) thus were eliminated. NB4, hyaluronidase and DNase became the standard enzyme combination. After seeding the Bioreactor with a median of 51 x 10E6 CBt-MSCs (range 45 to 62x10E6 cells), expansion in the Bioreactor for 5-6 days yielded a median of 1495 x 10E6 CBt-MSCs (range 1245 to 1935 x 10E6). The median doubling time (the time required for MSCS to proliferate and double in number) for CBt-MSCs was 28.2 hours (range 24.5 to 29.7) (n=3). The immunosuppression assay demonstrated that CBt MSCs inhibit the proliferation of CD4+ T cells in a dose-dependent manner. Moreover, CBt-MSCs reduce the cytokine expression on stimulated CD4+ T cells (interferon-gamma, tumor necrosis factor-a, IL-2) with each successive generation of CD4+ T-cells.Conclusion: We standardized a GMP-compliant protocol for the isolation of MSCs from whole CBt. Large-scale expansion of CBt-MSCs with immunosuppressive properties can be generated quickly and efficiently in the Terumo bioreactor. Clinical trials with these cells are planned. DisclosuresKurtzberg:Gamida Cell: Research Funding.

A Novel Single Next-Generation Sequencing (NGS) Approach for the Molecular Karyotyping and Genotyping of Patients with Myelodysplastic Syndromes

Myelodysplastic Syndromes (MDS) are a heterogeneous group of diseases, characterized by the clonal acquisition of somatic point mutations and chromosomal alterations. Conventional karyotyping remains one of the most important tools for MDS diagnosis because several cytogenetics abnormalities can be used to stratify patients into subtypes with different prognoses. However, a non-informative cytogenetics due to normal or unsuccessful karyotype could lead to an erroneous estimation of the prognostic risk. To overcome this drawback, we assessed the reliability of a single Next-Generation Sequencing (NGS) assay to simultaneously detect Single Nucleotide Variations (SNVs), including small indels, as well as Copy Number Alterations (CNAs) and copy-neutral Loss of Heterozygosity (cnLOH) for diagnostic application.We combined a custom panel, targeting 40 genes frequently implicated in myeloid neoplasms, with a target enrichment design (OneSeq, Agilent®), having a genome-wide backbone resolution of 1 Mb and 10 Mb for CNAs and cnLOH, respectively. Sequencing libraries were prepared following the “SureSelectQXT Library Prep” protocol and sequenced using the NextSeq 500 platform (Illumina®). Data processing and variant annotation were performed using an integrated in-house bioinformatic pipeline. SNVs and small indels were selected based on allele frequency (VAF ≥ 3%), their absence in the healthy population (UCSC Common SNP; MAF < 1%) and their putative effect on splicing and protein. For CNAs and cnLOH detection, we combined the analysis of the sequencing depth, using the DECoN tool, with the B-allele frequency (BAF) for a selection of high minor allele frequency single nucleotide polymorphisms. The CNA pathogenicity was evaluated taking into account gene content, frequency in the general population (e.g . Database of Genomic Variants) and reports in the literature.We performed a pilot study with a cohort of 30 patients clinically diagnosed with primary MDS at La Fe University Hospital in Valencia. Samples were analysed in parallel by NGS and CytoScanTM HD array (Affymetrix®) in order to establish criteria and thresholds for accurate filtering of sequencing data, especially for CNA identification and calculation of analytical sensitivity. Currently, we are evaluating the reliability of these criteria in a separate cohort of 30 additional patients.Preliminary results in the test cohort showed that we were able to identify at least one point mutation in 29 of 30 patients, with an average of 2 mutations per sample (range 0-7). Mutations were detected in 20 of the 40 genes covered in the panel. The epigenetic modifier TET2 was the most frequently mutated gene in the cohort (9 of 30 cases), followed by two splicing genes, SF3B1 and SRSF2 (each 8 of 30). In addition, we observed some of the described gene correlations, such as the co-occurrence of mutations in IDH2 and SRSF2 genes and the mutually exclusive presence of SF3B1 and SRSF2 .Although cytogenetic studies identified chromosomal abnormalities in 9 of 30 of cases, the number of MDS-related copy number changes detected by sequencing increased to 20 cases, including 9 with normal and 1 with unsuccessful karyotype. We observed the frequent CNAs, such as chromosome 5q and 7q deletions, 4 and 3 cases, respectively, the complete duplication of chr21 in 1 case and 9 cnLOH events. Interestingly, in patients with normal karyotype, although we focused on large chromosomal abnormalities, we have detected at least 3 small events (6-14 Mb) leading to focal deletions of ETV6, BTG1 and RUNX1 genes, as well as 6 cnLOH events, 2 of which involved chr7q22q36.We obtained a high level of concordance between clinical relevant CNAs larger than 1 Mb identified by the CytoScanTM HD array and our sequencing approach. However, the variation in probe distribution in the two backbones was responsible for differences in the detected sizes of deletions and duplications in ~10% of the observed CNAs.This NGS strategy allowed the identification of point mutations and large chromosomal alterations with a resolution of 1 Mb using a single assay, as well as other alterations invisible to conventional cytogenetics, such as cnLOH. Although automating the bioinformatic pipeline is still ongoing, this study demonstrated that a comprehensive NGS-based genomic approach could contribute to improve MDS diagnosis and prognosis. DisclosuresSanz:Gamida Cell: Research Funding.

Rapid Screening of Targetable Kinase Gene Fusions in Acute Lymphoblastic Leukemia

Background: Philadelphia-like (Ph-like) acute lymphoblastic leukemia (ALL) is a high-risk subtype characterized by a similar expression profiling to ALL with BCR-ABL rearrangement, but due to different genomic alterations that activate cytokine receptor and kinase signaling. Diagnose of this type of leukemia is challenging and current diagnostic algorithms include a combination of different techniques, most of them time-consuming and expensive.Here we present a multi-probe Fluorescence In Situ Hybridation (FISH)- Panel based screening test that permit a rapid diagnosis of ALL (including Ph-like ALL).Methods: We analysed 42 adolescent and adult patients (13 - 72 years old) diagnosed with ALL without BCR/ABL and KMT2A rearrangements. We performed a one-slide custom designed FISH panel in parallel with chromosome banding analysis. The panel included probes for ETV6/RUNX1, KMT2A, BCR/ABL1, E2A, CRLF2/P 2RY8, CSF1R, EPOR, PDGFRB, ABL2, JAK2, and IGH probes (Custom chromoprobe multiprobe ALL, Cytocell).Results: There were no hybridation failures. We identified 30 patients with alterations (71%), 20 of them (67%) with normal karyotype or without metaphases. The most common alterations were E2A deletion (8/30, 27%) [3 patients in a context of E2A/PBX rearrangement], hiperdiplid karyotype (6/30, 20%), ABL2 gain (5/30, 17%), CRLF2/IGH rearrangement (4/30, 13%), ETV6 deletion (4/30, 13%), IGH rearrangement (3/30, 10%) and JAK2 rearrangement (2/30, 7%). All together, Ph-like defining abnormalities comprised 20% of cases.Conclusions: We have validated a rapid and easy test to improve ALL subtype diagnosis, including Ph-like ALL. The panel allowed for 24h-diagnosis in cases without or not assessable metaphases. In conclusion, this panel can be a complementary technique for the immediate identification of most common rearrangements in ALL, particullary those with treatment implications. DisclosuresSanz:Gamida Cell: Research Funding. Solano:Neovii: Honoraria.

Impact of Treatment with Iron Chelation Therapy in Lower-Risk MDS Patients Participating in the European Leukemianet MDS (EUMDS) Registry

BackgroundIron overload/toxicity due to red blood cell transfusions (RBCT) is associated with morbidity and mortality in various patient groups, including patients with lower-risk myelodysplastic syndrome (LR-MDS). Many studies suggested improved overall survival (OS) after iron chelation therapy (ICT), but most studies suffer from methodological problems. In daily practice, many transfused LR-MDS patients receive ICT according to (inter)national guidelines to counteract the effects of RBCT. The value of ICT in LR-MDS remains unproven. The aim of this study is to assess the effect of ICT on OS in LR-MDS patients.MethodsThe EUMDS registry, prospectively collects observational data on LR-MDS patients from 142 centers in 16 countries in Europe and Israel. Three iron chelators are available in Europe for treatment of secondary iron overload, but availability varies between countries. We first assessed the impact of treatment of the three iron chelators on OS. Secondly, we compared the chelated patients with a contemporary control group within the EUMDS registry. The control group consisted of patients who met the eligibility criteria for using ICT (≥15 RBC units, RBCT intensity of ≥1 RBC unit/month during a six-month period between visits, or serum ferritin ≥1000 µg/L), but who did not receive ICT. A Cox proportional hazards model was used, treating receipt of ICT as an time-varying variable. Finally, all transfused chelated and non-chelated patients were compared with a propensity-score matched model (3:1 nearest matching with replacement) in which more confounding factors could be added to Cox model in order to deal with confounding as adequately as possible.ResultsThe EUMDS registry included 2205 patients as of July 2017. At this point, 205 patients received ICT. Table 1 shows the follow-up duration for all patients. Of the chelated patients, 154 received deferasirox as initial chelator, 39 deferoxamine, and 12 deferiprone. Nineteen patients switched from one chelator to another, but usually the treatment period of the 2nd chelator was short compared to the 1st chelator (data not shown). The median time on chelation for all 205 patients was 13 months (range 3-42). Patients receiving ICT were on average younger, had better performance scores and less comorbidities compared to the control group (table 2).Comparison of three iron chelators The OS from the start of ICT for 154 patients treated with deferasirox is not significantly different compared to deferoxamine (n=39; p=0.058). The Hazard Ratio (HR) and 95% confidence intervals (CI) for OS (deferasirox as reference group) adjusted for age, sex, comorbidity, performance status, and cumulative number of RBCT for deferoxamine was 1.95 (0.85-4.50) and for deferiprone 0.38 (0.04-4.06) (Table 2).Comparison with non-chelated control group The control group consisted of 657 non-chelated patients (table 2). The crude HR and 95% CI for OS for all chelated patients was 0.66 (0.52-0.85) (non-chelated group as reference). After adjusting for age, sex, comorbidity, performance status, RBCT intensity, cumulative number of RBCT, and IPSS-R, the HR was 0.75 (0.50-1.15). When the analysis was restricted to the patients treated with deferasirox, the crude HR was 0.61 (0.46-0.81) and the adjusted HR was 0.79 (0.51-1.22).Propensity-matched model The chelated and non-chelated patients were matched for age, RBCT intensity, ferritin level, comorbidity, and performance status. 128 chelated patients and 223 controls could be matched, the overlap of propensity scores in both groups was good (data not shown). The crude HR and 95% CI for OS for the chelated group (non-chelated group as reference) was 0.77 (0.55-1.07). When correcting for age, sex, comorbidity, performance status, RBCT intensity, cumulative RBCT number, and IPSS-R, the HR was 0.62 (0.39-0.98). When we again restricted the analysis to deferasirox, the crude HR was 0.71 (0.48-1.06) and the adjusted HR was 0.58 (0.33-1.01).ConclusionOS of LR-MDS patients treated with ICT, was better compared to a large, control group and significantly better in a propensity-score matched model. In the absence of randomized, controlled trials proving the survival advantage of ICT, our large, prospective, observational study of clinical practice in Europe and Israel provides sound evidence of a beneficial effect of ICT on OS. [Display omitted] DisclosuresFenaux:Novartis: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Sanz:Gamida Cell: Research Funding. skov-Holm:Celgene: Research Funding. Almeida:Alexion: Honoraria; Bristol Meyer Squibb: Honoraria; Servier: Consultancy; Celgene: Consultancy; Novartis: Consultancy. Germing:Novartis: Honoraria, Research Funding; Janssen: Honoraria; Celgene: Honoraria, Research Funding. Itzykson:Janssen: Research Funding; Novartis: Research Funding. Guerci-Bresler:BMS: Speakers Bureau; Incyte: Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Speakers Bureau.

Impact of Red Blood Cell Transfusion Intensity on Progression-Free Survival in Lower-Risk MDS Patients Included in the European Leukemianet MDS Registry

Abstract Background Progression-free survival (PFS) of lower-risk (LR) MDS patients treated with red blood cell transfusions (RBCT) is usually reduced, but whether the RBCT intensity is important for prognosis is unknown. The EUMDS Registry contains data on 2,192 newly diagnosed LR-MDS patients from 16 European countries and Israel, collected at diagnosis and at 6 months intervals.The aim of this analysis is to assess the effect of RBCT intensity on PFS of patients with LR-MDS in a prospective, observational setting. MethodsData on the number of RBCT units received during each visit-interval were analyzed using proportional hazards regression with time-varying co-variates. The cumulative dose received at the end of each interval was divided by the time since the beginning of the interval in which the first RBCT was received rather than for each visit-interval, to give an overall dose density. Dose density rises over time when RBCT intensity increases over time, but declines when patient becomes RBCT independent after treatment. In Cox regression with time-varying covariates, PFS was adjusted by relevant confounders, including age, gender, patient condition (proxied by EQ-5D index), and number of cytopenias at diagnosis. We analyzed a cohort of 1,509 patients with at least 3 visit reports available. Within this group 476 patients have died and 118 patients have progressed to higher-risk MDS or AML, which were defined as events. ResultsPatients with ring sideroblastic MDS (RS-MDS) received more frequently RBCT after diagnosis compared to non-RS-MDS (60% vs 54%). Very low-risk patients according to IPSS-R received RBCT less often compared to intermediate risk patients (35% vs 69%). Age, gender, presence of co-morbidities, and countries influenced RBCT dependency and RBCT rate. The transfused patients were subdivided in 3 groups according to the maximum RBCT rate over time: low rate ( 2 units/month) in order to analyse the impact of the RBCT rate in more detail (figure A). Unadjusted overall PFS stratified this way, is shown in figure B. Univariate analysis of the 404 patients transfused at a high rate showed a strong association of age (p ConclusionThe negative effect of RBCT treatment on PFS already occurs at low RBCT densities below 2 units/month and before 25 units of RBCT have been transfused. This indicates that the RBCT dependency, even at relatively low intensities, may be considered as an indicator of poor prognosis for survival. Download : Download high-res image (93KB) Download : Download full-size image Figure . Disclosures Fenaux: Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Sanz: Gamida Cell: Research Funding. Germing: Janssen: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Almeida: Servier: Consultancy; Alexion: Honoraria; Novartis: Consultancy; Celgene: Consultancy; Bristol Meyer Squibb: Honoraria. Itzykson: Janssen: Research Funding; Novartis: Research Funding. Park: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hospira/Pfizer: Research Funding; Celgene: Research Funding. de Witte: Novartis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Janssen Cilag: Research Funding.

The Impact of Diabetes Mellitus As Comorbid Condition, in Patients with Lower-Risk Myelodysplastic Syndromes (MDS)— a Study of the European Leukemianet-Based MDS (EUMDS) Registry

Background: Myelodysplastic syndrome is mainly a disease of the elderly, while the prevalence of Diabetes Mellitus (DM) in the aged population is about 25%.Aim: We sought to investigate the impact of DM as comorbid condition on the diagnosis of MDS.Patients and methods: We investigated the clinical and laboratory features at time of MDS diagnosis of 431 DM patients, occurring among a total of 2114 MDS patients registered in the EUMDS registry, and compared them with the non-DM patients. Data were collected by 145 centers located in 16 European countries and Israel.Results: The overall incidence of DM at registration visit was 23%. Higher frequency of DM was observed among MDS patients in Israel (40.3%), Portugal (26.3%) and the Netherlands (25.7%) and lower in Denmark (9.3%), Serbia (10.5%) and Romania (13.6%). Diabetic MDS patients were more commonly male (65.6% vs 60.2%, p=0.01), with higher frequency in Portugal (80%), United Kingdom (76.3%) and Greece (72.9%) and lower in Romania (33.3%), Germany (45.5%) and Israel (54.1%). Higher incidence of DM was encountered among patients with MDS-RA (24.3%, more prominently in the Netherlands, Israel and Spain) and lower among those with RCMD-RS (15.4%). Ring sideroblasts were less commonly encountered among DM patients (24.9% vs 29.5%, p: n.s.) and DM patients had a greater proportion of high MDS-CI risk than non-DM (9% vs 4.8%, p<0.001). The Performance Status (Karnofsky scale) was worse in DM than in non-DM patients (“able” persons 69.1% vs 79.4%, p<0.01). Moreover, DM patients were besides antidiabetic treatment more commonly receiving antiplatelet, anticoagulant and antihypertensive drugs, as well as proton pump inhibitors. No significant difference in the prognostic categorization distribution according to IPSS, WPSS or IPSS-R, between DM and non-DM patients was observed. DM patients were more anemic at diagnosis of MDS (Hb: 10.1±1.7 vs 10.3±1.9 g/dl, p=0.03), had lower MCV (95.5±9.6 vs 98.1±10.6 fl, p<0.01), higher WBC count (5.6±3.3 vs 5.0±3.0 x 109/l, p<0.001), and higher absolute neutrophil count (3.3±2.5 vs 2.8±2.2 x 109/l, p<0.001). No significant difference in baseline platelet counts and in the percentages of patients, exhibiting 0, 1, 2 or 3 cytopenias, between DM and non-DM patients was noted. However, DM patients had higher mean serum creatinine levels (102±65 vs 89±35 μmol/l, p<0.001) and among them there was a significant negative correlation between Hb and serum creatinine levels (r= -0.131, p=0.02). All three iron status parameters (serum iron, transferrin saturation and serum ferritin levels were significantly decreased among DM-patients, implying a possible influence of DM on iron metabolism. Serum EPO levels were not significantly different between the two groups, nevertheless, considering that diabetic MDS patients were more anemic, it could be assumed that they might exhibit somewhat blunted response, probably as a result of some degree of impairment of their renal function. Finally, patient-reported Quality of Life, using the EQ-5D tool was significantly lower among DM-, compared to non-DM patients (0.70±0.24 vs 0.75±0.22, p<0.001).Conclusions: Diabetes Mellitus may modulate the common presenting features of MDS, and since some degree of normocytic, normochromic anemia is commonly associated with this disease, special attention is warranted to discriminate the real MDS patients among the diabetic patient population. DisclosuresFenaux:Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Sanz:Gamida Cell: Research Funding. Germing:Janssen: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Almeida:Novartis: Consultancy; Celgene: Consultancy; Bristol Meyer Squibb: Honoraria; Alexion: Honoraria; Servier: Consultancy. Guerci-Bresler:BMS: Speakers Bureau; Incyte: Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Speakers Bureau.

Can We Diagnose MDS without Bone Marrow Examination? a Proposed EUMDS-Based Non-Invasive Diagnostic Model

Background: Bone marrow examination (BME) is the gold standard for diagnosing myelodysplastic syndromes (MDS). Because it is invasive, many physicians and patients (pts) avoid BME, and the MDS Diagnosis is missed. Recently (Oster et al. Int MDS, Valencia, May 2017), we proposed a non-invasive MDS diagnostic model, using logistic regression (LoR) with a small group of patients (47 BME-proven MDS vs 63 controls with no MDS by BME). The variables gender, age, Hb, MCV, PLT and WBC were found to be the most important. Putting the variables in the formula (Fig 1) yielded a score Y, reflecting the probability of having MDS. The area under the curve (AUC) for the ROC curve was 0.748, indicating a good model, but one insufficient to provide a single Y, above which MDS could be established clearly. We therefore established two cut-off values: Pts with Y≥0.633 were found to have high likelihood for MDS, and those with Y≤0.288, a low likelihood of having MDS. Those pts (about 50%) where Y fell between the two cutoffs were indeterminate. In this study, the large European MDS Registry (EUMDS) database was used to validate and improve the model.Methods: The EUMDS registry contains data of 2200 MDS pts. A random sample (age≥65) of 131 MDS pts from the registry, and 115 controls with no MDS were added to the original dataset, providing 178 in each group. Two models, LoR with covariates selected using the Lasso method, and gradient-boosted (GB) were assessed. AUC was used to evaluate the models. Model stability was assessed by repeating the fit of the models using different randomly chosen groups of 131 EUMDS pts that replaced the first 131 EUMDS pt group (random augmentation). Another analysis was performed using all the EUMDS pts.Results: For the LoR model, MCV, PLT and WBC were selected, and the AUC was 0.75 (95% CI 0.70 - 0.80, Fig 2). For the GB model, the AUC was 0.87 (95% CI 0.84-0.91, Fig 2). The most influential variables were MCV and WBC. 50 repetitions of the random augmentation led to a mean AUC of 0.87 (IQR 0.86-0.88), attesting to the stability of the model. Using the entire 2200 pts EUMDS data set also provided consistent results.Conclusions: A classical LoR model using the large EUMDS dataset, confirmed our original finding that using simple parameters, MDS can be diagnosed or excluded in a large portion of pts without BME. Using the complex GB model, that not only combines the chosen variables, but also takes into account the interactions among them, the AUC approaches 90%. We will continue to improve and validate the model. In our original model using two cutoff points, we were able to establish or rule out MDS with high accuracy in approximately 50% of the patients. However, about half of the patients fell within the middle ‘indeterminate’ zone. With this improved AUC, it is likely that the ‘indeterminate’ zone will shrink and we will be able to establish or rule out MDS in an even greater proportion of patients without an invasive BME. Moreover, adding more controls will allow increasing the number of variables (e.g. folic acid, B12) that can have an additional impact on the model and its diagnostic capability. [Display omitted] DisclosuresFenaux:Celgene: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Astex: Honoraria, Research Funding. Sanz:Gamida Cell: Research Funding. Germing:Novartis: Honoraria, Research Funding; Janssen: Honoraria; Celgene: Honoraria, Research Funding. Almeida:Novartis: Consultancy; Celgene: Consultancy; Servier: Consultancy; Alexion: Honoraria; Bristol Meyer Squibb: Honoraria.

Preexisting Mutations in Hematopoietic Stem Cells in Patients with Therapy-Related Myeloid Neoplasms

Introduction: Recently, it has been suggested that some hematopoietic stem cell clones (HSC) harbor preexisting genomic mutations which could be selected for antineoplastic treatments received against a first neoplasm (1st-neo) that might, eventually, lead the development of therapy-related myeloid neoplasms (TRMN).Aim: To analyze genetic mutational profile in a cohort of patients with TRMN from different national centers. To determine the presence of preexisting mutations in HSC by deep massive sequencing: genetic composition and evolutive behavior.Methods: We studied 103 patients with TRMN from 6 national hospitals. The average age was 62 years old (range: 31-89); 45% were men; as 1st-neo: 36% were breast cancer, 34% lymphoma, 5% multiple myeloma and 25% other type of neoplasm. In 18 patients, a paired sample of bone marrow at the moment of the 1st-neo was available [previous disease: lymphoma (n=13), multiple myeloma (n=4), breast cancer neo (n=1)]. We sequenced the complete coding region of the genes: BCOR, BRAF, CDKN2A, CEBPA, DNMT3A, ETV6, EZH2, GNAS, LUC7L2, NF1, PHF6, PTPN11, RAD21, RPS14, SF1, SF3A1, SMC3, SPARC, SRSF2, STAG2 and ZRSR2 and the hotspot regions of genes: ASXL1, MPL, NPM1, JAK2, KRAS, NRAS, TET2, U2AF1, KIT, IDH1, RUNX1, IDH2, SETBP1, TP53, WT1, CBL, SF3B1 and FLT3 with a custom amplicon panel (Ampliseq). Variants were selected according to VAF≥1%, MAF<0,01 and its effects upon the protein. Depth coverage in 1st-neo samples was 10,000x and 2,000x for TRMN.Results: At least one variation was detected in the studied genes in 98% of patients with TRMN (n=101) [321 mutations (263 missense and 58 indels); 3,2 mut/pa (0-12)]. Most frequently mutated genes were TP53 (35%), TET2 (32%), DNMT3A (17%), RAD21 (14%), SETBP1 (12%), IDH2 (8%), SF3B1 (8%) and SRSF2 (7%). Half of the patients with paired sample harbored mutations in the 1st-neo sample (14/18). In total, 27 pathologic variations were detected in these samples (24 SNV and 3 indels). In 4 cases, mutations prevailed after evolution (22%), increasing their variant allelic frequency (VAF) and suggesting the selection of a preexisting clone after antineoplastic treatment (Table 1).Conclusions: At least one variation in the studied genes was detected in 98% of the patients with TRMN, being TP53 mutations the most frequent (35%). In 22% of the cases with paired sample was confirmed the expansion of a clone present in the apparently normal bone marrow at the moment of the first neoplasm, suggesting a possible mechanism of selective pressure in the context of the received antineoplastic therapy.Research funded by CIBERONC CB16/12/00284, PI12/01047, RD12/0036/0014, PIE13/00046, PI13/01640, PI13/02837, PT13/0010/0026, PI14/01649, AC15/00068, PI16/011113 and PI16/00665. [Display omitted] DisclosuresMontesinos:Celgene Corporation: Honoraria, Research Funding. Sanz:Gamida Cell: Research Funding.

A Prognostic Classifier Based on Early Platelet Drop in Lower-Risk MDS. a Study from the European Leukemianet Lower-Risk MDS (EUMDS) Registry

▪Context: Prognosis of lower-risk (IPSS low/int-1) MDS is heterogeneous. Current prognostic systems rely on steady-state values for cytopenias. Capturing the dynamics of these parameters could yield additional prognostic information. We analyzed the prognostic relevance of relative drop (%) in neutrophil (ANC) and platelet (PLT) counts during the first six months follow-up of lower-risk MDS patients included in the EUMDS registry.Methods: TheEUMDS registry includes prospectively patients (pts) within the first 100 days of diagnosis of lower-risk (IPSS low/intermediate-1) MDS. We performed a landmark analysis of overall survival (OS) in pts with a visit at 6±1 months from inclusion to assess the prognostic relevance of a relative drop in ANC and PLT over the first 6 months follow-up. Relative ANC and PLT drops were defined as: (ANC at landmark - ANC at inclusion) / ANC at inclusion, respectively (resp) for PLT.Results: As of Sept 2016,1,800 patients with ≥5 months follow-up were included in the registry. 807 patients with a second visit at 6±1 months from inclusion were analyzed. Reasons for exclusion from this cohort were: no visit within the strict limits of 6±1 month (n=904), no PLT count at baseline (n=40) or 6-month visit (n=20), and no follow-up beyond 6-month visit (n=19). Median age was 73 yr, IPSS-R was very-low, low, intermediate or higher in 26%, 43% 24% and 7% of pts, resp. Median time to landmark was 183 days. Median follow-up from landmark was 37.8 months. Median relative drop in ANC and PLT was 5.2% and 4.6%, resp. At landmark, 41 patients (5%) received treatments affecting ANC or PLT (hypomethylating agents, lenalidomide or hydroxycarbamide). Excluding them did not affect results. Relative ANC and PLT drop were dichotomized at the 25% threshold. Sensitivity analyses with different cutoffs did not affect our final conclusions. Multivariate logistic regressions identified RBC- transfusion dependency (TD) at inclusion (OR=1.7, p=0.02) as the main predictor of 6-month relative PLT drop > 25%, while higher baseline ANC as a continuous value was associated with 6-month ANC drop >25% (10-4). The latter suggests that the dynamic range of ANC does not allow uniform assessment of ANC drop in all MDS patients.In univariate analysis, a relative drop in PLT >25% (HR=2.3, p<10-4) was associated with shorter OS after the 6-month landmark (median 29.2 months vs 57.1 in pts with PLT drop ≤25%, p<10-4), and increased cumulative incidence of progression (CIP: standardized HR: 2.5, p<10-4), while relative ANC drop >25% only predicted higher CIP (standardized HR: 1.5, p=0.03), without significant impact on OS (p=0.12). The adverse prognosis of relative PLT drop was observed regardless of baseline IPSS-R or absolute PLT count at inclusion or landmark.We subsequently divided our cohort in a training (n=403) and a validation (n=404) set to derive a prognostic model applicable at the 6-month landmark. Variables included age, gender and IPSS-R at inclusion, RBC-TD, steady-state PLT and ANC values at landmark, and relative PLT and ANC drop (with the 25% cutoff). Cox models with variable selection by penalized regression identified older age (p<10-4), RBC-TD at landmark (p<10-4) and relative PLT drop >25% (p=0.005) as independent prognostic factors. We built a simple age-independent 6-month EUMDS classifier based on RBC-TD at landmark and relative PLT drop >25%, where patients with none (53%), either (31%) or both criteria (16%) had median OS from landmark of 71, 42 and 19 months, resp, p<10-4). The classifier performed equally well in the validation set (p<10-4). A sensitivity analysis relaxing the timing of landmark drop was carried on an ‘extended cohort’ of 1610 (89%) registry pts with a second visit within ten months of inclusion. This analysis confirmed the adverse prognostic value of a relative PLT drop >25% within 10 months of diagnosis of lower-risk MDS and the broad applicability of the EUMDS classifier, regardless of baseline IPSS-R risk (Figure).Conclusion: Early drop in platelets during the first 6 months of follow-up holds prognostic significance in lower-risk MDS. A 6-month classifier based on RBC-TD at 6 month and a relative platelet drop greater than 25% can inform prognosis of lower-risk MDS independently from IPSS-R. [Display omitted] DisclosuresItzykson:Novartis: Research Funding; Janssen: Research Funding. Sanz:Gamida Cell: Research Funding. Germing:Janssen: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Almeida:Novartis: Consultancy; Celgene: Consultancy; Bristol Meyer Squibb: Honoraria; Alexion: Honoraria; Servier: Consultancy. Fenaux:Astex: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding.

3 - A Multi-Center Biologic Assignment Trial Comparing Reduced Intensity Allogeneic Hematopoietic Cell Transplantation to Hypomethylating Therapy or Best Supportive Care in Patients Aged 50-75 with Advanced Myelodysplastic Syndrome: Blood and Marrow Transplant Clinical Trials Network Study 1102

3 - A Multi-Center Biologic Assignment Trial Comparing Reduced Intensity Allogeneic Hematopoietic Cell Transplantation to Hypomethylating Therapy or Best Supportive Care in Patients Aged 50-75 with Advanced Myelodysplastic Syndrome: Blood and Marrow Transplant Clinical Trials Network Study 1102