Siddiqi, Tanya

Abstract Background: Axi-cel, an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, is approved for the treatment of pts with relapsed/refractory LBCL with ≥ 2 prior systemic therapies. In the 2-year analysis of ZUMA-1 (NCT02348216), the multicenter, single-arm phase 1/2 study evaluating axi-cel in pts with refractory LBCL, the objective response rate (ORR) was 83%, including a complete response (CR) rate of 58%; 39% of pts had ongoing response with a median follow-up of 27.1 months (Locke et al. Lancet Oncol. 2019). EFS is emerging as a robust surrogate endpoint for OS in hematologic malignancies. A recent systematic analysis demonstrated a linear correlation between EFS and OS in pts with diffuse LBCL after first-line immunochemotherapy (Zhu et al. Leukemia. 2020). Here, we report updated survival findings from the phase 2 portion of ZUMA-1 after 4 years of follow-up, including an evaluation of the association of OS with EFS. Methods: Eligible pts had refractory LBCL (diffuse LBCL, primary mediastinal B cell lymphoma, transformed follicular lymphoma). After leukapheresis at enrollment, pts received low-dose conditioning chemotherapy (fludarabine and cyclophosphamide) followed by a target dose of 2×10 6 anti-CD19 CAR T cells/kg (Neelapu et al. N Engl J Med. 2017). The primary endpoint was ORR, with the first response assessment occurring 4 weeks following infusion. Additional endpoints included safety and translational evaluations. An exploratory analysis of OS by EFS at 12 and 24 months was performed. EFS was defined as the time from axi-cel infusion until disease progression, initiation of new lymphoma therapy (excluding stem cell transplant), or death from any cause. Comparisons of OS by EFS outcomes were analyzed via Kaplan-Meier estimates. Results: Of 111 enrolled pts, axi-cel was administered to 101 pts. As of August 11, 2020, median follow-up was 51.1 months. With over 4 years of follow-up, median OS was 25.8 months, and the 4-year OS rate was 44%. Median EFS in pts treated with axi-cel was 5.7 months, with a 12-month EFS rate of 43% (95% CI, 33-52) and a 24-month EFS rate of 38% (95% CI, 28-47). In pts with an EFS event by Month 12 (EFS12; n=57) vs those without EFS12 (n=44), 4-year OS rates were 7% (95% CI, 2-16) vs 91% (95% CI, 78-97), respectively. Among the 17 pts with EFS12 who were alive at Month 12, 13 (76%) died by Month 48, while among the 44 pts alive at Month 12 without EFS12, 4 (9%) died by Month 48. In pts with an EFS event by Month 24 (EFS24; n=62) vs those without EFS24 (n=39), 4-year OS rates were 13% (95% CI, 6-23) vs 92% (95% CI, 78-98), respectively. Among the 12 pts with EFS24 who were alive at Month 24, 4 (33%) died by Month 48, while among the 39 pts alive at Month 24 without EFS24, 3 (8%) died by Month 48. Since the 2-year analysis (Locke et al. Lancet Oncol. 2019), there have been no new safety signals reported, including no new serious adverse events, no axi-cel-related secondary malignancy, and no confirmed cases of replication-competent retrovirus. Overall, 26 pts received subsequent anti-cancer therapy; median time to next therapy was 8.7 months (range, 0.3 - 53.8). Immunoglobulin therapy was administered to 38 (38%) pts. Two pts in axi-cel-induced remission received allogeneic stem cell transplant; 1 pt was in CR and 1 pt was in partial response. Among treated pts, 58 (57%) have died, primarily due to progressive disease (46%; n=46), followed by other reasons (7%; n=7), adverse events (4%; n=4), and secondary malignancy (myelodysplastic syndrome, with onset on Day 574) unrelated to axi-cel (1%; n=1). Among pts without EFS12 and without EFS24, 1 pt each (2% and 3%, respectively) died due to disease progression >24 months following axi-cel infusion; >36 months, 2 pts each (5% for both) died due to disease progression (1 pt each [2% and 3%]) and other reasons (1 pt each [2% and 3%]. One pt (2%) without EFS12 died due to disease progression between 12 and 24 months. Updated findings with ≥5 years of follow-up, including translational correlations, will be presented. Conclusion: In this long-term survival analysis of ZUMA-1 with ≥4 years of follow-up, axi-cel demonstrated longer OS in pts without EFS events at Month 12 and Month 24 vs pts with events at these timepoints. These data support the use of EFS as a surrogate endpoint for long-term OS in refractory LBCL, and the relationship between EFS and 5-year OS will be presented. Disclosures Jacobson: Nkarta: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support; Axis: Speakers Bureau; Pfizer: Consultancy, Honoraria, Other: Travel support, Research Funding; Clinical Care Options: Speakers Bureau; Celgene: Consultancy, Honoraria, Other: Travel support; Precision Biosciences: Consultancy, Honoraria, Other: Travel support; Lonza: Consultancy, Honoraria, Other: Travel support; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Other: Travel support; Humanigen: Consultancy, Honoraria, Other: Travel support. Locke: Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy; Janssen: Consultancy, Other: Scientific Advisory Role; Gerson Lehrman Group: Consultancy; Novartis: Consultancy, Other, Research Funding; Legend Biotech: Consultancy, Other; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role; GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; Emerging Therapy Solutions: Consultancy; Takeda: Consultancy, Other; Wugen: Consultancy, Other; EcoR1: Consultancy; Umoja: Consultancy, Other; Cowen: Consultancy; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Amgen: Consultancy, Other: Scientific Advisory Role; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding. Ghobadi: Atara: Consultancy; Amgen: Consultancy, Research Funding; Wugen: Consultancy; Celgene: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding. Miklos: Pharmacyclics, Amgen, Kite, a Gilead Company, Novartis, Roche, Genentech, Becton Dickinson, Isoplexis, Miltenyi, Juno-Celgene-Bristol Myers Squibb, Allogene, Precision Biosciences, Adicet, Adaptive Biotechnologies: Research Funding; Adaptive Biotechnologies, Novartis, Juno/Celgene-BMS, Kite, a Gilead Company, Pharmacyclics-AbbVie, Janssen, Pharmacyclics, AlloGene, Precision Bioscience, Miltenyi Biotech, Adicet, Takeda: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Patents & Royalties; Kite, a Gilead Company, Amgen, Atara, Wugen, Celgene, Novartis, Juno-Celgene-Bristol Myers Squibb, Allogene, Precision Bioscience, Adicet, Pharmacyclics, Janssen, Takeda, Adaptive Biotechnologies and Miltenyi Biotechnologies: Consultancy. Oluwole: Kite, a Gilead Company: Consultancy, Research Funding; Janssen: Consultancy; Pfizer: Consultancy; Curio Science: Consultancy. Lin: Gamida Cell: Consultancy; Legend: Consultancy; Juno: Consultancy; Takeda: Research Funding; Merck: Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Bluebird Bio: Consultancy, Research Funding; Vineti: Consultancy; Sorrento: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding. Hill: Celgene (BMS): Consultancy, Honoraria, Research Funding; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Gentenech: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Epizyme: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Timmerman: Spectrum Pharmaceuticals: Research Funding; Bristol Myers Squibb: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Bluebird Bio: Current equity holder in publicly-traded company; Marker Therapeutics: Current equity holder in publicly-traded company; Corvus: Current equity holder in publicly-traded company; Genmab: Current equity holder in publicly-traded company; Merck: Research Funding; TG Therapeutics: Current equity holder in publicly-traded company. Deol: Kite, a Gilead Company: Consultancy. Reagan: Seagen: Research Funding; Kite, a Gilead Company: Consultancy; Genentech: Research Funding; Curis: Consultancy. Stiff: Karyopharm: Consultancy, Honoraria; CRISPR Therapeutics: Consultancy, Honoraria; Kite, a Gilead Company: Research Funding; Amgen: Research Funding; Macrogenics: Research Funding; Bristol Myers Squibb: Research Funding; Janssen: Research Funding; Gamida Cell: Research Funding; Seagen: Research Funding; Cellectar: Research Funding; Incyte: Research Funding; BioLineRX: Research Funding; Cellectar: Research Funding; Actinium: Research Funding; MorphoSys: Consultancy, Honoraria. Flinn: Celgene: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; AstraZeneca: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Rhizen Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Loxo: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Agios: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Karyopharm Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Forma Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Infinity Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; ArQule: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Calithera Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Verastem: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Unum Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding; Kite, a Gilead Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Genentech: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; TG Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Roche: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Incyte: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Takeda: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Constellation Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Acerta Pharma: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Novartis: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Gilead Sciences: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Merck: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Seagen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Portola Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; BeiGene: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Juno Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Janssen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Nurix Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Pfizer: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Forty Seven: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Curis: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; IGM Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; MorphoSys: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Great Point Partners: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Teva: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Trillium Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Triphase Research & Development Corp.: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Sarah Cannon Research Institute: Current Employment; Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Seagen: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Unum Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute, Research Funding; Johnson & Johnson: Current holder of individual stocks in a privately-held company; Seattle Genetics: Research Funding. Farooq: Kite, a Gilead Company: Honoraria. Goy: MorphoSys: Honoraria, Other; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; OncLive Peer Exchange: Honoraria; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Research Funding; Michael J Hennessey Associates INC: Consultancy; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria; Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; Medscape: Consultancy; Xcenda: Consultancy, Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Genentech/Hoffman la Roche: Research Funding; Infinity/Verastem: Research Funding; Janssen: Research Funding; Rosewell Park: Consultancy; LLC(Targeted Oncology): Consultancy; Hoffman la Roche: Consultancy; Xcenda: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Genomic Testing Cooperative: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Karyopharm: Research Funding; Phamacyclics: Research Funding; Constellation: Research Funding; COTA (Cancer Outcome Tracking Analysis): Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Hackensack Meridian Health, Regional Cancer Care Associates/OMI: Current Employment. Muñoz: Bayer, Kite, a Gilead Company, Celgene, Merck, Portola, Incyte, Genentech, Pharmacyclics, Seagen, and Janssen, Millennium: Research Funding; Kite, a Gilead Company, Kyowa, Bayer, Pharmacyclics, Janssen, Seagen, Acrotech, Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/Bristol Myers Squibb, Genentech, and Roche: Speakers Bureau; Pharmacyclics, Abbvie, Bayer, Kite, a Gilead Company, Pfizer, Janssen, Juno/Celgene, Bristol Myers Squibb, Kyowa, Alexion, Beigene, Fosun Kite, Innovent, Seagen, Debiopharm, Karyopharm, Genmab, ADC Therapeutics, Epizyme, Beigene, and Servier: Consultancy; Targeted Oncology, OncView, Kyowa, Physicians' Education Resource, and Seagen: Honoraria; OncView: Honoraria; Kyowa Kirin: Honoraria; Physicians' Education Resource: Honoraria. Siddiqi: Oncternal: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Speakers Bureau; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; TG Therapeutics: Research Funding. Shen: Atara: Current Employment, Current equity holder in publicly-traded company, Other: Leadership role, Patents & Royalties; Gilead Sciences: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment, Other: Leadership role, Patents & Royalties. Bot: Kite, a Gilead Company: Current Employment; Gilead Sciences: Consultancy, Current equity holder in publicly-traded company, Other: Travel support. Dong: GliaCure/Tufts: Consultancy, Patents & Royalties; Gilead: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment. Singh: Kite, a Gilead Company: Current Employment. Spooner: Kite, a Gilead Company: Current Employment; Gilead: Current equity holder in publicly-traded company. Karalliyadda: Kite, a Gilead Company: Current Employment; Gilead: Current equity holder in publicly-traded company. Kim: Gilead Sciences: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment. Zheng: Gilead Sciences: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment. Neelapu: Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene Therapeutics, Cell Medica/Kuur, Incyte, Precision Biosciences, Legend Biotech, Adicet Bio, Calibr, Unum Therapeutics and Bluebird Bio: Honoraria; Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene, Kuur, Incyte, Precision BioSciences, Legend, Adicet Bio, Calibr, and Unum Therapeutics: Other: personal fees; Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties; Kite, a Gilead Company, Bristol Myers Squibb, Merck, Poseida, Cellectis, Celgene, Karus Therapeutics, Unum Therapeutics (Cogent Biosciences), Allogene, Precision BioSciences, Acerta and Adicet Bio: Research Funding.

Abstract The SCHOLAR-1 international retrospective study highlighted poor clinical outcomes and survival among patients with refractory large B-cell lymphoma (LBCL) treated with conventional chemotherapy. Axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, demonstrated durable responses in patients with refractory LBCL in the pivotal phase 1/2 ZUMA-1 study (NCT02348216). Here, we compared SCHOLAR-1 with the 2-year outcomes of ZUMA-1. Prior to comparison of clinical outcomes, propensity scoring (based on a broad set of prognostic covariates) was used to create balance between ZUMA-1 and SCHOLAR-1 patients. In the pivotal phase 2 portion of ZUMA-1, 101 patients received axi-cel and were evaluable for response and survival. In SCHOLAR-1, 434 and 424 patients were evaluable for response and survival, respectively. ZUMA-1 patients were more heavily pretreated than were SCHOLAR-1 patients. The median follow-up was 27.1 months in ZUMA-1. The objective response rate (ORR) and complete response rate were 83% and 54% in ZUMA-1 vs 34% and 12% in SCHOLAR-1, respectively. The 2-year survival rate was 54% in ZUMA-1 and 20% in SCHOLAR-1, and a 73% reduction in the risk of death was observed in ZUMA-1 vs SCHOLAR-1. These results were consistent with those of an additional standardization analysis in which strata were limited to 2 prognostic factors (refractory categorization and presence/absence of stem cell transplant after refractoriness to chemotherapy) to conserve sample size. Despite the limitations of a nonrandomized analysis, these results indicate that axi-cel produces durable responses and a substantial survival benefit vs non–CAR T-cell salvage regimens for patients with refractory LBCL.

7552 Background: Axi-cel is approved in the US for the treatment of adult patients with relapsed or refractory LBCL after 2 or more lines of systemic therapy. Post-market long term follow up study of commercial Axi-cel recipients using the Center for International Blood and Marrow Transplant Research was recently completed. Methods: From October 2017 to August 2020, 1,500 Axi-cel recipients from 79 centers were enrolled. Of these, 1001 patients with at least 6 months of follow-up were included in this analysis. Outcomes include complete and overall responses rates (CR and ORR), duration of response (DOR), progression-free and overall survival (PFS and OS), cytokine release syndrome (CRS) (Lee D 2014 and American Society for Transplantation and Cellular Therapy [ASTCT]), immune effector cell associated neurotoxicity syndrome (ICANS), hematologic recovery and subsequent neoplasm (SN). Subgroup analysis by sensitivity to therapy, defined as responsive to the last line of therapy prior to Axi-cel. Median follow-up was 12 months (range, 6-28 months). Results: The median age overall was 62 years, 37% were ≥ 65 years, 83% with Eastern Cooperative Oncology Group (ECOG) performance score 0-1, 28% with transformed lymphoma, 14% with high grade lymphoma, 29% with prior autologous transplant, and 66% with chemotherapy-resistant disease prior to Axi-cel. The median time from diagnosis to Axi-cel infusion was 15 months. Best ORR was 70% (CR 53%). Landmark analysis of patients in CR at 6 months post Axi-cel demonstrates a low number of subsequent progression/death events. With respect to outcomes for chemotherapy-sensitive disease versus resistant disease, the ORR, CR, 12-month PFS and OS were 78% vs. 66%, 60% vs. 48%, 55% (95% CI, 48-62%) vs. 40% (95% CI, 37-44%), and 70% (95% CI, 63-76%) vs. 54% (95% CI, 50-58%), respectively. CRS of any grade was reported in 83% of patients. Incidence of Grades ≥ 3 CRS was 10% according to Lee et al 2014, and 13% according to ASTCT Consensus Grading. Median time to any grade CRS was 4 days (range, 1-28 days), and 93% of CRS cases resolved with a median duration of 7 days (range, 1-121 days). ICANS were reported in 576 (57%) patients, grade >3 was 26%. The median time to onset of ICANS was 7 days (range, 1-82 days), and 86% resolved with a median duration of 9 days (range, 1 to 115 days). Twenty-nine patients (2.9%) reported SN: hematologic (N = 17), solid tumors (N = 12). Conclusions: This is the largest report on Axi-cel in the real-world setting and demonstrates consistent efficacy outcomes and further characterizes safety outcomes. Patients in CR at 6 months have sustained disease control with low number of relapse events. Although patients with therapy-sensitive disease experience better outcomes than patients with therapy-resistant, the overall outcomes on both groups of patients are favorable.

Background: Axi-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for the treatment of patients (pts) with relapsed/refractory large B cell lymphoma (LBCL) with ≥ 2 prior systemic therapies. ZUMA-1 is the multicenter, single-arm, registrational Phase 1/2 study of axi-cel in pts with refractory LBCL. In a 2-year analysis of ZUMA-1 (median follow-up, 27.1 months; N=101), axi-cel demonstrated objective response, complete response (CR), and ongoing response rates of 83%, 58%, and 39%, respectively (Locke et al. Lancet Oncol. 2019). Here, we present additional survival follow up and recovery of normal, polyclonal B cells from ongoing responders in ZUMA-1. Methods: Eligible pts with refractory large B cell lymphoma (diffuse large B cell lymphoma, primary mediastinal B cell lymphoma, transformed follicular lymphoma) underwent leukapheresis at enrollment and subsequently received low-dose conditioning chemotherapy (fludarabine and cyclophosphamide) followed by a target dose of 2 × 106 anti-CD19 CAR T cells/kg (Neelapu et al. NEJM. 2017; NCT02348216). The primary endpoint was objective response rate (ORR), and the first response assessment was 4 weeks post infusion. Response assessments were performed per protocol up to 24 months or disease progression, whichever occurred first. For pts in ongoing response beyond Month 24, response assessments continued per institutional standard-of-care (SOC). Blood levels of CAR T cells were quantified using polymerase chain reaction and B cells were characterized using flow cytometry in pts with ongoing responses and evaluable samples. Results: A total of 111 pts were enrolled, and axi-cel was administered to 101 pts. As previously reported in the ZUMA-1 2-year analysis, among pts who received axi-cel, the median time from axi-cel infusion to both objective response and CR was 1.0 month (range, 1 - 12 months; Locke et al. Lancet Oncol 2019). When the entire enrolled population (N = 111) was included on an intent-to-treat basis, the median manufacturing time was 17 days (range, 14 - 51; n = 110 as manufacturing was not feasible for 1 pt). Additionally, among the 111 pts, the median time from enrollment/leukapheresis to objective response and CR was 1.7 months (range, 0.7 - 12.9) and 1.9 months (range, 0.7 - 13.3), respectively. Responses have been durable, and with a minimum of 3 years of follow-up (median, 39.1 months), the median overall survival (OS) was 25.8 months, and the 3-year OS rate was 47%. Importantly, no axi-cel-related secondary malignancies have been reported. As previously reported, pts in ongoing response after 2 years had significantly greater peak CAR T cell expansion in blood 7 - 14 days after axi-cel infusion than did those with relapse (P = 0.014) or no response (P = 0.0003; Locke et al. Lancet Oncol 2019). Blood samples from 22 pts in ongoing response (per institutional SOC) at ≥ 3 years were available for analysis of CAR T cells and evaluation of B cell recovery. All evaluable pts had detectable B cells in blood at 3 years post axi-cel. Notably, 91% of pts in ongoing response at 3-year follow-up demonstrated recovery of polyclonal B cells measured by presence of both kappa and lambda light chains on non-malignant CD19+CD20+ B cells. The median kappa-lambda ratio of 1.6 and relative levels of key B cell subsets, including memory and naive B cell immunophenotypes, suggested reconstitution of B cell repertoire, consistent with published data from healthy individuals (Deneys et al. J Immunol Methods 2001; Scott et al. J Clin Pathol 2018). Additionally, 15/22 (68%) had both minimal levels of detectable CAR gene-marked cells and detectable polyclonal B cells in blood. Altogether, these findings support the hypothesis that persistence of functional CAR T cells is not necessary for durable remissions of LBCL. Overall survival and translational findings with ≥ 4 years of follow-up will be presented. Conclusions: Axi-cel produced rapid responses and longterm disease control in pts with refractory LBCL. Most responses occurred by the first assessment, and the brief time elapsed between enrollment and response supports both the speed and success of manufacturing. Furthermore, axi-cel-treated pts with ongoing responses at ≥ 3 years showed evidence of restoration of a normal B cell compartment and clearance of functional CAR T cells, a critical component of the long-term safety of CD19-directed CAR T cell therapies. Disclosures Locke: Kite, a Gilead Company: Consultancy, Research Funding; Wugen: Consultancy; Calibr: Consultancy; Allogene: Consultancy; Cellular Biomedicine Group: Other: Consultancy with grant options; GammaDelta Therapeutics: Consultancy; Celgene/Bristol-Myers Squibb: Consultancy; Novartis: Consultancy. Ghobadi:Celegene: Consultancy; Wugen: Consultancy; Atara: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding, Speakers Bureau; EUSA: Consultancy. Miklos:Novartis: Consultancy, Other: Travel support, Research Funding; Allogene Therapeutics Inc.: Research Funding; Juno-Celgene-Bristol-Myers Squibb: Consultancy, Other: Travel support, Research Funding; Janssen: Consultancy, Other: Travel support; Miltenyi Biotec: Research Funding; Pharmacyclics: Consultancy, Other: Travel support, Patents & Royalties, Research Funding; Adaptive Biotech: Consultancy, Other: Travel support, Research Funding; Kite-Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding. Oluwole:Pfizer: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Spectrum Pharmaceuticals: Consultancy; Bayer: Consultancy. Lin:Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Gamida Cells: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Research Funding; Merck: Research Funding; Vineti: Consultancy. Hill:Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding. Timmerman:Merck: Research Funding; Corvus: Current equity holder in publicly-traded company; Marker Therapeutics: Current equity holder in publicly-traded company; Immune Design: Honoraria; Celldex Therapeutics: Consultancy; BMS: Other: Travel support, Research Funding; Spectrum Pharmaceuticals: Research Funding; Kite, a Gilead Company: Consultancy, Other: Travel support, Research Funding; Bluebird Bio: Current equity holder in publicly-traded company; Genmab: Current equity holder in publicly-traded company; Valor: Research Funding. Deol:Novartis: Consultancy; Kite, a Gilead Company: Consultancy. Reagan:Kite, a Gilead Company: Consultancy; Curis: Consultancy; Seattle Genetics: Research Funding. Stiff:Kite, a Gilead Company: Research Funding; Delta-Fly: Research Funding; Gamida Cell: Research Funding; Atara: Research Funding; Unum: Research Funding; Macrogenics: Research Funding; Amgen: Research Funding. Flinn:Celgene: Research Funding; TG Therapeutics: Consultancy, Research Funding; Trillium Therapeutics: Research Funding; Curio Science: Consultancy; Merck: Research Funding; Constellation Pharmaceuticals: Research Funding; BeiGene: Consultancy, Research Funding; ArQule: Research Funding; Kite Pharma: Consultancy, Research Funding; Genentech, Inc.: Research Funding; Pfizer: Research Funding; Calithera Biosciences: Research Funding; Agios: Research Funding; Karyopharm Therapeutics: Research Funding; AstraZeneca: Consultancy, Research Funding; Forty Seven: Research Funding; Forma Therapeutics: Research Funding; Loxo: Research Funding; F. Hoffmann-La Roche: Research Funding; Incyte: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Novartis: Research Funding; MorphoSys: Consultancy, Research Funding; Rhizen Pharmaceuticals: Research Funding; Yingli Pharmaceuticals ≠: Consultancy, Research Funding; Johnson & Johnson: Other; Roche: Consultancy, Research Funding; Vincera Pharma: Consultancy; Gilead Sciences: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Iksuda Therapeutics: Consultancy; Great Point Partners: Consultancy; Curis: Research Funding; Nurix Therapeutics: Consultancy; Portola Pharmaceuticals: Research Funding; Acerta Pharma: Research Funding; Juno Therapeutics: Consultancy, Research Funding; Unum Therapeutics: Consultancy, Research Funding; Infinity Pharmaceuticals: Research Funding; IGM Biosciences: Research Funding; Takeda: Consultancy, Research Funding; Teva: Research Funding; Seattle Genetics: Consultancy, Research Funding; Triphase Research & Development Corp.: Research Funding; Verastem: Consultancy, Research Funding. Farooq:Kite, a Gilead Company: Honoraria. Goy:COTA: Consultancy, Current equity holder in publicly-traded company, Other: leadership role; Karyopharm: Research Funding; Genentech/Roche: Research Funding; Constellation: Research Funding; Bayer: Research Funding; CALBG: Research Funding; PracticeUpdate Oncology: Consultancy; RCCA/OMI: Current Employment; Acerta: Consultancy, Honoraria, Other: leadership role, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: leadership role, Research Funding; Celgene: Honoraria, Research Funding; Hackensack UMC and University of Nebraska: Research Funding; Infinity: Research Funding; Xcenda: Consultancy; Infinity Verastem: Research Funding; Morphosys: Research Funding; AbbVie: Research Funding; MD Anderson: Research Funding; Regional Cancer Care Associates/OMI: Current Employment; Kite, a Gilead Company: Consultancy, Current equity holder in publicly-traded company, Honoraria, Other: leadership role, Research Funding; Janssen: Consultancy, Honoraria, Other: leadership role, Research Funding. McSweeney:Kite, a Gilead Company: Consultancy, Honoraria, Research Funding, Speakers Bureau; Colorado Blood Cancer Institute: Current Employment; Fred Hutchinson: Patents & Royalties. Munoz:Juno/Celgene/BMS: Consultancy, Research Funding, Speakers Bureau; Alexion: Consultancy; Beigene: Consultancy, Speakers Bureau; Fosunkite: Consultancy; Innovent: Consultancy; Acrotech/Aurobindo: Speakers Bureau; Kyowa: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy; Verastem: Speakers Bureau; AstraZeneca: Speakers Bureau; Genentech/Roche: Research Funding, Speakers Bureau; AbbVie: Consultancy, Speakers Bureau; Merck: Research Funding; Portola: Research Funding; Incyte: Research Funding; Millenium: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau. Siddiqi:Oncternal: Research Funding; TG Therapeutics: Research Funding; Janssen: Speakers Bureau; Seattle Genetics: Speakers Bureau; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; BeiGene: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding; Juno: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding. Rossi:Gilead Sciences: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment. Bot:Kite, a Gilead Company: Current Employment; Gilead Sciences: Consultancy, Current equity holder in publicly-traded company, Other: Travel support . Zheng:Kite, a Gilead Company: Current Employment; Gilead Sciences: Current equity holder in publicly-traded company. Vezan:Merck: Current equity holder in publicly-traded company; Abbvie: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment, Honoraria, Other: Travel support. Bashir:Kite, a Gilead Company: Current Employment; OmniacPharmConsult Ltd: Current Employment, Current equity holder in private company. Kim:Kite, a Gilead Company: Current Employment; Gilead Sciences: Current equity holder in publicly-traded company. Chu:Kite, a Gilead Company: Current Employment; Gilead Sciences: Current equity holder in publicly-traded company; Amgen: Current equity holder in publicly-traded company; Celgene: Current equity holder in publicly-traded company. Neelapu:N/A: Other; Takeda Pharmaceuticals: Patents & Royalties; Acerta: Research Funding; Karus Therapeutics: Research Funding; Cellectis: Research Funding; Poseida: Research Funding; Unum Therapeutics: Other, Research Funding; Calibr: Other; Kite, a Gilead Company: Other: personal fees, Research Funding; Bristol-Myers Squibb: Other: personal fees, Research Funding; Merck: Other: personal fees, Research Funding; Novartis: Other: personal fees; Celgene: Other: personal fees, Research Funding; Pfizer: Other: personal fees; Allogene Therapeutics: Other: personal fees, Research Funding; Adicet Bio: Other; Legend Biotech: Other; Precision Biosciences: Other: personal fees, Research Funding; Incyte: Other: personal fees; Cell Medica/Kuur: Other: personal fees.

Background: In the SCHOLAR-1 study, the largest published retrospective analysis of outcomes in patients with refractory large B-cell lymphoma (LBCL), the objective response rate (ORR) was 26% and complete response (CR) rate was 7% with available salvage therapies in the pre-chimeric antigen receptor (CAR) T cell therapy era (Crump et al. Blood. 2017). These results served as a benchmark for assessing novel therapies. ZUMA-1 (NCT02348216) is the pivotal, multicenter, single-arm Phase 1/2 study evaluating axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 CAR T cell therapy, in patients with refractory LBCL that supported the approval of axi-cel in the United States and Europe. At a median follow-up of 27.1 months, the ORR in ZUMA-1 was 83% and the CR rate was 58% (Locke et al. Lancet Oncol. 2019). Here, we describe comparative analyses of outcomes in ZUMA-1 and SCHOLAR-1 after adjusting for potential imbalances in refractory status between the 2 studies. Methods: Patients in both studies had refractory LBCL defined as stable disease of ≤ 6 months with ≥ 4 cycles of frontline or ≥ 2 cycles of later-line therapy, progressive disease as best response, or relapse ≤ 12 months post autologous stem cell transplant (SCT). To address potential imbalances between studies in refractory status which could affect response and survival outcomes, standardized analyses were performed which equally weighted the proportions of patients by refractory categorization (primary refractory, refractory to ≥ second-line therapy, or relapse after SCT) and presence of post-refractory SCT in each study. Stratified Cochran-Mantel-Haenszel (CMH) tests and Cox models were used to compare the odds ratio for response and hazard ratio (HR) for survival between ZUMA-1 and SCHOLAR-1. P values were descriptive and were not adjusted for multiplicity. Results: Axi-cel was administered to 101 patients in the pivotal Phase 2 portion of ZUMA-1. In the SCHOLAR-1 analysis, 508 patients were evaluable for response and 497 were evaluable for survival. The median follow-up in ZUMA-1 was 2.3 years, and the median follow-up from the overall SCHOLAR-1 study ranged from 7.6 to 14.8 years across different cohorts. In general, ZUMA-1 patients were more heavily pretreated with more patients receiving ≥ 3 lines of therapy as compared with SCHOLAR-1 (69% vs 23%). ZUMA-1 also had more patients who were refractory to second- or later-line therapy compared with SCHOLAR-1 (76% vs 62%). Fewer patients in ZUMA-1, however, were classified as primary refractory vs those in SCHOLAR-1 (26% vs 45%), and a similar proportion of patients between studies relapsed within 1 year of SCT (21% vs 18%). After standardization, the ORR and CR rate in ZUMA-1 vs SCHOLAR-1 were 72% and 54% vs 22% and 7%, respectively. The odds ratios for ORR and CR rate were 7.2-fold and 11.5-fold higher, respectively in ZUMA-1 vs SCHOLAR-1 (CMH test; P < .0001 for both ORR and CR rate). The 2-year survival rate after standardization was 50% (95% CI, 40% - 59%) in ZUMA-1 and 12% (95% CI, 9% - 15%) in SCHOLAR-1, which translated to a 73% reduction in the risk of death in ZUMA-1 relative to SCHOLAR-1 (HR, 0.27; P < .0001). Conclusions: This standardized analysis of the ZUMA-1 and SCHOLAR-1 studies indicates that treatment with axi-cel in this selected population results in 11.5-fold higher odds of CR and a 73% reduction in the risk of death compared with standard salvage regimens in an unselected population. Although limited by retrospective evaluation and cross-study comparisons, these results support the previous literature indicating that axi-cel is a highly effective treatment option for patients with refractory LBCL. Disclosures Neelapu: Pfizer: Consultancy; BMS: Research Funding; Cellectis: Research Funding; Precision Biosciences: Consultancy; Allogene: Consultancy; Acerta: Research Funding; Cell Medica: Consultancy; Celgene: Consultancy, Research Funding; Karus: Research Funding; Novartis: Consultancy; Poseida: Research Funding; Unum Therapeutics: Consultancy, Research Funding; Incyte: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Merck: Consultancy, Research Funding. Locke:Novartis: Other: Scientific Advisor; Kite: Other: Scientific Advisor; Cellular BioMedicine Group Inc.: Consultancy. Bartlett:Genentech, Inc.: Research Funding; Gilead: Research Funding; Autolus: Research Funding; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Forty Seven: Research Funding; Affimed: Research Funding; Immune Design: Research Funding; Incyte: Research Funding; Janssen: Research Funding; Kite Pharma: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pfizer: Research Funding; Pharmacyclics: Research Funding. Reagan:Kite, A Gilead Company: Consultancy; Curis: Consultancy; Seattle Genetics: Research Funding. Miklos:Celgene-Juno: Consultancy; Novartis: Consultancy; Adaptive Biotechnologies: Consultancy, Research Funding; Janssen: Consultancy; Miltenyi: Consultancy, Research Funding; AlloGene: Consultancy; Kite, A Gilead Company: Consultancy, Research Funding; Pharmacyclics: Consultancy, Patents & Royalties, Research Funding; Becton Dickinson: Consultancy; Precision Bioscience: Consultancy. Jacobson:Pfizer: Research Funding; Celgene: Consultancy, Other: travel support; Humanigen: Consultancy, Other: travel support; Precision Biosciences: Consultancy, Other: travel support; Bayer: Consultancy, Other: travel support; Novartis: Consultancy, Honoraria, Other: travel support; Kite, a Gilead Company: Consultancy, Honoraria, Other: travel support. Oluwole:Pfizer: Consultancy; Spectrum: Consultancy; Gilead Sciences: Consultancy; Bayer: Consultancy. Siddiqi:BeiGene: Research Funding; Celgene: Research Funding; TG Therapeutics: Research Funding; Kite, A Gilead Company: Research Funding; Seattle Genetics: Speakers Bureau; Janssen: Speakers Bureau; Juno Therapeutics: Consultancy, Other: travel support, Research Funding; PCYC: Consultancy, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Research Funding, Speakers Bureau. Crump:Kite/Gilead: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Servier: Consultancy. Kuruvilla:Seattle Genetics: Honoraria; Roche: Honoraria; Novartis: Honoraria; Merck: Honoraria; Karyopharm: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Celgene: Honoraria; BMS: Honoraria; Astra Zeneca: Honoraria; Amgen: Honoraria; Seattle Genetics: Consultancy; Roche: Consultancy; Merck: Consultancy; Karyopharm: Consultancy; Gilead: Consultancy; Abbvie: Consultancy; BMS: Consultancy; Janssen: Research Funding; Roche: Research Funding. Van Den Neste:Gilead: Other: travel support. Farooq:Celgene: Honoraria; Kite Pharma: Research Funding. Navale:Kite, A Gilead Company: Employment, Equity Ownership; Gilead: Equity Ownership; Allogene: Equity Ownership; Cellectis: Equity Ownership; Bluebird Bio: Equity Ownership; Amgen: Equity Ownership; Organesis: Equity Ownership; Jounce: Equity Ownership; Editas: Equity Ownership; Intellia: Equity Ownership. DePuy:Kite, A Gilead Company: Consultancy, Other: travel support. Kim:Kite, A Gilead Company: Employment.

Abstract Introduction: Given the availability of several active treatment (tx) options for CLL, providers frequently make tx recommendations based on their interpretation of objective data from consensus criteria and clinical trials. There are limited data describing patient (pt) experience, values, and insights when encountering multiple tx choices. The CLL Society, a pt-driven, physician-curated nonprofit organization focused on the unmet needs of the CLL community, sought to explore how CLL pts make tx decisions. Methods: A 64 question survey was distributed online and in paper to CLL pts from Oct-Dec 2017. The survey was developed by CLL experts. The research was IRB-approved. Chi square was used for statistical comparison; all other analyses are descriptive in nature. Results: 1147 pts from 48 states completed the survey. Median age was 65 (range 28-86), 46% male, 96% Caucasian. Who Influences Tx: Of the 79% of pts who have seen a CLL expert, defined as a provider focused on CLL at an academic/research center, 95% rated their provider as very/extremely influential. 83% of pts rated their own opinions as influential, and 59% rated the opinion of a general hematologist/oncologist (gen heme/onc), a provider who sees a variety of cancer types, as influential. Only 27% let their provider unilaterally decide on tx. Of these pts, 19% trusted their provider to select the best tx and 5% didn't have enough understanding to be involved in the decision. 64% were influenced by outside sources of information, such as family members, live CLL support groups, or online sources including pt experts and forums. Factors in Deciding Tx: Of the 67% pts surveyed who have been treated, 73% were offered > 1 tx choice by their provider. In deciding on a specific tx, 94% of respondents stated that it was very/extremely important to know there were tx options beyond their current regimen. The most important factors in selecting tx were response rate (91%), overall survival (88%), progression-free survival (86%), long-term side effects (82%), ability to achieve undetectable MRD (80%), cost/insurance coverage (66%), and location of tx (50%) with significant differences between subgroups (Table 1). Tx was impacted by cost or insurance issues for 16% (n=104). Of these 104 pts, cost/insurance issues resulted in tx delay for 34 and change in tx plan for 24 pts. 16 pts reported that an appeal led to coverage and 16 pts received financial assistance. Pts' willingness to accept potentially curable but high-risk tx was heavily influenced by availability of alternate options. For example, 18% of pts would be willing to consider cytotoxic chemotherapy if alternate options were available vs. 72% if no options were available. Similar patterns were seen with CAR-T tx (28% vs. 79%) and bone marrow transplantation (BMT) (15% vs. 66%) with significant differences between subgroups (Table 2). 82% were willing to take a life-long tx for long-term control without potential for cure. Willingness to accept long-term tx was significantly higher in treated vs. untreated pts (84% vs. 77%, p=.006) and men vs. women (84% vs. 78%, p=.008). Clinical Trial Education: Of those treated by a gen heme/onc, 31% received no education on clinical trials. Only 15% reported good understanding of trial opportunities vs. 52% treated by a CLL expert (p<.001). 9% of pts treated by gen heme/onc were offered clinical trial participation vs. 47% treated by a CLL expert (p<0.001). Pts who declined or would have declined participation cited reasons including preference for "proven" tx (38%), distance from trial site (29%), fear (20%), frequent imaging (20%), overall lack of understanding about trials (15%), and lack of information (14%). Summary: Most respondents want to be and are involved in tx decisions. While providers are influential in decision making, CLL pts also rely on outside sources. Gender, age, and tx status influence which factors drive decision making. Pts select tx based on response rate, survival, side effects, and ability to achieve deep response and want a plan in place for sequencing tx. The majority are willing to consider long-term tx without cure. Few want chemotherapy, CAR-T, or BMT unless they have no other options. A significant opportunity for improvement in education on clinical trial opportunities was identified. This description of pt experience, values, and preferences enriches the informed consent process and may lead to more tailored and patient-centered care. Disclosures Kennard: AbbVie, Gilead, Verastem: Consultancy. Furman:TG Therapeutics: Consultancy; Loxo Oncology: Consultancy; Sunesis: Consultancy; Verastem: Consultancy; Incyte: Consultancy, Other: DSMB; Genentech: Consultancy; Acerta: Consultancy, Research Funding; Gilead: Consultancy; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy; AbbVie: Consultancy. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Davids:Sunesis: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Surface Oncology: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Merck: Consultancy; Merck: Consultancy; MEI Pharma: Consultancy, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Research Funding; Surface Oncology: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Roche: Consultancy; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Verastem: Consultancy, Research Funding; BMS: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Surface Oncology: Research Funding; Verastem: Consultancy, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sunesis: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Roche: Consultancy. Nabhan:Cardinal Health: Employment, Equity Ownership. Kay:Acerta: Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees. Siddiqi:Juno Therapeutics: Other: Steering committee. Brander:Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Teva: Consultancy, Honoraria; Novartis: Consultancy, Other: DSMB; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Wierda:AbbVie, Inc: Research Funding; Genentech: Research Funding. Hill:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cheson:AbbVie, Roche/Genentech, Pharmacyclics, Acerta, TG Therapeutics: Consultancy. Choi:Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Gilead: Speakers Bureau; Rigel: Consultancy; Genentech: Speakers Bureau; AbbVie, Inc: Consultancy, Speakers Bureau. Mato:AstraZeneca: Consultancy; Prime Oncology: Honoraria; Portola: Research Funding; Johnson & Johnson: Consultancy; Medscape: Honoraria; Celgene: Consultancy; TG Therapeutics: Consultancy, Research Funding; Acerta: Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Regeneron: Research Funding.

Abstract Background: Axi-cel is a US FDA-approved, autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy for the treatment of patients with relapsed or refractory large B cell lymphoma with ≥ 2 prior systemic therapies. This report focuses on high-risk patient populations as well as long-term durability of response, and B cell recovery. Methods: In ZUMA-1, eligible patients with refractory large B cell lymphoma (diffuse large B cell lymphoma, primary mediastinal B cell lymphoma, transformed follicular lymphoma) underwent leukapheresis and received low-dose conditioning followed by a target dose of 2 × 106 anti-CD19 CAR T cells/kg (Neelapu and Locke et al. NEJM. 2017; NCT02348216). Outcomes in patients with double-expressor B cell lymphoma (MYC [≥ 40%] and BCL-2 [≥ 50%] protein expression by immunohistochemistry [IHC]) or high-grade B cell lymphoma (HGBCL), defined as double- or triple-hit (MYC+ and BCL2+ and/or BCL6+ by fluorescence in situ hybridization) or not otherwise specified (MYC- and > 70% Ki67 by IHC) were examined by independent pathology review. Exploratory analyses, including normal B cell levels in peripheral blood over time and frequency of use of safety interventions of interest, were also performed. A long-term follow-up analysis will be conducted with a data cutoff of August 11, 2018 for all 108 patients, including the HGBCL subgroup. Results: As of August 11, 2017, all 108 patients had at least 1 year of follow-up, with a median follow-up of 15.4 months. The objective response rate (ORR) was 82% with a complete response (CR) rate or 58%. The CR rate was 53% (29/55) in patients with disease refractory to ≥ 2 consecutive prior lines of therapy and 72% (18/25) in patients who had relapsed within 12 months after autologous stem cell transplantation. High-risk genetics were assessed in the 47 evaluable pre-treatment tumor samples: 37 patients (79%) had HGBCL or double-expressor B cell lymphoma and had an ORR of 89% (33/37) including a CR rate of 68% (25/37). Forty-two percent of patients overall had ongoing responses with a median follow-up of 15.4 months including 49% (18/37) of patients with high-risk genetics. To investigate the relationship between B cell recovery and ongoing response, B cell levels were assessed over time. Overall, of the 87 evaluable patients, 47% had no detectable B cells at baseline, and the remainder had levels close to or below the lower level of quantification of the assay. In patients with ongoing responses at 12 months post axi-cel infusion, 19 of the 35 (54%) patients with evaluable samples had detectable B cells at 12 months. This suggests B cell recovery in some patients with ongoing response as only 6 of 40 (15%) patients with evaluable samples had detectable B cells at 3 months after axi-cel infusion. Grade ≥ 3 cytokine release syndrome (CRS) and neurologic events (NE) were generally reversible and reported for 12% and 31% of patients, respectively. Tocilizumab (45%) and/or steroids (28%) were used for the management of CRS and NE. The use of vasopressors, dialysis, and intubation were minimal, used in only 17%, 3%, and 3% of patients, respectively. Thirty-four percent of patients (37/108) had either no CRS/NE (6%) or only Grade 1 CRS with (12%) or without (16%) Grade 1 NE. For these 37 patients, the median onset of CRS and NE was 2 and 7 days after infusion, respectively. Patients with Grade 0 - 1 CRS/NE had similar efficacy (ORR, 86%; CR, 65%) but lower peak/AUC CAR T cell levels vs the overall population. Updated safety and efficacy results will be presented with a minimum follow-up of 2 years and a median follow-up of 27.1 months. Conclusion: High rates of durable response were observed in patients with HGBCL and double-expressor B cell lymphoma, with approximately half of these patients (18/37) maintaining CR at ≥ 1 year. Efficacy in these high-risk populations was comparable to the overall patient population in ZUMA-1. At 12 months, B-cell recovery was observed in over half the patients with ongoing remission. About one-third of patients had only Grades 0 - 1 CRS/NE yet showed comparable efficacy with the overall patient population. High-grade CRS/NE were largely managed with tocilizumab and steroids with very low use of intensive or invasive interventions. Updated outcomes with a minimum of 2 years of follow-up will be presented. Disclosures Neelapu: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cellectis: Research Funding; Poseida: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Research Funding; Karus: Research Funding; Bristol-Myers Squibb: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Unum Therapeutics: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Miklos:Adaptive Biotechnologies: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pharmacyclics - Abbot: Consultancy, Research Funding; Kite - Gilead: Consultancy, Research Funding; Genentech: Research Funding; Janssen: Consultancy, Research Funding. Hill:Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Deol:Novartis: Consultancy; Kite Pharmaceuticals: Consultancy. Reagan:Seattle Genetics: Research Funding. Flinn:Agios: Research Funding; Forty Seven: Research Funding; Celgene: Research Funding; Calithera: Research Funding; Portola: Research Funding; Kite: Research Funding; Forma: Research Funding; Genentech: Research Funding; Verastem: Research Funding; BeiGene: Research Funding; Incyte: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Janssen: Research Funding; Merck: Research Funding; TG Therapeutics: Research Funding; ArQule: Research Funding; Constellation: Research Funding; Infinity: Research Funding; Novartis: Research Funding; Gilead: Research Funding; Curis: Research Funding; Pharmacyclics: Research Funding; Verastem: Consultancy, Research Funding; Takeda: Research Funding; Pfizer: Research Funding. McSweeney:Kite, a Gilead Company: Honoraria, Membership on an entity's Board of Directors or advisory committees. Munoz:Alexion: Consultancy; Genentech: Consultancy, Honoraria; Juno: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Janssen: Consultancy; Kite: Consultancy, Honoraria, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Gilead: Speakers Bureau; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy. Siddiqi:Juno Therapeutics: Other: Steering committee. Herrera:Bristol-Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Research Funding; Gilead Sciences: Research Funding; Merck, Inc.: Consultancy, Research Funding; KiTE Pharma: Consultancy, Research Funding; Immune Design: Research Funding. Xue:Kite, a Gilead Company: Employment. Jiang:Kite, a Gilead Company: Employment. Bot:KITE: Employment. Rossi:KITE: Employment. Kim:Kite, a Gilead Company: Employment. Go:KITE: Employment. Locke:Cellular BioMedicine Group Inc.: Consultancy; Novartis Pharmaceuticals: Other: Scientific Advisor; Kite Pharma: Other: Scientific Advisor.

Abstract Background: Patients (pts) with deletion 17p (del17p) CLL follow an aggressive clinical course and experience poor outcomes with chemoimmunotherapy. Ibrutinib, an oral inhibitor of Bruton's tyrosine kinase (BTK), is approved for pts with CLL with ≥1 prior therapy and for pts with del17p CLL (including first-line). In the phase 2 RESONATE-17 study (PCYC-1117), ibrutinib demonstrated high efficacy with a favorable risk-benefit profile in del17p CLL/SLL (O'Brien, ASH 2014). We evaluate the baseline genetic features and prognostic factors of these pts to determine their impact on outcome. Methods: Pts with del17p CLL or SLL defined by peripheral blood FISH who failed ≥1 therapy received 420 mg oral ibrutinib once daily until progression or unacceptable toxicity. Using the primary analysis data cut, the overall response rate (ORR; iwCLL 2008 criteria by investigators), progression-free survival (PFS), and overall survival (OS) were assessed by subgroup. Results: Among 144 treated pts (137 CLL, 7 SLL), the median age was 64 (range 36-89). At baseline, 63% of pts had Rai stage III or IV disease, and 39% had received ≥3 prior therapies. Baseline cytogenetics included del11q (16%), del13q (74%), and trisomy 12 (17%), in addition to del17p in all pts. Of 116 pts with valid baseline genomic samples, IGHV status was unmutated in 84%; genomic variants that included mutations, rearrangements, insertions, deletions, and copy number variants affecting coding regions were identified as follows: ATM (14%), BIRC3 (3%), BTK (1%), MYC (2%), MYD88 (2%), NOTCH1 (16%), PLCG2 (3%), SF3B1 (27%), and TP53 (92%), which were consistent with previously identified mutations in pts with CLL (Wang, NEJM 2011; Winkelmann, Haematologica 2015). At a median follow-up of 11.5 months, the investigator-assessed ORR including partial response with lymphocytosis (PR-L) for all treated pts was 83% (17% PR-L). Median PFS and OS were not reached, with 12-month PFS and OS rates of 79% and 84%. Any-grade adverse events (≥15%) included diarrhea (36%), fatigue (31%), cough (24%), arthralgia (22%), nausea (19%), hypertension (19%), anemia (19%), pyrexia (17%), decreased appetite (17%), muscle spasms (17%), neutropenia (17%), and peripheral edema (15%). Serious AEs occurred in 40% of pts (38% ≥ grade 3). ORR, 12-month PFS, and 12-month OS are presented by subgroup for baseline characteristics, cytogenetics, and genomic variants (Table). There were no substantial differences in response rates and survival outcomes in the subgroups with and without baseline cytogenetic aberrations or genomic variants (Table). Response rates were similar for pts with and without NOTCH1 or SF3B1 variants. Of 11 pts with del17p CLL who developed Richter transformation, baseline aberrations included ATM (n=2), SF3B1 (n=3), and/or NOTCH1 (n=3); none had BIRC3 variants. Overall at baseline, there were 3 pts with a PLCG2 mutation (L163F, H193Q, P236L), and 1 with a BTK mutation (R236Q); all achieved a best overall response of PR-L or better. None had received prior therapy with a BTK or PI3K inhibitor. Two pts had a baseline MYD88 mutation (L265P, L142F) with a best overall response of PR in 1 pt. Two pts had baseline MYC amplifications with 5 of 5 exons amplified to 6 and 7 copies, respectively; 1 pt achieved a best overall response of PR. Conclusions: These results provide further evidence of ibrutinib's robust clinical activity and encouraging survival outcomes in this high-risk population regardless of baseline cytogenetic aberrations or genomic variants. The prognostic role of these clinical characteristics and genetic anomalies will continue to be elucidated with longer term follow-up of this population. Figure 1. Investigator-assessed efficacy outcomes by subgroups Figure 1. Investigator-assessed efficacy outcomes by subgroups Disclosures Stilgenbauer: AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Jones:Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding. Coutre:AbbVie: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mato:Celgene: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; TA Therapeutics: Research Funding; Gilead: Consultancy, Other: Travel, Accommodations, Expenses; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: Travel, Accommodations, Expenses. Hillmen:AbbVie: Honoraria, Research Funding; Roche Pharmaceuticals: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria, Research Funding; Gilead: Honoraria, Research Funding. Tam:Janssen: Consultancy, Honoraria, Research Funding. Osterborg:Gilead: Honoraria; Janssen: Honoraria, Research Funding; GSK: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Amgen: Research Funding. Siddiqi:Pharmacyclics: Research Funding, Speakers Bureau; Janssen: Speakers Bureau. Thirman:Gilead: Research Funding; Merck: Research Funding; AbbVie: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding. Furman:Gilead: Consultancy; Acerta Pharma BV: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Speakers Bureau. Li:Pharmacyclics LLC, an AbbVie Company: Employment. Eckert:Pharmacyclics LLC, an AbbVie Company: Employment. Chang:Pharmacyclics LLC, an AbbVie Company: Employment. James:Pharmacyclics LLC, an AbbVie Company: Employment. Chu:Pharmacyclics LLC, an AbbVie Company: Employment. Hallek:Pharmacyclics LLC, an AbbVie Company: Consultancy, Speakers Bureau; Janssen: Speakers Bureau. O'Brien:Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding.

Abstract Background: Patients with chronic lymphocytic leukemia (CLL) with deletion of the short arm of chromosome 17 (del 17p) follow an aggressive clinical course and demonstrate a median survival of less than 2 years in the relapsed/refractory (R/R) setting. Ibrutinib (ImbruvicaTM), a first-in-class Bruton's tyrosine kinase (BTK) inhibitor, has been approved for previously treated patients with CLL and for patients with del 17p CLL. We report results from the primary analysis of the Phase II RESONATETM-17 (PCYC-1117-CA) study, designed to evaluate the efficacy and safety of single-agent ibrutinib for treatment of patients with R/R del 17p CLL or small lymphocytic leukemia (SLL). Methods: Patients with del 17p CLL or SLL who failed at least one therapy were enrolled to receive 420 mg oral ibrutinib once daily until progression. All patients receiving at least one dose of ibrutinib were included in the analysis. The primary endpoint was overall response rate (ORR) per an independent review committee (IRC). Other endpoints included duration of response (DOR), progression-free survival (PFS), and safety of ibrutinib. Results: Among 144 treated patients (137 with CLL, 7 with SLL), the median age was 64 (48% 65 years or older) and all had del 17p. Baseline characteristics included 63% of patients with Rai Stage III or IV disease, 49% with bulky lymphadenopathy of at least 5 cm, and 10% with lymphadenopathy of least 10 cm. The median baseline absolute lymphocyte count (ALC) was 32.9 x 109/L with 57% of patients with a baseline ALC at least 25.0 x 109/L. Baseline beta-2 microglobulin levels were at least 3.5 mg/L in 78% of patients (range 1.8-19.8 mg/L), and lactate dehydrogenase levels were at least 350 U/L in 24% of patients (range 127-1979 U/L). A median of 2 prior therapies (range 1-7) was reported. Investigator-assessed ORR was 82.6% including 17.4% partial response with lymphocytosis (PR-L). Complete response (CR)/complete response with incomplete bone marrow recovery (CRi) were reported in 3 patients. IRC-assessed ORR is pending. At a median follow up of 13.0 months (range 0.5-16.7 months), the median PFS (Figure 1) and DOR by investigator determination had not been reached. At 12 months, 79.3% were alive and progression-free, and 88.3% of responders were progression-free. Progressive disease was reported in 20 patients (13.9%). Richter transformation was reported in 11 of these patients (7.6%), 7 of the cases occurring within the first 24 weeks of treatment. Prolymphocytic leukemia was reported in 1 patient. The most frequently reported adverse events (AE) of any grade were diarrhea (36%; 2% Grade 3-4), fatigue (30%; 1% Grade 3-4), cough (24%; 1% Grade 3-4), and arthralgia (22%; 1% Grade 3-4). Atrial fibrillation of any grade was reported in 11 patients (7.6%; 3.5% Grade 3-4). Seven patients reported basal or squamous cell skin cancer and 1 patient had plasma cell myeloma. Most frequently reported Grade 3-4 AEs were neutropenia (14%), anemia (8%), pneumonia (8%), and hypertension (8%). Major hemorrhage was reported in 7 patients (4.9%, all Grade 2 or 3). Study treatment was discontinued in 16 patients (11.1%) due to AEs with 8 eventually having fatal events (pneumonia, sepsis, myocardial or renal infarction, health deterioration). At the time of data cut, the median treatment duration was 11.1 months, and 101 of 144 patients (70%) continued treatment with ibrutinib. Conclusions: In the largest prospective trial dedicated to the study of del 17p CLL/SLL, ibrutinib demonstrated marked efficacy in terms of ORR, DOR, and PFS, with a favorable risk-benefit profile. At a median follow up of 13 months, the median DOR had not yet been reached; 79.3% of patients remained progression-free at 12 months, consistent with efficacy observed in earlier studies (Byrd, NEJM 2013;369:32-42). The PFS in this previously treated population compares favorably to that of treatment-naïve del 17p CLL patients receiving fludarabine, cyclophosphamide, and rituximab (FCR) (Hallek, Lancet 2010;376:1164-74) or alemtuzumab (Hillmen, J Clin Oncol 2007;10:5616-23) with median PFS of 11 months. The AEs are consistent with those previously reported for ibrutinib (Byrd, NEJM 2014;371:213-23). These results support ibrutinib as an effective therapy for patients with del 17p CLL/SLL. Figure 1 Figure 1. Disclosures O'Brien: Amgen, Celgene, GSK: Consultancy; CLL Global Research Foundation: Membership on an entity's Board of Directors or advisory committees; Emergent, Genentech, Gilead, Infinity, Pharmacyclics, Spectrum: Consultancy, Research Funding; MorphoSys, Acerta, TG Therapeutics: Research Funding. Jones:Pharmacyclics: Consultancy, Research Funding. Coutre:Janssen, Pharmacyclics: Honoraria, Research Funding. Mato:Pharamcyclics, Genentech, Celegene, Millennium : Speakers Bureau. Hillmen:Pharmacyclics, Janssen, Gilead, Roche: Honoraria, Research Funding. Tam:Pharmacyclics and Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Siddiqi:Janssen: Speakers Bureau. Furman:Pharmacyclics: Consultancy, Speakers Bureau. Brown:Sanofi, Onyx, Vertex, Novartis, Boehringer, GSK, Roche/Genentech, Emergent, Morphosys, Celgene, Janssen, Pharmacyclics, Gilead: Consultancy. Stevens-Brogan:Pharmacyclics: Employment. Li:Pharmacyclics: Employment. Fardis:Pharmacyclics: Employment. Clow:Pharmacyclics: Employment. James:Pharmacyclics: Employment. Chu:Pharmacyclics: Employment, Equity Ownership. Hallek:Janssen, Pharmacyclics: Consultancy, Research Funding. Stilgenbauer:Pharmacyclics, Janssen Cilag: Consultancy, Honoraria, Research Funding.