Rossi, John M.

Abstract Background: ZUMA-1 is a pivotal, multicenter trial of axi-cel, an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy, for the treatment of patients with refractory, aggressive NHL. The objective response rate (ORR) was 82% with a 54% rate of complete response and 44% of responses were ongoing at the time of the primary analysis (Locke et al. AACR 2017. #9986). Grade ≥ 3 cytokine release syndrome (CRS) and neurologic events (NE) occurred in 13% and 28% of patients, respectively. A safety expansion cohort was added to further characterize mechanisms underlying CRS and NE associated with CAR T cell therapy and to evaluate the impact of prophylactic use of tocilizumab and levetiracetam on the rates of these adverse events (AEs). Methods: Patients (≥ 18 years) must have had an Eastern Cooperative Oncology Group performance status of 0-1 and refractory or relapsed transplant ineligible disease. Patients received low-dose conditioning of 500 mg/m2 cyclophosphamide and 30 mg/m2 fludarabine for 3 days followed by axi-cel at a target dose of 2 × 106 CAR T cells/kg. Patients also received prophylactic treatment with 750 mg of levetiracetam twice a day on day 0 and 8 mg/kg of tocilizumab on day 2 post axi-cel infusion. To evaluate the mechanisms of NE, paired serum and cerebrospinal fluid (CSF) were obtained for all patients prior to conditioning chemotherapy and after axi-cel infusion (day 5). Results: As of April 26, 2017, 31 patients received axi-cel. Median age was 51 years (range, 21-74), 52% were male, 65% had stage III-IV disease, 74% were refractory to ≥ second-line therapy, and 19% relapsed ≤ 12 months after autologous stem cell transplant. Most patients (97%) experienced at least 1 grade ≥ 3 AE. The most common grade ≥ 3 AEs were neutropenia/neutrophil count decreased (71%), anemia (55%), thrombocytopenia/platelet count decreased (52%), leukopenia/white blood cell count decreased (35%), febrile neutropenia (29%), encephalopathy (23%), and hypotension (23%). One patient (3%) experienced a grade ≥ 3 (grade 4) CRS. Grade 3 and 4 NE occurred in 29% and 6% of patients, respectively. One patient died of cerebral edema; there were no other deaths due to AE. Updated efficacy, safety, subgroups, and paired blood/serum/CSF biomarker associative analyses will be presented. Conclusions : Early use of tocilizumab may reduce the incidence of severe CRS but not NE in patients treated with CAR T cell therapy. These data provide evidence that the underlying pathophysiology of NE may differ from that of CRS. Understanding the mechanisms of NE may help to further improve the benefit:risk profile for CAR T cell therapy. Drs Locke and Neelapu contributed equally to this work. Disclosures Locke: Kite Pharma: Consultancy; Cellular Biomedicine Group Inc: Consultancy. Neelapu: Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Poseida: Research Funding; Cellectis: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Jacobson: Pharmacyclics, LLC: Consultancy; Kite Pharma: Consultancy. Braunschweig: Kite Pharma: Equity Ownership. Oluwole: Kite Pharma: Consultancy. Siddiqi: Seattle Genetics: Speakers Bureau; Juno: Other: Steering committee for JCAR017; Pharmacyclics, an AbbVie Company: Other: Steering committee for ibrutinib, Speakers Bureau. Timmerman: Celgene: Consultancy; Seattle Genetics: Consultancy; Kite Pharma: Research Funding; ImmuneGene: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Genmab: Consultancy, Equity Ownership. Reagan: Seattle Genetics: Research Funding. Bot: Kite Pharma: Employment, Equity Ownership. Rossi: Kite Pharma: Employment, Equity Ownership. Sherman: Kite Pharma: Employment, Equity Ownership. Navale: Kite Pharma: Employment, Equity Ownership. Jiang: Kite Pharma: Employment, Equity Ownership. Aycock: Kite Pharma: Employment, Equity Ownership. Elias: Kite Pharma: Employment, Equity Ownership. Wiezorek: Kite Pharma: Employment, Equity Ownership. Go: Kite Pharma: Employment, Equity Ownership. Miklos: Pharmacyclics, LLC: Consultancy, Other: Travel expenses, Patents & Royalties, Research Funding; Kite Pharma: Consultancy, Other: Travel expenses, Research Funding; Adaptive Biotechnologies: Consultancy, Other: Travel expenses; Roche: Research Funding; Genentech: Research Funding; Novartis: Research Funding; Janssen: Consultancy, Honoraria, Other: Travel expenses; Sanofi: Honoraria.

SummaryZUMA‐1 (NCT02348216) examined the safety and efficacy of axicabtagene ciloleucel (axi‐cel), an autologous CD19‐directed chimaeric antigen receptor (CAR)‐T cell therapy, in refractory large B‐cell lymphoma. To reduce treatment‐related toxicity, several exploratory safety management cohorts were added to ZUMA‐1. Specifically, cohort 6 investigated management of cytokine release syndrome (CRS) and neurologic events (NEs) with prophylactic corticosteroids and earlier corticosteroid and tocilizumab intervention. CRS and NE incidence and severity were primary end‐points. Following leukapheresis, patients could receive optional bridging therapy per investigator discretion. All patients received conditioning chemotherapy (days −5 through −3), 2 × 106 CAR‐T cells/kg (day 0) and once‐daily oral dexamethasone [10 mg, day 0 (before axi‐cel) through day 2]. Forty patients received axi‐cel. CRS occurred in 80% of patients (all grade ≤2). Any grade and grade 3 or higher NEs occurred in 58% and 13% of patients respectively. Sixty‐eight per cent of patients did not experience CRS or NEs within 72 h of axi‐cel. With a median follow‐up of 8·9 months, objective and complete response rates were 95% and 80% respectively. Overall, prophylactic corticosteroids and earlier corticosteroid and/or tocilizumab intervention resulted in no grade 3 or higher CRS, a low rate of grade 3 or higher NEs and high response rates in this study population.

Abstract Background: Conventional prognostic factors for LBCL were not associated with outcomes in the pivotal ZUMA-1 study of axi-cel in relapsed LBCL (Neelapu et al. NEJM. 2017); however, other attributes like chimeric antigen receptor (CAR) T-cell fitness and composition (CCR7+CD45RA+ T cells), reduced preTx tumor burden, and immune tumor microenvironment (TME) with presence of activated CD8+PD-1+LAG-3+/-TIM-3- T cells were associated with efficacy (Locke et al. Blood Adv. 2020; Galon et al. ASCO 2020. #3022). Here, we evaluated preTx immune cell phenotypes in premanufacturing apheresis (premfg aph) material, comprising peripheral blood mononuclear cells, to determine associations with product attributes, immune TME features, and clinical efficacy in ZUMA-1. Methods: Evaluable samples from patients (pts) in Phase (Ph) 1 and Ph2 Cohorts (C) 1-3 were analyzed (NCT02348216; Ph1 and Ph2 C1+2, ≥2-y follow-up; C3, ≥6-mo follow-up). Memory T, myeloid, NK, NKT, and B cells in premfg aph material (n=101, excluding C3) were characterized by flow cytometry (FC). PreTx immune TME was analyzed by multiplex IHC (n=18) and gene expression analysis (n=30) as previously described (Rossi et al. AACR 2018. #LB-016; Galon et al. ASCO 2020. #3022). CAR T-cell fitness was analyzed by doubling time, viability during manufacturing, and product T-cell phenotypes by FC (n=145). Associations between these covariates, and with routine hematology tests, were performed by Spearman rank correlation or Wilcoxon tests. Effects on survival were assessed by Kaplan-Meier with optimized cutpoint selection. Results: The percentage (%) of naive (CCR7+CD45RA+) T helper (Th; CD4+CD127+CD25low) cells coexpressing CD27 and CD28 (median, 1%; range, 0.01%-15.8%; IQR, 0.3%-3.8%) in aph associated positively with axi-cel efficacy. The % of intermediate monocytes (IMs; CD14+CD16+; median, 1.8%; range, 0.003%-16.7%; IQR, 1%-3%) in aph associated negatively with efficacy. The % of circulating CD27+CD28+ naive Th cells associated positively with an enriched preTx immune TME T-cell signature, % CCR7+CD45RA+ product T cells, objective response rate, PFS, and OS. An increased % of IMs associated directly with negative predictive markers (preTx serum levels of LDH, IL-6, and CRP) and inversely with TME T-cell signature, PFS, and OS. The premfg ratio of CD27+CD28+ naive Th cells/IMs associated directly with CAR T-cell expansion and efficacy. Conclusions: This work points to a link between the pre-existing state of the immune system, reflected in premfg aph, and immune TME, as well as product attributes influencing axi-cel efficacy in LBCL. These data bear practical implications towards the development of predictive biomarkers for axi-cel efficacy. [JB and JC contributed equally.] Citation Format: Justin Budka, Justin Chou, Vicki Plaks, Francesca Milletti, Zixing Wang, Frederick L. Locke, Sattva S. Neelapu, David B. Miklos, Caron A. Jacobson, Lazaros J. Lekakis, Yi Lin, Armin Ghobadi, Zahid Bashir, Nathalie Scholler, Jérôme Galon, John M. Rossi, Adrian Bot. Pretreatment (PreTx) immune cell phenotypes in peripheral blood associated with the tumor immune contexture, product attributes, and durable clinical efficacy in patients with large B-cell lymphoma (LBCL) treated with axicabtagene ciloleucel (axi-cel) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT166.

Abstract ZUMA-3 is a phase 1/2 study evaluating KTE-X19, an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, in adult relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). We report the phase 1 results. After fludarabine-cyclophosphamide lymphodepletion, patients received a single infusion of KTE-X19 at 2 × 106, 1 × 106, or 0.5 × 106 cells per kg. The rate of dose-limiting toxicities (DLTs) within 28 days after KTE-X19 infusion was the primary end point. KTE-X19 was manufactured for 54 enrolled patients and administered to 45 (median age, 46 years; range, 18-77 years). No DLTs occurred in the DLT-evaluable cohort. Grade ≥3 cytokine release syndrome (CRS) and neurologic events (NEs) occurred in 31% and 38% of patients, respectively. To optimize the risk-benefit ratio, revised adverse event (AE) management for CRS and NEs (earlier steroid use for NEs and tocilizumab only for CRS) was evaluated at 1 × 106 cells per kg KTE-X19. In the 9 patients treated under revised AE management, 33% had grade 3 CRS and 11% had grade 3 NEs, with no grade 4 or 5 NEs. The overall complete remission rate correlated with CAR T-cell expansion and was 83% in patients treated with 1 × 106 cells per kg and 69% in all patients. Minimal residual disease was undetectable in all responding patients. At a median follow-up of 22.1 months (range, 7.1-36.1 months), the median duration of remission was 17.6 months (95% confidence interval [CI], 5.8-17.6 months) in patients treated with 1 × 106 cells per kg and 14.5 months (95% CI, 5.8-18.1 months) in all patients. KTE-X19 treatment provided a high response rate and tolerable safety in adults with R/R B-ALL. Phase 2 is ongoing at 1 × 106 cells per kg with revised AE management. This trial is registered at www.clinicaltrials.gov as #NCT02614066.

Background: Axi-cel, an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy, is approved for treatment of adult pts with R/R LBCL after ≥ 2 lines of systemic therapy. In the pivotal ZUMA-1 study, axi-cel demonstrated durable responses and a largely manageable safety profile (Locke FL, et al. Lancet Oncol. 2019). ZUMA-9 (NCT03153462), a multicenter, open-label study, provided pts with R/R LBCL with expanded access to axi-cel until commercial availability (Cohort 1 [C1]) and later, if commercially manufactured product did not meet commercial release specification(s) (Cohort 2 [C2]). Safety and efficacy of axi-cel (C1 and C2) and translational analyses (C2) are presented. Methods: Eligible adults had histologically confirmed R/R LBCL, ECOG ≤ 1, and received prior CD20-targeting and an anthracycline-containing regimen. C2 pts must have had commercial OOS product. Pts underwent leukaphersis and conditioning chemotherapy (cyclophosphamide 500 mg/m2/day and fludarabine 30 mg/m2/day) for 3 days followed by a single axi-cel infusion (target dose, 2 × 106 CAR T cells/kg). C1 and C2 pts with high disease burden could receive bridging therapy before conditioning at investigator's discretion. Endpoints included frequency of adverse events (AEs), objective response rate (ORR) per standard-of-care imaging assessment, overall survival (OS) for C1 and C2, and blood CAR T cells levels and serum cytokines for C2 only. Outcomes were contextualized with the primary analysis of ZUMA-1 C1+2 (n = 101; ≥ 6 mo of follow-up; Neelapu SS, et al. NEJM. 2017). Results: As of 11/29/2019 (C1) and 3/15/2020 (C2), 25 C1 pts and 36 C2 pts received axi-cel with a median follow-up of 27.1 mo (range, 23.6 - 29.6) and 13.2 mo (range, 0.4 - 25.7), respectively. In C1, median age was 56 y (range, 28 - 76), 60% were male, 80% had DLBCL, 48%/0% had ECOG1/≥2, 44% had IPI ≥3, and 64% had ≥ 3 prior lines of therapy. In C2, median age was 61 y (range, 24 - 81), 75% were male, 78% had DLBCL, 58%/17% had ECOG 1/≥2, 56% had IPI ≥3, and 69% had ≥ 3 prior lines of therapy. In C2, 50% of pts had OOS product with low viability, 28% had high IFN-γ, 14% had low IFN-γ, 14% received a low dose, and 6% had high transduction ratio. The ORR was 76% (64% complete response [CR]) for C1, 53% (36% CR) for C2, and 82% (54% CR) for ZUMA-1 C1+2. Median OS was 23.8 mo (95% CI, 13.5 - NE) for C1 and not reached (95% CI, 3.4 - NE) for C2, respectively. ORR and OS were consistent in C2 OOS subgroups (Table). Grade ≥ 3 AEs were reported in 88% and 89% of C1 and C2 pts, respectively. Grade ≥ 3 CRS (Lee et al, Blood. 2014) was not observed in C1 but was reported in 3% of C2 pts (13% in ZUMA-1 C1+2). Grade ≥ 3 neurologic events (NEs) occurred in 36% and 19% of pts in C1 and C2, respectively, and 28% of pts in ZUMA-1 C1+2. No Grade 5 CRS or NEs occurred in C1 or C2. All CRS and NEs resolved in C1, and most CRS (29/30) and NEs (19/24) resolved in C2 as of the data cutoff. Of 3 Grade 5 AEs in C1, 2 were unrelated to axi-cel (clostridial sepsis [on Day (D) 6] and respiratory failure [on D212]) and 1 was related to conditioning (myelodysplastic syndrome [on D563]). Of 3 Grade 5 AEs in C2, 2 were unrelated to axi-cel (multiple organ dysfunction syndrome [on D6] and cardiac arrest [on D482]) and 1 was related to axi-cel (systemic mycosis [on D30]). Median peak CAR T cell levels and median CAR T cell expansion (area under the curve in the first 28 days) were lower in ZUMA-9 C2 (n = 32/36; 12 cells/µL [range, 0 - 442] and 112 cells/µL × days [range, 0 - 3413]) vs ZUMA-1 C1+2 (n = 96/101; 42 cells/µL [range, 1 - 1514] and 462 cells/µL × days [range, 5 - 14,329]). Serum IFN-γ levels peaked within 8 days after axi-cel infusion (median, 170 pg/mL [range, 8 - 1876]) and were lower vs ZUMA-1 C1+2 (median, 477 pg/mL [range, 8 - 8209]). Axi-cel in ZUMA-9 C2 contained fewer, less differentiated CCR7+ naïve and central memory T cells, and a greater proportion of more differentiated CCR7- effector memory and effector T cells vs ZUMA-1 C1+2. No cases of replication-competent retroviruses were reported in C1 or C2. Conclusion: Axi-cel treatment demonstrated a manageable safety profile and meaningful clinical benefit in this expanded access and OOS product study. While CAR T cell therapy showed clinical benefit in C2 (OOS product), the lower CR rate was corroborated by lower CAR T cell expansion and a more differentiated product vs ZUMA-1 C1+2, warranting further investigation. ZUMA-9 C2 is enrolling pts and evaluation is ongoing. Disclosures Jacobson: Precision Biosciences: Consultancy, Honoraria, Other: travel support; Celgene/BMS: Consultancy, Honoraria, Other: travel support; Novartis: Consultancy, Honoraria, Other: travel support; AXIS: Speakers Bureau; Nkarta: Consultancy, Honoraria, Other: travel support; Clinical Care Options: Speakers Bureau; Pfizer: Research Funding; Lonza: Consultancy, Honoraria, Other: travel support; Kite, a Gilead Company: Consultancy, Honoraria, Other: travel support. Locke:Calibr: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Wugen: Consultancy; GammaDelta Therapeutics: Consultancy; Celgene/Bristol-Myers Squibb: Consultancy; Novartis: Consultancy; Cellular Biomedicine Group: Other: Consultancy with grant options; Allogene: Consultancy. Miklos:Adaptive Biotech: Consultancy, Other: Travel support, Research Funding; Novartis: Consultancy, Other: Travel support, Research Funding; Pharmacyclics: Consultancy, Other: Travel support, Patents & Royalties, Research Funding; Juno-Celgene-Bristol-Myers Squibb: Consultancy, Other: Travel support, Research Funding; Allogene Therapeutics Inc.: Research Funding; Miltenyi Biotec: Research Funding; Janssen: Consultancy, Other: Travel support; Kite-Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding. Vose:Incyte: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding; Karyopharm Therapeutics: Consultancy, Honoraria; Allogene: Honoraria; Loxo: Consultancy, Honoraria, Research Funding; Seattle Genetics: Research Funding; Miltenyi Biotec: Honoraria; Janssen: Honoraria; Epizyme: Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Kite, a Gilead Company: Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Verastem: Consultancy, Honoraria; Wugen: Honoraria; Celgene: Honoraria; Roche/Genetech: Consultancy, Honoraria, Other. Lin:Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Vineti: Consultancy; Gamida Cells: Consultancy; Takeda: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding. Budde:Roche: Consultancy; Merck: Research Funding; Amgen: Research Funding; Kite, a Gilead Company: Consultancy; Gilead Sciences: Consultancy; Mustang Therapeutics: Research Funding; AstraZeneca: Research Funding. Maloney:Celgene: Consultancy, Honoraria, Research Funding; A2 Biotherapeutics: Consultancy, Current equity holder in publicly-traded company, Honoraria; Gilead Sciences: Consultancy, Honoraria; Juno Therapeutics: Consultancy, Honoraria, Patents & Royalties: Patents are pending, but not issued, licensed, no royalties, no licensees., Research Funding; Bioline Rx: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding. Jaglowski:Juno: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; CRISPR: Consultancy; Novartis: Consultancy, Research Funding. Riedell:MorphoSys: Research Funding; Kite/Gilead: Research Funding, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Karyopharm Therapeutics: Consultancy; Celgene/Bristol-Myers Squibb: Consultancy, Research Funding; Novartis Pharmaceuticals: Consultancy, Honoraria, Research Funding. Perales:Celgene: Honoraria; MolMed: Membership on an entity's Board of Directors or advisory committees; Omeros: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bellicum: 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; Kite/Gilead: Honoraria, Research Funding; Miltenyi Biotec: Research Funding; Merck: Consultancy, Honoraria; Nektar Therapeutics: 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; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Cidara Therapeutics: Other; Servier: Membership on an entity's Board of Directors or advisory committees, Other; Medigene: Membership on an entity's Board of Directors or advisory committees, Other; NexImmune: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Honoraria, Research Funding. Kim:Gilead Sciences: Current equity holder in publicly-traded company; Kite, a Gilead Company: Current Employment. Kawashima:Kite, a Gilead Company: Current Employment; Gilead Sciences: Other: stock or other ownership . Yang:Kite, a Gilead Company: Current Employment. Rossi:Kite, a Gilead Company: Current Employment; Gilead Sciences: Current equity holder in publicly-traded company. Goyal:Kite, a Gilead Company: Current Employment. Neelapu:Legend Biotech: Other; Allogene Therapeutics: Other: personal fees, Research Funding; Cell Medica/Kuur: Other: personal fees; Incyte: Other: personal fees; Unum Therapeutics: Other, Research Funding; Adicet Bio: Other; Novartis: Other: personal fees; Bristol-Myers Squibb: Other: personal fees, Research Funding; Merck: Other: personal fees, Research Funding; Kite, a Gilead Company: Other: personal fees, Research Funding; Precision Biosciences: Other: personal fees, Research Funding; Poseida: Research Funding; Calibr: Other; Acerta: Research Funding; Takeda Pharmaceuticals: Patents & Royalties; Celgene: Other: personal fees, Research Funding; Pfizer: Other: personal fees; Karus Therapeutics: Research Funding; Cellectis: Research Funding; N/A: Other.

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.

Abstract ZUMA-1 demonstrated a high rate of durable response and a manageable safety profile with axicabtagene ciloleucel (axi-cel), an anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, in patients with refractory large B-cell lymphoma. As previously reported, prespecified clinical covariates for secondary end point analysis were not clearly predictive of efficacy; these included Eastern Cooperative Oncology Group performance status (0 vs 1), age, disease subtype, disease stage, and International Prognostic Index score. We interrogated covariates included in the statistical analysis plan and an extensive panel of biomarkers according to an expanded translational biomarker plan. Univariable and multivariable analyses indicated that rapid CAR T-cell expansion commensurate with pretreatment tumor burden (influenced by product T-cell fitness), the number of CD8 and CCR7+CD45RA+ T cells infused, and host systemic inflammation, were the most significant determining factors for durable response. Key parameters differentially associated with clinical efficacy and toxicities, with both theoretical and practical implications for optimizing CAR T-cell therapy. This trial was registered at www.clinicaltrials.gov as #NCT02348216.

3022 Background: Axi-cel is a US and EU-approved autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy for pts with relapsed/refractory large B cell lymphoma after ≥ 2 prior therapies. In ZUMA-1 (NCT02348216), the objective response rate was 83% (58% complete response rate; Locke et al. Lancet Oncol. 2019). T cell-related biology (Immunosign 21; Immunoscore) measured pretreatment in the tumor microenvironment (TME) was associated with response to axi-cel (Rossi et al. AACR 2018. #LB-016; Rossi et al. AACR 2019. #CT153). This expanded analysis characterized the pretreatment TME immune contexture and examined associations between immune cell subsets and response. Methods: In ZUMA-1, pts received axi-cel at a target dose of 2.0 × 106 CAR T cells/kg. Archival pretreatment tumor biopsy samples were analyzed by multiplex immunohistochemistry (Brightplex). Two panels were developed and applied to assess T cell (CD3, CD8, FoxP3, PD-1, LAG-3, TIM-3) and myeloid cell (CD11b, CD14, CD15, LOX1, S100A9, CD68) subsets (n = 14 total). The association between T cell and myeloid cell subset density, prespecified immune scores (Immunosign 21; Immunoscore), and objective response was evaluated. T test values were based on Brightplex analysis. Results: Pretreatment tumor biopsy samples from 18 pts were analyzed (14 objective responders and 4 nonresponders). The pretreatment TME comprised all major myeloid and T cell subsets, with diverse distribution across samples analyzed. The median TME density of monocytes (CD11b+ CD15− CD14+; 1215 cells/mm2) and macrophages (CD68+; 530 cells/mm2) was greater than that of the total CD8+ T cell subset (312 cells/mm2). The pretreatment Immunosign 21 and Immunoscore scores associated positively with the density of all major T cell subsets and some myeloid subsets. The density of activated CD8+ T cells (PD-1+ LAG-3+/− TIM-3−) was most significantly associated with clinical response versus other T cell subsets. The density of nonactivated CD8+ T cells (PD-1− LAG-3− TIM-3−) and exhausted CD8+ T cells (PD-1+ LAG-3+ TIM-3+) were not significantly associated with response. Additional characterization of the immune contexture and correlative analysis of cell subsets will be presented. Conclusions: These results suggest that a TME associated with increased density of activated PD-1+ LAG-3+/− TIM-3− CD8+ T cells, measurable pretreatment, facilitates clinical response in pts post–axi-cel.

Background: Relapsed/refractory (R/R) large B cell lymphoma (LBCL) is associated with poor outcomes to standard salvage therapy (Crump M, et al. Blood. 2017). In SCHOLAR-1, a large multicenter, patient-level, retrospective study, patients with R/R diffuse LBCL had a 26% objective response rate (ORR) to the next line of therapy, a 7% complete response (CR) rate, and a median overall survival of 6.3 months (Crump M, et al. Blood 2017). Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for patients with R/R LBCL with ≥ 2 prior systemic therapies. With a median follow-up of 27.1 months in ZUMA-1, the ORR with axi-cel was 83% (58% CR rate) in patients with refractory LBCL (Locke FL, et al. Lancet Oncol. 2019). Activation of the costimulatory receptor 4-1BB (CD137) on CAR T cells may enhance axi-cel antitumor activity by enhancing T cell proliferation, function, and survival. Utomilumab (uto), an investigational monoclonal antibody agonist of the 4-1BB pathway, enhanced T cell function and survival in preclinical studies (Fisher TS, et al. Cancer Immunol Immunother. 2012) and had favorable single-agent safety in patients (Segal NH, et al. Clin Cancer Res. 2018). Possible mechanisms of resistance to axi-cel are thought to be suboptimal CAR T cell expansion an exclusionary tumor microenvironment and CD19 target antigen loss (Neelapu SS, et al. Blood 2017, Rossi JM, et al J Immunother Cancer. 2018). Combination strategies that increase proliferation, expansion, and persistence of CAR T cells or prevent activation-induced cell death of CAR T cells may improve clinical outcomes observed with axi-cel. ZUMA-11 is a Phase 1/2 study investigating the efficacy and safety of axi-cel + uto in patients with refractory LBCL. Methods: The primary objectives of this study are to determine the safety, recommended Phase 2 dosing and timing (Phase 1), and efficacy (Phase 2) of axi-cel + uto in adult patients with refractory LBCL. Patients with progressive or stable disease as the best response to second-line chemotherapy or relapse ≤ 12 months after autologous stem cell transplantation, a prior anti-CD20 antibody and anthracycline-containing regimen, and Eastern Cooperative Oncology Group performance status 0-1 are eligible. Patients with histologically proven primary mediastinal B cell lymphoma, history of Richter's transformation or chronic lymphocytic lymphoma, prior CAR T cell therapy, or central nervous system involvement of lymphoma are ineligible. In Phase 1, ≈24 patients in ≤ 3 cohorts will receive a single dose of axi-cel and escalating doses of uto (10, 30, or 100 mg) using a 3 + 3 design in up to 4 of 6 cohorts. The recommended uto dose will be based on dose-limiting toxicities and other factors. Patients will be leukapheresed and may receive optional, nonchemotherapy bridging therapy per investigator decision. After conditioning chemotherapy, patients will receive a single infusion of axi-cel (target dose, 2 × 106 CAR T cells/kg) on Day 0 followed by uto on Day 1 and every 4 weeks for 6 months or until progressive disease. Patients will be treated one at a time during Phase 1, and patients treated with axi-cel will be staggered by ≥ 2 weeks. Day 21 uto administration will be explored if toxicity is unacceptable with Day 1 administration. The primary endpoints are incidence of dose-limiting toxicities in Phase 1 and CR rate in Phase 2. Secondary endpoints include ORR, duration of response, progression-free survival, overall survival, safety, and levels of CAR T cells and cytokines in blood. This study uses a single-arm design to estimate the true CR rate; with a sample size of 27 patients, of which ≤ 3 patients will have been treated in the Phase 1 portion, the maximum half-width of the 95% confidence interval about response will be ≥ 21%. ZUMA-11 is open and accruing patients. Disclosures Reshef: Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Celgene: Research Funding; Incyte: Consultancy, Research Funding; Shire: Research Funding; BMS: Consultancy; Atara: Consultancy, Research Funding; Magenta: Consultancy; Pfizer: Consultancy; Pharmacyclics: Consultancy, Research Funding. Miklos:Pharmacyclics: Consultancy, Patents & Royalties, Research Funding; Precision Bioscience: Consultancy; Adaptive Biotechnologies: Consultancy, Research Funding; Miltenyi: Consultancy, Research Funding; Becton Dickinson: Consultancy; Janssen: Consultancy; AlloGene: Consultancy; Novartis: Consultancy; Kite, A Gilead Company: Consultancy, Research Funding; Celgene-Juno: Consultancy. Timmerman:Spectrum Pharmaceuticals: Research Funding; Kite, A Gilead Company: Consultancy, Honoraria, Other: travel support, Research Funding; ImmunGene: Research Funding; Merck: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Other: travel support, Research Funding. Jacobson:Novartis: Consultancy, Honoraria, Other: travel support; Bayer: Consultancy, Other: travel support; Precision Biosciences: Consultancy, Other: travel support; Humanigen: Consultancy, Other: travel support; Celgene: Consultancy, Other: travel support; Pfizer: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: travel support. Bennani:Kite, A Gilead Company: Consultancy, Research Funding. Rossi:Kite, A Gilead Company: Employment. Sherman:Kite, A Gilead Company: Employment. Sun:Kite, A Gilead Company: Employment. Palluconi:Kite, A Gilead Company: Employment. Kim:Kite, A Gilead Company: Employment. Jain:Kite/Gilead: Consultancy.

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.