Neelapu, Sattva S.

Abstract Polatuzumab vedotin (PV) is an antibody–drug conjugate targeting CD79b that is approved for patients with relapsed/refractory large B-cell lymphoma (LBCL). Patients who relapse after chimeric antigen receptor (CAR) T-cell therapy were not included in the registration study, and reports of PV use after CAR T cells are limited. This multicenter retrospective analysis included patients with LBCL who relapsed or progressed after CAR T-cell therapy and subsequently received PV with or without rituximab and bendamustine between July 2019 and May 2021. Response to treatment and progression were assessed based on the 2014 Lugano criteria. Fifty-seven patients were included in the study: 18 (32%) patients were primary refractory to CAR T-cell therapy, and 34 (60%) patients received PV-based therapy immediately after CAR T-cell therapy. PV was combined with rituximab in 54 (95%) patients and administered with bendamustine in 35 (61%) patients. A response was achieved in 25 (44%) patients, including complete remission in 8 (14%). No significant association between baseline characteristics and response was observed. After a median follow-up of 47 weeks (95% confidence interval [CI], 40-54), 46 (81%) patients had disease progression or died, and the median progression-free survival was 10 weeks (95% CI, 5-15). On a multivariate analysis, bone marrow involvement (hazard ratio, 5.2; 95% CI, 1.8-15; P = .003) and elevated lactate dehydrogenase levels (hazard ratio, 5.0; 95% CI, 1.4-16; P = .01) were associated with shorter progression-free survival. Studies aimed at better characterizing the intrinsic mechanism of resistance and identifying optimal consolidation strategies for these patients are warranted.

Abstract Introduction. About 60% of patients with large B-cell lymphoma (LBCL) relapse after standard of care (SOC) anti-CD19 autologous chimeric antigen receptor (CAR) T-cell therapy, CD19 downregulation representing a major mechanism of resistance. Therefore, agents able to target B-cell antigens other than CD19 could be clinically effective for these patients. Polatuzumab vedotin (PV) is an antibody-drug conjugate targeting CD79b, and approved by the FDA in combination with bendamustine and rituximab for patients with relapsed or refractory (r/r) LBCL. Patients who relapsed after CAR T-cell therapy were not included in the registration study, and reports of PV use after CAR T-cells in real world practice are very limited. Methods. This is a multi-center retrospective analysis of patients with LBCL who relapsed after SOC CAR T-cell therapy and subsequently received SOC PV with or without rituximab and bendamustine between 07/2019 and 04/2021. PV was given at the standard dose of 1.8 mg/kg IV every 3 weeks in all patients (except for one patient, who received 1.4 mg/Kg). Response to treatment and progression were defined according to 2014 Lugano criteria. Survival curves were calculated using Kaplan-Meier estimates, and were compared between subgroups using the log-rank test. Cox regression was used for multivariate analysis (MVA). Results. Fifty-four patients were included in the study: median age was 59 (range, 22-79 years), 38 (70%) were male, and 30 (56%) had an internal prognostic index score > 3. Median number of systemic therapies before CAR T-cell therapy was 2 (range, 2-6), 16 (30%) patients previously had autologous stem cell transplant (SCT), and 2 (4%) had allogeneic SCT. Sixteen (30%) patients were primary refractory to CAR T-cell therapy, and median time from CAR T-cell therapy to PV was 5 months (range, 1-40 months). CD19 status at time of relapse after CAR T-cell therapy was assessed by immunohistochemistry and/or flow cytometry in 41 patients, and positive in 34 (83%); CD79b status was assessed in 14 patients, and positive in all cases (100%). Thirty-two (59%) patients received PV-based therapy immediately after CAR T cell therapy, while 22 (41%) had intervening treatments (median 1, range 1-5). At time of PV initiation, median absolute neutrophil count was 2.9 (range 0.5-19 X10 9/L), median platelet count was 87 X10 9/L (range 15-437 X10 9/L), median serum creatinine was 0.9 mg/dL (range 0.4-22 mg/dL), and 44 (81%) patients had elevated serum lactate dehydrogenase (LDH). The median number of PV cycles was 2 (range, 1-16): PV was combined with rituximab in 51 (94%) patients, and administered with bendamustine in 33 (61%). A response was achieved in 24 (45%) patients, including complete remission (CR) in 8 (14%) patients and partial remission in 16 (30%)(Figure A), with a median duration of response of 11 weeks (95%CI, 5-17 weeks). No significant association between baseline characteristics and response was observed. To date, 49 (91%) patients stopped PV: 38 (70%) due to progression, 7 (13%) because of CR/patient decision, 3 (6%) to proceed to allogeneic SCT, and 1 (2%) to proceed to an immunotherapy clinical trial (despite absence of progression). No patients stopped therapy because of toxicity. After a median follow up of 45 weeks (95% CI, 20-70 weeks), 44 (81%) patients progressed/died, and median PFS was 9 weeks (95% CI, 4-14 weeks). To date, 34 (63%) died, and median OS was 16 weeks (95% CI, 13-19 weeks)(Figure B). Causes of death included progression in 31 patients and transplant-related complications in 3. On univariate analysis, a shorter median progression-free survival (PFS) was observed for patients with bone marrow (BM) involvement (3 vs 10 weeks, p=0.002), prior central nervous system involvement (4 vs 10 weeks, p=0.02), and elevated LDH (6 months vs not reached, p=0.004). On MVA, the association was maintained only for BM involvement (hazard ratio [HR] 4.8; 95% confidence interval [CI] 1.6-12.5, p=0.004) and elevated LDH (HR 5; 1.4-16.7, p=0.01)(Figure C). Discussion. PV is safe and effective, but has short duration of response in r/r LBCL after anti-CD19 CAR T-cell therapy, except for patients with normal LDH. Studies aimed at better characterizing intrinsic mechanism of resistance, including upregulation of BCL2 family proteins, to favor the development of more effective PV-based combination strategies for these patients, are warranted. Figure 1 Figure 1. Disclosures Crombie: Roche: Research Funding; Merck: Research Funding; Abbvie: Research Funding; Bayer: Research Funding; Karyopharm: Consultancy; Incyte: Consultancy. Kamdar: Celgene (BMS): Consultancy; Adaptive Biotechnologies: Consultancy; Genentech: Research Funding; Kite: Consultancy; AstraZeneca: Consultancy; ADC Therapeutics: Consultancy; Genetech: Other; TG Therapeutics: Research Funding; SeaGen: Speakers Bureau; Celgene: Other; KaryoPharm: Consultancy; AbbVie: Consultancy. Hess: ADC Therapeutics: Consultancy; BMS: Speakers Bureau. Neelapu: 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; 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. Lin: Novartis: Consultancy; Bluebird Bio: Consultancy, Research Funding; Juno: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Gamida Cell: Consultancy; Sorrento: Consultancy; Legend: Consultancy; Takeda: Research Funding; Merck: Research Funding; Vineti: Consultancy. Strati: Astrazeneca-Acerta: Research Funding; Roche-Genentech: Consultancy.

Abstract Introduction: Brexucabtagene autoleucel (brexu-cel) was approved by US FDA for relapsed/refractory (R/R) mantle cell lymphoma (MCL) on July 24, 2020 based on results from the pivotal ZUMA-2 (NCT02601313) study, in which an objective response rate (ORR) of 93% and a complete response (CR) rate of 67% were achieved among the 60 treated patients with at least 7 months of follow-up. The study had stringent eligibility criteria, including prior treatment with a BTK inhibitor (BTKi), and only allowed BTKi and/or corticosteroid for bridging therapy. We report here the safety and efficacy of brexu-cel in standard of care practice among centers in the US Lymphoma CAR-T Consortium. Methods: Fourteen centers participated in this retrospective study. Patients who underwent leukapheresis by 6/15/2021 with an intent to manufacture brexu-cel were included. Baseline clinical characteristics, bridging therapy, adverse events after brexu-cel infusion, and post-infusion outcome data were collected. Eligibility for ZUMA-2 was retrospectively determined based on characteristics at the time of leukapheresis. Duration of response (time from initial response to disease progression or death from any cause), progression-free survival (PFS; time from infusion to disease progression or death from any cause) and overall survival (OS; time from infusion to death from any cause) were analyzed using the Kaplan-Meier method. Results: At the data cut-off date of 7/9/2021, 107 patients underwent leukapheresis, among whom 93 (87%) completed brexu-cel infusion, 2 (2%) were waiting for infusion, and 12 (11%) did not receive infusion (manufacture failure n=6, organ dysfunction n=1, death n=5). Baseline clinical characteristics of the 93 infused patients are shown in Table 1. The median age was 67 years and 81% were male. 32% had high risk simplified MIPI, 77% had Ki-67≥30%, 45% had blastoid or pleomorphic variant, 46% had TP53 alteration, 29% had complex karyotype, and 7% had CNS involvement. The median number of prior lines of therapy was 3. Eighty-two percent had prior BTKi treatment, and 44% had refractory disease to the last line of therapy. Sixty-eight (73%) patients would not have met ZUMA-2 eligibility criteria. Reasons for ineligibility included ECOG PS ≥2 (n=8), CNS involvement by lymphoma (n=6), prior therapies (n=33), cytopenia (n=11), renal or hepatic dysfunction (n=13), other medical conditions (n=18), and active infection (n=2). Sixty (65%) of the 93 patients received bridging therapy, which included BTKi (n=27), venetoclax (n=14), chemotherapy (n=19), CD20 antibody (n=26), lenalidomide (n=3), corticosteroid (n=9), and radiotherapy (n=13). Only 13 (14%) patients received BTKi or corticosteroid alone as in ZUMA-2. Among 93 infused patients, cytokine release syndrome (CRS) rate was 88% (8% grade ≥3), and immune effector cell-associated neurotoxicity syndrome (ICANS) rate was 58% (33% grade ≥3). No grade 5 CRS or ICANS occurred. Medications used to manage CRS and ICANS were 71 (76%) for tocilizumab, 64 (69%) for steroid, and 16 (17%) for anakinra. Twenty-four (26%) patients required ICU admission, 9 patients required vasopressors, and 4 patients required mechanical ventilation. With a median follow-up of 3.0 months (range 0.1-9.6), day 30 response was evaluable in 81 patients, and the ORR was 86%, with 64% CR (Table 2). The ORR/CR rates were 94%/70% for blastoid or pleomorphic variants, 82%/50% for TP53 altered, 84%/61% for BTKi-exposed, 94%/76% for BTKi-naïve, and 88%/67% for those not meeting ZUMA-2 eligibility criteria. The ORR/CR rates were 87%/69% for patients who received bridging therapy and 85%/56% for those who did not. For patients who achieved a response at day 30, the rate of continued response at 3-month was 83.7% (95% CI 68.3%-92.0%). The 3-month PFS rate was 80.6% (95% CI 68.6%-88.4%), and the 6-month OS rate was 82.1% (95% CI 67.7%-90.5%). Conclusions: This multicenter retrospective study demonstrated encouraging safety and efficacy data of brexu-cel in R/R MCL in the real world practice. The CRS and ICANS incidences were comparable to those reported in ZUMA-2, but use of tocilizumab and steroid was more frequent than in ZUMA-2. Although 73% of the patients would have been ineligible for ZUMA-2, the ORR and CR rate were comparable to those reported in ZUMA-2. Longer follow-up is necessary to confirm long term safety and efficacy. YW, PJ and FLL are co-first authors, and YL, MW and MDJ are co-senior authors. Figure 1 Figure 1. Disclosures Wang: Novartis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; InnoCare: Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding. Jain: Kite: Consultancy; Lilly: Membership on an entity's Board of Directors or advisory committees. Locke: Gerson Lehrman Group: Consultancy; Emerging Therapy Solutions: Consultancy; EcoR1: Consultancy; Cowen: Consultancy; GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Umoja: Consultancy, Other; Janssen: Consultancy, Other: Scientific Advisory Role; Wugen: Consultancy, Other; Legend Biotech: Consultancy, Other; Takeda: Consultancy, Other; Novartis: Consultancy, Other, Research Funding; Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; Amgen: Consultancy, Other: Scientific Advisory Role; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding. Munoz: Bayer, Gilead/Kite Pharma, Celgene, Merck, Portola, Incyte, Genentech, Pharmacyclics, Seattle Genetics, Janssen, and Millennium: Research Funding; Kite, a Gilead Company, Kyowa, Bayer, Pharmacyclics/Janssen, Seagen, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau; Targeted Oncology, OncView, Kyowa Kirin, Physicians' Education Resource, and Seagen: Honoraria; Pharmacyclics/Abbvie, Bayer, Kite, a Gilead Company, Pfizer, Janssen, Juno/Celgene, Bristol Myers Squibb, Kyowa Kirin, Alexion, Fosun Kite, Innovent, Seagen, BeiGene, Debiopharm, Epizyme, Karyopharm, ADC Therapeutics, Servier, and Genmab: Consultancy, Other: advisory role; Alexion, AstraZeneca Rare Disease: Other: Study investigator. Maurer: BMS: Research Funding; Genentech: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Nanostring: Research Funding. Beitinjaneh: Kite/Gilead: Other: Ad Board Event Attendee. Frank: Allogene Therapeutics: Research Funding; Kite-Gilead: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Research Funding. Dahiya: Miltenyi Biotech: Research Funding; Kite, a Gilead Company: Consultancy; Jazz Pharmaceuticals: Research Funding; Atara Biotherapeutics: Consultancy; BMS: Consultancy. McGuirk: Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Gamida Cell: Research Funding; Novartis: Research Funding; Bellicum Pharmaceuticals: Research Funding; Fresenius Biotech: Research Funding; Astelllas Pharma: Research Funding; Novartis: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Pluristem Therapeutics: Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; EcoR1 Capital: Consultancy. Goy: Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; Michael J Hennessey Associates INC: Consultancy; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; Phamacyclics: Research Funding; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Rosewell Park: Consultancy; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Research Funding; Incyte: Honoraria; Hoffman la Roche: Consultancy; LLC(Targeted Oncology): Consultancy; Xcenda: Consultancy, Honoraria; OncLive Peer Exchange: Honoraria; Infinity/Verastem: Research Funding; Genentech/Hoffman la Roche: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Medscape: Consultancy; Xcenda: Consultancy; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Research Funding; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; 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; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; MorphoSys: Honoraria, Other; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, 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. Vose: Kite, a Gilead Company: Honoraria, Research Funding. Hill: Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Celgene (BMS): Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Gentenech: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria. Oluwole: Pfizer: Consultancy; Curio Science: Consultancy; Janssen: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Deol: Kite, a Gilead Company: Consultancy. Shah: Jazz Pharmaceuticals: Research Funding; Incyte: Research Funding; Pfizer: Consultancy, Other: Expenses; Novartis: Consultancy, Other: Expenses; Bristol-Myers Squibb/Celgene: Consultancy, Other: Expenses; BeiGene: Consultancy, Honoraria; Amgen: Consultancy; Precision Biosciences: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Other: Expenses, Research Funding; Pharmacyclics/Janssen: Honoraria, Other: Expenses; Acrotech/Spectrum: Honoraria; Servier Genetics: Other; Adaptive Biotechnologies: Consultancy. Paludo: Karyopharm: Research Funding. Miklos: Pharmacyclics: Patents & Royalties; 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, 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; 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. Ghobadi: Wugen: Consultancy; Atara: Consultancy; Amgen: Consultancy, Research Funding; Celgene: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding. 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; Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties; 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; 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. Lin: Legend: Consultancy; Novartis: Consultancy; Gamida Cell: Consultancy; Vineti: Consultancy; Bluebird Bio: Consultancy, Research Funding; Sorrento: Consultancy; Takeda: Research Funding; Merck: Research Funding; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Juno: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Wang: Moffit Cancer Center: Honoraria; Chinese Medical Association: Honoraria; InnoCare: Consultancy, Research Funding; Epizyme: Consultancy, Honoraria; Hebei Cancer Prevention Federation: Honoraria; Newbridge Pharmaceuticals: Honoraria; Genentech: Consultancy; OMI: Honoraria; Physicians Education Resources (PER): Honoraria; Clinical Care Options: Honoraria; CAHON: Honoraria; VelosBio: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; CStone: Consultancy; Loxo Oncology: Consultancy, Research Funding; BioInvent: Research Funding; Juno: Consultancy, Research Funding; DTRM Biopharma (Cayman) Limited: Consultancy; BGICS: Honoraria; Bayer Healthcare: Consultancy; Janssen: Consultancy, Honoraria, Research Funding; Kite Pharma: Consultancy, Honoraria, Research Funding; Molecular Templates: Research Funding; Imedex: Honoraria; Miltenyi Biomedicine GmbH: Consultancy, Honoraria; Dava Oncology: Honoraria; Oncternal: Consultancy, Research Funding; Lilly: Research Funding; Celgene: Research Funding; Anticancer Association: Honoraria; AstraZeneca: Consultancy, Honoraria, Research Funding; The First Afflicted Hospital of Zhejiang University: Honoraria; BeiGene: Consultancy, Honoraria, Research Funding; Scripps: Honoraria; Mumbai Hematology Group: Honoraria; Acerta Pharma: Consultancy, Honoraria, Research Funding. Jain: BMS, Kite/Gilead, Novartis, Precision Biosciences, Takeda: Consultancy.

Abstract Background: High-risk LBCL is associated with poor prognosis after first-line anti-CD20 mAb-containing regimens, highlighting the need for novel treatments. Axi-cel, an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, is approved for treatment of relapsed/refractory (R/R) LBCL after ≥2 lines of systemic therapy. Here we report the primary analysis of ZUMA-12, a Phase 2, multicenter, single-arm study of axi-cel as part of first-line therapy in patients with high-risk LBCL. Methods: Eligible adults had high-risk LBCL, defined by histology (double- or triple-hit status [MYC and BCL2 and/or BCL6 translocations] per investigator) or an IPI score ≥3, plus a positive interim PET per Lugano Classification (Deauville score [DS] 4/5) after 2 cycles of an anti-CD20 mAb and anthracycline-containing regimen. Patients underwent leukapheresis and received conditioning chemotherapy (cyclophosphamide and fludarabine) followed by a single axi-cel infusion at 2×10 6 CAR T cells/kg. Non-chemotherapy bridging could be administered before conditioning per investigator discretion. The primary endpoint was investigator-assessed complete response (CR) rate per Lugano. Secondary endpoints included objective response rate (ORR; CR + partial response), duration of response (DOR), event-free survival (EFS), progression-free survival (PFS), overall survival (OS), incidence of adverse events (AEs), and levels of CAR T cells in blood and cytokines in serum. The primary analysis occurred after all treated patients had ≥6 months of follow-up. Results: As of May 17, 2021, 42 patients were enrolled and 40 were treated with axi-cel. Median age was 61 years (range, 23-86); 68% of patients were male, 63% had ECOG 1, 95% had stage III/IV disease, 48% had DS4, 53% had DS5, 25% had double- or triple-hit status per central assessment, and 78% had IPI score ≥3. A total of 37 patients had centrally confirmed double- or triple-hit histology or an IPI score ≥3 and were evaluable for response, with 15.9 months of median follow-up (range, 6.0-26.7). The CR rate was 78% (n=29; 95% CI, 62-90); 89% of patients had an objective response, and median time to initial response was 1 month. Among all 40 treated patients, 90% had an objective response (80% CR rate). At data cutoff, 73% of response-evaluable patients had ongoing responses. Medians for DOR, EFS, and PFS were not reached; 12-month estimates were 81%, 73%, and 75%, respectively. The estimated OS at 12 months was 91%. All 40 treated patients had AEs of any grade; 85% of patients had Grade ≥3 AEs, most commonly cytopenias (68%). Grade ≥3 cytokine release syndrome (CRS) and neurologic events (NEs) occurred in 3 patients (8%) and 9 patients (23%), respectively. Median times to onset of CRS and NEs were 4 days (range, 1-10) and 9 days (range, 2-44), with median durations of 6 days and 7 days, respectively. All CRS and most NEs (28/29) of any grade resolved by data cutoff (1 ongoing Grade 1 tremor); 39/40 CRS events resolved by 14 days post-infusion and 19/29 NEs resolved by 21 days post-infusion. Tocilizumab was administered to 63% and 3% of patients for management of CRS or NEs, respectively; corticosteroids were administered to 35% and 33% of patients for CRS and NE management. One Grade 5 event of COVID-19 occurred (Day 350). Median peak CAR T-cell level in all treated patients was 36 cells/µL (range, 7-560), and median expansion by AUC 0-28 was 495 cells/µL × days (range, 74-4288). CAR T-cell levels peaked at a median of 8 days post-infusion (range, 8-37). Higher frequency of CCR7+CD45RA+ T cells in axi-cel product, previously associated with greater expansion of CAR T cells (Locke et al. Blood Adv. 2020), was observed in ZUMA-12, compared with the ZUMA-1 study in R/R LBCL (Neelapu et al. New Engl J Med. 2017). Conclusion: In the primary analysis of ZUMA-12, axi-cel demonstrated a high rate of rapid and complete responses in patients with high-risk LBCL, a population with high unmet need. With 15.9 months of median follow-up, responses were durable as medians for DOR, EFS, and PFS were not yet reached and over 70% of patients remained in response at data cutoff. No new safety signals were reported with axi-cel in an earlier line. Overall, axi-cel may benefit patients exposed to fewer prior therapies, and further trials in first-line high-risk LBCL are warranted to assess axi-cel in this setting. Figure 1 Figure 1. Disclosures Neelapu: 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; 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; Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties; 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. Dickinson: Janssen: Consultancy, Honoraria; Takeda: Research Funding; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria; Celgene: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau. Munoz: Kite, a Gilead Company, Kyowa, Bayer, Pharmacyclics/Janssen, Seagen, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau; Bayer, Gilead/Kite Pharma, Celgene, Merck, Portola, Incyte, Genentech, Pharmacyclics, Seattle Genetics, Janssen, and Millennium: Research Funding; Pharmacyclics/Abbvie, Bayer, Kite, a Gilead Company, Pfizer, Janssen, Juno/Celgene, Bristol Myers Squibb, Kyowa Kirin, Alexion, Fosun Kite, Innovent, Seagen, BeiGene, Debiopharm, Epizyme, Karyopharm, ADC Therapeutics, Servier, and Genmab: Consultancy, Other: advisory role; Alexion, AstraZeneca Rare Disease: Other: Study investigator; Targeted Oncology, OncView, Kyowa Kirin, Physicians' Education Resource, and Seagen: Honoraria. Thieblemont: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Hospira: Research Funding; Bayer: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses . Oluwole: Pfizer: Consultancy; Curio Science: Consultancy; Janssen: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Herrera: Takeda: Consultancy; Genentech: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Seagen: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Kite, a Gilead Company: Research Funding; Gilead Sciences: Research Funding; Tubulis: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Karyopharm: Consultancy. Ujjani: Loxo: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; TG Therapeutics: Honoraria; Gilead: Honoraria; ACDT: Honoraria; Kite, a Gilead Company: Honoraria; Adaptive Biotechnologies: Research Funding; Atara Bio: Consultancy; AbbVie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Lin: Sorrento: Consultancy; Legend: Consultancy; Novartis: Consultancy; Bluebird Bio: Consultancy, Research Funding; Gamida Cell: Consultancy; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Juno: Consultancy; Vineti: Consultancy; Takeda: Research Funding; Merck: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding. Riedell: Bayer: Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; Morphosys: Research Funding; Celgene/Bristol-Myers Squibb Company: Consultancy, Honoraria, Research Funding; Verastem Oncology: Honoraria; Kite, a Gilead Company: Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding; Takeda: Consultancy; BeiGene: Consultancy; Calibr: Research Funding; Xencor: Research Funding; Tessa Therapeutics: Research Funding. Kekre: Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Lui: Gilead Sciences: Other: stock or other ownership; Kite, a Gilead Company: Current Employment, Other: travel support. Milletti: Kite, a Gilead company: Current Employment; Gilead Sciences: Other: stock or other ownership . Dong: Kite, a Gilead Company: Current Employment; Gilead Sciences: Other: stock or other ownership ; GliaCure/Tufts: Consultancy, Other: advisory role, Patents & Royalties. Xu: Kite, A Gilead Company: Current Employment; Gilead Sciences: Other: stock or other ownership . Chavez: MorphoSys, Bayer, Karyopharm, Kite, a Gilead Company, Novartis, Janssen, AbbVie, TeneoBio, and Pfizer: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Merk: Research Funding; AstraZeneca: Research Funding; MorphoSys, AstraZeneca, BeiGene, Genentech, Kite, a Gilead Company, and Epizyme: Speakers Bureau; BMS: Speakers Bureau.

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 Introduction: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 Chimeric Antigen Receptor (CAR) T-cell therapy that induces durable responses in patients with relapsed or refractory large B-cell lymphoma. At a median of 27.1 months follow-up on the ZUMA-1 trial, median overall survival (OS) was 25.8 months with 39% progression free survival (PFS) at 2 years post-infusion (Locke, Lancet Onc 2019). We previously reported outcomes of axi-cel patients treated with standard of care therapy at a median follow up of 12.9 months, including 42% who did not meet eligibility criteria for ZUMA-1 based on co-morbidities (Nastoupil, JCO 2020). Here we report results from this cohort at a median follow up of 32.4 months, as well as late outcomes of interest including cytopenias, infections and secondary malignancies. Methods and Results: The US Lymphoma CAR-T Consortium comprised of 17 US academic centers who contributed data independent of the manufacturer. Two hundred and ninety-eight patients underwent leukapheresis with intent to manufacture standard of care axi-cel as of September 30, 2018. In infused patients (n=275), OS and PFS were calculated from date of infusion. After median follow-up of 32.4 months (95% CI 31.1 - 34.3), median OS was not reached (95% CI 25.6 - not evaluable) (Figure 1A) with 1-, 2- and 3-year OS of 68.5% (95% CI 62.6-73.7), 56.4% (95% CI 50.1-62.2) and 52.2% (95% CI 45.7-58.2%), respectively. Median PFS was 9 months (95% CI 5.9-19.6) (Figure 1B); 1-, 2- and 3-year PFS was 47.4% (95% CI 41.4-53.2), 41.6% (95% CI 35.6-47.5) and 37.3% (95% CI 31.3-43.2), respectively. Twenty-seven PFS events occurred at or after 1 year post infusion;19 events were progressive lymphoma, with the latest relapse observed 28 months after axi-cel infusion. Eight patients died while in remission from their lymphoma: 4 from secondary malignancy, 3 from infection, and 1 from unknown causes. Results of multivariable modeling were similar to our prior analysis: factors associated with both a shorter PFS and shorter OS included male sex, elevated pre-lymphodepletion LDH, and poor ECOG status. Complete blood count and B- and T-cell recovery data were collected at 1 and 2-years post-infusion, excluding patients who had relapsed or been treated for secondary malignancy at time of collection (Table 1). Rates of neutropenia (absolute neutrophil count ≤1000) at 1- and 2- years were 9.2% (10/109) and 11.2% (9/80) and rates of CD4 count ≤200/ul were 62% (23/37) and 27% (7/26). Recovery of B cells was seen in 54% (15/28) and 57% (13/23) at 1-and 2-years post infusion. Infections were reported in 31.2% (34/109) patients between 6- and 12-months post infusion, and 17% (18/109) were severe, requiring either hospitalization and/or IV antibiotics. Twenty-one patients (24%, 21/89) had an infection between 1- and 2- years, 11% of which were severe. Twenty percent (10/49) of patients between 2- and 3-years had an infection and 4 (8%) were severe. Neutropenia, low CD4 counts, and IgG levels were not associated with infection, though patients with infection between 6-12 months were more likely to have received IVIG (p<0.001). No patient in this cohort died of COVID-19. Twenty-two of 275 (8%) patients were diagnosed with subsequent malignancy after axi-cel treatment: 14/275 (5%) patients were diagnosed with myeloid malignancies (MDS (n=12), AML (n=1), CMML (n=1)); other malignancies included squamous cell carcinoma of skin (n=3); sarcoma (n=1); endometrial (n=1); lung (n=1); mesothelioma (n=1) and AITL (n=1). Patients with myeloid malignancy had a median age of 62 at axi-cel apheresis (IQR 56-67), 64% were male and median lines of prior therapy was 4 (IQR 3-6), including 36% with a prior autologous stem cell transplant. Eleven patients were in remission from lymphoma at myeloid malignancy diagnosis, while 3 were diagnosed after progression and interval therapy. Conclusion: This multi-center retrospective study showed similar long-term results to the ZUMA-1 trial, despite including patients who did not meet ZUMA-1 eligibility criteria based on comorbidities. Sixteen percent of PFS events were seen after 1 year, largely due to disease progression. Late infection was common but was not explained by persistent neutropenia or low CD4 counts. Subsequent malignancy, including MDS, occurred in 8% of patients and require further study to better identify patients at risk. J.Y.S and M.D.J contributed equally; S.D and M.L contributed equally. Figure 1 Figure 1. Disclosures Jain: BMS, Kite/Gilead, Novartis, Precision Biosciences, Takeda: Consultancy. Nastoupil: Pfizer: Honoraria, Research Funding; MorphoSys: Honoraria; Takeda: Honoraria, Other: DSMC, Research Funding; ADC Therapeutics: Honoraria; IGM Biosciences: Research Funding; Genentech: Honoraria, Research Funding; Epizyme: Honoraria, Research Funding; Caribou Biosciences: Research Funding; Gilead/Kite: Honoraria, Research Funding; TG Therapeutics: Honoraria, Research Funding; Denovo Pharma: Other: DSMC; Bayer: Honoraria; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol Myers Squibb/Celgene: Honoraria, Research Funding. Ghobadi: Atara: Consultancy; Amgen: Consultancy, Research Funding; Wugen: Consultancy; Celgene: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding. Lin: Gamida Cell: Consultancy; Juno: Consultancy; Merck: Research Funding; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Sorrento: Consultancy; Legend: Consultancy; Takeda: Research Funding; Vineti: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Reagan: Seagen: Research Funding; Kite, a Gilead Company: Consultancy; Genentech: Research Funding; Curis: Consultancy. Oluwole: Curio Science: Consultancy; Janssen: Consultancy; Pfizer: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. McGuirk: EcoR1 Capital: Consultancy; Gamida Cell: Research Funding; Bellicum Pharmaceuticals: Research Funding; Novartis: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Novartis: Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Astelllas Pharma: Research Funding; Pluristem Therapeutics: Research Funding; Fresenius Biotech: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding. Deol: Kite, a Gilead Company: Consultancy. Sehgal: Juno/Celgene: Research Funding; Kite/Gilead: Research Funding. Goy: AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; LLC(Targeted Oncology): Consultancy; Xcenda: Consultancy, Honoraria; Xcenda: Consultancy; Acerta: Consultancy, Research Funding; AbbVie/Pharmacyclics: Consultancy, Honoraria, 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; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; Hoffman la Roche: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Phamacyclics: Research Funding; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Michael J Hennessey Associates INC: Consultancy; Genentech/Hoffman la Roche: Research Funding; MorphoSys: Honoraria, Other; Karyopharm: Research Funding; Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; Incyte: Honoraria; Medscape: Consultancy; Novartis: Consultancy, Honoraria; 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; Infinity/Verastem: Research Funding; Rosewell Park: Consultancy; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; OncLive Peer Exchange: Honoraria; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, 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. Hill: Pfizer: Consultancy, Honoraria; Beigene: Consultancy, Honoraria, Research Funding; Gentenech: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Celgene (BMS): Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding. Andreadis: CRISPR Therapeutics: Research Funding; GenMAB: Research Funding; Novartis: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Epizyme: Honoraria; Incyte: Honoraria; TG Therapeutics: Honoraria; Kite: Honoraria; Karyopharm: Honoraria; Atara: Consultancy, Honoraria; BMS: Research Funding; Merck: Research Funding. Muñoz: Seagen: Consultancy, Honoraria, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Kite, a Gilead Company: Consultancy, Speakers Bureau; Pfizer: Consultancy; Janssen: Consultancy, Speakers Bureau; Juno/Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Alexion: Consultancy; BeiGene: Consultancy, Speakers Bureau; Fosunkite: Consultancy; Innovent: Consultancy; Debiopharma: Consultancy; Karyopharm: Consultancy; Genmab: Consultancy; ADC Therapeutics: Consultancy; Epizyme: Consultancy; Servier: Consultancy; Acrotech: Speakers Bureau; Verastem: Speakers Bureau; AstraZeneca: Speakers Bureau; Celgene/Bristol Myers Squibb: Speakers Bureau; Genentech: Speakers Bureau; Aurobindo: Speakers Bureau; Physicians' Education Resource: Honoraria; Kyowa Kirin: Consultancy, Honoraria, Speakers Bureau; OncView: Honoraria; Targeted Oncology: Honoraria. Westin: AstraZeneca: Consultancy, Research Funding; 47 Inc: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Morphosys: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Umoja: Consultancy; Iksuda Therapeutics: Consultancy; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Genentech: Consultancy, Research Funding. Chavez: Bristol Myers Squibb: Speakers Bureau; Karyopharm Therapeutics: Consultancy; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Kite/Gilead: Consultancy; Abbvie: Consultancy; MorphoSys: Speakers Bureau; BeiGene: Speakers Bureau; Novartis: Consultancy; Adaptive: Research Funding; Epizyme: Speakers Bureau; AstraZeneca: Research Funding. Bennani: Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board; Vividion: Consultancy, Other: Advisory Board. Vose: Kite, a Gilead Company: Honoraria, Research Funding. Miklos: Pharmacyclics: Patents & Royalties; 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; 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; 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. Neelapu: Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties; 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, Bristol Myers Squibb, Merck, Poseida, Cellectis, Celgene, Karus Therapeutics, Unum Therapeutics (Cogent Biosciences), Allogene, Precision BioSciences, Acerta and Adicet Bio: Research Funding; 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. Locke: GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Amgen: Consultancy, Other: Scientific Advisory Role; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Wugen: Consultancy, Other; Takeda: Consultancy, Other; Novartis: Consultancy, Other, Research Funding; Umoja: Consultancy, Other; Cowen: Consultancy; EcoR1: Consultancy; Emerging Therapy Solutions: Consultancy; Gerson Lehrman Group: Consultancy; Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy; Legend Biotech: Consultancy, Other; Janssen: Consultancy, Other: Scientific Advisory Role; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role. Dahiya: Kite, a Gilead Company: Consultancy; Atara Biotherapeutics: Consultancy; Miltenyi Biotech: Research Funding; Jazz Pharmaceuticals: Research Funding; BMS: Consultancy. Lunning: Spectrum: Consultancy; AstraZeneca: Consultancy; Acrotech: Consultancy; Legend: Consultancy; Novartis: Consultancy; Kyowa Kirin: Consultancy; Karyopharm: Consultancy; Morphosys: Consultancy; TG Therapeutics: Consultancy; Janssen: Consultancy; AbbVie: Consultancy; Verastem: Consultancy; Myeloid Therapeutics: Consultancy; Celgene, a Bristol Myers Squibb Co.: Consultancy; Daiichi-Sankyo: Consultancy; Beigene: Consultancy; ADC Therapeutics: Consultancy; Kite, a Gilead Company: Consultancy.

Abstract Background Allogeneic (off the shelf) chimeric antigen receptor (CAR) T-cell therapy addresses the logistical challenges, availability (including insufficient T-cell yields from low baseline absolute lymphocyte count), and variable product quality of autologous CAR T therapy. ALLO-501A is a genetically modified anti-CD19 AlloCAR T™ cell product that uses TALEN ® gene editing to disrupt the T-cell receptor alpha constant gene (TRAC) and the CD52 gene to reduce the risk of graft-versus-host disease (GvHD) and permit the use of ALLO-647, an anti-CD52 monoclonal antibody (mAb), for selective and transitory host lymphodepletion (LD). Here we present an update on the preliminary safety, efficacy, and correlative data. ALLO-501A uses Cellectis technologies. Methods ALPHA2 (NCT04416984) is a single-arm, open-label, Phase 1/2 trial of ALLO-501A in patients (pts) with relapsed/refractory (R/R) large B-cell lymphoma (LBCL including [R/R] diffuse LBCL [DLBCL], transformed follicular lymphoma [tFL], marginal zone lymphoma [tMZL], primary mediastinal B-cell lymphoma [PMBCL], follicular lymphoma grade 3B [FL3B]) who received ≥2 prior lines of therapy (including an anthracycline and anti-CD20 mAb), have an ECOG performance status of 0 or 1. Subjects with donor specific antibodies are excluded. Following LD with ALLO-647, fludarabine 30 mg/m 2/d x 3d (F), and cyclophosphamide 300 or 500 mg/m 2/d x 3d (C), either a single (40 [DL1] or 120 [DL2] x 10 6 viable CAR T cells) or consolidation dose of ALLO-501A (DL2) are given. For consolidation dose, pts with ≥stable disease (SD) at day 28 receive consolidation with second ALLO-647 (no chemo) for LD and ALLO-501A (DL2) cell infusion. Results As of July 9, 2021, 20 pts were enrolled; 15 pts were treated with ALLO-501A (12 evaluable and 3 pending D28 assessment); 3 pts pending treatment; 2 pts withdrew due to adverse event (AE)/progressing disease (PD) prior to dosing. Patients were heavily pretreated with advanced-stage disease (Stage III: 4 [22.2%], Stage IV: 8 [44.4%]), median number of prior treatments was 3 with a high of 7. Three pts (16.7%) had primary refractory disease. Safety profile was manageable in both single dose and consolidation cohorts. Events of interest in the single dose cohort have been previously reported (ASCO 2021). In the consolidation cohort (13 enrolled, 9 pts dosed thus far), no cytokine release syndrome (CRS), no GvHD, no immune effector cell-associated neurotoxicity syndrome (ICANS), no dose-limiting toxicities (DLTs), no dose reductions, no Grade (Gr) 3+ infections and no related serious adverse events (SAEs) occurred, and infusion-related reactions were Gr 1. Among all treated, cytopenias were the most common AE and occurred in 72% of pts. Of the 12 evaluable pts (6 each treated in the single dose and consolidation dose cohort), both the overall response rate (ORR) and complete response (CR) were 50% (95% CI: 21.1, 78.9). In the consolidation cohort, both ORR and CR rate were 66.7% (95% CI: 22.3, 95.7) with 3/3 partial responses (PRs) converting to CR after consolidation; 1 pt had CR at days 28 and 56 post consolidation and 2 pts had PD at month 1 and did not receive consolidation. In single dose cohort, 2 pts have ongoing CR at 9 and 12+ months. CAR T expansion was greater in pts who achieved a CR with a geometric mean area under the curve (AUC) at D1-28 of 206,990 copies/ug*days (n=6; GSD 4.94) compared to pts who did not achieve a CR with AUC at D1-28 of 3,571 copies/ug*days (n=3; GSD 2.41). Pts who received the consolidation dose continued to have CAR T expansion after the 2 nd CAR T infusion with geometric mean AUC from D30-56 of 92,893 copies/ug*days (n=4; GSD 5.42). Conclusions ALLO-501A with consolidation dosing demonstrated comparable safety and an improved efficacy profile compared to single dosing with all 4 pts who received consolidation remaining in CR. Persistence of CAR T at D28 and expansion after consolidation dose was observed in addition to the observed deepening of responses in pts whose initial response was PR. Additional follow up is needed to determine whether consolidation also improves the durability of response. Consolidation was well tolerated and given the generally favorable overall safety profile, ALLO-501A may have the potential to be given in the outpatient setting. Enrollment is ongoing. Updated efficacy and follow-up will be presented at the meeting. Currently, an ALLO-501A Phase 2 trial is planned. Disclosures Locke: Cowen: Consultancy; Umoja: Consultancy, Other; Wugen: Consultancy, Other; Takeda: Consultancy, Other; Novartis: Consultancy, Other, Research Funding; Janssen: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Amgen: Consultancy, Other: Scientific Advisory Role; GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Legend Biotech: Consultancy, Other; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role; EcoR1: Consultancy; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding; Emerging Therapy Solutions: Consultancy; Gerson Lehrman Group: Consultancy; Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy. 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; 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; Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties. Hamadani: Janssen, Incyte, ADC Therapeutics, Omeros, Morphosys, Kite: Consultancy; Sanofi, Genzyme, AstraZeneca, BeiGene: Speakers Bureau; Takeda, Spectrum Pharmaceuticals and Astellas Pharma: Research Funding. Frank: Allogene Therapeutics: Research Funding; Kite-Gilead: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Research Funding. Popplewell: Novartis: Other: Travel; Pfizer: Other: Travel; Hoffman La Roche: Other: Food. Abramson: Bluebird Bio: Consultancy; Kymera: Consultancy; BeiGene: Consultancy; Incyte Corporation: Consultancy; Astra-Zeneca: Consultancy; Allogene Therapeutics: Consultancy; Seagen Inc.: Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy; Novartis: Consultancy; Morphosys: Consultancy; Kite Pharma: Consultancy; C4 Therapeutics: Consultancy; Genmab: Consultancy; EMD Serono: Consultancy; Bristol-Myers Squibb Company: Consultancy, Research Funding; Genentech: Consultancy. Munoz: Pharmacyclics/Abbvie: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Gilead/Kite Pharma: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy; Janssen: Consultancy, Research Funding, Speakers Bureau; Juno/Celgene: Consultancy, Research Funding, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Kyowa: Consultancy, Honoraria, Speakers Bureau; Alexion: Consultancy; Beigene: Consultancy, Speakers Bureau; Fosunkite: Consultancy; Innovent: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Debiopharm: Consultancy; Karyopharm: Consultancy; Genmab: Consultancy; ADC Therapeutics: Consultancy; Epizyme: Consultancy; Servier: Consultancy; Merck: Research Funding; Portola: Research Funding; Incyte: Research Funding; Genentech: Research Funding, Speakers Bureau; Millennium: Research Funding; Targeted Oncology: Honoraria; OncView: Honoraria; Physicians' Education Resource: Honoraria; Roche: Speakers Bureau; AstraZeneca: Speakers Bureau; Verastem: Speakers Bureau; Acrotech/Aurobindo: Speakers Bureau. Shin: Allogene Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Loomis-Navale: Allogene: Current Employment, Current equity holder in publicly-traded company. 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; 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; 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. OffLabel Disclosure: Discussion of fludarabine and cyclophosphamide in combination with ALLO-647 as conditioning regimen prior to administration of ALLO-501A in patients with R/R LBCL.

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.

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.

The recent development and clinical implementation of novel immunotherapies for the treatment of Hodgkin and non-Hodgkin lymphoma have improved patient outcomes across subgroups. The rapid introduction of immunotherapeutic agents into the clinic, however, has presented significant questions regarding optimal treatment scheduling around existing chemotherapy/radiation options, as well as a need for improved understanding of how to properly manage patients and recognize toxicities. To address these challenges, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts in lymphoma to develop a clinical practice guideline for the education of healthcare professionals on various aspects of immunotherapeutic treatment. The panel discussed subjects including treatment scheduling, immune-related adverse events (irAEs), and the integration of immunotherapy and stem cell transplant to form recommendations to guide healthcare professionals treating patients with lymphoma.