Lin, Yi

Abstract Background and Rationale: Axi-cel is a standard-of-care treatment for relapsed or refractory LBCL after 2 or more lines of systemic therapy. Some patients who would have been ineligible for ZUMA-1 criteria due to comorbidities have been treated with axi-cel in the real-world setting. We interrogated a large registry of patients treated with standard-of-care axi-cel for a definitive report on the impact of age or certain comorbidities on safety and efficacy outcomes after axi-cel infusion. Methods: From October 2017 to August 2020, 1500 patients were enrolled in the postapproval safety observational study of axi-cel treated at 79 centers. Patients eligible for the protocol and followed up for at least 6 months with complete data entry by the time of analyses were included. One patient rescinded consent and 1 was deemed ineligible. Patients previously treated with immune effector cell therapy (n=31), with incomplete follow-up reporting (n=92), or alive but last contacted <180 days postinfusion (n=32) were excluded from analysis. Main efficacy outcomes included complete and objective response rates (CR and ORR), duration of response (DOR), progression-free and overall survival (PFS and OS). Safety endpoints of interest included cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Outcomes were assessed and compared by age and preselected coexisting disease or organ impairment within 3 months prior to the infusion included in the hematopoietic cell transplantation comorbidity index. Multivariate logistic and Cox regression models were used to assess the impact of age or coexistent organ dysfunction on outcomes via odds ratio (OR) or hazard ratio (HR) and their 95% CIs. Results A total of 1343 patients were included in the analysis with a median 25.1 months (range, 10.3-42.7 months) for potential follow-up, defined from infusion to data cutoff date, and a median 11.8 months (range, 0.1-38.8 months) for actual follow-up time, defined from infusion to date of death or last contact. Of these, 38% were 65 years or older (median 62 years), 4% had a performance score ≥2, 13% had cardiac comorbidities, 16% had a prior cancer, 9% were obese, 2% had moderate to severe hepatic comorbidities, and 2% had renal comorbidities. Transformed lymphoma, double or triple-hit by fluorescence in situ hybridization, prior autologous transplant and refractory disease were present in 28%, 15%, 27% and 66%, respectively. Bridging therapy was administered in 21% of patients. Overall, ORR was 74%, (CR 56%), and probabilities of DOR, PFS, and OS at 18 months were 61% (95% CI, 57-65%), 42% (95% CI, 39-45%) and 52% (95% CI, 49-55%), respectively. Overall rates of CRS and ICANS were 83% and 55%, respectively. ORR was 78% (CR 62%, median OS 17.5 [95% CI, 16.0-not evaluated (NE)] months) for patients ≥65 years, ORR 57% (CR 29%; median OS 4.3 [95% CI, 2.5-8.3] months) for patients with hepatic dysfunction, ORR 70% (CR 43%; median OS 8.9 [95% CI, 3.8-NE] months) for patients with renal dysfunction; and ORR 47% (CR 20%, median OS 4 [95% CI, 2.6-6.9] months) for patients with Eastern Cooperative Oncology Group (ECOG) 2 or 3. Multivariate analyses indicated that advanced age (≥65 years vs <65 years; OR 1.38; 95% CI, 1.05-1.83), moderate to severe pulmonary disease (yes vs no; OR 0.74; 95% CI, 0.55-0.98), and ECOG (2-3 vs 0-1; OR 0.31, 95% CI, 0.18-0.53) impacted ORR (Table). Age ≥65 years did not have an impact on survival (HR 1.05, 95% CI, 0.88-1.26), although it was associated with CRS (OR 1.42, 95% CI, 1.03-1.96) and ICANS (OR 1.78, 95% CI, 1.39-2.28). Coexistent cardiac disease (HR 1.44, 95% CI, 1.12-1.83), renal disease (HR 2.13, 95% CI, 1.32-3.46) and hepatic dysfunction (HR 2.65, 95% CI, 1.69-4.14) had an impact on OS, but not on response, CRS, and ICANS. ECOG significantly impacted all efficacy outcomes. None of the other comorbidities tested significantly impacted outcomes. Conclusion: Advanced age (≥65 years) was not associated with worse efficacy outcomes after axi-cel, despite higher rates of CRS and ICANS, which require closer monitoring. Performance status rather than age should be accounted for in patient selection and treatment decisions with axi-cel. Most coexistent organ dysfunctions have no clinically significant impact on axi-cel objective response and safety outcomes. Figure 1 Figure 1. Disclosures Locke: Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding; Amgen: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; EcoR1: Consultancy; Emerging Therapy Solutions: Consultancy; Gerson Lehrman Group: Consultancy; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role; Takeda: Consultancy, Other; Novartis: Consultancy, Other, Research Funding; Wugen: Consultancy, Other; GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; Umoja: Consultancy, Other; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Cowen: Consultancy; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Legend Biotech: Consultancy, Other; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Janssen: Consultancy, Other: Scientific Advisory Role. Jacobson: Axis: Speakers Bureau; Nkarta: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Other: Travel support, Research Funding; AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Other: Travel support; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Other: Travel support; Precision Biosciences: Consultancy, Honoraria, Other: Travel support; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support; Lonza: Consultancy, Honoraria, Other: Travel support; Humanigen: Consultancy, Honoraria, Other: Travel support; Clinical Care Options: Speakers Bureau. Ma: Kite, a Gilead Company: Current Employment. Dong: Kite, a Gilead Company: Current Employment. Hu: Kite, a Gilead Company: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Siddiqi: BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Oncternal: Research Funding; Janssen: Speakers Bureau; Juno Therapeutics: 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, Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; TG Therapeutics: Research Funding. Ahmed: Seagen: Research Funding; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Xencor: Research Funding. Ghobadi: Atara: Consultancy; Wugen: Consultancy; Amgen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Celgene: Consultancy. Miklos: 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; 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. Lin: Kite, a Gilead Company: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Legend: Consultancy; Vineti: Consultancy; Sorrento: Consultancy; Gamida Cell: Consultancy; Janssen: Consultancy, Research Funding; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Novartis: Consultancy; Merck: Research Funding; Takeda: Research Funding. Perales: Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Nektar Therapeutics: Honoraria, Other; Miltenyi Biotec: Honoraria, Other; MorphoSys: Honoraria; NexImmune: Honoraria; Sellas Life Sciences: Honoraria; Cidara: Honoraria; Merck: Honoraria; Omeros: Honoraria; Servier: Honoraria; Celgene: Honoraria; Novartis: Honoraria, Other; Kite/Gilead: Honoraria, Other; Incyte: Honoraria, Other; Medigene: Honoraria; Karyopharm: Honoraria; Equilium: Honoraria. Lunning: Daiichi-Sankyo: Consultancy; TG Therapeutics: Consultancy; Kite, a Gilead Company: Consultancy; ADC Therapeutics: Consultancy; Spectrum: Consultancy; Beigene: Consultancy; Celgene, a Bristol Myers Squibb Co.: Consultancy; Legend: Consultancy; AbbVie: Consultancy; AstraZeneca: Consultancy; Morphosys: Consultancy; Verastem: Consultancy; Novartis: Consultancy; Myeloid Therapeutics: Consultancy; Janssen: Consultancy; Acrotech: Consultancy; Kyowa Kirin: Consultancy; Karyopharm: Consultancy. Hill: Gentenech: Consultancy, Honoraria, Research Funding; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy, Honoraria; Celgene (BMS): Consultancy, Honoraria, Research Funding. Nikiforow: Kite/Gilead: Other: ad HOC Advisory Boards; Novartis: Other: ad Hoc Advisory Boards; Iovance: Other: ad Hoc Advisory Boards; Glaxo Smith Kline (GSK): Other: ad Hoc Advisory Boards. Xu: Gilead Sciences: Other: stock or other ownership ; Kite, A Gilead Company: Current Employment. Pasquini: Bristol Myers Squibb: Consultancy, Research Funding; Novartis: Research Funding; Kite Pharma: Research Funding; GlaxoSmithKline: Research Funding.

Abstract Background: Achievement of a complete response (CR) to therapy in multiple myeloma (MM) early in disease course correlates with improvement in clinical outcomes, reflective of therapeutically sensitive disease biology. While depth of response is known to impact overall survival (OS) and progression-free survival (PFS), the effect of known prognostic variables at baseline including FISH risk and International Staging System (ISS) score outside of clinical trial settings is not well described. We sought to determine the impact of known prognostic variables in MM including FISH and ISS risk in the context of NDMM patients achieving a CR to therapy and to also examine additional predictors of outcome among this cohort. Methods: A retrospective study was conducted on 1869 NDMM patients who had ≥ 2 consecutive monoclonal protein immunofixation (IFE) studies in the serum and urine available within 24 months from diagnosis. We identified the number of patients who had ≥ 2 negative serum and urine IFE as a surrogate for achieving CR (N=461), since a bone marrow biopsy is not routinely performed to confirm CR in the non-trial setting. A Kaplan-Meier model was used to compare median PFS and OS between patients achieving a CR vs. non-CR and a multivariate analysis was performed to adjust for known prognostic variables. A cox proportional hazards model was used to determine the prognostic impact of baseline FISH (high risk vs. standard risk) and ISS scores (3 vs.1 and 2) on PFS and OS, among patients achieving a CR vs. non-CR, and identify additional prognostically significant variables within the CR cohort. Results: The median length of follow-up for the entire cohort (n=1869) was 64 months (range: 1-199). The median time from diagnosis to achievement of CR among the CR cohort was 9.8 months (0.20-23.8 months). The median PFS for CR (n=461) vs. non-CR (n=1408) patients was 42.0 vs. 29.3 months (p<.0001) and median OS was 124.4 vs. 85.6 months (p<.0001), respectively (Figure 1). The impact of achieving a CR on outcomes was retained after adjusting for FISH, ISS, age, sex, autologous stem cell transplant, and involved heavy chain as follows: PFS HR 0.57 (0.43-0.76; p=0.0001); OS HR 0.56 (0.43-0.74; p<0.0001). The baseline FISH and ISS risk on PFS and OS comparing CR vs. non-CR patients are shown in Table 1, with both variables having statistically insignificant impact on PFS and OS among the CR cohort. We examined several variables present at baseline and at the time of CR to determine their impact on PFS and OS, including age, sex, and non-IgG involved heavy chain (baseline), and thrombocytopenia (<150,000), hypoalbuminemia (<3.5 g/dL), and immunoparesis (at time of CR). The following variables were found as inferior predictors on PFS within the CR cohort with hazard ratios as follows: male gender, HR 1.36 (1.05-1.75; p=0.02) and non-IgG involved heavy chain, HR 2.2 (1.55-3.2).The following variables were found as predictors for inferior outcomes on OS within the CR cohort with hazard ratios as follows: Age> 75 years, HR 2.7 (1.54-4.8; p=.0005); male gender, HR 1.5 (1.1-2.02; p=.008); serum albumin <3.5, HR 1.54 (1.1-2.08; p=.004); and non-IgG involved heavy chain, HR 1.75 (1.23-2.47; p=.002). On multivariate analysis, age, hypoalbuminemia, and non-IgG involved heavy chain retained prognostic significance for OS. Conclusion: Attainment of an early CR in NDMM confers improvement in PFS and OS. Our study confirms these findings and suggests that achievement of CR neutralizes the impact of baseline FISH and ISS risk on PFS and OS. Among the CR cohort, age> 75 years, male sex, non-IgG involved heavy chain, and hypoalbuminemia at the time of CR predict for inferior overall survival. Figure 1 Figure 1. Disclosures Dingli: Sanofi: Consultancy; Alexion: Consultancy; Novartis: Research Funding; GSK: Consultancy; Apellis: Consultancy; Janssen: Consultancy. Gertz: Akcea Therapeutics, Ambry Genetics, Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Karyopharm Therapeutics, Pfizer Inc (to Institution), Sanofi Genzyme: Honoraria; Aurora Biopharma: Other: Stock option; Ionis Pharmaceuticals: Other: Advisory Board; AbbVie Inc, Celgene Corporation: Other: Data Safetly & Monitoring; Akcea Therapeutics, Alnylam Pharmaceuticals Inc, Prothena: Consultancy. Dispenzieri: Alnylam: Research Funding; Pfizer: Research Funding; Takeda: Research Funding; Sorrento Therapeutics: Consultancy; Oncopeptides: Consultancy; Janssen: Consultancy, Research Funding. Kapoor: Karyopharm: Consultancy; Cellectar: Consultancy; BeiGene: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Amgen: Research Funding; Ichnos Sciences: Research Funding; Regeneron Pharmaceuticals: Research Funding; Glaxo SmithKline: Research Funding; Karyopharm: Research Funding; Sanofi: Research Funding; Takeda: Research Funding; AbbVie: Research Funding. Lin: Vineti: Consultancy; Bluebird Bio: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Juno: Consultancy; Merck: Research Funding; Sorrento: Consultancy; Celgene: Consultancy, Research Funding; Gamida Cell: Consultancy; Novartis: Consultancy; Takeda: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Legend: Consultancy. Kumar: Merck: Research Funding; Antengene: Consultancy, Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Carsgen: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Consultancy; Tenebio: Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy; Beigene: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Roche-Genentech: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy, Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding.

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: Ciltacabtagene autoleucel (cilta-cel) is a novel chimeric antigen receptor T-cell therapy that is being evaluated in the CARTITUDE-1 trial (NCT03548207) in patients with relapsed or refractory multiple myeloma (RRMM) who are triple-class exposed (to immunomodulatory drugs, proteasome inhibitors, and an anti-CD38 monoclonal antibody). As there is no clear standard of care for this patient population, and due to an absence of direct head-to-head trials evaluating cilta-cel and other relevant treatments, indirect treatment comparisons (ITCs) between cilta-cel and treatments used in current clinical practice, ie, physician's choice of treatment (PCT), have been previously conducted. Meta-analyses were performed to derive single summary effect estimates for overall survival (OS) and progression-free survival (PFS) by pooling ITCs evaluating cilta-cel versus PCT in patients with triple-class exposed RRMM. Methods: ITCs examining the comparative effectiveness of cilta-cel versus PCT on OS and PFS were included. Data on cilta-cel corresponded to the February 2021 data-cut for CARTITUDE-1. Data on PCT was leveraged from the following sources: (i) the Flatiron database, a primarily US community-based multiple myeloma registry, (ii) the long-term follow-up results of three global RRMM daratumumab randomized clinical trials (POLLUX [NCT02076009], CASTOR [NCT02136134], and EQUULEUS [NCT01998971]), (iii) the US-based retrospective MAMMOTH study, and (iv) a representative German patient registry maintained by OncologyInformationService (OIs). In each ITC, the PCT group was comprised of patients who satisfied key eligibility criteria for CARTITUDE-1 and was made comparable to CARTITUDE-1 using inverse probability of treatment weighting. Hence, the ITCs were deemed appropriate to meta-analyze. The meta-analyses used a robust variance estimator to account for the use of CARTITUDE-1 in each pairwise ITC. The main meta-analyses considered all participants treated with cilta-cel in CARTITUDE-1 compared with PCT. Sensitivity analyses considered ITC effect estimates based on all enrolled participants in CARTITUDE-1. Pooled summary effect estimates were presented as hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs). Results: Based on availability of data, the main meta-analyses included four ITCs for OS and three ITCs for PFS. Cilta-cel was associated with a statistically significant improvement in OS (HR: 0.21, 95% CI: 0.13 to 0.34; Figure 1) and PFS (HR: 0.20, 95% CI: 0.07 to 0.63; Figure 2) compared to PCT. Sensitivity analyses including all enrolled participants confirmed the results of the main meta-analyses. Conclusions: In the meta-analyses, cilta-cel demonstrated a significant advantage over PCT in terms of OS and PFS, highlighting its potential as an effective therapy in patients with triple-class exposed RRMM. Figure 1 Figure 1. Disclosures Hari: GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Celgene-BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Karyopharm: Consultancy; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Adaptive Biotech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees, Research Funding. Berdeja: EMD Sorono, Genentech: Research Funding; Celularity, CRISPR Therapeutics: Research Funding; Bluebird bio, BMS, Celgene, CRISPR Therapeutics, Janssen, Kite Pharma, Legend Biotech, SecuraBio, Takeda: Consultancy; Abbvie, Acetylon, Amgen: Research Funding; GSK, Ichnos Sciences, Incyte: Research Funding; Lilly, Novartis: Research Funding; Poseida, Sanofi, Teva: Research Funding. Gay: Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: 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; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria. Hooper: Eversana: Current Employment; Janssen: Consultancy. Haltner: Eversana: Current Employment; Janssen: Consultancy. Kumar: Carsgen: Research Funding; Novartis: Research Funding; Merck: Research Funding; Bluebird Bio: Consultancy; Roche-Genentech: Consultancy, Research Funding; Oncopeptides: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: Consultancy, Honoraria; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Beigene: Consultancy; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tenebio: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Sanofi: Research Funding. Martin: Sanofi: Research Funding; Janssen: Research Funding; GlaxoSmithKline: Consultancy; Amgen: Research Funding; Oncopeptides: Consultancy. Mateos: AbbVie: Honoraria; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: 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; Celgene - Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bluebird bio: Honoraria; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Honoraria; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sea-Gen: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Moreau: Sanofi: Honoraria; Janssen: Honoraria; Celgene BMS: Honoraria; Oncopeptides: Honoraria; Amgen: Honoraria; Abbvie: Honoraria. Rosta: EVERSANA: Current Employment; Janssen Inc.: Consultancy. Samjoo: EVERSANA: Current Employment; Janssen Inc.: Consultancy. Usmani: GSK: Consultancy, Research Funding; Abbvie: Consultancy; Array BioPharma: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding, Speakers Bureau; EdoPharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Janssen Oncology: Consultancy, Research Funding; SkylineDX: Consultancy, Research Funding; Takeda: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Merck: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding; Amgen: Consultancy, Research Funding, Speakers Bureau. Weisel: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, 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; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy; Novartis: Honoraria; Pfizer: Honoraria. Jackson: Janssen: Current Employment; Memorial Sloan Kettering Cancer Center: Consultancy. Olyslager: Janssen: Current Employment. Schecter: Janssen: Current Employment, Current holder of stock options in a privately-held company. Vogel: Janssen Global Services, LLC: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Divested equity in a private or publicly-traded company in the past 24 months. Garrett: Legend Biotech USA: Current Employment. Lee: Legend Biotech: Current Employment, Current equity holder in publicly-traded company. Nesheiwat: Legend Biotech USA: Current Employment. Pacaud: Legend Biotech: Current Employment. Valluri: Janssen: Current Employment, Current equity holder in publicly-traded company. Costa: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria. Lin: Merck: Research Funding; Bluebird Bio: Consultancy, Research Funding; Juno: Consultancy; Takeda: Research Funding; Legend: Consultancy; Sorrento: Consultancy; Gamida Cell: Consultancy; Vineti: Consultancy; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding.

Abstract Introduction: Chimeric antigen receptor T-cell (CAR-T) therapy is an effective treatment that has transformed hematologic malignancy management. However, its significant short-term toxicities, mainly cytokine release syndrome (CRS) and neurotoxicity, require frequent monitoring almost universally achieved via prolonged inpatient admissions. We have reported our institution's specialized, multi-disciplinary hospital-based outpatient (HBO) CAR-T service and experience (Bansal et.al, ASCO 2021). To enhance the HBO practice, we implemented a remote patient monitoring (RPM) program, comprised of in-home, electronic health record-integrated technology to monitor vital signs and neurologic symptoms for 30 days post CAR-T infusion. The RPM program's triaging algorithm generates alerts based on predetermined parameters to guide escalation of care if needed. In this report, we describe the characteristics of RPM program patients (pts), focusing on the alerts received within 48 hours (h) of first hospitalization in the post-CAR-T setting. Methods: Pts undergoing commercial CAR-T cell therapy at Mayo Clinic Rochester were enrolled in the RPM program as part of our standard of care from 06/2020 to 05/2021. Pts with detailed RPM data available were included in this analysis. Patient characteristics, health care utilization, inpatient interventions, and RPM alert data were reviewed. Wilcoxon test was used for continuous variables, chi-squared test was used for categorical variables. Results: Baseline characteristics are summarized in Table 1. Of 20 pts in this analysis, 13 had RPM alerts in the 48h preceding the first hospitalization post CAR-T. For the remaining 7 pts without RPM alerts, 3 were hospitalized within 24h of CAR-T infusion without significant RPM data, 1 patient hospitalized with acute pancreatitis (day +8 post CAR-T infusion), 1 for doubling of CRP (day +10), 1 for acute pain crisis (day +5), and 1 with neutropenic fever (day +5) with not reporting RPM data. The median RPM program duration was 18 days (range 3-32) which accounts for interruptions in the RPM monitoring while pts are hospitalized. The median number of data points per patient was 231 (range 22-532), with a median of 20 alerts per patient (range 2-81). The median missing data points per patient were 20 (10%) (range 0-95). Of the 13 pts with RPM alerts within 48h of first hospitalization, alerts met our definition of urgent criteria in 6 pts [temperature (temp) > 100F (n=3), temp > 100F + tachycardia (n=1), temp > 100F + hypoxia (n=1), and hypoxia (n=1)]. In the remaining 7 pts, the RPM alerts met our routine criteria definition [temp 99-100 (n=2), tachycardia + hypertension + weight loss (n=2), hypertension (n=2), new incontinence (n=1)]. CRS was reported in 12 pts [grade 1-2 (n=11), grade 3-4 (n=1)] and neurotoxicity in 8 pts [grade 1-2 (n=7), grade 3-4 (n=1)]. The median post CAR-T first hospitalization day was day +4 (range day +2-10), Figure 1. The median time from the last RPM alert to hospitalization was 5.8h for pts meeting urgent criteria vs 10.8h for those meeting routine criteria (p=0.13). Tocilizumab was used in 5 pts during the first hospitalization [3 (50%) in the urgent criteria group and 2 (28%) in the routine criteria group], with a median time from admission to tocilizumab of 12h in the urgent criteria group vs 43h in the routine criteria group (p=0.05). Early hospitalization (≤ 3 days) post CAR-T infusion was associated with later need for tocilizumab [median 51h (range 30-57) vs. 11.5h (range 6-33) from admission, p=0.03] than late hospitalization (> 4 days post CAR-T). Upon admission, oxygen supplementation was started on both pts with hypoxia noted in the RPM alerts. Only 1 patient (routine criteria group) required use of vasopressors while hospitalized, initiated more than 48h after admission. Conclusion: A CAR-T RPM program can identify adverse symptoms and vital sign changes in CAR-T pts managed in the outpatient setting. In this pilot implementation, the CAR-T RPM triaging algorithm identified pts requiring expedited hospitalization and facilitated early initiation of tocilizumab. The intermittent monitoring and proportion of missing data are the main limitations of the RPM in the acute care setting post-CAR-T infusion. Incorporation of wearable devices for continuous remote monitoring is being explored as a mitigating strategy to these limitations. Figure 1 Figure 1. Disclosures Paludo: Karyopharm: Research Funding. Dingli: Apellis: Consultancy; Janssen: Consultancy; GSK: Consultancy; Novartis: Research Funding; Sanofi: Consultancy; Alexion: Consultancy. Kapoor: Glaxo SmithKline: Research Funding; Sanofi: Consultancy; Amgen: Research Funding; AbbVie: Research Funding; Sanofi: Research Funding; Karyopharm: Research Funding; Ichnos Sciences: Research Funding; Pharmacyclics: Consultancy; Takeda: Research Funding; Regeneron Pharmaceuticals: Research Funding; Karyopharm: Consultancy; Cellectar: Consultancy; BeiGene: Consultancy. Gertz: Aurora Biopharma: Other: Stock option; Ionis Pharmaceuticals: Other: Advisory Board; Akcea Therapeutics, Alnylam Pharmaceuticals Inc, Prothena: Consultancy; AbbVie Inc, Celgene Corporation: Other: Data Safetly & Monitoring; Akcea Therapeutics, Ambry Genetics, Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Karyopharm Therapeutics, Pfizer Inc (to Institution), Sanofi Genzyme: Honoraria. Wang: InnoCare: Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; Genentech: Research Funding; Eli Lilly: 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. Kenderian: Humanigen, Inc.: Consultancy, Honoraria, Research Funding. Kumar: Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Oncopeptides: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche-Genentech: Consultancy, Research Funding; Carsgen: Research Funding; Antengene: Consultancy, Honoraria; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Bluebird Bio: Consultancy; Beigene: Consultancy; Tenebio: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. Bennani: Purdue Pharma: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Vividion: Other: Advisory Board; Kymera: Other: Advisory Board; Verastem: Other: Advisory Board. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Merck: Research Funding; Vineti: Consultancy; Gamida Cell: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Legend: Consultancy; Celgene: Consultancy, Research Funding; Sorrento: Consultancy; Takeda: Research Funding; Janssen: Consultancy, Research Funding; Novartis: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding.

Abstract Introduction: Factors contributing to the antitumor activity of systemic oncolytic virotherapy (OV) include (i) generalized innate immune activation due to virus infusion; (ii) direct oncolytic and/or immune-mediated destruction of OV infected tumor cells due to intratumoral spread of the virus infection; (iii) collateral boosting of tumor antigen-specific T cell responses that target uninfected tumor cells. We investigated the relative contributions of these 3 factors T cell lymphoma (TCL) patients (pts) responding to a single intravenous infusion of Voyager-V1, an oncolytic vesicular stomatitis virus (VSV) encoding IFNβ and sodium iodide symporter (NIS) on NCT03017820. Of relevance, the virally encoded IFNβ enhances tumor specificity, boosts proinflammatory activity & serves as a convenient serum biomarker of infection. Methods: In a first in human trial, a single infusion of Voyager-V1 was administered to 15 pts with relapsed refractory hematologic cancers; 4 dose levels (DL) were tested (5x10 9, 1.7x10 10, 5x10 10, 1.7x10 11 TCID50); 7 pts had TCL. Cytokine levels and CRS symptoms were determined as a measure of generalized immune activation; serum IFNβ levels were monitored as a pharmacodynamic biomarker of virus infection; antitumor T cell responses were measured using ELISPOT assays. Results: Of 8 TCL pts, 3 had RECIST responses: PR at DL 2, a CR & PR at DL 4. Most pts experience short lived CRS typically resolving within 24 hours of virus infusion. Serum IFNβ levels increased post-therapy in all pts, typically peaking by 24 hours post virus infusion and returning to baseline by median day 10. T cell responses could not be accurately determined in most cases due to suboptimal T cell viability and/or function after thawing of frozen PBMC. Factors contributing to tumor regression in each of the responding pts appeared to differ significantly, as exemplified by the case reports below. Pt (I) with CTCL experienced grade 1 CRS followed by brisk regression of multiple cutaneous lesions. The PR lasted 3 mo, after relapse of an eye lesion, but responses at other sites deepened after the relapsed lesion was irradiated; pt remained off active therapy for the next 2 yrs. Peak serum IFNβ 4 hours post infusion was only 182 pg/ml suggesting that disease response may have been driven by nonspecific innate immune activation associated with the virus infusion. Pt (IV) (CD30+ PTCL/ cutaneous relapse) had short lived grade 2 CRS, then developed signs of IFNβ toxicity with AST elevation and thrombocytopenia. Oral ruxolitinib was administered for 5 days as IFNβ toxicity mitigation leading to normalization of AST and platelets. All PET-avid tumors regressed completely. This CR continues 16 months post virus infusion. Peak serum IFNβ was 18,213 pg/ml strongly suggesting that response was driven by extensive intratumoral amplification of the virus and oncolytic tumor destruction. Robust CTL responses to tumor neoantigens were detected in this pt at baseline indicating that collateral boosting of tumor-specific T cells may have been responsible for the long term maintenance of this CR Pt (V) (CD30+ PTCL) had short lived grade 2 CRS followed by response at all disease sites (including complete normalization of an enlarged FDG-avid spleen). Her PR ended after 6 months due to relapse in cervical lymph nodes. Peak serum IFNβ level was modest, 600 pg/ml & sustained over 48 hours suggesting slower intratumoral spread of the virus infection. The deepening of the response long after resolution of the oncolytic phase points strongly to a contribution from antitumor CTL but the assay was technically unsatisfactory in this pt. Conclusion: Analysis of the correlative data supports that intravenous Voyager-V1 therapy can recruit diverse antitumor effector mechanisms to impact tumor response in pts with heavily pretreated TCL. Importantly, intratumoral virus amplification, which results in high circulating concentrations of IFNβ, does not necessarily lead to tumor regression perhaps because of defective immune cell recruitment and/or activation in some tumors but not in others. This will be further evaluated in future study participants by performing CTL assays on fresh, rather than frozen PBMC. In conclusion, a single IV infusion of Voyager-V1 shows highly promising activity against treatment refractory TCL and should be further advanced as a new single-shot or combination therapy for this therapeutically challenging indication. Figure 1 Figure 1. Disclosures Witzig: Karyopharm Therapeutics, Celgene/BMS, Incyte, Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS, Acerta Pharma, Kura Oncology, Acrotech Biopharma, Karyopharm Therapeutics: Research Funding. Paludo: Karyopharm: Research Funding. Patnaik: StemLine: Research Funding; Kura Oncology: Research Funding. Dispenzieri: Takeda: Research Funding; Alnylam: Research Funding; Pfizer: Research Funding; Oncopeptides: Consultancy; Sorrento Therapeutics: Consultancy; Janssen: Consultancy, Research Funding. Bennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Gertz: Aurora Biopharma: Other: Stock option; Akcea Therapeutics, Ambry Genetics, Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Karyopharm Therapeutics, Pfizer Inc (to Institution), Sanofi Genzyme: Honoraria; Akcea Therapeutics, Alnylam Pharmaceuticals Inc, Prothena: Consultancy; AbbVie Inc, Celgene Corporation: Other: Data Safetly & Monitoring; Ionis Pharmaceuticals: Other: Advisory Board. Dingli: Janssen: Consultancy; Sanofi: Consultancy; GSK: Consultancy; Apellis: Consultancy; Novartis: Research Funding; Alexion: Consultancy. Kumar: Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Beigene: Consultancy; Carsgen: Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Merck: Research Funding; Oncopeptides: Consultancy; Roche-Genentech: Consultancy, Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: Consultancy, Honoraria; Tenebio: Research Funding; Novartis: Research Funding; Bluebird Bio: Consultancy; Amgen: Consultancy, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. Bergsagel: Oncopeptides: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Genetech: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Patents & Royalties: human CRBN mouse; Janssen: Consultancy, Honoraria. Kapoor: Karyopharm: Consultancy; Cellectar: Consultancy; BeiGene: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Amgen: Research Funding; Ichnos Sciences: Research Funding; Regeneron Pharmaceuticals: Research Funding; Glaxo SmithKline: Research Funding; Karyopharm: Research Funding; Sanofi: Research Funding; Takeda: Research Funding; AbbVie: Research Funding. Lin: Sorrento: Consultancy; Vineti: Consultancy; Legend: Consultancy; Novartis: Consultancy; Bluebird Bio: Consultancy, Research Funding; Merck: Research Funding; Juno: Consultancy; Celgene: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Gamida Cell: Consultancy; Janssen: Consultancy, Research Funding; Takeda: Research Funding. OffLabel Disclosure: VSV-IFNβ-NIS is an oncolytic virus in clinical trial for systemic administration in hematologic malignancies

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 Background :COVID-19 adversely affects individuals with cancer. Several studies have found that seroconversion rates among patients with hematologic malignancies are suboptimal when compared to patients without cancer. Among patients with hematologic malignancies, seroconversion rates also appear to be influenced by recent treatment and the type of treatment they have received. Patients with non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) are immunocompromised due to impaired humoral and cellular immunity in addition to prescribed immunosuppressive therapy. Chimeric antigen receptor T-cell (CAR T) therapy is now widely used for NHL and MM, but little is known about seroconversion rates after COVID-19 vaccination among these populations. Current national guidelines recommend COVID-19 vaccination to be offered to CAR T recipients as early as three months thereafter. We retrospectively evaluated SARS-CoV-2 spike-binding IgG antibody levels following COVID-19 vaccination among NHL and MM CAR T therapy recipients. Methods:This retrospective study was conducted at three Mayo Clinic sites on NHL and MM patients that received CAR T infusions from Sept 2016 to June 2021. Baseline characteristics were ascertained from medical records. All NHL and MM patients who had received CAR T at any point and were alive at the time that the COVID-19 vaccine first became available were eligible for inclusion for antibody response evaluation. For antibody response to vaccination, antibody spike values > 0.80 U/mL were considered positive. Results: Out of 104 CAR T infusions, 73 patients are alive at the time of this submission. We have had 7 patients with known COVID-19 pre-CAR T and all 7 are currently alive (5 have antibody titers and 2 have not been tested yet). Nineteen patients developed known COVID infection post-CAR T (13 alive and 6 deceased). The mortality of COVID post-CAR T in our sample was 31.5%. Furthermore, of the 13 patients that survived COVID-19, they received CAR T an average of 416 days prior to COVID-19 infection (median = 337, range = 54 - 1406); the 6 patients who died from COVID-19 had received CAR T an average of 250 days prior to COVID-19 infection (median = 164, range = 7 - 846). All 6 deceased patients did not receive COVID-19 vaccination pre-CAR T. Out of 17 CAR T patients tested for antibody spike titers post COVID-19 vaccination, 76.4% were able to mount an antibody response. More patients with MM had a higher titer response to the vaccine (>250 U/mL) compared to the NHL counterparts (0.80-249 U/mL). All patients that received the vaccine, regardless of antibody response, were alive at the time of this submission. Conclusions:The majority of CAR T recipients with NHL and MM are able to mount an antibody response following COVID-19 vaccination in our relatively small sample. The frequency of seroconversion among CAR T recipients seems to be similar to patients with hematologic malignancy who had received a hematopoietic cell transplant reported elsewhere. These findings are limited by our small sample size and may be influenced by the timing of vaccination relative to CAR T. Furthermore, almost half of our patients received IVIG post CAR T which could potentially cause false positive antibody results as pooled immunoglobulin preparations may contain COVID-19 antibodies from vaccinated healthy donors. To better understand the characteristics of the immunologic response against SARS-CoV-2 in patients post-CAR T, larger multicenter studies exploring both humoral and cellular immunity will be needed. JEWN, MI and JM are co-first authors and PV, HM and AR are co-senior authors. Figure 1 Figure 1. Disclosures Munoz: Physicians' Education Resource: Honoraria; Seattle Genetics: Honoraria; Bayer: Research Funding; Gilead/Kite Pharma: Research Funding; Celgene: Research Funding; Merck: Research Funding; Portola: Research Funding; Incyte: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Research Funding; Janssen: Research Funding; Millennium: Research Funding; Gilead/Kite Pharma, Kyowa, Bayer, Pharmacyclics/Janssen, Seattle Genetics, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau; Pharmacyclics/Abbvie, Bayer, Gilead/Kite Pharma, Pfizer, Janssen, Juno/Celgene, BMS, Kyowa, Alexion, Beigene, Fosunkite, Innovent, Seattle Genetics, Debiopharm, Karyopharm, Genmab, ADC Therapeutics, Epizyme, Beigene, Servier: Consultancy; Targeted Oncology: Honoraria; OncView: Honoraria; Kyowa: Honoraria. Bergsagel: Oncopeptides: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Patents & Royalties: human CRBN mouse; Pfizer: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Genetech: Consultancy, Honoraria; GSK: Consultancy, Honoraria. Wang: Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; InnoCare: Research Funding; Novartis: Research Funding; MorphoSys: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Fonseca: Juno: Consultancy; Kite: Consultancy; Aduro: Consultancy; OncoTracker: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy; AbbVie: Consultancy; Patent: Prognosticaton of myeloma via FISH: Patents & Royalties; Caris Life Sciences: Membership on an entity's Board of Directors or advisory committees; Scientific Advisory Board: Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Merck: Consultancy; Mayo Clinic in Arizona: Current Employment; Celgene: Consultancy; Takeda: Consultancy; Bayer: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Pharmacyclics: Consultancy. Palmer: Sierra Oncology: Consultancy, Research Funding; CTI BioPharma: Consultancy, Research Funding; Protagonist: Consultancy, Research Funding; Incyte: Research Funding; PharmaEssentia: Research Funding. Dingli: Novartis: Research Funding; GSK: Consultancy; Apellis: Consultancy; Alexion: Consultancy; Sanofi: Consultancy; Janssen: Consultancy. Kapoor: Sanofi: Research Funding; AbbVie: Research Funding; Takeda: Research Funding; Karyopharm: Consultancy; Cellectar: Consultancy; BeiGene: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Amgen: Research Funding; Ichnos Sciences: Research Funding; Regeneron Pharmaceuticals: Research Funding; Glaxo SmithKline: Research Funding; Karyopharm: Research Funding. Kumar: Roche-Genentech: Consultancy, Research Funding; Oncopeptides: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Beigene: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tenebio: Research Funding; Merck: Research Funding; Carsgen: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Bluebird Bio: Consultancy; Antengene: Consultancy, Honoraria; Sanofi: Research Funding. Paludo: Karyopharm: Research Funding. Bennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Kite, a Gilead Company: Consultancy, Research Funding; Merck: Research Funding; Gamida Cell: Consultancy; Takeda: Research Funding; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Sorrento: Consultancy; Legend: Consultancy; Vineti: Consultancy. Murthy: CRISPR Therapeutics: Research Funding.

Abstract Background: While CD19 chimeric antigen receptor T cell therapy (CAR-T) therapy does not use myeloablative chemotherapy, patients with aggressive lymphoma treated with CAR-T are immunosuppressed from lymphodepletion chemotherapy, and prolonged B cell aplasia and hypogammaglobulinemia from CAR-T. The impact of CAR-T on immunologic protection from vaccine-preventable diseases (and thus the need to revaccinate) has not been formally studied. We report the vaccine titers of patients treated with CAR-T at Mayo Clinic, Rochester. Methods: We conducted a retrospective chart review of patients who received CAR-T from 9/2018 to 4/2021 for treatment of aggressive lymphoma at Mayo Clinic, Rochester. Data was collected on anti-viral and anti-bacterial titers prior to CAR-T infusion and at month 3 post CAR-T. Clinical assays for vaccine titers were used for patient assessment and threshold for clinical assays was used to define antibody titer as positive or negative. Results: In our cohort of 87 CAR-T patients, 83 (94%) patients were infused with axicabtagene ciloleucel, 4 (5%) patients received brexucabtagene autoleucel and 1 (1%) received tisagenlecleucel. Prior to CAR-T therapy, positive titer rate was highest for tetanus and lowest for Streptococcus pneumoniae (Strep PNA). Similar trends were seen whether patients had autologous stem cell transplant (ASCT) within 2 years of CAR-T (i.e. within immunization timeframe post ASCT) or not (Table 1). At 3 months post CAR-T, overall seropositivity rates were similar when compared to pre-CAR-T levels for the prior transplant and no prior transplant group. For patients who had received intravenous immunoglobulin (IVIG) supplement prophylactically (for IVIG<400 mg/dl), seropositivity rate for Strep PNA remained zero (Table 1). Among the 30 patients who received IVIG, variable rate of conversion from negative to positive titers were seen for measles (1/2, 50%), mumps (3/5, 60%), rubella (3/4, 75%), varicella-zoster (VZV, 4/4, 100%), hepatitis A (8/9, 89%) and hepatitis B (10/12, 83%). For patients who did not receive IVIG prophylaxis after CAR-T, seropositivity rate for hepatitis A and B was low. In addition, some of these patients had a loss of seropositivity for Strep PNA (2/5, 40%) and hepatitis A (1/4, 25%). Conclusion: The presence of protective vaccine titers is variable for patients receiving CAR-T therapy, regardless of recent ASCT. The loss of protective titers post CAR-T was low. The need for immunization post CAR-T may remain important regardless of transplant status prior to CAR-T. Prophylactic IVIG does not confer complete immunization protection. Optimal timing for immunization post CAR-T is probably unknown and may need to be considered earlier for patients not on prophylactic IVIG. Further study with longer follow-up is needed to inform the need for immunization and optimal timing post CAR-T. Figure 1 Figure 1. Disclosures Bennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Paludo: Karyopharm: Research Funding. Wang: LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding; Genentech: Research Funding; Novartis: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; InnoCare: Research Funding. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Sorrento: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Vineti: Consultancy; Juno: Consultancy; Legend: Consultancy; Gamida Cell: Consultancy; Merck: Research Funding; Bluebird Bio: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Takeda: Research Funding.