Bishop, Michael

Background: Obe-cel is an autologous chimeric antigen receptor (CAR) T cell product with a novel CD19 binding domain CAT conferring a fast antigen off-rate designed to mitigate safety concerns and improve persistence over approved CD19 CAR T therapies. Early results from the pivotal FELIX study Phase IIA cohort (N=94) were recently presented (Roddie C et al. J Clin Oncol 2023;41[16 Suppl]:7000). We report findings from a pooled analysis of all patients (pts) treated to date with obe-cel in the FELIX Phase Ib/II study (NCT04404660), with a focus on pts with low leukemia burden prior to obe-cel infusion. Methods: The FELIX study enrolled adults with R/R B-ALL at screening with either morphological disease ≥5% bone marrow (BM) blasts (Cohort A), or in ≥2 nd complete remission (CR)/CR with incomplete hematologic recovery (CRi) with measurable residual disease (MRD) (Cohort B), or with isolated extramedullary disease (EMD) (Cohort C). The Phase Ib part of the study enrolled Cohorts A and B; the Phase II part enrolled Cohorts A, B, and C. CAR T products were generated from leukapheresis material using an automated process. Pts received bridging therapy as needed and lymphodepletion with fludarabine (4 × 30mg/m 2) and cyclophosphamide (2 × 500mg/m 2). A target dose of 410 × 10 6 CAR T cells was infused as a split dose on Days 1 and 10 based on pre-lymphodepletion BM blast burden. The primary endpoint was overall remission rate (best response of CR/CRi by independent review). Secondary endpoints included duration of remission (DoR), MRD negative remission rate, safety, and CAR T expansion/persistence. This pooled analysis included data from pts treated with obe-cel across all cohorts in the Phase Ib/II parts of the study. Low leukemia burden was defined as morphological remission per investigator assessment (<5% BM blasts without EMD) as measured at screening or at the start of lymphodepletion. Results: Between September 2020 and December 2022, 152 pts were enrolled and underwent leukapheresis. As of 16 March 2023, obe-cel was successfully administered to 126/152 (83%) pts (Phase Ib: Cohort A n=13, B n=3; Phase II: Cohort A n=94, B n=9, C n=7). Baseline characteristics at screening (n=126): median age 46.5 (range 20-81) yrs; Philadelphia positive B-ALL 27%; median 2 (range 1-6) prior lines of therapy; prior blinatumomab/inotuzumab 42%/32%; median BM blast burden 37% (range 0-100) including 23% pts with EMD; prior allogeneic stem cell transplant 44%. At a median follow up of 11.0 (range 0.9-30.6) months, the CR/CRi rate was 77% (95/124 response evaluable pts) with CR rate 57% (71/124). Among MRD evaluable responders, 96% achieved MRD negative status by central flow cytometry analysis. Median DoR was not reached at the current follow up. Low rates of Grade (Gr) ≥3 cytokine release syndrome (CRS; 2.4%) and/or Gr ≥3 immune effector cell associated neurotoxicity syndrome (ICANS; 7.1%) were observed. CAR T expansion was similar across the Phase Ib/II cohorts and CAR T persistence was ongoing in the majority of responders at the current follow up. Preliminary data indicate favorable efficacy and safety in pts with low leukemia burden prior to obe-cel infusion. Among 12 pts with MRD at screening (Cohort B), two pts were not evaluable and 9/10 evaluable pts achieved CR/CRi, with 100% achieving MRD negative status by central flow cytometry analysis post obe-cel. Median DoR was not reached at the current follow up. In this subset, no Gr ≥3 CRS was observed; one pt had Gr ≥3 ICANS. In a subset of 28 pts (across all cohorts) in morphological remission at the time of lymphodepletion, 24/27 (89%) response evaluable pts achieved CR/CRi and 100% of MRD evaluable responders achieved MRD negative CR/CRi by central flow cytometry analysis post obe-cel. Median DoR was not reached at the current follow up. In this subset, no pts experienced Gr ≥3 CRS/ICANS. Conclusions:This pooled analysis of data from all pts treated to date in the FELIX study demonstrates high rates of CR/CRi after obe-cel treatment, durable responses (median DoR not reached), and a favorable safety profile. Preliminary data suggest better outcomes in pts with low leukemia burden at screening/lymphodepletion, with higher rates of deep MRD negative complete remission, median DoR not reached at the current follow up, no Gr ≥3 CRS and one Gr ≥3 ICANS. These data support further exploration of CAR T therapy earlier in the treatment algorithm for adults with ALL.

7010 Background: Brexucabtagene autoleucel (KTE-X19) is an autologous anti-CD19 CAR T-cell therapy approved in the US to treat adult R/R B-ALL based on the ZUMA-3 study. The overall complete remission (CR) rate (CR + CR with incomplete hematologic recovery [CRi]) was 71% (95% CI, 57-82) after 16.4 mo median follow-up (N = 55; Shah et al. Lancet 2021). Here, we report updated outcomes with longer follow-up in these pts and in a larger pooled analysis of Phase (Ph) 1 and 2 pts who received the pivotal dose of KTE-X19. Methods: Eligible adults (≥18 years) had R/R B-ALL and received a single infusion of KTE-X19 at the pivotal dose (1×106 CAR T cells/kg) following leukapheresis and conditioning chemotherapy. The primary endpoint was CR/CRi rate by central review. Results: As of 23 July 2021, median follow-up was 26.8 mo (range, 20.7-32.6) for treated Ph 2 pts (N = 55). The CR/CRi rate per central review was 71% (95% CI, 57-82; 56% CR; 15% CRi). Eleven pts (20%; 8 CR and 2 CRi) proceeded to subsequent allogeneic stem cell transplant (alloSCT). Median duration of remission (DOR) censored at subsequent alloSCT was 14.6 mo (9.4-not estimable [NE]); not censored: 18.6 mo (9.6-NE); 6/39 responders (15%) had ongoing responses at data cutoff. Median (95% CI) relapse-free survival (RFS) was 11.6 mo (2.7-20.5) censored at subsequent alloSCT and 11.7 mo (2.8-20.5) not censored at subsequent alloSCT; 18-mo RFS rates (95% CI) were 35% (20.5-50.6) and 42% (28.0-55.0), respectively. Median (95% CI) overall survival (OS) was 25.4 mo (16.2-NE) among all KTE-X19-treated pts and not reached (25.4-NE) in pts with CR (n = 31). For Ph 1/2 pts (N = 78) who received the pivotal KTE-X19 dose (median follow-up: 29.7 mo; range 20.7-58.3), the CR/CRi rate by independent review was 73% (95% CI, 62-82). Medians (95% CI) for DOR, RFS, and OS were 18.6 mo (9.6-NE), 11.7 mo (6.1-20.5), and 25.4 mo (16.2-NE), respectively. A subgroup analysis revealed that in pts aged 18-39 (n = 36), 40-59 (n = 27), and ≥60 (n = 15) years, the CR/CRi rates (95% CI) were 69% (52-84), 70% (50-86), and 87% (60-98); 24-mo OS rates (95% CI) were 48% (30-64), 54% (33-71), and 57% (28-78), respectively. In pts with pre-KTE-X19 infusion marrow blast percentages > 25 to ≤50 (n = 12), > 50 to ≤75 (n = 14), and > 75 to 100 (n = 30), CR/CRi rates (95% CI) were 83% (52-98), 86% (57-98), and 57% (37-75); 24-mo OS rates (95% CI) were 58% (27-80), 55% (26-77) and 37% (19-55), respectively. There were no new safety signals; the proportion of treated Ph 2 pts with Gr ≥3 treatment emergent adverse events was unchanged since prior data cutoff. One pt had an ongoing neurologic event of Gr 1 finger numbness. Conclusions: With longer follow-up and an expanded data set by independent review, outcomes remain durable in adults with R/R B-ALL, most of whom were heavily pretreated, with median OS not yet reached in pts with CR. Long-term safety was favorable. Clinical trial information: NCT02614066.

Abstract Background: Standard of care (SOC) for second-line (2L) therapy (tx) of relapsed/refractory aggressive B-cell non-Hodgkin lymphomas (R/R aNHL) includes platinum-based chemotherapy (PCT) followed by autologous hematopoietic cell transplantation (aHCT) in responders. Outcomes are poor for patients (pts) with R/R aNHL who experience progression during or within 12 months (mo) of 1L tx. Tisagenlecleucel (tisa-cel) is an autologous chimeric antigen receptor (CAR) T-cell tx targeting CD19 approved for pts with large B-cell lymphoma (LBCL; US) and diffuse LBCL (non-US) after ≥2 lines of tx. BELINDA (NCT03570892) is a Phase III, randomized, global (18 countries) study of tisa-cel vs SOC as 2L tx for R/R aNHL. Methods: Adults with confirmed R/R aNHL within 12 mo after 1L chemo-immunotherapy were eligible. All pts underwent leukapheresis for tisa-cel production and were randomized 1:1 to receive tisa-cel (Arm A) or SOC (Arm B) and stratified by 1L duration of response, International Prognostic Index (IPI), and geographic region. Arm A received optional bridging tx (investigator choice of protocol-defined PCT regimens) followed by lymphodepletion (LD; generally, fludarabine 25 mg/m 2/day [d] + cyclophosphamide 250 mg/m 2/d for 3 d) and followed by a single tisa-cel infusion (0.6-6×10 8 CAR-T cells). Arm B received investigator choice of PCT regimen followed by aHCT in responders or a second PCT in nonresponders. Disease assessments were performed at 6 and 12 weeks (wk), then planned every 3 mo for year (y) 1 and every 6 mo for y 2. The primary endpoint was event-free survival (EFS), defined as time from randomization to stable disease (SD) or progressive disease (PD) at or after wk 12 assessment or death at any time. SD/PD at wk 6 was not considered an event on either Arm. Arm A's wk 6 assessment evaluated disease burden before tisa-cel infusion and after bridging if administered. Arm B's wk 6 assessment determined if response was sufficient for aHCT or if a second PCT regimen was needed prior to aHCT. Results: As of May 6, 2021, 322 pts were randomized: 162 to Arm A and 160 to Arm B. In Arms A and B, 33% and 29% were ≥65 y, and 66% and 67% had primary refractory disease, respectively. Baseline characteristics indicated imbalances with more high-grade B-cell lymphomas (24% vs 17%) and IPI ≥2 (65% vs 58%) in Arm A vs B. In Arm A, 47% received ≥2 cycles of bridging PCT, 36% received 1 cycle, and 17% received 0. In Arm A, 96% received tisa-cel; the median dose was 2.9×10 8 cells. In Arm B, 96% received ≥2 PCT cycles and 54% received ≥2 different PCT regimens; 33% received aHCT, including 10% requiring ≥2 different PCT regimens before aHCT. Median time from randomization to aHCT was 92 d (range, 61-158 d). Median follow-up was 10 mo (range, 2.9-23.2 mo). At wk 6 assessment, 26% had PD in Arm A vs 14% in Arm B. Median EFS in Arms A and B was 3 mo (HR 1.07; 95% CI, 0.82-1.40; P=0.69); Arm A pts with PD at wk 6 had shorter EFS. Overall response rate (ORR) at wk 12 in Arm A was 46% vs 43% in Arm B; complete response rate in both arms was 28%. Some pts responded to tisa-cel after SD/PD at wk 12 without additional tx but were counted as an event in EFS analysis. In Arm B, 81 pts (51%) crossed over to receive tisa-cel, 71 without receiving aHCT. Of 72 crossover pts with response assessment, ORR to tisa-cel was 40%. Overall survival was immature at data cutoff. In Arm A, 84% had a grade ≥3 adverse event (AE; vs 90% in Arm B), including grade ≥3 cytokine release syndrome in 5% (CRS; Lee 2014) and grade ≥3 neurologic events (NE) in 3% (CTCAE v5.0), with no grade 5 CRS/NE. Median times to CRS and NE onset were 4 and 5 d, respectively; median time to resolution was 5 and 9 d. Fifty-two (32%) and 45 (28%) pts in Arms A and B died on study, including 42 (26%) and 32 (20%) deaths due to PD, respectively. Ten pts in Arm A and 13 in Arm B died of AEs. Conclusions: Tisa-cel as 2L tx in R/R aNHL pts did not have a higher EFS vs SOC. Possible contributing factors include study design elements, such as optional PCT bridging tx in Arm A with potential delay of tisa-cel infusion until after wk 6 assessment, allowance of a different PCT regimen to reach aHCT in Arm B after inadequate response to first PCT, and imbalances in relevant pt characteristics. Insights from this randomized Phase III study will inform use of cellular tx in the 2L R/R aNHL setting and the design of future CAR-T trials. Figure 1 Figure 1. Disclosures Bishop: Arcellx, Autolus, Bristol-Myers Squibb, CRISPR, Kite/Gilead, and Novartis: Consultancy, Research Funding; Bristol-Myers Squibb and Kite/Gilead: Other: fees for non-CME/CE services . Dickinson: Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Research Funding; Celgene: Research Funding; Amgen: Honoraria. Purtill: Novartis: Honoraria; Gilead: Honoraria; BMS Celgene: Honoraria. Barba: Amgen, Celgene, Gilead, Incyte, Jazz Pharmaceuticals, MSD, Novartis, Pfizer and Roche, Jazz Phar,aceuticals: Honoraria; Cqrlos III heqlth Institute, aSOCIACION espanola contra el cancer, PERIS: Research Funding. Santoro: Arqule: Consultancy, Speakers Bureau; Sanofi: Consultancy; Takeda: Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Speakers Bureau; AbbVie: Speakers Bureau; Amgen: Speakers Bureau; Celgene: Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eli-Lilly: Speakers Bureau; Sandoz: Speakers Bureau; Eisai: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hamad: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kato: Abbvie: Consultancy, Research Funding; AstraZeneca: Consultancy; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Chugai: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Dainippon-Sumitomo: Honoraria; Eisai: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; MSD: Honoraria; Mundi: Honoraria; Novartis: Consultancy, Research Funding; Ono: Honoraria, Research Funding. Sureda: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings and/or travel, Research Funding, Speakers Bureau; BMS/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings and/or travel, Speakers Bureau; MSD: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GSK: Consultancy, Honoraria, Speakers Bureau; Roche: Other: Support for attending meetings and/or travel; Bluebird: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Consultancy. Greil: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Sandoz: Honoraria, Research Funding. Thieblemont: Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Novartis: 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 ; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Janssen: 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; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; 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 . Morschhauser: F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, 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; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Chugai: Honoraria; Janssen: Honoraria; Genmab: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech, Inc.: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy; Incyte: Membership on an entity's Board of Directors or advisory committees. Janz: Janssen: Honoraria, Other: Meeting Fees; Novartis: Honoraria; Takeda: Honoraria, Other: Travel Accommodations, Expenses, Meeting fees; Roche: Honoraria; Gilead: Other: Travel Accommodations, Expenses, Meeting fees. Flinn: 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 equity holder in publicly-traded company; Seattle Genetics: Research Funding; Sarah Cannon Research Institute: Current Employment; Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Triphase Research & Development Corp.: 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; Teva: Other: All 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; Portola Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Pfizer: 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; Merck: 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; Karyopharm 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; Incyte: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; IGM Biosciences: 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; Forma Therapeutics: 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; Constellation Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Celgene: 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; ArQule: 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; Acerta Pharma: 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; TG Therapeutics: Consultancy, Other: All consultancy and 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; Seagen: 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; Pharmacyclics LLC, an AbbVie Company: 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; MorphoSys: 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; 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; Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Great Point Partners: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Gilead Sciences: 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; BeiGene: Consultancy, Other: All consultancy and 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; AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding. Kwong: Novartis: Consultancy, Honoraria, Research Funding. Kersten: Novartis: Consultancy, Honoraria, Other: Travel support; Takeda: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support, Research Funding; Celgene: Research Funding; Roche: Consultancy, Honoraria, Other: Travel support, Research Funding; Miltenyi Biotec: Consultancy, Honoraria, Other: Travel support; BMS/Celgene: Consultancy, Honoraria. Minnema: Janssen: Consultancy, Honoraria; Celgene: Other: Travel expenses; BMS: Consultancy; Kite/Gilead: Consultancy; Alnylam: Consultancy. Holte: Roche: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees. Martinez-Lopez: Amgen: 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; Bristol Myers Squibb: 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; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: 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; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees. Maziarz: Novartis: Consultancy, Other: Data and Safety Monitoring board, Research Funding; Incyte Corporation: Consultancy, Honoraria; Bristol-Myers, Squibb/Celgene,, Intellia, Kite: Honoraria; Allovir: Consultancy, Research Funding; Artiva Therapeutics: Consultancy; CRISPR Therapeutics: Consultancy; Intellia: Honoraria; Omeros: Research Funding; Athersys: Other: Data and Safety Monitoring Board, Patents & Royalties; Vor Pharma: Other: Data and Safety Monitoring Board. McGuirk: Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; EcoR1 Capital: Consultancy; Novartis: Research Funding; Fresenius Biotech: Research Funding; Astelllas Pharma: Research Funding; Bellicum Pharmaceuticals: Research Funding; Novartis: Research Funding; Gamida Cell: Research Funding; Pluristem Therapeutics: Research Funding. Bachy: Kite, a Gilead Company: Honoraria; Novartis: Honoraria; Daiishi: Research Funding; Roche: Consultancy; Takeda: Consultancy; Incyte: Consultancy. Dreyling: Amgen: Speakers Bureau; Astra Zeneca: Consultancy, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau; Gilead Kite: Consultancy, Research Funding, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Roche: Consultancy, Research Funding, Speakers Bureau; AbbVie: Research Funding; BeiGene: Consultancy, Speakers Bureau; Genmab: Consultancy; MorphoSys: Consultancy. Harigae: Bristol Myers Squibb: Honoraria; Novartis Pharma: Honoraria, Research Funding; Chugai Pharma: Honoraria; Janssen Pharma: Honoraria; Ono pharma: Honoraria, Other: Subsidies or Donations; Astellas Pharma: Other: Subsidies or Donations; Kyowakirin: Other: Subsidies or Donations. Bond: Kite/Gilead: Honoraria. Andreadis: Merck: Research Funding; BMS: Research Funding; CRISPR Therapeutics: Research Funding; GenMAB: Research Funding; Novartis: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Epizyme: Honoraria; Incyte: Honoraria; TG Therapeutics: Honoraria; Kite: Honoraria; Karyopharm: Honoraria; Atara: Consultancy, Honoraria. McSweeney: Kite-Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Gamida: Consultancy, Honoraria; TG Theraputics: Consultancy, Honoraria; Autolous Limited: Research Funding; Novartis: Research Funding; NKARTA: Research Funding; Allovir: Research Funding. Newsome: Novartis: Current Employment. Degtyarev: Novartis: Current Employment, Current equity holder in publicly-traded company. Del Corral: Novartis: Current Employment. Andreola: Novartis: Current Employment, Current holder of stock options in a privately-held company. Masood: Novartis: Current Employment, Current holder of stock options in a privately-held company. Schuster: AbbVie, Acerta, Celgene/Juno, DTRM Bio, Genentech, Incyte, Merck, Novartis, Portola, and TG Therapeutics: Research Funding; Acerta, AlloGene, AstraZeneca, BeiGene, Celgene/Juno, Genentech/Roche, LoxoOncology, Novartis, and Tessa Therapeutics: Consultancy; Acerta, AlloGene, AstraZeneca, BeiGene, Celgene, Genentech/Roche, LoxoOncology, Novartis, Nordic Nanovector, Pfizer, and Tessa Therapeutics;: Honoraria; Novartis: Other: Personal fees, Patents & Royalties; AbbVie, Celgene, Novartis, Juno, Nordic Nanovector, and Pfizer: Other: Steering Committee Participation. Jaeger: BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Norvartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: 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; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Westin: Kite, a Gilead Company: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Research Funding; Umoja: Consultancy; Iksuda Therapeutics: Consultancy; Curis: Research Funding; Morphosys: Research Funding; 47 Inc: Research Funding.

TPS7570 Background: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma (NHL), and although > 50% of pts achieve long-term remission with first-line therapy, pts with R/R disease as well as those with R/R grade 3b follicular lymphoma (FL), double-, or triple-hit high-grade lymphomas have poor long-term outcomes (Crump 2017; Kahl 2016; Jain 2012). Autologous (auto) chimeric antigen receptor (CAR) T cell therapy has provided additional options for pts with R/R disease, but only when leukapheresis and manufacturing prove feasible (Jacobson 2020). Allogeneic (allo) CAR-T cells were designed specifically to address these unmet needs by using healthy donor T cells to produce a readily available product and remove the need for bridging chemotherapy. We are currently investigating the safety and efficacy of CTX110, an allo anti-CD19 CAR-T cell product modified by using CRISPR/Cas9-editing to disrupt the endogenous T-cell receptor (TCR) alpha constant (TRAC) locus in order to remove TCR expression and disrupt β2-microglobulin, which eliminates major histocompatibility complex (MHC) class I expression. Disruption of the TCR should significantly reduce or eliminate risks of graft-versus-host disease and elimination of MHC class I expression may increase CAR-T cell persistence by mitigating CTX110 rejection. In addition, the anti-CD19 CAR transgene construct is precisely inserted into the TRAC locus. Methods: The Phase 1 CARBON trial (NCT04035434) is an open-label, multicenter, global study evaluating the safety and efficacy of CTX110 in pts ≥18 y with R/R DLBCL NOS, double- or triple-hit DLBCL, or transformed or grade 3b FL with ≥2 prior lines of therapy or who are ineligible for/refused prior auto hematopoietic stem cell transplant (HSCT). Pts who received prior auto CAR-T or allo HSCT are excluded. Pts will receive lymphodepleting chemotherapy with fludarabine 30mg/m2 and cyclophosphamide 500mg/m2 for 3 days, followed by CTX110 infusion. In part A, dose escalation will be performed using a 3+3 design. Upon completion of dose finding, the cohort will be expanded to further assess safety signals and efficacy including the primary efficacy endpoint of overall response rate. Key secondary efficacy endpoints include duration of response, progression-free survival, and overall survival. The trial is currently open and enrolling. Clinical trial information: NCT04035434.

7002 Background: ZUMA-3 is a Phase 1/2 multicenter study evaluating KTE-X19, an autologous anti-CD19 CAR T-cell therapy, in adult pts with R/R B-ALL. Phase 1 efficacy results at the recommended Phase 2 dose (1×106 CAR T cells/kg) were encouraging (Shah et al. ASCO 2019 #7006). Here, we present the pivotal Phase 2 results. Methods: Eligible adults had R/R B-ALL, > 5% bone marrow (BM) blasts by local evaluation, and ECOG 0–1. Pts received a single infusion of KTE-X19 after conditioning chemotherapy. The primary endpoint was the overall complete remission (CR) rate (CR + CR with incomplete hematologic recovery [CRi]) by central review. Key secondary endpoints were duration of remission (DOR), relapse-free survival (RFS), overall survival (OS), measurable residual disease negativity (MRD–) rate by flow cytometry, and safety. Data are reported in all treated pts. Results: As of 9/2020, 55 of 71 enrolled pts received KTE-X19, with a median follow-up of 16.4 mo (range, 10.3–22.1). Adverse events (AEs; n = 8) and ineligibility (n = 4) were the most common reasons enrolled pts did not receive KTE-X19 infusion. Median age was 40 y (range, 19–84), median BM blasts at screening were 65% (range, 5–100), and 47% of pts had ≥3 prior therapies, with 45%, 22%, and 42% having previously received blinatumomab, inotuzumab ozogamicin, or allogeneic stem cell transplant (alloSCT), respectively. The CR/CRi rate was 71% (95% CI, 57–82; 56% CR, 15% CRi); 31% of responders had ongoing responses. Median (95% CI) DOR, RFS, and OS were 12.8 mo (8.7–not estimable [NE]), 11.6 mo (2.7–15.5), and 18.2 mo (15.9–NE), respectively. In responders, median (95% CI) RFS and OS were 14.2 mo (11.6–NE) and not reached (16.2–NE). The MRD– rate was 97% among pts with CR/CRi. Among 25 pts with prior blinatumomab treatment, the CR/CRi rate was 60%. Ten pts (18%) received subsequent alloSCT at a median 98 days post–KTE-X19 infusion. Median DOR remained unchanged when not censoring for alloSCT. Grade ≥3 AEs occurred in 95% of pts, most commonly anemia (49%) and neutropenia (49% [febrile 13%]). Grade ≥3 cytokine release syndrome (CRS; per Lee at al. Blood 2014) and neurologic events occurred in 24% and 25% of pts, respectively, and were generally reversible. Two Grade 5 KTE-X19–related events occurred (brain herniation, n = 1; septic shock, n = 1). Median times to onset of CRS and neurologic events were 5 d and 9 d, with median durations of 7.5 d and 7 d, respectively. Median peak CAR T-cell levels (cells/µL) were 40.5 (range, 1.3–1533.4) in pts with CR and 0 in nonresponders. CAR T cells were undetectable by 9 mo in ongoing responders. Conclusions: After a median follow-up of 16.4 mo, KTE-X19 demonstrated compelling clinical benefit in heavily pretreated adults with R/R B-ALL, with the median OS not yet reached for responding pts and a manageable safety profile. Clinical trial information: NCT02614066.

7006 Background: KTE-X19 is an autologous anti-CD19 CAR T cell therapy under investigation for adult R/R ALL. In an interim analysis of Phase 1 of ZUMA-3, we reported manageable safety and encouraging efficacy of KTE-X19; 72% of pts achieved a complete remission (CR) or CR with incomplete bone marrow (BM) recovery (CRi; Wierda et al, ASH 2018. #897). Here, we present end of Phase 1 results. Methods: Adults with R/R B cell ALL, > 5% BM blasts, and ECOG 0-1 received 2, 1, or 0.5 × 106 KTE-X19 cells/kg after conditioning chemotherapy. Revised adverse event management (rAE mgmt) was implemented for additional pts in a 1 × 106 dose cohort: corticosteroids were given earlier at onset of Grade ≥ 2 neurologic events (NEs) and tocilizumab was used only for active toxicity. The primary endpoint was the dose-limiting toxicity (DLT) rate. Key additional endpoints were KTE-X19 levels, incidence of AEs, minimal residual disease (MRD), and CR/CRi rate. Results: As of 9/27/18, 45 pts had received KTE-X19 (median follow-up [f/u], 16 mo). The median age was 46 y (range, 18–77); 30 pts (66%) had ≥ 3 prior therapies and the median pre-conditioning BM blasts was 70% (range, 0–97). Six, 23, and 16 pts received 2, 1, and 0.5 × 106 cells/kg, respectively. There were no DLTs in the DLT-evaluable pts. The most common Grade ≥ 3 AEs were hypotension (38%), pyrexia (38%) and thrombocytopenia (31%). There were 2 previously reported KTE-X19–related Grade 5 AEs of cerebral infarction and multiorgan failure, both in the context of CRS. Grade ≥ 3 CRS and NEs occurred in 13 (29%) and 17 (38%) pts, respectively. Of 41 pts with ≥ 2 mo of f/u, 68% had CR/CRi, and 73% had undetectable MRD. Of 19 pts with ≥ 2 mo of f/u treated with 1 × 106 cells/kg, 16 (84%) had a CR/CRi and the median event-free survival was 15 mo. In 9 pts treated with 1 × 106 cells/kg and rAE mgmt, 2 (22%) had Grade 3 CRS and 1 (11%) had Grade 3 NE with no Grade 4/5 events. Conclusions: KTE-X19 dosing and safety mgmt have been successfully refined by testing 3 cell doses and evaluating a new AE mgmt guideline with altered corticosteroids/tocilizumab use for NE/CRS. Pivotal Phase 2 is ongoing at the 1 × 106 dose with rAE mgmt. Clinical trial information: NCT02614066.

Abstract The best conditioning regimen before allogeneic transplantation for high-risk diffuse large B-cell lymphoma (DLBCL) remains to be clarified. We analyzed data from 396 recipients of allotransplants for DLBCL receiving myeloablative (MAC; n = 165), reduced intensity (RIC; n = 143), or nonmyeloablative conditioning (NMAC; n = 88) regimens. Acute and chronic GVHD rates were similar across the groups. Five-year nonrelapse mortality (NRM) was higher in MAC than RIC and NMAC (56% vs 47% vs 36%; P = .007). Five-year relapse/progression was lower in MAC than in RIC/NMAC (26% vs 38% vs 40%; P = .031). Five-year progression-free survival (15%-25%) and overall survival (18%-26%) did not differ significantly between the cohorts. In multivariate analysis, NMAC and more recent transplant year were associated with lower NRM, whereas a lower Karnofsky performance score (< 90), prior relapse resistant to therapy, and use of unrelated donors were associated with higher NRM. NMAC transplants, no prior use of rituximab, and prior relapse resistant to therapy were associated with a greater risk of relapse/progression. In conclusion, allotransplantation with RIC or NMAC induces long-term progression-free survival in selected DLBCL patients with a lower risk of NRM but with higher risk of lymphoma progression or relapse.