Long-term survival outcomes of patients (pts) with relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) treated with brexucabtagene autoleucel (brexu-cel) in ZUMA-3.

6531 Background: Brexu-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for pts ≥18 y with R/R B-ALL in the US (≥26 y in the EU). In the 3-y follow-up of ZUMA-3, median overall survival (OS) was 25.6 mo (N=78). Survival benefit was seen regardless of age, prior treatment, or subsequent allogeneic stem cell transplant (sub alloSCT) status (Shah et al. ASCO 2023. #7023). Here we report 4-y survival outcomes for ZUMA-3. Methods: Eligible pts (≥18 y) had R/R B-ALL and received brexu-cel (1×10 6 CAR T cells/kg) after leukapheresis and lymphodepleting chemotherapy. The primary endpoint was overall complete remission (CR)/CR with incomplete hematologic recovery (CRi) rate per independent review with OS as a key secondary endpoint. Descriptive statistics are reported for post hoc exploratory subgroup analyses. Results: As of July 23, 2023, median follow-up time in Phase 1 and 2 pts who received the pivotal dose of brexu-cel (N=78) was 53.6 mo (range 44.7-82.3). Median OS (95% CI) was 25.6 mo (16.2-60.4) in all treated pts and 47.0 mo (23.2-not estimable NE) in pts with CR/CRi (n=57). In pts 4 y follow-up, pts in ZUMA-3 continued to experience OS benefit regardless of age, prior therapy, or sub alloSCT status, though pts with prior blina had a numerically lower 48-mo OS rate. Small subgroups and unbalanced pt characteristics limit interpretation of these results. No new safety signals were observed. Further studies are needed to fully assess the impact of age, prior therapies, and sub alloSCT on outcomes after brexu-cel. Clinical trial information: NCT02614066 . Table: see text