Outcomes of patients (pts) ≥ 65 years of age in ZUMA-1, a pivotal phase 1/2 study of axicabtagene ciloleucel (axi-cel) in refractory large B-cell lymphoma (LBCL).

Abstract

7555 Background: Axi-cel is a US FDA-approved, autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy for the treatment of pts with relapsed or refractory LBCL with ≥ 2 prior systemic therapies. In the 2-y follow-up of ZUMA-1, the objective response rate (ORR) was 83% with a complete response (CR) rate of 58%, and 39% of pts were in ongoing response (Locke et al. Lancet Oncol. 2019). Here we report efficacy and safety outcomes by age. Methods: Eligible pts with refractory LBCL underwent leukapheresis and conditioning chemotherapy followed by a target dose of 2 × 106 anti-CD19 CAR T cells/kg. The Phase 2 primary endpoint was investigator-assessed ORR. Additional key endpoints were adverse events (AEs), overall survival (OS), and levels of CAR gene-marked cells in peripheral blood. Efficacy was evaluated for Phase 2 pts; safety was evaluated for all treated pts (Phases 1 and 2). Pts were analyzed by ≥ 65 y vs < 65 y of age. Results: As of 8/11/2018, 108 pts were treated. Pts ≥ 65 y (n = 27) vs < 65 y (n = 81) had a median age of 69 y vs 55 y, respectively, were 81% vs 63% male, 70% vs 36% had an IPI score 3-4, 59% vs 57% had ECOG 1, 67% vs 72% had ≥ 3 prior therapies, and median tumor burdens were 3790 mm2 vs 3574 mm2. Median follow-up was 27.1 mo for Phase 2 pts (n = 101). The ORR for pts ≥ 65 y (n = 24) and < 65 y (n = 77) was 92% and 81% (CR rate 75% and 53%), respectively, with ongoing responses in 42% and 38% of pts (ongoing CR 42% and 35%). The 24-mo OS rate was 54% for pts ≥ 65 y and 49% for pts < 65 y. Most pts experienced Grade ≥ 3 AEs (100% of pts ≥ 65 y; 98% of pts < 65 y), and 4% of each group (1/27 pts ≥ 65 y and 3/81 pts < 65 y) died due to AEs as previously reported. Grade ≥ 3 neurologic events and cytokine release syndrome occurred in 44% vs 28% and 7% vs 12% of pts ≥ 65 y vs < 65 y, respectively. CAR T cell expansion by peak level (43 vs 35 cells/μl) or area under the curve (562 vs 448 d × cells/μl) was similar in pts ≥ 65 y vs < 65 y, respectively. Conclusions: The 2-y follow-up of ZUMA-1 demonstrates that axi-cel can induce high rates of durable responses with a manageable safety profile for pts ≥ and < 65 y. Axi-cel offers substantial clinical benefit for older pts with refractory LBCL who otherwise have limited treatment options. Clinical trial information: NCT02348216.