Abstract: PS1066

Type: Poster Presentation

Presentation during EHA24: On Saturday, June 15, 2019 from 17:30 - 19:00

Location: Poster area

Background
Axi-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved in the European Union and United States for the treatment of patients with relapsed or refractory large B cell lymphoma with ≥ 2 prior systemic therapies. In the 2-year follow-up of ZUMA-1, the objective response rate was 83%, with a complete response rate of 58%, and 39% of patients were in ongoing response (Locke et al. Lancet Oncol. 2019). 

Aims
To assess efficacy and safety outcomes of axi-cel in patients ≥ or < 65 years of age from ZUMA-1.

Methods
Eligible patients with refractory large B cell lymphoma 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 objective response rate. Additional key endpoints were adverse events, overall survival, and levels of CAR gene-marked cells in peripheral blood. Efficacy was evaluated for Phase 2 patients; safety was evaluated for all treated patients (Phases 1 and 2). Patients were analyzed by age ≥ 65 years vs < 65 years.

Results
As of August 11, 2018, 108 patients were treated. Patients ≥ 65 years (n = 27) vs < 65 years (n = 81) had a median age of 69 years vs 55 years, respectively, and were 81% vs 63% male; 70% vs 36% had an International Prognostic Index score of 3-4, 59% vs 57% had an Eastern Cooperative Oncology Group performance status of 1, 67% vs 72% had ≥ 3 prior therapies, and median tumor burdens were 3790 mm² vs 3574 mm². Median follow-up was 27.1 months for Phase 2 patients (n = 101). The objective response rate for patients ≥ 65 years (n = 24) and < 65 years (n = 77) was 92% and 81% (complete response rate, 75% and 53%), respectively, with ongoing responses in 42% and 38% of patients (ongoing complete response, 42% and 35%). The 24-month overall survival rate was 54% for patients ≥ 65 years and 49% for patients < 65 years. Most patients experienced Grade ≥ 3 adverse events (100% of patients ≥ 65 years; 98% of patients < 65 years), and 4% of each group (1/27 patients ≥ 65 years and 3/81 patients < 65 years) died due to adverse events as previously reported. Grade ≥ 3 neurologic events and cytokine release syndrome occurred in 44% vs 28% and 7% vs 12% of patients ≥ 65 years vs < 65 years, respectively. CAR T cell expansion by peak level (43 vs 35 cells/μL) or area under the curve (562 vs 448 days × cells/μL) was similar in patients ≥ 65 years vs < 65 years, respectively. 

Conclusion
The 2-year follow-up of ZUMA-1 demonstrates that axi-cel can induce high rates of durable responses with a manageable safety profile for patients ≥ and < 65 years. Axi-cel offers substantial clinical benefit for older patients with refractory large B cell lymphoma who otherwise have limited treatment options.

Session topic: 19. Aggressive Non-Hodgkin lymphoma - Clinical

Keyword(s): Cancer immunotherapy, CD19, Non-Hodgkin's lymphoma