Development and manufacturing of novel locally produced anti-BCMA CAR-T cells for the treatment of relapsed/refractory multiple myeloma: phase I clinical results

Abstract

Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T cell (CAR-T) therapy shows remarkable efficacy in patients with relapsed and/or refractory (R/R) multiple myeloma (MM). HBI0101, a novel second generation optimized anti-BCMA CAR-T cell therapy, was developed in an academic setting. We conducted a phase I dose-escalation study of HBI0101 (cohort 1, 150x10^6 CAR-T cells, N=6; cohort 2; 450x10^6 CAR-T cells, N=7 and cohort 3, 800x10^6 CAR-T cells, N=7) (NCT04720313) in 20 heavily pretreated R/R MM patients. Grade 1-2 cytokine release syndrome (CRS) was reported in 18 patients (90%). Neither grade 3-4 CRS, nor neurotoxicity of any grade were observed. No dose-limiting toxicities (DLTs) were observed in any cohort. The overall response rate (ORR), (stringent) complete response (CR/sCR) and very good partial response (VGPR) rates were 75%, 50% and 25%, respectively. Response rates were dose-dependent with 85% ORR, 71% CR and 57% minimal residual disease (MRD) negativity in the high-dose cohort 3. For the entire cohort, the median overall survival (OS) was 308 days (range, 25-466+), with an estimated OS of 55% as of data cutoff June 27th. The median progression-free survival (PFS) was 160 days, with 6 subjects remaining progression free at the time of data cutoff. Our findings demonstrate the manageable safety profile and efficacy of HBI0101. These favorable data are encouraging and support decentralization of CAR-T production at an academic setting, ensuring a sufficient CAR-T supply in the light of the increasing local demand.