Long-term safety and efficacy of the fully human CAR-T therapy CT103A in relapsed/refractory multiple myeloma.

CT103A is a fully human chimeric antigen receptor T cell (CAR-T) product for targeting B cell maturation antigen. This study presents the updated safety and efficacy profiles of CT103A in patients with relapsed/refractory multiple myeloma (RRMM) after long-term follow-up. As of July 31, 2023, the median follow-up time after CAR-T cell infusion was 45.0 months (range, 0.7-58.3 months). During long-term follow-up, the incidence of adverse events gradually decreased over time. One patient had a maximum duration of response of nearly 5 years. All 18 patients (100%) achieved partial remission or better; 77.8% (14 of 18) of patients eventually exhibited complete response or stringent complete response (sCR), with response increasing over time. At the time of data cutoff, nine patients were still alive and seven patients had an sCR status with negative minimal residual disease. The median progression-free survival was 22.6 months, and the median overall survival was 50.2 months for all 18 patients. The median CAR transgene persistence was 14.0 months (range, 0.7-57.3 months). Long-term follow-up demonstrated that CT103A confers durable clinical benefit for RRMM patients based on the sustained presence of fully human CAR-T cells.