Phase 2 study of relmacabtagene autoleucel (CD19 CAR-T) for relapsed/refractory mantle cell lymphoma in Chinese adults

Abstract

Relmacabtagene autoleucel (relma-cel), an anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy, is approved in China for relapsed/refractory (R/R) large B-cell lymphoma and follicular lymphoma. This phase 2, open-label, single-arm, multicenter study evaluated its efficacy and safety in Chinese patients with heavily pretreated R/R mantle cell lymphoma (MCL). A total of 70 patients with R/R MCL who had received 1 to 9 previous therapies (including anthracycline or bendamustine chemotherapy, anti-CD20 antibodies, and Bruton tyrosine kinase [BTK] inhibitors) were enrolled. Of these, 59 received a single infusion of 100 × 106 CAR-positive T cells following leukapheresis. The primary end point was the objective response rate (ORR) at 3 months after infusion, assessed using the Lugano 2014 criteria. Secondary end points included the duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. At 3 months, the ORR was 71.19% (95% confidence interval [CI], 57.92-82.24) with a complete response rate of 59.32% (95% CI, 45.75-71.93). After a median follow-up of 13.3 months (95% CI, 9.04-18.69), the median DOR was 18.1 months, PFS was 15.5 months, and OS was 19.5 months. Grade 3 or higher treatment-emergent adverse events were common, including neutropenia (76.3%), leukopenia (69.5%), and lymphopenia (47.5%). Severe cytokine release syndrome and neurotoxicity occurred in 6.8% of patients each, and all cases resolved fully. No fatal events were reported. These findings demonstrate that relma-cel offers high response rates, durable remissions, and manageable safety in Chinese patients with R/R MCL. This trial was registered at www.clinicaltrials.gov as #NCT04718883.