Phase 1 trial of the anti-GPRC5D CAR T-cell therapy RD118 for relapsed or refractory multiple myeloma

A phase 1 trial at the Institute of Hematology of Shanghai Jiao Tong University (China) evaluated the GPRC5D-directed CAR T-cell therapy RD118 for relapsed or refractory multiple myeloma (MM, n=17) or primary plasma cell leukemia (pPCL; n=1). At a median follow-up of 17.0 months, the overall response rate was 94.4%, including 72.2% complete or stringent complete response. Among seven patients previously exposed to BCMA-directed CAR T-cell therapy, ORR reached 85.7%. Median progression-free survival was 18.2 months, with 12-months PFS and overall survival rates of 82.1% and 93.3%, respectively. Cytokine release syndrome occurred in 88.9% of patients, primarily grade 1 or 2. One patient developed grade 3 immune effector cell associated neurotoxicity, which resolved within 72 hours. The authors conclude that RD118 is a highly effective and safe option for heavily pretreated RRMM.