Phase 1 trial of GPRC5D-targeted CAR T cells for relapsed or refractory multiple myeloma
CAR T-cell therapy targeting BCMA has shown activity for relapsed or refractory multiple myeloma (RRMM); however, relapse in common and new targets are needed. The phase 1 POLARIS trial at Zhejiang University (Hangzhou, China) evaluated G protein coupled receptor class C group 5 member D (GPRC5D)-targeted CAR T cell therapy (OriCAR-017) for RRMM, after at least three previous lines of therapy. There were no dose-limiting toxic effects in the escalation phase (maximum dose 6 x 106 CAR T cells per kg). In the expansion phase, with 3 x 106 CAR T cells per kg, six of ten patients had a stringent complete response and four of ten patients had very good partial response. The authors conclude that GPRC5D is an active target for immunotherapy in multiple myeloma, and that GPRC5D-targeted CAR T-cell therapy is a promising treatment modality in patients with RRMM.