Update of a phase 1 trial of GPRC5D-targeted CAR T-cell therapy MCARH109 for relapsed or refractory multiple myeloma

A phase 1 trial at Memorial Sloan Kettering Cancer Center (New York, NY) evaluated the GPRC5D-targeted CAR T-cell therapy MCARH109 among patients with relapsed or refractory multiple myeloma (RRMM). A publication in 2022 reported safety and activity of the therapy. Updated results of the trial with median follow-up of 37 months have now been published. Overall, 12 of 17 patients (71%) responded, including 7 of 10 patients (70%) previously treated with BCMA-targeted therapy. The median duration of response was 8.6 months (95% CI 5.7-NR), with two patients sustaining a stringent complete respons at the time of last follow-up, 32 months and 41 months, respectively. The median overall survival was not reached, with a 3-year OS estimate of 59% (95% CI 40-88). Possible GPRC5D loss was observed in 6 of 10 patients at relapse. The authors conclude that MCARH109 demonstrated durable activity among RRMM patients.