Off-the-Shelf CAR-T Therapy P-BCMA-ALLO1 Shows Strong Activity in R/R Myeloma
The overall response rate to P-BCMA-ALLO1 was 88% among 32 patients, including 100% in patients who had no prior BCMA-targeted therapy and 75% in patients who had received at least 1 prior anti-BCMA treatment. Among 9 patients who had received prior BCMA-targeted and GPRC5D-targeted therapy (talquetamab [Talvey]), the ORR was 78%.
Safety results showed that 42% of patients experienced grade 1/2 cytokine release syndrome (CRS), with a median time to onset of 8 days (range, 2-12), and median time to CRS resolution of 11 days (range, 4-39). There were cases of grade 3 or higher CRS reported. Grade 1/2 immune effector cell–associated neurotoxicity syndrome (ICANS) occurred in 14% of patients, with a median time to onset of 4 days (range, 3-9), and a median time to resolution of 7 days (range, 3-10). There were no grade 3 or higher cases of ICANS reported.
Half of patients had grade 1/2 infection and 5 patients had grade 3 or higher infection. There was no graft-versus-host disease observed at any study dose. Five patients experienced neurotoxicity, which was all grade 1, and there were no cases of Parkinsonism or neuropathies.
The most common grade 3 or higher treatment-related adverse events included neutropenia (50%), leukopenia (44%), thrombocytopenia (36%), and anemia (39%).
There was 1 patient death on day 6 of the trial due to complications from infection, which was determined to be related to lymphodepletion not to P-BCMA-ALLO1.