Clinical-stage allogeneic cell therapy and genetic medicines company Poseida Therapeutics, Inc. (Nasdaq: PSTX) announced on Friday new interim data from its ongoing Phase 1 trial of P-BCMA-ALLO1 for relapsed/refractory multiple myeloma.

P-BCMA-ALLO1 is an investigational non-viral, allogeneic CAR-T cell therapy developed in collaboration with Roche, targeting blood cancers using Poseida's TSCM-rich platform.

Results from Arm C, with 23 heavily pretreated patients, showed a 91% overall response rate (ORR) and favourable safety outcomes. Nearly 50% of Arm C patients were over 65 and 62% had prior BCMA-targeting therapy. Arm C demonstrated no dose-limiting toxicities, no Grade 3 or higher cytokine release syndrome (CRS) and no immune effector cell neurotoxicity syndrome (ICANS).

The trial continues to enrol patients using Arm C's lymphodepletion regimen.