Poseida Therapeutics says the lead allogeneic chimeric antigen receptor T-cell (CAR-T) candidate it is co-developing with Roche through an up-to-$6.2 billion-plus collaboration will advance to Phase Ib after generating positive interim clinical data in the Phase I portion of an early-stage trial in patients with relapsed/refractory multiple myeloma (RRMM). That lead candidate, P-BCMA-ALLO1, is an off-the-shelf, B-cell maturation antigen (BCMA)-targeted allogeneic, T stem cell memory (T )-rich CAR-T therapy.
P-BCMA-ALLO1 showed a 91% overall response rate (ORR) and safety results the companies termed “compelling” among 23 heavily pretreated patients in the optimized lymphodepletion arm, called “Arm C,” of the trial’s Phase I portion. The ORR rose to 100% in B-cell maturation antigen (BCMA)-naïve patients, but was 86% in patients who had received at least one prior BCMA-targeting treatment (all had received prior CAR-T and/or T-cell engagers [TCE]), and 86% in patients who had received at least one prior BCMA-targeting treatment and/or talquetamab. Researchers for Poseida, Roche and clinical partners presented their clinical data on Friday at the 21st International Myeloma Society (IMS) Annual Meeting, held September 25–28 in Rio de Janeiro.
The data came from the Phase I portion of an ongoing open-label, multicenter Phase I/Ib dose-escalation and expansion trial ( ) in patients with RRMM. The trial’s primary objectives are assessing the safety and maximum toler.
