New Roche/Poseida project isn’t P-BCMACD19-ALLO1

Roche’s selection of a new Car-T construct under its deal with Poseida, triggering a $15m milestone payment to the junior partner, will naturally prompt speculation about what the new project targets. All Poseida has revealed is that the new candidate is an allogeneic Car against two “known antigens” expressed in blood cancers including multiple myeloma. What might have passed unnoticed, however, is that last month Roche gave up on a disclosed project that fits this bill, namely P-BCMACD19-ALLO1, which hits BCMA and CD19. News that Roche had declined to extend its 2022 deal to opt into P-BCMACD19-ALLO1 was slipped quietly into the end of a 27 September SEC filing. It’s possible that the new asset hits BCMA and GPRC5D, for instance, or some more novel antigens, and Roche still retains the right to opt into an anti-CD70 Car. Clinical work under the deal focuses on P-CD19CD20-ALLO1 and P-BCMA-ALLO1, the latter of which yielded confounding multiple myeloma data at ASH 2023; the dataset now stands at 72 patients, with an all-comers ORR of 54%, and the focus is now on dose optimisation with a preferred lymphodepletion regimen of cyclophosphamide 750mg/m²/day.

The Roche/Poseida collaboration

Source: OncologyPipeline.