Poseida Therapeutics’ P-BCMA-101 shows efficacy in published case study

Poseida Therapeutics highlighted new data from a case study of a patient with relapsed multiple myeloma treated in a clinical trial of P-BCMA-101, the company’s original investigational T stem cell memory-rich BCMA targeting autologous CAR-T cell therapy. “This case study demonstrates the remarkable potential of T stem cell memory-based therapies, providing a strong anti-myeloma response with a long-term remission and notably CAR-T cell persistence,” said Thomas Martin, Clinical Professor of Medicine, Adult Leukemia and Bone Marrow Transplantation Program and Director of Hematology, Blood and Marrow Transplantation and Cellular Therapy at UCSF. “Most notably, we believe this is the first time that a T-cell engager has been seen to reactivate a CAR-T therapy, and the evidence suggests that this reactivation drove a second wave of CAR-T cell proliferation that led to another complete response three years after the initial successful CAR-T treatment. This patient is now off all anti-myeloma treatments and living in remission for more than nine months following 1 week of TCE therapy, a truly amazing outcome.” Two months after receiving treatment, the patient achieved a partial response that deepened into a stringent complete response and remained in remission for nearly 2 years. More than three years after receiving P-BCMA-101, she relapsed and was treated. The patient achieved complete remission with slow resolution of lymphocytosis. The patient continues to be in sCR and off all therapy more than nine months after receiving the last and only full dose of the T-cell engaging therapy. Poseida’s lead investigational allogeneic CAR-T program, P-BCMA-ALLO1, is currently being evaluated in patients with relapsed/refractory multiple myeloma. Additional P-BCMA-ALLO1 clinical updates are planned for the second half of 2024.