Pfizer and Sangamo's AFFINE Study Shows Positive Phase 3 Results for Hemophilia A Gene Therapy

Jul 24, 2024, 11:02 AM

Pfizer has announced positive topline results from its Phase 3 study of a gene therapy candidate for Hemophilia A. The gene therapy, developed in collaboration with Sangamo Therapeutics, met its primary and key secondary objectives in the pivotal AFFINE study. This included a statistically significant reduction in annualized bleeding rates (ABR) from week 12 to month 15 post-infusion compared to routine factor VIII prophylaxis, with a reduction from 4.73 to 1.24 (p=0.0040). Despite these promising results, questions remain about the long-term durability and commercial viability of the therapy. Additionally, 84% of patients achieved more than 5% of normal factor VIII levels, although critical details about the use of immunosuppressants were not provided. Pfizer's gene therapy aims to offer a new treatment option for adults with moderately severe to severe Hemophilia A. Cash from Pfizer, however, is unlikely for another few months.