Affine Formulations Ltd.

Pfizer has shared positive top-line results from a late-stage study of its investigational haemophilia A gene therapy in adults with moderately severe-to-severe cases of the rare bleeding disorder. Occurring in approximately 25 in every 100,000 male births globally, haemophilia A is an inherited condition resulting from insufficient levels of functioning factor VIII, a protein that is essential for blood clotting. Giroctocogene fitelparvovec, which is being developed as part of a collaboration agreement between Pfizer and Sangamo Therapeutics, is designed to enable patients to produce factor VIII themselves for an extended period of time following a single intravenous (IV) infusion. The phase 3 AFFINE study of the candidate met its primary objective of non-inferiority, as well as superiority, of the total annualised bleeding rate from week 12 to at least 15 months of follow-up post-infusion compared with routine factor VIII replacement prophylaxis treatment. Key secondary endpoints were also achieved, including 84% of patients maintaining factor VIII activity of more than 5% at 15 months post-infusion and the majority having factor VIII activity of at least 15%. The therapy was found to be generally well tolerated, with 13 serious treatment-related adverse events reported by ten patients that “generally resolved” in response to clinical management, Pfizer said. AFFINE lead investigator professor Andrew Leavitt, University of California, said the results “demonstrate the transformative potential of [the] gene therapy candidate to provide superior bleed protection compared with routine factor VIII prophylaxis, while helping relieve the treatment burden for people living with haemophilia A”. James Rusnak, senior vice president, chief development officer, internal medicine and infectious diseases, research and development, Pfizer, added that the company looks forward to advancing the candidate “to help address the medical and treatment burden associated with frequent and time-consuming IV infusions or injections”. Giroctocogene fitelparvovec has already been granted fast track and regenerative medicine advanced therapy designations from the US Food and Drug Administration (FDA), as well as orphan drug designations in the US and the EU. The readout comes three months after Pfizer’s haemophilia B gene therapy Beqvez (fidanacogene elaparvovec-dzkt) received approval from the FDA to treat adults with moderate-to-severe cases of the condition.