Pfizer reports positive Phase 3 results for hemophilia treatment HYMPAVZI
A Phase 3 study shows that once-weekly HYMPAVZI significantly reduces bleeding rates in patients with hemophilia A or B who have developed inhibitors.
Pfizer’s Phase 3 BASIS study has met its primary endpoints for HYMPAVZI (marstacimab), a potential treatment for adolescents and adults with hemophilia A or B who have developed inhibitors. These antibodies often neutralize standard factor replacement therapies, leaving patients with limited clinical options.
The study compared once-weekly subcutaneous administration of the drug against on-demand care. Results indicated a 93% reduction in the annualized bleeding rate (ABR) for those receiving the prophylactic treatment. Furthermore, the trial met all secondary bleeding endpoints, including reductions in spontaneous and target joint bleeds, with a safety profile described as generally well-tolerated.
Unlike traditional therapies that replace missing clotting factors, HYMPAVZI targets the tissue factor pathway inhibitor (TFPI) to rebalance blood clotting mechanisms. Pfizer intends to present the full dataset at upcoming medical conferences and engage with regulatory authorities to discuss potential market authorization.