The US Food and Drug Administration (FDA) has approved the use of Hympavzi, a monoclonal antibody drug called marstacimab, for routine bleeding prevention in patients with hemophilia A and B over the age of 12. Unlike the standard approach of replacing the missing clotting factor, marstacimab reduces the amount and activity of an anticoagulant protein called tissue factor inhibitor. This increases the amount of thrombin produced, an enzyme that plays an important role in blood clotting. The news of the approval is posted on the agency’s website.
The approval of Himpavzi is based on the results of an open-label, multicenter study involving 116 patients with severe hemophilia A or severe hemophilia B. The results showed that the annual bleeding rate was nearly 35 percent lower in the prophylaxis group than in the control group. The most common side effects of the drug were injection site reactions, headache, and itching.