US FDA Approved Pfizer's Hympavzi for hemophilia A or B, who do not have inhibitors | FDA Approved | iPharmaCenter

The U.S. Food and Drug Administration (FDA) has approved Pfizer's Hympavzi (marstacimab) for the treatment of adults and adolescents aged 12 years and older with hemophilia A or B, who do not have inhibitors.

This is a groundbreaking development as Hympavzi is the first once-weekly, subcutaneous prophylactic treatment available in the U.S. for individuals with hemophilia B, and it can also be administered via a pre-filled auto-injector pen or syringe for those with hemophilia A or B.

Hympavzi’s approval is supported by findings from the Phase 3 BASIS clinical trial, which demonstrated significant reductions in bleeding episodes compared to standard prophylactic care and on-demand treatments.

Specifically, the trial showed that Hympavzi reduced the annualized bleeding rate (ABR) by 35% compared to routine prophylaxis and by 92% compared to on-demand treatments in hemophilia A and B patients without inhibitors.

The drug offers a new option that simplifies management for people who are used to frequent intravenous infusions.

Hemophilia is a rare genetic disorder characterized by the body’s inability to properly form blood clots due to deficiencies in clotting factors—Factor VIII in hemophilia A and Factor IX in hemophilia B. Patients with this condition often face spontaneous bleeding, particularly into joints, which can cause lasting damage. Hympavzi, a tissue factor pathway inhibitor (TFPI) blocker, works by targeting a specific part of the TFPI protein, restoring balance to the clotting process and reducing the risk of bleeds.

The FDA's approval was based on the BASIS study, which involved 116 patients and compared the efficacy and safety of Hympavzi to standard treatment. Participants received a 300 mg initial loading dose followed by 150 mg weekly subcutaneous injections, with potential dose increases to 300 mg weekly. The trial results demonstrated superiority of Hympavzi over on-demand treatments in reducing spontaneous and joint bleeds, with a generally favorable safety profile. Common side effects included injection site reactions, headaches, and itching (pruritus).

This new treatment offers a promising and more convenient therapeutic option for individuals living with hemophilia, enabling them to manage their condition with less frequent and easier-to-administer doses.