The U.S. Food and Drug Administration (FDA) has granted approval to Pfizer's Hympavzi, a once-weekly injection designed to treat hemophilia A and B, a rare genetic bleeding disorder. This approval marks a significant milestone in the treatment of hemophilia, offering a new option for patients aged 12 and older who do not have inhibitors to factor VIII or IX. Hympavzi, also known as marstacimab-hncq, is the first anti-tissue factor pathway inhibitor (anti-TFPI) approved in the United States for hemophilia and is administered via a pre-filled auto-injector pen.

Hemophilia is a condition that affects the blood's ability to clot, leading to excessive bleeding following injuries or surgery. It primarily affects men, with an estimated 33,000 cases in the United States. The disorder is caused by a deficiency in clotting factors, specifically factor VIII in hemophilia A and factor IX in hemophilia B. Hympavzi aims to reduce the frequency of bleeding episodes, providing a more convenient alternative to the traditional intravenous infusions that many patients currently rely on.

The approval of Hympavzi was based on the results of the phase 3 BASIS trial, which demonstrated a significant reduction in annualized bleeding rates for patients treated with the drug. The trial included 116 patients and showed a 92% reduction in bleeding episodes after 12 months of treatment compared to standard care. The drug's safety profile was manageable, with common side effects including injection site reactions, headaches, and itchiness.

Pfizer's Hympavzi is expected to reach sales of $300 million by 2030, according to estimates compiled by LSEG. This approval is Pfizer's second hemophilia treatment to receive FDA approval this year, following the approval of its hemophilia B gene therapy, Beqvez, in April. The introduction of Hympavzi is seen as a significant advancement in the treatment of hemophilia, providing patients with a new, less burdensome treatment option.

Suchitra Acharya, director of the bleeding disorders program at Cohen Children's Medical Center, highlighted the importance of this new treatment, stating that it meets a critical need for patients who have required frequent, time-consuming intravenous treatments. The approval of Hympavzi underscores the FDA's commitment to advancing innovative therapies that improve the quality of life for patients with rare disorders.