WASHINGTON, USA – The US Food and Drug Administration has approved Hympavzi (marstacimab-hncq) for the routine prophylaxis of bleeding episodes in adult and pediatric patients aged 12 years and older with hemophilia A without factor VIII inhibitors or hemophilia B without factor IX inhibitors.
This groundbreaking approval introduces a novel treatment aimed at enhancing blood clotting processes. “The approval of Hympavzi signifies the availability of a new treatment alternative for hemophilia patients, as it uniquely targets a protein involved in the blood clotting mechanism,” stated a representative from the FDA’s Non-Malignant Hematology division, emphasizing the agency’s dedication to fostering the development of innovative and effective therapies.
Hemophilia A and B are hereditary bleeding disorders characterized by insufficient clotting factors—factor VIII (FVIII) for hemophilia A and factor IX (FIX) for hemophilia B. Individuals with these conditions often experience prolonged bleeding after injuries or surgeries and may encounter spontaneous bleeding episodes in muscles, joints, and organs, presenting serious health risks. Traditional treatments typically involve on-demand or prophylactic administration of FVIII or FIX products.
Hympavzi represents a new approach by reducing the activity of the naturally occurring anticoagulant, tissue factor pathway inhibitor, thereby increasing thrombin production, which is crucial for effective blood clotting. This mechanism aims to decrease the frequency of bleeding incidents among patients.
Clinical approval is based on an open-label, multi-center study involving 116 male patients with severe hemophilia A or B, all without inhibitors. Initially, patients received traditional factor replacement therapy for six months—either on-demand or prophylactically—followed by a 12-month treatment period with Hympavzi.
The efficacy of Hympavzi was primarily measured by annualized bleeding rates. Results showed a significant reduction in bleeding rates among patients who transitioned from on-demand treatment (an estimated 38 events) to Hympavzi, which recorded only 3.2 bleeding episodes annually. Similarly, those receiving prophylactic factor replacement experienced a decrease from an estimated 7.85 bleeds to 5.08 while on Hympavzi.
While Hympavzi presents a promising treatment, it comes with warnings regarding the risk of thromboembolic events, hypersensitivity reactions, and potential embryofetal toxicity. Common side effects include injection site reactions, headaches, and itching.
Hympavzi has received Orphan Drug designation from the FDA, reflecting its significance as a treatment for rare conditions. The approval of Hympavzi supports ongoing efforts to improve therapy options for those affected by hemophilia.
