Marstacimab Therapy for Hemophilia Shows Long-term Efficacy and Safety

A recent study demonstrated significant efficacy and safety of monoclonal antibody Marstacimab in the long-term management of severe hemophilia A (HA) or hemophilia B (HB) without inhibitors. This outcomes from the pivotal Phase 3 BASIS study could revolutionize the approach to treat bleeding disorders. The findings were published in American Society of Hematology.

Marstacimab enhances hemostasis through the extrinsic pathway of blood coagulation and already has shown promise in previous studies. Early Phase 1/2 trials indicated its effectiveness and safety in reducing bleeding episodes in adults with severe hemophilia A or B.

The study enrolled male participants aged 12 to 75 with severe HA or moderately severe to severe HB, with or without inhibitors. After a 6-month observational phase, participants were grouped into on-demand (OD) or routine prophylaxis (RP). The active treatment phase involved a subcutaneous loading dose of 300 mg followed by once-weekly 150 mg marstacimab.

The results involved 128 participants who showed impressive outcomes. The annualized bleeding rate (ABR) for treated bleeds significantly reduced for both OD and RP groups, with marstacimab demonstrating superiority over OD and RP therapy. Safety analyses revealed a favorable profile with less incidence of adverse events and no treatment-related serious adverse events recorded.

As a step forward, this study found that subcutaneous marstacimab given once-weekly is not only safe but also highly effective to reduce bleeding events for participants with severe HA or moderately severe to severe HB without inhibitors. The positive results persisted beyond the 12-month active treatment phase, providing hope for a paradigm shift in hemophilia management.

This highlights marstacimab as a potential game-changer for hemophilia treatment, offering hope to those suffering from challenging bleeding disorders. As the study participants move into the long-term extension (LTE) phase, the expectation is high for continued positive outcomes that could redefine hemophilia care.

Source:

Matino, D., Acharya, S., Palladino, A., Hwang, E., McDonald, R., Taylor, C. T., & Teeter, J. (2023). Efficacy and Safety of the Anti-Tissue Factor Pathway Inhibitor Marstacimab in Participants with Severe Hemophilia without Inhibitors: Results from the Phase 3 Basis Trial. In Blood (Vol. 142, Issue Supplement 1, pp. 285–285). American Society of Hematology. https://doi.org/10.1182/blood-2023-181263