FDA, EMA Regulatory Decisions on Marstacimab Expected Late 2024, Early 2025

The US Food and Drug Administration (FDA) biologics license application and the European Medicines Agency (EMA) Marketing Authorization application were accepted and passed validation, respectively, for marstacimab, an anti-tissue factor pathway inhibitor (anti-TFPI) for hemophilia A or B without inhibitors against factor (F)VIII or FIX developed by Pfizer.

“Marstacimab has demonstrated that it may be an efficacious treatment option with once-weekly, subcutaneous flat-dose administration via an auto-injector pen, for appropriate patients, if approved,” stated James Rusnak, MD, PhD, the Senior Vice President and Chief Development Officer of Internal Medicine and Infectious Diseases Research and Development at Pfizer.

The FDA has set a Prescription Drug User Fee Act action date in the fourth quarter of 2024, and the European Commission is expected to reach a decision in the first quarter of 2025. Marstacimab is expected to be the first treatment with once-weekly subcutaneous administered as a flat dose for patients with hemophilia A or B. “This is critical as intravenous infusions are typically required for people living with these diseases today,” Dr. Rusnak suggested.

The applications for marstacimab are based on data from the phase III BASIS trial after key findings were presented at the 65th American Society of Hematology Annual Meeting & Exposition in San Diego, California. The primary outcome of BASIS was annual bleed rate over 12 months of treatment.

BASIS data on patients with inhibitors is expected to be published “as early as late 2024,” and marstacimab is also being evaluated for pediatric patients in the open-label BASIS KIDS trial, according to Pfizer.