Overview
- The FDA expanded marstacimab-hncq (Hympavzi) Monday to permit routine prophylaxis for all patients aged 6 years and older with hemophilia A or B, including those with inhibitors.
- The approval makes Hympavzi the first subcutaneous nonfactor prophylaxis available for children 6 to 11 years with hemophilia B, opening a new pediatric treatment option.
- The expansion rests on Phase 3 BASIS adult/adolescent results and interim BASIS KIDS data that showed large reductions in mean treated annualized bleeding rates compared with historical or on-demand comparators.
- Hympavzi is given once weekly by auto-injector without routine lab monitoring, and trials reported mostly mild side effects such as injection-site reactions and headache while noting two thromboembolic events among 259 participants.
- Clinicians and Pfizer say the approval could cut caregiver and patient burden by replacing frequent intravenous infusions, and regulators and doctors will monitor safety and real-world access as use widens.