Marstacimab: First Approval.

Marstacimab (marstacimab-hncq; HYMPAVZI™) is a subcutaneously administered human monoclonal immunoglobulin G1 antibody against tissue factor pathway inhibitor (TFPI) that is being developed by Pfizer for the treatment of hemophilia A and B. Marstacimab received its first approval on 11 October 2024 in the USA. It was approved for use as routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia A without factor VIII inhibitors or hemophilia B without factor IX inhibitors. Marstacimab has since been approved on 18 Nov in the EU for the treatment of adults and adolescents with severe hemophilia A or B without inhibitors. This article summarizes the milestones in the development of marstacimab leading to this first approval for hemophilia.