Befovacimab (formerly BAY 1093884) is a fully human monoclonal antibody of the IgG2 isotype. It was developed as a non-replacement prophylactic therapy for individuals with hemophilia A or B, with or without inhibitors. Its mechanism is to act as an antagonist by binding to and inhibiting its target, thereby rebalancing the coagulation cascade to promote clot formation. By restoring thrombin generation, the antibody aims to reduce the frequency of bleeding episodes. The development of Befovacimab was prematurely terminated during a Phase 2 study due to the occurrence of drug-related thrombotic serious adverse events (clotting events), raising concerns about the predictability of thrombosis with anti-TFPI treatment.