Bristol Myers Squibb and Johnson & Johnson halted a Phase 3 trial of their factor‑XIa inhibitor milvexian for acute coronary syndrome after an interim analysis showed the drug was unlikely to meet the primary endpoint. The futility stop was disclosed by the sponsors and marks a setback for the next‑generation anticoagulant class. Milvexian had been tested across multiple Phase 3 programs in hopes of delivering safer anticoagulation with reduced bleeding. The trial closure clouds prospects for other factor‑XI programs and could reshape investor expectations for the class. Developers pursuing safer anticoagulants will now need to re‑examine trial designs, indication selection, and biomarker strategies to demonstrate clinical benefit.