Milvexian LIBREXIA ACS Phase 3 Trial Fails to Reduce Cardiovascular Events After Recent Acute Coronary Syndrome; Bristol Myers Squibb-Janssen Program Setback
The Factor XIa inhibitor milvexian (an oral small-molecule antithrombotic co-developed by Bristol Myers Squibb (NYSE: BMY) and Janssen) failed to reduce major adverse cardiovascular events versus placebo when added to standard antiplatelet therapy after recent acute coronary syndrome (ACS) in the Phase 3 LIBREXIA ACS trial presented in a Hot Line Session at ESC Congress 2026 Saturday August 29. The primary endpoint (cardiovascular death, myocardial infarction, or ischemic stroke) occurred in 5.4% of the milvexian arm versus 5.1% on placebo. Researchers observed no differences in intracranial or fatal bleeding between arms, addressing safety concerns that have historically constrained anticoagulant use in the post-ACS setting. The LIBREXIA program continues to assess milvexian in stroke and atrial fibrillation. The Factor XIa class as a whole (also including Bayer-Janssen's asundexian and Anthos Therapeutics' abelacimab) has struggled to demonstrate clean cardiovascular benefit at low bleeding cost.