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Getting the latest healthcare news for you
A promising new anticoagulant came up short in a major heart trial. The phase 3 LIBREXIA ACS trial found that milvexian, a factor XIa inhibitor, did not reduce cardiovascular events in patients after acute coronary syndrome compared to placebo. The trial was stopped early for futility, though notably, the drug also didn't increase major bleeding — keeping the door open for future research.
A new anticoagulant approach didn't deliver the hoped-for results in one of cardiology's most anticipated trials. The phase 3 LIBREXIA ACS trial tested milvexian — an investigational factor XIa inhibitor — on top of standard antiplatelet therapy in over 14,000 patients following acute coronary syndrome (ACS). The trial was halted early in November 2025 after a prespecified interim analysis deemed it unlikely to meet its primary endpoint. Final results, presented at ESC Congress 2026 and published in the New England Journal of Medicine, confirmed no meaningful benefit.
Researchers had hoped factor XIa inhibition could reduce thrombosis without the bleeding risks tied to conventional anticoagulants. Despite lab evidence confirming the drug was biologically active, it failed to translate into clinical benefit — possibly because most patients were already on intensive dual antiplatelet therapy (DAPT) with potent P2Y12 inhibitors, leaving little room for added protection.
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Why it matters: While milvexian missed the mark in ACS, its clean safety profile keeps the factor XIa inhibition concept alive. Two ongoing trials — LIBREXIA AF (using a higher 100 mg twice-daily dose) and LIBREXIA Stroke — may yet reveal where this drug class can shine.
