METHODS: In this phase 3, randomized, placebo-controlled trial, we evaluated the efficacy and safety of milvexian when added to standard antiplatelet therapy within 7 days after an acute coronary syndrome event. Patients were assigned in a 1:1 ratio to receive oral milvexian (25 mg twice daily) or matched placebo. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, or ischemic stroke as evaluated in a time-to-event analysis. The principal safety outcome was Bleeding Academic Research Consortium (BARC) type 3c or 5 bleeding (intracranial or intraocular bleeding that compromises vision or fatal bleeding).

RESULTS: After a planned interim analysis that was based on 556 adjudicated efficacy end points, the trial was terminated for futility. A total of 14,194 patients had been enrolled, with 7094 assigned to receive milvexian and 7100 to receive placebo. After a median follow-up of 12.2 months, a primary efficacy outcome event had occurred in 384 patients (5.4%) in the milvexian group and in 365 patients (5.1%) in the placebo group (hazard ratio, 1.05; 95% confidence interval, 0.91 to 1.21; P = 0.50). BARC type 3c or 5 bleeding occurred in 23 patients (0.3%) in the milvexian group and in 22 patients (0.3%) in the placebo group (P = 0.88).