Bayer reported that its factor XIa inhibitor asundexian reduced ischemic stroke recurrence by 26% in a large phase 3 study, without adding major safety signals. The company released details after an unexpected trial win, positioning asundexian as a potential new class of oral anticoagulant for secondary stroke prevention. The result intensifies competition with rival factor XIa programs from Bristol Myers Squibb and Johnson & Johnson, and could influence regulatory review pathways for next-generation antithrombotics. Factor XIa inhibitors aim to reduce clotting with lower bleeding risk versus traditional anticoagulants; clinicians consider them a mechanistically differentiated approach to thrombosis prevention. Commercial uptake will depend on confirmatory analyses, label indications, and payer willingness to reimburse a new class. A successful approval would expand Bayer’s cardiovascular portfolio and reshape late-stage antithrombotic development strategies across the industry.