The FDA approved Bayer’s asundexian (Sunharbo), a Factor XIa inhibitor, to reduce the risk of recurrent ischemic stroke in adults who recently had a mild-to-moderate non-cardioembolic ischemic stroke or a high-risk transient ischemic attack. The approval follows a large Phase 3 program in a population already receiving antiplatelet therapy. In the Phase 3 data highlighted at approval, Sunharbo reduced ischemic stroke risk by 26% versus placebo while reporting major bleeding rates similar to the control arm. The most frequently reported adverse reaction was diarrhea. Regulators cleared the indication as an add-on approach alongside antiplatelet therapy, positioning it within the search for safer clot prevention strategies that reduce thrombosis without the bleeding tradeoffs associated with some older anticoagulants. Commercially, FDA clearance may sharpen competitive dynamics in secondary stroke prevention, particularly as access and patient selection become central rollout variables for clinicians and payers.