Sunharbo approved as first factor XIa inhibitor for secondary stroke prevention

Clinical Takeaway: Consider Sunharbo as a new option for adults with a recent mild-to-moderate non-cardioembolic ischemic stroke or high-risk transient ischemic attack who require additional protection against recurrent ischemic events while receiving antiplatelet therapy. In a large phase 3 trial, treatment reduced recurrent ischemic stroke risk without an overall increase in major bleeding.

FDA has approved Sunharbo (asundexian) for use in combination with antiplatelet therapy to reduce the risk of stroke in adults with a recent mild-to-moderate non-cardioembolic ischemic stroke (National Institutes of Health Stroke Scale score ≤15) or high-risk transient ischemic attack (TIA). Sunharbo is administered as a 50-mg tablet once daily and is the first approved factor XIa inhibitor, introducing a new anticoagulation strategy that targets thrombus formation through the intrinsic coagulation pathway.

Approval was based on results from the OCEANIC-STROKE trial, which enrolled 12,327 adults treated within 72 hours of symptom onset. Patients receiving Sunharbo plus antiplatelet therapy experienced a 26% reduction in ischemic stroke risk compared with antiplatelet therapy alone over a median follow-up of 14.2 months. The benefit was consistent across prespecified patient subgroups and was accompanied by reductions in overall stroke and major cardiovascular events.

Overall rates of major bleeding were similar between treatment groups. However, bleeding risk was higher during the first 90 days of therapy and among adults older than 75 years. Gastrointestinal bleeding occurred more frequently with Sunharbo, although most events were non-major. Diarrhea was the most commonly reported adverse reaction, occurring in more than 3% of treated patients and typically resolving without treatment discontinuation. Elevated hepatic enzymes were also reported, with rare cases of serious liver injury.

Sunharbo is not indicated for stroke prevention in patients with atrial fibrillation. Clinicians should avoid concomitant use with combined P-glycoprotein (P-gp) and strong cytochrome P450 3A4 (CYP3A4) inducers, and the drug is not recommended in patients with moderate or severe hepatic impairment. Therapy should be interrupted before elective surgery or invasive procedures and temporarily withheld after thrombolysis for acute ischemic stroke.

“Today’s approval represents a meaningful advance for patients and health care providers seeking a new option for secondary stroke prevention,” said Hylton V. Joffe, M.D., MMSc, Director of the Office of Cardiology, Hematology, Endocrinology, and Nephrology in FDA’s Center for Drug Evaluation and Research.

Sources: FDA. (2026 Nov 09). FDA approves first Factor XIa inhibitor to help prevent stroke in certain adults at high risk; Bayer. (2026 Nov 10). Bayer’s asundexian first FXIa inhibitor approved by U.S. Food and Drug Administration for secondary stroke risk reduction