Asundexian Receives FDA Approval for Secondary Stroke Prevention

The US Food and Drug Administration (FDA) has approved Bayer’s asundexian with antiplatelet therapy to reduce stroke risk in adults after a recent mild to moderate non-cardioembolic ischemic stroke or high-risk transient ischemic attack (TIA).¹

The agency announced the approval on November 9, 2026, describing asundexian as the first factor XIa (FXIa) inhibitor approved in the US for this use. The decision rests on results from the phase 3 OCEANIC-STROKE trial and follows asundexian’s receipt of Fast Track and Priority Review designations earlier in the year.^1,2

“Stroke is a leading cause of disability and death in the United States, and survivors are at risk of having another stroke,” Hylton Joffe, MD, MMSc, Director of the Office of Cardiology, Hematology, Endocrinology, and Nephrology in the FDA’s Center for Drug Evaluation and Research, said in a statement. “Today’s approval represents a meaningful advance for patients and health care providers seeking a new option for secondary stroke prevention.”¹

Asundexian is a selective, once-daily oral FXIa inhibitor designed to reduce pathologic thrombus formation while largely preserving hemostasis. According to the OCEANIC-STROKE investigators, previous attempts to add anticoagulation to antiplatelet therapy for long-term secondary prevention failed because of insufficient efficacy, excess bleeding, or both.²

Evidence from OCEANIC-STROKE

OCEANIC-STROKE was a multicenter, randomized, double-blind, placebo-controlled, event-driven trial conducted at 702 centers in 37 countries. Investigators enrolled 12,327 adults with a National Institutes of Health Stroke Scale (NIHSS) score ≤15 or a high-risk TIA, randomizing them within 72 hours of symptom onset.^1,2

Patients received asundexian 50 mg once daily (n = 6162) or placebo (n = 6165) in addition to planned single or dual antiplatelet therapy. The primary efficacy endpoint was ischemic stroke, and the primary safety endpoint was International Society on Thrombosis and Haemostasis (ISTH) major bleeding.²

Ultimately, ischemic stroke occurred in 6.2% of patients receiving asundexian vs 8.4% of those receiving placebo (cause-specific hazard ratio [csHR], 0.74; 95% CI, 0.65-0.84; P < .001). The FDA characterized this as a 26% reduction in ischemic stroke risk over a median treatment duration of 14.2 months.^1,2

The key secondary composite of cardiovascular death, myocardial infarction, or stroke was also lower with asundexian. Ischemic stroke within the first 90 days did not differ significantly between groups (3.0% vs 3.5%; csHR, 0.84; 95% CI, 0.69-1.02; P = .08), which halted formal hierarchical testing of lower-ranked secondary endpoints.²

Asundexian safety, bleeding risk, and prescribing restrictions

ISTH major bleeding occurred in 1.9% of the asundexian group and 1.7% of the placebo group (csHR, 1.10; 95% CI, 0.85-1.44; P = .46). Overall adverse events (69.3% vs 70.1%) and serious adverse events (19.2% vs 19.5%) were similar between arms.²

The FDA flagged several subgroup signals in its announcement. Major bleeding was higher with asundexian among patients older than 75 years and during the first 90 days of treatment, and gastrointestinal bleeding was more frequent with asundexian than with placebo. Diarrhea was the most common adverse reaction, reported in at least 3% of patients.¹

The new label carries several practical restrictions. Coadministration with drugs acting as both P-glycoprotein (P-gp) inducers and strong CYP3A4 inducers, such as carbamazepine, is not recommended because these agents may reduce efficacy. Asundexian is also not recommended in patients with moderate or severe hepatic impairment.¹

Clinicians should withhold asundexian for at least 24 hours before elective surgery or invasive procedures and for at least 24 hours after thrombolysis for acute ischemic stroke. The approval does not extend to stroke prevention in patients with atrial fibrillation.¹

References

1. US Food and Drug Administration. FDA approves first factor XIa inhibitor to help prevent stroke in certain adults at high risk. Published November 9, 2026. Accessed November 9, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-factor-xla-inhibitor-help-prevent-stroke-certain-adults-high-risk

2. Sharma M, Dong Q, Hirano T, et al. Asundexian for secondary stroke prevention. N Engl J Med. 2026;394(15):1467-1479. doi:10.1056/NEJMoa2513880