The FDA approves Bayer’s SUNHARBO (asundexian), the first Factor XIa inhibitor for secondary stroke prevention, following a 26% reduction in ischemic stroke in Phase 3 OCEANIC-STROKE.
Written By: Siddhi Bhadekar, M. Pharm (QA)
Reviewed By: Pharmacally Editorial Team
The US Food and Drug Administration (FDA) approved SUNHARBO (asundexian) for use alongside antiplatelet therapy in adults with a recent mild-to-moderate non-cardioembolic ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score ≤15) or high-risk TIA. The recommended dosage is 50 mg once daily.
The approval introduces Factor XIa inhibition as a new approach to secondary stroke prevention, where treatment focuses on reducing the risk of subsequent cerebrovascular events. Asundexian selectively inhibits activated Factor XI (FXIa), a component of the coagulation cascade involved in amplifying thrombin generation.
By reducing pathological clot formation while potentially preserving normal hemostasis, FXIa inhibition offers a different approach to managing thrombotic risk compared with conventional anticoagulant strategies.
Commenting on the approval, Hylton V. Joffe, Director of the FDA’s Office of Cardiology, Hematology, Endocrinology, and Nephrology, said that stroke survivors remain at risk of another event and that the approval provides a new option for patients and healthcare providers seeking secondary stroke prevention.
OCEANIC-STROKE Demonstrates 26% Reduction in Ischemic Stroke
The approval was supported by OCEANIC-STROKE (NCT05686070), a multicenter, randomized, double-blind, placebo-controlled Phase 3 trial involving 12,327 adults. Participants had experienced a recent non-cardioembolic ischemic stroke (NIHSS ≤15) or high-risk TIA and were randomized to receive asundexian 50 mg once daily (n=6,162) or placebo (n=6,165), alongside antiplatelet therapy.
Treatment began within 72 hours of symptom onset, addressing the period when recurrent stroke risk is particularly high. The primary endpoint was time to first occurrence of ischemic stroke.
Over a median treatment period of 14.2 months, asundexian reduced ischemic stroke incidence by 26% compared with placebo (6.2% versus 8.4%; HR 0.74; 95% CI, 0.65–0.84; P<0.0001).
The treatment also reduced all strokes, including ischemic and hemorrhagic events, from 8.8% to 6.6% (HR 0.74; 95% CI, 0.65–0.84). The composite of cardiovascular death, myocardial infarction or stroke declined from 11.1% to 9.2% (HR 0.83; 95% CI, 0.74–0.92). Both secondary outcomes were primarily driven by fewer ischemic strokes.
Bleeding Risk and Treatment Restrictions
Overall major bleeding rates were similar between the treatment groups, at 1.6 versus 1.5 events per 100 patient-years. However, major bleeding increased among patients older than 75 years and during the first 90 days of treatment. Gastrointestinal bleeding also occurred more frequently with asundexian (2.7 versus 2.1 events per 100 patient-years; HR 1.3; 95% CI, 1.0–1.6).
Diarrhea was the most frequently reported adverse reaction, occurring in 3.4% of asundexian-treated patients compared with 2.8% receiving placebo.
The FDA advises against concomitant use with combined P-glycoprotein and strong CYP3A4 inducers, including carbamazepine, because they may reduce asundexian exposure and effectiveness. The medicine is also not recommended in patients with moderate or severe hepatic impairment. Treatment should be withheld for at least 24 hours before elective surgery or invasive procedures and for at least 24 hours after thrombolysis for acute ischemic stroke. SUNHARBO is not approved for stroke prevention in patients with atrial fibrillation.
Regulatory Expansion and Commercial Outlook
The FDA granted SUNHARBO Fast Track and Priority Review designations before approval. The authorization was granted to Bayer HealthCare Pharmaceuticals Inc., based in Whippany, New Jersey.
China’s National Medical Products Administration approved asundexian on October 26, 2026, while regulatory reviews remain ongoing in Europe and Japan. Bayer expects US commercial shipments to begin in mid-to-late November 2026, with subsequent availability through hospitals and pharmacies.
The approval establishes Factor XIa inhibition as a new therapeutic option in secondary stroke prevention. However, its clinical positioning will depend on patient selection, bleeding-risk assessment and longer-term experience with its use alongside established antiplatelet therapy.
Reference
FDA Approves First Factor Xla Inhibitor to Help Prevent Stroke in Certain Adults at High Risk, US FDA, 09 November 2026
Bayer’s SUNHARBO® (asundexian), 50 mg tablets, the First and Only Factor XIa Inhibitor, Approved by the U.S. FDA to Reduce the Risk of Stroke in Adults With Recent Non-Cardioembolic Ischemic Stroke or High-Risk Transient Ischemic Attack, Bayer via Businesswire, 09 November 2026
A Study to Test Asundexian for Preventing a Stroke Caused by a Clot in Participants After an Acute Ischemic Stroke or After a High-risk Transient Ischemic Attack, a So-called Mini Stroke (OCEANIC-STROKE), ClinicalTrials.gov ID NCT05686070
About the Writer
Siddhi Rajendra Bhadekar (Linkedin) is an M.Pharm professional with expertise in medical and scientific writing, literature review, publication writing, and evidence synthesis, supported by four peer-reviewed publications.
She brings working knowledge of ICH-GCP, MedDRA, pharmacovigilance, ADR/AE reporting, clinical data management, and regulatory documentation.
With experience across pharmaceutical R&D, Quality Control, and Quality Assurance, she combines scientific research skills with strong attention to accuracy and detail.
Her background in manuscript development, publication planning, and scientific communication enables her to translate complex healthcare information into clear, reliable content.