Bayer Wins China Approval for Asundexian as First Factor XIa Inhibitor

Bayer said on October 26, 2026 that China’s National Medical Products Administration (NMPA) has granted marketing authorization for asundexian under the brand name Sunharbo, which the company described as the first Factor XIa inhibitor approved worldwide. Sunharbo, a selective, once-daily oral Factor XIa inhibitor dosed at 50 mg, is indicated to reduce the risk of stroke in adults after a non-cardioembolic ischemic stroke or a high-risk transient ischemic attack (TIA).

According to Bayer’s announcement, the authorization follows a Priority Review designation from China’s Center of Drug Evaluation. A non-cardioembolic ischemic stroke occurs when a blood clot that formed outside the heart travels to the brain and blocks a vessel supplying it, while a high-risk TIA, often called a mini-stroke, involves blocked or reduced blood flow to part of the brain and carries a high risk of turning into a stroke, according to the trial’s registry record.

Stroke is the leading cause of death and disability in China, the company said, and between 2010 and 2021 the prevalence of ischemic stroke in the country increased by 10% to more than 20 million cases. Globally, approximately 1 in 10 non-cardioembolic ischemic stroke survivors experience another stroke within one year, even with available secondary stroke prevention strategies, according to the release.

“With the approval of asundexian, we have reached an important milestone and are proud soon to be able to offer physicians in China a new treatment option for stroke survivors after a non-cardioembolic ischemic stroke or high-risk transient ischemic attack,” said Christian Rommel, Ph.D., Global Head of Research and Development at Bayer’s Pharmaceuticals Division. Rommel said the approval allows Bayer to address an unmet need that has seen limited therapeutic advances over the past two decades, and that the company is working with stakeholders and medical communities to support equitable and timely access for eligible patients in China.

Phase III Data Behind the Authorization

The NMPA authorization is based on positive data from the pivotal, global Phase III OCEANIC-STROKE study. Bayer describes OCEANIC-STROKE as the first successfully completed Phase III study of a Factor XIa inhibitor administered in combination with dual antiplatelet therapy or single antiplatelet therapy (DAPT/SAPT) to demonstrate superiority in reducing ischemic stroke compared with DAPT/SAPT alone. Antiplatelet medicines, the current standard of care for these patients, work by preventing platelets, components of blood clotting, from clumping together, according to the registry record.

Asundexian 50 mg in combination with DAPT/SAPT significantly reduced ischemic stroke by 26% compared with DAPT/SAPT alone in patients after a non-cardioembolic ischemic stroke or high-risk TIA, the company said. The incidence of all bleeding events was similar between the two treatment groups. Bayer said the treatment effect for the primary endpoint was consistent across key subgroups, including age, sex, type of index event, non-cardioembolic stroke subtypes, stroke severity, and planned antiplatelet therapy. The full OCEANIC-STROKE results have been published in The New England Journal of Medicine, according to the release.

Trial Design and Factor XIa Mechanism

OCEANIC-STROKE was a multicenter, international, randomized, placebo-controlled, double-blind, parallel-group, event-driven study that randomized 12,327 participants worldwide. The study’s ClinicalTrials.gov record, filed under NCT05686070 with Bayer as lead sponsor, lists quadruple masking of participants, care providers, investigators, and outcomes assessors, and an actual enrollment of 12,327. Participants received once-daily oral asundexian or placebo for at least three months and up to 31 months.

The registry records an actual start date of January 26, 2023, a first posting on January 17, 2023, and actual primary completion and completion dates of October 23, 2025, with the study’s overall status now listed as completed. The primary efficacy endpoint was time to first occurrence of ischemic stroke, and the primary safety endpoint was time to first occurrence of major bleeding as defined by the International Society on Thrombosis and Hemostasis (ISTH). Secondary endpoints included all strokes (ischemic and hemorrhagic), a composite of cardiovascular death, myocardial infarction or stroke, disabling stroke defined as a modified Rankin Scale score of 3 or greater at 90 days, all-cause mortality, TIA, symptomatic intracranial hemorrhage, fatal bleeding, and ischemic stroke within the first 90 days, alongside several additional bleeding composites.

Eligible participants were aged 18 or older and had experienced an acute non-cardioembolic stroke or high-risk TIA, with systemic or cerebrovascular atherosclerosis or an acute non-lacunar infarct required for enrollment. Exclusion criteria included an ischemic stroke within seven days before the index event, an index stroke following procedures or due to other rare causes, and a history of atrial fibrillation or flutter, left ventricular thrombus, a mechanical valve, or another cardioembolic source of stroke requiring anticoagulation.

Factor XIa is a protein in the blood coagulation pathway that is thought to contribute to pathological thrombus growth and vessel blockage while playing a minor role in forming the hemostatic plug that seals a leak at the site of vessel injury, according to Bayer. The company said asundexian selectively inhibits Factor XIa to reduce pathological clot formation, describing the approach as uncoupling hemostasis from pathological thrombosis, with a similar incidence of all bleeding events between treatment groups in the study.

Bayer said its cardiovascular and cerebrovascular work focuses on conditions including stroke, heart failure, cardiomyopathies, and chronic kidney disease, with several products and compounds in preclinical and clinical development. In fiscal 2025, the group employed around 88,000 people and generated sales of 45.6 billion euros, with research and development expenses of 5.8 billion euros.

Asundexian has been submitted for marketing authorization in additional markets around the world. Bayer said those applications are currently under review and that it continues to work with health authorities worldwide to bring the drug to patients in other regions.