Bayer’s asundexian demonstrated a significant reduction in ischaemic stroke after a non-cardioembolic ischaemic stroke or high-risk transient ischaemic attack, with no increase in ISTH major bleeding versus placebo both in combination with antiplatelet therapy

Bayer has presented the results from the global, pivotal Phase III OCEANIC-STROKE study evaluating the use of its investigational, once-daily, oral Factor XIa inhibitor asundexian (50mg) compared to placebo, both in combination with dual or single antiplatelet therapy.¹ Asundexian significantly reduced ischaemic stroke by 26% (event rates: 6.2% vs 8.4%; csHR 0.74; 95% CI 0.65–0.84; p<0.001), in patients after a non-cardioembolic ischaemic stroke or high-risk transient ischaemic attack (TIA), with no increase in the risk of ISTH major bleeding. These findings were consistent regardless of age or sex, index event (stroke or high-risk TIA), stroke subtype, NIHSS (National Institutes of Health Stroke Scale), and acute stroke therapy like thrombolysis or planned secondary prevention strategies Single Anti-platelet Therapy (SAPT) or Dual Anti-platelet Therapy (DAPT). The results were presented at the International Stroke Conference 2026 in New Orleans, U.S. OCEANIC-STROKE is the first successfully completed Phase III study of a Factor XIa inhibitor which demonstrated superiority in reducing recurrent ischemic stroke compared to placebo in patients after a non-cardioembolic ischaemic stroke or high-risk transient ischaemic attack in combination with antiplatelet therapy.

“A stroke is a life-changing event for patients and a major public health burden. The findings from OCEANIC-STROKE are a notable research achievement, demonstrating a significant reduction in the risk of recurrent ischaemic stroke with asundexian compared to placebo, alongside a sustained treatment effect and a safety profile with no observed increase in ISTH major bleeding,” said Mike Sharma, Principal Investigator of the OCEANIC-STROKE study, Michael G. DeGroote Chair in Stroke Prevention, McMaster University and Senior Scientist at Population Health Research Institute, a joint institute of McMaster University and Hamilton Health Sciences. “For clinicians and researchers who have spent decades working to reduce the global burden of secondary stroke, the OCEANIC-STROKE results represent the kind of scientific progress the field has long been striving to achieve.”

Alongside the primary findings, secondary endpoints showed asundexian reduced the risk of a stroke of any kind (ischaemic and haemorrhagic) by 26% (6.6% vs. 8.8%; csHR 0.74; 95% CI, 0.65 to 0.84; p<0.001) compared to placebo. In addition, the following secondaryefficacy endpoints were met for asundexian compared to placebo, both in combination with antiplatelet therapy: the composite endpoint of cardiovascular death, myocardial infarction (MI) or stroke (9.2% vs 11.1%, csHR 0.83; 95% CI, 0.74-0.92, p <0.001), and the composite of death from any cause, MI or stroke (10.5% vs 12.3%, csHR 0.85; 95% CI, 0.77-0.95, p=0.003).

For the safety analyses, there was no increase in the rate of ISTH major bleeding between asundexian compared to placebo (1.9% vs. 1.7%; HR 1.10; 95% CI, 0.85–1.44). For the pre-specified secondary safety endpoints, the risk of bleeding was similar compared to the rates seen in the placebo-arm.

OCEANIC-STROKE enrolled all common stroke subtypes in its design, classified by the TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. Among patients with an index ischaemic stroke, the study enrolled patients with large-artery atherosclerosis (43%), small-vessel occlusion (lacunar) (23%), stroke of undetermined etiology (30%), other determined etiology (3%), and cardioembolic stroke (2%). Across all TOAST subtypes evaluated, rates of recurrent ischaemic stroke were lower with asundexian compared with placebo.

“The consistent reduction in secondary events with asundexian across all types of strokes included in the trial, is particularly striking” said Ashkan Shoamanesh, Co-Principal Investigator of OCEANIC-STROKE study and PHRI senior scientist. “OCEANIC-STROKE was deliberately designed with the goal of making the findings generalisable to the many ways stroke presents in clinical practice. These results provide confidence that, if approved, asundexian could become an important option for secondary stroke prevention across a broad range of stroke patients.”

Each year, approximately 12 million people worldwide will experience a stroke. Of these, 20-30% will be a recurrent stroke.^2,3 Despite available secondary stroke prevention options, the risk of secondary stroke remains high. Up to one in five stroke survivors will have another stroke within five years.⁴ Stroke is the second leading cause of death globally, and recurrent ischemic strokes tend to be more disabling and carry a higher mortality risk than the first stroke.^4,5,6

“OCEANIC-STROKE represents an important achievement made possible by the scientific ambition of the investigators, the patients who participated and the global teams who executed this study,” said Christian Rommel, Ph.D., Head of Research and Development, Bayer Pharmaceuticals. “We are proud of this collective accomplishment and Bayer’s continued commitment to advancing innovative research in thrombotic diseases. We look forward to engaging with regulatory authorities to evaluate the potential role of asundexian in the prevention of secondary stroke.”

Bayer will submit the data from OCEANIC-STROKE to health authorities for approval of marketing authorisations of asundexian. The compound has been granted Fast Track Designation by the U.S. Food and Drug Administration (FDA) as a potential treatment for stroke prevention in patients after a non-cardioembolic ischaemic stroke. Asundexian is an investigational compound and has not been approved by any health authority for use in any country for any indication.

ENDS

Notes To Editors

About OCEANIC-STROKE

The OCEANIC-STROKE study investigated the efficacy and safety profile of the oral Factor XIa inhibitor asundexian 50 mg once-daily compared to placebo, for prevention of ischaemic stroke in patients after a non-cardioembolic ischaemic stroke or high-risk transient ischaemic attack (TIA) in combination with antiplatelet therapy. It is a multicentre, international, randomised, placebo-controlled, double-blind, parallel group and event-driven study, that enrolled 12,327 participants worldwide. The primary endpoint was time to ischaemic stroke; the primary safety endpoint was ISTH major bleeding.

About FXIa inhibitors and Asundexian

Factor XIa (FXIa) is a protein in the blood coagulation pathway with different roles in hemostasis and thrombosis. FXIa has a minor role in the formation of a hemostatic plug that seals the leak at the site of vessel injury.

Following the results of the OCEANIC-STROKE study, Bayer is in discussions with regulatory authorities regarding asundexian as a potential treatment option for stroke prevention in appropriate patients. Asundexian is a once daily, oral investigational agent and has not been approved by any health authority for use in any country, for any indication.

About Bayer’s Commitment in Cardiovascular and Cerebrovascular Medicine

Bayer is a leader in cardiology and is advancing a portfolio of innovative treatments in cardiovascular (CV) and cerebrovascular diseases of high unmet medical need. We have set a clear focus on developing innovative therapies to treat such diseases (e.g., stroke, heart failure, cardiomyopathies, and chronic kidney disease) and it is our ambition to take a leading role in the care of patients with these diseases. Bayer is actively shaping the future of cardiology and neurology with a robust and diversified pipeline, strategically positioned to address critical unmet needs and drive significant long-term value. Bayer’s portfolio already includes several innovative products and compounds in various stages of preclinical and clinical development.

About Bayer

Bayer is a global enterprise with core competencies in the life science fields of health care and nutrition. In line with its mission, “Health for all, Hunger for none,” the company’s products and services are designed to help people and the planet thrive by supporting efforts to master the major challenges presented by a growing and aging global population. Bayer is committed to driving sustainable development and generating a positive impact with its businesses. At the same time, the Group aims to increase its earning power and create value through innovation and growth. The Bayer brand stands for trust, reliability and quality throughout the world. In fiscal 2024, the Group employed around 93,000 people and had sales of 46.6 billion euros. Research and Development (R&D) expenses amounted to 6.2 billion euros. For more information, go to www.bayer.co.uk.

Forward-Looking Statements

This release may contain forward-looking statements based on current assumptions and forecasts made by Bayer management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in Bayer’s public reports which are available on the Bayer website at www.bayer.co.uk. The company assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments.

References:

1. OCEANIC-STROKE - LB009. Factor XIa Inhibition with Asundexian in Acute Non-Cardioembolic Stroke or High-Risk Transient Ischemic Attack: Primary Results of the OCEANIC-STROKE Trial

Presented by Mukul Sharma, Population Health Research Institute, Hamilton, ON, Canada, at the International Stroke Conference, 5 February 2026.

2. Feigin VL, et al. World Stroke Organization (WSO): global stroke fact sheet 2022. International Journal of Stroke. 2022 Jan;17(1):18-29.

3. Feigin VL, et al. Pragmatic Solutions to Reduce Global Burden of Stroke. Lancet Neurol. 2023;22:1160–1206.

4. Kolmos M, et al. Recurrent ischemic stroke–a systematic review and meta-analysis. Journal of Stroke and Cerebrovascular Diseases. 2021 Aug 1;30(8):105935.

5. Rochmah TN, et al. Economic burden of stroke disease: a systematic review. International journal of environmental research and public health. 2021 Jul 15;18(14):7552.

6. Skajaa N, et al. Risks of stroke recurrence and mortality after first and recurrent strokes in Denmark: a nationwide registry study. Neurology. 2022 Jan 25;98(4):e329-42.

RP-Asun-GB-0018 / February 2026