Written By: Pharmacally Medical News Desk
Bayer’s investigational oral Factor XIa inhibitor Asundexian demonstrated significant success in the Phase III OCEANIC-STROKE trial, meeting both its primary efficacy and safety endpoints for secondary stroke prevention. The trial showed that once-daily administration of 50 mg Asundexian significantly reduced the risk of ischemic stroke compared to placebo, when combined with standard antiplatelet therapy, in patients who had suffered a non-cardioembolic ischemic stroke or high-risk transient ischemic attack (TIA). Importantly, this reduction in stroke risk did not come with an increased rate of major bleeding events, a common concern with blood-thinning medications.
OCEANIC-STROKE (Clinical Trial id NCT05686070) is a large, international, randomized, double-blind, placebo-controlled Phase III study that enrolled over 12,300 patients. It is the first successful Phase III trial of a Factor XIa inhibitor, targeting patients at high risk of recurrent ischemic stroke following their initial event. The study’s design included Asundexian at 50 mg once daily alongside antiplatelet therapy, compared against placebo plus antiplatelet therapy, to evaluate its effectiveness in preventing secondary strokes without increasing bleeding risk.
The main study results from the OCEANIC-STROKE trial will be shared at an upcoming scientific congress; however topline results demonstrated statistically significant reduction in the risk of ischemic stroke in patients treated with 50 mg once daily compared to placebo when added to standard antiplatelet therapy. The primary efficacy endpoint of recurrent ischemic stroke was met, with asundexian reducing the incidence of stroke events, confirming its benefit in secondary stroke prevention. Additionally, key secondary endpoints also showed favorable trends, including a reduction in the composite outcome of stroke, systemic embolism, and vascular death, further supporting asundexian’s protective effect.
Stroke remains the second leading cause of death globally, with recurrent strokes posing a higher risk of disability and mortality than initial events. Annually, approximately 12 million people suffer strokes worldwide, and 20-30% of these experience a recurrent event. Despite existing secondary prevention treatments, the risk of secondary strokes remains significantly high, with one in five survivors having another stroke within five years.
Asundexian is a direct oral inhibitor of Factor XIa (FXIa), a protein involved in the blood coagulation cascade that contributes to pathological thrombus formation while playing a limited role in normal hemostasis. By selectively inhibiting FXIa, asundexian minimizes the risk of clot formation that can lead to ischemic strokes with a reduced potential for major bleeding side effects commonly seen with other anticoagulants. The OCEANIC-STROKE trial confirmed this favorable safety profile, showing no increase in International Society on Thrombosis and Haemostasis (ISTH) major bleeding events compared to placebo.
Mike Sharma, MD, principal investigator of the OCEANIC-STROKE study and Director of the Stroke Program at Hamilton Health Sciences, emphasized the high risk and devastating impact of recurrent strokes despite current therapies, noting that the topline results indicate Asundexian may become a valuable new treatment option to reduce this risk.
Christian Rommel, Ph.D., Head of Research and Development at Bayer’s Pharmaceuticals Division, expressed excitement about the positive findings, highlighting Factor XIa inhibition as a promising new approach to protect patients from recurrent stroke and marking this as an important milestone in Bayer’s thrombosis prevention innovation efforts.
In summary, Bayer’s Asundexian offers a promising new approach to secondary stroke prevention by effectively reducing ischemic stroke risk without increasing major bleeding, addressing a significant unmet need in stroke patient care worldwide.
References
Bayer’s Asundexian Met Primary Efficacy and Safety Endpoints in Landmark Phase III OCEANIC-STROKE Study in Secondary Stroke Prevention, 23 November 2025, Bayer, https://www.bayer.com/media/en-us/bayers-asundexian-met-primary-efficacy-and-safety-endpoints-in-landmark-phase-iii-oceanic-stroke-study-in-secondary-stroke-prevention/
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, https://clinicaltrials.gov/study/NCT05686070
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, UCLA Health, https://www.uclahealth.org/clinical-trials/study-test-asundexian-preventing-stroke-caused-clot