Secondary Analyses of OCEANIC-STROKE Confirm Efficacy of Asundexian

Asundexian reduces stroke incidence and requires fewer interventions in patients after a non-cardioembolic ischemic stroke or high-risk transient ischemic attack (TIA), according to 4 late-breaking analyses presented at the European Stroke Organisation Conference (ESOC) 2026.1

The original OCEANIC-STROKE study confirmed the efficacy of asundexian, an investigational oral Factor XIa (FXIa) inhibitor, for the prevention of ischemic stroke in patients following non-cardioembolic ischemic stroke or high-risk TIA. Despite having an overall minor role in the formation of hemostatic plugs to seal leaks at vessel injury sites, FXIa is believed to also contribute to the formation of pathological thrombus growth and vessel blockage as well.1

“We’ve never had a trial previously where we’ve had such a large number of major and minor bleeds, and to see no excess risk with an antithrombotic versus placebo,” Ashkan Shoamanesh, MD, associate professor of medicine and Marta and Owen Boris Chair in Stroke Research and Care at McMaster University and co-principal investigator of the OCEANIC-STROKE trial, told HCPLive in an exclusive interview. “This would be the first time in history that we’ve seen this, and it really does make me hopeful about not only bringing this drug to market to implement the results we’ve seen thus far, but also what it could mean for cardiovascular disease on a broader scale.”

OCEANIC-STROKE Structure and Results

OCEANIC-STROKE was a phase 3, double-blind, event-driven, randomized, placebo-controlled trial conducted at 702 centers in 37 countries. Patients were eligible for inclusion if they had a non-cardioembolic ischemic stroke or high-risk TIA within 72 hours after the onset of symptoms. Those with ischemic stroke had a maximum score of 15 on the National Institutes of Health Stroke Scale (NIHSS), and high-risk TIA was defined as an ABCD2 score of 6 or 7. Patients who had undergone intravenous thrombolysis or mechanical thrombectomy were eligible if ≥24 hours had passed since treatment.2

Eligible patients were randomly assigned in a 1:1 ratio to either asundexian 50 mg daily or matching placebo on top of planned dual or single antiplatelet therapy. The primary outcome was first occurrence of ischemic stroke, while secondary endpoints included any stroke, a composite of death from myocardial infarction, cardiovascular causes, or stroke, death from any cause, and TIA, among others.2

A total of 12,327 patients were randomized, with 6162 receiving asundexian and 6165 receiving placebo. By the median follow-up of 567 days, a total of 1624 patients had discontinued asundexian and 1589 had discontinued placebo. Of the remainder, ischemic stroke occurred in 384 patients in the asundexian arm compared to 518 in the placebo arm (HR, 0.74; 95% CI, 0.65 to 0.84; P <.001).2

Results from New Analyses

In the present analyses of OCEANIC-STROKE, investigators examined several factors including the proportion of patients with a NIHSS score ≥8, the number of disabling strokes in each arm, the level of stroke severity in each arm, and the need for acute intervention in each arm. The results presented at ESOC 2026 largely supported the existing data of asundexian, reinforcing its efficacy for this population.1

Key findings from these analyses included the following data:

• Acute intervention: Of the ischemic strokes that did occur, 40 patients required acute intervention via intravenous thrombolysis and/or endovascular treatment in the asundexian group compared to 82 in the placebo group
• Disabling/fatal stroke risk: Disabling stroke occurred in 2.1% of the asundexian group and 3%% in the placebo group (HR, 0.69; 96^ CI, 0.55-0.87)
• Stroke severity: Moderate-to-high severity strokes (NIHSS ≥8) occurred in 88 patients in the asundexian group versus 157 in the placebo group
• Ischemic stroke with fatal outcomes: 16 patients experienced fatal outcomes in the asundexian group versus 28 in the placebo group (HR, 0.57; 95% CI, 0.31-1.06)1

With these data established and presented, Shoamanesh believes that the next step in the investigational and approval process for asundexian is confirmation of safety data.

“There’s no reason to believe that there’ll be any loss of safety over time,” Shoamanesh said. “If anything, we typically see with antithrombotics that the bleeding is front-loaded, and the further you go away from the time of initiation, the less the bleeding – that’s what the curves would suggest thus far, and that’s what we’ve seen in OCEANIC-STROKE.”

Editors’ Note: Shoamanesh reports disclosures with the Heart and Stroke Foundation of Canada, the Marta and Owen Boris Foundation, Bayer AG, Daiichi Sankyo, AstraZeneca, Octapharma, Inc., and others.

References

1. Bayer. Bayer announces new late-breaking data from OCEANIC-STROKE trial of asundexian. May 6, 2026. Accessed May 22, 2026. https://www.bayer.com/en/us/news-stories/data-from-oceanic-stroke-trial-of-asundexian

2. Sharma M, Dong Q, Hirano T, et al. Asundexian for secondary stroke prevention. NEJM. 2026;394(15):1467-1479. doi:10.1056/nejmoa2513880