Asundexian Safely Reduces Ischemic Stroke Risk Regardless of Infarct Patterns on MRI

Asundexian has successfully reduced ischemic stroke without increasing major bleeding, irrespective of baseline magnetic resonance imaging (MRI) infarct patterns, according to a recent analysis of the OCEANIC-STROKE trial.1

These data were presented at the World Stroke Congress (WSC) 2026 in Seoul, South Korea, by Raed Joundi, MD, DPhil, a stroke neurologist at Hamilton Health Sciences, assistant professor at McMaster University, investigator at the Population Health, and Anne Marie Brune/PHRI Chair in Vascular Dementia at McMaster University.1

“Infarct pattern on MRI is associated with risk of stroke recurrence and bleeding,” Joundi and colleagues wrote. “We obtained study-specific MRIs in OCEANIC-STROKE to identify the association of baseline infarct patterns on efficacy and bleeding outcomes of this novel antithrombotic.”1

OCEANIC-STROKE was a phase 3, double-blind trial evaluating the safety and efficacy of Bayer’s investigational Factor XIa inhibitor asundexian. Patients were eligible for enrollment if they had experienced an acute non-cardioembolic stroke or had a high risk of transient ischemic attack (TIA), as well as having systemic or cerebrovascular atherosclerosis or an acute non-lacunar infarct. Patients were excluded if they had experienced an ischemic stroke ≤7 days prior to the index event or had a history of atrial fibrillation/flutter, left ventricular thrombus, mechanic valve, or other cardioembolic sources of stroke requiring anticoagulation.2,3

Eligible patients were randomly assigned in a 1:1 ratio to receive either asundexian 50 mg once daily or matching placebo on top of planned dual or single antiplatelet therapy. The study’s primary endpoints were time to first occurrence of ischemic stroke and first occurrence of International Society on Thrombosis and Hemostasis (ISTH) major bleeding, both ≤31 months. Secondary endpoints included time to first occurrence of all strokes, cardiovascular death, myocardial infarction, all-cause mortality, and disabling stroke, among other criteria.3

A total of 12,327 patients underwent randomization, with 6162 assigned to asundexian and 6165 to placebo. These patients were followed up for a median of 19 months, during which the incidence of ischemic stroke was lower in the asundexian arm than the placebo arm (6.2% vs 8.4%; cause-specific HR, 0.74; 95% CI, 0.65-0.84; P <.001). Composite death from cardiovascular causes, myocardial infarction, or stroke was also lower in the asundexian arm, and major bleeding incidence was similar in both arms.2

In the present study, Joundi and colleagues enrolled consecutive patients with non-cardioembolic stroke, obtaining standardized MRI scans within 5 days of the index event. The team classified infarct patterns based on number, size, and location of diffusion restricting (DWI+) lesions. The baseline characteristics of these MRI participants were similar to the original trial population. A total of 1126 baseline MRI scans were evaluable – of these, 1076 (95.6%) had DWI+ lesions consistent with acute infarcts. Single small subcortical infarcts, defined as ≤15 mm, occurred in 297 patients, while multiple infarcts occurred in 565, ≥1 large infarct in 512, and ≥1 cortical infarct in 544.1

Over the course of follow-up, asundexian was associated with a reduction in ischemic stroke (8.2% vs 12.1%; csHR, 0.67; 95% CI, 0.46-0.98), with no statistically significant interaction with infarct pattern. Additionally, the team recorded only 2 intracerebral hemorrhages per group, with no significant increases in major bleeding with asundexian and no interaction with infarct pattern.1

Joundi and colleagues concluded that MRI infarct pattern at baseline had no significant influence on asundexian’s effects on ischemic stroke risk and major bleeding. The results ultimately support the overall safety and efficacy profile of asundexian based on the OCEANIC-STROKE study and its New Drug Application submission earlier in 2026.1

References

1. Joundi R. Effect of Factor XIa Inhibitor Asundexian on Ischemic Stroke Recurrence According to Baseline Infarct Pattern: MRI Substudy of OCEANIC-STROKE Trial. Presented at the World Stroke Congress (WSC) 2026, Seoul, South Korea. October 21-23, 2026.

2. Sharma M, Dong Q, Hirano T, et al. Asundexian for Secondary Stroke Prevention. New England Journal of Medicine. 2026;394(15):1467-1479. doi:10.1056/nejmoa2513880

3. Bayer. 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 Identifier: NCT05686070. Updated November 12, 2025. Accessed October 21, 2026. https://clinicaltrials.gov/study/NCT05686070