Bayer Aktiengesellschaft (ETR:BAYN) highlighted results from its OCEANIC-STROKE phase III trial during an investor webinar held at ISC 2026 in New Orleans, outlining what company executives and investigators described as a potentially significant advance in secondary stroke prevention. The session featured Bayer representatives Alexander Seidler, Christoph Koenen and Jan Voss, along with trial co–principal investigator Ashkan Shoamanesh of McMaster University.
Unmet need in recurrent stroke prevention
Koenen, Bayer’s head of clinical development and operations, said stroke remains a major global health burden, citing more than 100 million stroke survivors worldwide and an estimated 12 million new strokes each year. He said recurrent events are common and often more severe: one in five survivors experiences a second stroke within five years, and one in ten within one year. Koenen added that up to 30% of strokes are recurrent and that subsequent strokes can be more deadly, lead to higher disability, and increase dementia risk.
Trial design and patient population
Shoamanesh explained the rationale for targeting Factor XI, noting that genetic Factor XI deficiency is associated with reduced ischemic stroke risk without increased intracranial hemorrhage, which he attributed to Factor XI’s role in clot propagation with a limited role in hemostasis. He described asundexian as a direct oral Factor XIa inhibitor designed for once-daily dosing, and referenced a phase II program of more than 4,000 participants that showed greater than 90% Factor XIa inhibition at peak and trough without a significant increase in major bleeding versus placebo.
OCEANIC-STROKE was described as a placebo-controlled, double-blind, event-driven phase III trial comparing asundexian 50 mg once daily with placebo in patients with non-cardiomyopathic ischemic stroke or high-risk TIA who were planned to receive single or dual antiplatelet therapy. The study was conducted at 702 sites across 37 countries. The primary efficacy endpoint was time to first ischemic stroke; the primary safety endpoint was time to first ISTH major bleeding.
Participants were enrolled within 72 hours of symptom onset, with eligibility including non-cardiomyopathic ischemic stroke (NIHSS up to 15) or high-risk TIA (ABCD2 score 6–7). The trial included enrichment criteria related to stroke subtype and evidence of atherosclerosis in certain lacunar stroke cases. Exclusions included atrial fibrillation or other cardioembolic sources requiring anticoagulation, recent stroke within seven days prior to enrollment, end-stage renal disease requiring dialysis, active non-trivial bleeding, prior non-traumatic intracranial hemorrhage, and significant gastrointestinal bleeding within six months.
Of 12,578 screened participants, 12,327 were randomized 1:1. Shoamanesh emphasized high retention and compliance with allocation, with fewer than 100 not receiving assigned treatment and roughly 80 not completing the study. Baseline characteristics were balanced between arms. Mean age was about 68, and females represented about one-third of the population. Most participants (95%) had ischemic stroke as the qualifying event, while 5% had high-risk TIA. Stroke subtypes included 43% large artery atherosclerosis, 30% stroke of undetermined etiology, and 20% small vessel occlusive disease. Two-thirds of patients were planned for dual antiplatelet therapy, and about a quarter received acute revascularization treatment (intravenous thrombolysis or endovascular thrombectomy).
Efficacy outcomes presented
Shoamanesh reported that asundexian reduced the hazard of first ischemic stroke by 26% versus placebo, with early and continued separation of cumulative incidence curves over follow-up. He said the effect was consistent across several secondary endpoints, including:
- All stroke: 26% hazard reduction
- Three-point MACE (cardiovascular death, non-fatal MI, non-fatal stroke): significant reduction
- All-cause mortality, MI, or stroke: significant reduction
- Disabling or fatal stroke: 31% hazard reduction
For ischemic stroke within the first 90 days, Shoamanesh said the point estimate was consistent with other outcomes but did not reach statistical significance due to fewer events, with the upper bound of the confidence interval slightly crossing 1.0.
Safety outcomes and subgroup consistency
On safety, Shoamanesh said there was no increase in ISTH major bleeding versus placebo, and he reported no significant excess across secondary safety endpoints, including symptomatic intracranial hemorrhage and hemorrhagic stroke. He described the safety findings as showing “no offsetting harm” despite efficacy benefits, and he said subgroup analyses showed consistent results across prespecified groups (including age, sex, region, race, vascular risk factors, stroke subtype, stroke severity, revascularization status, and planned single vs. dual antiplatelet therapy).
He also highlighted analyses by ischemic stroke subtype, reporting consistent reductions in ischemic stroke across large artery atherosclerosis, small vessel occlusive disease, and stroke of undetermined etiology. Shoamanesh said the interaction p-value supported interpreting the result as consistent efficacy across subtypes rather than superiority in a specific subtype.
In an exploratory discussion of embolic stroke of undetermined source (ESUS), Shoamanesh reported a 47% risk reduction for recurrent stroke with asundexian versus placebo, noting an interaction p-value of 0.07. He said the absolute risk reduction in ESUS was 4% at one year (number needed to treat of 25), while in the overall study the absolute reduction was 2% at one year (number needed to treat of 50).
Commercial considerations and Q&A highlights
During Q&A, Shoamanesh said the divergence of efficacy curves throughout follow-up suggested lifelong treatment, while noting the trial’s enrollment window was within 72 hours of symptom onset. He also stated there was approximately 20% discontinuation over the trial’s duration for non-protocol-mandated reasons, but discontinuations were similar between arms. He added that Bayer plans a landmark analysis to be presented at the European Stroke Organization Congress (ESOC) in May.
Voss discussed stroke’s economic burden, citing World Stroke Organization figures he said put global financial impact near $900 billion and projected to exceed $1 trillion by 2030. He said preventing recurrent strokes could reduce economic strain and free healthcare resources, while also emphasizing that bleeding events can be cost drivers and affect patient persistence.
On peak sales expectations, Voss said it was too early to provide specific updates beyond Bayer’s previously communicated potential, pointing to label outcomes and a volatile global pricing environment. Bayer representatives also emphasized once-daily dosing as a practical attribute and said they could not yet disclose further plans regarding additional indications, while noting ongoing consideration of future trials.
About Bayer Aktiengesellschaft (ETR:BAYN)
Bayer Aktiengesellschaft, together its subsidiaries, operates as a life science company worldwide. It operates through Pharmaceuticals, Consumer Health, and Crop Science segments. The Pharmaceuticals segment offers prescription products primarily for cardiology and women's health care; specialty therapeutics in the areas of oncology, hematology, and ophthalmology; and diagnostic imaging equipment and digital solutions, and contrast agents, as well as cell and gene therapy. The Consumer Health segment markets nonprescription over-the-counter medicines for self-medication and self-care; and solutions for nutritional supplements, allergy, cough and cold, dermatology, pain and cardiovascular risk prevention, and digestive health.
