Combine Harvester/Alamy Stock Photo
Asundexian (Bayer), an investigational anti-clotting medication, reduces the occurrence of a stroke by 26% without increasing risk of major bleeding, according to the results of a phase III trial.
Publishing the findings of the OCEANIC‑STROKE international phase III trial in the New England Journal of Medicine on 15 April 2026, researchers analysed data from 12,327 adult patients from 37 countries, who had already experienced either a non‑cardioembolic stroke or transient ischaemic attack (TIA).
Patients would typically be given antiplatelet medications in these circumstances, whereas asundexian works by inhibiting activated factor XI.
During the trial, participants were randomly assigned to either asundexian at 50mg once daily (n=6,162) or a placebo (n=6,165), in addition to standard antiplatelet therapy, such as aspirin.
The treatment was started within 72 hours of a non‑cardioembolic stroke, which accounted for 95% of trial participants, or TIA, while patients were followed up at one month and then at three-monthly intervals thereafter for up to 31 months.
Trial results revealed that 6.2% (n=382) of participants who took asundexian experienced another ischemic stroke, compared with 8.4% (n=518) of those participants who took the placebo — a 26% reduction.
Researchers also observed a reduction in major cardiovascular events (e.g. stroke, heart attack or cardiovascular death). The trial results showed that 9.2% (n=567) of participants in the asundexian group experienced major cardiovascular events, compared with 11.1% of participants (n=684) in the placebo group — a 17% reduction.
There was a 31% reduction in the prevalence of disabling or fatal strokes in those taking asundexian (2.1% of patients taking asundexian, compared with 3% in the placebo group), according to the trial results.
Researchers also observed no increase in bleeding risk among patients taking asundexian.
Mike Sharma, the trial’s principal investigator, said: “This is something researchers have been working toward for decades.”
“This trial marks a major step toward safer and more effective long‑term treatment for stroke prevention,” he added.
Commenting on the study, Paul Wright, consultant cardiovascular pharmacist at Barts Health NHS Trust, said: “In general, there is a lot of excitement and anticipation for the factor XI/XIa inhibitors. It is hoped they will reduce ischaemic events with little to no increase in bleeding risk.
“To date, as a class, studies have shown mixed results depending on the indication. In this study, with asundexian, those with non-cardioembolic stroke have seen significant benefit when added to routine antiplatelets to reduce recurrent ischaemic stroke without a higher bleeding risk.
“This will be seen as a significant advancement in treatment options that have been limited to date.”
