New Drug Lowers Second Stroke Risk, No Bleeding Danger

Asundexian reduces recurrent stroke risk without increasing bleeding concerns, study finds

Feb. 5, 2026 at 11:07pm

Got story updates? Submit your updates here. ›

Research has found that the investigational anti-clotting medication asundexian, when added to standard blood-thinning medications, reduced the risk of a second ischemic (clot-caused) stroke by 26% without increasing the risk of bleeding. This is the first completed trial of a Factor XI inhibitor investigating whether asundexian is better than standard therapy at safely preventing recurrent strokes.

Why it matters

Nearly 1 in 4 stroke survivors will have another stroke, called a secondary stroke. Current antiplatelet therapies have limited effectiveness in preventing recurrent stroke due to bleeding risks. Asundexian holds the potential to reduce the risk of a recurrent stroke over the long term without an increased safety risk, which would be a major advance in stroke prevention.

The details

The OCEANIC-STROKE study included over 12,300 stroke survivors who recently had a mild to moderate ischemic stroke or a high-risk transient ischemic attack. Participants were randomly selected to receive either standard antiplatelet therapy plus a daily dose of asundexian or standard antiplatelet therapy plus a placebo. Compared to placebo, adding asundexian reduced ischemic stroke by 26%, reduced disabling strokes, and did not increase bleeding or serious adverse effects.

  • The study was conducted at 702 sites in 37 countries, with participants enrolled between January 2023 and February 2025.
  • Participants were followed for 3 to 31 months.

The players

Mike Sharma

The principal investigator of the study, the Michael G. Degroote Chair in Stroke Prevention, professor of medicine at McMaster University and senior scientist at the Population Health Research Institute.

Ashkan Shoamanesh

The co-principal investigator of OCEANIC-STROKE, associate professor of medicine at McMaster University and senior scientist at the Population Health Research Institute of Hamilton Health Sciences.

American Stroke Association

A division of the American Heart Association that states nearly 1 in 4 stroke survivors will have another stroke.

Bayer

The manufacturer of asundexian who funded the study and provided the medication and placebo used in the trial.

Got photos? Submit your photos here. ›

What they’re saying

“Asundexian holds the potential to reduce the risk of a recurrent stroke over the long term without an increased safety risk. This is a major advance in our ability to prevent strokes in people at risk of stroke recurrence.”

— Mike Sharma, Principal Investigator (Mirage News)

“Antiplatelet therapy has limited effectiveness in preventing recurrent stroke because of bleeding risks. Previous efforts to improve outcomes by adding other anticlotting or blood thinning medications have not succeeded due to the increased risk of bleeding, lack of benefit or both.”

— Mike Sharma, Principal Investigator (Mirage News)

What’s next

The U.S. Food and Drug Administration has granted asundexian fast-track designation for its potential use in stroke prevention after ischemic stroke not caused by a blood clot originating in the heart. Further analysis of brain imaging and standardized MRI data from the OCEANIC-STROKE substudy is still ongoing and could provide additional insights.

The takeaway

This study demonstrates that asundexian, a novel anticoagulant that inhibits Factor XI, has the potential to significantly reduce the risk of recurrent stroke in stroke survivors without increasing the risk of bleeding. If approved, asundexian could become an important new tool in the prevention of secondary strokes.