New blood-thinning drug cuts second stroke risk without bleeding trade-off

• Research suggests the investigational drug asundexian could reduce the risk of recurrent ischemic stroke in those who have recently experienced a stroke or high risk transient ischemic attack (TIA).
• Unlike many existing anti-clotting treatments, it did not increase major or intracranial bleeding, addressing a major limitation of current therapies.
• The drug works by inhibiting Factor XIa, a clotting protein involved in harmful clot formation but less critical for normal bleeding control.
• Findings from a large Phase 3 trial suggest it could represent a new, safer approach to long-term stroke prevention.

Nearly 1 in 4 people who have previously had a stroke will experience a recurrent stroke. To help reduce this risk, clinicians will typically recommend antiplatelet or anticoagulant therapy, in addition to making lifestyle changes.

Prescribing blood thinners can help to prevent future clots and reduce the risk of recurrent, often severe, strokes. They can be particularly crucial for those with atrial fibrillation, or other high risk cardioembolic causes, with research suggesting they can reduce stroke risk by 64%.

However, while these medications are generally safe and can significantly reduce the risk of recurrent strokes, they carry an increased risk of bleeding. In particular, the most dangerous complication of anticoagulant therapy can result in bleeding in or around the brain, known as a hemorrhagic stroke.

Now, a study suggests that a new investigational medication could offer protection without the heightened bleeding risk associated with current treatments.

Published in The New England Journal of Medicine, the findings indicate that asundexian reduced the risk of a second stroke by 26% in people who had recently experienced a clot-related stroke or TIA, without increasing bleeding risk.