New anti-clotting medication lowers risk of stroke without added bleeding

WASHINGTON, 20th April, 2026 (WAM) — A large international study has found that asundexian, an investigational anti-clotting medication, reduces the risk of a stroke in people who recently experienced a stroke or transient ischemic attack (TIA) caused by a clot forming outside of the heart (non-cardioembolic stroke), without increasing bleeding, the most serious and feared complication of existing stroke prevention treatments.

The study involved 12,327 adults from 37 countries who were enrolled within 72 hours of a non-cardioembolic stroke or a temporary blockage of blood flow to the brain (TIA).

The study, published by The New England Journal of Medicine, evaluated the safety and effectiveness of asundexian for the prevention of another stroke in these patients. Currently, preventing another stroke in these situations relies mainly on antiplatelet medications, a type of anti-clotting medication that reduces risk only modestly and increases bleeding when combined or used for long term.

Asundexian works differently from existing anti-clotting drugs by blocking Factor XIa, a protein involved in harmful clot formation but plays only a small role in stopping bleeding. By blocking Factor XIa, asundexian aimed to prevent dangerous clots while preserving the body’s natural bleeding control, a novel paradigm in anti-clotting medication that is now supported by the OCEANIC-STROKE results.

Asundexian is still under regulatory review and is not yet approved for clinical use.