Preventing a stroke is important, but preventing another one without increasing the risk of bleeding remains a major challenge in clinical practice. A new development is bringing fresh attention to this balance. On November 9, 2026, the US FDA approved asundexian ( Sunharbo ), the first Factor XIa inhibitor, for reducing the risk of recurrent ischaemic stroke in eligible adults. 1 Unlike conventional anticoagulants, which target established components of the clotting pathway, Factor XIa inhibitors focus on a specific part of the coagulation process.

Researchers are exploring whether this targeted approach can reduce abnormal clot formation while allowing the body's natural ability to control bleeding to remain relatively intact. What Does the Research Suggest? Factor XIa plays an important role in amplifying the coagulation cascade and supporting clot formation. Blocking its activity…