MW Bayer's stock is jumping on secondary stroke drug's trial success

By Steve Goldstein

Bayer shares rose on Monday after the company said a late-stage trial of a stroke drug met its goals.

Bayer stock jumped on Monday after the German healthcare company said a late-stage stroke drug trial achieved its goals.

Bayer didn't give too much away: on Sunday the company said a Phase III trial with 12,300 patients of an oral drug called Asundexian significantly reduced the risk of a secondary stroke, and that there also was no increase in the risk of major bleeding.

It will present detailed results at an upcoming scientific congress.

Bayer says that of the 12 million people who suffer a stroke each year, 20% to 30% will be a recurrent stroke, and that one in five stroke survivors have another one in five years. The drug works by inhibiting what's called Factor XIa, which can lead to blood clotting.

"This is a material de-risking event for Bayer's pipeline, validating FXIa inhibition as a differentiated anticoagulation approach," said analysts at Jefferies.

The positive result came after Bayer stopped a trial of the same drug to prevent stroke in patients with atrial fibrillation two years ago, because an existing treatment called apixaban performed better.

Analysts said the drug has the potential to be a blockbuster one, with sales of over $1 billion per year. Bayer said Asundexian has been granted fast track designation by the U.S. Food and Drug Administration.

Bayer shares (XE:BAYN) jumped 11%, adding some EUR3 billion in market cap.

-Steve Goldstein

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November 24, 2025 04:47 ET (09:47 GMT)

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