US FDA approves Bayer's blood thinner to prevent repeat strokes

The US Food and ​Drug Administration on Monday approved a new type of ​blood thinner developed by Bayer for the ‌prevention ​of strokes in patients who have already had one or have had a "mini-stroke."

The drug, which has the chemical name asundexian and will be sold under the brand name ‌Sunharbo, is the first approved treatment designed to prevent harmful blood clots by blocking the clotting protein Factor XIa. Current big-selling blood-clot preventers, such as Pfizer and Bristol Myers Squibb's Eliquis and Xarelto, sold by Johnson & Johnson and Bayer, work by blocking Factor ‌Xa, a different protein involved in the formation of blood clots. Sunharbo is approved as a once-daily treatment to ‌prevent another stroke in patients whose previous stroke was not caused by a clot from the heart. It is also approved for patients who have had a high-risk transient ischemic attack, often called a "mini-stroke."

Stroke is a leading cause of death in the United States, and Bayer estimates that ⁠each ​year approximately 795,000 people in the ⁠US are likely to experience a stroke. Bayer is betting on the drug to help offset declining revenue from older blockbuster medicines, such as ⁠Xarelto, which has faced competition from cheaper generics after losing patent protection.

"We believe that we're bringing a practice-changing innovation to the market," Sebastian ​Guth, president of Bayer's US operations, said in an interview. "There have not been any changes in the recurrence ⁠rates of stroke over the past 20 years, so there's a genuine and very significant excitement" for the drug, Guth said.

The company has previously ⁠described ​the drug as having blockbuster potential, which typically means at least $1 billion in annual sales. Guth said asundexian would be an important part of the company's future success. The approval was based on data from a late-stage study that showed ⁠the drug reduced both the frequency and severity of recurrent ischemic strokes, which are caused by clogged arteries.

China's drug regulator ⁠approved Sunharbo late last month. Other ⁠drugs in development that could eventually compete with Sunharbo include Novartis' abelacimab and milvexian, a joint effort by Bristol Myers and J&J, both of which have yet to report late-stage ‌stroke-prevention data.