Staff at the Food and Drug Administration recommended against immediate approval of Johnson & Johnson and Bayer AG drug Xarelto (chemically known as rivaroxaban) to treat blood clotting in patients with atrial fibrillation.
The news sent the company's shares steeply down.
“There is insufficient information about the drug to determine whether it is safe for use with its proposed labeling,” the Food and Drug Administration said in a staff report released Tuesday.
Shares of Bayer dropped as much as 17 percent. By midday Tuesday they were trading down 12.16 percent to 53 dollars in Frankfurt.
J&J shares fell 0.84 percent to 63.53 dollars each at the New York stock Exchange.
An advisory panel of experts will meet on Thursday with the FDA to discuss the new use of Xarelto.
About 2 million people in the United States have atrial fibrillation, according to the American Heart Association.