Eli Lilly and Co. has halted a study of its drug Xigris in children because the medicine was no more effective than a placebo at treating severe sepsis, U.S. regulators and the company said on Thursday.

More children treated with Xigris experienced central nervous system bleeding than those given a placebo, the Food and Drug Administration also said.

Four children with severe sepsis developed intracranial hemorrhages while being treated with Xigris, compared with one in the placebo group, FDA and Lilly officials said.

Xigris is sold for treating adults at a high risk of dying from severe sepsis, a dangerous reaction to bacteria in the bloodstream. The drug is not approved for treating children.

Lilly sent a letter to physicians about the discontinuation of the pediatric study on April 21. The letter was posted on the FDA Web site on Thursday.

Lilly shares fell 22 cents to $58.01 in afternoon trading on the New York Stock Exchange.