Bayer anti-clot drug misses goal of midstage-study

NEW ORLEANS, Nov 10 (Reuters) - An experimental blood clot preventer being developed by Bayer AG (BAYG.DE) and Johnson & Johnson (JNJ.N) missed its primary efficacy goal in a mid-stage study in patients with acute coronary syndrome and led to more bleeding than a placebo, according to data released on Monday.

However the drug, rivaroxaban, did show a combined risk reduction in death, heart attack and stroke compared with a placebo -- a secondary goal -- and the companies selected two doses they will move forward into late-stage testing, which was one of the main reasons for conducting the study.

Rivaroxaban failed to show a statistically significant risk reduction compared with placebo in the tougher-to-hit composite primary goal of all-cause death, heart attack, stroke and severe recurrent chest pain requiring angioplasty or bypass surgery.

Bleeding ranged from 6.1 percent in patients receiving 5 milligrams of rivaroxaban once a day to 15.3 percent in patients who received 20 mg daily, compared with 3.3 percent in the placebo group. Bleeding is typically a major concern with drugs designed to prevent blood clots.

Researchers, who presented the data at the American Heart Association scientific meeting in New Orleans, said 82 percent of the bleeding was considered mild. (Reporting by Bill Berkrot; Editing by Steve Orlofsky)