Merck halts vorapaxar study over bleeding concerns in stroke victims

Concern that its drug vorapaxar, in trial for its potential to prevent clots, actually increased the risk of bleeding in stroke victims has prompted Merck & Co. to halt a late-stage study of the drug, the Associated Press reported. The Whitehouse Station, N.J.-based company announced that it would stop giving the drug to about 6,000 patients with a history of stroke who were enrolled in a separate study.

The announcement followed communications issued by the academic centers leading TRA-2P and TRACER, the 2 large clinical studies of vorapaxar, and Merck. They reported on changes being made to the studies following recommendations from the joint Data and Safety Monitoring Board (DSMB).

Eugene Braunwald, MD, chairman of the TRA-2P study, reported to investigators that “the DSMB has communicated to us that, based on all of the data (safety and efficacy) available to them from both trials, they recommend that subjects with a history of stroke not receive vorapaxar. They have observed an increase in intracranial hemorrhage in patients with a history of stroke that is not outweighed by their considerations of potential benefit.”

Merck is studying vorapaxar for the prevention of cardiac events, and it had planned to submit the medication to FDA for approval this year.