Merck blood clot drug in limbo after mixed results

CHICAGO (Reuters) – Impressive efficacy but worrisome bleeding was seen for a new type of blood clot preventer tested by Merck & Co in one of the largest heart-drug studies ever conducted, researchers said on Saturday, raising questions whether the company will seek approval of the drug and whether it can pass muster with regulators. Vorapaxar has been dogged by bleeding concerns since January 2011, when a safety committee overseeing the 26,449-patient study said the new type of anti-platelet drug was not appropriate for patients who had suffered a stroke, due to bleeding risk. …