UPDATE 2-Merck stops giving clot drug in study, shares drop
10:20 am ET 01/13/2011 - Reuters
* Researchers say drug appears inappropriate for stroke
* Shares drop more than 6 pct (Adds details on drug setback, analyst comment, shares)
By Ransdell Pierson
NEW YORK, Jan 13 (Reuters) - Merck & Co <MRK.N> has stopped giving one of its most important experimental drugs, the blood clot preventer Vorapaxar, to patients in one study and to some in another late-stage trial, after it was deemed inappropriate for those who had suffered a stroke.
Merck shares tumbled more than 6 percent after the news, as the market appeared to be writing off the value of a drug once thought to have multibillion-dollar sales potential.
Merck on Thursday said it made the changes in the two pivotal trials at the recommendation of a Data and Safety Monitoring board. Such boards often require changes to trials, or halt them, should safety issues arise.
One of the trials, called TRA-2P, includes patients that have had a prior heart attack, stroke or peripheral artery disease -- a condition in which blood vessels typically in the lower part of the body are clogged and disrupt circulation.
The other study, called Tracer, enrolled patients with acute coronary syndrome, meaning patients that have chest pain or risk of heart attack.
"It does not appear to be appropriate in patients who have had a stroke," a researcher said in a separate release issued by Duke University.
The drug, acquired in Merck's recent merger with Schering-Plough Corp, works by blocking receptors to a clotting protein called thrombin. It is often called by its nickname, Thrombin Receptor Antagonist, or TRA, and has been deemed a potential mega-blockbuster treatment for heart and stroke patients.
In the TRA-2P trial, Merck said patients would continue to receive the drug if they have had a previous heart attack or peripheral artery disease. But it said the drug will be immediately discontinued in patients who had a stroke prior to entry into the study or during the study.
Merck said the Tracer study will be discontinued in a "timely and orderly fashion."
Merck shares fell $2.29, or 6.2 percent, to $34.86 in morning trading on the New York Stock Exchange.
Deutsche Bank analyst Barbara Ryan said the stock drop reflected the market reacting as if the drug was dead, although she said that she needed more details before drawing a conclusion.
"People aren't going to wait around for the details," Ryan said. "The market is wiping it out." (Reporting by Ransdell Pierson and Lewis Krauskopf, editing by Gerald E. McCormick, Dave Zimmerman) |
