Study questions Vytorin and Zetia in heart disease treatment
Monday, November 16, 2009
A widely prescribed and expensive cholesterol drug is not as effective as niacin, a cheap vitamin, in helping to unclog coronary arteries in people already taking statins, the standard medicines used to lower cholesterol, according to a new study.
The research, which appears Monday in the New England Journal of Medicine, is sending rumbles through the medical community because it is the third recent study to raise questions about the effectiveness of Zetia and its sister drug, Vytorin, highly profitable pharmaceuticals made by Merck & Co.
"This is the third strike," said Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic. "The studies are telling us that it doesn't appear to produce benefits. This is a drug used by millions of Americans, a very big seller, in a health-care system where costs are a major issue. And the question has to be, is this the right approach?"
Vytorin and Zetia are among the most popular prescription drugs. Last year, physicians in the United States wrote a total of more than 29 million prescriptions for them, and worldwide sales totaled $4.56 billion, according to Merck.
Although the drugs have been shown to reduce cholesterol, there is no evidence that they prevent heart attacks, strokes and other cardiovascular problems.
Top Merck executives are vigorously defending their drugs and have dismissed the new research as limited.
"I don't think a clinician or a doctor or a patient should use this as the basis for any decision-making whatsoever," said Richard Pasternak, vice president of Merck research laboratories. "I worry that people might unnecessarily come off a drug that is approved and accepted."
He and other critics said the study appearing Monday involved just 200 patients, was ended early, and examined what is known as a surrogate marker -- the amount of plaque on artery walls -- rather than evaluating the rate of heart attacks and stroke.
Because plaque can clog arteries and restrict blood flow to the heart and brain, cardiologists view plaque as a good indication for the risk of heart attack and stroke.
The study has been highly anticipated by the medical community and financial analysts, and is the buzz at the annual meeting of the American Heart Association, which began Sunday in Orlando.
Introduced in 2002 and 2004 amid heavy direct-to-consumer marketing, Zetia and Vytorin became blockbusters for Merck and Schering-Plough, which had collaborated on their development. The companies recently merged.
But new research has placed the drugs under greater scrutiny and the number of written prescriptions has been slipping, although together they still represent big business for Merck.