Two of the world's best-selling drugs to lower cholesterol might have no benefit, researchers reported yesterday, a development that significantly could alter how patients are treated for heart disease. Based on the news, a top medical journal encouraged doctors to stop prescribing them routinely.
Vytorin and a related drug, Zetia, did not reduce fatty plaque in arteries any more than a generic, researchers presenting at a cardiology conference in Chicago said. Plaque is a buildup of cholesterol in the arteries and is believed to play a key role in heart attacks and strokes.
In an online editorial, The New England Journal of Medicine recommended that until more research is available, patients should forgo using the drugs unless other medications such as statins or a better diet and more exercise fail to lower cholesterol levels in their blood.
Doctors said patients should not stop using the medicines without consulting their physicians. But specialists estimated that as many as two-thirds of people on the drugs eventually might be switched to other therapies.
The medicines, jointly sold by Merck & Co. and Schering-Plough, were taken by more than 4 million patients in the United States last year and accounted for $5 billion in sales.
"What this tells us is that we have had far too many patients on these drugs than the science supports," said Dr. W. Douglas Weaver, a cardiologist and president-elect of the American College of Cardiology. "I suspect we will see a significant decrease in prescriptions."
The trial, known as Enhance, was finished in 2006 but the full results were not released until now.
Merck and Schering-Plough released partial trial results in January, after news media reports about the delay and a proposal late last year to change the trial's main research goal raised eyebrows. Making such a change after a trial begins would be highly unusual, and the proposed move had some researchers worried that Merck and Schering-Plough were trying to undermine the scientific process.
The plan was scrapped after members of Congress raised questions late last year. Congress and state regulators are investigating whether the companies postponed releasing the study results to protect profits from the drugs, which Merck and Schering-Plough share equally.
In a joint statement yesterday, the Schering-Plough and Merck said that the drugs are effective and that they plan to continue marketing them as primary treatments for heart disease.
Dr. Sanjay Kaul, a cardiologist at Cedars-Sinai Heart Institute in Los Angeles, said he would review the findings released yesterday but didn't expect to cut back on prescribing the medications because he has so few patients on them. Still, he said, drug companies have an obligation to inform doctors about all research as quickly as possible.
Schering-Plough's Zetia came on market in 2002, and Vytorin, which combines Zetia with an older statin, became available in 2004.
The drugs have not been shown to prevent heart attacks. The Food and Drug Administration approved the medicines on the basis they reduce levels of LDL, or bad cholesterol. Doctors have long believed that lowering LDL levels helps slow heart disease.
In the Enhance trial, the drugs did lower cholesterol levels more than a statin but neither helped reduce thickening of a neck artery in the trial's subjects.
Daniel Costello writes for the Los Angeles Times.