Cholesterol-lowering drug Vytorin comes up short vs. statin in study
By Steve Sternberg
A controversial trial of the popular and costly cholesterol-lowering drug Vytorin showed that it offered no benefit over an older drug available in generic form, Merck and Schering-Plough said Monday.
The results come from a study of 720 patients that pitted Vytorin, a drug duo made of Zetia and Zocor, against Zocor alone. Researchers found that although Vytorin lowered bad cholesterol by 58%, it failed to slow the growth of carotid-artery plaques any more than Zocor, a statin now available as a much cheaper generic. "If anything, the trends go in the wrong direction," says Steven Nissen, chief of cardiology at the Cleveland Clinic. "The patients who got Vytorin had slightly more plaque growth."
The study is likely to fuel the debate over the companies' handling of Vytorin and its sister drug Zetia, which is also sold separately. Together, they generate more than $5 billion in sales each year. Last month, the House Committee on Energy and Commerce said it would investigate whether the two drugmakers were deliberately withholding data from the trial, which was completed in April 2006. The companies plan to give their findings to the committee this week, says Schering-Plough spokesman Lee Davies.
Zetia and statins work differently, doctors say. Statins block the formation of bad cholesterol in the liver. Zetia blocks absorption of cholesterol in the intestines, keeping it from filtering into arteries.
Although studies show Zetia and Vytorin lower cholesterol, no trial has shown that the two forms of the drug can prevent heart attacks or strokes, unlike rival statins.
"Zetia still needs to be proven effective," says Roger Blumenthal, director of the Johns Hopkins Ciccerone Preventive Cardiology Center. "The real story will be three large clinical-events trials."
Those studies involve more than 10,000 patients and will attempt to prove that Vytorin can prevent heart attacks, strokes and other life-threatening events, says Merck spokesman Chris Garland.
The new study relied on ultrasound images to measure artery plaque, an increasingly common way to gauge whether a drug works. The Cleveland Clinic said Monday that it will begin an ultrasound study of 1,200 patients in the first head-to-head trial of the blockbuster statins Lipitor and Crestor.
Imaging studies are no substitute for bigger trials designed to show whether a drug actually prevents heart attacks and saves lives, says Yale cardiologist Harlan Krumholz.
"What matters is what happens to patients," he says. "Not to their cholesterol and lab values, but to their lives."
What worries some doctors is that Zetia and Vytorin are so widely prescribed despite the lack of direct evidence of their effectiveness. Last year, doctors wrote 32 million prescriptions for the two drugs, according to IMS Health.
"I believe physicians should not use this drug as a mainstream treatment for high cholesterol," Nissen says. "It should be used as a last resort."
Find this article at: