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Jan. 15, 2008 -- Disappointing results from a long-awaited trial of the best-selling cholesterol drug Vytorin drew mixed reactions from some of the nation's leading cardiologists.
Vytorin, which combines the unique cholesterol drug Zetia with the traditional statin drug simvastatin, was found to be no better than simvastatin alone for reducing plaque buildup in the carotid arteries. The carotid arteries run through both sides of the neck to the brain.
In fact, patients taking Vytorin actually had slightly more plaque buildup during the trial than those taking simvastatin alone.
The findings were revealed Monday morning in a news release issued by the drug companies Merck and Schering-Plough, which jointly market Vytorin and Zetia.
In an interview with WebMD, cardiologist Steven E. Nissen, MD, called the results "a stunning reversal for Zetia and Vytorin."
Nissen is chairman of the department of cardiovascular medicine at the Cleveland Clinic, and is a past president of the American College of Cardiology.
"Zetia works only by blocking the absorption of cholesterol, but it has not been shown to produce any health benefits," he says. "I have been skeptical of these drugs from the beginning because I wasn't sure that Zetia's mechanism of cholesterol lowering would produce the same benefits that we see with statins."
But P.K. Shah, MD, who directs the cardiology department at Cedars-Sinai Medical Center in Los Angeles, tells WebMD that the trial results do not mean that the millions of patients taking Zetia or Vytorin derive no benefit from the drugs.
"I don't think this is a call for a moratorium on Zetia. That would be overreaching," he says. "This was a small study and it is not the last word."
(Do you take Zetia? Will you talk to your doctor now? Tell us about it on WebMD's Cholesterol Support Group board.)
The release of the results came just weeks after the announcement of a congressional investigation into the drug companies' actions surrounding the study, which ended nearly two years ago.
In addition to delays in presenting the results, critics had accused the companies of attempting to change the endpoints of the study, known as the ENHANCE trial, in an effort to present the results in a more favorable light.
In a news release issued Monday afternoon, the two congressmen leading the investigation had harsh words for Merck and Schering-Plough.
"Today's announcement that the ENHANCE study failed to find any positive benefit from the addition of Zetia to a common, inexpensive, generic therapy raised concerns that attempts were made to mask the minimal value of this new drug," Committee on Energy and Commerce chairman John Dingell, D-Mich., charged.
Rep. Bart Stupak, D-Mich., who chairs the oversight subcommittee, said the investigation will continue.
"In light of today's results, which were released nearly two years after the ENHANCE trial ended, it is easy to conclude that Merck and Schering-Plough intentionally sought to delay the release of this data," Stupak said. "It's currently unclear whether these companies knew that adding a new expensive drug accomplished nothing more than an established cheaper generic. But it is clear that our investigation is far from over."