Vytorin Fails ENHANCE Test - Expensive Drug No Better than Statin in Preventing Clogged ArteriesJan 15, 2008 | Parker Waichman LLP Vytorin, a blockbuster cholesterol drug that is a combination of cholesterol lowering Zetia and the statin Zocor, works no better to reduce artery clogging plaque than a high dose of a less-expensive, generically available statin, according to a long-awaited study on Vytorin. The results of the much-delayed ENHANCE study are not good news for drug makers Merck and Schering-Plough, which jointly market Vytorin and share the profits.
The ENHANCE study, which was funded by Merck and Schering-Plough, focused on a group of 720 patients with a rare condition predisposing them to high cholesterol. The patients were given either Vytorin or a high dose of simvastatin, the generic form of Zocor. While both Vytorin and Zetia were found to have significantly reduced cholesterol in these patients, neither drug provided any significant benefit versus the statin drug Zocor in slowing down clogging of the arteries. Overall, the study failed to meet its primary goal, which was to show whether Vytorin was more effective than Zocor alone in preventing progression of atherosclerosis in the carotid artery, which is in the neck.
Such plaque buildup is a major risk factor for heart attacks and stroke. Many doctors had been prescribing Vytorin or Zetia on the theory that the drugs would reduce this risk in people with high cholesterol. The ENHANCE study is a serious blow to this theory.
The medical community has been eagerly awaiting the results of the ENHANCE Vytorin study. The data from the ENHANCE trial was supposed to be released by March 2007, but that didn’t happen. In November, the doctor who supervised the ENHANCE trial told the New York Times that the drug’s makers, who controlled the study’s raw data, blocked its release. In December, a congressional committee requested more information on the ENHANCE study. Merck and Schering-Plough maintained that the ENHANCE results were delayed because of the complexity of the data.
Merck and Schering-Plough also tried at one point to change the ENHANCE study’s endpoint. The endpoint is the main medical result the study was meant to measure, and it is generally accepted among scientists that for a clinical trial to be valid, the endpoint must never change. Following a great deal of outcry, Merck and Schering-Plough backed off changing the ENHANCE endpoint in December.
It is understandable that Merck and Schering-Plough would have wanted to delay the disappointing results of the ENHANCE study. According to CNN, combined Vytorin and Zetia sales were about $3.7 billion for the nine months ended Sept. 30, up 33% from the year-earlier period. Those sales are now in jeopardy, as many doctors may opt to prescribe the generic version of the Zocor alone, rather than the combo pill Vytorin. Generic simvastatin costs roughly $1 per pill, compared with about $3 per Vytorin tablet, according to drugstore.com.
Dr. Steven Nissen, chairman of cardiology at the Cleveland Clinic, told CBS News that he would advise doctors to quit prescribing Vytorin, since it was not shown to be more effective than Zocor. “My advice to physicians is not to use this drug Vytorin nor to use Zetia as first line agents any more. These should be really relegated to drugs of last resort until we have some evidence that they produce a health outcomes benefit," he said. "Right now, five years into this, with nearly 1 million prescriptions per week being written, there is no evidence that the drugs actually produce any benefit for patients."