Vytorin prescriptions took a tremendous hit last week, following the release of a study that found the expensive cholesterol-lowering drug was no more effective than a statin alone. According to a report in The Wall Street Journal, Vytorin prescriptions fell 9.5% after Merck and Schering-Plough released the conclusions from the long-awaited ENHANCE study. The discovery that Vytorin was no better at reducing artery clogging plaque than a cheaper statin led some prominent cardiologists to call for limiting the use of Vytorin.
Vytorin is a combination of cholesterol lowering Zetia and the statin Zocor. The point of the ENHANCE study was to determine how well Vytorin prevented clogged arteries by reducing the formation of plaque. ENHANCE 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. Vytorin did not provide 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 on the theory that the drug would reduce this risk in people with high cholesterol. The ENHANCE study is a serious blow to this theory.
Those revelations caused many in the medical community to question the wisdom of prescribing Vytorin, which costs about $3/pill, rather than high dose of a less expensive statin at about $1.00 per pill. Among the new Vytorin critics was Dr. Steven Nissen, chairman of cardiology at the Cleveland Clinic. Dr. Nissen 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.”
The advice of doctors like Dr. Nissen and others seems to be sinking in. According to the Wall Street Journal, total U.S. prescriptions written for Vytorin in the week ended Jan. 18 fell about 9.5% to 359,659 from 397,533 in the week ended Jan. 11. If that trend continues, Merck and Schering-Plough could take a big hit, as Vytorin racked up $5 billion in sales annually before ENHANCE was released.
Those Vytorin sales are vital to Merck and Schering-Plough’s bottom line, and it does appear that the company’s tried to mitigate the effect ENHANCE would have on Vytorin sales. They knew the results of ENHANCE in April 2006, but delayed releasing the findings twice. The drug makers also tried to change the ENHANCE study’s endpoint – the main medical result the study was meant to measure. It is generally accepted that for a clinical trial to be effective, a study’s endpoint must be set at its beginning and remain unchanged. In December 2007, in response to the ENHANCE delays and the attempt by Merck and Schering-Plough to change the endpoint, Congress initiated an investigation of the ENHANCE study. The outcry over the attempted change led Merck and Schering-Plough to abandon the endpoint change.