Vytorin prescriptions have yet to recover from the dive they took in January, following the release of a study that showed the expensive cholesterol-lowering medication provides no more benefits than a cheaper statin. And Vytorin could take an even bigger hit later this month when that study, known as ENHANCE, is fully vetted at the annual meeting of the American College of Cardiology (ACC).
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. Even though ENHANCE was finished in April 2006, Merck and Schering-Plough did not register ENHANCE with the Clinical Trials Database until October 2007 – and even then they did not register the results. In fact, Merck and Schering-Plough delayed releasing the ENHANCE results twice, and the data was only made public in early January. At one point, the companies even tried to change the study’s endpoint – the main medical result it was supposed to measure. But a public outcry and a congressional investigation kept that from happening.
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/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.”
Schering-Plough, which markets Vytorin in a joint venture with Merck & Co., disclosed Monday that total prescriptions for February were 2.8 million, versus 3.2 million in January for it and its sister drug, Zetia.
Later this month, results from ENHANCE will be featured in a “showcase” at the ACC conference, where scientists will present the results and a panel of experts will discuss them on March 31. The idea of the showcase is to present the information and discuss the trial and the trial design, what it shows and didn’t show. Merck and Schering-Plough, analysts and investors will be closely watching the results of the ACC conference and measuring physician reaction to them to try to determine if they might enhance a rebound in sales or spell more trouble for Vytorin sales.