Vytorin Makers Try to Defend Ineffective Drug, Downplay ENHANCE StudyJan 21, 2008 | Parker Waichman LLP
Vytorin makers Merck and Schering-Plough are attempting to salvage the reputation of the blockbuster cholesterol drug, even though a study released last week showed that Vytorin was no more effective in preventing blocked arteries than a less-expensive statin drug. The drug makers ran print ads in the Sunday New York Times, as well as several other newspapers, proclaiming that they stood behind Vytorin despite the findings of the long-awaited ENHANCE which measured the cholesterol-lowering drug’s ability to reduce clogged arteries. But despite the drug makers’ assertion that Vytorin does lower LDL cholesterol, it does not provide any reason as to why Vytorin patients should continue taking it when a high dose of a significantly less-expensive, generically available statin does the very same thing. Nor did the ads address the reasons behind the Merck and Schering-Plough decision to delay the release of ENHANCE for nearly two years, and did it provide information about the companies’ attempt to change the study’s endpoint.
Vytorin, which was developed and marketed jointly by Merck and Schering-Plough, was approved for use by the Food and Drug Administration in 2004. Since it came on the market, Vytorin sales have reached $5 billion per year. Vytorin is a combination of cholesterol-lowering Zetia and the statin Zocor. Statins like Zocor reduce the amount of cholesterol produced by the liver, while Zetia lessens the amount of cholesterol in food that is absorbed in the intestines. High cholesterol levels put a person at risk of developing clogged arteries – a major risk factor for heart attacks and strokes. Doctors and Vytorin users were led to believe that the drug would effectively reduce both sources of cholesterol, thereby lessening the amount of plaque build up in the arteries, as well as the risk of having heart attacks and strokes.
But the ENHANCE study showed that Vytorin failed in its primary mission of preventing plaque buildup in arteries. ENHANCE, which began in June 2002, 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. The ENHANCE study found that Vytorin worked no better to reduce clogged arteries than a high dose of a less-expensive, generically available statin alone. In fact, some of the Vytorin patients in ENHANCE actually developed more arterial plaque than those taking Zocor alone, putting them at an even greater risk of heart attacks and strokes.
The ENHANCE study was supposed to have been released by Merck & Schering-Plough in November 2006, but that was delayed by the companies until March 2007. Then Merck and Schering-Plough announced the release of ENHANCE would be delayed again until March 2008. The drug makers also announced that they would be changing 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.
Sunday’s Vytorin print ad said that Vytorin users “may be worried about recent news stories questioning the benefit of these medicines" The ad cites the drugs' ability to lower LDL cholesterol and urges patients to follow their doctors' recommendations on taking prescribed medicines. It tries to downplay the ENHANCE findings by referring to it as merely a “single” study, and it does not mention Merck and Schering-Plough’s frantic attempts to suppress the ENHANCE findings.