Ezetimibe Fails to Further Slow Atherosclerosis

Design flaws in ENHANCE included its use of patients with heterozygous familial hypercholesterolemia who had already been on statin treatment, and its reliance on IMT measurements at three different sites in the carotid arteries, some of which are hard to measure reliably, Dr. Davidson said. He cited an effort by Merck/Schering Plough to refine the analysis by limiting the IMT measures used to only those from the common carotid as the main reason why release of the results had been delayed. Dr. Davidson is a consultant to and has received research support from Merck and Merck/Schering-Plough.

But relatively small, IMT studies have been fine in the past, contended Dr. Nissen, who disclosed that he has no conflicts of interest.

One thing experts agreed on was that ezetimibe's role remains unchanged: it's a second-line agent for patients who are already on a maximum statin dose but are still not at their LDL goal, and an alternative for those who can't tolerate statins.

But sales data suggest that not all physicians have been using it this way. According to analyst reports, combined U.S. sales of Zetia and Vytorin were more than $3 billion in 2006, and during the first half of 2007 alone combined sales topped $2 billion.

Using ezetimibe first “was never an evidence-based position,” said Dr. Ballantyne, who is a consultant to and receives research support from Merck, Merck/Schering Plough, and other companies.