A small study is causing a big splash in the multi-billion dollar world of cholesterol treatments. The test, pitting a prescription form of the B vitamin niacin against the prescription drug ezetimibe, found that niacin significantly shrank artery walls when taken in combination with a statin. The commercial version of ezetimibe by contrast, sold by Merck as Zetia, showed no measurable change in arterial plaque build-up. That result could give doctors pause for thought and has already created a stir among Merck investors concerned about the study’s impact on already-declining Zetia sales.

 

The study, led by Allen Taylor, director of the Advanced Cardiovascular Imaging and the Lipid/Prevention Clinic in the Department of Medicine at Washington Hospital Center in Washington, D.C., was presented at the American Heart Association’s Scientific Sessions 2009 and simultaneously published in The New England Journal of Medicine. Taylor and his colleagues conclude that the “the use of extended-release niacin causes a significant regression of carotid intima–media thickness when combined with a statin and that niacin is superior to ezetimibe.”

 

A second, larger study that relied on medical records collected by UnitedHealth Group found “no significant differences in cardiovascular outcomes when comparing the effectiveness of ezetimibe/simvastatin to equipotent doses of (the statins) simvastatin or atorvastatin alone.” Its results were presented in the Heart Association’s scientific sessions as well.

 

Merck Research Laboratories president, Peter Kim, defended Zetia, saying that "the results of the small ... study (called Arbiter 6) do not, in any way, change our view of Zetia and Vytorin as effective medicines for fighting high LDL cholesterol." The company also questioned the rigor and size of the 208-person study, suggesting it couldn’t provide “meaningful insight into the effect of either niacin or ezetimibe on clinical outcomes.”

 

Taylor’s study follows negative attention Vytorin received in 2008 after two studies questioned Vytorin effectiveness and safety when compared to the use of the statin simvastatin alone.