For the second time this year, a clinical trial has shown that the cholesterol-lowering drug Zetia does not prevent heart disease.
The first trial appeared last January. That trial compared Vytorin—a blockbuster drug that combines the active ingredient in Zetia with a generic cholesterol-buster known as simvastatin—against simvastatin alone in patients with a genetic condition causing them to have very high levels of LDL (bad) cholesterol and premature cardiovascular disease.
In that trial, Vytorin reduced LDL cholesterol levels much more than simvastatin alone but surprisingly, atherosclerotic plaques actually grew faster in the coronary arteries of the patients taking Vytorin.
The news was greeted with a precipitous fall in prescription volume for both Zetia and Vytorin.
The second study was published last week in the New England Journal of Medicine. This study compared Zetia to Niaspan, a drug that raises blood levels of HDL (good) cholesterol.
In the second study, Allen Taylor of the Walter Reed Army Medical Center and colleagues enrolled 363 people with coronary artery disease that had been taking statins for many years.
Taylor’s group found that Niaspan shrank carotid artery plaques by 2%, but Zetia had no such effect, even though it effectively reduced cholesterol levels (as it did in the first trial). In addition, patients who received Niaspan sustained 2 heart attacks or heart-related deaths during the study, while 9 patients receiving Zetia suffered that outcome, a significant difference.
Zetia “should be better for the arteries and it wasn’t,” Taylor told reporters covering last month’s American Heart Association meetings. “The drug wasn’t operating as you would expect.”
Officials at Merck, which co-markets Vytorin, said the study wasn’t large enough to draw firm conclusions and that larger trials of a similar nature are underway. Stay tuned.