Study Casts Doubts on Vytorin, Zetia
Cholesterol-Lowering Drugs May Not Reduce Plaque Buildup
Congressional Probe of Zetia, Vytorin Research continued...
In a news release issued Monday afternoon, the two congressmen leading the investigation had harsh words for Merck and Schering-Plough.
"Today's announcement that the ENHANCE study failed to find any positive benefit from the addition of Zetia to a common, inexpensive, generic therapy raised concerns that attempts were made to mask the minimal value of this new drug," Committee on Energy and Commerce chairman John Dingell, D-Mich., charged.
Rep. Bart Stupak, D-Mich., who chairs the oversight subcommittee, said the investigation will continue.
"In light of today's results, which were released nearly two years after the ENHANCE trial ended, it is easy to conclude that Merck and Schering-Plough intentionally sought to delay the release of this data," Stupak said. "It's currently unclear whether these companies knew that adding a new expensive drug accomplished nothing more than an established cheaper generic. But it is clear that our investigation is far from over."
A spokesman for Schering-Plough tells WebMD that the timing of the trial results release had nothing to do with the congressional investigation.
Lee Davies blamed the delay in presenting the findings on the complexity of interpreting the data, which included some 40,000 visual images that had to be analyzed.
Davies pointed out that the study was designed to assess plaque buildup in the arteries in a very high-risk patient population. The trial was not designed to look at outcomes such as heart attack, stroke, and death.
The trial included 720 patients with a rare genetic condition predisposing them to very high cholesterol.
During the two-year study, patients were treated with either high doses of simvastatin alone or Vytorin, which combines Zetia and simvastatin.
Vytorin was found to lower LDL "bad" cholesterol more than simvastatin alone, with patients on the combination drug showing a 58% reduction in LDL vs. a 41% drop for those on the single drug.
The side effect profile for the two treatments was similar, and was consistent with the labeling for Vytorin, Davies says.
But Vytorin users had slightly more plaque buildup in their carotid arteries, although the difference was not statistically significant and could have been due to chance.