Medical Industry Waits for Study on Vytorin

Washington, DCLess than a month away is the expected deadline for the medical world to hear the results of a study on Vytorin. The study has been undertaken to add to the published literature about Vytorin side effects and Vytorin effectiveness. So far, at least two studies regarding the drug, which combines ezetimibe (Zetia) and simvastatin (Zocor), have not shown that Vytorin is any more effective than Zocor alone.

On November 17, at the American Heart Association’s Scientific Sessions, researchers will provide the results of the IMPROVE-IT trial, which compares the use of Vytorin to using Zocor on its own. Although the American Heart Association has announced that the results will be made public that day, an abstract for the presentation is currently embargoed.

Doctors have been waiting for the results of this study for a few reasons. First, Vytorin was reportedly approved without clinical trials showing that it had benefits for its patients. Second, the results of the IMPROVE-IT trial have reportedly been delayed. In 2013, Merck announced that the study would conclude in September 2014 and was based on 5,250 clinical end points.

But Medscape reported in April 2008 that the IMPROVE-IT trial had already been delayed from 2011 to 2012 because of additional patients being enrolled. Initially, enrollment was targeted at 12,500, but that number was increased to 18,000. In other words, the results of the trial were already delayed from 2011 to 2012 and then again to 2014.

Two previous trials suggested that Vytorin was not as effective as other drugs. Those trials, ARBIRTER 6-HALTS and ENHANCE (reported on previously here), suggested that Zetia combined with Zocor was no more effective than either Niacin and Zocor or Zocor alone.

Merck has already come under fire for its handling of Vytorin-related studies. As Medscape reported in 2008, Merck and Schering-Plough were criticized for an 18-month delay in reporting results from the ENHANCE trial - and for doing so in a press release - and came under even more fire when they said an independent review panel had suggested changing the primary end point of the trial. Ultimately, the primary end point was not changed. Forbes (3/5/2008) noted in an article that no minutes were taken at the meeting of the expert panel convened by Merck and Schering-Plough, and no official vote happened, either.

Questions about Vytorin linger, with the hope being that the IMPROVE-IT trial will make the issue more clear.