Will We Be Left Waiting for Latest Vytorin Trial Results?

Whitehouse Station, NJIt's been awhile since Vytorin has been in the news. The hybrid drug that combines statins Zetia (ezetimibe) and Zocor (simvastatin) into one medication was thought to improve cardiovascular performance through the reduction of plaque accumulations on arterial walls—specifically, atherosclerosis in the carotid artery, located at the neck.

However, the release of the ENHANCE trial results in 2008 showed that the use of Vytorin provided no appreciable reduction in arterial plaque buildup when compared with using Zocor alone. Yes, Vytorin was found to achieve significantly reduced levels of cholesterol in those patients studied. However, critics pointed out that reduced levels of cholesterol, in the absence of capacity for plaque reduction in arteries, renders the positive cholesterol performance somewhat moot.

The American Heart Association (AHA) challenged the naysayers, suggesting that the ENHANCE study focused on physical changes to arterial walls, and not whether or not Vytorin delivered superior performance in the prevention of heart attacks or death over the use of Zocor alone.

Critics of the AHA position pointed to financial contributions made to the American Heart Association by Vytorin manufacturers Merck and Schering-Plough, as having the potential to cloud objectivity. Nonetheless, the AHA postulated that the ENHANCE study results were insufficient to direct a change in policy or protocol, until the completion of a large study this year.

We may be hearing from that study soon, according to a conference call last month between Vytorin co-manufacturer Merck & Co. Inc. and Barclays Capital. According to transcripts dated March 16 of this year, Senior Vice President of Global Scientific Strategy for Merck, Dr. Luciano Rossetti, referenced the SHARP trial and appeared upbeat with regard to preliminary findings.

"We are, number one, extremely pleased by the outcome of the SHARP trial," Dr. Rossetti is quoted as saying in the conference call, via transcripts. "Remember this end-stage renal disease have a very high incidence of cardiovascular events, vascular events, atherosclerotic event. And what this is, is the very first trial in which, in a prospective fashion, LDL lowering with Vytorin was shown to be able to decrease the risk of both vascular event and atherosclerotic event by 17 percent.

"The study was significant for intention to treat patients on both primary—original primary endpoint and also the additional endpoint selected by the investigators. So I think this is very exciting news for the nephrology community, was extremely well received.

"We expect to file this trial very soon—sometime in 2011."

Critics will be waiting to see if the release of the SHARP trial is a repeat of the disappointing ENHANCE study, which ended in April 2006 but not fully released to the public until some 20 months later, in January 2008.

According to the comments from Dr. Rossetti, there may be room for optimism this time about the results, and a more timely release of the study.

As for Vytorin liver damage, industry watchers will be looking to see if there is any news on this front. Vytorin has been found to raise liver enzymes in some patients. While higher enzymes are not solely indicative of reduced liver function or the emergence of serious health issues surrounding the liver, they are an indication that increased focus on the liver is prudent to determine the presence or potential of any Vytorin side effects in this regard.

Sales of Vytorin plunged following the release and publication of the ENHANCE trial in 2008. Industry watchers will be looking for the release of this latest trial in 2011, to see if it ultimately agrees, or disagrees with the findings of the ENHANCE trial with regard to Vytorin heart attack and other issues.