Merck, Schering drug fails in 'ENHANCE' study

Two pharmaceutical companies Merck and Schering-Plough Corp. suffered a major setback Monday after results of a long-awaited study on their co-marketed Vytorin, a combination of cholesterol-lowering drugs Zocor (simvastatin) and Zetia (ezetimibe) showed the drug provides no medical benefit to users.

In the trial, the popular cholesterol-lowering drug Vytorin failed to show that it has any medical benefits. The combination drug worked no better than less-expensive cholesterol drugs at preventing clogged arteries, a significant disappointment for the manufacturers.

Announcing the results of their own trial, called ENHANCE study, the two drugmakers said Vytorin did not slow the buildup of artery-clogging plaque, nor did it minimize the thickness of plaque lining artery walls.

Disappointed with the study results, Skip Irvine, a spokesman for Merck/Schering-Plough Pharmaceuticals, a joint venture between the two companies that markets Zetia and Vytorin, said, "Obviously, we would have preferred a more favorable result."

The ENHANCE study, which was already a year-and-a-half delayed, found that while the pricier statin-plus-Zetia combination-drug, Vytorin, succeeds in the measure of lowering cholesterol, it had no more of an effect on reducing plaque buildup in the arteries than Merck's older statin, Zocor, which lost patent protection last year.

The new ENHANCE trial involved 720 patients with a genetic condition that causes abnormally high levels of blood cholesterol. In the two-year study, the researchers found no statistically significant difference in heart attacks or stroke among trial participants who took Zetia along with a generic statin Zocor, versus those who received Zocor alone.

The researchers also observed that the speed at which arteries thickened with plaque almost doubled among those on Zetia/Zocor compared to those taking the widely used cholesterol-lower drug, Zocor alone, while safety profiles were similar for both groups.

"In the absence of any evidence of a clinical benefit, these drugs should now be used as a last resort," said Steven Nissen, head of cardiology at the Cleveland Clinic. "It should not be used as a routine therapy for high cholesterol unless we see some additional evidence of benefit."

The Whitehouse Station, New Jersey-based drug maker Merck and the Kenilworth, New Jersey-based Schering-Plough are now conducting three large trials involving more than 20,000 high-risk patients.

Shares of Merck yesterday were down 77 cents, or 1.2 percent, to close at $59.78, while Schering's stock slipped $2.21 or 7.9 percent, to $25.52.