In a clinical trial, the cholesterol-lowering drug Vytorin did not help people with heart-valve disease avoid further heart problems but did appear to increase their risk of cancer, scientists reported Monday.
The scientists who reported on the trial, called SEAS, cautioned against panicking over the cancer findings, saying that even well-designed clinical trials sometimes produce chance results. A review of two other, much larger trials did not find a similar risk, they said.
But other cardiologists and epidemiologists said the cancer risk could not be so easily dismissed. The findings of the SEAS trial will heighten concerns about Vytorin's safety and effectiveness, said Dr. Steven Nissen, a former president of the American College of Cardiology and a critic of Vytorin.
The study did find that Vytorin lowered cholesterol.
Vytorin and Zetia, a companion drug, are prescribed each month to almost 3-million people worldwide and are among the world's top-selling medicines.
Six months ago, another clinical trial, called Enhance, also failed to show that Vytorin benefited patients, leading a panel of top cardiologists to recommend using Vytorin and Zetia only as a last resort.
Since, Vytorin and Zetia prescriptions have plunged, though the drugs remain among the largest sellers for Merck and Schering-Plough, which jointly sell them. Sales last year totaled $5-billion.
Shares of Merck and Schering skidded after the SEAS trial results were reported, with Merck shares down 6 percent and Schering down 12 percent. After the close of trading, both companies reported second-quarter earnings that were slightly ahead of analysts' estimates.
Vytorin is a single pill that combines two cholesterol-lowering medicines — Zocor, or simvastatin, and Zetia, or ezetimibe. Both Zocor and Zetia are also available as single pills.
In the SEAS trial, which involved nearly 1,900 patients whose heart valves were partially blocked, participants were given either Vytorin or a placebo. Scientists hoped that the trial would show that patients taking Vytorin would have a lower risk of needing valve replacement surgery or having heart failure. But the drug did not show those benefits.