Merck and Schering-Plough prepare Vytorin letter

The letter affirms the companies' position that the spike in cancer deaths and higher incidence of cancer in a recent study involving 1,873 people was an anomaly. Results from the study, called SEAS, were released Monday. The companies maintain that the actual number of patients who died of cancer was too small to link to Vytorin.

While Merck and Schering-Plough have shared data from the study with the U.S. Food and Drug Administration, FDA did not require them to send the letter to doctors, Irvine noted.

"MSP (Merck/Schering-Plough) believes the cancer finding in SEAS is likely to be an anomaly that, taken in the light of all the available data, does not support an association with Vytorin," the letter says. "We are committed to working with regulatory agencies to further evaluate the available data and interpretations of those data; however, we do not believe that changes in the clinical use of Vytorin are warranted."

Vytorin, which has been under fire because of prior studies questioning its effectiveness, is a combination of Merck's Zocor and Schering-Plough's Zetia. Zocor is now available in cheaper generic versions.

The SEAS study's actual goal, which wasn't met, was to show whether Vytorin reduced the risk of major cardiovascular problems in patients with a sometimes-deadly heart valve disease, called aortic stenosis, that blocks flow of oxygen-rich blood out to the body. The study found the drug was no better than placebo at lowering risk of heart attack, stroke or death in those patients.