In a critical trial of two widely used heart drugs to lower cholesterol, Zetia and Vytorin, the lead investigator has said the drugs’ manufacturers, Merck and Schering-Plough, were purposely delaying the release of the trial results to hide something. Zetia blocks cholesterol’s absorption into the intestine, while Vytorin combines Zetia with simvastin, another cholesterol-lowering drug often called Zocor. The two companies did not release the preliminary results of the trial, called Enhance, until almost two years after the trial had concluded. The results, when released, showed the two drugs did not reduce plaque in arteries. In response, cardiologists have recommended the two drugs only be used as a last resort. The investigator for Merck and Schering hired to conduct the Enhance trial looked at arteries of 720 patients taking either Vytorin (the combination of Zetia and Zocor) or Zocor alone. Since Zocor lowers cholesterol less than Vytorin, the two manufacturers expected the patients taking Vytorin would have less of a plaque growth in their arteries than those who take Zocor. Therefore those taking Zocor would be at a higher risk still for stroke or heart attack. The companies kept delaying the results of the test, saying the pictures of the arteries may need to be re-examined because they were unclear. Many concerns are being raised against the two companies because the lead investigator, who should be the leader of the study, did not want the results to be delayed.
Zetia and Vytorin are two of the most widely prescribed medicines in the United States, raking in sales of $5 billion last year. Although sales have dropped fifteen percent, the drugs are still being widely used. About three million prescriptions are being written in the United States each month. For the drug manufacturers to prove the two medicines reduce the risk for heart attacks and strokes, they would have to enroll 10,000 patients in an expensive, multi-year clinical trial, called outcome trials. It would prove the patients have a reduced risk of heart disease. While Merck and Schering-Plough have begun registering patients, results are not expected until 2012 or later. http://www.nytimes.com/2008/04/01/business/01drug.html?_r=2&hp&oref=slogin&oref=slogin