Controversy Surrounding the ENHANCE Study

The medical community, eager to know if Vytorin lived up to its promise, had anxiously awaited the results of ENHANCE. But doctors and patients were forced to wait longer than expected for the ENHANCE data. The ENHANCE results should have been released by March 2007, but that didn’t happen.   In November 2007, the doctor who supervised the ENHANCE trial told the New York Times that the drug’s’ makers, who controlled the study’s raw data, blocked its release. In December of that year, a congressional committee requested more information on the ENHA NCE study. Merck and Schering-Plough maintained that the ENHANCE results were delayed because of the complexity of the data. According to the New York Times, Merck and Schering-Plough also tried at one point to change the ENHANCE study’s endpoint. The endpoint is the main medical result the study was meant to measure, and it is generally accepted among scientists that for a clinical trial to be valid, the endpoint must never change. In December 2007, following a great deal of outcry, Merck and Schering-Plough scrapped plans to change the ENHANCE endpoint.

Some question whether or not the Merck and Schering-Plough decision to delay releasing ENHANCE and the attempt to change the study’s endpoint could have been inspired by the disappointing Vytorin findings. Combined Vytorin and Zetia sales were about $3.7 billion for the nine months ended September 30, 2007, up 33% from the year-earlier period. The results of ENHANCE put those Vytorin sales at risk, as many doctors may opt to prescribe the generic version of the Zocor alone, rather than the combo pill Vytorin. Generic versions of Zocor cost roughly $1 per pill, compared with about $3 per Vytorin tablet. Obviously, Merck and Schering-Plough had reason to protect the reputation of Vytorin.