Senators request more information on Vytorin ENHANCE study

WASHINGTON Rep. John Dingell, chairman of the Committee on Energy and Commerce, and Rep. Bart Stupak, chairman of the Oversight and Investigations Subcommittee, both D-Mich., recently wrote to the chief executive officers of Schering-Plough and Merck and to Kerry Weems, acting administrator of the Centers for Medicare and Medicaid Services, requesting information about the ENHANCE study trial as part of their investigation to determine the possibility of data manipulation.

The ENHANCE study compared the drug Vytorin to the generic drug simvastatin, both of which are used to treat patients with high-cholesterol. The study showed that Vytorin, which is a combination of Zetia and the generic simvastatin, resulted in no significant difference when compared to simvastatin alone. The results were released on Jan. 14.

Dingell and Stupak are investigating an outside panel the companies asked to advise on how to handle the ENHANCE data. The panel recommended changing the trial’s primary endpoints, which could mean manipulation of trial data, the congressmen have said. The lawmakers want to determine if a scientific advisory board, in addition to the outside panel, was created at the beginning of the ENHANCE trial to discuss trial data. They also want to know whether ENHANCE had a data safety monitoring board.

The CMS is supposed to provide the dollar amount spent by Medicare and Medicaid on Vytorin since April 2006. “We are seriously concerned that while the manufacturers may have known that Vytorin was ineffective, huge sums of taxpayer dollars may have been spent on this expensive drug,” the letter says. Dingell and Stupak requested responses from the CMS and the companies by Feb. 4.

The Committee on Energy and Commerce began an investigation into the ENHANCE trial on Dec. 11, 2007. The investigation was launched following concerns that, although the ENHANCE trial ended in April 2006, the data had not yet been released.