Two lawmakers are looking for answers to the Vytorin debacle. Reps. John Dingell and Bart Stupak, both Michigan Democrats, sent letters to Merck and Schering-Plough on Wednesday, asking the drug makers to provide information involving the marketing campaign for Vytorin. Merck and Schering-Plough jointly developed and market Vytorin, the best selling cholesterol drug in the US. The ENHANCE study, completed nearly two years ago, showed that Vytorin was no better than Zocor alone in reducing plaque buildup in the arteries. However, Merck and Schering-Plough concealed that data for nearly two years, releasing it only this week. While withholding those results, the companies continued spending at least $155 million a year on clever TV ads that heralded Vytorin’s supposed superiority over statins alone.
Merck and Schering-Plough rake in roughly $5 million dollars in sales annually from Vytorin. The ENHANCE study put those sales at risk, and there is quite a bit of speculation that the companies tried to suppress the ENHANCE results to protect their bottom lines. Vytorin is a combination of cholesterol-lowering Zetia and the statin Zocor. Doctors and Vytorin users were led to believe that the drug would effectively reduce both sources of cholesterol, thereby lessening the amount of plaque build up in the arteries, as well as the risk of having heart attacks and strokes.
The ENHANCE study, which began in 2002, was the first designed to measure how well Vytorin reduced the amount of artery clogging plaque. ENHANCE focused on a group of 720 patients with a rare condition predisposing them to high cholesterol. The patients were given either Vytorin or a high dose of simvastatin, the generic form of Zocor. The ENHANCE study found that Vytorin worked no better to reduce clogged arteries than a high dose of the less-expensive, generically available statin alone. In fact, some of the Vytorin patients in ENHANCE actually developed more arterial plaque than those taking Zocor alone, putting them at an even greater risk of heart attacks and strokes.
Even though ENHANCE was finished in April 2006, Merck and Schering-Plough did not register ENHANCE with the Clinical Trials Database until October 2007 – and even then they did not register the results. In fact, Merck and Schering-Plough delayed releasing the ENHANCE results twice, and the data was only made public on January 14, 2008. At one point, the companies even tried to change the study’s endpoint – the main medical result it was supposed to measure. But a public outcry kept that from happening. Still, even though Merck and Schering-Plough knew Vytorin was ineffective in April 2006, the companies kept running their catchy Vytorin ads on TV, touting it as being more effective than a statin alone.
All of the Merck and Schering-Plough duplicity in regards to ENHANCE got the attention of the House of Representatives’ Committee on Energy and Commerce, which actually began investigating Vytorin in December 2007, after the drug makers’ announced a second ENHANCE delay and tried to change the study’s endpoint. On Wednesday, Stupak and Dingell sent Merck and Schering-Plough a letter informing them that the Committee was investigating the ”withholding of clinical trial data that may significantly affect the medical management of hypercholesterolemia, as well as the use of misleading statement in direct-to-consumer advertisements for prescription medicines.” The letter also states that the lawmakers are “concerned that the study’s results may have been available to Schering-Plough and Merck officials, and yet the massive advertisement campaign for Vytorin was allowed to continue.”
In addition to advertisement records, Dingell and Stupak have also asked for materials related to Enhance study leader John Kastelein based in the Netherlands and information about the press release that announced the study findings.