Merck & Co has elected to press on with a controversial study of its combination cholesterol treatment Vytorin that has already cost it nearly $690m to settle securities lawsuits.
The IMPROVE-IT study is comparing Vytorin (simvastatin and ezetimibe) to Zocor (simvastatin) in 18,000 patients and has been cleared to continue after an independent monitoring board concluded there were no safety issues.
The study is being conducted in patients with a recent acute coronary syndrome (ACS) event and got underway in 2005, after Vytorin had been on the US market for around a year. It is trying to show a benefit for the combination in reducing cardiovascular complications and death compared to simvastatin alone.
A planned interim analysis of the trial last year allowed it to continue, but said another look at the data would be needed at the start of this year, which raised concerns about a possible safety signal that could kill the study. With a green light to continue IMPROVE-IT’s results are due in September 2014, said Merck.
Vytorin has been a somewhat controversial product for Merck since the publication of the ENHANCE trial, which compared the drug to simvastatin alone in preventing the progression of atherosclerosis but found no additional benefit. Last month Merck agreed to pay $688m to settle investor claims that it delayed disclosure of the ENHANCE results.
The debate has dampened demand for Vytorin and also ezetimibe monotherapy Zetia, which has had its own problems including a study which suggested the drug increased atherosclerotic plaque volumes in peripheral artery disease (PAD) patients.
The products remain big earners for Merck however despite the questions over ezetimibe’s effectiveness, bringing in 2012 sales of $1.75bn and $2.6bn, respectively, and together accounting for almost 10 per cent of the company’s annual turnover.
Merck has also been trying to secure approval for a combination of ezetimibe and atorvastatin (Pfizer’s now off-patent blockbuster Lipitor), and resubmitted a marketing application in the US earlier this year after being knocked back in 2012 by an FDA request for more data. The agency also turned down an application for atorvastatin/ezetimibe in 2009.