Ama Journal Report Cites Risks for Pargluva

CHICAGO (Reuters) - The experimental diabetes drug Pargluva (muraglitazar), made by Merck and Co. Inc. and Bristol-Myers Squibb, may increase the risk of heart attack and cancer and should be studied further, researchers said on Thursday.

Of the diabetic patients who took the drug in company-funded trials, 1.47 percent suffered a heart attack, a stroke or died, more than double the rate among those taking a placebo or an already approved drug, Cleveland Clinic researcher Steven Nissen wrote in the report issued online by the Journal of the American Medical Association.

An editorial published by the journal also noted a higher cancer rate -- 34 cases in 2,374 patients taking the drug -- and questioned the methodology of the company-sponsored trials.

Editorial writer James Brophy of McGill University in Montreal wrote that the application for approval of the drug to the U.S. Food and Drug Administration "may foster an illusion of safety," and he questioned the studies' patient selection and focus on laboratory results rather than patients' health outcomes.

Last month, a scientific panel appointed by the FDA voted 8-1 urging approval of the drug, which lowers blood sugar and certain blood fats, as a stand-alone treatment.

But the companies on Tuesday said the FDA is seeking additional safety information to address more fully the cardiovascular safety profile of the drug. At the time, the companies said they were eager to discuss the issue with the FDA.

"The results of this analysis are concerning," Nissen wrote, citing the heightened risks even with limited exposure to the drug for between 24 and 104 weeks.

Eighteen million Americans have diabetes, and heart disease is the cause of death in roughly 80 percent of cases, so any drug that carries heart risks should be scrutinized carefully, Nissen wrote. He recommends the drug not receive approval until a trial is done to assess its cardiovascular risks.

Pargluva would be the first to reach the market of a class of drugs called glitizars, which reduce insulin resistance and control fats in the blood.

Competing drugs that treat insulin resistance, in a class called glitazones, include GlaxoSmithKline Plc's Avandia and Takeda Pharmaceutical Co.'s Actos.