US consumer advocacy group Public Citizen is requesting that the US Food and Drug Administration reject approval of Bristol-Myers Squibb’s diabetes agent Pargluva (muraglitazar) until additional trial data is generated to allay fears that it increases the risk of death.

In a letter sent to Andrew Von Eschenbach, acting commissioner of the FDA, the group questions the benefit of prescribing Pargluva when safer alternatives are available, and has urged that clearance of the product is placed on hold until at least until a new five-year trial is carried out to more thoroughly assess the risks of treatment with the drug.

According to Public Citizen, FDA briefing documents reveal a rise in deaths in patients taking Pargluva versus those on other diabetes treatment, with around half of these due to cardiovascular problems. In addition, the group notes that studies illustrate an increase in congestive heart failure, weight gain and cancer associated with Pargluva. Despite this, the FDA has voted to approve the drug on the condition that more heart safety data is made available before the full green light is given.

“The FDA clearly needs more information about this possibly lethal drug before it gives its stamp of approval,” stated Dr Peter Lurie, deputy director of Public Citizen’s Health Research Group. “Relatively safe and effective drug treatments exist for diabetes, and since there is no evidence to demonstrate that Pargluva has any unique benefit over other drugs, there is no basis for approving it before it has cleared additional safety hurdles,” he added.

But Bristol-Myers Squibb has said may have to abandon efforts to develop Pargluva as generating the additional information requested by the agency would require clinical trials that could take up to five years to complete, placing the future of the whole programme in doubt.

B-MS is developing Pargluva alongside Merck & Co, and both companies, facing patent expiries on key products, have been counting on the diabetes drug to contribute to future sales growth. Earlier forecasts of the product's sales potential had been as high as $3 billion dollars.