FDA Panel Recommends More Stringent Clinical Trials For Obesity Drugs

A Food and Drug Administration panel Thursday recommended more stringent clinical trials for obesity drugs to better assess heart risks.

The FDA convened a two-day advisory committee meeting to discuss the development of weight-loss drugs and whether the agency should require longer studies that are specifically designed to look at whether the products might increase the risks of heart attacks and strokes.

The development of obesity compounds has been a tough area for companies since the fen-phen drug combination was taken off the U.S. market in 1997, after one of the medication's components was linked to heart-valve damage.

Abbott Laboratories removed its weight-loss drug Meridia from the U.S. market in 2010 amid concerns about the drug's risk of side effects such as heart attack and stroke.

The FDA hasn't approved a new weight-loss drug in more than a decade, although the agency may soon approve Vivus Inc.'s (VVUS) Qnexa, which was endorsed, 20-2,by a similar advisory panel last month.

For now, Roche Holding AG's (ROG.VX) Xenical is the only long-term prescription weight-loss drug on the market, though it hasn't gained wide usage partly because of gastrointestinal side effects. The approval of Qnexa and two other weight-loss drugs has been held up for a variety of safety concerns, including whether the risk of heart problems is increased.

Current weight-loss drug development guidelines recommend studies of at least a year in overweight people to show whether people lose weight compared to patients in a placebo group and to look at whether there are any drug side-effects including changes in heart rate or blood pressure. But, the duration and size of most studies aren't able to show whether the drugs actually raise the risk of heart attacks and strokes.

The panel recommended that drug makers include heavier, older and sicker patients, or those at higher risk of having heart problems, in clinical studies. Often, people with a history of heart problems are excluded from initial studies. The panel also recommended, on a 17-6 vote, that experimental weight-loss drugs be required to show they don't increase the risk of heart attacks and strokes even if they don't have a signal for potential risk such as an increase in heart rate in initial, early-stage studies.

In 2008, the FDA toughened guidelines for diabetes drugs and now requires preapproval studies of two years that are designed to look at whether potential diabetes drugs increase heart-attack risks after safety questions were raised about GlaxoSmithKline PLC's (GSK, GSK.LN) diabetes drug Avandia. Access to that drug is severely restricted in the U.S. The FDA is considering whether to adopt similar guidelines for drugs to treat obesity.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-365-5521; [e-mail]