In long quest for diet drug, another setback for obese

The withdrawal of the diet drug Meridia on Friday marks the latest setback in the long, frustrating quest for a pharmaceutical solution to the nation's obesity epidemic.

Despite millions of dollars in research by scientists and drug companies, only a handful of government-approved weight-loss drugs remain on the market. Only one can be used long term, and none is considered very effective.

"It's been very frustrating," said Jennifer Lovejoy, incoming president of the Obesity Society, a research and advocacy group. "We desperately need safe new drugs so we can begin to have something effective against this public health epidemic."

The search for a weight loss cure, once dismissed as a cosmetic luxury, has intensified as more than two-thirds of Americans have become overweight, including one-third who are obese, boosting their risk for a host of health problems.

Experts stress that the best way to be healthy is to eat well and exercise regularly and to avoid gaining weight in the first place - and the failure to produce a pharmaceutical magic bullet makes the importance of that ever clearer. Doctors recommend that people always try to improve their eating habits and increase their physical activity to lose weight. But diets and exercise regimens often fail, and many people are unable to shed significant numbers of pounds or keep them off, so they resort to drugs or even surgery.

The effort to develop safe and effective weight-loss drugs, however, has suffered one setback after another. Part of the problem has been scientific, experts say. The body's hunger, fat storage and energy-burning system has turned out to be far more complex than originally thought.

"It's got lots of fail-safes and mechanisms in it," said Donna H. Ryan of the Pennington Biomedical Research Center in Baton Rouge. "Our biology is really designed to promote food intake and prevent weight loss. Our genes evolved to defend against starvation."

But some experts argue that obesity drugs are held to too high a standard and should be treated like medications for other chronic diseases, such as diabetes, and approved and allowed to remain on the market even if they have some risks.

"The criteria seem to be more strenuous to get a drug approved for obesity than it does for other chronic conditions," said George Blackburn, director of the division of nutrition at Harvard Medical School. "It's a real hardship for millions of Americans who are asked to live in an environment which is very difficult for them to restrain their eating."

Part of that, some experts argue, is because of a bias against obese people.

"The attitude is all people have to do is eat less and exercise more and that's going to be the solution to the problem," Ryan said. "That's a failure to understand the complex nature of what is essentially a complex disease."

The most stunning disappointment came 13 years ago, when the widely popular "fen-phen" two-drug combination was pulled off the market after being linked to heart-valve damage and to a rare but potentially deadly lung disease. Since then, a parade of major drug companies has abandoned once-promising diet drugs, most notably Sanofi-Aventis, which finally gave up on Acomplia after it was linked to depression.