A New Weight Loss Quick Fix?

A combination of two drugs shows real promise -- at least in mice.

July 14, 2009, 5:01 PM

July 14, 2009 — -- Millions of Americans want to lose weight. On their treadmills and over their salads they dream of a quick fix that doesn't require excessive dieting and exercise.

And the hope that those dreams could become reality got a boost Monday when a team of researchers at Indiana University released a study in the online journal Nature Chemical Biology that showed that two natural hormones combined into a single drug suppressed appetite and increased metabolism -- in rodents, anyway.

"There's a global epidemic of obesity," said Richard DiMarchi, chairman of the chemistry department at Indiana University in Bloomington and the study's lead researcher. "Our focus is finding therapies to lower body weight and treat diabetes."

A single injection of the drug decreased the rodents' body weight by 25 percent -- and fat mass by 42 percent -- after one week.

"I'm excited. It is rodent work that's representative of human obesity," said DiMarchi. "What we're doing is using the proven ability of two hormones to stop appetite and use more calories."

The drug, which researchers say might one day be taken as a weekly injection, happens to be the active ingredients in two medications already approved by the U.S. Food and Drug Administration.

Obesity specialists not affiliated with the study expressed enthusiasm over the findings.

"This has potential," said Keith-Thomas Ayoob, associate professor in the department of pediatrics at the Albert Einstein College of Medicine in Bronx, N.Y. "It's long been known that combination therapies can work well -- that is, multiple drugs at the same time to treat chronic illness, viruses, et cetera.

"With this paper, we see that a single drug is developed that acts in two different ways, which is a little different. It's like getting one drug to work in two distinct ways."

Likewise, Dr. Lou Aronne, weight-loss author and obesity expert, said that the new research "emphasizes that many approaches will probably be effective.

"Remember, even though these are mice, the treatment is affecting two receptor systems that exist in humans," he said.

Finding Could One Day Help Humans, Too

Currently, surgical interventions like gastric bypass remain the closest thing to an obesity cure. But some say this new drug may mimic the action of that surgery and may be the next step in our understanding of obesity.

"I'm excited. Finally, we're beginning to understand the pharmaceutical mechanisms of obesity," said Dr. Mitchell Roslin, chief of obesity surgery at Lenox Hill Hospital in New York.

The drug is still years away from human trials, so experts say don't give up your treadmills and salads just yet. Indeed, similar enthusiasm followed trials in 1995 of an appetite-suppressing hormone known as leptin, which also showed weight-loss potential in mice. However, this enthusiasm fizzled when human studies revealed no similar effect in humans.

And until human trials begin, nothing will be known about the potential side effects of the drug combo -- another hurdle for anyone hoping to cash in on the potential of such a treatment.

"As with leptin, we need to see the human data first before we jump for joy," Aronne cautioned.

Ayoob agreed. "I see this as potential, but right now it's only potential," he said. Long-term success still needs to be demonstrated, and by long-term I mean we'd have to see results 18 to 24 months down the road. Weight loss is one thing; maintaining it is more difficult."