Skepticism Over New Obesity Drugs
ROBERT SIEGEL, host:
Obesity researchers met here in Washington this week to discuss new developments in their field. Among the hottest topics, three new drugs to fight obesity. They may be on the market sometime in the next year or two. The drugs produce significant weight loss in people who are obese and also overweight -that's a majority of the population if you take those two groups together.
NPR's Scott Hensley was at that meeting, and he joins us now. Scott, it sounds like this could be real progress. There hasn't been a prescription weight loss drug approved in over a decade. What's the excitement? How much weight loss are we talking about?
SCOTT HENSLEY: Well, for the studies that were presented at the meeting, we're looking at on the order of 5 percent to 10 percent weight loss, which in some of those patients was 20 or more pounds.
SIEGEL: Is there enough of a track record to see whether people who take off weight with them keep the weight off or once they go off the drug do they put it back on?
HENSLEY: The studies that were presented looked mostly at patients for about a year. One study looked up to two years. The results over that time look good. But the companies may look to have people on these medicines as a maintenance therapy. That's one of the questions that remains open.
SIEGEL: How do they work? Is this a new method of drug?
HENSLEY: They mostly work in the brain and what they do there is curb appetite and maybe change around the metabolism a little bit. One is zeroing in on a receptor in a way that hasn't been done before.
SIEGEL: What are these drugs, actually, and do they have clever names that they can be marketed with already?
HENSLEY: Sure. Qnexa, one of the drugs, is a combination of epilepsy medicine called topiramate, or Topamax was the brand name for it - is the brand name for it, and Phentermine, which is the good phen from Fen-phen.
SIEGEL: From Fen-phen.
HENSLEY: Yeah, not the one that was taken off the market.
SIEGEL: That's Qnexa.
HENSLEY: Right. One of the other drugs with a clever name is Contrave and that's a combination of two drug warhorses, one an antidepressant that was sold under the brand name Wellbutrin and the other part of that drug is a drug called naltrexone, which is used to treat alcoholism and certain forms of drug dependence.
SIEGEL: And the third one, it's not a cocktail?
HENSLEY: No, it's not a cocktail. And it's a new medicine. It's called Lorcaserin.
SIEGEL: Now, these would be the first prescription drugs to be approved to fight obesity in more than a decade. What's taken so long?
HENSLEY: I think the safety issues like Fen-phen and then another drug that had a lot of hope called - it was going to be called Zimulti here in the U.S., flamed out in clinical tests. There were problems with depression and suicidal thinking that were too big a risk, the FDA thought, relative to the weight improvements.
SIEGEL: There have been big samples that have been taking these three new drugs that you're talking about?
HENSLEY: Thousands of patients, yes, and I think that's another reason for the delay. The studies required to get these to the point where the FDA even will look at them are longer term and require thousands of patients to participate.
SIEGEL: In the overall public health picture, I mean, how important, apart from cosmetic improvements, how important is weight loss?
HENSLEY: Very important, and I think that's one of the reasons that obesity researchers are interested in a drug option. It's certainly not the first thing to try. Eating better, exercising more is the way to go. But that doesn't work for everyone and being obese, being overweight can predispose you to diabetes, contribute to heart disease and a long list of things that cost a lot and aren't good for you.
SIEGEL: Thank you, Scott.
HENSLEY: Thank you.
SIEGEL: That's NPR's Scott Hensley.
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