Second chances for obesity drugs?

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The obesity epidemic has moved to the forefront of public health concerns, given that it s a major contributor to diabetes, heart disease, and other adverse health conditions. Yet for people who find it impossible to lose their excess weight, there still remains a paucity of successful treatment options, especially in the pharmaceutical sector. That s not to say, however, that drug companies aren t trying to create weight-loss medications in fact, there are currently three such drugs stuck in the all too familiar limbo of the FDA approval process.

Vivus Inc. s Qnexa, Orexigen Therapeutics Inc. s Contrave, and Arena Pharmaceuticals lorcaserin are all weight-loss drugs awaiting approval. This may become an even lengthier process than usual, since the FDA is now considering whether to require obesity treatments to undergo follow-up heart safety studies prior to approval. In a two-day meeting starting tomorrow, an FDA panel will weigh the potential heart health benefits gained by people losing weight on these drugs against the risks of heart problems that might arise while on the meds, in order to determine whether further safety studies are needed. The agency currently requires pharmaceutical companies to assess diabetes drugs for the potential to increase a patient s risk of heart problems.

The makers of Contrave, in fact, have already decided to start a new heart safety trial; the decision was made after the drug was initially rejected by the FDA last year.

Yet ACSH's Dr. Gilbert Ross doesn t see the point of requiring extra testing for weight-loss medications. Why are these obesity drugs singled out? he asks. If they have already demonstrated significant safety and efficacy in Phase I, II, and III trials, then I m not sure why the FDA would add another lengthy, expensive hurdle to the onerous approval process. These treatments are desperately needed to curb the obesity epidemic and help lower the risk of other chronic ailments that commonly afflict obese patients. Also, he adds, the additional requirements might dissuade other drug makers from entering the weight loss research arena, since the cost of added heart safety trials would be a major disincentive.

As ACSH s Dr. Josh Bloom points out, The unusually high burden being placed on weight-loss drugs is no doubt a result of the Fen-Phen debacle of 1997, where the only really effective obesity drug was withdrawn after cases of heart valve damage were detected. He explains that this damage was due to a metabolite of one of the drug s components: There is no reason to expect that different drugs would cause similar heart problems, he says.