by Marion Nestle
May 11 2012

FDA panel recommends approval of another iffy weight-loss drug

I was riveted by an article in today’s New York Times about the latest decision of an FDA drug advisory panel.

The panel voted to approve a new weight-loss drug, lorcaserin.  The vote was mixed: 18 for approval, 4 against, and 1 abstention. The majority felt that the benefits outweighed the risks and that even if there were risks, “new tools are needed to treat a major health problem.”

The benefits are worth a look.

  • People taking the drug lost an average of  5.8% of their body weight in a year, compared to 2.5% for people taking a placebo.  This difference is below the FDA’s standard for approval which requires a 5% difference.
  • Among those taking the drug, 47% lost at least 5 percent of their weight after a year, whereas only 23% of those taking the placebo did so.  This meets a second FDA standard for approval.

What about the risks?  The drug:

  • Causes tumors in rats (although perhaps at higher doses than might be taken by people).
  • Damages heart valves (in the same way the withdrawn drug, Fen-Phen, did).

Also in the Times is a piece by Dr. Danielle Ofri on her experience with patients who want weight-loss drugs.

She quotes from an essay called “Lemons for Obesity” by Dr. Michael S. Lauer, who was a minority voter on the FDA panel that approved the weight-loss drug Qnexa earlier this year.

The weight-loss field is strewn with lemons, more so than other areas of medicine, Dr. Lauer argues. Because of the enormous potential market for these drugs — two-thirds of American adults are overweight or obese — pharmaceutical companies rush new drugs to market after conducting only small clinical trials. The F.D.A. and doctors are complicit in the process, Dr. Lauer says, leaving the population at large to act essentially as guinea pigs.

Shares of the maker of the drug nearly doubled after the decision.  The Times reported that “Arguments by investors have been passionate.”

People who cannot easily lose weight are desperate for help.

But is it ethical to put them at this kind of risk?