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  • Damages heart valves (in the same way the withdrawn drug, Fen-Phen, did).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?

  • Louisa

    Oh, good, now the FDA believes losing weight is so important that it’s worth risking cancer and heart damage. Are they reading the same studies I am? Like the ones that have found that overweight people who have high levels of cardiovascular fitness have a lower risk of mortality than thin people who don’t exercise? Or how about the studies indicating losing weight can actually be damaging to fat people who are fit in other ways? It’s not all about weight. We have to stop this cultural preoccupation with weight as the only indicator for health, because people are going to more and more desperate and insane lengths to lose weight.

  • Matt R

    My favorite line from this post is, “new tools are needed to treat a major health problem.”

    Pretty sure the old tools of eating properly and exercising work just fine.

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  • Granted this is not a miracle drug or cure, but you’ve really overstated the risks.

    The risk of cancer is entirely theoretical at this point. It would be unfair to reject the drug on this point based on the current data, though it’s always a good idea to put in place a surveillance mechanism.

    The valve problem is NOT the same as with fen-phen. The overall incidence of valve problems was quite low in the studies. It is true that the FDA was unable to rule out the possibility of a small absolute excess risk associated with lorcaserin, but it should also be noted that it’s not even clear if the valve abnormalities found on echocardiography really cause harm. The advisory panel discussed requiring an echocardiogram before a lorcaserin prescription could be written. It is possible the FDA will be receptive to this idea, which seems reasonable to me. (It will have the additional advantage of bring complete clarity to this murky subject within a few years.)

  • Not when there are perfectly safe ways to lose weight through dieting and exercise. But prescribing drugs that may cause other health issues is a great way to make sure you stay in business, whether a private practice or a huge pharmaceutical company.

  • Jill

    Just give me the placebo. I’d be content to lose 2.5% of my body weight as long as there are no side effects such as heart valve damage or risk of cancer.

    What was the placebo? Is it possible there were other factors than just the drug lorcaserin in play here?

    Serious, I suspect that the study involved limiting kilocalories and increasing activities. The drug made it easier to lose weight. If researches put significant effort into helping these research subjects effectively decrease kilocalorie intake and increase physical activity and they would all lose weight.

    It has been demonstrated many times that people can lose weight. The really hard part is maintaining that weight loss. Unless that drug can be approved for a lifetime, it will not solve the obesity problem in our country.

    The FDA is wrong to encourage this kind of wishful thinking.

  • Anthro

    Oh my! Five percent of my body weight is about six pounds. I really think I could do that on my own just by giving up my cherished 5 oz glass of wine and my twice weekly piece of chocolate.

    But, if this helps the morbidly obese lose even some weight, it may go a ways to reducing the costs to us all of diabetes and other health problems.

    It’s all well and good to preach about “eating well”, but most people are simply unaware that they eat TOO MUCH–regardless of the healthy-ness of their food. In our food intense environment, it is difficult to make eating less happen, so medication is going to be a tool we will have to use. If people get a combined effect (placebo plus actual effect) the loss might even be meaningful!

  • Nick

    Wow… I happened upon this article doing a google search and was amazed at the blatant misrepresentation of the facts with regards to Lorcaserin. The author clearly didn’t do their homework or is attempting to sway readers.

    The article states the following 2 bullet points
    “•Damages heart valves (in the same way the withdrawn drug, Fen-Phen, did).”

    The fact is that Lorcaserin had one of the most robust CV studies in history. 20,000 echocardiograms. There was NO clinical signal of valvulopathy. The company took great strides to determine the safety risk of Lorcaserin. We all know what a disaster it would be if the FDA approved another Fen-Phen. You cannot therefore state that Lorcaserin damages heart valves as there is simply no scientific proof.

    “•Causes tumors in rats (although perhaps at higher doses than might be taken by people).”

    If you pump a rat with 82 X the reccommended dose, of course there will be consequences. You can do this with any already approved drug right off the pharmacy shelf.

    While I agree that a healthy lifestyle incorporating a good diet and exercise is always going to be better for people than taking a pill, please remember that there are morbidly obese people whom are also handicapped that can benefit from such a drug.

    There are a lot of fat-burning/weight loss supplements out there already on the shelf and readily available at your local nutrition shop/gym store that are not FDA approved and people take this stuff all the time.

  • Charlie L

    Ms. Nestle must’ve been thinking about the previous review of Lorcaserin, which “was originally turned down in 2010 over FDA scientists’ concerns that the drug carried heart-valve risks — a problem that also plagued the weight-loss drug fenfluramine, which was taken off the market…” ( However, a “new review of lorcaserin by the FDA concluded this week that there was only a ‘negligible risk’ of cancer and that preliminary trials showed no increased heart-valve risk, but the panel said that more study would be needed.” I wonder whether Lorcaserin was re-formulated differently compared to its original or whether the review design was re-done somehow to yield the reverse conclusion later, or perhaps a combination of both.

    I thought this Time’s quote was most interesting: “The drug [Lorcaserin], which is meant [to] be used in combination with a healthy diet and exercise, triggers weight loss by influencing brain chemistry and giving dieters a feeling of fullness.”

    What can possibly go wrong in messing around with brain chemistry to induce a false sensation of fullness? This is certainly one way to encourage people to eat less. We have all sorts of surgeries and pills to try to deal with the fact that many of our bodies weren’t evolved to handle our modern Frankenfoods (even many of the so-called “diet” foods).

  • Suzanne

    I took Phen-Fen in the 1990’s when it was an approved weight loss drug, while I was still eating processed (junk) foods. It had a very interesting effect that I wonder if Lorcaserin duplicates.

    Phen-Fen short circuited my emotional connection for, and compulsion to consume tempting foods. I remember walking in to a party where there was an enormous, beautiful cheese cake topped with fresh, glistening strawberries and a dusting of powdered sugar. Normally, sans drug, I would feel a compelling urge to dig right it. On Phen-Fen, there was no reaction. I walked right by. I lost 30 pounds and was so discouraged when the combination drug was taken off the market.

    Low carb eating offers me some real benefits for suppressing food compulsions, because the way I do it is free from including bio-chemical manipulating processed foods. Eliminating starches and grains also eliminates the phony surge of hunger I experience after consumption. But if a safer version of Phen-Fen was re-introduced so I could successfully manage the carb binges I occasionally indulge in while under stress, I would be very, very tempted. Blunting the urge to eat food compulsively, or even to suppress the urge to binge before it happens on unhealthy items is a very, very powerful tool in the weight loss arsenal.

    I know many people who seem to manage their diet so nobly, without falling off the wagon, but I am not one of them. I struggle still.