Diet Drugs – A Cupcake Commentary

It seems that there are lots of opinions floating around about the future of diet drugs in the wake of the recent FDA actions against QNEXA (Vivus) and LORQESS (Arena).  I’d like to add my opinion but I think the only opinion that really counts is that of the FDA and they have stated their opinion very clearly – it’s all about the benefit risk.

Consider if you will the Guidance that the FDA has on the proof of efficacy for drugs to treat weight loss.  There are 2 ways to prove efficacy and it must be proven in clinical trials of at least one years duration.  At one year, the FDA requires that there be a 5% difference between the drug and the placebo and the difference must be statistically significant OR at least 35% of those treated with the test drug lose 5% of their base line weight, this weight loss be at least double that achieved by the placebo group and be statistically significant. 

This is not the Mount Everest of clinical endpoints.  Do the arithmetic, yes, arithmetic, not statistics on this example.  Take a group of 200 pound people, put them on a diet.  If the placebo group doesn’t lose any weight, the drug group only has to lose 10 pounds to prove efficacy.  That’s probably the equivalent of one cupcake a week for the duration of the trial.

Now look at the regulatory decision the FDA has to make on benefit risk.  Against the benefit of just achieving efficacy per the Guidance, any increase in risk becomes unacceptable.

What does this mean for CONTRAVE which gets served up to the Advisory Committee on December 7, 2010 and the other diet drugs that are in development?  It means the benefit has got to be a lot bigger than a cupcake a week and the risk has got to be weigh weigh low.  The alternative treatment is diet and exercise – safe and effective, high benefit and low risk.