Lorcaserin is the First New Obesity Drug in Over a Decade

Last week, the US Food and Drug Administration (FDA) approved Arena’s lorcaserin (to be marketed in the US as Belviq), for the treatment of obesity.

Although widely touted as a new ‘diet’ or ‘weight loss’ pill – lorcaserin in neither. As all prescription medications, lorcaserin is to be used as indicated – in this case, its indication is for the treatment of obesity.

Anyone thinking they could simply go on this ‘diet’ pill to quickly (and effortlessly) lose a few pounds, should probably keep their hands off it.

Although the FDA has evidently deemed it not just effective but also rather safe (and it so happens, that I was on the Safety Monitoring Board for one of the early trials of this compound), adverse events undetected in clinical trials or with long-term use can never be completely ruled out – not for obesity drugs, nor for any other new compounds that enter the market for ANY indication.

Thus, as with the any drug, it is essential to weigh the potential benefits against any potential risks of treatment .

Obviously, even at low levels of risk (which will likely never be zero), the potential benefit is what determines the ‘value’ of a drug.

Thus, while losing a few pounds for someone who has obesity related health problems (Stage 2 or Stage 3 obesity), lorcaserin is likely to offer clinically relevant benefit, in an otherwise healthy overweight or obese person (Stage 0 or even Stage 1 obesity), benefit may modest to non-existant.

Remember, only when the risk of not treating exceeds the risk of treating, should we treat. This should apply as much to lorcaserin as it does to any other treatments.

For patients, who do have obesity related health problems, lorcaserin is the first new drug in over a decade that offers a chance – it is no magic bullet and not everyone will respond – but many will stand to benefit.

For those, who do not respond to lorcaserin or do not tolerate it, this FDA decision gives cause for hope that other obesity drugs awaiting approval will soon be added to the pharmacopeia.

After all, for treating high blood pressure we have over 100 compounds – for obesity we may soon have two!

Calgary, Alberta