All you need to read in the other general journalsBMJ 2010; 341 doi: https://doi.org/10.1136/bmj.c3861 (Published 21 July 2010) Cite this as: BMJ 2010;341:c3861
New weight loss drug clears its first hurdle
Lorcaserin, a selective serotonin receptor agonist, showed promise as a new weight loss drug in its first large trial. Overweight and obese adults taking the drug lost around 4 kg more in the first year than controls taking placebo (mean weight loss 5.8 kg v 2.2 kg, P<0.001).⇑ Both groups had regular counselling about diet and exercise.
Participants taking lorcaserin who lost ≥5% of their body weight in the first year were randomised again for the trial’s second year. Those switching to placebo put weight back on. Those continuing with lorcaserin rebounded less and ended up around 2 kg lighter than controls, on average.
The modest weight loss was accompanied by equally modest but potentially more important improvements in markers of cardiovascular risk including blood pressure, serum lipids, and measures of glucose metabolism. These fringe benefits set the new drug apart from orlistat and sibutramine, says an editorial (pp 288-90). A better safety profile also sets lorcaserin apart from its notorious cousins fenfluramine and dexfluramine. Both were taken off the market when evidence of damage to heart valves emerged.
The manufacturer designed lorcaserin to avoid serotonin receptors on heart valves, and it caused no discernible damage in this trial. But doctors, patients, and regulators will need to be vigilant as evaluation progresses. This trial was big, but not big enough to rule out the possibility of valvular side effects later. Most drugs licensed for weight loss have eventually been scrapped after causing serious harm, says the editorial. Sibutramine, the latest to go, was removed from the European market in January this year. It is still available in the US.