Following on from our news on Reductil yesterday, we have now heard that the FDA Advisory Panel has recommended against approving Lorcaserin as a weight loss drug in the USA. The vote was 9 – 5 against approval. The FDA does not have to follow the recommendation of the panel but it normally does so.
The Enrocrinologic and Metabolic Advisory Panel members were concerned about tumours in rodents that were used in early stage testing of Lorcaserin. The Panel was also concerned about potential depression and memory loss caused by the experimental drug as well as potential birth defects. Arena, the patent holder and applicant, has countered that the tumours in rats were not applicable to humans as they developed as a result of high dosing and biological process that are specific to rodents. Indeed, there are a number of drugs on the market that have caused tumours in rats but not in humans but clearly more tests are required here.
There was criticism of Arena for not including more subjects in the trials who had diabetes and high blood pressure as these two conditions often accompany obesity so would be likely to be relevant for the population group prescribed the drug in clinical practice.
Arena will now enter discussions with the FDA about a way forward. We know that trials involving patients with diabetes are under way and we should have results on those by the end of the year. Although the weight loss achieved was only 5.8%, this could make a dramatic difference in terms of health outlook for obese patients so we do not think that we have heard the end of Lorcaserin.