FDA approves lorcaserin for the treatment of obesity

June 27, 2012

San Diego, CA (updated) - The second trip before the Food and Drug Administration appears to have done the trick: today the agency approved lorcaserin (to be called Belviq, Arena Pharmaceuticals, San Diego, CA) for the treatment of obesity[1].

The approval follows an overwhelming vote by the Endocrinologic and Metabolic Drugs Advisory Committee in favor of lorcaserin as an adjunct to diet and exercise in patients with a body-mass index (BMI) >30. For patients with weight-related comorbidities, the drug is indicated for individuals with a BMI >27.

In October 2010, the FDA rejected lorcaserin because of concerns about a cancer signal detected in preclinical animal studies and asked for more data, including results from the BLOOM-DM trial, a study testing the weight-loss drug in overweight and obese subjects with diabetes. In addition, the 2010 advisory panel considered the weight loss in nondiabetic overweight and obese subjects "marginal." In the phase 3 clinical trials, known as BLOOM and BLOSSOM , the average weight loss in the lorcaserin-treated patients was 5 to 6 kg.

In May, the FDA advisory committee was presented with the new data, and the panel appeared satisfied that there was no increased risk of cancer with lorcaserin. The FDA, in its own review, also agreed that the risk of tumors in treated patients was "negligible." That said, it still expressed some concern about a possible increased risk of valvulopathy and adverse cardiovascular events associated with lorcaserin.

Dr Robert Eckel (University of Colorado School of Medicine, Denver) said there is a need for pharmacotherapy for the treatment of obesity and that the decision by the FDA opens the door to other pharmacological agents that also reduce body weight in overweight and obese patients. He noted that lorcaserin has a moderate effect on weight loss, with a reduction of 3% to 4% of the individual's body weight.

"The question then comes up, 'Does weight loss per se reduce cardiovascular disease events or related mortality?' " Eckel told heartwire . "We just don't know the answer to that yet. I think the bariatric-surgery data put forward by the Swedish group indicates that it does, but in terms of medical management of obesity with drug therapy or with lifestyle, we don't have any data that substantiate the hypothesis that weight loss is effective in reducing cardiovascular disease events or mortality."

Regarding the issues of cardiac valvulopathy, Eckel said he is comfortable with the data at this stage where clinicians can safely and confidently prescribe lorcaserin to patients. He cautioned, however, as with any drug, adverse events undetected in clinical trials can arise. In contrast to Eckel's confidence, Public Citizen, a nonprofit consumer-advocacy group, urged the FDA not to approve lorcaserin on the basis of the heart-valve concerns. The combination of fenfluramine/phentermine, popularly known as fen-phen, was pulled from the market in the late 1990s, given the risks of heart-valve damage. The risks from the drug were attributed to fenfluramine.

In February, as reported by heartwire , the FDA advisory committee also voted in favor of approving the obesity drug Qnexa (Vivus, Mountain View, CA), a combination of phentermine and controlled-release topiramate, but the FDA has still not approved the drug. A decision on Qnexa is expected in July, after the FDA requested additional time in April to review material from the company.

Lorcaserin is first approved drug for treating obesity since the approval of orlistat (Xenical, Roche; Alli, GlaxoSmithKline) in 1999.


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