On Thursday, a U.S. Food and Drug Administration (FDA) panel voted 18-to-4 to approve the prescription diet drug lorcaserin. It’s the second diet pill to be endorsed by an FDA advisory panel this year and, if approved, would be first new weight-loss drug in more than a decade.
Lorcaserin, made by Arena Pharmaceuticals, is actually one of three diet drugs currently vying for FDA approval — all of which were initially turned down in 2010 and 2011. Earlier this year, on its second attempt to win approval, competitor Vivus’ Qnexa received a favorable FDA panel vote, while Orexigen’s Contrave, which got the green light from an FDA advisory panel in 2010 before ultimately being rejected by the agency, will need additional long-term data on potential heart attack and stroke risks before the agency will reconsider it.
Lorcaserin was originally turned down in 2010 over FDA scientists’ concerns that the drug carried heart-valve risks — a problem that also plagued the weight-loss drug fenfluramine, which was taken off the market — and increased breast and brain tumor development in animal studies. A new review of lorcaserin by the FDA concluded this week that there was only a “negligible risk” of cancer and that preliminary trials showed no increased heart-valve risk, but the panel said that more study would be needed.
However, the panel concluded that lorcaserin’s benefits outweighed its potential risks when used long-term in overweight and obese patients. The drug, which is meant be used in combination with a healthy diet and exercise, triggers weight loss by influencing brain chemistry and giving dieters a feeling of fullness.
In clinical trials, patients who used lorcaserin lost an average of 3.1% of their starting weight over a year — a modest loss. About 38% of patients lost at least 5% of their body weight, compared with 16% in the placebo group, a result that met the FDA’s standard for effectiveness. In contrast, users of Qnexa lost an average 11% of their starting weight, and more than 83% of patients lost at least 5%, the Associated Press reports.
FDA advisory panel member Dr. Sanjay Kaul, a University of California, Los Angeles, cardiology professor, voted against approving lorcaserin because of the lingering uncertainty over heart-valve problems. “Given the totality of evidence, the potential benefits of [the drug] do not outweigh the potential risks,” he told WebMD.
The FDA is expected to announce its decision on lorcaserin by June 27. The agency will decide on Qnexa by July 17.
“The advisory committee’s positive vote supports our belief in lorcaserin as a potential new treatment option for the medical management of overweight and obesity,” Jack Lief, Arena’s president and CEO, said in a statement. “We will continue to work with the FDA as the agency completes its review of the lorcaserin new drug application.”
The drug is intended to be used in patients who are obese (with a BMI of 30) or greater or those who are overweight (BMI of at least 27) and have at least one weight-related health problem like high blood pressure.
Given America’s obesity rate — the Centers for Disease Control and Prevention recently projected that, left unchecked, 42% of Americans could be obese by 2030 — new strategies are desperately needed to stem the tide.
“We need both of these drugs (Qnexa and lorcaserin) and more,” Donna Ryan, professor emeritus at the Pennington Biomedical Research Center in Baton Rouge, told USA Today. “There are more than 200 medications to treat hypertension. There are more than 10 classes of medications to treat diabetes and 100 medication choices, but there is not much for obesity.”