WASHINGTON (AP) -- The Food and Drug Administration has approved Arena Pharmaceutical's anti-obesity pill Belviq, the first new prescription drug for long-term weight loss to enter the U.S. market in over a decade.
The agency cleared the pill Wednesday for adults who are obese or are overweight with at least one medical complication, such as diabetes or high cholesterol.
The FDA denied approval for Arena's drug in 2010 after scientists raised concerns about tumors that developed in animals studied with the drug. The company resubmitted the drug with additional data earlier this year, and the FDA said there was little risk of tumors in humans.
With U.S. obesity rates nearing 35 percent of the adult population, many doctors have called on the FDA to approve new weight loss treatments.
But a long line of prescription weight loss offerings have been associated with safety problems, most notably the fen-phen combination, which was linked to heart valve damage in 1997. The cocktail of phentermine and fenfluramine was a popular weight loss combination prescribed by doctors, though it was never approved by FDA.
In a rare move, the FDA explicitly stated in a press release that Belviq "does not appear to activate" a receptor that was linked to the heart problems seen with fen-phen.
Belviq is one of three experimental weight-loss drugs whose developers have been trying for a second time to win approval, after the FDA shot them all down in 2010 or early 2011 because of serious potential side effects.
Vivus Inc.'s Qnexa is thought to be the most promising of the drugs, achieving the most weight loss. But the FDA has delayed a decision on that pill until July.
Arena's studies showed that patients taking Belviq, known generically as lorcaserin, had modest weight loss. On average patients lost just 3 to 3.7 percent of their starting body weight over a year. About 47 percent of patients without diabetes lost at least 5 percent of their weight or more, which was enough to meet FDA standards for effectiveness. By comparison, average weight loss with Qnexa is 11 percent, with more than 83 percent of patients losing 5 percent of their weight or more.
Side effects with the drug include depression, migraine and memory lapses.
In May a panel of expert advisers to the FDA voted 18-4 to recommend approval of Arena's drug, concluding that its benefits "outweigh the potential risks when used long term" in overweight and obese people.
Arena Pharmaceuticals Inc. is based in San Diego.