Weight-loss pill wins US approval
WASHINGTON—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.
Despite only achieving modest weight loss in clinical studies, the drug appeared safe enough to win the FDA’s endorsement, amid calls from doctors for new weight-loss treatments.
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 chemical pathway that was linked to the heart problems seen with fen-phen.
The FDA says the drug acts on a different chemical pathway in the brain, which is believed to reduce appetite by boosting feelings of satiety and fullness.
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 three to 3.7 percent of their starting body weight over a year. About 47 percent of patients without diabetes lost at least five 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 five percent of their weight or more.
Side effects with the drug include depression, migraine and memory lapses.
While several drugs are available for short-term weight loss, until yesterday there was only one FDA-approved prescription drug for long-term weight loss: Xenical from Roche, which is seldom prescribed because unpleasant digestive side effects and modest weight loss.