Arena Pharmaceuticals Inc's experimental obesity drug is expected to clear a key safety review this month. The company's lead compound, lorcaserin, is a serotonin activator like fenfluramine, half of the infamous fen-phen diet pill that was recalled a decade ago after being linked to deadly side effects. Arena says its drug also blocks appetite signals in the brain, but is much more selective in the receptors it targets. Fenfluramine, which was tied to heart failure and a fatal lung disorder, also binds to a separate cell receptor in the heart. Arena is slated to announce some time this month results of a 12-month safety review of lorcaserin. Apparently, results at six months showed no evidence of heart valve damage. Arena has enrolled about 3,200 patients in the Phase 3 trial and will study them for two years. The safety board will review echocardiograms of patients again at 18 and 24 months, but the trial's main goal is efficacy at 12 months, the period just ended, Arena Chief Executive Jack Lief said. He said the study will conclude early next year and Arena expects to file for regulatory approval of lorcaserin toward the end of 2009.
Trial Results of New Obesity Drug Lorcaserin Coming Soon
The U.S. Food and Drug Administration is allowing Arena to enroll patients in two more trials without first determining if they have pre-existing heart valve problems. An earlier three-month study of lorcaserin, without diet or exercise, showed that participants lost an average of 7.3 pounds and saw an improvement in cholesterol levels. Lief said one-third of patients in the earlier study lost 5 percent or more of their weight -- a rate shown to cut the risk of diabetes by half. "Clearly with diet and exercise patients will lose a lot more weight," the CEO said.