Arena drug helps diabetics lose weight in trial

NEW YORK (Reuters) - A new clinical trial of Arena Pharmaceuticals Inc's diet pill, which was turned down last month by U.S. regulators, found that it helped diabetics lose weight, the company said on Tuesday.

The U.S. Food and Drug Administration declined to approve the drug, lorcaserin, for treatment of obesity, citing questions about its effectiveness and potential cancer risk.

The agency also requested that Arena provide results from this latest trial involving 604 obese diabetics.

The trial showed that after a year, 37.5 percent of patients taking a 10 mg dose of lorcaserin twice a day lost at least 5 percent of their body weight, compared with 16.1 percent of patients taking a placebo.

Lorcaserin patients had mean weight loss of 4.5 percent, or 4.7 kilograms (10.3 pounds), compared with 1.5 percent, or 1.6 kg, for placebo patients.

"Achieving weight loss in these patients can be difficult ... we are excited that the efficacy of lorcaserin was maintained in this diabetic population," said Jack Lief, Arena's chief executive.

The San Diego company, which is developing lorcaserin with Japan's Eisai Co Ltd, said the trial also showed that lorcaserin helped improve glucose levels, cholesterol and triglycerides.

Arena said side effects of the drug included headache, upper respiratory infections and back pain.

Lorcaserin is a serotonin activator like fenfluramine, one of the drugs that was used as part of the recalled fen-phen diet drug cocktail. But the Arena drug is more selective in the receptors it affects and thereby sidesteps heart-related side effects.

In the diabetes trial, 2.9 percent of lorcaserin patients developed valvulopathy (heart valve problems) after six months, compared with 1.9 percent of placebo patients. At one year, 2.9 percent of lorcaserin patients had new valvulopathy, compared with 0.5 percent of placebo patients.

Lief said the number of patients in each group was too small to detect a statistically significant difference.

Arena is one of three small drug developers looking to launch an approved weight loss drug. The FDA, also in October, turned down an application from rival Vivus Inc for its experimental obesity pill Qnexa.

Next up is Orexigen Therapeutics Inc, which will have its drug, Contrave, reviewed by an FDA advisory panel in December.