Another Anti-Obesity Hopeful About to Bite the Dust?

Many have tried, but for decades none have delivered a weight-loss drug that they can prove are both effective and safe.

Arena Pharmaceuticals Inc. is the latest company to have its fat-fighting drug rejected by an FDA panel over safety concerns.

The Endocrinologic and Metabolic Drugs Advisory Committee voted 9-5 September 16 to reject Arena's lorcaserin based on study data that showed laboratory animals developed tumors and memory loss during testing. No tumors were observed following Arena's one and two-year phase 3 trials but the panel expressed concerns that lorcaserin might increase the risk for developing brain or breast cancers in people.

The panel also faulted the company for not including trial data from a larger number of people with diabetes and high blood pressure- those most likely to use a diet medication. The FDA will issue its final decision by October 22 and is expected to follow the panel's recommendation.

Arena and its partner Eisai haven't thrown in the towel and plans to submit new data after it completes a trial of lorcaserin in a cohort of 600 diabetes patients. "We believe that lorcaserin has a positive benefit-risk profile and represents a potential advance in the treatment of obesity," said Arena CEO Jack Lief, in a written statement."We will work with the FDA as the agency completes its review of the lorcaserin new drug application.

Industry forecaster GlobalData predicts the global market for anti-obesity drugs -- now valued at $1.4 billion - could grow 11.7 percent each year over the next seven to reach $3.1 billion by 2016.

By 2015, approximately 2.3 billion adults will be overweight and more than 700 million will be obese, according to projections from the World Health Organization.

Yet, there are few options for the growing numbers that would consider pharmaceuticals to help shed pounds.

Prospects also look similarly grim for Vivus Inc.'s diet pill Qnexa, which is a combination of phentermine, an appetite suppressant, and topiramate, an anti-seizure medication. In July an FDA panel voted 10-6 against approval for Qnexa. The final decision is due October 28.

The FDA is also reviewing another anti-obesity drug cocktail, Orexigen Therapeutics Inc.'s Contrave, a combination of bupropion, an antidepressant, and naltrexone, a drug used to treat addictions. The FDA is expected to make a decision on Contrave by December 7.