Federal Food and Drug Administration officials approved a new weight-loss pill Wednesday, giving the nod to Belviq used in combination with a reduced-calorie diet and exercise to combat obesity.

The Arena Pharmaceuticals drug, which also goes by the generic name lorcaserin, is one of three new potential weight-loss treatments the agency is considering and the first new weight-loss medication approved in 13 years. More than two-thirds of adult Americans are overweight or obese. 

"Obesity threatens the overall well-being of patients and is a major public health concern," said Dr. Janet Woodcock, the director of the FDA's Center for Drug Evaluation and Research.

Lorcaserin was initially rejected because of concerns about safety issues, particularly concerns about heart valve problems, but a panel this spring agreed that the drug from Arena in conjunction with the Japanese firm Eisai Inc. was now suitable for use. 

The drug works by activating a receptor in the brain that may help a person eat less and feel full after eating smaller amounts of food.

It is approved for use in obese adults with a body mass index or BMI of 30 or greater and in overweight adults with a BMI of 27 or greater if they have at least one weight-related condition such as high blood pressure, type 2 diabetes or high cholesterol. For example, a 5-foot-7 woman who weighed 192 pounds would have a BMI of 30.

The drug was tested in three randomized, placebo-controlled clinical trials involving nearly 8,000 obese and overweight patients, including those with and without type 2 diabetes. They were treated for 52 to 104 weeks. All participants agreed to diet and exercise regimens. Compared with use of a placebo, or sugar pill, patients treated with Belviq for up to one year lost an average of 3 percent to 3.7 percent of their body weight. 

Nearly half of patients without diabetes lost at least 5 percent of their body weight, compared with about a quarter of those who took placebos. In people with diabetes, about 38 percent treated with lorcaserin lost 5 percent of their body weight, compared with about 16 percent treated with placebos. 

The drug is recommended to be discontinued in patients who fail to lose 5 percent of body weight after 12 weeks of treatment because they appear to be unlikely to achieve "clinically meaningful" weight loss. 

Approving lorcaserin will offer big benefits to patients approaching the 30 BMI mark, which increases health risks and decreases the likelihood of future weight loss, said Dr. Jaime Ponce, the new president of the American Society for Metabolic & Bariatric Surgery. 

"I think this is great," he said. "Thirteen years without any other medical option."

Select patients treated in a program that includes diet, exercise and medication may be able to lose weight without resorting to surgery, he added.

Arena Pharmaceuticals will be required to conduct six post-marketing studies including a long-term trial to evaluate cardiovascular risks including heart attacks and stroke. 

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