WASHINGTON -- The oral weight-loss drug lorcaserin hydrochloride (Belviq) was approved Wednesday as an adjunct to diet and exercise, making it the first new anti-obesity drug in more than a decade.
The FDA approved the drug, made by Arena Pharmaceuticals, as an option for those with a BMI of 30 or more, or a BMI of 27 with obesity-related comorbidities, such as hypertension.
Lorcaserin works by activating the serotonin 2C receptor in the brain. Activation of this receptor may help a person eat less and feel full after eating smaller amounts of food.
The approval was expected after the agency's Endocrinologic and Metabolic Drugs Advisory Committee voted in favor of the drug in May. The panel decided that the benefits of lorcaserin outweighed its risks, despite the modest weight loss provided by the drug and a lack of data to rule out heart valve issues.
In clinical trials against placebo, more than twice as many patients lost at least 5% of their total weight with lorcaserin, a benchmark the FDA requires for approving weight-loss drugs.
Overall, the difference in weight loss was small -- just 3.3% -- between the lorcaserin group and the placebo group.
However, more than a third of patients taking lorcaserin lost 11% of their weight, or 25 lbs. total, according to Arena.
In 2010, the FDA rejected Arena's application for lorcaserin, requesting more safety data.
This time around the advisory panel was still not convinced that there were enough data to rule out a link between lorcaserin and valvular heart disease.
Cardiovascular risks have long plagued diet drug development. Fen-phen was yanked from the market in the 1990s after reports of heart value issues, and more recently, in 2010 the obesity drug Meridia was pulled from the market after being linked to cardiovascular complications.
Because of those issues, the FDA is requiring that Arena conduct six postmarketing studies, including a long-term cardiovascular outcomes trial to assess the effect of lorcaserin on the risk for major adverse cardiac events such as MI and stroke.
Diet and nutrition experts contacted by ABC News/ڴŮ expressed restrained optimism about the approval of lorcaserin, but noted that obesity drugs are likely not the silver bullet for the obesity epidemic.
"Losing weight is still about consuming fewer calories than you need -- lorcaserin doesn't change that," Keith-Thomas Ayoob, a registered dietitian and associate professor of pediatrics at the Albert Einstein College of Medicine, wrote in an email. "It works by helping you feel satisfied so it makes it easier to stay compliant with a low-calorie diet."
Ayoobsaid the effects of lorcaserin were likely not more dramatic because chronically obese people eat for reasons other than because they're hungry.
"If someone eats for comfort, boredom, impulsivity, compulsively, or other reasons that have little to do with hunger or appetite, then this will probably blunt the effectiveness of the drug," he said.
David Katz, MD, associate professor in public health at Yale University said in an email that the role of pharmacotherapy in combating the nation's obesity epidemic "should be very modest."
"This is a job that only feet and forks can do with acceptable costs in both dollars and human terms," he said. "We have just about nothing at present and lorcaserin, like Qnexa, may be a bit better than that."
The FDA is expected to make a decision on Qnexa, a low-dose combination of phentermine and topiramate, for weight loss on July 17. An FDA advisory committee in February voted overwhelmingly in favor of its approval.
"The FDA approval of Belviq is an important development for patients who struggle with obesity or are overweight with comorbidities and need help with chronic weight management beyond diet and exercise," Jack Lief, Arena's president and CEO said in a statement.
According to the CDC, about 42% of adults will be obese by 2030.
This article was developed in collaboration with ABC News.