June 27, 2012 -- For the first time in more than a decade, the FDA has approved a new drug to help people lose weight.
Today, Arena Pharmaceuticals' Belviq (lorcaserin hydrochloride) became the first prescription weight loss drug approved by federal regulators in 13 years.
The FDA approved Belviq as an addition to a reduced-calorie diet and exercise, for use in chronic weight control.
The approval is specifically for use in adults with a BMI above 30 (considered obese), and for adults with a BMI of 27 (considered overweight) or above if they also have at least one weight-related medical condition, such as high blood pressure, type 2 diabetes, or high cholesterol.
Belviq should not be used during pregnancy.
Today's move comes almost two years after the FDA refused to approve the drug, citing concerns about its safety and effectiveness.
But last May, an FDA advisory committee overwhelmingly endorsed making the drug available to people who are obese and those with health issues related to being overweight.
The drug's manufacturer will be required to conduct six post-marketing studies, including a long-term trial to look for heart attack and stroke risks, the FDA announced today.
Belviq works by targeting a key area of the brain that regulates appetite, known as the serotonin 2C receptor.
This is the same appetite-controlling hormone targeted by fenfluramine, the "fen" component of the notorious 1990s diet drug combo fen-phen. Fen-phen was linked to potentially life-threatening heart valve problems in as many as one in three users.
But Belviq is much more selective than fenfluramine and much safer, its manufacturer says, because it specifically targets serotonin receptors associated with hunger.
In a study published two years ago in the New England Journal of Medicine, about half of obese people who took the drug for a year lost at least 5% of their body weight, compared to 20% of dieters who took a placebo pill, while about 1 in 5 Belviq users lost 10% or more of their body weight, compared to 1 in 14 placebo users.
People who continued on the drug for two years were able to maintain their weight loss better than those who switched to placebo after one year.
Study participants were monitored closely for heart valve irregularities, and no difference was seen in the two groups.