The weight loss pill Belviq (generically known as lorcaserin) was approved today by the Food and Drug Administration.
The drug, manufactured by Arena Pharmaceuticals GmbH of Zofingen, Switzerland, is intended to be used along with a reduced-calorie diet and exercise for chronic weight management, the FDA said in a statement
Belviq is approved for use in adults with a body mass index (BMI) of 30 or greater, and adults with a BMI of 27 or greater and who have at least one weight-related condition such as high blood pressure, Type 2 diabetes, or high cholesterol, the FDA said.
"Obesity threatens the overall well being of patients and is a major public health concern," Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, said in a statement. "The approval of this drug, used responsibly in combination with a healthy diet and lifestyle, provides a treatment option for Americans," Woodcock said.
Belviq works by activating a serotonin receptor in the brain. Activation of this receptor may help a person eat less and feel full after eating smaller amounts of food.
The drug was evaluated in three clinical trials that included nearly 8,000 obese and overweight patients, with and without Type 2 diabetes, who were treated for 52 to 104 weeks.
Compared with placebo, treatment with Belviq for up to one year was associated with average weight loss ranging from 3 percent to 3.7 percent, the FDA said.
About 47 percent of patients without Type 2 diabetes lost at least 5 percent of their body weight, compared with about 23 percent of patients treated with placebo. Among people with Type 2 diabetes, about 38 percent who were treated with Belviq, and 16 percent treated with placebo lost at least 5 percent of their body weight.
The approved labeling for Belviq recommends that the drug be discontinued in patients who fail to lose 5 percent of their body weight after 12 weeks of treatment, because the health of these patients is not likely to be improved by the treatment.
Belviq may cause serious side effects, including serotonin syndrome, a potentially life threatening drug reaction that causes the body to have too much serotonin, a chemical produced by nerve cells, according to the National Institutes of Health. The risk of this reaction is higher in people taking other drugs that increase serotonin levels, including drugs to treat depression and migraine. Belviq may also cause disturbances in attention or memory, the FDA says.
There has been concern that some weight loss drugs increase the risk of heart problems. In 1997, the weight-loss drugs fenfluramine and dexfenfluramine were withdrawn from the market after evidence emerged that they caused damage to heart valves.
In the studies evaluated by the FDA, patients who took Belviq were no more likely to have valve abnormalities compared with those that took a placebo.
The most common side effects of Belviq in non-diabetic patients were headache, dizziness, fatigue, nausea, dry mouth, and constipation, and in diabetic patients are low blood sugar, headache, back pain, cough and fatigue, the FDA said.