Lorcaserin, to be sold as Belviq, from Arena Pharmaceuticals works on brain chemistry to create a feeling of fullness. It helps people lose about 5% or more of their starting weight when used in combination with a healthy diet and exercise.
"Obesity threatens the overall well-being of patients and is a major public health concern," said Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research in a statement. "The approval of this drug, used responsibly in combination with a healthy diet and lifestyle, provides a treatment option for Americans who are obese" or overweight patients who have one other weight-related condition, such as high blood pressure, type 2 diabetes or high cholesterol.
The drug's approval "is a major step in the right direction," says Patrick O'Neil, president of the Obesity Society, a group of weight-control researchers. He worked as an investigator in three of the lorcaserin drug trials.
"No one expects a single medication to work for everyone or to work without nutritional and exercise changes. ... It's not a substitute for changes in eating, drinking and exercise patterns," he says.
Gary Foster, director of the Center for Obesity Research and Education at Temple University in Philadelphia, says the drug "will make the hard work of weight loss easier, but not effortless. You will still have to have a lot of skin in the game."
This is another "tool in the toolbox" for doctors and their patients, he says. He expects it'll work better for some dieters than others. "But to say it's a cure for obesity or a magic bullet would set people up to be disappointed."
Lorcaserin was rejected by an FDA advisory panel in 2010 over safety concerns. The second time the advisory committee met, the members discussed heart valve concerns but decided that the benefits of the drug outweighed the risks.
The drug's manufacturer will be required to conduct six post-marketing studies, including a long-term cardiovascular trial to assess the effect of Belviq on the risk for major adverse cardiac events such as heart attack and stroke, the FDA says.
Sidney Wolfe, director of the health research group at Public Citizen, a consumer group, says lorcaserin doesn't promote much weight loss. "Its benefits are really small, and practically everyone on the advisory committee agreed that there wasn't enough evidence to rule out clinically significant heart valve disease."
He says lorcaserin "will expose large numbers of obese patients, already at risk of cardiovascular disease, to the added risk of damaged heart valves."
History could repeat itself, Wolfe says. "We've already had a weight-reduction drug (fenfluramine) taken off the market because it damaged heart valves."
The FDA says that there "was no statistically significant difference" in the development of valve abnormalities between lorcaserin and placebo-treated patients.
The drug 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 FDA says.
"Because preliminary data suggest that the number of serotonin 2B receptors may be increased in patients with congestive heart failure, Belviq should be used with caution in patients with this condition. Belviq has not been studied in patients with serious valvular heart disease," the FDA statement says.
Lorcaserin should not be used during pregnancy, the FDA says. The medication may also cause disturbances in attention or memory.
About 36% of adults in this country are obese, which is roughly 30 or more pounds over a healthy weight. Extra pounds increase the risk of type 2 diabetes, heart disease, stroke, many types of cancer, sleep apnea and other debilitating and chronic diseases. About 42% of adults are projected to be obese by 2030, if something isn't done to reverse the trend.
Currently there are only two prescription drugs used to treat obesity, including phentermine, which suppresses appetite, and orlistat (Xenical), which keeps some dietary fat from being absorbed by the intestine. Orlistat is sold in a lower dose over-the-counter version as Alli.
Another diet drug awaiting possible FDA approval is Qnexa (kyoo-NEK-suh) from Vivus. The agency will announce its decision on Qnexa sometime on or before July 17. It helps obese people lose 10% of their weight in combination with diet and exercise.
Qnexa is made up of two other older medications: the appetite-suppressant phentermine and the anti-seizure medication topiramate, which is sold under the brand name Topamax. The latter is used to treat epilepsy and migraines. Some physicians already prescribe the two drugs together for weight loss in what is called an off-label use, which is the practice of prescribing medications for an unapproved indication.
If Qnexa is also approved, then these two medications "will be complete game changers," says Tim Church, director of preventive medicine research at the Pennington Biomedical Research Center in Baton Rouge and an adviser to Vivus.
"We are going to see a paradigm shift on how we treat obesity in this country. We are going to start treating it like a chronic disease. Insurance companies are going to start paying for these medications, and physicians are going to get extremely comfortable with these and other medications that impact weight."
By Nanci Hellmich, USA TODAY