, Osymiatm has the most impressive weight loss of any obesity drug. The FDA has recommended patients discontinue the drug if they lose less than 3% of body weight on the mid-dose formulation or less than 5% on the high dose after 12 weeks. They also recommended monitoring of heart rate for people on the drug and that women of child-bearing age have a negative pregnancy test every month while using the drug. A Risk Evaluation and Mitigation System (REMS) plan includes distribution through certified pharmacies, a medication guide and a timetable for assessments.
The first new prescription diet pill in 13 years won approval from the Food and Drug Administration on Wednesday, providing a new option for the roughly one-third of American adults considered obese.
Now the question is whether people will use it. Despite a seemingly huge market, diet drugs have not sold well in the past, in part because people tend to use them for only a short time.
The new drug, developed by Arena Pharmaceuticals of San Diego, has been known as lorcaserin and will be sold under the name Belviq by Eisai Inc., the American branch of the Japanese pharmaceutical company.
Before Belviq’s approval, only one anti-obesity medicine had been approved for long-term use — Roche’s Xenical, which reached the market in 1999 and is rarely used because of modest weight loss and unpleasant effects on the digestive system.
The history of diet pills has been marked by many safety problems and product withdrawals, which has made the F.D.A. reluctant to approve new drugs. Belviq itself was turned down by the agency in 2010, but Arena came back with new data that assuaged the agency’s safety concerns.
Some patient advocates and doctors who treat obesity say there is a need for new medicines to help to plug a “treatment gap” between diet and exercise, which do not work for many people, and the more radical option of bariatric surgery. They say obesity itself is a serious disease that causes other health problems like diabetes and heart disease.
In announcing the approval of Belviq, the F.D.A. suggested that it ascribed to that point of view. “Obesity threatens the overall well being of patients and is a major public health concern,” Dr. Janet Woodcock, director of the drug evaluation center at the F.D.A., said in a statement.
Belviq is the first drug to reach the market for Arena, which was founded in 1997. Its stock price has more than quadrupled in the last two months, with much of the gain coming after an advisory committee to the F.D.A. recommended approval of Belviq by a vote of 18 to 4 on May 10. On Wednesday, the stock rose 29 percent to $11.39.
Arena said it was not clear yet when the drug would be available to patients and what it would cost. Because the F.D.A. deemed that there was some potential for the drug to be abused, the Drug Enforcement Administration must now decide what controls to place on prescribers, a process that Arena said could take four to six months.
Belviq provides only modest weight loss. In the two main clinical trials, those who took the drug lost an average of 5.8 percent of their weight after a year, while those using a placebo lost 2.5 percent. However, some 23 percent of the patients using Belviq lost at least 10 percent of their body weight.
Taken twice a day, Belviq activates a receptor in the brain, called serotonin 2C, in a way that controls eating and makes people feel full.
The main safety concern is that Belviq works somewhat like fenfluramine, a drug that was part of the popular fen-phen combination but was withdrawn from the market in 1997 because it damaged heart valves. The F.D.A. said Wednesday that it was satisfied that Belviq was unlikely to cause such problems.
The agency is not requiring patients taking Belviq to be monitored for valve damage. However, it recommends that people stop taking the drug if they do not lose 5 percent of their weight in 12 weeks, because they are not likely to benefit and should not be exposed to the risks. (About 40 percent of patients taking the drug in clinical trials achieved that much weight loss in 12 weeks.)
Arena committed to conducting six studies after the drug reached the market, including one to determine whether the drug increased the risk of heart attacks and strokes.
Some advocates hailed the approval. “The F.D.A. seemed so scared of another fen-phen recall that they had like a psychological hurdle to approve any new drug,” said Morgan Downey, editor of the online Downey Obesity Report. “I think they maybe now have gotten beyond that.”
The F.D.A. could approve a second obesity drug, Vivus’s Qnexa, next month.
But Public Citizen, the consumer group, called the approval a “reckless” action and predicted Belviq would eventually have to be taken off the market for safety reasons.
The next hurdle for Arena and Eisai will be selling the drug. This would seem easy given the tens of millions of obese and overweight people. Some analysts are projecting annual Belviq sales will exceed $1 billion.
But no other obesity drug has done that well. Only a small percentage of obese people use such drugs now.
While that is partly because there are few good choices, another issue is that insurers have been reluctant to pay for such drugs. Medicare Part D, which pays for drugs for seniors, explicitly excludes obesity drugs, along with drugs for erectile dysfunction and hair growth. Only 10 state Medicaid programs clearly pay for weight-loss drugs, according to a 2010 study by researchers from George Washington University.
Another issue is that patients tend to stop using the drug, in part because they are dissatisfied with the weight loss. The 5.8 percent average weight loss in the clinical trials of Belviq means that a person weighing 220 pounds, the average weight at the start of the trial, would still weigh 207 pounds a year later.
Even in the clinical trials, in which people tend to take drugs more faithfully than in real life, more than 40 percent of patients stopped taking Belviq before the year was out.
Dr. Ed J. Hendricks, an obesity specialist in Sacramento, said that he and other doctors might try prescribing Belviq in combination with phentermine, to essentially reconstitute the once popular fen-phen combination. “Once that word gets out that it works the same way, you are going to have a huge demand,” said Dr. Hendricks, who was on the advisory committee that voted in favor of approving Belviq.
Perhaps to discourage this, the label of Belviq states that the drug has not been tested for use with other weight-loss agents.
Christine Ferguson, a professor of public health at George Washington University, said one concern had long been that obesity drugs would be used by people who were not obese. “One of the challenges will be to ensure that it’s responsibly used,” she said.
After a long day of discussing the significance of tumor development in rats taking lorcaserin, the FDA Endocrinologic and Metabolic Advisory Committee reversed a negative vote 2 years ago and have recommended approval by a vote of 18-4. FDA does not have to follow their recommendation but the FDA reviewers are satisfied that the drug has low risks. I expect they will approve it in the near future.
