For the second time in a month, the Food and Drug Administration has approved a prescription weight-loss medication for the nation's 78 million obese adults after maintaining for years that the measly benefits of the pills did not outweigh their significant costs.
Qsymia, a combination of two drugs already approved to treat other conditions, "provides another option for the chronic weight management of Americans" who are obese or who are overweight and suffer a related condition such as Type 2 diabetes, high blood pressure or worrisome cholesterol readings, said Dr. Janet Woodcock, the FDA's chief of drug evaluation, on Tuesday.
She underscored that the new medication — whose name is pronounced "kyoo-sim-EE-uh" — is to be taken by adult patients who also have cut back on calories and increased their physical activity.
When Qsymia becomes available in the fourth quarter of this year, it will have several strings attached. Exposure to Qsymia poses a risk of birth defects during the first trimester of pregnancy, so women of child-bearing age will be required to take a pregnancy test before starting the drug. They'll also have to be retested once a month and commit to contraceptive use. In addition, patients with glaucoma or hyperthyroidism should not take the drug, the FDA said.
Regulators continued to express concern about the cardiovascular safety profile of Qsymia, which helped sink the drug when it was up for review under the name Qnexa in 2010. This time, the FDA ordered the drug's maker, Vivus Inc. of Mountain View, Calif., to sponsor a multiyear follow-up study of as many as 10,000 overweight and obese patients. The study will be conducted by the Cleveland Clinic.
"We will call it the way we see it," said Dr. Steven Nissen, chair of cardiovascular medicine at the famed clinic, who will help lead the study.
Vivus will also study the effects of the medication's long-term use on kidney function and its use in obese pediatric and adolescent patients.
As is standard, the Drug Enforcement Administration will have to determine that Qsymia does not have addictive potential before it can be prescribed.
Qsymia contains the diet medication phentermine, which has been in limited use since the 1950s, and the anti-convulsant topiramate, known also by its commercial name Topamax. In clinical trials presented to the FDA, obese subjects who took Qsymia for a year — combined with dieting and exercise — lost 6.7% to 8.9% more weight than subjects who took a placebo.
In another measure of the drug's effectiveness, between 62% and 69% of subjects on Qsymia lost at least 5% of their body weight during the study, compared with 20% of those taking the placebo.
Side effects included tingling of hands and feet, dizziness, insomnia, constipation, altered taste sensation and dry mouth.
Subjects who lost weight in the drug's early trials saw expected improvements in important predictors of heart disease, such as blood pressure, metabolic function and cholesterol readings. At the same time, the drug appeared to cause a slight increase in heart rate in many patients, prompting experts to worry that Qsymia could lead to many heart attacks and strokes once it is embraced by a broad population of Americans.
The drug will be available in two doses. Physicians are being urged to start patients on the lower dose and reserve the higher dose for patients who failed to lose at least 3% of their body weight after three months of treatment. Doctors and patients should evaluate their progress after six months to decide whether to keep taking the drug, the FDA said.
Dr. Lee Kaplan, director of the Massachusetts General Hospital Weight Control Program, said that Qsymia was likely to help some obese patients in significant ways and others not at all.
"No one should assume that a majority of people are going to see sudden and dramatic changes" with Qsymia, he said. "But it will be tremendously beneficial for a subset of patients."
The agency's latest decision comes amid rising concern about Americans' excess weight and the resulting health consequences. More than 1 in 3 American adults has a body mass index that qualifies them as obese, and the rise in obesity-related diseases drives $150 billion in healthcare spending annually.
Qsymia is the second of three diet medications that have made fitful progress through the FDA's evaluation process in recent years. When they rejected Qnexa in October 2010, regulators asked Vivus to reanalyze some of its clinical trial data and to show how the firm could demonstrate the drug's safety in a large patient population.
By February of this year, an FDA advisory panel had seen the results and overwhelmingly recommended that the drug be approved.
Three weeks ago, the FDA approved the weight-loss drug lorcaserin — to be known commercially as Belviq — after a similarly tortuous evaluation process. Still to come is an FDA decision on a third diet drug, known as Contrave.
"We don't have many tools, and clinicians desperately need something they can use in the treatment of obesity," said Dr. Peter Vash, medical director for the chain of Lindora weight-loss clinics. "This is a step in the right direction."