Qnexa Ruling Renews Debate About Its Risks and Benefits

Diet drug offers new tool against obesity with risk of potential side effects.

Feb. 23, 2012— -- The decision by a federal advisory panel to recommend Qnexa for approval by the U.S. Food and Drug Administration is drawing praise and criticism from obesity and diet experts, reflecting a still-hot debate on the need for additional tools to treat obesity.

The 20 to 2 decision recommending approval Wednesday came as a surprise to many experts. The FDA has not approved a weight loss drug in the past 13 years and has withdrawn from the market many drugs due to concerns over heart risks and other side effects.

Qnexa was rejected by the agency in 2010 after a 10 to 6 vote against approval by the same panel, which included about half of the same members as Wednesday's.

But the panel this week agreed that the health risks of obesity and the benefits of losing weight outweighed the risks posed by the drug.

"The approval of Qnexa is a major step forward for the field of obesity treatment and is the result of advances in our understanding of the health consequences of obesity, and the resistance mechanisms that make it difficult to lose weight," said Dr. Louis Aronne, director of the Comprehensive Weight Control Program at New York Presbyterian Hospital.

Qnexa's rejection in 2010 was largely due to concerns over the potential for heart problems, birth defects and mental effects such as lack of concentration and fogginess for patients taking the drug.

The panel seemed to be moved this time by plans by the drug's manufacturer, Vivus, to minimize those risks through measures like labeling and an additional trial to investigate cardiovascular side effects.

But some experts say the side effects are still a major concern for a drug that will likely be sought by millions of people.

"This is far from a great drug," said Dr. David Katz, director of the Yale Prevention Research Center. "The FDA panel recommended approval of Qnexa only because the ranks of useful weight loss drugs are so thin, and desperate times call for desperate measures. Approval of Qnexa would reflect that...desperation."

One-third of Americans are obese and have chronic, expensive health problems as a result – diabetes, heart disease and arthritis, to name a few. Patients and doctors are often frustrated by the lack of middle ground options between traditional recommendations for diet and exercise and the more extreme approach of bariatric surgery.

Patients and doctors aren't the only ones antsy for a solution. The FDA has faced mounting pressures from health care groups and patient advocacy organizations to take obesity more seriously as a condition worthy of pharmacological treatment. In a letter in September, the U.S. Senate Appropriations Committee directed the FDA to file a report by March 30, 2012 on the steps it will take to "support the development of new treatments for obesity."

Critics say the search for an anti-obesity drug is nothing more than a search for a "magic bullet" cure for obesity to eliminate the need for making difficult lifestyle changes.

"The approval of Qnexa feeds into a quick-fix approach to weight management," said Dr. Gerard Mullin, associate professor at Johns Hopkins School of Medicine. "The solution to the overweight-obesity epidemic lies not in another effortless 'quick fix' but in a painful but permanent lifestyle solution."

Qnexa is a combination of two drugs already approved by the FDA: phentermine, a stimulant that suppresses appetite, and topiramate, a drug used to treat migraines and epilepsy that has weight loss as a side effect. Vivus recommends that the drug be prescribed as a part of weight loss plans that include diet and exercise.

Clinical trials so far show that the drug helps people shed 10 percent of their body weight, although patients regained some weight in the second year on the drug. It also seemed to have positive effects on blood sugar and blood pressure.

"I believe that this combination is different and a significant advance from any agents used in the past for weight loss," said Dr. Chip Lavie, medical director of cardiac rehab and prevention at the Ochsner Clinic Foundation in New Orleans. "Considering the dismal results that many experience with attempted weight loss with diet and exercise, which is always the first choice, and the explosion in the need and use of bariatric surgery, this combination drug should be a major advance."

The FDA will decide whether or not to approve Qnexa by April 17. Although the agency usually follows the recommendations of its panels, the drug's fate is not assured. In 2011, a panel recommended the weight loss drug Contrave for approval, but the FDA declined to follow its advice.