FDA panel votes against new obesity drug Qnexa

Washington - A drug that promises to help you lose weight, and also lowers your blood pressure, blood sugar and cholesterol, has been nixed by an F.D.A. panel for what it considers dangerous side-effects.

An obesity drug vying for the first time in a decade to be the panacea for America's weight problems was narrowly defeated by a federal advisory committee to the Food and Drug Administration. The New York Times reports that the committee's vote was 10 to 6 not to endorse Qnexa, developed by the drug company Vivus, because of worrisome side-effects, like increased heart rate, possible birth defects and psychiatric problems. Both the medical community and Wall Street had been closely watching how the panel would vote, taking it as sign of how the F.D.A. might handle the newest crop of weight-loss drugs. The worry is that obesity drugs have a history of safety problems and they are likely to be used by millions of people for long periods of time. This latest committee vote suggests that drug safety will continue to be their biggest concern. Panel member Elaine H. Morrato, of the University of Colorado, Denver said,

“No one wants to conduct a large public health experiment on the population."

The F.D.A. has until late October to make a decision on Qnexa. It usually abides by the advice of its advisory committees. But F.D.A. observers say a split vote like this one can be viewed by the agency as less definitive. In fact, there were several panel members who said they could just as easily have voted the other way. There are two other new obesity drugs due to face advisory committee hearings this year, Lorcaserin from Arena Pharmaceuticals and Contrave from Orexigen Therapeutics. And both will be watching closely the outcome with Qnexa. The effectiveness of Qnexa was not in question. Results from clinical trials showed that in reducing weight, Qnexa was superior to drugs currently being used, along with the other two possible new ones. Patients getting the highest dose of Qnexa lost an average of 10.6 percent of their weight after one year, compared to 1.7 percent for those on a placebo. But the F.D.A. panel spent most of the day looking at the drug's negative side effects, including possible psychiatric problems like depression and suicidal thinking, impaired memory and concentration, acid buildup in bodily fluids that could increase the risk of kidney stones, an increase in heart rate that could lead to cardiac problems and possible birth defects. The drug Qnexa is a combo of two already approved diet drugs: phentermine, the part of the fen-phen combination that remained on the market after fen-phen was withdrawn in 1997 for causing heart valve problems, and topiramate, an epilepsy and migraine drug sold as Topamax by Johnson & Johnson. Phentermine, a stimulant, is responsible for the faster heartbeat, and topiramate causes the other side effects. Leland F. Wilson, the chief executive of Vivus, said the company was disappointed with the vote but not deterred from trying to win approval. “The advisory committee vote is a recommendation, not a final step,” he said in a brief conference call. About one-third of American adults are obese and another third are overweight, which means a successful diet drug that is safe could bring in sales of billions of dollars a year to the pharmaceutical industry. So far, there have not been any really successful drugs for obesity. The two drugs that have gotten the F.D.A.'s stamp of approval for long-term use: Meridia from Abbott Laboratories and Xenical from Roche only have moderate sales, because of their side effects and the fact that they don't work as well as they should. When the panel met Thursday, Vivus representatives argued that obesity itself was a risk to health, causing a risk of diabetes, heart disease and other diseases. Dr. Louis J. Aronne, an obesity expert at Weill Cornell Medical College and a Vivus consultant says.

“Obesity treatment can improve health and save health care dollars. Weight loss now appears to be like a gift that keeps on giving.”

During its trials, Qnexa proved it could improve blood pressure, blood sugar and cholesterol levels. But F.D.A. reviewer, Dr. Mary Roberts notes it was unclear if the improvements would translate into what really matters, a reduction in heart attacks, strokes and death.