"People may well -- with the help of the company promoting it -- flock to this drug," Wolfe said. "For the FDA to put their blessing on that is unacceptable."
In testimony submitted to the panel, Wolfe and a colleague noted that increased blood pressure and heart rate caused 21 patients to withdraw from the Contrave clinical trials and that one of the FDA's own reviewers described as "concerning" the fatal heart attack of a study subject whose blood pressure rose despite significant weight loss. Wolfe also noted seizures among two study patients who took Contrave, but none among those receiving placebos.
Before voting to let the drug move ahead, the advisory panel voted 11-8 that if Contrave ultimately wins approval, its manufacturer must conduct an additional study of its cardiovascular effects.
Response to Tuesday's vote was mixed, based upon comments from nutritionists and physicians who deal with the medical consequences of obesity. Some called the panel's action reasonable given the oversized costs and health burdens of obesity. Contrave, developed by Orexigen Therapeutics of La Jolla, Calif., would be used by men and women with a body mass index of at least 30, or 27 if they also have an additional risk factor like diabetes, high cholesterol or high triglycerides.
"Perhaps FDA is getting the message that obese Americans need something short of major surgery to help them lose weight," said Carla Wolper, a dietitian with the St. Luke's Hospital Obesity Research Center in New York and an assistant professor of psychiatry in the Center for Eating Disorders Research at Columbia University Medical Center. "Surgical risks are far higher than those of appetite suppressants, but FDA approved obesity surgery." Dr. Ken Fujioka, director of nutrition and metabolic research and director of the Center for Weight Management at the Scripps Clinic in San Diego, Calif., was even more emphatic, calling the panel's endorsement "fantastic and badly needed. We were running out of options to treat weight with medications."
Connie Diekman, director of university nutrition at Washington University in St. Louis, described Contrave as "one more option in the tool chest to deal with the obesity issue," and said that the weight loss it helps achieve might help with overall blood pressure reduction.
At the same time, Dr. Rubert F. Kushner, clinical director of the Northwestern Comprehensive Center on Obesity in Chicago, said the key to proper use of the drug would be educating physicians "on how best to prescribe the medication -- identify patients who will benefit from the medication and accompany it with lifestyle behavioral recommendations."
Dr. Charles M. Clark Jr., an internationally renowned diabetes expert at the Indiana University School of Medicine, endorsed the concept of targeting appetite control medically: "We must look for innovative treatments acting on different parts of the complex mechanisms that control appetite such as the combination contained in Contrave."
But many experts expressed reservations about the limited amount of data available to the FDA from four trials involving more than 4,500 obese people with at least one complicating condition, such as diabetes or depression.