Whether or not Contrave is approved, some doctors predict the approach behind the drug will become a trend in obesity treatment.
"There is no question that drugs like Contrave are the way of the future," said Dr. Mitchell Roslin, of Lenox Hill Hospital in New York City. "For obesity drugs to be effective they will need to be this type of cocktail that hits multiple targets."
Kim said the weight-loss results that came with that approach had some additional health advantages -- patients feeling less grumpy, for example, lower LDL or "bad cholesterol" levels, lower triglycerides, less visceral fat between the organs and smaller waists. Diabetic patients on the drug also showed better control of their blood glucose levels.
The FDA requires at least a third of the patients on a weight-loss drug lose 5 percent of their body weight to call the drug effective. Of the people taking Contrave in two non-diabetic clinical trials, nearly half (48 -56 percent) lost more than 5 percent of their body weight in a year.
Contrave also exceeded the FDA expectation that twice as many people on the drug hit the 5 percent body weight goal as people on the placebo. In the two non-diabetic trials, three times more people hit the 5 percent reduction in body weight on the drug than on the placebo.
Keith Ayoob, director of the nutrition clinic at the Albert Einstein College of Medicine in Bronx, N.Y., wasn't exactly blown over by the results.
"This drug seems to have an edge on the others out there. It appears to have met the FDA criteria and there is a reasonable amount of weight loss over a year's time. However, let's keep real about this," said Ayoob. "Fifty six weeks is a long time to lose only 5 percent of weight. For a 200 pound person that amounts to 10 pounds in a year."
"It's good, no question, and better than placebos, but I wouldn't want people thinking this is some sort of miracle," he said.
Ayoob points out that the drug works by controlling cravings, but that people often overeat and become obese for other reasons.
Other doctors were concerned about what would happen if patients take the drug for a long period of time.
"Most significantly, what happens when the drug is stopped? Will the weight be regained? What will be the effects of years of use of these drugs?" said Katz. "Despite these issues, this is exciting data."
Kim said the FDA usually asks for year-long studies in drugs that are intended for chronic use, and predicts Contrave will be prescribed for long-term use.
"There will be a small number of patients who will be able to get off these drugs," said Kim. "But the vast majority of patients would probably need to take this medication chronically."