The experimental diet drug Acomplia (search) not only takes off weight and reduces waist size, it also has staying power.

Unlike many other diet medications that lose their effectiveness after a few months, Acomplia takes off weight and keeps it off for two years.

Acomplia has already received high marks for its ability to increase levels of "good" cholesterol (HDL) while reducing trigylcerides (blood fats) and improving the body’s ability to handle blood sugar.

“Obesity is a chronic problem,” says Xavier Pi-Sunyer, MD, chief of the division of endocrinology at St. Luke’s-Roosevelt Medical Center and Columbia University in New York, and with evidence of long-term effectiveness, Pi-Sunyer says Accomplia fits the bill as an obesity drug that can be used in much the same way as diabetic people use insulin or people with high blood pressure use blood pressure medications.

An estimated 97 million adults in the U.S. are overweight or obese, which substantially increases the risk for other diseases such as high blood pressure, heart disease, and diabetes.

Pi-Sunyer presented the results of the study at the American Heart Association 2004 Scientific Sessions.

In the study, the largest to date, 3,000 obese patients were treated with either 5 mg of Acomplia, 20 mg of Acomplia, or a placebo for two years. Pi-Sunyer says the higher dose of Acomplia was more effective.

At the beginning of the study, the average waist size was 40 inches for men and 35 inches for women.

After two years of treatment, the average weight loss was 19 pounds and the average reduction in waist size was just over 3 inches in the higher-dose Acomplia group.

Moreover, about two-thirds of the patients who took the higher-dose Acomplia lost more than 5 percent of their weight, and more than a third lost more than 10 percent of their weight.

But Pi-Sunyer tells WebMD that while the average weight loss with Accomplia is about 19 pounds, “moving beyond that plateau would require adding something like increasing exercise or decreasing calories.” The people enrolled in the study were only told to cut back on 600 calories a day, so someone eating a 3,000-calorie-a-day diet would have cut back to 2,400 calories. There was no exercise component.

"To maintain weight loss for two years is pretty good," says Robert Bono, MD, chief of cardiology at Northwestern University in Chicago and a past president of the American Heart Association. "This was also accomplished in a sizeable number of patients."

Pi-Sunyer says 80 percent of the patients in the study were women, “which is what we usually see in weight loss studies since women seem to be more concerned about weight than men.”

Pi-Sunyer says a low dose of the drug is better than the dummy pill, but the really effective dose is 20 mg.

All patients in the study had body mass index (BMI) of more than 30, indicating obesity. A BMI of less than 25 is considered a normal weight.

Pi-Sunyer says though Acomplia appears to be safe, the drug has been tested only in adults. With the obesity epidemic in America reaching into grade schools, he says interest in Acomplia is high but it is too soon to speculate about use in adolescents.

The drug, which acts by blocking a pleasure center in the brain, is also being studied for smoking cessation.

Douglas Greene, MD, vice president of corporate medical and regulatory affairs for Sanofi-Aventis, the developer of Acomplia, tells WebMD that the company plans to file for approval with the FDA in the second quarter of 2005.

By Peggy Peck, reviewed by Brunilda Nazario, MD

SOURCES: Xavier Pi-Sunyer, MD, chief, division of endocrinology, St. Luke’s-Roosevelt Medical Center and Columbia University, New York. Robert Bono, MD, chief of cardiology, Northwestern University, Chicago. Douglas Greene, MD, vice president of corporate medical and regulatory affairs, Sanofi-Aventis.