Wednesday, June 13, 2012

New Drug Shows Promise in Helping Obese Patients Lose Weight

After two years on a drug that affects the pleasure center of the brain, obese patients had reason to feel good: Their bellies shrank, their cholesterol improved and their insulin levels moved toward normal, according to research presented Tuesday in New Orleans.

In the trial, more than 3,000 patients lost an average of 19 pounds, including an important reduction of 3.1 inches on their waistlines, compared with a 5-pound weight loss in the placebo group. Central fat is the kind that is most associated with heart disease risk.

Results of the latest trial of the drug rimonabant, which works on certain receptors in brain cells, were presented at the American Heart Association's Scientific Sessions. A Milwaukee hospital will be conducting a new clinical trial of the drug beginning next month.

"It could be an exciting new player in obesity," said Robert Eckel, a physician and professor of physiology at the University of Colorado Health Sciences Center who was not associated with the study.

In addition to taking the drug or a placebo, patients in the clinical trial were instructed to cut food intake by 600 calories a day.

Along with the weight loss, their HDL cholesterol (the good kind) went up 24.5 percent, compared with a 13.8 percent increase in the placebo group, and triglycerides, an unhealthy type of fat in the blood, went down 9.9 percent, compared with 1.6 percent in the placebo group.

The patients also experienced a significant improvement in their ability to use insulin, which is important in preventing type 2 diabetes.

"This seems to be an encouraging drug for weight loss, in particular central fat," said lead author F. Xavier Pi-Sunyer, chief of the division of endocrinology at St. Luke's-Roosevelt Hospital at Columbia University.

The study, which is the third and largest trial of the drug, was sponsored by the drug's maker, Sanofi-Aventis. The company calls the drug Acomplia.

The drug appears to have a low level of side effects with no significant EKG or heart rate changes. It did have slightly higher rates of depression, anxiety and irritability than the placebo, Pi-Sunyer said.

About 13 percent of patients stopped taking the drug because of side effects, compared with about 7 percent in the placebo group.

Doctors not associated with the trial said they were encouraged that a new diet drug soon should be available in the battle against obesity, but they raised several concerns.

"What worries me is this may be an excuse to not go out and do what you are supposed to be doing in terms of lifestyle," said George Bakris, vice chairman of the department of preventive medicine at Rush University Medical Center in Chicago.

He also said he was concerned about the potential for the drug to cause depression.

"When you start interfering with that part of the brain, things can happen," Bakris said.

Others said that while the drug should be helpful, it is not the answer to the obesity epidemic.

"It is such a huge problem," said Robert Bonow, a professor of cardiology at the Northwestern University Feinberg School of Medicine. "Whether a single drug can be a cure-all is not clear."

Rimonabant is the first in a new class of drugs that target certain receptors on the surface of brain cells that are part of the endocannabinoid system, which helps regulate food intake and energy expenditure. In particular, the drug blocks the cannabinoid type 1 receptor, which is the same receptor that is active when people smoke marijuana and get hungry. The receptors also are found on the surface of fat cells.

People who overeat are believed to have an overactive cannabinoid system. The same system is active in cocaine use and smoking. Preliminary research suggests that rimonabant may help people quit smoking as well.

"It's that weird spot in the brain that makes you want to do bad things," said Dana Kappel, senior research coordinator and registered nurse with Cardiovascular Associates at St. Luke's Medical Center in Milwaukee.

The hospital plans to enroll about 10 people in a new study of the drug in December, she said. Researchers will be looking for people who are overweight, diabetic or who are smokers, and who have blockages in their coronary arteries. Once that is established, patients will be put on the drug for 18 months, and a repeat catheterization will be done to gauge whether the blockages have diminished.

Sanofi-Aventis plans to seek Food and Drug Administration approval for rimonabant in the second quarter of 2005, said Douglas Greene, a physician and vice president of corporate and medical affairs.

Greene acknowledged that other drug companies are developing their own compounds that work on the same brain receptors, but Sanofi-Aventis is the first to do clinical trials.

He said he did not know how much Acomplia would cost, but because obesity is now considered a health condition, insurance should pay for it.

"I think there is a strong rationale for this to be covered," Greene said. "It is like a statin (a cholesterol-lowering drug like Lipitor)."

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