Health Conditions

What is on the horizon?

Currently researchers are studying a new type of drug class called cannabinoid receptor antagonists. This type of drug would help decrease an individual's appetite. Rimonabant, which will be marketed as Acomplia, has the potential to become a major breakthrough in treating obesity. In four major clinical trials, Acomplia has been shown to help obese people lose weight, improve A1c level in diabetics -- a measure of blood sugar control, reduce cardiovascular risk factors, and stop smoking. The manufacturer has not said for which of these indications it is seeking approval.

The one-year results of a phase III trial were presented in 2005 to the American Diabetes Association (ADA). 1,045 people with type 2 diabetes took either rimonabant or a placebo. Participants in this trial had an average age of 56 years and an average (BMI) of 34. All participants in the trial were told to reduce their daily caloric intake by 600 calories.

Participants in this study on Acomplia lost an average of 11.7 lbs compared to 3 lbs for patients in the placebo group. In addition, patients treated with Acomplia saw a reduction in waist circumference of 2 inches versus 0.7 inches for those taking the placebo and a reduction in A1c of 0.6% versus an increase of 0.1%, respectively.

Acomplia also showed a beneficial effect on lipids. Among patients who entered the study, the good HDL-cholesterol increased by 15.4 percent in the group taking Acomplia dose versus 7.1 percent in the placebo group.

Researchers report that the results of all four studies have shown similar safety data with side effects that were mainly mild and temporary. The most experienced adverse effect was nausea, reported by 12.1 percent of patients on the Acomplia. Other common side effects included dizziness, diarrhea, hypoglycemia, and anxiety. Three percent of participants on the Acomplia dropped out of the study because of intolerable side effects compared to 1% of those on placebo.

One important note is that you have to stay on the drug to maintain the effects. It seems that if you stop the drug, the weight comes back. If approved by the FDA, post-market surveillance will play a major role in determining the efficacy of the drug. One member of the ADA said after the meeting, ?It's one thing to say that a drug is safe in 6,000 people tested in clinical trials, but we have to see what happens when 750,000 people are using the drug."

In addition to Acomplia, other drugs that could potentially treat obesity are currently being studied in humans. Axokine, a synthetic form of human ciliary neurotrophic factor (CNTF), has been linked to appetite suppression and weight loss in clinical trials. ATL-962, a drug being developed by British investigators, may help block fat absorption. And topiramate, a drug currently used to treat seizures in the U.S., has helped certain patients lose weight in clinical trials.

A non-prescription strength formulation of the obesity drug orlistat is also being studied in clinical trials. Currently available by prescription only, Xenical contains 120mg of orlistat. The non-prescription version of the drug, called Alli, would contain 60mg of orlistat. Studies have shown that this reduced strength of orlistat effectively promotes weight loss in obese patients when combined with a reduced-calorie diet. If over-the-counter status is accepted, Alli would be the only FDA-approved weight loss medication available to patients without a prescription.

Finally, research is ongoing to isolate the gene that leads to developing obesity. Researchers have successfully manipulated this gene in mice. However, the specific gene or genes responsible for obesity in humans is unknown. Many experts agree that more than one gene is likely involved in the development of human obesity. Therefore, while several drugs are showing promise, it is unlikely that a single drug will be found that can cure obesity.