CLINICAL TRIAL SHOWS EFFICACY OF “ANTI-MUNCHIE” DRUG

A Phase III multicenter clinical trial demonstrates that a new class of drug—a selective endocannabinoid receptor antagonist (CB1)—may be an effective treatment for obesity, according to a report at the recent Endocrine Society annual meeting in New Orleans.

Rimonabant, under development by Sanofi-Synthelabo, blocks receptors in the hypothalamus that bind with cannabinoid molecules contained in marijuana that stimulate appetite, commonly known as “the munchies.” Blocking the CB1 receptor appears to curb the craving for food and also for cigarettes. Rimonabant, under the brand name Accomplia, is being developed as a treatment for obesity and smoking cessation.

In a multicenter trial, 287 male and female subjects 18 to 65 years old with a body mass index (BMI) of 29 to 41 were randomized to receive 5, 10, or 20 mg of rimonabant or placebo while on a slightly hypocaloric diet. After 16 weeks, patients receiving the drug lost an average of two to four times more weight (5 to 8 lb.) than patients on placebo. In addition, the waist circumference among patients taking rimonabant decreased more than twice as much as those on placebo. No serious adverse effects were reported, according to principal investigator Xavier Pi-Sunyer, MD, director of the Obesity Research Center at St. Luke's Hospital Center in New York City.

Rimonabant has been tested in Phase III clinical trials involving more than 6,000 obese subjects in the United States and Europe.

Now that it has passed two clinical trials, rimonabant appears headed for review by the Food and Drug Administration. As long-term safety and efficacy are major concerns, the agency typically requires 2 years of data before approving obesity drugs. A New Drug Application for rimonabant could be filed within a year or two.