While millions of obese people are excited at rimonabant's potential in helping them reduce their weight, some researchers believe this novel drug could have a major role to play in helping smokers break the cigarette habit -- even though regulators on the first go-round refused to approve it for this use.

Rimonabant is the first in a new class of drugs that works by inhibiting the CB1 receptor, one of two receptors found in the EndoCannabinoid System (or EC System) that are located in the brain and other parts of the body.

While the EC System is associated with regulating the body's intake of food, it also is involved in tobacco dependency. Chronic tobacco use over-stimulates the EC system creating an imbalance. rimonabant, by blocking the CB1 receptor, helps restore balance to the EC system resulting in reduced dependence on tobacco.

Rimonabant has "roughly doubled the odds of quitting smoking," said Dr. Robert Anthenelli, associate professor of psychiatry at the University of Cincinnati College of Medicine in Ohio. "We also found remarkably reduced postcessation weight gain: a 77% reduction versus placebo....

"These dual effects on smoking cessation and reduced weight gain make rimonabant a promising agent for treating tobacco dependence," Anthenelli added.

Researchers say that while the percentage of smokers who benefit from rimonabant is considerably less than the very high number of obese and overweight individuals who benefit, the result among smokers is still significant and compares favorably with other smoking cessation products.

But while the initial smoking-cessation trial seemed pomising, results from a second trial were less encouraging and Sanofi was denied approval for use of rimonabant as a smoking cessation aid by both the U.S. Food and Drug Administration and the European Medicines Agency (EMEA).

The regulators asked for an additional clinical trial of rimonabant as an aid to helping break the smoking habit, and Sanofi has not yet indicated whether it intends to proceed with such a trial.