Some research has indicated that the drug rimonabant could be effective as a stop-smoking therapy, but the U.S. Food and Drug Administration (FDA) is not convinced.

The Dow Jones News Service reported Feb. 17 that the agency rejected the drug for smoking cessation, a blow to drug maker Sanofi-Aventis SA. The FDA did issue an "Approvable" letter for rimonabant as a possible weight-loss drug, indicating that it could be approved for this purpose if more research is produced.

Some observers had predicted that the drug could be worth billions if approved for both smoking cessation and weight loss.