Acomplia, which was to have been marketed in the United States as Zimulti, was withdrawn from FDA consideration last June after an expert panel unanimously recommended against approval out of concern over depressive and suicidal side-effects.

Data from a new clinical trial of possible use of Acomplia in slowing progression of coronary artery disease was reported this week along with news that 43.4 percent of patients who got rimonabant in this trial suffered psychiatric side effects such as anxiety and depression.

While the results of the heart trial were ambiguous at best, Cluzel put a positive face on it -- and reiterated that Sanofi intends to resubmit rimonabant to the FDA and regulators worldwide in 2009 for approval as a treatment for type 2 diabetes.

He noted that the Acomplia development program -- involving clinical trials for a variety of conditions in addition to obesity -- is only one-third completed.

"It's very difficult before 2011 to know exactly what will be the full benefits of the product," Cluzel told the news agency Reuters.

Another Sanofi executive, Belen Garijo, also expressed confidence that sales of Acomplia -- which have been disappointing to date -- will grow in Europe and other countries where it is on the market.

"We are very confident that Acomplia will grow in Europe," Garijo told Reuters, noting that it is being reimbursed by insurance in a growing number of markets.