The U.S. FDA action has once again postponed action on diet drug rimonabant (Acomplia / Zimulti), and some observers think Sanofi-Acomplia may be hoping it can get the drug approved in July for both weight loss and treatment of type 2 diabetes.

While safety issues related to Acomplia (rimonabant) still need to be resolved, Sanofi appears to have itself triggered the latest three-month delay by submitting additional data from its SERENADE study showing that the drug improves blood sugar control in type 2 diabetics.

Interestingly, Sanofi's Marc Cluzal, vice president for science and medical affairs, revealed on Feb. 13th that the latest FDA delay -- which will postpone any decision on approval until at least the end of July -- did not come about "because we had to add more safety data to the dossier.

"in this case, it is the efficacy that we are looking at," Cluzal said.

Since the SERENADE trial added little new to the fairly well established ability of Acomplia to help promote weight loss, Cluzal's remarks would seem to suggest that it is the efficacy of Acomplia in reducing HbA1c levels (a measure of glucose control) in patients with type 2 diabetes that is now before the FDA.

Sanofi executives responded with their customary refusal to comment when specifically asked following a presentation to analysts whether they could confirm that submission of the SERENADE data is the only reason for the delay at the FDA.

But given that Sanofi has failed in both Germany and France to get approval for state reimbursement of Acomplia when it is used strictly for weight loss, FDA approval of the drug for both weight loss and treatment of diabetes would clearly increase the chances of coverage by insurance in the United States.

Most analysts also believe, however, that FDA action on Acomplia will not occur until the agency's Endocrinologic and Metabolic Drugs Advisory Committee weighs in on the issue of the drug's side-effects. The advisory committee's next meeting is tentatively scheduled for June 13 and 14th.

While concern about side-effects from this novel drug, which blocks the CB-1 receptors in the brain and elsewhere in the body, has focused on psychiatric issues including depression, Sanofi executives contended on Tuesday that researchers have observed "relatively mild central nervous system activity.

"When it comes to tolerance to this drug, in Europe we have seen no particular tolerance signals aside from the elements which already were in the original" FDA filing, Clusal said.

Acomplia has been on sale in some parts of the European Union since last summer, and is now available in 10 European countries, Argentina and Mexico. Sanofi executives said they also plan to launch Acomplia in France at the beginning of March.

Despite the length delay in getting Acomplia approved in the U.S., where Sanofi had hoped to have the drug approved for marketing a year ago, Sanofi executives continue to profess optimism.

"We do not feel at all discouraged," said Sanofi CEO Gérard Le Fur.

"We are extremely optimistic about obtaining (FDA approval) for rimonabant," Cluzal said. "This will come about sooner or later, and hopefully, in the course of this year."