The moment of truth for Sanofi-Aventis, when it finally is pushed hard to come clean on where things really stand with the U.S. Food and Drug Administration on its highly anticipated diet pill rimonabant (Acomplia / Zimulti), may finally come scarily enough on Halloween.

October 31st is the date Sanofi's top executives plan to meet with financial analysts to report on the company's third quarter earnings, after which increasingly frustrated analysts get to ask their questions.

At similar sessions earlier this year, analysts largely allowed Sanofi to brush aside questions about why the FDA was delaying action on Acomplia, and continued to bullishly parrot the Sanofi line that approval of rimonabant for sale in the United States was expected before the end of the year.

But even Sanofi's strongest supporters among the analysts have become increasingly nervous as month-after-month passes, and there is no hint as to what the problem is at the FDA. And let there be no doubt: When this amount of time goes by with no word and no action, there IS a problem.

While the fate of Acomplia is not Sanofi's only problem these days, it clearly is a factor in the depressed price of Sanofi stock.

In the absense of information, a number of analysts are now boldly starting to suggest that Acomplia is not likely to get to the U.S. market until the first quarter of 2007 (a courageous prediction with only two months left in 2006). Some are even starting to talk about the second quarter of 2007.

But all of this is little more than speculation.

The big question, given Sanofi's huge multi-billion-dollar stakes in getting Acomplia into pharmacies in the United States, is how long analysts are going to keep writing favorable things about the stock without some candid answers from the company's executives?

While Sanofi may attempt to defuse the predicted line of attack on Oct. 31 by reporting strong sales of Acomplia in the United Kingdom, where the drug has been on the market since late June, European sales alone are never going to make rimonabant a blockbuster.

What we need from Sanofi is the French version of an "October surprise" -- openness and candor.