The European Medicines Agency plans to re-examine its authorization of Sanofi-Aventis’s fat pill now that an FDA advisory panel refusedt to recommend approval due to concerns over depression and suicide.

EMEA, which identified depression as a possible side effect when it approved Acomplia last year, says its committee for medicinal products for human use would review the data next week, The Financial Times reports. Acomplia generated $20 million in sales in Europe during this year’s first quarter.

The second guessing prompted brokers to downgrade Sanofi shares. The huge US market was coveted by the drugmaker, which drooled over the likelihood that fat Americans would help the company compensate for potential generic competition to its best-selling meds, Plavix and Lovenox. Instead, the setback is prompting some analysts to question managerial credibility.

“What does surprise us is the dramatic disconnect between Sanofi’s persistent optimistic assessment of the FDA regulatory process…and the FDA’s clearly negative presentation on the risk benefit assessment of the compound,” says Andrew Baum at Morgan Stanley. “The outcome of this meeting will raise further concerns in investors’ minds over the integrity of Sanofi’s guidance to investors.”

The FDA already rejected Acomplia’s alternative use as an aid to smokers trying to quit, and the drug’s future launch for weight loss could be threatened by the difficulty of conducting new clinical trials and competing against GlaxoSmithKline’s over-the-counter rival, Alli, that went on sale this week (see below).

Hat tip to PharmaGossip