Sanofi-Aventis says it will vigorously defend itself against another class-action lawsuit bid filed in the USA which alleges that the French drugmaker did not fully disclose details about the safety profile of its anti-obesity drug Acomplia.

Lawyers at Schiffrin, Barroway, Topaz & Kessler has filed the suit with the court for the Southern District of New York on behalf of all purchasers of the securities” of Sanofi from February 17, 2006 to June 13 last year. They allege that the company failed to disclose “material adverse data” about Acomplia (rimonabant), which would be called Zimulti in the USA, and its “tendency to cause a statistically significant increase in psychiatric problems, including suicidal thoughts and actions".

Last June 13, the drug was rejected unanimously by a US Food and Drug Administration advisory panel which said that the benefits of Zimulti do not outweigh the risk of psychiatric adverse effects, including suicide and seizures.

This is the second lawsuit filed against Sanofi over rimonabant because in November, Coughlin Stoia Geller Rudman & Robbins said it had commenced action on behalf of an institutional investor in the same court and on roughly the same grounds. Sanofi denies the allegations in both suits which have not as yet been granted class-action status.

Acomplia, which is available in Europe, was expected to be a blockbuster but Sanofi withdrew its US marketing application the damning judgement from the FDA committee. However Sanofi has repeatedly said that it has not given up on getting Acomplia approved across the Atlantic and plans at some stage to resubmit its application with new data from ongoing clinical trials.