Sanofi-Aventis on June 13th insisted that no "causal relationship" has been established between diet drug rimonabant (Acomplia / Zimulti) and "suicidality," but pledged to immediately begin asking all patients in ongoing clinical trials whether they are having any suicidal thoughts.

Appearing before a panel of independent experts, Dr. Paul Chew, a Sanofi vice president, presented a detailed challenge to FDA analyses linking rimonabant to a significantly increased rate of psychiatric adverse events, including depression and suicidality, and neurological adverse events, including seizures.

"The FDA and the sponsor analyzed this data differently," Chew told the FDA advisory panel.

While he conceded that there was "a consistent but modest difference" in depression among patients taking rimonabant compared to those on a placebo, he insisted that it was less than the FDA's analysis which concluded depression was almost twice as prevalent.

He also embraced a proposal made at the outset of the meeting by an FDA consultant who suggested that data relating to suicidal thoughts ought to be collected prospectively -- rather than retrospectively -- by using a brief questionnaire about suicidal indications with patients on each checkup.

"Sanofi-Aventis will be implementing the questionairre discussed today. We will be using it in the clinical trials going forward," Chew told the panel. "If you want to get the answer, you have to ask the question."

But he insisted that "a causal relationship has not been established between suicidality and rimonabant," and he also told the panel that based on "multiple analyses, there was no significant increase in risk in seizures" among those taking Acomplia.

The presentations came during the morning session of a day-long hearing by the FDA's Endocrinologic and Metabologic advisory committee, which will vote at the end of the day whether to recommend to the agency that it approve Zimulti for sale in the United States next month.