Sanofi-Aventis' Reformulated Ambien Gets Approvable Letter, Faces Delay

The launch of sanofi-aventis' newest insomnia medication is facing an indefinite delay after the FDA issued the French firm an approvable letter requesting additional information about the drug.

Sanofi-aventis disclosed very little information about the letter, saying only that FDA "outlined specific questions that have to be resolved" before its new drug application for Ambien CR (zolpidem tartrate) can be approved. Ambien CR is a controlled-release version of sanofi-aventis' blockbuster insomnia drug Ambien, which generated sales of approximately $1.8 billion in 2004.

Sanofi-aventis said it "is already working closely with the FDA" to resolve the issues raised in the letter, but the company didn't provide an updated timetable for the approval of Ambien CR. The company previously stated that it hoped to launch the drug by mid-2005.