The purpose of this study is to evaluate the safety and efficacy of clobazam as adjunctive
therapy in the treatment of seizures which lead to drop attacks (drop seizures) in patients 2
to 60 years of age with Lennox-Gastaut Syndrome (LGS). Patients will be enrolled at
approximately 65 sites in the U.S. and ex-US for up to 23 weeks. Patients will be randomly
assigned to either a low, medium or high dose, or placebo. The study will include a baseline
period, a titration period and a maintenance period. After the maintenance period, patients
will either continue into an open-label extension study or enter the taper period with a
final visit 1 week after the last dose.