DEERFIELD, Ill., September 4, 2007 — OVATION Pharmaceuticals, Inc. announced the initiation of a pivotal Phase III clinical trial evaluating clobazam, a unique 1,5 benzodiazapine with significant anticonvulsant properties, as adjunctive treatment for patients with Lennox-Gastaut syndrome (LGS), one of the most severe forms of childhood epilepsy that frequently persists into adulthood. In previous studies clobazam was shown to be well tolerated in patients with LGS and met the primary endpoint in a Phase II dose range finding study of a significant reduction in drop (or atonic) seizures compared to baseline. Drop seizures are the most debilitating of the LGS seizures types, which can result in severe trauma to the brain and body. This latest study demonstrates OVATION’s progress in advancing its central nervous system (CNS) development pipeline.