Adjunctive Zonisamide in Primary Generalised Tonic Clonic Seizures

Zonisamide is already marketed for the treatment of partial seizures in epilepsy. This study is intended to provide evidence that zonisamide is safe and effective in the treatment of primary generalised tonic-clonic seizures. The total trial duration will be 5.5-6.5 months. After that subjects who have completed the study will be eligible to enrol in an open-label extension study until zonisamide is marketed for this indication or further development in this indication stops. This extension study will be described in a separate protocol (E2090-E044-316).