- Subject with a confirmed diagnosis at least 24 weeks prior to Visit 1 and a disease onset prior to 30 years of age, consistent with idiopathic generalized epilepsy (IGE) experiencing primary generalizedtonic-clonic (PGTC) seizures (Type IIE) that are classifiable according to the International League Against Epilepsy (ILAE) Classification of Epileptic Seizures (ILAE, 1981)