A Double-Blind, Randomized, Placebo-Controlled, Phase 2 Trial of YKP3089 as Adjunctive Therapy in Subjects With Partial Onset Seizures

Inclusion Criteria: * Weight at least 40 kg * A diagnosis of partial epilepsy according to the International League Against Epilepsy's Classification of Epileptic Seizures. Diagnosis should have been established by clinical history and an electroencephalogram (EEG) that is consistent with localization related epilepsy; normal interictal EEGs will be allowed provided that the subject meets the other diagnosis criterion (ie, clinical history) * Have uncontrolled partial seizures despite having been treated with at least 1 AED within approximately the last 2 years * During the 8-week baseline period, subjects must have at least 8 partial seizures including only simple partial seizures with motor component, complex partial seizures, or secondarily generalized seizures without a seizure-free interval of greater than 25 days any time during the 8 weeks baseline. Subjects must have at least 3 of these partial seizures during each of the two consecutive 4-week segments of the baseline period * Currently on stable antiepileptic treatment regimen. Exclusion Criteria: * A history of nonepileptic or psychogenic seizures * Presence of only nonmotor simple partial seizures or primary generalized epilepsies * Presence or previous history of Lennox-Gastaut syndrome * An active CNS infection, demyelinating disease, degenerative neurologic disease, or any CNS disease deemed to be progressive during the course of the study that may confound the interpretation of the study results * Any clini…