Efficacy and Safety of BGG492 as Adjunctive Treatment in Patients With Partial Onset Seizures

Inclusion Criteria: * Outpatients ≥ 50 kg (110 lb) of weight. * A diagnosis of epilepsy (≥ 2 years prior to screening) with partial seizures with or without secondarily generalized seizures. * Uncontrolled partial seizures despite having been treated with at least two different antiepileptic drugs (AEDs) within the last 2 years prior to screening. * At least 4 partial seizures during the 4-week baseline period and at least 4 partial seizures during the 4 weeks prior to the baseline period. * Cohort 1 patients must be receiving stable treatment with 1 or a maximum of 2 AEDs.Cohort 2 patients must be receiving stable treatment with 1, 2, or 3 AEDs. Exclusion Criteria: * Presence of only non-motor simple partial seizures. * History of psychogenic seizures. * Absences, myoclonic seizures e.g. in the context of primary generalized epilepsy. * Previous history of Lennox-Gastaut syndrome. * Status epilepticus or seizure clusters, according to the judgement of the investigator, occurring within 52 weeks prior to randomization. * Pregnant or nursing (lactating) women. Other protocol-defined inclusion/exclusion criteria may apply