A double blind, randomised, placebo controlled, multi centre study to assess the efficacy and safety of adjunctive zonisamide in myoclonic seizures associated with idiopathic generalised epilepsy.

This study is designed to compare how safe and effective zonisamide is compared to placebo in people with myoclonic seizures associated with idiopathic generalised epilepsy who are already being treated with one or two other anti-epileptic drugs. Zonisamide is an investigational drug. RESEARCH OBJECTIVES To assess the efficacy of adjunctive zonisamide in idiopathic generalised epilepsy (IGE) in reducing the frequency of myoclonic seizures in subjects with continuing seizures despite treatment with 1 or 2 other anti epileptic drugs (AEDs). To assess the safety and tolerability of zonisamide and explore further efficacy in other seizure types. STUDY DESIGN This is a double blind, randomised, placebo controlled study comparing zonisamide and placebo in 110 subjects (1:1ratio). The study consists fo Baseline, Titration and Maintenance periods. Baseline Period once the Screening Visit has been performed, a seizure diary will be maintained to document the baseline seizure frequency in the eight weeks before the Randomisation Visit. Titration Period zonisamide/placebo dose will commence at at 50 mg. Further dose increases will occur at one week intervals until at dose of 300 mg is reached by Week 4. If adverse events (AEs) occur, one titration step will be omitted during Weeks 0 3, in which case the dose reached at Week 4 will be 250 mg. Subjects who require further down titration during this period will be withdrawn. Maintenance Period subjects will be treated with their Week 4 dose. In the event of seizures occurring in the first two weeks of the Maintenance Period, the dose will be increased to 400 mg (or 350 mg, if the subject omitted one dose in the Titration Period and the AE that led to this dose increase omission has subsided). The dose can be reduced to 200 mg in the case of dose-limiting AEs. Subjects who require further down titration or dose increases will be withdrawn (with the exception of those who had temporary dose decreases for not more that 4 days when necessitated by intercurrent illness). During the remainder of the Maintenance Period, the dose of study medication must remain unchanged. During the entire study the patient will keep a seizure diary to ascertain seizure frequency and type. Adverse events (AEs) will be reviewed at every visit, also physical and neurological exams and orthostatic vitals will be collected at every visit.