Effectiveness and Safety Study for RWJ-333369 as Adjunctive Therapy in Korean and Japanese Patients With Partial Onset Seizures

Despite the introduction of new antiepileptic drugs into overseas clinical settings after 1990's, there still exist those patients who cannot control seizures, and thus the advent of newer antiepileptic drugs is being desired. This is a multicenter, placebo-controlled, double-blind (neither the study physician nor the patient knows the name of the study assigned medication), randomized (study drug assigned by chance), parallel-group study. It consists of three periods: Pretreatment Phase (screening and baseline periods), Double-Blind Treatment Phase, and Posttreatment Phase (transitional period or dose-tapering/withdrawal period). Patients who complete Double-Blind Treatment Phase will be qualified to participate in the long-term extension study (Study 333369-KJ-03) following the present study. The primary hypothesis is that at 400mg/day of RWJ-333369 is effective in the adjunctive treatment of patients with partial onset epilepsy, as measured by the percent reduction from baseline in monthly seizure frequency of partial onset seizures. Safety is evaluated based on the following variables; Adverse event, Lab test, Electrocardiogram, Vital signs, Pregnancy test, Physician Withdrawal Checklist. Patients will receive the assigned dose (placebo, 200 mg/day, or 400 mg/day) twice daily orally for 12 weeks (85 days)