The trial was stopped based on information from the global phase 3 studies.

The purpose of the study is to evaluate the effectiveness and safety of adjunctive RWJ-333369 at a dose of 200 or 400 mg/day in comparison with placebo in Korean and Japanese partial epilepsy patients who have poor seizure control with one or two antiepileptics (AEDs).

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)

Inclusion Criteria:

• Body weight of 40 kg or more
• Established diagnosis of partial epilepsy for at least 1 year
• Current treatment with at least one and no more than two antiepileptics (AEDs)
• At least 6 episodes of simple partial motor seizures, complex partial seizures, or secondarily generalized seizures for 2 months (56 days) during the baseline period (No seizure free interval for more than 3 weeks)

Exclusion Criteria:

• Diagnosis of status epilepticus or epilepsia partialis continua within 6 months
• Patients with generalized epileptic syndrome
• Current or previous history of non-epileptic seizures, including psychogenic seizures
• Current or previous history of any serious or medically relevant systemic disease, including clinically apparent hepatic disease, renal failure, malignant neoplasm, insulin-requiring diabetes mellitus, or any disorder
• Patients with clinical evidence of significant cardiac disease
• Current or past (within 1 year) major significant psychotic disorder
• Have an ALT (GPT) greater than 1.5 times the upper reference limit or total bilirubin above the upper reference limit at screening laboratory tests