The Open Label Extension Portion of the Study Entitled A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Multicenter Study to Evaluate the Efficacy, Safety, and Tolerability of Carisbamate as Adjunctive Therapy in Subjects With Partial Onset Seizures.

CARISEPY3014 is the open-label extension study that follows the double-blind study CARISEPY3013 (NCT00740623). In an open label study such as CARISEPY3014, both the physician and the patient know the name of the assigned study medication. In a double blind study such as CARISEPY-3013, neither the physician nor the patient knows the name of the assigned study medication. Patients who complete the 14-week double-blind treatment phase of study CARISEPY3013 will be eligible to enter the open-label extension study during which patients will transition through a 1-week blinded period to open-label carisbamate. There will be a 1 week blinded transition during which patients will take blinded study medication; after this, patients will then take unblinded, open-label study medication. Safety assessments include the monitoring of the frequency, severity, and timing of adverse events, clinical laboratory test results, 12-lead electrocardiogram (ECG) recordings, vital signs measurements, physical and neurologic examinations, the Physician Withdrawal Checklist for symptoms of withdrawal for those patients who taper and/or discontinue study drug, and pregnancy tests for females of childbearing potential. Seizure counts will be obtained at every visit. The Quality of Life in Epilepsy-31 Patient Inventory questionnaire will be administered once during the study. A Medical Resource utilization questionnaire will be used to obtain cost-effectiveness information on carisbamate and will be administered twice during the study. There is no statistical testing hypothesis for this study. Carisbamate tablets taken twice daily in 2 equally divided doses, with or without food, and taken with noncarbonated water. During the first week on study, patients will take blinded transition study medication and thereafter will take a target dosage of 800 mg/day of unblinded, open-label study medication. The dosage of study medication will range from 400 to 1,200 mg/day. Patients will receive treatment for 1 year with the potential to receive treatment longer.