Carisbamate in Adult & Pediatric Subjects With Lennox-Gastaut Syndrome

A total of 24 subjects are planned: 6 subjects in each of 4 cohorts: Cohort I (≥18 years), Cohort II (12 to \<18 years), Cohort III (6 to \<12 years), and Cohort IV (2 to \<6 years). For Cohorts I and II, PK assessments of carisbamate, S-enantiomer and its R-enantiomer plasma concentrations, will be conducted on Days 1, 2 and 3 of the single dose period at pre-dose and 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 hours after dosing and on Day 17 of the multiple-dose period at pre dose and 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours after dosing; trough samples will be collected on Days 45 and 73 of the dose-adjustment period. For Cohort III, PK assessments of carisbamate, S-enantiomer and its R-enantiomer plasma concentrations will be conducted on Days 1, 2 and 3 of the single dose period at pre dose and 0.5, 1, 2, 4, 6, 8, 12, 24, and 48 hours after dosing and on Day 17 of the multiple-dose period at pre-dose and 2 hours after dosing; trough samples will be collected on Days 45 and 73 of the dose-adjustment period. For Cohort IV, a sparse PK sampling approach will be used, and the time of PK sampling time will be based on the PK results from the other cohorts. A maximum of 2 to 4 time points on each day (1 and 17) will be collected. Safety assessments include adverse event (AE) and concomitant medication reporting, clinical laboratory testing, vital sign measurements, 12 lead electrocardiograms (ECGs), physical examinations, and neurologic examinations.