The primary objective is to evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the number of drop seizures (tonic, atonic, and tonic-clonic) compared with placebo in pediatric and adult subjects (age 4-55 years) diagnosed with Lennox Gastaut Syndrome (LGS).
The secondary objectives are: * To evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the total number of seizures compared with placebo in pediatric and adult subjects diagnosed with Lennox Gastaut Syndrome (LGS) * Evaluate the safety, tolerability of carisbamate in the LGS population * Evaluate steady-state pharmacokinetics of carisbamate in subjects with Lennox Gastaut.
Adolescent subjects 12 to 18 years old will receive the same dose as adults. Subjects 4 to \< 12 years old in the carisbamate 200 mg BID arm will receive 4 mg/kg BID (not to exceed 200 mg BID \[or a total of 400 mg per day\]). Subjects 4 to \< 12 years old in the carisbamate 300 mg BID arm will receive 5.5 mg/kg BID (not to exceed 300 mg BID \[or a total of 600 mg per day\]).
Córdoba, Córdoba Province, Argentina
Mendoza, Mendoza Province, Argentina