Safety and Effectiveness of Open-Label Clobazam in Subjects With Lennox-Gastaut Syndrome

Inclusion Criteria: * The subject or subject's legally authorized representative (LAR) must sign and date the institutional review board (IRB)/independent ethics committee (IEC) approved Informed Consent Form/Health Insurance Portability and Accountability Act (HIPAA) Authorization (if required) prior to study participation. * Previous participation in Lundbeck-sponsored LGS study. * Subject must weigh ≥12.5 kilograms. * Male or female subjects must have been between 2 and 60 years of age at the time of the enrollment in the Phase 3 double-blind study (13110A/OV1012/NCT00518713) or between 2 and 30 years of age at the time of the enrollment in the Phase 2 double-blind study (13108A/OV1002/NCT00162981) study. * If female: * Subject is either not of childbearing potential, defined as premenarchal, postmenopausal for at least 1 year or surgically sterile (bilateral tubal ligation, bilateral oophorectomy or hysterectomy), or if of childbearing potential, must comply with a method of birth control acceptable to the investigator during the study, for at least 4 weeks prior to study entry and for 4 weeks following completion of the study. * Subject is not breastfeeding. * Subjects of childbearing potential must have a negative serum pregnancy test at Study Day 1. * In the investigator's opinion, parent or caregiver must be able to keep an accurate seizure diary. Exclusion Criteria: * Greater than 14 days have elapsed since the subject received his/her last dose of study me…