Cenobamate Open-Label Extension Study for YKP3089C025

Inclusion Criteria: * The subject must have successfully completed the Double-blind Treatment Period in the Core study. * Written informed consent signed by the subject or legal guardian, prior to entering the study, in accordance with the International Council for Harmonisation (ICH) Good Clinical Practice (GCP) guidelines. If the written informed consent is provided by the legal guardian because the subject is unable to do so, a written or verbal assent from the subject must also be obtained. As required by country-specific regulations, only the subject may sign the ICF in accordance with ICH guidelines. Exclusion Criteria: * Subject tests positive, via urine drug screen at Visit 14 of the Core study, for illicit drugs except for tetrahydrocannabinol and Cannabinoids. * Any significant changes to the subject's medical history that, in the opinion of the Principal Investigator, could affect the subject's safety or conduct of the study.