Generalized Tonic-Clonic Seizure Clinical Trials

• Subject is properly informed of the nature and risks of the study and gives informed consent in writing prior to entering the study (for adult subjects) and for adolescent subjects parent/legal guardian and subject gives informed consent or assent in writing prior to entering the study.

• Subject is ≥12 years of age with a BMI ≤40 kg/m2 at Visit 1.

• Subject must have had adequate trials of at least 2 ASMs, which were given (and tolerated) at adequate therapeutic doses, without achieving sustained seizure freedom.

• Subject has probable or possible PGTCS (with or without other subtypes of generalized seizures) for ≥1 year, in the setting of generalized epilepsy according to the International League Against Epilepsy 2017 classification criteria, and subject is approved by The Epilepsy Study Consortium (TESC).

• Subject is on a stable dose of 1 to 3 allowable current ASMs for at least 1 month prior to screening (Visit 1), during screening/baseline, and throughout the DBP.

• Subject is able to keep accurate seizure diaries.