Experimental Treatment for Focal Epilepsy

Eligibility Details: Key Inclusion Criteria: - Be properly informed of the nature and risks of the study and give informed consent in writing, prior to entering the study - BMI <35 kg/m2 - Diagnosis (≥2 years) of focal epilepsy according to the International League Against Epilepsy [ILAE] Classification of Epilepsy (2017) - Treatment with a stable dose of 1 to 3 allowable current AEDs for at least one month prior to screening, during baseline, and throughout the duration of the study - Must be willing to comply with the contraception requirements - Able to keep accurate seizure diaries Key Exclusion Criteria: - History of pseudoseizures, psychogenic seizures, primary generalized seizure, or focal aware non-motor seizures only - Presence or previous history of Lennox-Gastaut syndrome - Seizures secondary to other diseases or conditions - History of repetitive seizures within the last 12 months where the individual seizures cannot be counted - History of neurosurgery for seizures <1 year prior to enrollment, or radiosurgery <2 years prior to enrollment - Schizophrenia and other psychotic disorders, or active suicidal plan/intent in the past 6 months, or a history of suicide attempt in the last 2 years, or more than 1 lifetime suicide attempt - History or presence of any significant medical or surgical condition or uncontrolled medical illness at screening, or history of cancer within the past 2 years, with the exception of appropriately treated basal cell or squamous cell carcinoma - Any clinically significant abnormalities on pre-study physical examination, vital signs, laboratory values or ECG indicating a medical problem that would preclude study participation - Past use of vigabatrin without stable visual fields tested twice over the 12 months after the last dose of vigabatrin (concomitant use of vigabatrin is not allowed) - If felbamate is used as a concomitant AED, patients must be taking it for at least 2 years, with a stable dose for ≥49 days and acceptable hematology and LFT values (or discontinued felbamate no less than 49 days) prior to Screening. - Have had multiple drug allergies or a severe drug reaction to an AED(s), including dermatological (e.g., Stevens-Johnson syndrome), hematological, or organ toxicity reactions - Current use of a ketogenic diet