Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.
Inclusion Criteria:
* Participants who are characterized as having Lennox-Gastaut Syndrome (LGS) must fulfill all of the following criteria:
* Onset of seizures at ≤8 years old
* History of tonic/tonic-atonic seizures plus at least 1 of the following seizure type(s): atypical absence, atonic, myoclonic, focal impaired awareness, generalized tonic-clonic, nonconvulsive status epilepticus, or epileptic spasms
* Presence of developmental plateauing or regression
* History of electroencephalogram (EEG) showing generalized slow (<2.5 Hertz [Hz]) spike-and-wave complexes
* Participants who are characterized as having DEE (Other) must fulfill all of the following criteria:
* Does not meet criteria for LGS
* Onset of seizures at ≤5 years old
* Presence of developmental plateauing or regression
* History of multiple seizure types
* History of interictal EEG background showing diffuse or multifocal slowing (with or without epileptiform activity)
* The participant has a current occurrence of at least 1 of the following countable motor seizure types: generalized tonic-clonic, tonic (bilateral), clonic (bilateral), atonic (bilateral) with truncal/leg involvement, focal motor (including hemiclonic), and focal to bilateral tonic-clonic.
* The participant has demonstrated an average of at least 4 countable motor seizures per month for each of the 3 months prior to Screening.
* The participant has been taking 1 to 4 antiseizure medications (ASMs) at a stable dose for at least 4 weeks prior to Screening.
* The participant, parent, or caregiver is willing and able (in the judgment of the investigator) to comply with completion of the diaries throughout the study.
* The participant must be willing and able to provide written informed consent; in instances where the participant is unable to provide consent, an appropriate legal representative.
Exclusion Criteria:
* The participant has a diagnosis of Dravet Syndrome (DS) or has a mutation of the Sodium channel protein type 1 subunit alpha (SCN1A) gene consistent with DS.
* The participant has been admitted to a medical facility for treatment of status epilepticus requiring mechanical ventilation within 3 months prior to Screening.
* The participant has a neurodegenerative disorder as indicated by magnetic resonance imaging or genetic testing.
* The participant has an acquired lesion/injury unrelated to the primary etiology that could contribute as a secondary cause of seizures.
* The participant is receiving exclusionary medications.
* The participant has used of any cannabis product or cannabidiol that is not in oral solution/capsule/tablet form, not obtained from a government-approved dispensary, or contains ≥50% Delta-9-tetrahydrocannabinol (THC).
* The participant has unstable, clinically significant neurologic (other than the disease being studied; eg, recurrent strokes), psychiatric, cardiovascular (eg, pulmonary arterial hypertension, cardiac valvulopathy, orthostatic hypotension/tachycardia), pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, hematopoietic, or endocrine disease or other abnormality which may impact the ability of the participant to participate or potentially confound the study results.
* The participant is unable or unwilling to comply with any of the study requirements or timelines.
Note: Other protocol defined Inclusion/Exclusion Criteria may apply.
Eligibility last updated 12/31/2024. Questions regarding updates should be directed to the study team contact.