Clinical Trials

Key Inclusion Criteria:

• Subject is male or non-pregnant, non-lactating female.
• Female subjects of childbearing potential must not be pregnant or breast-feeding.
• Female subjects of childbearing potential must have a negative urine pregnancy test.
• Subjects of childbearing or child-fathering potential must be willing to use medically acceptable forms of birth control, which includes abstinence, while being treated on this study and for 90 days after the last dose of study drug.
• Satisfactory completion of the core study in the opinion of the investigator and the sponsor.
• A documented medical history to support a clinical diagnosis of Dravet syndrome, where convulsive seizures are not completely controlled by current antiepileptic drugs.
• Parent/caregiver is willing and able to be compliant with diary completion, visit schedule and study drug accountability.
• Subject's parent/caregiver has been compliant with diary completion during the core study, in the opinion of the investigator (eg, at least 90% compliant).

Key Exclusion Criteria:

• Current or past history of cardiovascular or cerebrovascular disease, myocardial infarction or stroke.
• Current cardiac valvulopathy or pulmonary hypertension that the investigator, parent, IPCAB, IDSMC, or sponsor deems clinically significant and warrants discontinuation of study medication.
• Current or past history of glaucoma.
• Moderate or severe hepatic impairment.
• Receiving concomitant therapy with: centrally-acting anorectic agents; monoamineoxidase inhibitors; any centrally-acting compound with clinically appreciable amount of serotonin agonist or antagonist properties, including serotonin reuptake inhibition; atomoxetine, or other centrally-acting noradrenergic agonist; cyproheptadine, and/or cytochrome P450 (CYP) 2D6/3A4/2B6 inhibitors/substrates.
• Currently taking carbamazepine, oxcarbamazepine, eslicarbazepine, phenobarbital, or phenytoin, or has taken any of these within the past 30 days, as maintenance therapy.
• Currently receiving or has received stiripentol in the past 21 days prior to Visit 1.
• Unwilling to refrain from large or daily servings of grapefruits and/or Seville oranges, and their juices beginning with the Visit 1 and throughout the study.
• A clinically significant condition, or has had clinically relevant symptoms or a clinically significant illness at Visit 1, other than epilepsy, that would negatively impact study participation, collection of study data, or pose a risk to the subject.