An Open-Label Extension Trial to Assess the Long-Term Safety of ZX008 (Fenfluramine Hydrochloride HCl) Oral Solution in Children and Young Adults With Dravet Syndrome

For people ages 2-18

Key Inclusion Criteria:

• Male or non-pregnant, non-lactating female, age 2 to 18 years, inclusive as of the day of the core study Screening Visit.
• 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.