A Study to Investigate the Efficacy and Safety of ZX008 (Fenfluramine Hydrochloride) as an Adjunctive Therapy in Children and Adults With Lennox-Gastaut Syndrome

Open to people ages 2-35

• Male or non-pregnant, non-lactating female, age 2 to 35 years, inclusive as of the day of the Screening Visit.
• Clinical diagnosis of Lennox-Gastaut syndrome, where seizures that result in drops are not completely controlled by current antiepileptic treatments.
• Onset of seizures at 11 years of age or younger.
• Abnormal cognitive development.
• Must be receiving at least 1 concomitant AED and up to 4 concomitant anti-epileptic treatments.

• Etiology of seizures is a degenerative neurological disease.
• History of hemiclonic seizures in the first year of life.
• Subject only has drop seizures in clusters, where individual seizures cannot be counted reliably.
• Pulmonary arterial hypertension.
• Current or past history of cardiovascular or cerebrovascular disease, such as cardiac valvulopathy, myocardial infarction or stroke.
• 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.
• Taking felbamate for less than 1 year prior to screening and/or does not have stable liver function and hematology laboratory tests, and/or the dose has not been stable for at least 60 days prior to the Screening Visit.
• Currently receiving an investigational product.
• Institutionalized in a general nursing home (ie, in a facility that does not specialize in epilepsy care).
• A clinically significant condition, or has had clinically relevant symptoms or a clinically significant illness in the 4 weeks prior to the Screening Visit, other than epilepsy, that would negatively impact study participation, collection of study data, or pose a risk to the subject.