A Study of EPX-100 (Clemizole Hydrochloride) in Participants With Dravet Syndrome

Prior treatment

• Known sensitivity, allergy, or previous exposure to clemizole HCl.
• Exposure to any investigational drug or device \<90 days prior to Screening or plans to participate in another drug or device trial at any time during the study.
• Seizures secondary to illicit drug (this includes concomitant use of tetrahydrocannabinol \[THC\] and nonprescription cannabidiol preparations) or alcohol use, infection, neoplasm, demyelinating disease, degenerative neurological disease, or central nervous system disease deemed progressive, metabolic illness, or progressive degenerative disease.
• Concurrent use of lorcaserin. Note: Prior use of lorcaserin is permitted if at least 30 days have passed since the last dose.
• Concurrent use of fenfluramine.
• Epilepsy surgery planned during the study or epilepsy surgery within 6 months prior to Screening.

• Male and female participants 2 years and older at time of consent.
• Participant or parent/legally authorized representative (LAR) willing and able to provide written informed consent and assent (if applicable) prior to initiation of any study related procedures.
• Clinical diagnosis of DS. Participants must have seizures which are not completely controlled by AEDs with the following criteria:
  • Onset of seizures prior to 18 months of age,
  • Normal development at onset,
  • History of at least one type of countable motor seizure (CMS),
  • Brain MRI without cortical malformation (not including mild atrophy associated with the natural progression of DS),
  • Genetic mutation of the SCN1A gene must be documented.