A Phase 3, Randomized, Multi-Center, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Efficacy, Safety, Tolerability, and Pharmacokinetics of Relutrigine in Participants With DEE Followed by an Open-Label Extension

Inclusion Criteria: * Has a documented diagnosis of a developmental and epileptic encephalopathy. * Onset of seizures \<12 years old. * Has a weight \>7 kg at the time of signing consent/assent. Exclusion Criteria: * Has a history of left bundle branch block, arrhythmias, Brugada syndrome, congenital heart disease, familial short QT syndrome, or family history of sudden death or ventricular arrhythmias, including idiopathic ventricular fibrillation. * Had 2 or more episodes of convulsive status epilepticus requiring hospitalization and intubation in the 6 months prior to Screening. * Has an…