RecruitingPhase 3Drug trialA Clinical Trial for Participants With DEE to Assess Efficacy, Safety, Tolerability, and PK of RelutrigineA Phase 3, Randomized, Multi-Center, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Efficacy, Safety, Tolerability, and Pharmacokinetics of Relutrigine in Participants with Developmental and Epileptic Encephalopathies Followed by an Open-Label Extension