A Multi-Center, Single-Arm Clinical Trial to Investigate the Efficacy and Safety of Elsunersen in Pediatric Participants With Early Onset SCN2A Developmental and Epileptic Encephalopathy

Inclusion Criteria: * Has a documented Gain of Function SCN2A variant confirmed through genetic testing. * Has onset of seizures prior to 3 months of age. * Seizure frequency of 4 or more countable motor seizures per 28-day during the Baseline Observation Period. Exclusion Criteria: * Has any clinically significant or known pathogenic genetic variant other than in the SCN2A gene, or a genetic variant that may explain or contribute to the participant's epilepsy and/or developmental disorder. * Has bone, spine (eg, kyphosis, scoliosis), bleeding, or other disorder. * Has received any experime…