S-230815

Study CL1-230815-001 (KANDLE) is a Phase Ib/II, First In Human, multicentre, open-label, multiple ascending dose study to assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamic (PD) effect of S230815 in pediatric participants with KCNT1-related Developmental Epileptic Encephalopathy. To participate in the study, participants must have a diagnosis of Developmental Epileptic Encephalopathy due to a documented pathogenic or likely pathogenic variant in KCNT1 (to be confirmed by central genetic testing at the screening visit). The study consists of a screening period followed by two consecutive interventional parts. Part 1 will evaluate multiple ascending doses of S230815. Part 2 is a long-term treatment extension for participants who have completed Part 1. Participants will seamlessly roll-over from Part 1 to Part 2, resuming the same cohort as they were assigned in Part 1, and will receive S230815 for a maximum of 72 weeks.