An Open-Label Study With Extension Phase to Evaluate the Efficacy and Safety of Perampanel Administered as an Adjunctive Therapy in Pediatric Subjects (Age 1 Month to Less Than 18 Years) With Childhood Epilepsy

This study will consist of a Core Study, Extension Phase A and Extension Phase B. 1. Core Study will consist of the following 2 phases: Pretreatment (4 weeks screening or baseline period) and Treatment Period. The Treatment Period (23 weeks) of Core study include Titration period (10 weeks) and Maintenance period (13 weeks). 2. Extension Phase A will consist of a Treatment Period (33 weeks) and a Follow-up Period (4 weeks). All participants who will complete the Core Study will be eligible to participate in Extension Phase A of the study. 3. Extension Phase B will only be for participants who…