KCNQ (Kv7) x GABAA receptor

To assess the long-term safety and tolerability of XEN496 in pediatric subjects with KCNQ2 developmental and epileptic encephalopathy (KCNQ2-DEE) who had participated in the primary study (XPF-009-301).

To investigate the potential antiseizure effects of adjunctive XEN496 (ezogabine) compared with placebo in children with KCNQ2 Developmental and Epileptic Encephalopathy (KCNQ2-DEE).

主要研究目的：本研究以天津红日药业股份有限公司生产的瑞替加滨片（50mg）为受试制剂，评估其在空腹条件下给药后的药代动力学初步特征。