Long-term, Open-label Safety Extension Study of Retigabine/Ezogabine in Pediatric Subjects (>= 12 Years Old) With POS or LGS

Epilepsy is among the most common serious neurologic disorders in childhood. Medicines with novel actions of mechanisms of action are needed to try to address the unmet clinical need for seizure control in patients with treatment-resistant epilepsy. The purpose of this study is to evaluate the long-term safety and tolerability of retigabine/ezogabine as an adjunctive treatment in subjects with either partial onset seizures (12 to \< 18 years old) or Lennox-Gastaut Syndrome (12 to \<30 years old) who have participated in a previous ("parent") study.