New York University Comprehensive Epilepsy Center A Phase 2 Randomized, Double-Masked Placebo-Controlled Crossover Safety and Tolerability Study of Ataluren for Drug Resistant Epilepsy in Patients with Nonsense Mutation CDKL5 or Dravet Syndrome The purpose of this research study is to find out whether ataluren is safe and decreases the frequency of seizures. We are looking for 6 individuals with Dravet syndrome. To participate, the subject must: 1 Age ≥ 2 years old and ≤ 12 years old, male or female, at Week 0 (at time informed consent/assent is signed) 2 Documentation of a diagnosis of Dravet syndrome or CDKL5 deficiency resulting from a nonsense mutation in 1 allele, as evidenced by medical records, genetic testing, and the following clinical feature: a. Failure to control seizures despite appropriate trial of 2 or more AEDs at therapeutic doses 3 Between 1 to 3 baseline AEDs at stable doses for a minimum for 4 weeks prior to the Baseline visit a. Vagus nerve stimulator (VNS), ketogenic diet, and modified Atkins diet do not count towards this limit but must be unchanged for 3 months prior to enrollment (Baseline). 4 VNS must be on stable settings for a minimum of 3 months prior to the Baseline visit 5 If on ketogenic or modified Atkins diet, must be on stable ratio for a minimum of 3 months prior to the Baseline visit 6 Written consent obtained from the patient or patient's legal representative must be obtained prior to performing any study procedures 7 Minimum of 6 convulsive or drop seizures with duration > 3 seconds over the 4 weeks of diary screening prior to randomization and ≥ 6 convulsive or drop seizures with duration > 3 seconds during the 4 weeks from Screening to Baseline. Study treatment will be provided at no charge. Compensation will be provided for participation. For Information Call: LaToya T. King, Study Coordinator, 646-558-0838 This research is conducted under the direction of: Orrin Devinsky, MD Director, New York University and Saint Barnabas Epilepsy Centers Professor of Neurology, Neurosurgery & Psychiatry New York University School of Medicine 223 East 34th Street New York City, NY, USA 10016 Phone 646-558-0801 [email protected] .