This open-label, multi-center study is open to patients 1 to 18 years of age at time of enrollment with medication resistant epilepsy.

This open-label, multi-center study is open to patients 1 to 18 years of age at time of enrollment with medication resistant epilepsy. The study consists of an 8 week baseline, titration, and treatment of Epidiolex in a daily dosage up to 25 mg/kg/day, with an optional secondary titration schedule after 26 weeks of treatment up to a maximal daily dosage up to 50 m/kg/day until End of Treatment, followed by a taper-down period, and a safety follow up. Treatment will be provided for a total of 52 weeks with an interim analysis conducted 12 weeks after achieving maximal dose (either 25 mg/kg/day or optimal dose with regards to safety and tolerability) and at the end of 1 year of treatment with treatment extensions conducted beyond 52 weeks until such time as there is market authorization for Epidiolex, if Epidiolex becomes unavailable, or the study is terminated. Cessation of Epidiolex administration will be concluded with a taper period and follow-up visit 4 weeks after the taper.

Inclusion Criteria:

• Patient should have history of trying at least four antiepileptic drugs (AEDs), including one trial of a combination of two concomitant drugs, without successful seizure control. Vagal nerve stimulation, RNS deep brain stimulation, or the ketogenic diet can be considered equivalent to a drug trial.
• Patient must be taking two or more AEDs at a dose which has been stable for at least four weeks.
• A State of Georgia resident.

Exclusion Criteria:

• Patient is diagnosed as having Dravet Syndrome or Lennox-Gastaut Syndrome and eligible for a GW Pharmaceutical-Sponsored Clinical Trial.
• Patients who have been part of a clinical trial involving another investigational product in the previous six months.