This study will assess the safety and tolerability of a cannabidiol-enriched Cannabis Herbal Extract in a small group of children with refractory epileptic encephalopathy. The dosage of Cannabis Herbal Extract will be gradually increased over a four month time period.

Epileptic Encephalopathies are a group of epilepsies that develop in children. These epilepsies can cause frequent and difficult to control seizures. Because of the ongoing seizures, these epilepsies can also cause cognitive impairment and neurological impairment.

In many children with these Epileptic Encephalopathies, seizures are difficult to control with medical treatment, such as anti-convulsants or non-drug treatments like the ketogenic diet (a high fat, adequate-protein, low-carbohydrate diet). This has resulted in a need to find therapies that are effective and better tolerated for children with epileptic encephalopathies.

There is very limited data regarding the use of cannabis products in children, in particular cannabidiol-enriched cannabis oil in children with epilepsy. However, hemp oil products with high cannabidiol and low tetrahydrocannabinol ratios have been reported to provide seizure relief and cognitive improvement in children who take them.

Inclusion Criteria:

• Age 1-10 years
• Epileptic Encephalopathy
• A minimum of at least 1 major seizure per week or 4 major seizures per month. For the purposes of this research study, a major seizure would include atonic, tonic, clonic, tonic-clonic, major myoclonic, myoclonic astatic seizures and epileptic spasms (including infantile spasms)
• Refractory to anticonvulsant medication as per the International League Against Epilepsy (ILAE) Definition of failing 2 appropriate anticonvulsants at therapeutic doses
• The ability to attend appointments regularly
• Negative pregnancy test at screening for females who have reached menarche

Exclusion Criteria:

• Recent (<1 month) change in anticonvulsant therapies including anticonvulsant medications, ketogenic diet or settings on Vagal Nerve Stimulator
• Recent (<6 months) change in intravenous immunoglobulin (IVIG) treatment
• Initiation of ketogenic diet within 6 months (Patients must be on the ketogenic diet for at least 6 months to prevent any delayed response from the ketogenic diet affecting study results)
• Implantation and activation of Vagal Nerve Stimulator within 12 months (Patients may have a vagal nerve stimulator for at least one year once again to prevent delayed response from the vagal nerve stimulator affecting study results)
• Use of cannabis-based therapy within 2 months (Participants who have previously used a cannabis based therapy may be included if they have a 2 month period without use of cannabis based therapy prior to enrolment in the study)
• Use of selective serotonin reuptake inhibitor (SSRI), tricyclic antidepressant or atypical neuroleptic medication in last month
• Concomitant regular use of narcotics (Use of narcotics in emergency situations and supervised by a physician is allowed)
• Initiation or dosage change of oral or injected steroids within 3 months
• Allergy or known intolerance to any of the compounds within the study preparation
• Inability of study participants to attend assessments on a monthly basis
• Clinically significant cardiac, renal or hepatic disease (as assessed by the site investigator)