Inclusion Criteria:

• Patient has completed the treatment phase of their Core Study.
• Patient and/or parent(s)/legal representative must be willing and able to give informed consent/assent for participation in the study.
• Patient and their caregiver must be willing and able (in the Investigator’s opinion) to comply with all study requirements.
• Patient and/or parent(s)/legal representative is willing to allow his or her primary care practitioner and consultant to be notified of participation in the study.

Exclusion Criteria:

• Patient is currently using or has in the past used recreational or medicinal cannabis, or synthetic cannabinoid-based medications (including Sativex®) within the 3 months prior to study entry, not including IMP received during the Core study.
• Patient is unwilling to abstain from using recreational or medicinal cannabis, or synthetic cannabinoid-based medications (including Sativex) during the study.
• Patient has a history of symptoms (e.g., dizziness, light-headedness, blurred vision, palpitations, weakness, syncope) related to a drop in blood pressure due to postural changes.
• Any history of suicidal behavior or any suicidal ideation of type 4 or 5 on the C-SSRS at Visit 1.
• Patient has been part of a clinical trial involving an IMP during the inter-study period.
• Patient has previously been enrolled and dosed in this study.
• Female patient is of child bearing potential or male patient’s partner is of child bearing potential; unless willing to ensure that they or their partner use highly effective contraception for the duration of the study and for 3 months thereafter. Highly
• effective methods of contraception are defined as those, alone or in combination, that result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly. Such methods include hormonal contraceptives, intrauterine devices/hormone-releasing systems, bilateral tubal occlusion, vasectomized partner or sexual abstinence.
• Female patient who is pregnant (positive pregnancy test), lactating or planning pregnancy during the course of the study and for 3 months thereafter.
• Any other significant disease or disorder which, in the opinion of the Investigator, may either put the patient at risk because of participation in the study, may influence the result of the study, or affect the patient’s ability to participate in the study.
• Following a physical examination the patient has any abnormalities that, in the opinion of the Investigator, would prevent the patient from safe participation in the study.
• Patient is unwilling to abstain from donation of blood during the study.
• Patient has significantly impaired hepatic function at the ‘End of Treatment’ visit of their Core Study or at Visit 1 if re-assessed, defined as any of the following:
  • ALT or AST > 5 × upper limit of normal (ULN);
  • ALT or AST > 3 × ULN and (TBL > 2 × ULN or INR > 1.5);
  • ALT or AST > 3 × ULN with the presence of fatigue, nausea, vomiting, right upper quadrant pain or tenderness, fever, rash, and/or eosinophilia (> 5%).
• If the Core Study ‘End of Treatment’/‘End of Taper Period’ visit assessments or Visit 1 re-assessments (as applicable) raise any safety concerns, the Investigator should consider whether it will be appropriate for the patient to continue to participate in the OLE study, or if the patient should be withdrawn.