GWPCARE2 A Study to Investigate the Efficacy and Safety of Cannabidiol (GWP42003-P) in Children and Young Adults With Dravet Syndrome

This study was a 2:2:1:1 randomized, double-blind, 14-week comparison of two dose levels of GWP42003-P (10 milligram/kilogram [mg/kg]/day and 20 mg/kg/day) versus placebo (10 mg/kg/day dose-volume equivalent and 20 mg/kg/day dose-volume equivalent; presented as pooled placebo in the study). A 28-day screening period prior to randomization (to establish baseline parameters) preceded the treatment period, which consisted of a 2-week titration period followed by a 12-week maintenance period. The study aimed to determine the efficacy, safety, and tolerability of GWP42003-P compared with placebo. 20 mg/kg/day was recommended by the Data Safety Monitoring Committee (DSMC) after assessment of safety and pharmacokinetic data from Part A of study GWEP1332 (NCT02091206). The first participant did not enroll into this study until the DSMC reviewed the safety data from Part A of study GWEP1332 (NCT02091206).

Following study completion, all participants were invited to continue to receive GWP42003-P in a separate open-label extension study (GWEP1415; NCT02224573).

Key Inclusion Criteria:

• Participant must have been male or female, aged between 2 and 18 years (inclusive).
• Participant must have had a documented history of Dravet syndrome that was not completely controlled by current antiepileptic drugs.
• Participant must have been taking 1 or more antiepileptic drugs at a dose that had been stable for at least 4 weeks.
• All medications or interventions for epilepsy (including ketogenic diet and vagus nerve stimulation) must have been stable for 4 weeks prior to screening and participant was willing to maintain a stable regimen throughout the study.

Key Exclusion Criteria:

• Participant had clinically significant unstable medical conditions other than epilepsy.
• Participant had clinically relevant symptoms or a clinically significant illness in the 4 weeks prior to screening or randomization, other than epilepsy.
• Participant was currently using or had in the past used recreational cannabis, medicinal cannabis, or synthetic cannabinoid-based medications (including Sativex®) within the 3 months prior to study entry and was unwilling to abstain for the duration for the study.
• Participant had any known or suspected hypersensitivity to cannabinoids or any of the excipients of the investigational medicinal products.
• There were plans for the participant to travel outside their country of residence during the study.
• Any history of suicidal behavior or any suicidal ideation of type four or five on the Columbia-Suicide Severity Rating Scale (Children's) at screening.