Conditions: Epilepsy Dravet Syndrome
Keywords: Cannabidiol CBD Epidiolex GWP42003-P
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 34
Healthy volunteers: no

Brief summary:
To evaluate the safety and pharmacokinetics (PK) of multiple doses of GWP42003-P compared with placebo in children with Dravet syndrome.

Detailed description:
This multi-center study consisted of 2 parts: Part A and Part B. Only Part A is described in this record. Part A was a randomized, double-blind 21-day treatment study period. Participants were randomized to one of 3 doses of active drug or placebo at a 4:1 ratio.

Participants who satisfied all inclusion and none of the exclusion criteria were assigned a unique participant number and then began a 28-day baseline observation period.

Eligible participants were then randomly assigned to receive one of 3 dose levels of GWP42003-P: 5 milligrams (mg) per kilogram (kg) per day, 10 mg/kg/day, 20 mg/kg/day, or matching placebo.

There were three groups of ten participants. In each group, participants were randomly assigned so that eight participants received active treatment and two participants received placebo. Participants received GWP42003-P or placebo for a 21-day exposure period, which consisted of a titration period, followed by a stable dose period.

A PK assessment took place after the first single dose of GWP42003-P. There was a second PK assessment after 21 days of consecutive dosing with GWP42003-P. Participants who took clobazam (CLB) as an adjunctive treatment were asked to take their usual dose 2 hours prior to attending the clinic. The same recommendation was made for other concomitant antiepileptic drugs (AEDs), if applicable. This was so that the pre-treatment (with GWP42003-P) plasma concentrations of CLB, its major metabolite N-desmethylclobazam, and any other concomitant AEDs could be measured, and the impact of GWP42003-P treatment on these levels evaluated. Interim clinic visits to (primarily) evaluate safety and adherence to the titration regimen took place at 7 and 14 days of treatment.

After 21 days of treatment, all participants commenced a 10-day down-titration taper period. An independent Data Safety Monitoring Committee reviewed unblinded safety and PK data and recommended the target dose (up to 20 mg/kg/day) for Part B of the study and for an open label extension study. Once the safety review of Part A data had taken place, participants had the option of entering the open label extension study.

A follow-up telephone call was made 28 days after the end of dosing for participants who did not enter the open label extension study within this time-frame.

Throughout the 21-day treatment period and the 10-day taper period, there were regular safety telephone calls (approximately every 2 days) to check participant status. Weekly safety telephone calls were made during the 28-day follow-up period.

Arms:
arm 1: Participants received GWP42003-P 5 mg/kg/day administered orally, half in the morning and half in the evening. Participants titrated GWP42003-P to 5 mg/kg/day over 3 days and remained at this dose for the rest of the 21-day treatment period (19 days). The 21-day treatment period was followed by a 10-day taper (10% per day) period. arm 2: Participants received GWP42003-P 10 mg/kg/day administered orally, half in the morning and half in the evening. Participants titrated GWP42003-P to 10 mg/kg/day over 7 days and remained at this dose for the rest of the 21-day treatment period (15 days). The 21-day treatment period was followed by a 10-day taper (10% per day) period. arm 3: Participants received GWP42003-P 20 mg/kg/day administered orally, half in the morning and half in the evening. Participants titrated GWP42003-P to 20 mg/kg/day over 11 days and remained at this dose for the rest of the 21-day treatment period (11 days). The 21-day treatment period was followed by a 10-day taper (10% per day) period. arm 4: Participants received placebo (0 mg/mL CBD), volume matched to one of the 3 dose levels (5, 10, or 20 mg/kg/day), administered orally, half in the morning and half in the evening for 21 days. To maintain the blinded aspect of the study, participants titrated the placebo dose over 3 to 11 days according to the matched investigational medicinal product (IMP) group (3, 7, and 11 days for the 5, 10, or 20 mg/kg/day GWP42003-P groups, respectively) and remained at this dose for the rest of the 21-day treatment period. The 21-day treatment period was followed by a 10-day taper (10% per day of the matched dose) period.

Interventions: intervention 1: GWP42003-P 5 mg/kg/day Dose intervention 2: Placebo control intervention 3: GWP42003-P 10 mg/kg/day Dose intervention 4: GWP42003-P 20 mg/kg/day Dose
Intervention descriptions: intervention 1: GWP42003-P was an oral solution containing 25 mg/milliliter (mL) cannabidiol (CBD) or 100 mg/mL CBD dissolved in the excipients sesame oil and anhydrous ethanol (79 mg/mL) with added sweetener (0.5 mg/mL sucralose) and strawberry flavoring (0.2 mg/mL). Participants were randomly assigned to receive either 5, 10 or 20 mg/kg/day. intervention 2: Placebo oral solution contained the excipients sesame oil and anhydrous ethanol (79 mg/mL) with added sweetener (0.5 mg/mL sucralose) and strawberry flavoring (0.2 mg/mL). intervention 3: GWP42003-P was an oral solution containing 25 mg/mL CBD or 100 mg/mL CBD dissolved in the excipients sesame oil and anhydrous ethanol (79 mg/mL) with added sweetener (0.5 mg/mL sucralose) and strawberry flavoring (0.2 mg/mL). Participants were randomly assigned to receive either 5, 10 or 20 mg/kg/day. intervention 4: GWP42003-P was an oral solution containing 25 mg/mL CBD or 100 mg/mL CBD dissolved in the excipients sesame oil and anhydrous ethanol (79 mg/mL) with added sweetener (0.5 mg/mL sucralose) and strawberry flavoring (0.2 mg/mL). Participants were randomly assigned to receive either 5, 10 or 20 mg/kg/day.

Protocol document: