Conditions: Epilepsy Lennox Gastaut Syndrome
Keywords: Cannabidiol CBD Epidiolex GWP42003-P
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 225
Healthy volunteers: no

Brief summary:
The primary objective of this study was to evaluate the efficacy of GWP42003-P as adjunctive treatment in reducing the number of drop seizures when compared with placebo in participants with Lennox-Gastaut syndrome (LGS).

Detailed description:
This study was a 1:1:1 randomized, double-blind, 14-week comparison of 2 dose levels (10 milligram \[mg\] per kilogram \[kg\] per day \[mg/kg/day\] and 20 mg/kg/day) of GWP42003-P versus placebo. Participants who satisfied all inclusion and none of the exclusion criteria began a 28-day baseline observation period. The treatment period consisted of a 2-week titration period followed by a 12-week maintenance period. The 20 mg/kg/day dose was recommended by the Data Safety Monitoring Committee (DSMC) after assessment of safety and pharmacokinetic data from Part A of study GWEP1332 (NCT02091206). The 10 mg/kg/day dose was defined as 50% of the 20 mg/kg/day dose. The first participant was not enrolled into this study until the DSMC had reviewed the safety data from Part A of study GWEP1332.

Participants who satisfied all eligibility criteria were randomized at Day 1 to receive 10 mg/kg/day GWP42003-P, 20 mg/kg/day GWP42003-P, or placebo at a 1:1:1 ratio. Participants in the placebo group were split into 2 equivalent cohorts; one half received 10 mg/kg/day dosing volumes and one half received 20 mg/kg/day dosing volumes. The 2 placebo cohorts were pooled for the analyses of efficacy. Participants titrated GWP42003-P to the 10 mg/kg/day or 20 mg/kg/day (or equivalent volume of placebo) dose over 7 and 11 days, respectively, and remained at this dose for the 12-week maintenance period. Following the end of treatment (Day 99), participants were invited to continue to receive GWP42003-P in an open-label extension (OLE) study under a separate protocol (GWEP1415; NCT02224573). All participants who did not immediately enter the OLE study tapered investigational medicinal product (IMP) (10% per day over 10 days). However, the taper period could be interrupted if the participant wished to enter the OLE study within a 7-day timeframe. Participants who down-titrated IMP returned for an end of taper period visit (Day 109). Participants who did not enter the OLE study or who withdrew prematurely had a safety follow-up visit 28 days later (Day 137).

Arms:
arm 1: 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 12-week maintenance period. If the participant did not immediately enter the OLE study, the maintenance 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 12-week maintenance period. If the participant did not immediately enter the OLE study, the maintenance period was followed by a 10-day taper (10% per day) period. arm 3: Participants received placebo (0 mg/mL CBD) volume matched to 1 of the 2 dose levels (10 or 20 mg/kg/day) administered orally, half in the morning and half in the evening. To maintain the blinded aspect of the study, participants titrated the placebo dose over 7 to 11 days according to the matched IMP group (7 or 11 days for the 10 or 20 mg/kg/day GWP42003-P groups, respectively) and remained at this dose for the 12-week maintenance period. If the participant did not immediately enter the OLE study, the maintenance period was followed by a 10-day taper (10% per day of the matched dose) period.

Interventions: intervention 1: GWP42003-P intervention 2: Placebo control
Intervention descriptions: intervention 1: GWP42003-P was presented as an oral solution containing 100 mg/milliliter (mL) cannabidiol (CBD) 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 10 or 20 mg/kg/day. intervention 2: Placebo was presented as an oral solution containing 0 mg/mL CBD 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).

Protocol document: