Clinical Trial: An Open-label Extension Trial of Cannabidiol (GWP42003-P, CBD) for Seizures in Tuberous Sclerosis Complex (GWPCARE6)

Study Status: Enrolling by invitation
Recruit Status: Enrolling by invitation
Study Type: Interventional

Official Title: A Double-blind, Randomized, Placebo-controlled Study to Investigate the Efficacy and Safety of Cannabidiol (GWP42003-P, CBD) as Add-on Therapy in Patients With Tuberous Sclerosis

Brief Summary: This trial consists of 2 parts: a double-blinded phase and an open-label extension phase. The open-label extension phase only will be described in this record. All participants will receive the same dose of GWP42003-P. However, investigators may subsequently decrease or increase the participant's dose until the optimal dose is found.

Detailed Summary:
Sponsor: GW Research Ltd

Current Primary Outcome: Incidence of adverse events [ Time Frame: From OLE screening until market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]

Original Primary Outcome: Incidence of adverse events [ Time Frame: From OLE screening until market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]

The number of participants who experienced an adverse event during the trial is presented.


Current Secondary Outcome:

  • Change in seizure frequency [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Number of treatment responders [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Number of participants with worsening, no change, or improvements in seizure frequency [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in composite focal seizure score [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in number of seizure-free days [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in number of seizures by subtype [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in number of infantile/epileptic spasms. [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in use of rescue medication [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in number of episodes of status epilepticus [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in duration of seizures by subtype [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in overall condition as assessed by the participant/caregiver [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in overall condition as assessed by the physician [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in Vineland-II score [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in Wechsler score by subtest [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in Behavior Checklist score [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in Social Communication Questionnaire score [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in Quality of Life score [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Change in serum IGF-1 levels [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Number of participants with changes in Tanner stage [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
  • Incidence of suicidality [ Time Frame: From OLE screening until market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]


Original Secondary Outcome:

  • Change in focal seizure frequency [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The percentage change from the pre-randomization baseline of the blinded phase in number of focal seizures (average per 28 days) is presented.
  • Number of treatment responders [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The number of participants considered treatment responders, defined as those with a ≥ 25%, ≥ 50%, ≥ 75% or 100% reduction in focal seizure frequency, are presented.
  • Number of participants with worsening, no change, or improvements in focal seizure frequency [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The number of participants experiencing a > 25% worsening, −25 to +25% no change, 25-50% improvement, 50-75% improvement or > 75% improvement in focal seizure frequency is presented.
  • Change in composite focal seizure score [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The change from the pre-randomization baseline of the blinded phase in composite focal seizure score (frequency × severity) is presented.
  • Change in number of focal seizure-free days [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The change from the pre-randomization baseline of the blinded phase in number of focal seizure-free days is presented.
  • Change in number of seizures by subtype [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The change from the pre-randomization baseline of the blinded phase in number of seizures of each subtype is presented.
  • Change in number of infantile/epileptic spasms. [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The change from the pre-randomization baseline of the blinded phase in number of infantile/epileptic spasms is presented.
  • Change in use of rescue medication [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The change from the pre-randomization baseline of the blinded phase in use of rescue medication is presented.
  • Change in number of episodes of status epilepticus [ Time Frame: Baseline and once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]
    The change from the pre-randomization baseline of the blinded phase in the number of episodes of status epilepticus (convulsive and non-convulsive) is presented.
  • Change in duration of seizures by subtype [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]

    The change in the duration of seizures of each subtype was assessed using the Subject- or Caregiver Global Impression of Change in Seizure Duration (SGIC-SD/CGIC-SD), which comprise the following:

    • SGIC-SD: "Since you started treatment, please assess the average duration of your seizures (comparing your condition now to your condition before treatment) using the scale below."
    • CGIC-SD: "Since the patient started treatment, please assess the average duration of the patient's seizures (comparing their condition now to their condition before treatment) using the scale below."

    The markers are "Average duration of seizures has decreased"; "Average duration of seizures has stayed the same"; "Average duration of seizures has increased".

    The number of participants/caregivers who selected each marker at the end of treatment is presented.

  • Change in overall condition as assessed by the participant/caregiver [ Time Frame: Once market authorization is granted for GWP42003-P in TSC (anticipated to be 2 years after the OLE trial start date) ]

    The change in overall condition was assessed using the Subject- or Caregiver Global Impression of Change (SGIC/CGIC), which comprise the following: