An Open-label Extension Study to Investigate Possible Drug-drug Interactions Between Clobazam and Cannabidiol
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ClinicalTrials.gov Identifier: NCT02564952 |
Recruitment Status :
Completed
First Posted : October 1, 2015
Results First Posted : September 11, 2018
Last Update Posted : September 28, 2022
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Epilepsy | Drug: GWP42003-P Drug: Clobazam | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 18 participants |
Allocation: | N/A |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Other |
Official Title: | A Phase 2, Double-blind, Randomized, Placebo-controlled Study to Investigate Possible Drug-drug Interactions Between Clobazam and Cannabidiol (GWP42003-P) |
Actual Study Start Date : | March 11, 2016 |
Actual Primary Completion Date : | June 7, 2017 |
Actual Study Completion Date : | June 7, 2017 |

Arm | Intervention/treatment |
---|---|
Experimental: GWP42003-P
Participants who transferred from the DB phase (NCT02565108) to the OLE (still blinded at that stage) tapered off their GWP42003-P or placebo treatment by reducing their maintenance dose by 10% per day and concomitantly titrating GWP42003-P to 20 mg/kg/day initially for the OLE; doses could then be adjusted up or down, dependent on investigator opinion, to a maximum of 30 mg/kg/day GWP42003-P. Clobazam (CLB) was administered in line with the physician's preferred CLB dosing regimen for each participant. |
Drug: GWP42003-P
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 received up to a maximum of 30 mg/kg/day.
Other Names:
Drug: Clobazam Participants were taking CLB upon entry into the OLE phase of the trial. CLB was not an investigational medicinal product (IMP) for the OLE phase and was not administered by the Sponsor, but was administered at the physician's discretion, as required for each participant. CLB could be stopped, if clinically indicated, without impact on analysis.
Other Name: CLB |
- Number Of Participants Who Experienced Severe OLE-Emergent AEs [ Time Frame: Postdose on Day 2 of Visit 4 up to Safety follow-up (28 [± 3] days following the last dose of IMP) ]
An OLE-emergent AE was defined as an AE with an onset date after the first dose of IMP in the OLE phase of the study. The number of participants who experienced 1 or more severe OLE-emergent AEs after the first dose of IMP in the OLE phase of the study up to the Safety follow-up visit (28 [± 3] days following the last dose of IMP) is presented.
A summary of serious and all other non-serious AEs, regardless of causality, is located in the Reported Adverse Events module.

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Ages Eligible for Study: | 18 Years to 65 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Key Inclusion Criteria:
- Participant must have had epilepsy, as determined by the investigator, and must have been taking CLB.
- Participant must have had a documented magnetic resonance imaging/computerized tomography of the brain ruling out a progressive neurologic condition.
- Participant must have experienced at least 1 seizure of any type (that is, convulsive: tonic-clonic, tonic, clonic, atonic; focal: focal seizures with retained consciousness and a motor component, focal seizures with impaired consciousness, focal seizures evolving to bilateral secondary generalization) within the 2 months prior to randomization.
- Participant must have been taking CLB and no more than 2 other antiepileptic drugs (AEDs) during the course of the study. However, any participants who were taking these medications after screening were not withdrawn from the study unless there were safety concerns.
- AED(s), including CLB, must have been stable for 4 weeks prior to screening and regimen must have remained stable throughout the duration of the double-blind phase of the study.
- Intervention with vagus nerve stimulation and/or ketogenic diet must have been stable for 4 weeks prior to Baseline and participant/caregiver must have been willing to maintain a stable regimen throughout the double-blind phase of the study.
Key Exclusion Criteria:
- Participant had clinically significant unstable medical conditions other than epilepsy.
- Participants were on CLB at doses above 20 mg per day.
- Participants taking CLB intermittently as rescue medication.
- Participant had a history of symptoms related to a drop in blood pressure due to postural changes (for example, dizziness, light-headedness, blurred vision, palpitations, weakness, syncope).
- Participant had any history of suicidal behavior or any suicidal ideation of type 4 or 5 on the Columbia Suicide Severity Rating Scale in the last month or at screening.
- Participant had clinically relevant symptoms or a clinically significant illness, other than epilepsy in the 4 weeks prior to screening or enrollment, other than epilepsy.
- Participant had consumed alcohol during the 7 days prior to enrollment and was unwilling to abstain during the double-blind phase of the study.
- Participant was 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.
- Participant had any known or suspected history of any drug abuse or addiction.
- Participant was unwilling to abstain from recreational or medicinal cannabis, or synthetic cannabinoid-based medications (including Sativex) for the duration for the study.
- Participant consumed grapefruit or grapefruit juice 7 days prior to enrollment and was unwilling to abstain from drinking grapefruit juice within 7 days of pharmacokinetic visits.
- Participant had any known or suspected hypersensitivity to cannabinoids or any of the excipients of the IMP, for example, sesame oil.
- Participant received an IMP within the 12 weeks prior to the screening visit.
- Participant had significantly impaired hepatic function at the screening or randomization visit, defined as any of the following: (A) Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 5 × upper limit of normal (ULN). (B) ALT or AST > 3 × ULN and total bilirubin > 2 × ULN or international normalized ratio > 1.5. (C) ALT or AST > 3 × ULN with the presence of fatigue, nausea, vomiting, right upper quadrant pain or tenderness, fever, rash, and/or eosinophilia (> 5%).

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02564952
Spain | |
Barcelona, Spain, 08035 | |
Barcelona, Spain, 08036 | |
United Kingdom | |
Birmingham, United Kingdom, B15 2FG | |
Brighton, United Kingdom, BN2 5BE | |
Leeds, United Kingdom, LS1 3EX | |
Salford, United Kingdom, M6 8HD |
Documents provided by Jazz Pharmaceuticals:
Responsible Party: | Jazz Pharmaceuticals |
ClinicalTrials.gov Identifier: | NCT02564952 |
Other Study ID Numbers: |
GWEP1428 Open-Label Extension 2014-002942-33 ( EudraCT Number ) |
First Posted: | October 1, 2015 Key Record Dates |
Results First Posted: | September 11, 2018 |
Last Update Posted: | September 28, 2022 |
Last Verified: | September 2022 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Cannabidiol (CBD) GWP42003-P Clobazam Epidiolex |
Epilepsy Brain Diseases Central Nervous System Diseases Nervous System Diseases Cannabidiol Clobazam Anticonvulsants Anti-Anxiety Agents Tranquilizing Agents |
Central Nervous System Depressants Physiological Effects of Drugs Psychotropic Drugs GABA-A Receptor Agonists GABA Agonists GABA Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action |