Trial reportEpilepsia2019
Long-term cannabidiol treatment in patients with Dravet syndrome: An open-label extension trial.
Trial report in Epilepsia, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 4 registered trials, which are not on this map. Cited by 110 papers, 11 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Double Blind, Placebo-controlled, Two-part Study to Investigate the Dose-ranging Safety and Pharmacokinetics, Followed by the Efficacy and Safety of Cannabidiol (GWP42003-P) in Children and Young Adults With Dravet Syndrome
A Double Blind, Placebo Controlled Two-part Study to Investigate the Dose-ranging Safety and Pharmacokinetics, Followed by the Efficacy and Safety of Cannabidiol (GWP42003-P) in Children and Young Adults With Dravet Syndrome
An Open Label Extension Study to Investigate the Safety of Cannabidiol (GWP42003-P; CBD) in Children and Adults With Inadequately Controlled Dravet or Lennox-Gastaut Syndromes.
A Randomized, Double-blind, Placebo-controlled Study to Investigate the Efficacy and Safety of Cannabidiol (GWP42003-P) in Children and Young Adults With Dravet Syndrome.
Who cites it
110 citing papers in PubMed, 11 syntheses or guidelines pooled it, 266 citations in OpenAlex.
- SUDEP and mortality in developmental and epileptic encephalopathies: A meta-analysis of randomized clinical trials and extension studies.Epilepsia · 2026Pooled it
- The efficacy and safety of cannabidiol (CBD) in pediatric patients with Dravet Syndrome: a narrative review of clinical trials.European journal of medical research · 2024Pooled it
- Dravet syndrome: A systematic literature review of the illness burden.Epilepsia open · 2023Pooled it
- Adverse Events of Cannabidiol Use in Patients With Epilepsy: A Systematic Review and Meta-analysis.JAMA network open · 2023Pooled it
- Update on Cannabidiol Clinical Toxicity and Adverse Effects: A Systematic Review.Current neuropharmacology · 2023Pooled it
- Impact of Antiseizure Medications on Appetite and Weight in Children.Paediatric drugs · 2022Pooled it
- Movement Disorders Secondary to Novel Antiseizure Medications in Pediatric Populations: A Systematic Review and Meta-analysis of Risk.Journal of child neurology · 2022Pooled it
- Efficacy and safety of adjunctive antiseizure medications for dravet syndrome: A systematic review and network meta-analysis.Frontiers in pharmacology · 2022Pooled it
- A Pharmacological Perspective on Plant-derived Bioactive Molecules for Epilepsy.Neurochemical research · 2021Pooled it
- A Mapping Literature Review of Medical Cannabis Clinical Outcomes and Quality of Evidence in Approved Conditions in the USA from 2016 to 2019.Medical cannabis and cannabinoids · 2021Pooled it
- Adjunctive Cannabidiol in Patients with Dravet Syndrome: A Systematic Review and Meta-Analysis of Efficacy and Safety.CNS drugs · 2020Pooled it
- Phase 2, open-label INSPIRE trial to assess the tolerability and effectiveness of transdermal cannabidiol gel in children and adolescents with 22q11.2 deletion syndrome (ZYN2-CL-031).Journal of neurodevelopmental disorders · 2026Trial
- Long-term safety and tolerability of transdermal cannabidiol gel in children and adolescents with Fragile X syndrome (ZYN2-CL-017): an interim analysis of an ongoing open-label extension study.Journal of neurodevelopmental disorders · 2025Trial
- Assessment of Orally Administered Δ9-Tetrahydrocannabinol When Coadministered With Cannabidiol on Δ9-Tetrahydrocannabinol Pharmacokinetics and Pharmacodynamics in Healthy Adults: A Randomized Clinical Trial.JAMA network open · 2023Trial
- Long-term cannabidiol treatment for seizures in patients with tuberous sclerosis complex: An open-label extension trial.Epilepsia · 2022Trial
- Fenfluramine HCl (FinteplaEpilepsia · 2020Trial
- Trial
- Long-term cannabidiol treatment in patients with Dravet syndrome: An open-label extension trial.Epilepsia · 2019Trial
- GABACellular and molecular neurobiology · 2026Review
- Ameliorating Seizures in Dravet Syndrome: A Review of Newly Approved and Investigational Drugs, RNA and Gene-Based Therapies.CNS drugs · 2026Review
50 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 5 institutions in 3 countries.
Funding
Abstract
objectiveAdd-on cannabidiol (CBD) significantly reduced seizures associated with Dravet syndrome (DS) in a randomized, double-blind, placebo-controlled trial: GWPCARE1 Part B (NCT02091375). Patients who completed GWPCARE1 Part A (NCT02091206) or Part B, or a second placebo-controlled trial, GWPCARE2 (NCT02224703), were invited to enroll in a long-term open-label extension trial, GWPCARE5 (NCT02224573). We present an interim analysis of the safety, efficacy, and patient-reported outcomes from GWPCARE5.
methodsPatients received a pharmaceutical formulation of highly purified CBD in oral solution (100 mg/mL), titrated from 2.5 to 20 mg/kg/d over a 2-week period, with their existing medications. Based on response and tolerance, CBD could be reduced or increased up to 30 mg/kg/d.
resultsBy November 2016, a total of 278 patients had completed the original randomized trials, and 264 (95%) enrolled in this open-label extension. Median treatment duration was 274 days (range 1-512) with a mean modal dose of 21 mg/kg/d, and patients received a median of 3 concomitant antiepileptic medications. Adverse events (AEs) occurred in 93.2% of patients and were mostly mild (36.7%) or moderate (39.0%). Commonly reported AEs were diarrhea (34.5%), pyrexia (27.3%), decreased appetite (25.4%), and somnolence (24.6%). Seventeen patients (6.4%) discontinued due to AEs. Twenty-two of the 128 patients from GWPCARE1 (17.2%), all taking valproic acid, had liver transaminase elevations ≥3 times the upper limit of normal. In patients from GWPCARE1 Part B, the median reduction from baseline in monthly seizure frequency assessed in 12-week periods up to week 48 ranged from 38% to 44% for convulsive seizures and 39% to 51% for total seizures. After 48 weeks of treatment, 85% of patients/caregivers reported improvement in the patient's overall condition on the Subject/Caregiver Global Impression of Change scale. SIGNIFICANCE: This trial shows that long-term CBD treatment had an acceptable safety profile and led to sustained, clinically meaningful reductions in seizure frequency in patients with treatment-resistant DS.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.