1. Placebo response in patients with Dravet syndrome: Post-hoc analysis of two clinical trials.
- Author
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Devinsky O, Hyland K, Loftus R, Nortvedt C, and Nabbout R
- Subjects
- Humans, Adolescent, Child, Female, Male, Child, Preschool, Anticonvulsants therapeutic use, Quality of Life, Treatment Outcome, Double-Blind Method, Epilepsies, Myoclonic drug therapy, Cannabidiol therapeutic use, Placebo Effect
- Abstract
Objective: Dravet syndrome is a rare, early childhood-onset epileptic and developmental encephalopathy. Responses to placebo in clinical trials for epilepsy therapies range widely, but factors influencing placebo response remain poorly understood. This study explored placebo response and its effects on safety, efficacy, and quality of life outcomes in patients with Dravet syndrome., Methods: We performed exploratory post-hoc analyses of pooled data from placebo-treated patients from the GWPCARE 1B and GWPCARE 2 randomized controlled phase III trials, comparing cannabidiol and matched placebo in 2-18 year old Dravet syndrome patients. All patients had ≥4 convulsive seizures during a baseline period of 4 weeks., Results: 124 Dravet syndrome-treated patients were included in the analysis (2-5 years: n = 35; 6-12 years: n = 52; 13-18 years: n = 37). Convulsive seizures were experienced by all placebo group patients at all timepoints, with decreased median convulsive seizure frequency during the treatment period versus baseline; the number of convulsive seizure-free days was similar to baseline. Convulsive seizure frequency had a nominally significant positive correlation with age and a nominally significant negative correlation with body mass index. Most placebo-treated patients experienced a treatment-emergent adverse event; however, most resolved quickly, and serious adverse events were infrequent. Placebo treatment had very little effect on reported Caregiver Global Impression of Change outcomes versus baseline., Interpretation: Placebo had little impact on convulsive seizure-free days and Caregiver Global Impression of Change versus baseline, suggesting that these metrics may help differentiate placebo and active treatment effects in future studies. However, future research should further assess placebo responses to confirm these results., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This post-hoc analysis was funded by Jazz Pharmaceuticals. Editorial and medical writing services were provided by Costello Medical, funded by Jazz Pharmaceuticals. RN: Received compensation for consulting work and/or attending Scientific Advisory Boards from GW Pharma, LivaNova, Lundbeck, Marinus, Stoke, Supernus, Advicenne, Takeda, UCB Inc., Servier, Eisai, Ionis, Zogenix, Neuraxpharm. She has research grants from European FP7 program, European joint program on rare diseases; KH, RL, CN: Employees of Jazz Pharmaceuticals; OD: Receives grant support from NINDS, NIMH, MURI, CDC and NSF. He has equity and/or compensation from the following companies: Tilray, Receptor Life Sciences, Qstate Biosciences, Hitch Biosciences, Tevard Biosciences, Empatica, SilverSpike, and California Cannabis Enterprises (CCE). He has received consulting fees from Zogenix, Ultragenyx, BridgeBio, and Marinus. He holds patents for the use of cannabidiol in treating neurological disorders but these are owned by Jazz Pharmaceuticals and he has waived any financial interests. He holds other patents in molecular biology., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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