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Efficacy and safety of cannabidiol-based hand gel (ZYN002) for young people with Fragile X Syndrome

Introduction: Young people with Fragile X Syndrome (FXS) tend to experience irritability and social difficulties (e.g., extreme shyness). However, there are no approved treatments for people with both FXS and these difficulties. Cannabidiol comes from the cannabis plant (non-euphoric component) and may improve these difficulties by helping the brain chemicals to work properly. A new hand gel- ZYN002 containing 4.2% cannabidiol was shown to be effective for some of those most with the most pronounced difficulties.

Method: The study recruited 212 young people with FXS, aged 3 to 17 years old, in the USA, Australia and New Zealand. The young people had two types of genetic change on the FMR1 gene - either ≥90% methylation (167 children/adolescents), or 100% methylation (45 children/adolescents). The young people with ≥90% methylation tended to experience more behavioural and cognitive challenges compared to those with 100% methylation. A computer randomly assigned all participants to either the real treatment/ZYN002 or the fake treatment/placebo. To avoid bias, neither the researchers, nor the participating families knew what treatment the participants were receiving.

Results: After the 12-week treatment, only young people with ≥90% methylation, who received the real treatment/ZYN002, and their caregivers reported less social avoidance and irritability. All participants tolerated ZYN002 well and most found it easy to use. ZYN002 was also safe to use with minimal side effects (e.g., mild pain on the site of application).

Limitations: The study was small and only a fifth of the children and adolescents tested had 100% methylation, meaning more young people with this methylation are needed to check whether ZYN002 is truly less effective for them. Most of the participants (80%) were young males with FXS, meaning the results are less relevant for females and adults with FXS. The dose of the gel (ZYN002) may not have always been sufficient to produce beneficial effects in this study. Future research should therefore tailor the dose to each young person.

Original article: Berry-Kravis, E., Hagerman, R., Budimirovic, D., Erickson, C., Heussler, H., Tartaglia, N., ... & O’Quinn, S. (2022). A randomized, controlled trial of ZYN002 cannabidiol transdermal gel in children and adolescents with fragile X syndrome (CONNECT-FX). Journal of Neurodevelopmental Disorders, 14(1), 56.


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