Clinical Study of Cannabidiol in Children, Adolescents, and Young Adults With Fragile X Syndrome

The study will be comprised of a Screening visit and a combination of seven visits both onsite (face-to-face) and virtual. The assignment of study drug or placebo will be done by a computer-generated system and neither the study doctor, participant or their caregivers will know which treatment is being given to them. The dose of the treatment will depend on the weight of the participants. If the participants weigh less than or equal to 30 kg, they will receive 2 sachets of the gel per day (1 sachet approximately every 12 hours). If the participant weighs more than 30 kg but less than or equal to 50 kg, they will receive 4 sachets of gel per day (2 sachets approximately every 12 hours). Participants who weigh more than 50 kg will receive 6 sachets of gel per day (3 sachets approximately every 12 hours). Parents/ caregivers will be instructed on proper application of the gel. The gel will be applied to clean, dry, intact skin of the upper arms/ shoulders. Blood samples will be collected for safety analysis of ZYN002. An independent analytical laboratory will also perform CGG repeat and methylation status analyses. Additionally, the parents/caregivers and study doctor will be asked to complete some questionnaires for efficacy and safety assessment.