Amsterdam UMC
Amsterdam, The Netherlands
Not yet recruitingRare disease
Cannabidiol for behavioral problems in patients with Tuberous Sclerosis Complex, Sanfilippo syndrome, and Fragile X syndrome
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What is this trial about?
A plain-language summary of the goals, design and what participants do
This study is looking at three different conditions: Tuberous Sclerosis Complex, Sanfilippo syndrome, and Fragile X syndrome. These are genetic conditions that can cause behavioral problems such as irritability, aggression, and other challenging behaviors that affect daily life. The treatment being tested is Epidyolex, which is an oral solution containing cannabidiol (also known as CBD). Participants will also receive an oral solution with beta-carotene as part of the study.
The purpose of this study is to investigate whether CBD is effective in reducing irritability and other behavioral problems in children and adults with these three conditions. The study will look at how CBD affects various aspects of behavior, including symptom severity, quality of life, anxiety, depression, mood, autism symptoms, sensory processing, parental stress, and personal goals. For those who also experience seizures, the study will track seizure frequency. The safety of the treatment will be monitored by recording any side effects and checking liver enzyme levels throughout the study.
The study uses a special design called an N-of-1 series, which means each participant will be studied individually over time. Participants will take the CBD oral solution for up to 24 weeks while maintaining their current medications and treatments stable. During this time, caregivers will complete questionnaires and keep diaries to track behavioral changes and any seizures that occur. The maximum daily dose of CBD will be 25 milligrams per kilogram of body weight. Participants need to be at least 6 years old and must have a caregiver who can provide regular reports about their behavior and well-being.
The research process
The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.
Who can join the trial?
7 criteria
- You must be at least 6 years old or older to take part in this study
- You must have a confirmed diagnosis of one of these conditions: Tuberous Sclerosis Complex (also called TSC, a genetic condition that causes non-cancerous tumors to grow in different parts of the body), Sanfilippo syndrome (a rare inherited condition that affects the body's ability to break down certain complex sugars), or Fragile X syndrome (also called FXS, a genetic condition that can cause learning disabilities and behavioral challenges)
- Your diagnosis must be confirmed by specific medical tests such as genetic testing
- You must have severe behavioral problems, which means scoring at least 4 on a medical scale called the Clinical Global Impressions scale (a tool doctors use to measure how severe symptoms are)
- If you are taking any medications or receiving treatments for seizures (sudden bursts of electrical activity in the brain that can cause changes in behavior, movements, or consciousness) or behavioral problems, these must have been at the same dose for at least one month before starting the study
- You must be willing to keep taking the same medications and treatments at the same doses throughout the entire study without making changes
- You must have a caregiver (a person who regularly helps take care of you) who can attend study visits and answer questions about your symptoms and behavior
Who cannot join the trial?
2 criteria
- The information about specific reasons why patients cannot participate in this study is not available in the provided data
- If you are interested in participating, a doctor involved in the study would need to review your individual medical situation to determine if you meet the requirements
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Investigated drugs
Cannabidiol (also known as Epidyolex) is a medicine derived from the cannabis plant. It is used to help reduce behavioral problems such as irritability and other difficult behaviors in patients. In this trial, it is being tested to see if it can improve behavior in people with certain genetic conditions.
What is already known about the treatment
Epidyolex – Epidyolex is a liquid oral medication containing cannabidiol (CBD), a natural substance derived from cannabis plants, which is taken by mouth usually twice daily. This medication is approved in several countries for treating certain types of seizures and is being studied for its potential to help reduce irritability and behavioral problems in people with genetic conditions affecting brain development. It works by interacting with the body's natural signaling systems in the brain that help control nerve cell activity and inflammation, though the exact way it affects behavior is still being researched. Epidyolex belongs to a class of medications called cannabinoids and represents one of the first cannabis-derived treatments to receive regulatory approval for medical use.
Investigated diseases
Tuberous Sclerosis Complex
Tuberous Sclerosis Complex is a genetic disorder that causes non-cancerous tumors to grow in various organs throughout the body, most commonly in the brain, skin, kidneys, heart, and lungs. The condition is present from birth and results from changes in specific genes that control cell growth and division. People with this condition often experience seizures, developmental delays, and behavioral problems including irritability and autism-like symptoms. Skin abnormalities such as light-colored patches and thickened areas may appear during childhood. The severity of symptoms varies widely from person to person, with some individuals experiencing mild effects while others have more significant challenges. Brain tumors associated with this condition can lead to learning difficulties and problems with thinking and reasoning skills.
Sanfilippo Syndrome
Sanfilippo syndrome is a rare inherited metabolic disorder where the body cannot break down certain complex sugar molecules called heparan sulfate. This occurs because the body lacks or has insufficient amounts of specific enzymes needed to process these molecules. As heparan sulfate builds up in cells throughout the body, it particularly affects the brain and nervous system. Children with this condition typically develop normally for the first few years of life before symptoms begin to appear. Behavioral problems including hyperactivity, aggression, irritability, and sleep disturbances are common features of the condition. As the condition advances, affected individuals experience progressive loss of skills they had previously learned, including speech and motor abilities.
Fragile X Syndrome
Fragile X syndrome is a genetic condition that affects brain development and is the most common inherited cause of intellectual disability and autism. The condition results from changes in a specific gene on the X chromosome that produces a protein necessary for normal brain development. Children with this syndrome often show delayed development in speech, language, and motor skills during early childhood. Behavioral characteristics include anxiety, hyperactivity, attention problems, and irritability, with many individuals also displaying features associated with autism spectrum disorder. Physical features may include a long face, large ears, and flexible joints, though these become more noticeable with age. The severity of symptoms varies considerably, with males typically more severely affected than females.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-520846-31-00Estimated enrolment30 patientsSponsorAmsterdam UMC
sourced from the EU Clinical Trials Register and site verification
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