ClinicalTrials.gov record NCT06333041

Study of Cannabidiol in Sanfilippo Syndrome

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

Randomized, Double-Blind, Placebo-Controlled Cross-Over Study to Evaluate the Effects of Cannabidiol on Neurobehavioral and Function Outcomes in Sanfilippo Syndrome

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 2/3A study that tests whether a treatment works while continuing to check safety, in a larger group than a phase 2 study alone. It combines the aims of phase 2 and phase 3 in one protocol.
AgeSee eligibility The registry's age field and its own written criteria give different ages for this study. Check the full criteria below and ask the study team.
SexAll
LocationUnited States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This trial tests Epidiolex (a pharmaceutical cannabidiol oral solution) in people with Sanfilippo syndrome (MPS III) aged 4 years and older. It first enrolls a small sentinel safety group, then a randomized, double‑blind crossover comparison of Epidiolex versus placebo with an 8‑week washout, followed by a 52‑week open‑label period where all receive Epidiolex. Caregivers complete regular questionnaires about behavior, sleep, stooling, pain, and caregiver stress while safety labs and adverse events are monitored.

What it is studying. The study is testing the safety of Epidiolex (cannabidiol) in people with Sanfilippo syndrome and exploring whether Epidiolex changes neurobehavioral symptoms (for example mood, anger, aggression) and functional outcomes compared with placebo. It also collects the type and severity of adverse events and longer‑term safety data during a subsequent open‑label period.

What the researchers hope to learn. Measure safety of Epidiolex in Sanfilippo syndrome; describe adverse events. Explore whether Epidiolex affects neurobehavioral symptoms and functional outcomes compared with placebo, and collect longer‑term safety data during open‑label treatment.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The goal of this clinical trial is to test cannabidiol in Sanfilippo syndrome. The main questions it aims to answer are: 1) determine the safety of cannabidiol in Sanfilippo syndrome, and 2) explore the efficacy of cannabidiol in treating the neurobehavioral symptoms and functional outcomes of Sanfilippo syndrome. Each participant's caregiver will be asked to complete surveys related to the participant's behavior, mood, sleep, stooling, pain, and caregiver stress intermittently throughout the study. All participants will be enrolled into one of two cohorts based on enrollment order:

  • Sentinel Safety Cohort (first 5 participants) - all participants treated with Epidiolex (cannabidiol)
  • Controlled Cohort (next 30 participants) - participants randomized 1:1 (equal chance) to start treatment with Epidiolex (cannabidiol) or placebo for 16 weeks, followed by an 8-week washout period (no treatment). Participants then switch to the opposite treatment group for 16 weeks followed by all participants treated for 52 weeks with Epidiolex (cannabidiol).

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • Epidiolex
  • Placebo

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • MPS III diagnosis confirmed by genetic testing
  • ≥ 4 years of age
  • Patient or parent/legal guardian is able and willing to provide informed consent. For patients 7 to 16 years of age, assent must also be provided when cognitively possible.
  • If taking any of the following, no dose changes for the last 8 weeks:
  • Anakinra
  • Fluoxetine
  • Probiotic supplement
  • One of the following criteria are met:
  • Previous participation in a gene/cell therapy or enzyme restorative clinical trial.
  • Previously ineligible to participate in a gene/cell therapy or enzyme restorative clinical trial due to advanced disease state.
  • Functional age, as measured by the Vineland, is ≤ 0.5 chronological age

Exclusion criteria

  • Equitable selection will be used when choosing participants. An individual who meets any of the following criteria will be excluded from participation in this study:
  • Mutation known to cause slowly progressive disease
  • Taken any form of cannabis, including cannabidiol, in the last 8 weeks
  • Currently enrolled in another ongoing clinical trial
  • Concomitant use of any of the following therapies:
  • Rifampin
  • Diazepam (except for intermittent use as needed for treatment of a prolonged seizure episode)
  • Clobazam
  • Stiripentol
  • Everolimus, sirolimus, tacrolimus
  • Digoxin
  • Valproate
  • Recreational or medical Tetrahydrocannabinol (THC) or synthetic cannabinoid medications (including Sativex) within the last three months
  • Felbamate (if taking for less than one year)
  • Non-pharmacological therapies (e.g. ketogenic diet) must be stable for up to four weeks prior to enrollment
  • Clinical evidence of liver disease or liver injury as indicated by the presence of abnormal tests (AST or ALT \> 2 x ULN; Bilirubin \> 2 x ULN)
  • Known hypersensitivity to any components of Epidiolex (cannabidiol)
  • Pregnant or lactating women
  • Any other social or medical condition that the investigator believes would pose a significant hazard to the subject if the investigational therapy were initiated or be detrimental to the study

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

Sanfilippo syndrome, or Mucopolysaccharidosis type III (MPS III), is a rare genetic lysosomal storage disease characterized by the accumulation of heparan sulfate due to insufficient production of lysosomal enzymes. Consequently, a buildup of heparan sulfate causes progressive neurodegeneration, leading to significant neurobehavioral problems. These neurobehavioral symptoms are highly disruptive and distressing to families, have a significant impact on the quality of life of the patients and their families, and likely interfere with adjunctive therapeutic attempts at supporting the child. To date, there are no approved therapies for the treatment of the neurobehavioral symptoms of Sanfilippo syndrome. Cannabidiol (CBD), a compound derived from the cannabis plant but without the psychoactive effects, has been shown to be safe and effective in the treatment of children with severe epilepsy disorders. Studies have shown that CBD improves behavior in children with autism. This study will use Epidiolex, a pharmaceutical-grade purified oral solution of cannabidiol that was approved by the FDA for the treatment of severe pediatric epilepsy disorders. Study subjects will include approximately 35 participants with Sanfilippo syndrome. Participants will undergo baseline clinical evaluations, and neurobehavioral, and functional outcomes will be collected from parent-reported questionnaires. Participants will then receive either Epidiolex or placebo for 16 weeks. Following this period and an 8-week washout, participants will cross over and receive the opposite treatment for 16 weeks. Safety labs and questionnaires will be collected throughout these periods to assess safety and efficacy. Participants and study personnel will be blinded to the treatment status of each participant. When this blinded portion of the trial is completed, all participants will receive Epidiolex open-label for 52 weeks to measure long-term safety. The type and severity of adverse events will be collected to measure safety, and different behavioral and functional outcomes will be collected to measure efficacy.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Caregivers will complete questionnaires about the participant’s behavior, mood, sleep, stooling, pain, and caregiver stress at baseline and intermittently. Participants in the controlled cohort are randomized (blinded) to 16 weeks of Epidiolex (cannabidiol) or placebo, followed by an 8‑week washout and a crossover to the other 16‑week treatment (the first five participants form a sentinel safety cohort who all receive Epidiolex). After the blinded crossover, all participants receive open‑label Epidiolex for 52 weeks; safety blood tests and questionnaires are collected during the treatment and follow-up periods.

How the study is structured. Interventional drug trial. Participants first enter a small sentinel safety cohort, then most are randomized 1:1 to start either Epidiolex or placebo for 16 weeks, followed by an 8‑week washout, then they switch to the other treatment for 16 weeks (a crossover). The study is double‑blind (participants, caregivers, investigators, and outcome assessors are masked). After the blinded crossover phases, all participants receive open‑label Epidiolex for 52 weeks. Dosing is escalated over the 16‑week treatment periods and safety labs and caregiver questionnaires are collected throughout.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
  • The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on Sanfilippo syndrome

Clinical trials12 trials listed for Sanfilippo syndromeEvery trial the registry lists for Sanfilippo syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Sanfilippo syndrome researchLatest monthly update: September 2026. Includes: Approved drug shortlist. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Apr 1, 2026
Primary completion
April 2027 (estimated)
Study completion
December 2028 (estimated)
Target enrollment
35 participants (estimated)
Last updated on registry
Sep 15, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center
Principal investigator
Lynda E Polgreen, Associate Professor of Pediatrics
Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

  • The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterRecruiting

    Torrance, California, 90502 · United States

Terms used on this page · explanations by MedicalUpdates.ai

enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
Cohort
A group of people who share a characteristic, such as a diagnosis, and are studied together. 'Prospective' means they are followed forward from enrolment; 'retrospective' means existing records are reviewed.
randomized
Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
1:1
How many participants go to each group. In a 2:1 ratio, two are assigned to the first group for every one assigned to the second.
placebo
A treatment that looks like the study treatment but contains no active ingredient. Some participants receive it instead of the study treatment, usually without knowing which they got.
washout period
A period during which a participant stops a previous treatment before starting the study treatment, so the earlier treatment does not affect the results.
legal guardian
A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
assent
A child's or dependent adult's agreement to take part, given alongside the formal consent of a parent or legal representative.
x ULN
The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
investigational
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
blinded
Who does not know which intervention a participant is receiving. It can apply to participants, the people giving the treatment, those assessing results, or those analysing the data.
open-label
No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
adverse events
Any unwanted medical problem that happens during a study, whether or not it was caused by the treatment. A 'serious' adverse event is one that meets specific criteria, such as causing death, being life-threatening, requiring or prolonging hospital admission, causing significant disability, or another medically important outcome.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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