Sanfilippo Syndrome (MPS III)Phase 1/2NCT07818759
Single Injection of rAAV9-CMV-hNAGLUop Gene for Patients With Mucopolysaccharidosis (MPS) IIIB
A Phase 1/2 study testing rAAV9-CMV-hNAGLUop in people with Sanfilippo Syndrome (MPS III), run by NeuroGT at 1 site in United States.
Trial summary
The goal of this clinical trial is to learn if one infusion of rAAV9-CMV-hNAGLUop can treat patients with Sanfilippo syndrome (MPS III) 6 months or older. The main questions it aims to answer are: Is the treatment safe? Is there a change in enzyme activities,? Is there a change in natural history trajectory of motor… Read more about this study
- Who is it for?
- Ages 6 months and older
- Conditions the study is for
- Sanfilippo Syndrome (MPS III)
- What is being tested?
- rAAV9-CMV-hNAGLUop
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 9 participants
- Where
- 1 siteUnited States
- Study dates
- 18 Jan 2027to 31 Dec 2029
- Phase
- Phase 1/2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 months and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Age >6 months
- Confirmed diagnosis of MPS IIIB based upon meeting the following conditions:
- No detectable or significantly reduced N-acetyl-α-glucosaminidase (NAGLU) enzyme activity by leukocyte assay from CLIA-certified laboratory
- Two variants classified as pathogenic or likely pathogenic in NAGLU on clinical laboratory testing. Variants will be interpreted using the American College of Medical Genetics guidelines for the interpretation of sequence variants and testing must be performed by a CLIA-certified laboratory.
- Clinical history of developmental delays defined as a score of >1 standard deviation below the mean in at least one domain of neuropsychological function (language, memory, non-verbal ability), OR documented historical evidence of a decline of >1 standard deviation on sequential testing, OR a score between 0.75 and 1 standard deviation below the mean and the cognitive defect affects daily performance.
Who cannot join
- Receipt of an investigational drug or procedure within 30 days of signing consent.
- A condition, medical or other, that prevents participation in the study, including severe auditory or visual impairment, significant lumbar pathology, lumbar catheter, airway or other factors that preclude the use of general anesthesia, bleeding diathesis, or recent major surgery within 6 weeks of screening that would preclude the patient's ability to participate.
- Active viral infection (includes HIV, or serology consistent with active hepatitis A, B or C infection)
- Clinically significant abnormal hematology within 1 month of infusion (complete blood count with differential), blood chemistry (including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), bilirubin, creatinine, and CRP), coagulability labs (international normalized ration (INR), prothrombin time (PT), activated partial thromboplastin time (aPTT). An abnormal laboratory value will be based on clinical laboratory reference ranges and Investigator's clinical judgment and will be deemed clinically significant if either of the following are met at baseline:
- The abnormality suggests a disease and/or organ toxicity beyond what is expected in Sanfilippo syndrome and/or beyond what would be considered safe for viral vector administration in the opinion of the investigator, or
- The abnormality is of a degree that requires additional active management, such as close observation, change in medication, or further diagnostic investigation.
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- Concomitant febrile illness or requirement for chronic drug treatment that in the opinion of the Investigator creates unnecessary risks for gene transfer.
- Anti-AAV9 antibody titers > 1:100 as determined by binding ELISA assay
- Participants who, in the opinion of the Investigator, are unable to comply with the protocol. Examples of inability to comply include unwillingness to travel to the study site, suspected noncompliance with study procedures, behavior that jeopardizes the safety or security of the data or study staff, and other causes of inability to comply.
- Uncontrolled seizure disorder. Participants who are stable on anticonvulsive medications may be included.
- Implanted metal objects or pacemakers that preclude MRI
- Patients with severe cardiomyopathy or significant congenital heart abnormalities
- The presence of significant non-MPS IIIB related CNS impairment or behavioral disturbances that would confound the scientific rigor or interpretation of results of the study
- Patients with signs, symptoms, or treatment of infection or administration of vaccines in the 6 weeks prior to study enrollment
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Washington University School of Medicine Division of Genetics and Genomic Medicine, Rare Diseases Department of Pediatrics
St Louis, Missouri, 63110
About this study
Official title: An Open-Label, Single Injection, Ascending Dose Phase I/II Clinical Study of rAAV9-CMV-hNAGLUop Gene for Patients With Mucopolysaccharidosis (MPS) IIIB
The goal of this clinical trial is to learn if one infusion of rAAV9-CMV-hNAGLUop can treat patients with Sanfilippo syndrome (MPS III) 6 months or older. The main questions it aims to answer are:
- Is the treatment safe?
- Is there a change in enzyme activities,?
- Is there a change in natural history trajectory of motor, language, feeding, adaptive and cognitive function?
Participants will be asked to come to Washington University St. Louis and stay in the hospital overnight following the infusion. Partcipant and caregiver(s) will be asked to stay near the hospital for the first month and come back periodically for clinic visits.
Read the detailed description
This is a dose escalation study where one infusion of rAAV9-CMV-hNAGLUop will be administered to patients with Sanfilippo Disease (MPS III).
Patients will go through an Informed Consent process and eligibility assessed by reviewing patient medical history and laboratory values.
Eligible patients will receive the infusion of rAAV9-CMV-hNAGLUop followed by an inpatient stay in the hospital for at least one night. Over the next 30 days, participants and their caregiver(s) will stay in a home near the hospital to facilitate visits back to the hospital. Participants will have laboratory samples collected at a lab near their home at days 45 and 75. Participants will come back to Washington University St. Louis at Day 60, Day 90, Day 120, Day 180, Month 12, Month 18 and Month 12 to have laboratory tests and other assessments, including ECG, motor skills assessments, gait test, questionnaires, and evaluation by the PI completed.
- Conditions
- Sanfilippo Syndrome (MPS III)
- Being tested
- rAAV9-CMV-hNAGLUop
- Keywords
- Gene Therapy, NeuroGT, Mucopolysaccharidoses, Lysosomal Storage Diseases, Congenital, Hereditary, and Neonatal Diseases and Abnormalities, Metabolism, Inborn Errors, Genetic Diseases, Inborn, Carbohydrate Metabolism, Inborn Errors, Mucopolysaccharidosis III, Metabolic Diseases, Skin and Connective Tissue Diseases, Mucinoses, Connective Tissue Diseases
- Medical subject headings
- Mucopolysaccharidosis III, Mucopolysaccharidoses, Lysosomal Storage Diseases, Congenital, Hereditary, and Neonatal Diseases and Abnormalities, Metabolism, Inborn Errors, Genetic Diseases, Inborn, Carbohydrate Metabolism, Inborn Errors, Metabolic Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
rAAV9-CMV-hNAGLUopBiological
Systemic rAAV9-CMV-hNAGLUop gene delivery given once
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 | Experimental | rAAV9-CMV-hNAGLUop Low Dose Receives: Biological: rAAV9-CMV-hNAGLUop |
| Cohort 2 | Experimental | rAAV9-CMV-hNAGLUop High Dose Receives: Biological: rAAV9-CMV-hNAGLUop |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assessment of Safety
Incidence of unacceptable toxicity defined as the occurrence of two or more unanticipated Grade III or higher treatment-related toxicities
Measured: 24 months
Secondary outcomes (1)
Biopotency Outcome Measures
Increase in enzyme activity levels above baseline
Measured: 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Sep 2026
- Study start18 Jan 2027 (estimated)
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sanfilippo Syndrome (MPS III)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Model description
- * Cohort 1 will enroll 3 participants * Cohort 2 will enroll 6 participants
- Masking
- None (open label)
- Enrolment
- 9 participants (estimated)
Sponsor and investigators
- Lead sponsor
- NeuroGT
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07818759
- Sponsor's protocol ID
- NGT104-101
- Status last verified
- Sep 2026
- First submitted
- 31 Aug 2026
- Last updated
- 14 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Corporate decision on whether to share information is undecided based on stage of company