Single Injection of rAAV9-CMV-hNAGLUop Gene for Patients With Mucopolysaccharidosis (MPS) IIIB

NCT07818759 | Not Yet Recruiting Phase 1 FDA Drug

• 1 other identifier: NGT104-101
• Study Type: interventional
• Target: 9
• Locations: 1 country
• Sites: 1

Brief 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, 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.

Conditions

Sanfilippo Syndrome (MPS III)

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

Outcome Measures

Primary Outcomes (1)

• Assessment of Safety

  Incidence of unacceptable toxicity defined as the occurrence of two or more unanticipated Grade III or higher treatment-related toxicities

  24 months

Secondary Outcomes (1)

• Biopotency Outcome Measures

  24 months

Other Outcomes (1)

• Exploratory Efficacy Outcome Measures

  24 months

Study Arms (2)

Cohort 1

EXPERIMENTAL

rAAV9-CMV-hNAGLUop Low Dose

Biological: rAAV9-CMV-hNAGLUop

Cohort 2

EXPERIMENTAL

rAAV9-CMV-hNAGLUop High Dose

Biological: rAAV9-CMV-hNAGLUop

Interventions

rAAV9-CMV-hNAGLUop BIOLOGICAL

Systemic rAAV9-CMV-hNAGLUop gene delivery given once

Cohort 1; Cohort 2

Eligibility Criteria

• Age: 6 Months+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.
• 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

Sponsors & Collaborators

• NeuroGT: lead

Study Sites (1)

Washington University School of Medicine Division of Genetics and Genomic Medicine, Rare Diseases Department of Pediatrics

St Louis, Missouri, 63110, United States

Location

MeSH Terms

Conditions

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; Skin and Connective Tissue Diseases; Mucinoses; Connective Tissue Diseases

Condition Hierarchy (Ancestors)

Nutritional and Metabolic Diseases

Central Study Contacts

Amy Fadden

CONTACT

980-297-5490; clinicaltrials@neurogt.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: * Cohort 1 will enroll 3 participants * Cohort 2 will enroll 6 participants

Study Record Dates

• First Submitted: August 31, 2026
• First Posted: September 14, 2026
• Study Start (Estimated): January 18, 2027
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2029
• Last Updated: September 14, 2026

Record last verified: 2026-09

Locations

US (1)