Natural History Study of Participants With Sanfilippo Syndrome Type IIIC

NCT05825131 | Recruiting

• 1 other identifier: JLK-447
• Study Type: observational
• Target: 30
• Locations: 2 countries
• Sites: 2

Brief Summary

This study is planned to document, through retrospective and prospective data collection, syndrome progression in children and young adults with MPS IIIC.

Conditions

Sanfilippo Syndrome Type C

Keywords

Sanfilippo syndrome type C; Mucopolysaccharidosis type III C; MPS IIIC

Outcome Measures

Primary Outcomes (2)

• Change From Baseline in Development Quotient (DQ) Using Bayley Scales of Infant Development Assessment Fourth Edition

  The Bayley Scales of Infant and Toddler Development, 4th edition (Bayley-4) is a standardized developmental assessment that provides raw scores for 5 subtests (cognitive, expressive communication, receptive communication, fine motor, gross motor) and standard score norms converted to percentiles for 3 scales (cognition, communication, motor). The Bayley-4 raw scores range from 0-162 for the cognitive subtest, 0-84 for the receptive communication subtest, 0-74 for the expressive communication subtest, 0-92 for the fine motor subtest, and 0-116 for the gross motor subtest; a higher score denotes a better outcome. The Bayley-4 standard score norms are converted to percentiles from \<0.1 to \>99.9 for the cognitive, language, and motor scales; a higher percentile denotes a better outcome.

  Baseline, 12 months and 24 months

• Change From Baseline in Vineland Adaptive Behavior Scales Second Edition (VABS-II) Development Quotient (DQ) Score

  The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. The DQ is a means to express a neurodevelopmental/cognitive delay. The DQ was computed as a ratio and expressed as a percentage using the age-equivalent score divided by the age at testing (\[age-equivalent score/chronological age\] × 100; range, 0, 100). The overall DQ score is calculated from the mean age-equivalent score obtained by averaging out the age-equivalent scores for the all the sub-domains except for Gross and Fine motor skills. This test measures the following 5 key domains: communication, daily living skills, socialization, motor skills, and the adaptive behavior composite (a composite of the other 4 domains). A positive value indicates improvement in health and cognition.

  Baseline, 12 months and 24 months

Secondary Outcomes (7)

• Change From Baseline on the Color Trail Test Time Score

  Baseline, 12 months and 24 months

• Change From Baseline of Regional Brain Volumes

  Baseline, 12 months and 24 months

• Change From Baseline on the Assessment of Behavioral Changes in Sanfilippo (ABCS)

  Baseline, 6 months, 12 months, 18 months, 24 months

• Change From Baseline on the Functional Abilities Descriptive Analysis of Type C- Recording Application for Real-world Evidence (C-RARE)

  Baseline, 6 months, 12 months, 18 months, 24 months

• Change From Baseline on the Peabody Picture Vocabulary Test, Fifth Edition

  Baseline, 12 months, 24 months

Study Arms (3)

Retrospective and prospective observational study of patients living with MPS IIIC

Cohort 1: These participants will be a part of the retrospective and prospective Natural History Study, including the C-RARE video assessments. In clinic visits will include: neurocognitive, developmental and behavioral clinical outcome assessments as well as biochemical sample analysis, imaging measures and retrospective medical record review. Participants will record daily living activities through the C-RARE app on their mobile device.

Remote video recording study and retrospective medical chart review of patients living with MPS IIIC

Cohort 2: These participants will not attend in clinic visits. They will be a part of the C-RARE and retrospective medical chart review analysis. 35 patients with a confirmed diagnosis of MPS IIIC from English, Spanish and Portuguese speaking households will be recruited for this portion of the study.

Retrospective medical chart review of MPS IIIC patients either living or deceased

Cohort 3: Deceased or living medical record analysis only of patients with MPS IIIC. Living patients will not be participating in cohort 1 clinical study or cohort 2 C-RARE study.

Eligibility Criteria

• Age: 12 Months+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with a documented diagnosis of Sanfilippo syndrome type C and who are currently untreated with investigational products (drugs/device) for this disease.

You may qualify if:

• Confirmed diagnosis of Sanfilippo syndrome type C disease by all of the following:
• Deficiency in heparan-alpha-glucosaminide N-acetyltransferase enzyme activity
• Has presented with signs/symptoms consistent with Sanfilippo syndrome type C, or, for individuals who have not presented with signs/symptoms of disease (eg, siblings of known patients), the determination of eligibility will be at the discretion of the Sponsor in conjunction with the site Investigator
• Genomic DNA analysis demonstrating homozygous or compound heterozygous, pathogenic and/or potentially pathogenic variants in the HGSNAT gene
• Accumulated GAG HS in urine
• Written informed consent from parent or legal guardian and assent from patient, if required
• Parent/legal guardian willing to accompany the patient to all study visits
• Ability to comply with protocol requirements, in the opinion of the Investigator
• Negative urine pregnancy test at screening (nonsterile females of childbearing potential only).
• Functional abilities:
• Able to take food or liquid by mouth, able to walk with or without assistance.
• Has an age equivalent on the Vineland Adaptive Behavior Scales (VABS) of ≥1 year.

You may not qualify if:

• Patients who meet any of the following criteria will not be eligible to participate in the study:
• Have received an investigational drug within 30 days prior to the Baseline Visit
• Concomitant illness or medical condition or extenuating circumstance that, in the opinion of the Investigator, might compromise the patient's ability to comply with protocol requirements, the patient's well-being or safety, or the interpretability of the patient's clinical data
• The presence of significant non-MPS IIIC-related CNS impairment or behavioral disturbances that would confound the scientific rigor or interpretation of results of the study

Sponsors & Collaborators

• Phoenix Nest: lead
• Vaincres Les Maladies Lysosomales: collaborator
• Association Sanfilippo Sud: collaborator
• Aparito Ltd.: collaborator

Study Sites (2)

The University of Texas Southwestern Medical Center

Dallas, Texas, 75390, United States

NOT YET RECRUITING

Hospices Civils De Lyon

Bron, 690007539, France

RECRUITING

Biospecimen

Retention: SAMPLES WITH DNA

Blood (plasma and serum), cerebrospinal fluid (CSF), urine.

MeSH Terms

Conditions

Mucopolysaccharidosis III

Condition Hierarchy (Ancestors)

Mucopolysaccharidoses; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Lysosomal Storage Diseases; Mucinoses; Connective Tissue Diseases; Skin and Connective Tissue Diseases; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Officials

• Nathalie Guffon, MD

  Hospices Civils de Lyon

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Nathalie Reynes

CONTACT

04 72 12 95 37; nathalie.reynes@chu-lyon.fr

Nathalie Guffon, MD

CONTACT

04 72 12 95 37; nathalie.guffon-fouilhoux@chu-lyon.fr

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Target Duration: 2 Years
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 23, 2023
• First Posted: April 24, 2023
• Study Start: November 10, 2024
• Primary Completion (Estimated): July 30, 2027
• Study Completion (Estimated): November 1, 2027
• Last Updated: August 1, 2025

Record last verified: 2025-07

Locations

US (1); FR (1)