Natural History Study of Participants With Sanfilippo Syndrome Type IIIC

Official title

A Combination Retrospective and Prospective Natural History Study of Participants With Sanfilippo Syndrome Mucopolysaccharidosis Type IIIC (MPS IIIC)

Overview

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

Detailed description

This is a multi-center, natural history study of subjects with Sanfilippo syndrome type C or MPS IIIC. This study will combine a retrospective review of medical records and an ongoing collection of clinical data on an observational basis. Real-world data will be collected at home using a recording device.

Participants will be asked to attend clinic visits in person on a yearly basis. In clinic visits will include neurocognitive, developmental, behavioral, biochemical, imaging measures as well as retrospective medical record analysis.

At 6-month intervals between clinic visits, participants will be contacted remotely for some safety assessments (e.g., collecting information about concomitant medications, concurrent illnesses, and procedure-related adverse events \[AEs\] and serious AEs \[SAEs\] since last clinic visit).

At 6-month intervals, caregivers will complete questionnaires and record home video assessments using a dedicated, compliant study application (app) called C-RARE (Recording Application for Real-World Evidence). The C-RARE app consists of 9 tasks of Activities of Daily Living and socialization as well as three parent reported Sanfilippo specific questionnaires.

The objectives of this study are:

* To enhance the understanding of the natural history and progression of MPS IIIC syndrome on behavior, cognitive abilities, mobility, vision, hearing, speech, and expressive and receptive language * To define and categorize clinical endpoints that may be used in future clinical trials

Primary outcome measures

• Change From Baseline in Development Quotient (DQ) Using Bayley Scales of Infant Development Assessment Fourth Edition [Time frame: Baseline, 12 months and 24 months]
• Change From Baseline in Vineland Adaptive Behavior Scales Second Edition (VABS-II) Development Quotient (DQ) Score [Time frame: Baseline, 12 months and 24 months]

Secondary outcome measures (7)

• Change From Baseline on the Color Trail Test Time Score [Time frame: Baseline, 12 months and 24 months]
• Change From Baseline of Regional Brain Volumes [Time frame: Baseline, 12 months and 24 months]
• Change From Baseline on the Assessment of Behavioral Changes in Sanfilippo (ABCS) [Time frame: 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) [Time frame: Baseline, 6 months, 12 months, 18 months, 24 months]
• Change From Baseline on the Peabody Picture Vocabulary Test, Fifth Edition [Time frame: Baseline, 12 months, 24 months]
• Change From Baseline on the Expressive Vocabulary Test Third Edition [Time frame: Baseline, 12 months, 24 months]
• Change From Baseline in Speech Through Picture Description [Time frame: Baseline, 12 months, 24 months]

Eligibility criteria

Inclusion criteria

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.

Exclusion criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

United States · 1 center

• The University of Texas Southwestern Medical Center — Dallas

France · 1 center

• Hospices Civils De Lyon — Bron

Identifiers

NCT: NCT05825131 · JLK-447

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗