Follow-up Study of AAV-Mediated Gene Transfer (UX111; Previously Known as ABO-102) for MPS Type IIIA

A Long-term Follow-up Study of Patients With MPS IIIA From Gene Therapy Clinical Trials Involving the Administration of ABO-102 (scAAV9.U1a.hSGSH)

The main objective of this study is to evaluate the safety/tolerability and efficacy of UX111 (previously known as ABO-102) in participants with Mucopolysaccharidosis IIIA (MPS IIIA).

Study Overview

• Status: Enrolling by invitation
• Conditions: Sanfilippo Syndrome; MPS IIIA; Sanfilippo A; Mucopolysaccharidosis IIIA
• Intervention / Treatment: Other: No Investigational Product; Drug: Adjuvant Immunomodulatory (IM) Therapy

Detailed Description

This is a multicenter, long-term follow-up study of patients with MPS IIIA who have participated in a prior clinical trial involving the administration of UX111 (NCT02716246 and NCT04088734). No investigational product will be provided. At approved sites adjuvant immunomodulatory (IM) therapy may be administered to selected participants. The Principal Investigator and/or caregiver, in consultation with the medical monitor, will determine whether to initiate adjuvant IM therapy. Not all participants may receive IM therapy.

This study was previously posted by Abeona Therapeutics, Inc and was transferred to Ultragenyx in August 2022.

• Study Type: Interventional
• Enrollment (Estimated): 41
• Phase: Phase 3

Contacts and Locations

Study Locations

• Australia
  • South Australia
    • North Adelaide, South Australia, Australia
      • Women's and Children's Hospital
• Spain
  • Barcelona, Spain, 08035
    • Vall d'Hebron Barcelona Campus
  • Santiago de Compostela, Spain
    • Hospital Clinico Universitario de Santiago
• United States
  • Ohio
    • Columbus, Ohio, United States, 43205
      • Nationwide Children's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Study Population

This long-term follow-up study will enroll up to 50 patients with MPS IIIA from prior ABO-102 clinical trials. Participants from the previous trials are of any racial, ethnic, or gender background, and could be in the early, middle or advanced phase of the disease.

Description

Inclusion Criteria:

• Participants that have participated in a prior clinical trial in which they received UX111
• Parent(s)/legal guardian(s) of participant willing and able to complete the informed consent process and comply with study procedures and visit schedule

Exclusion Criteria:

• Planned or current participation in another clinical trial that may confound the safety or efficacy evaluation of UX111 during this study
• Any other situation or medical condition that precludes the participant from undergoing procedures required in this study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Cohort A; Participants who have participated in a prior clinical trial involving the administration of UX111 (rebisufligene etisparvovec) and are able to comply with onsite scheduled visits and assessments. Select participants may receive adjuvant IM therapy.	Other: No Investigational Product; No investigational product will be administered in this follow-up trial.; Drug: Adjuvant Immunomodulatory (IM) Therapy; The Principal Investigator and/or caregiver, in consultation with the medical monitor, will determine whether to initiate adjuvant IM therapy. Not all participants may receive IM therapy.
Other: Cohort B; Participants who have participated in a prior clinical trial involving the administration of UX111 (rebisufligene etisparvovec) and who cannot participate in Cohort A. Participants will partake in a reduced number of assessments, performed either onsite or at home via a combination of telehealth and home healthcare visits.	Other: No Investigational Product; No investigational product will be administered in this follow-up trial.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of Participants with Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (SAEs)	Up to Year 5
Bayley Scales of Infant and Toddler Development - Third Edition (BSITD-III) Cognitive Raw Score Over Time	Up to Year 5

Secondary Outcome Measures

Outcome Measure	Time Frame
Cerebrospinal Fluid (CSF) Heparin Sulfate (HS) (Disaccharide) Exposure	Baseline, Up to Month 36
Percent Change From Baseline in Prior Trial in CSF HS	Baseline, Up to Month 36
BSITD-III Receptive Communication Raw Score Over Time	Up to Year 5
BSITD-III Expressive Communication Raw Score Over Time	Up to Year 5
Annualized Percentage Change from Baseline in Prior Trial in Total Cortical Volume	Baseline, Up to Month 36
Survival	Up to Year 5

Collaborators and Investigators

• Sponsor: Ultragenyx Pharmaceutical Inc
• Collaborators: Abeona Therapeutics, Inc
• Investigators: Study Director: Medical Director, Ultragenyx Pharmaceutical Inc

Publications and helpful links

Helpful Links

• Ultragenyx Transparency Commitment

Study record dates

Study Major Dates

• Study Start (Actual): September 28, 2020
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027

Study Registration Dates

• First Submitted: April 20, 2020
• First Submitted That Met QC Criteria: April 21, 2020
• First Posted (Actual): April 24, 2020

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Gene Therapy; MPS IIIA; Sanfilippo
• Additional Relevant MeSH Terms: Metabolism, Inborn Errors; Genetic Diseases, Inborn; Metabolic Diseases; Connective Tissue Diseases; Carbohydrate Metabolism, Inborn Errors; Lysosomal Storage Diseases; Mucinoses; Mucopolysaccharidoses; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Nutritional and Metabolic Diseases; Skin and Connective Tissue Diseases; Mucopolysaccharidosis III; Therapeutics
• Other Study ID Numbers: LTFU-ABO-102; 2019-002979-34 (EudraCT Number); UX111-CL302 (Other Identifier: Ultragenyx Pharmaceutical Inc); 2023-510392-66-00 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No