Who may be eligible for the MPS IIIA Disease Monitoring Program trial?

Inclusion Criteria: * Confirmed diagnosis of MPS IIIA * Patient who: 1. Group 1: Received rebisufligene etisparvovec in a prior interventional clinical trial. May be enrolled upon completion of Study ABT-001 (Cohort 4) or end of study (EOS) or early termination (ET) visit from the prior clinical trial (Study ABT-003 or Study LTFU-ABO-102). OR 2. Group 2: Received (or plans to receive) rebisufligene etisparvovec in a postmarketing setting. * Provide informed consent after the nature of the study has been explained, and prior to any research-related procedures. If a minor or an adult with cognitive limitations, willing and able (if possible) to provide assent and have a legally authorized representative provide informed consent after the nature of the study has been explained, and prior to any research-related procedures. Exclusion Criteria: * Presence or history of any condition that, in the view of the Investigator, would interfere with participation, pose undue risk, or would confound interpretation of results.

ClinicalTrials.gov record NCT07855562

MPS IIIA Disease Monitoring Program

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Oct 10, 2026

Mucopolysaccharidosis Type IIIA (MPS IIIA) Disease Monitoring Program

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusNot yet recruitingThe study has been registered but has not started enrolling. Sites and contacts may not be listed yet.

Study typeObservationalA study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.

SexAll

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This prospective, observational cohort study follows people with MPS IIIA who received or will receive rebisufligene etisparvovec. It collects safety and clinical outcomes for up to 10 years after administration. No study drug is given as part of this program; participants are grouped by prior clinical-trial recipients and post-marketing recipients.

What it is studying. Long-term safety events related to rebisufligene etisparvovec and changes in clinical outcomes, including cognitive development, measured over 10 years.

What the researchers hope to learn. To evaluate long-term safety and effectiveness of rebisufligene etisparvovec and to collect clinical outcomes data for up to 10 years, including serious and targeted adverse events and trajectories of cognitive development.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The main objective of this observational study is to evaluate the long-term safety and effectiveness of rebisufligene etisparvovec for 10 years after rebisufligene etisparvovec administration.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Other: No Intervention

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

Confirmed diagnosis of MPS IIIA
Patient who:
Group 1: Received rebisufligene etisparvovec in a prior interventional clinical trial.
May be enrolled upon completion of Study ABT-001 (Cohort 4) or end of study (EOS) or early termination (ET) visit from the prior clinical trial (Study ABT-003 or Study LTFU-ABO-102). OR
Group 2: Received (or plans to receive) rebisufligene etisparvovec in a postmarketing setting.
Provide informed consent after the nature of the study has been explained, and prior to any research-related procedures. If a minor or an adult with cognitive limitations, willing and able (if possible) to provide assent and have a legally authorized representative provide informed consent after the nature of the study has been explained, and prior to any research-related procedures.

Exclusion criteria

Presence or history of any condition that, in the view of the Investigator, would interfere with participation, pose undue risk, or would confound interpretation of results.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

The UX111-CL401 MPS IIIA Disease Monitoring Program is a prospective, multicenter, long term outcomes study to obtain safety and clinical outcomes data for 10 years after the administration of rebisufligene etisparvovec in either a clinical trial or post-marketing setting.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants are followed for up to 10 years after rebisufligene etisparvovec administration so the study can collect long-term safety and clinical outcome information. The study will record serious adverse events and targeted adverse events and will assess development over time using the Bayley Scales of Infant and Toddler Development. No investigational or study product will be given as part of this program. The registry record does not state the schedule of visits or list other specific tests or procedures that will occur during follow-up.

How the study is structured. A prospective, multicenter observational cohort with up to 10 years of follow-up. Two groups are enrolled: people who received rebisufligene etisparvovec in a prior clinical trial, and people who received or plan to receive it in a post-marketing setting. The program does not administer any study drug; it collects safety events (including serious and targeted adverse events) and clinical measures such as Bayley Scales cognitive testing over time.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

This is an observational study, so the study itself gives no treatment. What would taking part involve for me, and would it change my usual care?
The registry says recruitment has not started. When is it expected to open, and can I register interest now?
No sites are listed on the registry yet. Where will the study take place?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on Sanfilippo syndrome

Clinical trials12 trials listed for Sanfilippo syndromeEvery trial the registry lists for Sanfilippo syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Sanfilippo syndrome researchLatest monthly update: September 2026. Includes: Approved drug shortlist. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: November 2026 (estimated)
Primary completion: October 2038 (estimated)
Study completion: October 2038 (estimated)
Target enrollment: 55 participants (estimated)
Last updated on registry: Oct 2, 2026
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: Ultragenyx Pharmaceutical Inc

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Patients Contact: Trial Recruitment 📞 1-888-756-8657 ✉ trialrecruitment@ultragenyx.com
HCPs Contact: Medical Information 📞 1-888-756-8657 ✉ medinfo@ultragenyx.com

Participating sites

Study locations have not been posted on ClinicalTrials.gov yet. This study is not yet recruiting, so sites may be added when recruitment begins. The central study contact above may be able to tell you about planned sites.

Terms used on this page · explanations by MedicalUpdates.ai

interventional: A study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
Cohort: A group of people who share a characteristic, such as a diagnosis, and are studied together. 'Prospective' means they are followed forward from enrolment; 'retrospective' means existing records are reviewed.
informed consent: The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
assent: A child's or dependent adult's agreement to take part, given alongside the formal consent of a parent or legal representative.
legally authorized representative: A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
Inclusion Criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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