Mucopolysaccharidosis IIIAPhase 3NCT04360265
Follow-up Study of AAV-Mediated Gene Transfer (UX111; Previously Known as ABO-102) for MPS Type IIIA
A Phase 3 study testing No Investigational Product and Adjuvant Immunomodulatory (IM) Therapy in people with Mucopolysaccharidosis IIIA and MPS IIIA, run by Ultragenyx Pharmaceutical Inc at 4 sites in 3 countries.
Trial summary
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). Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Mucopolysaccharidosis IIIA, MPS IIIA, Sanfilippo Syndrome
- What is being tested?
- No Investigational Product and Adjuvant Immunomodulatory (IM) Therapy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 41 participants
- Where
- 4 sitesin 3 countries
- Study dates
- 28 Sep 2020to Aug 2027
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
4 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
4 sites in 3 countries
Spain2 sites
Vall d'Hebron Barcelona Campus
Barcelona, 08035
Hospital Clínico Universitario de Santiago
Santiago de Compostela
United States1 site
Nationwide Children's Hospital
Columbus, Ohio, 43205
Australia1 site
Women's and Children's Hospital
North Adelaide, South Australia
About this study
Official title: 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).
Read the 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.
- Being tested
- No Investigational Product, Adjuvant Immunomodulatory (IM) Therapy
- Keywords
- MPS IIIA, Sanfilippo, Gene Therapy
- Medical subject headings
- Mucopolysaccharidosis III
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No Investigational ProductOther
No investigational product will be administered in this follow-up trial.
Adjuvant Immunomodulatory (IM) TherapyDrug
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.
| Study group | Role | What they receive |
|---|---|---|
| Cohort A | Other | 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. Receives: Other: No Investigational Product; Drug: Adjuvant Immunomodulatory (IM) Therapy |
| Cohort B | Other | 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. Receives: Other: No Investigational Product |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (SAEs)
Measured: Up to Year 5
Bayley Scales of Infant and Toddler Development - Third Edition (BSITD-III) Cognitive Raw Score Over Time
Measured: Up to Year 5
Secondary outcomes (6)
Cerebrospinal Fluid (CSF) Heparin Sulfate (HS) (Disaccharide) Exposure
Measured: Baseline, Up to Month 36
Percent Change From Baseline in Prior Trial in CSF HS
Measured: Baseline, Up to Month 36
BSITD-III Receptive Communication Raw Score Over Time
Measured: Up to Year 5
BSITD-III Expressive Communication Raw Score Over Time
Measured: Up to Year 5
Annualized Percentage Change from Baseline in Prior Trial in Total Cortical Volume
Measured: Baseline, Up to Month 36
Survival
Measured: Up to Year 5
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2020
- Study start28 Sep 2020
- Primary completionAug 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mucopolysaccharidosis IIIAStudies of the same condition, open and under way.
- More trials run by Ultragenyx Pharmaceutical IncThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 41 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ultragenyx Pharmaceutical Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Ultragenyx Pharmaceutical Inc
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04360265
- Sponsor's protocol ID
- LTFU-ABO-102
- Other IDs
- 2019-002979-34, UX111-CL302, 2023-510392-66-00, 2023, 2019
- Status last verified
- Jul 2026
- First submitted
- 20 Apr 2020
- Last updated
- 17 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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)
- ClinicalTrials.gov ID
- NCT04360265
- Acronym / sponsor ID
- LTFU-ABO-102
- Keywords
- MPS IIIA, Sanfilippo, Gene Therapy
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 41 participants (estimated)
- Lead sponsor
- Ultragenyx Pharmaceutical IncIndustry (pharma, biotech, devices)
- Study start
- 28 Sep 2020 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 24 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
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 design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cohort A | Other | Other: No Investigational Product, Drug: Adjuvant Immunomodulatory (IM) TherapyParticipants 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. |
| Cohort B | Other | Other: No Investigational ProductParticipants 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. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (2 listed)
- 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
Key exclusion criteria (2 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No Investigational ProductNo investigational product will be administered in this follow-up trial. | Other | Cohort A, Cohort B |
| Adjuvant Immunomodulatory (IM) TherapyThe 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. | Drug | Cohort A |
Primary outcome
Number of Participants with Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (SAEs)
Time frame: Up to Year 5
Bayley Scales of Infant and Toddler Development - Third Edition (BSITD-III) Cognitive Raw Score Over Time
Time frame: Up to Year 5
6 secondary outcomes
Cerebrospinal Fluid (CSF) Heparin Sulfate (HS) (Disaccharide) Exposure
Time frame: Baseline, Up to Month 36
Percent Change From Baseline in Prior Trial in CSF HS
Time frame: Baseline, Up to Month 36
BSITD-III Receptive Communication Raw Score Over Time
Time frame: Up to Year 5
BSITD-III Expressive Communication Raw Score Over Time
Time frame: Up to Year 5
Annualized Percentage Change from Baseline in Prior Trial in Total Cortical Volume
Time frame: Baseline, Up to Month 36
Survival
Time frame: Up to Year 5
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jul 2026.
- Ultragenyx Transparency CommitmentLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Medical Director study director
Ultragenyx Pharmaceutical Inc
4 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing No Investigational Product and Adjuvant Immunomodulatory (IM) Therapy in people with Mucopolysaccharidosis IIIA and MPS IIIA, run by Ultragenyx Pharmaceutical Inc at 4 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 17 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Spain, United States, Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants with Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (SAEs) (time frame: Up to Year 5). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Jul 2026.