ClinicalTrials.gov record NCT02716246

Phase I/II/III Gene Transfer Clinical Trial of scAAV9.U1a.hSGSH

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

Phase I/II/III Gene Transfer Clinical Trial of scAAV9.U1a.hSGSH for Mucopolysaccharidosis (MPS) IIIA

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA 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.
PhasePhase 2/3A study that tests whether a treatment works while continuing to check safety, in a larger group than a phase 2 study alone. It combines the aims of phase 2 and phase 3 in one protocol.
SexAll
LocationAustralia, Spain, United States
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 open-label trial gives a single intravenous dose of UX111 (scAAV9.U1a.hSGSH) to people with MPS IIIA and follows them over time. The study uses sequential dose-escalation cohorts and includes a short course of preventive immune-suppressing medication; additional immune therapy may be given to some participants. Outcomes include biomarkers in spinal fluid and developmental and brain measures assessed up to 24 months. The main goal is to evaluate the safety and activity of UX111 for treating MPS IIIA.

What it is studying. Whether a one-time intravenous delivery of scAAV9 carrying the SGSH gene (called UX111) given with planned immunomodulatory therapy is safe and has biological effects in people with MPS IIIA. The study measures changes in spinal-fluid heparan sulfate and other biomarkers, and tracks developmental and brain imaging outcomes.

What the researchers hope to learn. To evaluate the safety and efficacy of UX111 in MPS IIIA. To measure whether UX111 changes cerebrospinal fluid heparan sulfate levels over time and to assess related biomarkers (CSF GM2 and GM3), cognitive/developmental scores (BSITD-III), and brain cortical volume up to 24 months.

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 study is to evaluate the efficacy and safety of UX111 for the treatment of MPS IIIA.

Interventions being studied

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

Drug
  • Prophylactic Immunomodulatory (IM) Therapy
  • Optimized Prophylactic IM Therapy
  • Adjuvant IM Therapy
Biological
  • UX111

Eligibility

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

Inclusion criteria

  • Diagnosis of MPS IIIA confirmed by the following methods:
  • No detectable or significantly reduced SGSH enzyme activity by leukocyte assay, and
  • Genomic DNA analysis demonstrating homozygous or compound heterozygous mutations in the SGSH gene (based upon review of documented results from a qualified laboratory, and with confirmation with Medical Monitor)
  • Age:
  • For Cohort 1-3: From birth (participating sites in USA and Australia) OR 6 months (participating sites in Spain) to 2 years of age with no BSITD-III Cognitive Development Quotient (DQ) requirement, or older than 2 years with a BSITD-III Cognitive DQ of 60 or above (participating sites globally).
  • For Cohort 4 (participating sites in Spain): 3 months to ≤ 2 years of age with no BSITD-III Cognitive DQ requirement or > 2 years of age with a BSITD-III Cognitive DQ ≥ 60 (n = up to 6). Up to 2 additional subjects > 2 years and ≤ 5 years of age with a BSITD-III Cognitive DQ < 60 may also be enrolled. •Subjects must be ≥ 6 months of age before UX111 administration. However, subjects may be consented and initiate relevant Screening Procedures and IM treatment < 6 months of age. Refer to Section 8.2 for relevant screening procedures •For children ≤ 24 months chronological age who were born prematurely, defined as born at < 36 weeks gestational age, the corrected gestational age must be used for determining inclusion •The BSITD-III Cognitive DQ is assessed during the onsite Screening visit, for subjects who require it •The age of the child on the date of the Screening BSITD-III assessment is used to determine the requirement for the BSITD-III Cognitive DQ score.
  • Cohort 4 only: Vaccination status based on age according to country-specific guidelines that is up to date 30 days prior to Enrollment as verified by documentation from the subject's primary care physician, and willing to defer vaccines through 6 months after completion of the subject's IM medication, or longer per Principal Investigator (PI) judgment. Emergency use authorization or conditional marketing authorization of coronavirus disease (COVID) vaccines is included unless there is an accepted medical exemption.

Exclusion criteria

  • Inability to participate in the clinical evaluation as determined by PI
  • Cohorts 1 to 3 only: Identification of two nonsense or null variants on genetic testing of the SGSH gene (based upon review of documented results from a qualified laboratory, and with confirmation with Medical Monitor)
  • At least one S298P mutation in the SGSH gene (based upon review of documented results from a qualified laboratory, and with confirmation with Medical Monitor)
  • Has evidence of an attenuated phenotype of MPS IIIA, in the judgement of the PI
  • Presence of a concomitant medical condition that precludes lumbar puncture or use of anesthetics
  • Active viral infection based on clinical observations
  • Concomitant illness or requirement for chronic drug treatment that in the opinion of the PI creates unnecessary risks for gene transfer or precludes the child from participating in the protocol assessments and follow up
  • Cohorts 1 to 3 only: Subjects with total anti-AAV9 antibody titers ≥ 1:100 equivalent to a positive screen as determined by ELISA binding assay in serum
  • Cohorts 1-3 only: Subjects with a positive response for the enzyme-linked immunosorbent spot assay (ELISpot) for T-cell responses to AAV9
  • Cohorts 1-3 only: Serology consistent with exposure to human immunodeficiency virus (HIV), or serology consistent with active hepatitis B or C infection, Cohort 4: Current clinically significant infections (including any requiring systemic treatment including, but not limited to, HIV; hepatitis A, B, or C; varicella zosters virus; human T-cell lymphotropic virus type 1 [HTLV-1]; tuberculosis; or COVID-19) that would interfere with participation in the study.
  • Bleeding disorder or any other medical condition or circumstance in which a lumbar puncture (for collection of CSF) is contraindicated according to local institutional policy
  • Visual, hearing, or other impairment sufficient to preclude cooperation with neurodevelopmental testing
  • Uncontrolled seizure disorder
  • Any item (braces, etc.) or circumstance that would exclude the subject from being able to undergo MRI according to local institutional policy
  • Any other situation that precludes the subject from undergoing procedures required in this study
  • Subjects with cardiomyopathy or significant congenital heart abnormalities
  • The presence of significant non-MPS IlIA related CNS impairment or behavioral disturbances that would confound the scientific rigor or interpretation of results of the study
  • Cohorts 1-3: Abnormal laboratory values Grade 2 or higher as defined in common terminology criteria for adverse events (CTCAE) v4.03 for gamma-glutamyl transferase (GGT), total bilirubin, creatinine, hemoglobin, white blood cell (WBC) count, platelet count, prothrombin time (PT) and activated partial thromboplastin time (aPTT), Cohort 4: Any of the following abnormal laboratory values from screening assessment:
  • Aspartate aminotransferase (AST), alanine aminotransferase (ALT), GGT, and/or alkaline phosphatase ≥ 2 × upper limit of normal (ULN) and/or total bilirubin > 1.5 × ULN
  • Anemia (hemoglobin < 10 g/dL)
  • Leukopenia or leukocytosis (total WBC count < 3,000/mm3 and > 15,000/mm3 respectively)
  • Abnormal absolute neutrophil count (ANC) of < 1000/mm3
  • Platelet count < 100,000/mm3
  • Coagulopathy (international normalized ratio [INR] > 1.5) or aPTT > 40 seconds
  • Renal impairment, defined as estimated glomerular filtration rate (eGFR) below the lower limit of normal (age and sex appropriate) based on Bedside Schwartz equation
  • Female of childbearing potential who is pregnant or demonstrates a positive urine or bhCG result at screening assessment (if applicable)
  • Cohorts 1-3: Any vaccination with viral attenuated vaccines less than 30 days prior to the scheduled date of treatment (and use of prednisolone)
  • Previous treatment by hematopoietic stem cell transplantation
  • Previous participation in a gene/cell therapy or enzyme replacement therapy (ERT) clinical trial
  • Cohort 4 only:
  • Known hypersensitivity, that in the judgment of the PI, places the subject at increased risk for adverse effects.
  • Unwilling to avoid consumption of grapefruit juice and the use of strong inhibitors of CYP3A4 and/or P-gp (eg, ketoconazole, voriconazole, itraconazole, erythromycin, telithromycin, or clarithromycin), strong inducers of CYP3A4 and/or P-gp (eg, rifampin, rifabutin, phenobarbital, carbamazepine, or phenytoin), and St. John's Wort from 30 days prior to Screening through completion of the IM regimen.

Study description and what participation involves

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

Detailed description from the registry

Open-label, single dose, dose-escalation clinical trial of UX111 (scAAV9.U1a.hSGSH) injected intravenously through a peripheral limb vein. A limited course of prophylactic immunomodulatory (IM) therapy will be administered. At approved sites adjuvant 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 adjuvant IM therapy. This study was previously posted by Abeona Therapeutics, Inc and was transferred to Ultragenyx in August 2022.

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 receive a single intravenous dose of UX111 through a peripheral limb vein and a limited course of prophylactic immunomodulatory (IM) therapy; some may also receive adjuvant IM therapy at the investigator's discretion. Study visits include lumbar punctures to collect cerebrospinal fluid, MRI scans, neurodevelopmental testing (e.g. BSITD‑III), blood draws, and regular follow‑up visits through the Month 24 assessment period. Procedures may require anesthesia and repeated clinic visits for monitoring. Not all participants will receive adjuvant IM therapy.

How the study is structured. Open-label (non-masked), non-randomized trial with sequential dose-escalation cohorts. Participants receive a single IV infusion of UX111 through a peripheral limb vein. A limited course of prophylactic immunomodulatory (IM) drugs is given; some sites may use additional (adjuvant) IM therapy for selected participants. Participants are followed with biomarker tests, developmental testing, and imaging through scheduled visits, with key measurements reported up to Month 24.

Questions you could ask

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

  • The listed sites are in Australia, Spain, United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on Sanfilippo syndrome

Important dates

Study start
Apr 25, 2016
Primary completion
March 2029 (estimated)
Study completion
March 2029 (estimated)
Target enrollment
36 participants (estimated)
Last updated on registry
Sep 22, 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
Collaborators
  • Abeona Therapeutics, 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.

Participating sites (5)

  • Nationwide Children's HospitalCompleted

    Columbus, Ohio, 43205 · United States

  • Children's Hospital of PittsburghCompleted

    Pittsburgh, Pennsylvania, 15224 · United States

  • Women's and Children's HospitalCompleted

    North Adelaide, South Australia, 5006 · Australia

  • Vall d'Hebron Barcelona Hospital CampusRecruiting

    Barcelona, Barcelona, 08035 · Spain

  • Hospital Clínico Universitario de SantiagoRecruiting

    Santiago de Compostela, 15706 · Spain

Terms used on this page · explanations by MedicalUpdates.ai

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.
Screening visit
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
Enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
Principal Investigator
The doctor or scientist responsible for running the study at a site or overall.
lumbar puncture
A procedure in which a needle is placed between the bones of the lower back to collect spinal fluid or to give a treatment.
follow up
The period after treatment or enrolment during which participants are observed or contacted, for example to record side effects or outcomes.
contraindicated
A reason a particular test or treatment should not be used for a person, for example a metal implant that rules out an MRI scan.
MRI
A scan that uses magnets and radio waves, not X-rays, to make detailed pictures of the inside of the body. Some implants and metal objects mean a person cannot have one.
adverse events
Any unwanted medical problem that happens during a study, whether or not it was caused by the treatment. A 'serious' adverse event is one that meets specific criteria, such as causing death, being life-threatening, requiring or prolonging hospital admission, causing significant disability, or another medically important outcome.
upper limit of normal
The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
absolute neutrophil count
The number of neutrophils, a type of white blood cell that fights infection, in a blood sample. Studies often require it to be above a set level.
estimated glomerular filtration rate
A blood-test estimate of how well the kidneys are filtering. Lower numbers mean reduced kidney function; many studies set a minimum value.
childbearing potential
Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
prednisolone
Steroid medicines, such as prednisone, that reduce inflammation. Studies often require a stable dose at entry or measure whether the study treatment allows the dose to be reduced.
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.
Open-label
No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
dose-escalation
Groups of participants receive increasing doses of a treatment, one group after another, to find a dose that can be given safely.

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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