Mucopolysaccharidosis IIPhase 1/2NCT05665166
Gene Therapy With Modified Autologous Hematopoietic Stem Cells for Patients With Mucopolysaccharidosis Type II
A Phase 1/2 study testing Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII in people with Mucopolysaccharidosis II, run by University of Manchester at 1 site in United Kingdom.
Trial summary
MPS II is a genetic disorder that affects boys. Boys with MPS II are missing a working enzyme known as iduronate-2-sulfatase (IDS) which is needed to break down long sugar chains in the body. Read more about this study
- Who is it for?
- Ages 3 to 22 months, men only
- Conditions the study is for
- Mucopolysaccharidosis II
- What is being tested?
- Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 5 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Jun 2023to Jul 2028
- Phase
- Phase 1/2
- 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 3 to 22 months
- Men only
- No healthy volunteers
- Child
Who may be able to join
- Written informed consent from a legally authorized guardian.
- Male, age at consent ≥3 months and ≤22 months.
- Normal cognitive function or mild cognitive dysfunction (patient has a Development Quotient (DQ) score ≥70 at screening as determined by the Bayley Scale of Infant Development-third edition (BSID-III), cognitive domain), or assessed as normal or only mildly impaired by experienced neuropsychologist.
- Close male relative with known severe (progressive neuronopathic) phenotype of MPSII, or genotype associated with progressive neuronopathic phenotype. This is to be confirmed by the independent expert reviewers.
- IDS activity ≤10% of the Lower Limit of Normal as measured in leucocytes or plasma, plus either (1) a normal enzyme activity level of at least one other sulfatase (to rule out multiple sulfatase deficiency) as measured in leucocytes, or (2) a documented mutation in the IDS gene.
- Medically stable and able to accommodate the protocol requirements, including travel without placing an undue burden on the patient/patient's family, as determined by the CI.
- Patients and their parents/legal guardians must be willing and able to comply with study restrictions and to commit to attend clinic for the required duration during the study and follow-up period as specified in the protocol.
Who cannot join
- The patient has previously received stem cell or gene therapy
- The patient has received modified intravenous ERT or intra-thecal ERT in a trial setting.
- Patient currently enrolled in another interventional clinical trial
- The patient has a history of poorly controlled seizures
- Hemizygous for mutation known to be associated with non-neuropathic phenotype
- The patient is currently receiving psychotropic or other medications which, in the CI's opinion, would be likely to substantially confound test results
Show all 16Show fewer
- The patient has received any investigational medicinal product (including Genistein) within 30 days prior to the Baseline visit or is scheduled to receive any investigational medicinal product during the course of the study
- Documented Human Immunodeficiency Virus (HIV) infection (positive HIV RNA and/or anti-p24 antibodies)
- Malignant neoplasia (except local skin cancer) or a documented history of hereditary cancer syndrome. Patients with a prior successfully treated malignancy and a sufficient follow-up to exclude recurrence (based on oncologist opinion) can be included after discussion and approval by the Medical Monitor
- Myelodysplasia, cytogenetic alterations characteristic of myelodysplastic syndrome and acute myeloid leukaemia, or other serious haematological disorders
- The patient has a medical condition or extenuating circumstance that, in the opinion of the CI, 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
- Visual or hearing impairment sufficient to preclude adequate neurodevelopmental testing
- Severe behavioural disturbances due to reasons other than MPS II and likely to interfere with protocol compliance, as determined by the CI
- Known sensitivity to Busulfan
- The receipt of live vaccinations within 30 days prior to treatment start
- Known sensitivity to DMSO
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Phase I-II Study Of Cryopreserved Autologous CD34+ Haematopoietic Stem Cells Transduced Ex Vivo With CD11b Lentiviral Vector Encoding Human IDS Tagged With ApoEII In Patients With Neuronopathic Mucopolysaccharidosis Type II (nMPS II, Hunters Syndrome)
MPS II is a genetic disorder that affects boys. Boys with MPS II are missing a working enzyme known as iduronate-2-sulfatase (IDS) which is needed to break down long sugar chains in the body. When this enzyme is missing, these sugars build up to excess causing damage, and stop organs such as the brain from working properly. Children with MPS II often have progressive symptoms such as developmental delay and physical problems.
The only approved treatment for MPS II is enzyme replacement therapy. This involves a regular infusion of the missing enzyme into the blood stream. But this treatment only helps some symptoms and cannot help problems in the brain.
Read more
This study will be the first in human clinical trial to check whether using a gene therapy in children with MPS II is safe and is able to provide enough enzyme to help with disease symptoms. Gene therapy involves changing the genetic information that makes up a person, by taking a correct version of the gene that is needed to make the working IDS enzyme and putting it back into the body. This means that the body can then make the missing enzyme itself. The good thing with this therapy is that the body should be able to make this enzyme forever.
To make sure the therapy is safe and working patients will be closely followed for 2 years.
Read the detailed description
Mucopolysaccharidosis type II (MPSII, Hunter Syndrome) is a rare paediatric X-linked lysosomal storage disease caused by a deficiency in iduronate-2-sulphatase (IDS), due to a mutation on the IDS gene. IDS is essential for the breakdown of the sugar glycosaminoglycans (GAGs), in particular, heparan sulphate (HS) and dermatan sulphate (DS). Without this enzyme, these sugars accumulate in cells causing damage.
Currently, enzyme replacement therapy (ERT) is the only clinically approved treatment available for MPSII. However, ERT is a supportive therapy and is intended to alleviate symptoms and improve patient quality of life, rather than addressing the pathogenic mechanisms of the disease. To date, there is no effective disease-modifying treatment.
This study aims to recruit 5 patients with MPS II who satisfy the inclusion and exclusion criteria and provide full consent, between 3 months and 22 months of age at screening. The investigational medicinal product (IMP) will be a cell-based gene therapy that uses genetically modified autologous CD34+ haematopoietic stem cells transduced with a lentiviral vector containing the human IDS gene tagged with ApoEII. Patients will be followed up for a minimum of 2 years after gene therapy.
The therapy works by adding the gene therapy to cells taken from the child's body. The cells are then frozen and tested for safety before being given back to the child. To collect the cells, we will give the child some medicine to mobilize hematopoietic stem cells (HSC) from their bone marrow into the blood which can then be easily collected. A working copy of the IDS gene is then placed into these cells in the laboratory (ex vivo). The modified HSCs are then given back to the child via a blood infusion where they can travel to and live in the bone marrow. In the bone marrow compartment, these cells will produce new blood cells that can make the IDS enzyme and can carry it around the whole body, including to the brain. This means the excess sugar chains can be broken down which may help cells to function normally. We think this will reduce MPS II symptoms and may help to prevent damage to the brain.
To make sure the therapy is safe patients will be closely followed for 2 years within this trial. Additional follow up for a minimum 15 years post therapy or as per current guidance will then be offered.
- Conditions
- Mucopolysaccharidosis II
- Being tested
- Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII
- Medical subject headings
- Mucopolysaccharidosis II
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEIIGenetic
Autologous CD34+ haematopoietic stem cells from MPS II patients will be genetically modified ex vivo using CD11b.IDS-ApoEII Lentiviral Vector (LV), a self-inactivating (SIN) LV expressing the human codon-optimized IDS gene tagged with ApoEII and regulated by a human CD11b myeloid-specific promoter. These transduced CD34+ HSCs will then be cryopreserved until the time of infusion back to the patients
| Study group | Role | What they receive |
|---|---|---|
| Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII | Experimental | Not described Receives: Genetic: Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the tolerability of the IMP in MPS II patients
Adverse events will be recorded and graded according to an adapted Paediatric Clinical Toxicity Scale from the National Institute Allergy and Infectious Diseases (NIAID), Autoimmuno-deficiency Syndrome (AIDS) Division
Measured: Up to 24 months post-IMP delivery
To assess the safety of the IMP in MPS II patients
Presence of replication competent virus and integration events in the leukocytes
Measured: Up to 24 months post-IMP delivery
Secondary outcomes (13)
IDS enzyme activity in total leukocytes
Enzyme within or above normal range measured using an IDS enzyme activity assay
Measured: Baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Heparan sulphate in plasma
Heparan sulphate, the substrate for IDS measured within or above normal range
Measured: baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Heparan sulphate in urine
Heparan sulphate, the substrate for IDS measured within or above normal range
Measured: baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Glycosaminoglycan (GAG) ratio in urine
GAG ration measured by dimethylmethylene blue [DMB]
Measured: baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
IDS enzyme activity in plasma
Enzyme within or above normal range measured using an IDS enzyme activity assay
Measured: Baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Heparan sulphate in cerebrospinal fluid (CSF)
Heparan sulphate, the substrate for IDS measured within or above normal range
Measured: baseline, 3, 6, 12, and 24 months post-IMP delivery
IDS enzyme activity in CSF
Enzyme within or above normal range measured using an IDS enzyme activity assay
Measured: Baseline, 3, 6, 12, and 24 months post-IMP delivery
VCN in total leukocytes and the bone marrow
Measured using PCR
Measured: baseline and 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Proportion of cells containing the inserted IDS.ApoEII gene in total bone marrow colony forming units (CFUs)
CFU assay performed using isolated CD34+ cells and VCN within colonies measured
Measured: baseline, 1, 6, 12 and 24 month's post-IMP delivery
IDS enzyme activity in the bone marrow
Enzyme within or above normal range measured using an IDS enzyme activity assay
Measured: 12 months and at multiple other visits over time
Cognitive scores (standard scores, age-equivalent scores and development quotient)
Measured using the Bayley Scales of Infant Development, 3rd Edition (BSID-III) or Kaufman Assessment Battery for Children, 2nd Edition (KABC-II)
Measured: baseline, 6, 12, 18 and 24 months post- IMP delivery
Adaptive behaviour (age-equivalent scores)
Measured using the Vineland Adaptive Behaviour Scales, 3rd Edition (VABS-III)
Measured: baseline, 6, 12, 18 and 24 months post-IMP delivery
Quality of life of patient and parents/caregivers
Measured using questionnaires
Measured: baseline, 6, 12, 18 and 24 months post-IMP delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Dec 2022
- Study start1 Jun 2023
- Primary completionJul 2028 (estimated)
- Study completionJul 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mucopolysaccharidosis IIStudies of the same condition, open and under way.
- More trials run by University of ManchesterThe 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 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Phase I-II prospective, single-centre, non-randomised, open label, safety and proof of concept study
- Masking
- None (open label)
- Enrolment
- 5 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Manchester
- Sponsor type
- University, hospital or other
- Collaborators
- CTI Clinical Trial and Consulting Services, Great Ormond Street Hospital for Children NHS Foundation Trust, Manchester University NHS Foundation Trust, LifeArc
- Responsible party
- Sponsor
- Investigators
- Robert Wynn, Principal investigator, Manchester Foundation Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05665166
- Sponsor's protocol ID
- R125432
- Other IDs
- 2021-000400-38
- Status last verified
- Mar 2026
- First submitted
- 7 Dec 2022
- Last updated
- 27 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase I-II Study Of Cryopreserved Autologous CD34+ Haematopoietic Stem Cells Transduced Ex Vivo With CD11b Lentiviral Vector Encoding Human IDS Tagged With ApoEII In Patients With Neuronopathic Mucopolysaccharidosis Type II (nMPS II, Hunters Syndrome)
- ClinicalTrials.gov ID
- NCT05665166
- Acronym / sponsor ID
- R125432
- Conditions
- Mucopolysaccharidosis II
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 5 participants (estimated)
- Lead sponsor
- University of ManchesterUniversity, hospital or other
- Collaborators
- CTI Clinical Trial and Consulting Services, Great Ormond Street Hospital for Children NHS Foundation Trust, Manchester University NHS Foundation Trust, LifeArc
- Study start
- 1 Jun 2023 (actual)
- Primary completion
- Jul 2028 (estimated)
- Study completion
- Jul 2028 (estimated)
- First posted
- 27 Dec 2022 (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.
MPS II is a genetic disorder that affects boys. Boys with MPS II are missing a working enzyme known as iduronate-2-sulfatase (IDS) which is needed to break down long sugar chains in the body. When this enzyme is missing, these sugars build up to excess causing damage, and stop organs such as the brain from working properly. Children with MPS II often have progressive symptoms such as developmental delay and physical problems.
The only approved treatment for MPS II is enzyme replacement therapy. This involves a regular infusion of the missing enzyme into the blood stream. But this treatment only helps some symptoms and cannot help problems in the brain.
This study will be the first in human clinical trial to check whether using a gene therapy in children with MPS II is safe and is able to provide enough enzyme to help with disease symptoms. Gene therapy involves changing the genetic information that makes up a person, by taking a correct version of the gene that is needed to make the working IDS enzyme and putting it back into the body. This means that the body can then make the missing enzyme itself. The good thing with this therapy is that the body should be able to make this enzyme forever.
To make sure the therapy is safe and working patients will be closely followed for 2 years.
Detailed description
Mucopolysaccharidosis type II (MPSII, Hunter Syndrome) is a rare paediatric X-linked lysosomal storage disease caused by a deficiency in iduronate-2-sulphatase (IDS), due to a mutation on the IDS gene. IDS is essential for the breakdown of the sugar glycosaminoglycans (GAGs), in particular, heparan sulphate (HS) and dermatan sulphate (DS). Without this enzyme, these sugars accumulate in cells causing damage.
Currently, enzyme replacement therapy (ERT) is the only clinically approved treatment available for MPSII. However, ERT is a supportive therapy and is intended to alleviate symptoms and improve patient quality of life, rather than addressing the pathogenic mechanisms of the disease. To date, there is no effective disease-modifying treatment.
This study aims to recruit 5 patients with MPS II who satisfy the inclusion and exclusion criteria and provide full consent, between 3 months and 22 months of age at screening. The investigational medicinal product (IMP) will be a cell-based gene therapy that uses genetically modified autologous CD34+ haematopoietic stem cells transduced with a lentiviral vector containing the human IDS gene tagged with ApoEII. Patients will be followed up for a minimum of 2 years after gene therapy.
The therapy works by adding the gene therapy to cells taken from the child's body. The cells are then frozen and tested for safety before being given back to the child. To collect the cells, we will give the child some medicine to mobilize hematopoietic stem cells (HSC) from their bone marrow into the blood which can then be easily collected. A working copy of the IDS gene is then placed into these cells in the laboratory (ex vivo). The modified HSCs are then given back to the child via a blood infusion where they can travel to and live in the bone marrow. In the bone marrow compartment, these cells will produce new blood cells that can make the IDS enzyme and can carry it around the whole body, including to the brain. This means the excess sugar chains can be broken down which may help cells to function normally. We think this will reduce MPS II symptoms and may help to prevent damage to the brain.
To make sure the therapy is safe patients will be closely followed for 2 years within this trial. Additional follow up for a minimum 15 years post therapy or as per current guidance will then be offered.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Phase I-II prospective, single-centre, non-randomised, open label, safety and proof of concept study
| Arm | Type | Receives |
|---|---|---|
| Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII | Experimental | Genetic: Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII |
Who may qualify
- Ages
- 3 to 22 months
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (7 listed)
- Written informed consent from a legally authorized guardian.
- Male, age at consent ≥3 months and ≤22 months.
- Normal cognitive function or mild cognitive dysfunction (patient has a Development Quotient (DQ) score ≥70 at screening as determined by the Bayley Scale of Infant Development-third edition (BSID-III), cognitive domain), or assessed as normal or only mildly impaired by experienced neuropsychologist.
- Close male relative with known severe (progressive neuronopathic) phenotype of MPSII, or genotype associated with progressive neuronopathic phenotype. This is to be confirmed by the independent expert reviewers.
- IDS activity ≤10% of the Lower Limit of Normal as measured in leucocytes or plasma, plus either (1) a normal enzyme activity level of at least one other sulfatase (to rule out multiple sulfatase deficiency) as measured in leucocytes, or (2) a documented mutation in the IDS gene.
Key exclusion criteria (16 listed)
- The patient has previously received stem cell or gene therapy
- The patient has received modified intravenous ERT or intra-thecal ERT in a trial setting.
- Patient currently enrolled in another interventional clinical trial
- The patient has a history of poorly controlled seizures
- Hemizygous for mutation known to be associated with non-neuropathic phenotype
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 |
|---|---|---|
| Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEIIAutologous CD34+ haematopoietic stem cells from MPS II patients will be genetically modified ex vivo using CD11b.IDS-ApoEII Lentiviral Vector (LV), a self-inactivating (SIN) LV expressing the human codon-optimized IDS gene tagged with ApoEII and regulated by a human CD11b myeloid-specific promoter. These transduced CD34+ HSCs will then be cryopreserved until the time of infusion back to the patients | Genetic | Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII |
Primary outcome
To evaluate the tolerability of the IMP in MPS II patients
Time frame: Up to 24 months post-IMP delivery
Adverse events will be recorded and graded according to an adapted Paediatric Clinical Toxicity Scale from the National Institute Allergy and Infectious Diseases (NIAID), Autoimmuno-deficiency Syndrome (AIDS) Division
To assess the safety of the IMP in MPS II patients
Time frame: Up to 24 months post-IMP delivery
Presence of replication competent virus and integration events in the leukocytes
13 secondary outcomes
IDS enzyme activity in total leukocytes
Time frame: Baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Heparan sulphate in plasma
Time frame: baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Heparan sulphate in urine
Time frame: baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Glycosaminoglycan (GAG) ratio in urine
Time frame: baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
IDS enzyme activity in plasma
Time frame: Baseline, 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Heparan sulphate in cerebrospinal fluid (CSF)
Time frame: baseline, 3, 6, 12, and 24 months post-IMP delivery
IDS enzyme activity in CSF
Time frame: Baseline, 3, 6, 12, and 24 months post-IMP delivery
VCN in total leukocytes and the bone marrow
Time frame: baseline and 1, 3, 6, 9, 12, 18 and 24 months post-IMP delivery
Proportion of cells containing the inserted IDS.ApoEII gene in total bone marrow colony forming units (CFUs)
Time frame: baseline, 1, 6, 12 and 24 month's post-IMP delivery
IDS enzyme activity in the bone marrow
Time frame: 12 months and at multiple other visits over time
Cognitive scores (standard scores, age-equivalent scores and development quotient)
Time frame: baseline, 6, 12, 18 and 24 months post- IMP delivery
Adaptive behaviour (age-equivalent scores)
Time frame: baseline, 6, 12, 18 and 24 months post-IMP delivery
Quality of life of patient and parents/caregivers
Time frame: baseline, 6, 12, 18 and 24 months post-IMP delivery
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 27 Mar 2026.
Related trials for Mucopolysaccharidosis II
Active, not recruitingPhase 2
MT2013-31: Allo HCT for Metabolic Disorders and Severe Osteopetrosis
Mucopolysaccharidosis Disorders, Hurler Syndrome
Enrolling by invitationPhase 2/3
An Extension Study of the Long-Term Safety, Tolerability, and Efficacy of Tividenofusp Alfa (DNL310) in Participants With Mucopolysaccharidosis Type II (MPS II) From Study DNLI-E-0002 or Study DNLI-E-0007
Mucopolysaccharidosis II
Active, not recruitingPhase 3
A Phase III Study of JR-141 in Patients With Mucopolysaccharidosis II (STARLIGHT)
Mucopolysaccharidosis II
Active, not recruitingPhase 1/2
An Open-label Phase I/II Study of JR-446 in Mucopolysaccharidosis Type IIIB
Mucopolysaccharidosis III-B
RecruitingPhase 2/3
Phase I/II/III Gene Transfer Clinical Trial of scAAV9.U1a.hSGSH
MPS IIIA, Sanfilippo Syndrome
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. This study is not recruiting at the moment.
Robert Wynn principal investigator
Manchester Foundation Trust
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Autologous CD34+ HSCs transduced ex vivo with CD11B LV encoding human IDS tagged with ApoEII in people with Mucopolysaccharidosis II, run by University of Manchester at 1 site in United Kingdom.
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 7 inclusion and 16 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: under way, not looking for participants, as of the sponsor's last update on 27 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. 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 combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
To evaluate the tolerability of the IMP in MPS II patients (time frame: Up to 24 months post-IMP delivery). 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 27 Mar 2026.