A Phase 1/2 interventional study of Frozen autologous CD34+ hematopoietic stem and progenitor cells genetically modified with the lentiviral vector IDUA LVV, encoding for the α-L-iduronidase cDNA, in their final formulation medium. in Mucopolysaccharidosis IH, sponsored by Orchard Therapeutics. Active, not recruiting at 1 site in Italy. Open to participants aged 28 Days to 11 Years. Per ClinicalTrials.gov, last updated 2026-07-16.
Sponsored by Orchard Therapeutics (part of Kyowa Kirin Co., Ltd.) · Phase 1/2, Interventional, and Treatment
This is a phase I/II study evaluating safety and efficacy of autologous hematopoietic stem and progenitor cells genetically modified with IDUA lentiviral vector encoding for the human α-L-iduronidase gene for the treatment of patients affected by Mucopolysaccharidosis Type I, Hurler variant
Pediatric patients with mucopolysaccharidosis type I will be treated with genetically modified autologous hematopoietic stem cells collected from mobilized peripheral blood (or bone marrow if mobilization is not feasible) and transduced with IDUA lentiviral vector encoding for the human α-L-iduronidase gene.
Participants will be followed for up to 15 years post treatment (per regulatory guidelines for follow up of patients treated with ATMPs, under this study (TigetT10_MPSIH) or via enrollment into a separate long term follow-up (LTFU) study for the overall OTL-203 Clinical Development Program, if one is set up prior to their Year 15 visit.
74 studies on the registry are indexed under Mucopolysaccharidosis I; 7 are open to participants now.
This study's enrollment of 8 is below the median of 14 across 47 interventional studies indexed under Mucopolysaccharidosis I.
Browse Mucopolysaccharidosis I studies →Orchard Therapeutics is the lead sponsor of 5 studies on the registry; none are open to participants now.
First submitted before Orchard Therapeutics became part of Kyowa Kirin Co., Ltd..
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Allogeneic and autologous transplant
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Gene therapy (autologous, CD34+ cell enriched cells fraction containing HSPCs, transduced with the IDUA LVV encoding for the human IDUA gene and cryopreserved in cryoformulation medium)
Genetic: Frozen autologous CD34+ hematopoietic stem and progenitor cells genetically modified with the lentiviral vector IDUA LVV, encoding for the α-L-iduronidase cDNA, in their final formulation medium.
The drug product target dose is more or equal to 8x10\^6 CD34+ cells/Kg, with a minimum dose of 4x10\^6 CD34+ cells/Kg and a maximum dose of 35x10\^6 CD34+ cells/Kg. The product will be injected intravenously.
Overall survival
Number and percentage of subjects alive at the end of the trial
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Achievement of haematological engraftment
Percentage of subjects with both neutrophil count more than 500/mm3 and platelets more than 20,000/mm3 (in the absence of platelet transfusion for seven consecutive days) on 3 consecutive blood counts in the first 45 days from ATIMP injection.
Time frame: within day +45 after gene therapy
Safety of the administration of autologous haematopoietic stem cells transduced with IDUA LVV - Short term tolerability
Percentage of subjects not experiencing short-term adverse events of any grade and systemic reactions
Time frame: 0-24 hours from ATIMP injection
Safety of the administration of autologous haematopoietic stem cells transduced with IDUA LVV - Absence of Replication Competent Lentivirus
Percentage of subjects without Replication Competent Lentivirus
Time frame: Assessed at multiple timepoints up to 8 years post-treatment, or if clinically indicated
Safety of the administration of autologous haematopoietic stem cells transduced with IDUA LVV - Absence of malignancy or abnormal clonal proliferation
Percentage of subjects without abnormal clonal proliferation
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Overall safety and tolerability (AE)
The number of AEs (expected/unexpected and/or related/not related) and SAEs (expected/unexpected and/or related/not related) and the percentage of subjects experiencing AEs (expected/unexpected and/or related/not related) and SAEs (expected/unexpected and/or related/not related) will be summarized by severity and within body system involved. Narratives will also be presented. The rate of occurrence of these events will also be estimated.
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
IDUA activity in blood (up to supraphysiologic levels) at 1-year post-treatment
IDUA activity measured on peripheral dried blood spot
Time frame: At 1 year post-treatment
Anti-IDUA antibody immune response
Presence or absence and titer of anti-IDUA antibody on plasma or serum
Time frame: Assessed at multiple timepoints up to 8 years post-treatment, or if clinically indicated
Achievement of supraphysiologic IDUA activity in blood
IDUA activity measured on peripheral dried blood spots up to supraphysiologic levels as compared with healthy donors. A supraphysiologic IDUA level is defined as \>24.31 μmol/L/h, which is the 97.5th percentile of the IDUA distribution in healthy children
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
IDUA activity in plasma
IDUA activity measured on plasma samples from peripheral blood.
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Engraftment of transduced cells ≥ 0.30 VCN/genome
Percentage of subjects with engraftment of transduced cells ≥ 0.30 VCN/genome on peripheral blood mononuclear cells (PBMC) and/or bone marrow (BM) progenitor cells.
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Normalization of urinary GAGs
Percentage of subjects achieving normalization of urinary GAG levels (heparan sulfate and dermatan sulfate) measured by HPLC
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Normalization of spleen and liver
Percentage of subjects with normal spleen and liver assessed by clinical examination (palpation) and/or ultrasound
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Growth velocity
Length/height for age (cm) per month vs. WHO percentiles
Time frame: Assessed at multiple timepoints up to 15 years post-treatment
Plan to share: Undecided
This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.