Do you have a patient with metachromatic leukodystrophy (MLD) whose family may be interested in participating in a clinical trial?

They may be eligible for a gene therapy study in MLD, currently recruiting patients (NCT03392987)

Study aims

To assess safety and efficacy of treatment using a cryopreserved formulation of OTL-200 in children with MLD

OTL-200 is an autologous CD34+-enriched cell fraction that contains CD34+ cells transduced with lentiviral vector that encodes for the human arylsulfatase A (ARSA) cDNA sequence

Study location

Ospedale San Raffaele – Telethon Institute for Gene Therapy (OSR-TIGET) in Milan, Italy

Reasonable costs of travel/accommodation related to study visits will be reimbursed for both study participants and their caregiver. Each child will need to meet with the study physician to assess whether they are eligible to participate

Study design

  • Single-arm, open-label study, sponsored by Orchard Therapeutics Ltd
  • All patients will receive intravenous infusion of OTL-200 gene therapy and conditioning regimen with busulfan
  • Patients will be followed up for 8 years post-gene therapy
  • Primary outcome: change in Gross Motor Function Measure (GMFM) 2 years after gene therapy
  • Other assessments include: neurological examinations, brain MRI, IQ testing, measures of engraftment of transduced cells, ARSA activity, safety and tolerability



Infants and children with pre-symptomatic early-onset MLD may be eligible to participate in this study (with informed consent from their parent/guardian). Eligibility criteria include:

  • Confirmed diagnosis of MLD
    • Documented biochemical and molecular diagnosis of MLD, based on ARSA activity below the normal range and identification of two disease-causing ARSA alleles, either known or novel mutations
    • Novel mutations will be analyzed with in silico prediction tools and excluded from being known common polymorphisms
    • In the case of a novel mutation(s), a 24-hour urine collection must show elevated sulfatide levels
  • Aged up to 6 years
  • Family is ready and willing to travel to the study site and participate in the trial

Early-onset status must be confirmed by EITHER of the following criteria:

  • Previous MLD diagnosis in an older sibling, whose age at symptom onset was 6 years or younger


  • In the absence of an older affected sibling, the child must be 6 years of age or younger and confirmed to have an early onset form of MLD

Contact details

For more information about this MLD gene therapy study, please contact the clinical trial team at Orchard Therapeutics Ltd, or visit (NCT03392987)

Download a PDF of the Study Summary here