Safety and Efficacy Study of Gene Therapy for Treatment of Metachromatic Leukodystrophy (MLD)

Why is this research study being done?

The purpose of this ongoing study is to gather information about how safe and effective an experimental MLD gene therapy is in children with pre-symptomatic early onset (Late Infantile - Early Juvenile) MLD.

Who can participate in this MLD gene therapy study?

Only children with pre-symptomatic early onset MLD will be eligible to participate in this study.

In addition to a confirmed MLD diagnosis, early onset status must be confirmed by EITHER:

a) Previous MLD diagnosis in an older sibling, whose age of symptom onset was 6 years or younger


b) 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. More detailed information about this study, including the selection criteria, can found on

Where is the study being done?

The study is being conducted at Ospedale San Raffaele - Telethon Institute for Gene Therapy (OSR-TIGET) in Milan, Italy.

What is my child expected to do in this study?

Participation in this study will last up to 8 years. During this time, study participants will undergo various tests, visit the study site in Milan and study staff will monitor any changes to health through the different phases of the study:

Will it cost anything to be part of this study?

As part of the study, study participants will receive the gene therapy and all the study tests and procedures at no cost. Reasonable costs of travelling/accommodation related to study visits will be reimbursed for both study participants and their caregiver.

Who should I ask if I have questions?

If you have questions or would like more information about this MLD gene therapy study, please ask your physician to contact the study investigator Prof. Aiuti at Ospedale San Raffaele - Telethon Institute for Gene Therapy (OSR-TIGET), Milan, Italy or Orchard’s clinical trial team at

Download a PDF of the FAQs here