Study of AAVrh10-h.SGSH Gene Therapy in Patients With Mucopolysaccharidosis Type IIIA (MPS IIIA)

Open-label, Single-arm, Multi-center Study of Intracerebral Administration of Adeno-associated Viral (AAV) Serotype rh.10 Carrying Human N-sulfoglucosamine Sulfohydrolase (SGSH) cDNA for Treatment of Mucopolysaccharidosis Type IIIA

MPS IIIA is predominantly a central nervous system disease causing cognitive disability, progressive loss of acquired skills, behavioral and sleep disturbance. LYS-SAF302 is a gene therapy which is intended to deliver a functional copy of the SGSH gene to the brain. This is a phase 2-3 study to assess the efficacy in improving or stabilizing the neurodevelopmental state of MPS IIIA patients.

The study is interventional, single arm and multi-center. Evolution under treatment will be compared to expected natural evolution based on natural history studies.

Inclusion Criteria:

• Documented MPS IIIA diagnosis based on genotyping confirming the SGSH gene mutations
• Cognitive DQ score on BSID-III: 50% and above

Exclusion Criteria:

• Homozygous for the S298P mutation or non-classical severe form of MPS IIIA, based on investigator's judgement.
• Participation in another gene or cell therapy clinical trial.
• Past use of SGSH enzyme replacement therapy for a period exceeding 3 months. A washout period of at least 2 months is required prior to screening.
• Current participation in a clinical trial of another investigational medicinal product.
• History of bleeding disorder or current use of medications that, in the opinion of the investigator, place them at risk of bleeding following surgery.
• Any condition that would contraindicate treatment with immunosuppressants such as tacrolimus, mycophenolate mofetil or steroids.