Lysogene’s LYS-SAF302 gene therapy candidate for MPS IIIA is being studied in a global, open-label, single-arm, multi-center Phase II/III clinical trial in 20 children with MPS IIIA: the AAVance study.
Lysogene is dedicated to developing
a treatment for MPS IIIA
It is hypothesized that LYS-SAF302 has the potential to slow
or even reverse the neuro-developmental damage suffered by
children with mucopolysaccharidosis type IIIA (MPSIIIA),
or Sanfilippo syndrome type A.

Study Details
LYS-SAF302’s efficacy, safety and tolerability are being assessed in a Phase II/III trial in the US and Europe, called the AAVance study. This ongoing study will recruit 20 children with MPS IIIA from four US and four European clinical sites. It will measure whether a one-time administration of LYS-SAF302 (delivered directly to the brain under general anesthesia) can improve children’s neuro-developmental status after 24 months. Patients’ progress, scored as a cognitive development quotient, will be compared with natural history data for the disease. As well as tracking the therapy’s efficacy in helping delay or even reverse neurodegeneration suffered by children with MPS IIIA, the study will also measure how safe and tolerable the treatment is. The therapy’s effects on behavior, sleep and on both patient and parent quality of life will also be monitored.
This important study has been carefully planned in collaboration with medical experts, regulators, HTA bodies and patient representatives.
Mutations to the SGSH gene in children with MPS IIIA are responsible for the developmental, physical and behavioral symptoms of the disease. LYS-SAF302 delivers a working copy of the human SGSH gene directly to the brain through intra-cerebral injection. By providing the fully-functional gene, and thereby enabling downstream enzymes to operate normally, this therapy may help stabilize and/or repair neuronal damage.
The therapy has Orphan Drug Designation in the US and European Union. In the US it also has Fast Track and Rare Pediatric Disease designations.
PROVide Study
The PROVide sub-study, running in parallel to AAVance, collects video outcomes of patients in their home environment. This innovative, app-based approach is designed to provide further supportive evidence of the treatment’s effect on children’s development in a convenient and minimally invasive fashion.
Earlier Studies
The AAVance study builds on encouraging efficacy and safety data from a Phase I-II clinical trial of an earlier-generation gene therapy, involving four children with MPSIIIA. This trial showed improved behavior, less hyperactivity and fewer sleep disturbances in three patients, and cognitive improvement in one patient. There were no treatment-related adverse events five-years post-surgery (Tardieu et al., 2014). LYS-SAF302 is an improved design that should lead to more efficient gene delivery and greater enzyme expression in the brain.