Lysogene S.A. a phase 3 gene therapy platform company targeting central nervous system (CNS) diseases, provided updated clinical data from the ongoing AAVance phase 2/3 clinical trial with the investigational gene therapy LYS-SAF302 for the treatment of MPS IIIA (NCT03612869) during the 25 Annual Meeting of the ASGCT (American Society for Gene & Cell Therapy) in Washington, DC. The preliminary results from the AAVance study evaluating LYS-SAF302 in patients with Sanfilippo syndrome type A (MPS IIIA) who have been followed for at least two years demonstrated improvement, stabilization, or slowing down of decline in cognitive developmental age (DA) in about half of the patients. Notably, in all 6 patients enrolled under the age of 30 months, a persistent increase or stabilization of the cognitive, language and motor domains of the BSID-III was
observed in the 24 months period post-treatment. Two (2) of these 6 patients, including 1 patient over 4 years of age, have already exceeded by several months the highest cognitive DA (35 months) observed in the natural history cohort. The 2 patients reached 41 and 42 months of cognitive DA in the 24 months period post-treatment with an increase of 25 and 17 months compared to their baseline, respectively. These results, which suggest that younger patients are more responsive to the gene therapy treatment, need to be corroborated and confirmed by the final statistical analyses.