LVV-EFS-PNP

LVV-EFS-PNP is an autologous gene therapy candidate designed for the treatment of Purine Nucleoside Phosphorylase (PNP) deficiency. It utilizes a third-generation self-inactivating lentiviral vector to deliver a codon-optimized human PNP gene, driven by the elongation factor-1 alpha short (EFS) promoter. The therapy aims to restore PNP enzyme activity in hematopoietic stem cells, thereby correcting the progressive T-cell defect and metabolic abnormalities (such as low urinary uric acid) characteristic of the disease. Preclinical studies in Pnp-/- mouse models have demonstrated restoration of T-cell populations, immune function, and metabolic markers without evidence of genotoxicity or malignant transformation. The development is a collaboration between the Hospital for Sick Children, University of Toronto, Hannover Medical School, and Tailored Genes Inc.