Lentivector Iterations and Pre-Clinical Scale-Up/Toxicity Testing: Targeting Mobilized CD34⁺ Cells for Correction of...

Area of Science:

• Genetics and Gene Therapy
• Hematology
• Biochemistry

Background:

• Fabry disease is a rare lysosomal storage disorder (LSD) caused by deficient alpha-galactosidase A (α-gal A) activity.
• Hematopoietic stem cell (HSC) gene therapy offers a potential treatment strategy for Fabry disease by enabling sustained enzyme production.

Purpose of the Study:

• To develop and evaluate lentivirus vectors (LVs) for efficient gene transfer of human α-gal A into patient-derived CD34+ hematopoietic cells.
• To assess the safety and efficacy of a clinically directed LV/AGA vector in preclinical models of Fabry disease.

Main Methods:

• Design and testing of multiple recombinant lentivirus vectors (LVs) for α-gal A expression.
• Ex vivo transduction of Fabry patient CD34+ cells and in vivo studies in Fabry mice and NOD/SCID/Fabry (NSF) mice.
• GMP-compliant scale-up of the LV/AGA transduction process and subsequent xenotransplantation studies.

Main Results:

• LV/AGA-transduced hematopoietic cells from Fabry patients showed high α-gal A activity, exceeding normal levels.
• Transplantation of transduced cells in Fabry mice led to increased α-gal A activity and reduced lipid accumulation in multiple tissues.
• Xenotransplantation in NSF mice demonstrated successful α-gal A correction and lipid reduction, with minimal adverse effects observed in toxicology studies.

Conclusions:

• LV/AGA gene therapy is a promising approach for treating Fabry disease, demonstrating efficacy and safety in preclinical models.
• Successful scale-up and preclinical validation paved the way for a clinical trial application to Health Canada.
• This research supports the initiation of a first-in-the-world gene therapy trial for Fabry disease.