Design and validation of a GMP stem cell manufacturing protocol for MPSII hematopoietic stem cell gene therapy

• Published in: Molecular therapy. Methods & clinical development 2024-06, Vol.32 (2), p.101271, Article 101271
• Main Authors: Ellison, Stuart, Buckland, Karen, Learmonth, Yuko, Day, Victoria, Kalra, Spandan, Howe, Lauren, Roman-Rodriguez, Francisco José, Bonafont, Jose, Booth, Laura, Holley, Rebecca, Smythe, Jon, Jones, Simon, Thrasher, Adrian, Booth, Claire, Bigger, Brian W.
• Format: Article
• Language: English
• Subjects: cleanroom validation studies; GMP cell manufacturing; hCD34+ cell transduction; hematopoietic stem cell gene therapy; investigational medicinal product; lentiviral vector; MPSII; mucopolysaccharidosis; transduction enhancers
• ISSN: 2329-0501; 2329-0501
• DOI: 10.1016/j.omtm.2024.101271

Hematopoietic stem cell gene therapy (HSCGT) is a promising therapeutic strategy for the treatment of neurodegenerative, metabolic disorders. The approach involves the ex vivo introduction of a missing gene into patients’ own stem cells via lentiviral-mediated transduction (TD). Once transplanted back into a fully conditioned patient, these genetically modified HSCs can repopulate the blood system and produce the functional protein, previously absent or non-functional in the patient, which can then cross-correct other affected cells in somatic organs and the central nervous system. We previously developed an HSCGT approach for the treatment of Mucopolysaccharidosis type II (MPSII) (Hunter syndrome), a debilitating pediatric lysosomal disorder caused by mutations in the iduronate-2-sulphatase (IDS) gene, leading to the accumulation of heparan and dermatan sulfate, which causes severe neurodegeneration, skeletal abnormalities, and cardiorespiratory disease. In HSCGT proof-of-concept studies using lentiviral IDS fused to a brain-targeting peptide ApoEII (IDS.ApoEII), we were able to normalize brain pathology and behavior of MPSII mice. Here we present an optimized and validated good manufacturing practice hematopoietic stem cell TD protocol for MPSII in preparation for first-in-man studies. Inclusion of TEs LentiBOOST and protamine sulfate significantly improved TD efficiency by at least 3-fold without causing adverse toxicity, thereby reducing vector quantity required. [Display omitted] Bigger and colleagues describe the fundamental steps required to develop, optimize, and validate a GMP stem cell manufacturing process for clinical application. With an increasing number of HSCGT treatments advancing toward clinical translation, development of improved IMP manufacturing processes becomes critically important.