title: Preclinical Testing of the Safety and Tolerability of Lentiviral Vector-Mediated Above-Normal Alpha-L-Iduronidase Expression in Murine and Human Hematopoietic Cells Using Toxicology and Biodistribution Good Laboratory Practice Studies.
abstract: In order to support the clinical application of hematopoietic stem cell (HSC) gene therapy for mucopolysaccharidosis I (MPS I), biosafety studies were conducted to assess the toxicity and tumorigenic potential, as well as the biodistribution of HSCs and progenitor cells (HSPCs) transduced with lentiviral vectors (LV) encoding the cDNA of the alpha-iduronidase (IDUA) gene, which is mutated in MPS I patients. To this goal, toxicology and biodistribution studies were conducted, employing Good Laboratory Practice principles. Vector integration site (IS) studies were applied in order to predict adverse consequences of vector gene transfer and to obtain HSC-related information. Overall, the results obtained in these studies provided robust evidence to support the safety and tolerability of high-efficiency LV-mediated gene transfer and above-normal IDUA enzyme expression in both murine and human HSPCs and their in vivo progeny. Taken together, these investigations provide essential safety data to support clinical testing of HSC gene therapy in MPS I patients. These studies also underline criticisms associated with the use of currently available models, and highlight the value of surrogate markers of tumorigenicity that may be further explored in the future. Notably, biological evidence supporting the efficacy of gene therapy on MPS I disease and its feasibility on patients' HSCs were also generated, employing clinical-grade LVs. Finally, the clonal contribution of LV-transduced HSPCs to hematopoiesis along serial transplantation was quantified in a minimum of 200-300 clones, with the different level of repopulating cells in primary recipients being reflected in the secondary.
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Visigalli
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Delai
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ferro
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cecere
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Vezzoli
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.|2 Department of Pathology, IRCCS San Raffaele Scientific Institute , Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Sanvito
authors.affiliation: 3 Glaxo Smith Kline R&D UK Safety Assessment , Stevenage, United Kingdom.|5 Sanofi , Montpellier, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Chanut
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Benedicenti
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Spinozzi
authors.affiliation: 6 Royal Manchester Children's Hospital , Manchester, United Kingdom .
authors.forename: Rob
authors.initials: R
authors.lastname: Wynn
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Calabria
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.|4 Vita Salute San Raffaele University , Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Naldini
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Montini
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.|3 Glaxo Smith Kline R&D UK Safety Assessment , Stevenage, United Kingdom.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Cristofori
authors.affiliation: 1 San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) , Division of Regenerative Medicine, Stem Cells and Gene Therapy, Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Biffi
mesh_terms: D000818:Animals; D015971:Gene Expression Regulation, Enzymologic; D018014:Gene Transfer Techniques / Q000009:adverse effects; D015316:Genetic Therapy / Q000009:adverse effects* / Q000379:methods; D005822:Genetic Vectors / Q000009:adverse effects; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006412:Hematopoietic Stem Cells / Q000201:enzymology; D006801:Humans; D007068:Iduronidase / Q000009:adverse effects / Q000235:genetics* / Q000627:therapeutic use; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008059:Mucopolysaccharidosis I / Q000235:genetics / Q000628:therapy*
chemical_list: D007068:Iduronidase