Intravenous delivery for treatment of mucopolysaccharidosis type I: A comparison of AAV serotypes 9 and rh10

Lalitha R Belur; Kelly M Podetz-Pedersen; Thuy An Tran; Joshua A Mesick; Nathaniel M Singh; Maureen Riedl; Lucy Vulchanova; Karen F Kozarsky; R Scott McIvor

doi:10.1016/j.ymgmr.2020.100604

Intravenous delivery for treatment of mucopolysaccharidosis type I: A comparison of AAV serotypes 9 and rh10

Mol Genet Metab Rep. 2020 May 20:24:100604. doi: 10.1016/j.ymgmr.2020.100604. eCollection 2020 Sep.

Authors

Lalitha R Belur¹, Kelly M Podetz-Pedersen¹, Thuy An Tran¹, Joshua A Mesick¹, Nathaniel M Singh¹, Maureen Riedl², Lucy Vulchanova², Karen F Kozarsky³, R Scott McIvor¹

Affiliations

¹ Center for Genome Engineering, Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall, Church St. S. E, Minneapolis, MN 55455, USA.
² Department of Neuroscience, University of Minnesota, 6-145 Jackson Hall, Church St. S.E, Minneapolis, MN 55455, USA.
³ REGENXBIO Inc., 9600 Blackwell Road, Suite 210, Rockville, MD 20850, USA.

Abstract

Mucopolysaccharidosis type I (MPS I) is an inherited metabolic disorder caused by deficiency of alpha-L-iduronidase (IDUA), resulting in accumulation of heparan and dermatan sulfate glycosaminoglycans (GAGs). Individuals with the most severe form of the disease (Hurler syndrome) suffer from neurodegeneration, intellectual disability, and death by age 10. Current treatments for this disease include allogeneic hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT). However, these treatments do not address CNS manifestations of the disease. In this study we compared the ability of intravenously administered AAV serotypes 9 and rh10 (AAV9 and AAVrh10) for delivery and expression of the IDUA gene in the CNS. Adult C57BL/6 MPS I mice were infused intravenously with either AAV9 or AAVrh10 vector encoding the human IDUA gene. Treated animals demonstrated supraphysiological levels and widespread restoration of IDUA enzyme activity in the plasma and all organs including the CNS. High levels of IDUA enzyme activity were observed in the plasma, brain and spinal cord ranging from 10 to 100-fold higher than heterozygote controls, while levels in peripheral organs were also high, ranging from 1000 to 10,000-fold higher than control animals. In general, levels of IDUA expression were slightly higher in peripheral organs for AAVrh10 administered animals although these differences were not significant except for the lung. Levels of IDUA expression between AAV 9 and rh10 were roughly equivalent in the brain. Urinary and tissue GAGs were significantly reduced starting at 3 weeks after vector infusion, with restoration of normal GAG levels by the end of the study in animals treated with either AAV9 or rh10. These results demonstrate that non-invasive intravenous AAV9 or AAVrh10-mediated IDUA gene therapy is a potentially effective treatment for both systemic and CNS manifestations of MPS I, with implications for the treatment of other metabolic and neurological diseases as well.

Keywords: AAV9; AAVrh10; Gene therapy; Iduronidase (IDUA); Intravenous delivery; Mucopolysaccharidosis Type I (MPS I).

Abstract

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