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Molecular analysis of AAV5-hFVIII-SQ vector-genome-processing kinetics in transduced mouse and nonhuman primate livers.

Authors :
Sihn CR
Handyside B
Liu S
Zhang L
Murphy R
Yates B
Xie L
Torres R
Russell CB
O'Neill CA
Pungor E
Bunting S
Fong S
Source :
Molecular therapy. Methods & clinical development [Mol Ther Methods Clin Dev] 2021 Dec 21; Vol. 24, pp. 142-153. Date of Electronic Publication: 2021 Dec 21 (Print Publication: 2022).
Publication Year :
2021

Abstract

Valoctocogene roxaparvovec (AAV5-hFVIII-SQ) is an adeno-associated virus serotype 5 (AAV5)-based gene therapy vector containing a B-domain-deleted human coagulation factor VIII (hFVIII) gene controlled by a liver-selective promoter. AAV5-hFVIII-SQ is currently under clinical investigation as a treatment for severe hemophilia A. The full-length AAV5-hFVIII-SQ is >4.9 kb, which is over the optimal packaging limit of AAV5. Following administration, the vector must undergo a number of genome-processing, assembly, and repair steps to form full-length circularized episomes that mediate long-term FVIII expression in target tissues. To understand the processing kinetics of the oversized AAV5-hFVIII-SQ vector genome into circular episomes, we characterized the various molecular forms of the AAV5-hFVIII-SQ genome at multiple time points up to 6 months postdose in the liver of murine and non-human primate models. Full-length circular episomes were detected in liver tissue beginning 1 week postdosing. Over 6 months, quantities of circular episomes (in a predominantly head-to-tail configuration) increased, while DNA species lacking inverted terminal repeats were preferentially degraded. Levels of duplex, circular, full-length genomes significantly correlated with levels of hFVIII-SQ RNA transcripts in mice and non-human primates dosed with AAV5-hFVIII-SQ. Altogether, we show that formation of full-length circular episomes in the liver following AAV5-hFVIII-SQ transduction was associated with long-term FVIII expression.<br />Competing Interests: C.-R.S., B.H., L.Z., R.M., B.Y., L.X., C.B.R., C.A.O., E.P., S.B., and S.F. are employees and stockholders of BioMarin Pharmaceutical. R.T. and S.L. are former employees of BioMarin Pharmaceutical and may hold stock.<br /> (© 2021.)

Details

Language :
English
ISSN :
2329-0501
Volume :
24
Database :
MEDLINE
Journal :
Molecular therapy. Methods & clinical development
Publication Type :
Academic Journal
Accession number :
35036471
Full Text :
https://doi.org/10.1016/j.omtm.2021.12.004