Correction of pathology in mice displaying Gaucher disease type 1 by a clinically-applicable lentiviral vector

Maria Dahl,Emma M.K Smith,Sarah Warsi,Michael Rothe,Maria J Ferraz,Johannes M.F.G Aerts,Azadeh Golipour,Claudia Harper,Richard Pfeifer,Daniella Pizzurro,Axel Schambach,Chris Mason,Stefan Karlsson

doi:10.1016/j.omtm.2020.11.018

Abstract

Gaucher disease type 1 (GD1) is an inherited lysosomal disorder with multisystemic effects in patients. Hallmark symptoms include hepatosplenomegaly, cytopenias, and bone disease with varying degrees of severity. Mutations in a single gene, glucosidase beta acid 1 (GBA1), are the underlying cause for the disorder, resulting in insufficient activity of the enzyme glucocerebrosidase, which in turn leads to a progressive accumulation of the lipid component glucocerebroside. In this study, we treat mice with signs consistent with GD1, with hematopoietic stem/progenitor cells transduced with a lentiviral vector containing an RNA transcript that, after reverse transcription, results in codon-optimized cDNA that, upon its integration into the genome encodes for functional human glucocerebrosidase. Five months after gene transfer, a highly significant reduction in glucocerebroside accumulation with subsequent reversal of hepatosplenomegaly, restoration of blood parameters, and a tendency of increased bone mass and density was evident in vector-treated mice compared to non-treated controls. Furthermore, histopathology revealed a prominent reduction of Gaucher cell infiltration after gene therapy. The vector displayed an oligoclonal distribution pattern but with no sign of vector-induced clonal dominance and a typical lentiviral vector integration profile. Cumulatively, our findings support the initiation of the first clinical trial for GD1 using the lentiviral vector described here.

Highlights

Gaucher disease (GD) belongs to the family of lysosomal disorders and is inherited in an autosomal recessive manner.[1,2] The disorder may present at any age from early childhood to old age and symptom presentation and burden vary significantly between patients.[3]
We aimed to evaluate whether a lentiviral vector containing an ribonucleic acid (RNA) transcript that, after reverse transcription, results in codon-optimized cDNA that, upon its integration into the human genome, encodes for functional human glucocerebrosidase under the control of the elongation factor 1a short (EFS) promoter, could halt Gaucher disease type 1 progression, or alternatively correct an already established disease state (Figures 1A and 1B)
The lineage negative (Lin–) bone marrow compartment enriched with hematopoietic stem- and progenitor cells from donor Gaucher disease type 1 (GD1) animals was used for overnight transduction with the lentiviral vector (LV)

Summary

Introduction

Gaucher disease (GD) belongs to the family of lysosomal disorders and is inherited in an autosomal recessive manner.[1,2] The disorder may present at any age from early childhood to old age and symptom presentation and burden vary significantly between patients.[3]. There are currently more than 350 patients, with more than 10 different monogenetic disorders, who have undergone ex vivo genetic correction of autologous HSPCs using lentiviral vectors as recently reviewed by Cavazzana and others.[15,16] To date, no serious adverse events (SAEs) due to insertional mutagenesis have been reported for these patients.[15] Clinical trials using lentiviral vectors for treating the metabolic disorders cerebral adrenoleukodystrophy (CALD) (ClinicalTrials.gov: NCT01896102) and metachromatic leukodystrophy (MLD) (ClinicalTrials.gov: NCT01560182) are ongoing with highly beneficial results to date.[17,18,19,20] Previous proof-of-concept studies using retroviral and lentiviral vectors have been successful in treating hallmark GD1 signs in our murine disease model.[21,22] In this paper, we show that a single gene self-inactivating (SIN) lentiviral vector enabling the integration of human glucocerebrosidase gene under the control of a physiological promoter into hematopoietic stem/progenitor cells, may support a safe and efficacious therapy for treating GD1. These data provided the necessary proof-of-concept for a successful regulatory filing in USA, Canada, and Australia and the ongoing phase 1/2 clinical trial (“Phase 1/2 Lentiviral Vector Gene Therapy - The GuardOne Trial of AVR-RD-02 for Subjects With Type 1 Gaucher Disease,” ClinicalTrials.gov: NCT04145037)

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