Genotoxicity by retrovirus (RV), lentivirus (LV) and adeno-associated virus vectors (AAV) has been demonstrated both in vitro and in vivo.The aim of the InMutaGene CRACK IT Challenge is to develop a comprehensive, human relevant risk assessment platform that will improve the safety of novel gene therapy products and reduce the reliance on animal models.

The CRACK IT competition is run in two phases, with funding for six month proof-of-concept studies awarded to up to three consortia in Phase 1. During Phase 2, a single consortium is selected who will receive full funding for three years to solve the Challenge.

In Phase 1 of this CRACK-IT Challenge, the team at Brunel University London led by Dr Michael Themis together with GeneWerk GmbH Heidelberg led by Dr Manfred Schmidt, set up the basis of an individualized genotoxicity study (InGeTox) approach to test vector safety and efficacy.

The team is accomplished by the expertise of leading researchers at University College London, King’s College London and The Natural and Medical Sciences Institute at the University of Tübingen, Germany. World leading pharma companies GlaxoSmithKline and Novartis act as sponsors of the challenge.

In this model, human induced pluripotent stem cells (hiPSC) are used for reprogramming to liver cells in order to test vector associated genotoxicity. This approach finally enables to use patient cells, incorporating the individual’s genetic and disease background to measure the genotoxic risc of an individual under a specific gene therapy regimen. Riscs include the effects of the vector on cellular gene expression by vector promoters and enhancers, vector splicing with host genes to form aberrant transcripts and changes of host epigenetic response to gene transfer. In addition, these factors are scored alongside the therapeutic effect of the expressed transgene.

• The development of a gene therapy eligibility assay that measures the patient’s target cell’s capacity for repair of DNA damage caused by      vector integration
  
  
• Optimized hiPSc differentiation to hepatocytes in 3D culture
  
  
• Efficient gene transfer by LV of iPSC
  
  
• Genome wide vector integration site distribution SIN LV versus unmodified LTR LV
  
  
• Successfully set up the basis for Phase 2 of the Challenge

In Phase 2 of the project the team at GeneWerk continues with the validation and standardization of the results according to international quality control standards to provide a modular service omics-platform that measures genotoxic factors by gene therapy vectors, a comprehensive package predicting patient eligibility and outcome before vectors and gene therapy regimen are considered to move to the clinic.