To gain a better understanding of or to confirm design of how a gene therapy agent will travel throughout the body to the on and off target organs, a biodistribution study should be conducted. Additionally, this study will inform on the persistence of the gene therapy and to an extent the potential for delayed adverse events. PCR is the tool of choice for determination of viral vector biodistribution and transgene expression. There are a number of critical factors that will be discussed herein that go into developing and validating a suitable qPCR assay for biodistribution and an appropriate RT-qPCR assay to evaluate transgene expression.
Additionally, we will briefly explore the impact of the immune response on a gene therapy agent and how it can impact study design and endpoints. Considerations include screening for neutralizing antibodies, using immune suppression protocols and evaluating immunogenicity. The talk will focus in more detail on the utility of the ELISpot assay to monitor for cellular mediated immune activity in response to the gene therapy vector/transgene.