Challenges of developing anti-drug antibody & concentration (PK or PD) assays for liposomal transgene enzymes on an automated immunoassay platform

Gene therapy can be used to permanently correct genetic disorders by delivering a transgene product into the nucleus of affected or alternative cells. One of the biggest challenges faced by the gene therapy bioanalytical sector is the lack of a true reference material for transgene products. As a result, in most assays, an alternative commercially available therapeutic (for example, an enzyme replacement therapy product) can be used as a surrogate for the transgene enzyme. This article discusses approaches taken in order to monitor the concentration of the expressed transgene product and any associated immunogenicity.