Currently, there is no regulatory guidance to describe expectations for the bioanalytical assay development and validation of functional activity assay in support gene therapy products. Here we present the method development and qualification strategy of an assay to measure functional activity in plasma collected during a non-clinical study for our developed gene therapy. In this case, expression levels of protein were informative to demonstrate successful vector delivery and synthesis by targeted cells in vivo, yet direct measurement of functional enzyme was necessary to ensure efficacy. In this case study, we present our method selection strategy, evaluation of commercial assays and internal adaptations thereof, optimization of reaction kinetics, and mitigation of matrix interference and small dynamic range lending to successful development and method qualification. We additionally performed a correlation assessment of measured functional activity with total protein to demonstrate assay robustness and reliability at the conclusion of sample testing.
Learning Objectives:
Upon completion, participants will be able to understand challenges and strategies in qualification of functional activity assays in gene therapy space.
Upon completion, participants will be able to understand utility of correlation assessment of measured functional activity with total protein in sample analysis in gene therapy space.
Upon completion, participants will be able to understand the commonalities and applicability of previously published guidelines for protein analysis while identifying opportunities for new regulatory guidelines for activity assays in gene therapy space.
