Abstract:
The genome packaging efficiency (full to total capsid ratio, or F/T ratio) for Adeno-Associated Virus (AAV) is a critical quality attribute for the manufacturing and commercialization of AAV-based gene therapies. A higher F/T ratio has the potential for reducing dosage and eventually the cost of goods (COGS). In this study, we present design improvements in pHelper and pRepCap plasmids that can support increased AAV titers, whilst improving F/T ratio in upstream crude harvest using a triple-plasmid transfection process. Performance was measured both at Lonza and at BMS R&D labs independently. Both scenarios show significant increments in full ratio. A tentative plan to further improve productivity will also be shared. In summary, this study demonstrates that we can significantly increase the AAV productivity and packaging efficiency for various AAV serotypes and client-specific Gene of Interest (GOIs) at the upstream production stage through plasmid engineering approaches..
Author: Chien-Ting Li, PhD, R&T Scientist II