End-To-End Process Scalability Of HEK 293 Media For High Titer AAV Production

By Phi Le, David Chiu, Migueal Betancourt, Jean-Phillipe Ayandokon, Tam Duong, Anitha Jayapalan, and Yiqun Chen

Shake flasks play an important role in early-stage process development by enabling rapid screening and optimization studies. However, their performance does not always translate directly to controlled bioreactor environments, where key process parameters such as pH, dissolved oxygen (DO), temperature, and agitation can significantly influence cell growth, productivity, and critical quality attributes (CQAs), including viral titer, capsid integrity, and the percentage of full capsids.

Benchtop stirred-tank bioreactors at the 3 L scale provide an essential bridge between laboratory-scale development and larger-scale manufacturing. By offering precise control over process conditions, these systems enable more representative evaluation of AAV production in suspension HEK293-based cell lines while generating data that can support scale-up strategies and process robustness. This level of control helps developers better understand process sensitivities and establish operating parameters that are more predictive of commercial manufacturing performance.

Beyond upstream production, bioreactor-based process development also facilitates alignment with downstream operations, including clarification, chromatography, filtration, and impurity removal. Establishing scalable conditions early in development can improve overall process integration, reduce variability across unit operations, and support more efficient technology transfer. By connecting upstream and downstream workflows, bioreactor scalability helps minimize late-stage process re-engineering, reduce development costs and labor demands, and accelerate the path to clinical and commercial success for AAV-based gene therapy programs.