Recent advances in upstream process development for production of recombinant adeno-associated virus

Recombinant adeno-associated virus (rAAV) is rapidly emerging as the preferred delivery vehicle for gene therapies, with promising advantages in safety and efficacy. Key challenges in systemic in-vivo rAAV gene therapy applications are the gap in production capabilities versus potential market demand and complex production process. This review summarizes current available information on rAAV upstream manufacturing processes and proposed optimizations for production. The advancements in rAAV production media were reviewed with proposals to speed up the cell culture process development. Furthermore, major methods for genetic element delivery to host cells were summarized with their advantages, limitations, and future directions for optimization. In addition, culture vessel selection criteria were listed based on production cell system, scale, and development stage. Process control at the production step was also outlined with an in-depth understanding of production kinetics and quality control. Advancement of upstream process development is described to overcome the challenges for complex recombinant adeno-associated virus production. Public information and trends in four major areas, that is, cell culture media, genetic element delivery to host cell, culture vessel (a.k.a bioreactor) selection, and process control at the production step were summarized targeting a high yield and high-quality process. The advantages and limitations of each technology were evaluated as part of process robustness assessment.image