Manufacturing Clinical Grade Recombinant Adeno-Associated Virus Using Invertebrate Cell Lines

Recombinant adeno-associated virus (rAAV) vectors are proving to be a reliable gene transfer system for several clinical applications, with an increasing body of evidence supporting safety and efficacy. Realizing the clinical and commercial potential of rAAV depends on a reliable source of high-quality, well-characterized rAAV lots. This requirement has been very challenging to achieve due to limits of manufacturing platforms, lot-to-lot variability, or differences in the rigor applied to quality-control assays. In addition to reliable, high-quality vectors, limited quantities of rAAV have hampered clinical development and discouraged investigations into applications that require large therapeutic doses or quantities needed to treat large patient populations. A minimal number of vector production runs should be sufficient to support all phases of clinical development, including non-clinical, pharmacological, and toxicological studies, as well as clinical studies and commercial supply. The production platform using the Sf9 invertebrate cell line has emerged as a scalable and economical source of rAAV. Access to larger quantities of rAAV has now enabled evaluation of gene therapeutics for diseases that require large doses per patient or diseases with large patient populations. The only licensed rAAV product, Glybera, was produced in Sf9 cells, and other rAAV products are in clinical trials in the United States and Europe. The development of the Sf9 rAAV genetics, processes, and overview of the current system are described.