Perfusion enables increased lentivirus production using the iCELLis® bioreactor system

Background & Aim Historically, there have been no manufacturers using Good Manufacturing Practices (GMP) to produce lentivirus in Canada, which has hampered gene therapy and CAR-T clinical programs in the country. The Ottawa Hospital recently developed a lentivirus manufacturing process using adherent cells in a flatware culture system, and used this process to produce sufficient amounts of clinical-grade lentivirus in a GMP manner for the Canadian CLIC-1901 CD19-CAR T Phase I/II clinical trial. While our previously established lentivirus manufacturing process used a flatware culture system, we plan to develop a larger-scale production process for clinical-grade lentivirus using the iCELLis bioreactor system. The iCELLis bioreactor system provides a large surface area for adherent cell growth, has a small physical footprint, and recently emerged as the leading scalable, single-use bioreactor technology for clinical manufacturing of viral vectors and vaccines. Methods, Results & Conclusion Our initial estimates suggest we could produce lentiviral vectors for approximately 2000 clinical doses for CAR-T cell therapy applications in a full-scale iCELLis 500+ bioreactor system; however, observed experimental titers in the first several iCELLis Nano batches were low. We hypothesized that this low titer was due to product instability in the bioreactor for long exposure times, and therefore implement a perfusion-based feeding system to remove product form the bioreactor for storage at more stable conditions. In this poster, we demonstrate that this perfusion strategy successfully resulted in bioreactor titers greater than the legacy flatware process for n=4 batches.