Development of a novel bioreactor platform for CAR T-Cells expansion

Background & Aim Chimeric Antigen Receptor (CAR) T-cell immunotherapies have successfully demonstrated a new therapeutic approach to combat serious life-threatening diseases, culminating with the approval of Yescarta® (Gilead) and Kymriah® (Novartis) by FDA and EMA. But while the clinical success of these products has been remarkable, the need for a consistent and cost effective manufacturing process still needs to be assessed. At present, T-cell manufacturing and production capabilities are greatly lagging and will not be able to meet the predicted surge in demand unless new technologies and processes are developed. These processes need to be highly regulated, and consistently achieve high yield and good cells quality. A number of systems have been used for CAR-T cell expansion (e.g. static and rocking bag systems). These technologies have many advantages, but they generally lack in scalability, suffer from manufacturing bottlenecks or low automation. Our group demonstrated that it is possible to grow T-cells in a stirred tank, without affecting cell growth or quality. However, the development of a novel platform, specifically designed for cell and gene therapies, enables us to address limitations of existing platforms. Methods, Results & Conclusion The focus of this work is to design and develop a novel bioreactor platform that is both closed and automated, and suitable for the production of adherent and suspension cells for cell and gene therapy applications. We have analyzed the cell growth kinetics in the platform and have compared it with existing systems. The process is tightly controlled via an online monitoring and control system which measures metabolites, dissolved oxygen and pH, with the possibility of automated culture volume expansion. T-Cells from healthy donors were expanded in different bioreactors (stirred tanks, bags, static gas permeable bags, gas permeable membrane flasks) for 7 days in batch or fed-batch conditions. To ensure the systems could be appropriately compared, the dissolved oxygen concentration, titer and spent medium was used as the basis for comparison. The results show the performance of the examined system in terms of cell growth and fold expansion is comparable with the other bioreactors. The quality of the final product (with respect to cell viability, phenotype and differentiation) was also determined by flow cytometry analysis. This work presents the initial assessment of the platform and the data will be used to optimize the design of the bioreactor system.