Abstract A036: Development of a stirred-tank bioreactor scale-up approach to allogeneic natural killer cell culture

Abstract

Abstract Natural killer (NK) cells are innate lymphocytes that play a critical role in the immune response, as they recognize and eliminate virus-infected, cancerous, and other abnormal cells in an antigen-independent manner. This unique method of recognition makes NK cells an attractive target for utilization as an immunotherapy, as studies have demonstrated they reduce both the induction of graft-versus-host disease and the risk of cytokine release syndrome compared to T-cell based therapies. Additionally, these advantages over canonical T-cell therapies make NK therapies attractive candidates for allogeneic, as opposed to autologous, products. Given their cost-effective scale-up potential, developing a stirred-tank bioreactor (STR)-based NK cell expansion platform to achieve clinical-level expansion is of significant interest, as it would reduce the cost of producing such therapies and improve patient accessibility. To test ideal culture conditions for STR expansion, NK cells were first isolated from healthy donor Leukopaks prior to cryopreservation. Frozen, isolated NK cells were then thawed, co-cultured with varying ratios of irradiated K562 cells and supplemental cytokines from Cytiva in a 6-well G-Rex or DASbox® STR. Finally, cells were harvested for downstream analytics, including identity and functional characterization by flow cytometry and potency assays. A fold expansion of greater than 100 was achieved once the ratio of irradiated K562 to NK cells was optimized. One of the primary challenges encountered was donor-to-donor variation, not only with respect to proliferative capacity, but NK functional phenotype and activity as well. Therefore, a small-scale donor screen was conducted and donors with similar proliferative and functional capabilities were selected for large-scale expansion. Future work will focus on optimizing NK cell transduction to enable genetic customization and scaling-up to a clinically-relevant STR. The successful small-scale NK expansion in an STR demonstrated here lays the groundwork for an expansion platform that enables the manufacturing of various NK-based therapeutics at clinical scale. Citation Format: Mathura Yogalingam, Rebecca Jagroop, Alireza Khalajzadeh, Thergiory Irrazabal, Melissa Perea, Pooja Pushparaj, Roxana Roshankhah, Paul Bowles, Michael Le. Development of a stirred-tank bioreactor scale-up approach to allogeneic natural killer cell culture [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A036.