Abstract 6334: Metabolic reprogramming enhances expansion and potency of CAR T cells
Authors: Xing Yewei , Eaker Shannon , Bronevetsky Yelena , Garcia Candy , Lemar Hadia , Massi Evan , Wong Albert , Barnes Sheri , Germain Derrik , Wise Scott , Lim James 
Published: March 2024

Abstract
Cell therapies, such as Chimeric Antigen Receptor (CAR) T cell therapy, have revolutionized the treatment of hematological malignancies, but their use in solid tumors remains a significant challenge for the field. This is due, in part, to immunosuppressive mechanisms in the tumor microenvironment (TME), which include reduced oxygen tension, high interstitial pressure, and an abundance of immunosuppressive proteins, resulting in mitochondrial dysfunction, exhaustion, and depletion of adoptively transferred cells. Metabolic manipulation of therapeutic cells could overcome these barriers to enable cell therapy success in solid tumors. To this end, we have employed AVATAR technology (Xcellbio, San Francisco, CA), an incubation system that enables precise control of oxygen tension and hyperbaric pressure on cells in culture to improve the manufacture of adoptive T cell therapies. Using a CD19 CAR T model system, we have shown that transduction and expansion of CAR T cells under reduced oxygen and hyperbaric pressure conditions yield greater percentages and total numbers of lentiviral-transduced cells. While cells transduced in a standard CO2 incubator yielded 10-20% CD19 CAR+ cells, transduction in the AVATAR system with increased pressure yielded 15-40% CD19 CAR+ cells. Similarly, T cell cultures performed under pressurized AVATAR conditions generated ~2X more viable cells after 10 days. Furthermore, these metabolically reprogrammed cells exhibit enhanced potency, with improved anti-tumor cytotoxic activity in vitro. We have extended these studies to measure the ability of AVATAR-expanded CD19 CAR T cells to control the growth of CD19-expressing NALM6-Luc tumor cells in vivo compared to CAR T cells grown in a conventional CO2 incubator. Mice (female NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ, Jackson Laboratories, Bar Harbor, ME) dosed with the AVATAR-expanded cells exhibited good tumor control and increased persistence of CAR T cells in relevant organs, along with alterations in cell trafficking to the bone marrow and spleen. The transferred cells maintained a less differentiated phenotype, with central memory and effector memory populations, as measured by expression of the markers CD45RA and CD62L, dominating the T cell compartment. This work showcases the benefits of metabolic reprogramming to improve the yield and functional potency of CAR T cells, which has direct applications to reducing the cost and improving the efficacy of these lifesaving treatments. The AVATAR technology is currently being translated into a closed system bioreactor for use in GMP cell therapy manufacturing.
Citation Format: Yewei Xing, Shannon Eaker, Yelena Bronevetsky, Candy Garcia, Hadia Lemar, Evan Massi, Albert Wong, Sheri Barnes, Derrik Germain, Scott Wise, James Lim. Metabolic reprogramming enhances expansion and potency of CAR T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6334.