Abstract 2835: Chimeric antigen receptor (CAR) T-cell generation for therapeutic testing in the disseminated NALM6 human B-cell acute lymphoblastic leukemia mouse model
Authors: Karalewitz Andrew , Czeryba Natalie , Xing Yewei , Germain Derrik , Lapinski Philip , Barnes Sheri , Cameron Mark , Saims Daniel , Rowse Amber , Nielsen Heidi , Wise Scott 
Published: June 2022

Abstract
Cancer immunotherapies reprogram the patient’s immune system to mount a coordinated response against a malignant target. T cells engineered to express Chimeric Antigen Receptors (CARs) through transduction with a lentiviral vector represent an effective strategy to specifically eliminate cancerous cells from a patient. Currently, five CAR T cell therapies are approved by the FDA for the treatment of hematological malignancies. With the recent clinical and regulatory success of CAR T cell therapies, the next generation of CAR T cells are undergoing preclinical development. Labcorp Drug Development produces CAR T cells to support the development of new preclinical strategies. Here, the CAR T Cell Generation Service is demonstrated using an anti-CD19 CAR T cell as an example.
Using peripheral blood mononuclear cells from healthy, human donors as a T-cell source, CAR T cells were produced by lentivirus transduction. Flow cytometry featuring a CAR-specific monoclonal antibody was used to determine transduction efficiency. To assess in vitro activity, co-cultures of T cells and CD19-expressing NALM6 cells were used to measure cytotoxicity. Proinflammatory cytokine production was analyzed using a Meso Scale Discovery V-PLEX assay. For evaluation of in vivo efficacy, a disseminated NALM6-Luc-mCh-Puro human acute B cell lymphoblastic leukemia model in female NSG mice was conducted.
After T cells were treated with lentivirus, approximately 25% of total cells were CD3+/CAR+. Greater than 95% of all target NALM6 cells were killed by a high dose of anti-CD19 CAR T cells. In contrast, only 33% of target cells were killed by untransduced (UTD) T cells at the highest concentration tested. Cytotoxicity against the negative control MV-4-11 cells was equal for a high dose of UTD and a high dose of anti-CD19 CAR T cells. When co-cultured with CD19-expressing NALM6 cells, anti-CD19 CAR T cells produced proinflammatory cytokines including IFN-γ. Relative to mock-treated control mice, treatment with anti-CD19 CAR T cells at high, medium, and low doses increased the time of in vivo disease progression by 175%, 125%, and 16%, respectively.
Anti-CD19 CAR T cells generated in our lab were specifically active against CD19-expressing target cells. As a premier contract research organization, Labcorp Drug Development is experienced in producing, handling and culturing T cells and CAR T cells for in vitro and in vivo early discovery studies. Preclinical screening of multiple CAR T cell candidates, alone or in combination with other agents, would facilitate the identification and selection of CARs with the most favorable activity profile for progression through the drug development pipeline. By providing a reliable source of CAR T cells, we are supporting early discovery studies and the development of therapeutic strategies in oncology.
Citation Format: Andrew Karalewitz, Natalie Czeryba, Yewei Xing, Derrik Germain, Philip Lapinski, Sheri Barnes, Mark Cameron, Daniel Saims, Amber Rowse, Heidi Nielsen, Scott Wise. Chimeric antigen receptor (CAR) T-cell generation for therapeutic testing in the disseminated NALM6 human B-cell acute lymphoblastic leukemia mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2835.