Abstract P32: CAR-NK Specific Targeting of Clonal TCRVβ Chain to Treat T-cell Non-Hodgkin's Lymphoma

Abstract T-cell Non-Hodgkin Lymphoma (T-NHL) is a diverse group of aggressive malignancies. Therapies are characterized by pan T-cell cytotoxicity, poor response rates, and the requirement for multiple levels of treatments that results in excess toxicity and devastation of the immune system. Clinical trials are often considered the first line option for advanced disease, speaking to the lack of viable treatments. While there has been success targeting B-cells with CD20 and CD19, there are little to no specific targets for T-cells that would not result in T-cell aplasia. Recently, Lucero et. al. and others showed specific binding, targeting, and killing of T-cells' TCRVβ chains for T-cell NHLs with an expanded TCRVβ clone. We propose using CAR-NK cell therapy targeting the expanded TCRVβ chain for patients with advanced T-cell NHL. The TCRVβ CAR-NK cells were manufactured from an NK-92 cell line, HaNK, which expresses a high affinity CD16 V158 FcγRIIIa receptor. NK/T-cell lymphoma cell lines, EL4 (mouse) and Jurkat (human), were transduced via a lentiviral vector containing a plasmid to express our Vβ of interest, Vβ13. We performed in vitro cytotoxicity co-culture assays on T-cell lymphoma cell lines, EL4 and Jurkat, with and without the TCRVβ13 transfected onto the cells to check functional activity of our CAR-HaNK cells. From the in vitro cytotoxicity assay, supernatants from each of the co-cultures were measured for changes in cytokines INF- γ and TNF-α levels compared to HaNK cells without the TCRVβ CAR. T-LGL cells expressing Vβ13 from a T-NHL patient were isolated and enriched for T-cells which were then co-cultured with either CAR-NK or HaNK cells. Potential off-target and on-target, off-tumor effects of our TCRVβ target will be tested through a panel of primary human tissue and cells. In vivo experiments are in progress to ensure safety and efficacy of the CAR-HaNK Vβ13. Four-hour co-culture in vitro cytotoxicity assays showed an increase in cytotoxicity of EL-4 Vβ13 and Jurkat Vβ13 when co-cultured with TCRVβ CAR-HaNK cells versus HaNK cells alone. Targeting of the EL-4 cell line without the transduced Vβ13 showed comparable cytotoxicity levels when co-cultured with CAR-HaNK cells versus HaNK cells alone. The cytokine assay from supernatants of EL-4 Vβ13 and Jurkat Vβ13 showed similar changes of INF-γ, TNF-α, and other cytokines for both CAR-HaNK and HaNK cells alone co-cultured with target cells. Patient T-LGL cells expressing Vβ13 showed increased death when co-cultured with CAR-HaNK cells versus HaNK cells. These preclinical studies show promising results in the specific targeting and killing of T-cell expressing Vβ13. Future studies developing targets for other functional TCRVβ’s will be conducted with the goal of developing a phase I clinical trial. The successful development of a CAR-NK targeting the TCRVβ will provide patients with mature T-cell lymphomas and leukemias with more treatment options, which are desperately needed in this patient population. Citation Format: Karen E Morris, Jenna Bowman, Ji-Ann Lee, Jeffrey Tyner, Mike Palazzolo, Brian J Druker, Nick Lydon, Peter M Bowers, Olivia M Lucero. CAR-NK Specific Targeting of Clonal TCRVβ Chain to Treat T-cell Non-Hodgkin's Lymphoma abstract. In: Proceedings of the Blood Cancer Discovery Symposium; 2024 Mar 4-6; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5 (2Suppl): Abstract nr P32.