Abstract 705: Potentiation of immunotherapy by LSD1 modulation

Abstract LSD1 has emerged as a potential therapeutic target to increase the effectiveness of cancer immunotherapy. We have developed a series of novel small molecules, exemplified by the lead substance BEA-17, that modulates LSD1 via binding to an allosteric site, without directly inhibiting its enzymatic activity. In cells, BEA-17 induces a reduction of LSD1 levels. In addition, BEA-17 upregulates the expression of endogenous retroviral genes and T cell-attractant chemokines and does so in an LSD1-dependent manner. In a co-culture of HeLa and PBMCs, BEA-17 increases cell kill of cancer cells by immune effector T cells, also in an LSD1-dependent manner. In a CT26 syngeneic animal model of colon cancer, BEA-17 potentiates the activity of anti-PD1 inhibitors. Finally, in a syngeneic GL261 animal model of glioblastoma, BEA-17 increases the effectiveness of standard-of-care temozolomide + radiation. Citation Format: Wei B. Emond, Rajiv Sawant, Matthis Geitmann, Johan Winquist, Peter Brandt, Ulf Bremberg, Per Källblad, Vendela Parrow, Claes Andersson, Kristin Blom, Nasrin Najafi, Tobias Bergström, Fredrik J. Swartling, Mats Hellström, Konrad F. Koehler. Potentiation of immunotherapy by LSD1 modulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 705.