Abstract 5299: A novel anti-4-1BB antibody with no liver toxicity and its application in a bi-specific antibody

Abstract 4-1BB (CD137, TNFRSF9) is a co-stimulatory receptor initially identified on T cells, belonging to the tumor necrosis factor receptor superfamily. Primarily expressed on activated CD8+ T cells, it plays a crucial role in immune activation. Moreover, the intracellular domain of 4-1BB is leveraged to enhance the proliferation and cytotoxicity of Chimeric Antigen Receptor-T (CAR-T) cells. However, the development of 4-1BB agonist antibodies has encountered challenges, with limited clinical efficacy (e. g. , utomilumab) or dose-dependent liver toxicity (e. g. , urelumab). Consequently, there is a significant demand for the development of next-generation 4-1BB agonist antibodies, leading to numerous ongoing preclinical R Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 5299.