LAUSR

Checkpoint inhibitors represent a major advance in cancer immunotherapy, and combinatorial immunotherapies with secondary drivers of anti-tumor immunity provide beneficial effects for patients that do not show a strong endogenous immune response. CD40 is a member of the TNF family of receptors that has been shown to play a crucial role in enhancing B cell and dendritic cell activity and fostering anti-tumor immune responses. Engagement of the inhibitory Fcg-receptor (FcgR) IIb is an absolute requirement for in vivo antitumor activity of agonistic anti-CD40 monoclonal antibodies, and Fc region mutant designs of anti-CD40 antibodies had been discovered to enhance FcgRIIb engagement. With Twist’s precision DNA writing technologies, we have created phage display VHH and scFv libraries with diversity greater than 1 × 1010 for optimal discovery. In this study, we performed high affinity binding of the antibodies by SPR and cell surface binding. The leads are reformatted on human IgG1, IgG4, and IgG1 mutant. The in vitro properties of the CD40 agonistic antibodies demonstrate enhanced FcgRIIb engagement by NFkB activation. B cell activation is also detected by upregulation of CD86 and IL6 secretion. In humanized hCD40 mice model, we observed the engineered anti-CD40 agonists enhance anti-tumor immune function in vivo. These studies suggest that our antibodies can be potential drug for cancer immunotherapy. Citation Format: Linya Wang, Tom Z. Yuan, Mouna Villalta, Zhen Han, Hansika Wadhwa, Kara Y. Chan, Marisa Yang, Tammy Htoy, Paul VanDyke, Carson Holliday, Hector Franco, Hoa Giang, Fumiko Axelrod, Aaron Sato. Human anti-CD40 agonistic antibodies with enhanced FcgR engagement activate immune cell and promote anti-tumor efficacy [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 1531.