| الوصف: |
Immunotherapy is one of the most effective modern treatments for cancer. While immunotherapy operates through a broad class of mechanisms, modulating immune checkpoints have provided some of the most effective approaches, including inhibition of PD-1/PD-L1 pathway, CTLA-4, LAG-3, OX40, Tim-3, KIR and TIGIT to reverse tumor immune escape.OX40, also known as CD134 or TNFRSF4, is a membrane protein expressed in CD4+ and CD8+ T cells, neutrophils and NK cells. In the process of T cell activation, OX40 plays a synergistic stimulating function by binding with ligand OX40L. OX40 agonist immunotherapy has been previously shown to improve the survival rate of glioblastoma in mice, prevent tumor growth in ovarian cancer, increase the prognostic significance of CD8+ cell infiltration in colorectal cancer, and eliminate the inhibitory function of Foxp3+ Treg cells that constitutively Express OX40. On the contrary, blocking OX40 axis is a promising strategy to treat T cell hyperactivation in autoimmune diseases. As recently reported in the literature, a two-armed, random, double blinded phase 2b clinical trial demonstrated that telazorlimab, an antagonist OX40 antibody developed by Ichnos Sciences, met primary efficacy endpoints in treating atopic dermatitis.In this research, we developed a set of novel antibodies to OX40 using a hybridoma and VHH synthetic library; the set of antibodies includes both agonists and antagonists.We developed one hybridoma origin mAb into a human framework. Agonist activity was equal to MOXR0916 in NF- κB reporter-Jurkat assay, dependent on coupling by proteinA/cell-bound CD32b, non-competing with OX40L, and epitope mapped to domain 2+3.We identified dozens of binders from our synthetic single domain VH library. After construction into a IgG1Fc fusion form, 4 VHHs were obtained with significant agonistic activity, dependent on coupling by proteinA/cell bound CD32b. Another 5 VHHs were also obtained with significant antagonistic activity without coupling by proteinA/cell-bound CD32b. The 4 agonistic VHHs were confirmed with binding to domain 1+2, competitive to OX40L’s binding.These VHHs constructs represent a promising set of novel biologics to modulate OX40—as agonists or antagonists—and serve as the basis for development of potential new therapies in the clinic. Citation Format: Chenguang Cai, Xiang Li, Shin-Chen Hou, Guoqian Sun, Ying Li, Ting Yang, Fengzhi Zhang, Qi Sun, Shiying Fu, Shuang Zhao, You'you Lin, Feizheng Xue. Novel set of OX40 targeted antibodies and VHHs include agonists and antagonists for future development [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 5552. |
