Abstract 1451: AN3025: A novel anti-human TNFR2 antibody that exhibits immune activation and strong anti-tumor activity in vivo

Abstract

Background: The unique biology and expression pattern of tumor necrosis factor receptor-2 (TNFR2) make it an attractive therapeutic target for immuno-oncology. TNFR2 highly expresses on a subset of regulatory T cells (Tregs) and MDSCs within tumor microenvironment that can activate these cells through nuclear factor kappa B (NF-kB) pathway. TNFR2+ Treg has been shown to be most suppressive among all Treg populations in tumor. On the other hand, TNFR2 is also abundantly expressed on the surface of many human tumors. TNFR2 blocking antibody is expected to relieve TNFR2-mediated immunosuppression and inhibit TNFR2-expressing tumor cell survival. AN3025 is a novel humanized IgG1 (variant) anti-hTNFR2 antibody under preclinical development. The immunomodulatory and anti-tumor activity of AN3025 were evaluated both in vitro and in vivo. Materials and methods: AN3025 was generated through rabbit immunization followed by phage display, then humanized by CDRs grafting. The binding affinity and specificity were studied by ELISA and FACS. The ability of AN3025 to mitigate TNF/TNFR2 signaling pathway was characterized using TNFR2 overexpressing Jurkat cell line in vitro. The in vivo anti-tumor activity was evaluated in TNFR2 humanized mouse model bearing MC38 tumor. The tumor samples from control and AN3025 treated mice were taken for further FACS and RNA seq analysis. Results: AN3025 binds to the extracellular domain of human TNFR2 with sub-nanomolar affinity and specificity. It cross-reacts with cynomolgus TNFR2 with similar affinity, but not with mouse or rat TNFR2. Mechanistically, AN3025 partially competes with TNFα for binding to TNFR2 receptor and inhibits TNFα induced hTNFR2 overexpressing Jurkat cell death, however it lacks of agonist activity towards TNFR2 even in the presence of hFC crosslinking. In vivo AN3025 significantly inhibits MC38 tumor growth as a monotherapy in hTNFR2 mouse model, while no impact on body weight. Subsequent FACS analysis suggests decreased Tregs% in AN3025 treated tumor. RNA seq suggests immune activation such as increased IFN-gamma and Granzyme expression. In addition, AN3025 enhances anti-tumor efficacy of mPD-1 antibody in a combination study. Conclusions: AN3025 is a novel anti-hTNFR2 antibody and demonstrates immunomodulatory activity and potent anti-tumor efficacy in vivo, supporting its clinical development for the treatment of human cancers. Citation Format: Yonglin Chen, Manxue Jia, Sherry Xu, Yanhui Zhao, Eric Chan, Meng Zhang, Emma Chen, Yi Zhang. AN3025: A novel anti-human TNFR2 antibody that exhibits immune activation and strong anti-tumor activity in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1451.

The TNF-α/TNFR2 Pathway: Targeting a Brake to Release the Anti-tumor Immune Response

“…They reported an antitumor effect on several cancer types using the murine version and found corresponding activity of human agonist TNFR2 antibodies that could be used in patients. • Encouraging unpublished results were also presented at the AACR annual meetings in 2020 and 2021, regarding advances in both agonists and antagonists targeting TNFR2 and tested in the context of cancer (Mårtensson et al, 2020;Chen et al, 2021).…”

“…Encouraging unpublished results were also presented at the AACR annual meetings in 2020 and 2021, regarding advances in both agonists and antagonists targeting TNFR2 and tested in the context of cancer ( Mårtensson et al, 2020 ; Chen et al, 2021 ).…”

Targeting TNFR2 in Cancer: All Roads Lead to Rome

“…AN3025 from Adlai Nortye can significantly inhibit MC38 tumor growth without impaction on body weight through Treg depletion and increased expression of IFNγ and granzyme. In addition, the combined use of AN3025 and PD-1 antibody can achieve a synergistic effect in vivo ( 59 ). SIM0235 is a mAb that targets and inhibits TNFR2 from Simcere.…”

Antibody-based approaches to modulate immune response

“…[44][45][46] , (ii) granzyme and perforin mediated cytolysis 18,19 , (iii) metabolic alterations to promote pro-inflammatory cytokine deprivation such as IL-2 starvation or generation of adenosine, adenosine monophosphate (AMP) and kynurenine 49,50 , (iv) interaction with antigen presenting cells (APC) to modulate CD80 and CD86 expression, maturation and functional stage through immune checkpoint regulation 51,52 , (v) generation of extracellular vesicles (EVs) 53 , (vi) promoting differentiation towards anti-inflammatory macrophages M2 54,55 , (vii) induction of suppressive phenotype in neutrophils and reduction of ILC2 cytokine secretion 56 Tregs are involved in the maintenance of the tolerance to self-antigens by preventing autoimmune and inflammatory diseases and in controlling an effector immune response upon pathogen elimination by antigen-specific immune response. Therefore, immunosuppressive activity carried out by Tregs plays pivotal role in autoimmune and inflammatory disorders such as type 1 diabetes, multiple sclerosis, and cancer disease, making the Tregs an important target for therapeutic applications [57][58][59] .…”

“…Their dysfunction causes severe autoimmune disease 56 . The concept of suppressor T cells was first described in 1970 by Gershon and Kondo 57 . After several years of research and the discovery of CD25 as a Treg marker in 1995, Treg populations became substantially better characterized 56 .…”