[HTML][HTML] An Fc-competent anti-human TIGIT blocking antibody ociperlimab (BGB-A1217) elicits strong immune responses and potent anti-tumor efficacy in pre-clinical …

X Chen, L Xue, X Ding, J Zhang, L Jiang, S Liu… - Frontiers in …, 2022 - frontiersin.org
X Chen, L Xue, X Ding, J Zhang, L Jiang, S Liu, H Hou, B Jiang, L Cheng, Q Zhu, L Zhang…
Frontiers in Immunology, 2022frontiersin.org
TIGIT (T-cell immunoglobulin and ITIM domain) has emerged as a promising target in cancer
immunotherapy. It is an immune “checkpoint” inhibitor primarily expressed on activated T
cells, NK cells and Tregs. Engagement of TIGIT to its ligands PVR and PVR-L2 leads to
inhibitory signaling in T cells, promoting functional exhaustion of tumor-infiltrating T
lymphocytes. Here, we described the pre-clinical characterization of Ociperlimab (BGB-
A1217), a novel humanized IgG1 anti-TIGIT antibody (mAb), and systemically evaluated the …
TIGIT (T-cell immunoglobulin and ITIM domain) has emerged as a promising target in cancer immunotherapy. It is an immune “checkpoint” inhibitor primarily expressed on activated T cells, NK cells and Tregs. Engagement of TIGIT to its ligands PVR and PVR-L2 leads to inhibitory signaling in T cells, promoting functional exhaustion of tumor-infiltrating T lymphocytes. Here, we described the pre-clinical characterization of Ociperlimab (BGB-A1217), a novel humanized IgG1 anti-TIGIT antibody (mAb), and systemically evaluated the contribution of Fc functions in the TIGIT mAb-mediated anti-tumor activities. BGB-A1217 binds to the extracellular domain of human TIGIT with high affinity (KD = 0.135 nM) and specificity, and efficiently blocks the interaction between TIGIT and its ligands PVR or PVR-L2. Cell-based assays show that BGB-A1217 significantly enhances T-cell functions. In addition, BGB-A1217 induces antibody dependent cellular cytotoxicity (ADCC) against Treg cells, activates NK cells and monocytes, and removes TIGIT from T cell surfaces in an Fc-dependent manner, In vivo, BGB-A1217, either alone or in combination with an anti-PD-1 mAb elicits strong immune responses and potent anti-tumor efficacy in pre-clinical models. Moreover, the Fc effector function is critical for the anti-tumor activity of BGB-A1217 in a syngeneic human TIGIT-knock-in mouse model. The observed anti-tumor efficacy is associated with a pharmacodynamic change of TIGIT down-regulation and Treg reduction. These data support the selection of BGB-A1217 with an effector function competent Fc region for clinical development for the treatment of human cancers.
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