Geptanolimab (CBT-501) is a humanized IgG4k monoclonal antibody against programmed death-1 (PD-1). Siplizumab inhibits the binding of PD-L1/L2 to PD-1 through a competitive action. Siplizumab can be used in research of cancer.
Geptanolimab (CBT-501) has highly specific binding to PD-1 of human (KD=505 pM) and cynomolgus (KD=7.2 nM)[1].Geptanolimab enhances human T-cell activation in the Mix Lymphocyte Reaction (MLR), increasing release of IL-2 and INF-γ[1].
Geptanolimab (ip; once every two weeks, for 6 weeks; mice with MC38 syngeneic tumor models) has anti-tumor activity and tumor inhibition rate reached 83%[1].
References:
[1]. Qing Z, et, al. Activity of CBT-501, a novel humanized anti-PD-1 antibody, in a humanized genetically engineered mouse model of colon carcinoma. Journal of Clinical Oncology. 2017;35 (7_suppl):108-108.