Fig. 1: IBI319 activates CD137 in a PD-1 dependent manner. | Nature Communications

Fig. 1: IBI319 activates CD137 in a PD-1 dependent manner.

From: Cancer immune therapy with PD-1-dependent CD137 co-stimulation provides localized tumour killing without systemic toxicity

Fig. 1

a Structure diagram of IBI319 on a human IgG1 backbone. IBI319 consists of a Fab region binding to PD-1 and CD137 and an Fc fragment with null effector function. b The dissociation constants (KDs) of IBI319, αPD-1, and αCD137 for human PD-1 and human CD137, respectively, determined via SPR (3 independent experiments; mean ± standard deviation (SD); n.a. not analysed). c CD137 ligand-blocking properties of IBI319, αCD137, in-house-generated urelumab and utomilumab via BLI. d PD-1 and CD137 expression on CD4 + and CD8 + T cells from a representative healthy donor before (black) and after activation by anti-CD3/CD28 antibody-coated beads (red) measured by flow cytometry (FACS). e Binding affinities of IBI319 and control antibodies for activated CD4 + T cells and CD8 + T cells measured by FACS. f Binding affinities of IBI319 and control antibodies for Jurkat-CD137 cells co-cultured with CHO-S or CHO-S-PD-1 cells determined by FACS and calculated from the CTV + CFSE + population. e, f two technical replicates of one representative experiment from three independent experiments; mean and SD.

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