Figure 1.

Screen of inhibitory activity against CD73 on COR-L23 cells. The inhibition of CD73 activity (%) was determined following exposure to antibodies for 4 h using a LC-MS–based assay with a heavy-isotope AMP substrate (white shading: 0–49% inhibition at 1 ug/ml; pale green: 50–69% inhibition; green: 70–89% inhibition; and dark green: 90–100% inhibition). Each square, except the furthest right in each row, represents a biparatopic produced by the combination of parental antibodies indicated on the horizontal and vertical axes. The furthest right square in each row represents the parental bivalent anti-CD73 antibody reconstructed using Fab-arm exchange. The bottom row (AS30) indicates pairings with an irrelevant antibody AS30, to produce monovalent versions of the parental antibodies. Values represent the mean inhibition at 1 μg/ml observed with four replicates of single analyte dilutions.