FIGURE 4.

The bell-shaped concentration-effect curves for bispecific T-cell engaging antibodies. (A) Simulated relationship between blinatumomab concentration and maximum amount of bivalent complex formed. (B) At suboptimal concentrations of bispecific antibodies, bivalent complex formation is limited by the number of bispecific molecules. At optimal concentrations, the number of bivalent complexes formed is maximized. Above the optimal concentration range, target saturation leads to inefficient crosslinking and bivalent complex formation is limited. This condition reduces cell-cell engagement and, potentially, therapeutic efficacy.