Figure 2.

The pharmacodynamic modeling framework for PROTAC assessment and characterization consists of three models. (1) The $k_{cat}$ model links the biochemical parameters which govern target engagement to target degradation. (2) The hook model relates target degradation to PROTAC concentrations and incubation time. (3) The $PD$ model integrates two mechanisms of target modulation, i.e., target degradation and target inhibition, and translates them to a downstream pharmacodynamic readout.