Figure 1.

Schematic of the physiologically‐based pharmacokinetic (PBPK) model: (a) full PBPK model, (b) organ‐level model, (c) endosomal‐level model. FcRn, neonatal Fc receptor; Ab, antibody; FR, volume fraction of pinocytosis from vascular space (apical); CLup, pinocytotic uptake rate of endothelial cells; 1‐FR, volume fraction of pinocytosis from intestitial space (basolateral); kdeg_FcRn_Ab, degradation rate of FcRn bound mAb; Prob_deg, probability of mAb degradation in the absence of FcRn binding; PS_KD, equilibrium constant for mAb‐cell membrane site non‐specific interactions.