FIGURE 2.

Relevant reactions for target- and FcRn-binding. Drug can bind to and dissociate from target and FcRn. Target is produced constantly. Target and drug-target-complex are internalized with different rates. Target turnover and target binding is only applicable to NHP and humans, not to rabbits. FcRn: neonatal Fc Receptor, k_deg,end: degradation rate constant in endosomes, k_int,C:internalization rate of the drug-target-complex, k_int,T: internalization rate of the target, k_off dissociation rate constant of the drug-target-complex, k_{off, FcRn}: dissociation rate constant of the drug-FcRn-complex, k_on: association rate constant of the drug-target-complex, k_on,FcRn: association rate constant of the drug-FcRn-complex, R_syn: zero-order synthesis rate of the target, T_ss: target concentration in steady state.