“…High-affinity antibodies can drastically alter the time course of ligand exposure, and the rate and extent of these alterations depends on the pharmacokinetic properties of the antibody, the pharmacokinetics of the ligand, the binding kinetics between antibody and ligand, and the dosing protocols employed. In most cases, administration of high affinity antibodies leads to an increased binding of ligand in plasma, redistribution of ligand from tissues to the systemic circulation (Rosenblum et al, 1990), increased total plasma ligand concentrations, reduced ligand concentrations in tissues, and decreased unbound ligand concentrations in plasma (Balthasar and Fung, 1994; Pentel et al, 1991; Terrien et al, 1989; Valentine and Owens, 1996). However, antibodies often impart a “restrictive” effect on the clearance of the ligand, which often leads to increased total cumulative systemic exposure of the ligand (AUC) and increases in the half-life of ligand in plasma.…”