Promoting the disappearance of the antigen, antibody affinity for FcRn is changed

The present invention is to increase a method of promoting the uptake into the cell of an antigen by antigen-binding molecules, a method of promoting a reduction in the antigen concentration in plasma, the number of antigens that the antigen-binding molecules of one molecule can bind, method of improving the pharmacokinetics of antigen-binding molecules, the antigen binding molecules decreased antigen concentration can be promoted antigen of the antigen-binding molecules uptake is accelerated into the cell, in plasma, it can bind to multiple antigens antigen-binding molecule, an antigen binding molecule pharmacokinetics is improved, and to provide such antigen binding molecules pharmaceutical compositions comprising, and methods for their preparation. The present inventors have weak antigen-binding activity at pH in the early endosome compared to antigen-binding activity at pH in plasma and antibodies with human FcRn-binding activity at pH in plasma, the antigen promote uptake of intracellular, such antibodies can increase the number of antigen to which an antibody of one molecule can bind, to facilitate the antigen decrease in plasma by administration of such antibodies can be found that can improve the pharmacokinetics of the antibody by the use of such antibodies.