Retention of antigen-binding molecules in blood plasma and method for modifying immunogenicity

The present invention involves the discovery that by modifying the Fc region of an antigen-binding molecule to an Fc region in which a heterocomplex containing a bimolecular FcRn and four activating Fc y receptors does not form in the neutral pH range, pharmacokinetics improve due to the antigen-binding molecule, and immune response decreases due to the antigen-binding molecule. In addition, the present invention resulted in the discovery of a method for manufacturing antigen-binding molecules having the abovementioned characteristics, and also resulted in the discovery that when a drug composition, which contains such antigen-binding molecules or antigen-binding molecules manufactured according to the manufacturing method of the present invention as an active ingredient, is administered, the antigen-binding molecules have excellent characteristics, such as improving pharmacokinetics and decreasing immune response by a living organism that has been administered the drug, compared to antigen-binding molecules of the prior art.