PROBLEM TO BE SOLVED: To provide: a method for improving pharmacokinetics of an antigen-binding molecule a method for increasing the number of times for the antigen-binding molecule to bind to an antigen an antigen-binding molecule improved in pharmacokinetics an antigen-binding molecule improved in the number of times for oneself to bind to an antigen and methods for producing those and others.SOLUTION: This antigen-binding molecule has a value of KD(pH 5.8)/KD(pH 7.4) which is a ratio of KD (dissociation constant) at pH 5.8 to KD at pH 7.4 to an antigen is 2 or more. There is provided a method for improving pharmacokinetics of an antigen by weakening the antigen-binding activity of the antigen-binding molecule at pH 5.8 than that of antigen-binding activity at pH 7.4.COPYRIGHT: (C)2013,JPO&INPIT【課題】抗原結合分子の薬物動態を向上する方法、抗原結合分子の抗原への結合回数を増やす方法、薬物動態が向上した抗原結合分子、抗原結合分子の抗原への結合回数が向上した抗原結合分子、および、それらの製造法等の提供。【解決手段】抗原に対するpH5.8でのKDとpH7.4でのKDの比であるKD(pH5.8)/KD(pH7.4)の値が2以上である抗原結合分子。抗原結合分子のpH5.8における抗原結合活性をpH7.4における抗原結合活性より弱くすることにより抗原結合分子の薬物動態を向上させる方法。【選択図】なし
