PROBLEM TO BE SOLVED: To provide an antigen-binding molecule that promotes disappearance of an antigen via FcγRIIB.SOLUTION: An antigen binding molecule including an antigen-binding domain in which binding activity to an antigen changes by a condition of ion concentration, and an Fc region in which 238th position of amino acid expressed by an EU numbering is Asp, furthermore, any one or more of the following: 233th position of amino acid expressed by the EU numbering is Asp； 234th position of amino acid expressed by the EU numbering is Trp or Tyr； 237th position of amino acid expressed by the EU numbering is Ala, Asp, Glu, Phe, Leu, Met, Trp or Tyr； 239th position of amino acid expressed by the EU numbering is Asp； 267th position of amino acid expressed by the EU numbering is Ala, Gln or Val； 268th position of amino acid expressed by the EU numbering is Asp, Glu or Asn； 296th position of amino acid expressed by the EU numbering is Asp； 323th position of amino acid expressed by the EU numbering is Ile, Leu or Met； 326th position of amino acid expressed by the EU numbering is Ala, Asp, Glu, Leu, Met, Asn, Gln, Ser or Thr； and 330th position of amino acid expressed by the EU numbering is Lys, Met or Arg.SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】ＦｃγＲＩＩＢを介して抗原の消失を促進する抗原結合分子の提供。【解決手段】抗原に対する結合活性がイオン濃度の条件によって変化する抗原結合ドメイン、及びEUナンバリングで表される238位のアミノ酸がAspであり、更にEUナンバリングで表される；233位のアミノ酸がAsp、234位のアミノ酸がTrp又はTyr、237位のアミノ酸がAla、Asp、Glu、Phe、Leu、Met、Trp又はTyr、239位のアミノ酸がAsp、267位のアミノ酸がAla、Gln又はVal、268位のアミノ酸がAsp、Glu又はAsn、296位のアミノ酸がAsp、323位のアミノ酸がIle、Leu又はMet、326位のアミノ酸がAla、Asp、Glu、Leu、Met、Asn、Gln、Ser又はThr、330位のアミノ酸がLys、MetまたはArg、のいずれかひとつ以上であるFc領域を含む抗原結合分子。【選択図】なし
