The present invention relates to humanized anti-CD40 antibodies that have similar antigen binding properties and increased Fcγ receptor binding affinity as the parent chimeric anti-CD40 antibody. In particular, the present invention is directed to humanized anti-CD40 antibodies that are useful in treating cancer, infections and immunodeficiencies. We have found humanized anti-CD40 antibodies that have the same antigen binding affinity as the parent chimeric antibody from which they were derived. Furthermore, these humanized antibodies show enhanced Fcγ receptor binding affinity, especially for FcγRII. Therefore, in a first aspect, the present invention is a humanized antibody capable of binding to CD40 and comprising a heavy chain variable region, wherein the heavy chain variable region is of amino acid sequence SEQ ID NO: 11 or SEQ ID NO: 11 A humanized antibody is included that comprises an amino acid sequence that is at least 90% identical to the amino acid sequence.本発明は、親キメラ抗ＣＤ４０抗体と同様の抗原結合特性およびＦｃγ受容体結合親和性の増大を有するヒト化抗ＣＤ４０抗体に関する。特に本発明は、がん、感染および免疫不全の処置において有用であるヒト化抗ＣＤ４０抗体を対象とする。本発明者らは、それらが由来する親キメラ抗体と同じ抗原結合親和性を有するヒト化抗ＣＤ４０抗体を見出した。さらに、これらのヒト化抗体は、Ｆｃγ受容体結合親和性の増強を、特にＦｃγＲＩＩに関して示す。したがって、第１の態様においては、本発明は、ＣＤ４０に結合することができ、重鎖可変領域を含むヒト化抗体であって、重鎖可変領域が配列番号１１のアミノ酸配列または配列番号１１のアミノ酸配列と少なくとも９０％同一であるアミノ酸配列を含む、ヒト化抗体を対象とする。
