The present invention provides an antibody having at least one binding site that specifically binds to the LukGH complex, wherein the antibody is one of the CDR1-CDR3 sequences listed in Table 1, or a functionally active one thereof. It comprises at least an antibody heavy chain variable region (VH) comprising CDR variants. [Selection figure] None本発明は、LukGH複合体に特異的に結合する少なくとも1つの結合部位を有する抗体を提供し、当該抗体は、表1に挙げられたCDR1~CDR3配列のいずれか、又は機能的に活性なそのCDR変異体を含む抗体重鎖可変領域(VH)を少なくとも含む。【選択図】なし