Disclosed is the use of a humanized anti-a2 integrin antibody comprising (i) a heavy chain variable region comprising the amino acid sequence of (a) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (b) SEQ ID NO:40 and (ii) a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6) or a composition comprising said humanized anti-a2 integrin antibody and a pharmaceutically acceptable carrier for the preparation of a medicament for the treatment of metastatic cancer.