The invention relates to engineered antibodies which specifically bind to integrinreceptors, especially the alpha V integrin receptor subunit. The antibodiescomprise the antigen binding sites (CDRs) of a known mouse anti-integrin antibody,as well as hybrid light chain variable sequences, mutated heavy chain variablesequences (Frs) and modified heavy chain constant sequences. The novel antibodieshave improved immunogenic and expression properties and elicit excellent anti-angiogenicas well as anti-tumor activities in humans in monotherapy but also and above allin combination with other angiogenesis and tumor inhibiting agents.
