Integrin v 3 targeted therapy for Kaposi’s sarcoma with an in vitro evolved antibody

Using a phage display strategy that preserves only the original CDR3 sequences of light and heavy chain while subjecting the remaining sequence to selection from naive human V gene libraries, we previously reported the full humanization of mouse monoclonal antibody (mAb) LM609 directed to human integrin v 3. Here we further improved the affinity of humanized LM609 using a phage display strategy for sequential and parallel optimization of three complementarity determining regions (LCDR1, HCDR1, and HCDR3) of the antibody molecule. The evolved Fab, designated JC-7U, had an affinity of 150 pM and was converted into IgG1 using a new mammalian expression vector (Fig. 1).