A, BLI of monovalent oa Fab SEED (AG) antibodies to soluble c-MET ECD, including a schematic antibody representation. B10 and F06 are parental and B10v5 and CS06 are the affinity-matured variants thereof. Affinities for c-MET are given as the dissociation equilibrium constant (KD) (nm). B, BLI of monovalent oa scFv SEED (GA) antibodies to soluble EGFR ECD, including a schematic antibody representation. Variants of humanized cetuximab with low (225-L), medium (225-M), and high (225-H) affinity as well as humanized matuzumab (mAb 425) were analyzed. Affinities for EGFR are given in nm. C, simultaneous binding of soluble recombinant c-MET and EGFR by bsAb B10v5 × 225-H analyzed by BLI. Biotinylated c-MET ECD is captured to streptavidin octet biosensors. bsAb and EGFR-ECD are associated in two steps employing buffer and non-related isotype control (anti-HEL). Shown is a schematic representation of bispecific EGFR × c-MET antibody using the SEED technology.