Figure 8.

(A) Binding of the monoclonal bivalent antibody mAb3 (EC50 = 5.9 nM) and Fabs thereof (mAb3 digested with GingisKHAN™, and a purified mAb3 Fab obtained from an in-solution papain digest) to cell surface-associated carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) on the human MKN-45 cell line, as measured by flow cytometry. Negative controls included an anti-human fibroblast activation protein α (anti-FAP) and the GingisKHAN™ protease alone. (B and C) Binding to CEACAM5 on the human MKN-45 cell line of the intact (bivalent CEACAM5-binding) and GingisKHAN™-digested (monovalent CEACAM5-binding) bispecific (B) mAb4 (intact: EC50 = 6.8 nM) and (C) mAb5 derived 2+1 CrossMabs (intact/digested: EC50 = 9.3 nM/10.1, respectively), as measured by flow cytometry. Negative controls with the GingisKHAN™ protease alone were included.