title: Anti-EGFR biparatopic-SEED antibody has enhanced combination-activity in a single molecule.
abstract: Certain combinations of non-competitive anti-EGFR antibodies have been reported to produce new effects on cells compared to either antibody used separately. New and enhanced combination-activity includes increased inhibition of signaling, increased receptor internalization and degradation, reduced proliferation of tumor cell lines and induction of complement-dependent cytotoxicity (CDC) effector function. To test requirements and mechanisms to elicit enhanced combination-activity with different EGFR binding domains, we created an anti-EGFR biparatopic antibody. A biparatopic antibody interacts through two different antigen-binding sites to a single antigen. A heterodimeric antibody with one binding domain derived from the C225 antibody and one binding domain derived from the humanized 425 (hu425) antibody was built on the strand-exchange engineered domain (SEED) scaffold. This anti-EGFR biparatopic-SEED antibody was compared to parental antibodies used alone and in combination, and to the corresponding monovalent anti-EGFR-SEED antibodies used alone or in combination. We found that the anti-EGFR biparatopic-SEED had enhanced activity, similar to the combination of the two parental antibodies. Combinations of monovalent anti-EGFR-SEED antibodies did not produce enhanced effectiveness in cellular assays. Our results show that the anti-EGFR biparatopic antibody created using the SEED scaffold has enhanced combination-activity in a single molecule. Furthermore, these data suggest that the potential to cross-link the two different epitopes is an important requirement in the mechanism of enhanced combination-activity.
authors.affiliation: EMD Serono Research Institute, Inc., 45A Middlesex Turnpike, Billerica, MA 01821, USA.
authors.forename: Christie
authors.initials: C
authors.lastname: Kelton
authors.forename: John S
authors.initials: JS
authors.lastname: Wesolowski
authors.forename: Maria
authors.initials: M
authors.lastname: Soloviev
authors.forename: Rene
authors.initials: R
authors.lastname: Schweickhardt
authors.forename: David
authors.initials: D
authors.lastname: Fischer
authors.forename: Emmi
authors.initials: E
authors.lastname: Kurosawa
authors.forename: Sean D
authors.initials: SD
authors.lastname: McKenna
authors.forename: Alec W
authors.initials: AW
authors.lastname: Gross
mesh_terms: D018033:Antibodies, Bispecific / Q000737:chemistry / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry / Q000276:immunology*; D001666:Binding Sites, Antibody; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D000068818:Cetuximab; D000939:Epitopes / Q000276:immunology; D066246:ErbB Receptors / Q000276:immunology*; D006801:Humans; D017434:Protein Structure, Tertiary
chemical_list: D018033:Antibodies, Bispecific; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000939:Epitopes; D066246:ErbB Receptors; C520777:matuzumab; D000068818:Cetuximab