Antibodies that bind EGFR and ErbB3
The invention relates in one aspect to bispecific antibodies comprising a first antigen-binding site that binds EGFR and a second antigen-binding site that binds Erb B-3, wherein the antibody has a half maximal growth inhibitory concentration (IC50) of less than 200 pM for inhibiting EGFR and/or Erb B-3 ligand induced growth of Bx PC3 cells or Bx PC3-luc2 cells. Further described are method for producing the bispecific antibodies and means and methods for the treatment of subjects with the antibodies.
1. A bispecific antibody comprising a first variable domain comprising a first antigen-binding site that binds domain III of EGFR, wherein said first variable domain comprises a heavy chain variable region comprising a CDR1 comprising SEQ ID NO: 9, a CDR2 comprising SEQ ID NO: 11, and a CDR3 comprising SEQ ID NO: 13; and a second variable domain comprising a second antigen-binding site that binds domain III of Erb-B3, wherein said second variable domain comprises a heavy chain variable region comprising a CDR1 comprising SEQ ID NO: 90, a CDR2 comprising SEQ ID NO: 156, and a CDR3 comprising SEQ ID NO: 92, wherein said first and said second variable domains each comprise a common light chain comprising SEQ ID NO: 153, and wherein the heavy chain variable regions of the bispecific antibody are different from each other.
2. The bispecific antibody of claim 1 , wherein the antibody has a half maximal growth inhibitory concentration (IC50) for inhibiting EGFR and Erb-B3 ligand induced growth of BxPC3 cells (ATCC CRL 1687) or BxPC3-luc2 cells (Perkin Elmer 125058) of less than 100 pM.
3. The bispecific antibody of claim 1 , that can reduce a ligand-induced receptor function of Erb-B3 on an EGFR and Erb-B3 positive cell.
4. The bispecific antibody of claim 2 , wherein said ligand induced BxPC3 cells are EGFR and Erb-B3 ligand induced BxPC3 cells.
5. The bispecific antibody of claim 4 , wherein said BxPC3 cells are induced with a ligand comprising EGF, neuregulin1, or a combination thereof.
6. The bispecific antibody of claim 1 , wherein the antibody can reduce ligand-induced growth of an EGFR and Erb-B3 positive cell.
7. The bispecific antibody of claim 1 , wherein the affinity (KD) of said second antigen-binding site for an Erb-B3 positive cell is lower than or equal to 2.0 nM.
8. The bispecific antibody of claim 1 , comprising an antigen-binding site that binds at least one amino acid of domain III of Erb-B3 selected from the group consisting of R426 and surface-exposed amino acid residues that are located within 11.2 Å from R426 in the native Erb-B3 protein.
9. The bispecific antibody of claim 1 , wherein said first variable domain comprises a heavy chain variable region at least 90% identical to SEQ ID NO: 7.
10. The bispecific antibody of claim 1 , wherein said second variable domain comprises a heavy chain variable region at least 90% identical to SEQ ID NO: 120.
11. The bispecific antibody of claim 1 , which is afucosylated in order to enhance ADCC.
12. The bispecific antibody of claim 1 , comprising two different immunoglobulin heavy chains with compatible heterodimerization domains.
13. The bispecific antibody of claim 12 , wherein said compatible hetero-dimerization domains are compatible immunoglobulin heavy chain CH3 hetero-dimerization domains.
14. A pharmaceutical composition comprising the bispecific antibody of claim 10 .
15. The bispecific antibody of claim 1 , wherein the common light chain comprises a light chain variable region IGKV1-39.
16. The bispecific antibody of claim 15 , wherein the common light chain comprises a germ-line light chain variable region IGKV1-39.
17. The bispecific antibody of claim 1 , wherein said first variable domain comprises a heavy chain variable region comprising SEQ ID NO: 7.
18. The bispecific antibody of claim 17 , wherein said second variable domain comprises a heavy chain variable region comprising SEQ ID NO: 120.