Bispecific antibody which binds to CD40 and EpCAM

1. A bispecific antibody, comprising an antigen-binding domain that binds to CD40 and an antigen-binding domain that binds to an epithelial cell adhesion molecule (EpCAM),

wherein the antigen-binding domain that binds to CD40 comprises a heavy chain variable region (VH) and a light chain variable region (VL) of an antibody (anti-CD40 antibody) that specifically binds to CD40, wherein the VL comprises complementarity determining regions (CDRS) 1 to 3 comprising the amino acid sequences represented by SEQ ID NOS: 23 to 25, respectively, and wherein the VH comprises CDRS l to 3 comprising the amino acid sequences represented by SEQ ID NOS: 33 to 35, respectively, and

wherein the antigen-binding domain that binds to EpCAM comprises VH and VL of an antibody (anti-EpCAM antibody) that specifically binds to EpCAM, wherein the VL comprises CDRS 1 to 3 comprising the amino acid sequences represented by SEQ ID NOS: 23 to 25, respectively, and wherein the VH comprises CDRS 1 to 3 comprising the amino acid sequenceS represented by SEQ ID NOS: 57 to 59, respectively.

2. The bispecific antibody according to claim 1 , which bivalently binds to each of CD40 and EpCAM.

3. The bispecific antibody according to claim 1 , wherein the VL is VL comprising the amino acid sequence represented by SEQ ID NO: 22.

4. The bispecific antibody according to claim 1 , wherein the anti-CD40 antibody is an anti-CD40 antibody comprising VH comprising the amino acid sequence represented by SEQ ID NO: 32.

5. The bispecific antibody according to claim 1 , wherein the anti-EpCAM antibody is an anti-EpCAM antibody comprising VH comprising the amino acid sequence represented by SEQ ID NO: 56.

6. The bispecific antibody according to claim 1 , wherein the antibody is an antibody fragment selected from the group consisting of a Fab-type bispecific antibody fragment and a F(ab′)2-type bispecific antibody fragment.

7. The bispecific antibody according to claim 1 , which has a CD40 agonistic activity.

8. The bispecific antibody according to claim 1 , which does not exhibit a CD40 agonistic activity in the absence of a cell that expresses EpCAM, but exhibits the CD40 agonistic activity only in the presence of a cell that expresses EpCAM.

9. The bispecific antibody according to claim 1 ,

which has two identical heavy chains comprising a polypeptide represented by a formula of VH1-X-VH2-Y in order from the N terminus

{wherein VH1 represents VH of a first antibody,

VH2 represents VH of a second antibody,

X and Y each represents a polypeptide comprising CH1 of the antibody (wherein at least one of X and Y further comprises a hinge region of the antibody)} and

four light chains comprising the same VL, and

wherein one of the first antibody and the second antibody is the anti-CD40 antibody, and the other is the anti-EpCAM antibody.

10. The bispecific antibody according to claim 9 , wherein the light chain is a κ chain.

11. The bispecific antibody according to claim 9 , wherein X in the formula is a polypeptide composed of CH1 of human IgG, and Y is a polypeptide composed of CH1, a hinge region, CH2, and CH3 of human IgG.

12. The bispecific antibody according to claim 9 , wherein X in the formula is a polypeptide comprising the amino acid sequence represented by SEQ ID NO: 75, and Y is a polypeptide comprising the amino acid sequence represented by SEQ ID NO: 77.

13. The bispecific antibody according to claim 9 , wherein X in the formula is a polypeptide comprising CH1, a hinge region, CH2, and CH3 of human IgG, and Y is a polypeptide comprising CH1 of human IgG.

14. The bispecific antibody according to claim 9 , wherein X in the formula is a polypeptide comprising the amino acid sequence represented by SEQ ID NO: 77, and Y is a polypeptide comprising the amino acid sequence represented by SEQ ID NO: 75.

15. The bispecific antibody according to claim 9 , wherein the first antibody is the anti-CD40 antibody, and the second antibody is the anti-EpCAM antibody.

16. The bispecific antibody according to claim 9 , wherein the first antibody is the anti-EpCAM antibody, and the second antibody is the anti-CD40 antibody.

17. The bispecific antibody according to claim 9 , which bivalently binds to each of CD40 and EpCAM, wherein X in the formula is a polypeptide comprising the amino acid sequence represented by SEQ ID NO: 77, and Y is a polypeptide comprising the amino acid sequence represented by SEQ ID NO: 75, wherein the first antibody is the anti-CD40 antibody, and the second antibody is the anti-EpCAM antibody, wherein the VL is VL comprising the amino acid sequence represented by SEQ ID NO: 22, wherein the anti-CD40 antibody is an anti-CD40 antibody comprising VH comprising the amino acid sequence represented by SEQ ID NO: 32, wherein the anti-EpCAM antibody is an anti-EpCAM antibody comprising VH comprising the amino acid sequence represented by SEQ ID NO: 56.

18. The bispecific antibody according to claim 9 , which bivalently binds to each of CD40 and EpCAM, wherein X in the formula is a polypeptide comprising CH1, a hinge region, CH2, and CH3 of human IgG, and Y is a polypeptide comprising CH1 of human IgG, wherein the first antibody is the anti-CD40 antibody, and the second antibody is the anti-EpCAM antibody, wherein the VL is VL comprising the amino acid sequence represented by SEQ ID NO: 22, wherein the anti-CD40 antibody is an anti-CD40 antibody comprising VH comprising the amino acid sequence represented by SEQ ID NO: 32, wherein the anti-EpCAM antibody is an anti-EpCAM antibody comprising VH comprising the amino acid sequence represented by SEQ ID NO: 56.