Multimeric death domain-containing receptor-5 (DR5) antibodies and uses thereof

1. An antibody comprising two, five, or six bivalent binding units or variants or fragments thereof,

wherein each binding unit comprises two IgA or IgM heavy chain constant regions or fragments thereof, each associated with an antibody antigen-binding domain,

wherein at least three of the antigen-binding domains of the antibody specifically and agonistically bind to the tumor necrosis factor (TNF) superfamily receptor protein death domain-containing receptor-5 (DR5) and can induce apoptosis of a cell expressing DR5, and

wherein the antibody can cross-link at least three DR5 proteins expressed on the surface of a cell, thereby inducing apoptosis of the cell.

2. The antibody of claim 1 , which induces DR5-mediated apoptosis in a DR5-expressing cell at a higher potency than an equivalent amount of a bivalent IgG antibody or fragment thereof, which also specifically binds to and agonizes DR5.

3. The antibody of claim 1 , wherein the two, five, or six binding units are human, humanized, or chimeric immunoglobulin binding units.

4. The antibody of claim 1 , wherein the cell is a cancer cell.

5. The antibody of claim 1 wherein at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, or twelve antigen-binding domains comprise a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and VL comprise six immunoglobulin complementarity determining regions HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the CDRs of an antibody comprising the VH and VL amino acid sequences SEQ ID NO: 1 and SEQ ID NO: 2; SEQ ID NO: 3 and SEQ ID NO: 4; SEQ ID NO: 5 and SEQ ID NO: 6; SEQ ID NO: 9 and SEQ ID NO: 10; SEQ ID NO: 11 and SEQ ID NO: 12; SEQ ID NO: 15 and SEQ ID NO: 16; SEQ ID NO: 21 and SEQ ID NO: 22; SEQ ID NO: 23 and SEQ ID NO: 24; SEQ ID NO: 25 and SEQ ID NO: 26; SEQ ID NO: 27 and SEQ ID NO: 28; SEQ ID NO: 29 and SEQ ID NO: 30; SEQ ID NO: 31 and SEQ ID NO: 32; SEQ ID NO: 33 and SEQ ID NO: 34; SEQ ID NO: 35 and SEQ ID NO: 36; SEQ ID NO: 37 and SEQ ID NO: 38; SEQ ID NO: 39 and SEQ ID NO: 40; SEQ ID NO: 41 and SEQ ID NO: 42; SEQ ID NO: 43 and SEQ ID NO: 44; SEQ ID NO: 45 and SEQ ID NO: 46; SEQ ID NO: 47 and SEQ ID NO: 48; SEQ ID NO: 49 and SEQ ID NO: 50; SEQ ID NO: 51 and SEQ ID NO: 52; SEQ ID NO: 53 and SEQ ID NO: 54; SEQ ID NO: 55 and SEQ ID NO: 56; SEQ ID NO: 82 and SEQ ID NO: 83; SEQ ID NO: 84 and SEQ ID NO: 85; SEQ ID NO: 86 and SEQ ID NO: 87; or SEQ ID NO: 88 and SEQ ID NO: 89 respectively; the VH or VL amino scid sequences contained within SEQ ID NO: 7 and SEQ ID NO:8; SEQ ID NO:13 and SEQ ID NO:14; SEQ ID NO:17 and SEQ ID NO:; or SEQ ID NO:19 and SEQ ID NO 20, respectively; or the ScFv sequence SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, or SEQ ID NO: 73.

6. The antibody of claim 5 wherein at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, or twelve antigen-binding domains comprise an antibody VH and a VL, wherein the VH and VL comprise amino acid sequences at least 90% identical to SEQ ID NO: 1 and SEQ ID NO: 2; SEQ ID NO: 3 and SEQ ID NO: 4; SEQ ID NO: 5 and SEQ ID NO: 6; SEQ ID NO: 9 and SEQ ID NO: 10; SEQ ID NO: 11 and SEQ ID NO: 12; SEQ ID NO: 15 and SEQ ID NO: 16; SEQ ID NO: 21 and SEQ ID NO: 22; SEQ ID NO: 23 and SEQ ID NO: 24; SEQ ID NO: 25 and SEQ ID NO: 26; SEQ ID NO: 27 and SEQ ID NO: 28; SEQ ID NO: 29 and SEQ ID NO: 30; SEQ ID NO: 31 and SEQ ID NO: 32; SEQ ID NO: 33 and SEQ ID NO: 34; SEQ ID NO: 35 and SEQ ID NO: 36; SEQ ID NO: 37 and SEQ ID NO: 38; SEQ ID NO: 39 and SEQ ID NO: 40; SEQ ID NO: 41 and SEQ ID NO: 42; SEQ ID NO: 43 and SEQ ID NO: 44; SEQ ID NO: 45 and SEQ ID NO: 46; SEQ ID NO: 47 and SEQ ID NO: 48; SEQ ID NO: 49 and SEQ ID NO: 50; SEQ ID NO: 51 and SEQ ID NO: 52; SEQ ID NO: 53 and SEQ ID NO: 54; SEQ ID NO: 55 and SEQ ID NO: 56; SEQ ID NO: 82 and SEQ ID NO: 83; SEQ ID NO: 84 and SEQ ID NO: 85; SEQ ID NO: 86 and SEQ ID NO: 87; or SEQ ID NO: 88 and SEQ ID NO: 89 respectively, wherein the VH or VL comprise amino acid sequences at least 90% identical to the VH and VL amino acid sequences contained within SEQ ID NO: 7 and SEQ ID NO:8; SEQ ID NO:13 and SEQ ID NO:14; SEQ ID NO:17 and SEQ ID NO:; or SEQ ID NO:19 and SEQ ID NO 20, respectively; or wherein the VH and VL are contained in an ScFv with an amino acid sequence at least 90% identical to SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, or SEQ ID NO: 73.

7. The antibody of claim 6 , wherein at least four, at least ten, or twelve antigen-binding domains comprise antibody VH and VL regions comprising the amino acid sequences SEQ ID NO: 1 and SEQ ID NO: 2, SEQ ID NO: 5 and SEQ ID NO: 6, SEQ ID NO: 84 and SEQ ID NO: 85, or SEQ ID NO: 88 and SEQ ID NO: 89, respectively.

8. The antibody of claim 1 , which is a dimeric IgA antibody comprising two bivalent IgA binding units or fragments thereof and a J chain or fragment or variant thereof, wherein each binding unit comprises two IgA heavy chain constant regions or fragments thereof each associated with an antibody antigen-binding domain.

9. The antibody of claim 8 , further comprising a secretory component, or fragment or variant thereof.

10. The antibody of claim 8 , wherein the IgA heavy chain constant regions or fragments thereof each comprise a Cα1 domain, a Cα2 domain, and a Cα3-tp domain.

11. The antibody of claim 8 , wherein the IgA heavy chain constant region is a human IgA constant region.

12. The antibody of claim 8 , wherein each binding unit comprises two IgA heavy chains each comprising a VH situated amino-terminal to the IgA constant region or fragment thereof, and two immunoglobulin light chains each comprising a VL situated amino-terminal to an immunoglobulin light chain constant region.

13. The antibody of claim 1 , which is a pentameric or a hexameric IgM antibody comprising five or six bivalent IgM binding units, respectively, wherein each binding unit comprises two IgM heavy chain constant regions or fragments thereof each associated with an antibody antigen-binding domain, and wherein the IgM heavy chain constant regions or fragments thereof each comprise a Cμ1 domain, a Cμ2 domain, a Cμ3 domain and a Cμ4-tp domain.

14. The antibody of claim 13 , wherein the antibody is pentameric, and further comprises a J chain, or fragment thereof, or variant thereof.

15. The antibody of claim 13 , wherein the IgM heavy chain constant region is a human IgM constant region.

16. The antibody of claim 13 , wherein each binding unit comprises two IgM heavy chains each comprising a VH situated amino-terminal to the IgM constant region or fragment thereof, and two immunoglobulin light chains each comprising a VL situated amino-terminal to an immunoglobulin light chain constant region.

17. A composition comprising the antibody of claim 1 .

18. A method of treating cancer comprising administering to a subject in need of treatment an effective amount of the antibody of claim 1 , wherein the cancer cells in the subject express DR5, and wherein the antibody can induce apoptosis of the cancer cells.

19. The method of claim 18 , wherein the antibody can induce greater apoptosis of cancer cells than of non-cancer cells.

20. The method of claim 19 , wherein the non-cancer cells are normal hepatocytes.

21. The method of claim 18 , wherein the subject is human.

22. The antibody of claim 14 , wherein ten antigen-binding domains comprise a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and VL comprise six immunoglobulin complementarity determining regions HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the CDRs of an antibody comprising the VH and VL amino acid sequences of SEQ ID NO: 5 and SEQ ID NO: 6, respectively.

23. The antibody of claim 22 , wherein ten antigen-binding domains comprise an antibody VH and a VL, wherein the VH and VL comprise amino acid sequences at least 90% identical to SEQ ID NO: 5 and SEQ ID NO: 6, respectively.

24. The antibody of claim 14 , wherein ten antigen-binding domains comprise a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and VL comprise six immunoglobulin complementarity determining regions HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3comprise the CDRs of an antibody comprising the VH and VL amino acid sequences contained within SEQ ID NO: 7 and SEQ ID NO: 8, respectively.

25. The antibody of claim 24 , wherein ten antigen-binding domains comprise an antibody VH and a VL, wherein the VH and VL comprise amino acid sequences at least 90% identical to the VH and VL sequences contained within SEQ ID NO: 7 and SEQ ID NO: 8, respectively.

26. The antibody of claim 13 , wherein the antibody is hexameric.

27. The antibody of claim 26 , wherein twelve antigen-binding domains comprise a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and VL comprise six immunoglobulin complementarity determining regions HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the CDRs of an antibody comprising the VH and VL amino acid sequences of SEQ ID NO: 5 and SEQ ID NO: 6, respectively.

28. The antibody of claim 27 , wherein twelve antigen-binding domains comprise an antibody VH and a VL, wherein the VH and VL comprise amino acid sequences at least 90% identical to SEQ ID NO: 5 and SEQ ID NO: 6, respectively.

29. The antibody of claim 26 , wherein twelve antigen-binding domains comprise a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and VL comprise six immunoglobulin complementarity determining regions HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the CDRs of an antibody comprising the VH and VL amino acid sequences contained within SEQ ID NO: 7 and SEQ ID NO: 8, respectively.

30. The antibody of claim 29 , wherein twelve antigen-binding domains comprise an antibody VH and a VL, wherein the VH and VL comprise amino acid sequences at least 90% identical to the VH and VL sequences contained within SEQ ID NO: 7 and SEQ ID NO: 8, respectively.