B7-H3 binding molecules, antibody drug conjugates thereof and methods of use thereof

1. An anti B7-H3 antibody drug conjugate (B7-H3-ADC) that comprises the formula:

Ab-(LM) m -(D) n ,

wherein:

Ab is a humanized B7-H3 antibody or B7-H3 binding fragment thereof that binds to B7-H3 and comprises:

(i) a Variable Light Chain (VL) domain comprising the amino acid sequence of SEQ ID NO:20, and

(ii) a Variable Heavy Chain (VH) domain comprising the amino acid sequence of SEQ ID NO:21;

D is a cytotoxic drug moiety that comprises a duocarmycin cytotoxin;

LM comprises at least one bond or a Linker Molecule that covalently links Ab and D;

m is an integer between 0 and n and denotes the number of linker molecules of the B7-H3-ADC;

and

n is an integer between 1 and 10 and denotes the number of cytotoxic drug moieties covalently linked to the B7-H3-ADC molecule.

2. The B7-H3-ADC of claim 1 , wherein said Ab further comprises an Fc domain of a human IgG.

3. The B7-H3-ADC of claim 2 , wherein said human IgG is a human IgG1, IgG2, IgG3, or IgG4.

4. The B7-H3-ADC of claim 2 , wherein said Fc Domain is a variant Fc Domain that comprises:

(a) one or more amino acid modifications that reduces the affinity of the variant Fc Domain for an FcγR; and/or

(b) one or more amino acid modifications that enhances the serum half-life of the variant Fc Domain.

5. The B7-H3-ADC of claim 4 , wherein said modifications that reduce the affinity of the variant Fc Domain for an FcγR comprise the substitution of L234A; L235A; or L234A and L235A, wherein the numbering is that of the EU index as in Kabat.

6. The B7-H3-ADC of claim 4 , wherein said modifications that enhance the serum half-life of the variant Fc Domain comprise the substitution of M252Y; M252Y and S254T; M252Y and T256E; M252Y, S254T and T256E; or K288D and H435K, wherein the numbering is that of the EU index as in Kabat.

7. The B7-H3-ADC of claim 1 , wherein at least one of said LM moieties is a Linker Molecule.

8. The B7-H3-ADC of claim 7 , wherein said LM Linker Molecule comprises a cleavable linker.

9. The B7-H3-ADC of claim 8 , wherein said cleavable linker is a peptidic linker.

10. The B7-H3-ADC of claim 9 , wherein said peptidic linker is a valine-citrulline dipeptide linker.

11. The B7-H3-ADC of claim 8 , wherein said LM Linker Molecule further comprises a self-eliminating spacer between the cleavable linker and D.

12. The B7-H3-ADC of claim 11 , wherein said self-eliminating spacer comprises a para-aminobenzyloxycarbonyl moiety.

13. The B7-H3-ADC of claim 8 , wherein said Linker Molecule further comprises a maleimide linker moiety between the cleavable linker and Ab.

14. The B7-H3-ADC of claim 7 , wherein said conjugate comprises the formula:

Ab[V-(W) k -(X) 1 -A]-D, and LM comprises the formula:

[V-(W) k -(X) 1 -A],

wherein:

V is a cleavable linker,

(W) k -(X) 1 -A is an elongated, self-eliminating spacer system, that self-eliminates via a l,(4+2n)-elimination,

W and X are each a l,(4+2n) electronic cascade spacer, being the same or different,

A is either a spacer group of formula (Y) m , wherein Y is a l,(4+2n) electronic cascade spacer, or a group of formula U, being a cyclisation elimination spacer,

k, l and m are independently an integer of 0 (included) to 5 (included),

n is an integer of 0 (included) to 10 (included),

with the provisos that:

when A is (Y) m : then k+l+m≥1, and

if k+l+m=l, then n>l;

when A is U: then k+1≥1;

W, X, and Y are independently selected from compounds having the formula:

or the formula:

wherein:

Q is —R 5 C═CR 6 -, S, O, NR 5 , —R 5 C═N-, or —N═CR 5 —

P is NR 7 , O or S

a, b, and c are independently an integer of 0 (included) to 5 (included);

I, F and G are independently selected from compounds having the formula:

wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 independently represent H, C 1-6 alkyl, C 3-20 heterocyclyl, C 5-20 aryl, C 1-6 alkoxy, hydroxy (OH), amino (NH 2 ), mono-substituted amino (NR x H), di-substituted amino (NR x 1 R x 2 ), nitro (NO 2 ), halogen, CF 3 , CN, CONH 2 , SO 2 Me, CONHMe, cyclic C 1-5 alkylamino, imidazolyl, C 1-6 alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulphoxy (S(═O) 2 OH), sulphonate (S(═O) 2 OR x ), sulphonyl (S(═O) 2 R x ), sulphixy (S(═O)OH), sulphinate (S(═O)OR x ), sulphinyl (S(═O)R x ), phosphonooxy (OP(═O)(OH) 2 ), and phosphate (OP(═O)(OR x ) 2 ), where R x , R x 1 and R x 2 are independently selected from a C 1-6 alkyl group, a C 3-20 heterocyclyl group or a C 5-20 aryl group, two or more of the substituents R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , or R 9 optionally being connected to one another to form one or more aliphatic or aromatic cyclic structures;

U is selected from compounds having the formula:

wherein:

a, b and c are independently selected to be an integer of 0 or 1; provided that a+b+c=2 or 3;

R 1 and/or R 2 independently represent H, C 1-6 alkyl, the alkyl being optionally substituted with one or more of the following groups: hydroxy (OH), ether (OR x ), amino (NH 2 ), mono-substituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro (NO 2 ), halogen, CF 3 , CN, CONH 2 , SO 2 Me, CONHMe, cyclic C 1-5 alkylamino, imidazolyl, C 1-6 alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulphoxy (S(═O) 2 OH), sulphonate (S(═O) 2 OR x c), sulphonyl (S(═O) 2 R x ), sulphixy (S(═O)OH), sulphinate (S(═O)OR x ), sulphinyl (S(═O)R x ), phosphonooxy (OP(═O)(OH) 2 ), and phosphate (OP(═O)(OR x ) 2 ), where R x , R x 1 and R x 2 are selected from a C 1-6 alkyl group, a C 3-20 heterocyclyl group or a C 5-20 aryl group; and

R 3 , R 4 , R 5 , R 6 , R 7 and R 8 independently represent H, C 1-6 alkyl, C 3-20 heterocyclyl, C 5-20 aryl, C 1-6 alkoxy, hydroxy (OH), amino (NH 2 ), mono-substituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro (NO 2 ), halogen, CF 3 , CN, CONH 2 , SO 2 Me, CONHMe, cyclic C 1-5 alkylamino, imidazolyl, C 1-6 alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulphoxy (S(═O) 2 OH), sulphonate (S(═O) 2 OR x ), sulphonyl (S(═O) 2 R x ), sulphixy (S(═O)OH), sulphinate (S(═O)OR x ), sulphinyl (S(═O)R x ), phosphonooxy (OP(═O)(OH) 2 ), and phosphate (OP(═O)(OR x ) 2 ), where R x , R x 1 and R x 2 are selected from a C 1-6 alkyl group, a C 3-20 heterocyclyl group or a C 5-20 aryl group, and two or more of the substituents R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , or R 8 are optionally connected to one another to form one or more aliphatic or aromatic cyclic structures.

15. The B7-H3-ADC of claim 14 , wherein said LM linker molecule comprises:

(1) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl;

(2) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl;

(3) p-ammocinnamyloxycarbonyl;

(4) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl;

(5) p-amino-benzyloxycarbonyl-p-aminocinnamyloxycarbonyl;

(6) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl;

(7) p-aminophenylpentadienyloxycarbonyl;

(8) p-aminophenylpentadienyloxycarbonyl-p-arninocinnamyloxycarbonyl;

(9) p-aminophenylpentadienyloxycarbonyl-paminobenzyloxycarbonyl;

(10) p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyloxycarbonyl;

(11) p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino) carbonyl;

(12) p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino) carbonyl;

(13) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl;

(14) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl (methylamino)ethyl(methylamino)carbonyl;

(15) p-aminobenzyloxycarbonyl-p-aminocinnamyloxycarbonyl (methylamino)ethyl(methylamino)-carbonyl;

(16) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl (methylamino)ethyl(methylamino)carbonyl;

(17) p-aminobenzyloxycarbonyl-p-aminobenzyl;

(18) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyl;

(19) p-aminocinnamyl;

(20) p-aminocinnamyloxycarbonyl-p-aminobenzyl;

(21) p-aminobenzyloxycarbonyl-p-aminocinnamyl;

(22) p-amino-cinnamyloxycarbonyl-p-aminocinnamyl;

(23) p-aminophenylpentadienyl;

(24) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyl;

(25) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyl; or

(26) p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyl.

16. The B7-H3-ADC of claim 7 , wherein said LM Linker Molecule is conjugated to the side chain of an amino acid of a polypeptide chain of Ab and binds the Ab to a molecule of the cytotoxic drug moiety D.

17. The B7-H3-ADC of claim 1 , wherein said duocarmycin cytotoxin is selected from the group consisting of: duocarmycin A, duocarmycin B1, duocarmycin B2, duocarmycin C1, duocarmycin C2, duocarmycin D, duocarmycin SA, CC-1065, adozelesin, bizelesin, carzelesin (U-80244), seco-duocarmycin and spiro-duocarmycin (DUBA).

18. The B7-H3-ADC of claim 17 , wherein said duocarmycin cytotoxin is seco-duocarmycin.

19. The B7-H3-ADC of claim 1 , wherein said LM Linker Molecule is covalently linked to the Ab via reduced inter-chain disulfides.

20. A B7-H3 binding molecule, wherein said B7-H3 binding molecule is an antibody, a diabody, or an epitope-binding fragment thereof, which is capable of binding to B7-H3, wherein said B7-H3 binding molecule comprises:

(i) a humanized Variable Light Chain (VL) domain comprising the amino acid sequence of SEQ ID NO:20; and

(ii) a humanized Variable Heavy Chain (VH) domain comprising the amino acid sequence of SEQ ID NO:21.

21. The B7-H3 binding molecule of claim 20 , which further comprises an Fc Domain of a human IgG.

22. The B7-H3 binding molecule of claim 21 , wherein said human IgG is a human IgG1, IgG2, IgG3, or IgG4.

23. The B7-H3 binding molecule of claim 21 , wherein said Fc Domain is a variant Fc Domain that comprises:

(a) one or more amino acid modifications that reduces the affinity of the variant Fc Domain for an FcγR; and/or

(b) one or more amino acid modifications that enhances the serum half-life of the variant Fc Domain.

24. The B7-H3 binding molecule of claim 23 , wherein said modifications that reduce the affinity of the variant Fc Domain for an FcγR comprise the substitution of L234A; L235A; or L234A and L235A, wherein the numbering is that of the EU index as in Kabat.

25. The B7-H3 binding molecule of claim 23 , wherein said modifications that enhance the serum half-life of the variant Fc Domain comprise the substitution of M252Y; M252Y and S254T; M252Y and T256E; M252Y, S254T and T256E; or K288D and H435K, wherein the numbering is that of the EU index as in Kabat.

26. A pharmaceutical composition that comprises an effective amount of the B7-H3-ADC of claim 1 and a pharmaceutically acceptable carrier, excipient or diluent.

27. A pharmaceutical composition that comprises an effective amount of the B7-H3 binding molecule of claim 20 and a pharmaceutically acceptable carrier, excipient or diluent.

28. A method of treating a subject having a cancer associated with or characterized by the expression of B7-H3, comprising administering a therapeutically effective amount of an anti B7-H3 antibody drug conjugate (B7-H3-ADC) to the subject, wherein the B7-H3-ADC comprises the formula:

Ab-(LM) m -(D) n ,

wherein:

Ab is a humanized B7-H3 antibody or B7-H3 binding fragment thereof that binds to B7-H3 and comprises:

(i) a Variable Light Chain (VL) domain comprising the amino acid sequence of SEQ ID NO:20, and

(ii) a Variable Heavy Chain (VH) domain comprising the amino acid sequence of SEQ ID NO:21;

D is a cytotoxic drug moiety comprising a duocarmycin cytotoxin;

LM comprises at least one bond or a Linker Molecule that covalently links Ab and D;

m is an integer between 0 and n and denotes the number of Linker Molecules of the B7-H3-ADC;

and

n is an integer between 1 and 10 and denotes the number of cytotoxic drug moieties covalently linked to the B7-H3-ADC molecule.

29. The method of claim 28 , wherein said B7-H3-ADC is in a pharmaceutical composition.

30. The method of claim 28 , wherein said cancer is selected from the group consisting of: an adrenal gland tumor, an AIDS-associated cancer, an alveolar soft part sarcoma, an astrocytic tumor, an adrenal cancer, a bladder cancer, a bone cancer, a brain and spinal cord cancer, a metastatic brain tumor, a B-cell cancer, a breast cancer, a carotid body tumors, a cervical cancer, a chondrosarcoma, a chordoma, a chromophobe renal cell carcinoma, a clear cell carcinoma, a colon cancer, a colorectal cancer, a cutaneous benign fibrous histiocytoma, a desmoplastic small round cell tumor, an ependymoma, a Ewing's tumor, an extraskeletal myxoid chondrosarcoma, a fibrogenesis imperfecta ossium, a fibrous dysplasia of the bone, a gallbladder or bile duct cancer, a gastric cancer, a gestational trophoblastic disease, a germ cell tumor, a head and neck cancer, a glioblastoma, a hematological malignancy, a hepatocellular carcinoma, an islet cell tumor, a Kaposi's Sarcoma, a kidney cancer, a leukemia, an acute myeloid leukemia, a chronic lymphocytic leukemia, a chronic myeloid leukemia, a hairy cell leukemia, a liposarcoma/malignant lipomatous tumor, a liver cancer, a lymphoma, a Burkett's lymphoma, a diffuse large B cell lymphoma, a follicular lymphoma, a mantle cell lymphoma, a marginal zone lymphoma, a non-Hodgkin's lymphoma, a small lymphocytic lymphoma, a lung cancer, a non-small-cell lung cancer (NSCLC), a medulloblastoma, a melanoma, a meningioma, a mesothelioma pharyngeal cancer, a multiple endocrine neoplasia, a multiple myeloma, a myelodysplastic syndrome, a neuroblastoma, a neuroendocrine tumors, an ovarian cancer, a pancreatic cancer, a papillary thyroid carcinoma, a parathyroid tumor, a pediatric cancer, a peripheral nerve sheath tumor, a phaeochromocytoma, a pituitary tumor, a prostate cancer, a posterious uveal melanoma, a renal cell carcinoma, a renal metastatic cancer, a rhabdoid tumor, a rhabdomysarcoma, a sarcoma, a skin cancer, a small round blue cell tumor of childhood, a soft-tissue sarcoma, a squamous cell cancer, a squamous cell cancer of the head and neck (SCCHN), a stomach cancer, a synovial sarcoma, a testicular cancer, a thymic carcinoma, a thymoma, a thyroid cancer, a thyroid metastatic cancer, and a uterine cancer.

31. A method of treating a subject having a cancer associated with or characterized by the expression of B7-H3, comprising administering a therapeutically effective amount of said B7-H3 binding molecule of claim 20 to the subject.

32. The method of claim 31 , wherein said B7-H3 binding molecule is in a pharmaceutical composition.

33. The method of claim 31 , wherein said cancer is selected is selected from the group consisting of: an adrenal gland tumor, an AIDS-associated cancer, an alveolar soft part sarcoma, an astrocytic tumor, an adrenal cancer, a bladder cancer, a bone cancer, a brain and spinal cord cancer, a metastatic brain tumor, a B-cell cancer, a breast cancer, a carotid body tumors, a cervical cancer, a chondrosarcoma, a chordoma, a chromophobe renal cell carcinoma, a clear cell carcinoma, a colon cancer, a colorectal cancer, a cutaneous benign fibrous histiocytoma, a desmoplastic small round cell tumor, an ependymoma, a Ewing's tumor, an extraskeletal myxoid chondrosarcoma, a fibrogenesis imperfecta ossium, a fibrous dysplasia of the bone, a gallbladder or bile duct cancer, a gastric cancer, a gestational trophoblastic disease, a germ cell tumor, a head and neck cancer, a glioblastoma, a hematological malignancy, a hepatocellular carcinoma, an islet cell tumor, a Kaposi's Sarcoma, a kidney cancer, a leukemia, an acute myeloid leukemia, a chronic lymphocytic leukemia, a chronic myeloid leukemia, a hairy cell leukemia, a liposarcoma/malignant lipomatous tumor, a liver cancer, a lymphoma, a Burkett's lymphoma, a diffuse large B cell lymphoma, a follicular lymphoma, a mantle cell lymphoma, a marginal zone lymphoma, a non-Hodgkin's lymphoma, a small lymphocytic lymphoma, a lung cancer, a non-small-cell lung cancer (NSCLC), a medulloblastoma, a melanoma, a meningioma, a mesothelioma pharyngeal cancer, a multiple endocrine neoplasia, a multiple myeloma, a myelodysplastic syndrome, a neuroblastoma, a neuroendocrine tumors, an ovarian cancer, a pancreatic cancer, a papillary thyroid carcinoma, a parathyroid tumor, a pediatric cancer, a peripheral nerve sheath tumor, a phaeochromocytoma, a pituitary tumor, a prostate cancer, a posterious uveal melanoma, a renal cell carcinoma, a renal metastatic cancer, a rhabdoid tumor, a rhabdomysarcoma, a sarcoma, a skin cancer, a small round blue cell tumor of childhood, a soft-tissue sarcoma, a squamous cell cancer, a squamous cell cancer of the head and neck (SCCHN), a stomach cancer, a synovial sarcoma, a testicular cancer, a thymic carcinoma, a thymoma, a thyroid cancer, a thyroid metastatic cancer, and a uterine cancer.

34. The B7-H3-ADC of claim 1 , wherein:

said Ab comprises:

(i) a light chain comprising the Variable Light Chain (VL) domain comprising the amino acid sequence of SEQ ID NO:20 and a CL Kappa Domain of SEQ ID NO:1; and

(ii) a heavy chain comprising the Variable Heavy Chain (VH) domain comprising the amino acid sequence of SEQ ID NO:21, a CH1 Domain of SEQ ID NO:3, a Hinge Domain of SEQ ID NO:7 and a Fc Domain comprising a CH2-CH3 Domain of SEQ ID NO:12;

said D comprises seco-duocarmycin; and

said LM comprises a Linker Molecule comprising a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

35. The method of claim 28 , wherein:

said Ab comprises:

(i) a light chain comprising the Variable Light Chain (VL) domain comprising the amino acid sequence of SEQ ID NO:20 and a CL Kappa Domain of SEQ ID NO:1; and

(ii) a heavy chain comprising the Variable Heavy Chain (VH) domain comprising the amino acid sequence of SEQ ID NO:21, a CH1 Domain of SEQ ID NO:3, a Hinge Domain of SEQ ID NO:7 and a Fc Domain comprising a CH2-CH3 Domain of SEQ ID NO:12;

said D comprises seco-duocarmycin; and

said LM comprises a Linker Molecule comprising a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

36. The method of claim 30 , wherein said cancer is selected from the group consisting of: an acute myeloid leukemia, a non-small cell lung cancer, a neuroblastoma, a squamous cell cancer of the head and neck, a prostate cancer and a thyroid metastatic cancer.

37. The method of claim 33 , wherein said cancer is selected from the group consisting of: an acute myeloid leukemia, a non-small cell lung cancer, a neuroblastoma, a squamous cell cancer of the head and neck, a prostate cancer and a thyroid metastatic cancer.

38. The method of claim 36 , wherein the cancer is a prostate cancer.

39. The method of claim 37 , wherein the cancer is a prostate cancer.