Oncofetal antigen binding proteins and related compositions and methods
The present disclosure relates to protein molecules that specifically bind to 5T4 and/or 4-1BB. The molecules may have at least one humanized 5T4-binding or 4-1BB-binding domain. Such molecules are useful for the treatment of cancer. The protein molecule binding to 5T4 or 4-1BB may have a second binding domain that binds to another target. The molecules may bind both 5T4-expressing cells and a cell-surface molecule expressed by an effector cell to enhance effector cell activation, proliferation, survival and/or effector-cell mediated cytotoxicity. The disclosure also provides pharmaceutical compositions comprising the 5T4-binding or 4-1BB-binding polypeptide or protein molecules, nucleic acid molecules encoding these polypeptides and methods of making and using these molecules.
1. A multispecific polypeptide comprising a first scFv domain and a second scFv domain, wherein the first and second scFv domains are linked together by a binding domain linker or a binding domain linker and an immunoglobulin Fc domain, wherein the immunoglobulin Fc domain comprises a hinge region and an immunoglobulin constant region; and wherein the second scFv domain specifically binds to human 4-1BB and comprises:
(i) an immunoglobulin heavy chain variable region comprising an HCDR1 amino acid sequence of SEQ ID NO: 2, an HCDR2 amino acid sequence of SEQ ID NO: 4, and an HCDR3 amino acid sequence of SEQ ID NO: 6; and
(ii) an immunoglobulin light chain variable region comprising an LCDR1 amino acid sequence of SEQ ID NO: 8, an LCDR2 amino acid sequence of SEQ ID NO: 10, and an LCDR3 amino acid sequence of SEQ ID NO: 12.
2. The multispecific polypeptide of claim 1 , wherein the multispecific polypeptide comprises, from amino-terminus to carboxyl-terminus, (i) the first scFv domain, (ii) a binding domain linker, and (iii) the second scFv domain.
3. The multispecific polypeptide of claim 1 , wherein the multispecific polypeptide comprises, from amino-terminus to carboxyl-terminus, (i) the second scFv domain, (ii) a binding domain linker, and (iii) the first scFv domain.
4. The multispecific polypeptide of claim 1 , wherein the multispecific polypeptide comprises, from amino-terminus to carboxyl-terminus, (i) the first scFv domain, (ii) a hinge region, (iii) an immunoglobulin constant region, (iv) a binding domain linker, and (v) the second scFv domain.
5. The multispecific polypeptide of claim 1 , wherein the binding domain linker comprises an amino acid sequence selected from SEQ ID NOs: 85-108.
6. The multispecific polypeptide of claim 1 , wherein the second scFv domain comprises a heavy chain variable region comprising SEQ ID NO:14 and a light chain variable region selected from the group consisting of SEQ ID NO: 16 and 22.
7. The multi specific polypeptide of claim 1 , wherein the first scFv domain specifically binds to human 5T4 and comprises:
(i) an immunoglobulin heavy chain variable region comprising an HCDR1 amino acid sequence of SEQ ID NO: 30, an HCDR2 amino acid sequence of SEQ ID NO: 32, and an HCDR3 amino acid sequence of SEQ ID NO: 34; and
(ii) an immunoglobulin light chain variable region comprising an LCDR1 amino acid sequence of SEQ ID NO: 42, an LCDR2 amino acid sequence of SEQ ID NO: 10, and an LCDR3 amino acid sequence of SEQ ID NO: 36.
8. The multispecific polypeptide of claim 7 , wherein the first scFv domain specifically binds to human 5T4 and comprises the amino acid sequence selected from the group consisting of SEQ ID NOs: 120, 122, and 124.
9. The multi specific polypeptide of claim 7 , wherein the polypeptide comprises an amino acid sequence having at least 90% sequence identity to a sequence selected from the group consisting of SEQ ID NOs: 138, 140, 172, and 174.
10. The multispecific polypeptide of claim 7 , wherein the first scFv domain is capable of binding 5T4 with a kD value of less than 50 nM.
11. The multispecific polypeptide of claim 1 , wherein the first scFv domain binds to an extracellular domain of 5T4 and wherein the second scFv domain binds to an extracellular domain of 4-1BB.
12. The multispecific polypeptide of claim 1 , wherein binding of the multispecific polypeptide to an effector cell results in enhanced effector cell activation.
13. The multispecific polypeptide of claim 1 , wherein the light chain variable region and/or the heavy chain variable region of the first scFv domain or the 4-1BB-binding domain is humanized.
14. The multispecific polypeptide of claim 1 , wherein the first scFv domain specifically binds to human 5T4 and comprises:
(i) an immunoglobulin heavy chain variable region comprising an HCDR1 amino acid sequence of SEQ ID NOs: 30, an HCDR2 amino acid sequence of SEQ ID NO: 32, and an HCDR3 amino acid sequence of SEQ ID NO: 34; and
(ii) an immunoglobulin light chain variable region comprising an LCDR1 amino acid sequence of SEQ ID NO: 8, an LCDR2 amino acid sequence of SEQ ID NOs: 10, and an LCDR3 amino acid sequence of SEQ ID NOs: 36.
15. The multispecific polypeptide of claim 1 , wherein the first scFv domain specifically binds to human 5T4 and comprises:
(i) an immunoglobulin heavy chain variable region comprising an HCDR1 amino acid sequence of SEQ ID NOs: 30, an HCDR2 amino acid sequence of SEQ ID NO: 32, and an HCDR3 amino acid sequence of SEQ ID NO: 34; and
(ii) an immunoglobulin light chain variable region comprising an LCDR1 amino acid sequence of SEQ ID NO: 42, an LCDR2 amino acid sequence of SEQ ID NOs: 10, and an LCDR3 amino acid sequence of SEQ ID NOs: 36.
16. The multispecific polypeptide of claim 1 , wherein the first scFv domain specifically binds to human 5T4 and comprises:
(i) an immunoglobulin heavy chain variable region comprising an HCDR1 amino acid sequence of SEQ ID NOs: 52, an HCDR2 amino acid sequence of SEQ ID NO: 32, and an HCDR3 amino acid sequence of SEQ ID NO: 34; and
(ii) an immunoglobulin light chain variable region comprising an LCDR1 amino acid sequence of SEQ ID NO: 42, an LCDR2 amino acid sequence of SEQ ID NOs: 10, and an LCDR3 amino acid sequence of SEQ ID NOs: 36.
17. The multispecific polypeptide of claim 1 , wherein the first scFv domain specifically binds to human 5T4 and comprises:
(i) an immunoglobulin heavy chain variable region comprising an HCDR1 amino acid sequence of SEQ ID NOs: 60, an HCDR2 amino acid sequence of SEQ ID NO: 62, and an HCDR3 amino acid sequence of SEQ ID NO: 34; and
(ii) an immunoglobulin light chain variable region comprising an LCDR1 amino acid sequence of SEQ ID NO: 54, an LCDR2 amino acid sequence of SEQ ID NOs: 10, and an LCDR3 amino acid sequence of SEQ ID NOs: 36.
18. A method for treating a cancer in a subject, wherein said cancer is characterized by expression of 5T4, the method comprising administering to the subject a therapeutically effective amount of the multispecific polypeptide of claim 1 .
19. The method of claim 18 , wherein the cancer is breast cancer, pancreatic cancer, ovarian cancer, non-small cell lung cancer, mesothelioma, chronic lymphocytic leukemia (CLL), mantle cell leukemia (MCL), acute lymphoblastic leukemia (ALL), squamous cell carcinoma, melanoma, adrenal cancer, bladder cancer, cervical cancer, renal cancer, gastric cancer, prostate cancer, thyroid cancer, liver cancer, uterine cancer, sarcoma, carcinoma, or head and neck cancer.