Method of treating cancer by administering an antibody which binds to 5T4

1 . A method of treating esophageal cancer, Non-small Cell Lung Cancer (NSCLC) or Squamous Cell Carcinoma of the Head and Neck (SCCHN), the method comprising administering to a subject in need thereof an antibody which binds to 5T4, wherein the antibody comprises a heavy chain and a light chain, and wherein the antibody comprises:

a) a heavy chain variable region (VH) comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 6, 7 and 8, respectively, and a light chain variable region (VL) comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 10, the sequence AAS, and SEQ ID NO: 11, respectively,

b) a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 13, 14 and 15, respectively; and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 17, the sequence DAS, and SEQ ID NO:18, respectively,

c) a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 20, 21 and 22, respectively; and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 24, the sequence DAS, and SEQ ID NO: 25, respectively,

d) a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 27, 28 and 29, respectively; and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 31, the sequence DVS, and SEQ ID NO: 32, respectively,

e) a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 34, 35 and 36, respectively; and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 38, the sequence DAS, and SEQ ID NO: 39, respectively,

f) a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 41, 42 and 43, respectively, and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 45, the sequence DAS, and SEQ ID NO: 46, respectively, or

g) a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 48, 49 and 50, respectively, and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 52, the sequence DAS, and SEQ ID NO: 53, respectively.

2 . The method of claim 1 , wherein:

(a) the esophageal cancer is an adenocarcinoma, a squamous cell carcinoma, an adenosquamous carcinoma, a Siewert type I adenocarcinoma of the esophagogastric junction (EGJ) or a HER2/neu-positive cancer;

(b) the NSCLC is an adenocarcinoma, a squamous cell carcinoma or an adenosquamous carcinoma; or

(c) the SCCHN is human papillomavirus (HPV)-positive SCCHN or HPV-associated SCCHN, HPV-negative SCCHN, squamous cell carcinoma of the oral cavity, squamous cell carcinoma of the oropharynx, squamous cell carcinoma of the paranasal sinuses, squamous cell carcinoma of the nasal cavity, squamous cell carcinoma of the hypopharynx or squamous cell carcinoma of the larynx.

3 . The method of claim 1 , wherein the esophageal cancer or NSCLC is advanced, locally advanced or metastatic.

4 . The method of claim 1 , wherein the subject with esophageal cancer:

(a) has received at least one prior line of systemic treatment for advanced esophageal cancer;

(b) has progressed on or after at least one prior line of systemic treatment for advanced esophageal cancer; or

(c) has received prior treatment with HER2/neu targeted therapy.

5 . The method of claim 1 , wherein the subject with NSCLC:

(a) has received at least one prior line of systemic treatment for locally advanced, advanced or metastatic NSCLC;

(b) has experienced progression of the NSCLC on or after prior systemic treatment for locally advanced or metastatic NSCLC; or

(c) has received prior therapy with a platinum-based regimen, a tyrosine kinase inhibitor or anti-PD-1/PD-L1 therapy.

6 . The method of claim 5 , wherein:

(a) the platinum-based regimen comprises tubulin inhibition in combination with platin and 5-fluorouracil (5-FU) or irinotecan; or

(b) the tyrosine kinase inhibitor is selected from the group consisting of an inhibitor of Anaplastic lymphoma kinase, an inhibitor of proto-oncogene tyrosine-protein kinase ROS1 and an inhibitor of the epidermal growth factor receptor (EGFR).

7 . The method of claim 1 , wherein the subject with SCCHN has received prior therapy selected from the group consisting of therapy with a platinum-based regimen, an anti-PD-1/PD-L1 therapy, anti-EGFR therapy and 5-fluorouracil.

8 . The method of claim 7 , wherein:

(a) the platinum-based regimen comprises cisplatin or carboplatin;

(b) the anti-PD-1/PD-L1 PD-1 therapy is selected from the group consisting of nivolumab, genolimzumab, atezolizumab, durvalumab, avelumab, pembrolizumab, genolimzumab, nivolumab, cemiplimab and tislelizumab; or

(c) the anti-EGFR therapy is selected from the group consisting of erlotinib, osimertinib, gefintinib, olmutinib, nazartinib, avitinib, cetuximab and panitumumab.

9 . The method of claim 1 , wherein the antibody binds to the same epitope as, or competes for binding to 5T4 with, a reference antibody selected from the group consisting of:

a) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 5 and a VL region comprising the sequence set forth in SEQ ID NO: 9,

b) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 12 and a VL region comprising the sequence set forth in SEQ ID NO: 16,

c) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 19 and a VL region comprising the sequence set forth in SEQ ID NO: 23,

d) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 26 and a VL region comprising the sequence set forth in SEQ ID NO: 30,

e) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 33 and a VL region comprising the sequence set forth in SEQ ID NO: 37,

f) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 40 and a VL region comprising the sequence set forth in SEQ ID NO: 44; and

g) an antibody comprising a VH region comprising the sequence set forth in SEQ ID NO: 47 and a VL region comprising the sequence set forth in SEQ ID NO: 51.

10 . The method of claim 1 , wherein the antibody binds to an epitope on human 5T4 comprising:

(a) the amino acid residues R73, Y92 and R94;

(b) the amino acid residues S69, R73, Y92 and R94; or

(c) the amino acid residues R73, T74, Y92, R94 and N95;

wherein the numbering of each amino acid residue refers to its position in SEQ ID NO: 1.

11 . The method of claim 1 , wherein:

(a) one or more of the following additional amino acid residues of 5T4 is/are involved binding of the antigen binding region capable of binding to 5T4: L89, F111, L117, F138, L144, D148 and N152;

(b) the antibody binds to an epitope on human 5T4 within which amino acid residues R73, Y92 and R94 are directly involved in binding the antibody, and wherein one or more of amino acid residues F111, F138, L144 and D148 are indirectly involved in said binding;

(c) the antibody binds to an epitope on human 5T4 within which amino acid residues S69, R73, Y92 and R94 are directly involved in binding the antibody, and wherein one or more of amino acid residues F111, F138 and D148 are indirectly involved in said binding; or

(d) the antibody binds to an epitope on human 5T4 within which amino acid residues R73, T74, Y92, R94 and N95 are directly involved in binding the antibody, and wherein amino acid residue F138 is indirectly involved in said binding;

wherein the numbering of each amino acid residue refers to its position in SEQ ID NO: 1.

12 . The method of claim 1 , wherein:

(a) there is loss of binding or binding is reduced by the antibody if any one or more of the amino acid residues R73, Y92 and R94 is/are substituted with alanine;

(b) there is loss of binding or binding is reduced if any one or more of the amino acid residues S69, R73, Y92 and R94 is/are substituted with alanine;

(c) there is loss of binding or binding is reduced if any one or more of the amino acid residues R73, T74, Y92, R94 and N95 is/are substituted with alanine; the numbering of each amino acid residue referring to its position in SEQ ID NO: 1;

(d) there is loss of binding or binding is reduced if any one or more of the amino acid residues: L89, F111, L117, F138, L144, D148 and N152 is/are substituted with alanine; the numbering of each amino acid residue referring to its position in SEQ ID NO: 1;

(e) there is loss of binding or binding is reduced if any one or more of the amino acid residues R73, Y92, R94, F111, F138, L144 and D148 is/are substituted with alanine; the numbering of each amino acid residue referring to its position in SEQ ID NO: 1;

(f) there is loss of binding or binding is reduced if any one or more of the amino acid residues S69, R73, Y92, R94, F111, F138 and D148 is/are substituted with alanine; or

(g) there is loss of binding or binding is reduced if any one or more of the amino acid residues R73, T74, Y92, R94, N95 and F138 is/are substituted with alanine;

wherein the numbering of each amino acid residue referring to its position in SEQ ID NO: 1.

13 . The method of claim 1 , wherein the antibody comprises:

a) a heavy chain variable region (VH) comprising the sequence of SEQ ID NO: 5, and a light chain variable region (VL) comprising the sequence of SEQ ID NO: 9,

b) a VH comprising the sequence of SEQ ID NO: 12, and a VL comprising the sequence of SEQ ID NO: 16,

c) a VH comprising the sequence of SEQ ID NO: 19, and a VL comprising the sequence of SEQ ID NO: 23,

d) a VH comprising the sequence of SEQ ID NO: 26, and a VL comprising the sequence of SEQ ID NO: 30,

e) a VH comprising the sequence of SEQ ID NO: 33, and a VL comprising the sequence of SEQ ID NO: 37,

f) a VH comprising the sequence of SEQ ID NO: 40, and a VL comprising the sequence of SEQ ID NO: 44; or

g) a VH comprising the sequence of SEQ ID NO: 47, and a VL comprising the sequence of SEQ ID NO: 51.

14 . The method of claim 1 , wherein the antibody comprises a first and a second heavy chain, each of said first heavy chain and second heavy chain comprises at least a hinge region, a CH2 and CH3 region, wherein in said first heavy chain at least one of the amino acids in the positions corresponding to positions selected from the group consisting of T366, L368, K370, D399, F405, Y407 and K409 in a human IgG1 heavy chain has been substituted, and in said second heavy chain at least one of the amino acids in the positions corresponding to a position selected from the group consisting of T366, L368, K370, D399, F405, Y407, and K409 in a human IgG1 heavy chain has been substituted, wherein said substitutions of said first heavy chain and said second heavy chain are not in the same positions, and wherein the amino acid positions are numbered according to EU numbering.

15 . The method of claim 1 , wherein the antibody comprises a first and a second heavy chain, and wherein in both the first heavy chain and the second heavy chain, the amino acid residues at the positions corresponding to positions L234 and L235 in a human IgG1 heavy chain according to EU numbering are F and E, respectively, and/or the amino acid residue at the position corresponding to position D265 in a human IgG1 heavy chain according to EU numbering is A.

16 . The method of claim 1 , wherein the antibody comprises a first and a second heavy chain, and the constant region of said first heavy chain or second heavy chain comprises an amino acid sequence selected from the group consisting of:

a) the sequence set forth in SEQ ID NO: 89,

b) a subsequence of the sequence in a), wherein 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 consecutive amino acids has/have deleted, starting from the N-terminus or C-terminus of the sequence defined in a); and

c) a sequence having at the most 5 substitutions compared to the amino acid sequence defined in a) or b).

17 . The method of claim 1 , wherein said antibody comprises a first heavy chain and a second heavy chain, and wherein the first heavy chain and the second heavy chain are modified so that the antibody induces Fc-mediated effector function to a lesser extent relative to an identical non-modified antibody.

18 . The method of claim 1 , wherein said antibody comprises a kappa (κ) light chain or a lambda (λ) light chain.

19 . The method of claim 18 , wherein:

(I) the kappa (κ) light chain comprises an amino acid sequence selected from the group consisting of:

a) the sequence set forth in SEQ ID NO: 95,

b) a subsequence of the sequence in a), wherein 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 consecutive amino acids has/have deleted, starting from the N-terminus or C-terminus of the sequence defined in a); and

c) a sequence having at the most 5 substitutions compared to the amino acid sequence defined in a) or b); or

(II) the lambda (λ) light chain comprises an amino acid sequence selected from the group consisting of:

a) the sequence set forth in SEQ ID NO: 96,

b) a subsequence of the sequence in a), wherein 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 consecutive amino acids has/have deleted, starting from the N-terminus or C-terminus of the sequence defined in a); and

c) a sequence having at the most 5 substitutions compared to the amino acid sequence defined in a) or b).

20 . The method of claim 1 , wherein the antibody comprises a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 6, 7 and 8 , respectively, and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 10, the sequence AAS, and SEQ ID NO: 11, respectively.

21 . The method of claim 1 , wherein the antibody comprises a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 41, 42 and 43, respectively, and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 45, the sequence DAS, and SEQ ID NO: 46, respectively.

22 . The method of claim 1 , wherein the antibody comprises a VH comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NOs: 48, 49 and 50, respectively, and a VL comprising the CDR1, CDR2, and CDR3 sequences of SEQ ID NO: 52, the sequence DAS, and SEQ ID NO: 53, respectively.

23 . The method of claim 13 , wherein the antibody comprises a VH comprising the sequence of SEQ ID NO: 5, and a VL comprising the sequence of SEQ ID NO: 9.

24 . The method of claim 13 , wherein the antibody comprises a VH comprising the sequence of SEQ ID NO: 40, and a VL comprising the sequence of SEQ ID NO: 44.

25 . The method of claim 13 , wherein the antibody comprises a VH comprising the sequence of SEQ ID NO: 47, and a VL comprising the sequence of SEQ ID NO: 51.