Antigen-binding protein that specifically binds to CT45

Abstract

The present invention relates to an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, the CT45 antigenic peptide comprising or consisting of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a first polypeptide comprising a variable domain VA comprising complementarity determining regions CDRa1, CDRa2 and CDRa3, and a variable domain V comprising CDRb1, CDRb2 and CDRb3. B and a second polypeptide comprising the nucleic acid encoding the antigen binding protein. Nucleic acids encoding the antigen binding protein, vectors comprising the nucleic acid, recombinant cells expressing the antigen binding protein and pharmaceutical compositions comprising the antigen binding protein are also provided. The invention further provides antigen binding proteins for use in medicine and methods of producing the antigen binding proteins.

Description

[Technical field]

[0001] The present invention relates to antigen binding proteins against antigens derived from CT45 protein, in particular antigen binding proteins that specifically bind to tumor-expressed CT45-IP antigen peptides in complex with MHC. The antigen binding proteins are provided for use in the diagnosis, treatment and prevention of CT45-expressing proliferative diseases. Nucleic acids encoding the antigen binding proteins, vectors containing the nucleic acids, recombinant cells expressing the antigen binding proteins and pharmaceutical compositions containing the antigen binding proteins are further provided. [Background technology]

[0002] T cell-based immunotherapy targets peptide epitopes derived from tumor-associated or tumor-specific proteins presented by molecules of the major histocompatibility complex (MHC). These tumor-associated antigens (TAA) can be peptides derived from all protein classes, such as enzymes, receptors, transcription factors, etc., that are specifically expressed by and / or upregulated in cancer cells. Unlike CAR-T therapy and current antibody-based approaches, which can only target cell surface proteins, T cell-based immunotherapy allows the targeting of otherwise inaccessible intracellular proteins, thus greatly increasing the number and diversity of targets.

[0003] "Cancer Testis Antigen 45 (CT45)" is a multigene family of nine nearly identical genes (typically named A1, A2, A3, A5, A6, A7, A8, A9 and A10) in direct tandem repeats. All nine CT45 genes encode a putative protein of 189 amino acids. CT45A1 protein, normally expressed only in testicular germ cells, has been shown to be expressed in lung, breast and ovarian cancers [Chen, YT et al., Int.J Cancer 124 (2009): 2893-2898]. CT45A1 has also been shown to be associated with poor prognosis and poor outcome in multiple myeloma [Andrade, VC et al., Exp.Hematol. 37 (2009): 446-449]. CT45A1 was described as a gene that upregulates epithelial-mesenchymal transition (EMT) and metastasis genes to promote EMT and tumor dissemination. In addition, CT45A1 was described as involved in the initiation or maintenance of cancer stem-like cells to promote tumorigenesis and malignant progression [Yang, P. et al., Curr.Pharm.Des 21 (2015): 1292-1300]. CT45A1 overexpression in breast cancer models was shown to result in upregulation of various oncogenic and metastatic genes, constitutive activation of ERK and CREB signaling pathways, and increased tumor formation, invasion, and metastasis. Silencing of CT45A1 was shown to decrease cancer cell migration and invasion. CT45A2 has been shown to be a novel spliced ​​MLL fusion partner in pediatric patients with de novo biphenotypic acute leukemia and may therefore be relevant to leukemogenesis [Cerveira, N. et al., BMC.Cancer 10 (2010): 518]. CT45 has been shown to be frequently expressed in both cancer cell lines and lung cancer specimens [Chen, L. et al., Cancer Res 65 (2005): 5599-5606]. CT45 has limited or no expression in normal adult tissues, making it an attractive target for immunotherapeutic intervention.

[0004] The development of new anti-cancer drugs that specifically recognize intracellular targets in complex with MHC is one of the most important keys to solving difficult-to-treat cancers, especially solid tumors. Therefore, there is a need to develop new anti-cancer drugs that specifically target intracellular proteins that are highly specific to cancer cells. The present invention addresses that need by providing novel antigen binding proteins that specifically bind to the CT45 antigen peptide comprising the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and methods of using such molecules in the treatment of proliferative diseases, especially cancer. The antigen binding proteins of the present invention are characterized by high stability, high affinity, high functional avidity, high efficacy and high specificity. Compared to previously described antigen binding proteins that bind to the CT45 antigen peptide, the antigen binding proteins of the present invention exhibit at least one of increased stability, increased affinity, increased functional avidity, increased efficacy and / or increased specificity. The antigen binding proteins of the present invention are therefore both more effective and safer than the antigen binding proteins of the prior art. Summary of the Invention [Problem to be solved by the invention]

[0005] [Means for solving the problem]

[0006] In a first aspect, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, the CT45 antigenic peptide comprising or consisting of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprising a variable domain V comprising the complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. B and a second polypeptide comprising CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 80, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 82, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 85, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 87; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 71, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 72, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 77; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 63, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 68; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 90, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 92, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 96; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO:2, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO:4, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO:8, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:10; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 53, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 55, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 60; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 133, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 136; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 99, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 101, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 104; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 14, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 16, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 19, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 21; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 107, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 109, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 114; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 125, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 127, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 130; or CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 117, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 119, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 122; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 35, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 38, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 40; CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 26, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 29, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 31; or CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 43, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 45, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 48, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 50; The antigen binding protein comprises said CDRa1, CDRa3, CDRb1 and CDRb3 sequences, which do not have more than one, two or three amino acid mutations. Concerning antigen-binding proteins.

[0007] In a second aspect, the present invention relates to a nucleic acid comprising a sequence encoding an antigen-binding protein according to the first aspect of the invention.

[0008] In a third aspect, the present invention relates to a vector comprising the nucleic acid of the second aspect of the invention.

[0009] In a fourth aspect, the present invention relates to a host cell comprising the antigen binding protein of the first aspect of the invention, the nucleic acid of the second aspect of the invention, or the vector of the third aspect of the invention.

[0010] In a fifth aspect, the present invention relates to a pharmaceutical composition comprising an antigen binding protein according to the first aspect of the invention, a nucleic acid according to the second aspect of the invention, a vector according to the third aspect of the invention or a host cell according to the fourth aspect of the invention and optionally a pharma- ceutical acceptable carrier.

[0011] In a sixth aspect, the present invention relates to a method of producing an antigen binding protein of the first aspect of the invention, the method comprising the steps of: (a) providing a host cell; (b) providing a genetic construct comprising a coding sequence encoding any of the antigen binding proteins of the first aspect of the invention; (c) introducing the genetic construct into the host cell; and (d) expressing the genetic construct by the host cell.

[0012] In a seventh aspect, the present invention relates to an antigen-binding protein of the first aspect of the invention, a nucleic acid of the second aspect of the invention, a vector of the third aspect of the invention, a host cell of the fourth aspect of the invention or a pharmaceutical composition of the fourth aspect of the invention for use in medicine.

[0013] In an eighth aspect, the present invention relates to an antigen binding protein of the first aspect of the invention, a nucleic acid of the second aspect of the invention, a vector of the third aspect of the invention, a host cell of the fourth aspect of the invention or a pharmaceutical composition of the fourth aspect of the invention for use in a method for the treatment and / or diagnosis of a proliferative disease.

[0014] In a ninth aspect, the present invention relates to an in vitro method of detecting cancer in a biological sample comprising the steps of: (a) contacting the biological sample with an antigen binding protein of the first aspect of the invention; and (b) detecting binding of the antigen binding protein to the biological sample.

[0015] definition A "CT45 antigenic peptide" comprises or consists of the amino acid sequence KIFEMLEGV (SEQ ID NO: 138) corresponding to amino acids 143-151 of CT45A1 (SEQ ID NO: 749 accessible under Uniprot accession number Q5HYN5), CT45A2, CT45A3, CT45A5, CT45A6, CT45A7, CT45A8, CT45A9 and CT45A10. This CT45 antigenic peptide is also referred to herein as "CT45 peptide" or "CT45-IP". CT45 antigenic peptides are peptide epitopes derived from tumor-associated or tumor-specific proteins and are presented on the cell surface by molecules of the major histocompatibility complex (MHC), preferably MHC I. More specifically, CT45 antigenic peptides are presented on the cell surface in complex with an HLA protein, preferably HLA-A, more preferably HLA-A*02. In the most preferred embodiment, the CT45 antigenic peptide consists of the amino acid sequence KIFEMLEGV (SEQ ID NO: 138). If the CT45 antigenic peptide contains additional amino acids in addition to the amino acid sequence KIFEMLEGV (SEQ ID NO: 138), the total length of the CT45 antigenic peptide is preferably not more than 30 or 20 amino acids, more preferably not more than 15 amino acids, and even more preferably not more than 12 amino acids. If the CT45 antigenic peptide contains additional amino acids in addition to SEQ ID NO: 138, the amino acids of SEQ ID NO: 138 are preferably located in the peptide-binding groove of the MHC protein when the antigenic peptide is in a complex with the MHC protein. Those skilled in the art are aware that the antigenic peptide presented on MHC I is usually 12 amino acids or less. However, when the peptide is artificially loaded onto the MHC protein, it is reasonable that the antigenic peptide artificially loaded onto MHC I may be longer than 12 amino acids. The term "antigen" or "target antigen" as used herein refers to a molecule or part of a molecule or complex capable of being bound by an antigen binding site, said antigen binding site being present in an antigen binding protein, preferably an antigen binding protein of the invention.The antigen relevant to the present invention is a CT45 antigenic peptide, more specifically a CT45 antigenic peptide in complex with an MHC protein, such as an HLA protein, such as HLA-A*02.

[0016] "CT45-IP:MHC complex-presenting cells" herein refers to cells that present CT45-IP in a complex with an MHC molecule on their surface. In a preferred embodiment, the CT45-IP:MHC complex-presenting cells are tumor cells, and the tumor is preferably a cancer as defined herein below in the "Methods of Treatment and Use" section. In the context of the present invention, the CT45-IP:MHC complex is over-presented on the cell surface of the CT45-IP:MHC complex-presenting cells, compared to the level of said complex on the surface of cells in normal (healthy) tissue (also referred to as "healthy cells") or on the surface of control cells loaded with a different antigen-presenting peptide or no peptide. "Over-presented" means that the CT45-IP:MHC complex is present at a level at least 2-fold, preferably 5-fold to 10-fold, of the level present in the healthy tissue or control cells.

[0017] Examples of "CT45-IP:MHC complex-presenting cells" are CT45-IP-loaded T2 cells or NCIH1703 or A375 tumor cells used in the examples of this application.

[0018] A "domain" can be any region of a protein, is generally defined on the basis of sequence homology, and often refers to a particular structural or functional entity.

[0019] The term "immunoglobulin (Ig) domain" in the context of the present invention refers to a protein domain consisting of a two-layer sandwich of seven to nine antiparallel β-strands arranged in two β-sheets with a Greek key topology. Ig domains are perhaps the most frequently used "building blocks" in naturally occurring proteins. Proteins containing Ig domains are incorporated into the immunoglobulin superfamily, including, for example, antibodies, T-cell receptors (TCRs), and cell adhesion molecules. Examples of Ig domains are the variable and constant domains of antibodies and TCRs.

[0020] "V" related to the present invention A " refers to a TCR variable domain comprising TCR-derived CDR sequences and TCR-derived framework sequences. The CDR and framework sequences are derived from the TCR α chain (V α ), β-chain (V β ), γ chain (V γ ) or δ chain (V δ ), preferably the variable domain of V α The V related to the present invention may be derived from A The CDR and framework sequences of the domains do not necessarily have to be from the same TCR chain. In some embodiments, the CDRs from one TCR variable domain (the TCR variable domain of a donor TCR) are grafted onto another TCR variable domain (the TCR variable domain of an acceptor TCR). For example, the donor TCR is a TCR variable domain encoded by TRAV5 and TRAJ17. α and the acceptor TCR may comprise a V encoded by TRAV14 and TRAJ33. A When CDR1, CDR3 and optionally CDR2 of a donor TCR are grafted onto an acceptor TCR, although the CDRs are present in the context of different framework regions, the affinity and specificity for the antigenic peptide conferred by the CDRs does not change, i.e. after grafting the variable domains of the acceptor TCR have substantially the same affinity and specificity for the antigenic peptide as the variable domains of the donor TCR.

[0021] "V" related to the present invention B " refers to a variable domain comprising TCR-derived CDR sequences and TCR-derived framework sequences. The CDR and framework sequences are derived from the TCR α chain (V α ), β-chain (V β ), γ chain (V γ ) or δ chain (V δ ), preferably the variable domain of V β The V related to the present invention may be derived from B The CDR and framework sequences of the domains do not necessarily have to be from the same TCR. In some embodiments, the CDRs from one TCR variable domain (the TCR variable domain of a donor TCR) are grafted onto another TCR variable domain (the TCR variable domain of an acceptor TCR). For example, the donor TCR is a TCR variable domain encoded by TRBV2 and TRBJ2-1. v and the acceptor TCR may comprise a V encoded by TRBV27 and TRBJ1-5. A When CDR1, CDR3 and optionally CDR2 of a donor TCR are grafted onto an acceptor TCR, although the CDRs are present in the context of different framework regions, the affinity and specificity for the antigenic peptide conferred by the CDRs does not change, i.e. after grafting the variable domains of the acceptor TCR have substantially the same affinity and specificity for the antigenic peptide as the variable domains of the donor TCR.

[0022] CDRs may be swapped / grafted between different alpha variable domains or different beta variable domains, as well as grafted from a TCR alpha variable domain to a TCR beta, gamma or delta variable domain, or from a TCR beta variable domain to a TCR alpha, gamma or delta variable domain.

[0023] V related to this invention α refers to the variable domain of the TCR α chain.

[0024] V related to this invention β refers to the variable domain of the TCR β chain.

[0025] Vγ in the context of the present invention refers to the variable domain of the TCR γ chain.

[0026] V related to this invention δ refers to the variable domain of the TCR delta chain.

[0027] V related to this invention L refers to the variable domain of an antibody light chain.

[0028] V related to this invention H refers to the variable domain of an antibody heavy chain.

[0029] C related to the present invention L refers to the constant domain of an antibody light chain.

[0030] C related to the present invention H1 , C H2 , and C H3 refers to the constant domain of an antibody heavy chain, specifically an IgG heavy chain.

[0031] The term "epitope", also known as antigenic determinant, refers to a portion of an antigen that is recognized by the immune system. As used herein, the term epitope includes the terms "structural epitope" and "functional epitope". A "structural epitope" is an amino acid of an antigen (e.g., a peptide-MHC complex) that is covered by an antigen-binding protein when bound to the antigen. Typically, all amino acids of an antigen that are within 5 Å of any atom of an amino acid of the antigen-binding protein are considered to be covered. Structural epitopes of antigens can be determined by methods known in the art, including X-ray crystallography or NMR analysis. Structural epitopes of antibodies typically include 20-30 amino acids. Structural epitopes of TCRs typically include 20-30 amino acids. A "functional epitope" as defined herein is a subset of amino acids that form a structural epitope, including amino acids of an antigen that are important for forming an interface with an antigen-binding protein of the invention or a functional fragment thereof, either directly by forming non-covalent interactions (e.g., H-bonds, salt bridges, aromatic stacking, or hydrophobic interactions) or indirectly by stabilizing the antigen-binding conformation, as determined, for example, by mutational scanning. In the context of the present invention, a functional epitope is also referred to as a "binding motif". Typically, a functional epitope of an antibody-bound antigen comprises 4-6 amino acids. Typically, a functional epitope of a peptide-MHC complex comprises 2-6 or 7 amino acids of the peptide and 2-7 amino acids of the MHC molecule. Since peptides presented by MHC I typically have 8-10 amino acids, only a subset of the amino acids of each given peptide are part of the functional epitope of the peptide-MHC complex. An epitope (particularly a functional epitope to which an antigen binding protein of the invention binds) comprises or consists of amino acids of an antigen that are required for formation of a binding interface.

[0032] The "major histocompatibility complex" (MHC) is a set of cell surface proteins essential for the adaptive immune system to recognize foreign molecules in vertebrates, thus determining histocompatibility. The main function of MHC molecules is to bind antigens from pathogens and present them on the cell surface for recognition by appropriate T cells. Human MHC is also called HLA (human leukocyte antigen) complex (or simply HLA). Thus, in a preferred embodiment, the MHC is HLA. The MHC gene family is divided into three subgroups: class I, class II, and class III. Complexes of peptides and MHC class I molecules (MHC I) are typically recognized by CD8 positive T cells (CD8+ T cells) bearing the appropriate T cell receptor (TCR), and complexes of peptides and MHC class II molecules (MHC II) are typically recognized by CD4 positive helper T cells (CD4+ T cells) bearing the appropriate TCR. CD4 and CD8 typically function as co-receptors for TCR in binding to MHC I and MHC II, respectively. In some exceptional cases, peptide-MHC I complexes are recognized by CD8-negative (especially CD8-negative, CD4-positive) T cells [Soto et al., 2013, Cancer Immunol Immunother. 2013 Feb;62(2): 359-369]. CD8-positive and CD4-positive T cell responses jointly contribute synergistically to antitumor effects, so the identification and characterization of tumor-associated antigens and corresponding T cell receptors are important in the development of cancer immunotherapy, such as vaccines and cell therapy. The HLA-A gene is located on the short arm of chromosome 6 and encodes the large α chain that is a component of HLA-A. Mutations in the HLA-A α chain are important for HLA function. This mutation promotes genetic diversity in the population. Each HLA has a different affinity for peptides of a certain structure, so a large number of HLA types means a large number of antigens that are "presented" on the cell surface.The MHC class I HLA protein relevant to the present disclosure may be an HLA-A protein, an HLA-B protein, or an HLA-C protein, preferably an HLA-A protein, for example HLA-A*02. In an MHC class I dependent immune response, a peptide must not only be capable of binding to a certain MHC class I molecule expressed by a tumor cell, but must then be recognized by T cells bearing a specific T cell receptor (TCR).

[0033] An "antigenic peptide in a complex with an MHC protein" herein refers to an antigenic peptide that is non-covalently bound to an MHC molecule. Specifically, the antigenic peptide is located in the "peptide binding groove" formed by the MHC molecule. A complex of an MHC molecule and an antigenic peptide is also referred to herein as a "peptide-MHC complex" or "pMHC complex." In the case of the CT45 antigenic peptide, this complex is also referred to as a "CT45 antigenic peptide-MHC complex" or "CT45-IP:MHC complex."

[0034] "HLA-A*02" indicates a particular HLA allele, where the letter A indicates the allele, and the prefix "*02 prefix" indicates the A2 serotype.

[0035] The term "antigen-binding protein" as used herein refers to a polypeptide or a complex of two or more polypeptides that comprises an antigen-binding site capable of specifically binding to an antigen, particularly an antigenic peptide in a complex with MHC. As used in the context of this specification, the term antigen-binding protein includes antigen-binding proteins in a number of different formats, as described below, including soluble antigen-binding proteins, membrane-bound antigen-binding proteins, monovalent, bivalent and multivalent antigen-binding proteins, monospecific, bispecific and multispecific antigen-binding proteins, single-chain antigen-binding proteins, and antigen-binding proteins that comprise two or more chains, fusion proteins and chimeric proteins. The term includes antigen-binding proteins that have the overall structure of a TCR, an antibody or a chimeric antigen receptor (CAR). The antigen-binding proteins of the present invention are characterized by a variable domain V that comprises TCR-derived CDRs, particularly TCR-derived CDRa1, CDRa3 and, where appropriate, CDRa2. A and a variable domain V comprising TCR-derived CDRb1, CDRb3, and optionally CDRb2. B In certain embodiments, V A Domain-wide and / or V B The entire domain is derived from the TCR and therefore is a TCR alpha, beta, gamma or delta variable domain (V α , V β , V γ or V δ In a preferred embodiment, the antigen binding protein is a TCR. In some embodiments, the antigen binding protein of the present invention is a V A and V B , and further, V A or V B Such antigen-binding proteins may be referred to as "fusion proteins". Examples of additional domains contained in the antigen-binding proteins of the invention that are "fusion proteins" are listed below. When the antigen-binding protein is a bispecific or multispecific antigen-binding protein, it may include an additional domain fused directly or indirectly to the V, as defined herein. A and VB In addition to the V, at least one further variable domain, preferably two variable domains, and optionally a constant domain, the variable and / or constant domains may be derived from an antibody or a TCR. The antigen-binding protein therefore has two different antigen-binding sites (one is V A and V B and one formed by at least one additional, preferably two, variable domains) and can specifically bind to two different antigens simultaneously, e.g. as known in bispecific antibodies. In some embodiments, the antigen binding protein comprises a TCR-derived V A and V B and additionally two antibody-derived variable domains, in particular V L and V H Such constructs containing both antibody and TCR elements represent a hybrid format and may be referred to as, for example, a "bispecific TCR-antibody fusion protein". In such bispecific fusion proteins, the variable domains may be arranged in various orientations. Techniques for producing such bispecific fusion proteins are known to those skilled in the art, and therefore, the skilled artisan can easily use the variable domains defined herein to generate and produce bispecific antigen binding proteins in various formats. The skilled artisan is fully capable of selecting a suitable linker to ensure folding in the desired conformation.

[0036] "At least one," as used herein, refers to one or more of a specified object, e.g., 1, 2, 3, 4, 5, or 6, or more of a specified object. For example, at least one binding site, as used herein, refers to 1, 2, 3, 4, 5, or 6, or more of a specified binding site.

[0037] The term "bispecific" in the context of the present invention refers to an antigen-binding protein that has at least two valencies and binding specificities for two different antigens, and therefore contains at least two antigen-binding sites. The term "valency" refers to the number of binding sites of an antigen-binding protein, for example, a bivalent antigen-binding protein relates to an antigen-binding protein that has two binding sites. The binding sites may bind to the same or different targets, i.e., a bivalent antigen-binding protein may be monospecific (i.e., binds to one target) or bispecific (i.e., binds to two different targets). The antigen-binding molecules of the present invention contain at least one antigen-binding site that comprises a CDR derived from a TCR. In a preferred embodiment, the antigen-binding molecules of the present invention contain at least one antigen-binding site derived from a TCR.

[0038] Preferably, the antigen binding protein is a TCR. The term "TCR" as used herein includes both native and engineered TCRs.

[0039] "Native TCR" refers to a wild-type TCR that can be isolated from nature. Native TCRs are heterodimeric cell surface proteins of the immunoglobulin superfamily that associate with invariant proteins of the CD3 complex, which are involved in mediating signal transduction. Native heterodimeric TCRs exist in αβ and γδ forms, which are structurally similar but differ in location and possibly function. Native, full-length αβ heterodimeric TCRs consist of an α chain and a β chain. The α chain contains a variable region (V region) encoded by the TRAV gene, a joining region (J region) encoded by the TRAJ gene, and a constant region (C region) encoded by the TRAC gene. The β chain contains a variable region (V region) encoded by the TRBV gene, a joining region (J region) encoded by the TRBJ gene, and a constant region (C region) encoded by the TRBC gene, and usually contains a short diversity region (D region) encoded by the TRBD gene between the V and J regions, but this D region is often considered to be part of the J region [Lefranc, (2001), Curr Protoc Immunol Appendix 1: Appendix 10]. The genes encoding the different α and β chain variable, joining, and constant regions are referred to by unique numbers in the IMGT nomenclature [Folch and Lefranc, (2000), Exp Clin Immunogenet 17(1): 42-54;Scaviner and Lefranc, (2000), Exp Clin Immunogenet 17(2): 83-96;LeFranc and LeFranc, (2001), "T cell Receptor Factsbook", Academic Press]. Further information regarding TCR genes can be found in the international ImMunoGeneTics information system®, Lefranc MP et al., (Nucleic Acids Res. 2015 Jan;43(Database issue):D413-22; and http: / / www.imgt.org / ).

[0040] At the protein level, the TCR α, β, γ and δ chains comprise two immunoglobulin domains, a variable domain and a constant domain. The variable domain corresponds to the V(D)J region. The constant domain corresponds to the C region. The constant domain is the membrane proximal domain and in the context of the present invention also comprises the transmembrane (TM) domain and the short cytoplasmic tail. Each of the constant and variable domains contains an intrachain disulfide bond. The variable domain (V in αβ TCR) α and V β and V in γδ TCRs γ and V δ ) contain highly polymorphic loops that encompass the complementarity determining regions (CDRs).

[0041] Each TCR variable domain comprises three "TCR complementarity determining regions" (CDRs) embedded in framework sequences, one hypervariable region designated CDR3. In the context of the present invention, CDRa1, CDRa2 and CDRa3 denote the α chain CDRs, and CDRb1, CDRb2 and CDRb3 denote the β chain CDRs. The sequences encoding CDRa1 and CDRa2 are comprised in TRAV, the sequences encoding CDRa3 are comprised in TRAV and TRAJ, the sequences encoding CDRb1 and CDRb2 are comprised in TRBV and the sequences encoding CDRb3 are comprised in TRBV, TRBD and TRBJ. In the TCR, the CDR1 and CDR3 amino acid residues contact the antigen peptide, and the CDR2 amino acid residues primarily contact the HLA molecule (Stadinski et al., J Immunol. 2014 June 15; 192(12): 6071-6082; Cole et al., J Biol Chem. 2014 Jan 10;289(2):628-38). Thus, the antigen specificity of the TCR is defined by the CDR3 and CDR1 sequences. The CDR2 sequence is not necessary to determine antigen specificity, but may play a role in the overall affinity of the TCR for the peptide:MHC complex.

[0042] "TCR framework region" (FR) refers to the amino acid sequence flanked by the CDRs, i.e., the portion of the variable domain that is conserved to some degree among different TCRs. The α, β, γ, and δ chain variable domains each have four FRs, referred to herein as FR1-a, FR2-a, FR3-a, FR4-a (for the α or γ chain), and FR1-b, FR2-b, FR3-b, FR4-b (for the β or δ chain), respectively. Thus, an α or γ chain variable domain can be described as (FR1-a)-(CDRa1)-(FR2-a)-(CDRa2)-(FR3-a)-(CDRa3)-(FR4-a), and a β or δ chain variable domain can be described as (FR1-b)-(CDRb1)-(FR2-b)-(CDRb2)-(FR3-b)-(CDRb3)-(FR4-b). In the context of the present invention, the CDR / FR sequences in an α, β, γ or δ chain variable domain are determined based on the IMGT definition (Lefranc et al., Dev. Comp. Immunol., 2003, 27(1):55-77; www.imgt.org). Thus, the CDR / FR amino acid positions when related to a TCR or a TCR-derived domain are indicated according to said IMGT definition. Preferably, the CDR / FR sequences in the variable domain V α The IMGT positions of the CDR / FR amino acid positions of the variable domain V are assigned similarly to the IMGT numbering of TRAV24*01. β The IMGT positions of the CDR / FR amino acid positions are assigned similarly to the IMGT numbering of TRBV12-3*01.

[0043] An "engineered TCR" may be a protein which closely resembles a native TCR but contains minor modifications in the variable and / or constant domains, e.g. a humanized TCR, or a TCR with improved heterodimerization or expression levels, or may be a single chain TCR, a soluble TCR, a monovalent, bivalent or polyvalent TCR, a monospecific, bispecific or multispecific TCR, a functional fragment of a TCR, or a fusion or chimeric protein comprising a functional fragment of a TCR.

[0044] A "functional fragment of a TCR" refers to a fragment of a TCR that retains or substantially retains the affinity, functional avidity and / or specificity of the parent TCR from which it is derived for a target antigen. A "parent TCR" in this context refers to the full-length TCR from which the functional fragment is derived. Since binding to a target antigen peptide is defined by the CDR1 and CDR3 sequences, and binding to a target antigen peptide-MHC complex is defined by the CDR1, CDR2 and CDR3, an antigen binding protein comprising the CDR1 and CDR3 and optionally the CDR2 sequence of the parent TCR retains the affinity, functional avidity and / or specificity of the parent TCR for the target antigen. The skilled artisan will recognize that the CDRs must be flanked by framework regions (FR), but the particular amino acid sequences of the framework regions are not directly involved in target antigen specificity. Examples of functional TCR fragments include a single variable domain, such as a TCR alpha, beta, gamma or delta variable domain, or a fragment of the α, β, δ or γ chain, such as the α, β, δ or γ chain without the transmembrane domain and the short cytoplasmic tail. The term "fragment", as used herein, refers to naturally occurring fragments (e.g. splice variants or peptide fragments) and artificially constructed fragments, in particular fragments obtained by genetic technical means.

[0045] A functional fragment of a TCR may, for example, be characterized by a K for binding to a target antigen measured as outlined below. D However, the parent TCR K D or is increased or reduced, preferably reduced, no more than 10x, 5x, 3x, or 2x, or is reduced by a factor of 10, 5, 3, or 2, preferably 10x, 5x, 3x, or 2x.

[0046] A functional fragment of a TCR is considered to have retained or substantially retained functional avidity for a target antigen, for example, if the functional avidity for the target antigen is the same as or is increased or decreased by no more than 50%, 40%, 30%, 20%, 15%, 10%, 8%, 5%, 3%, 2% or 1%, preferably decreased, as that of the parent TCR. In particular, a functional fragment of a TCR is considered to have retained or substantially retained functional avidity for a target antigen, for example, if its cytotoxic activity in response to the parent protein target, as measured in a cytotoxicity assay, preferably a luciferase release assay as described below, is the same as or is increased or decreased by no more than 50%, 40%, 30%, 20%, 15%, 10%, 8%, 5%, 3%, 2% or 1%, preferably increased or decreased, as that of the parent TCR.

[0047] A functional fragment of a TCR is considered to have retained or substantially retained specificity for a target antigen (i.e., the ability to specifically bind to a target antigen) if it does not significantly bind to peptides other than the target antigen peptide of the parent TCR.

[0048] The terms "α / β TCR" or "γ / δ TCR" refer to a TCR comprising the α and β or γ and δ chains, respectively, as described above. Such TCRs may also be described as "full-length TCRs" or "conventional TCRs". The α / β or γ / δ TCR may be a native TCR or an engineered TCR that retains the structure of the native TCR, i.e., an engineered TCR that includes minor modifications in the variable and / or constant domains as described above, e.g. a humanized TCR.

[0049] "Single chain TCR (scTCR)" as used herein refers to a TCR in which the variable domains of the TCR are located on a single polypeptide. Typically, the variable domains in a scTCR are separated by a linker, which typically comprises 10-30 amino acids, for example 25 amino acids.

[0050] "Chimeric protein" as used herein refers to a protein that comprises sequences from multiple species. "Chimeric TCR" as used herein refers to a TCR that comprises sequences from multiple species. Preferably, a chimeric TCR related to the present invention may comprise an alpha chain that comprises at least one domain from human and one domain from mouse. More preferably, a chimeric TCR related to the present invention may comprise an alpha chain that comprises a variable domain of a human alpha chain and a constant domain of, for example, a mouse TCR alpha chain.

[0051] The term "antibody" as used herein is meant to include native and engineered antibodies. The term "engineered antibodies" includes functional antibody fragments, single chain antibodies, single domain antibodies, bispecific or multispecific antibodies.

[0052] A native "antibody" comprises two heavy chains and two light chains; the heavy chains are linked to each other by disulfide bonds, and each heavy chain is linked to a light chain by a disulfide bond. There are two types of light chains: lambda (λ) and kappa (κ). There are five main heavy chain classes (or isotypes) that determine the functional activity of the antibody molecule: IgM, IgD, IgG, IgA, and IgE. Each chain contains different domains (also called regions). The light chains contain a variable domain (V L ) and the constant domain (C L The heavy chain contains two domains, the variable domain (V H ), as well as three or four constant domains (collectively C H It is called C H1 , C H2, and C H3 , C as appropriate H4 ). Light (V L ) chain and heavy (V H The variable domains of both light (C) chains determine binding recognition and specificity to the antigen. L ) chain and heavy (C H The constant domains of the Fc chains are involved in antibody chain assembly, secretion, placental transport, complement fixation, and function as Fc receptors (F c R)

[0053] The specificity of an antibody resides in the structural complementarity between the antibody binding site and the antigenic determinant. The antibody binding site is composed of residues mainly from the "antibody complementarity determining region" (CDR) or hypervariable region. Sometimes, residues from non-hypervariable or framework regions (FR) influence the structure of the entire domain and thus the binding site. CDR refers to the amino acid sequence that defines the binding affinity and specificity of the natural Fv region of the native antibody binding site. The light and heavy chains of an antibody each have three CDRs, called CDR1-L, CDR2-L, CDR3-L, and CDR1-H, CDR2-H, CDR3-H, respectively. Thus, the antigen binding site of an antibody contains six CDRs, including the CDR set from each of the heavy and light chain V regions. "Antibody framework region" (FR) refers to the amino acid sequence intervening between the CDRs, i.e., the portion of the variable region of the antibody light and heavy chains that is relatively conserved among different antibodies in a single species. The light and heavy chains of an antibody each have four FRs, designated FR1-L, FR2-L, FR3-L, FR4-L, and FR1-H, FR2-H, FR3-H, FR4-H, respectively. Thus, the light chain variable domain can be described as (FR1-L)-(CDR1-L)-(FR2-L)-(CDR2-L)-(FR3-L)-(CDR3-L)-(FR4-L), and the heavy chain variable domain can be described as (FR1-H)-(CDR1-H)-(FR2-H)-(CDR2-H)-(FR3-H)-(CDR3-H)-(FR4-H). As used herein, a "human framework region" refers to a framework region that is substantially identical (about 85% or more, particularly 90%, 95%, 97%, 99%, or 100%) to the framework region of a naturally occurring human antibody. In the context of the present invention, the CDR / FR definitions in the variable domain of an antibody light or heavy chain are determined based on the IMGT definitions (Lefranc et al., Dev. Comp. Immunol., 2003, 27(1):55-77; www.imgt.org). Thus, the amino acid sequences of CDR1, CDR2, and CDR3, as well as the amino acid sequences of FR1, FR2, FR3, and FR4 of a given variable chain are indicated according to said IMGT definitions.

[0054] By knowing the amino acid sequence of the CDR of the antibody, TCR, or antigen-binding protein of the present invention, one skilled in the art can easily determine the framework region (e.g., TCR framework region or antibody framework region). If the CDR is not shown, one skilled in the art can first determine the CDR amino acid sequence based on the IMGT definition for TCR or the IMGT definition for antibody, and then determine the amino acid sequence of the framework region.

[0055] Engineered antibody formats include functional antibody fragments, single chain antibodies, single domain antibodies, and chimeric, humanized, bispecific, or multispecific antibodies. Engineered antibody formats further include constructs in which the light chain variable domain of an antibody may be replaced with the alpha chain variable domain of a TCR and the heavy chain variable domain may be replaced with the beta chain variable domain of a TCR, or vice versa. A "functional antibody fragment" refers to a portion of a full-length antibody that retains the ability to bind to its target antigen, in particular the affinity and / or specificity for that target antigen. Preferably, a functional antibody fragment comprises the antigen-binding or variable region of a full-length antibody. Examples of functional antibody fragments include Fv, Fab, F(ab')2, Fab', dsFv, (dsFv)2, scFv, sc(Fv)2, and diabodies. A functional antibody fragment can also be a single domain antibody, such as a heavy chain antibody. The term "Fab" refers to an antibody fragment obtained by treating IgG with a protease (e.g., papain), in which about half of the N-terminal side of the H chain and the entire L chain are bound to each other via a disulfide bond, has a molecular weight of about 50,000 daltons, and has antigen-binding activity. The Fv fragment is the N-terminal portion of the Fab fragment of an antibody, and consists of one light chain and one variable portion of one heavy chain.

[0056] As used herein, the "format" of an antigen-binding protein designates a defined spatial arrangement of domains, particularly variable domains and, where appropriate, constant domains. Important features of such antigen-binding protein formats are: the number of polypeptide chains (single-, double-, or multiple-chain), the type and length of linkers connecting different domains, the number of variable domains (and thus the number of valencies), the number of different variable domains (and thus the number of specificities for different antigens, e.g., bispecific, multispecific), and the order and orientation of the variable domains (e.g., crossover, parallel).

[0057] The term "humanized antibody" refers to an antibody that is wholly or partially of non-human origin and that has been modified by replacing certain amino acids, particularly in the framework regions of the heavy and light chains, to avoid or minimize immune responses in humans. The constant domains of a humanized antibody are primarily composed of human C H Domain and C L Domains. Numerous methods for humanizing antibody sequences are known in the art; see, for example, the review by Almagro & Fransson (2008) Front Biosci. 13: 1619-1633.

[0058] In the context of this application, a sequence that is "at least 85% identical to a reference sequence" refers to a sequence that has 85% or more, in particular 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity over the entire length of the reference sequence. A protein consisting of an amino acid sequence that is "at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identical" to a reference sequence may contain mutations (e.g., deletions, insertions, and / or substitutions) compared to the reference sequence. In the case of substitutions, a protein consisting of an amino acid sequence that is at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identical to a reference sequence may correspond to a homologous sequence from another species than the reference sequence.

[0059] In the context of this application, "percentage of identity" may be calculated using global pairwise alignment (i.e., two sequences are compared over their entire length). Methods for comparing the identity of two or more sequences are known in the art. For example, the "Needle" program may be used, which uses the Needleman-Wunsch global alignment algorithm (Needleman and Wunsch, 1970 J. Mol. Biol. 48:443-453) to find the optimal alignment (including gaps) when considering the entire length of two sequences. The Needle program is available, for example, at the ebi.ac.uk World Wide Web site and is further described in the following publications: EMBOSS: The European Molecular Biology Open Software Suite (2000) Rice, P. Longden, I. and Bleasby, A. Trends in Genetics 16, (6) pp. 276-277. The percentage of identity between two polypeptides according to the invention is calculated using the EMBOSS:Needle (Global) program with the "Gap Open" parameter of 10.0, the "Gap Extend" parameter of 0.5, and the Blosum62 matrix.

[0060] An "amino acid mutation" may be a deletion, insertion or substitution.

[0061] "Amino acid substitutions" may be conservative or non-conservative. In one embodiment, the substitutions are conservative, in which one amino acid is replaced with another amino acid having similar structural and / or chemical properties.

[0062] In one embodiment, conservative amino acid substitutions may include substitutions of one amino acid with another amino acid of the same class, such as (1) non-polar: Ala, Val, Leu, Ile, Pro, Met, Phe, Trp; (2) uncharged polar: Gly, Ser, Thr, Cys, Tyr, Asn, Gln; (3) acidic: Asp, Glu; and (4) basic: Lys, Arg, His. Other conservative amino acid substitutions may also be made as follows: (1) aromatic: Phe, Tyr, His; (2) proton donor: Asn, Gln, Lys, Arg, His, Trp; and (3) proton acceptor: Glu, Asp, Thr, Ser, Tyr, Asn, Gln (see, for example, U.S. Patent No. 10,106,805, the entire contents of which are incorporated by reference).

[0063] In another embodiment, conservative substitutions can be made according to Table 1. Methods for predicting tolerance to protein modifications can be found, for example, in Guo et al., Proc. Natl. Acad. Sci., USA, 101(25):9205-9210 (2004), the contents of which are incorporated by reference in their entirety.

[0064] [Table 1]

[0065] The antigen binding proteins of the invention may contain synthetic amino acids in place of one or more naturally occurring amino acids. Such synthetic amino acids are known in the art and include, for example, aminocyclohexane carboxylic acid, norleucine, α-amino n-decanoic acid, homoserine, S-acetylaminomethyl-cysteine, trans-3- and trans-4-hydroxyproline, 4-aminophenylalanine, 4-nitrophenylalanine, 4-chlorophenylalanine, 4-carboxyphenylalanine, β-phenylserine β-hydroxyphenylalanine, phenylglycine, α-naphthylalanine, cyclohexylalanine, cyclohexylglycine, indoline-2-carboxylic acid, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid, aminomalonic acid, aminomalonic acid monoamide, N'-benzyl-N'-methyl-lysine, N',N'-dibenzyl-lysine, 6-hydroxylysine, ornithine, α-aminocyclopentane carboxylic acid, α-aminocyclohexane carboxylic acid, α-aminocycloheptane Carboxylic acid, α-(2-amino-2-norbornane)-carboxylic acid, α,γ-diaminobutyric acid, α,β-diaminopropionic acid, homophenylalanine, and α-tert-butylglycine.

[0066] In one embodiment, the antigen binding proteins of the invention may be glycosylated, amidated, carboxylated, phosphorylated, esterified, N-acylated, cyclized, e.g., via disulfide bridges, or converted into acid addition salts, and / or dimerized or polymerized, or conjugated.

[0067] "Covalent linkage," as used herein, refers to a peptide linkage or a covalent linkage, for example, via a disulfide bond, or a linker or linker sequence, such as a polypeptide linker.

[0068] The term "linker," as used herein, refers to one or more amino acid residues inserted between domains or between a domain and an agent to provide sufficient flexibility for the domain or element (e.g., a variable domain in a bispecific antigen binding) to fold correctly to form an antigen-binding site.

[0069] In some embodiments, the linker consists of 0 amino acids, which means that the linker is not present. The linker is inserted at the transition between variable domains or between variable and constant domains (or between dimerization domains) at the amino acid sequence level, respectively. The approximate sizes of antibody and TCR domains are well understood, so that the transition between domains can be specified. The precise location of the domain transition can be determined by locating secondary structure elements, such as beta-sheets or peptide stretches that do not form alpha-helices, as can be demonstrated by experimental data or predicted by modeling or secondary structure prediction techniques.

[0070] The linker may be at least 1-30 amino acids in length, unless otherwise specified in the respective context. In some embodiments, the linker may be 2-25, 2-20, or 3-18 amino acids in length. In some embodiments, the linker may be a peptide of 14, 13, 12, 11, 10, 9, 8, 7, 6, or 5 amino acids or less in length. In other embodiments, the linker may be 5-25, 5-15, 4-11, 10-20, or 20-30 amino acids in length. In other embodiments, the linker may be about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. In certain embodiments, the linker may be less than 24, less than 20, less than 16 amino acid residues in length, less than 12, less than 10, e.g., less than 5-24, less than 10-24, or less than 5-10 amino acid residues in length. In some embodiments, the linker is one or more amino acid residues in length, e.g., more than 1, more than 2, more than 5, more than 10, more than 20 amino acid residues in length, more than 22 amino acid residues in length. In a preferred embodiment, the linker is a glycine / serine linker, i.e., a linker consisting of, or consisting essentially of, glycine and serine residues.

[0071] The antigen binding proteins of the present disclosure may be synthetic, recombinant, isolated, engineered, and / or purified.

[0072] An "engineered" antigen binding protein, in particular an engineered TCR in the context of the present invention, refers to a protein that has been modified by biotechnological methods, in particular by introducing amino acid mutations into the native protein sequence. Such biotechnological methods are well known to those skilled in the art.

[0073] "Purified," when referring to a polypeptide (e.g., an antigen binding protein of the invention) or a nucleotide sequence (e.g., a nucleotide sequence encoding an antigen binding protein or functional fragment thereof described herein), means that the indicated molecule is present in the substantial absence of other biological macromolecules of the same type. The term "purified," particularly as used herein, means that at least 75%, 85%, 95%, or 98% by weight of the same type of biological macromolecules are present. The term "purified," as used herein, can further indicate that the antigen binding protein is free of DNA, RNA, proteins, polypeptides, or cells that would interfere with its therapeutic, diagnostic, prophylactic, research, or other uses.

[0074] A purified nucleic acid molecule encoding a particular polypeptide refers to a nucleic acid molecule that is substantially free of other nucleic acid molecules that do not encode the subject polypeptide; however, the molecule may contain some additional bases or moieties that do not adversely affect the basic characteristics of the composition.

[0075] The term "isolated" means changed or removed from the natural state. For example, a nucleic acid or peptide naturally occurring in a living animal is not "isolated", but the same nucleic acid or peptide partially or completely separated from the coexisting materials of the natural state is "isolated". An isolated nucleic acid or protein may exist in a substantially purified form or may exist in a non-native environment, such as a host cell. An isolated antigen binding protein is substantially free of other antigen binding proteins with different antigen specificities (e.g., an antigen binding protein that specifically binds to CT45-IP is substantially free of antigen binding proteins that specifically bind to antigens other than CT45-IP). Additionally, an isolated antigen binding protein may be substantially free of other cellular material and / or chemicals.

[0076] A "recombinant" molecule is one that has been prepared, expressed, produced, or isolated by recombinant means. Recombinant molecules do not occur in nature.

[0077] The term "gene" refers to a DNA sequence that codes for or corresponds to a specific sequence of amino acids that constitutes all or part of one or more proteins or enzymes, and may or may not include regulatory DNA sequences (e.g., promoter sequences) that determine, for example, the conditions under which the gene is expressed. Some genes that are not structural genes can be transcribed from DNA into RNA but are not translated into an amino acid sequence. Other genes may function as regulators of structural genes or as regulators of DNA transcription. In particular, the term gene can cover genomic sequences that code for proteins (i.e., sequences that include regulators, promoters, introns, and exon sequences).

[0078] "Affinity" in the context of the present invention is defined as the equilibrium binding between an antigen-binding protein and its antigen (i.e., the CT45-IP peptide in complex with an MHC protein). Affinity is determined by the equilibrium dissociation constant (K D )

[0079] "K D " is the equilibrium dissociation constant (k off / k on (the ratio of K D and affinity are inversely related. D The value is related to the concentration of the antigen-binding protein, K D The lower the value, the higher the affinity of the antigen-binding protein. D The values ​​can be experimentally evaluated by various known methods, such as measuring the association and dissociation rates by surface plasmon resonance (SPR) or biolayer interferometry (BLI). As known to those skilled in the art, the experimental conditions used for those experiments, such as the buffers used, the concentration of the protein, can strongly influence the results.

[0080] "Functional avidity" is defined in the context of the present invention as a parameter describing the ability of an antigen binding protein, preferably a TCR, to activate effector cells, preferably T cells, on binding to a target antigen peptide in complex with MHC. Activation of effector cells, preferably T cells, can be measured in a functional assay, in particular a cytokine production assay or a cytotoxicity assay, as described below. In some embodiments, the functional avidity of an antigen binding protein is determined by the EC 50 A protein is considered high if its avidity is low, e.g., less than about 60 nM, less than about 10 nM, or less than about 1 nM in the cytotoxicity assays described below, and / or if its activity as determined in a functional assay is high, e.g., at least 50%, at least 60%, at least 70%, at least 75%, preferably at least 80%, at least 85%, at least 90%, or at least 95% of the maximum activity defined in the respective functional assay. Depending on the functional assay, the maximum activity may be the activity of a reference protein with known high functional avidity or the activity of a "maximum lysis control" described below.

[0081] "Efficacy" is defined in the context of the present invention as a parameter describing the ability of an antigen-binding protein, preferably a TCR, to activate effector cells, preferably T cells, to kill cancer cells that present on their surface a target antigen peptide in complex with MHC. Efficacy can be determined in a functional assay, in particular a live cell monitoring cytotoxicity assay, as described below.

[0082] In a "functional assay", the antigen-binding protein is expressed, for example, in an "effector cell (E)" and the effector cell is co-cultured with a "target cell (T)", i.e., an antigen-presenting cell presenting a peptide-MHC complex. The functional assay may therefore also be described as a "co-culture assay". For all cell culture assays described herein, the cell culture temperature is preferably about 37°C. Preferably, the antigen-binding protein is a TCR and the effector cell is a T cell. The target cell may be a cell artificially loaded with an antigen peptide (e.g., a T2 cell) or a cell that endogenously presents the target antigen peptide on its surface (e.g., a cancer cell expressing CT45). Binding of the antigen-binding protein to the peptide-MHC complex results in activation of the effector cell. Depending on the type of functional assay, there are different readouts for measuring the degree of activation. In cytokine production assay, effector cells determine the production of cytokines (e.g., TNF-α, IFN-γ, CD107a+, IL-2 and / or granzyme B).In cytotoxicity assay, effector cells determine the killing of target cells, for example, by measuring the decrease in the proliferation of target cells, particularly cancer cells (e.g., in live cell monitoring cytotoxicity assay), or by measuring the release of intracellular protein from target cells.The suitable intracellular protein to be measured in cytotoxicity assay can be endogenous protein, for example, LDH expressed by antigen-presenting cells, or transgenic protein, for example, luciferase.

[0083] In the context of the present invention, the term "T2 cells" refers to cells expressing MHCI molecules (HLA-A2) that lack TAP function. T2 cells can be easily artificially loaded with different concentrations of exogenous antigen peptides. T2 cells are described, for example, in [Hosken and Bevan, Science 1990 Apr 20;248(4953):367-70]. T2 cells are commercially available, for example, from ATCC (American Type Culture Collection). Loading of T2 cells can be achieved by incubating T2 cells with the desired concentration of antigen peptide for about 2 hours under standard cell culture conditions known to those skilled in the art. In the context of the present invention, T2 cells incubated with an antigen peptide at a certain concentration, for example, 1 μM, 100 nM, 10 nM, 1 nM, 100 pM, 10 pM, 1 pM, are referred to as T2 cells loaded with the antigen peptide at said concentration, for example, T2 cells incubated with 10 μM antigen peptide are referred to as T2 cells loaded with 10 μM antigen peptide.

[0084] The term "E:T ratio" refers to the ratio of effector cells (i.e. immune cells, especially T cells, expressing antigen-binding proteins, especially TCR) to target cells. In some embodiments, the E:T ratio corresponds to the seeding ratio, i.e. the ratio of the total number of immune cells, especially T cells, to the total number of target cells. In some embodiments, the E:T ratio is lower than the seeding ratio. This applies when not all immune cells express the antigen-binding protein, i.e. not all immune cells are effector cells, e.g. due to low electroporation efficiency. In some embodiments, the seeding ratio is used as an approximate value of the E:T ratio. In some embodiments, the E:T ratio is determined by adjusting the seeding ratio to take into account the electroporation efficiency.

[0085] An exemplary luciferase release assay is described in the Methods section and performed in Examples 1 and 2. In a particular embodiment of the luciferase release assay, the effector cells are T cells that transiently or stably express a TCR, preferably prestimulated T cells, e.g., T cells electroporated with an mRNA encoding a TCR, or T cells stably transduced with a nucleic acid encoding a TCR, e.g., T cells transduced with a lentiviral vector containing a nucleic acid encoding a TCR. These effector cells are co-cultured with target cells that express luciferase. Preferably, the target cells are T2 cells loaded with an antigenic peptide. Preferably, the effector cells and target cells are seeded at a ratio of 2:1 to 1:2, preferably 1:1. After a defined time of co-culture, for example 12-38 hours, preferably 18-30 hours, more preferably about 24 hours, the amount of luciferase in the supernatant is measured, a high luciferase concentration indicates a high killing activity and therefore a high functional avidity of the antigen-binding protein, preferably TCR, for the presented peptide. The functional avidity of the antigen-binding protein is considered high if the cytotoxic activity of the effector cells against the target cells in a cytotoxicity assay, preferably a luciferase release assay as defined above, is at least 50%, at least 60%, at least 70%, at least 75%, preferably at least 80%, at least 85%, at least 90%, or at least 95% of the cytotoxic activity of the control toxic reagent. The skilled person is aware that the cytotoxic activity can be higher than 100%. This is due to the fact that 100% cytotoxic activity is defined by the "maximal lysis control" which refers to the incubation of the target cells with the toxic reagent. In some embodiments, the toxic reagent is a detergent that results in lysis of the target cells, such as Triton-X100, Tween-20, Tween-80, or NP-40. In some embodiments, the maximum lysis control comprises adding a 0.2% Triton-X100 solution to the target cell culture.The cytotoxic activity of a toxic reagent, i.e., the number of target cells killed by the toxic reagent, is defined as 100%. Since the target cells can still proliferate during co-culture, the effector cells may ultimately kill a greater number of target cells during the cytotoxicity assay than the toxic reagent killed during the maximum lysis control. In such cases, the calculated cytotoxic activity is higher than 100%.

[0086] An exemplary cytokine production assay is described in the methods section and performed in Example 3. In a particular embodiment of the cytokine production assay, the effector cells are T cells expressing a TCR, preferably pre-stimulated T cells, e.g., T cells transiently transfected or stably transduced with a nucleic acid encoding a TCR, preferably T cells electroporated with an mRNA encoding a TCR. These effector cells are co-cultured with target cells, preferably T2 cells loaded with an antigenic peptide. Preferably, the effector and target cells are seeded in a ratio of 2:1 to 1:2, preferably 1:1. The co-culture is preferably performed in the presence of a secretion blocking agent. After a defined time of co-culture, e.g., 3 to 7 hours, preferably about 5 hours, the effector cells are stained for at least one intracellular cytokine, e.g., selected from CD107a+, IFN-gamma, TNF-alpha, IL-2 and granzyme B, to determine the amount of effector cells producing cytokines. The functional avidity of an antigen-binding protein is determined when the antigen is capable of activating effector cells in a cytokine production assay as defined above, in particular when the number of effector cells producing cytokines in co-culture with target cells is increased by increasing the number of immune cells, e.g. live CD4 + , CD8 + and / or CD3 +It is considered high when it is at least 2%, at least 2.5%, preferably at least 3% per cell population.Preferably, the number of effector cells that produce cytokines in co-culture with target cells is at least 10%, at least 25%, at least 50% per total number of effector cells.As explained above, for example due to low electroporation efficiency, not all immune cells express antigen-binding protein, i.e. not all immune cells seeded in co-culture assay are effector cells.

[0087] An exemplary live cell monitoring cytotoxicity assay is described in the methods section and performed in Example 5. In certain embodiments of the live cell monitoring cytotoxicity assay, the effector cells are T cells that transiently or stably express a TCR, preferably pre-stimulated T cells, e.g., T cells electroporated with mRNA encoding a TCR. These effector cells are co-cultured with tumor cells that endogenously express and present CT45-IP antigenic peptides and are optionally additionally loaded with CT45-IP antigenic peptides. In some embodiments, the tumor cells are A375 cells or NCIH-1703 cells. The tumor cells are preferably fluorescently labeled. In some embodiments of the live cell monitoring cytotoxicity assay, the seeding ratio of total T cells [including TCR-expressing T cells (=effector cells) and T cells not expressing a TCR] is 9:1 to 0.5:1, e.g., 9:1, 6:1, 3:1, 2:1 or 1:1. In some embodiments, the E:T ratio is between 6:1 and 0.2:1. The efficacy of an antigen binding protein is considered high when, in a live cell monitoring cytotoxicity assay as defined above, tumor cell killing (as determined by a reduction in tumor cell proliferation) is observed at an E:T ratio of 6:1 or less, 5:1 or less, 4:1 or less, 3:1 or less, preferably 2:1 or less, more preferably 1:1 or less, and even more preferably 0.5:1 or less.

[0088] "EC50 The "half maximal effective concentration," also called the "maximal effective concentration," typically refers to the concentration of a molecule that elicits a response halfway between the baseline and maximum after a specific exposure time. EC 50 The lower the value, the higher the functional avidity of the molecule. EC 50 Values ​​can be assessed experimentally by a variety of known methods, for example, using the functional assays described above or other ELISA or flow cytometry-based killing assays.

[0089] EC 50 To determine the EC, different concentrations of antigen peptide loaded onto antigen presenting cells, e.g., T2 cells, need to be used in a "peptide titration experiment". An exemplary luciferase release assay with peptide titration is described in the Methods section and performed in Example 1. In certain embodiments, the "EC 50 " refers to the concentration of antigenic peptide loaded onto target cells, in particular T2 cells loaded with CT45 antigenic peptide, which induces a response halfway between baseline and maximum when said target cells are co-cultured with effector cells in luciferase release as defined above. The functional avidity of an antigen-binding protein is determined by the EC50-EC50 concentration determined in a cytotoxicity assay, preferably a luciferase release assay as defined above. 50 is considered high when it is less than about 60 nM, less than about 50 nM, less than about 30 nM, less than about 25 nM, preferably less than about 20 nM, less than about 15 nM, less than about 10 nM, more preferably less than about 5 nM, less than about 2.5 nM, less than about 1.5 nM or less than about 1 nM.

[0090] "Dextramer staining" involves contacting cells expressing an antigen-binding protein with a fluorescently labeled multimer containing 10 CT45-IP:MHC complexes.

[0091] The term "specificity" in the context of the present invention refers to the ability of an antigen-binding protein to distinguish its target peptide from peptides with different amino acid sequences, e.g., similar peptides as defined below. An antigen-binding protein is considered to be specific for a target peptide if binding to the target peptide occurs with significantly higher affinity and / or higher functional avidity than binding to similar peptides. The specificity of an antigen-binding protein is determined by the amino acid sequences CDRa1, CDRa3, CDRb1 and CDRb3. The amino acid sequences of CDRa2 and CDRb2 contact the MHC molecule and are not required for antigen specificity.

[0092] In the context of the present invention, "analogous peptide" refers herein to a potential off-target peptide, i.e., a peptide (e.g., but not limited to, a homologous sequence or a similar motif) to which the antigen-binding molecule of the present invention may potentially bind based on biochemical / biophysical properties. Analogous peptides are typically 8-12 amino acids in length. Analogous peptides in the context of the present invention are typically MHC-presented, particularly MHCI. Furthermore, analogous peptides in the context of the present invention include peptides that contain or consist of an amino acid sequence similar to the amino acid sequence of the CT45 antigenic peptide, more particularly, peptides that contain an epitope in which some or all amino acids have the same and / or similar biochemical / biophysical properties as the amino acids that constitute the epitope of the CT45 antigenic peptide, as compared to the epitope of the CT45 antigenic peptide. In some examples, the analogous peptides investigated in the context of the present invention were selected from a database of HLA-A*02-binding peptides presented by tumor and normal tissues (XPRESIDENT® database) using similarity scoring within the binding-relevant positions of CT45-IP and the requirement of at least one detection in normal tissue. Binding of antigen-binding proteins to similar peptides presented by MHC proteins can cause adverse reactions, which may be "off-tumor" side effects, such as cross-reactivity of certain TCRs with similar peptides in healthy tissues, as reported in Lowdell et al., Cytotherapy, published on December 4, 2018.

[0093] In particular, the following peptides are similar peptides relevant to the present invention: SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009) and SEQ ID NO: 155 (SP-05-0010).

[0094] Those skilled in the art will recognize that among the similar peptides, there are some similar peptides that are not bound by the antigen-binding proteins of the invention to a detectable extent, e.g., peptides that do not provide a detectable binding signal or response in a functional assay above background levels. "Background levels" in this context refers to the binding signal or response in a functional assay observed for a non-homologous, "non-analogous" peptide, e.g., the control peptide NYESO1-001, or in the absence of the peptide.

[0095] For other similar peptides, low but insignificant binding may be detectable. These latter similar peptides may also be described as "potentially related" similar peptides. An antigen-binding protein is considered to not significantly bind to a similar peptide and to be specific for its target antigen peptide if at least one of the following is true when binding to the similar peptide and the target antigen peptide is compared under similar, preferably identical, experimental conditions: - the functional avidity in response to the analogous peptide is 25% or less, 20% or less, 15% or less, 10% or less of the functional avidity in response to the target antigen peptide CT45-IP, as determined in the functional assay described above. - the cytotoxic activity in response to the analogous peptide is 25% or less, 20% or less, 15% or less, 10% or less than the cytotoxic activity in response to the target antigen peptide CT45-IP, as determined in the cytotoxicity assay described above. - the EC of the similar peptides, as determined in a functional assay, preferably a cytotoxicity assay, as described above; 50 However, the EC of the target antigen peptide CT45-IP 50 is increased by at least 50, at least 100, at least 200 or at least 500 fold compared to - K for similar peptides DHowever, the K D is increased by at least 25, at least 30, at least 40, at least 50, at least 75, or at least 100 fold compared to

[0096] In the context of this specification, the term "about" when referring to a particular value is meant to indicate that the value may deviate by up to ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3%, ±2% or ±1%.

[0097] Antigen-binding proteins In a first aspect, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, the CT45 antigenic peptide comprising or consisting of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprising a variable domain V comprising the complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. B and a second polypeptide comprising 1) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 14, CDRa3 comprises the amino acid sequence of SEQ ID NO: 489, preferably SEQ ID NO: 519, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 19, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 504; 2) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises the amino acid sequence of SEQ ID NO: 490, preferably SEQ ID NO: 520, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 505, preferably SEQ ID NO: 526; 3) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises the amino acid sequence of SEQ ID NO: 491, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 506, preferably SEQ ID NO: 527; 4) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 90, CDRa3 comprises the amino acid sequence of SEQ ID NO: 492, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 507, preferably SEQ ID NO: 528; 5) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 2, CDRa3 comprises the amino acid sequence of SEQ ID NO: 493, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 8, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 508, preferably SEQ ID NO: 529; 6) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 53, CDRa3 comprises the amino acid sequence of SEQ ID NO: 494, preferably SEQ ID NO: 521, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 509, preferably SEQ ID NO: 530; 7) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 71, CDRa3 comprises the amino acid sequence of SEQ ID NO: 495, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 510, preferably SEQ ID NO: 531; 8) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 99, CDRa3 comprises the amino acid sequence of SEQ ID NO: 496, preferably SEQ ID NO: 522, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 511; 9) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 80, CDRa3 comprises the amino acid sequence of SEQ ID NO: 497, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 85, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 512, preferably SEQ ID NO: 532; 10) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 107, CDRa3 comprises the amino acid sequence of SEQ ID NO: 498, preferably SEQ ID NO: 523, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 513, preferably SEQ ID NO: 533; 11) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 125, CDRa3 comprises the amino acid sequence of SEQ ID NO: 499, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 514, preferably SEQ ID NO: 534; 12) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 117, CDRa3 comprises the amino acid sequence of SEQ ID NO: 500, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 515, preferably SEQ ID NO: 535; 13) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises the amino acid sequence of SEQ ID NO: 501, preferably SEQ ID NO: 524, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 38, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 516, preferably SEQ ID NO: 536; 14) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises the amino acid sequence of SEQ ID NO: 502, preferably SEQ ID NO: 525, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 29, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 517, preferably SEQ ID NO: 537, or 15) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 43, CDRa3 comprises the amino acid sequence of SEQ ID NO: 503, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 48, and CDRb3 comprises the amino acid sequence of SEQ ID NO: 518, preferably SEQ ID NO: 538; The antigen binding protein comprises said CDRa1, CDRa3, CDRb1 and CDRb3 sequences, which do not have more than one, two or three amino acid mutations. Concerning antigen-binding proteins.

[0098] The above amino acid sequences contained in CDRa3 and CDRb3 are the core amino acids of CDRa3 and CDRb3 (also referred to herein as "CDR3 core"). The inventors have found that within the CDR3 sequence, a core sequence can be defined that contains the amino acids most associated with specific binding to an antigen peptide, and that amino acids outside the CDR3 core are less associated with specific binding to an antigen peptide (data not shown). The CDR3 core comprises the central 8 amino acids of the CDR3. In some embodiments, the CDR3 core consists of the central 8 amino acids of the CDR3, especially when the CDR3 sequence is 12 amino acids or less. In the case of a CDR3 sequence longer than 12 amino acids, the CDR3 core may comprise additional amino acids, especially the central 9 to 13 amino acids.

[0099] All embodiments described herein as embodiment 1 (out of 15) are preferably combined with other embodiments 1 (out of 15).Similarly, all embodiments described herein as embodiment 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 (out of 15), respectively, are preferably combined with other embodiments 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 (out of 15), respectively.For example, the CDR1 and CDR3 sequences of embodiment 1 (out of 15) are preferably combined with the CDR2 sequences of embodiment 1 (out of 15).

[0100] In a preferred embodiment, 1) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 16 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 21; 2) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 133 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 136; 3) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 63 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 68; 4) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 92 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 96; 5) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 4 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 10; 6) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 55 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 60; 7) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 72 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 77; 8) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 101 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 104; 9) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 82 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 87; 10) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 109 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 114; 11) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 127 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 130; or 12) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 119 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 122; 13) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 35 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 40; 14) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 26 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 31; or 15) CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 45 and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 50; The antigen binding protein comprises said CDRa1, CDRa3, CDRb1 and CDRb3 sequences having no more than one, two or three amino acid mutations.

[0101] An antigen binding protein comprising CDRa1, CDRa3, CDRb1 and CDRb3 sequences that does not have more than one, two or three amino acid mutations refers herein to an antigen binding protein that may contain one, two or three amino acid mutations in each of CDRa1, CDRa3, CDRb1 and / or CDRb3.

[0102] In a preferred embodiment of the antigen binding protein, 1) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 15 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 20; 2) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76; 3) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 67; 4) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 91 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 95; 5) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 3 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 9; 6) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 54 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 59; 7) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 15 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76; 8) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 100 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76; 9) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 81 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 86; 10) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 108 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 113; 11) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 126 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 113; 12) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 118 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 59; 13) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 39; 14) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 30; or 15) CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 44 and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 49; The antigen binding protein comprises said CDRa2 and CDRb2 sequences having no more than one, two, three or four amino acid mutations.

[0103] An antigen binding protein comprising a CDRa2 and CDRb2 sequence that does not have more than one, two, three or four amino acid mutations refers herein to an antigen binding protein that may contain one, two, three or four amino acid mutations in CDRa2 and / or CDRb2, respectively.

[0104] In all embodiments of the antigen binding protein of the present invention, if there is an amino acid mutation in the CDRa1, CDRa2, CDRa3, CDRb1, CDRb2 and CDRb3 sequence, it is preferably an amino acid substitution, more preferably a conservative amino acid substitution (see Table 1). It is preferred that the CDR sequence does not contain more than two, preferably more than one, amino acid mutations. It is even more preferred that if there is an amino acid mutation, it is at the first or last position of each CDR sequence. In the most preferred embodiment, the CDR sequence does not contain any amino acid mutation.

[0105] The introduction of mutations into known amino acid sequences is a standard procedure well known in the art and is a routine task for those skilled in the art.The respective methods are known in the art (e.g., Stratagene's QuikChange Site Directed Mutagenesis Kit since 2007).The skilled artisan is therefore very well able to introduce specific mutations, such as substitutions, into amino acid sequences in general and into CDR sequences in particular.

[0106] Screening of CDR mutants for binding to their targets is also a standard procedure applied by those skilled in the art. The present application refers to functional assays, including cytokine production and luciferase release assays, to determine the binding of the antigen binding protein of the present invention to the CT45-IP peptide. The binding of the antigen binding protein of the present invention to the CT45-IP peptide can also be determined by dextramer staining.

[0107] Although the outcome of amino acid mutations in the CDRs may not be easily predictable, one skilled in the art is well able to generate and screen multiple mutants without undue burden. One skilled in the art can therefore generate antigen binding proteins with one, two or three amino acid mutations in the CDRs and subsequently identify antigen binding proteins that have the same binding properties as the antigen binding protein comprising the CDR sequences of Table 3.

[0108] In a preferred embodiment, no more than one or two amino acid mutations, preferably no more than one amino acid mutation, more preferably no more than one amino acid substitution, most preferably no more than one conservative amino acid substitution, are contained within the central 8 amino acids of CDRa3 and / or CDRb3, i.e., within the CDR3 core. If the CDR3 contains more than 12 amino acids, it is even more preferred that no more than one or two amino acid mutations, preferably no more than one amino acid mutation, more preferably no more than one amino acid substitution, most preferably no more than one conservative amino acid substitution, are contained within the central 9-13 amino acids of CDRa3 and / or CDRb3, i.e., within the CDR3 core max (Table 3).

[0109] In some embodiments, the antigen binding protein induces an immune response, for example in cells expressing the antigen binding protein (if the antigen binding protein is membrane bound), preferably lymphocytes, more preferably T cells or NK cells, more preferably T cells. In some embodiments, an immune response may also be induced in cells recruited by the antigen binding protein of the invention (if the antigen binding protein is a soluble, bispecific antigen binding protein capable of binding to and thereby recruiting T cells or NK cells, for example). Preferably, the immune response is characterized by an increase in the production of interferon (IFN) gamma and / or tumor necrosis factor (TNF) alpha. The immune response is preferably against tumor cells presenting a complex of the CT45 antigen peptide and an MHC protein on their surface.

[0110] In some embodiments, the antigen binding protein specifically binds to a complex of the CT45 antigenic peptide and an MHC protein. In some embodiments, the CT45 antigenic peptide consists of SEQ ID NO: 138. In some embodiments, the antigen binding protein specifically binds to the amino acid sequence of SEQ ID NO: 138 in a complex with an MHC protein.

[0111] In all aspects of the invention, the CT45 antigenic peptide is preferably present in a complex with an MHC class I HLA protein, such as HLA-A, HLA-B or HLA-C, preferably HLA-A, more preferably HLA-A*02.

[0112] The antigen binding proteins of the invention are characterized by high stability, high affinity for the CT45-IP antigenic peptide, high functional avidity for the CT45-IP antigenic peptide, high efficacy in killing tumor cells presenting the CT45-IP antigenic peptide, and / or high specificity for the CT45-IP antigenic peptide.

[0113] The antigen binding proteins of the invention have increased stability, increased binding affinity, increased functional avidity, increased potency and / or increased specificity, preferably increased binding affinity, increased functional avidity, increased potency and / or increased specificity compared to a reference protein when measured under similar, preferably identical, experimental conditions.

[0114] "Reference protein" refers herein to a protein with which the antigen-binding protein of the present invention is compared. The comparison of the antigen-binding protein of the present invention with the reference protein is preferably performed in parallel and under similar (preferably identical) experimental conditions. Depending on the parameters to be compared, such a reference protein may be, for example, a TCR that binds to a CT45 antigen peptide that does not contain a CDR sequence as defined in the context of the present invention, a TCR that binds to a different antigen peptide derived from CT45, or a TCR that binds to an unrelated antigen peptide, such as the antigen peptide NYESO1-001 (SEQ ID NO: 188). The reference protein is preferably in the same format as the antigen-binding protein to be compared. If the antigen-binding protein is a TCR, a suitable reference protein is also a TCR.

[0115] "Increased stability" as used herein refers to, for example, an increased expression level of an antigen-binding protein compared to a reference protein under the same experimental conditions. The antigen-binding protein of the present invention has a high expression level, in particular an increased expression level compared to a reference protein when measured under similar, preferably identical, experimental conditions. The inventors have shown in Example 4 that the antigen-binding protein exhibits a high expression level in T cells. The expression level of an antigen-binding protein can be measured, for example, by dextramer staining.

[0116] The antigen binding proteins of the invention have high affinity for the CT45-IP antigenic peptide, in particular an increased affinity compared to a reference protein when measured under similar, preferably identical, experimental conditions.

[0117] The antigen-binding proteins of the invention have high functional avidity for the CT45-IP antigenic peptide, in particular an increased functional avidity compared to a reference protein when measured under similar, preferably identical, experimental conditions. The inventors have shown in Example 1 that the antigen-binding proteins exhibit high functional avidity for the CT45-IP antigenic peptide. The functional avidity can be determined in a functional assay, in particular the cytotoxicity assay described above. The measurement of functional activity is based on the EC 50 The method may include determining:

[0118] The antigen binding proteins of the present invention have high efficacy in killing tumor cells presenting the CT45-IP antigenic peptide, in particular an increased efficacy compared to a reference protein when measured under similar, preferably identical, experimental conditions. The inventors have shown in Example 5 that the antigen binding proteins exhibit high efficacy in killing tumor cells presenting the CT45-IP antigenic peptide. Efficacy can be determined in a functional assay, in particular a live cell monitoring cytotoxicity assay as described above.

[0119] In a preferred embodiment, the antigen binding protein specifically binds to a structural epitope of CT45-IP. In a more preferred embodiment, the antigen binding protein specifically binds to a functional epitope of CT45-IP. The inventors performed experiments to identify the residues of CT45-IP that are relevant for binding by the antigen binding protein of the present invention (Example 2, Table 4). The inventors identified amino acid positions 3, 4, 5, 6 and 7 of SEQ ID NO: 138 as relevant for binding. Thus, in some embodiments, the antigen binding protein specifically binds to a functional epitope that includes or consists of 2, 3 or 4 amino acid positions selected from the group consisting of positions 3, 4, 5, 6 and 7 of SEQ ID NO: 138. The residues that are relevant for binding by the antigen binding protein may also be referred to as the "binding motif" of CT45-IP. Those skilled in the art will recognize that the determination of the exact epitope or functional epitope may vary slightly depending on the method used and the cutoff value selected. In the context of the present invention, the epitope has been determined in a cytotoxicity assay (luciferase release) as described above. The experimental conditions are further defined in Example 2.

[0120] An amino acid sequence according to SEQ ID NO: 138 in which at least one position is substituted is referred to in the context of the present specification as a "CT45-IP mutant sequence". In particular, one position is substituted with alanine (SEQ ID NOs: 139-145). A peptide having a CT45-IP mutant sequence is also referred to herein as a CT45-IP mutant peptide. In one embodiment, the antigen binding protein of the present invention exhibits reduced functional avidity, in particular reduced cytotoxic activity in a cytotoxicity assay, more particularly in a luciferase release assay as described above, against a CT45-IP mutant peptide in which at least one of positions 3, 4, 5, 6 and 7 of SEQ ID NO: 138 is substituted with alanine, in particular a functional avidity that is reduced by more than 70%, more than 80%, more than 90% or more than 95% compared to the functional avidity for CT45-IP.

[0121] The antigen-binding proteins of the invention have high specificity for the CT45-IP antigenic peptide, in particular an increased specificity compared to a reference protein when measured under similar, preferably identical, experimental conditions. In Example 2, the inventors demonstrate that the antigen-binding proteins of the invention bind with high specificity to the target antigen, i.e. the CT45 antigenic peptide in complex with an MHC protein.

[0122] For example, the inventors have identified potential off-target peptides that are similar to sequences and / or motifs of CT45-IP and therefore increase the risk of antigen-binding proteins binding to CT45-IP.

[0123] In some embodiments, the antigen binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009), and SEQ ID NO:155 (SP-05-0010). In some embodiments, the antigen binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010). In some embodiments, the antigen binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:147 (SP-05-0002), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), and SEQ ID NO:155 (SP-05-0010).

[0124] In a preferred embodiment, V A and V B is a TCR variable domain, in particular a TCR alpha, beta, gamma or delta variable domain. A is a TCR alpha, gamma or delta variable domain, and V B is a TCR beta, gamma or delta variable domain. Ais a TCR alpha variable domain, and V B is a TCR beta variable domain, or V A is a TCR gamma variable domain, and V B is a TCR delta variable domain, or V A is a TCR alpha variable domain, and V B is a TCR gamma variable domain, or V A is a TCR delta variable domain, and V B is a TCR beta variable domain. In a preferred embodiment, V A is a TCR alpha variable domain, and V B is a TCR beta variable domain. In some embodiments, V A is a TCR gamma variable domain comprising CDR1 and CDR3 and optionally CDR2 from a TCR alpha variable domain, and / or B is a TCR delta variable domain comprising CDR1 and CDR3 and optionally CDR2 from a TCR beta variable domain.

[0125] Preferably, V A Within, 1) FR1-a comprises or consists of SEQ ID NO: 539, 554, or 569; FR2-a comprises or consists of SEQ ID NO: 584; FR3-a comprises or consists of SEQ ID NO: 599 or 614; and / or FR4-a comprises or consists of SEQ ID NO: 629; or 2) FR1-a comprises or consists of SEQ ID NO: 540, 555, or 570; FR2-a comprises or consists of SEQ ID NO: 585; FR3-a comprises or consists of SEQ ID NO: 600 or 615; and / or FR4-a comprises or consists of SEQ ID NO: 630; or 3) FR1-a comprises or consists of SEQ ID NO: 541, 556, or 571; FR2-a comprises or consists of SEQ ID NO: 586; FR3-a comprises or consists of SEQ ID NO: 601 or 616; and / or FR4-a comprises or consists of SEQ ID NO: 631; or 4) FR1-a comprises or consists of SEQ ID NO: 542, 557, or 572; FR2-a comprises or consists of SEQ ID NO: 587; FR3-a comprises or consists of SEQ ID NO: 602 or 617; and / or FR4-a comprises or consists of SEQ ID NO: 632; or 5) FR1-a comprises or consists of SEQ ID NO: 543, 558, or 573; FR2-a comprises or consists of SEQ ID NO: 588; FR3-a comprises or consists of SEQ ID NO: 603 or 618; and / or FR4-a comprises or consists of SEQ ID NO: 633; ​​or 6) FR1-a comprises or consists of SEQ ID NO: 544, 559, or 574; FR2-a comprises or consists of SEQ ID NO: 589; FR3-a comprises or consists of SEQ ID NO: 604 or 619; and / or FR4-a comprises or consists of SEQ ID NO: 634; or 7) FR1-a comprises or consists of SEQ ID NO: 545, 560, or 575; FR2-a comprises or consists of SEQ ID NO:590; FR3-a comprises or consists of SEQ ID NO: 605 or 620; and / or FR4-a comprises or consists of SEQ ID NO: 635; or 8) FR1-a comprises or consists of SEQ ID NO: 546, 561, or 576; FR2-a comprises or consists of SEQ ID NO: 591; FR3-a comprises or consists of SEQ ID NO: 606 or 621; and / or FR4-a comprises or consists of SEQ ID NO: 636; or 9) FR1-a comprises or consists of SEQ ID NO: 547, 562, or 577; FR2-a comprises or consists of SEQ ID NO: 592; FR3-a comprises or consists of SEQ ID NO: 607 or 622; and / or FR4-a comprises or consists of SEQ ID NO: 637; or 10) FR1-a comprises or consists of SEQ ID NO: 548, 563, or 578; FR2-a comprises or consists of SEQ ID NO: 593; FR3-a comprises or consists of SEQ ID NO: 608 or 623; and / or FR4-a comprises or consists of SEQ ID NO: 638; 11) FR1-a comprises or consists of SEQ ID NO: 549, 564, or 579; FR2-a comprises or consists of SEQ ID NO:594; FR3-a comprises or consists of SEQ ID NO: 609 or 624; and / or FR4-a comprises or consists of SEQ ID NO: 639; or 12) FR1-a comprises or consists of SEQ ID NO: 550, 565, or 580; FR2-a comprises or consists of SEQ ID NO: 595; FR3-a comprises or consists of SEQ ID NO: 610 or 625; and / or FR4-a comprises or consists of SEQ ID NO: 640; or 13) FR1-a comprises or consists of SEQ ID NO: 551, 566, or 581; FR2-a comprises or consists of SEQ ID NO:596; FR3-a comprises or consists of SEQ ID NO: 611 or 626; and / or FR4-a comprises or consists of SEQ ID NO: 641; or 14) FR1-a comprises or consists of SEQ ID NO: 552, 567, or 582; FR2-a comprises or consists of SEQ ID NO:597; FR3-a comprises or consists of SEQ ID NO: 612 or 627; and / or FR4-a comprises or consists of SEQ ID NO: 642; or 15) FR1-a comprises or consists of SEQ ID NO: 553, 568, or 583; FR2-a comprises or consists of SEQ ID NO:598; FR3-a comprises or consists of SEQ ID NO: 613 or 628; and / or FR4-a comprises or consists of SEQ ID NO:643; and V B Within, 1) FR1-b comprises or consists of SEQ ID NO: 644 or 659; FR2-b comprises or consists of SEQ ID NO: 674 or 689; FR3-b comprises or consists of SEQ ID NO: 704 or 719; and / or FR4-b comprises or consists of SEQ ID NO: 734; or 2) FR1-b comprises or consists of SEQ ID NO: 645 or 660; FR2-b comprises or consists of SEQ ID NO: 675 or 690; FR3-b comprises or consists of SEQ ID NO: 705 or 720; and / or FR4-b comprises or consists of SEQ ID NO: 735; or 3) FR1-b comprises or consists of SEQ ID NO: 646 or 661; FR2-b comprises or consists of SEQ ID NO: 676 or 691; FR3-b comprises or consists of SEQ ID NO: 706 or 721; and / or FR4-b comprises or consists of SEQ ID NO: 736; or 4) FR1-b comprises or consists of SEQ ID NO: 647 or 662; FR2-b comprises or consists of SEQ ID NO: 677 or 692; FR3-b comprises or consists of SEQ ID NO: 707 or 722; and / or FR4-b comprises or consists of SEQ ID NO: 737; or 5) FR1-b comprises or consists of SEQ ID NO: 648 or 663; FR2-b comprises or consists of SEQ ID NO: 678 or 693; FR3-b comprises or consists of SEQ ID NO: 708 or 723; and / or FR4-b comprises or consists of SEQ ID NO: 738; or 6) FR1-b comprises or consists of SEQ ID NO: 649 or 664; FR2-b comprises or consists of SEQ ID NO: 679 or 694; FR3-b comprises or consists of SEQ ID NO: 709 or 724; and / or FR4-b comprises or consists of SEQ ID NO: 739; or 7) FR1-b comprises or consists of SEQ ID NO: 650 or 665; FR2-b comprises or consists of SEQ ID NO: 680 or 695; FR3-b comprises or consists of SEQ ID NO: 710 or 725; and / or FR4-b comprises or consists of SEQ ID NO: 740; or 8) FR1-b comprises or consists of SEQ ID NO: 651 or 666; FR2-b comprises or consists of SEQ ID NO: 681 or 696; FR3-b comprises or consists of SEQ ID NO: 711 or 726; and / or FR4-b comprises or consists of SEQ ID NO: 741; or 9) FR1-b comprises or consists of SEQ ID NO: 652 or 667; FR2-b comprises or consists of SEQ ID NO: 682 or 697; FR3-b comprises or consists of SEQ ID NO: 712 or 727; and / or FR4-b comprises or consists of SEQ ID NO: 742; or 10) FR1-b comprises or consists of SEQ ID NO: 653 or 668; FR2-b comprises or consists of SEQ ID NO: 683 or 698; FR3-b comprises or consists of SEQ ID NO: 713 or 728; and / or FR4-b comprises or consists of SEQ ID NO: 743; or 11) FR1-b comprises or consists of SEQ ID NO: 654 or 669; FR2-b comprises or consists of SEQ ID NO: 684 or 699; FR3-b comprises or consists of SEQ ID NO: 714 or 729; and / or FR4-b comprises or consists of SEQ ID NO: 744; or 12) FR1-b comprises or consists of SEQ ID NO: 655 or 670; FR2-b comprises or consists of SEQ ID NO: 685 or 700; FR3-b comprises or consists of SEQ ID NO: 715 or 730; and / or FR4-b comprises or consists of SEQ ID NO: 745; or 13) FR1-b comprises or consists of SEQ ID NO: 656 or 671; FR2-b comprises or consists of SEQ ID NO: 686 or 701; FR3-b comprises or consists of SEQ ID NO: 716 or 731; and / or FR4-b comprises or consists of SEQ ID NO: 746; or 14) FR1-b comprises or consists of SEQ ID NO: 657 or 672; FR2-b comprises or consists of SEQ ID NO: 687 or 702; FR3-b comprises or consists of SEQ ID NO: 717 or 732; and / or FR4-b comprises or consists of SEQ ID NO: 747; or 15) FR1-b comprises or consists of SEQ ID NO: 658 or 673; FR2-b comprises or consists of SEQ ID NO: 688 or 703; FR3-b comprises or consists of SEQ ID NO: 718 or 733; and / or FR4-b comprises or consists of SEQ ID NO: 748; Each of FR1-a, FR2-a, FR3-a, FR4-a, FR1-b, FR2-b, FR3-b and FR4-b may contain 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations, as appropriate.

[0126] In some embodiments, preferably 1) FR1-a comprises or consists of SEQ ID NO: 539; 2) FR1-a comprises or consists of SEQ ID NO: 540; 3) FR1-a comprises or consists of SEQ ID NO: 541; 4) FR1-a comprises or consists of SEQ ID NO: 542; 5) FR1-a comprises or consists of SEQ ID NO: 543; 6) FR1-a comprises or consists of SEQ ID NO: 544; 7) FR1-a comprises or consists of SEQ ID NO: 545; 8) FR1-a comprises or consists of SEQ ID NO: 546; 9) FR1-a comprises or consists of SEQ ID NO: 547; 10) FR1-a comprises or consists of SEQ ID NO: 548; 11) FR1-a comprises or consists of SEQ ID NO: 549; 12) FR1-a comprises or consists of SEQ ID NO: 550; 13) FR1-a comprises or consists of SEQ ID NO: 551; 14) FR1-a comprises or consists of SEQ ID NO: 552; or 15) FR1-a comprises or consists of SEQ ID NO: 553; Each of FR1-a, FR2-a, FR3-a and FR4-a may optionally contain 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations.

[0127] In some embodiments, preferably 1) FR3-a comprises or consists of SEQ ID NO: 599, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 10 of SEQ ID NO: 599; 2) FR3-a comprises or consists of SEQ ID NO: 600, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 11 of SEQ ID NO: 600; 3) FR3-a comprises or consists of SEQ ID NO: 601, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 5 of SEQ ID NO: 601; 4) FR3-a comprises or consists of SEQ ID NO: 602, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 12 of SEQ ID NO: 602; 5) FR3-a comprises or consists of SEQ ID NO: 603, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 22 of SEQ ID NO: 603; 6) FR3-a comprises or consists of SEQ ID NO: 604, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 25 of SEQ ID NO: 604; 7) FR3-a comprises or consists of SEQ ID NO: 605, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 21 of SEQ ID NO: 605; 8) FR3-a comprises or consists of SEQ ID NO: 606, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 18 of SEQ ID NO: 606; 9) FR3-a comprises or consists of SEQ ID NO: 607, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 24 of SEQ ID NO: 607; 10) FR3-a comprises or consists of SEQ ID NO: 608, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 21 of SEQ ID NO: 608; 11) FR3-a comprises or consists of SEQ ID NO: 609, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 7 of SEQ ID NO: 609; 12) FR3-a comprises or consists of SEQ ID NO: 610, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 30 of SEQ ID NO: 610; 13) FR3-a comprises or consists of SEQ ID NO: 611, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 18 of SEQ ID NO: 611; 14) FR3-a comprises or consists of SEQ ID NO: 612, optionally containing 8, 7, 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 19 of SEQ ID NO: 612; or 15) FR3-a comprises or consists of SEQ ID NO: 613, optionally containing 8, 7, 6, 5, 4, 3, 2, or 1 amino acid mutations outside position 23 of SEQ ID NO: 613.

[0128] In some embodiments, preferably 1) FR2-b comprises or consists of SEQ ID NO: 674; 2) FR2-b comprises or consists of SEQ ID NO: 675; 3) FR2-b comprises or consists of SEQ ID NO: 676; 4) FR2-b comprises or consists of SEQ ID NO: 677; 5) FR2-b comprises or consists of SEQ ID NO: 678; 6) FR2-b comprises or consists of SEQ ID NO: 679; 7) FR2-b comprises or consists of SEQ ID NO: 680; 8) FR2-b comprises or consists of SEQ ID NO: 681; 9) FR2-b comprises or consists of SEQ ID NO: 682; 10) FR2-b comprises or consists of SEQ ID NO: 683; 11) FR2-b comprises or consists of SEQ ID NO: 684; 12) FR2-b comprises or consists of SEQ ID NO: 685; 13) FR2-b comprises or consists of SEQ ID NO: 686; 14) FR2-b comprises or consists of SEQ ID NO: 687; or 15) FR2-b comprises or consists of SEQ ID NO: 688; Each of FR1-b, FR2-b, FR3-b and FR4-b may optionally contain 6, 5, 4, 3, 2 or 1 amino acid mutations.

[0129] In some embodiments, preferably 1) FR2-b comprises or consists of SEQ ID NO: 689, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 16 of SEQ ID NO: 689; or 2) FR2-b comprises or consists of SEQ ID NO: 690, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 17 of SEQ ID NO: 690; 3) FR2-b comprises or consists of SEQ ID NO: 691, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 5 of SEQ ID NO: 691; 4) FR2-b comprises or consists of SEQ ID NO: 692, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 15 of SEQ ID NO: 692; 5) FR2-b comprises or consists of SEQ ID NO: 693, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 7 of SEQ ID NO: 693; 6) FR2-b comprises or consists of SEQ ID NO: 694, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 13 of SEQ ID NO: 694; 7) FR2-b comprises or consists of SEQ ID NO: 695, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 11 of SEQ ID NO: 695; 8) FR2-b comprises or consists of SEQ ID NO: 696, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 11 of SEQ ID NO: 696; 9) FR2-b comprises or consists of SEQ ID NO: 697, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 1 of SEQ ID NO: 697; 10) FR2-b comprises or consists of SEQ ID NO: 698, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 1 of SEQ ID NO: 698; 11) FR2-b comprises or consists of SEQ ID NO: 699, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 16 of SEQ ID NO: 699; 12) FR2-b comprises or consists of SEQ ID NO: 700, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 7 of SEQ ID NO: 700; 13) FR2-b comprises or consists of SEQ ID NO: 701, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 11 of SEQ ID NO: 701; 14) FR2-b comprises or consists of SEQ ID NO: 702, optionally including 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 1 of SEQ ID NO: 702; or 15) FR2-b comprises or consists of SEQ ID NO: 703, optionally containing 6, 5, 4, 3, 2 or 1 amino acid mutations outside position 7 of SEQ ID NO: 703.

[0130] In a preferred embodiment, 1) V A comprises an amino acid sequence of SEQ ID NO: 189, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 189, and comprising a CDRa1 comprising SEQ ID NO: 14, a CDRa3 comprising SEQ ID NO: 489, and optionally a CDRa2 comprising SEQ ID NO: 15; and V B comprises SEQ ID NO: 339, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 339 and comprising CDRb1 comprising SEQ ID NO: 19, CDRb3 comprising SEQ ID NO: 504 and optionally CDRb2 comprising SEQ ID NO: 20; or 2) V A comprises an amino acid sequence of SEQ ID NO: 190, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 190, and comprising a CDRa1 comprising SEQ ID NO: 24, a CDRa3 comprising SEQ ID NO: 490, and optionally a CDRa2 comprising SEQ ID NO: 25; and V B comprises an amino acid sequence of SEQ ID NO: 340, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 340 and comprising CDRb1 comprising SEQ ID NO: 75, CDRb3 comprising SEQ ID NO: 505 and optionally CDRb2 comprising SEQ ID NO: 76; or 3) V Acomprises an amino acid sequence of SEQ ID NO: 191, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 191, and comprising a CDRa1 comprising SEQ ID NO: 24, a CDRa3 comprising SEQ ID NO: 491, and optionally a CDRa2 comprising SEQ ID NO: 25; and B comprises an amino acid sequence of SEQ ID NO: 341, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 341 and comprising CDRb1 comprising SEQ ID NO: 66, CDRb3 comprising SEQ ID NO: 506 and optionally CDRb2 comprising SEQ ID NO: 67; or 4) V A comprises an amino acid sequence of SEQ ID NO: 192, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 192, and comprises a CDRa1 comprising SEQ ID NO: 90, a CDRa3 comprising SEQ ID NO: 492, and optionally a CDRa2 comprising SEQ ID NO: 91; and V B comprises an amino acid sequence of SEQ ID NO: 342 or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 342 and comprising CDRb1 comprising SEQ ID NO: 66, CDRb3 comprising SEQ ID NO: 507 and optionally CDRb2 comprising SEQ ID NO: 95; or 5) V A comprises an amino acid sequence of SEQ ID NO: 193, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 193, and comprising a CDRa1 comprising SEQ ID NO: 2, a CDRa3 comprising SEQ ID NO: 493, and optionally a CDRa2 comprising SEQ ID NO: 3; and V B comprises an amino acid sequence of SEQ ID NO: 343, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 343 and comprising CDRb1 comprising SEQ ID NO: 8, CDRb3 comprising SEQ ID NO: 508 and optionally CDRb2 comprising SEQ ID NO: 9; or 6) V Acomprises an amino acid sequence of SEQ ID NO: 194, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 194, and comprising a CDRa1 comprising SEQ ID NO: 53, a CDRa3 comprising SEQ ID NO: 494, and optionally a CDRa2 comprising SEQ ID NO: 54; and B comprises SEQ ID NO: 344, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 344 and comprising CDRb1 comprising SEQ ID NO: 58, CDRb3 comprising SEQ ID NO: 509 and optionally CDRb2 comprising SEQ ID NO: 59; or 7) V A comprises an amino acid sequence of SEQ ID NO: 195, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 195, and comprising a CDRa1 comprising SEQ ID NO: 71, a CDRa3 comprising SEQ ID NO: 495, and optionally a CDRa2 comprising SEQ ID NO: 15; and B comprises SEQ ID NO: 345, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 345 and comprising CDRb1 comprising SEQ ID NO: 75, CDRb3 comprising SEQ ID NO: 510 and optionally CDRb2 comprising SEQ ID NO: 76; or 8) V A comprises an amino acid sequence of SEQ ID NO: 196, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 196, and comprising a CDRa1 comprising SEQ ID NO: 99, a CDRa3 comprising SEQ ID NO: 496, and optionally a CDRa2 comprising SEQ ID NO: 100; and B comprises SEQ ID NO: 346, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 346 and comprising CDRb1 comprising SEQ ID NO: 75, CDRb3 comprising SEQ ID NO: 511 and optionally CDRb2 comprising SEQ ID NO: 76; or 9) V Acomprises an amino acid sequence of SEQ ID NO: 197, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 197, and comprising a CDRa1 comprising SEQ ID NO: 80, a CDRa3 comprising SEQ ID NO: 497, and optionally a CDRa2 comprising SEQ ID NO: 81; and B comprises SEQ ID NO: 347, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 347 and comprising CDRb1 comprising SEQ ID NO: 85, CDRb3 comprising SEQ ID NO: 512 and optionally CDRb2 comprising SEQ ID NO: 86; or 10) V A comprises an amino acid sequence of SEQ ID NO: 198, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 198, and comprising a CDRa1 comprising SEQ ID NO: 107, a CDRa3 comprising SEQ ID NO: 498, and optionally a CDRa2 comprising SEQ ID NO: 108; and V B comprises an amino acid sequence of SEQ ID NO: 348, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 348 and comprising CDRb1 comprising SEQ ID NO: 112, CDRb3 comprising SEQ ID NO: 513 and optionally CDRb2 comprising SEQ ID NO: 113; or 11) V A comprises an amino acid sequence of SEQ ID NO: 199, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 199, and comprising a CDRa1 comprising SEQ ID NO: 125, a CDRa3 comprising SEQ ID NO: 499, and optionally a CDRa2 comprising SEQ ID NO: 126; and B comprises an amino acid sequence of SEQ ID NO: 349, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 349 and comprising CDRb1 comprising SEQ ID NO: 112, CDRb3 comprising SEQ ID NO: 514 and optionally CDRb2 comprising SEQ ID NO: 113; or 12) V Acomprises an amino acid sequence of SEQ ID NO:200, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:200, and comprising a CDRa1 comprising SEQ ID NO:117, a CDRa3 comprising SEQ ID NO:500, and optionally a CDRa2 comprising SEQ ID NO:118; and V B comprises SEQ ID NO: 350, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 350 and comprising CDRb1 comprising SEQ ID NO: 58, CDRb3 comprising SEQ ID NO: 515 and optionally CDRb2 comprising SEQ ID NO: 59; or 13) V A comprises an amino acid sequence of SEQ ID NO:201, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:201, and comprising a CDRa1 comprising SEQ ID NO:24, a CDRa3 comprising SEQ ID NO:501, and optionally a CDRa2 comprising SEQ ID NO:25; and V B comprises SEQ ID NO: 351, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 351 and comprising CDRb1 comprising SEQ ID NO: 38, CDRb3 comprising SEQ ID NO: 516 and optionally CDRb2 comprising SEQ ID NO: 39; or 14) V A comprises an amino acid sequence of SEQ ID NO: 202, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 202, and comprising a CDRa1 comprising SEQ ID NO: 24, a CDRa3 comprising SEQ ID NO: 502, and optionally a CDRa2 comprising SEQ ID NO: 25; and V B comprises an amino acid sequence of SEQ ID NO: 352, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 352 and comprising CDRb1 comprising SEQ ID NO: 29, CDRb3 comprising SEQ ID NO: 517 and optionally CDRb2 comprising SEQ ID NO: 30; or 15) V Acomprises an amino acid sequence of SEQ ID NO: 203, or having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 203, and comprising a CDRa1 comprising SEQ ID NO: 43, a CDRa3 comprising SEQ ID NO: 503, and optionally a CDRa2 comprising SEQ ID NO: 44; and B comprises an amino acid sequence of SEQ ID NO: 353, or at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identical to SEQ ID NO: 353, and comprising CDRb1 comprising SEQ ID NO: 48, CDRb3 comprising SEQ ID NO: 518 and, optionally, CDRb2 comprising SEQ ID NO: 49.

[0131] In a preferred embodiment, 1) V A comprises SEQ ID NO: 189, 249, 264 or 279; and V B comprises SEQ ID NO: 339, 399, 414 or 429, or 2) V A comprises SEQ ID NO: 190, 250, 265 or 280; and V B comprises SEQ ID NO: 340, 400, 415 or 430; or 3) V A comprises SEQ ID NO: 191, 251, 266 or 281; and V B comprises SEQ ID NO: 341, 401, 416 or 431; or 4) V A comprises SEQ ID NO: 192, 252, 267 or 282; and V B comprises SEQ ID NO: 342, 402, 417 or 432; or 5) V A comprises SEQ ID NO: 193, 253, 268 or 283; and V B comprises SEQ ID NO: 343, 403, 418 or 433; or 6) V A comprises SEQ ID NO: 194, 254, 269 or 284; and V B comprises SEQ ID NO: 344, 404, 419 or 434; or 7) V Acomprises SEQ ID NO: 195, 255, 270 or 285; and V B comprises SEQ ID NO: 345, 405, 420 or 435; or 8) V A comprises SEQ ID NO: 196, 256, 271 or 286; and V B comprises SEQ ID NO: 346, 406, 421 or 436; or 9) V A comprises SEQ ID NO: 197, 257, 272 or 287; and V B comprises SEQ ID NO: 347, 407, 422, or 437; or 10) V A comprises SEQ ID NO: 198, 258, 273 or 288; and V B comprises SEQ ID NO: 348, 408, 423 or 438; or 11) V A comprises SEQ ID NO: 199, 259, 274 or 289; and V B comprises SEQ ID NO: 349, 409, 424 or 439; or 12) V A comprises SEQ ID NO: 200, 260, 275 or 290; and V B comprises SEQ ID NO: 350, 410, 425 or 440; or 13) V A comprises SEQ ID NO: 201, 261, 276 or 291; and V B comprises SEQ ID NO: 351, 411, 426 or 441; or 14) V A comprises SEQ ID NO: 202, 262, 277 or 292; and V B comprises SEQ ID NO: 352, 412, 427 or 442; or 15) V A comprises SEQ ID NO: 203, 263, 278 or 293; and V B comprises SEQ ID NO: 353, 413, 428 or 443.

[0132] In some embodiments, 1) V Acomprises SEQ ID NO: 189; and V B comprises SEQ ID NO: 414, or 2) V A comprises SEQ ID NO: 190; and V B comprises SEQ ID NO: 415, or 3) V A comprises SEQ ID NO: 191; and V B comprises SEQ ID NO: 416, or 4) V A comprises SEQ ID NO: 192; and V B comprises SEQ ID NO: 417, or 5) V A comprises SEQ ID NO: 193; and V B comprises SEQ ID NO: 418, or 6) V A comprises SEQ ID NO: 194; and V B comprises SEQ ID NO: 419, or 7) V A comprises SEQ ID NO: 195; and V B comprises SEQ ID NO: 420, or 8) V A comprises SEQ ID NO: 196; and V B comprises SEQ ID NO: 421, or 9) V A comprises SEQ ID NO: 197; and V B comprises SEQ ID NO: 422, or 10) V A comprises SEQ ID NO: 198; and V B comprises SEQ ID NO: 423, or 11) V A comprises SEQ ID NO: 199; and V B comprises SEQ ID NO: 424, or 12) V A comprises SEQ ID NO: 200; and V B comprises SEQ ID NO: 425, or 13) V A comprises SEQ ID NO:201; and V B comprises SEQ ID NO: 426, or 14) V A comprises SEQ ID NO:202; and V B comprises SEQ ID NO: 427, or 15) VA comprises SEQ ID NO: 203; and V B comprises sequence number 428.

[0133] V A preferably comprises or consists of an amino acid sequence selected from the group consisting of SEQ ID NOs: 13, 132, 62, 89, 1, 52, 70, 98, 79, 106, 124, 116, 34, 23, and 42, or an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as defined in the context of the antigen binding protein of the invention having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NOs: 13, 132, 62, 89, 1, 52, 70, 98, 79, 106, 124, 116, 34, 23, and 42, and wherein the CDRa1, CDRa2 and CDRa3 sequences may comprise 1, 2 or 3 amino acid mutations. B preferably comprises or consists of an amino acid sequence selected from the group consisting of SEQ ID NOs: 18, 135, 65, 94, 7, 57, 74, 103, 84, 111, 129, 121, 37, 28 and 47, or an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as defined in the context of the antigen binding protein of the invention having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NOs: 18, 135, 65, 94, 7, 57, 74, 103, 84, 111, 129, 121, 37, 28 and 47 and wherein the CDRb1, CDRb2 and CDRb3 sequences may comprise 1, 2 or 3 amino acid mutations.

[0134] Modifications and changes can be made in the amino acid sequences of the antigen binding proteins of the present invention, and the corresponding DNA sequences, respectively, and still obtain a functional antigen binding protein or polypeptide possessing desirable properties.

[0135] In a preferred embodiment, 1) V Acomprises or consists of the amino acid sequence of SEQ ID NO: 13 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 13, and B comprises or consists of the amino acid sequence of SEQ ID NO: 18, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 18; 2) V A comprises or consists of the amino acid sequence of SEQ ID NO: 132 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 132, and B comprises or consists of the amino acid sequence of SEQ ID NO: 135, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 135; 3) V A comprises or consists of the amino acid sequence of SEQ ID NO: 62 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 62, and B comprises or consists of the amino acid sequence of SEQ ID NO:65, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:65; 4) V A comprises or consists of the amino acid sequence of SEQ ID NO: 89 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 89, and B comprises or consists of the amino acid sequence of SEQ ID NO:94, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:94; 5) V Acomprises or consists of the amino acid sequence of SEQ ID NO:1 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:1, and B comprises or consists of the amino acid sequence of SEQ ID NO:7 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:7; 6) V A comprises or consists of the amino acid sequence of SEQ ID NO:52 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:52, and B comprises or consists of the amino acid sequence of SEQ ID NO:57, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:57; 7) V A comprises or consists of the amino acid sequence of SEQ ID NO: 70 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 70, and B comprises or consists of the amino acid sequence of SEQ ID NO: 74, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 74; 8) V A comprises or consists of the amino acid sequence of SEQ ID NO: 98 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 98, and B comprises or consists of the amino acid sequence of SEQ ID NO: 103, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 103; 9) V Acomprises or consists of the amino acid sequence of SEQ ID NO: 79 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 79, and B comprises or consists of the amino acid sequence of SEQ ID NO: 84, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 84; 10) V A comprises or consists of the amino acid sequence of SEQ ID NO: 106 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 106, and B comprises or consists of the amino acid sequence of SEQ ID NO: 111, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 111; 11) V A comprises or consists of the amino acid sequence of SEQ ID NO: 124 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 124, and B comprises or consists of the amino acid sequence of SEQ ID NO: 129, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 129; 12) V A comprises or consists of the amino acid sequence of SEQ ID NO: 116 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 116, and B comprises or consists of the amino acid sequence of SEQ ID NO: 121, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 121; 13) V Acomprises or consists of the amino acid sequence of SEQ ID NO: 34 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 34, and B comprises or consists of the amino acid sequence of SEQ ID NO: 37, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 37; 14) V A comprises or consists of the amino acid sequence of SEQ ID NO:23 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:23, and B comprises or consists of the amino acid sequence of SEQ ID NO:28 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:28; or 15) V A comprises or consists of the amino acid sequence of SEQ ID NO: 42 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 42, and B comprises or consists of the amino acid sequence of SEQ ID NO: 47 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 47; V A and V B comprises a CDR sequence as defined in relation to an antigen binding protein of the present invention, which may comprise one, two or three amino acid mutations, and preferably does not comprise an amino acid mutation.

[0136] In a preferred embodiment, 1) V A comprises or consists of SEQ ID NO: 13, 204, 219 or 234; and V B comprises or consists of SEQ ID NO: 18, 354, 369 or 384; or 2) V A comprises or consists of SEQ ID NO: 132, 205, 220 or 235; and V B comprises or consists of SEQ ID NO: 135, 355, 370 or 385; or 3) V A comprises or consists of SEQ ID NO: 62, 206, 221 or 236; and V B comprises or consists of SEQ ID NO: 65, 356, 371 or 386; or 4) V A comprises or consists of SEQ ID NO: 89, 207, 222 or 237; and V B comprises or consists of SEQ ID NO: 94, 357, 372 or 387; or 5) V A comprises or consists of SEQ ID NO: 1, 208, 223 or 238; and V B comprises or consists of SEQ ID NO: 7, 358, 373 or 388; or 6) V A comprises or consists of SEQ ID NO: 52, 209, 224 or 239; and V B comprises or consists of SEQ ID NO: 57, 359, 374 or 389; or 7) V A comprises or consists of SEQ ID NO: 70, 210, 225 or 240; and V B comprises or consists of SEQ ID NO: 74, 360, 375 or 390; or 8) V A comprises or consists of SEQ ID NO: 198, 211, 226 or 241; and V B comprises or consists of SEQ ID NO: 103, 361, 376 or 391; or 9) V A comprises or consists of SEQ ID NO: 79, 212, 227 or 242; and V B comprises or consists of SEQ ID NO: 84, 362, 377, or 392; or 10) VA comprises or consists of SEQ ID NO: 106, 213, 228 or 243; and V B comprises or consists of SEQ ID NO: 111, 363, 378 or 393; or 11) V A comprises or consists of SEQ ID NO: 124, 214, 229 or 244; and V B comprises or consists of SEQ ID NO: 129, 364, 379 or 394; or 12) V A comprises or consists of SEQ ID NO: 116, 215, 230 or 245; and V B comprises or consists of SEQ ID NO: 121, 365, 380 or 395; or 13) V A comprises or consists of SEQ ID NO: 34, 216, 231 or 246; and V B comprises or consists of SEQ ID NO: 37, 366, 381 or 396; or 14) V A comprises or consists of SEQ ID NO: 23, 217, 232 or 247; and V B comprises or consists of SEQ ID NO: 28, 367, 382 or 397; or 15) V A comprises or consists of SEQ ID NO: 42, 218, 233 or 248; and V B comprises or consists of SEQ ID NO: 47, 368, 383 or 398.

[0137] More preferably, 1) V A comprises or consists of the amino acid sequence of SEQ ID NO: 13, and B comprises or consists of the amino acid sequence of SEQ ID NO: 18; 2) V A comprises or consists of the amino acid sequence of SEQ ID NO: 132, and B comprises or consists of the amino acid sequence of SEQ ID NO: 135; 3) VA comprises or consists of the amino acid sequence of SEQ ID NO: 62, and B comprises or consists of the amino acid sequence of SEQ ID NO: 65; 4) V A comprises or consists of the amino acid sequence of SEQ ID NO: 89, and B comprises or consists of the amino acid sequence of SEQ ID NO:94; 5) V A comprises or consists of the amino acid sequence of SEQ ID NO: 1, and V B comprises or consists of the amino acid sequence of SEQ ID NO:7; 6) V A comprises or consists of the amino acid sequence of SEQ ID NO: 52, and B comprises or consists of the amino acid sequence of SEQ ID NO:57; 7) V A comprises or consists of the amino acid sequence of SEQ ID NO: 70, and B comprises or consists of the amino acid sequence of SEQ ID NO: 74; 8) V A comprises or consists of the amino acid sequence of SEQ ID NO: 98, and B comprises or consists of the amino acid sequence of SEQ ID NO: 103; 9) V A comprises or consists of the amino acid sequence of SEQ ID NO: 79, and B comprises or consists of the amino acid sequence of SEQ ID NO: 84; 10) V A comprises or consists of the amino acid sequence of SEQ ID NO: 106, and B comprises or consists of the amino acid sequence of SEQ ID NO: 111; 11) V A comprises or consists of the amino acid sequence of SEQ ID NO: 124, and B comprises or consists of the amino acid sequence of SEQ ID NO: 129; 12) V A comprises or consists of the amino acid sequence of SEQ ID NO: 116, and Bcomprises or consists of the amino acid sequence of SEQ ID NO: 121; 13) V A comprises or consists of the amino acid sequence of SEQ ID NO: 34, and B comprises or consists of the amino acid sequence of SEQ ID NO: 37; 14) V A comprises or consists of the amino acid sequence of SEQ ID NO: 23, and B comprises or consists of the amino acid sequence of SEQ ID NO: 28; or 15) V A comprises or consists of the amino acid sequence of SEQ ID NO: 42, and B comprises or consists of the amino acid sequence of SEQ ID NO:47.

[0138] In another embodiment, 1) V A comprises or consists of SEQ ID NO: 13, and V B comprises or consists of SEQ ID NO: 369, or 2) V A comprises or consists of SEQ ID NO: 132, and V B comprises or consists of SEQ ID NO: 370; or 3) V A comprises or consists of SEQ ID NO: 62, and V B comprises or consists of SEQ ID NO: 371, or 4) V A comprises or consists of SEQ ID NO: 89, and V B comprises or consists of SEQ ID NO: 372, or 5) V A comprises or consists of SEQ ID NO: 1, and V B comprises or consists of SEQ ID NO: 373; or 6) V A comprises or consists of SEQ ID NO: 52, and V B comprises or consists of SEQ ID NO: 374, or 7) V Acomprises or consists of SEQ ID NO: 70, and V B comprises or consists of SEQ ID NO: 375, or 8) V A comprises or consists of SEQ ID NO: 198, and V B comprises or consists of SEQ ID NO: 376; or 9) V A comprises or consists of SEQ ID NO: 79, and V B comprises or consists of SEQ ID NO: 377, or 10) V A comprises or consists of SEQ ID NO: 106, and V B comprises or consists of SEQ ID NO: 378; or 11) V A comprises or consists of SEQ ID NO: 124, and V B comprises or consists of SEQ ID NO: 379, or 12) V A comprises or consists of SEQ ID NO: 116, and V B comprises or consists of SEQ ID NO: 380; or 13) V A comprises or consists of SEQ ID NO: 34, and V B comprises or consists of SEQ ID NO: 381, or 14) V A comprises or consists of SEQ ID NO: 23, and V B comprises or consists of SEQ ID NO: 382; or 15) V A comprises or consists of SEQ ID NO: 42, and V B comprises or consists of SEQ ID NO:383.

[0139] The antigen binding protein may be monovalent or multivalent, for example tetravalent, trivalent or bivalent.

[0140] Antigen binding proteins can be monospecific or multispecific, e.g., tetraspecific, trispecific or bispecific.

[0141] In some embodiments, the antigen binding protein is a soluble protein.

[0142] In the antigen-binding proteins of the invention, the first and second polypeptides may be comprised in a single polypeptide chain. Such a single chain construct may for example be a single chain TCR (scTCR) or a single chain bispecific antigen-binding protein, in particular a single chain bispecific TCR, or a single chain bispecific TCR-antibody molecule.

[0143] The first and second polypeptides are comprised in two polypeptide chains, i.e., V A is included in the first polypeptide chain, and V B is preferably comprised in the second polypeptide chain.

[0144] Preferably, the antigen-binding protein is a TCR. The TCR may be selected from the group consisting of α / β TCR, γ / δ TCR, single chain TCR, membrane-bound TCR, soluble TCR, monovalent, bivalent or multivalent TCR, monospecific, bispecific or multispecific TCR, functional fragment of a TCR, fusion protein comprising a functional fragment of a TCR or chimeric protein comprising a functional fragment of a TCR. In a preferred embodiment, the TCR is an α / β TCR or a γ / δ TCR, preferably an α / β TCR. In the context of the present invention, whenever it is stated that the antigen-binding protein is preferably a TCR, this further implies that most preferably, the antigen-binding protein is an α / β TCR or a γ / δ TCR, preferably an α / β TCR. In one embodiment, the TCR constant domain sequence may be derived from any suitable species, such as any mammal, for example human, rat, monkey, rabbit, donkey or mouse, preferably human or mouse, more preferably human. In one embodiment, the TCR is an αβ TCR and comprises an α chain constant domain (TRAC) sequence of SEQ ID NO: 5, 750, 751 or 156, preferably SEQ ID NO: 5, 750 or 751, and a β chain constant domain (TRBC1 or TRBC2) sequence of SEQ ID NO: 11, 32 or 157, preferably SEQ ID NO: 11 or 32.

[0145] Preferably, the first polypeptide is selected from the group consisting of SEQ ID NOs: 17, 134, 64, 93, 6, 56, 73, 102, 83, 110, 128, 120, 36, 27, 46 and 158 to 172, preferably an amino acid sequence selected from the group consisting of SEQ ID NOs: 17, 134, 64, 93, 6, 56, 73, 102, 83, 110, 128, 120, 36, 27 and 46, or SEQ ID NOs: 17, 134, 64, 93, 6, 56, 73, 102, or consisting of an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as defined in the context of the antigen binding protein of the invention, which has at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to 83, 110, 128, 120, 36, 27, 46 or 158-172, and wherein the CDRa1, CDRa2 and CDRa3 sequences may contain one, two or three amino acid mutations. and the second polypeptide is selected from the group consisting of SEQ ID NOs: 22, 137, 69, 97, 12, 61, 78, 105, 88, 115, 131, 123, 41, 33, 51 and 173 to 187, preferably selected from the group consisting of SEQ ID NOs: 22, 137, 69, 97, 12, 61, 78, 105, 88, 115, 131, 123, 41, 33 and 51, or SEQ ID NOs: 22, 137, 69, 97, 12, 61, 78, 105, or consisting of an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as defined in relation to the antigen binding protein of the invention, which has at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to 88, 115, 131, 123, 41, 33, 51 or 173-187, and wherein the CDRb1, CDRb2 and CDRb3 sequences may contain 1, 2 or 3 amino acid mutations.

[0146] More preferably, the first polypeptide is selected from the group consisting of SEQ ID NOs: 17, 134, 64, 93, 6, 56, 73, 102, 83, 110, 128, 120, 36, 27, 46 and 158 to 172, preferably an amino acid sequence selected from the group consisting of SEQ ID NOs: 17, 134, 64, 93, 6, 56, 73, 102, 83, 110, 128, 120, 36, 27 and 46, or SEQ ID NOs: 17, 134, 64, 93, 6, 56, 73, 102, and the second polypeptide comprises or consists of an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as defined in relation to the antigen binding protein of the invention having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NOs: 22, 137, 69, 97, 12, 61, 78, 110, 128, 120, 36, 27, 46, or 158-172 and no amino acid mutations; and or consisting of an amino acid sequence selected from the group consisting of SEQ ID NO: 22, 137, 69, 97, 12, 61, 78 105, 88, 115, 131, 123, 41, 33 and 51, preferably selected from the group consisting of SEQ ID NO: 22, 137, 69, 97, 12, 61, 78 105, 88, 115, 131, 123, 41, 33 and 51, or an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as defined in relation to the antigen binding protein of the invention having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 22, 137, 69, 97, 12, 61, 78 105, 88, 115, 131, 123, 41, 33, 51 or 173-187 and no amino acid mutations.

[0147] In a preferred embodiment, 1) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:17, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:17, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:22, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:22; 2) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 134, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 134, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 137, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 137; 3) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:64, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:64, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:69, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:69; 4) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:93, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:93, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:97, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:97; 5) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:6 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:6, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:12 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:12; 6) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:56, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:56, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:61, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:61; 7) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 73, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 73, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 78, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 78; 8) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 102, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 102, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 105, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 105; 9) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:83, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:83, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:88, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:88; 10) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:110, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:110, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:115, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:115; 11) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 128, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 128, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 131, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 131; 12) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 120, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 120, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 123, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 123; 13) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 36, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 36, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 41, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 41; 14) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:27 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:27, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO:33 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:33; or 15) the first polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 46, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 46, and the second polypeptide comprises or consists of an amino acid sequence of SEQ ID NO: 51, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 51; The first and second polypeptides comprise the CDR sequences as defined in relation to the antigen binding proteins of the invention, which CDR sequences may comprise one, two or three amino acid mutations, and preferably no amino acid mutations.

[0148] In a preferred embodiment, 1) the first polypeptide comprises or consists of SEQ ID NO: 17, 294, 309 or 324 and the second polypeptide comprises or consists of SEQ ID NO: 22, 444, 459 or 474; 2) the first polypeptide comprises or consists of SEQ ID NO: 134, 295, 310 or 325 and the second polypeptide comprises or consists of SEQ ID NO: 137, 445, 460 or 475; 3) the first polypeptide comprises or consists of SEQ ID NO: 64, 296, 311 or 326 and the second polypeptide comprises or consists of SEQ ID NO: 69, 446, 461 or 476; 4) the first polypeptide comprises or consists of SEQ ID NO: 93, 297, 312 or 327 and the second polypeptide comprises or consists of SEQ ID NO: 97, 447, 462 or 477; 5) the first polypeptide comprises or consists of SEQ ID NO: 6, 298, 313 or 328 and the second polypeptide comprises or consists of SEQ ID NO: 12, 448, 463 or 478; 6) the first polypeptide comprises or consists of SEQ ID NO: 56, 299, 314 or 329 and the second polypeptide comprises or consists of SEQ ID NO: 61, 449, 464 or 479; 7) the first polypeptide comprises or consists of SEQ ID NO: 73, 300, 315 or 330 and the second polypeptide comprises or consists of SEQ ID NO: 78, 450, 465 or 480; 8) the first polypeptide comprises or consists of SEQ ID NO: 102, 301, 316 or 331 and the second polypeptide comprises or consists of SEQ ID NO: 105, 451, 466 or 481; 9) the first polypeptide comprises or consists of SEQ ID NO: 83, 302, 317 or 332 and the second polypeptide comprises or consists of SEQ ID NO: 88, 452, 467 or 482; 10) the first polypeptide comprises or consists of SEQ ID NO: 110, 303, 318 or 333 and the second polypeptide comprises or consists of SEQ ID NO: 115, 453, 468 or 483; 11) the first polypeptide comprises or consists of SEQ ID NO: 128, 304, 319 or 334 and the second polypeptide comprises or consists of SEQ ID NO: 131, 454, 469 or 484; 12) the first polypeptide comprises or consists of SEQ ID NO: 120, 305, 320 or 335 and the second polypeptide comprises or consists of SEQ ID NO: 123, 455, 470 or 485; 13) the first polypeptide comprises or consists of SEQ ID NO: 36, 306, 321 or 336 and the second polypeptide comprises or consists of SEQ ID NO: 41, 456, 471 or 486; 14) the first polypeptide comprises or consists of SEQ ID NO: 27, 307, 322 or 337 and the second polypeptide comprises or consists of SEQ ID NO: 33, 457, 472 or 487; or 15) The first polypeptide comprises or consists of SEQ ID NO: 46, 308, 323 or 338 and the second polypeptide comprises or consists of SEQ ID NO: 51, 458, 473 or 488.

[0149] More preferably, 1) the first polypeptide comprises or consists of SEQ ID NO:17 and the second polypeptide comprises or consists of SEQ ID NO:22; 2) the first polypeptide comprises or consists of SEQ ID NO: 134 and the second polypeptide comprises or consists of SEQ ID NO: 137; 3) the first polypeptide comprises or consists of SEQ ID NO:64 and the second polypeptide comprises or consists of SEQ ID NO:69; 4) the first polypeptide comprises or consists of SEQ ID NO:93 and the second polypeptide comprises or consists of SEQ ID NO:97; 5) the first polypeptide comprises or consists of SEQ ID NO:6 and the second polypeptide comprises or consists of SEQ ID NO:12; 6) the first polypeptide comprises or consists of SEQ ID NO:56 and the second polypeptide comprises or consists of SEQ ID NO:61; 7) the first polypeptide comprises or consists of SEQ ID NO: 73 and the second polypeptide comprises or consists of SEQ ID NO: 78; 8) the first polypeptide comprises or consists of SEQ ID NO: 102 and the second polypeptide comprises or consists of SEQ ID NO: 105; 9) the first polypeptide comprises or consists of SEQ ID NO: 83 and the second polypeptide comprises or consists of SEQ ID NO: 88; 10) the first polypeptide comprises or consists of SEQ ID NO: 110 and the second polypeptide comprises or consists of SEQ ID NO: 115; 11) the first polypeptide comprises or consists of SEQ ID NO: 128 and the second polypeptide comprises or consists of SEQ ID NO: 131; 12) the first polypeptide comprises or consists of SEQ ID NO: 120 and the second polypeptide comprises or consists of SEQ ID NO: 123; 13) the first polypeptide comprises or consists of SEQ ID NO: 36 and the second polypeptide comprises or consists of SEQ ID NO: 41; 14) the first polypeptide comprises or consists of SEQ ID NO:27 and the second polypeptide comprises or consists of SEQ ID NO:33; or 15) The first polypeptide comprises or consists of SEQ ID NO:46 and the second polypeptide comprises or consists of SEQ ID NO:51.

[0150] In another embodiment, 1) the first polypeptide comprises or consists of SEQ ID NO: 17 and the second polypeptide comprises or consists of SEQ ID NO: 459; 2) the first polypeptide comprises or consists of SEQ ID NO: 134 and the second polypeptide comprises or consists of SEQ ID NO: 460; 3) the first polypeptide comprises or consists of SEQ ID NO:64 and the second polypeptide comprises or consists of SEQ ID NO:461; 4) the first polypeptide comprises or consists of SEQ ID NO:93 and the second polypeptide comprises or consists of SEQ ID NO:462; 5) the first polypeptide comprises or consists of SEQ ID NO:6 and the second polypeptide comprises or consists of SEQ ID NO:463; 6) the first polypeptide comprises or consists of SEQ ID NO:56 and the second polypeptide comprises or consists of SEQ ID NO:464; 7) the first polypeptide comprises or consists of SEQ ID NO: 73 and the second polypeptide comprises or consists of SEQ ID NO: 465; 8) the first polypeptide comprises or consists of SEQ ID NO: 102 and the second polypeptide comprises or consists of SEQ ID NO: 466; 9) the first polypeptide comprises or consists of SEQ ID NO: 83 and the second polypeptide comprises or consists of SEQ ID NO: 467; 10) the first polypeptide comprises or consists of SEQ ID NO: 110 and the second polypeptide comprises or consists of SEQ ID NO: 468; 11) the first polypeptide comprises or consists of SEQ ID NO: 128 and the second polypeptide comprises or consists of SEQ ID NO: 469; 12) the first polypeptide comprises or consists of SEQ ID NO: 120 and the second polypeptide comprises or consists of SEQ ID NO: 470; 13) the first polypeptide comprises or consists of SEQ ID NO: 36 and the second polypeptide comprises or consists of SEQ ID NO: 471; 14) the first polypeptide comprises or consists of SEQ ID NO: 27 and the second polypeptide comprises or consists of SEQ ID NO: 472; or 15) The first polypeptide comprises or consists of SEQ ID NO: 46 and the second polypeptide comprises or consists of SEQ ID NO: 473.

[0151] In some preferred embodiments, the antigen binding proteins of the present invention may be engineered, for example, by the introduction of heterologous sequences, preferably mouse sequences, which may increase expression and stability. Also, additional stabilizing mutations known in the art (e.g., WO2018 / 104407, PCT / EP2018 / 069151, WO2011 / 044186, WO2014 / 018863), such as the replacement of undesired amino acids in the variable domains and / or the introduction of disulfide bonds and removal of unpaired cysteines, for example between the constant domains of the TCR, may be introduced.

[0152] In particular, the TCR constant domain sequence may be modified by truncation or substitution to delete the native disulfide bond between Cys4 of exon 2 of TRAC and Cys2 of exon 2 of TRBC1 or TRBC2. The alpha and / or delta chain constant domain sequences may also be modified by substitution of cysteine ​​residues at Thr48 of TRAC and Ser57 of TRBC1 or TRBC2, which form a disulfide bond between the alpha and beta constant domains of the TCR. TRBC1 or TRBC2 may further comprise a cysteine ​​to alanine mutation at position 75 of the constant domain and an asparagine to aspartic acid mutation at position 89 of the constant domain. The constant domain may also or alternatively comprise further mutations, substitutions, or deletions to the native TRAC and / or TRBC1 / 2 sequence. The terms TRAC and TRBC1 / 2 encompass natural polymorphic variants (eg, N to K at position 4 of TRAC) (Bragado et al Int Immunol. 1994 Feb;6(2):223-30).

[0153] In some embodiments, the antigen binding protein is monovalent or multivalent, such as tetravalent, trivalent or bivalent.

[0154] In some embodiments, the antigen-binding protein is bispecific, in particular a bispecific TCR, bispecific antibody or bispecific TCR-antibody molecule. If the antigen-binding protein is a bispecific "antibody", the skilled artisan will recognize that one of the antigen-binding sites comprises the TCR-derived CDR1, CDR3 and optionally CDR2 sequences as defined in relation to the antigen-binding protein of the invention, and the other antigen-binding site may be entirely derived from an antibody.

[0155] In some embodiments, the antigen binding protein is a soluble protein. In some embodiments, the antigen binding protein is a soluble TCR. As used herein, the term "soluble TCR" refers to a heterodimeric truncated mutant of native TCR that includes the extracellular portions of the TCR α and β chains, e.g., linked by disulfide bonds, but lacks the transmembrane and cytosolic domains of the native protein.

[0156] In one embodiment, the antigen binding protein is of human origin, which is understood as being produced from a human locus and thus comprising human sequences.

[0157] In some embodiments, the antigen binding protein is humanized, chimerized and / or murine.

[0158] In one embodiment, the antigen binding protein of the present invention has the structure: (i) one or more additional antigen-binding sites; (ii) a transmembrane region that may include a cytoplasmic signaling region; (iii) diagnostic agents; (iv) therapeutic drugs; The present invention further includes one or more of:

[0159] When the above listed components (i) to (v) are polypeptides fused to an antigen-binding protein of the present invention, the antigen-binding protein may also be referred to as a "TCR fusion protein."

[0160] If an additional antigen-binding site is present, it is preferably derived from an antibody.

[0161] Antigen binding proteins, particularly TCRs, with alternative domains, e.g., membrane anchor domains in place of the endogenous transmembrane region, are encompassed by the present invention. Also encompassed are antigen binding proteins, particularly TCRs, with point mutations in the TCR variable or constant domains to improve TCR expression or stability and / or chain pairing.

[0162] A "transmembrane region" in the context of the present invention may be, for example, a TCR alpha or beta transmembrane domain.

[0163] The "cytoplasmic signaling region" can be, for example, a TCR alpha or beta intracellular domain.

[0164] "Diagnostic agent," as used herein, refers to a detectable molecule or substance (e.g., a fluorescent molecule, a radioactive molecule, or any other label known in the art to produce (directly or indirectly) a signal.

[0165] "Fluorescent molecules" known in the art include fluorescein isothiocyanate (FITC), phycoerythrin (PE), fluorophores used with blue lasers (e.g., PerCP, PE-Cy7, PE-Cy5, FL3, and APC or Cy5, FL4), fluorophores used with red, violet, or UV lasers (e.g., Pacific Blue, Pacific Orange).

[0166] As a "radioactive molecule", I 123 , I 124 , In 111 , Re 186 , Re 188 , Tc 99 Antigen binding proteins of the invention may also include spin labels (e.g., iodine-123, indium-111, fluorine-19, carbon-13, nitrogen-15, oxygen-17, gadolinium, manganese, or iron) for nuclear magnetic resonance (NMR) imaging (also known as magnetic resonance imaging, MRI).

[0167] Such diagnostic agents may be directly bound (ie, physically linked) or indirectly linked to the antigen binding protein.

[0168] "Therapeutic agent" as used herein refers to an agent that has a therapeutic effect. The terms therapeutic agent and therapeutic drug are used interchangeably herein. In one embodiment, a therapeutic agent can be a growth inhibitory agent, such as a cytotoxic agent or a radioisotope.

[0169] "Growth inhibitory agent" or "anti-proliferative agent" (these terms may be used interchangeably) refers to a compound or composition that inhibits the growth of cells, especially tumor cells, either in vitro or in vivo.

[0170] The term "cytotoxic agent" as used herein refers to a substance that inhibits or prevents the function of a cell and / or causes the destruction of a cell. The term "cytotoxic agent" is intended to include chemotherapeutic agents, enzymes, antibiotics, and toxins (e.g., small molecule or enzymatically active toxins of bacterial, fungal, plant, or animal origin), including fragments and / or variants thereof, as well as various antitumor or anticancer agents disclosed below. In some embodiments, the cytotoxic agent is a taxoid, vinca, taxane, maytansinoid or maytansinoid analog (e.g., DM1 or DM4), small drug, tomaymycin or pyrrolobenzodiazepine derivative, cryptophycin derivative, leptomycin derivative, auristatin or dolastatin analog, prodrug, topoisomerase II inhibitor, DNA alkylating agent, antitubulin agent, CC-1065, or CC-1065 analog.

[0171] The term "radioisotope" is intended to include radioisotopes suitable for the treatment of cancer, such as At 211 , Bi 212 , Er 169 , I 131 , I 125 , Y 90 , In 111 , P 32 , Re 186 , Re 188 , Sm 153 , Sr 89The term "radioisotopes" is intended to include radioisotopes of Lu, Cr, and Lu. Such radioisotopes generally emit primarily beta radiation. In one embodiment, the radioisotope is an alpha-emitter isotope, more precisely, thorium-227, which emits alpha radiation.

[0172] In some embodiments, the antigen-binding protein of the present invention is covalently linked to at least one growth inhibitory agent, either directly or through a cleavable or non-cleavable linker. Such an antigen-binding protein with at least one growth inhibitory agent attached thereto may also be referred to as a conjugate. The cleavable linker facilitates the release of the cytotoxic agent or growth inhibitory agent from the antigen-binding protein in cells. For example, an acid-labile linker, a peptidase-sensitive linker, an esterase-labile linker, a photolabile linker, or a disulfide-containing linker (see, for example, U.S. Patent No. 5,208,020) may be used. The linker may also be a "non-cleavable linker" (e.g., SMCC linker), which may provide better tolerance in some cases.

[0173] The preparation of such conjugates (e.g., immunoconjugates) is described in WO 2004 / 091668, or in Hudecz, F., Methods Mol. Biol. 298: 209-223 (2005) and Kirin et al., Inorg Chem. 44(15): 5405-5415 (2005), the contents of which are incorporated herein by reference in their entireties, and can be adapted by the skilled artisan to prepare such antigen-binding proteins of the invention having at least one growth inhibitory agent attached thereto.

[0174] Alternatively, a fusion protein comprising an antigen binding protein of the invention and a cytotoxic or growth inhibitory polypeptide may be produced by recombinant techniques or peptide synthesis. The length of DNA may include the respective regions encoding the two portions of the conjugate adjacent to each other or may include the respective regions encoding the two portions of the conjugate separated by a region encoding a linker peptide that does not destroy the desired properties of the conjugate.

[0175] The antigen binding proteins of the invention may also be used in dependent enzyme mediated prodrug therapy by conjugating the polypeptide to a prodrug activating enzyme that converts a prodrug (e.g., a peptidyl chemotherapeutic agent, see WO 81 / 01145) into an active anti-cancer drug (see, e.g., WO 88 / 07378 and U.S. Pat. No. 4,975,278).

[0176] In some embodiments, the antigen binding proteins specifically bind to a functional epitope that comprises or consists of amino acids 1, 3 and 4 of SEQ ID NO: 138. In some preferred embodiments, these antigen binding proteins specifically bind to a functional epitope that comprises or consists of amino acids 1, 3, 4 and 5, or 1, 3, 4 and 6, or 1, 3, 4, 5 and 6, or 1, 3, 4, 5, 6 and 7 of SEQ ID NO: 138.

[0177] In some embodiments, the antigen binding proteins specifically bind to a functional epitope that comprises or consists of amino acids 4, 6 and 7 of SEQ ID NO: 138. In some preferred embodiments, these antigen binding proteins specifically bind to a functional epitope that comprises or consists of amino acids 1, 4, 6 and 7, or 3, 4, 6 and 7, or 1, 3, 4, 6 and 7 of SEQ ID NO: 138.

[0178] In some embodiments, the antigen binding proteins specifically bind to a functional epitope that comprises or consists of amino acids 5 and 7 of SEQ ID NO: 138. In some preferred embodiments, these antigen binding proteins specifically bind to a functional epitope that comprises or consists of amino acids 5, 6 and 7, or 3, 4, 5, 6 and 7 of SEQ ID NO: 138.

[0179] In some embodiments, the antigen binding protein does not significantly bind to similar peptides of the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010).

[0180] In some embodiments, the antigen binding protein does not significantly bind to similar peptides of the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010).

[0181] V of the antigen-binding protein of the present invention A and V B The genes encoding the V and J regions contained in are listed in Table 2. Annotation was performed with GeneData 11.0.1 using IMGT / GENE-DB (version: 28 / 11 / 2019) as the reference database.

[0182] In some embodiments, V Acomprises the V regions encoded by TRAV14, in particular TRAV14 / DV4, as well as CDRa1 of SEQ ID NO:24 and CDRa2 of SEQ ID NO:25.

[0183] In some embodiments, V B comprises the V region encoded by TRBV13, and CDRb1 of SEQ ID NO:75 and CDRb2 of SEQ ID NO:76.

[0184] In some embodiments, V B comprises the V region encoded by TRBV4-1, and CDRb1 of SEQ ID NO:58 and CDRb2 of SEQ ID NO:59.

[0185] In some embodiments, V B comprises the V region encoded by TRBV6-1, and CDRb1 of SEQ ID NO:112 and CDRb2 of SEQ ID NO:113.

[0186] The inventors have shown that the antigen-binding proteins of the invention, when expressed in CD8+ T cells, are capable of activating said CD8+ T cells upon binding to CT45-IP presented on MHC by antigen-presenting cells.

[0187] Besides CD8+ T cells, CD4+ T cells, also called helper T cells, are crucial for a coordinated and directed immune response that engages all kinds of different immune cells. For full activation of a T cell after encounter with its cognate peptide-MHC complex, additional binding of the respective co-receptor is usually required. In the case of CD8+ T cells, this help is provided by the CD8 co-receptor, and in the case of CD4+ T cells, this help is provided by the CD4 co-receptor. Only in rare cases can the TCR derived from CD8+ T cells, when transferred to CD4+ T cells, induce a sufficiently strong intracellular signaling to result in the activation of the CD4+ T cells.

[0188] The inventors have shown that some of the antigen-binding proteins of the invention, when expressed in CD4+ T cells, in particular CD4+ CD8- T cells, are capable of activating said CD4+ CD8- T cells upon binding to CT45-IP presented on MHC by antigen-presenting cells (Example 3, data not shown).

[0189] In the context of the present invention, an antigen binding protein is an antigen that is capable of producing at least one intracellular cytokine in a cytokine production assay as defined above, where T cells expressing the antigen binding protein (i.e. effector cells) produce at least one intracellular cytokine in co-culture with target cells presenting the CT45-IP antigenic peptide, and in particular where the number of T cells expressing the antigen binding protein and producing at least one intracellular cytokine is a significant predictor of the population of T cells analyzed, e.g. CD4 + or CD8 + A T cell is considered "capable of activating" if it is at least 2%, at least 2.5%, preferably at least 3% per T cell.

[0190] Thus, in some embodiments, the antigen binding protein is capable of activating CD8+ T cells, particularly CD8+ CD4- T cells, and / or CD4+ T cells, particularly CD4+ CD8- T cells. In a preferred embodiment, the antigen binding protein is capable of activating CD4+ T cells, particularly CD4+ CD8- T cells. In other words, the antigen binding protein, preferably a TCR, is capable of activating CD4+ T cells independent of CD8. In other words, the antigen binding protein, preferably a TCR, is capable of binding to a complex of a CT45 antigen peptide and an MHC molecule in the absence of CD8. In a most preferred embodiment, the antigen binding protein is capable of activating both CD4+ T cells, particularly CD4+ CD8- T cells, and CD8+ T cells, particularly CD8+ CD4- T cells. In a preferred embodiment, the antigen binding protein is a TCR.

[0191] In the context of the present invention, an antigen binding protein is considered to be capable of activating a T cell population if cytokine production is detected in at least 2%, at least 2.5%, preferably at least 3% of said CD4+ or CD4- CD8+ T cell population in a functional cytokine production assay as described above. The secreted cytokines may for example be IFN-gamma and / or TNF-alpha.

[0192] Activation of CD4+ T cells via CD8+ T cell-derived TCR can be enhanced by transferring CD8 coreceptor together with TCR into CD4+ cells. We have shown that co-transfection of CD4+ T cells with CT45-IP-specific TCR and CD8 as described herein significantly enhances the killing of CT45-IP-presenting tumor cells (Example 8, data not shown). Engaged CD4+ T cells, along with CD8+ T cells, offer many advantages for cellular immunotherapy. CD4+ T cells can not only induce direct cytotoxicity against tumor cells, but also engage other immune cells to contribute to long-lasting antitumor effects. This helper function is exerted by providing cytokines, chemokines and costimulatory molecules, and includes support of cytotoxic CD8+ T cells, formation of effector and memory T cells, activation and maturation of macrophages / dendritic cells, licensing of dendritic cells (which then effectively stimulate CD8+ T cells to drive CD8+ T cell effector and memory formation), activation of innate immune cells such as NK cells, formation of memory B cells, and many other effects.

[0193] In some embodiments, the antigen binding protein has an average expression of at least 5%, at least 10%, at least 20%, at least 30%, or at least 40%, particularly after transient expression. The average expression of the TCR can be determined by TCR surface staining as described in the Examples. Staining can be performed by techniques known in the art. For example, staining can be performed to identify specific V BThis can be done using antibodies (in the case of human TCRs), or anti-mTCRB antibodies (in the case of chimeric TCRs), or labeled CT45-IP:MHC multimers (e.g., tetramers or dextramers). Such staining can be further combined with staining to identify specific cell populations.

[0194] Antigen-binding protein 1 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 14, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 16, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 19, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 21, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 1". In a preferred embodiment of antigen binding protein 1, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 15, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 20, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 1 specifically binds to a functional epitope comprising or consisting of 4, 5 or 6 amino acid positions selected from the group consisting of positions 1, 3, 4, 5, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 1, as measured, e.g., in a luciferase release assay. 50 is less than about 30 nM, less than about 25 nM, less than about 20 nM, less than about 15 nM, or less than about 10 nM. Antigen binding protein 1 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of antigen binding protein 1, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 13 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 13, and B comprises or consists of the amino acid sequence of SEQ ID NO: 18 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 18; A and V B comprises the CDR sequences as described above for antigen binding protein 1, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 1 is encoded by TRAV38-1 and / or the beta chain variable region of antigen binding protein 1 is encoded by TRBV7-9. In a preferred embodiment, antigen binding protein 1 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0195] Antigen-binding protein 2 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 136, wherein CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 133, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 136, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 2". In a preferred embodiment of antigen binding protein 2, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 2 specifically binds to a functional epitope that includes or consists of 3, 4 or 5 amino acid positions selected from the group consisting of positions 3, 4, 5, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 2, as measured, e.g., in a luciferase release assay. 50 is less than about 30 nM, less than about 25 nM, less than about 20 nM, less than about 15 nM, less than about 10 nM, or less than about 5 nM. Antigen binding protein 2 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all of the similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of antigen binding protein 2, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 132 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 132, and B comprises or consists of the amino acid sequence of SEQ ID NO: 135, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 135; A and V B comprises the CDR sequences as described above for antigen binding protein 2, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 2 is encoded by TRAV14 / DV4 and / or the beta chain variable region of antigen binding protein 2 is encoded by TRBV13. In a preferred embodiment, antigen binding protein 2 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0196] Antigen-binding protein 3 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 67, wherein CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 63, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 68, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 3". In a preferred embodiment of antigen binding protein 3, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 67, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 3 specifically binds to a functional epitope that includes or consists of 3, 4 or 5 amino acid positions selected from the group consisting of positions 3, 4, 5, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 3, as measured, e.g., in a luciferase release assay. 50is less than about 15 nM, less than about 10 nM, less than about 5 nM, less than about 2.5 nM or less than about 1.5 nM. The antigen binding protein 3 is selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009) and SEQ ID NO: 155 (SP-05-0010), preferably SEQ ID NO: 146 (SP In a preferred embodiment of the antigen binding protein 3, the V-binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:147 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010). A comprises or consists of the amino acid sequence of SEQ ID NO: 62 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 62, and B comprises or consists of the amino acid sequence of SEQ ID NO: 65 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 65; A and V Bcomprises the CDR sequences as described above for antigen binding protein 3, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 3 is encoded by TRAV14 / DV4 and / or the beta chain variable region of antigen binding protein 3 is encoded by TRBV27. In a preferred embodiment, antigen binding protein 3 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0197] Antigen-binding protein 4 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 96, wherein CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 90, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 92, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 96, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 4". In a preferred embodiment of antigen binding protein 4, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 91, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 95, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 4 specifically binds to a functional epitope that includes or consists of 3, 4 or 5 amino acid positions selected from the group consisting of positions 3, 4, 6, 7 and 8 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 4, as measured, e.g., in a luciferase release assay. 50is less than about 25 nM, less than about 20 nM, less than about 15 nM, less than about 10 nM, less than about 5 nM, less than about 2.5 nM or less than about 1.5 nM. Antigen binding protein 1 is selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009) and SEQ ID NO: 155 (SP-05-0010), preferably In a preferred embodiment of the antigen binding protein 4, the V does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). A comprises or consists of the amino acid sequence of SEQ ID NO: 89 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 89, and B comprises or consists of the amino acid sequence of SEQ ID NO:94 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:94; A and V Bcomprises the CDR sequences as described above for antigen binding protein 4, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 4 is encoded by TRAV3 and / or the beta chain variable region of antigen binding protein 4 is encoded by TRBV6-2. In a preferred embodiment, antigen binding protein 4 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0198] Antigen-binding protein 5 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 10, wherein CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 2, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 4, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 8, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 10, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 5". In a preferred embodiment of antigen binding protein 5, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 3, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 9, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 5 specifically binds to a functional epitope that includes or consists of two, three or four amino acid positions selected from the group consisting of positions 3, 6, 7 and 8 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 5, as measured, e.g., in a luciferase release assay. 50 is less than about 25 nM, less than about 15 nM, less than about 10 nM, less than about 5 nM, less than about 2.5 nM, less than about 1.5 nM, or less than about 1 nM. Antigen binding protein 5 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010). In a preferred embodiment of antigen binding protein 5, V Acomprises or consists of the amino acid sequence of SEQ ID NO:1 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:1, and B comprises or consists of the amino acid sequence of SEQ ID NO: 7 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 7; A and V B comprises the CDR sequences as described above for antigen binding protein 5, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 5 is encoded by TRAV35 and / or the beta chain variable region of antigen binding protein 5 is encoded by TRBV9. In a preferred embodiment, antigen binding protein 5 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0199] Antigen-binding protein 6 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 53, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 55, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 60, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 6". In a preferred embodiment of antigen binding protein 6, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 54, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 59, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 6 specifically binds to a functional epitope that includes or consists of two, three or four amino acid positions selected from the group consisting of positions 1, 3, 4 and 6 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 6, as measured, e.g., in a luciferase release assay. 50is less than about 30 nM, less than about 25 nM, less than about 20 nM, less than about 15 nM, less than about 10 nM, or less than about 5 nM. Antigen binding protein 6 is selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009) and SEQ ID NO: 155 (SP-05-0010), preferably SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP- In a preferred embodiment of the antigen-binding protein 6, the V-binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009), and SEQ ID NO:155 (SP-05-0010), more preferably selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), and SEQ ID NO:155 (SP-05-0010). A comprises or consists of the amino acid sequence of SEQ ID NO:52 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:52, and B comprises or consists of the amino acid sequence of SEQ ID NO:57 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:57; A and V Bcomprises the CDR sequences as described above for antigen binding protein 6, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 6 is encoded by TRAV12-3 and / or the beta chain variable region of antigen binding protein 6 is encoded by TRBV4-1. In a preferred embodiment, antigen binding protein 6 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0200] Antigen-binding protein 7 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 71, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 72, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 77, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 7". In a preferred embodiment of antigen binding protein 7, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 15, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 7 specifically binds to a functional epitope that includes or consists of three or four amino acid positions selected from the group consisting of positions 1, 4, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 7, as measured, e.g., in a luciferase release assay. 50 is less than about 5 nM, less than about 2.5 nM, less than about 1.5 nM, or less than about 1 nM. Antigen binding protein 7 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of antigen binding protein 7, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 70 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 70, and B comprises or consists of the amino acid sequence of SEQ ID NO: 74 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 74; A and V B comprises the CDR sequences as described above for antigen binding protein 7, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 7 is encoded by TRAV38-2 / DV8 and / or the beta chain variable region of antigen binding protein 7 is encoded by TRBV13. In a preferred embodiment, antigen binding protein 7 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0201] Antigen-binding protein 8 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 104, wherein CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 99, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 101, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 104, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 8". In a preferred embodiment of antigen binding protein 8, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 100, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 8 specifically binds to a functional epitope that includes or consists of one or two amino acid positions selected from the group consisting of positions 5 and 7 of SEQ ID NO: 138. EC for inducing killing of CT45-IP:MHC complex-presenting cells, e.g., CT45-IP-loaded T2 cells, by T cells expressing antigen binding protein 8, as measured, for example, in a luciferase release assay. 50is less than about 30 nM, less than about 25 nM, less than about 20 nM, less than about 15 nM, or less than about 10 nM. The antigen binding protein 8 is selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009) and SEQ ID NO: 155 (SP-05-0010), preferably SEQ ID NO: 146 (SP In a preferred embodiment of antigen binding protein 8, the V-binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:147 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010). A comprises or consists of the amino acid sequence of SEQ ID NO: 98 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 98, and B comprises or consists of the amino acid sequence of SEQ ID NO: 103 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 103; A and V Bcomprises the CDR sequences as described above for antigen binding protein 8, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 8 is encoded by TRAV19 and / or the beta chain variable region of antigen binding protein 8 is encoded by TRBV13. In a preferred embodiment, antigen binding protein 8 is capable of activating CD8+ T cells, in particular CD8+ CD4− T cells, and / or CD4+ T cells, in particular CD4+ CD8− T cells.

[0202] Antigen-binding protein 9 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 80, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 82, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 85, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 87, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 9". In a preferred embodiment of antigen binding protein 9, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 81, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 86, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 9 specifically binds to a functional epitope that includes or consists of 5, 6 or 7 amino acid positions selected from the group consisting of positions 1, 3, 4, 5, 6, 7 and 8 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 9, as measured, e.g., in a luciferase release assay. 50is less than about 5 nM, less than about 2.5 nM, less than about 1.5 nM or less than about 1 nM. The antigen binding protein 9 is selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009) and SEQ ID NO: 155 (SP-05-0010), preferably SEQ ID NO: 146 (SP In a preferred embodiment of the antigen-binding protein 9, the V-binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:147 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009), and SEQ ID NO:155 (SP-05-0010). A comprises or consists of the amino acid sequence of SEQ ID NO: 79 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 79, and B comprises or consists of the amino acid sequence of SEQ ID NO: 84 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 84; A and V Bcomprises the CDR sequences as described above for antigen binding protein 9, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 9 is encoded by TRAV5 and / or the beta chain variable region of antigen binding protein 9 is encoded by TRBV2. In a preferred embodiment, antigen binding protein 9 is capable of activating CD8+ T cells, particularly CD8+ CD4− T cells, and / or CD4+ T cells, particularly CD4+ CD8− T cells.

[0203] Antigen-binding protein 10 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 107, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 109, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 114, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 10". In a preferred embodiment of antigen binding protein 10, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 108, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 113, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 10 specifically binds to a functional epitope that includes or consists of two or three amino acid positions selected from the group consisting of positions 5, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 10, as measured, e.g., in a luciferase release assay. 50 is less than about 30 nM, less than about 25 nM, less than about 20 nM, less than about 15 nM, or less than about 10 nM. Antigen binding protein 10 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all of the similar peptides selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009), and SEQ ID NO:155 (SP-05-0010). In a preferred embodiment of the antigen binding protein 10, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 106 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 106, and B comprises or consists of the amino acid sequence of SEQ ID NO: 111, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 111; A and V B comprises the CDR sequences as described above for antigen binding protein 10, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 10 is encoded by TRAV1-2 and / or the beta chain variable region of antigen binding protein 10 is encoded by TRBV6-1. In a preferred embodiment, antigen binding protein 10 is capable of activating CD8+ T cells, particularly CD8+ CD4- T cells, and / or CD4+ T cells, particularly CD4+ CD8- T cells.

[0204] Antigen-binding protein 11 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 125, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 127, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 130, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 11". In a preferred embodiment of antigen binding protein 11, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 126, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 113, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 11 specifically binds to a functional epitope that includes or consists of 4, 5 or 6 amino acid positions selected from the group consisting of positions 1, 3, 4, 5, 6 and 8 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex-presenting cells, e.g., CT45-IP-loaded T2 cells, by T cells expressing antigen binding protein 11, as measured, e.g., in a luciferase release assay. 50 is less than about 60 nM. Antigen binding protein 11 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO:146 (SP-05-0001), SEQ ID NO:147 (SP-05-0002), SEQ ID NO:148 (SP-05-0003), SEQ ID NO:149 (SP-05-0004), SEQ ID NO:150 (SP-05-0005), SEQ ID NO:151 (SP-05-0006), SEQ ID NO:152 (SP-05-0007), SEQ ID NO:153 (SP-05-0008), SEQ ID NO:154 (SP-05-0009) and SEQ ID NO:155 (SP-05-0010). In a preferred embodiment of antigen binding protein 11, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 124 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 124, and B comprises or consists of the amino acid sequence of SEQ ID NO: 129 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 129; A and V B comprises the CDR sequences as described above for antigen binding protein 11, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 11 is encoded by TRAV22 and / or the beta chain variable region of antigen binding protein 11 is encoded by TRBV6-1. In a preferred embodiment, antigen binding protein 11 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0205] Antigen-binding protein 12 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 117, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 119, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 122, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 12". In a preferred embodiment of antigen binding protein 12, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 118, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 59, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 12 specifically binds to a functional epitope that includes or consists of two, three or four amino acid positions selected from the group consisting of positions 3, 4, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 12, as measured, e.g., in a luciferase release assay. 50 is less than about 60 nM, or less than about 50 nM. Antigen binding protein 12 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of antigen binding protein 12, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 116 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 116, and B comprises or consists of the amino acid sequence of SEQ ID NO: 121 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 121; A and V B comprises the CDR sequences as described above for antigen binding protein 12, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 12 is encoded by TRAV27 and / or the beta chain variable region of antigen binding protein 12 is encoded by TRBV4-1. In a preferred embodiment, antigen binding protein 12 is capable of activating CD8+ T cells, particularly CD8+ CD4- T cells, and / or CD4+ T cells, particularly CD4+ CD8- T cells.

[0206] Antigen-binding protein 13 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 35, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 38, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 40, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 13". In a preferred embodiment of antigen binding protein 13, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 39, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 13 specifically binds to a functional epitope that includes or consists of 3, 4 or 5 amino acid positions selected from the group consisting of positions 1, 3, 4, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 13, as measured, e.g., in a luciferase release assay. 50 is less than about 50 nM, less than about 30 nM, less than about 25 nM, less than about 20 nM, or less than about 15 nM. Antigen binding protein 13 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all of the similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of the antigen-binding protein 13, V Acomprises or consists of the amino acid sequence of SEQ ID NO: 34 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 34, and B comprises or consists of the amino acid sequence of SEQ ID NO: 37 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 37; A and V B comprises the CDR sequences as described above for antigen binding protein 13, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 13 is encoded by TRAV14 / DV4 and / or the beta chain variable region of antigen binding protein 13 is encoded by TRBV19. In a preferred embodiment, antigen binding protein 13 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0207] Antigen-binding protein 14 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 26, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 29, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 31, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 14". In a preferred embodiment of antigen binding protein 14, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 30, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 14 specifically binds to a functional epitope that includes or consists of two, three or four amino acid positions selected from the group consisting of positions 1, 3, 4 and 5 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 14, as measured, e.g., in a luciferase release assay. 50 is less than about 50 nM, less than about 30 nM, less than about 25 nM, or less than about 20 nM. The antigen binding protein 14 does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all of the similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of the antigen binding protein 14, V Acomprises or consists of the amino acid sequence of SEQ ID NO:23 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:23, and B comprises or consists of the amino acid sequence of SEQ ID NO:28 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:28; A and V B comprises the CDR sequences as described above for antigen binding protein 14, which may comprise one, two or three amino acid mutations, preferably none. Preferably, the alpha chain variable region of antigen binding protein 14 is encoded by TRAV14 / DV4 and / or the beta chain variable region of antigen binding protein 14 is encoded by TRBV11-2. In a preferred embodiment, antigen binding protein 14 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0208] Antigen-binding protein 15 In some embodiments, the present invention provides an antigen binding protein that specifically binds to a CT45 antigenic peptide that is present in a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigenic peptide comprises or consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGV), and the antigen binding protein comprises a variable domain V comprising complementarity determining regions (CDRs) CDRa1, CDRa2 and CDRa3. A and a first polypeptide comprising a variable domain V comprising CDRb1, CDRb2 and CDRb3. Band a second polypeptide comprising the amino acid sequence of SEQ ID NO: 43, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 45, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 48, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 50, and the CDRa1, CDRa3, CDRb1 and / or CDRb3 sequences may comprise one, two or three amino acid mutations. The antigen binding protein comprising said CDR sequences is hereinafter also referred to as "antigen binding protein 15". In a preferred embodiment of antigen binding protein 15, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 44, and CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 49, and the CDRa2 and / or CDRb2 sequences may comprise one, two, three or four amino acid mutations. Antigen binding protein 15 specifically binds to a functional epitope that includes or consists of 4, 5 or 6 amino acid positions selected from the group consisting of positions 1, 3, 4, 5, 6 and 7 of SEQ ID NO: 138. EC for induction of killing of CT45-IP:MHC complex presenting cells, e.g., CT45-IP loaded T2 cells, by T cells expressing antigen binding protein 15, as measured, e.g., in a luciferase release assay. 50is less than about 50 nM, less than about 30 nM, less than about 25 nM, or less than about 20 nM. The antigen binding protein 15 is selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010). In a preferred embodiment of the antigen-binding protein 15, the V-binding protein does not significantly bind to at least one, at least two, at least three, at least four, at least five, or all similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), and SEQ ID NO: 155 (SP-05-0010). A comprises or consists of the amino acid sequence of SEQ ID NO: 42 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO: 42, and B comprises or consists of the amino acid sequence of SEQ ID NO:27 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NO:27; A and V Bcomprises the CDR sequences as described above for antigen binding protein 15, which may comprise one, two or three amino acid mutations, preferably no amino acid mutations. Preferably, the alpha chain variable region of antigen binding protein 15 is encoded by TRAV21 and / or the beta chain variable region of antigen binding protein 15 is encoded by TRBV5-1. In a preferred embodiment, antigen binding protein 15 is capable of activating CD8+ T cells, in particular CD8+ CD4- T cells, and / or CD4+ T cells, in particular CD4+ CD8- T cells.

[0209] The present invention also includes particles that display antigen-binding proteins (especially TCRs) and the inclusion of said particles in a library of particles. Such particles include, but are not limited to, phage, yeast, ribosomes, or mammalian cells. Methods for producing such particles and libraries are known in the art (see, for example, WO 2004 / 044004; WO 01 / 48145, Chervin et al. (2008) J. Immuno. Methods 339.2: 175-184).

[0210] Nucleic Acids, Vectors, and Recombinant Host Cells The polypeptides of the antigen binding proteins of the invention may be encoded by nucleic acids and expressed in vivo, ex vivo or in vitro. Thus, in a second aspect, the present invention relates to one or more nucleic acids comprising or consisting of one or more sequences encoding an antigen binding protein of the first aspect of the invention.

[0211] The nucleic acid may be comprised in one nucleic acid molecule or may be separated into two or more nucleic acid molecules, each nucleic acid molecule comprising at least one of the one or more sequences encoding the antigen binding protein of the first aspect of the invention. In some embodiments, one nucleic acid molecule encodes one portion or monomer of the antigen binding protein of the invention (e.g. one of the two chains of the TCR of the invention) and another nucleic acid molecule encodes another portion or monomer of the antigen binding protein of the invention (e.g. the other of the two chains of the TCR). In some embodiments, the nucleic acid encodes two or more antigen binding protein polypeptide chains, e.g. at least two TCR chains. The nucleic acid encoding multiple antigen binding protein polypeptide chains may comprise a nucleic acid cleavage site between at least two chain sequences, may encode a transcription or translation initiation site, e.g. an internal ribosome entry site (IRES) between the two or more chain sequences, and / or may encode a proteolytic target site between the two or more antigen binding protein chains. When two or more antigen binding protein polypeptide chains are encoded on one nucleic acid molecule, the two or more antigen binding protein polypeptide chains can be under the control of the same promoter or under the control of separate promoters.

[0212] The term "nucleic acid", in the context of the present invention, refers to a single- or double-stranded oligomer or polymer of deoxyribonucleotides, or ribonucleotide bases, or both. A nucleotide monomer is composed of a nucleobase, a five-carbon sugar (such as, but not limited to, ribose or 2'-deoxyribose), and one to three phosphate groups. Typically, nucleic acids are formed by phosphodiester bonds between individual nucleotide monomers. In the context of the present invention, the term nucleic acid includes, but is not limited to, ribonucleic acid (RNA) molecules and deoxyribonucleic acid (DNA) molecules, as well as synthetic forms of nucleic acids containing other bonds [e.g., peptide nucleic acids, as described in Nielsen et al. (Science 254:1497-1500, 1991)]. Typically, nucleic acids are single- or double-stranded molecules, composed of naturally occurring nucleotides. The description of a single strand of a nucleic acid also defines (at least in part) the sequence of the complementary strand. A nucleic acid may be single-stranded or double-stranded, or may contain portions of both double-stranded and single-stranded sequences. The illustrated double-stranded nucleic acid molecules may have 3' or 5' overhangs, and thus are not necessarily, but likely to be, completely double-stranded over their entire length. The term nucleic acid includes chromosomes or chromosome segments, vectors (e.g., expression vectors), expression cassettes, naked DNA or RNA polymers, primers, probes, cDNA, genomic DNA, recombinant DNA, cRNA, mRNA, tRNA, microRNA (miRNA), or small interfering RNA (siRNA). A nucleic acid may be, for example, single-stranded, double-stranded, or triple-stranded, and is not limited to any particular length. Unless otherwise indicated, a particular nucleic acid sequence includes or encodes complementary sequences in addition to any sequence explicitly indicated.

[0213] In a preferred embodiment, the nucleic acid is an isolated nucleic acid. In a preferred embodiment, the nucleic acid is a recombinant nucleic acid.

[0214] The nucleic acid may be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form. A nucleic acid is "isolated" or "substantially pure" if it has been purified from other cellular components or other contaminants (e.g., other cellular nucleic acids or proteins) by standard techniques.

[0215] The nucleic acid molecules of the present disclosure can be obtained using standard molecular biology techniques, including but not limited to methods of amplification and reverse transcription of RNA. For example, once a DNA fragment encoding a variable chain is obtained, the DNA fragment can be further manipulated by standard recombinant DNA techniques, for example, to convert the variable region gene into a full-length gene. In this manipulation, the DNA fragment encoding the variant is operably linked to another DNA molecule, or to a fragment encoding another protein (e.g., a constant region or a flexible linker). The term "operably linked" as used in this context is intended to mean that the two DNA fragments are functionally linked, for example, such that the amino acid sequences encoded by the two DNA fragments remain in frame, or such that a protein is expressed under the control of a desired promoter. The isolated DNA encoding a variable region (e.g., a variable alpha region and / or a variable beta region) can be converted into a full-length gene by operably linking the variable-encoding DNA to another DNA molecule encoding a constant region. For example, the sequences of human constant region genes for TCRs or antibodies are known in the art, and DNA fragments encompassing this region can be obtained by standard PCR amplification.

[0216] Typically, the nucleic acid comprises one or more DNA or RNA molecules, which may be contained in one or more suitable vectors.

[0217] In a third aspect, the present invention relates to a vector or a collection of vectors comprising the nucleic acid of the second aspect of the present invention.Preferably, the sequence encoding the antigen-binding protein is operably linked to a promoter sequence.A "collection of vectors" herein refers to two or more vectors.When two or more antigen-binding protein polypeptide chains are encoded on one vector, the two or more antigen-binding protein polypeptide chains can be under the control of the same promoter or under the control of separate promoters.

[0218] The terms "vector," "cloning vector," and "expression vector" refer to a vehicle by which DNA or RNA sequences (e.g., foreign genes) can be introduced into a host cell to transform the host and promote the expression (e.g., transcription and translation) of the introduced sequences.

[0219] Various expression vectors can be employed to express the polynucleotide that codes for antigen binding protein or its functional fragment.Both viral and non-viral expression vectors can be used to produce the antigen binding protein or its functional fragment described herein in mammalian host cells.Non-viral vectors and systems include multiple plasmids, plasmids, cosmids, episomes, artificial chromosomes, phages, or viral vectors.

[0220] Such vectors can contain regulatory elements (e.g., promoters, enhancers, terminators, and the like) to cause or induce the expression of said polypeptide when administered to a subject.Examples of promoters and enhancers used in animal cell expression vectors include SV40 early promoter and enhancer (Mizukami T. et al. 1987), Moloney murine leukemia virus LTR promoter and enhancer (Kuwana Y et al. 1987), antibody heavy chain promoter (Mason JO et al. 1985) and enhancer (Gillies SD et al. 1983), and the like.

[0221] For example, non-viral vectors useful for expressing the polynucleotides and polypeptides described herein in mammalian (e.g., human or non-human) cells include any suitable vector known in the art for expressing proteins. Other examples of plasmids include replicative plasmids that contain an origin of replication, or integrative plasmids (e.g., pUC, pcDNA, pBR, and the like).

[0222] The term "viral vector" refers to a nucleic acid vector construct that contains at least one element of viral origin, has the ability to be packaged into a viral vector particle, and encodes at least a foreign nucleic acid. The vector and / or particle can be utilized to introduce a nucleic acid of interest into cells either in vitro or in vivo. Numerous forms of viral vectors are known in the art. Useful viral vectors include vectors based on retroviruses, lentiviruses, adenoviruses, adeno-associated viruses, herpes viruses, SV40, papilloma viruses, Epstein-Barr virus, vaccinia virus vectors, and Semliki Forest virus (SFV) vectors. Recombinant viruses can be produced by techniques known in the art, for example, by transfecting packaging cells or by transient transfection with helper plasmids or viruses. Typical examples of viral packaging cells include PA317 cells, PsiCRIP cells, GPenv+ cells, 293 cells, and the like. Detailed protocols for producing such replication-defective recombinant viruses can be found, for example, in WO 95 / 14785, WO 96 / 22378, U.S. Pat. Nos. 5,882,877, 6,013,516, 4,861,719, 5,278,056, and WO 94 / 19478.

[0223] The first polypeptide and the second polypeptide described herein can be present in the same vector or in separate vectors, ie, a collection of vectors.

[0224] In a fourth aspect, the present invention relates to a host cell comprising an antigen binding protein according to the first aspect of the invention, a nucleic acid according to the second aspect of the invention or a vector according to the third aspect of the invention. The host cell may in particular be transfected, infected or transduced or transformed with a nucleic acid and / or a vector according to the invention.

[0225] The host cell may be a eukaryotic cell, such as a plant, animal, fungus, or algae, or a prokaryotic cell, such as a bacterium or a protozoan. The host cell may be a cultured cell or a primary cell, i.e., a cell directly isolated from an organism, such as a human. The host cell may be an adherent cell or a suspended cell, i.e., a cell that grows in suspension. For the purpose of producing a recombinant antigen-binding protein, such as a TCR, a polypeptide, or a protein, the host cell is preferably a mammalian cell. Most preferably, the host cell is a human cell. The host cell may be any cell type, may originate from any type of tissue, and may be at any developmental stage, but the host cell is preferably a peripheral blood leukocyte (PBL) or a peripheral blood mononuclear cell (PBMC). More preferably, the host cell is a lymphocyte, such as a T cell, a T cell precursor, or a NK cell. NK cells are naturally occurring lymphocytic non-T cells that can rapidly kill virus-infected cells and tumor cells. NK cells can be engineered to express tumor-specific TCRs for use as cell therapy products in cancer therapy (Shimasaki et al., Nat Rev Drug Discov. 2020 Mar;19(3):200-218). In a preferred embodiment, the host cell is a T cell, such as a CD4 or CD8 positive T cell or a γδ T cell. The T cell can be any T cell, such as a cultured T cell, such as a primary T cell, or a T cell from a cultured T cell line, such as Jurkat, SupT1, etc., or a T cell obtained from a mammal, preferably a T cell or T cell precursor from a human patient. If obtained from a mammal, the T cell can be obtained from a number of sources, including, but not limited to, blood, bone marrow, lymph nodes, thymus, or other tissues or fluids. The T cells can also be enriched or purified. Preferably, the T cell is a human T cell. More preferably, the T cell is a T cell isolated from a human.T cells can be any type of T cell and at any stage of development, including, but not limited to, CD4 positive helper T cells, e.g., Th1 and Th2 cells, CD8 positive T cells (e.g., cytotoxic T cells), tumor infiltrating cells (TILs), memory T cells, naive T cells, and γδ T cells.

[0226] In other preferred embodiments, the host cell is or is a cell for recombinant expression, such as a Chinese Hamster Ovary (CHO) cell or a yeast cell.

[0227] The term "transformation" refers to the introduction of a "foreign" (i.e., exogenous) gene, DNA, or RNA sequence into a host cell, such that the host cell expresses the introduced gene or sequence to produce a desired substance (typically an antigen binding protein or functional fragment thereof as described herein). A host cell that receives and expresses the introduced DNA or RNA has been "transformed."

[0228] The nucleic acids of the invention can be used to produce recombinant antigen binding proteins of the invention in a suitable expression system. The term "expression system" refers to a host cell and a compatible vector under suitable conditions for the expression of a protein encoded by foreign DNA carried by the vector and introduced into the host cell.

[0229] Common expression systems include E. coli host cells and plasmid vectors, insect host cells and Baculovirus vectors, and mammalian host cells and vectors. Other examples of host cells include, but are not limited to, prokaryotic cells (e.g., bacteria), and eukaryotic cells (e.g., yeast cells, mammalian cells, insect cells, plant cells, etc.). Specific examples include E. coli, yeast of the genus Kluyveromyces or Saccharomyces, mammalian cell lines (e.g., Vero cells, CHO cells, 3T3 cells, COS cells, HEK cells, etc.), and primary or established mammalian cell cultures (e.g., those produced from lymphoblasts, fibroblasts, embryonic cells, epithelial cells, neuronal cells, adipocytes, etc.). Examples also include mouse SP2 / 0-Ag14 cells (ATCC CRL1581), mouse P3X63-Ag8.653 cells (ATCC CRL1580), CHO cells with a deleted dihydrofolate reductase gene (Urlaub G et al;1980), rat YB2 / 3HL.P2.G11.16Ag.20 cells (ATCC CRL1662), and the like. In some embodiments, YB2 / 0 cells may be preferred because the ADCC activity of chimeric or humanized antibodies is enhanced when expressed in these cells. In a preferred embodiment, the host cells described above are used as expression systems.

[0230] In particular, for the expression of some of the antigen-binding proteins of the present invention, particularly antigen-binding proteins comprising two unlinked polypeptides, the expression vector may be either a type in which a gene encoding a first polypeptide, such as a TCR alpha chain, and a gene encoding a second polypeptide, such as a TCR beta chain, are present on separate vectors, or a type in which both genes are present on the same vector (tandem type). In terms of ease of constructing an antigen-binding protein expression vector, ease of introduction into animal cells, and balance between the expression levels of two polypeptides, such as TCR alpha and beta chains, in animal cells, tandem type expression vectors described in relation to humanized antibodies are preferred (Shitara K et al. J Immunol Methods. 1994 Jan. 3; 167(1-2):271-8). Examples of tandem type expression vectors described in relation to humanized antibodies include pKANTEX93 (WO 97 / 10354 pamphlet) and pEE18.

[0231] In one embodiment, such recombinant host cells may be used for the production of at least one antigen binding protein of the invention.

[0232] Pharmaceutical Compositions In a fifth aspect, the present invention relates to a pharmaceutical composition comprising an antigen binding protein according to the first aspect of the invention, a nucleic acid according to the second aspect of the invention, a vector according to the third aspect of the invention or a host cell according to the fourth aspect of the invention and optionally a pharma- ceutical acceptable carrier.

[0233] It has been shown that the antigen binding proteins of the present invention are capable of producing cytotoxicity against cells presenting the CT45-IP antigen peptide. Since this peptide is particularly presented by tumor cells, the antigen binding proteins of the present invention are useful for destroying tumor cells in patients. An immune response in a patient can be induced by direct administration of the described antigen binding proteins to the patient, ideally in combination with an immunogenicity enhancing agent (i.e., an adjuvant). The immune response generated by such therapeutic vaccination can be expected to be highly specific against tumor cells, since the peptide KIFEMLEGV (SEQ ID NO: 138) is not presented in the same copy number or in excess on normal tissues, preventing the risk of an undesired autoimmune response against normal tissue cells in the patient.

[0234] The present invention also relates to an antigen-binding protein according to the invention for use as a medicament.The present invention also relates to a pharmaceutical composition according to the invention for use as a medicament.

[0235] The term "pharmaceutical composition" or "therapeutic composition," as used herein, refers to a compound or composition capable of inducing a desired therapeutic effect when properly administered to a subject.

[0236] In some embodiments, a subject may also be referred to as a patient.

[0237] Such therapeutic or pharmaceutical compositions may contain a therapeutically effective amount of the antigen binding protein of the invention, or an antigen binding protein further comprising a therapeutic agent, in a mixture with a pharma- ceutically or physiologically acceptable formulation selected to be compatible with the mode of administration.

[0238] In some embodiments, the antigen binding proteins of the invention will be supplied as part of a sterile pharmaceutical composition that will normally include a pharma- ceutically acceptable carrier.

[0239] "Pharmaceutically" or "pharmacologically acceptable" refers to molecular entities and compositions that do not produce adverse, allergic, or other untoward reactions when administered to a mammal, particularly a human, as appropriate. A pharmaceutically acceptable carrier refers to any type of non-toxic solid, semi-solid, or liquid filler, diluent, encapsulating material, or formulation auxiliary.

[0240] A "pharmaceutical acceptable carrier" may include physiologically compatible solvents, bulking agents, stabilizers, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like. In one embodiment, the carrier is an aqueous carrier. In some embodiments, the aqueous carrier can impart improved properties (e.g., improved solubility, efficacy, and / or improved immunotherapy) when combined with the antigen binding proteins described herein.

[0241] Further examples of pharma- ceutically acceptable carriers or diluents useful in the present invention include stabilizers such as SPGA, carbohydrates (e.g., sorbitol, mannitol, starch, sucrose, glucose, dextran), proteins such as albumin or casein, protein-containing agents such as bovine serum or skim milk powder, and buffers (e.g., phosphate buffers).

[0242] The form, route of administration, dosage, and regimen of the pharmaceutical composition will, of course, depend on the condition to be treated, the severity of the disease, the age, weight, and sex of the patient, etc. The pharmaceutical composition may be in any suitable form (depending on the desired method of administration to the patient). The pharmaceutical composition may be provided in a unit dosage form, generally provided in a sealed container, and provided as part of a kit. Such a kit will usually (but not necessarily) include instructions for use. Such a kit may also include a plurality of said unit dosage forms.

[0243] Preferably, the pharmaceutical composition is administered by injection, e.g., intravenously. When the pharmaceutical composition comprises host cells expressing an antigen binding protein, preferably a TCR, of the present invention, the pharma- ceutically acceptable carrier for the cells for injection may include any isotonic carrier, such as saline (about 0.90% w / v NaCl in water, about 300 mOsm / L NaCl in water, or about 9.0 g NaCl per liter of water), NORMOSOL R electrolyte solution (Abbott, Chicago, IL), PLASMALYTE A (Baxter, Deerfield, IL), about 5% dextrose in water, or lactated Ringer's solution, etc. In one embodiment, the pharma-ceutically acceptable carrier is supplemented with human serum albumen.

[0244] Empirical considerations such as biological half-life generally contribute to the determination of dosage. The frequency of administration can be determined and adjusted during the treatment period, and is based on the reduction of the number of cancer cells, the maintenance of the reduction of cancer cells, the reduction of the proliferation of cancer cells, or the killing of cancer cells. Alternatively, sustained continuous release formulations of antigen-binding proteins may be appropriate. Various formulations and devices for achieving sustained release are known in the art.

[0245] In one embodiment, the dosage of antigen-binding molecule can be empirically determined in an individual receiving one or more doses. The individual is administered increasing doses of antigen-binding protein. To evaluate the effectiveness of antigen-binding protein, markers of cancer cell status can be tracked. This includes direct measurement of cancer cell proliferation and cell death by FACS, other imaging techniques, improved health status as measured by such measurements, or improved quality of life or prolonged survival as measured by accepted tests. It will be clear to those skilled in the art that dosage will vary depending on the individual, stage of disease, and previous and concurrent treatments being used.

[0246] The dose used for administration may be adapted as a function of various parameters, in particular as a function of the mode of administration used, as a function of the pathology involved or as a function of the desired duration of treatment.

[0247] The pharmaceutical compositions, vectors, nucleic acids, and cells of the invention may be provided in a substantially pure form, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% pure form.

[0248] Methods for Producing Antigen-Binding Proteins In a sixth aspect, the present invention relates to a method of producing an antigen binding protein of the first aspect of the invention, the method comprising the steps of: (a) providing a host cell; (b) providing a genetic construct comprising a coding sequence encoding any of the antigen binding proteins of the first aspect of the invention; (c) introducing the genetic construct into the host cell; and (d) expressing the genetic construct by the host cell.

[0249] In one embodiment, the method further comprises the isolation and purification of the antigen binding protein from the host cell and, where appropriate, the reconstitution of the antigen binding protein in a host cell, preferably a lymphocyte, more preferably a T cell or a NK cell, most preferably a T cell. The skilled person is fully capable of selecting a suitable host cell for expressing the antigen binding protein.

[0250] The antigen binding proteins of the present invention may be produced by any technique known in the art, including but not limited to any chemical, biological, genetic, or enzymatic techniques, alone or in combination.

[0251] The antigen binding proteins of the invention are suitably separated from the culture medium by antibody purification procedures such as, for example, protein A-Sepharose, hydroxylapatite chromatography, gel electrophoresis, dialysis, or affinity chromatography.

[0252] In one embodiment, recovering the expressed antigen binding protein or polypeptide, as used herein, refers to performing Protein A chromatography, Kappa Select chromatography, and / or size exclusion chromatography, preferably Protein A chromatography and / or size exclusion chromatography, more preferably Protein A chromatography and size exclusion chromatography.

[0253] By knowing the amino acid sequence of the desired sequence, one skilled in the art can produce the antigen-binding protein of the present invention by standard techniques for the production of polypeptides. For example, the protein can be synthesized using known solid-phase methods, in particular using commercially available peptide synthesizers (e.g., those manufactured by Applied Biosystems, Foster City, California) and following the manufacturer's instructions. Alternatively, the antibodies and antigen-binding proteins of the present invention can be produced by recombinant DNA and genetic transfection techniques known in the art (see Morrison SL. et al. (1984) and patent documents US5,202,238; and US5,204, 244). For example, a fragment can be obtained as a DNA expression product after incorporating a DNA sequence encoding the desired (poly)peptide into an expression vector and introducing such a vector into a suitable eukaryotic or prokaryotic host that expresses the desired polypeptide, and the fragment can then be isolated using known techniques.

[0254] Methods for producing humanized antibodies based on conventional recombinant DNA and gene transfection techniques are known in the art (see, for example, Riechmann L. et al. 1988; Neuberger MS. et al. 1985) and can be readily applied to the production of the antigen-binding proteins of the present invention.

[0255] In one example, vectors for the expression of recombinant antigen-binding proteins of the invention were designed as monocistronic, controlled by, for example, a promoter element from HCMV, a pUC19 derivative. Plasmid DNA was amplified, for example, in E. coli according to standard culture methods and subsequently purified using a commercially available kit (Macherey & Nagel). Purified plasmid DNA was used for transient transfection of CHO-S cells, for example, according to the manufacturer's instructions (ExpiCHO™ System; Thermo Fisher Scientific). Transfected CHO cells were cultured, for example, at 32°C to 37°C for 6 to 14 days and fed 1 to 2 times with ExpiCHO™ Feed solution.

[0256] The conditioned cell supernatant was clarified by filtration (0.22 μm), for example, using a Sartoclear Dynamics® Lab Filter Aid (Sartorius). The bispecific antigen-binding protein was purified, for example, using an Aekta Pure 25 L FPLC system (GE Lifesciences) equipped to perform affinity and size-exclusion chromatography in-line. Affinity chromatography was performed, for example, on a Protein A or L column (GE Lifesciences) according to standard affinity chromatography protocols. For example, size-exclusion chromatography was performed immediately after elution (pH 2.8) from the affinity column, for example, using a Superdex 200 pg 16 / 600 column (GE Lifesciences) according to standard protocols, to obtain highly pure monomeric protein. Protein concentration was determined, for example, on a NanoDrop system (Thermo Scientific) using the calculated extinction coefficient according to the predicted protein sequence. Concentration was adjusted, if necessary, using a Vivaspin device (Sartorius). Finally, the purified molecule was stored, for example, in phosphate buffered saline at a concentration of approximately 1 mg / mL at a temperature of 2-8°C.

[0257] The quality of the purified bispecific antigen-binding proteins was determined by HPLC-SEC, e.g., on a MabPac SEC-1 column (5 μm, 7.8×300 mm) run in 50 mM sodium phosphate (pH 6.8) containing 300 mM NaCl in a Vanquish UHPLC-System.

[0258] Therapeutic Methods and Uses In a seventh aspect, the present invention relates to an antigen binding protein of the first aspect of the invention, a nucleic acid of the second aspect of the invention, a vector of the third aspect of the invention, a host cell of the fourth aspect of the invention or a pharmaceutical composition of the fourth aspect of the invention for use in medicine.

[0259] In an eighth aspect, the present invention relates to an antigen binding protein of the first aspect of the invention, a nucleic acid of the second aspect of the invention, a vector of the third aspect of the invention, a host cell of the fourth aspect of the invention or a pharmaceutical composition of the fourth aspect of the invention for use in a method for the treatment and / or diagnosis of a proliferative disease.

[0260] The antigen binding proteins of the present invention are for use in immunotherapy, preferably adoptive cell therapy, more preferably adoptive T cell therapy, in particular for the prevention and / or treatment of proliferative diseases. The administration of the compounds of the present invention can for example involve the infusion of lymphocytes of the present invention, preferably NK cells or T cells, more preferably T cells, into said patient. Preferably, such lymphocytes are autologous lymphocytes of the patient and are transduced in vitro with a nucleic acid or antigen binding protein of the present invention.

[0261] In a preferred embodiment, the proliferative disease is cancer, particularly a CT45-expressing cancer.

[0262] In the context of the present invention, a cancer is considered to be a "CT45-expressing cancer" (also referred to as a CT45 "positive" cancer) if the relevant peptide, such as the CT45-IP peptide, is present in more than 98% of all cancers according to guidelines by the NCI. In all other indications listed here, a biopsy may be performed as is standard in the treatment of these cancers, and peptides may be identified according to XPresident® and related methods [WO 03 / 100432; WO 2005 / 076009; WO 2011 / 128448; WO 2016 / 107740; U.S. Patent Nos. 7,811,828, 9,791,444, and U.S. Patent Publication No. 2016 / 0187351, the contents of each of which are incorporated herein by reference in their entirety]. In one embodiment, for example, cancer is easily assayed (i.e., diagnosed) by using the antigen binding proteins of the present invention. Methods of using antigen binding proteins to identify cancers that express antigens are known to those of skill in the art. It should be understood that the terms "cancer" and "carcinoma" are not used interchangeably herein, since carcinoma is a specific type of cancer that appears in the skin or tissues that underpin or cover the organs of the body.

[0263] In one embodiment, the CT45-expressing cancer is selected from the group consisting of lung cancer, NSCLC, gallbladder cancer, bile duct cancer, lymph node cancer, ovarian cancer, esophageal cancer, liver cancer, uterine cancer and melanoma.

[0264] In one embodiment, the cancer is one in which the CT45 antigen is overexpressed, mutated, and / or CT45 antigen peptide is presented. Such cancers are easily assayed (i.e., diagnosed), for example, by using the antigen binding protein of the present invention. Methods for identifying cancers that express the antigen using antigen binding proteins are known to those skilled in the art.

[0265] In another aspect, the present invention relates to a method for the treatment of a proliferative disease comprising administering to a subject in need thereof a therapeutically effective amount of an antigen binding protein, a nucleic acid or vector, a host cell or a pharmaceutical composition of the invention as defined herein above.

[0266] In a particular embodiment, the present invention relates to a method of treating a subject having a proliferative disease, comprising administering to said subject lymphocytes, preferably NK cells or T cells, more preferably T cells, which express an antigen binding protein of the present invention on their cell surface.

[0267] The terms "subject" or "individual" are used interchangeably and can be, for example, a human or non-human mammal, preferably a human.

[0268] In the context of the present invention, the term "treat" or "treatment" includes both therapeutic treatment (i.e., in subjects with a given disease) and / or prophylactic or preventative treatment (i.e., in subjects susceptible to developing a given disease). Therapeutic treatment means and means improving, alleviating and / or inhibiting the progression of one or more symptoms of a disorder or condition. Preventative treatment means preventing the occurrence of one or more symptoms of a disorder or condition. Thus, treatment refers not only to treatment that results in a complete cure of a disease, but also to treatment that slows down the progression of a disease, prevents or delays the onset of a disease, and / or prolongs the survival of a subject.

[0269] In one embodiment, a "disease" or "disorder" refers to any condition that would benefit from treatment with an antigen binding protein of the invention. In one embodiment, this includes chronic and acute disorders or diseases, including pathological conditions that predispose a subject to the disorder in question. The term "in need of treatment" refers to subjects already with the disorder, as well as subjects in which the disorder is to be prevented.

[0270] "Proliferative disorders," such as cancer, involve unregulated and / or inappropriate proliferation of cells.

[0271] In one embodiment, the method of treatment comprises immunotherapy, in particular adoptive autologous or xenogeneic cell therapy, preferably T cell therapy.

[0272] In a preferred embodiment, the antigen binding protein is or comprises a TCR or a functional fragment thereof.

[0273] Preferably, the antigen binding protein is expressed on the surface of the host cell.

[0274] In one embodiment, the method of treatment comprises the administration of a host cell expressing the antigen binding protein, the host cell being a T cell, a T cell precursor or an NK cell, preferably a T cell.

[0275] In one embodiment, the host cells, preferably T cells, T cell precursors or NK cells, more preferably T cells, are autologous.

[0276] In one embodiment, the host cells, preferably T cells, T cell precursors or NK cells, more preferably T cells, are allogeneic.

[0277] In one embodiment, the antigen binding protein is conjugated to a therapeutically active agent, preferably a therapeutically active agent selected from the group consisting of a radionuclide, a chemotherapeutic agent and a toxin.

[0278] In one embodiment, the method of treatment further comprises administering to the subject in need of treatment at least one chemotherapeutic agent.

[0279] In one embodiment, the method of treatment further comprises administering radiation therapy to the subject in need of treatment.

[0280] In a related aspect, the present invention relates to a method of eliciting an immune response in a patient with a proliferative disease, in particular a cancer presenting a peptide comprising or consisting of the amino acid sequence of KIFEMLEGV (SEQ ID NO: 138) in complex with an MHC protein, comprising administering to the patient an antigen binding protein of the present disclosure, wherein the cancer is selected from the group of cancers consisting of lung cancer, NSCLC, gallbladder cancer, bile duct cancer, lymph node cancer, ovarian cancer, esophageal cancer, liver cancer, uterine cancer and melanoma. In one embodiment, the immune response referred to in the method is a cytotoxic T cell response.

[0281] In yet another aspect, the invention relates to the use of the antigen binding protein, nucleic acid or vector, host cell or pharmaceutical composition of the invention for the manufacture of a medicament for the treatment of a proliferative disease in a subject.

[0282] In yet another aspect, the invention relates to the use of the antigen binding protein, the nucleic acid or vector, the host cell or the pharmaceutical composition of the invention for treating a disease in a subject.

[0283] A textbook providing guidelines for cancer therapy is Cancer, Principles and Practice of Oncology, 4th Edition, DeVita et al, Eds. JB Lippincott Co., Philadelphia, Pa. (1993). As recognized in the relevant field, appropriate therapeutic approaches are selected according to the particular type of cancer and other factors, such as the patient's general condition. The antigen binding proteins of the present invention may be used by themselves or may be added to therapeutic regimens using other anti-neoplastic agents in the treatment of cancer patients.

[0284] Thus, in some embodiments, for example, the antigen binding protein may be administered concurrently with, prior to, or following a variety of drugs and treatments commonly employed in cancer treatment, such as chemotherapeutic agents, non-chemotherapeutic agents, antineoplastic agents, and / or radiation.

[0285] "Diagnosis" herein refers to a medical diagnosis and to determining what disease or condition explains a person's symptoms and signs.

[0286] A "therapeutically effective amount" of an antigen binding protein or pharmaceutical composition thereof means an amount of antigen binding protein sufficient to treat said proliferative disease at a reasonable benefit / risk ratio applicable to any medical treatment. However, it will be understood that the total daily usage of the antigen binding protein, nucleic acid or vector, host cell or pharmaceutical composition of the present invention will be determined by the attending physician within the scope of sound medical judgment. The specific therapeutically effective dose for any particular patient will depend on a variety of factors, including: the disorder being treated and the severity of the disorder; the activity of the specific antigen binding protein employed; the specific composition employed; the age, weight, general health, sex, and diet of the patient; the administration time, route of administration, and excretion rate of the specific polypeptide employed; the duration of treatment; drugs used in combination or simultaneously with the specific polypeptide employed; and similar factors known in the medical arts. For example, it is known to those skilled in the art to start the dose of the compound at a level lower than that required to obtain the desired therapeutic effect, and gradually increase the dosage until the desired effect is obtained.

[0287] In one embodiment, the effectiveness of treatment with an antigen binding protein of the invention is assayed in vivo, e.g., in a mouse model of cancer, e.g., by measuring the change in tumor volume between treated and control groups.

[0288] The antigen-binding protein of the invention, the nucleic acid of the invention or the vector of the invention, the host cell of the invention or the pharmaceutical composition of the invention may be administered by any feasible method.

[0289] As disclosed herein, in some embodiments, the host cell as defined herein above is used in the medical applications or treatment methods described herein. In such embodiments, the host cell is preferably a lymphocyte, such as a NK cell, a T cell or a T cell precursor, preferably a CD4 and / or CD8 positive T cell or a γδ T cell, most preferably a CD4 and / or CD8 positive T cell, most preferably a CD4 and / or CD8 positive T cell.

[0290] Thus, the host cells (preferably T cells) of the present invention can be used as an active ingredient of a therapeutic composition.Therefore, the present invention also provides a method for killing target cells in a patient in which the target cells abnormally express a polypeptide comprising the peptide KIFEMLEGV (SEQ ID NO: 138), comprising administering to the patient an effective number of host cells (preferably T cells).In connection with this method, the host cells preferably induce an immune response when administered to a subject.

[0291] In some embodiments, a TCR-induced response, or a T cell response, can refer to the increase and activation of effector functions induced by a peptide, such as KIFEMLEGV (SEQ ID NO: 138), in vitro, ex vivo, or in vivo. In the case of MHC class I-restricted cytotoxic T cells, for example, the effector functions can be lysis of peptide-pulsed, peptide precursor-pulsed, or naturally peptide-presenting target cells, peptide-induced secretion of cytokines (preferably interferon-gamma, TNF-alpha, or IL-2), peptide-induced secretion of effector molecules (e.g., granzymes or perforins), or degranulation.

[0292] In the context of the present invention, when T cells are used as medicine, T cells are usually harvested from cells by apheresis.Then, T cells are genetically engineered to express the antigen-binding protein of the present invention on their cell surface, and then the genetically engineered T cells are expanded and then reinjected into the subject.In this example, the antigen-binding protein is preferably a membrane-bound antigen-binding protein, more preferably TCR.

[0293] Thus, host cells are transfected, infected or transformed with the nucleic acids and / or vectors of the invention, as described herein above in the "Nucleic Acids, Vectors and Recombinant Host Cells" section.

[0294] When a host cell is transfected to express an antigen binding protein of the invention, the cell preferably contains an expression vector capable of expressing the antigen binding protein, and the host cell may then be referred to as an activated host cell.

[0295] This so-called adoptive transfer of T cells protocol is known in the art, and reviews can be found in Gattioni et al. and Morgan et al. [Gattinoni, L. et al., Nat. Rev. Immunol. 6 (2006): 383-393; Morgan, RA et al., Science 314 (2006): 126-129].

[0296] For purposes of the present invention, the amount or dose of the antigen binding protein of the first aspect of the invention, the nucleic acid of the second aspect of the invention, the vector of the third aspect of the invention, the host cell of the fourth aspect of the invention, or the pharmaceutical composition of the fifth aspect of the invention administered may be sufficient to effect, e.g., a therapeutic or prophylactic response in a subject or animal over a reasonable time frame. For example, a dose of an antigen binding protein, nucleic acid, vector, host cell, or pharmaceutical composition of the invention should be sufficient to bind to a cancer antigen or to detect, treat or prevent cancer for about 2 hours or a longer period, e.g., 12-24 hours or a longer period, from the time of administration. In certain embodiments, the period may be even longer. The dose is determined by the efficacy of the antigen binding protein, nucleic acid, vector, host cell, or pharmaceutical composition of the invention and the condition of the animal (e.g., human), as well as the body weight of the animal (e.g., human) to be treated.

[0297] Many other methods can be used to generate T cells in vitro. For example, autologous tumor-infiltrating lymphocytes can be used in generating CTL. Plebanski et al. (Plebanski, M. et al., Eur.J Immunol 25 (1995): 1783-1787) used autologous peripheral blood lymphocytes (PLB) in preparing T cells. Similarly, B cells can be used in producing autologous T cells.

[0298] Allogeneic cells may also be used in the preparation of T cells, methods of which are described in detail in US Pat. No. 6,805,861, which is incorporated herein by reference.

[0299] Host cells expressing the antigen binding protein of the invention against peptide KIFEMLEGV (SEQ ID NO: 138) are useful for therapy. Thus, a further aspect of the present invention provides an activated host cell obtainable by the above-mentioned method of the invention.

[0300] The activated host cells produced by the above method are capable of specifically recognizing cells that aberrantly express a polypeptide comprising the peptide KIFEMLEGV (SEQ ID NO: 138).

[0301] By "aberrantly expressed" we also mean that the polypeptide is overexpressed compared to expression levels in normal (healthy) tissue, or that the gene is silent in the tissue from which the tumor originates, but is expressed in the tumor. By "overexpressed" we mean that the polypeptide is present at a level at least 1.2-fold that present in normal tissue, preferably at least 2-fold, and more preferably at least 5-fold or 10-fold that present in normal tissue.

[0302] In one embodiment, the host cell (particularly the T cell) recognizes the cell by interacting with (e.g. binding to) the CT45-IP:MHC complex via its antigen binding protein (particularly its TCR). The host cell is useful in a method of killing target cells in a patient in which the target cells aberrantly express a polypeptide comprising the peptide KIFEMLEGV (SEQ ID NO: 138), to which an effective number of activated host cells are administered. The T cells administered to the patient may be derived from the patient and activated as described above (i.e. they are autologous T cells). Alternatively, the T cells are not derived from the patient, but from another individual (i.e. they are xenogeneic T cells). In such cases, this is preferred when the individual is a healthy individual. By "healthy individual" we mean that the individual is in generally good health, preferably has a competent immune system, and more preferably is not suffering from any disease that can be easily tested for and detected.

[0303] In vivo, target cells for the CD8 positive T cells of the present invention may be cells of the tumor (which may express MHC class II) and / or stromal cells surrounding the tumor (tumor cells) (which may also express MHC class II) [Dengjel, J. et al., Clin Cancer Res 12 (2006): 4163-4170].

[0304] Diagnostic Uses CT45 is expressed on the surface of cancer as defined herein above.CT45 antigen peptide constitutes a cancer marker and therefore has the potential to be used to indicate the effectiveness of anti-cancer treatment or to detect disease recurrence.

[0305] Therefore, in another aspect, the present invention provides an antigen binding protein of the first aspect, a nucleic acid of the second aspect, a vector of the third aspect, a host cell of the fourth aspect, or a pharmaceutical composition of the fifth aspect for use as a diagnostic, in particular for use as an in vivo diagnostic. In a preferred embodiment, the diagnostic is for diagnosing a proliferative disease. In a more preferred embodiment, the diagnostic is for diagnosing a cancer presenting a peptide comprising or consisting of the amino acid sequence of KIFEMLEGV (SEQ ID NO: 138) in complex with an MHC protein, preferably said cancer is selected from the group of cancers consisting of lung cancer, NSCLC, gallbladder cancer, bile duct cancer, lymph node cancer, ovarian cancer, esophageal cancer, liver cancer, uterine cancer and melanoma.

[0306] In certain embodiments, the antigen binding proteins of the invention are used as components of therapy-related assays targeting tumors expressing CT45 to determine a patient's sensitivity to a therapeutic agent, to monitor the effectiveness of anti-cancer therapy, or to detect disease recurrence following treatment.

[0307] Therefore, a further object of the present invention relates to an antigen-binding protein according to the invention for use in vivo to detect CT45 expression in a subject or for use in ex vivo or in vitro to detect CT45 expression in a biological sample of a subject. a) diagnosing the presence of cancer in a subject; or b) determining the sensitivity of a patient with cancer to a therapeutic agent that targets CT45; or c) by detecting the presentation of CT45 antigenic peptides on tumor cells; monitoring the effectiveness of anti-CT45 cancer therapy or detecting the recurrence of cancer after anti-CT45 cancer therapy, particularly for therapy using an antigen binding protein of the invention. may be intended for.

[0308] In one embodiment, the antigen binding protein is intended for in vitro or ex vivo use.

[0309] In yet another aspect, the present invention relates to an in vitro method of detecting cancer in a biological sample comprising the steps of: (a) contacting the biological sample with an antigen binding protein of the first aspect of the invention; and (b) detecting binding of the antigen binding protein to the biological sample.

[0310] kit Finally, the present invention also provides kits comprising at least one antigen binding protein of the present invention.

[0311] In one embodiment, the kit comprises: a) at least one antigen binding protein of the invention as defined herein above in the "Antigen binding proteins" section, a nucleic acid encoding said antigen binding protein, a vector comprising said nucleic acid, or a host cell comprising said antigen binding protein, nucleic acid and / or vector, b) Where appropriate, packaging materials, and c) optionally, a label or packaging insert contained within said packaging material indicating that said antigen binding protein is effective for treating cancer or is for use for the treatment of cancer. Includes.

[0312] In a preferred embodiment, the kit comprises a nucleic acid encoding an antigen binding protein of the invention, or a vector comprising this nucleic acid. The kit may further comprise instructions for regulatable expression of the antigen binding protein on the surface of a cell, preferably a T cell, a T cell precursor or a NK cell, more preferably a T cell.

[0313] The kits of the present disclosure may further comprise any other reagents useful for regulatable expression of an antigen binding protein on the surface of a cell, preferably a T cell, a T cell precursor or a NK cell, more preferably a T cell, such as a transfection / transduction reagent useful for introducing a nucleic acid or an expression vector into a cell.

[0314] It may also be preferred that the kit comprises a host cell comprising a nucleic acid encoding the antigen binding protein of the invention, or a vector comprising this nucleic acid, ie a host cell capable of expressing the antigen binding protein of the invention.

[0315] The components of the kit may be in separate containers, or multiple components may be in a single container. Suitable containers include a single tube, or one or more wells of a plate (e.g., a 96-well plate, a 384-well plate, etc.), etc.

[0316] In a related embodiment, at least one antigen binding protein of the present invention is contained in single and / or multi-chambered pre-filled syringes (eg, liquid syringes and lyosyringes).

[0317] In one embodiment, the invention encompasses a kit for producing a single dosage unit.

[0318] Thus, in one embodiment the at least one antigen binding protein of the invention referred to under a) of the kit of the invention is a dried antigen binding protein of the invention in a first container, which kit then further comprises a second container which contains an aqueous formulation.

[0319] Thus, in one embodiment, the kit comprises: a) a first container containing at least one dried antigen binding protein of the invention as defined herein above in the "Antigen binding proteins" section; b) a second container containing the aqueous formulation; c) Packaging materials, as appropriate; and d) optionally, a label or packaging insert included in said packaging material indicating that said antigen binding protein is effective for treating or for use in treating cancer. Includes.

[0320] Aqueous formulations are typically aqueous solutions that include a pharma- ceutically acceptable carrier as defined in the "Pharmaceutical Compositions" section herein above.

[0321] In related embodiments, the "first container" and "second" container refer to the chambers of a multi-chambered pre-filled syringe (eg, a lyophilization syringe).

[0322] Throughout this application, the term "and / or" is a grammatical conjunction that should be interpreted to include one or more of the cases in which it is connected. For example, the phrase "such native sequence proteins may be prepared using standard recombinant and / or synthetic methods" indicates that the native sequence protein may be prepared using standard recombinant and synthetic methods, or that the native sequence protein may be prepared using standard recombinant methods, or that the native sequence protein may be prepared using synthetic methods.

[0323] Moreover, throughout this application, the term "comprising" should be interpreted to encompass not only all features specifically mentioned, but also any additional, unspecified ones. As used herein, use of the term "comprising" also discloses embodiments in which no features are present (i.e., "consisting of") other features than those specifically mentioned.

[0324] Moreover, the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0325] The present invention will now be described in more detail with reference to the following figures and examples. All publications and patents cited herein are incorporated herein by reference. The present invention is shown and explained in detail in the following description, but the examples should be considered as illustrative and not limiting. [Brief description of the drawings]

[0326] [Figure 1-1] Functional avidity measured by the killing efficiency of CT45-IP peptide-loaded T2 cells by TCR-transfected T cells (EC50). T2 cells constitutively expressing luciferase were loaded with titrated amounts of CT45-IP peptide and then co-cultured with CD8+ T cells transfected with a specific TCR. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. Assays were repeated twice with cells from two different donors (indicated by filled circle and diamond symbols). Functional avidity was assessed by calculating the half-maximal killing efficiency of the tested TCRs. [Figure 1-2]Functional avidity measured by the killing efficiency of CT45-IP peptide-loaded T2 cells by TCR-transfected T cells (EC50). T2 cells constitutively expressing luciferase were loaded with titrated amounts of CT45-IP peptide and then co-cultured with CD8+ T cells transfected with a specific TCR. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. Assays were repeated twice with cells from two different donors (indicated by filled circle and diamond symbols). Functional avidity was assessed by calculating the half-maximal killing efficiency of the tested TCRs. [Figure 1-3] Functional avidity measured by the killing efficiency of CT45-IP peptide-loaded T2 cells by TCR-transfected T cells (EC50). T2 cells constitutively expressing luciferase were loaded with titrated amounts of CT45-IP peptide and then co-cultured with CD8+ T cells transfected with a specific TCR. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. Assays were repeated twice with cells from two different donors (indicated by filled circle and diamond symbols). Functional avidity was assessed by calculating the half-maximal killing efficiency of the tested TCRs. [Figure 1-4] Functional avidity measured by the killing efficiency of CT45-IP peptide-loaded T2 cells by TCR-transfected T cells (EC50). T2 cells constitutively expressing luciferase were loaded with titrated amounts of CT45-IP peptide and then co-cultured with CD8+ T cells transfected with a specific TCR. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. Assays were repeated twice with cells from two different donors (indicated by filled circle and diamond symbols). Functional avidity was assessed by calculating the half-maximal killing efficiency of the tested TCRs. [Figure 1-5]Functional avidity measured by the killing efficiency of CT45-IP peptide-loaded T2 cells by TCR-transfected T cells (EC50). T2 cells constitutively expressing luciferase were loaded with titrated amounts of CT45-IP peptide and then co-cultured with CD8+ T cells transfected with a specific TCR. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. Assays were repeated twice with cells from two different donors (indicated by filled circle and diamond symbols). Functional avidity was assessed by calculating the half-maximal killing efficiency of the tested TCRs. [Figure 2-1] Confirmation of cross-reactivity for sequence-similar peptides. T2 cells constitutively expressing luciferase were loaded with CT45-IP peptide at a concentration of 10 μM per peptide, 10 different sequence-similar peptides, an irrelevant peptide control NYESO1-001, or not. These T2 cells were then co-cultured with CD8+ T cells transfected with specific TCRs. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. The assay was repeated twice with cells from two different donors (black bars = assay 1, donor 1; red bars = assay 2, donor 2). [Figure 2-2] Confirmation of cross-reactivity for sequence-similar peptides. T2 cells constitutively expressing luciferase were loaded with CT45-IP peptide at a concentration of 10 μM per peptide, 10 different sequence-similar peptides, an irrelevant peptide control NYESO1-001, or not. These T2 cells were then co-cultured with CD8+ T cells transfected with specific TCRs. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. The assay was repeated twice with cells from two different donors (black bars = assay 1, donor 1; red bars = assay 2, donor 2). [Figure 2-3]Confirmation of cross-reactivity for sequence-similar peptides. T2 cells constitutively expressing luciferase were loaded with CT45-IP peptide at a concentration of 10 μM per peptide, 10 different sequence-similar peptides, an irrelevant peptide control NYESO1-001, or not. These T2 cells were then co-cultured with CD8+ T cells transfected with specific TCRs. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. The assay was repeated twice with cells from two different donors (black bars = assay 1, donor 1; red bars = assay 2, donor 2). [Figure 2-4] Confirmation of cross-reactivity for sequence-similar peptides. T2 cells constitutively expressing luciferase were loaded with CT45-IP peptide at a concentration of 10 μM per peptide, 10 different sequence-similar peptides, an irrelevant peptide control NYESO1-001, or not. These T2 cells were then co-cultured with CD8+ T cells transfected with specific TCRs. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. The assay was repeated twice with cells from two different donors (black bars = assay 1, donor 1; red bars = assay 2, donor 2). [Figure 2-5] Confirmation of cross-reactivity for sequence-similar peptides. T2 cells constitutively expressing luciferase were loaded with CT45-IP peptide at a concentration of 10 μM per peptide, 10 different sequence-similar peptides, an irrelevant peptide control NYESO1-001, or not. These T2 cells were then co-cultured with CD8+ T cells transfected with specific TCRs. Killing was analyzed by measuring luciferase activity in the supernatant released by dying T2 cells. The assay was repeated twice with cells from two different donors (black bars = assay 1, donor 1; red bars = assay 2, donor 2). [Figure 3-1]TCR surface staining. Flow cytometric assessment of TCR expression measured by pHLA-Dextramer binding. Histograms show TCR-mRNA electroporated T cells (black line) and Mock-TCR control (light grey dotted line) after staining with CT45-IP-HLA-A2*02 dextramer. Percent positive events are plotted. Mock-TCR control is used as a reference for the dextramer negative compartment. [Figure 3-2] TCR surface staining. Flow cytometric assessment of TCR expression measured by pHLA-Dextramer binding. Histograms show TCR-mRNA electroporated T cells (black line) and Mock-TCR control (light grey dotted line) after staining with CT45-IP-HLA-A2*02 dextramer. Percent positive events are plotted. Mock-TCR control is used as a reference for the dextramer negative compartment. [Figure 4] Efficacy on tumor cell lines. Live cell monitoring of tumor cell lines expressing RFP co-cultured with or without T cells expressing our TCR of interest. Red counts representing tumor cells were quantified over a 48h period and normalized to time point 0h. The plot on the left shows the tumor cell line NCIH1703, while the plot on the right shows proliferation of cell line A375. CD8+ T cells electroporated with Mock-TCR (negative control, top), TCR-9 (middle) and TCR-7 (bottom) are shown. Target cells additionally loaded with 10μM CT45-IP peptide (circle with a dot in the middle) as a positive control were used as well as target cells without effector cells (asterisk) and effector cells with different E:T ratios expressing the TCR of interest (circles with different shades of grey). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0327] material and method TCR Identification Alpha and beta TCR chain sequences were isolated from T cells of healthy donors. To ensure enrichment of peptide-specific T cells, cells were repeatedly stimulated with artificial antigen-presenting cells coated with CT45-IP-MHC and CD28 (Priming) as described in Walter et al., 2003 J Immunol., Nov 15;171(10):4974-8, followed by single cell sorting using CT45-IP-HLA-A*02 tetramers or alternatively stimulated with CT45-IP-loaded T2 cells. After sufficient expansion, cells were sorted using CT45-IP-HLA-A*02 tetramers.

[0328] TCR nucleotide sequences were obtained via standard methods, e.g., 5' RACE and Sanger sequencing, as described, e.g., in Molecular Cloning, Laboratory Manual, Fourth Edition by Green and Sambrook. Genes encoding the V and J regions of the TCR are listed in Table 2. Annotation was performed with GeneData 11.0.1 using IMGT / GENE-DB (Version: 28 / 11 / 2019) as the reference database. TCR amino acid sequences are listed in Table 3.

[0329] [Table 2]

[0330] [Table 3-1] [Table 3-2] [Table 3-3] [Table 3-4] [Table 3-5] [Table 3-6] [Table 3-7] [Table 3-8] [Table 3-9] [Table 3-10] [Table 3-11] [Table 3-12]

[0331] TCR re-expression The human constant chain domains were replaced by their mouse counterparts with additional mutations in the transmembrane domain to enhance hydrophobicity. Both modifications are described in Jin et al., JCI Insight. 2018;3(8):e99488.

[0332] To evaluate the functional properties, the identified TCRs were re-expressed in primary T cells of healthy donors using TCR mRNA electroporation technology. Briefly, T7 transcription was performed on DNA templates of TCR alpha and beta chain nucleotide sequences. The resulting TCR mRNA was used for electroporation of preactivated T cells for transient expression of exogenous TCRs, which was verified in co-culture experiments.

[0333] Co-culture assays (assessment of functional avidity, specificity, and TCR motifs) The functional properties of the TCR were evaluated in co-culture experiments with T2 cells. CD8+ T cells were pre-stimulated and electroporated with TCR mRNA. On the day of co-culture, luciferase-transduced T2 cells were treated with different concentrations of peptide CT45-IP (SEQ ID NO: 138) (assessment of functional avidity, EC 50 ), a sequence similar peptide (SEQ ID NOs: 146 to 155) at a concentration of 10 μM, or the average EC 50 T2 cells were loaded with either alanine-substituted variants of the CT45-IP peptide (SEQ ID NO: 139-145) (TCR motif determination) at concentrations ranging from 10-30 fold above the T45-IP peptide. As controls, a concentration of 10 μM of the irrelevant peptide NYESO1-001 (SEQ ID NO: 188) and unloaded T2 cells were used. Briefly, T2 cells were incubated with the respective amounts of peptide for 2 hours, followed by washing and harvesting.

[0334] Besides cells electroporated with the model TCR 1G4-a95Ly, mock-electroporated T cells without exogenous TCR served as controls. T cells and peptide-loaded T2 cells were seeded at a 1:1 ratio and incubated for 24 h before harvesting the supernatants. The supernatants were analyzed for the presence of luciferase released by apoptotic / necrotic T2 cells killed by peptide-specific T cells. By adding a specific substrate, the amount of luciferase present in the supernatants was determined by measuring the chemiluminescence signal in a microplate reader.

[0335] Testing for functionality in CD4+ T cells CD3+ T cells were stimulated and electroporated with TCR mRNA. After overnight incubation, TCR-transfected T cells were co-cultured at a 1:1 ratio with T2 cells loaded with either 10 μM CT45-IP (SEQ ID NO: 138) or 10 μM irrelevant NYESO1-001 (SEQ ID NO: 188) peptide. Immediately after the start of co-culture, cytokine secretion blocking reagent was added and incubated at 37° C. for 5 h. T cells were then stained with fluorescently labeled antibodies for different surface markers, e.g., CD4 and CD8. After fixation and permeabilization, cells were stained for intracellular cytokines (TNF-α and IFN-γ) and analyzed on a flow cytometer (data not shown).

[0336] Lentiviral co-transduction of the costimulatory molecule CD8 To involve CD4 T cells in immune responses after transduction of MHC class I restricted TCR, co-transduction with the costimulatory molecule CD8 was performed. For that purpose, lentiviral vectors encoding CD8 molecules in addition to TCR chains were used for transduction of prestimulated CD3+ T cells. T cells were activated for 24 h using CD3 and anti-CD28 coated on plates with the addition of IL-2. Pre-titrated concentrated lentiviral supernatant was added to cells together with adjuvants for enhanced transduction of lentiviral particles, e.g., Lentiboost® Reagent (Sirion Biotech). T cells were expanded over 10 days using increasing volumes of medium and decreasing concentrations of IL-2, while T cells were successively transferred to larger cell culture flasks. Transduction efficiency and quiescence of T cells were confirmed via flow cytometry prior to freezing of cells. The effect of CD8 co-transfection on killing efficiency against CT45-IP presenting tumor cells was then analyzed in a live cell monitoring killing assay (data not shown).

[0337] TCR surface staining Surface marker staining was performed with electroporated and preactivated CD8+ T cells. For this purpose, in addition to using anti-CD8, CD3 and / or mTCRB antibodies, TCR staining was performed with fluorescently labeled Dextramer (Dextramer scaffold with conjugated CT45-IP-HLA-A*02 or irrelevant NYESO1-001-HLA-A*02). After 30 min, cells were washed, fixed and subsequently analyzed by flow cytometry. To define dextramer-positive cells, gates were set according to the signal of cells stained with irrelevant peptide-MHC dextramer.

[0338] Live cell monitoring killing assay The proliferation of tumor cell lines expressing red fluorescent protein (RFP) was monitored by quantifying red object counts over time using a live cell imaging system. Cell lines NCIH1703 and A375 were co-cultured with T cells expressing the TCR of the present invention at an E:T ratio of 9:1, 3:1 or 1:1, or cultured without T cells, and monitored over a period of 48h. As a positive control, target cells were loaded with 10 μM peptide CT45-IP. A decrease in tumor cell line proliferation over time is an indication of tumor cell killing. [Example 1]

[0339] Functional Avidity All 15 identified CT45-IP-specific TCRs exhibited the half-maximal killing capacity EC 50 The peptides show high functional avidity as measured by peptide titration experiments, expressed as EC 50 The values ​​range from 0.15 nM to 59.5 nM. In particular, the EC 50The values ​​are 7.78nM(TCR-1);4.69nM(TCR-2);1.02nM(TCR-3);1.31nM(TCR-4);1.32nM(TCR-5);3.25nM(TCR-6);0.48nM(TCR-7);6.52nM(TCR-8 ); 0.15 nM (TCR-9); 8.75 nM (TCR-10); 59.50 nM (TCR-11); 47.47 nM (TCR-12); 11.38 nM (TCR-13); 17.69 nM (TCR-14); 18.60 nM (TCR-15). [Example 2]

[0340] Specificity and TCR motifs The TCRs described herein were tested for their specificity profile by testing their ability to recognize 10 CT45-IP sequence-similar peptides (SEQ ID NO: 146-155). Loading with CT45-IP and CT45-IP sequence-similar peptides was performed at a very high concentration of 10 μM in order to detect low signals. The TCRs did not show binding to other peptides other than CT45-IP. As depicted in FIG. 2, minor binding signals to peptide SP-05-0004 (SEQ ID NO: 149) were detected for TCR-9 and TCR-6. Characterization of the TCRs also involved the determination of the TCR binding motifs to the CT45-IP peptides listed in Table 4. To this end, CT45-IP alanine-exchanged peptide variants (SEQ ID NO: 139-145) were tested in co-culture experiments with all 15 TCRs. The alanine-exchanged peptides were found to bind to the average EC 50 The peptides were tested at concentrations ranging from 10- to 30-fold above the 5'-amino acid range. Relevant positions are indicated by numbers (referring to the position of the amino acid in the peptide), non-relevant positions are represented by a hyphen, and positions that were not tested are labeled by an x.

[0341] [Table 4] [Example 3]

[0342] CD4 functionality Tests for functionality in CD4+ T cells were performed as described above. Among the 15 tested TCRs, we identified TCRs that showed functionality in CD4+ T cells in addition to CD8+ T cells (data not shown). [Example 4]

[0343] Surface expression Surface expression of the TCRs described herein was measured by CT45-IP-HLA-A2*02 dextramer staining and is shown in Figure 3. Surface expression varied from 0.53% (TCR-11) to 55.5% (TCR-5) positive events after gating on CD3+ T cells after TCR mRNA electroporation. In particular, surface expression was 8.9% (TCR-1); 39.1% (TCR-2); 27.2% (TCR-3); 39.1% (TCR-4); 61.1% (TCR-5); 2.9% (TCR-6); 53.3% (TCR-7); 60.7% (TCR-8); 44.0% (TCR-9); 52.8% (TCR-10); 6.6% (TCR-11); 20.1% (TCR-12); 53.1% (TCR-13); 11.6% (TCR-14); 22.6% (TCR-15). [Example 5]

[0344] Efficacy against tumor cell lines Two tumor cell lines, A375 with approximately 30 copies of CT45-IP per cell and NCIH1703 with approximately 150 copies of CT45-IP per cell, were co-cultured with CD8+ T cells expressing TCR-9, TCR-7 or Mock-TCR (Figure 4). The efficacy of those TCRs to kill the two cell lines was evaluated in live cell monitoring experiments. While Mock-TCR does not result in a significant reduction in tumor cell proliferation as measured by a normalized red object count of <2, TCR-9 and TCR-7 efficiently kill tumor cell lines loaded with CT45-IP peptide at an E:T ratio of 6:1 (TCR-9) or 1.8:1 (TCR-7) (NCIH1703&A375), tumor cell lines without additional peptide loading at an E:T ratio of 6:1 (TCR-9) or 1.8:1 (TCR-7) (NCIH1703&A375), and tumor cell lines at an E:T ratio of 2:1 (TCR-9) or 0.6:1 (TCR-7) and 0.6:1 (TCR-9) or 0.2:1 (TCR-7) (NICIH1703). [Example 6]

[0345] Safety Window Co-culture assays were performed using T2 cells loaded with a titration series of peptides CT45-IP and SP-05-0004, respectively. EC 50 SP-05-0004 EC 50 The safety wi...

Claims

Claim 1 An antigen-binding protein that specifically binds to a CT45 antigen peptide present as a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigen peptide consists of the amino acid sequence of SEQ ID NO: 138 (KIFELEG), and the antigen-binding protein comprises a variable domain V containing complementarity-determining regions (CDRs) CDRa1, CDRa2, and CDRa3 Ａ a first polypeptide comprising V Ａ containing CDRb1, CDRb2, and CDRb3 Ｂ and a second polypeptide comprising V Ｂ 1) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 80, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 81, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 82, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 85, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 86, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 87; 2) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 14, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 15, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 16, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 19, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 20, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 21; 3) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 133, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 136; 4) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 63, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 67, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 68; 5) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 90, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 91, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 92, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 95, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

96. 6) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 2, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 3, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 4, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 8, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 9, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

10. 7) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 53, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 54, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 55, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 59, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

60. 8) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 71, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 15, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 72, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

77. 9) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 99, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 100, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 101, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 76, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 104, 10) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 107, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 108, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 109, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 113, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 114, 11) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 125, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 126, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 127, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 113, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 130, or 12) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 117, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 118, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 119, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 59, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 122, 13) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 35, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 38, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 39, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

40. 14) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 25, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 26, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 29, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 30, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 31, or 15) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 43, CDRa2 comprises or consists of the amino acid sequence of SEQ ID NO: 44, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 45, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 48, CDRb2 comprises or consists of the amino acid sequence of SEQ ID NO: 49, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

50. The antigen-binding protein comprises the CDRa1, CDRa3, CDRb1 and CDRb3 sequences having no more than one amino acid substitution, and each of CDRa1, CDRa3, CDRb1 and / or CDRb3 may contain one substitution. Antigen-binding protein. **Claim 2**: An antigen-binding protein that specifically binds to a CT45 antigen peptide present as a complex with a major histocompatibility complex (MHC) protein, wherein the CT45 antigen peptide consists of the amino acid sequence of SEQ ID NO: 138 (KIFEMLEGVA), and the antigen-binding protein is a TCR and comprises a first polypeptide comprising a variable domain VA containing complementarity-determining regions (CDRs) CDRa1, CDRa2, and CDRa3, and a second polypeptide comprising a variable domain VB containing CDRb1, CDRb2, and CDRb3, 1) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 80, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 82, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 85, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 87, 2) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 14, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 16, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 19, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 21, 3) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 133, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 136, 4) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 63, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 68, 5) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 90, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 92, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 66, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 96, 6) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 2, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 4, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 8, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

10. 7) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 53, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 55, CDRb1 comprises the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

60. 8) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 71, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 72, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

77. 9) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 99, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 101, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 75, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

104. 10) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 107, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 109, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

114. 11) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 125, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 127, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 112, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

130. 12) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 117, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 119, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 58, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO:

122. 13) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 35, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 38, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 40 14) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 24, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 26, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 29, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 31, or 15) CDRa1 comprises or consists of the amino acid sequence of SEQ ID NO: 43, CDRa3 comprises or consists of the amino acid sequence of SEQ ID NO: 45, CDRb1 comprises or consists of the amino acid sequence of SEQ ID NO: 48, and CDRb3 comprises or consists of the amino acid sequence of SEQ ID NO: 50 The antigen-binding protein comprises the CDRa1, CDRa3, CDRb1 and CDRb3 sequences having no more than one amino acid substitution, and each of CDRa1, CDRa3, CDRb1 and / or CDRb3 may contain one amino acid substitution. Antigen-binding protein.

3. The antigen-binding protein is a TCR, and preferably, the TCR is selected from the group consisting of an α / β TCR, a γ / δ TCR, a single-chain TCR, a membrane-bound TCR, a soluble TCR, a monovalent, divalent or multivalent TCR, a single-specificity, dual-specificity or multi-specificity TCR, a functional fragment of a TCR, and a fusion protein or chimeric protein containing a functional fragment of a TCR; more preferably, the TCR is an α / β TCR or a γ / δ TCR; most preferably, the TCR is an α / β TCR. The antigen-binding protein according to claim 1.

4. V Ａ is an amino acid sequence selected from the group consisting of SEQ ID NOs: 79, 13, 132, 62, 89, 1, 52, 70, 98, 106, 124, 116, 34, 23, and 42, or has at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NOs: 79, 13, 132, 62, 89, 1, 52, 70, 98, 106, 124, 116, 34, 23, and 42, and contains or consists of an amino acid sequence comprising CDRa1, CDRa2 and CDRa3 as recited in claim 1 or 2; and V Ｂ is an amino acid sequence selected from the group consisting of SEQ ID NOs: 84, 18, 135, 65, 94, 7, 57, 74, 103, 111, 129, 121, 37, 28 and 47, or has at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% identity to SEQ ID NOs: 84, 18, 135, 65, 94, 7, 57, 74, 103, 111, 129, 121, 37, 28 and 47, and contains or consists of an amino acid sequence comprising CDRb1, CDRb2 and CDRb3 as recited in claim 1 or 2, wherein the CDRa1, CDRa2, CDRa3, CDRb1, CDRb2 and / or CDRb3 sequences may comprise 1, 2 or 3 amino acid mutations, preferably amino acid substitutions, the antigen-binding protein according to claim 1 or 2.

5. The antigen-binding protein further comprises a constant domain, and the constant domain is selected from the group consisting of SEQ ID NO: 5, 750, 751, 156, 11, 32, and 157, preferably an amino acid sequence selected from the group consisting of SEQ ID NO: 5, 750, 751, 11, and 32, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identity to SEQ ID NO: 5, 750, 751, 156, 11, 32, or 157, or consisting of, the antigen-binding protein according to claim 1 or 2.

6. The first polypeptide is selected from the group consisting of SEQ ID NO: 83, 17, 134, 64, 93, 6, 56, 73, 102, 110, 128, 120, 36, 27, 46, and 158-172, preferably an amino acid sequence selected from the group consisting of SEQ ID NO: 83, 17, 134, 64, 93, 6, 56, 73, 102, 110, 128, 120, 36, 27, and 46, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identity to SEQ ID NO: 83, 17, 134, 64, 93, 6, 56, 73, 102, 110, 128, 120, 36, 27, 46, or 158-172, and the second polypeptide is selected from the group consisting of SEQ ID NO: 88, 22, 137, 69, 97, 12, 61, 78, 105, 115, 131, 123, 41, 33, 51, and 173-187, preferably an amino acid sequence selected from the group consisting of SEQ ID NO: 88, 22, 137, 69, 97, 12, 61, 78, 105, 115, 131, 123, 41, 33, and 51, or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identity to SEQ ID NO: 88, 22, 137, 69, 97, 12, 61, 78, 105, 115, 131, 123, 41, 33, 51, or 173-187, or consisting of, the antigen-binding protein according to claim 1 or 2.

7. The antigen-binding protein does not significantly bind to at least 1, at least 2, at least 3, at least 4, at least 5, or all similar peptides selected from the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 149 (SP-05-0004), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010); preferably the group consisting of SEQ ID NO: 146 (SP-05-0001), SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 148 (SP-05-0003), SEQ ID NO: 150 (SP-05-0005), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), SEQ ID NO: 153 (SP-05-0008), SEQ ID NO: 154 (SP-05-0009), and SEQ ID NO: 155 (SP-05-0010); more preferably at least 1, at least 2, at least 3, at least 4, at least 5, or all similar peptides selected from the group consisting of SEQ ID NO: 147 (SP-05-0002), SEQ ID NO: 151 (SP-05-0006), SEQ ID NO: 152 (SP-05-0007), and SEQ ID NO: 155 (SP-05-0010), the antigen-binding protein according to claim 1 or 2.

8. The antigen-binding protein is - CD4+ T cells, particularly CD4+ CD8- T cells, and / or - CD8+ T cells, particularly CD8+ CD4- T cells can be activated, and the antigen-binding protein is preferably TCR, more preferably α / β TCR or γ / δ TCR, the antigen-binding protein according to claim 1 or 2.

9. A nucleic acid comprising a sequence encoding the antigen-binding protein according to claim 1.

10. A vector comprising the nucleic acid according to claim 9.

11. A host cell comprising the antigen-binding protein according to claim 1 or 2, or the nucleic acid according to claim 9, or the vector according to claim 10.

12. A pharmaceutical composition comprising the antigen-binding protein according to claim 1 or 2, the nucleic acid according to claim 9, the vector according to claim 10, or a host cell comprising the antigen-binding protein according to claim 1, and optionally a pharmaceutically acceptable carrier.

13. The antigen-binding protein according to claim 1 or 2, the nucleic acid according to claim 9, the vector according to claim 10, or the host cell comprising the antigen-binding protein according to claim 1, for use in medicine, preferably for use in the treatment and / or diagnosis of proliferative diseases, in particular cancer.

14. An in vitro method for detecting cancer in a biological sample, in particular cancer expressing CT45, comprising: a) contacting the biological sample with the antigen-binding protein according to claim 1 or 2, and b) detecting the binding of the antigen-binding protein to the biological sample. A method comprising the steps.

15. A method for producing the antigen-binding protein according to claim 1 or 2, comprising: a) preparing a host cell, b) preparing a gene construct comprising a nucleic acid encoding the antigen-binding protein according to claim 1 or 2, c) introducing the gene construct into the host cell, and d) expressing the gene construct by the host cell. A method comprising the steps.

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