Anti-LYPD3 antibody

Abstract

The present invention relates to anti-LYPD3 antibodies that bind to LYPD3 in an O-glycosylation dependent manner. Therefore, the antibody has specificity to tumor-associated LYPD3 (LYPD3). The invention also provides a pharmaceutical composition containing the anti-LYPD3 antibody and an application of the pharmaceutical composition in cancer treatment.

Description

Technical Field

[0001] The present invention relates to the field of antibodies. In particular, anti-LYPD3 antibodies that show strong antigen binding in a glycosylation-dependent manner are provided. In a specific embodiment, the present invention relates to anti-LYPD3 antibodies for therapeutic and diagnostic use. Background Art

[0002] At present, antibodies are widely used agents in medicine and research. In medicine, they have applications in many different fields. For example, antibodies are used as therapeutic agents in the treatment and prevention of various diseases (such as cancer, cardiovascular disease, inflammatory diseases, macular degeneration, transplant rejection, multiple sclerosis and viral infections). In these therapies, the antibodies themselves may have therapeutic activity, for example, by blocking receptors or messenger molecules, or by recruiting and activating components of the patient's immune system, thereby inhibiting its disease-related functions.

[0003] In cancer treatment, the key characteristic of therapeutic antibodies is their specificity for tumor tissue. This means that the antibody should target epitopes that are found only on cancer cells or mainly on cancer cells and only to a lesser extent on normal tissue cells. Therefore, the therapeutic activity of the antibody (such as inducing an immune response against target cells or destroying cells by cytotoxic payloads) acts specifically on the tumor site. Due to the binding of antibodies to non-tumor cells, their respective activities in normal tissues may cause serious side effects. Therefore, increasing the specificity for tumor cells can reduce the risk of adverse reactions and enhance the safety of the intended therapy.

[0004] A possible cancer antigen is LYPD3 (C4.4A). This protein is a glycosylphosphatidylinositol (GPI)-anchored, heavily glycosylated cell surface protein that has been shown to be upregulated in migrating keratinocytes during wound healing. LYPD3 was first described as a metastasis-associated cell surface protein in rat pancreatic tumor cells, and since then, LYPD3 has been implicated in carcinogenesis in several different cancers. In cancer, LYPD3 is thought to be specifically involved in tumor cell invasion through interaction with the extracellular matrix.

[0005] LYPD3 is strongly overexpressed in non-small cell lung cancer (NSCLC), with LYPD3 preferentially expressed in the squamous cell carcinoma (SCC) subtype compared to the other two most common NSCLC subtypes: adenocarcinoma (AC) and large cell carcinoma (LCC). Lung cancer is the most commonly diagnosed cancer, with an estimated 1.8 million new cases in 2012. NSCLC accounts for 85% of all lung cancers, and SCC is the second most common histological subtype, accounting for 30% of NSCLC cases, explaining the approximately 400,000 deaths worldwide each year.

[0006] Overexpression of LYPD3 has also been detected in head and neck SCC (HNSCC), including esophageal SCC (ESCC) subtypes. At the transcriptional level, approximately 50% of primary lung cancers and 75% of metastatic lung cancers express LYPD3 mRNA, whereas no expression is detected in normal lung tissues. In addition, LYPD3 is expressed in colorectal cancer and breast cancer.

[0007] Overexpression of LYPD3 has been shown to be associated with a malignant phenotype and poor prognosis in NSCLC, colorectal cancer, and ESCC, whereas in breast cancer, overexpression of LYPD3 is associated with a favorable prognosis. Therefore, LYPD3 represents an interesting target for antitumor immunotherapy.

[0008] However, under normal physiological conditions, LYPD3 is expressed in skin keratinocytes, esophageal endothelial cells, and placental cells. This may cause unwanted side effects in cancer therapy because antibodies cannot distinguish between LYPD3 on normal tissues and cancer-associated LYPD3.

[0009] Therefore, there is a need in the art to provide tumor-specific anti-LYPD3 antibodies. Summary of the invention

[0010] The inventors have developed anti-LYPD3 antibodies with enhanced tumor specificity. These antibodies bind to tumor-associated LYPD3 in an O-glycosylation-dependent manner to recognize O-glycan structures present on LYPD3 of cancer cells. The O-glycosylation of cancer cells contains a large number of short chain structures, especially monosaccharides, disaccharides and trisaccharides, such as Thomsen-Friedenreich antigen (TF; Galβ1-3GalNAcα1-), sialylated Thomsen-Friedenreich antigen (sTF), Thomsennouvelle antigen (Tn; GalNAcα1-) and sialylated Thomsen nouvelle antigen (Siaα2-6GalNAcα1-). In contrast, in normal cells, O-glycosylation covers longer oligosaccharide chains. Since the developed antibodies specifically bind to LYPD3 carrying short O-glycosylation derived from cancer cells, the antibodies distinguish between tumor-associated LYPD3 (i.e., LYPD3 present on cancer cells) and LYPD3 on normal tissue cells. Therefore, the antibodies of the present invention preferentially bind to LYPD3 on tumor cells and thus have excellent cancer specificity and reduced binding to normal tissues, resulting in a lower risk of adverse reactions in cancer immunotherapy.

[0011] Mature LYPD3 consists of two Ly-6 (leukocyte antigen 6) / uPAR / α-neurotoxin domains (LU domains) and is heavily modified by post-translational glycosylation, including 5 N-glycosylation sites located in or near the second LU domain and approximately 15 O-linked carbohydrates clustered in a C-terminal Ser / Thr / Pro-rich region. The antibodies of the present invention recognize LYPD3 in an O-glycosylation-dependent manner by binding to a C-terminal STP-rich region at amino acids 234 to 303 (particularly at amino acids 247 to 297) of the human LYPD3 sequence (SEQ ID NO: 137). The O-glycosylation site of LYPD3 is located in this region.

[0012] In summary, in the first aspect, the present invention relates to an antibody that is capable of specifically binding to glycosylated human LYPD3 at an epitope comprising an oligosaccharide structure, wherein the oligosaccharide structure is selected from: GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-, which is linked to a serine or threonine residue of LYPD3.

[0013] In a second aspect, the present invention relates to an anti-LYPD3 antibody, comprising:

[0014] (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 1, the CDR-H2 has the amino acid sequence of SEQ ID NO: 2, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 3, and

[0015] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 4, the CDR-L2 has the amino acid sequence of SEQ ID NO: 5, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 6; or

[0016] (ii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 9, CDR-H2 has an amino acid sequence of SEQ ID NO: 10, and CDR-H3 has an amino acid sequence of SEQ ID NO: 11, and

[0017] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 12, the CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 14; or

[0018] (iii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 17, CDR-H2 has an amino acid sequence of SEQ ID NO: 18, and CDR-H3 has an amino acid sequence of SEQ ID NO: 19, and

[0019] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 20, the CDR-L2 has the amino acid sequence of SEQ ID NO: 21, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 22; or

[0020] (iv) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 25, CDR-H2 has an amino acid sequence of SEQ ID NO: 26, and CDR-H3 has an amino acid sequence of SEQ ID NO: 27, and

[0021] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 28, the CDR-L2 has the amino acid sequence of SEQ ID NO: 29, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 30; or

[0022] (v) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 33, the CDR-H2 has an amino acid sequence of SEQ ID NO: 34, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 35, and

[0023] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 36, the CDR-L2 has the amino acid sequence of SEQ ID NO: 37, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 38; or

[0024] (vi) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 41, the CDR-H2 has an amino acid sequence of SEQ ID NO: 42, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 43, and

[0025] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 44, the CDR-L2 has the amino acid sequence of SEQ ID NO: 45, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 46; or

[0026] (vii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 49, CDR-H2 has an amino acid sequence of SEQ ID NO: 50, and CDR-H3 has an amino acid sequence of SEQ ID NO: 51, and

[0027] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 52, the CDR-L2 has the amino acid sequence of SEQ ID NO: 53, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 54; or

[0028] (viii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 57, CDR-H2 has an amino acid sequence of SEQ ID NO: 58, and CDR-H3 has an amino acid sequence of SEQ ID NO: 59, and

[0029] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 60, the CDR-L2 has the amino acid sequence of SEQ ID NO: 61, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 62; or

[0030] (ix) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 65, CDR-H2 has an amino acid sequence of SEQ ID NO: 66, and CDR-H3 has an amino acid sequence of SEQ ID NO: 67, and

[0031] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 68, the CDR-L2 has the amino acid sequence of SEQ ID NO: 69, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 70; or

[0032] (x) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 73, CDR-H2 has an amino acid sequence of SEQ ID NO: 74, and CDR-H3 has an amino acid sequence of SEQ ID NO: 75, and

[0033] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 76, the CDR-L2 has the amino acid sequence of SEQ ID NO: 77, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 78; or

[0034] (xi) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 81, CDR-H2 has an amino acid sequence of SEQ ID NO: 82, and CDR-H3 has an amino acid sequence of SEQ ID NO: 83, and

[0035] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 84, the CDR-L2 has an amino acid sequence of SEQ ID NO: 85, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 86; or

[0036] (xii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 89, CDR-H2 has an amino acid sequence of SEQ ID NO: 90, and CDR-H3 has an amino acid sequence of SEQ ID NO: 91, and

[0037] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 92, the CDR-L2 has the amino acid sequence of SEQ ID NO: 93, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 94; or

[0038] (xiii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 97, CDR-H2 has an amino acid sequence of SEQ ID NO: 98, and CDR-H3 has an amino acid sequence of SEQ ID NO: 99, and

[0039] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 100, the CDR-L2 has the amino acid sequence of SEQ ID NO: 101, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 102; or

[0040] (xiv) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 105, CDR-H2 has an amino acid sequence of SEQ ID NO: 106, and CDR-H3 has an amino acid sequence of SEQ ID NO: 107, and

[0041] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 108, the CDR-L2 has an amino acid sequence of SEQ ID NO: 109, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 110; or

[0042] (xv) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 113, CDR-H2 has an amino acid sequence of SEQ ID NO: 114, and CDR-H3 has an amino acid sequence of SEQ ID NO: 115, and

[0043] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 116, the CDR-L2 has an amino acid sequence of SEQ ID NO: 117, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 118; or

[0044] (xvi) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 121, CDR-H2 has an amino acid sequence of SEQ ID NO: 122, and CDR-H3 has an amino acid sequence of SEQ ID NO: 123, and

[0045] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 124, the CDR-L2 has an amino acid sequence of SEQ ID NO: 125, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 126; or

[0046] (xvii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 129, CDR-H2 has an amino acid sequence of SEQ ID NO: 130, and CDR-H3 has an amino acid sequence of SEQ ID NO: 131, and

[0047] A light chain variable region, which comprises complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 132, the CDR-L2 has an amino acid sequence of SEQ ID NO: 133, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 134.

[0048] In a third aspect, the present invention provides a nucleic acid encoding the antibody of the first or second aspect of the present invention. In addition, in a fourth aspect, an expression cassette or vector comprising a nucleic acid of the present invention and a promoter operably connected to the nucleic acid is provided, and in a fifth aspect, a host cell comprising the nucleic acid of the present invention or the expression cassette or vector is provided.

[0049] In a sixth aspect, the present invention provides a conjugate comprising the antibody according to the first or second aspect of the present invention conjugated to another agent.

[0050] In the seventh aspect, the present invention relates to a composition comprising: the antibody described in the first or second aspect of the invention, the nucleic acid described in the third aspect of the invention, the expression cassette or vector described in the fourth aspect of the invention, the host cell described in the fifth aspect of the invention, or the conjugate described in the sixth aspect of the invention.

[0051] According to an eighth aspect, the present invention provides the antibody, nucleic acid, expression cassette or vector, host cell, composition or conjugate of the present invention for medical use, in particular for the treatment of cancer.

[0052] Through the following description and the appended claims, other objects, features, advantages and aspects of the present invention will become apparent to those skilled in the art. However, it should be understood that the following description, the appended claims and the specific examples (representing the preferred embodiments of the application) are provided only as illustrations. By reading the following, those skilled in the art will easily understand various changes and modifications within the spirit and scope of the present invention.

[0053] definition

[0054] As used herein, the following expressions are generally intended to preferably have the meanings set forth below, unless the context in which they are used indicates otherwise.

[0055] As used herein, the expression "comprising", in addition to its literal meaning, also includes and specifically refers to the expressions "consisting essentially of" and "consisting of". Thus, the expression "comprising" refers to embodiments in which the subject matter of the elements specifically listed "comprising" does not contain other elements, as well as embodiments in which the subject matter of the elements specifically listed "comprising" can and / or does contain other elements. Similarly, the expression "having" should be understood as the expression "comprising", also including and specifically referring to the expressions "consisting essentially of" and "consisting of". The term "consisting essentially of" specifically refers, where possible, to embodiments in which the subject matter contains 20% or less, particularly 15% or less, 10% or less, or especially 5% or less of other elements in addition to the specifically listed elements in which the subject matter is essentially composed.

[0056] The term "antibody" refers in particular to a protein comprising at least two heavy chains and two light chains (connected by disulfide bonds). Each heavy chain comprises a heavy chain variable region (VH) and a heavy chain constant region (CH). Each light chain comprises a light chain variable region (VL) and a light chain constant region (CL). The heavy chain constant region comprises three heavy chain constant domains or four heavy chain constant domains (CH1, CH2, CH3 and CH4) in the case of IgM or IgE type antibodies, wherein the first constant domain CH1 is adjacent to the variable region and can be connected to the second constant domain CH2 by a hinge region. The light chain constant region consists of only one constant domain. The variable region can also be subdivided into a region of high variability, referred to as a complementary determining region (CDR), interspersed with more conservative regions, referred to as framework regions (FR), wherein each variable region comprises three CDRs and four FRs. The amino acid residues of CDRs are determined based on CDR positioning according to the IMGT system in particular.

[0057] The variable regions of the heavy and light chains contain binding domains that interact with antigens. The heavy chain constant region can be of any type, such as γ, δ, α, μ or ε type heavy chains. Preferably, the heavy chain of the antibody is a γ chain. In addition, the light chain constant region can also be of any type, such as a κ or λ type light chain. Preferably, the light chain of the antibody is a κ chain. The terms "γ (δ, α, μ or ε) type heavy chain" and "κ (λ) type light chain" refer to an antibody heavy chain or an antibody light chain, respectively, having a constant region amino acid sequence (especially a human heavy chain or light chain constant region amino acid sequence) derived from a naturally occurring heavy chain or light chain constant region amino acid sequence. In particular, the amino acid sequence of the constant domain of a γ-type (especially γ1-type) heavy chain is at least 95%, especially at least 98% identical to the amino acid sequence of the constant domain of a human γ (especially one of the allotypes of human γ1) antibody heavy chain. In addition, the amino acid sequence of the constant domain of the κ type light chain is particularly at least 95%, especially at least 98% identical to the amino acid sequence of the constant domain of one of the allotypes of the human κ antibody light chain. The constant region of the antibody can mediate the binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (C1q) of the classical complement system. The antibody can be, for example, a humanized antibody, a human antibody, or a chimeric antibody.

[0058] The antigen-binding portion of an antibody generally refers to the full length or one or more fragments of an antibody that retains the ability to specifically bind to an antigen. It has been shown that the antigen-binding function of an antibody can be performed by a fragment of a full-length antibody. Examples of binding fragments of antibodies include: a Fab fragment (a monovalent fragment consisting of the VL, VH, CL, and CH1 domains); a F(ab)2 fragment (a bivalent fragment comprising two Fab fragments linked by a disulfide bond in the hinge region, each Fab fragment binding to the same antigen); a Fd fragment consisting of the VH and CH1 domains; a Fv fragment consisting of the VL and VH domains of a single arm of an antibody; and a dAb fragment consisting of the VH domain.

[0059] The "Fab portion" of an antibody refers specifically to a portion of an antibody that includes the variable regions of the heavy and light chains (VH and VL) and the first domains of the constant regions of the heavy and light chains (CH1 and CL). In the case where the antibody does not include all of these regions, the term "Fab portion" refers only to the VH, VL, CH1 and CL regions present in the antibody. Preferably, the "Fab portion" refers to a portion of an antibody that corresponds to a fragment containing the antigen-binding activity of the antibody obtained by digesting a natural antibody with papain. In particular, the Fab portion of an antibody encompasses its antigen-binding site or antigen-binding ability. Preferably, the Fab portion includes at least the VH, VL, CH1 and CL regions of the antibody. H district.

[0060] The "Fc portion" of an antibody refers in particular to the portion of the antibody comprising heavy chain constant regions 2, 3 and, where applicable, 4 (CH2, CH3 and CH4). In particular, the Fc portion comprises two or each of these regions. In the case where the antibody does not comprise all of these regions, the term "Fc portion" refers only to those Fc portions of the CH2, CH3 and CH4 regions present in the antibody. Preferably, the Fc portion comprises at least the CH2 region of the antibody. Preferably, the "Fc portion" refers to the portion of the antibody corresponding to a fragment obtained by digesting a natural antibody with papain that does not contain the antigen binding activity of the antibody. In particular, the Fc portion of an antibody is capable of binding to an Fc receptor, and therefore, for example, comprises an Fc receptor binding site or an Fc receptor binding capacity.

[0061] According to the invention, the term "chimeric antibody" refers in particular to an antibody wherein the constant region is derived from a human antibody or a human antibody consensus sequence and wherein at least one and preferably both variable regions are derived from a non-human antibody (e.g. from a rodent antibody, such as a mouse antibody).

[0062] According to the present invention, the term "humanized antibody" refers in particular to a non-human antibody comprising a human constant region and a modified variable region of an amino acid sequence, wherein the modification reduces the immunogenicity of the antibody when applied to the human body. An exemplary method for constructing a humanized antibody is CDR transplantation, in which the CDR or specificity determining residues (SDR) of a non-human antibody are combined with a framework region derived from a human. Optionally, some residues of the human framework region can be reversed to the residues of the parent non-human antibody, for example, for increasing or restoring antigen binding affinity. Other humanization methods include, for example, surface reconstruction, superhumanization, and human string content optimization. In the surface reconstruction method, only those residues of the non-human framework region on the surface of the antibody are replaced by residues present in the corresponding human antibody sequence at the position. Superhumanization corresponds substantially to CDR transplantation. However, although in the CDR transplantation process, the human framework region is usually selected based on the homology of the human framework region to the non-human framework region, in the superhumanization process, the basis for selecting the human framework region is the similarity of the CDR. In human string content optimization, the difference between the non-human antibody sequence and the human germline sequence is scored, and then the antibody is mutated to minimize the score. In addition, humanized antibodies can also be obtained by empirical methods, where a large library of human framework regions or human antibodies is used to generate multiple antibody humanization candidates, and then the most promising candidates are determined by screening methods. Similarly, by the above-mentioned reasonable methods, several humanized antibody candidates can be generated, and then, for example, their antigen binding is screened.

[0063] As used herein, the term "human antibody" is intended to include antibodies having variable regions in which both the framework and CDR regions are derived from sequences of human origin.

[0064] As used herein, the term "antibody" refers in certain embodiments to a population of antibodies of the same kind. In particular, all antibodies in the population of antibodies exhibit the characteristics used to define the antibody. In certain embodiments, all antibodies in the population of antibodies have the same amino acid sequence. Reference to a particular class of antibodies, such as anti-LYPD3 antibodies, specifically refers to a population of such antibodies.

[0065] The term "antibody" as used herein includes full-length antibodies as well as fragments and derivatives of said antibodies. A "fragment or derivative" of an antibody is particularly a protein or glycoprotein derived from said antibody and capable of binding to the same antigen (particularly binding to the same epitope as the antibody). Therefore, a fragment or derivative of an antibody herein generally refers to a functional fragment or derivative. In a particularly preferred embodiment, the fragment or derivative of an antibody comprises a heavy chain variable region. It has been shown that the antigen-binding function of an antibody can be performed by a fragment of a full-length antibody or a derivative thereof. Examples of antibody fragments include: (i) a Fab fragment (a monovalent fragment consisting of the variable region and the first constant domain of each heavy and light chain);

[0066] (ii) F(ab)2 fragment (a bivalent fragment comprising two Fab fragments linked by a disulfide bond at the hinge region); (iii) Fd fragment consisting of the variable region of the heavy chain and the first constant domain CH1; (iv) Fv fragment consisting of the heavy chain and light chain variable regions of a single arm of an antibody; (v) scFv fragment (Fv fragment consisting of a single polypeptide chain); (vi) (Fv)2 fragment consisting of two Fv fragments covalently linked together; (vii) heavy chain variable domain; and (viii) multimers consisting of heavy chain variable regions and light chain variable regions covalently linked together in a manner such that the association of the heavy chain and light chain variable regions can only occur between molecules and not within molecules. Antibody derivatives particularly include antibodies that bind to the same antigen as the parent antibody, but the derivatives have an amino acid sequence different from the parent antibody from which they are derived. These antibody fragments and derivatives are obtained using conventional techniques known to those skilled in the art.

[0067] A target amino acid sequence is "derived from" or "corresponds to" a reference amino acid sequence if the target amino acid sequence has at least 75% (more preferably at least 80%, at least 85%, at least 90%, at least 93%, at least 95%, at least 97%, at least 98% or at least 99%) homology or identity with the corresponding part of the reference amino acid sequence over its entire length. "Corresponding part" means, for example, that the framework region 1 (FRH1) of the heavy chain variable region of the target antibody corresponds to the framework region 1 of the heavy chain variable region of the reference antibody. In a particular embodiment, a target amino acid sequence that is "derived from" or "corresponds to" a reference amino acid sequence is 100% homologous, or in particular 100% identical, to the corresponding part of the reference amino acid sequence over its entire length. The "homology" or "identity" of an amino acid sequence or nucleotide sequence is preferably determined according to the invention over the entire length of the reference sequence or over the entire length of the corresponding part of the reference sequence corresponding to the sequence defining the homology or identity. An antibody derived from a parent antibody defined by one or more amino acid sequences (such as a specific CDR sequence or a specific variable region sequence), in particular an antibody having an amino acid sequence (such as a CDR sequence or a variable region sequence) that is at least 75%, preferably at least 80%, at least 85%, at least 90%, at least 93%, at least 95%, at least 97%, at least 98% or at least 99% homologous or identical (especially identical) to the corresponding amino acid sequence of the parent antibody. In certain embodiments, an antibody derived from a parent antibody (i.e., a derivative of a parent antibody) comprises the same CDR sequence as the parent antibody, but the remaining sequence of the variable region is different.

[0068] The term "antibody" as used herein also refers to multivalent antibodies (i.e., antibody constructs having more than two binding sites, each of which binds to the same epitope) and multispecific antibodies (i.e., antibody constructs having one or more binding sites that bind to a first epitope and one or more binding sites that bind to a second epitope and optionally even additional binding sites that bind to other epitopes).

[0069] "Specific binding" preferably means that an agent (such as an antibody) binds more strongly to the target (such as an epitope) for which it is specific than to another target. d ) binds to the first target more strongly than to the second target. Preferably, the dissociation constant of the target to which the agent specifically binds is less than 1 / 10, 1 / 30, 1 / 100 or less than 1 / 500 of the dissociation constant of the target to which the agent non-specifically binds. In addition, the term "specific binding" particularly refers to the binding affinity between binding partners, and the affinity constant K a For at least 10 5 M -1, preferably at least 10 6 M -1 , more preferably at least 10 7 M -1 , for example at least 10 8 M -1 Antibodies specific for an antigen are specifically antibodies that can 5 M -1 , preferably at least 10 6 M -1 , more preferably at least 10 7 M -1 K a For example, the term "anti-LYPD3 antibody" refers to an antibody that specifically binds to LYPD3 and is preferably able to bind to the antigen with an affinity of at least 10 5 M -1 , preferably at least 10 6 M -1 , more preferably at least 10 7 M -1 The term "binding" as used herein particularly refers to specific binding.

[0070] The term "epitope" as used herein refers to amino acid residues and glycan structures on an antibody antigen that directly contact or are in close proximity to the antibody's amino acids, particularly the antibody's CDR amino acids, and affect the binding of the antibody to its antigen.

[0071] The term "LYPD3" as used herein refers in particular to human LYPD3 protein, in particular to mature human LYPD3 protein. LYPD3 as used herein refers in particular to human LYPD3 protein as shown in UniProt entry O95274. LYPD3 in particular comprises / in particular consists of the following: the amino acid sequence from positions 31 to 326 of SEQ ID NO: 137, or an amino acid sequence that is at least 90%, in particular at least 95%, identical to positions 31 to 326 of SEQ ID NO: 137 over the entire length. LYPD3 is in particular post-translationally modified and may carry O-glycosylation, N-glycosylation and / or a glycosylphosphatidylinositol (GPI) anchor. For example, LYPD3 can carry O-glycosylation at one or more positions corresponding to Ser223, Ser232, Thr247, Thr248, Ser251, Thr252, Thr253, Ser254, Thr256, Thr257, Ser258, Thr259, Ser260, Thr266, Ser267, Thr268, Thr269, Thr276, Ser277, Thr279, Ser289, Thr297, Ser307 and Ser309 of SEQ ID NO:137.

[0072] The term "GalNAcα1-", also known as "Tn", "Tn antigen" or "Thomsen nouvelle antigen", refers to a monosaccharide structure consisting of an N-acetylgalactosamine residue linked by an α-glycosidic bond to a supporting structure, in particular to a serine or threonine residue of a protein or peptide.

[0073] The term "sialylated GalNAcα1-", also known as "sTn", "sialylated Tn antigen" or "sialylated Thomsen nouvelle antigen", refers to a disaccharide structure consisting of an N-acetylgalactosamine residue linked by an α-glycosidic bond to a supporting structure, especially a serine or threonine residue of a protein or peptide. For this structure, a sialic acid residue is linked to an N-acetylgalactosamine residue by an α2-6 bond to produce the disaccharide structure Siaα2-6GalNAcα1-.

[0074] The term "Galβ1-3GalNAcα1-", also known as "TF", "TF antigen", "T antigen" or "ThomsenFriedenreich antigen", refers to a disaccharide structure consisting of a galactose residue linked by a β1-3 linkage to an N-acetylgalactosamine residue, which is linked by an α1-glycosidic bond to a supporting structure, in particular to a serine or threonine residue of a protein or peptide.

[0075] The term "sialylated Galβ1-3GalNAcα1-", also known as "sTF", "sTF antigen", "sialylated TF antigen", "sialylated T antigen" or "sialylated Thomsen Friedenreich antigen", refers to a trisaccharide or tetrasaccharide structure consisting of a galactose residue linked by a β1-3 linkage to an N-acetylgalactosamine residue which is linked by an α1-glycosidic bond to a supporting structure, in particular to a serine or threonine residue of a protein or peptide. For this structure, a sialic acid residue is linked to a galactose residue via an α2-3 bond, and / or a sialic acid residue is linked to an N-acetylgalactosamine residue via an α2-6 bond to produce a trisaccharide structure Siaα2-3Galβ1-3GalNAcα1- and Galβ1-3(Siaα2-6)GalNAcα1- or a tetrasaccharide structure Siaα2-6(Siaα2-3Galβ1-3)GalNAcα1-.

[0076] In the above structure, Gal represents a galactose residue, and GalNAc represents an N-acetylgalactosamine residue. "β1-3", "α2-3" and "α2-6" represent the connection of two adjacent monosaccharide residues, specifically the connection between the carbon atom C1 or C2 of the left monosaccharide and the carbon atom C3 or C6 of the right monosaccharide, respectively, where the connection can be at the α or β position (as shown in the scheme of glucose below):

[0077]

[0078] The term "GalNAcα1-" means that the GalNAc residue at the reducing end of the oligosaccharide is linked to the supporting structure via its carbon atom C1 in the α configuration.

[0079] The term "sialic acid" refers in particular to any N- or O-substituted derivative of neuraminic acid. It may refer to 5-N-acetylneuraminic acid (NeuNAc) and 5-N-glycolylneuraminic acid (NeuGc), but preferably refers only to 5-N-acetylneuraminic acid.

[0080] The terms "glycan," "glycan structure," "carbohydrate," "carbohydrate chain," and "carbohydrate structure" are often used synonymously herein.

[0081] In a "conjugate", two or more compounds are linked together. In certain embodiments, at least some properties from each compound are retained in the conjugate. Connection can be achieved by covalent bonds or non-covalent bonds. Preferably, the compounds of the conjugate are linked by covalent bonds. The different compounds of the conjugate can be directly bound to each other through one or more covalent bonds between the atoms of the compound. Alternatively, the compounds can be bound to each other through a chemical moiety (such as a linker molecule), wherein the linker is covalently linked to the atoms of the compound. If the conjugate is composed of more than two compounds, these compounds can be, for example, linked in a chain conformation (i.e., one compound is linked to the next compound), or several compounds can each be linked to a central compound.

[0082] The term "nucleic acid" includes single-stranded and double-stranded nucleic acids and ribonucleic acids as well as deoxyribonucleic acids. It may contain naturally occurring as well as synthetic nucleotides and may be naturally or synthetically modified, for example by methylation, 5'- and / or 3'-capping.

[0083] The term "expression cassette" refers in particular to a nucleic acid construct capable of achieving and regulating the expression of a coding nucleic acid sequence introduced therein. The expression cassette may comprise a promoter, a ribosome binding site, an enhancer and other control elements for regulating the transcription of a gene or the translation of mRNA. The exact structure of the expression cassette may vary with species or cell type, but generally comprises 5'-non-transcribed sequences and 5'- and 3'-non-translated sequences, such as a TATA box, a capping sequence, a CAAT sequence, etc., which are involved in the initiation of transcription and translation, respectively. More specifically, the 5'-non-transcribed expression control sequence comprises a promoter region, which comprises a promoter sequence for the transcriptional control of an operably linked nucleic acid. The expression cassette may also comprise an enhancer sequence or an upstream activator sequence.

[0084] According to the present invention, the term "promoter" refers to a nucleic acid sequence that is located upstream (5') of a nucleic acid sequence to be expressed, and controls the expression of a sequence by providing recognition and binding sites for RNA polymerase."Promoter" may include additional recognition and binding sites for other factors that participate in the regulation of gene transcription. Promoters may control the transcription of prokaryotic or eukaryotic genes. In addition, promoters may be "inducible", i.e., initiate transcription in response to an inducing agent, or if transcription is not controlled by an inducing agent, promoters may be "constitutive". If there is no inducing agent, the gene controlled by the inducible promoter is not expressed or only expressed in small amounts. In the presence of an inducing agent, a gene is activated or the transcription level increases. Typically, this is mediated by binding to a specific transcription factor.

[0085] The term "vector" is used here in its most general sense and comprises any intermediate carrier of nucleic acid, which enables the nucleic acid, for example, to be introduced into prokaryotic and / or eukaryotic cells and to be integrated into the genome under appropriate circumstances. Such carriers are preferably replicated and / or expressed in cells. The carrier comprises a plasmid, a phagemid, a phage or a viral genome. The term "plasmid" as used herein generally relates to a construct (usually a circular DNA duplex) of extrachromosomal genetic material that can replicate independently of chromosomal DNA.

[0086] According to the present invention, the term "host cell" refers to any cell that can be transformed or transfected with exogenous nucleic acid. According to the present invention, the term "host cell" includes prokaryotic cells (e.g., Escherichia coli (E. coli)) or eukaryotic cells (e.g., mammalian cells, particularly human or hamster cells, yeast cells, and insect cells). Mammalian cells are particularly preferred, such as cells from humans, mice, hamsters, pigs, goats, or primates. Cells can be derived from a variety of tissue types and include primary cells and cell lines. Nucleic acids can be present in host cells in the form of single copies or double copies or more copies, and in one embodiment, the nucleic acids are expressed in host cells.

[0087] The term "patient" of the present invention refers to humans, non-human primates or other animals, particularly mammals, such as cows, horses, pigs, sheep, goats, dogs, cats or rodents, such as mice and rats. In a particularly preferred embodiment, the patient is a human.

[0088] The term "cancer" as used herein particularly includes leukemia, seminoma, melanoma, teratoma, lymphoma, neuroblastoma, glioma, rectal cancer, endometrial cancer, kidney cancer, adrenal cancer, thyroid cancer, blood cancer, skin cancer, brain cancer, cervical cancer, intestinal cancer, liver cancer, colon cancer, stomach cancer, large intestine cancer, head and neck cancer, gastrointestinal cancer, lymph node cancer, esophageal cancer, colorectal cancer, pancreatic cancer, ear, nose and throat (NET) cancer, bladder cancer, breast cancer, prostate cancer, uterine cancer, ovarian cancer and lung cancer and their metastases. The term cancer as used herein also includes cancer metastasis. The term cancer also refers to and / or includes cancer stem cells, especially cancer stem cells of the specific types of cancer listed above.

[0089] "Tumor" means a group of cells or tissue formed by unregulated cell proliferation. Tumors may exhibit a partial or complete lack of structural organization and functional coordination with normal tissue, and often form a distinct mass of tissue that may be benign or malignant.

[0090] "Metastasis" means the spread of cancer cells from their original site to another part of the body. The formation of metastasis is a very complex process that usually involves cancer cells breaking away from the primary tumor, entering the body's circulation and settling down to grow in normal tissues elsewhere in the body. When tumor cells metastasize, the new tumor is called a secondary or metastatic tumor, and its cells are usually similar to those in the original tumor. This means, for example, that if breast cancer metastasizes to the lungs, the secondary tumor is made up of abnormal breast cells, not abnormal lung cells. The tumor in the lung is called metastatic breast cancer, not lung cancer.

[0091] The term "pharmaceutical composition" refers in particular to a composition suitable for administration to humans or animals, i.e. a composition containing pharmaceutically acceptable components. Preferably, the pharmaceutical composition comprises an active compound or a salt or prodrug thereof and a carrier, diluent or pharmaceutical excipient (such as a buffer, preservative and tonicity regulator). DETAILED DESCRIPTION

[0092] The present invention is based on the development of anti-LYPD3 antibodies that specifically bind to tumor-associated LYPD3. These antibodies are produced using LYPD3 or LYPD3 fragments that carry O-glycan structures produced by cancer cells and selecting those antibodies that bind to LYPD3 in an O-glycosylation-dependent manner. The O-glycosylation produced by normal cells is significantly different from the O-glycosylation produced by cancer cells. For example, normal cells produce large O-glycan structures, while LYPD3 on tumor cells mainly carries monosaccharides, disaccharides and trisaccharides, such as GalNAcα1-(Tn), sialylated GalNAcα1-(sTn), Galβ1-3GalNAcα1-(TF) and sialylated Galβ1-3GalNAcα1-(sTF). The antibodies described in the present invention recognize and bind to these small O-glycan structures of tumor-associated LYPD3. Therefore, these antibodies bind to LYPD3 on tumor cells with a higher affinity than LYPD3 for normal tissues, and are able to distinguish between tumor-associated and non-tumor-associated LYPD3.

[0093] 1. Anti-LYPD3 Antibody

[0094] In view of these findings, the present invention provides an antibody in a first aspect, which is capable of specifically binding to glycosylated human LYPD3 at an epitope comprising an oligosaccharide structure, wherein the oligosaccharide structure is selected from: GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-, wherein the oligosaccharide structure is linked to a serine or threonine residue of LYPD3. Preferably, the antibody is capable of specifically binding to glycosylated human LYPD3 at an epitope comprising one or more GalNAcα1- and / or Galβ1-3GalNAcα1-oligosaccharide structures, wherein the oligosaccharide structure is linked to a serine and / or threonine residue of LYPD3.

[0095] Compared to non-glycosylated human LYPD3, an antibody capable of specifically binding to glycosylated human LYPD3 binds to glycosylated human LYPD3 with a higher binding affinity. In certain embodiments, an antibody capable of specifically binding to glycosylated human LYPD3 binds to glycosylated human LYPD3 with a higher binding affinity than an unrelated protein carrying the same glycan structure. The term "higher binding affinity" as used herein particularly refers to a difference in dissociation constant of at least 10 times, in particular at least 25 times, and in particular at least 100 times.

[0096] In certain embodiments, the antibody is capable of binding to human LYPD3 at an epitope comprising more than one oligosaccharide structure (e.g., 2, 3, or 4 oligosaccharide structures) linked to serine and / or threonine residues of LYPD3. One or more of these other oligosaccharide structures may also be selected from: GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1-. In a specific embodiment, the antibody is capable of binding to human LYPD3 at an epitope comprising two oligosaccharide structures, each of which is selected from: GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1-, and each of which is linked to a serine or threonine residue of LYPD3. In particular, the antibody is capable of binding to human LYPD3 at an epitope comprising three oligosaccharide structures, each of which is selected from: GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-, and each of which is linked to a serine or threonine residue of LYPD3.

[0097] One or more oligosaccharide structures are particularly present in the C-terminal Ser / Thr / Pro-rich domain of LYPD3. In certain embodiments, at least one and in particular all oligosaccharide structures are linked to serine or threonine residues within positions 234 to 303 of SEQ ID NO: 137. In particular, at least one and in particular all oligosaccharide structures are linked to serine or threonine residues within positions 247 to 297 of SEQ ID NO: 137.

[0098] The antibody is capable of binding to human LYPD3 at a bound peptide and carbohydrate epitope. For example, the epitope comprises one or more amino acids within positions 234 to 303 of SEQ ID NO: 137. In particular, the epitope comprises one or more amino acids within positions 247 to 297 of SEQ ID NO: 137. In a particular embodiment, at least 25%, in particular at least 50%, in particular at least 75% of the amino acids of the epitope are present within positions 234 to 303 of SEQ ID NO: 137, in particular within positions 247 to 297 of SEQ ID NO: 137. Preferably, all amino acids of the epitope are present within positions 234 to 303 of SEQ ID NO: 137.

[0099] In this regard, the term "capable of binding to human LYPD3 at a bound peptide and carbohydrate epitope" means that the antibody either directly interacts with the amino acids and one or more glycan structures of LYPD3, directly interacts only with the amino acids of LYPD3, or directly interacts only with the carbohydrate chains of LYPD3. In all cases, the antibody has a higher binding affinity for LYPD3 if an oligosaccharide structure selected from the group consisting of GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1- is attached to the amino acids of LYPD3 compared to non-glycosylated LYPD3. In embodiments where the antibody directly interacts only with the amino acids of LYPD3 and not with the carbohydrate chains, the higher affinity for O-glycosylated LYPD3 is based on conformational changes of the polypeptide chain induced by the oligosaccharides attached to LYPD3.

[0100] In certain embodiments, the antibody specifically binds to tumor-associated LYPD3. The antibody binds to glycosylated human LYPD3 with a higher binding affinity than an oligosaccharide structure selected from the group consisting of GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1-, and the oligosaccharide structure is connected to a carrier molecule unrelated to LYPD3. For example, the carrier molecule can be polyacrylamide (PAA) or a random peptide. In certain embodiments, the antibody can bind to tumor-associated LYPD3 with a higher binding affinity than LYPD3 expressed by cells of normal tissue.

[0101] In certain embodiments, the antibody is capable of binding to human LYPD3 glycosylated with any one or more of GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1-. Thus, if LYPD3 is glycosylated with GalNAcα1, sialylated GalNAcα1, Galβ1-3GalNAcα1, sialylated Galβ1-3GalNAcα1, or any mixture of two or all of these glycan structures, the antibody binds to LYPD3. In these embodiments, LYPD3 may also carry other glycan structures as long as at least one of the above glycan structures is also present. In particular, these antibodies specifically bind to human LYPD3 glycosylated with any one or more of GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1-.

[0102] In certain embodiments, the antibodies are capable of binding to human LYPD3 glycosylated with either or both of GalNAcα1- and Galβ1-3GalNAcα1-. Thus, if LYPD3 is glycosylated with GalNAcα1-, Galβ1-3GalNAcα1-, or any mixture of these two glycan structures, the antibodies bind to LYPD3. In these embodiments, LYPD3 may also carry other glycan structures as long as at least one of the above glycan structures is also present. In particular, these antibodies specifically bind to human LYPD3 glycosylated with either or both of GalNAcα1- and Galβ1-3GalNAcα1-.

[0103] In certain embodiments, the antibody is capable of binding to human LYPD3 glycosylated with either or both of Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-. Thus, if LYPD3 is glycosylated with Galβ1-3GalNAcα1, sialylated Galβ1-3GalNAcα1, or any mixture of these two glycan structures, the antibody binds to LYPD3. In these embodiments, LYPD3 may also carry other glycan structures as long as at least one of the above glycan structures is also present. In particular, these antibodies specifically bind to human LYPD3 glycosylated with either or both of Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-.

[0104] In certain embodiments, the antibodies are capable of binding to human LYPD3 glycosylated with Galβ1-3GalNAcα1-. Thus, if LYPD3 is glycosylated with Galβ1-3GalNAcα1-, the antibodies bind to LYPD3. In these embodiments, LYPD3 may also carry other glycan structures as long as Galβ1-3GalNAcα1- is also present. In particular, these antibodies specifically bind to human LYPD3 glycosylated with Galβ1-3GalNAcα1-.

[0105] In a second aspect, the present invention provides an anti-LYPD3 antibody, comprising:

[0106] (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 1, the CDR-H2 has the amino acid sequence of SEQ ID NO: 2, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 3, and

[0107] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 4, the CDR-L2 has the amino acid sequence of SEQ ID NO: 5, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 6; or

[0108] (ii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 9, CDR-H2 has an amino acid sequence of SEQ ID NO: 10, and CDR-H3 has an amino acid sequence of SEQ ID NO: 11, and

[0109] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 12, the CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 14; or

[0110] (iii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 17, CDR-H2 has an amino acid sequence of SEQ ID NO: 18, and CDR-H3 has an amino acid sequence of SEQ ID NO: 19, and

[0111] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 20, the CDR-L2 has the amino acid sequence of SEQ ID NO: 21, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 22; or

[0112] (iv) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 25, CDR-H2 has an amino acid sequence of SEQ ID NO: 26, and CDR-H3 has an amino acid sequence of SEQ ID NO: 27, and

[0113] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 28, the CDR-L2 has the amino acid sequence of SEQ ID NO: 29, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 30; or

[0114] (v) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 33, the CDR-H2 has an amino acid sequence of SEQ ID NO: 34, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 35, and

[0115] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 36, the CDR-L2 has the amino acid sequence of SEQ ID NO: 37, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 38; or

[0116] (vi) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 41, the CDR-H2 has an amino acid sequence of SEQ ID NO: 42, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 43, and

[0117] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 44, the CDR-L2 has the amino acid sequence of SEQ ID NO: 45, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 46; or

[0118] (vii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 49, CDR-H2 has an amino acid sequence of SEQ ID NO: 50, and CDR-H3 has an amino acid sequence of SEQ ID NO: 51, and

[0119] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 52, the CDR-L2 has the amino acid sequence of SEQ ID NO: 53, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 54; or

[0120] (viii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 57, CDR-H2 has an amino acid sequence of SEQ ID NO: 58, and CDR-H3 has an amino acid sequence of SEQ ID NO: 59, and

[0121] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 60, the CDR-L2 has the amino acid sequence of SEQ ID NO: 61, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 62; or

[0122] (ix) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 65, CDR-H2 has an amino acid sequence of SEQ ID NO: 66, and CDR-H3 has an amino acid sequence of SEQ ID NO: 67, and

[0123] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 68, the CDR-L2 has the amino acid sequence of SEQ ID NO: 69, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 70; or

[0124] (x) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 73, CDR-H2 has an amino acid sequence of SEQ ID NO: 74, and CDR-H3 has an amino acid sequence of SEQ ID NO: 75, and

[0125] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 76, the CDR-L2 has the amino acid sequence of SEQ ID NO: 77, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 78; or

[0126] (xi) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 81, CDR-H2 has an amino acid sequence of SEQ ID NO: 82, and CDR-H3 has an amino acid sequence of SEQ ID NO: 83, and

[0127] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 84, the CDR-L2 has an amino acid sequence of SEQ ID NO: 85, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 86; or

[0128] (xii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 89, CDR-H2 has an amino acid sequence of SEQ ID NO: 90, and CDR-H3 has an amino acid sequence of SEQ ID NO: 91, and

[0129] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 92, the CDR-L2 has the amino acid sequence of SEQ ID NO: 93, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 94; or

[0130] (xiii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 97, CDR-H2 has an amino acid sequence of SEQ ID NO: 98, and CDR-H3 has an amino acid sequence of SEQ ID NO: 99, and

[0131] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 100, the CDR-L2 has the amino acid sequence of SEQ ID NO: 101, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 102; or

[0132] (xiv) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 105, CDR-H2 has an amino acid sequence of SEQ ID NO: 106, and CDR-H3 has an amino acid sequence of SEQ ID NO: 107, and

[0133] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 108, the CDR-L2 has an amino acid sequence of SEQ ID NO: 109, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 110; or

[0134] (xv) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 113, CDR-H2 has an amino acid sequence of SEQ ID NO: 114, and CDR-H3 has an amino acid sequence of SEQ ID NO: 115, and

[0135] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 116, the CDR-L2 has an amino acid sequence of SEQ ID NO: 117, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 118; or

[0136] (xvi) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 121, CDR-H2 has an amino acid sequence of SEQ ID NO: 122, and CDR-H3 has an amino acid sequence of SEQ ID NO: 123, and

[0137] A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 124, the CDR-L2 has an amino acid sequence of SEQ ID NO: 125, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 126; or

[0138] (xvii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 129, CDR-H2 has an amino acid sequence of SEQ ID NO: 130, and CDR-H3 has an amino acid sequence of SEQ ID NO: 131, and

[0139] A light chain variable region, which comprises complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 132, the CDR-L2 has an amino acid sequence of SEQ ID NO: 133, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 134.

[0140] In certain embodiments, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to any one of items (i) to (viii) above. In a preferred embodiment, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to item (ii) above. In a preferred embodiment, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to item (v) above.

[0141] In certain embodiments, the anti-LYPD3 antibody may have a total of 1, 2 or 3 amino acid substitutions in the six CDR sequences, particularly 1 or 2, and especially 1 amino acid substitution. In these embodiments, the anti-LYPD3 antibody retains the antigenic specificity of the antibody without the amino acid substitution. As used herein, "amino acid substitution" also includes amino acid additions and amino acid deletions. In certain embodiments, the amino acid substitution is a conservative amino acid substitution.

[0142] The antibody of the second aspect of the invention particularly exhibits one or more binding activities defined for the antibody of the first aspect. In particular, the antibody of the second aspect is the antibody of the first aspect.

[0143] In certain embodiments, the antibodies described herein comprise a heavy chain variable region and a light chain variable region selected from the group consisting of:

[0144] (i) a heavy chain variable region having an amino acid sequence that is at least 60% identical to the amino acid sequence of SEQ ID NO:7 over its entire length, and comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:1, CDR-H2 has the amino acid sequence of SEQ ID NO:2, and CDR-H3 has the amino acid sequence of SEQ ID NO:3, and

[0145] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:8, and comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:4, CDR-L2 has the amino acid sequence of SEQ ID NO:5, and CDR-L3 has the amino acid sequence of SEQ ID NO:6;

[0146] (ii) a heavy chain variable region having an amino acid sequence that is at least 60% identical to the amino acid sequence of SEQ ID NO: 15 over its entire length, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO: 9, CDR-H2 has the amino acid sequence of SEQ ID NO: 10, and CDR-H3 has the amino acid sequence of SEQ ID NO: 11, and

[0147] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 16, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 12, CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and CDR-L3 has the amino acid sequence of SEQ ID NO: 14;

[0148] (iii) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:23, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:17, CDR-H2 has the amino acid sequence of SEQ ID NO:18, and CDR-H3 has the amino acid sequence of SEQ ID NO:19, and

[0149] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 24, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 20, CDR-L2 has the amino acid sequence of SEQ ID NO: 21, and CDR-L3 has the amino acid sequence of SEQ ID NO: 22;

[0150] (iv) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:31, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:25, CDR-H2 having the amino acid sequence of SEQ ID NO:26, and CDR-H3 having the amino acid sequence of SEQ ID NO:27, and

[0151] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:32, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO:28, CDR-L2 having the amino acid sequence of SEQ ID NO:29, and CDR-L3 having the amino acid sequence of SEQ ID NO:30;

[0152] (v) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 39, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO: 33, CDR-H2 has the amino acid sequence of SEQ ID NO: 34, and CDR-H3 has the amino acid sequence of SEQ ID NO: 35, and

[0153] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:40, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:36, CDR-L2 has the amino acid sequence of SEQ ID NO:37, and CDR-L3 has the amino acid sequence of SEQ ID NO:38;

[0154] (vi) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:47, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:41, CDR-H2 has the amino acid sequence of SEQ ID NO:42, and CDR-H3 has the amino acid sequence of SEQ ID NO:43, and

[0155] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:48, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:44, CDR-L2 has the amino acid sequence of SEQ ID NO:45, and CDR-L3 has the amino acid sequence of SEQ ID NO:46;

[0156] (vii) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:55, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:49, CDR-H2 having the amino acid sequence of SEQ ID NO:50, and CDR-H3 having the amino acid sequence of SEQ ID NO:51, and

[0157] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:56, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO:52, CDR-L2 having the amino acid sequence of SEQ ID NO:53, and CDR-L3 having the amino acid sequence of SEQ ID NO:54; and

[0158] (viii) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:63, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:57, CDR-H2 having the amino acid sequence of SEQ ID NO:58, and CDR-H3 having the amino acid sequence of SEQ ID NO:59, and

[0159] A light chain variable region, which has an amino acid sequence that is at least 60% identical to the amino acid sequence of SEQ ID NO:64 over its entire length, and comprises CDR-L1, CDR-L2 and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:60, CDR-L2 has the amino acid sequence of SEQ ID NO:61, and CDR-L3 has the amino acid sequence of SEQ ID NO:62.

[0160] In a preferred embodiment, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to item (ii) above. In a preferred embodiment, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to item (v) above. In the above embodiments, the sequence identity may in particular be at least 70%, preferably at least 80%, and more preferably at least 90%. The above embodiments are in particular humanized versions of the corresponding antibodies, wherein the changes in the amino acid sequence are substitutions of amino acid residues of the relevant human antibody sequence.

[0161] In certain embodiments, the anti-LYPD3 antibody may additionally have a total of 1, 2 or 3 amino acid substitutions in the six CDR sequences, particularly 1 or 2, especially 1 amino acid substitution. In these embodiments, the anti-LYPD3 antibody retains the antigenic specificity of the antibody without the amino acid substitutions.

[0162] In a further embodiment, the antibody of the present invention comprises a heavy chain variable region and a light chain variable region selected from the group consisting of:

[0163] (ix) a heavy chain variable region having an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO:71 over its entire length, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:65, CDR-H2 has the amino acid sequence of SEQ ID NO:66, and CDR-H3 has the amino acid sequence of SEQ ID NO:67, and

[0164] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO:72, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO:68, CDR-L2 having the amino acid sequence of SEQ ID NO:69, and CDR-L3 having the amino acid sequence of SEQ ID NO:70;

[0165] (x) a heavy chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO:79, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:73, CDR-H2 having the amino acid sequence of SEQ ID NO:74, and CDR-H3 having the amino acid sequence of SEQ ID NO:75, and

[0166] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 80, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO: 76, CDR-L2 having the amino acid sequence of SEQ ID NO: 77, and CDR-L3 having the amino acid sequence of SEQ ID NO: 78;

[0167] (xi) a heavy chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO:87, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:81, CDR-H2 having the amino acid sequence of SEQ ID NO:82, and CDR-H3 having the amino acid sequence of SEQ ID NO:83, and

[0168] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO:88, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO:84, CDR-L2 having the amino acid sequence of SEQ ID NO:85, and CDR-L3 having the amino acid sequence of SEQ ID NO:86;

[0169] (xii) a heavy chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO:95, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:89, CDR-H2 having the amino acid sequence of SEQ ID NO:90, and CDR-H3 having the amino acid sequence of SEQ ID NO:91, and

[0170] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO:96, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO:92, CDR-L2 having the amino acid sequence of SEQ ID NO:93, and CDR-L3 having the amino acid sequence of SEQ ID NO:94;

[0171] (xiii) a heavy chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 103, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO: 97, CDR-H2 having the amino acid sequence of SEQ ID NO: 98, and CDR-H3 having the amino acid sequence of SEQ ID NO: 99, and

[0172] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 104, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 100, CDR-L2 has the amino acid sequence of SEQ ID NO: 101, and CDR-L3 has the amino acid sequence of SEQ ID NO: 102;

[0173] (xiv) a heavy chain variable region having an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 111 over its entire length, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO: 105, CDR-H2 has the amino acid sequence of SEQ ID NO: 106, and CDR-H3 has the amino acid sequence of SEQ ID NO: 107, and

[0174] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 112, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO: 108, CDR-L2 having the amino acid sequence of SEQ ID NO: 109, and CDR-L3 having the amino acid sequence of SEQ ID NO: 110;

[0175] (xv) a heavy chain variable region having an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 119 over its entire length, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO: 113, CDR-H2 has the amino acid sequence of SEQ ID NO: 114, and CDR-H3 has the amino acid sequence of SEQ ID NO: 115, and

[0176] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 120, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 116, CDR-L2 has the amino acid sequence of SEQ ID NO: 117, and CDR-L3 has the amino acid sequence of SEQ ID NO: 118;

[0177] (xvi) a heavy chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 127, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO: 121, CDR-H2 having the amino acid sequence of SEQ ID NO: 122, and CDR-H3 having the amino acid sequence of SEQ ID NO: 123, and

[0178] a light chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 128, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO: 124, CDR-L2 having the amino acid sequence of SEQ ID NO: 125, and CDR-L3 having the amino acid sequence of SEQ ID NO: 126; and

[0179] (xvii) a heavy chain variable region having an amino acid sequence that is at least 90% identical over its entire length to the amino acid sequence of SEQ ID NO: 135, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO: 129, CDR-H2 having the amino acid sequence of SEQ ID NO: 130, and CDR-H3 having the amino acid sequence of SEQ ID NO: 131, and

[0180] A light chain variable region, which has an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 136 over its entire length, and comprises CDR-L1, CDR-L2 and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 132, CDR-L2 has the amino acid sequence of SEQ ID NO: 133, and CDR-L3 has the amino acid sequence of SEQ ID NO: 134.

[0181] In the above embodiments, the sequence identity may in particular be at least 95%. In certain embodiments, the anti-LYPD3 antibody may additionally have a total of 1, 2 or 3 amino acid substitutions, in particular 1 or 2, especially 1 amino acid substitution in the six CDR sequences. In these embodiments, the anti-LYPD3 antibody retains the antigenic specificity of the antibody without the amino acid substitutions.

[0182] In particular, the antibodies of the present invention comprise a heavy chain variable region and a light chain variable region selected from the group consisting of:

[0183] (i) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 7, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 8;

[0184] (ii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16;

[0185] (iii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 23, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 24;

[0186] (iv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 31, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 32;

[0187] (v) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 39, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 40;

[0188] (vi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:47, and a light chain variable region comprising the amino acid sequence of SEQ ID NO:48;

[0189] (vii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 55, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 56;

[0190] (viii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:63, and a light chain variable region comprising the amino acid sequence of SEQ ID NO:64.

[0191] In a preferred embodiment, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to item (ii) above. In a preferred embodiment, the anti-LYPD3 antibody comprises the heavy chain variable region and the light chain variable region according to item (v) above. In certain embodiments, the antibody is a humanized version of the antibody according to any one of items (i) to (viii) above. The humanized version has at least 60%, especially at least 70%, preferably at least 80%, and more preferably at least 90% amino acid sequence identity with the above-mentioned antibody over the entire length of the original sequence. In certain embodiments, the antibody of the present invention is a humanized antibody derived from an antibody having a heavy chain variable region comprising an amino acid sequence of SEQ ID NO: 15 and a light chain variable region comprising an amino acid sequence of SEQ ID NO: 16, or from an antibody having a heavy chain variable region comprising an amino acid sequence of SEQ ID NO: 39 and a light chain variable region comprising an amino acid sequence of SEQ ID NO: 40.

[0192] In particular, the antibody of the present invention is a humanized antibody comprising a heavy chain variable region and a light chain variable region selected from the following:

[0193] (i) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 139, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0194] (ii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 140, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0195] (iii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 141, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0196] (iv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0197] (v) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 143;

[0198] (vi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 145;

[0199] (vii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 146;

[0200] (viii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 138, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 145; and

[0201] (ix) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 140, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 145.

[0202] The antibody of the present invention may further comprise a heavy chain variable region and a light chain variable region selected from the following:

[0203] (ix) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 71, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 72;

[0204] (x) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 79, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 80;

[0205] (xi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 87, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 88;

[0206] (xii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 95, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 96;

[0207] (xiii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 103, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 104;

[0208] (xiv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 111, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 112;

[0209] (xv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 119, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 120;

[0210] (xvi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 127, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 128; and

[0211] (xvii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 135, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 136.

[0212] In embodiments, wherein the heavy and / or light chain variable regions comprise an amino acid sequence having a certain identity to the amino acid sequence of SEQ ID NO: 7, 8, 15, 16, 23, 24, 31, 32, 39, 40, 47, 48, 55, 56, 63, 64, 71, 72, 79, 80, 87, 88, 95, 96, 103, 104, 111, 112, 119, 120, 127, 128, 135 or 136, any sequence deviations from said amino acid sequence are particularly located in the framework regions but not in the CDRs. Thus, in these embodiments, the heavy and light chain variable regions comprise the respective CDR sequences as defined herein.

[0213] In certain embodiments, the antibody is capable of binding to human LYPD3 glycosylated with any one or more of GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1-, and sialylated Galβ1-3GalNAcα1-, and comprises a heavy chain variable region and a light chain variable region selected from the following:

[0214] (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 1, the CDR-H2 has the amino acid sequence of SEQ ID NO: 2, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 3, and

[0215] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 4, the CDR-L2 has an amino acid sequence of SEQ ID NO: 5, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 6;

[0216] (ii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 49, CDR-H2 has an amino acid sequence of SEQ ID NO: 50, and CDR-H3 has an amino acid sequence of SEQ ID NO: 51, and

[0217] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 52, the CDR-L2 has an amino acid sequence of SEQ ID NO: 53, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 54;

[0218] (iii) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:7, and comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:1, CDR-H2 has the amino acid sequence of SEQ ID NO:2, and CDR-H3 has the amino acid sequence of SEQ ID NO:3, and

[0219] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:8, and comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:4, CDR-L2 has the amino acid sequence of SEQ ID NO:5, and CDR-L3 has the amino acid sequence of SEQ ID NO:6;

[0220] (iv) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:55, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:49, CDR-H2 having the amino acid sequence of SEQ ID NO:50, and CDR-H3 having the amino acid sequence of SEQ ID NO:51, and

[0221] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:56, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:52, CDR-L2 has the amino acid sequence of SEQ ID NO:53, and CDR-L3 has the amino acid sequence of SEQ ID NO:54;

[0222] (v) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 7, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 8; and

[0223] (vi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:55, and a light chain variable region comprising the amino acid sequence of SEQ ID NO:56.

[0224] In certain embodiments, the antibody is capable of binding to human LYPD3 glycosylated with either or both of GalNAcα1- and Galβ1-3GalNAcα1-, and comprises a heavy chain variable region and a light chain variable region selected from the group consisting of:

[0225] (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 33, the CDR-H2 has an amino acid sequence of SEQ ID NO: 34, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 35, and

[0226] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 36, the CDR-L2 has an amino acid sequence of SEQ ID NO: 37, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 38;

[0227] (ii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 41, CDR-H2 has an amino acid sequence of SEQ ID NO: 42, and CDR-H3 has an amino acid sequence of SEQ ID NO: 43, and

[0228] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 44, the CDR-L2 has an amino acid sequence of SEQ ID NO: 45, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 46;

[0229] (iii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 57, CDR-H2 has an amino acid sequence of SEQ ID NO: 58, and CDR-H3 has an amino acid sequence of SEQ ID NO: 59, and

[0230] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 60, the CDR-L2 has an amino acid sequence of SEQ ID NO: 61, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 62;

[0231] (iv) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 39, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO: 33, CDR-H2 having the amino acid sequence of SEQ ID NO: 34, and CDR-H3 having the amino acid sequence of SEQ ID NO: 35, and

[0232] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:40, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:36, CDR-L2 has the amino acid sequence of SEQ ID NO:37, and CDR-L3 has the amino acid sequence of SEQ ID NO:38;

[0233] (v) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:47, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:41, CDR-H2 has the amino acid sequence of SEQ ID NO:42, and CDR-H3 has the amino acid sequence of SEQ ID NO:43, and

[0234] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:48, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:44, CDR-L2 has the amino acid sequence of SEQ ID NO:45, and CDR-L3 has the amino acid sequence of SEQ ID NO:46;

[0235] (vi) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:63, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:57, CDR-H2 has the amino acid sequence of SEQ ID NO:58, and CDR-H3 has the amino acid sequence of SEQ ID NO:59, and

[0236] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:64, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:60, CDR-L2 has the amino acid sequence of SEQ ID NO:61, and CDR-L3 has the amino acid sequence of SEQ ID NO:62;

[0237] (vii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 39, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 40;

[0238] (viii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 139, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0239] (ix) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 140, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0240] (x) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 141, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0241] (xi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 144;

[0242] (xi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 143;

[0243] (xii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 145;

[0244] (xiii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 142, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 146;

[0245] (xiv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 138, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 145;

[0246] (xv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 140, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 145;

[0247] (xvi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 47, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 48; and

[0248] (xvii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:63, and a light chain variable region comprising the amino acid sequence of SEQ ID NO:64.

[0249] In a preferred embodiment, the antibody is capable of binding to human LYPD3 glycosylated with either or both of GalNAcα1- and Galβ1-3GalNAcα1-, and comprises the heavy chain variable region and light chain variable region according to any one of items (i), (iv), (vii), and (viii) to (xv) above.

[0250] In certain embodiments, the antibody is capable of binding to human LYPD3 glycosylated with either or both of Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-, and comprises a heavy chain variable region and a light chain variable region selected from the following:

[0251] (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 25, the CDR-H2 has an amino acid sequence of SEQ ID NO: 26, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 27, and

[0252] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 28, the CDR-L2 has an amino acid sequence of SEQ ID NO: 29, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 30;

[0253] (ii) a heavy chain variable region having an amino acid sequence that is at least 60% identical to the amino acid sequence of SEQ ID NO:31 over its entire length, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO:25, CDR-H2 has the amino acid sequence of SEQ ID NO:26, and CDR-H3 has the amino acid sequence of SEQ ID NO:27, and

[0254] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 32, and comprising CDR-L1 having the amino acid sequence of SEQ ID NO: 28, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 30; and

[0255] (iii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 31, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 32.

[0256] In certain embodiments, the antibody is capable of binding to human LYPD3 that is glycosylated with Galβ1-3GalNAcα1 and comprises a heavy chain variable region and a light chain variable region selected from the group consisting of:

[0257] (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 9, the CDR-H2 has an amino acid sequence of SEQ ID NO: 10, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 11, and

[0258] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 12, the CDR-L2 has an amino acid sequence of SEQ ID NO: 13, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 14;

[0259] (ii) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein CDR-H1 has an amino acid sequence of SEQ ID NO: 17, CDR-H2 has an amino acid sequence of SEQ ID NO: 18, and CDR-H3 has an amino acid sequence of SEQ ID NO: 19, and

[0260] a light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has an amino acid sequence of SEQ ID NO: 20, the CDR-L2 has an amino acid sequence of SEQ ID NO: 21, and the CDR-L3 has an amino acid sequence of SEQ ID NO: 22;

[0261] (iii) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 15, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO: 9, CDR-H2 has the amino acid sequence of SEQ ID NO: 10, and CDR-H3 has the amino acid sequence of SEQ ID NO: 11, and

[0262] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 16, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 12, CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and CDR-L3 has the amino acid sequence of SEQ ID NO: 14;

[0263] (iv) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:23, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO:17, CDR-H2 having the amino acid sequence of SEQ ID NO:18, and CDR-H3 having the amino acid sequence of SEQ ID NO:19, and

[0264] a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 24, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 20, CDR-L2 has the amino acid sequence of SEQ ID NO: 21, and CDR-L3 has the amino acid sequence of SEQ ID NO: 22;

[0265] (v) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16; and

[0266] (vi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 23 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 24.

[0267] In a preferred embodiment, the antibody is capable of binding to human LYPD3 glycosylated with Galβ1-3GalNAcα1, and comprises the heavy chain variable region and the light chain variable region according to any one of the above items (i), (iii) and (v).

[0268] In the above embodiments, the sequence identity may in particular be at least 70%, preferably at least 80%, and more preferably at least 90%. In the above embodiments relating to sequence identity, the antibodies are in particular humanized versions of the corresponding antibodies, wherein the changes in the amino acid sequence are substitutions of amino acid residues of the relevant human antibody sequence.

[0269] In certain embodiments, the anti-LYPD3 antibody may additionally have a total of 1, 2 or 3 amino acid substitutions in the six CDR sequences, particularly 1 or 2, especially 1 amino acid substitution. In these embodiments, the anti-LYPD3 antibody retains the antigenic specificity of the antibody without the amino acid substitutions.

[0270] In certain embodiments, the antibody comprises an Fc region. The antibody may be, in particular, a complete antibody. In particular, the antibody may comprise two heavy chains and two light chains. The antibody may be of any isotype, and in particular an IgG type antibody, in particular IgG1, IgG2 or IgG4. In a specific embodiment, the antibody is an IgG1 type antibody. The antibody is particularly capable of binding to one or more human Fc receptors, in particular human Fcγ receptors such as Fcγ receptor IIIa. In certain embodiments, the anti-LYPD3 antibody is a chimeric antibody, a humanized antibody or a human antibody.

[0271] In further embodiments, the anti-LYPD3 antibody is a fragment of an antibody. In particular, the fragment is selected from: (i) a Fab fragment; (ii) a F(ab)2 fragment; (iii) a Fd fragment; (iv) a Fv fragment; (v) a scFv fragment; and (vi) a (Fv)2 fragment. In certain embodiments, the anti-LYPD3 antibody does not comprise an Fc region.

[0272] In certain embodiments, the anti-LYPD3 antibody is glycosylated, in particular N-glycosylated. In particular, the antibody has a glycosylation site in the second constant domain (CH2) of the heavy chain. Antibodies typically have two heavy chains with the same amino acid sequence. Therefore, the antibody preferably has at least two glycosylation sites, one in each of its two CH2 domains. According to Kabat numbering, the glycosylation site is particularly at the amino acid position corresponding to amino acid position 297 of the heavy chain and has an amino acid sequence motif Asn Xaa Ser / Thr, wherein Xaa can be any amino acid other than proline. N-linked glycosylation at Asn297 is conserved in homologous regions of mammalian IgG and other antibody isotypes. Since there may be optional additional amino acids or other sequence modifications in the variable region, the actual position of the conserved glycosylation site may be different in the amino acid sequence of the antibody.

[0273] In a preferred embodiment, the anti-LYPD3 antibody does not contain N-glycolylneuraminic acid (NeuGc) or a detectable amount of NeuGc. In addition, the antibody preferably also does not contain a Galili epitope (Galα1,3-Gal structure) or a detectable amount of a Galili epitope. In particular, the relative amount of glycans carrying NeuGc and / or Galα1,3-Gal structures is less than 0.1% or even less than 0.02% of the total amount of glycans attached to the Fc portion of the antibody in the antibody population.

[0274] In other embodiments, the anti-LYPD3 antibody is not glycosylated at its CH2 domain. In these embodiments, the CH2 domain of the antibody may be mutated, for example, by replacing the asparagine residue at position 297 (or a corresponding position) of the heavy chain with any other amino acid (e.g., alanine or glutamine). Antibodies lacking glycosylation in the CH2 domain have reduced binding to Fcγ receptors and therefore have reduced effector function. In further embodiments, the anti-LYPD3 antibody may have other or additional amino acid substitutions that reduce Fc receptor binding, the amino acid substitutions comprising, for example, Leu235Glu ("LE mutation"), Leu234Ala / Leu235Ala ("LALA" mutation), Ser228Pro / Leu235Glu ("SPLE" mutation), Leu234Ala / Leu235Ala / Pro329Gly ("LALA-PG" mutation) and combinations thereof.

[0275] The present invention also provides an anti-LYPD3 antibody that competes with the antibody as described herein, in particular with the antibody as described in the second aspect of the present invention for binding to LYPD3. In certain embodiments, the competing anti-LYPD3 antibody competes with an antibody comprising a heavy chain variable region and a light chain variable region selected from the following:

[0276] (i) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 7, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 8;

[0277] (ii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16;

[0278] (iii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 23, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 24;

[0279] (iv) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 31, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 32;

[0280] (v) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 39, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 40;

[0281] (vi) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:47, and a light chain variable region comprising the amino acid sequence of SEQ ID NO:48;

[0282] (vii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 55, and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 56; and

[0283] (viii) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:63, and a light chain variable region comprising the amino acid sequence of SEQ ID NO:64.

[0284] Assays for determining competitive binding of two antibodies are well known in the art. For example, an ELISA can be used in which LYPD3 is immobilized and the first antibody is labeled and an excess of the second antibody is added to the immobilized LYPD3. If the label can be detected in the sample with the immobilized LYPD3 after washing, no competitive binding is observed. In a preferred embodiment, a control experiment is performed in which the second antibody is labeled and the first antibody is added in excess. Alternatively, one of the antibodies can also be immobilized, and LYPD3 can be labeled and the other antibody added in excess.

[0285] 2. Generation of anti-LYPD3 antibodies

[0286] The anti-LYPD3 antibody is preferably produced recombinantly in a host cell. Therefore, the antibody is particularly a monoclonal antibody. The host cell used to produce the antibody can be any host cell that can be used for antibody production. Suitable host cells are particularly eukaryotic host cells, especially mammalian host cells. Exemplary host cells include yeast cells such as Pichia pastoris cell lines, insect cells such as SF9 and SF21 cell lines, plant cells, avian cells such as EB66 duck cell lines, rodent cells such as CHO, NS0, SP2 / 0 and YB2 / 0 cell lines, and human cells such as HEK293, PER.C6, CAP, CAP-T, AGE1.HN, Mutz-3 and KG1 cell lines.

[0287] In certain embodiments, the anti-LYPD3 antibody is recombinantly produced in a human cell line, in particular in a human myeloid leukemia cell line. Preferred human cell lines and suitable production procedures that can be used to produce anti-LYPD3 antibodies are described in WO 2008 / 028686 A2. In a specific embodiment, the anti-LYPD3 antibody is obtained by expression in a human myeloid leukemia cell line selected from NM-H9D8, NM-H9D8-E6 and NM-H9D8-E6Q12. These cell lines were purchased from Glycotope GmbH (Robert- -Str.101325Berlin (Germany)) was deposited at the German Collection of Microorganisms (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), Inhoffenstraβe 7B, 38124 Braunschweig (Germany)) under the accession numbers DSMACC2806 (NM-H9D8; deposited on September 15, 2006), DSMACC2807 (NM-H9D8-E6; deposited on October 5, 2006) and DSM ACC2856 (NM-H9D8-E6Q12; deposited on August 8, 2007). NM-H9D8 cells provide a glycosylation pattern with high sialylation, high bisecting GlycNAc, high galactosylation and high fucosylation. NM-H9D8-E6 and NM-H9D8-E6Q12 cells provide a glycosylation pattern similar to that of NM-H9D8 cells, except that the degree of fucosylation is very low. Other suitable cell lines include K562 (a human myeloid leukemia cell line deposited with the American Type Culture Collection (ATCC CCL-243)), CHO cells, and cell lines derived from the above cells. In a specific embodiment, the anti-LYPD3 antibody is expressed in CHO cells, especially in CHO dhfr - Produced recombinantly in cells.

[0288] 3. Anti-LYPD3 Antibody Conjugates

[0289] In certain embodiments, the anti-LYPD3 antibody is provided as a conjugate comprising an antibody conjugated to other agents, such as detectable markers or therapeutically active substances. The antibody may be conjugated to one or more other agents. If there is more than one other agent in the conjugate, these other agents may be the same or different, and in particular all agents are the same. Conjugation of other agents to the antibody may be achieved using any method known in the art. Other agents may be covalently attached to the antibody, in particular by fusion or chemical coupling, or non-covalently attached to the antibody. In certain embodiments, other agents are covalently attached to the antibody (in particular by a linker portion). The linker portion may be any chemical entity suitable for attaching other agents to the antibody.

[0290] The other agents are preferably used for the treatment, diagnosis, prognosis and / or monitoring of a disease, particularly cancer. For example, the other agents may be selected from the group consisting of: radionuclides, chemotherapeutic agents, antibodies, bispecific antibodies or antibody fragments, particularly those of a different species and / or different specificity than the anti-LYPD3 antibody, enzymes, interaction domains, detectable labels, toxins, cytolytic components, immunomodulators, immune effectors, cytokines, chemokines, MHC class I or class II antigens and liposomes.

[0291] In certain embodiments, the other agent is a polypeptide or protein. The polypeptide or protein may be fused, in particular, to a polypeptide chain of an anti-LYPD3 antibody. In certain embodiments, the other agent as a polypeptide or protein is fused to the C-terminus of the antibody light chain of the anti-LYPD3 antibody. In embodiments in which the anti-LYPD3 antibody comprises two antibody light chains, the other agent as a polypeptide or protein may be fused to the C-terminus of each of the two antibody light chains. In other embodiments, the other agent as a polypeptide or protein is fused to the C-terminus of the antibody heavy chain of the anti-LYPD3 antibody. In embodiments in which the antibody comprises two antibody heavy chains, the other agent as a polypeptide or protein may be fused to the C-terminus of each of the two antibody heavy chains. The other agent may be the same or different, in particular having the same amino acid sequence. In embodiments in which the antibody does not comprise one or more light chains and one or more heavy chains, for example in the case where the antibody is an antibody fragment, the other agent as a polypeptide or protein may be fused to the C-terminus or N-terminus of the polypeptide chain of the antibody. Examples of such other agents as polypeptides or proteins may be selected from: cytokines, chemokines, antibodies, antigen binding fragments, enzymes, and interaction domains.

[0292] In certain embodiments, other agents as polypeptides or proteins are checkpoint antibodies that block and / or trigger activation signals. Examples of respective targets include the following: CD40, CD3, CD137 (4-1BB), OX40, GITR, CD27, CD278 (ICOS), CD154 (CD40 ligand), CD270 (HVEM) and CD258 (LIGHT), which are used as activation targets; CTLA4, PD1, CD80, CD244, A2AR, B7-H3 (CD276), B7-H4 (VTCN1), BTLA, IDO, KIR, LAG3, TIM-3, VISTA and phosphatidylserine, which are used as inhibitory targets, and their respective ligands such as PDL1. In other embodiments, other agents as polypeptides or proteins are anticancer antibodies for tumor-associated antigens. Exemplary suitable tumor targets and anticancer antibodies that can be used as fusion partners are described below with respect to combined therapy.

[0293] In further embodiments, other agents that are polypeptides or proteins are immunomodulatory compounds, such as chemokines, cytokines or growth factors. Suitable cytokines in this regard include interferons such as interferon-α, interferon-β and interferon-γ, and interleukins such as IL-15. Suitable growth factors include G-CSF and GM-CSF.

[0294] A conjugate comprising an anti-LYPD3 antibody conjugated to another agent is a chimeric antigen receptor (CAR). Such a conjugate is also referred to herein as an anti-LYPD3 CAR.

[0295] In these embodiments, the other agent is an antigen receptor, especially a T cell receptor or a T cell co-receptor, or a portion and / or chimera thereof. In particular, an anti-LYPD3 antibody is fused with a transmembrane domain and an intracellular T cell signaling domain to form a chimeric antigen receptor (CAR). The intracellular domain is particularly derived from one or more T cell receptors or co-receptors. Optionally, CAR also includes a hinge region between the antibody and the transmembrane domain.

[0296] In these embodiments, the anti-LYPD3 antibody is particularly a single-chain antibody fragment comprising a heavy chain variable region and a light chain variable region in one polypeptide chain, especially a scFv fragment. The hinge region can be, for example, based on a hinge region or a proximal membrane region of a member of the immunoglobulin superfamily. Exemplary hinge regions include hinge regions derived from IgG, CD8, and CD28. The transmembrane domain can be a hydrophobic alpha helix across the cell membrane. For example, it is derived from CD28. The intracellular T cell signaling domain particularly comprises the cytoplasmic domain of the ζ chain of the T cell receptor. In addition, the intracellular T cell signaling domain may comprise other domains of a co-stimulatory protein of a T cell. Exemplary other domains include signaling domains from CD28, CD27, CD134 (OX40), and CD137 (4-1BB).

[0297] An exemplary CAR may comprise, from N-terminus to C-terminus: (i) an anti-LYPD3 antibody in the form of a scFv fragment, (ii) an extracellular hinge region derived from CD8, (iii) a transmembrane domain derived from CD28, (iv) a cytoplasmic signaling domain derived from CD28, and (v) a signaling domain derived from the zeta chain of a T cell receptor.

[0298] Alternatively, anti-LYPD3 antibodies, especially single-chain antibodies such as scFv, can be fused to the CD3 chain of the T cell receptor complex, especially the CD3ε chain, at the N-terminus to form a chimeric antigen receptor. Or anti-LYPD3 antibodies, especially single-chain antibodies such as scFv, can be fused to a binding domain that can specifically bind to a naturally occurring or engineered receptor on a T cell or NK cell.

[0299] In certain embodiments, the other agent is a cytotoxic agent or a chemotherapeutic agent, particularly a cytotoxin. Specific examples of chemotherapeutic agents that can be conjugated as other agents include alkylating agents such as cisplatin, antimetabolites, plant alkaloids and terpenoids, vinca alkaloids, podophyllotoxin, taxanes such as paclitaxel, topoisomerase inhibitors such as irinotecan and topotecan, antitumor drugs such as doxorubicin or microtubule inhibitors such as auristatins and maytansine / maytansinoids.

[0300] The chemotherapeutic agent may be particularly selected from: V-ATPase inhibitors, pro-apoptotic agents, Bcl2 inhibitors, MCL1 inhibitors, HSP90 inhibitors, IAP inhibitors, mTor inhibitors, microtubule stabilizers, microtubule destabilizers, auristatins, dolastatins, maytansine, maytansine compounds, amatoxins, methionine aminopeptidase, protein CRM1 nuclear export inhibitors, DPPIV inhibitors, proteasome inhibitors, mitochondrial phosphotransferase inhibitors, protein synthesis inhibitors, kinase inhibitors, CDK2 inhibitors, CDK9 inhibitors, kinesin inhibitors, HDAC inhibitors, topoisomerase I inhibitors, DNA damaging agents, DNA alkylating agents, DNA intercalators, DNA minor groove binders, DHFR inhibitors, microtubule formation inhibitors, stabilizers of tubulin, stabilizers of actin, topoisomerase II inhibitors, platinum compounds, ribosome inhibitors, RNA polymerase II inhibitors and bacterial toxins. In certain embodiments, the chemotherapeutic agent linked to the anti-LYPD3 antibody is selected from the group consisting of an auristatin, a maytansinoid, a topoisomerase I inhibitor, a DNA damaging agent, a DNA alkylating agent, and a DNA minor groove binder.

[0301] In some embodiments of the chemotherapeutic agent, the chemotherapeutic agent is maytansine or a maytansine-like compound. Specific examples of maytansine-like compounds that can be used for conjugation include the following: maytansinol, N 2 '-Deacetyl-N 2 '-(3-Mercapto-1-oxopropyl)-Maytansine (DM1), N 2 '-Deacetyl-N 2 '-(4-mercapto-1-oxopentyl)-maytansine (DM3) and N 2 '-Deacetyl-N 2'-(4-methyl-4-mercapto-1-oxopentyl)-maytansine (DM4). In particular, DM1 or DM4 is linked to an anti-LYPD3 antibody. In some embodiments, the chemotherapeutic agent linked to the anti-LYPD3 antibody is an auristatin, in particular monomethyl auristatin F (MMAF), monomethyl auristatin E (MMAE) or auristatin T. In some embodiments, the chemotherapeutic agent linked to the anti-LYPD3 antibody is a DNA minor groove binder, in particular a pyrrolobenzodiazepine. (PBD), pyrrolobenzodiazepine dimer (PBD dimer), duocarmycin, duocarmycin-hydroxybenzamide-azaindole (DUBA), seco-duocarmycin-hydroxybenzamide-azaindole (seco-DUBA) or doxorubicin. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a DNA alkylating agent, particularly an indolinobenzodiazepine. Oxazolidinone or benzodiazepine In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a DNA damaging agent, particularly calicheamicin. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a topoisomerase I inhibitor, particularly camptothecin and its derivatives, such as 7-ethyl-10-hydroxycamptothecin (SN-38), (S)-9-dimethylaminomethyl-10-hydroxycamptothecin (topotecan), (1S,9S)-1-amino-9-ethyl-5-fluoro-1,2,3,9,12,15-hexahydro-9-hydroxy-4-methyl-10H,13H-benzo[de]pyrano[3',4':6,7]indolizine[1,2-b]quinoline-10,13-dione (Exatecan (DX-8951f)) and DXd. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is an inhibitor of microtubule formation, in particular tubulolytic enzymes, ansamitocin, podophyllotoxin or vinblastine. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a stabilizer of tubulin, in particular paclitaxel or epothilone. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a stabilizer of actin, in particular phalloidin. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a topoisomerase II inhibitor, in particular teniposide, XK469, razoxane, ansacrine, idarubicin or mebarone. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a platinum compound, in particular cisplatin, carboplatin, oxaliplatin, nedaplatin, tetranitrate triplatin, phenanthriplatin, picoplatin or sattraplatin. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a ribosomal inhibitor, in particular ricin, saporin, abrin, diphtheria toxin or exotoxin A. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is an RNA polymerase II inhibitor, in particular an amatoxin, such as, for example, amanitin. In some embodiments, the chemotherapeutic agent attached to the anti-LYPD3 antibody is a bacterial toxin, in particular anthrax toxin. Suitable antibody drug conjugates are also described in EP 16 151 774.3 and LU 92659, which are explicitly mentioned here.

[0302] With respect to combination therapy, other suitable toxins that may be conjugated to anti-LYPD3 antibodies are described below.

[0303] 4. Nucleic Acids Encoding Anti-LYPD3 Antibodies

[0304] In another aspect, the present invention provides a nucleic acid encoding an anti-LYPD3 antibody. The nucleic acid sequence of the nucleic acid may have any nucleotide sequence suitable for encoding an antibody. However, preferably, the nucleic acid sequence is at least partially adapted to the specific codon usage of the host cell or organism in which the nucleic acid is to be expressed, in particular human codon usage. The nucleic acid may be double-stranded or single-stranded DNA or RNA, preferably double-stranded DNA such as cDNA or single-stranded RNA such as mRNA. It may be a continuous nucleic acid molecule or may be composed of several nucleic acid molecules, each of which encodes a different part of the antibody.

[0305] If the anti-LYPD3 antibody consists of more than one different amino acid chain (such as a light chain and a heavy chain), the nucleic acid can be, for example, a single nucleic acid molecule comprising multiple coding regions, each coding region encoding one amino acid chain of the antibody, preferably separated by regulatory elements such as IRES elements to produce separate amino acid chains, or the nucleic acid can be composed of multiple nucleic acid molecules, wherein each nucleic acid molecule comprises one or more coding regions, each coding region encoding one amino acid chain of the antibody. Alternatively, the nucleic acid can be a single nucleic acid molecule containing a coding region encoding a heavy chain and a light chain, the heavy chain and the light chain being separated by a self-cleaving peptide (such as a 2A peptide) and / or a linker peptide containing a protease recognition site (such as a furin protease recognition site). In addition to the coding region encoding the antibody, the nucleic acid may also contain other nucleic acid sequences or other modifications, for example, the other nucleic acid sequences or other modifications may encode other proteins, may affect the transcription and / or translation of the coding region, may affect the stability or other physical or chemical properties of the nucleic acid, or may not have a function at all.

[0306] In certain embodiments, the nucleic acid is a viral vector that can be used to infect human cells. These viral vectors can be suitable for, for example, human therapy, for example, by directing viral infection and / or replication to disease cells such as tumor cells, or in embodiments where the anti-LYPD3 antibody is in the form of a chimeric antigen receptor to modify T cells to obtain CAR T cells.

[0307] On the other hand, the present invention provides an expression cassette or vector, which comprises nucleic acid of the present invention and a promoter operably connected to the nucleic acid. In addition, the expression cassette or vector may comprise other elements, particularly elements that can affect and / or regulate the following: transcription and / or translation of nucleic acid, amplification and / or regeneration of the expression cassette or vector, integration of the expression cassette or vector into the host cell genome, and / or the copy number of the expression cassette or vector in the host cell. Suitable expression cassettes and vectors comprising the corresponding expression cassette for expressing antibodies are well known in the prior art, and therefore, no further description is needed here.

[0308] 5. Host Cells

[0309] In addition, the present invention provides a host cell comprising nucleic acid according to the present invention or expression cassette or vector according to the present invention. The host cell can be any host cell. The host cell can be a separated cell or a cell contained in a tissue. Preferably, the host cell is a cultured cell, particularly a primary cell or a cell of a cell line established, preferably a cell derived from a tumor. Suitable host cells are particularly eukaryotic host cells, especially mammalian host cells. Exemplary host cells include yeast cells such as Pichia pastoris cell lines, insect cells such as SF9 and SF21 cell lines, plant cells, avian cells such as EB66 duck cell lines, rodent cells such as CHO, NS0, SP2 / 0 and YB2 / 0 cell lines, and human cells such as HEK293, PER.C6, CAP, CAP-T, AGE1.HN, Mutz-3 and KG1 cell lines.

[0310] In a preferred embodiment of the present invention, the host cell is a CHO cell or a cell derived from a human myeloid leukemia cell. Preferably, the host cell is selected from the following cells or cell lines: K562, KG1, MUTZ-3, CHO or cells or cell lines derived therefrom. The host cell is preferably selected from: CHO, NM-H9D8, NM-H9D8-E6, NM H9D8-E6Q12 and cells or cell lines derived from any of the host cells. These cell lines and their properties are described in detail in PCT application WO 2008 / 028686A2. In certain embodiments, the host cell is optimized for the expression of glycoproteins, particularly antibodies, with a specific glycosylation pattern. Preferably, the codon usage in the coding region and / or promoter of the nucleic acid described in the present invention and other elements of the expression cassette or vector are compatible with the type of host cell used, and more preferably optimized for the type of host cell used. Preferably, the anti-LYPD3 antibody is produced by a host cell or cell line as described above.

[0311] The present invention also provides a host cell carrying an anti-LYPD3 CAR. Such a host cell is also referred to herein as a CAR cell. The CAR cell particularly comprises a nucleic acid described in the present invention or an expression cassette or vector described in the present invention, which encodes an anti-LYPD3 CAR. In certain embodiments, the CAR cell is engineered to express an anti-LYPD3 CAR, for example by introducing a vector comprising an expression cassette for an anti-LYPD3 CAR.

[0312] In certain embodiments, the CAR cell is a leukocyte, especially a lymphocyte such as a T cell, a NK cell, and a NKT cell, or a monocyte such as a macrophage. The CAR cell is particularly a primary leukocyte. In certain embodiments, the CAR cell is selected from: a primary T cell, a primary NK cell, a primary NKT cell, and a primary macrophage, especially a primary T cell.

[0313] 6. Pharmaceutical compositions and therapeutic uses

[0314] On the other hand, the present invention provides a composition comprising an anti-LYPD3 antibody, a nucleic acid, an expression cassette or vector, a host cell or a conjugate. The composition may also contain more than one of these components. In addition, the composition may include one or more other components selected from the following: a solvent, a diluent and an excipient. Preferably, the composition is a pharmaceutical composition. In this embodiment, the components of the composition are preferably all pharmaceutically acceptable. The composition may be a solid or fluid composition, particularly a solution (preferably an aqueous solution), an emulsion or a suspension or a lyophilized powder.

[0315] Anti-LYPD3 antibodies or conjugates thereof or CAR cells are particularly useful in medicine, particularly in the therapy, diagnosis, prognosis and / or monitoring of diseases, particularly diseases as described herein, such as cancer and infection, preferably cancer. Therefore, on the other hand, the present invention provides anti-LYPD3 antibodies, nucleic acids, expression cassettes or vectors, host cells, conjugates or compositions for medical use. Preferably, the use in medicine is for the treatment, prognosis, diagnosis and / or monitoring of diseases (especially diseases associated with LYPD3). Exemplary diseases include diseases associated with abnormal cell growth, such as cancer, juvenile idiopathic scoliosis, cholesterol ester transfer protein (CETP) deficiency, fish eye disease, mixed hyperlipidemia, citrullinemia and familial hypercholesterolemia.

[0316] In a preferred embodiment, the disease is cancer. Preferably, the cancer is selected from the group consisting of: head and neck cancer, colon cancer, colorectal cancer, hepatocellular carcinoma, skin cancer, cervical cancer, breast cancer, ovarian cancer, prostate cancer, kidney cancer, esophageal cancer, lung cancer, and cancer of the reproductive region. For example, the cancer can be squamous cell carcinoma of the head and neck, esophageal cancer, breast cancer, cervical cancer, skin cancer, or squamous cell carcinoma of the anal region, rectum, oral cavity, lip, buccal cavity, nose, penis, vulva, epiglottis, tongue, or skin.

[0317] The cancer is LYPD3 positive, and in particular comprises cancer cells that carry LYPD3 on their cell surface. In a particular embodiment, the anti-LYPD3 antibody is used in combination with another anti-cancer therapeutic agent. The other therapeutic agent can be any known anti-cancer drug, and in particular can be an antibody against a cancer antigen. Suitable antibodies for use in combination with the anti-LYPD3 antibody include: anti-EGFR antibodies, such as cetuximab (Erbitux), tomozutuximab (tomuzotuximab), panitumomab (panitumomab, Vectibix) and nimotuzumab (Nimotuzumab, Theraloc); anti-HER2 antibodies, such as trastuzumab (Trastuzumab, Herceptin), timigutuzumab (timigutuzumab) and pertuzumab (pertuzumab); anti-VEGF antibodies, such as Bevacizumab (Avastin) and vanuzizumab; anti-CD52 antibodies, such as alemtuzumab (Campath); anti-CD30 antibodies, such as brentuximab (Adcetris); anti-CD33 antibodies, such as gemtuzumab (Mylotarg); anti-CD20 antibodies, such as rituximab (Rituxan); tuxan (Mabthera), tositumomab (Bexxar), and ibritumomab (Zevalin); anti-CTLA-4 antibodies such as ipilimumab and tremelimumab, anti-PD1 / PD-L1 antibodies such as pembrolizumab, nivolumab, cemiplima, atezolizumab, Antibodies include olizumab, durvalumab, and avelumab; antibodies against TNF and TNFR superfamily members, such as urelumab, MEDI6469, TRX518, and varilumab; CSF1R antibodies, such as emactuzumab; anti-B7-H3 antibodies, such as enoblituzumab; anti-LAG3 antibodies; anti-4-1BB antibodies; anti-ICOS antibodies; and anti-OX-40 antibodies.Other suitable antibodies for use in combination with anti-LYPD3 antibodies include bispecific antibodies, particularly immune cell recruiting bispecific antibodies such as blinatumomab (targeting CD19 and CD3), odronextamab (targeting CD20 and CD3), Regn4018 (targeting MUC16 and CD3), Regn4336 (targeting PSMA and CD3), and Regn7075 (targeting EGFR and CD28).

[0318] Other anti-cancer therapeutic agents that can be used in combination with the anti-LYPD3 antibody and optionally one or more other antibodies can be selected from: taxanes, such as paclitaxel (Taxol), docetaxel (Taxotere) and SB-T-1214; cyclophosphamide; lapatinib; erlotinib; imatinib; pazopanib; capecitabine; cytarabine; vinorelbine; gemcitabine; anthracyclines, such as daunorubicin, doxorubicin, epirubicin, idarubicin, valrubicin and mitoxantrone; aromatase inhibitors , such as aminoglutethimide, testolactone (Teslac), anastrozole (Arimidex), letrozole (Femara), exemestane (Aromasin), vorozole (Rivizor), formestane (Lentaron), fadrozole (Afema), 4-hydroxyandrostenedione, 1,4,6-androstriatriene-3,17-dione (ATD), and 4-androstene-3,6,17-trione (6-OXO); topoisomerase inhibitors, such as irinotecan, toloxetine, Potican, camptothecin, laminarin D, etoposide (VP-16), teniposide, doxorubicin, daunorubicin, mitoxantrone, amylase, ellipticine, aurintricarboxylic acid, and HU-331; platinum-based chemotherapeutic agents such as cis-diaminedichloroplatinum(II) (cisplatin), cis-diamine(1,1-cyclobutanedicarboxylic acid)platinum(II) (carboplatin), and [(1R,2R)-cyclohexane-1,2-diamine](ethylene glycol-O,O')platinum(II) (oxaliplatin); antimetabolites, especially antifolates , such as methotrexate, pemetrexed, raltitrexed and pralatrexate; pyrimidine analogs, such as fluorouracil, gemcitabine, floxuridine, 5-fluorouracil and tegafur-uracil, and purine analogs; and inhibitors of the enzyme poly ADP ribose polymerase (PARP inhibitors), such as olaparib, rucaparib, niraparib and talazoparib. Other suitable toxins that can be used in combination with anti-LYPD3 antibodies are described above for agents that may be conjugated to the antibodies.

[0319] Treatment with anti-LYPD3 antibodies can also be combined with the following: immunostimulants, cytokines, chemokines, radiotherapy, therapeutic cells such as natural immune cells or engineered immune cells (CAR-T cells, TCR-T cells, CAR-NK cells, CAR-monocytes, CAR-NKT cells, etc.), vaccines such as protein, peptide or RNA vaccines, B-Raf inhibitors such as vemurafenib, dexamethasone, protease inhibitors such as bortezomib and lenalidomide.

[0320] For use in treating cancers in which cells express LYPD3, the antibodies can be coupled to other agents as described above, wherein the other agents are preferably cytotoxic agents, such as radionuclides or cytotoxins. Exemplary cytotoxic agents are described above. Cytotoxic agents also include precursor compounds that produce cytotoxic activity only when activated (e.g., by photoirradiation or enzymatic reactions in vivo). One or more of the above-mentioned anticancer therapeutic agents can also be used as other agents coupled to anti-LYPD3 antibodies. In addition, the antibodies can be engineered to enhance their ability to activate the patient's immune response, particularly the ability to activate ADCC (antibody-dependent cell-mediated cytotoxicity) and / or CDC (complement-dependent cytotoxicity). For example, this can be achieved by optimizing the amino acid sequence and / or glycosylation pattern of the antibody (particularly the constant region of the antibody).

[0321] In order to be used as a detection agent in the diagnosis, prognosis and / or monitoring of a disease, the antibody is preferably coupled to a labeling agent capable of generating a detectable signal. In particular, the labeling agent may be a radionuclide, a fluorophore or an enzyme. BRIEF DESCRIPTION OF THE DRAWINGS

[0322] Figure 1 The biosynthetic pathways of Tn and TF carbohydrate antigens and their structures are shown. In the structures, squares represent GalNAc, circles represent Gal, and diamonds represent sialic acid.

[0323] Figure 2The sugar-dependent targeted binding of anti-LYPD3 antibodies to the following is shown: A) LYPD3-ECD or B) the STP-rich C-terminal portion of ECD (LYPD3-STP-ECD). Binding to equimolar amounts of antigen (35nM) was evaluated in an antigen ELISA using 5μg / ml of a-LYPD3 mAb. To control the antigen coating on the ELISA plate, aLYPD3 pAb or aMBLAb was used. The proteins were expressed and purified in transfected NM-F9 cells with their respective O-glycosylation patterns (F9, O-glyc), and these NM-F9 proteins were enzymatically digested to produce de-O-glycosylated proteins (F9-de-O-glyc). Binding to LYPD3-STP-ECD (aglyc) recombinantly expressed and purified from O-glycosylation-deficient CHO cells was also tested. High OD signals indicate strong binding of the antibody to the antigen.

[0324] Figure 3 Binding of anti-LYPD3 clones to differently glycosylated LYPD3 variants is shown. Binding to equimolar amounts of antigen (35 nM) was assessed in an antigen ELISA using aLYPD3 mAb at the indicated concentrations. aLYPD3 pAb or aMBL Ab was used as coating controls, and aTF and aTn antibodies were used as glycosylation controls. As described in Example 1, proteins carrying TF and Tn were recombinantly expressed and purified from NM F9 cells, de-O-glycosylated proteins were produced by enzymatic digestion of proteins derived from NM-F9, and Tn proteins were produced by degalactosylation of proteins derived from NM-F9. High OD signals indicate strong binding of the antibody to the antigen.

[0325] Figure 4 Analysis of anti-LYPD3 clones tested for glycan binding by ELISA is shown. Binding of PAA-conjugated glycans coated with 10 μg / ml was assessed in antigen ELISA using aLYPD3 mAb at 5 μg / ml; aTn, aTF, and a-sTn mAbs were used to control coating of the indicated four glycans on ELISA plates. High OD signals indicate strong binding of the antibody to the antigen.

[0326] Figure 5 Binding curve of anti-huLYPD3 antibody to LYPD3-STP derived from NM-F9 in ELISA is shown. Anti-LYPD3 antibody was titrated on ELISA plates coated with LYPD3-STP-ECD target protein. High OD signal indicates strong binding of antibody to antigen.

[0327] Figure 6Anti-LYPD3 antibodies are shown to bind to the carbohydrate-dependent antigen of LYPD3-ECD compared to aLYPD3 mAb, aTF, and aTn. Binding to equimolar amounts of antigen was assessed in an antigen ELISA using a-LYPD3 mAb. Proteins were expressed and purified in transfected NM-F9 or NM-H9D8 cells with their respective O-glycosylation patterns (NM-F9: predominantly TF; H9D8: predominantly sTF and TF). Desialylated proteins were produced by enzymatic treatment of proteins with sialidase (H9D8, de-sialyl.: predominantly TF), and degalactosylated proteins were produced by treatment with galactosidase (NM-F9, Tn-glyc: predominantly Tn). High OD signals indicate strong binding of the antibody to the antigen.

[0328] Figure 7 Binding of aLYPD3 clones to cellular O-glyc and de-O-glyc LYPD3 is shown. Cell lines with different LYPD3 expression (LYPD3-F9 = high O-glycosylation, high LYPD3; NM-F9 = high O-glycosylation, low LYPD3; LYPD3-HEK-O-glyc KO = no O-glycosylation, high LYPD3) were stained with 1 μg / ml of aLYPD3 clones, control aLYPD3 pAb and mAb, and aTF mAb. Shown is the signal-to-noise ratio of stained cells: MFI (median fluorescence intensity) of stained cells divided by the MFI of cells stained with the isotype.

[0329] Figure 8 Shown is titration of aLYPD3 clones compared to a control aLYPD3 mAb on LYPD3-F9 cells expressing high levels of O-glyc LYPD3. Cells were stained with various concentrations of aLYPD3 clones and aLYPD3 mAb control and detected with a fluorophore-conjugated anti-human IgG secondary reagent. Shown is the MFI of live cells.

[0330] Fig. 9 Shown is titration of aLYPD3 clones on LYPD3-F9 cells expressing high levels of O-glyc LYPD3. Cells were stained with different concentrations of aLYPD3 clones and detected with fluorophore-conjugated anti-human IgG secondary reagent. Shown is the MFI of live cells.

[0331] Fig.10Binding of aLYPD3 clone to normal human epithelial mammary cells (HMEC) is shown. HMEC from healthy donors were stained with 10 μg / ml aLYPD3 clone and fluorophore-conjugated anti-human IgG secondary reagent. Expression of LYPD3 and TFa was confirmed using control aLYPD3 pAb and mAb and aTF mAb. Shown is the signal-to-noise ratio of stained cells: MFI (median fluorescence intensity) of stained cells divided by the MFI of cells stained with the isotype.

[0332] Fig.11 Binding of aLYPD3 clones to Caov-3 cells, ZR-75-1 cells with and without sialidase treatment, and MDA-MB-231 cells after sialidase treatment is shown. (A) Caov-3 cells were stained with 10 μg / ml aLYPD3 clone and fluorophore-coupled anti-human IgG secondary reagent. (B) ZR-75-1 cells were treated with sialidase (30 minutes, 5 mU / ml) or not, washed and stained with 10 μg / ml aLYPD3 clone and fluorophore-coupled anti-human IgG secondary reagent. (C) MDA-MB-231 cells were treated with sialidase (30 minutes, 5 mU / ml) and then stained with 10 μg / ml aLYPD3 clone and fluorophore-coupled anti-human IgG secondary reagent. Expression of LYPD3 and TFa was confirmed using control aLYPD3 pAb and mAb and aTF mAb. Shown is the signal-to-noise ratio of stained cells: MFI (median fluorescence intensity) of stained cells divided by the MFI of isotype stained cells.

[0333] Fig.12 The ability of aLYPD3 clone 17B3 to inhibit the proliferation of LYPD3-F9 cells is shown. Cells were incubated with different concentrations of aLYPD3 antibody 17B3 and a constant amount of protein G-MMAE. Proliferation was measured after 4 days. An irrelevant human IgG1 control showed no inhibition. Based on the luminescent signal, proliferation is shown as a percentage (%) relative to a medium control without antibody.

[0334] Fig.13 Binding of selected anti-LYPD3 clones to healthy esophageal tissue sections is shown compared to aLYPD3 pAb control antibody.

[0335] Fig.14Binding of humanized aLYPD3 antibodies to cellular O-glyc and de-O-glyc LYPD3 as determined by flow cytometry is shown. (A) Cell lines with different LYPD3 expression and O-glycosylation (LYPD3-ECD HEK O-glyc KO = no O-glycosylation, high LYPD3; mock F9 O-glyc. = high O-glycosylation with TF, low LYPD3; LYPD3-ECD F9 = high O-glycosylation with TF, high LYPD3) were stained with 10 μg / ml of humanized aLYPD3 antibodies (21E9-219 to 21E9-228), parental antibodies (parental 21E9) and control antibodies against LYPD3 (aLYPD3 pAb and aLYPD3 mAb). (B) Cell line NM-F9 expressing LYPD3 with TF O-glycosylation was stained with different concentrations (0.1 μg / ml and 10 μg / ml) of humanized antibodies. Shown is the signal-to-noise ratio of stained cells: MFI (median fluorescence intensity) of stained cells divided by the MFI of isotype stained cells.

[0336] Fig.15 Binding of humanized aLYPD3 antibody to O-glycosylated LYPD3-STP-ECD in F9 cells is shown. Binding to equimolar amounts of antigen was assessed in an antigen ELISA using indicated concentrations of humanized aLYPD3 mAb and parental aLYPD3 mAb. Protein was expressed and purified in transfected NM F9 cells and carries TF O-glycosylation. High OD signal indicates strong binding of the antibody to the antigen.

[0337] Fig.16 Glycan-specific binding of humanized aLYPD3 antibodies is shown. Binding to equimolar amounts of antigen was assessed in antigen ELISA using indicated concentrations of aLYPD3 mAb. Proteins were expressed and purified in transfected NMF9 cells with the respective O-glycosylation pattern and were left untreated (F9 O-glyc.: predominantly TF), degalactosylated (F9 O-glyc.de-gal.: predominantly Tn) or deglycosylated (F9 de-O-glyc.: no O-glycosylation). High OD signals indicate strong binding of the antibody to the antigen.

[0338] Example

[0339] Example 1: Generation of Antigens

[0340] Different O-glycosylation variants of human LYPD3 were generated for optimal selection of antibodies that specifically bind to human LYPD3 with tumor-associated glycosylation patterns. Since the C-terminal portion of the huLYPD3 extracellular domain (amino acids 234-303) contains a large number of Ser / Thr / Pro residues and, therefore, a high density of O-glycosylation sites, this huLYPD3 amino acid sequence was selected as a target structure ("LYPD3-STP") for antibody production, with a high potential for producing sugar-dependent anti-LYPD3 antibodies in the antibody production method described in Example 2.

[0341] Different cell lines were transfected with DNA encoding the extracellular domain (ECD; amino acids 31-303) of huLYPD3, particularly the C-terminal Ser / Thr / Pro-rich domain (STP-ECD; amino acids 234-303) of huLYPD3, to generate cells expressing soluble LYPD3-ECD or LYPD3-STP-ECD. The soluble protein constructs were recombinantly expressed as fusion proteins, e.g., tandem versions of ( IBA, Germany), maltose binding lectin (herein referred to as MBL) or a polyhistidine tag to purify from cell supernatants by affinity chromatography and detect the protein independently of LYPD3 via the fusion moiety. In addition, different cell lines were transfected with DNA encoding the complete human LYPD3 propeptide sequence (amino acids 31 to 346) or a fusion of the C-terminal Ser / Thr / Pro-rich domain of the huLYPD3 propeptide (amino acids 234-346) fused to C-terminal EGFP to generate cells expressing membrane-bound LYPD3 or LYPD3-STP on the cell surface, respectively.

[0342] NM F9 and NM-H9D8 cells derived from cancer cell lines were used to express human LYPD3 and LYPD3-STP proteins with tumor-associated O-glycosylation patterns: While NM-H9D8 cells provide glycosylation of LYPD3 with high sialylation (mainly sTF and sTn), sialylation-deficient NM-F9 cells mainly produce LYPD3 carrying TF and lesser amounts of Tn. O-glycosylation-deficient (O-glyc KO) CHO (CH-O-deleted; GlycoDisplay Aps, Copenhagen, Denmark) or HEK cells (HEK GALE / GALEK2 KO, Kerafast, Inc, Boston, MA, USA) were used to produce LYPD3 variants without O-glycosylation.

[0343] Tn-LYPD3-STP-ECD was either recombinantly expressed in HEK cells defective in producing core 1 O-glycan extensions (HEK293cosmc KO, Glycodisplay) or generated by enzymatic digestion of NM-F9-derived LYPD3-STP-ECD with β-galactosidase (GalactEXO, Genovis) to remove galactose residues from the TF structure, resulting in GalNAc attachment to serine or threonine, referred to as Tn antigen.

[0344] Soluble LYPD3 proteins without O-glycosylation were either purified directly from the supernatant of transfected O-glycosylation-deficient CHO cells or generated by enzymatic digestion of proteins purified from NM-H9D8 or NM-F9 transfectants. The latter was performed in microspin columns using soluble sialidase, O-glycosidase and α-N-acetylgalactosaminidase or immobilized β-galactosidase and GalNAcase enzymes to remove sialic acids (α2-3, α2-6 and α2-8), core 1 O-glycans and GalNAc residues on glycoproteins (SialExo, Oglyzor, GalNAcEXO, GalactEXO all from Genovis).

[0345] Binding of anti-huLYPD3 antibodies to purified soluble protein was assessed in an ELISA assay as described in Example 3, while binding to differentially glycosylated membrane-bound LYPD3 was analyzed using flow cytometry.

[0346] Example 2: Generation of anti-LYPD3 antibodies

[0347] Monoclonal antibodies that specifically recognize the STP-rich domain of huLYPD3 with tumor-associated glycosylation patterns were generated by phage display technology or by animal immunization. In any case, huLYPD3 carrying the O-glycan structure produced by cancer cells in protein form and the cells described in Example 1 are integral to the antibody generation process. All antibodies were selected to bind to human LYPD3 in an O-glycosylation-dependent manner.

[0348] HybriFree technology is used to isolate LYPD3-specific antibodies from spleen cells of chickens and rabbits immunized with LYPD3-ECD or STP-enriched ECD fractions (LYPD3-STP-ECD) purified from transfected NM-F9 cells and boosted with LYPD3-ECD. After the last immunization of the animals, cells are isolated from the spleen and serum or chicken egg yolk preparations are evaluated for confirmed antigen-specific antibody responses by flow cytometry (similar to the procedures described in Example 4) and / or ELISA assays (similar to the procedures described in Example 3). Splenic B cells with antigenic specificity for O-glycosylated LYPD3-STP are initially enriched by depleting cells that show unwanted protein binding. This includes binding to LYPD3-STP-ECD without glycosylation and / or binding to recombinantly expressed protein fusion partners in the absence of any LYPD3 sequence, and / or binding to unrelated glycoproteins that are produced in a manner similar to O-glycosylated LYPD3-STP-ECD and by containing the same protein fusion partner and similar glycan structures that bind to non-homologous protein sequences. For this negative selection step, spleen cells are first incubated with off-target proteins fixed on microtiter plates and / or present in the panning solution. Subsequently, unbound cells are transferred to a plate coated with O-glycosylated LYPD3-STP-ECD or LYPD3-ECD protein purified from NM-F9 cells to capture spleen B cells with target specificity. The cDNA of the antibody variable domain is amplified from the captured cells and cloned into plasmids with separate expression cassettes for IgG heavy and light chains, respectively, to construct a combined human IgG1 encoding library in a mammalian expression vector. Plasmid DNA from the resulting antibody library set is transfected into CHO cells to transiently produce chimeric antibodies. Antibody mini-library cell culture supernatants are tested for target specific binding in ELISA with various targeted and off-target proteins and additionally by flow cytometry on LYPD3-transfected HEK O-glyc KO cells and / or LYPD3-transfected F9 compared with untransfected NM-F9 cells. Proteins used for ELISA screening included O-glycosylated LYPD3-ECD and LYPD3-STP-ECD (both expressed in and purified from NM-F9 cells), as well as LYPD3-ECD and LYPD3-STP-ECD (both not glycosylated). Single clones were generated from an antibody library showing specific binding to O-glycosylated LYPD3-STP. VH and VL cDNAs of antigen-specific monoclonal clones were sequenced and antibodies with unique sequences were expressed in CHO cells. Prior to antibody purification, the production of antigen-specific antibodies in monoclonal supernatants was confirmed by ELISA as well as flow cytometry.

[0349] The following glycosylation-specific anti-huLYPD3 antibodies were obtained by immunizing chicken or rabbit:

[0350] 16F9 17B3 19B4 19G10 21E9

[0351] 22A11 25A6 26A4

[0352] Completely human sugar-specific anti-huLYPD3 antibodies were isolated from the naive human antibody library of Yumab ​​(YUMAB GmbH, Braunschweig, Germany) by phage display technology. In short, different strategies (combined with the subsequent panning reaction of purified protein and cells) were used to enrich phages with antigenic specificity for O-glycosylated LYPD3-STP from the library by three rounds of antibody selection. In each step, the positive selection of phages producing scFv was achieved by combining with O-glycosylated LYPD3-STP-ECD or LYPD3-ECD, wherein both O-glycosylated LYPD3-STP-ECD or LYPD3-ECD were produced from NM-F9 cells and fixed on microtiter plates. In order to compete, there were purified recombinantly expressed protein fusion partners without LYPD3 sequences and LYPD3-ECD and LYPD3-STP-ECD without O-glycosylation in the panning solution to exhaust antibodies that recognize these structures. For some strategies, after depletion of phages bound to untransfected NM-F9 cells, the second and / or third enrichment steps were completed by incubation with LYPD3-STP-transfected NM-F9 cells. For other strategies, after depletion of phages not bound to transfected NM-F9, antibody selection was performed using binding to LYPD3-transfected NM-F9 cells or neuraminidase-treated Caov-3 cells (ovarian adenocarcinoma cell line expressing high levels of LYPD3 and TFa glycans). Soluble scFv antibodies were generated from individual clones of each selection strategy and screened by ELISA on LYPD3-ECD and LYPD3-STP-ECD proteins with and without O-glycosylation. ScFv antibodies with sugar-dependent LYPD3 binding in ELISA were also tested by flow cytometry for specific binding to NM-F9 cells transfected with LYPD3 or LYPD3-STP and Caov-3 cells treated with neuraminidase. After sequencing the cloned VH and VL DNA that specifically recognized O-glycosylated LYPD3-STP in ELISA and on LYPD3-positive cells, the unique antibody VH and VL sequences were cloned into a murine IgG2a expression vector for transfection of HEK cells.

[0353] The following glycosylation-specific anti-huLYPD3 antibodies were isolated from a phage display library of human antibodies:

[0354] YU912-B09 YU912-G05 YU912-B06 YU913-B01 YU912-D06

[0355] YU912-A03 YU912-C07 YU912-G08 YU912-G07

[0356] All selected antibodies were purified from mammalian cell culture supernatants by affinity chromatography with Protein A. The purity and integrity of the mAbs were confirmed by SDS-PAGE and analytical SEC.

[0357] For some experiments, the VH and VL sequences of anti-human LYPD3 antibodies were also cloned into a mouse IgG1 expression vector to purify chimeric antibodies with a mouse IgG backbone. Purified chimeric anti-LYPD3 expressed as human IgG1 or mouse IgG1 with the same VH and VL combination showed similar binding properties to both soluble and membrane-bound proteins as determined by ELISA and flow cytometry.

[0358] Example 3: Antigen ELISA with targeted and non-targeted controls

[0359] The specific binding of the antibodies to LYPD3 carrying tumor-associated glycans was analyzed in an antigen ELISA assay.

[0360] Briefly, different glycosylated and non-glycosylated protein antigens or polysaccharides conjugated with carbohydrate-polyacrylamide conjugates (carbohydrate-PAA conjugates, GlycoNZ) were coated into 96-well plates overnight, non-specific binding was blocked and the test antibody samples were added. In some assays, an anti-huLYPD3 huIgG1 control monoclonal Ab was used, which was purified from CHO cell supernatant after expressing the antibody sequence derived from patent application WO 2011 / 070088 A1 (SEQ ID NO: 51 and 52 of WO 2011 / 070088) ("aLYPD3 mAb"). This control anti-huLYPD3 antibody binds to the extracellular domain of human LYPD3 in a glycosylation-independent manner. To control protein antigen coating on ELISA plates, anti-huLYPD3 rabbit polyclonal antibody (R&D Systems, catalog number AF5428) ("aLYPD3-pAb") or a-MBL antibody (Novusbio) ("aMBL", constructs expressed as MBL fusion proteins) were used. Antibodies that recognize specific glycan structures are used to detect glycosylation of coated proteins. Anti-TFa ("aTF") antibody clone HH8 was provided by Professor Clausen at the University of Copenhagen. The antibody that specifically recognizes Tn ("aTn") (clone 5F4) was purchased from SBH Sciences or provided by Professor Clausen at the University of Copenhagen. Then, a peroxidase-conjugated anti-IgG secondary antibody was added, followed by a 3,3',5,5'-tetramethylbenzidine (TMB) substrate reaction. The antibody binding rate was determined by measuring the absorbance at 450 nm and 620 nm or 630 nm (as a reference wavelength) using a multi-function microplate reader (PerkinElmer EnSpire2300 or Tecan Spark).

[0361] The generated α-huLYPD3 antibodies were evaluated for carbohydrate-dependent binding to the STP-rich domain of huLYPD3 in an antigen ELISA ( Figure 2). All antibodies showed significant binding to O-glycosylated LYPD3-STP-ECD and O-glycosylated LYPD3-ECD proteins (which also contain LYPD3-STP sequences), confirming that the epitope recognized by these antibodies is present in the huLYPD3 amino acid sequence R234-H303. The absence of O-glycosylation on the tested LYPD3 proteins was achieved by enzymatic de-O-glycosylation or by recombinant expression and purification from O-glycosylation-deficient cells, thereby eliminating the binding of the a-LYPD3 antibodies. This clearly shows that antibody binding requires an O-glycosylated LYPD3 epitope and thus confirms the sugar dependence of LYPD3 binding for all selected antibodies. However, the a-LYPD3 control mAb was able to recognize LYPD3-ECD independently of O-glycosylation and was unable to bind to any of the LYPD3-STP-ECD variants. Therefore, this antibody binds to the LYPD3 epitope located in amino acids 31-233 of huLYP3 independently of glycosylation.

[0362] Furthermore, the anti-huLYPD3 antibody clones appeared to elicit a variety of fine specificities regarding the types of LYPD3 O-glycosylation. This was evident from the different degrees of recognition of LYPD3 protein expressed and purified from NM-H9D8 (which provided a high degree of sialylation) (carrying mainly sTF and some TF), LYPD3 expressed from NM-H9D8 treated with sialidase (carrying mainly TF), and degalactosylated LYPD3-STP-ECD (carrying mainly Tn glycosylation, Tn-glyc.). The relative amounts of different O-glycosylation structures on LYPD3 were determined for LYPD3 expressed in different cell lines with and without enzyme treatment:

[0363] Table 1 – Glycosylation structures on LYPD3

[0364] %TF %Tn %sTF %sTn LYPD3(NM-F9) 96.6 3.4 0 0 LYPD3 (NM-F9, de-gal.) 6.6 93.4 0 0 LYPD3(NM-H9D8) 38.9 2.0 52.3 6.8 LYPD3 (NM-H9D8, de-sial.) 91.1 8.9 0 0

[0365] The analyzed antibodies showed strong, highly specific binding to O-glycosylated LYPD3, but not to unrelated O-glycosylated proteins ( Figure 3 ) or pure carbohydrate antigen ( Figure 4 ) had no significant binding. Therefore, the binding of anti-LYPD3 antibody clones also specifically depends on the LYPD3 protein backbone.

[0366] The binding affinity of anti-LYPD3 antibodies to glycosylated LYPD3-STP-ECD (expressed in NM-F9 cells) was compared. All anti-LYPD3 antibodies showed dose-dependent binding to the O-glycosylated LYPD3-STP target structure with high affinity and EC50 values ​​in the range of 4x10 -10 Up to 4x10 -11Between M Figure 5 ).

[0367] The binding affinities of the anti-LYPD3 clones 17B3 and 21E9 to LYPD3 carrying TF (expressed in NM-F9 cells, or expressed in NM-H9D8 and treated with sialidase), LYPD3 carrying mainly sTF (sialylated TF) and some TF (expressed in NM-H9D8 cells), and LYPD3 carrying Tn (expressed in NM-F9 cells and treated with galactosidase) were also compared. Both clones showed strong binding to LYPD3 glycosylated with TF, while 21E9 additionally recognized LYPD3 glycosylated with Tn ( Figure 6 ).

[0368] Example 4: Binding to O-glyc. and de-O-glyc. LYPD3 expressed in cell lines

[0369] The binding of aLYPD3 clones to cell lines with different glycosylation states of LYPD3 was tested. LYPD3-transfected NM-F9 (LYPD3-F9) expressing LYPD3 carrying non-sialylated O-glycans, untransfected NM-F9 (corresponding WT cells) expressing endogenous levels of LYPD3, and LYPD3-transfected HEK-O-glyc KO (LYPD3-HEK-O-glyc.KO) expressing LYPD3 without O-glycans were stained with aLYPD3 clone and detected by fluorophore-conjugated anti-human IgG secondary reagent. Expression of LYPD3 and TFa was confirmed using control aLYPD3 pAb and mAb and aTF mAb. An irrelevant hIgG1 control was included to determine background staining. DAPI was used to distinguish live from dead cells. Cells were analyzed using a Canto II (BD) flow cytometer.

[0370] The results showed that all aLYPD3 clones bound to O-glycosylated LYPD3 on LYPD3-F9 and NM-F9, but not to non-O-glycosylated LYPD3 on LYPD3-HEK-O-glyc KO cells. Binding to NM-F9 cells was comparable to staining with aLYPD3 pAb and mAb ( Figure 7 ).

[0371] Example 5: Titration of aLYPD3 clones on LYPD3-F9 cells

[0372] To compare the binding affinity of different aLYPD3 clones, LYPD3-F9 cells expressing high levels of O-glyc.LYPD3 were stained with different concentrations of aLYPD3 clones and bound antibodies were detected with a fluorophore-conjugated anti-human IgG secondary reagent. To determine background staining, an irrelevant hIgG1 control was included and DAPI was used to distinguish live from dead cells. Cells were analyzed using a Canto II (BD) flow cytometer.

[0373] All aLYPD3 clones showed dose-dependent binding to LYPD3-F9 cells ( Figure 8 and 9 The binding of the aLYPD3 clones was in the same range as the aLYPD3 mAb control ( Figure 8 Clones 16F9, 19G10, 21E9, 22A11 and 25A6 showed very similar binding affinities, which were slightly higher than those of clones 17B3, 19B4 and 26A4 ( Fig. 9 ).

[0374] Example 6: aLYPD3 clone does not bind to LYPD3 expressed on normal human epithelial breast cells

[0375] To demonstrate that the aLYPD3 clone does not bind to the LYPD3 glycoform found primarily on normal human cells, human epithelial mammary cells (HMEC) from healthy donors were stained with the aLYPD3 clone and detected by a fluorophore-conjugated anti-human IgG secondary reagent. Expression of LYPD3 and TFa was confirmed using control aLYPD3 pAb and mAb and aTF mAb. An irrelevant hIgG1 control was included to determine background staining. DAPI was used to distinguish live from dead cells. Cells were analyzed using a Canto II (BD) flow cytometer.

[0376] HMECs expressed moderate levels of LYPD3 ( LYPD3 positive), but almost no TFa. None of the aLYPD3 clones showed binding to LYPD3 expressed on HMEC ( Fig.10 ).

[0377] Example 7: Binding of aLYPD3 clones to tumor cell lines

[0378] To test the binding of aLYPD3 clones to tumor cell lines, different cell lines with different expression levels of LYPD3 and TFa were selected: Caov-3 (ovarian adenocarcinoma cell line, LYPD3+), ZR-75-1 (breast cancer cell line, LYPD3+) and MDA-MB-231 (breast cancer cell line, LYPD3-). MDA-MB-231 and ZR-75-1 were treated with sialidase to remove sialic acid from the cell surface. Tumor cell lines were stained with aLYPD3 clone and binding was detected using a fluorophore-conjugated anti-human IgG secondary reagent. Expression of LYPD3 and TFa was confirmed using control aLYPD3 pAb and aTF mAb. To determine background staining, an irrelevant hIgG1 control was included. DAPI was used to distinguish live from dead cells. Cells were analyzed using a Canto II (BD) flow cytometer.

[0379] All tested aLYPD3 clones bound to the cell line Caov-3, which expresses high levels of LYPD3 and TFa. Binding was comparable to that of aLYPD3 pAb ( Fig.11 A). The ZR-75-1 cell line expresses lower levels of TFa compared to Caov-3, and therefore the binding of aLYPD3 clones to ZR-75-1 was investigated before and after sialidase treatment (to expose other TFa molecules). All aLYPD3 clones bound to sialidase-treated ZR-75-1 ( Fig.11 B). Some aLYPD3 clones (16F9, 19G10, 25A6, and 26A4) were shown to also bind to untreated ZR-75-1. aLYPD3 clones did not bind to MDA-MB-231 cells, which show high levels of TFa but do not express LYPD3 after sialidase treatment ( Fig.11 C).

[0380] Example 8: Inhibition of proliferation using protein G-drug conjugated aLYPD3 antibodies

[0381] To investigate the potential of aLYPD3 clones to deliver cytotoxic drugs into target cells, a protein G-drug conjugate assay was performed. 5000 LYPD3-F9 cells were seeded per well in a flat-bottom 96-well plate in the presence of the indicated test antibody dilutions and a constant concentration of protein G preloaded with the toxin MMAE (Protein G-MMAE, Levena Biopharma). After 4 days of incubation, the cells were incubated with 5% paraformaldehyde (4% paraformaldehyde) according to the manufacturer’s instructions. Cell viability was assessed using a luminescent cell viability assay (Promega) and analyzed in a microplate reader TECAN Infinite F200 (Tecan). The percentage of proliferation relative to the control of medium without antibody was calculated based on the luminescent signal.

[0382] The results demonstrated that aLYPD3 clone 17B3 conjugated with protein G-MMAE inhibited the proliferation of LYPD3-F9 in a dose-dependent manner, indicating efficient internalization of the aLYPD3 clone ( Fig.12 )

[0383] Example 9: Tissue Binding of Carbohydrate-Specific Anti-LYPD3 Antibodies

[0384] Formalin-fixed paraffin-embedded tissue sections were stained with 10 μg / ml aLYPD3 clone and detected using HRP-labeled polymer conjugated to anti-mouse or anti-human secondary antibodies. A commercial polyclonal aLYPD3 antibody was included to detect the protein level of LYPD3 in various tissues.

[0385] Staining of cancer tissue sections showed that aLYPD3 clones were associated with squamous cell carcinomas of the head and neck, esophageal carcinoma, breast carcinoma, cervical carcinoma, and skin carcinoma of different origins. Fig.13 As shown in Table 2, the reactivity to healthy tissues was absent or reduced compared to the protein-specific control aLYPD3 pAb. In summary, aLYPD3 clones were found to react with several cancer tissue sections but not with healthy counterparts. In particular, 17B3 and 21E9 clones showed strong interactions with SCC cancer tissue sections of the anal region / rectum, oral cavity, lip, buccal cavity, nose, penis, vulva, epiglottis, tongue, and skin (data not shown).

[0386] Table 2 - Binding of aLYPD3 clones to healthy tissues

[0387]

[0388]

[0389] Binding of aLYPD3 clones to healthy tissues compared to the pAb control antibody is shown, categorized according to staining intensity: + moderate to strong staining, + / - weak staining, - no staining observed.

[0390] In particular, the 17B3 and 21E9 clones showed strong interactions with SCC tissue sections of the anal region / rectum, oral cavity, lips, buccal cavity, nose, penis, vulva, epiglottis, tongue and skin.

[0391] Example 10: Humanization of rabbit heavy and light chain variable regions of anti-huLYPD3 antibody 21E9

[0392] Nucleic acid sequences encoding the rabbit heavy and light chain variable regions (SEQ ID NOs: 39 and 40) of the monoclonal anti-huLYPD3 antibody 21E9 were linked to sequences of the human constant γ1 region (CH) and the human constant κ region (CL), respectively.

[0393] On the basis of these chimeric clones, humanized antibodies were constructed. To this end, point mutations were introduced into the nucleotide sequences of the rabbit framework regions of VH and VL to produce corresponding human framework regions. The target human framework region was selected from the database generated from the NCBI GenBank entry (cleaned to remove incomplete and non-human sequences) to include germline and mature antibody frameworks. In particular, depending on their overall sequence similarity and their CDR loop classification, the most relevant framework regions were selected from the library. All the data obtained were considered to design a group of different variable sequences of the humanized variable light chain and variable heavy chain of the parent rabbit antibody. Some variants contain back mutations of rabbit sequences at key positions. Eight humanized variants of the light chain variable region were cloned into a κ chain vector, and eight humanized variants of the heavy chain variable region were cloned into a γ1 chain vector.

[0394] Antibodies containing different combinations of obtained heavy and light chains (64 antibody variants in total) were transiently expressed and screened for expression and LYPD3 binding in ELISA according to Example 3. The following humanized antibody heavy and light chain variable regions were selected for further analysis.

[0395] Table 3 - Humanized antibody heavy chain and light chain variable regions

[0396] VH SEQ ID NO V L SEQ ID NO 1 138 1 143 2 139 2 144 3 140 4 145 6 141 8 146 7 142

[0397] Nine selected antibody combinations of humanized VH and VL sequences were produced as human IgG1 / κ by transient expression in CHO cells and purified by protein A chromatography.

[0398] Table 4 - Humanized antibodies tested

[0399] Antibody production batch number VH V L 21E9-219 2 2 21E9-220 3 2 21E9-221 6 2 21E9-222 7 2 21E9-224 7 1 21E9-225 7 4 21E9-226 7 8 21E9-227 1 4 21E9-228 3 4

[0400] According to Examples 3 and 4, their binding specificity and affinity were analyzed in ELISA and flow cytometry assays and compared with the parent chimeric antibody. The data are summarized in Fig.14 , 15 and 16. All humanized antibody variants showed the same binding affinity and specificity to LYPD3 carrying TF or Tn as the parent antibody 21E9.

[0401] Sequence Listing

[0402]

[0403]

[0404]

[0405]

[0406]

[0407]

[0408]

[0409] Identification of deposited biological material

[0410] The cell line DSMACC 2606 was provided by Nemod Biotherapeutics GmbH & Co. KG (Robert- -Str.10,13125Berlin (Germany)) was deposited at the German Collection of Microorganisms (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), Mascheroder Weg 1b, 38124 Braunschweig (Germany)) on the dates indicated in the table below. Since the biological material was simultaneously transferred to Glycotope GmbH by Nemod Biotherapeutics GmbH & Co. KG, Glycotope has the right to refer to the biological material.

[0411] Cell lines DSMACC 2806, DSMACC 2807 and DSMACC 2856 were provided by Glycotope GmbH (Robert- -Str. 10, 13125 Berlin (Germany)) was deposited with the German Collection of Microorganisms (DSMZ, Inhoffenstraβe 7B, 38124 Braunschweig (Germany)) on the dates indicated in the table below.

[0412]

Claims

1. An antibody capable of specifically binding to glycosylated human LYPD3 at an epitope comprising an oligosaccharide structure, wherein the oligosaccharide structure is selected from: GalNAcα1-, sialylated GalNAcα1-, Galβ1-3GalNAcα1- and sialylated Galβ1-3GalNAcα1-, wherein the oligosaccharide structure is linked to a serine or threonine residue of LYPD3.

2. The antibody according to claim 1, wherein the oligosaccharide structure is linked to a serine or threonine residue within positions 234 to 303 of SEQ ID NO:

137.

3. The antibody according to claim 1 or 2, wherein the epitope comprises one or more amino acids within positions 234 to 303 of SEQ ID NO: 137, and wherein in particular at least 50% of the amino acids of the epitope are present within positions 234 to 303 of SEQ ID NO:

137. The antibody according to any one of claims 1 to 3, which is capable of specifically binding to human LYPD3 glycosylated with either or both of GalNAcα1- and Galβ1-3GalNAcα1-. 5 . The antibody according to any one of claims 1 to 3 , which is capable of specifically binding to human LYPD3 glycosylated with Galβ1-3GalNAcα1.

6. An antibody capable of binding to LYPD3, the antibody comprising: (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 1, the CDR-H2 has the amino acid sequence of SEQ ID NO: 2, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 3, and A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 4, the CDR-L2 has the amino acid sequence of SEQ ID NO: 5, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 6; or (ii) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 9, the CDR-H2 has the amino acid sequence of SEQ ID NO: 10, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 11, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 12, the CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 14; or (iii) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 17, the CDR-H2 has the amino acid sequence of SEQ ID NO: 18, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 19, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 20, the CDR-L2 has the amino acid sequence of SEQ ID NO: 21, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 22; or (iv) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 25, the CDR-H2 has the amino acid sequence of SEQ ID NO: 26, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 27, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 28, the CDR-L2 has the amino acid sequence of SEQ ID NO: 29, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 30; or (v) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 33, the CDR-H2 has the amino acid sequence of SEQ ID NO: 34, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 35, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 36, the CDR-L2 has the amino acid sequence of SEQ ID NO: 37, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 38; or (vi) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO:41, the CDR-H2 has the amino acid sequence of SEQ ID NO:42, and the CDR-H3 has the amino acid sequence of SEQ ID NO:43, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 44, the CDR-L2 has the amino acid sequence of SEQ ID NO: 45, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 46; or (vii) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 49, the CDR-H2 has the amino acid sequence of SEQ ID NO: 50, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 51, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 52, the CDR-L2 has the amino acid sequence of SEQ ID NO: 53, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 54; or (viii) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 57, the CDR-H2 has the amino acid sequence of SEQ ID NO: 58, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 59, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 60, the CDR-L2 has the amino acid sequence of SEQ ID NO: 61, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 62; or (ix) The heavy chain variable region and light chain variable region according to any one of (i) to (viii) above, comprising a total of 1, 2 or 3 amino acid substitutions in the six CDR sequences.

7. The antibody according to claim 6, wherein: (i) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 7, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 8; or (ii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 15, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 16; or (iii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 23, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 24; or (iv) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 31, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 32; or (v) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 39, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 40; or (vi) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 47, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 48; or (vii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 55, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 56; or (viii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 63, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 64; or (ix) the amino acid sequences comprised in the heavy chain variable region and the light chain variable region are at least 60% identical in their entire length to the heavy chain variable region sequence and the light chain variable region sequence described in any one of items (i) to (viii) above, respectively, wherein the antibody is preferably a humanized version of the antibody described in any one of items (i) to (viii) above.

8. The antibody according to claim 6 or 7, further comprising an Fc region.

9. The antibody according to any one of claims 1 to 5, which is the antibody according to any one of claims 6 to 8.

10. The antibody according to any one of claims 6 to 9, comprising: (i) a heavy chain variable region comprising complementarity determining regions (CDRs): CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has an amino acid sequence of SEQ ID NO: 33, the CDR-H2 has an amino acid sequence of SEQ ID NO: 34, and the CDR-H3 has an amino acid sequence of SEQ ID NO: 35, and A light chain variable region comprising complementarity determining regions (CDRs): CDR-L1, CDR-L2, and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 36, the CDR-L2 has the amino acid sequence of SEQ ID NO: 37, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 38; or (ii) a heavy chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 39, and comprising CDR-H1 having the amino acid sequence of SEQ ID NO: 33, CDR-H2 having the amino acid sequence of SEQ ID NO: 34, and CDR-H3 having the amino acid sequence of SEQ ID NO: 35, and a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO:40, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO:36, CDR-L2 has the amino acid sequence of SEQ ID NO:37, and CDR-L3 has the amino acid sequence of SEQ ID NO:38; The antibody is capable of specifically binding to human LYPD3 glycosylated with either or both of GalNAcα1- and Galβ1-3GalNAcα1-.

11. The antibody according to any one of claims 6 to 9, comprising: (i) a heavy chain variable region comprising CDR-H1, CDR-H2 and CDR-H3, wherein the CDR-H1 has the amino acid sequence of SEQ ID NO: 9, the CDR-H2 has the amino acid sequence of SEQ ID NO: 10, and the CDR-H3 has the amino acid sequence of SEQ ID NO: 11, and A light chain variable region comprising CDR-L1, CDR-L2 and CDR-L3, wherein the CDR-L1 has the amino acid sequence of SEQ ID NO: 12, the CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and the CDR-L3 has the amino acid sequence of SEQ ID NO: 14; or (ii) a heavy chain variable region having an amino acid sequence that is at least 60% identical to the amino acid sequence of SEQ ID NO: 15 over its entire length, and comprising CDR-H1, CDR-H2, and CDR-H3, wherein CDR-H1 has the amino acid sequence of SEQ ID NO: 9, CDR-H2 has the amino acid sequence of SEQ ID NO: 10, and CDR-H3 has the amino acid sequence of SEQ ID NO: 11, and a light chain variable region having an amino acid sequence that is at least 60% identical over its entire length to the amino acid sequence of SEQ ID NO: 16, and comprising CDR-L1, CDR-L2, and CDR-L3, wherein CDR-L1 has the amino acid sequence of SEQ ID NO: 12, CDR-L2 has the amino acid sequence of SEQ ID NO: 13, and CDR-L3 has the amino acid sequence of SEQ ID NO: 14; The antibody is capable of specifically binding to human LYPD3 glycosylated with Galβ1-3GalNAcα1.

12. The antibody according to any one of claims 6 and 8 to 10, which is a humanized antibody, wherein: (i) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 139, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 144; or (ii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 140, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 144; or (iii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 141, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 144; or (iv) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 142, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 144; or (v) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 142, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 143; or (vi) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 142, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 145; or (vii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 142, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 146; or (viii) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 138, and the light chain variable region comprises the amino acid sequence of SEQ ID NO: 145; or (ix) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 140, and the light chain variable region comprises the amino acid sequence of SEQ ID NO:

145.

13. The antibody according to any one of claims 1 to 12, which is an IgG1, IgG2, IgG3 or IgG4 type antibody, in particular an IgG1 type antibody.

14. A conjugate comprising the antibody according to any one of claims 1 to 13 conjugated to another agent.

15. The conjugate of claim 14, wherein the other agent is a cytotoxic agent, a tumor-specific antibody, or an immune checkpoint blocking or activating antibody.

16. The conjugate of claim 14, which is a chimeric antigen receptor.

17. A nucleic acid encoding the antibody according to any one of claims 1 to 13 or the conjugate according to any one of claims 14 to 16, wherein the other agent is a polypeptide or protein fused to the antibody.

18. An expression cassette or vector comprising the nucleic acid according to claim 17 and a promoter operably linked to the nucleic acid.

19. A host cell comprising the nucleic acid according to claim 17 or the expression cassette or vector according to claim 18.

20. The host cell of claim 19, wherein the host cell is a leukocyte and comprises a nucleic acid encoding the conjugate of claim 16.

21. A composition comprising the antibody of any one of claims 1 to 13, the conjugate of any one of claims 14 to 16, the nucleic acid of claim 17, the expression cassette or vector of claim 18 or the host cell of claim 19 or 20.

22. The composition according to claim 21, which is a pharmaceutical composition, optionally further comprising one or more components selected from the group consisting of a solvent, a diluent and an excipient.

23. The antibody according to any one of claims 1 to 13, the conjugate according to any one of claims 14 to 16, the host cell according to claim 20 or the composition according to claim 22 for use in medicine.

24. The antibody, conjugate, host cell or composition of claim 23, for use in treating cancer, juvenile idiopathic scoliosis, cholesteryl ester transfer protein (CETP) deficiency, fish eye disease, combined hyperlipidemia, citrullinemia or familial hypercholesterolemia.

25. The antibody, conjugate, host cell or composition of claim 24, wherein the cancer is selected from the group consisting of head and neck cancer, colon cancer, colorectal cancer, hepatocellular carcinoma, skin cancer, cervical cancer, breast cancer, ovarian cancer, prostate cancer, kidney cancer, esophageal cancer, lung cancer and cancer of the reproductive region, in particular non-small cell lung cancer (NSCLC) and squamous cell carcinoma (SCC).

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