Anti-5T4 antigen binding domains, antibody-drug conjugates, and methods of use thereof

Abstract

The present disclosure provides anti-5T4 antigen binding domains that can be incorporated into antibodies and recipients, including bispecific anti-5T4 antibodies, biparatopic anti-5T4 antibodies, and antibody-drug conjugates thereof, the antibody-drug conjugates comprising: a first antigen binding domain that specifically binds to a first 5T4 epitope; a second antibody antigen binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antigen binding domain is operably linked to the second antigen binding domain; and a chemotherapeutic agent. The disclosure further provides methods of using the same for treating cancer.

Description

[0001] Related applications This application claims priority and interest in U.S. Provisional Application No. 63 / 453,929, filed March 22, 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] References to electronic sequence listings The contents of the electronic sequence list (SBTI-005_001WO_SeqList_St26.xml; size: 163,004 bytes; and creation date: February 29, 2024) are incorporated herein by reference in their entirety. Background of the Invention Cancer is one of the leading causes of death in developed countries. In the United States alone, an estimated 1.8 million people were newly diagnosed with cancer in 2020, and more than 600,000 cancer deaths occurred. In cancer, a subject's cells grow and divide abnormally, spreading into surrounding tissues. Each type of cancer is believed to have a combination of genetic alterations that can differ between cancers, allowing cancer cells to evade the body's natural control over cell proliferation and allowing the cancer to spread. While some cancers are currently treatable, many are not. There is a need in the art for compositions and methods for treating cancer.

[0004] Human 5T4 is expressed in various cancer types, including bladder cancer, breast cancer, cervical cancer, endometrial cancer, lung cancer, esophageal cancer, ovarian cancer, pancreatic cancer, gastric cancer, and testicular cancer. Human 5T4 is generally not found in normal tissues, and when it is found, it is expressed at low levels, making it an ideal therapeutic target for cancer treatment. This disclosure provides antibodies and antibody-drug conjugates containing chemotherapeutic agents that specifically bind to a first 5T4 epitope and, in some cases, a second 5T4 epitope, compositions containing the same, and methods for preparing and using them for treating diseases such as cancer. Invention Overview This disclosure provides a 5T4 antigen-binding domain, as well as antibodies, antibody-drug conjugates, and receptors containing the domain.

[0006] This disclosure provides 5T4 biparatopic antibody-drug conjugates comprising: (a) a first antigen-binding domain that specifically binds to a first 5T4 epitope; (b) an antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; and (c) a chemotherapeutic agent; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain. In some embodiments of the 5T4 biparatopic antibodies and antibody-drug conjugates described herein, the biparatopic antibody or antibody-drug conjugate comprises a full-length IgG antibody comprising the first antigen-binding domain, and the second antigen-binding domain comprises scFv.

[0007] In some embodiments of the antibody-drug conjugates disclosed herein, the N-terminus of the second antigen-binding domain is operatively linked to the C-terminus of the heavy chain of the first antigen-binding domain. In some embodiments, the C-terminus of the second antigen-binding domain is operatively linked to the N-terminus of the heavy chain of the first antigen-binding domain. In some embodiments, the second antigen-binding domain is operatively linked to the heavy chain of the first antigen-binding domain using a linker. In some embodiments, the antibody or antibody-drug conjugate comprises a full-length IgG antibody comprising the first antigen-binding domain, and the second antigen-binding domain comprises scFv, and the antibody or antibody-drug conjugate comprises four polypeptides comprising: (a) two polypeptides comprising the heavy chain of the first antigen-binding domain, a linker, and the second antigen-binding domain from the N-terminus to the C-terminus; and (b) two polypeptides comprising the light chain of the first antigen-binding domain. In some embodiments, the antibody or antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain and a second antigen-binding domain containing scFv, and the antibody-drug conjugate comprises four peptides: (a) two peptides containing a second antigen-binding domain, a linker, and a heavy chain of the first antigen-binding domain from the N-terminus to the C-terminus; and (b) two peptides containing a light chain of the first antigen-binding domain.

[0008] In some embodiments, the chemotherapeutic agent is olistatin, such as olistatin selected from olistatin E (AE), monomethylolistatin D (MMAD), monomethylolistatin E (MMAE), monomethylolistatin F (MMAF) and synthetic analogues of dolasstatin.

[0009] This disclosure provides nucleic acid systems and vectors encoding antigen-binding domains, antibodies, and receptors of the present disclosure.

[0010] This disclosure provides pharmaceutical compositions comprising an antigen-binding domain, an antibody, an antibody-drug conjugate, and an immune cell comprising the receptor of this disclosure.

[0011] This disclosure provides a pharmaceutical composition comprising an antigen-binding domain, an antibody, an antibody-drug conjugate, and an immune cell comprising the receptor of this disclosure, for use in treating cancer in a subject.

[0012] This disclosure provides a pharmaceutical composition comprising an antigen-binding domain, an antibody, an antibody-drug conjugate, and an immune cell comprising a receptor of this disclosure, for use in manufacturing a medicament for treating cancer in a subject.

[0013] This disclosure provides a method for treating cancer in a subject with this need, the method comprising administering to the subject with a therapeutically effective amount of an antigen-binding domain, an antibody, an antibody-drug conjugate, or an immune cell comprising a receptor of this disclosure. In some embodiments, the method comprises administering an antibody-drug conjugate comprising: (a) a first antigen-binding domain that specifically binds to a first 5T4 epitope; (b) a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; and (c) a chemotherapeutic agent; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain.

[0014] This disclosure provides a method for manufacturing antibody-drug conjugates, the method comprising: (a) culturing cells containing a nucleic acid system encoding an antibody under conditions that induce antibody expression; (b) recovering the antibody; and (c) conjugating the antibody to a chemotherapeutic agent. Brief description of the attached diagram Figs. 1A-1B This is a schematic diagram depicting the structural configuration of an exemplary anti-5T4 dual complementary antibody-drug conjugate. Fig. 1A The first exemplary antibody-drug conjugate (Bs2 orientation) is shown. Fig. 1B A second exemplary antibody-drug conjugate (Bs3 orientation) is shown. VH: variable heavy chain; VL: variable light chain; scFv: single-chain variable fragment.

[0016] Figs. 2A-2C The graphs and tables shown depict the size exclusion chromatography analysis of protein A after purification of four exemplary anti-5T4 dual complementary site antibodies. Fig. 2A Two graphs were plotted, which showed Fig. 1A The image shows monomer peak analysis of two exemplary antibodies with Bs2 orientation. The left panel shows the antibody with scFv oriented in VL-VH, while the right panel shows the antibody with scFv oriented in VH-VL. Fig. 2B Two graphs were plotted, which showed Fig. 1B The image shows monomer peak analysis of two exemplary antibodies with Bs3 orientation. The left panel shows the antibody with scFv oriented VL-VH, while the right panel shows the antibody with scFv oriented VH-VL.Fig. 2C It shows information about the harvest from 10 days of cultivation. Figs. 2A-2B The antibody variants described are presented in the table, along with the quantitative soluble protein yield expressed in mg / L and the relative purity obtained through size exclusion chromatography (SEC) peaks.

[0017] Figs. 3A-3C Two graphs and tables were plotted to illustrate the SPR-based binding assay to confirm that the 5T4 epitope bound by antibodies 1 and 2 is non-competitive. Fig. 3A An assay was shown in which mouse Ab1 ((m)Ab1) was captured onto a sensor chip using an anti-mouse IgG antibody, followed by an injection of 5T4, and then humanized Ab1 or Ab2 with human Fc. Fig. 3B An assay was shown in which mouse Ab2 ((m)Ab2) was captured onto a sensor chip using an anti-mouse IgG antibody, followed by an injection of 5T4, and then humanized Ab1 or Ab2 with human Fc. Fig. 3C It is a table displaying a legend, which shows information about... Figs. 3A-3B The combined sensor image and the injected sample. Fig. 3A and 3B The y-axis indicates the relative response (in resonant units or RU), while the x-axis indicates time (in seconds or s).

[0018] Figs. 4A-4E The binding affinity of the parental monospecific antibody and the dual complementary site antibody to 5T4 was shown, as determined by Biacore analysis. Fig. 4A The binding of a first exemplary monospecific antibody, humanized antibody Ab1, is shown. Fig. 4B The binding of a second exemplary monospecific antibody, humanized antibody Ab2, is shown. Fig. 4C The binding of an exemplary dual complementary site antibody (Bs3-HL) with a VH-VL oriented scFv and a Bs3 oriented scFv is shown. Fig. 4D The binding of a second exemplary dual complementary site antibody (Bs3-HL-FCA, with Bs3 having scFv oriented in VH-VL and having L234F, S239C and N434A mutations) is shown. Fig. 4E It summarizes the sources from Figs. 4A-4D A table showing the equilibrium dissociation constant (KD), dissociation rate constant (Kd), and binding rate constant (Ka) for antibody binding assays. (Regarding...) Figs. 4A-4D The y-axis displays the response (in RU), and the x-axis displays the time (in seconds).

[0019] Fig. 5 This is a table showing the percentage sequence identity of 5T4 proteins from rhesus monkeys, cynomolgus monkeys, mice, and rats to human 5T4.

[0020] Fig. 6 This is a graph depicting the binding of exemplary Bs3-oriented, double-complementary 5T4 antibodies to 5T4 proteins from various species, as determined by ELISA. NHP: Non-human primates.

[0021] Figs. 7A-7D It is a series of graphs depicting the binding specificity of exemplary Bs3-oriented dual complementary site antibodies to 5T4 proteins from various species, as determined by surface plasmon resonance (SPR). Fig. 7A It shows the combination with human 5T4. Fig. 7B The binding with NHP 5T4 was shown. NHP: Non-human primates. Fig. 7C Binding with mouse 5T4 was shown. Fig. 7D Binding with rat 5T4 was demonstrated. Figs. 7A-7D The y-axis in the entire graph indicates the relative response (denoted by RU), while the x-axis indicates time (in seconds). Figs. 7A-7D The antibody concentrations were as follows: 100 nM (purple), 33.3 nM (yellow), 11.1 nM (pink), 3.7 nM (green), 1.2 nM (orange), and 133 pM (blue).

[0022] Fig. 8 The table describes about Fig. 1A The diagram illustrates an overview of the equilibrium dissociation constant (KD) for the binding of an exemplary dual complementary antibody with an Fc mutation in the form of Bs3 HL to a parent Ab1 without the Fc mutation, for the selection of the Fcγ receptor (FcγR). FCA: L234F, S239C, and N434A mutations.

[0023] Figs. 9A-9L A series of figures are shown depicting flow cytometry analysis of 5T4 expression on the cell surface in experimental groups of 5T4-negative and 5T4-positive cell lines. Fig. 9A AGS cells are shown. Fig. 9B HepG2 cells were shown. Fig. 9C LoVo cells are shown. Fig. 9D PCI-N87 cells were shown. Fig. 9E A549 cells are shown. Fig. 9F DU145 cells are shown. Fig. 9G PANC-1 cells are shown. Fig. 9H T-47D cells were shown. Fig. 9I MCF7 cells are shown. Fig. 9J HEK293-5T4 (3G9) cells were shown. Fig. 9KHEK293-5T4 (4F2) cells are shown. Fig. 9L HEK293-5T4 (5C10) cells are shown.

[0024] Figs. 10A-10F These are a series of graphs depicting the internalization of the 5T4 receptor induced by bicomplementary antibodies in the form of Bs3-HL and Bs2-HL, with or without FCA (L234F, S239C, and N434A) mutations, compared to parental monospecific antibodies (humanized forms of antibodies Ab1 and Ab2). 5T4 receptor internalization was determined in cell types that multiply express 5T4. Fig. 10A DU145 cells are shown. Fig. 10B PANC-1 cells are shown. Fig. 10C MCF7 cells are shown. Fig. 10D HEK293-5T4 (3G9) cells were shown. Fig. 10E HEK293-5T4 (4F2) cells are shown. Fig. 10F T-47D cells were shown.

[0025] Figs. 11A-11F These are a series of graphs depicting the mean percentage survival of cancer cell lines incubated with a bicomponent antibody conjugated to MMAE in the form of Bs3-HL, compared to a non-5T4-specific IgG antibody (IgG-Ctrl) and MMAE (antibody-free) control. Survival was measured in cell types that multiply express 5T4. Fig. 11A AGS cells are shown. Fig. 11B DU145 cells are shown. Fig. 11C T-47D cells were shown. Fig. 11D MCF7 cells are shown. Fig. 11E HEK293-5T4 (3G9) cells were shown. Fig. 11F HEK293-5T4 (4F2) cells are shown. cc4 and cc8 indicate different drug-antibody ratios (DARs) of approximately 4 and 8, respectively. The y-axis shows percentage survival, while the x-axis indicates the concentration of the antibody-drug conjugate (in pM). MMAE: Monomethyl oliquistatin E.

[0026] Figs. 12A-12F These are a series of graphs depicting the mean percentage growth inhibition of cancer cell lines incubated with a double complementary site 5T4 antibody conjugated to MMAE in the form of Bs3-HL, compared to a non-5T4-specific IgG antibody (IgG-Ctrl) conjugated to MMAE and a MMAE (antibody-free) control. Growth inhibition was measured in cell types that multiply express 5T4. Fig. 12A AGS cells are shown.Fig. 12B DU145 cells are shown. Fig. 12C MCF7 cells are shown. Fig. 12D T-47D cells were shown. Fig. 12E HEK293-5T4 (3G9) cells were shown. Fig. 12F HEK293-5T4 (4F2) cells are shown. cc4 and cc8 indicate different drug-antibody ratios (DARs) of approximately 4 and 8, respectively. The y-axis shows percentage growth inhibition, while the x-axis indicates the concentration of the antibody-drug conjugate (in pM). MMAE: Monomethyl ozogluconate E.

[0027] Figs. 13A-13B The graphs depict tumor growth and mouse survival in immunocompromised mice implanted with NCI-H1975 lung adenocarcinoma tumors and treated with a 5T4 double complementary antibody conjugated to MMAE with a Bs3 orientation (two dose concentrations), compared with an isotype control antibody conjugated to MMAE and a PBS-simulated control. Fig. 13A It showed tumor growth. Fig. 13B Survival probabilities are shown. ADC: Antibody-drug conjugate; MMAE: Monomethyl olprestatin E.

[0028] Figs. 14A-14C It is a series of graphs depicting tumor growth in immunocompromised mice implanted with various CDX tumor models and treated with multiple concentrations of 5T4 double-complementary antibodies conjugated to MMAE with Bs3 orientation, compared with isotype control antibodies conjugated to MMAE or PBS-mimicking controls. Fig. 14A The MDA-MD-361 breast cancer model is shown. Fig. 14B A DU145 prostate cancer model is shown. Fig. 14C The A549 lung cancer model is shown. ADC: antibody-drug conjugate; MMAE: monomethylolpropionate E.

[0029] Figs. 15A-15D It is a series of sensor maps that depict the binding affinity of the 5T4 parent antibody compared to the 5T4 bicomplementary antibody in the Bs3 configuration. Fig. 15A The binding affinity of the parent antibody (m)Ab1 was demonstrated. Fig. 15B The binding affinity of the parent antibody (m)Ab2 was demonstrated. Fig. 15C The binding affinity of the bispecific antibody oriented towards Bs3-HL was demonstrated. Fig. 15D The binding affinity of the bispecific antibody conjugated to MMAE (monomethyl ozretamine E) with a Bs3-HL orientation was demonstrated.

[0030] Fig. 16 The table describes, for example Figs. 15A-15D The diagram shows a summary of the equilibrium dissociation constant (KD) for the binding of 5T4 antibodies with and without MMAE conjugation to 5T4. Invention Details This disclosure provides an antigen-binding domain that specifically binds to 5T4, as well as methods for preparing and using the domain. The 5T4 antigen-binding domain of this disclosure includes, but is not limited to, Fab fragments, F(ab')2 fragments, scFv, scab, dAb, single-domain antibodies, full-length IgG antibodies, etc. Non-limiting uses of the 5T4 antigen-binding domain considered to be within the scope of this disclosure include immunotherapy, use as an antibody-drug conjugate, and incorporation into chimeric antigen receptors (CARs) for adoptive cell therapy.

[0032] Accordingly, this disclosure provides antibody-drug conjugates comprising the 5T4 antigen-binding domain described herein. In some embodiments, the antibody-drug conjugate is doubly complementary, i.e., comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope and a second antigen-binding domain that specifically binds to a second 5T4 epitope, and the two 5T4 epitopes are not identical. In some embodiments, the antibody-drug conjugate comprises a first antigen-binding domain that specifically binds to a first 5T4 epitope and a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope, and comprises a chemotherapeutic agent.

[0033] The bi-complementary antibody and its antibody-drug conjugate disclosed herein bind to two different epitopes of the same target 5T4 molecule, thereby cross-linking 5T4 on the surface of cells, such as cancer cells, and inducing the formation of 5T4-antibody immune complexes. This improved cross-linking provides functional benefits beyond those of known 5T4-binding proteins (e.g., monospecific antibodies or other proteins that specifically bind to a single 5T4 epitope). Such benefits include more robust and rapid internalization of the 5T4 molecule bound to the antibody-drug conjugate, which can lead to better cytotoxic killing of target cancer cells. It is not intended to be theoretically sound, but rather that increased cross-linking and / or aggregation of the antibody-immune complex leads to more robust internalization of the immune complex within the cell, lysosomal transport and degradation, and intracellular release of the cytotoxic payload within the host cell. The bi-complementary antibody-drug conjugates described herein exhibit improved internalization and specific killing of 5T4-expressing cancer cells. Therefore, the bi-complementary antibody and antibody-drug conjugates of this disclosure may provide improved efficacy against cancer cells and more effective treatment for subjects with 5T4-positive cancers.

[0034] In some embodiments, the dual complementary site antibodies and antibody-drug conjugates of this disclosure comprise an IgG constant (Fc) region domain containing at least one mutation that reduces effector function, prolongs half-life, or a combination thereof. For example, by reducing affinity for at least Fcγ receptor I (FcγRI) and / or Fcγ receptor IIIa (FcγRIIIa) compared to antibodies without the Fc mutation, without reducing the binding affinity of the antibody-drug conjugate to 5T4, the Fc mutations in the antibody-drug conjugates provided herein offer additional benefits beyond those of 5T4-binding proteins known in the art. Exemplary Fc mutations that minimize antibody effector function and prolong the half-life of antibody-drug conjugates are shown in Table 3.

[0035] In some embodiments, the bicomplementary antibody of this disclosure comprises a first antigen-binding domain operatively linked to a second antigen-binding domain. In some embodiments, the first and second antigen-binding domains are independently selected from Fab fragments, F(ab')2 fragments, scFv, scab, dAb, single-domain heavy chain antibodies, single-domain light chain antibodies, and full-length IgG antibodies. In some embodiments, the bicomplementary antibody comprises a full-length IgG antibody containing a first antigen-binding domain, and the second antigen-binding domain comprises scFv. In some embodiments, a chemotherapeutic agent is conjugated via a linker to at least one of a full-length IgG antibody containing a first antigen-binding domain or a second antigen-binding domain. In some embodiments, the chemotherapeutic agent is oliquistatin, such as, but not limited to, oliquistatin E (AE), monomethyloliquistatin D (MMAD), monomethyloliquistatin E (MMAE), monomethyloliquistatin F (MMAF), and synthetic analogs of dorlastatin.

[0036] This document also provides polynucleotides and vectors encoding antigen-binding domains, antibodies and antibody-drug conjugates comprising the antigen-binding domains, chimeric antigen receptors (CARs) comprising the antigen-binding domains of this disclosure, pharmaceutical compositions comprising the antigen-binding domains, and methods for preparing and using the antigen-binding domains. Antigen-binding domains, antibodies, antibody-drug conjugates, and CARs can be used to treat a variety of diseases and conditions, including cancer.

[0037] Definitions Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] For the purposes of this specification, the following definitions apply, and where appropriate, terms used in the singular also include the plural and vice versa. In the event of any conflict between any definition set forth below and any document incorporated herein by reference, the definition set forth below shall prevail.

[0039] As used herein, the term "subject" includes, but is not limited to, mammals, including, for example, humans; non-human primates (e.g., monkeys), mice, pigs, cattle, goats, rabbits, rats, guinea pigs, hamsters, horses, monkeys, sheep, or other non-human mammals; non-mammals, including, for example, non-mammalian vertebrates, such as birds (e.g., chickens or ducks) or fish; and non-mammalian invertebrates. In some embodiments, the methods and compositions of the present invention are used for (preventative and / or therapeutic) treatment of non-human animals. The term "subject" may also refer to a patient, i.e., an individual who is awaiting or receiving medical care.

[0040] The term "pharmaceutical composition" as used herein means a composition suitable for pharmaceutical use in subjects, including animals or humans. A pharmaceutical composition generally comprises an effective amount of an active ingredient (e.g., an antibody or antibody-drug conjugate of this disclosure) and a pharmaceutically acceptable carrier, diluent, or excipient (e.g., a buffer, adjuvant, etc.).

[0041] The term "effective amount" refers to a dose or amount sufficient to produce the desired result. The desired result may include objective or subjective improvement in the recipient of the dose or amount (e.g., long-term survival, reduction in the number and / or size of tumors, effective prevention of disease states, etc.).

[0042] "Prophylactic treatment" is a treatment administered to a subject who does not exhibit signs or symptoms of a disease, pathology, or medical condition, or who exhibits only early signs or symptoms of a disease, pathology, or medical condition, such that the treatment is administered for the purpose of reducing, preventing, or minimizing the risk of developing that disease, pathology, or medical condition. Prophylactic treatment acts as a preventative treatment against a disease or condition. "Prophylactic activity" is the activity of the reagents disclosed herein, such as anti-5T4 bispecific antibody-drug conjugates or combinations thereof, which, when administered to a subject who does not exhibit signs or symptoms of a pathology, disease, or medical condition (or who exhibits only early signs or symptoms of a pathology, disease, or medical condition), reduces, prevents, or minimizes the risk of the subject developing that pathology, disease, or medical condition. "Prophylactically useful" formulations or compounds (e.g., anti-5T4 bispecific antibody-drug conjugates) refer to reagents or compounds that can be used to reduce, prevent, treat, or minimize the development of a pathology, disease, or medical condition.

[0043] "Therapeutic treatment" is treatment administered to a subject exhibiting symptoms or signs of a pathological condition, disease, or symptom, wherein the treatment is administered to the subject for the purpose of reducing or eliminating those signs or symptoms of the pathological condition, disease, or symptom. "Therapeutic activity" is the activity of an agent, such as an antibody-drug conjugate or a combination thereof disclosed herein, which, when administered to a subject suffering from such signs or symptoms, eliminates or reduces the signs or symptoms of the pathological condition, disease, or symptom. A "therapeuticly effective" agent or compound (e.g., an anti-5T4 bispecific antibody-drug conjugate) indicates that the agent or compound effectively reduces, treats, or eliminates such signs or symptoms of the pathological condition, disease, or symptom.

[0044] Unless otherwise stated, as used herein, the term "treatment of cancer" means to partially or completely reverse, alleviate, inhibit, or stop the growth of tumors, metastases, or other carcinogenic or neoplastic cells in a subject. Unless otherwise stated, as used herein, the term "treatment" refers to the act of treatment.

[0045] In the context of two or more nucleic acid or polypeptide sequences, the term "identity" or "percentage identity" refers to two or more sequences or subsequences that are identical or have a specified percentage of identical nucleotide or amino acid residues when compared and aligned for maximum correspondence. To determine percentage identity, sequences are aligned for optimal comparison purposes (e.g., vacancies may be introduced into the sequence of the first amino acid or nucleic acid sequence for optimal alignment with a second amino acid or nucleic acid sequence). Amino acid residues or nucleotides at corresponding amino acid or nucleotide positions are then compared. When a position in the first sequence is occupied by the same amino acid residue or nucleotide as the corresponding position in the second sequence, the molecules are identical at that position. Percentage identity between two sequences is a function of the number of identical positions shared by the sequences (i.e., % identity equals the number of identical positions / total number of positions (e.g., overlapping positions × 100)). In some embodiments, the two sequences have the same length.

[0046] In the context of two nucleic acids or polypeptides, the term "substantially identical" refers to two or more sequences or subsequences having at least 60%, at least 70%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity (e.g., as determined using one of the methods set forth below).

[0047] Determining the percentage identity between two sequences can be accomplished using mathematical algorithms. A non-restricted example of a mathematical algorithm for comparing two sequences is, for instance, Karlin and Altschul (1993). , Proc. Natl. Acad. Sci. USA Modified from 90:5873-5877, Karlin and Altschul, 1990 , Proc. Natl. Acad. Sci. USA Algorithms 87:2264-2268. This type of algorithm is incorporated into Altschul et al., 1990. , J. Mol. Biol. Within the NBLAST and XBLAST programs in 215:403-410, a BLAST nucleotide search can be performed using the NBLAST program with a score of 100 and a word length of 12 to obtain nucleotide sequences homologous to the nucleic acid encoding the protein of interest. A BLAST protein search can be performed using the XBLAST program with a score of 50 and a word length of 3 to obtain amino acid sequences homologous to the protein of interest. For obtaining gap-aligned sequences for comparative purposes, methods such as those described in Altschul et al., 1997, can be used. , Nucleic Acids Res. Gapped BLAST as described in 25:3389-3402. Alternatively, PSI-Blast can be used to perform iterative searches that detect distant relationships between molecules (as above). When using the BLAST, Gapped BLAST, and PSI-BLAST procedures, the default parameters of the respective procedures (e.g., XBLAST and NBLAST) can be used. Another non-limiting example of a mathematical algorithm for sequence comparison is the algorithm of Myers and Miller, CABIOS (1989). Such algorithms are incorporated into the ALIGN program (version 2.0), which is part of the GCG sequence alignment software package. When using the ALIGN program to compare amino acid sequences, the PAM120 residue weight table, vacancy length penalty 12, and vacancy penalty 4 can be used. Other algorithms for sequence analysis are known in the art and include, for example, Torellis and Robotti, 1994. , Comput. Appl. Biosci. ADVANCE and ADAM as described in 10:3-5; and Pearson and Lipman, 1988. , Proc. Natl. Acad. Sci. USA FASTA as described in 85:2444-8. Alternatively, one can use, as in Higgins et al., 1996. , Methods Enzymol. The CLUSTAL W algorithm described in 266:383-402 is used for protein sequence alignment.

[0048] As used herein, an "antigen-binding domain" refers to a region on an antibody that binds to an antigen. An exemplary antigen-binding domain comprises a constant domain and a variable domain, respectively, of the heavy and light chains of the antibody. However, alternative arrangements, such as single-domain antigen-binding domains, are considered within the scope of this disclosure, provided that such domains are capable of binding antigens. Exemplary antigen-binding domains include, but are not limited to, scFv, Fab fragments, Fab' fragments, F(ab')2 fragments, etc., and are described in further detail below.

[0049] As used herein, the terms “binding,” “specific binding,” or “specificity” refer to a measurable and reproducible interaction, such as the binding between a target and an antigen-binding domain, which determines the presence of the target in the presence of a heterogeneous molecular population comprising biomolecules. For example, an antibody that specifically binds to a target (which may be an epitope) is an antibody that binds to such a target with greater affinity, strength, ease, and / or duration of binding compared to binding to other targets. In one embodiment, the degree of binding of the antigen-binding domain to an irrelevant target is less than about 10% of the antibody binding to the target, as measured, for example, by radioimmunoassay (RIA). In some embodiments, the antibody that specifically binds to the target has a dissociation constant (Kd) of <1 μM, <100 nM, <10 nM, <1 nM, <0.1 nM, or <0.01 nM.

[0050] In some embodiments, the antigen-binding domain specifically binds to an epitope on a protein that is conserved across proteins from different species. In another embodiment, specific binding may include, but is not required to be, exclusive binding.

[0051] As used in this specification, the singular forms “an,” “a,” and “the” include plural indicators unless the context clearly specifies otherwise. References to “formulation” or “method” include one or more formulations, methods, and / or steps of the type described herein and / or that will become apparent to a person skilled in the art upon reading this disclosure.

[0052] The term "polypeptide" refers to a polymer of amino acids and their equivalents, and does not refer to a specific length of the product; therefore, "peptide" and "protein" are included within the definition of a polypeptide. A protein may have one or more polypeptides. The definition of a polypeptide also includes "antibody" as defined herein. A "polypeptide region" refers to a segment of a polypeptide that may contain, for example, one or more domains or motifs (e.g., the polypeptide region of an antibody may contain, for example, one or more complementarity-determining regions (CDRs)). The term "fragment" refers to a portion of a polypeptide smaller than the whole polypeptide, as is the case in naturally occurring polypeptides.

[0053] Unless the context otherwise requires, a “derivative” is a polypeptide or fragment thereof having one or more non-conserved or conserved amino acid substitutions, or deletions or insertions, relative to a second polypeptide (also referred to as a “variant”); or a polypeptide or fragment thereof modified by covalent attachment to a second molecule, such as by attachment to a heteropeptide, or by glycosylation, acetylation, phosphorylation, etc. The definition of “derivative” further includes, for example, polypeptides containing one or more amino acid analogs (e.g., non-natural amino acids, etc.), polypeptides with unsubstituted bonds, and other modifications known in the art, both naturally occurring and non-naturally occurring.

[0054] "Isolated" polypeptides are polypeptides that have been identified and separated from and / or recovered from components in their natural environment. Contaminants in their natural environment are substances that would interfere with the diagnostic or therapeutic use of the polypeptide and may include enzymes, hormones, and other protein or non-protein solutes. Isolated polypeptides include isolated antibodies, fragments of which or their derivatives.

[0055] As used herein, the term "chimeric antigen receptor (CAR)" refers to an artificial transmembrane protein receptor comprising: (i) an extracellular domain capable of binding to at least one predetermined CAR ligand or antigen, such as the 5T4 antigen-binding domain as described herein; (ii) an intracellular segment comprising one or more cytoplasmic domains derived from signal transduction proteins distinct from polypeptides derived from the extracellular domains; and (iii) a transmembrane domain. In some cases, the CAR also includes a hinge domain. CARs can be used to artificially specifically transplant onto specific immune effector cells, such as helper T cells (CD4+), cytotoxic T cells (CD8+), or NK cells. CARs can be used to confer specificity on T cells with monoclonal antibodies, thereby allowing the generation of large numbers of specific T cells, for example, for adoptive cell therapy. Depending on the specific architecture of the CAR and the intracellular signal transduction domains employed, the CAR can be an activating or inhibitory receptor. An exemplary activating CAR includes an intracellular domain of CD3ζ, one or more intracellular domains for additional co-stimulatory signaling such as ICOS, CD137 (4-1BB), CD27, CD28, CD134, CD152 (CTLA-4), CD223 (LAG4), DAP10, and / or OX-40, and an optional extracellular hinge region, for example, derived from CD8a or CD28. Many different CARs are known in the art, all of which are contemplated within the scope of this invention.

[0056] As used herein, the term "T-cell bispecific antibody" refers to an antibody that has dual binding specificity to cancer-associated antigens such as 5T4 and CD3 subunits (e.g., any one of CD3ε, CD3γ, CD3δ, or CD3ζ) present on the surface of T cells. Without being bound by theory, it is thought that this allows T-cell bispecific antibodies to crosslink and bring T cells and cancer cells closer together, inducing T-cell activation and subsequent cancer cell death.

[0057] As used herein, the term “about” means a quantitative item of plus or minus 5%, or in another embodiment plus or minus 10%, or in another embodiment plus or minus 15%, or in another embodiment plus or minus 20%.

[0058] Unless otherwise stated herein or explicitly contradicted by the context, all methods described herein may be performed in any suitable order. The use of any and all instances or exemplary language (e.g., “for example”) provided herein is intended only to better illustrate the invention and does not constitute a limitation on the scope of the invention, unless otherwise required. No language in the specification should be construed as indicating that any unclaimed element is necessary for the practice of the invention.

[0059] All publications, patents and patent applications mentioned in this specification are incorporated herein by reference to the same extent as each individual publication, patent or patent application specifically and individually indicates that they are incorporated by reference.

[0060] 5T4 One example of a cancer-associated antigen is trophoblast glycoprotein (TPBG), also known as human 5T4 antigen (5T4), 5T4 carcinoembryonic antigen, or Wnt activation inhibitor 1 (WAIF1). Human 5T4 antigen is a 72 kDa type I transmembrane glycoprotein expressed in embryonic tissues such as the placenta, as well as in various types of solid tumors and cancers, including prostate, gastric, and colorectal cancers. See, for example, U.S. Patent No. 7,074,909 or U.S. Patent No. 7,514,546. However, 5T4 antigen is expressed at low levels or not at all in the epithelial tissues of most healthy adults. See Woods et al., Biochem. J. (2002) 366, 353-365.

[0061] Expression or overexpression of the 5T4 antigen in various tumor types, particularly ovarian, gastric, and colorectal tumors, is associated with poorer clinical outcomes. Furthermore, overexpression is associated with alterations in cell morphology and motility, consistent with tumor invasion. Therefore, the 5T4 antigen is believed to play a role in the progression or malignant transformation of some solid tumors.

[0062] This disclosure provides an antigen-binding domain that binds to 5T4, as well as antibodies, antibody-drug conjugates, and receptors containing the antigen-binding domain.

[0063] This disclosure provides antigen-binding domains that can be used to target cells expressing the 5T4 antigen, such as cancer cells. In some embodiments, the antigen-binding domain is incorporated into an antibody-drug conjugate that can be used for cancer therapy targeting 5T4. Exemplary antibody-drug conjugates include bicomponent antibodies binding to two different 5T4 epitopes, and 5T4 antibody-drug conjugates that can bind to a single 5T4 epitope. In some embodiments, the 5T4 antibody-drug conjugate comprises a bicomponent 5T4 antibody and binds to two different 5T4 epitopes. The antibody-drug conjugates provided herein may comprise a 5T4 antigen-binding moiety of an anti-5T4 antibody modified into a single-chain form and fused with a chemotherapeutic agent. In some embodiments, the 5T4 antibody-drug conjugate comprises a bicomponent 5T4 antibody that includes a full-length IgG antibody linked to an scFv.

[0064] This disclosure provides pharmaceutical compositions comprising the antigen-binding domain, antibody, antibody-drug conjugate, and receptor described herein. In some embodiments, the pharmaceutical composition comprises a dual complementary 5T4 antibody-drug conjugate comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope, a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope, and a chemotherapeutic agent.

[0065] Additionally, this disclosure provides a method for treating a disease or condition involving cell expression of the 5T4 antigen, the method comprising administering to a subject in need a therapeutically effective amount of the pharmaceutical composition described herein, such as a pharmaceutical composition comprising a dual complementary 5T4 antibody-drug conjugate, the conjugate comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope, a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope, and a chemotherapeutic agent.

[0066] This disclosure provides an antigen-binding domain that binds to the human 5T4 antigen. Human 5T4 comprises the amino acid sequence according to the NCBI reference sequence NP_001363851.1: 1 MPGGCSRGPA AGDGRLRLAR LALVLLGWVS SSSPTSSASS FSSSAPFLAS AVSAQPPLPD 61 QCPALCECSE AARTVKCVNR NLTEVPTDLP AYVRNLFLTG NQLAVLPAGA FARRPPLAEL 121 AALNLSGSRL DEVRAGAFEH LPSLRQLDLS HNPLADLSPF AFSGSNASVS APSPLVELIL 181 NHIVPPEDER QNRSFEGMVV AALLAGRALQ GLRRLELASN HFLYLPRDVL AQLPSLRHLD 241 LSNNSLVSLT YVSFRNLTHL ESLHLEDNAL KVLHNGTLAE LQGLPHIRVF LDNNPWVCDC 301 HMADMVTWLK ETEVVQGKDR LTCAYPEKMR NRVLLELNSA DLDCDPILPP SLQTSYVFLG 361 IVLALIGAIF LLVLYLNRKG IKKWMHNIRD ACRDHMEGYH YRYEINADPR LTNLSSNSDV (SEQ ID NO: 27).

[0067] Within the scope of this disclosure, any suitable antigen-binding domain or fragment thereof capable of specifically binding to 5T4 is contemplated, including but not limited to Fab fragments, F(ab')2 fragments, single-chain variable fragments (scFv), scabs, dAbs, single-domain antibodies (sdAbs) (e.g., VHH single-domain antibodies, single-domain heavy chain antibodies, or single-domain light chain antibodies), full-length IgG antibodies, antibody fragments, antigen-binding domains, or fragments containing antigen-binding domains, as further described in detail below. Additionally, full-length antibodies, dual complementary site antibodies, T-cell bispecific antibodies, fusion proteins, and receptors such as chimeric antigen receptors described herein are considered to be within the scope of this disclosure.

[0068] This disclosure provides antibodies comprising the antigen-binding domain specific to the 5T4 antigen described herein. For example, the antibody may be a monoclonal antibody, such as a full-length IgG antibody.

[0069] As used herein, an "antibody" refers to a protein that contains one or more polypeptides encoded substantially or partially by immunoglobulin genes or segments thereof. Recognized immunoglobulin genes include κ, λ, α, γ, δ, ε, and μ constant region genes, as well as numerous immunoglobulin variable region genes. Light chains are classified as κ or λ. Heavy chains are classified as γ, μ, α, δ, or ε, which in turn define the immunoglobulin classes: IgG, IgM, IgA, IgD, and IgE, respectively. Typical immunoglobulin (e.g., antibody) structural units comprise tetramers. Each tetramer consists of two pairs of identical polypeptide chains, each pair having one "light" chain (approximately 25 kD) and one "heavy" chain (approximately 50–70 kD). The N-terminus of each chain defines a variable region, primarily responsible for antigen recognition, having approximately 100 to 110 or more amino acids. The terms variable light chain (VL) and variable heavy chain (VH) refer to these light and heavy chains, respectively. The term "antibody" includes antibody molecules prepared, expressed, generated, or isolated by recombinant means, such as antibodies isolated from host cells transfected to express the antibody. The term "antibody" also includes bispecific antibodies (e.g., T-cell bispecific antibodies) or bicomponent antibodies, which may include heterotetrameric immunoglobulins capable of binding to more than one different epitope. Bispecific antibodies are generally described in U.S. Patent Application Publication No. 2010 / 0331527, which is incorporated herein by reference. The term "antibody" is used herein in the broadest sense and specifically covers intact monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies) formed from at least two intact antibodies, and antibody fragments, provided they exhibit the desired biological activity.

[0070] The term 'antibody' also includes one or more segments of an antibody that retain the ability to bind specifically to an antigen, such as the antibody-binding portion or domain of an antibody, which are sometimes referred to herein as the 'antigen-binding domain' or 'antigen-binding portion'.

[0071] As used herein, the term "antigen-binding domain" or "antigen-binding region" refers to the domain of the antigen-binding moiety responsible for the specific binding between the antigen-binding moiety and the antigen. For example, the antigen-binding region of an antibody or fragment thereof is formed by amino acid residues of the N-terminal variable regions of the heavy chain (abbreviated as VH) and the light chain (abbreviated as VL). The variable regions of VH and VL each contain three hypervariable regions called complementarity-determining regions (CDRs). The three CDRs of VH and the three CDRs of VL are arranged three-dimensionally relative to each other to form an antigen-binding surface. Examples of binding fragments covered within the term "antigen-binding portion" of antibody include (i) Fab fragments, monovalent fragments consisting of VL, VH, CL, and CH1 domains; (ii) F(ab')2 fragments, bivalent fragments comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) Fd fragments consisting of VH and CH1 domains; (iv) Fv fragments consisting of the VL and VH domains of the antibody single arm; (v) dAb fragments (Ward et al. (1989) Nature 241:544-546) consisting of VH domains; (vi) isolated CDRs; and (vii) scFv fragments consisting of the two domains VL and VH of an Fv fragment linked by a synthetic linker to form a single protein chain in which the VL and VH regions pair to form a monovalent molecule. Other forms of single-chain antibodies, such as biantibodies, are also covered under the term “antibody” (see, for example, Holliger et al. (1993) PNAS USA 90:6444-6448; Poljak et al. (1994) Structure 2:1 121-1 123).

[0072] Furthermore, the antibody or its antigen-binding domain can be part of a larger immunoadhesion molecule formed by covalent or non-covalent binding of the antibody or antigen-binding domain to one or more other proteins or peptides. Examples of such immunoadhesion molecules include the preparation of tetrameric scFv molecules using the streptavidin core region (Kipriyanov et al. (1995) Human Antibodies and Hybridomas 6:93-101), and the preparation of divalent and biotinylated scFv molecules using cysteine ​​residues, a labeled peptide, and a C-terminal polyhistidine tag (Kipriyanov et al. (1994) Mol. Immunol. 31: 1047-1058). Antibody fragments, such as Fab and F(ab')2 fragments, can be prepared from intact antibodies using conventional techniques, such as digestion with papain or pepsin. Additionally, antibodies, antibody fragments, and immunoadhesion molecules can be obtained using standard recombinant DNA techniques generally known in the art (see Sambrook et al., 1989).

[0073] The term "human antibody" or "humanized antibody" is intended to include antibodies having variable and constant regions derived from human immunoglobulin sequences. Human antibodies of the present invention may include, for example, amino acid residues in the CDR, and particularly CDR3, that are not encoded by human immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutations in vivo). "Humanized" forms of non-human (e.g., mouse) antibodies are chimeric immunoglobulins, immunoglobulin chains or fragments thereof (e.g., Fv, Fab, Fab′, F(ab′)2, or other antigen-binding sequence of the antibody) containing a minimal sequence derived from a non-human immunoglobulin. In most cases, humanized antibodies are human immunoglobulins (recipient antibodies) in which residues from the recipient's complementarity-determining region (CDR) are replaced with residues from the CDR of a non-human species (donor antibody) having the desired specificity, affinity, and capability, such as mouse, rat, or rabbit. In some cases, Fv framework residues of human immunoglobulins are replaced with corresponding non-human residues. Furthermore, humanized antibodies may contain residues not found in the recipient antibody or the input CDR or frame sequence. These modifications are prepared to further improve and optimize antibody performance. Generally, humanized antibodies will contain at least one, and typically substantially all, of two variable domains, wherein all or substantially all of the CDR regions correspond to those CDR regions of non-human immunoglobulins, and all or substantially all of the FR regions are those FR regions of human immunoglobulin sequences. Humanized antibodies may also contain immunoglobulin constant regions (Fc), typically at least a portion of the Fc constant regions of human immunoglobulins.

[0074] As used herein, the term "recombinant human antibody" is intended to include all human antibodies prepared, expressed, generated, or isolated by recombinant means, such as antibodies expressed using a recombinant expression vector transfected into host cells, antibodies isolated from a recombinant combined human antibody library, antibodies isolated from animals (e.g., mice) that are transgenic for the human immunoglobulin gene, or antibodies prepared, expressed, generated, or isolated by any other means involving splicing of the human immunoglobulin gene sequence with other DNA sequences. Such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences. However, in some embodiments, such recombinant human antibodies are subjected to in vitro mutagenesis (or, when using animals transgenic for the human Ig sequence, in vivo somatic cell mutagenesis), and therefore the amino acid sequences of the VH and VL regions of the recombinant antibody are sequences that, while derived from and associated with human germline VH and VL sequences, may not be naturally present in the in vivo human antibody germline reservoir. The general structure of antibodies is known in the art. Briefly, an immunoglobulin monomer comprises two heavy chains and two light chains linked by disulfide bonds. Each heavy chain pairs with one of the light chains, directly binding to it via disulfide bonds. Each heavy chain contains a constant region (which varies depending on the antibody isotype) and a variable region. The variable region contains three hypervariable regions (or complementarity-determining regions), designated CDRH1, CDRH2, and CDRH3, and is supported within the frame region. Each light chain contains a constant region and a variable region, wherein the variable region contains three hypervariable regions (designated CDRL1, CDRL2, and CDRL3) supported by the frame region, in a manner similar to the variable region of the heavy chain.

[0075] The hypervariable regions of each pair of heavy and light chains cooperate to provide antigen-binding sites capable of binding to the target antigen. The binding specificity of a pair of heavy and light chains is defined by the CDR1, CDR2, and CDR3 sequences of the heavy and light chains. Therefore, once a set of CDR sequences that produces a specific binding specificity (i.e., the CDR1, CDR2, and CDR3 sequences for the heavy and light chains) is determined, in principle, this set of CDR sequences can be inserted into appropriate positions within any other antibody frame region linked to any antibody constant region to provide different antibodies with the same antigen-binding specificity.

[0076] Antibodies or antigen-binding domains exist either as intact immunoglobulins or as a variety of well-characterized fragments produced by digestion with various peptidases. Thus, for example, pepsin digests antibodies below disulfide bonds in the hinge region to produce F(ab′)2, a dimer of Fab, which itself is a light chain linked to VH-CH1 by disulfide bonds. F(ab′)2 can be reduced under mild conditions to break the disulfide bonds in the hinge region, thereby converting the F(ab′)2 dimer into Fab′ monomers. Fab′ monomers are essentially Fab with the hinge region portion. While various antibody fragments are defined according to the digestion of intact antibodies, those skilled in the art will understand that such Fab′ fragments, etc., can be synthesized de novo by chemical methods or by methods utilizing recombinant DNA. Therefore, as used herein, the term antibody also includes antibody fragments produced by modification of intact antibodies or antibody fragments synthesized de novo using recombinant DNA methods.

[0077] Antibody or antigen-binding domains include single-chain antibodies, such as single-chain Fv (sFv or scFv) antibodies, in which variable heavy chains and variable light chains are linked together (directly or through peptide linkers) to form a continuous polypeptide.

[0078] Antibody or antigen-binding domains, including single-domain antibodies, comprise antibody fragments consisting of a single monomeric variable antibody domain capable of selectively binding to an antigen domain. Examples include, but are not limited to, heavy-chain antibodies, antibodies naturally lacking a light chain, single-domain antibodies derived from conventional four-chain antibodies, modified antibodies, and single-domain scaffolds other than those derived from antibodies. A single-domain antibody can be any, or any future, single-domain antibody in the art. Single-domain antibodies can be derived from any species, including but not limited to mice, humans, camels, llamas, goats, rabbits, and cattle.

[0079] As explained above, depending on the specific requirements of the embodiment, the antibody or antigen-binding domains used herein optionally include F(ab)2, F(ab′)2, Fab, Fab′, scFv, single-domain antibodies, etc. Some embodiments use antibodies containing IgG domains. However, other embodiments include alternative immunoglobulins, such as IgM, IgA, IgD, and IgE. Furthermore, all possible isotypes of various immunoglobulins are also covered within the present embodiments. Thus, IgG1, IgG2, IgG3, IgG4, etc., are all possible molecules for the antibody domains used in this invention. In addition to the selection of immunoglobulin and isotype types, different embodiments of the invention may also include various hinge regions (or their functional equivalents). Such hinge regions provide flexibility between different domains of the antibody and, for example, effectors fused to it.

[0080] The antibody or antigen-binding domains disclosed herein include “chimeric” antibody or antigen-binding domains (immunoglobulins) wherein a portion of the heavy chain and / or light chain is identical or homologous to a corresponding sequence in an antibody derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain is identical or homologous to a corresponding sequence in an antibody derived from another species or belonging to another antibody class or subclass, and fragments of such antibodies, provided they exhibit the desired biological activity.

[0081] In some embodiments, the antibodies and antibody-drug conjugates of this disclosure include an antigen-binding domain specific for 5T4, which includes any of the CDRs disclosed in Tables 1-2.

[0082] Table 1. Heavy chain CDR sequences for the 5T4 binding domain

[0083] Table 2. Light chain CDR sequences related to the 5T4 binding domain

[0084] Those skilled in the art will understand that each row in Table 1 discloses three heavy chain CDR sequences, and each row in Table 2 discloses three light chain CDR sequences, which together can bind to 5T4. Therefore, the 5T4-specific antigen-binding domain disclosed herein should be understood in some embodiments to have six CDRs, three concerning the variable heavy domain and three concerning the variable light domain, corresponding to the rows at the same positions in Tables 1 and 2, respectively, identified by numbers on the left. Any combination of CDRs from a row of Table 1 that includes a combination with a row of CDRs from Table 2 is contemplated to be within the scope of the 5T4 antibodies disclosed herein. Furthermore, antibodies that specifically bind to the 5T4 epitope, antigen-binding domains, CDRs, and their sequences can be derived by methods known in the art. For example, the monoclonal antibody to be used herein can be prepared by a hybridoma method first described by Kohler et al., 1975, Nature 256:495, or by a recombinant DNA method (see, for example, U.S. Patent No. 4,816,567). Monoclonal antibodies can also be isolated from phage antibody libraries using techniques described in Clackson et al., 1991, Nature 352:624-628 and Marks et al., 1991, J. Mol. Biol. 222:581-597, such as the sequence of the antibody and the corresponding encoding nucleic acid determined by methods known in the art.

[0085] Bispecific antibodies are antibodies that have binding specificity with respect to at least two different antigens. Bis-complementary-site antibodies are antibodies that bind to two different epitopes of the same antigen. Bispecific antibodies, for example, those that bind to 5T4 using the 5T4 antigen-binding domain as described herein and also bind to other antigens, and bi-complementary-site antibodies that bind to 5T4, are both considered to be within the scope of this disclosure.

[0086] This disclosure provides a dual complementary antibody-drug conjugate having a first antigen-binding domain that binds to a first 5T4 epitope and a second antigen-binding domain that binds to a second 5T4 epitope different from the first 5T4 epitope, wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain. In some embodiments, the first antigen-binding domain is linked to the second antigen-binding domain via a linker.

[0087] Antibodies with more than two valences are also considered to be within the scope of this disclosure. For example, trispecific antibodies can be prepared. See Tutt et al., J. Immunol. 147:60 (1991).

[0088] In some respects, the first antigen-binding domain and the second antigen-binding domain are independently selected from Fab fragments, F(ab')2 fragments, scFv, scab, dAb, single-domain heavy chain antibodies, single-domain light chain antibodies, and full-length IgG antibodies.

[0089] In some aspects, the dual complementary antibody of this disclosure comprises a first antibody, which includes a full-length IgG antibody comprising a first antigen-binding domain. In some aspects, the second antigen-binding domain comprises scFv. In some aspects, the antibody-drug conjugate is tetravalent for binding the 5T4 antigen.

[0090] In some aspects, the 5T4 dual complementary site antibody described herein comprises an scFv. In some embodiments, the antibody-drug conjugate comprises two scFvs, both of which specifically bind to the 5T4 epitope. In some aspects, the scFv comprises a heavy chain and a light chain, wherein the C-terminus of the light chain is operatively linked to the N-terminus of the heavy chain via a adapter, or the C-terminus of the heavy chain is operatively linked to the N-terminus of the light chain via a adapter. In some embodiments, the adapter comprises the sequence of SEQ ID NO: 153.

[0091] In some aspects, the dual complementary site antibody comprises an scFv and a full-length IgG antibody. In some embodiments, the N-terminus of the scFv is operatively linked to the C-terminus of the heavy chain of the full-length IgG antibody. In some aspects, the C-terminus of the scFv is operatively linked to the N-terminus of the heavy chain of the full-length IgG antibody.

[0092] In some respects, the scFv uses a adapter to operatively link to the heavy chain of a full-length IgG antibody. In some respects, the adapter comprises or consists of the amino acid sequence of SEQ ID NO: 152.

[0093] In some aspects of the dual complementary antibody-drug conjugates described herein, the dual complementary antibody includes a full-length IgG antibody comprising a first antigen-binding domain and a second antigen-binding domain comprising scFv, and the antibody-drug conjugate comprises four polypeptides, including two polypeptides comprising a full-length IgG antibody heavy chain, a linker, and a second antigen-binding domain from the N-terminus to the C-terminus; and two polypeptides comprising a full-length IgG antibody light chain.

[0094] In some aspects of antibody-drug conjugates, antibody-drug conjugates include a full-length IgG antibody comprising a first antigen-binding domain and a second antigen-binding domain comprising scFv, and antibody-drug conjugates comprising four polypeptides, including two polypeptides comprising a full-length IgG antibody heavy chain, a linker, and a second antigen-binding domain from the N-terminus to the C-terminus; and two polypeptides comprising a full-length IgG antibody light chain.

[0095] As used herein, “binding affinity” refers to the tendency of one molecule to bind to another molecule (usually non-covalently), such as the tendency of one member of a particular binding pair to bind to the other member of that pair. Binding affinity can be measured as a dissociation constant, which for a particular binding pair (e.g., antibody / antigen pair) can be less than 1 × 10⁻⁶. −5 M, below 1×10 −6 M, below 1×10 −7 M, below 1×10 −8 M, below 1×10 −9 M, below 1×10 −10 M, below 1×10 − 11 M or less than 1×10 −12 M. In one aspect, combining affinity through the work of Frankel et al., Mol. Immunol., The calculations are performed using modifications of the Scatchard method described in 1979, 16:101-106. Alternatively, binding affinity is measured by the binding constant. Another option is to measure binding affinity by the antigen / antibody dissociation rate. Yet another option is to measure high binding affinity using a competitive radioimmunoassay.

[0096] As used herein, the term "dissociation constant" or "KD" (M) refers to the dissociation equilibrium constant of a particular antibody-antigen interaction. In one aspect, KD is determined by surface plasmon resonance (SPR) technology, for example, in a BIAcore 8000 instrument, using the antigen as a ligand and the antibody as the analyte. In other aspects, the antibody binds to a predetermined antigen with an affinity corresponding to a KD that is at most 1 / 10, for example, at most 1 / 100, for example, at most 1 / 1,000, for example, at most 1 / 10,000, for example, at most 1 / 100,000, for example, at most 1 / 100,000. The amount of affinity reduction depends on the antibody's KD, such that when the antibody's KD is very low (i.e., the antibody is highly specific), then the amount by which the affinity for the antigen is lower than the affinity for the nonspecific antigen can be at most 1 / 10,000.

[0097] In some respects, the equilibrium dissociation constant (KD) of the antigen-binding domain for binding to 5T4 is approximately 1 x 10⁻⁶. -12 To approximately 1 x 10 -7 M, approximately 1 x 10 -12 To approximately 1 x 10 -8 M, approximately 1 x 10 -12 To approximately 1 x 10 -9 M, approximately 1 x 10 -11 To approximately 1 x 10 -9 M, or approximately 1 x 10 -11 To approximately 9 x 10 -10 M. In some respects, the antigen-binding domain has a KD of approximately 7.42 x 10⁻⁶ for binding to 5T₄. -11 To approximately 7.75 x 10 -10 M. In some respects, KD is less than or equal to 7.75 x 10 -10 M, for example, less than or equal to 3.20 x 10 -10 M, less than or equal to 1.98 x 10 -10 M, or less than or equal to 7.42 x 10 -11 M. In some respects, the KD for combining 5T4 is approximately 3.63 x 10. -12 From approximately 1.43 x 10 -9 M. In some respects, the KD for combining 5T4 is approximately 3.63 x 10. -12 From approximately 1.34 x 10 -9 M. In some respects, the antigen-binding domain has a KD of approximately 3.63 x 10⁻⁶ for binding to 5T₄. -12 To approximately 1.59 x 10 -11M. In some respects, the KD for combining 5T4 is approximately 7.42 x 10. -11 To approximately 7.75 x 10 - 10 M. In some respects, the KD for combining 5T4 is approximately 7.42 x 10. -11 To approximately 7.75 x 10 -10 M.

[0098] In some aspects of the bicomplementary antibody or bicomplementary antibody-drug conjugate described herein, the equilibrium dissociation constant (KD) for binding 5T4 to at least one of the first or second antigen-binding domains is approximately 1 x 10⁻⁶. -12 To approximately 1 x 10 -7 M, approximately 1 x 10 -12 To approximately 1 x 10 -8 M, approximately 1 x 10 -12 To approximately 1 x 10 -9 M, approximately 1 x 10 -11 To approximately 1 x 10 -9 M, or approximately 1 x 10 -11 To approximately 9 x 10 -10 M. In some respects, the KD for binding 5T4 to at least one of the first antigen-binding domains or the second antigen-binding domain is approximately 7.42 x 10⁻⁶. -11 To approximately 7.75 x 10 -10 M. In some respects, the KD for binding 5T4 to at least one of the first antigen-binding domains or the second antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 To approximately 7.75 x 10 -10 M. In some respects, KD is less than or equal to 7.75 x 10 -10 M, for example, less than or equal to 3.20 x 10 -10 M, less than or equal to 1.98 x 10 -10 M, or less than or equal to 7.42 x 10 -11 M. In some respects, the KD for the binding of the first antibody or antigen-binding domain to 5T4 is approximately 7.42 x 10⁻⁶. -11 To approximately 7.75 x 10 -10 M. In some respects, the KD for binding 5T4 to the first antibody or antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 From approximately 1.43 x 10 -9 M. In some respects, the KD of the first antibody or antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 From approximately 1.34 x 10 -9M. In some respects, the KD of the first antibody or antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 To approximately 1.59 x 10 -11 M. In some respects, the KD for at least the second antibody or antigen-binding domain binding to 5T4 is approximately 7.42 x 10⁻⁶. -11 To approximately 7.75 x 10 -10 M. In some respects, the KD for binding 5T4 to the second antibody or antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 From approximately 1.43 x 10 -9 M. In some respects, the KD of the second antibody or antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 From approximately 1.34 x 10 -9 M. In some respects, the KD of the second antibody or antigen-binding domain is approximately 3.63 x 10⁻⁶. -12 To approximately 1.59 x 10 -11 M. In some respects, the KD for the binding of both the first antibody or antigen-binding domain and at least the second antibody or antigen-binding domain to 5T4 is approximately 7.42 x 10⁻⁴. -11 To approximately 7.75 x 10 -10 M. In some respects, KD is approximately 3.63 x 10 -12 To approximately 7.75 x 10 -10 M. In some respects, KD is approximately 3.63 x 10 -12 To approximately 1.59 x 10 -11 M.

[0099] In some respects, the equilibrium dissociation constant (KD) for antibody binding to Fcγ receptor I containing the antigen-binding domain is less than or equal to about 1.0 x 10⁻⁶. -7 M, for example, less than or equal to approximately 5.0 x 10 -8 M, less than or equal to approximately 4.0 x 10 - 8 M, less than or equal to approximately 3.0 x 10 -8 M, less than or equal to approximately 1.0 x 10 -8 M, less than or equal to approximately 5.0 x 10 -9 M is less than or equal to approximately 1.0 x 10 -9 M. In some respects, KD is less than or equal to approximately 3.96 x 10⁻⁶. -8 M. In some respects, KD is less than 3.73 x 10 -9 M.

[0100] In some respects, the KD for antibody-binding Fcγ receptor IIa containing the antigen-binding domain is less than or equal to about 3.74 x 10⁻⁶. -6 M, for example, less than or equal to approximately 5.0 x 10 -7 M, less than or equal to approximately 1.0 x 10 -7 M, less than or equal to approximately 9.86 x 10 -8 M, less than or equal to approximately 9.15 x 10 -8 M, less than or equal to approximately 5.0 x 10 -8 M is less than or equal to approximately 1.0 x 10 -8 M. In some respects, the KD for antibody-binding Fcγ receptor IIa containing the antigen-binding domain is less than or equal to about 9.15 x 10⁻⁶. -8 M. In some respects, the KD for binding to Fcγ receptor IIa is less than or equal to about 9.86 x 10⁻⁶. -8 M.

[0101] In some respects, the KD for antibody-binding Fcγ receptor IIb containing the antigen-binding domain is less than or equal to about 2.0 x 10⁻⁶. -7 M, for example, less than or equal to approximately 1.16 x 10 -7 M, less than or equal to approximately 1.11 x 10 -7 M, less than or equal to approximately 1.0 x 10 -7 M, less than or equal to approximately 5.0 x 10 -8 M, less than or equal to approximately 1.0 x 10 -8 M is less than or equal to approximately 5.0 x 10 -9 M. In some respects, the KD for binding Fcγ receptor IIb is less than or equal to about 1.16 x 10⁻⁶. -7 M. In some respects, the KD for binding Fcγ receptor IIb is less than or equal to about 1.11 x 10⁻⁶. -7 M.

[0102] In some respects, the KD for antibody-binding Fcγ receptor IIIa containing the antigen-binding domain is less than or equal to about 6.0 x 10⁻⁶. -7 M, for example, less than or equal to approximately 1.0 x 10 -7 M, less than or equal to approximately 7.0 x 10 -8 M, less than or equal to approximately 5.05 x 10 -8 M, less than or equal to approximately 5.0 x 10 -8 M, less than or equal to approximately 1.0 x 10 -8 M, or less than or equal to approximately 5.0 x 10 -9M. In some respects, the KD for binding to Fcγ receptor IIIa is less than or equal to about 6.0 x 10⁻⁶. -8 M. In some respects, the KD for binding to Fcγ receptor IIIa is less than or equal to about 5.05 x 10⁻⁶. -8 M. In some respects, the antibody cannot detectably bind to Fcγ receptor IIIa.

[0103] In some respects, antibodies containing antigen-binding domains cannot detectably bind to Fcγ receptor IIIb.

[0104] In some respects, the equilibrium dissociation constant (KD) for antibody binding to Fcγ receptor I containing at least one of a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to about 1.0 x 10⁻⁶. -7 M, for example, less than or equal to approximately 5.0 x 10 -8 M, less than or equal to approximately 4.0 x 10 -8 M, less than or equal to approximately 3.0 x 10 -8 M, less than or equal to approximately 1.0 x 10 -8 M, less than or equal to approximately 5.0 x 10 -9 M is less than or equal to approximately 1.0 x 10 -9 M. In some respects, KD is less than or equal to approximately 3.96 x 10⁻⁶. -8 M. In some respects, KD is less than 3.73 x 10 -9 M.

[0105] In some respects, the KD of an antibody binding to Fcγ receptor IIa containing at least one of a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to about 3.74 x 10⁻⁶. -6 M, for example, less than or equal to approximately 5.0 x 10 -7 M, less than or equal to approximately 1.0 x 10 -7 M, less than or equal to approximately 9.86 x 10 -8 M, less than or equal to approximately 9.15 x 10 -8 M, less than or equal to approximately 5.0 x 10 -8 M is less than or equal to approximately 1.0 x 10 -8 M. In some respects, the KD for binding to Fcγ receptor IIa is less than or equal to about 9.15 x 10⁻⁶. -8 M. In some respects, the KD for binding to Fcγ receptor IIa is less than or equal to about 9.86 x 10⁻⁶. -8 M. In some respects, the KD for binding Fcγ receptor IIb is less than or equal to about 1.16 x 10⁻⁶. -7 M.

[0106] In some respects, the KD of an antibody binding to Fcγ receptor IIb containing at least one of a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to about 2.0 x 10⁻⁶. -7 M, for example, less than or equal to approximately 1.16 x 10 -7 M, less than or equal to approximately 1.11 x 10 -7 M, less than or equal to approximately 1.0 x 10 -7 M, less than or equal to approximately 5.0 x 10 -8 M, less than or equal to approximately 1.0 x 10 -8 M is less than or equal to approximately 5.0 x 10 -9 M. In some respects, the KD for binding Fcγ receptor IIb is less than or equal to about 1.16 x 10⁻⁶. -7 M. In some respects, the KD for binding Fcγ receptor IIb is less than or equal to about 1.11 x 10⁻⁶. -7 M.

[0107] In some respects, the KD of an antibody binding to Fcγ receptor IIIa containing at least one of a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to about 6.0 x 10⁻⁶. -7 M, for example, less than or equal to approximately 1.0 x 10 -7 M, less than or equal to approximately 7.0 x 10 -8 M, less than or equal to approximately 5.05 x 10 -8 M, less than or equal to approximately 5.0 x 10 -8 M, less than or equal to approximately 1.0 x 10 -8 M, or less than or equal to approximately 5.0 x 10 -9 M. In some respects, the KD for binding to Fcγ receptor IIIa is less than or equal to about 6.0 x 10⁻⁶. -8 M. In some respects, the KD for binding to Fcγ receptor IIIa is less than or equal to about 5.05 x 10⁻⁶. -8 M. In some respects, the antibody cannot detectably bind to Fcγ receptor IIIa.

[0108] In some respects, antibodies containing at least one of a first antigen-binding domain and / or a second antigen-binding domain cannot detectably bind to Fcγ receptor IIIb.

[0109] In some respects, the first and second antibodies bind to different 5T4 molecules on the surface of different cancer cells. In some respects, the first and second antibodies bind to different 5T4 molecules on the surface of the same cancer cell. In some respects, the first and second antibodies bind to the same 5T4 molecules on the surface of cancer cells. In some respects, the first and second 5T4 epitopes are non-overlapping epitopes.

[0110] Fc effector function In some implementations, site mutations in the Fc region of the antibody-drug conjugate mitigate potential side effects caused by antibody effector functions, such as binding affinity at least to the Fcγ receptor (FcγR). It is not desirable to be bound by theory, but it is thought that binding to the Fcγ receptor can induce activation or inhibition of immune system pathways, such as antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent phagocytosis (ADCP), and complement-dependent cytotoxicity (CDC).

[0111] In some embodiments, the antibody-drug conjugates described herein comprise a full-length IgG antibody. In some embodiments, the full-length IgG antibody comprises a constant region (Fc) domain. In some embodiments, such as those where the antibody-drug conjugate comprises an IgG Fc domain, the Fc domain is an IgG1 isotype constant region domain. In some embodiments, the IgG1 constant region domain comprises at least one mutation that reduces effector function, prolongs half-life, or a combination thereof. In some embodiments, the antibody-drug conjugates disclosed herein comprise an Fc mutation that reduces binding affinity to the Fcγ receptor. In some embodiments, the Fc mutation reduces binding affinity to Fcγ receptors including FcγRI. In some embodiments, the Fc mutation reduces binding affinity to Fcγ receptors including FcγRII. In some embodiments, the Fc mutation reduces binding affinity to Fcγ receptors including FcγRIII. In some embodiments, the Fc mutation of the antibody-drug conjugate reduces binding affinity against FcγRI compared to a 5T4 antibody without the Fc mutation. In some embodiments, at least one mutation includes F (L234F) at position 237 relative to SEQ ID NO: 100, C or A (S239C / A) at position 242 relative to SEQ ID NO: 100, or a combination thereof.

[0112] In some implementations, Fc site mutations that reduce binding affinity for FcγRI include L234F and S239C, or S239A.

[0113] In some embodiments, the Fc domain may be an IgG1 isotype constant region domain. In some embodiments, the IgG1 constant region domain contains at least one mutation that reduces effector function, prolongs half-life, or a combination thereof. In some embodiments, mutations in the IgG1 constant region domain prolong the half-life of the antibody-drug conjugate. Fc mutations in the antibody-drug conjugate can prolong the half-life of the antibody-drug conjugate. In some embodiments, at least one mutation includes a mutation (N434) at position 437 relative to SEQ ID NO: 100. In some embodiments, at least one mutation, wherein the mutation includes an A (N434A) at position 437 relative to SEQ ID NO: 100. These amino acids are indicated in bold and underlined in Table 5 below. In some embodiments, the antibody-drug conjugate contains at least one mutation that prolongs the half-life of the antibody-drug conjugate, wherein the at least one mutation includes a mutation at position 437, wherein the mutation further includes an A (N434A) at position 437 relative to SEQ ID NO: 100. In some embodiments, the antibody-drug conjugate comprises a mutation that prolongs the half-life of the antibody-drug conjugate, wherein said mutation comprises a mutation at position 437, and said mutation further comprises A (N434A) at position 437 relative to SEQ ID NO: 100. In some embodiments, the antibody-drug conjugate comprises a mutation that prolongs the half-life of the antibody-drug conjugate, wherein said mutation comprises a mutation at position 437, and said mutation further comprises A (N434A) at position 437 relative to SEQ ID NO: 100.

[0114] Table 3. Summary of the equilibrium dissociation constant (KD) for the binding of exemplary antibody-drug conjugates to selected Fcγ receptors (FcγRs).

[0115] In some respects, the antibody-drug conjugates disclosed herein comprise monoclonal antibodies. In some respects, the monoclonal antibody binds to only a single 5T4 epitope. In some respects, the monoclonal antibody comprises only a primary antibody; that is, it is not a bispecific antibody. In some respects, the monoclonal antibody binds to only a single epitope; that is, it is not a double complementary site antibody.

[0116] In some respects, the antibodies disclosed herein are bispecific or bicomplementary monoclonal antibodies. In some respects, the antibodies comprise a first antigen-binding domain (e.g., scFv) and a second antigen-binding domain (e.g., a full-length IgG antibody). In some respects, the antibodies comprise a first antigen-binding domain that binds to a first 5T4 epitope and a second antigen-binding domain that binds to a second 5T4 epitope.

[0117] In some respects, the antibody comprises a first antigen-binding domain that binds to the 5T4 epitope and a second antigen-binding domain that binds to a second antigen (e.g., an antigen expressed by cancer cells). Suitable cancer antigens and antigen-binding domains that bind to these antigens are known to those skilled in the art and include, for example, B cell maturation antigen (BCMA), CD19 molecule (CD19), CD20, CD30, CD33, CD38, CD44, CD123, CD138, cell adhesion molecule (CEA), C-type lectin domain family 12 member A (CLEC12A), chorionic chorionic villus factor 1 (CS-1), epidermal growth factor receptor (EGFR), EGFRvIII, epithelial cell adhesion molecule (EPCAM), delta-like classical Notch ligand 3 (DLL3), leucine-rich G protein-coupled receptor 5 (LGR5), mesothelin (MSLN), programmed death ligand 1 (PD-L1), folate receptor α (FOLR1), folate receptor γ (FOLR3), and erb-b2 receptor tyrosine kinase 2. (ERBB2 or HER2), HER3, bone marrow stromal cell antigen 2 (HM1.24), sperm mitochondrial-associated cysteine-rich protein (MCSP), and prostate-specific membrane antigen (PSMA). Alternatively, the bispecific antibodies disclosed herein are T-cell bispecific (TCB) antibodies. In these cases, the second antigen is expressed by T cells, such as CD3e antigen, and the bispecific antibodies described herein help recruit and bind T cells in the presence of 5T4-positive cancer cells.

[0118] In some embodiments, the antigen-binding domain of this disclosure includes an antigen-binding domain specific for 5T4, which includes any CDR disclosed in Tables 1-2. Exemplary variable heavy and light chains of the antigen-binding domain of this disclosure incorporated with CDRs disclosed in Tables 1-2 are provided in Table 4 below.

[0119] Table 4. 5T4 heavy and light chain sequences

[0120] Table 5 below provides exemplary full-length heavy and light chains (HC: heavy chain; LC: light chain) of the antigen-binding domain of this disclosure. In Table 5, the complete sequence of the heavy chain of the first antibody (full-length IgG1 antibody) is in italics, and mutations in the constant region are underlined. The first linker is underlined, and the VH and VL sequences of the second antibody (scFv) are in bold and linked by their italicized and underlined linkers.

[0121] Table 5. Full-length amino acid sequences of the anti-5T4 heavy and light chains

[0122] Tables 6 and 7 provide nucleotide sequences encoding exemplary CDRs for the 5T4 antigen-binding domain of this disclosure.

[0123] Table 6. Exemplary anti-5T4 heavy chain CDR nucleotide sequences

[0124] Table 7. Exemplary anti-5T4 light chain CDR nucleotide sequences

[0125] Table 8 provides additional humanized variable heavy and light chain amino acid sequences for the 5T4 antigen-binding domain of this disclosure. In Table 8, the CDR sequence is in bold.

[0126] Table 8. Amino acid sequences of the variable heavy and light chains resisting 5T4 humanization

[0127] Those skilled in the art will understand that the 5T4 antigen-binding domain may comprise any combination of the variable heavy and variable light domains disclosed in Table 8 or 9. Alternatively, the 5T4 antigen-binding domain may comprise a specific pair of variable heavy and variable light domains identified by the numbers in the left column of Table 8 or 9.

[0128] Table 9 provides additional mouse variable heavy and light chain amino acid sequences for the 5T4 antigen-binding domain of this disclosure. Those skilled in the art will understand that the mouse variable heavy and light domains may be humanized.

[0129] Table 9. Amino acid sequences of the variable heavy and light chains in anti-5T4 mice

[0130] This disclosure provides antigen-binding domains, antibodies, bispecific antibodies (e.g., T-cell bispecific antibodies), antibody-drug conjugates, and chimeric receptors (CARs) comprising antigen-binding domains including variable heavy domains paired with any variable light chain domain listed in Tables 8 and 9. In some embodiments, the antibody or antibody-drug conjugate comprises a bicomponent antibody comprising a first antigen-binding domain specifically binding to a first 5T4 epitope, a second antigen-binding domain specifically binding to a second 5T4 epitope different from the first 5T4 epitope (wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain), and a chemotherapeutic agent. In some embodiments, the first antigen-binding domain and / or the second antigen-binding domain comprises any variable heavy domain paired with any variable light chain domain listed in Tables 8 and 9.

[0131] This document provides antibody-drug conjugates that bind to at least one epitope of the 5T4 protein. In some embodiments, the antibody-drug conjugate binds to one epitope of the 5T4 antigen. In some embodiments, the antibody-drug conjugate binds to two epitopes of the 5T4 antigen.

[0132] In some embodiments, the antibody-drug conjugate comprises a first antigen-binding domain that specifically binds to a first 5T4 epitope; and a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain. In some embodiments, the first and second antigen-binding domains are independently selected from Fab fragments, F(ab')2 fragments, scFv, scab, dAb, single-domain heavy chain antibodies, single-domain light chain antibodies, and full-length IgG antibodies. In some embodiments, the first antigen-binding domain comprises a full-length IgG antibody. In some embodiments, the full-length IgG antibody comprises two heavy chains and two light chains. In some embodiments of the antibody-drug conjugates disclosed herein, the second antigen-binding domain comprises scFv. In some embodiments, the antibody-drug conjugate comprises two second antigen-binding domains scFv, both of which specifically bind to the second 5T4 epitope.

[0133] In some embodiments, the scFv comprises a heavy chain and a light chain. In some embodiments, the C-terminus of the light chain is operatively connected to the N-terminus of the heavy chain via a connector, or the C-terminus of the heavy chain is operatively connected to the N-terminus of the light chain via a connector. In some embodiments, the connector connecting the heavy chain and the light chain comprises the sequence of SEQ ID NO: 153.

[0134] In some embodiments, the N-terminus of the second antigen-binding domain is operatively linked to the C-terminus of the heavy chain of the first antigen-binding domain. In some embodiments, the C-terminus of the second antigen-binding domain is operatively linked to the N-terminus of the heavy chain of the first antigen-binding domain. In some embodiments, the second antigen-binding domain is operatively linked to the heavy chain of the first antigen-binding domain using a linker. In some embodiments, the linker comprises or consists of the amino acid sequence of SEQ ID NO: 152.

[0135] Antibody constant region domain Antibodies, including monoclonal antibodies comprising full-length IgG antibodies, bispecific antibodies, and antibodies with dual complementary sites, are considered to be within the scope of this disclosure. In some embodiments, the full-length IgG antibody comprises two heavy chains and two light chains, each comprising a variable region domain and a constant region domain, as described in more detail below. Those skilled in the art will understand that monoclonal antibodies comprising full-length IgG antibodies having the variable and constant domain arrangements described below, as well as bispecific antibodies and antibodies with dual complementary sites, are considered to be within the scope of this disclosure.

[0136] In some embodiments, the constant region domain is an IgG1 isotype constant region domain. In some embodiments, the constant region domain comprises the amino acid sequence of SEQ ID NO: 148.

[0137] In some embodiments, the antibody light chain includes a variable region domain and a constant region domain. In some embodiments, the constant region domain is an IgG1 isotype constant region domain. In some embodiments, the light chain contains an IgG1 isotype constant region domain comprising the amino acid sequence of SEQ ID NO: 149.

[0138] In some embodiments, such as those in which the antibody comprises an IgG1 constant region domain, the IgG1 constant region domain comprising at least one mutation that reduces effector function, prolongs half-life, or a combination thereof.

[0139] In some embodiments, at least one mutation includes F (L234F) at position 237 relative to SEQ ID NO: 100, C or A (S239C / A) at position 242 relative to SEQ ID NO: 100, A (N434A) at position 437 relative to SEQ ID NO: 100, or a combination thereof. In some embodiments, the constant region domain includes F (L234F) at position 237 relative to SEQ ID NO: 100, C or A (S239C / A) at position 242 relative to SEQ ID NO: 100, and A (N434A) at position 437 relative to SEQ ID NO: 100. In some embodiments, at least one mutation includes F (L234F) at position 237 relative to SEQ ID NO: 100. In some embodiments, at least one mutation includes C or A (S239C / A) at position 242 relative to SEQ ID NO: 100. In some embodiments, at least one mutation is contained in C (S239C / A) at position 242 relative to SEQ ID NO: 100. In some embodiments, at least one mutation is contained in A (S239C / A) at position 242 relative to SEQ ID NO: 100. In some embodiments, at least one mutation is contained in A (N434A) at position 437 relative to SEQ ID NO: 100.

[0140] In some embodiments, the antibody heavy chain includes a constant region domain comprising the amino acid sequence of SEQ ID NO: 148, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antibody light chain includes a constant region domain comprising the amino acid sequence of SEQ ID NO: 149, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antibody heavy chain includes a constant region domain comprising the amino acid sequence of SEQ ID NO: 148, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and the first antibody light chain includes a constant region domain comprising the amino acid sequence of SEQ ID NO: 149, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0141] In some embodiments, the antibody heavy chain includes a constant region domain containing the amino acid sequence of SEQ ID NO: 148. In some embodiments, the antibody light chain includes a constant region domain containing the amino acid sequence of SEQ ID NO: 149. In some embodiments, the antibody heavy chain includes a constant region domain containing the amino acid sequence of SEQ ID NO: 148; and the first antibody light chain includes a constant region domain containing the amino acid sequence of SEQ ID NO: 149.

[0142] In some embodiments of the antibody-drug conjugates disclosed herein, the antibody-drug conjugate includes a full-length IgG antibody comprising a first antigen-binding domain and a second antigen-binding domain comprising scFv. In some embodiments, the antibody-drug conjugate comprises four polypeptides. In some embodiments, the antibody-drug conjugate comprises two polypeptides comprising an IgG antibody heavy chain, a linker, and a second antigen-binding domain from the N-terminus to the C-terminus. In some embodiments, the antibody-drug conjugate comprises four polypeptides: (a) two polypeptides comprising a full-length IgG antibody heavy chain, a linker, and a second antigen-binding domain from the N-terminus to the C-terminus; and (b) two polypeptides comprising a full-length IgG antibody light chain. In some embodiments, the linker connecting the full-length IgG antibody heavy chain and the second antigen-binding domain comprises the amino acid sequence of SEQ ID NO: 152.

[0143] In some embodiments of the antibody-drug conjugates disclosed herein, the antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain and a second antigen-binding domain containing scFv, and the antibody-drug conjugate comprises two polypeptides that contain a second antigen-binding domain, a linker, and a full-length IgG antibody heavy chain from the N-terminus to the C-terminus. In some embodiments, the first antigen-binding domain comprises a full-length IgG antibody and the second antigen-binding domain comprises scFv, and the antibody-drug conjugate comprises four polypeptides: (a) two polypeptides containing a second antigen-binding domain, a linker, and a heavy chain of the first antigen-binding domain from the N-terminus to the C-terminus; and (b) two polypeptides containing a light chain of the first antigen-binding domain. In some embodiments, the linker connecting the second antigen-binding domain and the heavy chain of the first antigen-binding domain comprises the amino acid sequence of SEQ ID NO: 152.

[0144] Heavy chain CDR In some embodiments, the antigen-binding domains described herein, as well as antibodies, antibody-drug conjugates, and receptors containing them, comprise a heavy chain (HC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 1, 4, and 13-23, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; an HC CDR2 sequence selected from SEQ ID NO: 2, 5, and 24-26 and 28-39, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; and an HC CDR3 sequence selected from SEQ ID NO: 3, 6, and 40-52, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto.

[0145] In some embodiments, the antigen-binding domain described herein comprises a heavy chain (HC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 1, 4 and 13-23; an HC CDR2 sequence selected from SEQ ID NO: 2, 5, 24-26 and 28-39; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3.

[0146] In some embodiments, the antigen-binding domain described herein comprises a heavy chain (HC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 1, 4 and 13-23; an HC CDR2 sequence selected from SEQ ID NO: 2, 5, 24-26 and 28-39; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3, 6 and 40-52.

[0147] In some embodiments, the antibodies and antibody-drug conjugates described herein include a first antigen-binding domain and at least a second antigen-binding domain, wherein the first antigen-binding domain and / or the second antigen-binding domain comprises a heavy chain containing a heavy chain (HC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 1, 4, and 13-23, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; an HC CDR2 sequence selected from SEQ ID NO: 2, 5, and 24-26 and 28-39, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; and an HC CDR3 sequence selected from SEQ ID NO: 3, 6, and 40-52, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto, wherein one or more of the CDR1, CDR2, and CDR3 sequences are not identical between the first antigen-binding domain and the second antigen-binding domain.

[0148] In some embodiments, the antibodies and antibody-drug conjugates described herein include a first antigen-binding domain and at least a second antigen-binding domain, wherein the first antigen-binding domain and / or the second antigen-binding domain comprises a heavy chain containing a heavy chain (HC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 1, 4, and 13-23; an HC CDR2 sequence selected from SEQ ID NO: 2, 5, 24-26, and 28-39; and an HCCDR3 sequence selected from SEQ ID NO: 3, 6, and 40-52, wherein one or more of the CDR1, CDR2, and CDR3 sequences are distinct between the first antigen-binding domain and the second antigen-binding domain.

[0149] In some embodiments, the antibodies and antibody-drug conjugates described herein comprise an antigen-binding domain comprising a heavy chain (HC) complementarity-determining region (CDR1) sequence selected from any heavy chain CDR1 (CDRH1) sequence listed in Table 1; an HC CDR2 sequence selected from any heavy chain CDR2 (CDRH2) sequence listed in Table 1; and an HC CDR3 sequence selected from any heavy chain CDR3 (CDRH3) sequence listed in Table 1.

[0150] Those skilled in the art will understand that the antigen-binding domains, antibodies, antibody-drug conjugates, and receptors of this disclosure may comprise heavy chains containing any CDRH1, CDRH2, or CDRH3 sequences listed in Table 1. In some embodiments, the heavy chain may comprise a combination of one CDRH1, one CDRH2, and one CDRH3 within a single row of Table 1. In some embodiments, the antibody-drug conjugate may comprise a heavy chain comprising a combination of one CDRH1, one CDRH2, and one CDRH3, wherein said CDRH1, CDRH2, and CDRH3 are not in the same row of Table 1. Those skilled in the art will understand that the antibody-drug conjugates of this disclosure may comprise heavy chains containing any CDRH1 sequence listed in Table 1 in combination with any CDRH2 sequence listed in Table 1, any CDRH3 sequence listed in Table 1, or any CDRH1 sequence listed in Table 1.

[0151] In some implementations, the heavy chain variable region structural domain includes: (a) HCCDR1 containing SEQ ID NO: 1, HCCDR2 containing SEQ ID NO: 2, and HCCDR3 containing SEQ ID NO: 3; (b) HCCDR1 containing SEQ ID NO: 4, HCCDR2 containing SEQ ID NO: 5, and HCCDR3 containing SEQ ID NO: 6; (c) HCCDR1 containing SEQ ID NO: 4, HCCDR2 containing SEQ ID NO: 24, and HCCDR3 containing SEQ ID NO: 40; (d) HCCDR1 containing SEQ ID NO: 13, HCCDR2 containing SEQ ID NO: 25, and HCCDR3 containing SEQ ID NO: 41; (e) HCCDR1 containing SEQ ID NO: 14, HCCDR2 containing SEQ ID NO: 26, and HCCDR3 containing SEQ ID NO: 42; (f) HCCDR3 containing SEQ ID NO: 15. CDR1, HC CDR2 containing SEQ ID NO: 28, and HC CDR3 containing SEQ ID NO: 43; (g) HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 29, and HC CDR3 containing SEQ ID NO: 44; (h) HC CDR1 containing SEQ ID NO: 16, HC CDR2 containing SEQ ID NO: 30, and HC CDR3 containing SEQ ID NO: 45; (i) HC CDR1 containing SEQ ID NO: 17, HC CDR2 containing SEQ ID NO: 31, and HC CDR3 containing SEQ ID NO: 46; (j) HC CDR1 containing SEQ ID NO: 18, HC CDR2 containing SEQ ID NO: 32, and HC CDR3 containing SEQ ID NO: 47; (k) HC CDR1 containing SEQ ID NO: 19, HC CDR2 containing SEQ ID NO: 33, and HC CDR3 containing SEQ ID NO: 44. HC CDR3 of SEQ ID NO: 48; (l) containing HC CDR1 of SEQ ID NO: 20, HC CDR2 of SEQ ID NO: 34 and HC CDR3 of SEQ ID NO: 49; (m) containing HC CDR1 of SEQ ID NO: 4, HC CDR2 of SEQ ID NO: 35 and HC CDR3 of SEQ ID NO: 50;(n) HCCDR1 containing SEQ ID NO: 14, HCCDR2 containing SEQ ID NO: 36, and HCCDR3 containing SEQ ID NO: 51; (o) HCCDR1 containing SEQ ID NO: 15, HCCDR2 containing SEQ ID NO: 37, and HCCDR3 containing SEQ ID NO: 3; (p) HCCDR1 containing SEQ ID NO: 21, HCCDR2 containing SEQ ID NO: 38, and HCCDR3 containing SEQ ID NO: 3; (q) HCCDR1 containing SEQ ID NO: 22, HCCDR2 containing SEQ ID NO: 39, and HCCDR3 containing SEQ ID NO: 45; or (r) HCCDR1 containing SEQ ID NO: 23, HCCDR2 containing SEQ ID NO: 32, and HCCDR3 containing SEQ ID NO: 52.

[0152] Light chain CDR In some embodiments, the antigen-binding domains described herein, as well as antibodies, antibody-drug conjugates, and receptors containing them, comprise a light chain (LC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 7, 10, and 53-66, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; an LC CDR2 sequence selected from SEQ ID NO: 8, 11, and 67-75, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; and an LC CDR3 sequence selected from SEQ ID NO: 9, 12, and 76-83, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto.

[0153] In some embodiments, the antibody-drug conjugates described herein comprise a first antigen-binding domain and a second antigen-binding domain, wherein the first antigen-binding domain and / or the second antigen-binding domain comprises a light chain (LC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 7, 10, and 53-66, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thererelative to it; an LC CDR2 sequence selected from SEQ ID NO: 8, 11, and 67-75, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thererelative to it; or an LC CDR3 sequence selected from SEQ ID NO: 9, 12, and 76-83, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thererelative to it, wherein one or more of the CDR1, CDR2, and CDR3 sequences are not identical between the first antigen-binding domain and the second antigen-binding domain.

[0154] In some embodiments, the antibody-drug conjugates described herein comprise a first antigen-binding domain and a second antigen-binding domain, wherein the first antigen-binding domain and / or the second antigen-binding domain comprises a light chain (LC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 7, 10, and 53-66; an LC CDR2 sequence selected from SEQ ID NO: 8, 11, and 67-75; and an LC CDR3 sequence selected from SEQ ID NO: 9, 12, and 76-83, wherein one or more of the CDR1, CDR2, and CDR3 sequences are distinct between the first antigen-binding domain and the second antigen-binding domain.

[0155] In some embodiments, the first antigen-binding domain includes a heavy chain variable region domain comprising an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto.

[0156] In some embodiments, the first antigen-binding domain includes a light chain variable region domain comprising an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions thereto.

[0157] In some embodiments, the first antigen-binding domain includes a heavy chain variable region domain comprising an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3. In some embodiments, the first antigen-binding domain includes a light chain variable region domain comprising an LCCDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LCCDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; and an LCCDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9.

[0158] In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain, which includes an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and a light chain variable region domain, which includes an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9.

[0159] In some embodiments of the antibody-drug conjugate, the first antigen-binding domain comprises a heavy chain variable region domain comprising an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and a light chain variable region domain comprising an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 12.

[0160] In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain, which includes an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain, which includes an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 12.

[0161] In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain, which includes an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and a light chain variable region domain, which includes an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9; and the second antigen-binding domain comprises a heavy chain variable region domain, which includes an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6; and a light chain variable region domain, which includes an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 11. The CDR2 sequence; and the LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 12.

[0162] In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain including an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and a light chain variable region domain including an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 12; and the second antigen-binding domain comprises a heavy chain variable region domain including an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6; and a light chain variable region domain including an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9. The CDR2 sequence; and the LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 9.

[0163] Those skilled in the art will understand that the antigen-binding domains, antibodies, antibody-drug conjugates, and receptors comprising the present disclosure may comprise light chains comprising any CDRL1, CDRL2, or CDRL3 sequences listed in Table 2. In some embodiments, the light chain may comprise a combination of one CDRL1, one CDRL2, and one CDRL3 within a single row of Table 2. In some embodiments, the antigen-binding domain comprises a light chain comprising a combination of one CDRL1, one CDRL2, and one CDRL3, wherein said CDRL1, CDRL2, and CDRL3 are not in the same row of Table 2. Those skilled in the art will understand that the antigen-binding domains of the present disclosure may comprise light chains comprising any CDRL1 sequence listed in Table 2 in combination with any CDRL2 sequence listed in Table 2, any CDRL3 sequence listed in Table 2, or any CDRL1 sequence listed in Table 2.

[0164] In some embodiments, the antigen-binding domain includes a light chain variable region domain, comprising: (a) LC CDR1 comprising SEQ ID NO: 7, LC CDR2 comprising SEQ ID NO: 8, and LC CDR3 comprising SEQ ID NO: 9; (b) LC CDR1 comprising SEQ ID NO: 10, LC CDR2 comprising SEQ ID NO: 11, and LC CDR3 comprising SEQ ID NO: 12; (c) LC CDR1 comprising SEQ ID NO: 53, LC CDR2 comprising SEQ ID NO: 11, and LC CDR3 comprising SEQ ID NO: 76; (d) LC CDR1 comprising SEQ ID NO: 54, LC CDR2 comprising SEQ ID NO: 67, and LC CDR3 comprising SEQ ID NO: 77; (e) LC CDR1 comprising SEQ ID NO: 55, LC CDR2 comprising SEQ ID NO: 68, and LC CDR3 comprising SEQ ID NO: 78; (f) comprising SEQ ID NO: 9. (g) LC CDR1 containing SEQ ID NO: 56, LC CDR2 containing SEQ ID NO: 69, and LC CDR3 containing SEQ ID NO: 79; (h) LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; (i) LCCDR1 containing SEQ ID NO: 59, LC CDR2 containing SEQ ID NO: 70, and LC CDR3 containing SEQ ID NO: 80; (j) LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71, and LC CDR3 containing SEQ ID NO: 81; (k) LC CDR1 containing SEQ ID NO: 61, LC CDR2 containing SEQ ID NO: 72, and LC CDR3 containing SEQ ID NO: 79 ... CDR2 and LC CDR3 containing SEQ ID NO: 77; (l) LC CDR1 containing SEQ ID NO: 62, LC CDR2 containing SEQ ID NO: 70 and LCCDR3 containing SEQ ID NO: 82; (m) LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 73 and LC CDR3 containing SEQ ID NO: 12;(n) LC CDR1 containing SEQ ID NO: 63, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; (o) LC CDR1 containing SEQ ID NO: 64, LC CDR2 containing SEQ ID NO: 68, and LC CDR3 containing SEQ ID NO: 78; (p) LC CDR1 containing SEQ ID NO: 65, LC CDR2 containing SEQ ID NO: 74, and LC CDR3 containing SEQ ID NO: 9; (q) LC CDR1 containing SEQ ID NO: 66, LC CDR2 containing SEQ ID NO: 75, and LC CDR3 containing SEQ ID NO: 9; (q) LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; or (s) LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 63, LC CDR3 containing SEQ ID NO: 64, LC CDR2 containing SEQ ID NO: 68, and LC CDR3 containing SEQ ID NO: 78; (p) LC CDR1 containing SEQ ID NO: 65, LC CDR2 containing SEQ ID NO: 75, and LC CDR3 containing SEQ ID NO: 9; (q) LC CDR1 containing SEQ ID NO: 66, LC CDR2 containing SEQ ID NO: 75, and LC CDR3 containing SEQ ID NO: 9; (s) LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 64, LC CDR3 containing SEQ ID NO: 65, LC CDR2 containing SEQ ID NO: 66, and LC CDR3 containing SEQ ID NO: 66; LC CDR2 containing SEQ ID NO: 71 and LC CDR3 containing SEQ ID NO: 83.

[0165] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 1, HC CDR2 containing SEQ ID NO: 2, and HC CDR3 containing SEQ ID NO: 3, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 7, LC CDR2 containing SEQ ID NO: 8, and LC CDR3 containing SEQ ID NO: 9.

[0166] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 5, and HC CDR3 containing SEQ ID NO: 6, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 11, and LCCDR3 containing SEQ ID NO: 12.

[0167] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 24, and HC CDR3 containing SEQ ID NO: 40, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 53, LC CDR2 containing SEQ ID NO: 11, and LCCDR3 containing SEQ ID NO: 76.

[0168] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 13, HC CDR2 containing SEQ ID NO: 25, and HC CDR3 containing SEQ ID NO: 41, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 54, LC CDR2 containing SEQ ID NO: 67, and LCCDR3 containing SEQ ID NO: 77.

[0169] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 14, HC CDR2 containing SEQ ID NO: 26, and HC CDR3 containing SEQ ID NO: 42, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 55, LC CDR2 containing SEQ ID NO: 68, and LCCDR3 containing SEQ ID NO: 78.

[0170] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 28, and HC CDR3 containing SEQ ID NO: 43, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 56, LC CDR2 containing SEQ ID NO: 69, and LCCDR3 containing SEQ ID NO: 79.

[0171] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 29, and HC CDR3 containing SEQ ID NO: 44, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 57, LC CDR2 containing SEQ ID NO: 69, and LCCDR3 containing SEQ ID NO: 79.

[0172] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 16, HC CDR2 containing SEQ ID NO: 30, and HC CDR3 containing SEQ ID NO: 45, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LCCDR3 containing SEQ ID NO: 76.

[0173] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 17, HC CDR2 containing SEQ ID NO: 31, and HC CDR3 containing SEQ ID NO: 46, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 59, LC CDR2 containing SEQ ID NO: 70, and LCCDR3 containing SEQ ID NO: 80.

[0174] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 18, HC CDR2 containing SEQ ID NO: 32, and HC CDR3 containing SEQ ID NO: 47, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71, and LCCDR3 containing SEQ ID NO: 81.

[0175] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 19, HC CDR2 containing SEQ ID NO: 33, and HC CDR3 containing SEQ ID NO: 48, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 61, LC CDR2 containing SEQ ID NO: 72, and LCCDR3 containing SEQ ID NO: 77.

[0176] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 20, HC CDR2 containing SEQ ID NO: 34, and HC CDR3 containing SEQ ID NO: 49, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 62, LC CDR2 containing SEQ ID NO: 70, and LCCDR3 containing SEQ ID NO: 82.

[0177] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 35, and HC CDR3 containing SEQ ID NO: 50, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 73, and LC CDR3 containing SEQ ID NO: 12.

[0178] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 5, and HC CDR3 containing SEQ ID NO: 6, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 63, LC CDR2 containing SEQ ID NO: 11, and LCCDR3 containing SEQ ID NO: 76.

[0179] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 14, HC CDR2 containing SEQ ID NO: 36, and HC CDR3 containing SEQ ID NO: 51, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 64, LC CDR2 containing SEQ ID NO: 68, and LCCDR3 containing SEQ ID NO: 78.

[0180] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 37, and HC CDR3 containing SEQ ID NO: 3, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 65, LC CDR2 containing SEQ ID NO: 74, and LCCDR3 containing SEQ ID NO: 9.

[0181] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 21, HC CDR2 containing SEQ ID NO: 38, and HC CDR3 containing SEQ ID NO: 3, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 66, LC CDR2 containing SEQ ID NO: 75, and LCCDR3 containing SEQ ID NO: 9.

[0182] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 22, HC CDR2 containing SEQ ID NO: 39, and HC CDR3 containing SEQ ID NO: 45, and the light chain variable region includes LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76.

[0183] In some embodiments, the heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 23, HC CDR2 containing SEQ ID NO: 32, and HC CDR3 containing SEQ ID NO: 52, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71, and LCCDR3 containing SEQ ID NO: 83.

[0184] Heavy chain variable region domain In some embodiments of the antigen-binding domain disclosed herein, and antibodies, antibody-drug conjugates, and receptors comprising the antigen-binding domain, the antigen-binding domain comprises at least one heavy chain variable region domain comprising a sequence selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 169, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences. In some embodiments, the antigen-binding domain comprises a single heavy chain variable region domain comprising a sequence selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 169, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

[0185] In some embodiments, the antibody or antibody-drug conjugate comprises at least two heavy chain variable region domains, each comprising a sequence independently selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 169, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences. In some embodiments, the antibody or antibody-drug conjugate comprises two heavy chain variable region domains, each containing a sequence independently selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 169, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences. In some embodiments, the two heavy chain variable region domains are not identical. In some embodiments, the antibody or antibody-drug conjugate comprises more than two heavy chain variable region domains, which include sequences selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 169, 170, and 172, or sequences having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with those sequences.

[0186] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0187] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0188] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:102, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0189] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:104, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0190] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:106, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0191] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:108, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0192] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:112, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0193] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:114, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0194] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:116, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0195] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:118, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0196] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:120, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0197] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:122, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0198] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:124, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0199] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:126, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0200] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:128, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0201] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:132, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0202] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:134, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0203] In some embodiments, the antibody-drug conjugate comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:136, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0204] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:138, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0205] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:140, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0206] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:156, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0207] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:158, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0208] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:160, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0209] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:162, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0210] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:164, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0211] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:166, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0212] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:168, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0213] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:170, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0214] In some embodiments, the antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO:172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0215] In some embodiments, such as those in which the antigen-binding domain is incorporated into a dual complementary antibody or antibody-drug conjugate, the first antigen-binding domain and / or the second antigen-binding domain comprises a heavy chain variable region domain comprising a sequence selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 56, 158, 160, 162, 164, 166, 169, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

[0216] In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 102, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 104, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 106, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 108, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 112, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 114, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 116, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 118, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 120, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 122, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 124, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 126, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 128, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 132, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 134, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 136, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 138, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 140, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 156, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 158, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 160, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 162, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 164, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 166, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 168, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 170, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0217] In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 102, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 104, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 106, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 108, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 112, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 114, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 116, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 118, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 120, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 122, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 124, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 126, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 128, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 132, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 134, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 136, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 138, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 140, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 156, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 158, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 160, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 162, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 164, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 166, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 168, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 170, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0218] Light chain variable region domain In some embodiments of the antigen-binding domain disclosed herein, and antibodies, antibody-drug conjugates, and receptors comprising therein, the antibody-drug conjugate comprises a light chain variable region domain comprising a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences. In some embodiments, the antibody or antibody-drug conjugate comprises at least one light chain variable region domain comprising a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

[0219] In some embodiments, the antibody or antibody-drug conjugate comprises at least two light chain variable region domains, each comprising a sequence independently selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences. In some embodiments, the antibody or antibody-drug conjugate comprises two light chain variable region domains, each comprising a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences. In some embodiments, the two light chain variable region domains are not identical. In some embodiments of the antibodies or antibody-drug conjugates disclosed herein, the antibodies or antibody-drug conjugates comprise more than two light chain variable region domains comprising sequences selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or sequences having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with those sequences.

[0220] In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

[0221] In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 103, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 105, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 107, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 109, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments of the antigen-binding domain of this disclosure, the antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 113, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 115, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 117, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 119, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 121, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 123, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 125, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 127, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 129, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 131, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 133, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 135, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 137, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 139, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 141, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 157, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 159, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 161, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 163, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 165, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 167, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 169, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 171, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the antigen-binding domain includes a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0222] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 96, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 98.

[0223] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 97, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 99.

[0224] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 102, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 103.

[0225] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 104, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 105.

[0226] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 106, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 107.

[0227] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 108, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 109.

[0228] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 112, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 113.

[0229] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 114, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 115.

[0230] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 116, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 117.

[0231] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 118, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 119.

[0232] In some embodiments, the heavy chain variable region domain contains the amino acid sequence of SEQ ID NO: 120, and the light chain variable region domain contains the amino acid sequence of SEQ ID NO: 121.

[0233] In some embodiments, such as those in which the antigen-binding domain is incorporated into a dual complementary antibody or antibody-drug conjugate, the first antibody and / or the second antibody comprises a light chain variable region domain comprising a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

[0234] In some embodiments, the first antigen-binding domain and the second antigen-binding domain comprise a light chain variable region domain comprising a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

[0235] In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 103, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 105, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 107, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 109, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 113, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 115, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 117, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 119, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 121, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 123, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 125, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 127, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 129, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 131, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 133, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 135, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 137, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 139, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 141, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 157, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 159, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 161, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 163, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 165, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 167, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 169, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 171, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0236] In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 103, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 105, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 107, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 109, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 113, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 115, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 117, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 119, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 121, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 123, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 125, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 127, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 129, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 131, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 133, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 135, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 137, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 139, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 141, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 157, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 159, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 161, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 163, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 165, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 167, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 169, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 171, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0237] In some embodiments of the antibody-antibody-drug conjugates disclosed herein, the first antigen-binding domain and / or the second antigen-binding domain comprises a heavy chain variable region domain comprising a sequence selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 168, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences; and a light chain variable region domain comprising a sequence selected from SEQ ID NO: The sequences 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or sequences having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with them.

[0238] In some embodiments, the first antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 96 or 97. In some embodiments, the first antigen-binding domain includes a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 98 or 99. In some embodiments, the first antigen-binding domain includes a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 96 or 97, and a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 98 or 99.

[0239] In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID NO: 96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0240] In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain containing the amino acid sequence of SEQ ID 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain comprises a light chain variable region domain containing the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0241] In some embodiments, the second antigen-binding domain comprises a heavy chain variable region domain comprising the amino acid sequence of SEQ ID 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0242] In some embodiments, the first antigen-binding domain comprises a heavy chain variable region domain comprising the amino acid sequence of SEQ ID NO: 96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and the second antigen-binding domain comprises a heavy chain variable region domain comprising the amino acid sequence of SEQ ID NO: 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0243] In some embodiments, the dual complementary antibody or antibody-drug conjugate comprises a full-length IgG1 antibody containing a first antigen-binding domain, and the antibody or antibody-drug conjugate comprises two peptides containing the first antigen-binding domain heavy chain variable region of SEQ ID NO: 96, the first linker of SEQ ID NO: 152, the second antigen-binding domain heavy chain variable region of SEQ ID NO: 97, the second linker of SEQ ID NO: 153, and the light chain variable region of SEQ ID NO: 99. In some embodiments, the antibody or antibody-drug conjugate comprises two peptides containing the light chain variable region of SEQ ID NO: 98. In some embodiments, the antibody-drug conjugate comprises two peptides containing a first antigen-binding domain heavy chain variable region domain of SEQ ID NO: 96, a first linker of SEQ ID NO: 152, a second antigen-binding domain heavy chain variable region domain of SEQ ID NO: 97, a second linker of SEQ ID NO: 153, and a light chain variable region of SEQ ID NO: 99, and the antibody or antibody-drug conjugate further comprises two peptides containing an antibody light chain variable region domain of SEQ ID NO: 98. In some embodiments, the heavy and light chains of full-length IgG1 contain IgG1 isotype constant region domains.

[0244] In some embodiments, the second antigen-binding domain is an scFv containing a first heavy chain domain, the first heavy chain domain comprising SEQ ID NO: 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain is an scFv containing a first heavy chain domain, the first heavy chain domain comprising SEQ ID NO: 97.

[0245] In some embodiments, the second antigen-binding domain is an scFv comprising a light chain variable region domain comprising SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the second antigen-binding domain is an scFv comprising a light chain variable region domain comprising SEQ ID NO: 99.

[0246] In some embodiments of the antibody-drug conjugate, the second antigen-binding domain is scFv, which includes a first heavy chain domain comprising SEQ ID NO: 97; and a light chain variable region domain comprising SEQ ID NO: 99.

[0247] In some embodiments, the antibody or antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain, and the antigen-binding domain antibody contains scFv, and the antibody or antibody-drug conjugate comprises two polypeptides that, from the N-terminus to the C-terminus, contain the first antibody heavy chain variable region domain of SEQ ID NO: 96, the IgG1 isotype constant region domain of SEQ ID NO: 148, the first linker of SEQ ID NO: 152, the second antibody heavy chain variable region domain of SEQ ID NO: 97, the second linker of SEQ ID NO: 153, and the light chain variable region of SEQ ID NO: 99. In some embodiments, the antibody or antibody-drug conjugate comprises two polypeptides that, from the N-terminus to the C-terminus, include a first antibody heavy chain variable region domain of SEQ ID NO: 96, an IgG1 isotype constant region domain of SEQ ID NO: 148, a first linker of SEQ ID NO: 152, a second antibody light chain variable region of SEQ ID NO: 99, a second linker of SEQ ID NO: 153, and a heavy chain variable region domain of SEQ ID NO: 97.

[0248] In some embodiments, the antibody or antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain and a second antigen-binding domain containing scFv, and the antibody or antibody-drug conjugate comprises two polypeptides that contain a first antibody variable light chain domain of SEQ ID NO: 98 and a first antibody light chain constant region domain of SEQ ID NO: 149 from the N-terminus to the C-terminus.

[0249] In some embodiments, the antibody or antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain and a second antigen-binding domain containing scFv, and the antibody or antibody-drug conjugate comprises four peptides comprising: two peptides comprising, from the N-terminus to the C-terminus, the first antigen-binding domain heavy chain variable region domain of SEQ ID NO: 96, the IgG1 isotype constant region domain of SEQ ID NO: 148, the first linker of SEQ ID NO: 152, the second antigen-binding domain heavy chain variable region domain of SEQ ID NO: 97, the second linker of SEQ ID NO: 153, and the light chain variable region of SEQ ID NO: 99; and two peptides comprising, from the N-terminus to the C-terminus, the first antigen-binding domain light chain variable region domain of SEQ ID NO: 98 and the first antigen-binding domain light chain constant region domain of SEQ ID NO: 149.

[0250] In some embodiments, the antibody or antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain and a second antigen-binding domain containing scFv, and the antibody or antibody-drug conjugate comprises four peptides comprising: two peptides comprising, from the N-terminus to the C-terminus, the first antigen-binding domain heavy chain variable region domain of SEQ ID NO: 96, the IgG1 isotype constant region domain of SEQ ID NO: 148, the first linker of SEQ ID NO: 152, the second antigen-binding domain light chain variable region of SEQ ID NO: 99, the second linker of SEQ ID NO: 153, and the heavy chain variable region domain of SEQ ID NO: 97; and two peptides comprising, from the N-terminus to the C-terminus, the first antigen-binding domain light chain variable region domain of SEQ ID NO: 98 and the first antigen-binding domain light chain constant region domain of SEQ ID NO: 149.

[0251] In some embodiments, the antibody or antibody-drug conjugate comprises two polypeptides containing the sequence of SEQ ID NO:100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and two polypeptides containing the sequence of SEQ ID NO:101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0252] In some embodiments, the antibody or antibody-drug conjugate comprises two polypeptides containing the sequence of SEQ ID NO: 100; and two polypeptides containing the sequence of SEQ ID NO: 101.

[0253] This disclosure provides antibodies and antibody-drug conjugates comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope; a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain; and a chemotherapeutic agent wherein the first antigen-binding domain comprises a full-length IgG antibody and the second antigen-binding domain comprises scFv, and the antibody or antibody-drug conjugate comprises: (a) two polypeptides comprising at least one heavy chain variable region domain, said heavy chain variable region domain comprising: an HCCDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HCCDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; an HCCDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and wherein said polypeptide further comprises SEQ ID NO: (a) an amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) two polypeptides comprising at least one light chain variable region domain, the light chain variable region domain comprising: an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9; and wherein the polypeptide further comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0254] This disclosure provides an antibody or antibody-drug conjugate comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope; a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain; and a chemotherapeutic agent wherein the first antigen-binding domain comprises a full-length IgG antibody and the second antigen-binding domain comprises scFv, and the antibody or antibody-drug conjugate comprises: (a) two polypeptides comprising at least one heavy chain variable region domain, said heavy chain variable region domain comprising: an HCCDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HCCDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; an HCCDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6; and wherein said polypeptide further comprises SEQ ID NO: (a) an amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) two polypeptides comprising at least one light chain variable region domain, the light chain variable region domain comprising: an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; and an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 12; and wherein the polypeptide further comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0255] This disclosure provides an antibody or antibody-drug conjugate comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope; a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain; and a chemotherapeutic agent wherein the first antigen-binding domain comprises a full-length IgG antibody and the second antigen-binding domain comprises scFv, and the antibody or antibody-drug conjugate comprises: (a) two polypeptides comprising a first heavy chain variable region domain comprising: an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HCCDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and at least a second heavy chain variable region domain comprising: an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6; and at least a second heavy chain variable region domain comprising: an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6. The polypeptide comprises: (a) an LC CDR3 sequence; and a light chain variable region domain comprising: an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9; and wherein the polypeptide further comprises the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) two polypeptides comprising a light chain variable region domain comprising: an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 12; and wherein the polypeptide further comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0256] This disclosure provides an antibody or antibody-drug conjugate comprising a first antigen-binding domain that specifically binds to a first 5T4 epitope; a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antigen-binding domain is operatively linked to the second antigen-binding domain; and a chemotherapeutic agent wherein the first antigen-binding domain comprises a full-length IgG antibody and the second antigen-binding domain comprises scFv, and the antibody or antibody-drug conjugate comprises: (a) two polypeptides comprising a first heavy chain variable region domain comprising: an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 1; an HCCDR2 sequence comprising the amino acid sequence of SEQ ID NO: 2; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 3; and at least a second heavy chain variable region domain comprising: an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6; and at least a second heavy chain variable region domain comprising: an HC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 4; an HC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 5; and an HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6. The polypeptide comprises: (a) a CDR3 sequence; and a light chain variable region domain comprising: an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 10; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11; an LCCDR3 sequence comprising the amino acid sequence of SEQ ID NO: 12; and wherein the polypeptide further comprises the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) two polypeptides comprising a light chain variable region domain comprising: an LC CDR1 sequence comprising the amino acid sequence of SEQ ID NO: 7; an LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8; an LC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 9; and wherein the polypeptide further comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0257] Therapeutic agent The disclosed 5T4-specific antigen-binding domains and antibodies can be conjugated to therapeutic agents or effector molecules, including but not limited to molecules in which a covalent bond exists between the therapeutic agent and the antigen-binding domain or antibody. A therapeutic agent is an agent possessing specific biological activity against a specific target molecule or a cell carrying the target molecule. Those skilled in the art will understand that therapeutic agents can include various drugs, such as vincristine, donomycin, etc., and cytotoxins such as natural or modified Pseudomonas spp. (…). Pseudomonas Exotoxins or diphtheria toxins, which themselves contain encapsulating agents (e.g., liposomes) of pharmacological compositions, and radioactive agents such as... 125 I, 32 P, 14 C 3 H and 35 S, as well as other tags, target portions, and ligands.

[0258] In some implementations, the treatment agent is a chemotherapeutic agent.

[0259] The choice of a specific therapeutic agent depends on the specific target molecule or cell and the desired biological effect. Thus, for example, a therapeutic agent could be a cytotoxin used to induce the death of specific target cells (e.g., tumor cells). Conversely, when it is desired to induce a non-lethal biological response, the therapeutic agent can be conjugated to a non-lethal pharmacological agent or a liposome containing a non-lethal pharmacological agent.

[0260] Effector molecules can be attached to an antigen-binding domain of interest or an antibody using any number of means known to those skilled in the art. Both covalent and non-covalent attachment methods can be used. The procedure for attaching an effector molecule to an antibody varies depending on the chemical structure of the effector. Peptides typically contain a variety of functional groups; for example, carboxylic acid (COOH), free ammonia (—NH2), or thiol (—SH) groups, which can be used to react with suitable functional groups on the antibody to result in the binding of the effector molecule. Alternatively, the antigen-binding domain or antibody may be derivatized to expose or attach additional reactive functional groups. Derivatization can involve the attachment of any of a variety of known linker molecules. The linker can be any molecule used to attach the antibody to the effector molecule. The linker is capable of forming a covalent bond with both the protein and the effector molecule. Suitable linkers are well known to those skilled in the art and include, but are not limited to, straight-chain or branched-chain carbon linkers, heterocyclic carbon linkers, or peptide linkers. When the protein and effector molecule are peptides, the linker can be attached to the constituent amino acid via its side group (e.g., via disulfide bonding with cysteine) or to the α-carbon amino and carboxyl groups of the terminal amino acid.

[0261] In some cases, once the immunoconjugate has reached the target site, it is desirable to release the effector molecule from the antigen-binding domain or antibody. Therefore, in these situations, the immunoconjugate will contain a linker that can be cleaved near the target site. Enzymatic activity or conditions experienced by the immunoconjugate inside or near the target cell can induce linker cleavage to release the effector molecule from the antibody.

[0262] Those skilled in the art will be able to determine a suitable method for attaching a given reagent to an antibody or other peptide.

[0263] In some aspects, the chemotherapeutic agent is conjugated via a linker to at least one of the first antigen-binding domain or the second antigen-binding domain of the dual complementary antibody described herein. In some aspects, the chemotherapeutic agent is oliquistatin. In some aspects, oliquistatin is selected from oliquistatin E (AE), monomethyloliquistatin D (MMAD), monomethyloliquistatin E (MMAE), monomethyloliquistatin F (MMAF), and synthetic analogues of dolasstatin. In some aspects, the linker is a cleavable linker. In some aspects, the linker is a non-cleavable linker.

[0264] The disclosed anti-5T4 dual-complement antibody-drug conjugate (ADC) comprises a first antigen-binding domain that specifically binds to a first 5T4 epitope, a second antigen-binding domain that specifically binds to a second 5T4 epitope different from the first 5T4 epitope, and the first antigen-binding domain is operatively linked to the second antigen-binding domain. It is conjugated to a cytotoxic agent or an immunosuppressant, such that the resulting ADC exerts cytotoxic or inhibitory effects against 5T4-expressing cancer cells. Therefore, the anti-5T4 dual-complement antibody-drug conjugate exerts cytotoxic or inhibitory effects against 5T4-expressing cancer cells. In one embodiment, the anti-5T4 ADC is internalized and accumulates within 5T4-expressing cells, whereby the ADC exerts a therapeutic effect (e.g., cytotoxic, inhibitory, or immunosuppressive effect).

[0265] Examples of suitable portions of an antibody that can be conjugated to an antigen-binding domain include chemotherapeutic agents, prodrug-converting enzymes, radioisotopes or compounds, or toxins. In an exemplary embodiment, an anti-5T4 antibody or its antigen-binding portion is conjugated to olistatin, such as MMAF or MMAE. Any agent that exerts a therapeutic effect on cancer cells or activated immune cells can be used as a therapeutic agent for conjugation to an anti-5T4 antibody or a derivative thereof (see, for example, WO 2004 / 010957, “DrugConjugates and Their Use for Treating Cancer, An Autoimmune Disease or an Infectious Disease” (ibid.) and U.S. Provisional Application No. 60 / 400,403 (ibid.)). Typically, the therapeutic agent is a cytotoxic agent. In some embodiments, the anti-5T4 antibody-drug conjugate contains more than one therapeutic agent / conjugate, for example, about 1 to about 20 therapeutic agents / conjugates (often referred to as the drug-antibody ratio, or DAR).

[0266] In some embodiments, an anti-5T4 antibody or its antigen-binding portion is conjugated to olistatin. Olistatin has been shown to interfere with microtubule dynamics, GTP hydrolysis, and / or nuclear and cell division, and has anticancer and / or antifungal activity.

[0267] The anti-5T4 antibody or antigen-binding domain disclosed herein can be conjugated to at least one olistatin. Olistatin represents a group of dorasstatin analogues that have generally been shown to inhibit cell division by interfering with microtubule dynamics and GTP hydrolysis, thereby inhibiting cell division. For example, olistatin E (described in U.S. Patent No. 5,635,483, which is incorporated herein by reference) is a synthetic analogue of the marine natural product dorasstatin 10, a compound that inhibits microtubule polymerization by binding to the same site on microtubules as the anticancer drug vincristine (GR Pettit, Prog. Chem. Org. Nat. Prod, 70: 1-79 (1997)). Dorasstatin 10, olistatin PE, and olistatin E are linear peptides having four amino acids, three of which are specific to the dorasstatin class of compounds. Exemplary embodiments of the oprestatin subclass of mitotic inhibitors include, but are not limited to, monomethyloprestatin D (MMAD or oprestatin D derivative), monomethyloprestatin E (MMAE or oprestatin E derivative), monomethyloprestatin F (MMAF or oprestatin F derivative), oprestatin F phenylenediamine (AFP), oprestatin EB (AEB), oprestatin EFP (AEFP), and 5-benzoylvaleric acid-AE ester (AEVB). The synthesis and structure of olistatin derivatives are described in the following: U.S. Patent Application Publications Nos. 2003-0083263, 2005-0238649, and 2005-0009751; International Patent Publications Nos. WO 04 / 010957, WO 02 / 088172; and U.S. Patent Nos. 6,323,315; 6,239,104; 6,034,065; 5,780,588; 5,665,860; 5,663,149; 5,635,483; 5,599,902; 5,554,725; 5,530,097; 5,521,284; and 5,504,191. 5,410,024; 5,138,036; 5,076,973; 4,986,988; 4,978,744; 4,879,278; 4,816,444; and 4,486,414, each incorporated herein by reference.

[0268] In some embodiments, the anti-5T4 antibody or antigen-binding domain is conjugated to at least one MMAF (monomethyl auripitin F) via a linker (e.g., but not limited to, maleimide hexanoyl (mc-MMAF)). The anti-5T4 ADC can have a drug-to-antibody ratio (DAR) of 2, 4, 6, or 8. Notably, the DAR of the ADC can range from 0 to 8, although higher loadings, such as 10, 12, or 14, are also possible. Monomethyl auripitin F (MMAF) inhibits cell division by blocking the polymerization of microtubules. It has a charged C-terminal phenylalanine residue, which attenuates its cytotoxic activity compared to its uncharged counterpart, MMAE. Due to its toxicity, it cannot be used as a drug on its own but can be conjugated to a monoclonal antibody (mAb) to guide it to cancer cells. In one embodiment, the linker to the anti-5T4 antibody is stable in the extracellular fluid but is cleaved by cathepsins once the conjugate has entered tumor cells, thus activating an anti-mitotic mechanism.

[0269] In some embodiments, the anti-5T4 antibody or antigen-binding domain of the present invention is conjugated to at least one MMAE (monomethylolpropionate E). Monomethylolpropionate E (MMAE, vedoltin) inhibits cell division by blocking the polymerization of microtubules. Due to its toxicity, it is generally not suitable as a drug on its own. In recent cancer therapy development, it is linked to a monoclonal antibody (mAb) that recognizes specific markers expressed in cancer cells and directs the MMAE to the cancer cells. In some embodiments, the linker connecting the MMAE to the anti-5T4 antibody or antigen-binding domain is stable in the extracellular fluid (i.e., the medium or environment outside the cell), but once the ADC has bound to a specific cancer cell antigen and entered the cancer cell, it is cleaved by cathepsins, thus releasing the toxic MMAE and activating a potent anti-mitotic mechanism.

[0270] In some embodiments, an anti-5T4 antibody or its antigen-binding portion is conjugated to oliquistatin, which is an MMAF. In some embodiments, an anti-5T4 ADC is covalently linked to one or more monomethyl oliquistatin F (MMAF) molecules. In some embodiments, to generate an anti-5T4 ADC covalently linked to one or more MMAF molecules, the interchain disulfide bonds of the ADC are reduced to thiol groups. The MMAF is then coupled to the antibody via these thiol groups. In some embodiments, an incleavable linker, i.e., an incleavable maleimide hexanoyl (mc) bond, is used to generate the anti-5T4 ADC.

[0271] ADCs can be labeled with detectable or functional markers. Detectable markers include, but are not limited to, radioactive markers, such as isotopes ²H, ³H, ¹¹C, ¹³C, ¹³H ...H, ¹³H, 4C、³²P、³³S、³ 4 S、³ 5 S、³ 6 S、³ 6 Cl、 5 ¹Cr、 57 Co、 58 Co、 59 Fe、 90 Y、¹²¹I、¹² 4 I、¹² 5 I、¹³¹I、²¹¹At、¹ 98 Au、 67 Cu、²² 5 Ac、²¹³Bi、 99 Tc and¹ 86 The antibodies of the present invention can be attached to using conventional chemistry known in the field of antibody imaging. The labeling also includes fluorescent labels and labels conventionally used in the art for MRI-CT imaging. They also include enzyme labels, such as horseradish peroxidase. The labeling further includes a chemical portion, such as biotin, which can be detected via binding to a specific homologous detectable portion, such as a labeled avidin.

[0272] Functional markers can also include substances designed to target tumor sites to cause tumor tissue destruction. Such functional markers include cytotoxic drugs such as 5-fluorouracil or ricin, and enzymes such as bacterial carboxypeptidase or nitroreductase, which can convert prodrugs into active drugs at the tumor site.

[0273] As those skilled in the art will understand, the reagents described above, as well as other suitable reagents, can be conjugated or attached to anti-5T4 antibodies in any suitable manner, for example... Figs. 1A-1B The antibodies described herein are used to generate the anti-5T4 ADC of this disclosure. For example, and not limitingly, in various embodiments of this disclosure, the anti-5T4 antibody and reagent may be covalently attached and / or conjugated using linker, spacer, and / or extension compounds, which may be cleavable or non-cleavable in various embodiments of the invention, and result in the internalization of the therapeutic agent into the target cells.

[0274] In one implementation, the anti-5T4 antibody or antigen-binding domain is conjugated to MMAF using an incleavable maleimide hexanoyl bond.

[0275] Techniques for conjugating therapeutic agents to proteins, and particularly antibodies, are known in the art (see, for example, Arnon et al., “Monoclonal Antibodies For Immunotargeting Of Drugs In Cancer Therapy,” in Monoclonal Antibodies And Cancer Therapy (edited by Reisfeld et al., Alan R. Liss, Inc., 1985); Hellstrom et al., “Antibodies For Drug Delivery,” in Controlled Drug Delivery (edited by Robinson et al., Marcel Dekker, Inc., 2nd ed., 1987); Thorpe, “Antibody Carriers Of Cytotoxic Agents In Cancer Therapy: A Review,” in Monoclonal Antibodies '84: Biological And Clinical Applications (edited by Pinchera et al., 1985); “Analysis, Results, and Future Prospective of the Therapeutic Use of Radiolabeled Antibody In Cancer Therapy,” in Monoclonal Antibodies For Cancer Detection And Therapy (edited by Baldwin et al., Academic). Press, 1985; and Thorpe et al., 1982, Immunol. Rev. 62:119-58. See also, for example, PCT Publication No. WO 89 / 12624).

[0276] In some embodiments, the ADC includes a linker region between the cytotoxic agent and the antibody or antigen-binding domain. Such linker, spacer, and / or extension compounds include, for example, but are not limited to, the following: aminobenzoic acid spacers (see, for example, but not limited to, U.S. Patent Nos. 7,091,186 and 7,553,816, each of which is incorporated herein by reference in its entirety); maleimide hexanoyl; p-aminobenzylcarbamoyl (PAB); lysosomal enzyme-cleavable linkers (see, for example, but not limited to, U.S. Patent No. 6,214,345, which is incorporated herein by reference in its entirety); maleimide hexanoyl-polyethylene glycol 20 (MC(PEG)6-OH); N-methylvaline-citrulline; N-succinimide-4-(N-maleimidemethyl)cyclohexane-1-carboxylic acid ester (SMCC) (see, for example, but not limited to, Yoshitake et al. (1979) Eur. J.). Biochem., 101, 395-399 (which is incorporated herein by reference in its entirety); N-succinimide-4-(2-pyridyldithio)butyrate (SPDB) (See, for example, but not limited to, U.S. Patent No. 4,563,304, which is incorporated herein by reference in its entirety 25); N-succinimide-4-(2-pyridylthio)valerate (SPP); valine-citrulline; and other linker, spacer, and / or extension compounds (see, for example, but not limited to, U.S. Patent Nos. 7,090,843, 7,223,837, and 7,659,241, and U.S. Patent Publications 2004 / 0018194, 2004 / 0121940, 2006 / 0116422, 2007 / 0258987, 2008 / 0213289, 2008 / 0241128, 2008 / 0311136, 2008 / 0317747, and 2009 / 0010945, each of which is incorporated herein by reference in its entirety). Generally, techniques for attaching and / or conjugating the reagents described above, as well as other reagents, to specific binding members of the present invention, particularly antibodies and fragments thereof, are known in the art.See, for example, but not limited to, Hellstrom et al., “Antibodies For Drug Delivery”, in Controlled Drug Delivery (2nd ed.), Robinson et al. (eds.), pp. 623-653 (Marcel Dekker, Inc. 1987); Thorpe, “Antibody Carriers Of Cytotoxic Agents In Cancer Therapy: A Review”, in Monoclonal Antibodies '84: Biological And Clinical Applications, Pinchera et al. (eds.), pp. 475-506 (1985), each of which is incorporated herein by reference in its entirety.

[0277] A variety of different reactions can be used to covalently attach drugs to antibody or antigen-binding domains. This is often accomplished through reactions of amino acid residues in antibody molecules, including the amino group of lysine, the free carboxyl groups of glutamic acid and aspartic acid, the thiol group of cysteine, and various moieties of aromatic amino acids. One of the most commonly used nonspecific covalent attachment methods is the carbodiimide reaction, which links the carboxyl (or amino) group of a compound to the amino (or carboxyl) group of an antibody. Additionally, bifunctional reagents such as dialdehydes or imides have been used to link the amino group of a compound to the amino group of an antibody molecule. Schiff base reactions can also be used to attach drugs to antibodies. This method involves the periodic acid oxidation of drugs containing diol or hydroxyl groups, thus forming an aldehyde that subsequently reacts with the antibody molecule. Attachment occurs via the formation of a Schiff base using the amino group of the antibody molecule. Isothiocyanates can also be used as coupling agents for covalently attaching drugs to antibodies. Other techniques are known to those skilled in the art and are within the scope of this invention. Non-limiting examples of such techniques are described, for example, in U.S. Patent Nos. 5,665,358; 5,643,573; and 5,556,623, which are incorporated herein by reference in their entirety.

[0278] In some embodiments, the intermediate, which is a precursor of the linker, reacts with the drug under appropriate conditions. In some embodiments, reactive groups are used on the drug and / or the intermediate. The reaction product between the drug and the intermediate, or the derivatized drug, is then reacted with the anti-5T4 antibody under appropriate conditions.

[0279] Other examples of the conjugation method are described in U.S. Patent No. 7,837,980 (Seattle Genetics), Carter and Senter (2008) Cancer J, 14(3):154, and U.S. Publication Nos. 2004-0157782 A1 and 2005-0238649 and International Patent Application No. PCT / US04 / 038392.

[0280] In some embodiments, the anti-5T4 ADC can be purified to obtain an ADC having a desired drug-antibody ratio (DAR). In one embodiment of the invention, the formulation comprises a mixture of anti-5T4 ADCs having an average desired drug-antibody ratio (DAR), for example, an average DAR of about 3. In another embodiment of the invention, the formulation comprises a mixture of ADCs having anti-5T4 ADCs having a desired DAR range, for example, about 2-4, 2-8, or 4-8.

[0281] In one embodiment, the formulation contains an ADC mixture, wherein 70% of the ADCs present have 8 or fewer drug loading species, and wherein the ADCs comprise an anti-5T4 antibody and olistatin. Alternatively, 75% of the ADCs present have 8 or fewer drug loading species; 80% of the ADCs present have 8 or fewer drug loading species; 85% of the ADCs present have 4 or fewer drug loading species; 90% of the ADCs present have 8 or fewer drug loading species; or 95% of the ADCs present have 8 or fewer drug loading species.

[0282] Polynucleotides and vectors This disclosure provides polynucleotides and polynucleotide systems comprising one or more polynucleotides, said polynucleotides encoding the anti-5T4 antibody, antigen-binding domain, and receptor described herein.

[0283] In some embodiments, the polynucleotide or polynucleotide system described herein comprises a sequence encoding any light chain CDR sequence and / or heavy chain CDR sequence of the anti-5T4 bicomplementary antibody described herein.

[0284] In some implementations, the polynucleotide or polynucleotide system described herein comprises sequences of any light and heavy chains encoding the anti-5T4 bicomplementary antibody described herein.

[0285] In some implementations, the polynucleotide or polynucleotide system described herein comprises sequences listed in any of Tables 4-7.

[0286] This disclosure provides a first polynucleotide encoding a first heavy chain of the anti-5T4 antigen-binding domain of the present disclosure, and a second polynucleotide encoding a light chain of the anti-5T4 antigen-binding domain. In some embodiments, the first and second polynucleotides are separate molecules. Alternatively, the first and second polynucleotides may constitute part of a single adjacent polynucleotide molecule.

[0287] In some embodiments, this disclosure provides a first polynucleotide encoding a first anti-5T4 antigen-binding domain heavy chain, a linker, and a second anti-5T4 antigen-binding domain; and a second polynucleotide encoding a first anti-5T4 antigen-binding domain light chain. In some embodiments, this disclosure provides a single adjacent polynucleotide molecule encoding a first anti-5T4 antigen-binding domain heavy chain, a first anti-5T4 antigen-binding domain light chain, and a second anti-5T4 antigen-binding domain.

[0288] In some embodiments, the first polynucleotide encodes the sequence of a first polypeptide, the first polypeptide comprising, from its N-terminus to its C-terminus, a first anti-5T4 antigen-binding domain heavy chain, a linker, and a first anti-5T4 antigen-binding domain heavy chain. In some embodiments, the first polynucleotide encodes the sequence of a first polypeptide, the first polypeptide comprising, from its N-terminus to its C-terminus, a second anti-5T4 antigen-binding domain, a linker, and a first anti-5T4 antigen-binding domain heavy chain. In some embodiments, the first polynucleotide encodes the sequence of a first polypeptide, the first polypeptide comprising, from its N-terminus to its C-terminus, a second anti-5T4 antigen-binding domain, a linker, and a first anti-5T4 antigen-binding domain heavy chain. In some embodiments, the first polynucleotide comprises the nucleotide sequence of SEQ ID NO: 144 or 145. In some embodiments, the first polynucleotide comprises the nucleotide sequences of SEQ ID NO: 144 and 150. In some embodiments, the first polynucleotide comprises the nucleotide sequences of SEQ ID NO: 145 and 150. In some embodiments, the first polynucleotide comprises the nucleotide sequence of SEQ ID NO: 142.

[0289] In some embodiments, the second polynucleotide encodes a second polypeptide comprising a light chain containing a first anti-5T4 antigen-binding domain. In some embodiments, the second polynucleotide comprises the nucleotide sequence of SEQ ID NO: 146 or 147. In some embodiments, the second polynucleotide comprises the nucleotide sequences of SEQ ID NO: 146 and 151. In some embodiments, the second polynucleotide comprises the nucleotide sequences of SEQ ID NO: 147 and 151. In some embodiments, the second polynucleotide comprises the nucleotide sequence of SEQ ID NO: 143.

[0290] In some embodiments, the polypeptide encoded by the first polynucleotide comprises the sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it. In some embodiments, the polypeptide encoded by the second polynucleotide comprises the sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

[0291] In some embodiments, the polynucleotide sequences encoding the first and second polypeptides are operatively linked to one or more promoters. For example, the sequences of the polypeptides may be operatively linked (to their control) to the same promoter and separated by one or more elements that produce separate polypeptides, such as self-cleaving polypeptides, internal ribosome entry sites, etc.

[0292] In alternative embodiments, the sequences of the first or second polynucleotide encoding the first or second polypeptide are under the control of separate promoters. For example, the first and second polynucleotides may each be cloned into separate expression vectors, each containing its own promoter and / or regulatory sequence. In some embodiments, the promoters operatively linked to the first and second polynucleotides are the same. In some embodiments, the promoters operatively linked to the first and second polynucleotides are different.

[0293] In some embodiments, the polynucleotides of the present invention are prepared using PCR technology, employing procedures and methods known to those skilled in the art. In some embodiments, the procedure involves the ligation of two different DNA sequences (see, for example, "Current Protocols in Molecular Biology," edited by Ausubel et al., John Wiley & Sons, 1992).

[0294] Using the antigen-binding domains, antibodies, and receptors described herein, those skilled in the art can readily construct various clones containing functionally equivalent nucleic acids, such as nucleic acids that differ in sequence but encode the same protein sequence. Therefore, this disclosure provides nucleic acids encoding their antibodies.

[0295] When a polynucleotide sequence is placed within a functional relationship with another polynucleotide sequence, it is "operably linked." For example, if a polynucleotide presequence or secretory leader region is expressed as a preprotein involved in polypeptide secretion, it is operably linked to the nucleic acid encoding the polypeptide; if a promoter or enhancer affects the transcription of the sequence, it is operably linked to the coding sequence; or, if a ribosome binding site is positioned to facilitate translation, it is operably linked to the coding sequence. Generally, "operably linked" means that the polynucleotide sequences to be linked are adjacent, and, in the case of a secretory leader region, adjacent and within the reading frame. However, enhancers are optionally adjacent. Linkage can be accomplished, for example, by linking at a convenient restriction site. If such a site is not available, synthetic oligonucleotide adaptors, linkers, or other methods known in the art can be used. In another embodiment, "operably linked" also refers to the functional pairing of different amino acid sequences, peptides, or proteins, such as the combination of a first anti-5T4 antigen-binding domain heavy chain and a second anti-5T4 antigen-binding domain described herein, which is optionally operably linked via a linker sequence also described herein. For example, the first anti-5T4 antigen-binding domain heavy chain is "operably linked" to the second anti-5T4 antigen-binding domain via a linker sequence as described herein.

[0296] This disclosure provides a vector comprising a polynucleotide containing a sequence encoding the 5T4 antigen-binding domain, antibody, and receptor described herein.

[0297] The terms "vector," "cloning vector," and "expression vector" refer to media through which DNA or RNA sequences (e.g., foreign genes) can be introduced into host cells to transform the host and promote the expression (e.g., transcription and translation) of the introduced sequences. Vectors include plasmids, bacteriophages, viruses, etc.

[0298] The terms "expression" and "expression" refer to the process by which information in a gene or DNA sequence becomes visible, for example, by activating cellular functions involved in transcription and translation of the corresponding gene or DNA sequence to produce a protein. The DNA sequence is expressed within or by the cell to form an "expression product," such as a protein. The expression product itself, for example, the resulting protein, can also be described as "expressed" by the cell. Expression products can be characterized as intracellular, extracellular, or transmembrane. The term "intracellular" refers to a substance inside the cell. The term "extracellular" refers to a substance outside the cell. The term "transmembrane" refers to a substance having extracellular domains outside the cell, portions embedded in the cell membrane, and intracellular domains inside the cell.

[0299] In some embodiments, the polynucleotides of this disclosure are inserted into the expression vector (i.e., nucleic acid construct) to allow expression of the polypeptides described herein.

[0300] In some embodiments, the expression vectors of this disclosure include additional sequences that make the vector suitable for replication and integration in prokaryotes. In some embodiments, the expression vectors of this disclosure include additional sequences that make the vector suitable for replication and integration in eukaryotes. In some embodiments, the expression vectors of this disclosure include shuttle vectors that make the vector suitable for replication and integration in both prokaryotes and eukaryotes. For example, such vectors may include selectable markers suitable for both eukaryotic and prokaryotic cells. Suitable markers will be apparent to those skilled in the art.

[0301] In some embodiments, the cloning vector contains transcription and translation initiation sequences (e.g., promoters, enhancers) and transcription and translation terminators (e.g., polyadenylation signals) to enhance the expression of the thereby expressed polypeptide. Suitable translation terminators include, but are not limited to, bovine growth hormone polyadenylation signals (BGH polyA). Suitable promoters will be apparent to those skilled in the art and include CMV promoters, actin promoters, etc.

[0302] In some embodiments, the expression vector of this disclosure may further include additional polynucleotide sequences that allow translation of several proteins, such as from a single mRNA, such as internal ribosome entry sites (IRES), and sequences for genome integration of promoter-chimeric polypeptides.

[0303] In some embodiments, the expression vector of this disclosure includes elements that enhance the expression of the antibody of the present invention. Such features include, but are not limited to, the selection of promoters and polyadenylations. In some embodiments, the polyadenylation sequence is a bovine growth hormone (BGH) polyadenylation sequence. In some embodiments, the promoter comprises a constitutively active promoter. In some embodiments, the promoter comprises a cytomegalovirus promoter (pCMV). In some embodiments, the promoter may be combined with additional elements to promote the expression of the recombinant protein of the present invention, such as introns (e.g., rabbit β-globin introns, EF1a introns, etc.) and enhancer elements (CMV immediate early enhancer, SV40 enhancer, EF1a enhancer, adenovirus major late protein enhancer, etc.).

[0304] Exemplary mammalian expression vectors include, but are not limited to, pcDNA3, pcDNA3.1(+ / −), pGL3, pZeoSV2(+ / −), pSecTag2, pDisplay, pEF / myc / cyto, pCMV / myc / cyto, pCR3.1, pSinRep5, DH26S, DHBB, pNMT1, pNMT41, and pNMT81, which are available from Invitrogen; pCI, which is available from Promega; pMbac, pPbac, pBK-RSV, and pBK-CMV, which are available from Strategene; and pTRES and its derivatives, which are available from Clontech.

[0305] In some embodiments, the present invention uses expression vectors containing regulatory elements derived from eukaryotic viruses such as retroviruses. SV40 vectors include pSVT7 and pMT2. In some embodiments, vectors derived from bovine papillomavirus include pBV-1MTHA, and vectors derived from Epstein-Barr virus include pHEBO and p205. Other exemplary vectors include pMSG, pAV009 / A+, pMTO10 / A+, pMAMneo-5, baculovirus pDSVE, and any other vectors that allow protein expression guided by: the SV-40 early promoter, the SV-40 late promoter, the metallothionein promoter, the murine mammary tumor virus promoter, the Laureth sarcoma virus promoter, the polyhedrosis protein promoter, or other promoters shown to be effective for expression in eukaryotic cells.

[0306] In some embodiments, such as in bacterial systems used to express the peptides of the present invention, a variety of expression vectors can be advantageously selected depending on the intended use of the expressed protein. In some embodiments, a vector is needed to guide high-level expression of a protein product, which may be a fusion with a hydrophobic signal sequence that directs the expressed product into the bacterial periplasm or culture medium, where the protein product can be readily purified. In one embodiment, vectors suitable for such operations include, but are not limited to, *Escherichia coli* (…). E. coli pET series of expression vectors (see Studier et al., Methods in Enzymol. 185:60-89 (1990)).

[0307] In some embodiments, a yeast expression system is used to express the polypeptides of this disclosure. In one embodiment, various vectors containing constitutive or inducible promoters can be used in yeast, such as those disclosed in U.S. Patent No. 5,932,447. In another embodiment, a vector that facilitates the integration of a foreign DNA sequence into the yeast chromosome is used.

[0308] In some embodiments, recombinant viral vectors can be used for in vivo expression of the peptides of the present invention because they offer advantages such as lateral spread and target specificity. In one embodiment, lateral spread is inherent in the life cycle of, for example, retroviruses and is the process by which a single infected cell produces multiple progeny viral particles that bud and infect neighboring cells. In one embodiment, the result is that a large area becomes rapidly infected, with most of that area initially not infected by the original viral particles. In one embodiment, a viral vector that cannot spread laterally is produced. In one embodiment, this property can be useful if the desired objective is to introduce a specified gene into only a limited number of target cells.

[0309] In some embodiments, a mammalian cell expression system is used to express the polypeptides disclosed herein. The mammalian cell may be, for example, Chinese hamster ovary (CHO) cells or derivatives thereof, and the vector is suitable for expressing the polypeptide in CHO cells. In some embodiments, the mammalian cell may be ExpiCHO-S™ cells.

[0310] It should be understood that, in addition to the elements necessary for transcription and translation containing the inserted coding sequence (coding polypeptide), the expression construct of the present invention may also include sequences modified to optimize the stability, production, purification, yield, or activity of the expressed polypeptide.

[0311] Manufacturing methods This disclosure provides a method for preparing the anti-5T4 antibody described herein, comprising: (a) contacting a variety of cells with a polynucleotide, polynucleotide system or vector encoding the antibody; (b) culturing the variety of cells under conditions in which the antibody is expressed by at least one of the variety of cells; and (c) purifying the antibody.

[0312] This disclosure provides a method for preparing the anti-5T4 antibody-drug conjugate described herein, comprising: (a) contacting a variety of cells with a polynucleotide, polynucleotide system, or carrier encoding the antibody; (b) culturing the variety of cells under conditions in which the bispecific antibody is expressed by at least one of the variety of cells; (c) purifying the antibody; and (d) conjugating the antibody to a chemotherapeutic agent. In some embodiments, the antibody is bispecific or has two complementary sites, as described herein.

[0313] This disclosure provides a method for manufacturing the antibody-drug conjugates described herein, comprising: (a) culturing cells containing a nucleic acid construct encoding a bispecific or complementary antibody under conditions that result in the expression of a bispecific or complementary antibody; (b) recovering the bispecific or complementary antibody; and (c) conjugating the bispecific or complementary antibody to a chemotherapeutic agent.

[0314] This disclosure provides a method for manufacturing the antibody described herein, comprising: (a) culturing cells containing a nucleic acid construct encoding an antibody under conditions that induce antibody expression, wherein the antibody comprises: i) a first antibody that specifically binds to a first 5T4 epitope; ii) a second antibody that specifically binds to a second 5T4 epitope different from the first 5T4 epitope; wherein the first antibody is operatively linked to the second antibody; and (b) recovering the bispecific antibody.

[0315] Various prokaryotic or eukaryotic cells can be used as host expression systems to express the antibodies of the present invention. In some embodiments, these include, but are not limited to, microorganisms, such as bacteria transformed with recombinant bacterial phage DNA, plasmid DNA, or copious DNA expression vectors containing polypeptide coding sequences; and yeast transformed with recombinant yeast expression vectors containing polypeptide coding sequences.

[0316] In some embodiments, the cell lines comprise eukaryotic cells. In some embodiments, the eukaryotic cells are mammalian cells. Suitable mammalian cells for expressing antibody-drug conjugates include CHO cells, PER.C6 cells, mouse NSO cells, and HEK293 cells. The selection of a suitable cell line will be apparent to those skilled in the art.

[0317] In some implementations, the cell types include prokaryotic cells, such as Escherichia coli cells.

[0318] Various methods can be used to introduce expression vectors encoding the antibodies disclosed herein into cells. Such methods are generally described in the following: Sambrook et al., Molecular Cloning: A Laboratory Manual, ColdSprings Harbor Laboratory, New York (1989, 1992); Ausubel et al., Current Protocols in Molecular Biology, John Wiley and Sons, Baltimore, Md. (1989); Chang et al., Somatic Gene Therapy, CRC Press, Ann Arbor, Mich. (1995); Vega et al., Gene Targeting, CRC Press, Ann Arbor, Mich. (1995); Vectors: A Survey of Molecular Cloning Vectors and Their Uses, Butterworths, Boston Mass. (1988); and Gilboa et al. [Biotechniques 4 (6): 504-512, 1986], and include, for example, stable or transient transfection, lipid transfection, electroporation, and infection with recombinant viral vectors. Additionally, for information on positive-negative selection methods, see U.S. Patent Nos. 5,464,764 and 5,487,992.

[0319] In some implementations, contacting multiple cells with a polynucleotide or vector encoding an antibody disclosed herein includes transfection.

[0320] The term "transfection" refers to the introduction of foreign nucleic acids into a cell using recombinant DNA technology. The term "transformation" refers to the introduction of a "foreign" (i.e., external or extracellular) gene, DNA, or RNA sequence into a host cell, causing the host cell to express the introduced gene or sequence to produce a desired substance, typically a protein or enzyme encoded by the introduced gene or sequence. The introduced gene or sequence may also be referred to as a "cloned" or "foreign" gene or sequence and may include regulatory or control sequences, such as initiation sequences, termination sequences, promoter sequences, signal sequences, secretory sequences, or other sequences used by the cell's genetic mechanisms. Genes or sequences may include non-functional sequences or sequences that do not have a known function. A host cell that accepts and expresses the introduced DNA or RNA has been "transformed" and is a "transformer" or "clone." The DNA or RNA introduced into the host cell can come from any source, including cells of the same genus or species as the host cell or cells of a different genus or species.

[0321] In some embodiments, contacting multiple cells with a polynucleotide or vector encoding an antibody disclosed herein includes transduction. The term "transduction" refers to the introduction of exogenous nucleic acid into cells using a viral vector, such as a lentiviral vector.

[0322] In some embodiments, non-bacterial expression systems (e.g., mammalian expression systems, such as CHO cells) are used to express antibody peptides. In some embodiments, the expression vector contains a CMV promoter and a neomycin resistance gene. In alternative embodiments, the expression vector contains a glutamine synthetase marker (GS) under the control of the SV40 promoter.

[0323] In some implementations, the introduction of nucleic acids via viral infection offers several advantages over other methods such as lipid transfection and electroporation, as higher transfection efficiency can be achieved due to the infectious nature of the virus.

[0324] In some embodiments, the transformed cells are cultured under effective conditions that allow for the expression of large amounts of antibodies or peptides. In some embodiments, effective culture conditions include, but are not limited to, effective culture media, bioreactors, temperature, pH, and oxygen conditions that allow for protein production. Culture media typically comprise aqueous solutions containing assimilated carbon, nitrogen, and phosphate sources, as well as appropriate salts, minerals, metals, and other nutrients, such as vitamins. The cells of the present invention can be cultured in conventional bioreactors, shake flasks, test tubes, microtiter plates, and culture dishes. In some embodiments, culture is carried out at temperatures, pH, and oxygen levels suitable for the recombinant cells. The culture conditions are within the expertise of those skilled in the art.

[0325] For example, suitable culture media for eukaryotic cell culture include, but are not limited to, Iscove modified Dulbecco medium, RPMI 1640, Minimal Essential Medium-α (MEM-α), Dulbecco modified Eagle medium (DMEM), Grace complete insect medium, Ham's F-10 or F-12 containing L-glutamine, Schneider insect medium, or any other medium known to those skilled in the art. Additionally, the culture media described herein include, but are not limited to, chemically defined media, media containing hydrolysates, and simple media. The selection of appropriate culture media and cell culture conditions for a specific cell type will be apparent to those skilled in the art.

[0326] In some embodiments, depending on the vector and host system used for production, the polypeptides obtained by the present invention are retained in recombinant cells, secreted into fermentation medium, secreted into the space between two cell membranes (e.g., the periplasmic space in Escherichia coli); or retained on the outer surface of a cell or viral membrane.

[0327] In some implementations, the antibody or peptide is recovered after a predetermined incubation period.

[0328] The polypeptides of the present invention are purified using various standard protein purification techniques, such as, but not limited to, affinity chromatography, ion exchange chromatography, filtration, electrophoresis, hydrophobic interaction chromatography, gel filtration chromatography, reverse phase chromatography, concanavalin A chromatography, chromatographic focusing, and differential dissolution.

[0329] In some embodiments, to facilitate recovery, the expressed coding sequence may be modified to encode the polypeptide and the fused cleavable moiety of the present invention. For example, the polypeptide may be designed such that it can be readily separated by affinity chromatography, for example by immobilization onto a column specific to the cleavable moiety. In one embodiment, the cleavage site is modified between the polypeptide and the cleavable moiety, and the polypeptide can be released from the chromatography column by treatment with a suitable enzyme or reagent that specifically cleaves the polypeptide at that site [e.g., see Booth et al., Immunol. Lett. 19:65-70 (1988); and Gardella et al., J. Biol. Chem. 265:15854-15859 (1990)].

[0330] In some embodiments, the polypeptides of the present invention are recovered in a "substantially pure" form. The phrase "substantially pure" refers to a purity that allows the protein to be used effectively in the applications described herein.

[0331] In some embodiments, the polypeptides of the present invention can also be synthesized using an in vitro expression system. In one embodiment, the in vitro synthesis method is well known in the art, and the components of the system are commercially available.

[0332] In some implementations, the peptide is synthesized and purified; and its therapeutic efficacy is determined in vivo or in vitro.

[0333] Pharmaceutical compositions This disclosure provides pharmaceutical compositions comprising the anti-5T4 antigen-binding domain, antibody, and bispecific or bicomplementary antibody-drug conjugates described herein, as well as pharmaceutically acceptable carriers, diluents, or excipients. Pharmaceutical compositions comprising immune cells are also considered within the scope of this disclosure, said immune cells including CARs comprising the antigen-binding domain described herein.

[0334] As used herein, "drug carrier" includes any and all physiologically compatible solvents, dispersion media, coatings, antimicrobial and antifungal agents, isotonic agents, and absorption delay agents. The carrier material is non-toxic and does not interfere with the bioavailability of the active ingredient. Such formulations may conventionally contain salts, buffers, preservatives, compatible carriers, and optionally other therapeutic agents. Such pharmaceutically acceptable formulations may also conventionally contain compatible solid or liquid fillers, diluents, or encapsulating substances suitable for human administration. The term "carrier" refers to a natural or synthetic organic or inorganic component with which the active ingredient is combined to facilitate administration. Preferably, the carrier is suitable for intravenous, intramuscular, subcutaneous, parenteral, spinal, or epidermal administration (e.g., by injection or infusion).

[0335] Pharmaceutically acceptable diluents include saline and aqueous buffer solutions. Drug carriers include sterile aqueous solutions or dispersions, as well as sterile powders for the ad hoc preparation of sterile injections or dispersions. The use of such media and reagents for pharmaceutically active substances is known in the art.

[0336] The pharmaceutical composition may be present in a form known in the art and acceptable for therapeutic use. In some embodiments, the pharmaceutical composition of the present invention is a liquid formulation. In other embodiments, the pharmaceutical composition of the present invention is lyophilized. In further embodiments, the pharmaceutical composition of the present invention is a reconstituted liquid formulation. In some embodiments, the liquid formulation of the present invention is an aqueous formulation. In other embodiments, the liquid formulation is non-aqueous.

[0337] Compositions comprising the anti-5T4 antigen-binding domain, antibody, and bispecific antibody-drug conjugate of this disclosure can be formulated for administration via various methods known in the art. As will be appreciated by those skilled in the art, the route and / or mode of administration vary depending on the desired outcome. For certain routes of administration, it may be necessary to co-administer the composition with a substance to prevent its inactivation. For example, antibody-drug conjugates may be administered to a subject in a suitable carrier such as liposomes or diluents.

[0338] In some embodiments, the formulation for administration to a subject comprises sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Some embodiments include non-aqueous solvents such as propylene glycol, polyethylene glycol, vegetable oils (e.g., olive oil), organic esters (e.g., ethyl oleate), and other solvents known to those skilled in the art. In some embodiments of the invention, physiologically acceptable carriers (or excipients) are optionally used. Examples of such carriers include, for example, saline, PBS, Ringer's solution, lactated Ringer's solution, etc. Additionally, preservatives and additives are optionally incorporated into the composition to help ensure stability and sterility. For example, antibiotics and other bactericides, antioxidants, chelating agents, etc., are all optionally present in the various embodiments of the compositions herein.

[0339] Regardless of the chosen route of administration, the compositions of this disclosure and / or the pharmaceutical compositions of the present invention, which can be used in a suitable hydrated form, can be formulated into pharmaceutically acceptable dosage forms by conventional methods known to those skilled in the art.

[0340] The pharmaceutical composition may optionally be administered to a subject requiring treatment (therapeutic or prophylactic) in any suitable sterile drug carrier. Such drug carriers act to maintain the solubility and efficacy of the anti-5T4 antibody or antibody-drug conjugate.

[0341] In some embodiments, the composition used in the methods disclosed herein comprises a solution or emulsion intended for use in various routes of administration, and in some embodiments, it is an aqueous solution or emulsion comprising a safe and effective amount of the compounds disclosed herein, and optionally other compounds.

[0342] The composition must be sterile and flowable to the point that it can be delivered via a syringe. Besides water, the carrier is preferably an isotonic buffered saline solution. Suitable flowability can be maintained, for example, by using a coating such as lecithin, maintaining the desired particle size in the case of a dispersion, and using a surfactant. In many cases, it is preferable to include an isotonic agent in the composition, such as sugars, polyols such as mannitol or sorbitol, and sodium chloride.

[0343] The actual dose level of the active ingredient in the pharmaceutical composition of the present invention can be modified to obtain an amount of active ingredient that is effective in achieving the desired therapeutic response for a specific subject, composition, and administration method, without being toxic to the subject. The selected dose level depends on various pharmacokinetic factors, including the activity of the specific composition of the present invention used, the route of administration, the time of administration, the excretion rate of the specific compound to be used, the duration of treatment, other drugs, compounds, and / or materials used in combination with the specific composition used, the age, sex, weight, condition, general health, and medical history of the subject to be treated, and similar factors well known in the medical field.

[0344] Therapeutic methods This disclosure provides methods for treating diseases or conditions in subjects with such needs, methods comprising administering a therapeutically effective amount of an anti-5T4 bispecific antibody-drug conjugate or a pharmaceutical composition comprising the bispecific antibody-drug conjugate disclosed herein. Methods comprising administering an anti-5T4 antigen-binding domain, for example as part of immunotherapy, are also considered to be within the scope of this disclosure. Methods of this disclosure also include adoptive cell therapy comprising administering immune cells, such as T cells or NK cells, expressing a receptor comprising the 5T4 antigen-binding domain described herein.

[0345] In some implementations, the disease or symptom is cancer. In some implementations, cancer includes solid tumors.

[0346] In some implementations, the cancer includes solid tumors. In some implementations, the cancer is selected from melanoma, renal cell carcinoma, mesothelioma, small cell lung cancer, uveal melanoma, bladder cancer, gastric cancer, head and neck squamous cell carcinoma, skin cancer, non-small cell lung cancer, colorectal cancer, prostate cancer, ovarian cancer, cervical cancer, endometrial cancer, breast cancer, pancreatic cancer, urothelial carcinoma, esophageal cancer, hepatocellular carcinoma, glioblastoma, glioma, or sarcoma.

[0347] In some implementation schemes, the cancer is selected from adrenocortical carcinoma, AIDS-related cancer, AIDS-related lymphoma, anal cancer, anorectal cancer, anal canal cancer, appendiceal cancer, pediatric cerebellar astrocytoma, pediatric astrocytoma, basal cell carcinoma, skin cancer (non-melanoma), biliary tract cancer, extrahepatic bile duct cancer, intrahepatic bile duct cancer, bladder cancer, urinary tract bladder cancer, bone cancer and joint cancer, osteosarcoma and malignant fibrous histiocytoma, brain cancer, brain tumor, brainstem glioma, cerebellar astrocytoma, and astrocytoma / malignant glioma. Ependymoma, medulloblastoma, supratentorial primitive neuroectodermal tumor, visual pathway and hypothalamic glioma, breast cancer, bronchial adenoma / carcinoid, gastrointestinal carcinoid tumor, nervous system cancers, nervous system lymphoma, central nervous system cancers, central nervous system lymphoma, cervical cancer, childhood cancers, chronic lymphocytic leukemia, chronic myeloid leukemia, chronic myelodysplastic syndrome, colon cancer, colorectal cancer, cutaneous T-cell lymphoma, lymphoid vegetations, mycosis fungoides, Cezari syndrome, endometrial cancer, esophageal cancer, extracranial germ cell tumors, gonadal extragerminal tumors, extrahepatic bile duct cancer, ocular cancer, intraocular melanoma, retinoblastoma, gallbladder cancer, gastric cancer.Gastric cancer, gastrointestinal carcinoid tumors, gastrointestinal stromal tumors (GIST), germ cell tumors, ovarian germ cell tumors, gestational trophoblastic tumors, gliomas, head and neck cancer, hepatocellular carcinoma, Hodgkin's lymphoma, hypopharyngeal cancer, intraocular melanoma, ocular cancer, islet cell tumors (endocrine pancreas), Kaposi's sarcoma, kidney cancer, renal cancer, laryngeal cancer, acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia. Chronic myeloid leukemia, hairy cell leukemia, lip and oral cancer, liver cancer, lung cancer, non-small cell lung cancer, small cell lung cancer, AIDS-related lymphoma, non-Hodgkin's lymphoma, primary central nervous system lymphoma, Waldenström macroglobulinemia, medulloblastoma, melanoma, intraocular (ocular) melanoma, Merkel cell carcinoma, malignant mesothelioma, mesothelioma, metastatic squamous neck cancer, oral cancer, tongue cancer, multiple endocrine neoplasia syndrome, mycosis fungoides, myelodysplastic syndrome Syndrome, myelodysplastic / myeloproliferative disorders, chronic myeloid leukemia, acute myeloid leukemia, multiple myeloma, chronic myeloproliferative disorders, nasopharyngeal carcinoma, neuroblastoma, oral cancer, oral cavity cancer, oropharyngeal cancer, ovarian cancer, ovarian epithelial cancer, low-grade malignant potential ovarian tumors, pancreatic cancer, islet cell pancreatic cancer, paranasal sinus cancer and nasal cavity cancer, parathyroid cancer, penile cancer, pharyngeal cancer, pheochromocytoma, pineal blastoma and supratentorial primitive neuroectodermal tumors, pituitary adenoma Plasma cell growths / multiple myeloma, pleural pulmonary blastoma, prostate cancer, rectal cancer, transitional cell carcinoma of the renal pelvis and ureter, retinoblastoma, rhabdomyosarcoma, salivary gland cancer, Ewing's sarcoma family tumors, Kaposi's sarcoma, soft tissue sarcoma, epithelioid sarcoma, synovial sarcoma, uterine cancer, uterine sarcoma, skin cancer (non-melanoma), skin cancer (melanoma), Merkel cell skin cancer, small intestine cancer, soft tissue sarcoma, squamous cell carcinoma, stomach (gastric) cancer, supratentorial primitive neuroectodermal tumors, testicular cancer, laryngeal cancer, thymoma, thymoma and thymic carcinoma, thyroid cancer, transitional cell carcinoma of the renal pelvis and ureter and other urinary organs, gestational trophoblastic tumors, urethral cancer, endometrial uterine cancer, uterine sarcoma, uterine corpus cancer, vaginal cancer, vulvar cancer, and nephroblastoma.

[0348] Cancers treated with the antigen-binding domains, antibodies, immune cells, or antibody-drug conjugates or pharmaceutical compositions comprising the present disclosure may be staged according to the American Joint Committee on Cancer (AJCC) classification as stage I, IIA, IIB, IIIA, IIIB, IIIC, or IV. The cancer to be treated may be classified according to the AJCC classification as grade GX (e.g., grade not evaluable), grade 1, grade 2, grade 3, or grade 4. The cancer to be treated may be staged according to the AJCC pathological classification (pN) as pNX, pN0, PN0 (I-), PN0 (I+), PN0 (mol-), PN0 (mol+), PN1, PN1 (mi), PN1a, PN1b, PN1c, pN2, pN2a, pN2b, pN3, pN3a, pN3b, or pN3c. Alternatively or additionally, cancer can be staged according to the TNM staging system, which divides most types of cancer into four stages. Stage 1 typically means that the cancer is relatively small and confined to the organ of origin. Stage 2 cancer usually has not yet begun to spread to surrounding tissues, but the tumor is larger than that of Stage 1. In some implementations, Stage 2 means that the cancer has spread to lymph nodes near the tumor. Stage 3 cancer is usually large and has begun to spread to surrounding tissues and lymph nodes. Stage 4 cancer, or metastatic cancer, is typically cancer that has spread from its point of origin to other organs in the body.

[0349] As used herein, "normal cell" refers to a portion of the cell that cannot be classified as a "cell proliferation disorder." Normal cells lack unregulated or abnormal growth, or both, which can lead to the development of undesirable conditions or diseases. Preferably, normal cells have a properly functioning cell cycle checkpoint control mechanism.

[0350] As used herein, “cell contact” refers to a condition in which an antibody-drug conjugate or other composition of substances is in direct contact with a cell, or close enough to induce a desired biological effect in the cell.

[0351] As used herein, “monotherapy” refers to the administration of a single active or therapeutic compound to a subject in need. Preferably, monotherapy involves the administration of a therapeutically effective amount of an active compound. Monotherapy can be contrasted with combination therapy, in which a combination of multiple active compounds is administered, preferably wherein each component in the combination is present in a therapeutically effective amount.

[0352] As used herein, “treating” or “treatment” describes the management and care of a subject for the purpose of combating a disease, condition, or symptom, and includes the administration of the anti-5T4 antigen-binding domain, antibody, antibody-drug conjugate, immune cells expressing the anti-5T4 receptor, or pharmaceutical compositions comprising the present disclosure to alleviate symptoms or complications of cancer or to eliminate cancer.

[0353] As used herein, the term "relief" is intended to describe the process by which the severity of signs or symptoms of cancer is reduced. Importantly, the signs or symptoms can be relieved rather than eliminated. In a preferred embodiment, administration of the recombinant anti-5T4 bispecific antibody-drug conjugate or pharmaceutical composition of this disclosure results in the elimination of signs or symptoms; however, elimination is not required. An effective dose is expected to reduce the severity of signs or symptoms. For example, if the severity of cancer is reduced in at least one of multiple localizations, the signs or symptoms of the condition, such as cancer (which can occur in multiple localizations), are relieved.

[0354] As used herein, the term “severity” is intended to describe the potential of cancer to progress from a precancerous or benign state to a malignant state. Alternatively or additionally, severity is intended to describe cancer staging, for example, according to the TNM system (recognized by the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC)) or other field-recognized methods. Cancer staging refers to the extent or severity of cancer based on factors such as the location of the primary tumor, tumor size, number of tumors, and lymph node involvement (cancer spread to the lymph nodes). Alternatively or additionally, severity is intended to describe tumor grading according to field-recognized methods (see National Cancer Institute, www.cancer.gov). Tumor grading is a system used to classify cancer cells according to the degree of abnormality they exhibit under a microscope and the rate at which they may grow and spread. A variety of factors are considered in determining tumor grading, including cell structure and growth patterns. The specific factors used to determine tumor grading vary from type to type of cancer. Severity also describes histological grading, also known as differentiation, which refers to the degree of similarity between tumor cells and normal cells of the same tissue type (see National Cancer Institute, www.cancer.gov). Additionally, severity describes nuclear grading, which refers to the size and shape of the nuclei within the tumor cells and the percentage of tumor cells that are dividing (see National Cancer Institute, www.cancer.gov).

[0355] As used herein, the term "invasive" refers to cancer that can grow, form, or spread rapidly. Cancers described as "invasive" may be treatment-sensitive, or they may be treatment-resistant. Invasive cancer can encompass any type of cancer. Alternatively or additionally, the term "invasive" may describe cancer that requires more intense or intensive treatment than the usual forms of treatment used for that cancer.

[0356] As used in this article, the term "refractory" describes cancer that does not respond to attempted forms of treatment. Refractory cancer can also be referred to as resistant cancer.

[0357] In another aspect of this disclosure, severity describes the extent to which a tumor has secreted growth factors, degraded the extracellular matrix, become vascularized, lost adhesion to adjacent tissues, or metastasized. Furthermore, severity describes the number of locations where the primary tumor has metastasized. Finally, severity includes the difficulty of treating different types and locations of tumors. For example, inoperable tumors, cancers with greater proximity to multiple body systems (hematologic and immune system tumors), and those most resistant to conventional treatments are considered the most severe. In these cases, prolonging the subject's life expectancy and / or alleviating pain, reducing the proportion of cancer cells or confining cancer cells to one system, and improving cancer staging / tumor grade / histological grade / nuclear grade are considered relief of signs or symptoms of cancer.

[0358] As used in this article, the term "symptom" is defined as an indication of a disease, illness, injury, or abnormality in the body. Symptoms are perceived or noticed by the individual experiencing them but may not be easily noticed by others. Others are defined as non-healthcare professionals.

[0359] As used in this article, the term "vital signs" is also defined as indications of bodily abnormalities. However, vital signs are defined as phenomena that can be observed by a doctor, nurse, or other healthcare professional.

[0360] Cancer is a group of diseases that can cause almost any sign or symptom. Signs and symptoms depend on the location of the cancer, its size, and the extent to which it affects nearby organs or structures. If the cancer spreads (metastasizes), symptoms can appear in different parts of the body.

[0361] As cancer grows, it begins to compress nearby organs, blood vessels, and nerves. This compression causes some of the signs and symptoms of cancer. Cancer can form in certain locations without causing any symptoms until it has grown to a considerable size.

[0362] Cancer can also cause symptoms such as fever, fatigue, or weight loss. This may be because cancer cells consume a large portion of the body's energy supply or release substances that alter the body's metabolism. Alternatively, cancer may prompt the immune system to react in ways that produce these symptoms. While the signs and symptoms listed above are among the more common signs and symptoms observed in cancer, many other less common signs and symptoms exist and are not listed here. However, this disclosure considers and covers all the signs and symptoms of cancer recognized in all fields.

[0363] Cancer treatment can lead to a reduction in tumor size. This reduction in tumor size can also be referred to as "tumor regression." Preferably, after treatment according to the method of this disclosure, the tumor size is reduced by 5% or more relative to its size before treatment; more preferably, the tumor size is reduced by 10% or more; more preferably, by 20% or more; more preferably, by 30% or more; more preferably, by 40% or more; even more preferably, by 50% or more; and most preferably, by more than 75% or more. Tumor size can be measured by any repeatable means. Tumor size can be measured as tumor diameter.

[0364] Cancer treatment can result in a reduction in tumor volume. Preferably, after treatment according to the method of this disclosure, the tumor volume is reduced by 5% or more relative to its size before treatment; more preferably, the tumor volume is reduced by 10% or more; more preferably, by 20% or more; more preferably, by 30% or more; more preferably, by 40% or more; even more preferably, by 50% or more; and most preferably, by more than 75% or more. The tumor volume can be measured by any repeatable means.

[0365] Cancer treatment can lead to a reduction in the number of tumors. Preferably, after treatment, the number of tumors is reduced by 5% or more compared to the number before treatment; more preferably, the number of tumors is reduced by 10% or more; even more preferably, by 20% or more; more preferably, by 30% or more; even more preferably, by 40% or more; even more preferably, by 50% or more; and most preferably, by more than 75%. The number of tumors can be measured by any repeatable measurement method. The number of tumors can be measured by counting tumors visible to the naked eye or visible at a specified magnification. Preferably, the specified magnification is 2x, 3x, 4x, 5x, 10x, or 50x.

[0366] Cancer treatment can lead to a reduction in the number of metastatic lesions in tissues or organs distant from the primary tumor site. Preferably, after treatment according to the method of this disclosure, the number of metastatic lesions is reduced by 5% or more relative to the number before treatment; more preferably, the number of metastatic lesions is reduced by 10% or more; more preferably, by 20% or more; more preferably, by 30% or more; more preferably, by 40% or more; even more preferably, by 50% or more; and most preferably, by more than 75%. The number of metastatic lesions can be measured by any repeatable measurement means. The number of metastatic lesions can be measured by counting metastatic lesions visible to the naked eye or visible at a specified magnification. Preferably, the specified magnification is 2x, 3x, 4x, 5x, 10x, or 50x.

[0367] Cancer treatment can lead to an increase in the mean survival time of the treated subject population compared to a population that has not received the anti-5T4 bispecific antibody-drug conjugate or a pharmaceutical composition comprising the present disclosure. Preferably, the mean survival time is increased by more than 30 days; more preferably, by more than 60 days; more preferably, by more than 90 days; and most preferably, by more than 120 days. The increase in the mean survival time of the population can be measured by any reproducible means. For example, the increase in the mean survival time of the population can be measured by calculating the mean survival length of the population after the initiation of treatment with the active compound. For example, the increase in the mean survival time of the population can also be measured by calculating the mean survival length of the population after the completion of the first round of treatment with the active compound.

[0368] Cancer treatment can result in a reduced mortality rate in the treated subject population compared to a population that has not received the anti-5T4 bispecific antibody-drug conjugate or a pharmaceutical composition comprising thereof. Cancer treatment can also result in a reduced mortality rate in the treated subject population compared to an untreated population. Furthermore, cancer treatment can result in a reduced mortality rate in the treated subject population compared to a population receiving monotherapy with a drug that is not an anti-5T4 bispecific antibody-drug conjugate or a pharmaceutical composition not disclosed herein. The reduction in mortality rate in the treated subject population can be measured by any reproducible means. For example, the reduction in population mortality rate can be measured by calculating the average number of disease-related deaths per unit time after the initiation of treatment with the active compound for the population. Alternatively, the reduction in population mortality rate can be measured by calculating the average number of disease-related deaths per unit time after the completion of the first round of treatment with the antibody-drug conjugate described herein for the population.

[0369] Cancer treatment can lead to a reduction in tumor growth rate. Preferably, after treatment, the tumor growth rate is reduced by at least 5% relative to the pre-treatment rate; more preferably, the tumor growth rate is reduced by at least 10%; more preferably, by at least 20%; more preferably, by at least 30%; more preferably, by at least 40%; more preferably, by at least 50%; even more preferably, by at least 50%; and most preferably, by at least 75%. The tumor growth rate can be measured by any repeatable measurement method. The tumor growth rate can be measured based on the change in tumor diameter per unit time.

[0370] Cancer treatment can lead to a reduction in tumor regrowth. Preferably, after treatment, tumor regrowth is less than 5%; more preferably, less than 10%; more preferably, less than 20%; more preferably, less than 30%; more preferably, less than 40%; more preferably, less than 50%; even more preferably, less than 50%; and most preferably, less than 75%. Tumor regrowth can be measured by any repeatable means. For example, tumor regrowth can be measured by measuring the increase in tumor diameter after previous tumor shrinkage following treatment. A reduction in tumor regrowth is indicated by the failure of the tumor to reappear after treatment has been stopped.

[0371] Cancer treatment can lead to a decrease in cell proliferation rate. Preferably, after treatment, the cell proliferation rate is reduced by at least 5%; more preferably, at least 10%; even more preferably, at least 20%; more preferably, at least 30%; even more preferably, at least 40%; even more preferably, at least 50%; and most preferably, at least 75%. The cell proliferation rate can be measured by any reproducible measurement method. For example, the cell proliferation rate can be measured by measuring the number of dividing cells in a tissue sample per unit time.

[0372] Cancer treatment can lead to a decrease in the proportion of proliferating cells. Preferably, after treatment, the proportion of proliferating cells decreases by at least 5%; more preferably, at least 10%; more preferably, at least 20%; more preferably, at least 30%; more preferably, at least 40%; more preferably, at least 50%; even more preferably, at least 50%; and most preferably, at least 75%. The proportion of proliferating cells can be measured by any reproducible measurement method. Preferably, for example, the proportion of proliferating cells is measured by quantifying the number of dividing cells relative to the number of undivided cells in a tissue sample. The proportion of proliferating cells can be equivalent to the mitotic index.

[0373] Cancer treatment can lead to a reduction in cell proliferation regions or bands. Preferably, after treatment, the size of the cell proliferation region or band is reduced by at least 5% relative to its size before treatment; more preferably, by at least 10%; more preferably, by at least 20%; more preferably, by at least 30%; more preferably, by at least 40%; more preferably, by at least 50%; even more preferably, by at least 50%; and most preferably, by at least 75%. The size of the cell proliferation region or band can be measured by any reproducible measurement method. The size of the cell proliferation region or band can be measured as the diameter or width of the cell proliferation region or band.

[0374] Cancer treatment can lead to a reduction in the number or proportion of cells with abnormal appearance or morphology. Preferably, after treatment, the number of cells with abnormal morphology is reduced by at least 5% relative to their size before treatment; more preferably, by at least 10%; more preferably, by at least 20%; more preferably, by at least 30%; more preferably, by at least 40%; more preferably, by at least 50%; even more preferably, by at least 50%; and most preferably, by at least 75%. The appearance or morphology of abnormal cells can be measured by any reproducible measurement method. Abnormal cell morphology can be measured by microscopic examination, for example, using an inverted tissue culture microscope. Abnormal cell morphology can manifest as nuclear pleomorphism.

[0375] Cancer treatment can induce cell death, and preferably, cell death results in a reduction of at least 10% in the number of cells in a population. More preferably, cell death means a reduction of at least 20%; more preferably, at least 30%; more preferably, at least 40%; more preferably, at least 50%; and most preferably, at least 75%. The number of cells in the population can be measured by any reproducible means. The number of cells in the population can be measured by fluorescence-activated cell sorting (FACS), immunofluorescence microscopy, and optical microscopy. Methods for measuring cell death include those described by Li et al. Proc Natl Acad Sci U S A. As shown in 100(5): 2674-8, 2003. In one respect, cell death occurs through apoptosis.

[0376] Combination therapy In some embodiments, it may be desirable to administer additional cancer treatments in combination with antigen-binding domains, antibodies, antibody-drug conjugates, adoptive cell therapies comprising them, or pharmaceutical compositions. For example, in some treatment regimens, chemotherapy agents, antibiotics, additional formulations comprising the antibody-drug conjugates of this disclosure, and one or more standard therapeutic agents are optionally all comprised of the compositions of the present invention. In some embodiments, the antibody-drug conjugate is administered in combination with one or more of chemotherapy, small molecule inhibitors, radiation, surgery, immunotherapy, or adoptive cell therapy.

[0377] As used herein, the terms “combination therapy,” “combination therapy,” and “combination therapy” are used interchangeably and generally refer to a treatment modality characterized as an antibody-drug conjugate or pharmaceutical composition comprising such a conjugate as provided herein, along with additional therapeutic agents or methods. Typically, a combination therapy modality is part of a specific treatment regimen intended to provide a beneficial effect from the synergistic effect of the combination of therapeutic agents. The beneficial effect of the combination may include, but is not limited to, synergistic pharmacokinetic or pharmacodynamic effects arising from the combination of therapeutic agents. The administration of these therapeutic agents in combination typically occurs over a defined time period (typically minutes, hours, days, or weeks, depending on the chosen combination). In some embodiments, combination therapy includes the sequential administration of two or more therapeutic agents, wherein each therapeutic agent is administered at different times; and the administration of these therapeutic agents, or at least two therapeutic agents, in a substantially simultaneous manner. For example, substantially simultaneous administration can be achieved by administering a single dosage form of each therapeutic agent in a fixed ratio to a subject, or by administering multiple separate dosage forms of the therapeutic agents. The sequential or substantially simultaneous administration of each therapeutic agent can be achieved via any suitable route, including but not limited to oral, intravenous, intramuscular, and direct absorption through mucosal tissues. Therapeutic agents can be administered via the same or different routes. They can be administered at the same or different intervals. For example, the first therapeutic agent in a selected combination can be administered via intravenous injection, while the other therapeutic agents in the combination can be administered orally. Alternatively, for example, all therapeutic agents can be administered orally, or all therapeutic agents can be administered via intravenous injection.

[0378] In some implementations, the combination therapy further includes the administration of the therapeutic agent as described above in combination with other bioactive ingredients and non-pharmacological therapies (e.g., surgery or radiation therapy). When the combination therapy further includes non-pharmacological treatment, the non-pharmacological treatment can be administered at any suitable time, as long as the beneficial effect from the combined action of the therapeutic agent and the non-pharmacological treatment is achieved. For example, where appropriate, the beneficial effect may still be achieved even when the non-pharmacological treatment is temporarily removed from the administration of the therapeutic agent, possibly for several days or even weeks.

[0379] In some embodiments, the additional therapeutic agent is a chemotherapeutic agent (also known as an anti-vesicle agent or antiproliferator), such as an alkylating agent; antibiotics; antimetabolites; antidotes; interferons; polyclonal or monoclonal antibodies; EGFR inhibitors; HER2 inhibitors; histone deacetylase inhibitors; hormones; mitotic inhibitors; MTOR inhibitors; multi-kinase inhibitors; serine / threonine kinase inhibitors; tyrosine kinase inhibitors; VEGF / VEGFR inhibitors; taxanes or taxane derivatives; aromatase inhibitors; anthracene rings; microtubule-targeting drugs; topoisomerase toxic drugs; inhibitors of molecular targets or enzymes (e.g., kinases or protein methyltransferases); cytidine analogues or any chemotherapeutic agent; immune checkpoint inhibitors; platinum-based anti-vesicle agents; CDK inhibitors; PARP inhibitors; or any anti-vesicle agent or antiproliferator known to those skilled in the art.

[0380] Exemplary alkylating agents suitable for use in combination therapy modalities provided herein include, but are not limited to, cyclophosphamide (Cytoxan; Neosar); chlorambucil (Leukeran); melphalan (Alkeran); carmustine (BiCNU); busulfan (Busulfex); lomustine (CeeNU); dacarbazine (DTIC-Dome); oxaliplatin (Eloxatin); carmustine (Gliadel); ifosfamide (Ifex); nitrogen mustard (Mustargen); busulfan (Myleran); carboplatin (Paraplatin); cisplatin (CDDP; Platinol); temozolomide (Temodar); thioplex; bendamustine (Treanda); or streptozotocin (Zanosar).

[0381] Suitable anthracyclines, including but not limited to, doxorubicin (doxorubicin); doxorubicin liposome (Doxil); mitoxrone (Novantrone); bleoxane; daunorubicin (Cerubidine); daunorubicin liposome (DaunoXome); actinomycin D (Cosmegen); epirubicin (Ellence); idarubicin (Idamycin); prithracin; mitamycin (Mutamycin); pentostatin (Nipent); or valstar.

[0382] Exemplary antimetabolites include, but are not limited to, fluorouracil (Adrucil); capecitabine (Xeloda); hydroxyurea (Hydrea); mercaptopurine (Purinethol); pemetrexed (Alimta); fludarabine (Fludara); nelabine (Arranon); cladribine (Cladribine Novaplus); clofarabine (Clolar); cytarabine (Cytosar-U); decitabine (Dacogen); cytarabine liposome (DepoCyt); hydroxyurea (Droxia); pralatrexate (Folotyn); fluorouracil (FUDR); gemcitabine (Gemzar); cladribine (Leustatin); fludarabine (Oforta); methotrexate (MTX; Rheumatrex); methotrexate (Trexall); thioguanine (Tabloid); TS-1 or cytarabine (TarabinPFS).

[0383] Exemplary antidotes include, but are not limited to, ethyol or mesnex.

[0384] Exemplary interferons include, but are not limited to, interferon α-2b (Intron A) or interferon α-2a (Roferon-A).

[0385] Exemplary polyclonal or monoclonal antibodies include, but are not limited to, trastuzumab (Herceptin); oflavumab (Arzerra); bevacizumab (Avastin); rituximab (Rituxan); cetuximab (Erbitux); perumumab (Vectibix); tosimomab / iodine-131 tosimomab (Bexxar); alenzamab (Campath); ibritumomab (Zevalin; In-111; Y-90 Zevalin); gemutuzumab (Mylotarg); eculizumab (Soliris); or denosumab.

[0386] Exemplary EGFR inhibitors include, but are not limited to, gefitinib (Iressa); lapatinib (Tykerb); cetuximab (Erbitux); erlotinib (Tarceva); pemumumab (Vectibix); PKI-166; cannatinib (CI-1033); mateuzumab (EMD 72000); or EKB-569.

[0387] Exemplary HER2 inhibitors include, but are not limited to, trastuzumab (Herceptin), lapatinib (Tykerb), or AC-480.

[0388] Histone deacetylase inhibitors include, but are not limited to, vorinostat (Zolinza).

[0389] Exemplary hormones include, but are not limited to, tamoxifen (Soltamox; Nolvadex); raloxifene (Evista); megestrol acetate (Megace); leuprorelin (Lupron; Lupron Depot; Eligar; Viadur); fulvestrant (Faslodex); letrozole (Femara); and triptorelin (Trelstar LA; Trelstar). Depot); Aromasin; Zoladex; Casodex; Arimidex; Androxy; Halotetin; Provera; Depo-Provera; Emcyt; Eulexin; Fareston; Firmagon; Nilandron; Plenaxis; or Teslac.

[0390] Exemplary mitotic inhibitors include, but are not limited to, paclitaxel (Taxol; Onxol; Abraxane); docetaxel (Taxotere); vincristine (Oncovin; Vincasar PFS); vinblastine (Velban); etoposide (Toposar; Etopophos; VePesid); teniposide (Vumon); ixaprazole (Ixempra); nocodazole; epothilone; vinorelbine (Navelbine); camptothecin (CPT); irinotecan (Camptosar); topotecan (Hycamtin); acridine or lamellarin D (LAM-D).

[0391] Exemplary MTOR inhibitors include, but are not limited to, everolimus (Afinitor) or tamsulosin (Torisel); rapamycin, desfomol; or AP23573.

[0392] Exemplary multi-kinase inhibitors include, but are not limited to, sorafenib (Nexavar); sunitinib (Sutent); BIBW 2992; E7080; Zd6474; PKC-412; motixab; or AP24534.

[0393] Exemplary serine / threonine kinase inhibitors include, but are not limited to, rubutux; eril / fasudil hydrochloride; frapinol; celecoxib (CYC202; Roscovitine); SNS-032 (BMS-387032); Pkc412; lichenin; KAI-9803; SF1126; VX-680; Azd1152; Arry-142886 (AZD-6244); SCIO-469; GW681323; CC-401; CEP-1347 or PD 332991.

[0394] Exemplary tyrosine kinase inhibitors include, but are not limited to, erlotinib (Tarceva); gefitinib (Iressa); imatinib (Gleevec); sorafenib (Nexavar); sunitinib (Sutent); trastuzumab (Herceptin); bevacizumab (Avastin); rituximab (Rituxan); lapatinib (Tykerb); cetuximab (Erbitux); pemumab (Vectibix); everolimus ( Afinitor; alenzusmab (Campath); gemtuzumab (Mylotarg); tamsulosinib (Torisel); pazopanib (Votrient); dasatinib (Sprycel); nilotinib (Tasigna); vatalanib (PTK787; ZK222584); CEP-701; SU5614; MLN518; XL999; VX-322; Azd0530; BMS-354825; SKI-606; CP-690; AG-490; WHI-P154; WHI-P131; AC-220; or AMG888.

[0395] Exemplary VEGF / VEGFR inhibitors include, but are not limited to, bevacizumab (Avastin), sorafenib (Nexavar), sunitinib (Sutent), ranibizumab, pilgatanib, or vandetanib.

[0396] Exemplary microtubule-targeting drugs include, but are not limited to, paclitaxel, docetaxel, vincristine, vinblastine, nocodazole, epothilone, and novibentine.

[0397] Exemplary topoisomerase toxic drugs include, but are not limited to, teniposide, etoposide, doxorubicin, camptothecin, daunorubicin, actinomycin D, mitoxantrone, acridine, epirubicin, and idarubicin.

[0398] Exemplary taxanes or taxane derivatives include, but are not limited to, paclitaxel and docetaxel.

[0399] Exemplary immune checkpoint inhibitors include programmed death receptor 1 (PD-1) inhibitors and CD274 molecule (PD-L1) inhibitors. Exemplary PD-1 inhibitors include pembrolizumab, nivolumab, and cimiprimab. Further examples of PD-1 inhibitors include retifanlimab, spartazolizumab, camrelizumab, tislelizumab, toripalimab, and dostalimab. Exemplary PD-L1 inhibitors include atezolizumab, avelumab, and durvalumab. Further examples of PD-L1 inhibitors include envorimab.

[0400] Exemplary platinum-based anti-biodegenerative agents include cisplatin and carboplatin.

[0401] Exemplary cyclin-dependent kinase (CDK) inhibitors include abemaciclib, palbociclib, and ribociclib.

[0402] Exemplary poly(ADP-ribose) polymerase (PARP) inhibitors include tapazolidinyl, olaparib, rucapapazolidinyl, nirapazolidinyl, and veliparib.

[0403] Exemplary generic chemotherapeutic agents, anti-proliferative agents, and anti-growth agents include, but are not limited to, Hexalen; Accutane (Amnesteem, Claravis, Sotret); Vesanoid; Vidaza; Velcade; Elspar; Ergamisol; Lysodren; and Matula. ne); Pegasparase (Oncaspar); Ontak; Photofrin; Proleukin; Revlimid; Targretin; Thalidomide; Torisel; Trisenox; Visudyne; Leucenol; (1M tegafur-0.4M 5-chloro-2,4-dihydroxypyrimidine-1M oxazine potassium) and lovastatin.

[0404] Small molecule inhibitors are drugs that, due to their small size, can be used to target both extracellular and intracellular proteins expressed by cancer cells. Small molecule inhibitors target serine / threonine / tyrosine kinases, matrix metalloproteinases (MMPs), heat shock proteins (HSPs), proteasomes, and other proteins that function in signal transduction pathways. Exemplary small molecule inhibitors include axitinib, erlotinib, imatinib, gefitinib, sunitinib, lapatinib, noritinib, cabozantinib, crizotinib, sorafenib, vemurafenib, trametinib, everolimus, tesimolimus, ruxolimus, bortezomib, pazopanib, ruzotinib, vandetinib, bosutinib, cabozantinib, ponatinib, regorafenib, ibrutinib, trametinib, perifoxine, batimistat, neovastat, prinstat, remmasostat, Ganettespib, marimastat, ocbaclata, venetoclax, and carfilzomib.

[0405] In some implementations, combination therapy modalities are provided, in which additional therapeutic agents are cytokines, such as G-CSF (granulocyte colony-stimulating factor).

[0406] In some embodiments, the pharmaceutical compositions provided herein may be administered in combination with radiotherapy. Radiotherapy may also be administered as part of a multi-agent therapy, in combination with the pharmaceutical compositions provided herein and another chemotherapeutic agent described herein. In another aspect, the pharmaceutical compositions provided herein can be combined with standard chemotherapy for administration, such as, but not limited to, CMF (cyclophosphamide, methotrexate, and 5-fluorouracil), CAF (cyclophosphamide, doxorubicin, and 5-fluorouracil), AC (doxorubicin and cyclophosphamide), FEC (5-fluorouracil, epirubicin, and cyclophosphamide), ACT or ATC (doxorubicin, cyclophosphamide, and paclitaxel), rituximab, Xeloda (capecitabine), cisplatin (CDDP), carboplatin, TS-1 (tegafur, gememstat, and oseltamistat potassium in a molar ratio of 1:0.4:1), camptothecin-11 (CPT-11, irinotecan, or Camptosar™), CHOP (cyclophosphamide, hydroxydaunorubicin, acetamiprid, and prednisone or prednisolone), R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, acetamiprid, prednisone, or prednisolone), or CMFP. (Cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone).

[0407] In some preferred embodiments, the pharmaceutical compositions provided herein can be administered in combination with inhibitors of enzymes such as receptor kinases or non-receptor kinases. Receptor kinases and non-receptor kinases are, for example, tyrosine kinases or serine / threonine kinases. The kinase inhibitors described herein are small molecules, polynucleotides, peptides, or antibodies.

[0408] Exemplary kinase inhibitors include, but are not limited to, bevacizumab (targeting VEGF), BIBW 2992 (targeting EGFR and Erb2), cetuximab / Erbitux (targeting Erb1), imatinib / Gleevec (targeting Bcr-Abl), trastuzumab (targeting Erb2), gefitinib / Iressa (targeting EGFR), ranibizumab (targeting VEGF), pilgatanib (targeting VEGF), erlotinib / Tarceva (targeting Erb1), nilotinib (targeting Bcr-Abl), lapatinib (targeting Erb1 and Erb2 / Her2), GW-572016 / lapatinib besylate (targeting HER2 / Erb2), pemumumab / Vectibix (targeting EGFR), vandetanib (targeting RET / VEGFR), E7080 (multi-target including RET and VEGFR), Herceptin (targeting HER2 / Erb2), and PKI-166. (Targeting EGFR), Canatinib / CI-1033 (Targeting EGFR), Sunitinib / SU-11464 / Sutent (Targeting EGFR and FLT3), Matozumab / Emd7200 (Targeting EGFR), EKB-569 (Targeting EGFR), Zd6474 (Targeting EGFR and VEGFR), PKC-412 (Targeting VEGFR and FLT3), Vatalanib / Ptk787 / ZK222584 (Targeting VEGFR), CEP-701 (Targeting FLT3), SU5614 (Targeting FLT3), MLN518 (Targeting FLT3), XL999 (Targeting FLT3), VX-322 (Targeting FLT3), Azd0530 (Targeting SRC), BMS-354825 (Targeting SRC), SKI-606 (Targeting SRC), CP-690 (Targeting JAK), AG-490 (Targeting JAK), WHI-P154 (Targeting JAK), WHI-P131 (Targeting JAK), Sorafenib / Nexavar (Targeting RAF kinase, VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-β, KIT, FLT-3 and RET), Dasatinib / Sprycel (BCR / ABL and Src), AC-220 (Targeting Flt3), AC-480 (Targeting all HER proteins, "pan-HER"), Motisab bisphosphate (Targeting VEGF1-3, PDGFR and c-kit), Denosumab (Targeting RANKL, inhibiting SRC), AMG888 (Targeting HER3) and AP24534 (Multiple targets including Flt3).

[0409] In some embodiments, the antibody-drug conjugate or a pharmaceutical composition comprising it is administered in combination with an adoptive cell therapy. In some embodiments, the adoptive cell therapy is chimeric antigen receptor T cell (CAR T) or CARNK cell therapy.

[0410] Dosage and administration In some embodiments, the method includes administering a dual complementary 5T4 antibody-drug conjugate. In some embodiments, the anti-5T4 antibody-drug conjugate or a pharmaceutical composition comprising it is administered to the subject as follows: daily, every 2 days, every 3 days, every 4 days, every 5 days, every 6 days, every 7 days, every 8 days, every 9 days, every 10 days, every 11 days, every 12 days, every 13 days, every 2 weeks, every 3 weeks, every 4 weeks, every 5 weeks, every 6 weeks, every 7 weeks, every 8 weeks, every 9 weeks, every 10 weeks, every 11 weeks, every 12 weeks, every 13 weeks, every 2 months, every 3 months, or every 4 months.

[0411] In some implementations, the anti-5T4 antibody-drug conjugate or a pharmaceutical composition containing it is administered to the subject daily, every 2 days, every 3 days, every 4 days, every 5 days, every 6 days, every 7 days, every 8 days, every 9 days, every 10 days, every two weeks, every three weeks, or monthly.

[0412] In some embodiments, the anti-5T4 antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject once daily. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every two days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every three days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every four days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every five days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every six days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every seven days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every eight days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every nine days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every ten days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject every eleven days. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject every twelve days. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject every thirteen days. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject every two weeks. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject every three weeks. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject monthly. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject two or more times per year. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject two or more times every two years. In some embodiments, the antibody-drug conjugate or composition comprising it is administered to the subject two or more times every two years or more.

[0413] In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject once every 7-14 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject once every 10-20 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject once every 5-15 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject once every 15-30 days.

[0414] In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 36 hours. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 48 hours. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 60 hours. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 72 hours. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 84 hours. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 96 hours. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 5 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 6 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 7 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 8-10 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 10-12 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 12-15 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 15-25 days. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 20-30 days.

[0415] In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at least once every month, at least once every two months, at least once every three months, at least once every four months, or at least once every six months. In one embodiment, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at least once every 6-12 months. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered once per quarter. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered once daily, once weekly, once every two weeks, once monthly, or once a year. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered once daily, once weekly, once monthly, or once a year, twice, or twice or more. In another embodiment, the dose is administered every two, three, four, or at least five years.

[0416] In some embodiments, administration of the antibody-drug conjugate or a pharmaceutical composition comprising thereof includes dosing intervals. For example, the antibody-drug conjugate or a pharmaceutical composition comprising thereof may be administered to the subject every three days, followed by a one-week, two-week, three-week, or one-month dosing-free period, followed by the resumption of dosing. Those skilled in the art will understand that this dosing interval is exemplary. Other durations and frequencies of dosing intervals are considered to be within the scope of this disclosure.

[0417] In some implementations, the antibody-drug conjugate or drug composition is administered for at least one week, at least two weeks, at least three weeks, at least four weeks, at least five weeks, at least six weeks, at least two months, at least three months, at least four months, at least five months, at least six months, at least seven months, at least eight months, at least nine months, at least ten months, at least eleven months, at least twelve months, at least fourteen months, at least sixteen months, at least eighteen months, at least twenty months, at least twenty-two months, at least two years, at least two and a half years, or at least three years.

[0418] In some embodiments, the anti-5T4 antibody-drug conjugate comprising the pharmaceutical composition is administered in the following doses: 0.01 µg / kg to 50.0 mg / kg, 0.01 µg / kg to 30 mg / kg, 0.01 µg / kg to 20 mg / kg, 0.01 µg / kg to 10 mg / kg, 0.01 µg / kg to 1.0 mg / kg, 0.01 µg / kg to 100 µg / kg, 1 µg / kg to 50 mg / kg, 1 µg / kg to 30 mg / kg, 1 µg / kg to 20 mg / kg, 1 µg / kg to 10 mg / kg, 1 µg / kg to 1.0 mg / kg, 1 µg / kg to 100 µg / kg, 10 µg / kg to 50.0 mg / kg, 10 µg / kg to 30 mg / kg, 10 µg / kg to 20 mg / kg, 10 µg / kg to 10 mg / kg. kg, 10 µg / kg to 1.0 mg / kg, 10 µg / kg to 100 µg / kg, 20 µg / kg to 50.0 mg / kg, 20 µg / kg to 30 mg / kg, 20 µg / kg to 20 mg / kg, 20 µg / kg to 10 mg / kg, 20 µg / kg to 1.0 mg / kg, 20 µg / kg to 100 µg / kg, 50 µg / kg to 50.0 mg / kg, 50 µg / kg to 30 mg / kg, 50 µg / kg to 20 mg / kg, 50 µg / kg to 10 mg / kg, 50 µg / kg to 5.0 mg / kg, 50 µg / kg to 4.0 mg / kg, 50 µg / kg to 3.0 mg / kg, 50 µg / kg to 2.0 mg / kg, 50 µg / kg to 1.0 mg / kg, 50 µg / kg to 100 mg / kg µg / kg, 100 µg / kg to 50.0 mg / kg, 100 µg / kg to 30 mg / kg, 100 µg / kg to 20 mg / kg, 100 µg / kg to 10 mg / kg, 100 µg / kg to 5.0 mg / kg, 100 µg / kg to 4.0 mg / kg, 100 µg / kg to 3.0 mg / kg, 100 µg / kg to 2.0 mg / kg, 100 µg / kg to 1.0 mg / kg, 1 mg / kg to 50.0 mg / kg, 1 mg / kg to 30 mg / kg, 1 mg / kg to 20 mg / kg, 1 mg / kg to 10 mg / kg, 1 mg / kg to 5.0 mg / kg, 1 mg / kg to 4.0 mg / kg, 1 mg / kg to 3.0 mg / kg, 1 mg / kg to 2.0 mg / kg.0 mg / kg, 3 mg / kg to 50.0 mg / kg, 3 mg / kg to 30 mg / kg, 3 mg / kg to 20 mg / kg, 3 mg / kg to 10 mg / kg, 3 mg / kg to 5.0 mg / kg, 5 mg / kg to 50.0 mg / kg, 5 mg / kg to 30 mg / kg, 5 mg / kg to 20 mg / kg, or 5 mg / kg to 10 mg / kg.

[0419] In some embodiments, the anti-5T4 bispecific antibody-drug conjugate or pharmaceutical composition comprising it is administered at a dose of 0.01 µg / kg to 50 mg / kg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at a dose of 20 µg / kg to 20 mg / kg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at a dose of 1 mg / kg to 10.0 mg / kg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered at a dose of 0.1 µg / kg to 10.0 mg / kg.

[0420] In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject in doses ranging from: 10 µg to 5000 mg, 10 µg to 4000 mg, 10 µg to 3000 mg, 10 µg to 2000 mg, 10 µg to 1000 mg, 10 µg to 750 mg, 10 µg to 500 mg, 10 µg to 400 mg, 10 µg to 300 mg, 10 µg to 200 mg, 10 µg to 100 mg, 100 µg to 50 mg, 100 µg to 40 mg, 100 µg to 30 mg, 100 µg to 20 mg, 100 µg to 10 mg, 100 µg to 5 mg, 100 µg to 4 mg, 100 µg to 3 mg, 300 µg to 5000 mg, 300 µg to 4000 mg, 300 µg to 4000 mg, 300 µg to 5 ... µg to 3000 mg, 300 µg to 2000 mg, 300 µg to 1000 mg, 300 µg to 500 mg, 300 µg to 400 mg, 300 µg to 300 mg, 300 µg to 200 mg, 300 µg to 100 mg, 500 µg to 50 mg, 500 µg to 40 mg, 500 µg to 30 mg, 500 µg to 20 mg, 500 µg to 10 mg, 500 µg to 5 mg, 500 µg to 4 mg, 500 µg to 3 mg, 500 µg to 2 mg, 500 µg to 1 mg, 1 mg to 500 mg, 1 mg to 400 mg, 1 mg to 300 mg, 1 mg to 200 mg, 1 mg to 100 mg, 1 mg to 50 mg, 1 mg to 40 mg, 1 mg to 30 mg, 1 mg to 20 mg, 1 mg to 10 mg, 5 mg to 500 mg, 5 mg to 400 mg, 5 mg to 300 mg, 5 mg to 200 mg, 5 mg to 100 mg, 5 mg to 50 mg, 5 mg to 40 mg, 5 mg to 30 mg, 5 mg to 20 mg, 5 mg to 10 mg, 10 mg to 500 mg, 10 mg to 400 mg, 10 mg to 300 mg, 10 mg to 200 mg, 10 mg to 100 mg, 10 mg to 50 mg, 20 mg to 500 mg, 20 mg to 300 mg, 20 mg to 200 mg, 5 mg to 100 mg, or 20 mg to 50 mg.

[0421] In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at a dose ranging from 0.05 µg to 5,000 mg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at a dose ranging from 1 mg to 3,000 mg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at a dose ranging from 10 mg to 2,000 mg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at a dose ranging from 1.0 µg to 1,000 mg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at a dose ranging from 50 µg to 500 mg. In some embodiments, the antibody-drug conjugate or pharmaceutical composition comprising it is administered to the subject at a dose ranging from 100 µg to 100 mg. In some embodiments, the anti...

Claims

1. An antibody-drug conjugate comprising: a. The first antigen-binding domain specifically binds to the first 5T4 epitope; b. A second antigen-binding domain that specifically binds to a second 5T4 epitope that is different from the first 5T4 epitope; and c. Chemotherapy agents; The first antigen-binding domain is operatively connected to the second antigen-binding domain.

2. The antibody-drug conjugate according to claim 1, wherein the first antigen-binding domain and the second antigen-binding domain are independently selected from Fab fragments, F(ab')2 fragments, scFv, scab, dAb, single-domain heavy chain antibodies, and single-domain light chain antibodies.

3. The antibody-drug conjugate according to claim 1, comprising a full-length IgG antibody containing a first antigen-binding domain.

4. The antibody-drug conjugate according to any one of claims 1-3, wherein the second antigen-binding domain comprises scFv.

5. The antibody-drug conjugate according to any one of claims 1-4, wherein the full-length IgG antigen-binding domain comprises two heavy chains and two light chains.

6. The antibody-drug conjugate according to any one of claims 1-5, wherein the second antigen-binding domain comprises scFv, and wherein the antibody-drug conjugate comprises two second antigen-binding domains scFv, both of which specifically bind to the second 5T4 epitope.

7. The antibody-drug conjugate according to any one of claims 2-6, wherein the scFv comprises a heavy chain and a light chain, and wherein: (a) The C-end of the light chain is operably connected to the N-end of the heavy chain via a connector, or (b) The C end of the heavy chain is operatively connected to the N end of the light chain via a connector.

8. The antibody-drug conjugate of claim 7, wherein the linker comprises the sequence of SEQ ID NO:

153.

9. The antibody-drug conjugate according to any one of claims 6-8, wherein the N-terminus of the second antigen-binding domain is operatively linked to the C-terminus of the heavy chain of the full-length IgG antibody comprising the first antigen-binding domain.

10. The antibody-drug conjugate according to any one of claims 6-8, wherein the C-terminus of the second antigen-binding domain is operatively linked to the N-terminus of the heavy chain of the full-length IgG antibody.

11. The antibody-drug conjugate according to claim 9 or 10, wherein the second antigen-binding domain is operatively linked to the heavy chain of the full-length IgG antibody using a linker.

12. The antibody-drug conjugate according to any one of claims 9-11, wherein the linker comprises or is composed of the amino acid sequence of SEQ ID NO:

152.

13. The antibody-drug conjugate according to any one of claims 5-12, wherein the full-length IgG antibody heavy chain comprises a heavy chain variable region domain and a heavy chain constant region domain.

14. The antibody-drug conjugate according to claim 13, wherein the heavy chain constant region domain is an IgG1 isotype constant region domain.

15. The antibody-drug conjugate according to any one of claims 5-14, wherein the full-length IgG antibody light chain comprises a light chain variable region domain and a light chain constant region domain.

16. The antibody-drug conjugate according to claim 15, wherein the light chain constant region domain is an IgG1 isotype constant region domain.

17. The antibody-drug conjugate according to any one of claims 13-16, wherein the heavy chain constant region domain comprises at least one mutation that reduces effector function, prolongs half-life, or a combination thereof.

18. The antibody-drug conjugate of claim 17, wherein the at least one mutation comprises F (L234F) at position 237 relative to SEQ ID NO: 100, C or A (S239C / A) at position 242 relative to SEQ ID NO: 100, A (N434A) at position 437 relative to SEQ ID NO: 100, or a combination thereof.

19. The antibody-drug conjugate of claim 17, wherein the at least one mutation comprises F (L234F) at position 237 relative to SEQ ID NO: 100, C or A (S239C / A) at position 242 relative to SEQ ID NO: 100, and A (N434A) at position 437 relative to SEQ ID NO:

100.

20. The antibody-drug conjugate according to any one of claims 1-19, comprising a full-length IgG antibody containing a first antigen-binding domain, wherein the second antigen-binding domain comprises scFv, and the antibody-drug conjugate comprises four polypeptides comprising: (a) Two polypeptides comprising a full-length IgG antibody heavy chain, a linker, and a second antigen-binding domain from the N-terminus to the C-terminus; and (b) Two polypeptides containing the full-length IgG antibody light chain.

21. The antibody-drug conjugate according to any one of claims 1-19, comprising a full-length IgG antibody containing a first antigen-binding domain, wherein the second antigen-binding domain comprises scFv, and the antibody-drug conjugate comprises four polypeptides comprising: (a) Two polypeptides comprising a second antigen-binding domain, a linker, and a full-length IgG antibody from the N-terminus to the C-terminus; and (b) Two polypeptides containing the full-length IgG antibody light chain.

22. The antibody-drug conjugate according to claim 20 or 21, wherein the linker comprises the amino acid sequence of SEQ ID NO:

152.

23. The antibody-drug conjugate according to any one of claims 1-22, wherein both the first antigen-binding domain and the second antigen-binding domain comprise: a. Heavy chain (HC) complementarity-determining region (CDR1) sequences selected from SEQ ID NO: 1, 4 and 13-23; b. HC CDR2 sequences selected from SEQ ID NO: 2, 5, and 24-26 and 28-39; and c. HC CDR3 sequences selected from SEQ ID NO: 3, 6 and 40-52; and One or more of the CDR1, CDR2 and CDR3 sequences are not identical between the first antigen-binding domain and the second antigen-binding domain.

24. The antibody-drug conjugate according to any one of claims 1-23, wherein both the first antigen-binding domain and the second antigen-binding domain comprise: a. Light chain (LC) complementarity-determining region (CDR1) sequences selected from SEQ ID NO: 7, 10 and 53-66; b. LC CDR2 sequences selected from SEQ ID NO: 8, 11 and 67-75; c. LC CDR3 sequences selected from SEQ ID NO: 9, 12 and 76-83; and One or more of the CDR1, CDR2 and CDR3 sequences are not identical between the first antigen-binding domain and the second antigen-binding domain.

25. The antibody-drug conjugate according to any one of claims 1-24, wherein the first antigen-binding domain comprises a heavy chain variable region domain including: a. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 1, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions relative to it; b. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 2, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions relative to it; c. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 3, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; and The first antigen-binding domain includes a light chain variable region domain comprising the following: a. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 7, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; b. An LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 8, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; and c. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 9, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions relative to it.

26. The antibody-drug conjugate according to any one of claims 1-25, wherein the second antigen-binding domain comprises a heavy chain variable region domain including: a. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 4, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; b. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 5, or a sequence having 1, 2 or 3 substitutions, insertions or deletions relative to it; c. An HC CDR3 sequence comprising the amino acid sequence of SEQ ID NO: 6, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; and The second antigen-binding domain includes a light chain variable region domain comprising the following: a. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 10, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; b. An LC CDR2 sequence comprising the amino acid sequence of SEQ ID NO: 11, or a sequence having one, two, or three substitutions, insertions, or deletions relative to it; and c. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 12, or a sequence having 1, 2, or 3 substitutions, insertions, or deletions relative to it.

27. The antibody-drug conjugate according to any one of claims 1-26, wherein the first antigen-binding domain and / or the second antigen-binding domain comprises a heavy chain variable region domain comprising a sequence selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 168, 170, and 172, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and The first antigen-binding domain and / or the second antigen-binding domain comprises a light chain variable region domain, which contains a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with such sequences.

28. The antibody-drug conjugate according to any one of claims 1-27, wherein the first antigen-binding domain and / or the second antigen-binding domain comprises a heavy chain variable region domain comprising the amino acid sequence of SEQ ID NO: 96 or 97, and a light chain variable region domain comprising the amino acid sequence of SEQ ID NO: 98 or 99.

29. The antibody-drug conjugate according to any one of claims 1-28, wherein: The first antigen-binding domain includes a. A heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 96, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and b. A light chain variable region comprising the amino acid sequence of SEQ ID NO: 98, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and The second antigen-binding domain includes: a. A heavy chain variable region comprising the amino acid sequence of SEQ ID 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and b. A light chain variable region containing the amino acid sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

30. The antibody-drug conjugate according to any one of claims 1-29, comprising a full-length IgG antibody containing a first antigen-binding domain, and wherein the antibody-drug conjugate comprises: Two polypeptides comprising a first antigen-binding domain heavy chain variable region containing the sequence of SEQ ID NO: 96, a first adapter containing the sequence of SEQ ID NO: 152, a second antigen-binding domain heavy chain variable region containing the sequence of SEQ ID NO: 97, a second adapter containing the sequence of SEQ ID NO: 153, and a second antigen-binding domain light chain variable region containing the sequence of SEQ ID NO:

99.

31. The antibody-drug conjugate of claim 30, comprising two polypeptides, said two polypeptides including a second antigen-binding domain and a light chain variable region domain comprising the sequence of SEQ ID NO:

98.

32. The antibody-drug conjugate of claim 31, wherein the full-length IgG antibody comprises an IgG1 isotype constant region domain.

33. The antibody-drug conjugate according to any one of claims 1-32, wherein the second antigen-binding domain is an scFv comprising a heavy chain domain and a light chain variable region domain, wherein the heavy chain domain comprises the sequence of SEQ ID NO: 97, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and the light chain variable region domain comprises the sequence of SEQ ID NO: 99, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

34. The antibody-drug conjugate according to any one of claims 1-33, comprising a full-length IgG antibody containing a first antigen-binding domain, wherein the second antigen-binding domain comprises scFv, and the antibody-drug conjugate comprises four polypeptides comprising: (a) Two polypeptides, which include, from the N-terminus to the C-terminus: The sequence includes a first antigen-binding domain heavy chain variable region containing the sequence of SEQ ID NO: 96, an IgG1 isotype constant region containing the sequence of SEQ ID NO: 148, a first adapter containing the sequence of SEQ ID NO: 152, a second antigen-binding domain heavy chain variable region containing the sequence of SEQ ID NO: 97, a second adapter containing the sequence of SEQ ID NO: 153, and a second antigen-binding domain light chain variable region containing the sequence of SEQ ID NO:

99. (b) Two polypeptides comprising, from the N-terminus to the C-terminus, a first antigen-binding domain and a variable light chain domain containing the sequence of SEQ ID NO: 98, and The light chain constant region structural domain containing the sequence of SEQ ID NO:

149.

35. The antibody-drug conjugate according to any one of claims 1-34, comprising a full-length IgG antibody containing a first antigen-binding domain, wherein the second antigen-binding domain comprises scFv, and the antibody-drug conjugate comprises four polypeptides comprising: (a) Two polypeptides comprising the sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) Two polypeptides comprising the sequence of SEQ ID NO: 101, or having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

36. The antibody-drug conjugate according to any one of claims 1-35, wherein the chemotherapeutic agent is conjugated via a linker to at least one of a full-length IgG antibody comprising a first antigen-binding domain or a second antigen-binding domain.

37. The antibody-drug conjugate according to any one of claims 1-36, wherein the chemotherapeutic agent is olistatin.

38. The antibody-drug conjugate of claim 37, wherein the oprestatin is selected from oprestatin E (AE), monomethyl oprestatin D (MMAD), monomethyl oprestatin E (MMAE), monomethyl oprestatin F (MMAF), and synthetic analogues of dolasstatin.

39. The antibody-drug conjugate according to any one of claims 36-38, wherein the adapter is a cleavable adapter.

40. The antibody-drug conjugate according to any one of claims 36-38, wherein the linker is an uncuttable linker.

41. The antibody-drug conjugate according to any one of claims 1-40, wherein the antibody-drug conjugate is tetravalent for binding to the 5T4 antigen.

42. The antibody-drug conjugate according to any one of claims 1-41, wherein the equilibrium dissociation constant (KD) for binding 5T4 with respect to at least one of the first antigen-binding domain or the second antigen-binding domain is from 3.63 x 10⁻¹² to 7.75 x 10⁻¹⁰ M.

43. The antibody-drug conjugate according to claim 42, wherein the KD is less than or equal to 7.75 x 10⁻¹⁰ M.

44. The antibody-drug conjugate according to any one of claims 1-43, wherein the equilibrium dissociation constant (KD) for the binding of the first antigen-binding domain to 5T4 is from 3.63 x 10⁻¹² to 1.43 x 10⁻⁹ M.

45. The antibody-drug conjugate according to any one of claims 1-44, wherein the equilibrium dissociation constant (KD) for the binding of 5T4 with respect to the second antigen-binding domain is from 3.63 x 10⁻¹² to 1.34 x 10⁻⁹ M.

46. ​​The antibody-drug conjugate according to any one of claims 1-45, wherein the equilibrium dissociation constant (KD) for the binding of both the first antigen-binding domain and the second antigen-binding domain is 3.63 x 10⁻¹² to 7.75 x 10⁻¹⁰ M.

47. The antibody-drug conjugate according to any one of claims 1-46, wherein the equilibrium dissociation constant (KD) for binding of Fcγ receptor IIa to an IgG antibody comprising a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to 3.74 x 10⁻⁶ M.

48. The antibody-drug conjugate according to any one of claims 1-47, wherein the equilibrium dissociation constant (KD) for the binding of Fcγ receptor IIb to an IgG antibody comprising a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to 1.16 x 10⁻⁷ M.

49. The antibody-drug conjugate according to any one of claims 1-48, wherein the equilibrium dissociation constant (KD) for binding of Fcγ receptor IIIa to an IgG antibody comprising a first antigen-binding domain and / or a second antigen-binding domain is less than or equal to 5.05 x 10⁻⁸ M.

50. A nucleic acid system encoding a bispecific antibody according to any one of claims 1-49.

51. One or more vectors comprising the nucleic acid system according to claim 50.

52. A cell comprising the nucleic acid system of claim 50 or the vector of claim 51.

53. A pharmaceutical composition comprising an antibody-drug conjugate according to any one of claims 1-49, and a pharmaceutically acceptable carrier, diluent, or excipient.

54. A method for preparing antibody-drug conjugates, comprising: a. Contacting various cells with the nucleic acid system according to claim 50 or the carrier according to claim 51; (b) The plurality of cells are cultured under conditions in which the bispecific antibody is expressed by at least one of the plurality of cells; c. Purify the bispecific antibody; and d. Conjugate the bispecific antibody to a chemotherapeutic agent.

55. The antibody-drug conjugate according to any one of claims 1-49 or the pharmaceutical composition according to claim 52, in a method of treating cancer in a subject.

56. The antibody-drug conjugate according to any one of claims 1-49, used to manufacture a medicament for treating cancer in a subject.

57. A method of treating cancer in a subject, comprising administering a therapeutically effective amount of an antibody-drug conjugate according to any one of claims 1-49.

58. A method of treating cancer in a subject with this need, the method comprising administering to the subject with this need a therapeutically effective amount of an antibody-drug conjugate, wherein the antibody-drug conjugate comprises: a. The first antigen-binding domain specifically binds to the first 5T4 epitope; b. A second antigen-binding domain that specifically binds to a second 5T4 epitope that is different from the first 5T4 epitope; and c. Chemotherapy agents; The first antigen-binding domain is operatively connected to the second antigen-binding domain.

59. The method of claim 58, wherein the antibody-drug conjugate comprises two polypeptides having the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and Two polypeptides comprising the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

60. The method according to any one of claims 57-59, wherein the cancer cells express 5T4.

61. The method according to any one of claims 57-60, wherein the cancer is selected from lung cancer, gastric cancer, ovarian cancer, colorectal cancer, bladder cancer, breast cancer, cervical cancer, mesothelioma, ovarian cancer, pancreatic cancer, prostate cancer, and kidney cancer.

62. The method of claim 61, wherein the lung cancer is non-small cell lung cancer.

63. The method according to any one of claims 57-62, wherein the first antibody and the second antibody bind to at least one different 5T4 molecule on the surface of a cancer cell.

64. The method according to any one of claims 57-62, wherein the first antibody and the second antibody bind to the same 5T4 molecule on the surface of cancer cells.

65. The method according to any one of claims 57-64, wherein the method alleviates signs or symptoms of cancer.

66. The method according to any one of claims 57-65, wherein the method reduces tumor volume, tumor number, slows tumor growth rate, or a combination thereof.

67. The method according to any one of claims 57-66, wherein the method increases the survival of the subject.

68. A method for manufacturing a bispecific antibody-drug conjugate, the method comprising: (a) Culturing cells containing a nucleic acid system encoding a bispecific antibody under conditions that induce bispecific antibody expression, wherein the bispecific antibody comprises the following structure: a. The first antigen-binding domain specifically binds to the first 5T4 epitope; b. A second antigen-binding domain that specifically binds to a second 5T4 epitope that is different from the first 5T4 epitope; and c. Chemotherapy agents; The first antigen-binding domain is operatively connected to the second antigen-binding domain; and (b) Recover the bispecific antibody; and (c) Conjugate the bispecific antibody to a chemotherapeutic agent.

69. A kit comprising an antibody-drug conjugate according to any one of claims 1-49, a nucleic acid system according to claim 50, a vector according to claim 51, a cell according to claim 52, or a pharmaceutical composition according to claim 53.

70. An antigen-binding domain comprising a heavy chain variable region domain and a light chain variable region domain; The heavy chain variable region structural domain includes: a. A heavy chain (HC) complementarity-determining region (CDR1) sequence selected from SEQ ID NO: 1, 4 and 13-23, or a sequence having 1, 2 or 3 substitutions, insertions or deletions relative to it; b. HC CDR2 sequences selected from SEQ ID NO: 2, 5, and 24-39, or sequences having 1, 2, or 3 substitutions, insertions, or deletions relative to them; and c. HC CDR3 sequences selected from SEQ ID NO: 3, 6, and 40-52, or sequences having 1, 2, or 3 substitutions, insertions, or deletions relative to them; and The light chain variable region structural domain includes: a. Light chain (LC) complementarity-determining region (CDR1) sequences selected from SEQ ID NO: 7, 10 and 53-66, or sequences having 1, 2 or 3 substitutions, insertions or deletions relative to them; b. LC CDR2 sequences selected from SEQ ID NO: 8, 11, and 67-75, or sequences having 1, 2, or 3 substitutions, insertions, or deletions relative to them; and c. LC CDR3 sequences selected from SEQ ID NO: 9, 12 and 76-83, or sequences having 1, 2 or 3 substitutions, insertions or deletions relative to them.

71. The antigen-binding domain according to claim 70, wherein the heavy chain variable region domain comprises: a. HC CDR1 containing SEQ ID NO: 1, HC CDR2 containing SEQ ID NO: 2, and HC CDR3 containing SEQ ID NO: 3; b. HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 5, and HC CDR3 containing SEQ ID NO: 6; c. HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 24, and HC CDR3 containing SEQ ID NO: 40; d. HC CDR1 containing SEQ ID NO: 13, HC CDR2 containing SEQ ID NO: 25, and HC CDR3 containing SEQ ID NO: 41; e. HC CDR1 containing SEQ ID NO: 14, HC CDR2 containing SEQ ID NO: 26, and HC CDR3 containing SEQ ID NO: 42; f. HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 28, and HC CDR3 containing SEQ ID NO: 43; g. HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 29, and HC CDR3 containing SEQ ID NO: 44; h. HC CDR1 containing SEQ ID NO: 16, HC CDR2 containing SEQ ID NO: 30, and HC CDR3 containing SEQ ID NO: 45; i. HC CDR1 containing SEQ ID NO: 17, HC CDR2 containing SEQ ID NO: 31, and HC CDR3 containing SEQ ID NO: 46; j. HC CDR1 containing SEQ ID NO: 18, HC CDR2 containing SEQ ID NO: 32, and HC CDR3 containing SEQ ID NO: 47; k. HC CDR1 containing SEQ ID NO: 19, HC CDR2 containing SEQ ID NO: 33, and HC CDR3 containing SEQ ID NO: 48; The HC CDR1 containing SEQ ID NO: 20, the HC CDR2 containing SEQ ID NO: 34, and the HC CDR3 containing SEQ ID NO: 49; m. Containing HC CDR1 of SEQ ID NO: 4, HC CDR2 of SEQ ID NO: 35, and HC CDR3 of SEQ ID NO: 50; n. HC CDR1 containing SEQ ID NO: 14, HC CDR2 containing SEQ ID NO: 36, and HC CDR3 containing SEQ ID NO: 51; o. HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 37, and HC CDR3 containing SEQ ID NO: 3; p. HC CDR1 containing SEQ ID NO: 21, HC CDR2 containing SEQ ID NO: 38, and HC CDR3 containing SEQ ID NO: 3; q. HC CDR1 containing SEQ ID NO: 22, HC CDR2 containing SEQ ID NO: 39, and HC CDR3 containing SEQ ID NO: 45; or r. HC CDR1 containing SEQ ID NO: 23, HC CDR2 containing SEQ ID NO: 32 and HC CDR3 containing SEQ ID NO:

52.

72. The antigen-binding domain according to claim 70 or 71, wherein the light chain variable region comprises: a. LC CDR1 containing SEQ ID NO: 7, LC CDR2 containing SEQ ID NO: 8, and LC CDR3 containing SEQ ID NO: 9; b. LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 12; c. LC CDR1 containing SEQ ID NO: 53, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; d. LC CDR1 containing SEQ ID NO: 54, LC CDR2 containing SEQ ID NO: 67, and LC CDR3 containing SEQ ID NO: 77; e. LC CDR1 containing SEQ ID NO: 55, LC CDR2 containing SEQ ID NO: 68, and LC CDR3 containing SEQ ID NO: 78; f. LC CDR1 containing SEQ ID NO: 56, LC CDR2 containing SEQ ID NO: 69, and LC CDR3 containing SEQ ID NO: 79; g. LC CDR1 containing SEQ ID NO: 57, LC CDR2 containing SEQ ID NO: 69, and LC CDR3 containing SEQ ID NO: 79; h. LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; i. LC CDR1 containing SEQ ID NO: 59, LC CDR2 containing SEQ ID NO: 70, and LC CDR3 containing SEQ ID NO: 80; j. LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71, and LC CDR3 containing SEQ ID NO: 81; k. LC CDR1 containing SEQ ID NO: 61, LC CDR2 containing SEQ ID NO: 72, and LC CDR3 containing SEQ ID NO: 77; l. LC CDR1 containing SEQ ID NO: 62, LC CDR2 containing SEQ ID NO: 70 and LC CDR3 containing SEQ ID NO: 82; m. LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 73, and LC CDR3 containing SEQ ID NO: 12; n. LC CDR1 containing SEQ ID NO: 63, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; o. LC CDR1 containing SEQ ID NO: 64, LC CDR2 containing SEQ ID NO: 68, and LC CDR3 containing SEQ ID NO: 78; p. LC CDR1 containing SEQ ID NO: 65, LC CDR2 containing SEQ ID NO: 74, and LC CDR3 containing SEQ ID NO: 9; q. LC CDR1 containing SEQ ID NO: 66, LC CDR2 containing SEQ ID NO: 75, and LC CDR3 containing SEQ ID NO: 9; r. LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; or s. LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71 and LC CDR3 containing SEQ ID NO:

83.

73. The antigen-binding domain according to any one of claims 70-72, wherein: a. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 1, HCCDR2 containing SEQ ID NO: 2, and HC CDR3 containing SEQ ID NO: 3, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 7, LC CDR2 containing SEQ ID NO: 8, and LC CDR3 containing SEQ ID NO: 9; b. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HCCDR2 containing SEQ ID NO: 5, and HC CDR3 containing SEQ ID NO: 6, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 12; c. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 24, and HC CDR3 containing SEQ ID NO: 40, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 53, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; d. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 13, HC CDR2 containing SEQ ID NO: 25, and HC CDR3 containing SEQ ID NO: 41, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 54, LC CDR2 containing SEQ ID NO: 67, and LC CDR3 containing SEQ ID NO: 77; e. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 14, HC CDR2 containing SEQ ID NO: 26, and HC CDR3 containing SEQ ID NO: 42, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 55, LC CDR2 containing SEQ ID NO: 68, and LC CDR3 containing SEQ ID NO: 78; f. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 28, and HC CDR3 containing SEQ ID NO: 43, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 56, LC CDR2 containing SEQ ID NO: 69, and LC CDR3 containing SEQ ID NO: 79; g. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 29, and HC CDR3 containing SEQ ID NO: 44, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 57, LC CDR2 containing SEQ ID NO: 69, and LC CDR3 containing SEQ ID NO: 79; h. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 16, HC CDR2 containing SEQ ID NO: 30, and HC CDR3 containing SEQ ID NO: 45, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; i. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 17, HC CDR2 containing SEQ ID NO: 31, and HC CDR3 containing SEQ ID NO: 46, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 59, LC CDR2 containing SEQ ID NO: 70, and LC CDR3 containing SEQ ID NO: 80; j. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 18, HC CDR2 containing SEQ ID NO: 32, and HC CDR3 containing SEQ ID NO: 47, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71, and LC CDR3 containing SEQ ID NO: 81; k. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 19, HC CDR2 containing SEQ ID NO: 33, and HC CDR3 containing SEQ ID NO: 48, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 61, LC CDR2 containing SEQ ID NO: 72, and LC CDR3 containing SEQ ID NO: 77; l. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 20, HC CDR2 containing SEQ ID NO: 34, and HC CDR3 containing SEQ ID NO: 49, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 62, LC CDR2 containing SEQ ID NO: 70, and LC CDR3 containing SEQ ID NO: 82; m. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HC CDR2 containing SEQ ID NO: 35, and HC CDR3 containing SEQ ID NO: 50, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 10, LC CDR2 containing SEQ ID NO: 73, and LC CDR3 containing SEQ ID NO: 12; n. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 4, HCCDR2 containing SEQ ID NO: 5, and HC CDR3 containing SEQ ID NO: 6, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 63, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; o. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 14, HC CDR2 containing SEQ ID NO: 36, and HC CDR3 containing SEQ ID NO: 51, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 64, LC CDR2 containing SEQ ID NO: 68, and LC CDR3 containing SEQ ID NO: 78; p. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 15, HC CDR2 containing SEQ ID NO: 37, and HC CDR3 containing SEQ ID NO: 3, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 65, LC CDR2 containing SEQ ID NO: 74, and LC CDR3 containing SEQ ID NO: 9; q. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 21, HC CDR2 containing SEQ ID NO: 38, and HC CDR3 containing SEQ ID NO: 3, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 66, LC CDR2 containing SEQ ID NO: 75, and LC CDR3 containing SEQ ID NO: 9; r. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 22, HC CDR2 containing SEQ ID NO: 39, and HC CDR3 containing SEQ ID NO: 45, and the light chain variable region includes LC CDR1 containing SEQ ID NO: 58, LC CDR2 containing SEQ ID NO: 11, and LC CDR3 containing SEQ ID NO: 76; or s. The heavy chain variable region structural domain includes HC CDR1 containing SEQ ID NO: 23, HC CDR2 containing SEQ ID NO: 32, and HC CDR3 containing SEQ ID NO: 52, and the light chain variable region structural domain includes LC CDR1 containing SEQ ID NO: 60, LC CDR2 containing SEQ ID NO: 71, and LC CDR3 containing SEQ ID NO:

83.

74. The antigen-binding domain according to any one of claims 70-73, wherein the heavy chain variable region domain comprises a sequence selected from SEQ ID NO: 96, 97, 102, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 156, 158, 160, 162, 164, 166, 168, 170, and 172, or a sequence having at least 80%, at least 90%, or at least 95% identity with such sequences.

75. The antigen-binding domain according to any one of claims 70-74, wherein the light chain variable region domain comprises a sequence selected from SEQ ID NO: 98, 99, 103, 105, 107, 109, 113, 115, 117, 119, 121, 122, 125, 127, 129, 131, 133, 135, 137, 139, 141, 157, 159, 161, 163, 165, 167, 169, 171, and 173, or a sequence having at least 80%, at least 90%, or at least 95% identity with such sequences.

76. The antigen-binding domain according to any one of claims 70-75, wherein: a. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 96, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 98; b. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 97, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 99; c. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 102, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 103; d. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 104, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 105; e. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 106, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 107; f. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 108, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 109; g. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 112, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 113; h. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 114, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 115; i. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 116, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 117; j. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 118, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO: 119; or k. The heavy chain variable region domain comprises the amino acid sequence of SEQ ID NO: 120, wherein the light chain variable region domain comprises the amino acid sequence of SEQ ID NO:

121.

77. The antigen-binding domain according to any one of claims 70-76, wherein the antigen-binding domain comprises a Fab fragment, an F(ab')2 fragment, scFv, scab, dAb, a single-domain heavy chain antibody, or a single-domain light chain antibody.

78. An antibody comprising an antigen-binding domain according to any one of claims 70-76.

79. A chimeric antigen receptor (CAR) comprising an antigen-binding domain according to any one of claims 70-76.

80. An immune cell comprising the CAR according to claim 79.

81. The immune cell of claim 80, wherein the immune cell is a T cell or a natural killer (NK) cell.

82. An antibody-drug conjugate comprising... (a) Specifically binds to the first antigen-binding domain of the first 5T4 epitope; (b) Specifically binds to a second antigen-binding domain of a second 5T4 epitope that is different from the first 5T4 epitope; and (c) Chemotherapy agents; The first antigen-binding domain is operatively connected to the second antigen-binding domain; The antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain, and the second antigen-binding domain contains scFv; and The antibody-drug conjugates mentioned above include: (a) Two polypeptides comprising a heavy chain variable region domain, wherein the heavy chain variable region domain comprises: i. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 1; ii. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 2; and iii. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 3; The polypeptide comprises the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) Two polypeptides comprising a light chain variable region domain, wherein the light chain variable region domain comprises: i. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 7; ii. An LC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 8; and iii. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 9; The polypeptide comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

83. An antibody-drug conjugate comprising... (a) Specifically binds to the first antigen-binding domain of the first 5T4 epitope; (b) Specifically binds to a second antigen-binding domain of a second 5T4 epitope that is different from the first 5T4 epitope; and (c) Chemotherapy agents; The first antigen-binding domain is operatively connected to the second antigen-binding domain; The antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain, and the second antigen-binding domain contains scFv. The antibody-drug conjugates mentioned above include: (a) Two polypeptides comprising a heavy chain variable region domain, wherein the heavy chain variable region domain comprises: i. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 4; ii. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 5; and iii. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 6; The polypeptide comprises the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) Two polypeptides comprising a light chain variable region domain, wherein the light chain variable region domain comprises: i. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 10; ii. An LC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 11; and iii. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 12; The polypeptide comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

84. An antibody-drug conjugate comprising... (a) Specifically binds to the first antigen-binding domain of the first 5T4 epitope; (b) Specifically binds to a second antigen-binding domain of a second 5T4 epitope that is different from the first 5T4 epitope; and (c) Chemotherapy agents; The first antigen-binding domain is operatively linked to the second antibody; The antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain, and the second antigen-binding domain contains scFv. The antibody-drug conjugates mentioned above include: (a) Two polypeptides comprising a first heavy chain variable region domain, wherein the first heavy chain variable region domain comprises: i. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 1; ii. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 2; and iii. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 3; It contains the following second-chain variable region structural domains: i. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 4; ii. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 5; and iii. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 6; And includes the following light chain variable region structural domains: i. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 7; ii. An LC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 8; and iii. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 9; The polypeptide comprises the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) Two polypeptides comprising a light chain variable region domain, wherein the light chain variable region domain comprises: i. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 10; ii. An LC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 11; and iii. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 12; The polypeptide comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

85. An antibody-drug conjugate comprising... (a) Specifically binds to the first antigen-binding domain of the first 5T4 epitope; (b) Specifically binds to a second antigen-binding domain of a second 5T4 epitope that is different from the first 5T4 epitope; and (c) Chemotherapy agents; The first antigen-binding domain is operatively connected to the second antigen-binding domain; The antibody-drug conjugate comprises a full-length IgG antibody containing a first antigen-binding domain, and the second antigen-binding domain contains scFv. The antibody-drug conjugates mentioned above include: (a) Two polypeptides comprising a first heavy chain variable region domain, wherein the first heavy chain variable region domain comprises: i. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 1; ii. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 2; and iii. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 3; It contains the following second-chain variable region structural domains: i. An HC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 4; ii. An HC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 5; and iii. An HC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 6; It contains the following light chain variable region structural domains: i. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 10; ii. An LC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 11; and iii. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 12; The polypeptide comprises the amino acid sequence of SEQ ID NO: 100, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it; and (b) Two polypeptides comprising a light chain variable region domain, wherein the light chain variable region domain comprises: i. An LC CDR1 sequence containing the amino acid sequence of SEQ ID NO: 7; ii. An LC CDR2 sequence containing the amino acid sequence of SEQ ID NO: 8; and iii. An LC CDR3 sequence containing the amino acid sequence of SEQ ID NO: 9; The polypeptide comprises the amino acid sequence of SEQ ID NO: 101, or a sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, or at least 99% identity with it.

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