Antibodies capable of specifically binding to TL1a and use thereof

Abstract

SOLUTION: The present disclosure relates to antibodies that specifically binding to TL1A and uses thereof, in particular to antibodies that specifically bind to TL1A or antigen-binding fragments thereof, nucleic acids encoding the antibodies or antigen-binding fragments thereof, vectors containing the nucleic acids, and host cells containing the nucleic acids or the vectors. Pharmaceutical compositions comprising the antibodies as well as methods of treatment using the antibodies are also provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application claims the benefit of the filing date and priority of Chinese Patent Application No. CN202410115198.1, filed on January 26, 2024, the entire contents of which, including any drawings and sequence listing, are incorporated herein by reference.

[0002] This application contains a Sequence Listing XML file that has been submitted electronically in XML format. The Sequence Listing XML file is incorporated herein by reference. The Sequence Listing XML file was created on January 15, 2025, is named 140255-00102_SL.xml, and is 68,100 bytes in size.

[0003] The present invention relates to the field of biotechnology, and more particularly to anti-TL1A antibodies and uses thereof. [Background technology]

[0004] TL1A (TNF-like ligand 1A) is a member of the tumor necrosis factor superfamily (TNFSF) encoded by the TNFSF15 gene and exists in two forms: membrane-bound and soluble. TL1A initially exists in the membrane-bound form, which is subsequently cleaved by metalloproteinases to release the soluble form, forming trimers and functioning (Kokkotis, Georgios, and Giorgos Bamias. Expert review of clinical immunology 18, 6 (2022): 551-555; Migone, Thi Sau, et al. Immunity 16, 3 (2002): 479-92). Under resting conditions, TL1A is expressed at low levels in various cell types. Upon induction of proinflammatory stimuli, TL1A expression levels rapidly increase and are primarily expressed in endothelial cells, monocytes, dendritic cells, macrophages, and several lymphocyte subsets (Richard, Arianne C et al., Journal of Leukocyte Biology, Vol. 98, 3 (2015): 333-45; Prehn, John et al., Clinical Immunology (Orlando, Fla.), Vol. 112, 1 (2004): 66-77). TL1A possesses two receptors, namely, DR3 (death receptor 3, TNFRSF25) and DcR3 (decoy receptor 3, TNFRSF6B), which are members of the tumor necrosis factor receptor superfamily (TNFRSF). DR3 is expressed on T cells, NK cells, and innate lymphoid cells (ILCs), particularly activated T cells. DcR3 lacks an intracellular signal transduction structure and plays a biological regulatory role primarily by competing with the DR3 receptor for ligand binding (Zhan, Chenyang et al., Biochemistry 48, 32 (2009): 7636-45; Papadakis, Konstantinos A et al., Journal of Immunology (Baltimore, Md.: 1950) 172, 11 (2004): 7002-7; Bamias, Giorgos et al., Journal of Immunology (Baltimore, Md.: 1950) 171, 9 (2003): 4868-74).

[0005] After binding to DR3, TL1A can regulate a series of downstream signaling pathways, including NF-κB. As an early T cell activation cofactor, TL1A provides costimulatory signals for T cell activation and proliferation, and can amplify the effector responses of Th1, Th17, Th2, and other cells, including, but not limited to, increasing the expression of IL-2 and IL-2 receptors to upregulate IL-2 signaling, costimulating the secretion of IFN-γ and other Th1-dependent proinflammatory cytokines together with IL-12 and IL-18, enhancing the production of IL-17 by binding to DR3 on Th17, and regulating the differentiation, proliferation, and function of Treg cells (Jin, S et al. Mucosal immunology 6, 5 (2013): 886-99; Holmkvist, P et al. Mucosal immunology 8, 3 (2015): 545-58; Kamada, Nobuhiko et al. Inflammatory bowel diseases 16, 4 (2010): 568-75; Takedatsu, Hidetoshi et al. Gastroenterology 135, 2 (2008): 552-67). In addition to costimulating T cells and influencing T cell-mediated inflammatory responses, TL1A can also costimulate innate lymphoid cells (ILCs) to play an important role in maintaining tissue homeostasis and defense against pathogens, particularly in mucosal tissues. Furthermore, TL1A binds to DR3 on fibroblasts and promotes the expression of collagen and IL-31R, thereby promoting the development and progression of fibrosis. As a result, the TL1A / DR3 signaling pathway is thought to be involved in a range of autoimmune, inflammatory, and fibrotic diseases (Kokkotis, Georgios, and Giorgos Bamias, supra).

[0006] Inflammatory bowel disease (IBD) is a chronic, nonspecific intestinal inflammatory disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Targeting TL1A is considered a powerful strategy for the treatment of IBD and has been initially validated in clinical trials. Representative TL1A-targeting drugs currently in clinical development include Pfizer / Roivant's TL1A monoclonal antibody RVT-3101 and Merck / Prometheus' TL1A monoclonal antibody PRA023. Although the efficacy of TL1A antibodies is promising, the issue of anti-drug antibodies (ADAs) has raised concerns. In a Phase 1 clinical trial of RVT-3101, 56 of 57 (98.2%) of 68 subjects tested positive for ADA, excluding 11 subjects with indeterminate results. 24 of 68 (35.3%) tested positive for NAb (antibody antibody antibody) (Banfield, Christopher et al., British Journal of Clinical Pharmacology, Vol. 86, 4 (2020): 812-824). RVT-3101 also demonstrated strong immunogenicity in the Phase 2a TUSCANY trial in UC patients, with 82% of 50 subjects testing positive for ADA and 10% testing positive for NAb (Danese, Silvio et al., Clinical Gastroenterology and Hepatology: The Official Clinical Practice Journal of the American Gastroenterological Association, Vol. 19, 11 (2021): 2324-2332. e6). Prometheus discloses in patent WO2022178158A1 that in a Phase 1 clinical trial of PRA023, the incidence of ADA did not exceed 20% at clinically relevant doses (high doses). However, the high concentrations of PRA023 present in the clinically relevant dose group may interfere with the detection of ADA; indeed, Prometheus reported that ADA positivity only occurred at low PRA023 concentrations, and ADA titers were inversely proportional to PRA023 exposure (the lower the drug in serum, the less interference there was).Therefore, it is reasonable to speculate that the true ADA positivity rate of PRA023 may be higher than 20%, and that the incidence of ADA may increase significantly after repeated administration. Furthermore, current TL1A antibodies also have the problems of high dosage and frequent administration. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2022 / 178158 [Non-patent literature]

[0008] [Non-Patent Document 1] Kokkotis, Georgios and Giorgos Bamias. Expert review of clinical immunology, Vol. 18, 6 (2022): 551-555 [Non-patent document 2] Migone, Thi Sau et al. Immunity Vol. 16, 3 (2002): 479-92 [Non-patent document 3] Richard, Arianne C et al. Journal of leukocyte biology 98, 3 (2015): 333-45 [Non-patent document 4] Prehn, John et al. Clinical Immunology (Orlando, Fla.) 112, 1 (2004): 66-77 [Non-Patent Document 5] Zhan, Chenyang et al. Biochemistry 48, 32 (2009): 7636-45 [Non-patent document 6] Papadakis, Konstantinos A. et al. Journal of Immunology (Baltimore, Md.: 1950) Vol. 172, 11 (2004): 7002-7 [Non-Patent Document 7] Bamias, Giorgos et al. Journal of Immunology (Baltimore, Md.: 1950) Vol. 171, 9 (2003): pp. 4868-74 [Non-patent document 8] Jin, S. et al. Mucosal immunology, vol. 6, 5 (2013): pp. 886-99 [Non-Patent Document 9] Holmkvist, P. et al. Mucosal immunology, vol. 8, 3 (2015): 545-58 [Non-Patent Document 10] Kamada, Nobuhiko et al. Inflammatory bowel diseases Vol. 16, 4 (2010): 568-75 [Non-Patent Document 11] Takedatsu, Hidetoshi et al. Gastroenterology Vol. 135, 2(2008): 552-67 [Non-Patent Document 12] Banfield, Christopher et al. British Journal of Clinical Pharmacology, Vol. 86, 4 (2020): 812-824 [Non-Patent Document 13] Danese, Silvio et al. Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association Volume 19, 11 (2021): pp. 2324-2332.e6. Summary of the Invention [Problem to be solved by the invention]

[0009] There is a need in the art to develop novel TL1A-targeting antibodies that can overcome the immunogenicity problems of current TL1A antibodies, while at the same time having better biological activity and pharmacokinetic properties. [Means for solving the problem]

[0010] (Summary of the Invention) The present invention provides specific TL1A-binding epitopes and a series of novel TL1A antibodies specific to the TL1A-binding epitopes. The novel TL1A antibodies of the present invention bind to TL1A at the specific epitopes, form smaller immune complexes with TL1A, are not readily recognized by the body, have lower immunogenicity, have better biological activity, and / or have pH-dependent TL1A-binding properties, which can reduce the level of TL1A in the body by accelerating the clearance of TL1A in lysosomes. Furthermore, optionally, the binding properties of the antibody to FcRn can be altered by Fc mutation, thereby extending the half-life of the antibody and reducing the frequency of administration.

[0011] In a first aspect of the present invention, there is provided an antigen-binding protein (e.g., an antibody) or antigen-binding fragment thereof that binds to TL1A, wherein the antigen-binding protein or antigen-binding fragment thereof binds to an epitope in TL1A comprising one or more (e.g., all or substantially all) amino acid residues selected from the group consisting of R103, G124, M196, Q193, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105, wherein the amino acid positions are numbered according to the amino acid sequence of TL1A as set forth in SEQ ID NO:68.

[0012] In some embodiments, the epitope comprises R103, G124, Y238, T239, E120, and V102. In preferred embodiments, the epitope further comprises one or more (e.g., all or substantially all) amino acid residues selected from the group consisting of M196, K240, E241, H118, H121, E122, L123, and T105.

[0013] In some embodiments, the epitope comprises amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0014] In some embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0015] In some embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, E120, and V102.

[0016] In some embodiments, the epitope consists of amino acid residues G124, M196, Y238, T239 and E120.

[0017] In some embodiments of the TL1A-binding antigen binding proteins (e.g., antibodies) or antigen-binding fragments thereof disclosed herein, the antigen binding proteins comprise a heavy chain variable region (VH) and a light chain variable region (VL), (1) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 2, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 1; (2) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 4, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 3; (3) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 6, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 5; (4) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 8, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 7; (5) VH comprises heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 10, and VL comprises light chain CDR1, light chain CDR2, and light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 9; or (6) VH comprises heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 12, and VL comprises light chain CDR1, light chain CDR2, and light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 11.

[0018] In certain embodiments, the heavy chain variable region has the amino acid sequence set forth in SEQ ID NO:10 and the light chain variable region has the amino acid sequence set forth in SEQ ID NO:9.

[0019] In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 16 to 18, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 13 to 15, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 22 to 24, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 19 to 21, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 28 to 30, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 25 to 27, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 34 to 36, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 31 to 33, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 40 to 42, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 37 to 39, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 46 to 48, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 43 to 45, respectively.

[0020] In certain embodiments, VH CDRs 1 to 3 have the amino acid sequences shown in SEQ ID NOs: 40 to 42, respectively, and VL CDRs have the amino acid sequences shown in SEQ ID NOs: 37 to 39, respectively.

[0021] In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 2, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 4, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 3. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 6, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 5. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 8, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 7.In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 9. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 12, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 11.

[0022] In certain embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 9.

[0023] In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:2, and the VL comprises the amino acid sequence set forth in SEQ ID NO:1. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:4, and the VL comprises the amino acid sequence set forth in SEQ ID NO:3. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:6, and the VL comprises the amino acid sequence set forth in SEQ ID NO:5. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:8, and the VL comprises the amino acid sequence set forth in SEQ ID NO:7. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:10, and the VL comprises the amino acid sequence set forth in SEQ ID NO:9. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:12, and the VL comprises the amino acid sequence set forth in SEQ ID NO:11.

[0024] In certain embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:10, and the VL comprises the amino acid sequence set forth in SEQ ID NO:9.

[0025] In some embodiments of the antigen binding proteins or antigen binding fragments thereof disclosed herein that bind to TL1A, the antigen binding protein is an antibody.

[0026] In some embodiments, the antibody is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0027] In some embodiments, the antibody is selected from the group consisting of a murine antibody, a chimeric antibody, a humanized antibody, and a fully human antibody.

[0028] In some embodiments, the antibody comprises an Fc region.

[0029] In some embodiments, the antibody is of an isotype selected from IgG, IgA, IgM, IgE, and IgD.

[0030] In some embodiments, the antibody is of a subtype selected from IgG1, IgG2, IgG3, and IgG4.

[0031] In some embodiments of the antigen binding proteins or antigen binding fragments thereof disclosed herein that bind to TL1A, the Fc region of the antibody comprises a modification that can increase binding to FcRn.

[0032] In some embodiments, the antibody comprises a heavy chain (HC) and a light chain (LC), (1) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO:50, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO:49; (2) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 52, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 51; (3) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 54, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 53; (4) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 56, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 55; (5) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 57; or (6) The heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 60, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 59.

[0033] In certain embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 57.

[0034] In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:50, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:49. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:52, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:51. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:54, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:53. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:56, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:55. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:60, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:59.

[0035] In certain embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57.

[0036] In some embodiments of the antigen-binding proteins or antigen-binding fragments thereof disclosed herein that bind to TL1A, the antigen-binding fragment is selected from the group consisting of Fab, Fab', F(ab')2, Fv, scFv, and ds-scFv.

[0037] In some embodiments of the antigen-binding proteins or antigen-binding fragments thereof disclosed herein that bind to TL1A, the antibodies form smaller complexes upon binding to TL1A compared to anti-TL1A antibodies that bind to epitopes other than the epitope in TL1A. In some embodiments, the particle size of the complex formed between the antibody and TL1A is less than 33 nm. In preferred embodiments, the particle size of the complex formed between the antibody and TL1A is less than 30 nm. In preferred embodiments, the particle size of the complex formed between the antibody and TL1A is less than 25 nm.

[0038] In some embodiments of the antigen-binding proteins or antigen-binding fragments thereof disclosed herein that bind to TL1A, the antibody binds to TL1A in a 1:1 ratio to form an antigen-antibody complex. In some embodiments, the Fc valency of the complex formed by the antibody and TL1A is less than 5. In a preferred embodiment, the Fc valency of the complex formed by the antibody and TL1A is 2.

[0039] In some embodiments of the antigen-binding proteins or antigen-binding fragments thereof disclosed herein that bind to TL1A, the binding of the antibody to TL1A under neutral pH conditions is stronger than the binding to TL1A under acidic conditions. In preferred embodiments, the binding of the antibody to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 6.0 or lower (e.g., pH 6.0, 5.8, 5.6). In some embodiments of the antigen-binding proteins or antigen-binding fragments thereof disclosed herein that bind to TL1A, the antibody has a 10 -9 It has a binding affinity constant (KD) of M and does not bind to TL1A at pH 5.6.

[0040] In a related further first aspect of the present invention, the present invention provides an isolated antibody or antigen-binding fragment thereof that specifically binds to TL1A, the isolated antibody comprising an immunoglobulin heavy chain (HC) comprising a heavy chain variable region (VH) comprising heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 (VH CDR1-3), and an immunoglobulin light chain (LC) comprising a variable region (VL) comprising light chain CDR1, light chain CDR2, and light chain CDR3 (VL CDR1-3), wherein VH CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 40-42, respectively, and VL CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 37-39, respectively.

[0041] In certain embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% amino acid sequence identity to SEQ ID NO: 9.

[0042] In certain embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:10, and the VL comprises the amino acid sequence set forth in SEQ ID NO:9.

[0043] In certain embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 57.

[0044] In certain embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57.

[0045] In certain embodiments, the isolated antibody is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0046] In certain embodiments, the isolated antibody is a murine antibody, a chimeric antibody, a humanized antibody, or a fully human antibody.

[0047] In certain embodiments, the isolated antibody or antigen-binding fragment thereof binds to an epitope in TL1A, wherein the epitope comprises one or more amino acid residues selected from the group consisting of R103, G124, M196, Q193, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105, wherein the amino acid positions are numbered according to the amino acid sequence of TL1A set forth in SEQ ID NO:68.

[0048] In certain embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0049] In certain embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, E120, and V102.

[0050] In certain embodiments, the epitope consists of amino acid residues G124, M196, Y238, T239 and E120.

[0051] In certain embodiments, the isolated antibody comprises an Fc region.

[0052] In certain embodiments, the antibody is of an isotype selected from the group consisting of IgG, IgA, IgM, IgE, and IgD.

[0053] In certain embodiments, the antibody is of a subtype selected from the group consisting of IgG1, IgG2, IgG3, and IgG4.

[0054] In certain embodiments, the Fc region comprises a modification capable of increasing binding to FcRn.

[0055] In certain embodiments, the antigen-binding fragment is selected from the group consisting of Fab, Fab', F(ab')2, Fv, scFv, and ds-scFv.

[0056] In certain embodiments, when compared to a control anti-TL1A antibody that binds to an epitope other than the epitope in TL1A and forms a control complex, the isolated antibody binds to TL1A to form a complex of smaller size compared to the control complex.

[0057] In certain embodiments, the size of the complex formed by the isolated antibody and TL1A is less than 33 nm, preferably less than 30 nm, and more preferably less than 25 nm.

[0058] In certain embodiments, the antibody binds to TL1A at a 1:1 molar ratio to form an antigen-antibody complex.

[0059] In certain embodiments, the Fc valency of the complex formed by the antibody and TL1A is less than 5, preferably 2.

[0060] In certain embodiments, the binding of the antibody to TL1A under neutral pH conditions is stronger than the binding to TL1A under acidic conditions, preferably the binding of the antibody to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 6.0 or below (e.g., pH 6.0, 5.8, 5.6).

[0061] In one particular embodiment, the antibody has a 10 -9 It has a binding affinity constant (KD) of M and does not bind to TL1A at pH 5.6.

[0062] In a second aspect, the present invention provides a nucleic acid encoding an antigen binding protein (e.g. an antibody) or antigen binding fragment thereof according to the first aspect of the invention, including the related first aspect of the invention.

[0063] In a third aspect, the present invention provides a vector comprising a nucleic acid according to the second aspect of the invention.

[0064] In a fourth aspect, the present invention provides a host cell comprising a nucleic acid according to the second aspect of the invention or a vector according to the third aspect of the invention.

[0065] In a fifth aspect, the present invention provides a method for preparing an antigen-binding protein (e.g. an antibody) or antigen-binding fragment thereof according to the first aspect of the invention, including the related first aspect of the invention, the method comprising: a) culturing a host cell according to the fourth aspect of the invention under conditions suitable for expression of an antigen binding protein (e.g. an antibody) or antigen binding fragment thereof; and b) isolating the antigen-binding protein (e.g., antibody) or antigen-binding fragment thereof from the host cell culture and / or culture supernatant. Includes:

[0066] In a sixth aspect, the present invention provides a pharmaceutical composition comprising an antibody or antigen-binding fragment thereof according to the first aspect of the invention (including the related first aspect of the invention), a nucleic acid according to the second aspect of the invention, a vector according to the third aspect of the invention or a host cell according to the fourth aspect of the invention and optionally a pharmaceutically acceptable carrier or excipient.

[0067] In some embodiments, the pharmaceutical composition further comprises a second therapeutic agent, optionally selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g., siRNA), a peptide, and a small molecule drug.

[0068] In a seventh aspect, the present invention provides a method of treating a disease in a subject, comprising administering to the subject an effective amount of an antibody or antigen-binding fragment thereof according to the first aspect of the invention (including the related first aspect of the invention), a nucleic acid according to the second aspect of the invention, a vector according to the third aspect of the invention, a host cell according to the fourth aspect of the invention or a pharmaceutical composition according to the sixth aspect of the invention.

[0069] In some embodiments, the disease is selected from an autoimmune disease, an inflammatory disease, and a fibrotic disease.

[0070] In some embodiments, the disease is selected from the group consisting of inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system injury, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis, and arthrofibrosis.

[0071] In some embodiments, the method further comprises a second therapeutic agent, optionally selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g., siRNA), a peptide, and a small molecule drug.

[0072] In an eighth aspect, the present invention provides the use of an antibody or antigen-binding fragment thereof according to the first aspect of the invention (including the related first aspect of the invention), a nucleic acid according to the second aspect of the invention, a vector according to the third aspect of the invention, a host cell according to the fourth aspect of the invention or a pharmaceutical composition according to the sixth aspect of the invention in the manufacture of a medicament for treating a disease in a subject.

[0073] In some embodiments, the disease is selected from an autoimmune disease, an inflammatory disease, and a fibrotic disease.

[0074] In some embodiments, the disease is selected from the group consisting of inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system injury, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis, and arthrofibrosis.

[0075] In some embodiments, the medicament is used for administration in combination with a second therapeutic agent, optionally wherein the second therapeutic agent is selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g., siRNA), a peptide, and a small molecule drug.

[0076] In a ninth aspect, the present invention provides an antibody or antigen-binding fragment thereof according to the first aspect of the invention (including the related first aspect of the invention), a nucleic acid according to the second aspect of the invention, a vector according to the third aspect of the invention, a host cell according to the fourth aspect of the invention or a pharmaceutical composition according to the sixth aspect of the invention for use in treating a disease in a subject.

[0077] In some embodiments, the disease is selected from an autoimmune disease, an inflammatory disease, and a fibrotic disease.

[0078] In some embodiments, the disease is selected from the group consisting of inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system injury, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis, and arthrofibrosis.

[0079] In some embodiments, the antibody or antigen-binding fragment thereof, nucleic acid, vector, host cell, conjugate or pharmaceutical composition is used for administration in combination with a second therapeutic agent, optionally wherein the second therapeutic agent is selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g., siRNA), a peptide, and a small molecule drug.

[0080] The invention described herein is also described in the following numbered paragraphs:

[0081] 1. An antigen-binding protein or antigen-binding fragment thereof that binds to TL1A, wherein the antigen-binding protein or antigen-binding fragment thereof binds to an epitope in TL1A, the epitope comprising one or more amino acid residues selected from the group consisting of R103, G124, M196, Q193, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102, and T105, and the amino acid positions are numbered according to the amino acid sequence of TL1A set forth in SEQ ID NO:68.

[0082] 2. The antigen-binding protein or antigen-binding fragment thereof of paragraph 1, wherein the epitope comprises R103, G124, Y238, T239, E120, V102, and preferably the epitope further comprises one or more amino acid residues selected from M196, K240, E241, H118, H121, E122, L123, and T105.

[0083] 3. The antigen-binding protein or antigen-binding fragment thereof of paragraph 1 or 2, wherein the epitope comprises amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0084] 4. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 1 to 3, wherein the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102, and T105.

[0085] 5. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 1 to 3, wherein the epitope consists of amino acid residues R103, G124, M196, Y238, T239, E120, and V102.

[0086] 6. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 1 to 3, wherein the epitope consists of amino acid residues G124, M196, Y238, T239 and E120.

[0087] 7. The antigen-binding protein comprises an immunoglobulin heavy chain variable region (VH) and a light chain variable region (VL), (1) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 10, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 9, (2) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 2, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 1; (3) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 4, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 3, (4) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 6, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 5; (5) VH comprises heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 8, and VL comprises light chain CDR1, light chain CDR2, and light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 7, or (6) The antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 4, wherein VH comprises heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 of a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO: 12, and VL comprises light chain CDR1, light chain CDR2, and light chain CDR3 of a light chain variable region having the amino acid sequence set forth in SEQ ID NO: 11.

[0088] 8. The antigen-binding protein or antigen-binding fragment thereof of paragraph 7, wherein the heavy chain variable region has the amino acid sequence set forth in SEQ ID NO: 10 and the light chain variable region has the amino acid sequence set forth in SEQ ID NO: 9.

[0089] 9. (1) VH comprises heavy chain CDRs 1 to 3 having the amino acid sequences shown in SEQ ID NOs: 40 to 42, respectively, and VL comprises light chain CDRs having the amino acid sequences shown in SEQ ID NOs: 37 to 39, respectively; (2) VH comprises heavy chain CDRs 1 to 3 having the amino acid sequences shown in SEQ ID NOs: 16 to 18, respectively, and VL comprises light chain CDRs having the amino acid sequences shown in SEQ ID NOs: 13 to 15, respectively. (3) VH comprises heavy chain CDRs 1 to 3 having the amino acid sequences shown in SEQ ID NOs: 22 to 24, respectively, and VL comprises light chain CDRs having the amino acid sequences shown in SEQ ID NOs: 19 to 21, respectively. (4) VH comprises heavy chain CDRs 1 to 3 having the amino acid sequences shown in SEQ ID NOs: 28 to 30, respectively, and VL comprises light chain CDRs having the amino acid sequences shown in SEQ ID NOs: 25 to 27, respectively. (5) VH comprises heavy chain CDRs 1 to 3 having the amino acid sequences shown in SEQ ID NOs: 34 to 36, respectively, and VL comprises light chain CDRs having the amino acid sequences shown in SEQ ID NOs: 31 to 33, respectively; or (6) The antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 8, wherein VH comprises heavy chain CDRs 1 to 3 having the amino acid sequences shown in SEQ ID NOs: 46 to 48, respectively, and VL comprises light chain CDRs having the amino acid sequences shown in SEQ ID NOs: 43 to 45, respectively.

[0090] 10. The antigen-binding protein or antigen-binding fragment thereof according to paragraph 9, wherein VH CDR1 to 3 have the amino acid sequences shown in SEQ ID NOs: 40 to 42, respectively, and VL CDR has the amino acid sequences shown in SEQ ID NOs: 37 to 39, respectively.

[0091] 11.(1) VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 10, and VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 9; (2) VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity with SEQ ID NO: 2, and VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity with SEQ ID NO: 1; (3) VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity with SEQ ID NO: 4, and VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity with SEQ ID NO: 3; (4) VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity with SEQ ID NO: 6, and VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity with SEQ ID NO: 5; (5) VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 8, and VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 7; or (6) The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 1 to 10, wherein VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 12, and VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 11.

[0092] 12. The antigen-binding protein or antigen-binding fragment thereof of paragraph 11, wherein the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 9.

[0093] 13. (1) VH comprises the amino acid sequence shown in SEQ ID NO: 10, and VL comprises the amino acid sequence shown in SEQ ID NO: 9; (2) VH comprises the amino acid sequence shown in SEQ ID NO: 2, and VL comprises the amino acid sequence shown in SEQ ID NO: 1; (3) VH comprises the amino acid sequence shown in SEQ ID NO: 4, and VL comprises the amino acid sequence shown in SEQ ID NO: 3; (4) VH comprises the amino acid sequence shown in SEQ ID NO: 6, and VL comprises the amino acid sequence shown in SEQ ID NO: 5; (5) VH comprises the amino acid sequence shown in SEQ ID NO: 8 and VL comprises the amino acid sequence shown in SEQ ID NO: 7, or (6) The antigen-binding protein or antigen-binding fragment thereof according to paragraph 12, wherein VH comprises the amino acid sequence shown in SEQ ID NO: 12 and VL comprises the amino acid sequence shown in SEQ ID NO: 11.

[0094] 14. An antigen-binding protein or antigen-binding fragment thereof according to paragraph 13, wherein VH comprises the amino acid sequence set forth in SEQ ID NO: 10 and VL comprises the amino acid sequence set forth in SEQ ID NO: 9.

[0095] 15. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 1 to 14, wherein the antigen-binding protein is an antibody.

[0096] 16. The antigen-binding protein or antigen-binding fragment thereof of paragraph 15, wherein the antibody is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0097] 17. The antigen-binding protein or antigen-binding fragment thereof of paragraph 15 or 16, wherein the antibody is selected from the group consisting of a murine antibody, a chimeric antibody, a humanized antibody, and a fully human antibody.

[0098] 18. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 15 to 17, wherein the antibody comprises an Fc region.

[0099] 19. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 15 to 18, wherein the antibody is of an isotype selected from the group consisting of IgG, IgA, IgM, IgE, and IgD.

[0100] 20. The antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 15 to 19, wherein the antibody is of a subtype selected from the group consisting of IgG1, IgG2, IgG3, and IgG4.

[0101] 21. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 15 to 20, wherein the Fc region comprises a modification capable of increasing binding to FcRn.

[0102] 22. The antibody comprises a heavy chain (HC) and a light chain (LC), (1) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 57; (2) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 50, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 49; (3) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 52, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 51; (4) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 54, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 53; (5) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 56, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 55; or (6) The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 15 to 21, wherein the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 60, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 59.

[0103] 23. The antigen-binding protein or antigen-binding fragment thereof of paragraph 22, wherein the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 57.

[0104] 24. (1) The heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 57; (2) the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 50, and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 49; (3) the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 52, and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 51; (4) The heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 54, and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 53; (5) the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 56 and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 55; or (6) The antigen-binding protein or antigen-binding fragment thereof according to paragraph 22 or 23, wherein the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 60 and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 59.

[0105] 25. The antigen-binding protein or antigen-binding fragment thereof of paragraph 24, wherein the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 58 and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 57.

[0106] 26. The antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 25, wherein the antigen-binding fragment is selected from the group consisting of Fab, Fab', F(ab')2, Fv, scFv and ds-scFv.

[0107] 27. The antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 15 to 26, which forms a complex of smaller size when bound to TL1A compared to an anti-TL1A antibody that binds to an epitope other than the epitope in TL1A.

[0108] 28. The antigen-binding protein or antigen-binding fragment thereof according to paragraph 27, wherein the particle size of the complex formed by the antibody and TL1A is less than 33 nm, preferably less than 30 nm, more preferably less than 25 nm.

[0109] 29. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 15 to 28, wherein the antibody binds to TL1A in a 1:1 ratio to form an antigen-antibody complex.

[0110] 30. The antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 15 to 29, wherein the Fc valency of the complex formed by the antibody and TL1A is less than 5, preferably 2.

[0111] 31. The antigen-binding protein or antigen-binding fragment thereof of any one of paragraphs 15 to 30, wherein the binding of the antibody to TL1A under neutral pH conditions is stronger than the binding to TL1A under acidic conditions, and preferably the binding of the antibody to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 6.0 or lower (e.g., pH 6.0, 5.8, 5.6).

[0112] 32. Antibody against TL1A at pH 7.4 -9 32. The antigen-binding protein or antigen-binding fragment thereof of paragraph 31, which has a binding affinity constant (KD) of M and does not bind to TL1A at pH 5.6.

[0113] 33. An isolated antibody that specifically binds to TL1A, comprising an immunoglobulin heavy chain (HC) comprising a heavy chain variable region (VH) including heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 (VH CDR1-3), and an immunoglobulin light chain (LC) comprising a variable region (VL) including light chain CDR1, light chain CDR2, and light chain CDR3 (VL CDR1-3), wherein VH CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 40-42, respectively, and VL CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 37-39, respectively.

[0114] 34. The isolated antibody or antigen-binding fragment thereof of paragraph 33, wherein the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% amino acid sequence identity to SEQ ID NO: 9.

[0115] 35. The isolated antibody or antigen-binding fragment thereof of paragraph 33 or 34, wherein the VH comprises the amino acid sequence set forth in SEQ ID NO: 10 and the VL comprises the amino acid sequence set forth in SEQ ID NO: 9.

[0116] 36. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 35, wherein the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% amino acid sequence identity to SEQ ID NO: 57.

[0117] 36. The isolated antibody or antigen-binding fragment thereof of paragraph 36, wherein the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 58 and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 57.

[0118] 37. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 36, wherein the isolated antibody is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0119] 38. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 37, wherein the isolated antibody is a murine antibody, a chimeric antibody, a humanized antibody, or a fully human antibody.

[0120] 39. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 38, wherein the isolated antibody or antigen-binding fragment thereof binds to an epitope in TL1A, and the epitope comprises one or more amino acid residues selected from the group consisting of R103, G124, M196, Q193, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102, and T105, and the amino acid positions are numbered according to the amino acid sequence of TL1A set forth in SEQ ID NO: 68.

[0121] 40. The isolated antibody or antigen-binding fragment thereof of paragraph 39, wherein the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0122] 41. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33-40, wherein the isolated antibody comprises an Fc region.

[0123] 42. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 41, wherein the antibody is of an isotype selected from the group consisting of IgG, IgA, IgM, IgE, and IgD.

[0124] 43. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 42, wherein the antibody is of a subtype selected from the group consisting of IgG1, IgG2, IgG3, and IgG4.

[0125] 44. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 41 to 43, wherein the Fc region comprises a modification capable of increasing binding to FcRn.

[0126] 45. An isolated antibody or antigen-binding fragment thereof according to any one of paragraphs 33 to 44, wherein the antigen-binding fragment is selected from the group consisting of Fab, Fab', F(ab')2, Fv, scFv and ds-scFv.

[0127] 46. An isolated antibody or antigen-binding fragment thereof described in any one of paragraphs 39 to 45, wherein when compared to a control anti-TL1A antibody that binds to an epitope other than the epitope in TL1A and forms a control complex, the isolated antibody binds to TL1A to form a complex of smaller size compared to the control complex.

[0128] 47. An isolated antibody or antigen-binding fragment thereof according to paragraph 46, wherein the size of the complex formed by the isolated antibody and TL1A is less than 33 nm, preferably less than 30 nm, more preferably less than 25 nm.

[0129] 48. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 47, wherein the antibody binds to TL1A at a 1:1 molar ratio to form an antigen-antibody complex.

[0130] 49. The isolated antibody or antigen-binding fragment thereof of any one of paragraphs 33 to 48, wherein the Fc valency of the complex formed by the antibody and TL1A is less than 5, preferably 2.

[0131] 50. An isolated antibody or antigen-binding fragment thereof described in any one of paragraphs 33 to 49, wherein the binding of the antibody to TL1A under neutral pH conditions is stronger than the binding to TL1A under acidic conditions, preferably the binding of the antibody to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 6.0 or lower (e.g., pH 6.0, 5.8, 5.6).

[0132] 51. Antibody against TL1A at pH 7.4 -9 51. The isolated antibody or antigen-binding fragment thereof of paragraph 50, having a binding affinity constant (KD) of M and not binding to TL1A at pH 5.6.

[0133] 52. A nucleic acid comprising a nucleotide sequence encoding an antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 51.

[0134] 53. A vector comprising a nucleic acid according to paragraph 52.

[0135] 54. A host cell comprising a nucleic acid according to paragraph 52 or a vector according to paragraph 53.

[0136] 55. A method for preparing an antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 51, comprising: a) culturing the host cell of paragraph 54 under conditions suitable for expression of the antigen binding protein or antigen binding fragment thereof; b) isolating the antigen-binding protein or antigen-binding fragment thereof from the host cell culture and / or culture supernatant.

[0137] 56. A pharmaceutical composition comprising an antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 51, a nucleic acid according to paragraph 52, a vector according to paragraph 53 or a host cell according to paragraph 54, and optionally a pharmaceutically acceptable carrier or excipient.

[0138] 57. The pharmaceutical composition of paragraph 56, further comprising a second therapeutic agent, optionally wherein the second therapeutic agent is selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g., siRNA), a peptide, and a small molecule drug.

[0139] 58. A method of treating a disease in a subject (e.g. a disease treatable by inhibiting or antagonizing the activity of TL1A and / or by the binding of TL1A to a receptor of TL1A such as DR3), comprising the step of administering to the subject an effective amount of an antigen-binding protein or antigen-binding fragment thereof described in any one of paragraphs 1 to 51, a nucleic acid described in paragraph 52, a vector described in paragraph 53, a host cell described in paragraph 54 or a pharmaceutical composition described in paragraph 56 or 57, wherein the disease is optionally selected from an autoimmune disease, an inflammatory disease and a fibrotic disease.

[0140] 59. The method of paragraph 58, wherein the disease is selected from the group consisting of inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system damage, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive blockade fibrosis, and arthrofibrosis.

[0141] 60. The method of paragraph 58 or 59, further comprising the step of administering a second therapeutic agent to the subject, preferably wherein the second therapeutic agent is selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g., siRNA), a peptide, and a small molecule drug.

[0142] 61. Use of an antigen-binding protein or antigen-binding fragment thereof according to any one of paragraphs 1 to 51, a nucleic acid according to paragraph 52, a vector according to paragraph 53, a host cell according to paragraph 54 or a pharmaceutical composition according to paragraph 56 or 57 in the manufacture of a medicament for treating a disease in a subject (e.g. a disease treatable by inhibiting or antagonizing the activity of TL1A and / or by binding of TL1A to a receptor of TL1A such as DR3), wherein the disease is optionally selected from an autoimmune disease, an inflammatory disease and a fibrotic disease.

[0143] 62. The use according to paragraph 61, wherein the disease is selected from the group consisting of inflammatory bowel disease (e.g. ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system damage, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis and arthrofibrosis.

[0144] 63. The use of paragraph 61 or 62, wherein the medicament is for use in combination administration with a second therapeutic agent, preferably the second therapeutic agent is selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an antisense oligonucleotide (e.g. siRNA), a peptide and a small molecule drug.

[0145] 64. An isolated antibody that specifically binds to TL1A, comprising an immunoglobulin heavy chain (HC) comprising a heavy chain variable region (VH) including heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 (VH CDR1-3), and an immunoglobulin light chain (LC) comprising a variable region (VL) including light chain CDR1, light chain CDR2, and light chain CDR3 (VL CDR1-3), wherein VH CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 40-42, respectively, and VL CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 37-39, respectively.

[0146] 65. The isolated antibody of paragraph 64, wherein the VH comprises the amino acid sequence set forth in SEQ ID NO: 10 and the VL comprises the amino acid sequence set forth in SEQ ID NO: 9.

[0147] 66. The isolated antibody of paragraph 64 or 65, wherein the heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 58 and the light chain comprises the amino acid sequence set forth in SEQ ID NO: 57.

[0148] 67. The isolated antibody of any one of paragraphs 64 to 66, comprising an Fc region.

[0149] 68. A nucleic acid comprising a nucleotide sequence encoding the isolated antibody of any one of paragraphs 64 to 67.

[0150] 69. A nucleic acid according to paragraph 68, comprising a nucleotide sequence encoding the isolated antibody according to paragraph 66.

[0151] 70. A vector comprising a nucleic acid according to paragraph 68 or 69.

[0152] 71. A vector according to paragraph 70, comprising a nucleic acid according to paragraph 69.

[0153] 72. A host cell comprising a nucleic acid according to paragraph 68 or 69 or a vector according to paragraph 70 or 71.

[0154] 73. A host cell according to paragraph 72, comprising a nucleic acid according to paragraph 69 or a vector according to paragraph 71.

[0155] 74. A method for preparing an isolated antibody according to any one of paragraphs 64 to 67, comprising: a) culturing a host cell according to paragraph 72 or 73 under conditions suitable for expression of the isolated antibody; and b) isolating the antibody isolated from the host cell culture and / or culture supernatant. A method comprising:

[0156] 75. A pharmaceutical composition comprising an isolated antibody according to any one of paragraphs 64 to 67 and optionally a pharmaceutically acceptable carrier or excipient.

[0157] 76. A pharmaceutical composition according to paragraph 75, comprising the isolated antibody according to paragraph 66 and a pharmaceutically acceptable carrier or excipient.

[0158] 77. A method of treating a disease in a subject, comprising administering to the subject an effective amount of an isolated antibody of any one of paragraphs 64-67.

[0159] 78. The method of paragraph 77, wherein the disease is an autoimmune disease, an inflammatory disease, or a fibrotic disease.

[0160] 79. The method of paragraph 77 or 78, comprising administering to a subject an effective amount of the isolated antibody of paragraph 66 and a pharmaceutically acceptable carrier or excipient.

[0161] 80. Use of an isolated antibody according to any one of paragraphs 64 to 67 in the manufacture of a medicament for treating a disease in a subject.

[0162] 81. The use according to paragraph 80, wherein the disease is an autoimmune disease, an inflammatory disease or a fibrotic disease.

[0163] 82. The use according to paragraph 80 or 81, wherein the isolated antibody is an isolated antibody according to paragraph 66.

[0164] Specific features of the invention to which this application pertains are set forth in the appended claims. An understanding of the features and advantages of the invention to which this application pertains can be obtained by reference to the following detailed description that sets forth illustrative embodiments and the accompanying drawings, a brief description of which follows. [Brief explanation of the drawings]

[0165] [Figure 1] ELISA binding curves of M701 antibody and control antibody to human TL1A at pH 7.4. [Figure 2] ELISA binding curves of M701 antibody and control antibody to human TL1A at pH 7.4 and pH 6.0. [Figure 3] ELISA binding curves of M701 antibody and control antibody to human TL1A at pH 7.4, pH 5.8, and pH 5.6. [Figure 4] Binding and dissociation curves of M701 antibody and control antibody to human TL1A at pH 7.4 and pH 5.6. [Figure 5] Spatial location of epitopes of M701 and control antibodies. [Figure 6A] Design (A) and results (B) of an Ouchterlony double immunodiffusion experiment for M701 and control antibodies. [Figure 6B] Design (A) and results (B) of an Ouchterlony double immunodiffusion experiment for M701 and control antibodies. [Figure 7] SEC spectra of the mixture of M701 antibody and control antibody with human TL1A. [Figure 8] Negative staining electron microscopy images of M701 antibody and control antibody binding to human TL1A. [Figure 9] Conformation of the complex of M701-4007 antibody bound to human TL1A. [Figure 10]SEC spectra of mixtures of M701-4007 Fab and human TL1A at various ratios. [Figure 11] Soluble TL1A neutralizing activity of M701 and control antibodies measured by reporter gene assay. [Figure 12] Membrane-bound TL1A neutralizing activity of M701 and control antibodies measured by reporter gene assay. [Figure 13A] Effect of M701 and control antibodies on DcR3 / TL1A interaction. [Figure 13B] Effect of M701 and control antibodies on DcR3 / TL1A interaction. [Figure 14] Inhibition of exogenous TL1A-activated T cells by M701 antibody and control antibody. [Figure 15] Inhibition of endogenous TL1A-activated immune cells by M701 and control antibodies. [Figure 16A] Pharmacokinetic study of M701 antibody and control antibody in SCID mice: (A) serum concentration-time curve of antibody, (B) serum concentration-time curve of human TL1A. [Figure 16B] Pharmacokinetic study of M701 antibody and control antibody in SCID mice: (A) serum concentration-time curve of antibody, (B) serum concentration-time curve of human TL1A. [Figure 17] Serum concentration-time curves of M701 antibody and control antibody in rhesus monkeys. DETAILED DESCRIPTION OF THE INVENTION

[0166] The above-mentioned features and advantages of the present invention, as well as further features and advantages thereof, will be more clearly understood from the following detailed description of the embodiments when considered in conjunction with the drawings.

[0167] The embodiments described in this specification with reference to the drawings are for explanation and example purposes and are used to generally understand the present invention. The embodiments should not be construed as limiting the scope of the present invention. Identical or similar elements and elements having identical or similar functions are represented by the same reference numerals throughout this specification. Definition of Terms Unless otherwise indicated or defined, all terms used have their ordinary meaning in the art, as would be apparent to one of ordinary skill in the art. Reference is made, for example, to standard handbooks such as Leuenberger, HGW, Nagel, B. and Klbl, H. (eds.), "A multilingual glossary of biotechnological terms: (IUPAC Recommendations)", Helvetica Chimica Acta (1995), CH-4010 Basel, Switzerland; Sambrook et al., "Molecular Cloning: A Laboratory Manual" (2nd ed.), vols. 1-3, Cold Spring Harbor Laboratory Press (1989); F. Ausubel et al., eds., "Current protocols in molecular biology", Green Publishing and Wiley InterScience, New York (1987); Roitt et al., "Immunology" (6th ed.), Mosby / Elsevier, Edinburgh (2001); and Janeway et al., "Immunobiology" (6th ed.), Garland Science Publishing / Churchill Livingstone, New York (2005), as well as the general background art cited above.

[0168] As used herein, "antigen" refers broadly to a molecule or portion of a molecule capable of being bound by an antibody, which in turn is capable of eliciting the production of antibodies in an animal that are capable of binding to an epitope of the antigen. An antigen can have one epitope or more than one epitope.

[0169] As used herein, the term "epitope" refers to a site on an antigen to which an antigen-binding protein binds. Epitopes can be formed from contiguous amino acids or non-contiguous amino acids juxtaposed by one or more tertiary folding of a protein. Epitopes formed by contiguous amino acids (also called linear epitopes) are generally retained upon exposure to denaturing solvents, whereas epitopes formed by tertiary folding (also called conformational epitopes) are usually lost upon treatment with denaturing solvents. An epitope typically contains at least two, more typically at least five or 8-10 amino acids in a unique spatial conformation. An epitope defines the minimal binding site of an antigen-binding protein and is therefore the specific target of an antigen-binding protein or its antigen-binding fragment.

[0170] As used herein, an "antigen-binding protein" refers to a protein or polypeptide comprising an antigen-binding portion, particularly a protein or polypeptide comprising the heavy chain variable region (VH) and / or light chain variable region (VL) of an anti-TL1A antibody disclosed herein, and capable of binding to TL1A. Examples of antigen-binding proteins include antibodies, antibody fragments (e.g., antigen-binding portions of antibodies), antibody derivatives, antibody analogs, T cell receptors (TCRs), chimeric antigen receptors (CARs), etc.

[0171] As used herein, the term "antibody" refers to an immunoglobulin molecule capable of specifically binding to a particular antigen. Such molecules typically comprise two heavy (H) chains and two light (L) chains interconnected by disulfide bonds. Each heavy chain consists of a heavy chain variable region (or domain) (abbreviated herein as VH) and a heavy chain constant region. The heavy chain constant region consists of three domains: CH1, CH2, and CH3. Each light chain consists of a light chain variable region (or domain) (abbreviated herein as VL) and a light chain constant region. The light chain constant region consists of one domain: CL. The variable regions of the heavy and light chains of an antibody contain a binding domain that interacts with an antigen. The constant regions of an antibody can mediate the binding of the immunoglobulin to host tissues or host factors, including various cells of the immune system (e.g., effector cells) and components of the complement system, such as C1q (the first component in the classical pathway of complement activation).

[0172] The heavy chain of an immunoglobulin can be divided into three functional regions: the Fd region, the hinge region, and the Fc region (fragment crystallizable). The Fd region contains the VH and CH1 domains and, when combined with the light chain, forms the Fab (fragment antigen-binding) fragment. The Fc fragment is responsible for the effector functions of the immunoglobulin, including, for example, complement fixation and binding to the analogous Fc receptor on effector cells. The hinge region, found in IgG, IgA, and IgD immunoglobulin classes, acts as a flexible spacer, allowing the Fab portion to move freely in space relative to the Fc region. Hinge domains are structurally diverse, varying in sequence and length between immunoglobulin classes and subclasses.

[0173] A "light chain variable region" (VL) or "heavy chain variable region" (VH) consists of a "framework" region interrupted by three "complementarity determining regions," or "CDRs." The framework regions serve to align the CDRs for specific binding to an epitope of an antigen. The CDRs contain the amino acid residues of an antibody primarily responsible for antigen binding. From the amino to carboxyl terminus, both the VL and VH domains comprise the following framework (FR) and CDR regions: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. CDR1, 2, and 3 of the VL domain are also referred to herein as LCDR1, LCDR2, and LCDR3, respectively. CDR1, 2, and 3 of the VH domain are also referred to herein as HCDR1, HCDR2, and HCDR3, respectively.

[0174] The assignment of amino acids to each VL and VH domain follows any conventional definition of CDR, including the Kabat definition (Kabat, Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, MD, 1987 and 1991)), the Chothia definition (Chothia and Lesk, J. Mol. Biol. 196:901-917, 1987; Chothia et al., Nature 342:878-883, 1989), the Chothia-Kabat CDR combination in which CDR-H1 is a combination of the Chothia and Kabat CDRs, the AbM definition used by Oxford Molecular's antibody modeling software, and the CONTACT definition of Martin et al. (world wide web bioinfo.org.uk / abs).

[0175] In the technical solution of the present invention, amino acid residues in a variable domain sequence can be determined using the Kabat definition, the Chothia definition, a combined definition rule including the Kabat definition and the Chothia definition, the AbM definition, the CONTACT definition, and others. For details, see the table below. It will be understood by those skilled in the art that, unless otherwise specified, the "CDR" and "complementarity determining region" of an antibody or a region thereof (e.g., a variable region) should be understood to encompass the complementarity determining region defined by any of the above-mentioned known schemes described in the present invention. In a preferred embodiment, the amino acid sequence of a CDR is shown based on the Kabat definition rule, but corresponding amino acid sequences according to other CDR definition rules should also fall within the scope of protection of the present invention.

[0176] [Table 1]

[0177] As used herein, the term "antibody" should be understood in its broadest sense and includes monoclonal antibodies (including full-length monoclonal antibodies), polyclonal antibodies, antibody fragments, single-arm antibodies, and multispecific antibodies (e.g., bispecific antibodies) comprising at least two different antigen-binding regions. Antibodies may contain additional modifications, such as non-naturally occurring amino acids, mutations in the Fc region, and mutations in glycosylation sites. Antibodies also include post-translationally modified antibodies, fusion proteins comprising antigenic determinants of antibodies, and immunoglobulin molecules (e.g., single-arm antibodies) comprising any other modifications to the antigen recognition site, so long as these antibodies exhibit the desired biological activity.

[0178] As used herein, the term "antigen-binding fragment" of an antigen-binding protein refers to one or more fragments of an antigen-binding protein that retain the ability to specifically bind to an antigen (e.g., a TL1A protein). For example, the antigen-binding function of an antibody can be performed by a fragment of a full-length antibody.

[0179] Examples of "antigen-binding fragments" include: (i) a Fab fragment, i.e., a monovalent fragment consisting of the VL, VH, CL, and CH1 domains; (ii) an F(ab')2 fragment, i.e., a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fab' fragment, which is essentially a Fab with part of the hinge region; (iv) an Fd fragment consisting of the VH and CH1 domains; (v) an Fd' fragment having the VH and CH1 domains and one or more cysteine residues at the C-terminus of the CH1 domain; (vi) an Fv fragment consisting of the VL and VH domains of a single arm of an antibody; (vii) a dAb fragment consisting of the VH domain; (viii) an isolated complementarity-determining region (CDR); and (ix) a nanobody, i.e., a heavy chain variable region comprising a single variable domain and two constant domains. Furthermore, although the two domains of the Fv fragment, VL and VH, are encoded by separate genes, they can be recombinantly joined by a synthetic linker that allows them to be produced as a single protein chain in which the VL and VH regions pair to form a monovalent molecule, known as a single-chain Fv (scFv). Such single-chain antibodies are also intended to be encompassed within the term "antigen-binding fragment" of an antibody. Furthermore, this term also includes "linear antibodies" comprising a pair of tandem Fd fragments (VH-CH1-VH-CH1) that form an antigen-binding region together with complementary light chain polypeptides, as well as modified versions of any of the above fragments that retain antigen-binding activity.

[0180] These antigen-binding fragments can be obtained using conventional techniques known to those with skill in the art, and the fragments are screened for utility in the same manner as are intact antibodies.

[0181] As used herein, the term "Fc region" generally refers to a dimeric complex comprising an immunoglobulin heavy chain C-terminal polypeptide sequence obtainable by papain digestion of a whole antibody. The Fc region may comprise a native or variant Fc sequence. Although the boundaries of the Fc sequence of an immunoglobulin heavy chain can vary, a human IgG heavy chain Fc sequence is generally defined as the amino acid residue at about Cys226 or the fragment of the Fc sequence from about Pro230 to the carboxyl terminus. However, the C-terminal lysine (Lys447) of the Fc sequence may or may not be present. The Fc sequence of an immunoglobulin generally comprises two constant domains, namely, a CH2 domain and a CH3 domain, and optionally, a CH4 domain.

[0182] "Fc receptor" or "FcR" refers to a receptor that binds to the Fc region of an antibody. For example, an FcR may be an FcR (gamma receptor) that binds to IgG antibodies, including receptors of the FcγRI, FcγRII, and FcγRIII subclasses. Fc receptors, i.e., FcRs, also include the neonatal receptor FcRn, which is involved in the control of maternal IgG transfer to the fetus (Guyer et al., J. Immunol. 117:587 (1976); and Kim et al., J. Immunol. 24:249 (1994)) and immunoglobulin homeostasis. Research has found that the FcRn receptor plays an important role in the in vivo half-life of antibodies and Fc fusion proteins. The presence of the FcRn receptor results in a longer serum half-life for circulating IgG and Fc fusion proteins. The FcRn receptor can specifically bind to the Fc region of monoclonal antibodies and Fc fusion proteins, and this binding ability is controlled by the pH value. Fc fusion proteins and antibody molecules can be taken up into cells by pinocytosis. Once the protein is endocytosed, the FcRn receptor binds to the antibody or Fc fusion protein with high affinity under acidic pH (pH 6.0) conditions, and the antibody or Fc fusion protein is then released into the blood circulation by exocytosis. The pH during exocytosis matches that of the blood circulation (pH 7.4). At this time, the affinity of the antibody or Fc fusion protein to FcRn is greatly reduced, thereby allowing it to be successfully released from the cell membrane. During the endocytosis process, some antibody or Fc fusion proteins cannot bind to FcRn or are shed during the binding process and are then taken up into lysosomes and degraded.

[0183] As used herein, the terms "bind" or "specifically bind" refer to a non-random binding reaction between two molecules, for example, between an antibody and its target antigen. The binding specificity of an antibody can be determined based on affinity and / or avidity. Affinity, expressed by the equilibrium constant (KD) of dissociation of an antigen with an antibody, is a measure of the binding strength between an antigenic determinant and an antigen-binding site on the antibody; the smaller the KD value, the greater the binding strength between the antigenic determinant and the antibody. Alternatively, affinity can be expressed as an affinity constant (KA), which is 1 / KD. Avidity is a measure of the strength of binding between an antibody and an associated antigen. Avidity is related to both the affinity between an antigenic determinant and an antigen-binding site on the antibody and the number of associated binding sites present on the antibody. Typically, antibodies have a binding strength of 10 -5 ~10 -12 M or less, preferably 10 -7 ~10 -12 M or less, preferably 10 -8 ~10 -12 Dissociation constant (KD) of M and / or at least 10 7 M -1 , preferably at least 10 8 M -1 , more preferably at least 10 9 M -1 , e.g. at least 10 10 M -1 It will bind to the antigen with a binding affinity of 10. -4 Any K value greater than M is generally considered to indicate nonspecific binding. Specific binding of an antibody to an antigen or antigenic determinant can be determined in any suitable known manner, including, for example, Scatchard analysis and / or competitive binding assays, such as radioimmunoassays (RIA), enzyme immunoassays (EIA), and sandwich competition assays, and various modifications thereof known in the art.

[0184] In this application, the term "KD" generally refers to the equilibrium dissociation constant, which is the ratio of the dissociation rate constant (kdis, also known as the "off rate (koff)" or "kd") to the on rate constant (k, also referred to as the "on rate" or "ka"). The binding affinity of an antigen-binding protein (e.g., an antibody) for an antigen can be expressed using the association rate constant (k), the dissociation rate constant (kdis), and the equilibrium dissociation constant (KD). Methods for determining association and dissociation rate constants are well known in the art and include, but are not limited to, biofilm interference (BLI), radioimmunoassay (RIA), equilibrium dialysis, surface plasmon resonance (SPR) and fluorescence resonance energy transfer (FRET), co-immunoprecipitation (Co-IP), and protein chip techniques. The affinity measured for a particular protein-protein interaction may differ when measured under different conditions (e.g., salt concentration, pH).

[0185] As used herein, the term "sequence identity" refers to the degree to which two sequences (amino acids) have the same residues at the same positions when aligned. For example, "an amino acid sequence is X% identical to SEQ ID NO: Y" refers to the % identity of an amino acid sequence to SEQ ID NO: Y, and explains that X% of the residues in the amino acid sequence are identical to the residues in the sequence disclosed by SEQ ID NO: Y.

[0186] Generally, computer programs are employed for such calculations. Exemplary programs for comparing and aligning pairs of sequences include ALIGN (Myers and Miller, 1988), FASTA (Pearson and Lipman, 1988; Pearson, 1990), and Gapped BLAST (Altschul et al., 1997), BLASTP, BLASTN, or GCG (Devereux et al., 1984).

[0187] As used herein, the term "monoclonal antibody" refers to an antibody obtained from a substantially homogeneous antibody population. That is, each antibody comprising the population is identical except for possible minor naturally occurring mutations. Monoclonal antibodies are highly specific, being directed against a single antigen. Furthermore, unlike conventional polyclonal antibody populations, which typically have different antibodies directed against different determinants, each monoclonal antibody is directed against a single determinant on the antigen. In addition to their specificity, an advantage of monoclonal antibodies is that they can be synthesized by hybridoma culture, uncontaminated by other immunoglobulins. The modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies and is not to be construed as requiring production of the antibody by any particular method. For example, monoclonal antibodies used in accordance with the present invention may be prepared by hybridoma cells or by recombinant DNA methodologies.

[0188] In the context of the present invention, the term "bispecific antibody" should be understood as an antibody having two different antigen-binding regions defined by different antibody sequences. This can be understood as binding to different targets, but also includes binding to different epitopes within a single target. As used herein, the term "bispecific antibody" should be understood in the broadest sense and includes full-length bispecific antibodies and antigen-binding fragments thereof. Bispecific antibodies may contain additional modifications such as non-naturally occurring amino acids, mutations in the Fc region, and mutations in glycosylation sites. Bispecific antibodies also include post-translationally modified antibodies, fusion proteins containing antigenic determinants of antibodies, and immunoglobulin molecules containing any other modifications to the antigen recognition site, so long as these antibodies exhibit the desired biological activity.

[0189] In this application, the term "chimeric antibody" generally refers to an antibody whose variable region is derived from one species and whose constant region is derived from another species. Typically, the variable region is derived from an antibody of a laboratory animal such as a rodent (the "parent antibody"), and the constant region is derived from a human antibody, such that the resulting chimeric antibody is less likely to provoke a harmful immune response in a human individual than the parent (e.g., mouse-derived) antibody.

[0190] In this application, the term "humanized antibody" generally refers to an antibody in which some or all of the amino acids outside the CDR regions of a non-human antibody (e.g., a murine antibody) have been replaced with corresponding amino acids from a human immunoglobulin. Small additions, deletions, insertions, substitutions, or modifications of amino acids in the CDR regions are also permissible as long as they still retain the antibody's ability to bind to a specific antigen. A humanized antibody may optionally contain at least a portion of a human immunoglobulin constant region. A "humanized antibody" retains the same antigen specificity as the original antibody. "Humanized" forms of non-human (e.g., murine) antibodies may minimally comprise chimeric antibodies derived from non-human immunoglobulin sequences. In some cases, CDR region residues of a human immunoglobulin (recipient antibody) may be replaced with CDR region residues from a non-human species (donor antibody) (e.g., mouse, rat, rabbit, or non-human primate) having desired properties, affinity, and / or capacity. In some cases, FR region residues of a human immunoglobulin may be replaced with corresponding non-human residues. Furthermore, humanized antibodies may contain amino acid modifications that are not present in the recipient antibody or in the donor antibody. These modifications may be made to further improve antibody performance, for example, binding affinity.

[0191] In this application, the term "fully human antibody" generally refers to an antibody expressed in an animal by transferring a gene encoding a human antibody into a genetically engineered animal that is deficient in antibody genes. All parts of the antibody (including the variable and constant regions of the antibody) are encoded by genes of human origin. Fully human antibodies can significantly reduce the adverse immune reactions induced in the human body by heterologous antibodies. Methods for obtaining fully human antibodies in this field include phage display technology, transgenic mouse technology, ribosome display technology, and RNA-peptide technology.

[0192] As used herein, the term "single-arm antibody" refers to a genetically engineered monovalent antibody having only one Fab fragment and having an Fc structure.

[0193] As used herein, the term "subject" generally refers to a mammal, including, but not limited to, domesticated animals (e.g., cows, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates, such as monkeys), rabbits, and rodents (e.g., mice and rats). The term "primate" generally refers to monkey and ape species, and includes monkey species such as Macaca (e.g., Macaca fascicularis and Macaca mulatta) and baboon (Papio ursinus), as well as marmosets (Callithrix species), squirrel monkeys (Saimiri species), and tamarins (Saguinus species), and ape species such as monkeys of the genus Pan troglodytes, including Homo sapiens.

[0194] In this application, the term "nucleic acid" generally refers to nucleotides, deoxynucleotides or ribonucleotides or analogs thereof of any length in isolated form, isolated from their natural environment or artificially synthesized.

[0195] In this application, the term "vector" generally refers to a nucleic acid molecule capable of autonomous replication in a suitable host that transfers an inserted nucleic acid molecule into and / or between host cells. Vectors may include vectors primarily used to insert DNA or RNA into cells, vectors primarily used to replicate DNA or RNA, and vectors primarily used for transcriptional and / or translational expression of DNA or RNA. Vectors also include vectors having more than one of the above functions. A vector may be a polynucleotide that can be transcribed and translated into a polypeptide when introduced into a suitable host cell. Generally, the vector can produce a desired expression product by culturing a suitable host cell containing the vector.

[0196] In this application, the term "host cell" generally refers to an individual cell, cell line, or cell culture that can contain, or already contains, a plasmid or vector containing a nucleic acid molecule described in this application, or that is capable of expressing an antibody or antigen-binding fragment thereof described in this application. A cell may include the progeny of a single host cell. Due to natural, accidental, or deliberate mutation, the daughter cells may not necessarily be completely identical in morphology or genome to the original parent cell, but they are capable of expressing an antibody or antigen-binding fragment thereof described in this application. Cells can be obtained by transfecting cells in vitro with a vector described in this application. The cell may be a prokaryotic cell (e.g., Escherichia coli) or a eukaryotic cell (e.g., a yeast cell, such as a COS cell, a Chinese hamster ovary (CHO) cell, a HeLa cell, a HEK293 cell, a COS-1 cell, an NS0 cell, or a myeloma cell). In some cases, the cell may be a mammalian cell. For example, the mammalian cell may be a CHO-K1 cell. In this application, the term "recombinant cell" generally refers to a cell into which a recombinant expression vector has been introduced. A recombinant host cell includes not only the particular cell but also the progeny of such a cell.

[0197] In this application, the term "pharmaceutical composition" generally refers to a preparation that is in a form that allows the biological activity of the active ingredient to be effective and that does not contain additional ingredients that are unacceptably toxic to the subject to which the composition is administered.

[0198] In this application, the term "pharmaceutically acceptable carrier" generally includes pharmaceutically acceptable carriers, excipients, or stabilizers that are non-toxic to cells or mammals exposed thereto at the dosages and concentrations employed. Typically, physiologically acceptable carriers are pH-buffered aqueous solutions. Examples of physiologically acceptable carriers can include buffers, antioxidants, low molecular weight (less than about 10 residues) polypeptides, proteins, hydrophilic polymers, amino acids, monosaccharides, disaccharides, and other carbohydrates, chelating agents, sugar alcohols, salt-forming counterions such as sodium, and / or non-ionic surfactants.

[0199] As used herein, the terms "treatment," "treating," "treating," and the like refer to administering an agent or performing a procedure for the purpose of achieving an effect. The effect may be prophylactic, in the sense of completely or partially preventing a disease or its symptoms, and / or therapeutic, in the sense of partially or completely curing a disease and / or its symptoms. As used herein, "treatment" may include the treatment of a disease or disorder (e.g., cancer) in a mammal, particularly a human, and includes (a) preventing the onset of a disease (e.g., including a disease that may be associated with or caused by a primary disease) or symptoms of a disease in a subject who may be predisposed to the disease but has not yet been diagnosed with the disease, (b) arresting the disease, i.e., preventing its development, and (c) mitigating the disease, i.e., causing the reversal of the disease. Treating can refer to any indication of success in treating or ameliorating or preventing cancer, including any objective or subjective parameter, such as reduction, remission, disappearance of symptoms, or making the condition more tolerable to the patient, slowing the rate of degeneration or decline, or making the end point of degeneration less debilitating. The treatment or amelioration of symptoms is based on one or more objective or subjective parameters, including the results of an examination by a clinician. Thus, the term "treating" includes administering an antibody or composition or conjugate disclosed herein to prevent or delay, alleviate, or arrest or inhibit the progression of symptoms or conditions associated with a disease (e.g., a disease mediated by TL1A).

[0200] As used herein, the term "TL1A" includes variants, isoforms, and species homologs of TL1A. Thus, the antibodies of the present invention can bind to human TL1A and cross-react with TL1A from species other than humans, such as cynomolgus monkeys and rhesus monkeys. TL1A is also known as TNFSF15, TNF-like protein 1A, VEGI, and TNFγβ. Human TL1A is designated GeneID: 9966 in EntrezGene and HGNC: 11931 in HGNC. TL1A may be encoded by a gene designated TNFSF15 / TL1A. The complete amino acid sequence of an exemplary human TL1A has Swiss-Prot accession number O95150 (TNFSF15HUMAN), and its sequence is as follows:

[0201] [ka]

[0202] As used herein, an "autoimmune disease" is a disease or condition that originates in and targets an individual's own tissues. Examples of autoimmune diseases or disorders include, but are not limited to, inflammatory responses, such as inflammatory skin diseases, including psoriasis and dermatitis (e.g., atopic dermatitis), systemic sclerosis and sclerosis, responses associated with inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis), respiratory distress syndrome (including adult respiratory distress syndrome, ARDS), dermatitis, meningitis, encephalitis, uveitis, colitis, glomerulonephritis, allergic conditions, such as eczema and asthma, and other conditions involving T-cell infiltration and chronic inflammatory responses, atherosclerosis, leukocyte adhesion deficiency, rheumatoid arthritis, systemic lupus erythematosus (SLE), diabetes (e.g., Type 1 diabetes or insulin-dependent diabetes mellitus), multiple sclerosis, Raynaud's syndrome, autoimmune thyroiditis, allergic encephalomyelitis, Sjogren's syndrome, juvenile-onset diabetes, and cytokines typically found in tuberculosis. These include immune responses involving acute and delayed hypersensitivity mediated by lymphocytes and T lymphocytes, sarcoidosis, polymyositis, inflammatory myopathies, interstitial lung disease, granulomatous diseases and vasculitis, pernicious anemia (Addison's disease), diseases involving leukocyte leakage, central nervous system (CNS) inflammatory disorders, multiple organ injury syndrome, hemolytic anemia (including, but not limited to, cryoglobulinemia or Coombs' positive anemia), myasthenia gravis, diseases mediated by antigen-antibody complexes, antiglomerular basement membrane disease, antiphospholipid syndrome, allergic neuritis, Graves' disease, Lambert-Eaton myasthenic syndrome, bullous pemphigoid, pemphigus, autoimmune polyendocrinopathy, Reiter's disease, stiff-man syndrome, Behçet's disease, giant cell arthritis, immune complex nephritis, IgA nephritis, IgM polyneuropathy, immune thrombocytopenic purpura (ITP), or autoimmune thrombocytopenia.

[0203] As used herein, the term "inflammatory disease" should be understood in its broadest sense and includes inflammatory diseases and chronic pro-inflammatory diseases. For example, inflammatory disease refers to a disease or condition characterized by one or more of the following symptoms: pain (pain due to production of harmful substances and nerve irritation), fever (fever due to vasodilation), redness (redness due to vasodilation and increased blood flow), swelling (tumor due to excessive fluid inflow or restricted outflow), and loss of function (loss of function, which may be partial or complete, temporary or permanent). Inflammation takes many forms, including, but not limited to, inflammation that is one or more of the following: acute, adhesive, atopic, catarrhal, chronic, cirrhotic, diffuse, disseminated, exudative, fibrotic, desmoplastic, focal, granulomatous, hyperplastic, hypertrophic, interstitial, metastatic, necrotizing, obstructive, parenchymal, plastic, productive, proliferative, pseudomembranous, purulent, sclerosing, seroplastic, serous, simple, idiosyncratic, subacute, suppurative, toxic, traumatic, and / or ulcerative. Inflammatory disorders further include, but are not limited to, disorders affecting the blood vessels (polyarteritis), joints (arthritis; episodic, crystalline, osteo-, psoriatic, reactive, rheumatic, Reiter), gastrointestinal tract (inflammatory bowel disease, Crohn's disease, ulcerative colitis, etc.), skin (dermatitis, psoriasis, etc.), allergic airway diseases (asthma, etc.), or disorders affecting multiple organs and tissues (systemic lupus erythematosus). Furthermore, chronic inflammation contributes to a variety of diseases, such as cardiovascular disease, cancer, diabetes, chronic kidney disease, fibrosis (pulmonary fibrosis, etc.), chronic obstructive pulmonary disease, acne scarring, atherosclerosis, and non-alcoholic fatty liver disease, as well as autoimmune and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, etc.), and these diseases, which are promoted by chronic inflammation, are also included in the definition of inflammatory disease.

[0204] As used herein, "fibrosis" refers to the formation of excess fibrous connective tissue due to excessive deposition of extracellular matrix components, such as collagen. The cellular and molecular mechanisms of fibrosis are described in Wynn, J. Pathol. (2008) 214(2):199210 and Wynn and Ramalingam, Nature Medicine (2012) 18:10281040, which are incorporated herein by reference in their entireties. As used herein, "fibrogenic disease" means a disease / condition characterized by fibrosis, including, but not limited to, subretinal fibrosis (e.g., associated with macular degeneration (e.g., wet age-related macular degeneration (AMD)), nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis, and arthrofibrosis.

[0205] As used herein, the term "effective amount" means the amount that, when administered to a subject for treating a disease, is sufficient to effect treatment for that disease.

[0206] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "an antibody" includes a plurality of antibodies; in some embodiments, a reference to "an antibody" includes a multiplicity of antibodies, and so forth.

[0207] Unless otherwise indicated or defined, the terms "comprise", "include", "contain" and "have" should be understood to imply the inclusion of a stated element or step or group of elements or steps, but not the exclusion of any other element or step or group of elements or steps.

[0208] In this application, the term "about" generally refers to a variation within 0.5% to 10% above and below the specified value, for example, a variation within 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% or 10%. Antigen-binding protein or antigen-binding fragment thereof that binds to TL1A In a first aspect, the present invention provides an antigen-binding protein or antigen-binding fragment thereof that binds to TL1A, wherein the antigen-binding protein or antigen-binding fragment thereof binds to an epitope of TL1A, the epitope comprising one or more amino acid residues selected from the group consisting of R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105, and the amino acid positions are numbered according to the amino acid sequence of TL1A as set forth in SEQ ID NO:68.

[0209] In some embodiments, the epitope comprises R103, G124, Y238, T239, E120, V102. In preferred embodiments, the epitope further comprises one or more amino acid residues selected from the group consisting of M196, K240, E241, H118, H121, E122, L123, and T105.

[0210] In some embodiments, the epitope comprises amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102, and T105.

[0211] In some embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0212] In some embodiments of the TL1A-binding antigen binding proteins or antigen-binding fragments thereof disclosed herein, the antigen binding proteins comprise a heavy chain variable region (VH) and a light chain variable region (VL), (1) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 2, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 1; (2) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 4, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 3; (3) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 6, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 5; (4) VH comprises a heavy chain CDR1, a heavy chain CDR2, and a heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 8, and VL comprises a light chain CDR1, a light chain CDR2, and a light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 7; (5) VH comprises heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 10, and VL comprises light chain CDR1, light chain CDR2, and light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 9; or (6) VH comprises heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 of a heavy chain variable region having the amino acid sequence shown in SEQ ID NO: 12, and VL comprises light chain CDR1, light chain CDR2, and light chain CDR3 of a light chain variable region having the amino acid sequence shown in SEQ ID NO: 11.

[0213] In certain embodiments, the heavy chain variable region has the amino acid sequence set forth in SEQ ID NO: 10, and the light chain variable region has the amino acid sequence set forth in SEQ ID NO: 9. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 16 to 18, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 13 to 15, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 22 to 24, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 19 to 21, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 28 to 30, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 25 to 27, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 34 to 36, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 31 to 33, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 40 to 42, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 37 to 39, respectively. In some embodiments, the VH comprises heavy chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 46 to 48, respectively, and the VL comprises light chain CDR1 to 3 having the amino acid sequences set forth in SEQ ID NOs: 43 to 45, respectively.

[0214] In certain embodiments, VH CDRs 1 to 3 have the amino acid sequences shown in SEQ ID NOs: 40 to 42, respectively, and VL CDRs have the amino acid sequences shown in SEQ ID NOs: 37 to 39, respectively.

[0215] In some embodiments, CDR sequences are defined according to the Kabat definition. In some embodiments, CDR sequences are defined according to the Chothia definition. In some embodiments, CDR sequences are defined according to the combined definition. In some embodiments, CDR sequences are defined according to the AbM definition. In some embodiments, CDR sequences are defined according to the CONTACT definition.

[0216] In a preferred embodiment, the CDR sequences are defined according to Kabat's definition rules, with the VH comprising heavy chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 16 to 18, respectively, and the VL comprising light chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 13 to 15, respectively. The VH comprising heavy chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 22 to 24, respectively, and the VL comprising light chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 19 to 21, respectively. The VH comprising heavy chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 28 to 30, respectively, and the VL comprising light chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 25 to 27, respectively. The VH comprising heavy chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 34 to 36, respectively, and the VL comprising light chain CDR1 to CDR3 having the amino acid sequences set forth in SEQ ID NOS: 31 to 33, respectively. VH comprises heavy chain CDR1 to 3 having the amino acid sequences shown in SEQ ID NOs: 40 to 42, respectively, and VL comprises light chain CDR1 to 3 having the amino acid sequences shown in SEQ ID NOs: 37 to 39, respectively. VH comprises heavy chain CDR1 to 3 having the amino acid sequences shown in SEQ ID NOs: 46 to 48, respectively, and VL comprises light chain CDR1 to 3 having the amino acid sequences shown in SEQ ID NOs: 43 to 45, respectively.

[0217] In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 2, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 4, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 3. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 6, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 5. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 8, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 7.In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 9. In some embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 12, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 11.

[0218] In certain embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 9.

[0219] In some embodiments, the VH comprises a functional variant formed by the insertion, deletion and / or substitution of one or more amino acids in the amino acid sequence set forth in any one of SEQ ID NOs: 2, 4, 6, 8, 10 and 12, provided that the functional variant retains the ability to bind to TL1A. In some embodiments, the VL comprises a functional variant formed by the insertion, deletion and / or substitution of one or more amino acids in the amino acid sequence set forth in any one of SEQ ID NOs: 1, 3, 5, 7, 9 and 11, provided that the functional variant retains the ability to bind to TL1A.

[0220] A functional variant comprises or consists of an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.1%, at least 99.2%, at least 99.3%, at least 99.4%, at least 99.5%, at least 99.6%, at least 99.7%, at least 99.8% or at least 99.9% sequence identity to the amino acid sequence of the parent polypeptide.

[0221] For functional variants, the number of inserted, deleted, and / or substituted amino acids preferably does not exceed 40%, more preferably does not exceed 35%, more preferably is 1 to 33%, more preferably is 5 to 30%, more preferably is 10 to 25%, and more preferably is 15 to 20% of the total number of amino acids in the parent amino acid sequence. For example, the number of inserted, deleted, and / or substituted amino acids may be 1 to 20, preferably 1 to 10, more preferably is 1 to 7, even more preferably is 1 to 5, and most preferably is 1 to 2. In a preferred embodiment, the number of inserted, deleted, and / or substituted amino acids is 1, 2, 3, 4, 5, 6, or 7.

[0222] In some embodiments, insertions, deletions and / or substitutions can be made in framework (FR) regions, such as FR1, FR2, FR3 and / or FR4.

[0223] In some embodiments, the substitution of one or more amino acids may be a conservative substitution of one or more amino acids. Such conservative substitutions are preferably those in which one amino acid in the following groups (a) to (e) is replaced by another amino acid residue in the same group: (a) small aliphatic non-polar or slightly polar residues: Ala, Ser, Thr, Pro, and Gly, (b) polar negatively charged residues and their (uncharged) amides: Asp, Asn, Glu, and Gln, (c) polar positively charged residues: His, Arg, and Lys, (d) large aliphatic non-polar residues: Met, Leu, Ile, Val, and Cys, and (e) aromatic residues: Phe, Tyr, and Trp.

[0224] Particularly preferred conservative substitutions are: Ala to Gly or Ser; Arg to Lys; Asn to Gln or His; Asp to Glu; Cys to Ser; Gln to Asn; Glu to Asp; Gly to Ala or Pro; His to Asn or Gln; Ile to Leu or Val; Leu to Ile or Val; Lys to Arg, Gln, or Glu; Met to Leu, Tyr, or Ile; Phe to Met, Leu, or Tyr; Ser to Thr; Thr to Ser; Trp to Tyr; Tyr to Trp; and / or Phe to Val, Ile, or Leu.

[0225] In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:2, and the VL comprises the amino acid sequence set forth in SEQ ID NO:1. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:4, and the VL comprises the amino acid sequence set forth in SEQ ID NO:3. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:6, and the VL comprises the amino acid sequence set forth in SEQ ID NO:5. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:8, and the VL comprises the amino acid sequence set forth in SEQ ID NO:7. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:10, and the VL comprises the amino acid sequence set forth in SEQ ID NO:9. In some embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:12, and the VL comprises the amino acid sequence set forth in SEQ ID NO:11.

[0226] In certain embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:10, and the VL comprises the amino acid sequence set forth in SEQ ID NO:9.

[0227] In some embodiments of the antigen binding proteins or antigen binding fragments thereof disclosed herein that bind to TL1A, the antigen binding protein is an antibody.

[0228] In some embodiments, the antibody is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0229] In some embodiments, the antibody is a bispecific antibody. The bispecific antibody comprises an antibody or antigen-binding fragment thereof described herein that binds to TL1A and a second antigen-binding domain that binds to a second antigen. The second antigen can be selected from the group consisting of a tumor-associated antigen, an immune cell antigen, and an immune checkpoint molecule.

[0230] In some embodiments, the second antigen is an immune cell antigen, e.g., a T cell antigen. In some embodiments, the T cell antigen is selected from the group consisting of T cell receptor (TCR), CD3, CD4, CD8, CD16, CD25, CD28, CD38, CD44, CD62L, CD69, ICOS, 41-BB (CD137), and NKG2D, or any combination thereof. In some embodiments, the T cell antigen is CD3, and the second antigen-binding region binds to any of the gamma, delta, epsilon, zeta, and eta chains of CD3.

[0231] In some embodiments, the second antigen is an immune checkpoint molecule, which can be selected from PD-1, PD-L1, CTLA-4, CD4, CD40, CD80, CD86, B7-H3, LAG3, TIM-3, IDO1, etc.

[0232] In some embodiments, the antibody is a murine antibody, a chimeric antibody, a humanized antibody, or a fully human antibody.

[0233] In some embodiments, antibodies of the present invention may comprise an Fc region. The Fc region may be of any isotype, including but not limited to IgG1, IgG2, IgG3, and IgG4, and may include one or more mutations or modifications. In one embodiment, the Fc region is of or derived from an IgG1 isotype, optionally with one or more mutations or modifications. In one embodiment, the Fc region is a human IgG Fc. In one embodiment, the Fc region is a human IgG1 Fc. In one embodiment, the Fc region is a mouse IgG Fc. In one embodiment, the Fc region is a mouse IgG1 Fc.

[0234] Based on the amino acid sequence of the constant region of the antibody heavy chain, immunoglobulin molecules can be divided into five categories (isotypes), namely, IgA, IgD, IgE, IgG, and IgM, and can be further divided into various subtypes, such as IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, etc. Based on the amino acid sequence of the light chain, the light chain of an antibody can be divided into lambda (λ) chains and kappa (κ) chains. The antibodies disclosed herein may belong to any of the above classes or subtypes.

[0235] In some embodiments, the antibody is of an isotype selected from IgG, IgA, IgM, IgE, and IgD. In some embodiments, the antibody is of a subtype selected from IgG1, IgG2, IgG3, and IgG4. In a preferred embodiment, the antibody is an IgG1 antibody.

[0236] In some embodiments, the antibody comprises a heavy chain (HC) and a light chain (LC), wherein the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO:50, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:49. In some embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 52, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 51. In some embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 54, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 53. In some embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:56, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:55.In some embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO:58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:57. In some embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:60, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO:59.

[0237] In certain embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 57.

[0238] In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:50, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:49. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:52, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:51. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:54, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:53. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:56, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:55. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:60, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:59.

[0239] In certain embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57.

[0240] In a related further first aspect of the present invention, the present invention provides an isolated antibody or antigen-binding fragment thereof that specifically binds to TL1A, the isolated antibody comprising an immunoglobulin heavy chain (HC) comprising a heavy chain variable region (VH) comprising heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 (VH CDR1-3), and an immunoglobulin light chain (LC) comprising a variable region (VL) comprising light chain CDR1, light chain CDR2, and light chain CDR3 (VL CDR1-3), wherein VH CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 40-42, respectively, and VL CDR1-3 have the amino acid sequences set forth in SEQ ID NOs: 37-39, respectively.

[0241] In certain embodiments, the VH comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 10, and the VL comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% amino acid sequence identity to SEQ ID NO: 9.

[0242] In certain embodiments, the VH comprises the amino acid sequence set forth in SEQ ID NO:10, and the VL comprises the amino acid sequence set forth in SEQ ID NO:9.

[0243] In certain embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 58, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% amino acid sequence identity to SEQ ID NO: 57.

[0244] In certain embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57.

[0245] In certain embodiments, the isolated antibody is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0246] In certain embodiments, the isolated antibody is a murine antibody, a chimeric antibody, a humanized antibody, or a fully human antibody.

[0247] In certain embodiments, the isolated antibody or antigen-binding fragment thereof binds to an epitope in TL1A, wherein the epitope comprises one or more amino acid residues selected from the group consisting of R103, G124, M196, Q193, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105, wherein the amino acid positions are numbered according to the amino acid sequence of TL1A set forth in SEQ ID NO:68.

[0248] In certain embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, H118, E120, H121, E122, L123, V102 and T105.

[0249] The antibodies disclosed herein may be whole antibodies or antigen-binding fragments thereof. In some embodiments, the antibodies disclosed herein are single-arm antibodies.

[0250] In some embodiments, the single-arm antibody comprises a heavy chain (HC) and a light chain (LC), (1) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 62, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 49; (2) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 63, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 51; (3) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 64, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 53; (4) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 65, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 55; (5) the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 66, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 57; or (6) The heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 67, the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 59, and the single-arm antibody further comprises an Fc chain of SEQ ID NO: 61.

[0251] In certain embodiments, the heavy chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 66, and the light chain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 57.

[0252] In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:62, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:49. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:63, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:51. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:64, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:53. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:65, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:55. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:66, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57. In some embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:67, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:59.

[0253] In certain embodiments, the heavy chain comprises the amino acid sequence set forth in SEQ ID NO:58, and the light chain comprises the amino acid sequence set forth in SEQ ID NO:57.

[0254] The Fc regions described herein may comprise one or more modifications, such as one or more amino acid mutations, insertions, or deletions that enhance the affinity or biological activity of the antibody, increase Fc dimerization, enhance the stability of the antibody, extend the half-life of the antibody, reduce an effector function, reduce the immunogenicity of the antibody, or reduce post-translational modifications of the antibody; for example, such modifications include mutations that enhance binding to FcRn and / or effector function-silencing mutations.

[0255] In some embodiments, the Fc region may comprise a modification that increases dimerization. In some embodiments, the Fc region of an antibody disclosed herein comprises a knobs-in-holes mutation.

[0256] Detailed descriptions of the knob and hole concept can be found, for example, in US Patent Nos. 5,731,168 and 7,186,076, as well as Ridgway et al., Protein Engineering, Design and Selection, 1996, 9(7):617-621; Atwell et al., J Mol Biol, 1997, 270(1):26-35; Merchant et al., Nat Biotechnol, 1998, 16:677-681; and Carter, J. Immunological Methods, 2001, 24(1-2):7-15. Briefly, a knob can be created at the CH3 domain interface of a first IgG Fc chain by replacing a smaller amino acid side chain with a larger one (e.g., T366W), and a hole can be created at a parallel position in the CH3 interface of a second IgG Fc chain by replacing a larger amino acid side chain with a smaller one (e.g., Y407V).

[0257] The amino acid residues forming the knob are typically naturally occurring amino acid residues selected from the group consisting of arginine (R), phenylalanine (F), tyrosine (Y), and tryptophan (W). In some preferred embodiments, the amino acid residues are tryptophan and tyrosine. In one embodiment, the original residues forming the knob have small side chain volumes, such as alanine, asparagine, aspartic acid, glycine, serine, threonine, or valine. Exemplary amino acid substitutions in the knob-forming CH3 domain include, but are not limited to, substitutions of T366W, T366Y, or F405W.

[0258] The amino acid residues that form the hole are generally naturally occurring amino acid residues and are selected from the group consisting of alanine (A), serine (S), threonine (T), and valine (V). In some preferred embodiments, the original residues that form the hole have large side chain volumes, such as tyrosine, arginine, phenylalanine, or tryptophan. Exemplary amino acid substitutions in the CH3 domain that create the hole include, but are not limited to, T366S, L368A, F405A, Y407A, Y407T, and Y407V substitutions. In some embodiments, the knob comprises a T366W substitution and the hole comprises a T366S / L368A / Y407V substitution.

[0259] Generally, preferred Fc domains for use herein are human IgG domains, typically IgG1 or IgG4. In some cases, for example, IgG4 is used when effector function is undesirable, and in some cases the hinge domain contains the S228P variant to prevent arm exchange.

[0260] The Fc region interacts with several receptors or ligands, including, but not limited to, Fc receptors (e.g., FcγRI, FcγRIIA, FcγRIIIA), complement protein C1q, and other molecules such as protein A and protein G. These interactions are necessary for multiple effector functions and downstream signaling events, including, but not limited to, antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement-dependent cytotoxicity (CDC). The Fc region can also interact with FcRn. The circulating half-life of antibodies or antibody-Fc region conjugates can be affected by modulating the Fc region-FcRn interaction.

[0261] Increasing the circulating half-life of an antibody or antibody-Fc region conjugate is achieved by increasing binding to FcRn and may result in increased efficacy, reduced dosage or administration frequency, or improved delivery to the target.

[0262] In one embodiment, the Fc region has increased binding to FcRn. Fc region variants with increased affinity for FcRn will have longer serum half-lives, and such molecules will have useful applications in methods of treating mammals where a prolonged systemic half-life of the administered antibody-Fc region conjugate is required, e.g., to treat a chronic disease or condition.

[0263] For example, modifications to the Fc region that can increase binding to FcRn have been reported to include one or more amino acid changes at amino acid positions 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424, and / or 434 (see US7371826). Studies have also shown that modifications to the Fc region that can increase binding to FcRn include one or more mutations at amino acid residues Thr250, Met252, Ser254, Thr256, Thr307, Glu380, Met428, His433, and Asn434 (see CN105899534). For example, an Fc region modification that enhances binding to FcRn includes a combination of the mutations M428L and N434S. As another example, an Fc region modification that can enhance binding to FcRn includes a combination of the mutations M252Y, S254T, and T256E (see Dall'Acqua, WF et al., J. Biol. Chem. 281 (2006) pp. 23514-23524).

[0264] In one embodiment, the Fc region has reduced effector function, such as reduced ADCC, ADCP, CDC, and / or Clq, FcγRI, FcγRII, or FcγRIIIA binding. For example, the Fc region may be of the IgG1 isotype or a non-IgG1 type, such as IgG2, IgG3, or IgG4, that has been mutated to reduce or even eliminate its ability to mediate effector function. Such mutations are described, for example, in Dall'Acqua WF et al., J Immunol. 177(2):1129-1138 (2006) and Hezareh M, J Virol. 75(24):12161-12168 (2001). For example, the Fc region may comprise an amino acid sequence having one or more of the following amino acid substitutions compared to the wild-type sequence: E233P, L234A, L234F, L235A, L235E, G237A, N297A, N297D, P331S, and P329G.

[0265] In one embodiment, the Fc region comprises a mutation that removes an acceptor site for Asn-linked glycosylation or is otherwise engineered to alter glycosylation characteristics. For example, in an IgG1 Fc region, an N297Q mutation can be used to remove an Asn-linked glycosylation site. Thus, in a specific embodiment, the Fc region comprises an IgG1 sequence with an N297Q mutation.

[0266] In a further embodiment, the Fc region is glycoengineered to reduce fucose and thereby enhance ADCC, for example, by adding compounds to the culture medium during antibody production, as described in US2009317869 or van Berkel et al. (2010) Biotechnol. Bioeng. 105:350, or by using FUT8 knockout cells, as described in Yamane-Ohnuki et al. (2004) Biotechnol. Bioeng. 87:614. Alternatively, ADCC can be optimized using the methods described in Umana et al. (1999) Nature Biotech 17:176. In another embodiment, the Fc region is engineered to enhance complement activation, as described in Natsume et al. (2009) Cancer Sci. 100:2411.

[0267] The antigen-binding fragment may be any fragment of an antibody that retains the ability to specifically bind to TL1A. Examples of antigen-binding fragments include, but are not limited to, Fab fragments, F(ab')2 fragments, Fab' fragments, Fd fragments, Fd' fragments, Fv fragments, scFv fragments, dAb fragments, individual complementarity-determining regions (CDRs), nanobodies, linear antibodies consisting of a pair of tandem Fd fragments (VH-CH1-VH-CH1), and modified forms of any of the above fragments that retain antigen-binding activity.

[0268] In some embodiments, the antigen-binding fragment is selected from Fab, Fab', F(ab')2, Fv, scFv, and ds-scFv. In a preferred embodiment, the antigen-binding fragment is a Fab. In another preferred embodiment, the antigen-binding fragment is an Fv. In another preferred embodiment, the antigen-binding fragment is an scFv.

[0269] In some embodiments, when bound to TL1A, the antibodies of the present invention form complexes of smaller size compared to anti-TL1A antibodies that do not bind to the epitopes described herein. In some embodiments, the complexes formed by the antibodies of the present invention and TL1A have a particle size of less than 33 nm, less than 30 nm, less than 25 nm, or less than 20 nm, as detected by DLS. In some embodiments, the particle size of the complexes formed by the antibodies of the present invention and TL1A is 17-20 nm, 18-20 nm, or 18-19.5 nm, as detected by DLS. In some embodiments, the particle size of the complex formed by the antibody of the present invention and TL1A is about 18.0 nm, about 18.1 nm, about 18.2 nm, about 18.3 nm, about 18.4 nm, about 18.5 nm, about 18.6 nm, about 18.7 nm, about 18.8 nm, about 18.9 nm, about 19.0 nm, about 19.1 nm, about 19.2 nm, about 19.3 nm, about 19.4 nm, or about 19.5 nm. In some embodiments, the antibody of the present invention forms uniformly dispersed small particles with TL1A, as observed by negative staining electron microscopy.

[0270] In some embodiments, antibodies of the present invention bind to TL1A at a 1:1 ratio to form an antigen-antibody complex. In some embodiments, antibodies of the present invention comprise two heavy chains and two light chains. In some embodiments, the Fc valency of the complex formed by an antibody of the present invention and TL1A is less than 5. In some embodiments, the Fc valency of the complex formed by an antibody of the present invention and TL1A is less than 4. In some embodiments, the Fc valency of the complex formed by an antibody of the present invention and TL1A is less than 3. In some embodiments, the Fc valency of the complex formed by an antibody of the present invention and TL1A is 2.

[0271] In some embodiments, the antibodies of the present invention have pH-dependent binding to TL1A. In some embodiments, the antibodies of the present invention bind strongly to TL1A under neutral pH conditions and weakly to TL1A under acidic conditions. In some embodiments, the binding of the antibodies of the present invention to TL1A in endosomes is significantly reduced compared to the binding to TL1A in serum. In some embodiments, the binding of the antibodies to TL1A under neutral pH conditions is stronger than the binding to TL1A under acidic conditions. In some embodiments, the binding of the antibodies to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 6.0. In some embodiments, the binding of the antibodies to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 5.8. In some embodiments, the binding of the antibodies to TL1A at pH 7.4 is stronger than the binding to TL1A at pH 5.6. In some embodiments, the binding of the antibodies to TL1A at pH 6.0 is stronger than the binding to TL1A at pH 5.8. In some embodiments, the binding of the antibody to TL1A at pH 5.8 is stronger than the binding to TL1A at pH 5.6. In some embodiments, the antibody of the invention binds to TL1A at pH 7.4 with a binding affinity of 10 -9 It has a binding affinity constant (KD) of M and does not bind to TL1A at pH 5.6.

[0272] In some embodiments, the antibodies of the present invention have low immunogenicity. In some embodiments, the antibodies of the present invention have a high safety profile. In some embodiments, the antibodies of the present invention can accelerate the clearance of TL1A in lysosomes, thereby reducing the level of TL1A in the body. In some embodiments, the antibodies of the present invention have increased blood circulation levels. In some embodiments, the antibodies of the present invention have an extended half-life.

[0273] In some embodiments, the antibodies of the present invention can bind to soluble TL1A. In some embodiments, the antibodies of the present invention can bind to membrane-bound TL1A. In some embodiments, the antibodies of the present invention can inhibit T cell activation by exogenous TL1A. In some embodiments, the antibodies of the present invention can inhibit immune cell activation by endogenous TL1A.

[0274] nucleic acid In yet another aspect, the present invention provides a nucleic acid molecule comprising a nucleotide sequence encoding the antigen-binding protein or antigen-binding fragment thereof disclosed in the present invention.

[0275] The term "nucleic acid" includes single- and double-stranded nucleotide polymers. Nucleic acids may be ribonucleotides or deoxynucleotides or modified forms of either type of nucleotide. Modifications include base modifications, such as bromouridine and inosine derivatives, ribose modifications, such as 2',3'-dideoxyribose, and internucleotide bond modifications, such as phosphorothioates, phosphorodithioates, selenophosphates, diselenophosphates, phenylthiophosphates, aniline phosphates, and phosphoramidates.

[0276] For example, the invention provides nucleic acid molecules encoding any of the heavy chain variable region sequences disclosed herein. The invention further provides nucleic acid molecules that are at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a nucleic acid encoding any of the heavy chain variable region sequences disclosed herein.

[0277] For example, the invention provides nucleic acid molecules encoding any of the light chain variable region sequences disclosed herein. The invention further provides nucleic acid molecules that are at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a nucleic acid encoding any of the light chain variable region sequences disclosed herein.

[0278] For example, the invention provides nucleic acid molecules encoding heavy chain variable region sequences comprising the CDR sequences of any of the heavy chain variable region sequences disclosed herein. The invention further provides nucleic acid molecules encoding heavy chain variable region sequences comprising CDR sequences that are at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the CDR sequences of any of the heavy chain variable region sequences disclosed herein.

[0279] For example, the invention provides nucleic acid molecules encoding light chain variable region sequences comprising the CDR sequences of any of the light chain variable region sequences disclosed herein. The invention further provides nucleic acid molecules encoding light chain variable region sequences comprising CDR sequences that are at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the CDR sequences of any of the light chain variable region sequences disclosed herein.

[0280] In some embodiments, the nucleic acid is ribonucleic acid (RNA) or deoxyribonucleic acid (DNA). In some embodiments, ribonucleic acid (RNA) comprising a nucleotide sequence encoding an antibody disclosed herein is provided. In some embodiments, the invention provides deoxyribonucleic acid (DNA) comprising a deoxynucleotide sequence encoding an antibody disclosed herein.

[0281] In some embodiments, deoxyribonucleic acid (DNA) can be introduced into human cells in vivo. In some embodiments, deoxyribonucleic acid (DNA) of the present invention is contained in a vector or delivery agent. In some embodiments, deoxyribonucleic acid (DNA) of the present invention is integrated into the genome of a cell.

[0282] In some embodiments, the ribonucleic acid (RNA) can be introduced into human cells in vivo. In some embodiments, the ribonucleic acid (RNA) of the present invention is comprised in a vector or delivery agent.

[0283] vector In another aspect, the present invention provides a vector comprising a nucleic acid disclosed herein that encodes a TL1A antigen binding protein or antigen-binding fragment thereof disclosed herein.

[0284] In some embodiments, the vector is an expression vector capable of expressing a polypeptide comprising the heavy chain variable region or the light chain variable region of the antigen binding protein. For example, the present invention provides expression vectors comprising any of the above-described nucleic acid molecules.

[0285] Any vector may be suitable for the present disclosure. In some embodiments, the vector is a viral vector. In some embodiments, the vector is a retroviral vector, a DNA vector, a murine leukemia virus vector, an SFG vector, a plasmid, an RNA vector, an adenoviral vector, a baculoviral vector, an Epstein-Barr virus vector, a papovavirus vector, a vaccinia virus vector, a herpes simplex virus vector, an adenovirus-associated vector (AAV), a lentiviral vector, or any combination thereof. Suitable exemplary vectors include, for example, pBY, pGAR, pBABE-puro, pBABE-neo largeTcDNA, pBABE-hygro-hTERT, pMKO.1 GFP, MSCV-IRES-GFP, pMSCV PIG (Puro IRES GFP empty plasmid), pMSCV-loxp-dsRed-loxp-eGFP-Puro-WPRE, MSCV IRES luciferase, pMIG, MDH1-PGK-GFP_2.0, TtRMPVIR, pMSCV-IRES-mCherry FP, pRetroX GFP T2A Cre, pRXTN, pLncEXP, and pLXIN-Luc.

[0286] The recombinant expression vector may be any suitable recombinant expression vector. Suitable vectors include vectors designed for propagation and amplification or expression, or both, such as plasmids and viruses. For example, vectors may be selected from the pUC series (Fermentas Life Sciences, Glen Burnie, Md.), pBluescript series (Stratagene, LaJolla, Calif.), pET series (Novagen, Madison, Wis.), pGEX series (Pharmacia Biotech, Uppsala, Sweden), and pEX series (Clontech, Palo Alto, Calif.). Bacteriophage vectors, such as λGT10, λGT11, λZapII (Stratagene), λEMBL4, and λNM1149, may also be used. Examples of plant expression vectors useful in connection with the present disclosure include pBY, pBI01, pBI101.2, pBI101.3, pBI121, and pBIN19 (Clontech). Examples of animal expression vectors useful in connection with the present disclosure include pcDNA, pEUK-Cl, pMAM and pMAMneo (Clontech).

[0287] Recombinant expression vectors can be prepared using standard recombinant DNA techniques, such as those described in Sambrook et al., Molecular Cloning: A Laboratory Manual, 3rd ed., Cold Spring Harbor Press, Cold Spring Harbor, NY 2001; and Ausubel et al., Current Protocols in Molecular Biology, Greene Publishing Associates and John Wiley & Sons, NY, 1994. Expression vector constructs can be circular or linear and prepared to contain a replication system functional in prokaryotic or eukaryotic host cells. Replication systems can be derived, for example, from ColEl, 2μ plasmid, λ, SV40, bovine papilloma virus, etc.

[0288] For example, the vector can be an adenoviral vector comprising a nucleotide sequence encoding an antibody disclosed herein. The vector is administered to a subject and then enters the subject's cells in vivo, thereby integrating the nucleotide sequence encoding the antibody disclosed herein into the genome of the cells, which can then express the antibody disclosed herein.

[0289] host cell In another aspect, the invention provides a host cell comprising a nucleic acid disclosed herein or a vector disclosed herein.

[0290] Any cell can be used as a host cell for the nucleic acids or vectors of the present disclosure. In some embodiments, the cell can be a prokaryotic cell, a fungal cell, a yeast cell, or a higher eukaryotic cell, such as a mammalian cell. Suitable prokaryotic cells include eubacteria, e.g., gram-negative or gram-positive organisms, such as Enterobacteriaceae, e.g., Escherichia, e.g., E. coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, e.g., Salmonella typhimurium, Serratia, e.g., Serratia marcescans, Examples of host cells include, but are not limited to, Bacilli, such as B. subtilis and B. licheniformis, Pseudomonas, such as P. aeruginosa and Streptomyces. In some embodiments, the cell is a human cell. In some embodiments, the cell is an immune cell. In some embodiments, the host cell includes, for example, CHO cells, such as CHOS cells and CHO-K1 cells, or HEK293 cells, such as HEK293A, HEK293T, and HEK293FS.

[0291] The host cells of the invention are prepared by introducing the vectors disclosed herein or the nucleic acids disclosed herein in vitro or ex vivo, and can be administered to a subject to express the antibodies disclosed herein in vivo.

[0292] Preparation method In another aspect, the present invention provides a method for preparing an antigen-binding protein or antigen-binding fragment thereof disclosed herein, the method comprising culturing a host cell provided by the present disclosure under conditions for expression of the antigen-binding protein or antigen-binding fragment thereof and isolating the antigen-binding protein or antigen-binding fragment thereof from the host cell culture and / or culture supernatant.

[0293] Any method suitable for producing antigen-binding proteins may be used to produce the antigen-binding proteins of the present application. For example, antibodies can be prepared using hybridoma methods, such as those described in Kohler and Milstein, Nature, 256:495 (1975). In the hybridoma approach, a mouse, hamster, or other suitable host animal is typically immunized with an immunizing agent to elicit lymphocytes that produce, or are capable of producing, antibodies that specifically bind to the immunizing agent. Alternatively, lymphocytes can be immunized in vitro.

[0294] The immunizing agent typically contains a protein antigen, a fragment thereof, or a fusion protein thereof. In the present application, any suitable form of TL1A can be used as the immunizing agent (antigen) for generating non-human antibodies specific to TL1A and screening the antibodies for biological activity. The immunizing agent may be full-length mature human TL1A, including the native homodimer or single / multiple epitope-containing peptides. The immunizing agent may be used alone or in combination with one or more immunogenicity enhancing agents known in the art. Typically, peripheral blood lymphocytes are used if cells of human origin are desired. If non-human mammalian sources are desired, spleen cells or lymph node cells are used. The lymphocytes are then fused to an immortalized cell line using a suitable fusing agent (e.g., polyethylene glycol) to form an immortalized hybridoma cell (Goding, Monoclonal Antibodies: Principles and Practice, Academic Press, (1986) pp. 59-103). The immortalized cell line is typically a transformed mammalian cell, particularly a myeloma cell of rodent, bovine, or human origin. Typically, rat or mouse myeloma cell lines are used. The hybridoma cells can be cultured in a suitable medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, immortalized cells. For example, if the parent cells lack hypoxanthine guanine phosphoribosyltransferase (HGPRT or HPRT), the hybridoma culture medium will usually contain hypoxanthine, aminopterin, and thymidine ("HAT medium"), which can prevent the growth of HGPRT-deficient cells.

[0295] Preferred immortalized cell lines are those that fuse efficiently, support stable high-level expression of antibody by the selected antibody-producing cells, and are sensitive to a medium such as HAT medium. More preferred immortalized cell lines are mouse myeloma cell lines, available, for example, from the Salk Institute Cell Distribution Center in San Diego, California, and the American Type Culture Collection in Manassas, Virginia. Human myeloma and mouse-human heteromyeloma cell lines for the production of human monoclonal antibodies have also been described (see Kozbor, J. Immunol., 133:3001 (1984); Brodeur et al., Monoclonal Antibody Production Techniques and Applications, Marcel Dekker, Inc., New York, (1987) pp. 51-63).

[0296] The culture medium in which the hybridoma cells are cultured can then be assayed for the presence of monoclonal antibodies directed against the antigen. Preferably, the binding specificity of the monoclonal antibodies produced by the hybridoma cells is determined by immunoprecipitation or an in vitro binding assay, such as radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA). Such techniques and assays are known in the art. The binding affinity of a monoclonal antibody can be determined, for example, by the Scatchard analysis of Munson and Pollard, Anal. Biochem., 107:220 (1980). Furthermore, in therapeutic applications of monoclonal antibodies, it is important to identify antibodies with high specificity and high binding affinity for the target antigen.

[0297] After the desired hybridoma cells are identified, the clones can be subcloned by limiting dilution procedures and cultured by standard methods (see Goding, Monoclonal Antibodies: Principles and Practice, Academic Press, (1986) pp. 59-103). Suitable media for this purpose include, for example, Dulbecco's modified Eagle's medium and RPMI-1640 medium. Alternatively, the hybridoma cells can be grown in vivo as ascites in a mammal.

[0298] The monoclonal antibodies secreted by the subclones can be isolated or purified from the culture medium or ascites fluid by conventional immunoglobulin purification procedures, such as protein A-Sepharose, hydroxylapatite chromatography, gel electrophoresis, dialysis, or affinity chromatography.

[0299] Monoclonal antibodies can also be prepared by recombinant DNA methods, such as those described in U.S. Patent No. 4,816,567. DNA encoding the monoclonal antibodies of the invention can be readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes capable of binding specifically to genes encoding murine antibody heavy and light chains). The hybridoma cells of the invention serve as a preferred source of such DNA. The isolated DNA can be incorporated into an expression vector and then transfected into host cells, such as monkey COS cells, Chinese hamster ovary (CHO) cells, or non-immunoglobulin-producing myeloma cells, to obtain the antibody in the recombinant host cells that synthesize the monoclonal antibody. The DNA can also be modified, for example, by substituting the coding sequence for human heavy and light chain constant domains for the homologous murine sequences (see U.S. Patent No. 4,816,567; Morrison, Nature 368, pp. 812-13 (1994)), or by covalently linking all or part of the coding sequence for a non-immunoglobulin polypeptide to the immunoglobulin coding sequence. Such a non-immunoglobulin polypeptide can replace the constant domains of an antibody of the invention or can replace the variable domains of one antigen-binding site of an antibody of the invention to produce a chimeric bivalent antibody.

[0300] A fully human antibody is an antibody molecule in which the entire light and heavy chain sequences, including the CDRs, are derived from human genes. Such antibodies are referred to herein as "human antibodies" or "fully human antibodies." Fully human monoclonal antibodies can be prepared using trioma technology, human B-cell hybridoma technology (see Kozbor et al., 1983 Immunol Today 4:72), and EBV hybridoma technology to produce human monoclonal antibodies (see Cole et al., 1985 In: MONOCLONAL ANTIBODIES AND CANCER THERAPY, Alan R. Liss, Inc., pp. 77-96). Human monoclonal antibodies can be used and can be obtained by using human hybridomas (see Cote et al., 1983. Proc Natl Acad Sci USA 80:2026-2030) or by in vitro transformation of human B cells with Epstein-Barr virus (Cole et al., 1985 In: MONOCLONAL ANTIBODIES AND CANCER THERAPY, Alan R. Liss, Inc., pp. 77-96).

[0301] The sequences of the antigen-binding proteins of the present application can be obtained using conventional techniques such as PCR amplification or genomic library screening. Additionally, the coding sequences for the light and heavy chains can be fused together to form single-chain antibodies.

[0302] Once the relevant sequence is obtained, it can be obtained in large quantities using recombination. This is typically done by cloning into a vector, transforming into cells, and then isolating the relevant sequence from the grown host cells by conventional methods. Additionally, synthetic methods can be used to synthesize the relevant sequence, especially if the fragment length is short. Fragments with long sequences are often obtained by first synthesizing many smaller fragments and then joining them together. The nucleic acid molecule can then be introduced into a variety of existing DNA molecules (or vectors) and cells known in the art.

[0303] Pharmaceutical Composition In another aspect, the present invention provides a pharmaceutical composition comprising an antigen-binding protein or antigen-binding fragment thereof disclosed herein, a nucleic acid molecule disclosed herein, a vector disclosed herein and / or a cell disclosed herein, and optionally a pharmaceutically acceptable carrier.

[0304] The antigen-binding proteins or antigen-binding fragments thereof or agents (also referred to herein as "active compounds") of the present invention can be incorporated into pharmaceutical compositions suitable for administration. Such compositions typically comprise the antigen-binding protein or antigen-binding fragments thereof or agent and a pharmaceutically acceptable carrier. As used herein, the term "pharmaceutically acceptable carrier" is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with drug administration. Preferred examples of such carriers or excipients include, but are not limited to, water, saline, Ringer's solution, dextrose solution, and 5% human serum albumin. Non-aqueous vehicles, such as liposomes and fixed oils, can also be used. The use of such media and agents for pharmaceutically active substances is well known in the art. Except as a conventional media or agent is incompatible with the active compound, its use in the compositions is contemplated. The pharmaceutical compositions of the present application may also contain two or more active compounds, typically compounds with complementary activities that do not adversely affect each other. The type and effective amount of such agent will depend, for example, on the amount and type of antagonist present in the formulation, as well as the clinical parameters of the subject.

[0305] In some embodiments of the pharmaceutical compositions disclosed herein, the pharmaceutical composition further comprises a second therapeutic agent, hi some embodiments, the second therapeutic agent is selected from the group consisting of an antibody, a chemotherapeutic agent, a radiotherapeutic agent, an siRNA, an antisense oligonucleotide, a polypeptide, and a small molecule drug.

[0306] In some embodiments, the second therapeutic agent is an immune checkpoint inhibitor. Examples of immune checkpoint inhibitors include, but are not limited to, a PD-1 inhibitor, a PD-L1 inhibitor, a CTLA-4 inhibitor, an adenosine A2A receptor inhibitor, a B7-H3 inhibitor, a B7-H4 inhibitor, a BTLA inhibitor, a KIR inhibitor, a LAG3 inhibitor, a TIM-3 inhibitor, a VISTA inhibitor, a galectin-9 inhibitor, or a TIGIT inhibitor. In some embodiments, the checkpoint inhibitor is a PD-1 or PD-L1 inhibitor.

[0307] In some embodiments, the second therapeutic agent is a cytokine. Examples of cytokines include, but are not limited to, interleukins (e.g., IL-2, IL-7, IL-10, IL-12, IL-15) and interferons (e.g., IFNa, IFNγ).

[0308] In some embodiments, the second therapeutic agent is a chemotherapeutic agent, which can include, for example, cytotoxic agents, antimetabolites (e.g., antifolates, purine analogs, pyrimidine analogs, etc.), topoisomerase inhibitors (e.g., camptothecin derivatives, anthracenediones, anthracyclines, epipodophyllotoxins, quinoline alkaloids, etc.), antimicrotubule agents (e.g., taxenes, vinca alkaloids), protein synthesis inhibitors (e.g., cephalotaxines, camptothecin derivatives, quinoline alkaloids), alkylating agents (e.g., alkylsulfonates, ethyleneimines, nitrogen mustards, nitrosoureas, platinum derivatives, triazenes, etc.), alkaloids, terpenoids, and kinase inhibitors.

[0309] In some embodiments, the second therapeutic agent is a radiotherapeutic agent, which refers to agents routinely employed in the therapeutic field, including photons with sufficient energy to ionize chemical bonds, such as alpha, beta, and gamma rays from radioactive nuclei and X-rays.

[0310] The pharmaceutical compositions of the present invention can be formulated to suit their intended route of administration. The routes of administration of the pharmaceutical compositions of the present invention are preferably parenteral, injectable, or oral. Injectable administration preferably includes intravenous, intramuscular, intraperitoneal, intradermal, or subcutaneous injection. The pharmaceutical compositions may be in various conventional dosage forms in the art, preferably in solid, semisolid, or liquid form, i.e., in the form of an aqueous, non-aqueous, or suspension, more preferably in the form of a tablet, capsule, granule, injection, or infusion. Administration via intravascular, subcutaneous, intraperitoneal, or intramuscular routes is more preferred. Preferably, the pharmaceutical compositions can be administered as an aerosol or coarse spray, i.e., intranasally or intrathecally, intramedullary, or intraventricularly. More preferably, the pharmaceutical compositions can be administered transdermally, percutaneously, topically, enterally, vaginally, sublingually, or rectally. The pharmaceutical compositions of the present invention can be prepared in various dosage forms as needed and can be administered by a physician based on the patient's type, age, weight, general disease state, administration method, and other factors to determine the dosage beneficial to the patient. The method of administration may be, for example, injection or other treatment method.

[0311] The dosage level of the pharmaceutical composition administered according to the present invention can be adjusted according to the amount of the composition required to achieve the desired therapeutic result. The administration regimen can be a single injection or multiple injections, and can be modified. The selected dosage level and regimen will be appropriately adjusted depending on various factors, including activity and stability (i.e., half-life), formulation, route of administration, combination with other drugs or treatments, the disease or condition being detected and / or treated, and the health status and past medical history of the subject being treated.

[0312] Treatment Methods and Uses The present disclosure provides a method of treating a disease in a subject, comprising administering to the subject an effective amount of an antigen-binding protein or antigen-binding fragment thereof disclosed herein, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein.

[0313] The present disclosure provides for the use of an antigen binding protein or antigen binding fragment thereof, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein in the manufacture of a medicament for treating a disease in a subject.

[0314] The present disclosure also provides an antigen binding protein or antigen binding fragment thereof, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein for use in treating a disease in a subject.

[0315] In some embodiments, the disease is a TL1A-mediated disease. In some embodiments, the disease is a disease associated with TL1A expression. In some embodiments, the disease is a disease associated with DR3 expression. In some embodiments, the disease is a disease associated with DcR3 expression. In some embodiments, the disease is a disease associated with the TL1A / DR3 signaling pathway. In some embodiments, the disease is selected from an autoimmune disease, an inflammatory disease, and a fibrotic disease.

[0316] In some embodiments, the disease is an inflammatory disease or condition. Non-limiting examples of inflammatory diseases include allergies, ankylosing spondylitis, asthma, atopic dermatitis, autoimmune diseases or conditions, cancer, celiac disease, chronic obstructive pulmonary disease (COPD), chronic peptic ulcer disease, cystic fibrosis, diabetes (e.g., type 1 diabetes and type 2 diabetes), glomerulonephritis, gout, hepatitis (e.g., active hepatitis), immune-mediated diseases or disorders, inflammatory bowel disease (IBD), such as Rohn's disease and ulcerative colitis, myositis, osteoarthritis, pelvic inflammatory disease (PID), multiple sclerosis, age-related neurodegenerative diseases, periodontal disease (e.g., periodontitis), preperfusion injury, transplant rejection, psoriasis, pulmonary fibrosis, rheumatic diseases, scleroderma, sinusitis, and tuberculosis.

[0317] In some embodiments, the disease is an autoimmune disease or disorder. Non-limiting examples of autoimmune diseases or disorders include achalasia, Addison's disease, adult Still's disease, agammaglobulinemia, alopecia areata, amyloidosis, ankylosing spondylitis, anti-GBM / anti-TBM nephritis, antiphospholipid syndrome, autoimmune angioedema, autoimmune autonomic neuropathy, autoimmune encephalomyelitis, autoimmune hepatitis, autoimmune inner ear disease (AIED), autoimmune myocarditis, autoimmune oophoritis, autoimmune orchitis, autoimmune pancreatitis, autoimmune retinopathy, autoimmune urticaria, axonal and neuronal neuropathy (AMN). AN), Baro's disease, Behçet's disease, benign mucous membrane pemphigoid, bullous pemphigoid, Castleman's disease (CD), celiac disease, Chagas' disease, chronic inflammatory demyelinating polyneuropathy (CIDP), chronic relapsing multifocal osteomyelitis (CRMO), Churg-Strauss syndrome (CSS) or eosinophilic granulomatosis with polyneuropathy (EGPA), cicatricial pemphigoid, Cogan's syndrome, cold agglutinin disease, congenital heart block, Coxsackie myocarditis, CREST syndrome, Crohn's disease Disease, dermatitis herpetiformis, dermatomyositis, Devic's disease (neuromyelitis optica), discoid lupus, Dressler's syndrome, endocarditis, eosinophilic esophagitis (EoE), eosinophilic fasciitis, erythema nodosum, essential mixed cryoglobulinemia, Evans' syndrome, fibromyalgia, fibrosing alveolitis, giant cell arteritis (temporal arteritis), giant cell myocarditis, glomerulonephritis, Goodpasture's syndrome, granulomatosis with polyangiitis, Graves' disease, Guillain-Barré syndrome , Hashimoto's thyroiditis, hemolytic anemia, Henoch-Schönlein purpura (HSP), herpes gestationis or pemphigoid of gestationis (PG), hidradenitis suppurativa (HS) (anti-acne), hypogammaglobulinemia, IgA nephropathy, IgG4-related sclerosing disease, immune thrombocytopenic purpura (ITP), inclusion body myositis (IBM), interstitial cystitis (IC), juvenile arthritis, juvenile diabetes mellitus (type 1 diabetes), juvenile myositis (JM), Kawasaki disease, Lambert-Eaton syndrome group, leukocytoclastic vasculitis, lichen planus, lichen sclerosus, lignified conjunctivitis, linear IgA disease (LAD), lupus, chronic Lyme disease, Meniere's disease, microscopic polyangiitis (MPA), mixed connective tissue disease (MCTD), Mooren's ulcer, Mucha-Habermann disease, multifocal motor neuropathy (MMN) or MMNCB, multiple sclerosis, myasthenia gravis, myositis, narcolepsy, neonatal lupus, neuromyelitis optica, neutropenia, ocular cicatricial pemphigoid,Optic neuritis, relapsing rheumatoid arthritis (PR), PANDAS, paraneoplastic cerebellar degeneration (PCD), paroxysmal nocturnal hemoglobinuria (PNH), Parry-Romberg syndrome, pars planitis (peripheral uveitis), Parsonage-Turner syndrome, pemphigus, peripheral neuropathy, paravenous encephalomyelitis, pernicious anemia (PA), POEMS syndrome, polyarteritis nodosa, polyglandular syndrome type I, polyglandular syndrome type II, polyglandular syndrome type III, polymyalgia rheumatica, polymyositis, post-myocardial infarction syndrome, post-pericardiotomy syndrome, primary biliary cirrhosis, primary sclerosing cholangitis, progesterone dermatitis, psoriasis, psoriatic arthritis, pure red cell aplasia (PRCA), pyoderma gangrenosum, Raynaud's phenomenon, reactive arthritis, reflex sexual intercourse These include neuropathic dystrophy, relapsing polychondritis, restless legs syndrome (RLS), retroperitoneal fibrosis, rheumatic fever, rheumatoid arthritis, sarcoidosis, Schmidt's syndrome, scleritis, scleroderma, Sjögren's syndrome, sperm and testicular autoimmunity, stiff-person syndrome (SPS), subacute bacterial endocarditis (SBE), Susac's syndrome, sympathetic ophthalmia (SO), Takayasu's arteritis, temporal artery / giant cell arteritis, thrombocytopenic purpura (TTP), Tolosa-Hunt syndrome (THS), transverse spondylitis, type 1 diabetes, ulcerative colitis (UC), undifferentiated connective tissue disease (UCTD), uveitis, vasculitis, vitiligo, and Vogt-Koyanagi-Harada disease.

[0318] In some embodiments, the disease is a fibrotic disease. "Fibrotic disease" refers to diseases / conditions characterized by fibrosis, including, but not limited to, respiratory conditions such as pulmonary fibrosis, cystic fibrosis, idiopathic pulmonary fibrosis, progressive extensive fibrosis, scleroderma, bronchiolitis obliterans, Hermansky-Pudlak syndrome, asbestosis, silicosis, chronic pulmonary hypertension, AIDS-related pulmonary hypertension, sarcoidosis, tumor interstitial space in lung disease and asthma, chronic liver disease, primary biliary cirrhosis (PBC), schistosomiasis liver disease, cirrhosis of the liver, cardiovascular conditions such as hypertrophic cardiomyopathy, dilated cardiomyopathy, Cardiac myocardial infarction (DCM), atrial fibrosis, atrial fibrillation, ventricular fibrosis, ventricular fibrillation, myocardial fibrosis, Brugada syndrome, myocarditis, endomyocardial fibrosis, myocardial infarction, fibrous vascular disease, hypertensive heart disease, arrhythmogenic right ventricular cardiomyopathy (ARVC), tubulointerstitial and glomerular fibrosis, atherosclerosis, varicose veins, cerebral infarction, neurological conditions such as gliosis and Alzheimer's disease, muscular dystrophies such as Duchenne muscular dystrophy (DMD) or Becker's muscular dystrophy (BMD), gastrointestinal conditions such as Crohn's disease Rohn's disease, microscopic colitis and primary sclerosing cholangitis (PSC), skin conditions such as scleroderma, nephrogenic systemic fibrosis and skin keloids, arthrofibrosis, Dupuytren's contracture, mediastinal fibrosis, retroperitoneal fibrosis, myelofibrosis, Peroni's disease, adhesive capsulitis, kidney diseases (e.g. renal fibrosis, nephrotic syndrome, Alport syndrome, HIV-associated nephropathy, polycystic kidney disease, Fabry disease, diabetic nephropathy, chronic glomerulonephritis, systemic lupus nephropathy), progressive systemic sclerosis (PSS), chronic graft-versus-host disease, eye diseases such as Includes Graves' ophthalmopathy, epiretinal fibrosis, retinal fibrosis, subretinal fibrosis (e.g., associated with macular degeneration (e.g., wet age-related retinal degeneration (AMD)), diabetic retinopathy, glaucoma, corneal fibrosis, post-surgical fibrosis (e.g., posterior capsule fibrosis after cataract surgery or bullous fibrosis after trabeculectomy for glaucoma), conjunctival fibrosis, subconjunctival fibrosis, arthritis, fibrotic pre-neoplastic and fibrotic neoplastic diseases, and fibrosis induced by chemical or environmental insults (e.g., cancer chemotherapy, pesticides, radiation / cancer radiotherapy).

[0319] In preferred embodiments, the disease is selected from the group consisting of inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system injury, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis, and arthrofibrosis.

[0320] In some embodiments, the dosage administered to a subject may vary depending on the embodiment, the medicament employed, the method of administration, and the site and subject to be treated. However, the dose should be sufficient to provide a therapeutic response. A clinician may determine the effective amount to be administered to a human or other subject to treat a medical condition. The exact amount required to be therapeutically effective may depend on many factors, such as the activity of the antibody and the route of administration.

[0321] The dose of an antibody, composition, or conjugate described herein can be administered to a mammal once, or in a series of subdoses over a suitable period of time, for example, daily, semi-weekly, weekly, biweekly, semi-monthly, bimonthly, semi-annually, or yearly, as needed. A dosage unit containing an effective amount of an antibody, composition, or conjugate can be administered in a single daily dose, or the total daily dosage can be administered daily in two, three, four, or more divided doses as needed.

[0322] Suitable means of administration can be selected by a medical professional. The route of administration can be parenteral, e.g., by injection, nasal, pulmonary, or transdermal. Administration can be systemic or local, e.g., by intravenous, intramuscular, intraperitoneal, or subcutaneous injection. In some embodiments, the antibody, composition, or conjugate is selected for parenteral delivery, for inhalation, or for delivery through the digestive tract, e.g., orally. The dosage and method of administration can vary depending on the subject's weight, age, condition, etc., and can be selected as appropriate.

[0323] The methods and compositions described herein can be used alone or in conjunction with or in combination with other therapeutic agents and / or procedures. As used herein, the term "conjoint" or "combined" administration should be understood to mean the delivery of two (or more) different treatments to a subject over the course of their condition, such that the effects of the treatments on the patient overlap at a certain point. In some embodiments, the delivery of one treatment is still ongoing when the delivery of a second treatment begins, thus resulting in an overlap in administration. This is sometimes referred to herein as "simultaneous" or "co-delivery." In other embodiments, the delivery of one treatment has concluded before the delivery of another treatment begins. In some embodiments, either case, the treatments are more effective when administered in combination. For example, when administered in combination with a first treatment, the same effect may be observed with a lower amount of the second treatment than would be observed if the second treatment were administered alone without the first treatment, or the second treatment significantly alleviates symptoms, or similar conditions exist as with the first treatment. In some embodiments, the co-administration results in a greater reduction in symptoms or other parameters associated with the condition than would be observed in the absence of the other treatment. The effect of the two treatments can be partially additive, fully additive, or greater than additive. Co-administration can be such that the effect of the first treatment administered is still detectable when the second treatment is administered.

[0324] The present disclosure provides methods of treating a subject by administering a second therapeutic agent in combination with an anti-TL1A antigen-binding protein or antigen-binding fragment thereof disclosed herein. Accordingly, in some embodiments, the method further comprises administering a second therapeutic agent to the subject.

[0325] The present disclosure provides for the use of an antigen binding protein or antigen binding fragment thereof, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein, and a second therapeutic agent in the manufacture of a medicament for treating a disease in a subject.

[0326] The present disclosure provides for the use of an antigen binding protein or antigen binding fragment thereof, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein in the manufacture of a medicament for administration in combination with a second therapeutic agent to treat a disease in a subject.

[0327] The present disclosure provides for the use of a second therapeutic agent in the manufacture of a medicament for administration in combination with an antigen binding protein or antigen binding fragment thereof, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein to treat a disease in a subject.

[0328] The present disclosure also provides an antigen binding protein or antigen binding fragment thereof, a nucleic acid disclosed herein, a vector disclosed herein, a host cell disclosed herein, or a pharmaceutical composition disclosed herein for use in administration in combination with a second therapeutic agent to treat a disease in a subject.

[0329] The amounts of the antigen-binding protein or antigen-binding fragment thereof and the second therapeutic agent, as well as the relative times of administration, can be selected to achieve a desired combined therapeutic effect. For example, when a combination therapy is administered to a patient in need of such administration, the therapeutic agents or one or more pharmaceutical compositions comprising the therapeutic agents in the combination can be administered in any order, such as sequentially, concomitantly, together, or simultaneously. Furthermore, for example, the antigen-binding protein or antigen-binding fragment thereof can be administered while the second therapeutic agent is exerting its prophylactic or therapeutic effect, or vice versa.

[0330] In certain embodiments, the antigen binding protein or antigen-binding fragment thereof, nucleic acid, vector, host cell or pharmaceutical composition disclosed herein is administered before, substantially simultaneously with, or after the administration of a second therapeutic agent.

[0331] In some embodiments, the second therapeutic agent is an immune checkpoint inhibitor. Examples of immune checkpoint inhibitors include, but are not limited to, a PD-1 inhibitor, a PD-L1 inhibitor, a CTLA-4 inhibitor, an adenosine A2A receptor inhibitor, a B7-H3 inhibitor, a B7-H4 inhibitor, a BTLA inhibitor, a KIR inhibitor, a LAG3 inhibitor, a TIM-3 inhibitor, a VISTA inhibitor, a galectin-9 inhibitor, or a TIGIT inhibitor. In some embodiments, the checkpoint inhibitor is a PD-1 or PD-L1 inhibitor.

[0332] In some embodiments, the second therapeutic agent is a cytokine. Examples of cytokines include, but are not limited to, interleukins (e.g., IL-2, IL-7, IL-10, IL-12, IL-15) and interferons (e.g., IFNa, IFNγ).

[0333] In some embodiments, the second therapeutic agent is a chemotherapeutic agent, which can include, for example, cytotoxic agents, antimetabolites (e.g., antifolates, purine analogs, pyrimidine analogs, etc.), topoisomerase inhibitors (e.g., camptothecin derivatives, anthracenediones, anthracyclines, epipodophyllotoxins, quinoline alkaloids, etc.), antimicrotubule agents (e.g., taxenes, vinca alkaloids), protein synthesis inhibitors (e.g., cephalotaxines, camptothecin derivatives, quinoline alkaloids), alkylating agents (e.g., alkylsulfonates, ethyleneimines, nitrogen mustards, nitrosoureas, platinum derivatives, triazenes, etc.), alkaloids, terpenoids, and kinase inhibitors.

[0334] In some embodiments, the second therapeutic agent is a radiotherapeutic agent, which refers to agents routinely employed in the therapeutic field, including photons with sufficient energy to ionize chemical bonds, such as alpha, beta, and gamma rays from radioactive nuclei and X-rays. Detection Methods and Uses In another aspect, the present disclosure provides a method for detecting TL1A protein in vitro or in vivo, comprising contacting a sample with a TL1A antigen binding protein disclosed herein and detecting the presence of TL1A protein.

[0335] where: (1) contacting the sample with an antigen-binding protein or antigen-binding fragment thereof disclosed herein; and (2) determining the presence or level of TL1A in the sample by detecting binding of the antigen-binding protein to the sample. A method for detecting the presence or level of TL1A in a sample is provided, comprising:

[0336] In some embodiments, the sample may be any sample, including, but not limited to, blood samples, tissue from biopsies, autopsies, and pathology specimens. Samples also include bodily fluids, such as blood, serum, plasma, sputum, spinal fluid, or urine. In some embodiments, the control sample is a sample from a subject without the disease. In certain embodiments, the sample is a blood or tissue sample.

[0337] In a preferred embodiment, the disease is selected from the group consisting of inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, psoriasis, hidradenitis suppurativa, uveitis, asthma, atopic dermatitis, systemic lupus erythematosus, multiple sclerosis, transplant rejection, central nervous system injury, optic neuritis, age-related macular degeneration, Sjogren's syndrome, scleroderma, systemic sclerosis, vasculitis, atherosclerosis, chronic kidney disease, nephrogenic systemic fibrosis, hepatic fibrosis, chronic bronchitis, interstitial pneumonia, pulmonary fibrosis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, pulmonary fibrosis caused by tuberculosis, retroperitoneal fibrosis, cystic fibrosis, endocardial fibrosis, atrial fibrosis, mediastinal fibrosis, spinal fibrosis, progressive fibrosis block fibrosis, and arthrofibrosis.

[0338] In some embodiments of the detection method, the anti-TL1A antibody is directly labeled with a detectable label. In another embodiment, the anti-TL1A antibody (first antibody) is unlabeled, and a second antibody or other molecule capable of binding to the first antibody is labeled. As is well known to those skilled in the art, a secondary antibody capable of specifically binding to the first antibody for a particular species and class is selected. For example, if the first antibody is human IgG, the second antibody can be an anti-human IgG. Other molecules capable of binding to antibodies include, but are not limited to, Protein A and Protein G, both of which are commercially available.

[0339] Suitable labels for antibodies or secondary antibodies include various enzymes, prosthetic groups, fluorescent materials, luminescent materials, magnetic agents, and radioactive materials. Non-limiting examples of suitable enzymes include horseradish peroxidase, alkaline phosphatase, beta-galactosidase, or acetylcholinesterase. Non-limiting examples of suitable prosthetic group complexes include streptavidin / biotin and avidin / biotin. Non-limiting examples of suitable fluorescent materials include umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazineamide fluorescein, dansyl chloride, or phycoerythrin. A non-limiting exemplary luminescent material is luminol. A non-limiting exemplary magnetic agent is gadolinium, and a non-limiting exemplary radioactive label is 125 I, 131 I, 35 S or 3 Contains H.

[0340] In an alternative embodiment, TL1A can be measured in a biological sample by a competitive immunoassay utilizing TL1A protein standards labeled with a detectable substance and unlabeled anti-TL1A antibodies. In this assay, the biological sample, labeled TL1A protein standards, and anti-TL1A antibodies are combined, and the amount of labeled TL1A protein standard that binds to the unlabeled antibody is measured. The amount of TL1A in the biological sample is inversely proportional to the amount of labeled TL1A protein standard that binds to the anti-TL1A antibodies.

[0341] The immunoassays and detection methods disclosed herein can be used for a variety of purposes. In one embodiment, anti-TL1A antibodies can be used to detect the production of TL1A in cells in cell culture. In another embodiment, the antibodies can be used to detect the amount of TL1A in a biological sample, such as a tissue sample or a blood or serum sample. In some examples, the TL1A is cell surface TL1A.

[0342] Kits / Delivery Devices In another aspect, the present invention provides a kit or delivery device comprising an antigen-binding protein or antigen-binding fragment thereof disclosed herein, a nucleic acid molecule disclosed herein, a vector disclosed herein, a host cell disclosed herein, and / or a pharmaceutical composition disclosed herein.

[0343] In some embodiments, the kit further comprises (i) a device and / or (ii) instructions for administering the antigen-binding protein or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, and / or the pharmaceutical composition.

[0344] In some embodiments, the present application provides kits that may include the antigen-binding proteins or antigen-binding fragments thereof, nucleic acid molecules, vectors, host cells, and / or pharmaceutical compositions of the present disclosure. These kits may contain the antibodies, nucleic acid molecules, vectors, host cells, and pharmaceutical compositions described herein in a single, commonly used container. In some cases, the kits may include instructions containing information about the antibodies, pharmaceutical compositions, and dosage forms in the kit. Generally, such information assists patients and physicians in the effective and safe use of the encapsulated antibodies, pharmaceutical compositions, and dosage forms. Containers used in such kits typically include at least one vial, test tube, flask, bottle, syringe, or other suitable container capable of containing, and preferably appropriately dispensing, one or more detection and / or treatment compositions. If a second therapeutic agent is also provided, the kit may also include a second, different container capable of containing the second detection and / or treatment composition. Alternatively, multiple compounds may be prepared as a single pharmaceutical composition and packaged together in a single container device, such as a vial, flask, syringe, bottle, or other suitable single container.

[0345] In one embodiment, the kit is used to detect TL1A in a biological sample. Kits for detecting polypeptides typically include an anti-TL1A antibody, such as any of the monoclonal antibodies disclosed herein. In a further embodiment, the antibody is labeled (e.g., fluorescently, radioactively, or enzymatically).

[0346] In some embodiments, the kit may also include additional components to facilitate the use for which the kit is designed. For example, the kit may further include means for detecting the label (e.g., an enzyme substrate for an enzymatic label, a filter set for detecting a fluorescent label, a suitable secondary label such as a secondary antibody, etc.). The kit may also include buffers and other reagents conventionally used in carrying out the particular method. Such kits and suitable contents are well known to those of skill in the art.

[0347] In some embodiments, the present application provides a drug delivery device (e.g., a plastic or vial, e.g., a hollow pin or syringe barrel) that can be used to administer the antigen-binding proteins or antigen-binding fragments thereof, nucleic acid molecules, vectors, host cells, and / or pharmaceutical compositions of the present disclosure. The device can introduce a substance into a patient via a parenteral route (e.g., intramuscularly, subcutaneously, or intravenously). For example, the injection device can be a syringe (e.g., a pre-filled syringe containing an antibody or pharmaceutical composition described herein, e.g., an autoinjector), which can include a syringe containing a fluid to be injected (e.g., an antibody or pharmaceutical composition described herein) and a needle (which can be used to puncture the skin and / or a blood vessel). The method of administration can vary. Routes of administration can include oral administration, intramuscular injection, subcutaneous injection, rectal administration, etc. [Example]

[0348] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples.

[0349] Example 1: Expression and purification of TL1A The cDNA sequence encoding human TL1A (HuTL1A) was cloned into the pcDNA3.4 vector (Invitrogen) and expressed in EXPI-293 cells (Invitrogen). The expressed protein was purified by Ni-NTA affinity chromatography and size-exclusion chromatography to obtain the TL1A antigen with a purity of >95%.

[0350] [Example 2] Screening of TL1A-specific antibodies from antibody phage libraries The library used for antibody screening was an scFv phage display library consisting of natural and synthetic libraries. Each scFv in the library was fused to the G3 protein of M13 phage and displayed on the surface of M13 phage. The phage library was used to screen for scFv antibody fragments that specifically bind to HuTL1A.

[0351] Using protein-based phage antibody panning technology, antibodies that specifically bind to HuTL1A were selected from a phage library through three rounds of screening. The specific method was as follows: In the first round of panning, HuTL1A was coated onto a microplate, and the corresponding phage library was premixed with an equal volume of 2% skim milk and then transferred to the HuTL1A-coated microplate wells for binding. After 1 hour of incubation, the supernatant in the wells was removed, and the wells were washed with sterile PBST (0.1% Tween 80). The bound phages were then eluted with a pH 3.0 buffer. The eluted phage solution was then neutralized, and M13K07 helper phage was added to amplify the eluted phage approximately 100-fold. The second and third rounds of screening were then performed in a manner similar to the first round of screening. After three rounds of screening, an enriched phage library was obtained. SS320 E. coli (SS320 (MC1061 F') electrotransfected competent cells, Lucigen) bacteria were then transformed with the enriched phage library and spread onto agarose plates for cultivation. Single colonies were picked and inoculated into wells of a 96-well deep-well plate with 2YT medium containing ampicillin and kanamycin. After shaking overnight at 37°C, the cells were pelleted and the supernatant containing the monoclonal phages was obtained. Each monoclonal supernatant was divided into two portions and transferred to two 96-well plates coated with HuTL1A and incubated for 1 hour. After incubation, one plate was washed with sterile PBST, pH 7.4, and the other plate was washed with sterile PBST, pH 6.0. Bound phages were detected by adding anti-M13-HRP (Sino Biological) followed by a color reaction. The absorbance at 455 nm was measured using a microplate reader, and anti-TL1A monoclonal phages that strongly bound to the TL1A antigen at pH 7.4 and those that weakly bound to the TL1A antigen at pH 6.0 were selected.

[0352] The phagemids of all selected monoclonal phage clones from the previous step were sequenced. The sequencing results were analyzed. Based on the sequence patterns, a new pH-dependent affinity maturation phage library was then constructed for the next round of screening. The above screening process was repeated to obtain antibodies with stronger affinity and more pronounced pH-dependent TL1A binding properties.

[0353] [Example 3] Preparation of recombinant TL1A monoclonal antibody The cDNA sequences of the light and heavy chain variable regions of the selected high-affinity pH-dependent monoclonal phage were cloned into the pcDNA3.4 vector (Invitrogen), which already contained antibody constant regions, to obtain a number of high-affinity pH-dependent anti-TL1A monoclonal antibodies, designated herein as "M701 antibodies." These M701 antibodies were numbered 3756, 3876, 3912, 3966, 4007, and 4019, respectively. 3756 was derived from the original library, while the other antibodies were derived from a library optimized based on 3756 (3756 was subjected to affinity maturation and modification of pH-dependent antigen-binding properties). Single-arm antibodies were prepared for affinity testing of these antibodies (the method was as described by Ridgway, JB; Presta, LG; Carter, P. Protein Eng. 1996, 9, pp. 617-621). The corresponding single-arm antibody numbers are 3672, 3900, 4035, 3952, 3973, and 3990. Concurrently, TL1A control antibodies were prepared, including Pfizer / Roivant's TL1A monoclonal antibody RVT-3101 (sequence derived from patent US9683998B2), designated BM1 antibody, the corresponding single-arm antibody designated SA-BM1 antibody, and Merck / Prometheus' TL1A monoclonal antibody PRA023 (INN sequence 12368), designated BM2 antibody. The corresponding single-arm antibody was designated SA-BM2 antibody. EXPI-293 cells (Invitrogen) were transiently transfected with the prepared plasmid using the PEI method and inoculated for 7–10 days to express the target protein. The cells were then pelleted, and the supernatant was collected. The supernatant was purified by protein A affinity chromatography to obtain purified anti-TL1A monoclonal antibodies.

[0354] The sequences of the light and heavy chain variable regions of the monoclonal and single-arm antibodies of the invention are shown in Table 1 below, and the corresponding CDR sequences (defined according to the Kabat numbering system) are shown in Table 2 below. The sequences of the full-length heavy and light chains of the monoclonal antibodies are shown in Table 3 below, and the sequences of the full-length heavy, light and Fc chains of the single-arm antibodies are shown in Table 4 below.

[0355] [Table 2] TIFF2025115976000005.tif206168

[0356] [Table 3] TIFF2025115976000007.tif239168

[0357] [Table 4] TIFF2025115976000009.tif250168TIFF2025115976000010.tif130168

[0358] [Table 5] TIFF2025115976000012.tif222168TIFF2025115976000013.tif243168TIFF2025115976000014.tif45168

[0359] Example 4: Characterization of binding affinity and pH-dependent binding of TL1A antibody pH-dependent antigen binding allows antibodies to bind to the HuTL1A antigen with high affinity in serum. However, once the antigen-antibody complex is endocytosed into cells and enters endosomes at pH levels below 6.0, the binding affinity drops significantly, allowing the antigen to be rapidly released and subsequently degraded in lysosomes. Meanwhile, the released antibody binds to the FcRn receptor and re-enters the blood circulation to fulfill its role. pH-dependent antigen binding also accelerates the clearance of the TL1A antigen in lysosomes, thereby reducing the level of TL1A in the circulation and increasing the effective exposure of TL1A-binding antibodies.

[0360] The HuTL1A-binding ability of monoclonal antibodies was assessed under various pH conditions using enzyme-linked immunosorbent assay (ELISA). A 96-well microplate was coated with 10 μg / ml streptavidin and blocked with 1% BSA, followed by the addition of 1 μg / ml biotin-labeled HuTL1A antigen. The corresponding antibody was added to specific wells, diluted in sodium dihydrogen phosphate-citrate buffer at pH 7.4, pH 6.0, pH 5.8, or pH 5.6. The binding assay was performed at room temperature for 30 minutes. After incubation, excess antibody was removed, and the wells were washed with PBST. HRP-anti-human Fc (Sino Biological) was then added to each well and incubated for 30 minutes to detect bound antibody. Finally, the substrate TMB was added and the color was developed for 5–10 minutes. The color reaction was stopped with 1 M sulfuric acid. OD450nm was recorded using a microplate reader, and the data were processed and fitted with a four-parameter logistic regression.

[0361] The ELISA results showed that the binding affinity of single-arm antibodies 3900, 4035, 3952, 3973, and 3990 (all based on the sequence optimization of 3672) to HuTL1A was significantly improved at pH 7.4 compared to single-arm antibody 3672 obtained from the initial library, which was stronger than SA-BM2 but slightly weaker or equivalent to SA-BM1 (Figure 1). For both control antibodies SA-BM1 and SA-BM2, the binding affinity to HuTL1A was not significantly different at pH 7.4 and 6.5. In contrast, the binding affinity of M701 antibodies 3672, 3900, 4035, 3952, 3973, and 3990 to HuTL1A was significantly reduced at pH 6.0 compared to pH 7.4, demonstrating pH-dependent antigen binding properties (Figure 2).

[0362] Because the pH of endosomes is often below 6.0, we compared the TL1A-binding ability of the M701 antibody and control antibodies at pH 7.4 and below 6.0. The results showed that there was no significant difference in binding affinity to HuTL1A between the control antibodies BM1 and BM2 at pH 7.4, pH 5.8, and pH 5.6, but the binding of M701 antibodies 3966 and 4007 to HuTL1A was clearly pH-dependent, with binding at pH 5.6 being weaker than at pH 5.8, and binding at these lower pH values being significantly weaker than binding at pH 7.4 (Figure 3).

[0363] The binding rate between the monoclonal antibody and the antigen was measured using the Gator, a label-free biomolecular interaction analyzer based on the principle of biolayer interferometry (BLI). The specific method was as follows: Using a Flex SA probe, biotin-labeled HuTL1A antigen was diluted to 50 nM and captured by the SA probe. Serially diluted single-arm M701 antibody and control antibody were then added. The antibody interacted with the antigen captured by the SA probe. The interaction was analyzed by detecting signal changes in the reflectance interference spectrum of the probe surface, and finally, the binding rate constant of the antibody was calculated. The rate constants of the antigen and antibody were measured in sodium dihydrogen phosphate-citrate buffer at pH 7.4 and 5.6.

[0364] The results showed that M701 antibodies 3952, 3973, and 3990 had high binding affinity to HuTL1A at pH 7.4 but little binding to the HuTL1A antigen at pH 5.6, demonstrating significant pH-dependent antigen binding properties. None of the control antibodies had significant differences in binding affinity to TL1A at pH 7.4 and 5.6 (see SA-BM1) or had stronger affinity for the antigen at pH 5.6 (see SA-BM2) (Table 5, Figure 4).

[0365] [Table 6]

[0366] [Example 5] Species specificity of TL1A antibody The binding kinetics between monoclonal antibodies and human TL1A and cynomolgus / rhesus TL1A were measured using the Gator, a label-free biomolecular interaction analyzer based on the principle of biolayer interferometry (BLI). His-tagged HuTL1A antigen was diluted to 50 nM and captured by an anti-His probe. Serially diluted single-arm M701 antibody and control antibody were then added. The antibodies interacted with the His-tagged TL1A antigen captured by the anti-His probe. The interaction was analyzed by detecting signal changes in the reflectance interference spectrum of the probe surface, and finally, the binding rate constants of the antibodies were calculated. The results showed that M701 antibodies 3952, 3973, and 3990 had high binding affinity to human TL1A and cynomolgus / rhesus TL1A, and the binding affinities were comparable among the M701 antibodies (Table 6).

[0367] ELISA was also used to evaluate antibody binding to human TL1A, cynomolgus / rhesus TL1A, rat TL1A, and mouse TL1A. The results showed that the M701 antibody was unable to bind to rat and mouse TL1A, but did bind to human and cynomolgus / rhesus TL1A, which have similar binding affinities (Table 6) and pH-dependent properties (results not shown).

[0368] [Table 7]

[0369] [Example 6] Binding specificity of TL1A antibody In this experiment, ELISA was used to evaluate the binding ability of monoclonal antibodies to TL1A homologous molecules. Representative members of the TNF ligand superfamily, TNFα, LT-α, LIGHT, and FASL, were selected for binding studies. 1 μg / mL TNFα, LT-α, LIGHT, or FASL was coated onto a microplate at 100 μL / well in carbonate buffer, pH 9.6, and incubated overnight at 4°C. The microplate was then washed five times with PBST, blocked with 300 μL / well of 1% BSA-containing PBS, and incubated at room temperature for 1 hour. After washing five times with PBST, approximately 100 μL each of the M701 monoclonal antibody and control antibody was added to each well and incubated at room temperature for 1 hour. After washing five times with PBST, 100 μL of HRP-anti-human Fc (Sino Biological) was added to each well and incubated at room temperature for 1 hour. After washing five times with PBST, 100 μL of the colorimetric substrate TMB was added to each well and allowed to develop for 10 minutes at room temperature. The reaction was then stopped by adding 1 M sulfuric acid. OD450nm was recorded using a microplate reader. The results showed that neither the M701 antibody nor the control TL1A antibody bound to TL1A homologs from the TNF superfamily (Table 7), suggesting the high specificity of all tested antibodies.

[0370] [Table 8]

[0371] [Example 7] Epitope of TL1A antibody Alanine scanning was used to determine the epitope of the M701 antibody. Three to four different amino acid sites were selected for point mutation in each representative region of the antigen, and all mutants were tested for binding by ELISA and Gator.

[0372] Experimental results demonstrated that the epitope of the M701 antibody is distinct from those of the control antibodies BM1 and BM2. The reported epitope of BM1 is K183 and T192 of TL1A, and BM1 binds only to TL1A trimers. Although the epitope of BM2 has not been disclosed, epitope binning studies reported in patent US20210070871A1 indicate that the epitopes of BM2 and BM1 are distinct, and that BM2 binds to both TL1A trimers and TL1A monomers. To determine the epitope of the M701 antibody, alanine screening was performed on representative regions of each antigen. The results indicated that the epitope of the M701 antibody was located in the region centered on R103, including amino acids R103, G124, M196, Y238, T239, E120, and V102 (Table 8, Figure 5). The epitope of BM2 is located near K225 (Table 8, Figure 5). When combined with structural analysis, it can be seen that the epitope of the M701 antibody is completely different from the epitopes of BM1 and BM2 (Figure 5).

[0373] [Table 9]

[0374] Epitope binning experiments were performed using BLI technology, capturing the antigen HuTL1A using an anti-His probe. The first antibody (BM1 or BM2) was then added to bind to the antigen, and the antigen was saturated with the first antibody. The second antibody (one of the M701 antibodies, BM1, and BM2) was then added to confirm binding to the antigen and analyze the interaction.

[0375] The results showed that the antigen was able to bind to the M701 antibody even after binding to the BM antibody, indicating that the M701 antibody has an epitope different from those of BM1 and BM2 and does not compete with them (Table 9). At the same time, the antigen was able to continue binding to BM2 after binding to BM1, indicating that BM1 and BM2 do not compete with each other. This is consistent with the results of the alanine screening experiment.

[0376] [Table 10]

[0377] [Example 8] Size evaluation of antigen-antibody complexes TL1A is a trimeric antigen that typically binds and crosslinks with bivalent antibodies to form extremely large immune complexes, which are more immunogenic and therefore more prone to undesirable immunogenicity problems (e.g., ADA). This in turn can lead to reduced drug exposure, decreased efficacy, and even safety issues. Therefore, controlling the size of the antigen-antibody complex is important for developing antibodies against trimeric antigens such as TL1A.

[0378] The size of immune complexes formed by antibody and antigen was determined using the Ouchterlony double immunodiffusion assay. 1.2% agarose was applied to a glass slide, and seven small wells of the same size were prepared using a template. 10 μL of 120 μM HuTL1A antigen was added to the center well, and 10 μL of M701 or BM antibody was added to the two peripheral wells. These were incubated overnight in a 37°C incubator, and the formation of a precipitation line was confirmed the next day. The formation of a precipitation line indicates the formation of a large immune complex. The results showed that the M701 antibody did not form a white precipitation line with the antigen, indicating the absence of large immune complexes. However, both control antibodies BM1 and BM2 formed clear precipitation lines with the antigen (Figure 6), suggesting the formation of large immune complexes.

[0379] The size of the antigen-antibody complex was then confirmed using dynamic light scattering (DLS) and size-exclusion chromatography (SEC). Equimolar mixtures of 60 μM antigen and antibody were incubated at room temperature for 30 minutes, and then molecular size was detected using UNCLE or SEC. The results showed that the particle size of the complex formed by the M701 antibody and TL1A antigen, as detected by DLS, was approximately 18 nm, significantly smaller than the 86 nm and 33 nm diameters of the BM1 and BM2 complexes, respectively (Figure 10). The elution volume of the M701 antibody-antigen complex in SEC was significantly larger than that of the control antibody-antigen complex (Figure 7), further confirming that the M701 antibody and antigen formed a smaller complex than the BM antibody.

[0380] [Table 11]

[0381] Finally, the particle size of the antigen-antibody complex was observed using a negative-staining electron microscope. The antigen and antibody were mixed according to a specific molar ratio (after mixing, the complex was formed, and no unbound antigen or antibody was present). The negative-staining experiment was performed to adsorb protein particles onto a grid containing a hydrophilic membrane. A biological sample spread on the grid was stained with electron-dense heavy metal salts. The polymer particles were coated with only a thin layer of heavy metal salts, while the background scattering of electrons was enhanced by the deposition of the dye solution. When observed under a transmission electron microscope, the sample structure was transparent and bright, with a gray or black background, allowing for preliminary evaluation of particle concentration, particle size, uniformity, aggregation state, and other characteristics at lower resolution.

[0382] The protein sample was applied to a glow-discharge hydrophilized negative stain grid (Xinxing Bairui, Cat. No.: T10044) and left for a certain period of time to allow the particles to adhere to the grid. Excess sample was absorbed using filter paper. The grid was then washed with deionized water to reduce the influence of salt ions in the sample buffer in subsequent experiments. The cleaned particles were then stained with the staining solution at room temperature. After staining, the edge of the carrier grid was touched with filter paper to absorb excess liquid, and the particles were allowed to dry naturally. Sample observation and data collection were completed using a Thermo Fisher Krios G4 300 kV transmission electron microscope. The electron detector used was a CETA direct electron counting detector. Data collection was completed using SerialEM software in super-resolution mode.

[0383] Based on the results of negative staining electron microscopy experiments, we directly observed that the size of the antigen-antibody complex formed between the M701 antibody and the TL1A antigen was significantly smaller than that of the complex formed between the control antibody and the TL1A antigen. Small, dispersed particles with regular shapes were formed. See the white circles in Figure 8, which shows a representative antigen-antibody complex. It can be seen that the complex formed between HuTL1A and M701-4007 was a uniformly dispersed small particle, while the complex formed between HuTL1A and the control antibody was largely aggregated (Figure 8). Specifically, the HuTL1A-BM1 complex was highly aggregated, with few single particles visible. A large proportion of the HuTL1A-BM2 complex was largely aggregated, although some small aggregates were also present. The negative staining results were consistent with the SEC results (Figure 7). Specifically, Figure 7 shows that the main SEC peak of BM2 partially overlaps with the elution volume of the main peak of the M701 antibody, but its peak distribution was significantly broader than that of the M701 antibody due to the heterogeneity of its particle size. Negative staining electron microscopy results were also consistent with the DLS results (Table 8).

[0384] [Example 9] Conformation of antigen-antibody complex The conformation of the complex formed by the M701 antibody and antigen was obtained by 2D averaging analysis of negatively stained electron microscopy images. Differences in underfocus or radiation damage can affect the results of 2D particle classification and averaging. To reduce these effects, the contrast transfer function (CTF) was corrected using Cistem software or Cryosmart. Particles were automatically extracted from the image using a box 2–3 times longer than the longest particle. Low-quality particles due to factors such as poor staining, proximity to other particles, and proximity to the edge of the image were excluded. The remaining particles were used for 2D classification using software such as Cistem or Cryosmart. Classification averaging removed background noise and enhanced common features / conformations among particles.

[0385] The results of 2D averaging analysis showed that the M701 antibody and antigen formed a stable, fixed antigen-antibody complex in the form of two antibodies plus two antigens (Figure 9). This conformation of the antigen-antibody complex may have prevented the antigen-antibody complex from forming a larger cross-linked structure.

[0386] The size of the antigen-antibody complex is thought to be related to immunogenicity, and the valency of Fc in the antigen-antibody complex is also thought to be related to immunogenicity. An excessively high Fc value (e.g., 5 or higher) can lead to the activation of immune cells, particularly antigen-presenting cells, thereby potentially exacerbating the problem of ADA. The Fc valency of the M701 antibody-antigen complex was determined to be 2, while the Fc valency of the control antibody-antigen complex was thought to be much greater than 5 due to the formed cross-linked network structure. Therefore, based on the size of the antibody-antigen complex or the valency of Fc, the M701 antibody likely has a lower risk of immunogenicity than the control antibody.

[0387] [Example 10] Mechanism of formation of special conformation of antigen complex SEC analysis was performed on various ratios of M701 antibody Fab:antigen mixtures. The results showed that even in the presence of a significant excess of Fab, the trimeric TL1A antigen still had difficulty binding to the three antibody Fabs (Figure 10). We speculate that after the antibody binds to the first and second epitopes of the antigen, the conformation of the third epitope may change, making it no longer able to bind to the third Fab.

[0388] In the epitope mapping experiments described above, the epitope region of M701 was determined. This region is located in the middle to lower part of the subunit interface and overlaps or partially overlaps with the DR3-TL1A binding region. When the M701 antibody binds to the first and second epitopes of TL1A, it directly blocks binding to DR3, and the third epitope appears to undergo a conformational change and lose its ability to bind to DR3.

[0389] [Example 11] Reporter gene method for determining neutralizing activity against soluble TL1A A reporter gene method was used to determine the activity of TL1A antibodies in blocking the biological function of soluble TL1A.

[0390] HEK293T / DR3-NFκB cells, which express DR3 and contain a SEAP reporter gene under the control of an NF-κB response element, were constructed by lentiviral transfection. When DR3 on HEK293T / DR3-NFκB cells is activated by binding to soluble TL1A, downstream NF-κB signaling is activated, which then induces the production of SEAP. Adding anti-TL1A antibody to neutralize TL1A can reduce SEAP production. The amount of secreted SEAP can be detected using QUANTI-Blue reagent, which reflects the degree to which anti-TL1A antibody blocks TL1A / DR3 binding.

[0391] The specific method / assay was performed as follows: HEK293T / DR3-NFκB cells were harvested and suspended in complete culture medium (RPMI 1640 containing 10% FBS) at 3E5 / mL and uniformly seeded into a 96-well plate at 100 μL / well, i.e., 3E4 cells / well. 50 μL / well of serially diluted anti-TL1A antibodies and control antibodies, as well as 50 μL / well of human TL1A, were then added. The 96-well plate was then incubated in an incubator at 37°C and 5% CO2 for 20-24 hours. The 96-well plate was then removed and centrifuged at 300 g for 5 minutes. 40 μL / well of the supernatant was then transferred to a new 96-well plate. 160 μL / well of QUANTI-BLUE reagent (InvivoGen) was added to the supernatant and incubated in an incubator at 37°C and 5% CO2 for 20-30 minutes. Finally, OD655 was read using a microplate reader (MD, SpectraMax iD3).

[0392] The results are shown in Figure 11. M701 antibodies 3756, 3876, 3966, 4007, and 4019, as well as control antibodies BM1 and BM2, all significantly blocked the activation of downstream signals by soluble TL1A, but M701 antibody has better TL1A neutralizing activity than BM1 and BM2 antibodies.

[0393] [Example 12] Reporter gene method to determine neutralizing activity against membrane-bound TL1A A reporter gene method was used to determine the activity of TL1A antibodies in blocking the biological function of membrane-bound TL1A.

[0394] HEK293T / DR3-NFκB cells (which express DR3 and contain a SEAP reporter gene under the control of an NF-κB response element) and HEK293T / TL1A-M cells (which express membrane TL1A) were constructed by lentiviral transfection. These HEK293T / DR3-NFκB cells and HEK293T / TL1A-M cells were used to establish a reporter gene assay for the neutralizing activity of membrane-bound TL1A.

[0395] The specific method / assay was performed as follows: HEK293T / DR3-NFκB cells were harvested and suspended in complete culture medium (RPMI1640 containing 10% FBS) at 3E5 / mL and uniformly seeded into a 96-well plate at 100 μL / well, i.e., 3E4 cells / well. Then, 50 μL / well of serially diluted anti-TL1A antibodies and control antibodies and 50 μL / well of 293T / TL1A-M cells (cell density 6E5 / mL, i.e., 3E4 cells / well) were added. The 96-well plate was incubated for 20-24 hours at 37°C in a 5% CO2 incubator. The plate was then removed and centrifuged at 300g for 5 minutes. 40 μL / well of the supernatant was then transferred to a new 96-well plate. 160 μL / well of QUANTI-BLUE reagent (InvivoGen) was added to the supernatant and incubated for 20-30 minutes at 37°C in a 5% CO2 incubator. Finally, the OD655 was read using a microplate reader (MD, SpectraMax iD3).

[0396] The results are shown in Figure 12. The M701 antibodies 3756, 3876, 3966, 4007, and 4019 all significantly blocked the activation of downstream signals by membrane-bound TL1A, but the neutralizing activity of the control antibodies BM1 and BM2 was significantly weaker than that of the M701 antibody.

[0397] [Example 13] Determination of the effect of TL1A antibodies on DcR3 / TL1A interaction TL1A has two receptors, DR3 and DcR3 (decoy receptor 3). DcR3 lacks an intracellular signal transduction structure and functions as an endogenous TL1A inhibitor by competing with the DR3 receptor for binding to TL1A.

[0398] The effects of M701 and control antibodies on DcR3 / TL1A interaction were detected using ELISA. The specific method was as follows: DcR3 (AcroBiosystems, Cat. No.: TNB-H5255) was coated onto a microplate at 1 μg / mL (100 μL / well) with a coating solution and incubated overnight at 4°C. The microplate was then washed five times with PBST, blocked with 200 μL / well of PBST containing 1% BSA, and incubated at room temperature for 1 hour. The microplate was then washed five times with PBST. M701 samples and control samples were gradient diluted with PBST containing 1% BSA and mixed with biotin-TL1A (FutureGen) at a 1:1 ratio. 100 μL of the mixture was then added to the enzyme microplate, and the microplate was incubated at room temperature for 1 hour. After washing five times with PBST, 100 μL of streptavidin-HRP (Biolegend, Cat. No. 405210) diluted in 1% BSA-containing PBST was added to each well, and the microplate was incubated for an additional 30 minutes at room temperature. Then, 100 μL / well of the colorimetric substrate TMB (BD, Cat. No. 555214) was added, and color was developed for 6 minutes at room temperature. Finally, 1 M sulfuric acid was added to each well to stop the reaction. OD450nm was read using a microplate reader, and results were analyzed, including fitting to a four-parameter binding curve.

[0399] The results are shown in Figures 13A and 13B. The control antibody BM1 exhibited extremely strong DcR3 / TL1A blocking activity. The control antibody BM2 also completely inhibited the DcR3 / TL1A interaction, but with weaker activity than BM1. In contrast, the M701 antibodies 3966, 4007, and 4019 only slightly interfered with the DcR3 / TL1A interaction. The data indicate that the M701 antibody neutralized the biological function of TL1A while preserving the biological function of the endogenous TL1A inhibitor, DcR3.

[0400] [Example 14] TL1A antibody inhibits T cell activation by exogenous TL1A.

[0401] Obtaining human T cells: Human PBMC cells were collected and isolated according to the instructions of the Pan T cell isolation kit (Miltenyi Biotech, Cat. No. 130-096-535). Briefly, PBMC cells were first washed once with PBS, and then 10 cells were collected. 7 Resuspend the cells in 40 μL isolation buffer (PBS containing 2 mM EDTA, 0.5% BSA, pH = 7.2) (the following dosages are 10 7 (Based on cells.) Then 10 μL of Pan T cell biotin antibody cocktail was added and incubated at 4°C for 5 minutes. Then 30 μL of separation buffer and 20 μL of Pan T cell microbead cocktail were added and incubated at 4°C for 10 minutes. T cells were obtained by passing through a MACS separation column.

[0402] T cells were resuspended at 2E6 / mL in complete medium (RPMI 1640 containing 10% FBS) containing 0.5 ng / mL IL-12 (Peprtech, 200-12) and 5 ng / mL IL-18 (MBL, B001-5) and added to a 96-well plate at 100 μL / well, i.e., 2E5 / well. Serially diluted anti-TL1A antibodies and control antibodies in complete medium were then added at 50 μL / well, followed by human TL1A diluted in complete medium at 50 μL / well. The culture plate was then incubated in a carbon dioxide incubator at 37°C for 3 days. After incubation, supernatants were removed from the wells and the cytokine IFN-γ (Biolegend, Cat. No. 430101) was detected according to the kit's instruction manual.

[0403] The results are shown in Figure 14. M701 antibodies 3966, 4007, and 4019, as well as control antibodies BM1 and BM2, all significantly inhibited T cell activation by exogenous TL1A. However, M701 antibody exhibited better biological activity than BM1 and BM2 antibodies.

[0404] [Example 15] TL1A antibody inhibits activation of immune cells by endogenous TL1A.

[0405] Stimulation of PBMCs with immune complexes (ICs) induces endogenous TL1A, and co-stimulation of immune cells with IL-12 and IL-18 leads to the production of IFN-γ.

[0406] TL1A antibodies can inhibit IFN-γ secretion from immune cells by inhibiting the function of TL1A. To evaluate the ability of M701 and control antibodies to neutralize endogenous TL1A, in this example, IFN-γ secretion levels were detected by ELISA. The specific method was as follows: 96-well flat-bottom plates (Corning, Cat. No. 3599) were coated with 25 μg / mL Flag-IgG fusion protein (FutureGen) in PBS at 50 μL / well and incubated overnight at 4°C. After washing three times with PBS, anti-Flag antibody (FutureGen) was diluted with PBS and added to the 96-well plate at a concentration of 25 μg / mL at 50 μL / well. After incubation at room temperature for 1 hour, the cells were washed three times with PBS. PBMC cells were collected and resuspended in complete culture medium (RPMI1640 containing 10% FBS) at a density of 2 × 10 6 The solution was adjusted to 100 μL / well, and IL-12 (Peprotech, Cat. No. 200-12) and IL-18 (MBL, Cat. No. B001-5) at final concentrations of 0.5 ng / mL were added. PBMC cells were then seeded into the 96-well flat-bottom plate described above. Serial dilutions of the M701 antibody and control antibody in complete medium were then added to the 96-well flat-bottom plate at 100 μL / well. The 96-well flat-bottom plate was then incubated in an incubator at 37°C and 5% CO for 3 days. After incubation, the supernatant was removed from the wells, and the cytokine IFN-γ was detected according to the kit's instruction manual (Biolegend, Cat. No. 430101).

[0407] The results are shown in Figure 15. M701 antibody 4007 and control antibodies BM1 and BM2 all significantly inhibited the activation of immune cells by endogenous TL1A. However, M701 antibody has better biological activity than BM1 and BM2 antibodies.

[0408] [Example 16] Pharmacokinetic study of TL1A antibody in SCID mice This example provides data comparing the serum concentration changes over time of the antibody in SCID mice after a single administration of M701 antibody or a control TL1A antibody, with or without administration of exogenous human TL1A, as well as the serum concentration changes over time of exogenous TL1A.

[0409] Six- to eight-week-old female SCID mice (Beijing Vital River Laboratory Animal Technology Co., Ltd.) were randomly divided into four groups (G1, G2, G3, and G4), with 10 mice per group. Mice in groups G1, G2, G3, and G4 were intravenously injected with 15 nmol / kg of BM2 antibody, M701 antibody, BM2 antibody, and M701 antibody, respectively. Groups G3 and G4 also received 10 nmol / kg of human TL1A antigen intravenously 1 hour after antibody injection. Whole blood samples were collected before antibody administration and at 30 minutes, 24 hours, 72 hours, 120 hours, 168 hours, 240 hours, 336 hours, and 480 hours after human TL1A antigen administration, and serum samples were prepared (five mice per group, alternate blood collection at each time point). Serum levels of M701 antibody or control TL1A antibody and human TL1A antigen were measured using ELISA. Pharmacokinetic parameters were calculated using a non-compartmental model in Phoenix WinNonlin 8.2 software.

[0410] The time course of antibody serum concentrations is shown in Figure 16A. In the absence of exogenous human TL1A antigen, the BM2 and M701-4007 antibodies exhibited similar pharmacokinetic properties (neither BM2 nor M701-4007 antibodies were able to bind to mouse TL1A). In contrast, in the presence of exogenous human TL1A antigen, the drug exposure of the BM2 antibody was significantly reduced, and its clearance was accelerated after binding to human TL1A antigen, whereas the drug exposure of the M701-4007 antibody was essentially unaffected (Table 11). This may be because the BM2 antibody formed a large complex with human TL1A, whereas the M701-4007 antibody only formed a small complex with human TL1A in the form of a 2+2 complex (see above). Large immune complexes are more easily recognized by the body, thereby accelerating the clearance of the complex and potentially causing immunogenicity problems (SCID mice without ADA interference were used in this study).

[0411] The time-dependent changes in serum concentrations of human TL1A are shown in Figure 16B. Human TL1A maintained higher concentrations over a long period in the BM2 antibody-treated group, whereas human TL1A was eliminated significantly faster in the M701-4007 antibody-treated group. This may be related to the pH-dependent binding of the M701-4007 antibody to human TL1A. The pH-dependent antigen-binding property allows the M701-4007 antibody to bind to the TL1A antigen with high affinity in serum. Once the antigen-antibody complex is endocytosed into cells at a pH below 6.0 and enters endosomes, the affinity of the antibody for the antigen is significantly reduced. As a result, TL1A is rapidly released and enters lysosomes for degradation, whereas the M701-4007 antibody is retrieved by FcRn and re-enters the blood circulation to fulfill its role. In contrast, the BM2 antibody maintains high binding affinity to TL1A even in endosomes. Therefore, TL1A cannot be rapidly released and degraded. Instead, TL1A may be collected by FcRn along with the BM2 antibody and accumulated in the blood. The pH-dependent antigen binding property can accelerate the clearance of TL1A in lysosomes, thereby reducing the level of TL1A in the body and increasing the effective exposure of the antibody.

[0412] [Table 12]

[0413] [Example 17] Pharmacokinetic study of TL1A antibody in rhesus monkeys The M701 antibody is an Fc-engineered IgG1 antibody that is expected to have slower elimination and a longer half-life. This example provides data to compare serum drug concentration changes over time in rhesus monkeys after a single dose of the M701 antibody or the control TL1A antibody.

[0414] Animal experiments were completed at Pharmaron Chemical (Beijing) Biotechnology Co., Ltd. Twelve male rhesus monkeys were randomly divided into four groups (groups G1, G2, G3, and G4), with three animals in each group. Monkeys in groups G1, G2, G3, and G4 were intravenously infused with 5 mg / kg of BM1 antibody, BM2 antibody, M701-3966 antibody, and M701-4019 antibody, respectively, at a dose volume of 10 mL / kg and an infusion time of 30 minutes. Whole blood was collected from each animal before antibody administration and at 30 minutes (i.e., immediately after the end of the infusion), 2 hours, 8 hours, 24 hours, 72 hours, 120 hours, 168 hours, 240 hours, 336 hours, 504 hours, 672 hours, and 840 hours after the start of the antibody infusion, and serum samples were prepared. Serum levels of M701 antibody or control TL1A antibody were measured using ELISA. Pharmacokinetic parameters were calculated using a non-compartmental model in Phoenix WinNonlin 8.2 software.

[0415] The experimental results after rhesus monkeys were given a single intravenous infusion of 5 mg / kg of BM1 antibody, BM2 antibody, M701-3966 antibody, or M701-4019 antibody are shown in Figure 17. Compared to the BM1 and BM2 antibodies, M701-3966 and 4019 were eliminated more slowly and had longer half-lives in rhesus monkeys.

Claims

1. An antibody that specifically binds to TNF-like ligand 1A (TL1A), comprising a heavy chain (HC) including a heavy chain variable region (VH) containing heavy chain CDR1, heavy chain CDR2, and heavy chain CDR3 (VH CDR1-3), and a light chain (LC) including a variable region (VL) containing light chain CDR1, light chain CDR2, and light chain CDR3 (VL CDR1-3), VH CDR1 contains the amino acid sequence shown in SEQ ID NO: 40, VH CDR2 contains the amino acid sequence shown in SEQ ID NO: 41, and VH CDR3 contains the amino acid sequence shown in SEQ ID NO:

42. An antibody in which VL-CDR1 contains the amino acid sequence shown in SEQ ID NO: 37, VL-CDR2 contains the amino acid sequence shown in SEQ ID NO: 38, and VL-CDR3 contains the amino acid sequence shown in SEQ ID NO:

39.

2. The antibody according to claim 1, wherein VH comprises the amino acid sequence shown in SEQ ID NO: 10, and VL comprises the amino acid sequence shown in SEQ ID NO:

9.

3. The antibody according to claim 2, wherein the heavy chain comprises the amino acid sequence shown in SEQ ID NO: 58, and the light chain comprises the amino acid sequence shown in SEQ ID NO:

57.

4. An antibody according to any one of claims 1 to 3, comprising an Fc region.

5. The antibody according to any one of claims 1 to 3, which is an IgG1 antibody.

6. A nucleic acid comprising a nucleotide sequence encoding an antibody according to any one of claims 1 to 3.

7. A nucleic acid comprising a nucleotide sequence encoding the antibody described in claim 3.

8. A vector comprising the nucleic acid described in claim 6.

9. A vector comprising the nucleic acid described in claim 7.

10. A host cell comprising the vector according to claim 9.

11. A host cell comprising the vector according to claim 8.

12. a) The step of culturing the host cells described in claim 10 under conditions suitable for antibody expression, and b) The step of isolating antibodies from the host cell culture and / or culture supernatant. A method for preparing antibodies, including [the specified ingredient].

13. A pharmaceutical composition comprising an antibody according to any one of claims 1 to 3 and an optionally pharmaceutically acceptable carrier or excipient.

14. A pharmaceutical composition comprising the antibody described in claim 3 and a pharmaceutically acceptable carrier or excipient.

15. A composition for treating a disease in a subject, comprising the antibody according to any one of claims 1 to 3.

16. A composition for treating a disease in a subject, comprising the antibody described in claim 3 and a pharmaceutically acceptable carrier or excipient.

17. A composition for treating a disease in a subject, comprising the antibody described in claim 3.

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