Engineered TL1a targeting regions and methods of use

Abstract

Provided herein are compositions, and methods of making and use of the compositions, wherein the compositions comprise TL1A binding engineered antibody comprising a heavy chain variable region and a light chain variable region that can bind an epitope on TL1A protein, a variant thereof or a fragment thereof, the TL1A binding engineered antibody comprises at least one modification in the heavy chain variable region and / or light chain variable region, the at least one modification changes isoelectric point (pI) of the TL1A binding region and provide a pH-dependent binding activity to the TL1A binding region, and a binding affinity of the TL1A binding region for the epitope is at least 75% of a corresponding TL1A binding region prior to modifications.

Description

Attorney Docket No. 220710-705601ENGINEERED TL1A TARGETING REGIONS AND METHODS OF USEFIELD

[0001] The disclosure generally relates to engineered regions capable of binding to TL1A.RELATED APPLICATIONS

[0002] This patent application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 696,851, filed on September 19, 2024, and U.S. Provisional Patent Application No. 63 / 723,546, filed on November 21, 2024; which are incorporated herein by reference in its entirety.REFERENCE TO SEQUENCE LISTING

[0003] The instant application contains a Sequence Listing which has been submitted electronically in XML file format and is hereby incorporated by reference in its entirety. Said XML copy, created on September 17, 2025, is named 220710-705601_PCT_SL. xml and is 303,037 bytes in size.BACKGROUND OF THE DISCLOSURE

[0004] A variety of therapeutic antibodies are currently in development for TL1A mediated inflammatory conditions. However, there is still unmet clinical need for further developing and improving existing therapeutics for effective management of the inflammatory conditions.SUMMARY OF THE DISCLOSURE

[0005] Provided herein are compositions comprising a TL1 A binding engineered antibody that binds to an epitope on TL1A protein, a variant thereof or a functional fragment thereof, wherein the TL1A binding engineered antibody comprises (a) a heavy chain complementarity determining region 1 (CDR-H1) amino acid sequence as set forth in SEQ ID NO: 256; a CDR-H2 amino acid sequence as set forth in SEQ ID NO: 117 or 257 with up to three amino acid substitution; a CDR- H3 amino acid sequence as set forth in SEQ ID NO: 327 with up to three amino acid substitution; a light chain complementarity determining region 1 (CDR-L1) amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to two amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution; or (b) a CDR- H1 amino acid sequence as set forth in SEQ ID NO: 116 with up to one amino acid substitution; a CDR-H2 amino acid sequence as set forth in any one of SEQ ID NOS: 257-270; a CDR-H3 amino acid sequence as set forth in SEQ ID NO: 327 with up to three amino acid substitution; aAtorney Docket No. 220710-705601CDR-L1 amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to two amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution. In some embodiments, the TL1A binding engineered antibody comprises a binding affinity that is at least about 10-fold higher at pH 7.4 than a binding affinity at pH 5.8. In some embodiments, compositions described herein are for use in treating a disease or condition. In some embodiments, said disease is gastric inflammatory disease. In some embodiments, said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0006] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises (a) a CDR-H1 amino acid sequence as set forth in SEQ ID NO: 98 with up to two amino acid substitution; a CDR-H2 amino acid sequence as set forth in SEQ ID NO: 99 with up to three amino acid substitution; a CDR-H3 amino acid sequence as set forth in any one of SEQ ID NOS: 100-103 with up to three amino acid substitution; a CDR- L1 amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to two amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution; or (b) a CDR-H1 amino acid sequence as set forth in SEQ ID NO: 116 with up to one amino acid substitution; a CDR-H2 amino acid sequence as set forth in SEQ ID NO: 117 with up to three amino acid substitution; a CDR-H3 amino acid sequence as set forth in any one of SEQ ID NOS: 118, 170-172 and 327 with up to three amino acid substitution; a CDR- L1 amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to three amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution. In some embodiments, the TL1 A binding engineered antibody comprises a binding affinity that is at least about 10-fold higher at pH 7.4 than a binding affinity at pH 5.8. In some embodiments, compositions described herein are for use in treating a disease or condition. In some embodiments, said disease is gastric inflammatory disease. In some embodiments, said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0007] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, whereinAtorney Docket No. 220710-705601 the TL1 A binding engineered antibody comprises (a) a heavy chain variable domain comprising an amino acid sequence that is at least 80% identical to any one of SEQ ID NOS: 168, 178-254 and 323-326; and (b) a light chain variable domain comprising an amino acid sequence that is at least 80% identical to any one of SEQ ID NOS: 97 and 316-322. In some embodiments, the TL1A binding engineered antibody comprises a binding affinity that is at least about 10-fold higher at pH 7.4 than a binding affinity at pH 5.8. In some embodiments, compositions described herein are for use in treating a disease or condition. In some embodiments, said disease is gastric inflammatory disease. In some embodiments, said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0008] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises (a) two TL1 A binding regions, each comprising a heavy chain variable (VH) domain, wherein at least one of the two TL1A binding regions comprise at least one amino acid modification that changes an isoelectric point (pl) of said TL1A binding engineered antibody relative to a pl of a corresponding antibody prior to said amino acid modification, thereby resulting in pH-dependent binding activity in said TL1 A binding engineered antibody, as measured by surface plasmon resonance spectroscopy; and (b) an engineered Fc region that comprises a first and a second subunit capable of stable association, wherein said two heavy chain variable regions are directly or indirectly linked to the engineered Fc region of the TL1A binding engineered antibody. In some embodiments, the two TL1A binding regions comprise a first VH domain and a second VH domain, wherein the first VH domain and the second VH domain are directly or indirectly linked to the first subunit of the engineered Fc region. In some embodiments, the two TL1 A binding regions comprise a first VH domain and a second VH domain, wherein the first VH domain and the second VH domain are directly or indirect linked to the first subunit and the second subunit of the engineered Fc region, respectively. In some embodiments, the first VH domain and the second VH domain are identical. In some embodiments, the first VH domain and the second VH domain are distinct. In some embodiments, each TL1A binding region further comprises a light chain variable (VL) domain. In some embodiments, a binding affinity of said TL1 A binding engineered antibody to said epitope is at least 75% of the binding affinity of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy. In some embodiments, said amino acid modification increases a binding affinity of said TL1 A binding engineered antibody for said epitope in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In someAttorney Docket No. 220710-705601 embodiments, said amino acid modification increases said binding affinity by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification reduces a binding affinity of said TL1 A binding engineered antibody for said epitope in acidic pH condition by at least 10% relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification increases a binding affinity of said TL1A binding engineered antibody for said epitope in trimeric TL1A in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification increases a binding affinity of said TL1A binding engineered antibody for said epitope in monomeric TL1 A in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In some embodiments, the compositions described herein comprises two identical light chain variable regions. In some embodiments, the compositions described herein comprises two nonidentical light chain variable regions. In some embodiments, compositions described herein are for use in treating a disease or condition. In some embodiments, said disease is gastric inflammatory disease. In some embodiments, said disease or condition is selected from the group consisting of rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0009] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises (a) at least three TL1 A binding regions, each comprising a heavy chain variable (VH) domain, wherein at least one of the at least three TL1 A binding regions comprise at least one amino acid modification that changes an isoelectric point (pl) of said TL1 A binding engineered antibody relative to a pl of a corresponding antibody prior to said amino acid modification, thereby resulting in pH-dependent binding activity in said TL1 A binding engineered antibody, as measured by surface plasmon resonance spectroscopy; and (b) an engineered Fc region that comprises a first and a second subunit capable of stable association, wherein two of said at least three heavy chain variable regions are directly or indirectly linked to the first subunit of the engineered Fc region of the TL1A binding engineered antibody. In some embodiments, the TL1 A binding engineered antibody comprises three TL1 A binding regions each comprising a TL1 A binding heavy chain variable (VH) domain. In some embodiments, the three TL1 A binding regions comprise a first VH domain, a second VH domain and a third VH domain, wherein a C-terminus of said first VH domain is linked to a N-terminus of said second VH domain, and wherein a C-terminus of said second VH domain is linked to a N-terminus of said first subunit of said engineered Fc region. In some embodiments, the three TL1 A binding regions comprises aAttorney Docket No. 220710-705601 first VH domain, a second VH domain and a third VH domain, a C-terminus of said first VH domain is linked to a N-terminus of said first subunit of said engineered Fc region, and a N- terminus of said second VH domain is linked to a C-terminus of said first subunit of said engineered Fc region. In some embodiments, at least two of said first VH domain, said second VH domain and said third VH domain are identical. In some embodiments, said first VH domain, said second VH domain and said third VH domain are identical. In some embodiments, said first VH domain, said second VH domain and said third VH domain are distinct. In some embodiments, the composition comprises four TL1 A binding regions. In some embodiments, said four TL1 A binding regions comprise a first VH domain, a second heavy variable region, a third VH domain and a fourth VH domain, and wherein a C-terminus of said first VH domain is linked to a N-terminus of said VH domain, wherein a C-terminus of said second VH domain is linked to a N-terminus of said first subunit of said engineered Fc region, wherein a C-terminus of said third VH domain is linked to a N-terminus of said fourth VH domain, and wherein a C-terminus of said fourth VH domain is linked to a N-terminus of said second subunit of said engineered Fc region. In some embodiments, said four TL1 A binding regions comprises a first VH domain, a second VH domain, a third VH domain and a fourth VH domain, wherein a C-terminus of said first VH domain is linked to a N-terminus of said second VH domain, wherein a C-terminus of said second VH domain is linked to a N-terminus of said first subunit of said engineered Fc region, wherein a C- terminus of said third VH domain is linked to a N-terminus of said fourth VH domain, and wherein a C-terminus of said fourth VH domain is linked to a N-terminus of said second subunit of said engineered Fc region. In some embodiments, at least two of said first VH domain, said second VH domain, said third VH domain and said fourth VH domain are identical. In some embodiments, said first VH domain, said second VH domain, said third VH domain and said fourth VH domain are identical. In some embodiments, said first VH domain, said second VH domain, said third VH domain and said fourth VH domain are distinct. In some embodiments, each TL1 A binding region further comprises a light chain variable (VL) domain. In some embodiments, a binding affinity of said TL1 A binding engineered antibody to said epitope is at least 75% of the binding affinity of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy. In some embodiments, said amino acid modification increases a binding affinity of said TL1 A binding engineered antibody for said epitope in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification increases said binding affinity by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification reduces a binding affinity of said TL1A binding engineered antibody for saidAttorney Docket No. 220710-705601 epitope in acidic pH condition by at least 10% relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification increases a binding affinity of said TL1 A binding engineered antibody for said epitope in trimeric TL1 A in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification increases a binding affinity of said TL1A binding engineered antibody for said epitope in monomeric TL1A in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In some embodiments, the compositions described herein comprises two identical light chain variable regions. In some embodiments, the compositions described herein comprises two nonidentical light chain variable regions. In some embodiments, said first and second Fc subunit comprises at least one amino acid modification relative to any one of amino acid sequences recited in TABLE 9. In some embodiments, said at least one amino acid modification is within said light chain variable region that comprises CDR-L1, CDR-L2 and CDR-L3. In some embodiments, said at least one amino acid modification is within at least one of said CDR-L1, said CDR-L2 and said CDR-L3. In some embodiments, said at least one amino acid modification is within at least one framework region of said light chain variable region. In some embodiments, said first and second Fc subunit comprises at least one amino acid modification relative to any one of amino acid sequences recited in TABLE 9. In some embodiments, a binding affinity of said engineered Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in acidic pH condition, and wherein a binding affinity of said engineered Fc region for said FcRn in neutral pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to said amino acid modification. In some embodiments, said binding affinity for said FcRn is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more in acidic pH condition. In some embodiments, said at least one amino acid modification decreases plasma clearance (CL), increases plasma retention time, or increases plasma half-life (t’ ) of said TL1 A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification. In some embodiments, a binding affinity of said engineered Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in neutral pH condition, and wherein a binding affinity of said engineered Fc region for said FcRn in acidic pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to said amino acid modification. In some embodiments, said binding affinity for said FcRn in neutral pH condition is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more. In some embodiments, said at least one amino acid modification increases antigen plasma clearance by said TL1 A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification. In some embodiments, compositions describedAtorney Docket No. 220710-705601 herein are for use in treating a disease or condition. In some embodiments, said disease is gastric inflammatory disease. In some embodiments, said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0010] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein said TL1 A binding engineered antibody comprises at least three heavy chain variable regions, each comprising a TL1A binding heavy chain variable (VH) domain and a TL1A binding light chain variable (VL) domain; and an engineered Fc region that comprises a first and a second subunit capable of stable association, wherein two of said at least three heavy chain variable regions are directly or indirectly linked to said first subunit of the engineered Fc region of the TL1 A binding engineered antibody. In some embodiments, the TL1 A binding engineered antibody comprises at least one amino acid modification in said heavy chain variable region that increases binding affinity of said TL1A binding engineered antibody for said epitope at pH 7.4 by at least 10% to that of a corresponding antibody prior to said amino acid modification as measured by surface plasmon resonance spectroscopy. In some embodiments, the TL1A binding engineered antibody comprises at least one amino acid modification in said heavy chain variable region that decreases binding affinity at pH 5.8 of said TL1A binding engineered antibody for said epitope by at least 10% to that of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy. In some embodiments, said light chain variable region comprises at least one amino acid modification that increases said binding affinity of said TL1A binding engineered antibody for said epitope at pH 7.4 by at least 10% to that of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy. In some embodiments, said light chain variable region comprises at least one amino acid modification that decreases binding affinity at pH 5.8 of said TL1A binding engineered antibody for said epitope by at least 10% to that of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy. In some embodiments, a ratio of the binding affinity at pH 7.4 and the binding affinity for trimeric TL1 A at pH 5.8 is at least 1.2. In some embodiments, a ratio of the binding affinity at pH 7.4 and the binding affinity for monomeric TL1A at pH 5.8 is at least 1.2. In some embodiments, the compositions described herein comprise two identical TL1A binding heavy chain variable domains. In some embodiments, the compositions described herein comprise two nonidentical TL1 A binding heavy chain variable domains. In some embodiments, said at least one amino acid modification is within said TL1A binding VH domain that comprises CDR-H1, CDR-H2 andAttorney Docket No. 220710-705601CDR-H3. In some embodiments, said at least one amino acid modification is within at least one of said CDR-H1, said CDR-H2 and said CDR-H3. In some embodiments, said at least one amino acid modification is within said CDR-H3. In some embodiments, said at least one amino acid modification in said CDR-H3 is a substitution of an uncharged amino acid residue with a charged amino acid residue. In some embodiments, said at least one amino acid modification in said CDR- H3 is a substitution of an uncharged amino acid residue with an aspartic acid residue. In some embodiments, said first and second Fc subunit comprises at least one amino acid modification relative to any one of amino acid sequences recited in TABLE 9. In some embodiments, said at least one amino acid modification is within said light chain variable region that comprises CDR- Ll, CDR-L2 and CDR-L3. In some embodiments, said at least one amino acid modification is within at least one of said CDR-L1, said CDR-L2 and said CDR-L3. In some embodiments, said at least one amino acid modification is within at least one framework region of said light chain variable region. In some embodiments, said first and second Fc subunit comprises at least one amino acid modification relative to any one of amino acid sequences recited in TABLE 9. In some embodiments, a binding affinity of said engineered Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in acidic pH condition, and wherein a binding affinity of said engineered Fc region for said FcRn in neutral pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to said amino acid modification. In some embodiments, said binding affinity for said FcRn is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more in acidic pH condition. In some embodiments, said at least one amino acid modification decreases plasma clearance (CL), increases plasma retention time, or increases plasma half-life (t’ ) of said TL1 A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification. In some embodiments, a binding affinity of said engineered Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in neutral pH condition, and wherein a binding affinity of said engineered Fc region for said FcRn in acidic pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to said amino acid modification. In some embodiments, said binding affinity for said FcRn in neutral pH condition is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more. In some embodiments, said at least one amino acid modification increases antigen plasma clearance by said TL1 A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification. In some embodiments, said light chain variable domain comprises an amino acid sequence that is at least 90% identical to any one of amino acid sequences recited in TABLE 7. In some embodiments, said CDR-H1, said CDR-H2, and said CDR-H3 independently comprise amino acid sequences according to amino acid sequences recitedAtorney Docket No. 220710-705601 in TABLE 3 or variants thereof, wherein said variants comprise at least one amino acid substitution, at least one amino acid deletion, at least one amino acid addition, or combinations thereof relative to a corresponding amino acid sequence recited in TABLE 3. In some embodiments, said heavy chain variable region comprises an amino acid sequence that is at least 90% identical to any one of amino acid sequences recited in TABLE 4. In some embodiments, said heavy chain variable region comprises an amino acid sequence that is at least 90% identical to SEQ ID NO: 104 In some embodiments, said heavy chain variable region comprises an amino acid sequence that comprises one or more modification relative to SEQ ID NO: 104, wherein the one or more modifications are substitutions at positions selected from the group consisting of S30, T69, L83, N84, T104, and F107. In some embodiments, said heavy chain variable region comprises an amino acid sequence that comprises one or more modification relative to SEQ ID NO: 104, wherein the one or more modifications are selected from the group consisting of S30T, T69I, L83V, N84K, T104D, F107N and F107D. In some embodiments, compositions described herein comprises two identical light chain variable regions. In some embodiments, compositions described herein comprise two nonidentical light chain variable regions. In some embodiments, compositions described herein are for use in treating a disease or condition. In some embodiments, said disease is gastric inflammatory disease. In some embodiments, said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0011] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to a target epitope on TL1 A protein, a variant thereof or a functional fragment thereof, said TL1A binding engineered antibody comprising at least one heavy chain variable region and at least one light chain variable region, and at least one amino acid modification in said heavy chain variable region and / or said light chain variable region, wherein said amino acid modification changes an isoelectric point (pl) of said TL1A binding engineered antibody relative to a pl of a corresponding antibody prior to said amino acid modification, thereby resulting in pH-dependent binding activity in said TL1 A binding engineered antibody, and wherein a binding affinity of said TL1A binding engineered antibody to said target epitope is at least 75% of a corresponding antibody prior to said amino acid modification as measured by surface plasmon resonance spectroscopy. In some embodiments, said amino acid modification increases a binding affinity of said TL1 A binding engineered antibody for said target epitope in neutral pH condition relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification increases said binding affinity by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to a correspondingAttorney Docket No. 220710-705601 antibody prior to said amino acid modification. In some embodiments, said amino acid modification reduces a binding affinity of said TL1 A binding engineered antibody for said target epitope in acidic pH condition by at least 10% relative to a corresponding antibody prior to said amino acid modification. In some embodiments, said amino acid modification is within said heavy chain variable region that comprises CDR-H1, CDR-H2 and CDR-H3. In some embodiments, said amino acid modification is within at least one of said CDR-H1, CDR-H2 and CDR-H3. In some embodiments, said amino acid modification is within said CDR-H3. In some embodiments, said amino acid modification in said CDR-H3 is a substitution of an uncharged amino acid residue with a charged amino acid residue. In some embodiments, said amino acid modification in said CDR- H3 is a substitution of an uncharged amino acid residue that an aspartic acid residue. In some embodiments, said amino acid modification is within at least one framework region of said heavy chain variable region. In some embodiments, said amino acid modification is within said light chain variable region that comprises CDR-L1, CDR-L2 and CDR-L3. In some embodiments, said amino acid modification is within at least one of said CDR-L1, CDR-L2 and CDR-L3. In some embodiments, said amino acid modification is within at least one framework region of said light chain variable region. In some embodiments, said heavy chain variable region comprises a constant region, wherein said constant region comprises at least one amino acid modification relative to any one of amino acid sequences recited in TABLE 9. In some embodiments, a binding affinity of said constant region for a neonatal fragment crystallizable receptor (FcRn) is increased in acidic pH condition, and wherein a binding affinity of said constant region for said FcRn in neutral pH condition remains within 20% of a binding affinity, each relative to a corresponding constant region prior to said amino acid modification. In some embodiments, said binding affinity for said FcRn is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more in acidic pH condition. In some embodiments, said amino acid modification decreases plasma clearance (CL), increases plasma retention time, or increases plasma half-life (t’ ) of said TL1A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification. In some embodiments, a binding affinity of said constant region for a neonatal fragment crystallizable receptor (FcRn) is increased in neutral pH condition, and wherein a binding affinity of said constant region for said FcRn in acidic pH condition remains within 20% of a binding affinity, each relative to a corresponding constant region prior to said amino acid modification. In some embodiments, said binding affinity for said FcRn in neutral pH condition is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more. In some embodiments, said amino acid modification increases antigen plasma clearance by said TL1 A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification. In someAtorney Docket No. 220710-705601 embodiments, said CDR-L1, CDR-L2, and CDR-L3 independently comprise amino acid sequences according to amino acid sequences recited in TABLE 5 or variants thereof, wherein said variants comprise at least one amino acid substitution, at least one amino acid deletion, at least one amino acid addition, or combinations thereof relative to a corresponding amino acid sequence recited in TABLE 5. In some embodiments, said light chain variable region comprises an amino acid sequence that is at least 90% identical to any one of amino acid sequences recited in TABLE 7. In some embodiments, said CDR-H1, CDR-H2, and CDR-H3 independently comprise amino acid sequences according to amino acid sequences recited in TABLE 3 or variants thereof, wherein said variants comprise at least one amino acid substitution, at least one amino acid deletion, at least one amino acid addition, or combinations thereof relative to a corresponding amino acid sequence recited in TABLE 3. In some embodiments, said heavy chain variable region comprises an amino acid sequence that is at least 90% identical to any one of amino acid sequences recited in TABLE 4. In some embodiments, said heavy chain variable region comprises an amino acid sequence that is at least 90% identical to SEQ ID NO: 104. In some embodiments, said heavy chain variable region comprises an amino acid sequence that comprises one or more modification relative to SEQ ID NO: 104, wherein the one or more modifications are substitutions at positions selected from the group consisting of S30, T69, L83, N84, T104, and F107. In some embodiments, said heavy chain variable region comprises an amino acid sequence that comprises one or more modification relative to SEQ ID NO: 104, wherein the one or more modifications are selected from the group consisting of S30T, T69I, L83V, N84K, T104D, F107N and F107D. In some embodiments, compositions described herein comprise two identical heavy chain variable regions. In some embodiments, compositions described herein comprise two nonidentical heavy chain variable regions. In some embodiments, compositions described herein comprise two identical light chain variable regions. In some embodiments, compositions described herein comprise two nonidentical light chain variable regions. In some embodiments, compositions described herein are for use in treating a disease or condition. In some embodiments, said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0012] Also provided herein are pharmaceutical compositions comprising compositions described herein, and a pharmaceutically acceptable carrier.

[0013] Also provided herein are methods of treating a disease or condition in a subject, the method comprise administering to the subject an effective amount of compositions described herein, or pharmaceutical compositions described herein, thereby treating the disease or condition. In some embodiments, the method comprises administering to the subject the effective amount of any oneAtorney Docket No. 220710-705601 of the compositions described herein, or the pharmaceutical composition described herein in an induction dosing regimen sufficient to improve signs and symptoms of said disease or condition by at least 12 weeks after the start of treatment, said induction dosing regimen comprising a plurality of individual induction doses, wherein the method further comprises administering to the subject a subsequent maintenance dosing regimen after completion of the induction dosing regimen, said maintenance dosing regimen comprising a plurality of individual maintenance doses separated from each other by at least 2 weeks.

[0014] Also provided herein are methods of making a TL1A binding engineered antibody with a binding affinity for a target epitope on TL1 A protein, a variant thereof or a functional fragment thereof, the methods comprise identifying a histidine rich binding pocket within said target epitope; constructing an antibody that comprises said heavy chain variable region and said light chain variable region; and modifying at least one amino acid of said heavy chain variable region and / or said light chain variable region to make said TL1A binding engineered antibody, wherein said amino acid modification changes an isoelectric point (pl) of said TL1A binding engineered antibody relative to a pl of a corresponding antibody prior to said amino acid modification, thereby resulting in pH-dependent binding activity in said TL1 A binding engineered antibody, wherein a binding affinity of said TL1 A binding region (or domain) for said target epitope in neutral pH is at least 10% higher than a corresponding binding affinity prior to said amino acid modification, and wherein a binding affinity of said TL1 A binding region (or domain) for said target epitope in acidic pH is less than 25% higher than a corresponding binding affinity prior to said amino acid modification. In some embodiments, the methods further comprise modifying a constant region of said heavy chain variable region, wherein said constant region comprises at least one modification relative to any one of amino acid sequences recited in TABLE 9.INCORPORATION BY REFERENCE

[0015] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.BRIEF DESCRIPTION OF THE FIGURES

[0016] The features of the present disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings of which:

[0017] FIGS. 1A-1E depicts TL1 A binding antibodies. FIG. 1A depicts an engineered antibodyAtorney Docket No. 220710-705601 comprising two TL1 A binding regions (or domains) linked to each other by a disulfide linkage in a hinge region. Specifically, FIG. IB depicts an engineered antibody comprising three TL1 A Fab fragments, wherein C-terminal end of a first TL1 A Fab fragment and a second TL1 A Fab fragment are fused to N-terminal end of a Fc region, wherein N-terminal end of the first TL1 A Fab fragment is fused to C-terminal end of the third TL1A Fab fragment. FIG. 1C depicts an engineered antibody comprising four TL1A Fab fragments, wherein C-terminal end of the first TL1A Fab fragment and the second TL1 A Fab fragment are fused to N-terminal end of the Fc region, wherein N-terminal end of the first TL1A Fab fragment is fused to C-terminal end of the third TL1A Fab fragment, and wherein N-terminal end of the second TL1A Fab fragment is fused to C-terminal end of the fourth TL1 A Fab fragment. FIG. ID depicts an engineered antibody comprising three TL1A Fab fragments, wherein C-terminal end of the first TL1A Fab fragment and the second TL1A Fab fragment are fused to N-terminal end of the Fc region, wherein N-terminal end of the third TL1A Fab fragment is fused to C-terminal end of the Fc region. FIG. IE depicts an engineered antibody comprising four TL1A Fab fragments, wherein C-terminal end of the first TL1A Fab fragment and the second TL1A Fab fragment are fused to N-terminal end of the Fc region, wherein N-terminal end of the third TLlAFab fragment and the fourth TLlAFab fragment are fused to C-terminal end of the Fc region.

[0018] FIGS. 2A-2B show results of competitive binding assay for lead TL1A binding antibody candidates. FIG. 2A shows result for the lead TL1 A binding antibody candidate comprising a VH amino acid sequence of SEQ ID NO: 104, and a VL amino acid sequence of SEQ ID NO: 97. Likewise, FIG. 2B shows result for the lead TL1 A binding antibody candidate comprising a VH amino acid sequence of SEQ ID NO: 119, and a VL amino acid sequence of SEQ ID NO: 97.

[0019] FIG. 3 shows results blocking effect of TL1A binding monoclonal antibody prepared by fab-arm exchange method using luciferase assay. Luciferase assay was conducted at 130.0 ng / mL concentration of TL1A with the antibody at a concentration ranging from 0.1, 1.0 or 10 pg / mL. The antibody comprised a VH amino acid sequence of SEQ ID NO: 92, a VL sequence comprising an amino acid sequence of SEQ ID NO: 96, and a hlgGl constant region with L234A, L235A, M252Y, S254T, T256E and P329G modifications. For negative and positive control, only cells and cells in combination with TL1 A were used, respectively.

[0020] FIG. 4 shows a heat map showing developability of TL1 A antibody constructs based on multiparametric profile analysis.DETAILED DESCRIPTION OF EMBODIMENTS

[0021] The following description and examples illustrate embodiments of the present disclosure in detail. It is to be understood that this disclosure is not limited to the particular embodimentsAtorney Docket No. 220710-705601 described herein and as such can vary. Those of skill in the art will recognize that there are numerous variations and modifications of this disclosure, which are encompassed within its scope.

[0022] All terms are intended to be understood as they would be understood by a person skilled in the art. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains.

[0023] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0024] Although various features of the present disclosure may be described in the context of a single embodiment, the features can also be provided separately or in any suitable combination. Conversely, although the present disclosure may be described herein in the context of separate embodiments for clarity, the present disclosure can also be implemented in a single embodiment.Definitions

[0025] The following definitions supplement those in the art and are directed to the current application and are not to be imputed to any related or unrelated case, e.g., to any commonly owned patent or application. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the present disclosure, the preferred materials and methods are described herein. Accordingly, the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0026] In this application, the use of the singular includes the plural unless specifically stated otherwise. It must be noted that, as used in the specification, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. In this application, the use of “or” means “and / or” unless stated otherwise. Furthermore, use of the term “including” as well as other forms, such as “include”, “includes,” and “included,” is not limiting.

[0027] Reference in the specification to “some embodiments,” “an embodiment,” “one embodiment” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the present disclosure.

[0028] As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open- ended and do not exclude additional, unrecited elements or method steps. It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method orAtorney Docket No. 220710-705601 composition of the present disclosure, and vice versa. Furthermore, compositions of the present disclosure can be used to achieve methods of the present disclosure.

[0029] The term “about” or “approximately” means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, z.e., the limitations of the measurement system. For example, “about” can mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, “about” can mean a range of up to 20%, up to 10%, up to 5%, or up to 1% of a given value. In another example, the amount “about 10” includes 10 and any amounts from 9 to 11. In yet another example, the term “about” in relation to a reference numerical value can also include a range of values plus or minus 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% from that value. Alternatively, particularly with respect to biological systems or processes, the term “about” can mean within an order of magnitude, preferably within 5-fold, and more preferably within 2-fold, of a value. Where particular values are described in the application and claims, unless otherwise stated the term “about” meaning within an acceptable error range for the particular value should be assumed.

[0030] As used herein, the terms, “disease”, “disorder”, and “condition,” which are used interchangeably herein, refer to any alternation in state of the body or of some of the organs, interrupting or disturbing the performance of the functions and / or causing symptoms such as discomfort, dysfunction, distress, or even death to the person afflicted or those in contact with a person. A disease or disorder can also be related to a distemper, ailing, ailment, malady, disorder, sickness, illness, complaint, or affectation.

[0031] As used herein, the term, “in need thereof,” when used in the context of a therapeutic or prophylactic treatment, means having a disease, being diagnosed with a disease, or being in need of preventing a disease, e.g., for one at risk of developing the disease. Thus, a subject in need thereof can be a subject in need of treating or preventing a disease.

[0032] As used herein, the term, "administering," refers to the placement of a compound (e.g., an antibody or fragment thereof as disclosed herein) into a subject by a method or route that results in at least partial delivery of the agent at a desired site. Pharmaceutical compositions comprising an antibody or fragment thereof, disclosed herein can be administered by any appropriate route which results in an effective treatment in the subject, including but not limited to intravenous, intraarterial, subcutaneous injection or infusion directly into a tissue parenchyma, etc. Where necessary or desired, administration can include, for example, intracerebroventricular (“icv”) administration, intranasal administration, intracranial administration, intracelial administration, intracerebellar administration, subcutaneous administration, or intrathecal administration.

[0033] As used herein, the term, "subject", “patient”, “individual” and like terms, which are usedAtorney Docket No. 220710-705601 interchangeably, refer to a vertebrate, a mammal, a primate, or a human. Mammals include, without limitation, humans, primates, rodents, wild or domesticated animals, including feral animals, farm animals, sport animals, and pets. Primates include, for example, chimpanzees, cynomolgus monkeys, spider monkeys, and macaques (e.g., Rhesus). Rodents include, for example, mice, rats, woodchucks, ferrets, rabbits and hamsters. Domestic and game animals include, for example, cows, horses, pigs, deer, bison, buffalo, feline species (e.g., domestic cat), and canine species (e.g., dog, fox and wolf,) avian species (e.g., chicken, emu and ostrich), and fish (e.g., trout, catfish and salmon). The terms, “individual,” “patient” and “subject” are used interchangeably herein. A subject can be male or female. In some embodiments, the subject is a mammal. The mammal can be a human, non-human primate, mouse, rat, dog, cat, horse, or cow, but is not limited to these examples. Mammals other than humans can be advantageously used as subjects that represent animal models of conditions or disorders. Non-limiting examples include murine models. In addition, the compositions and methods described herein can be used to treat domesticated animals and / or pets. A subject can be one who is diagnosed and currently being treated for, or seeking treatment, monitoring, adjustment or modification of an existing therapeutic treatment, or is at a risk of developing a given disorder.

[0034] As used herein, the terms, “protein", “peptide” and “polypeptide," which are used interchangeably, refer to designate a series of amino acid residues connected to each other by peptide bonds between the alpha-amino and carboxy groups of adjacent residues. The terms "protein", “peptide” and "polypeptide" refer to a polymer of amino acids, including modified amino acids (e.g., phosphorylated, glycated, glycosylated, etc.) and amino acid analogs, regardless of its size or function. "Protein" and “polypeptide” are often used in reference to relatively large polypeptides, whereas the term "peptide" is often used in reference to small polypeptides, but usage of these terms in the art overlaps. The terms "protein", “peptide” and "polypeptide" are used interchangeably herein when referring to a gene product and fragments thereof. These terms encompass, e.g., native and artificial proteins, protein fragments and polypeptide analogs (such as muteins, variants, and fusion proteins) of a protein sequence as well as post-translationally, or otherwise covalently or non-covalently, modified proteins. A peptide, polypeptide, or protein may be monomeric or polymeric. A polypeptide can have the amino acid sequence of naturally occurring polypeptide from any mammal. Such native sequence polypeptide can be isolated from nature or can be produced by recombinant or synthetic means. In some embodiments, the polypeptide is a “variant”. “Variant” means a biologically active polypeptide having at least about 80% amino acid sequence identity with the native sequence polypeptide after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Such variantsAtorney Docket No. 220710-705601 include, for instance, polypeptides wherein one or more amino acid residues are added, or deleted, at the N- or C-terminus of the polypeptide. In some embodiments, a variant will have at least about 80% amino acid sequence identity. In some embodiments, a variant will have at least about 90% amino acid sequence identity. In some embodiments, a variant will have at least about 95% amino acid sequence identity with the native sequence polypeptide. A “derivative” of a polypeptide is a polypeptide (e.g., an antibody) that has been chemically modified, e.g., via conjugation to another chemical moiety (such as, for example, polyethylene glycol or albumin, e.g., human serum albumin), phosphorylation, and glycosylation.

[0035] As used herein, the term, “percent identity,” in the context of two or more nucleic acid or polypeptide sequences, refer to two or more sequences or subsequences that have a specified percentage of nucleotides or amino acid residues that are the same, when compared and aligned for maximum correspondence, as measured using one of the sequence comparison algorithms described below (e.g., using publicly available computer software such as BLAST, BLASTP, BLASTN, BLAST-2, ALIGN, MEGALIGN (DNASTAR), CLUSTALW, CLUSTAL OMEGA, or MUSCLE software or other algorithms available to persons of skill) or by visual inspection. Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (ncbi.nlm.nih.gov). Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. Depending on the application, the percent “identity” can exist over a region of the sequence being compared, e.g., over a functional domain, or, alternatively, exist over the full length of the two sequences to be compared. For sequence comparison, typically one sequence acts as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence(s) relative to the reference sequence, based on the designated program parameters. Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by visual inspection (see generally Ausubel et al., infra).

[0036] As used herein, the terms, “increased” / ‘increase”, and “enhance,” refer to an increase by a statistically significant amount; for the avoidance of doubt, the terms “increased”, “increase”, orAtorney Docket No. 220710-705601“enhance”, mean an increase of at least 10% as compared to a reference level, for example an increase of at least about 10%, at least about 20%, or at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90% or up to and including a 100% increase or any increase between 10-100% as compared to a reference level, or at least about a 2-fold, or at least about a 3 -fold, or at least about a 4-fold, or at least about a 5-fold or at least about a 10-fold increase, or any increase between 2-fold and 10-fold or greater as compared to a reference level.

[0037] As used herein, the term “antibody” refers to an immunoglobulin molecule that specifically binds to, or is immunologically reactive toward, a specific target which in the current instance can be, for example, TL1A, a variant thereof, or a fragment thereof. Antibody can include, for example, polyclonal, monoclonal, genetically engineered, and fragments thereof. An antibody can be, for example, murine, chimeric, humanized, heteroconjugate, bispecific, diabody, triabody, or tetrabody. The fragment can include, for example, Fab’, F(ab’)2 , Fab, Fv, rlgG, scFv, hcAbs (heavy chain antibodies), a single domain antibody, VHH, VNAR , sdAbs, or nanobody. The term “monoclonal antibodies,” as used herein, refers to antibodies that are produced by a single clone of B-cells and bind to the same epitope. In contrast, “polyclonal antibodies” refer to a population of antibodies that are produced by different B-cells and bind to different epitopes of the same target. A whole antibody may comprise four polypeptides: two identical copies of a heavy (H) chain polypeptide and two identical copies of a light (L) chain polypeptide. Each of the heavy chains may contain one N-terminal variable (VH) region and three C-terminal constant (CHI, CH2 and CH3) regions, and each light chain may contain one N-terminal variable (VL) region and one C-terminal constant (CL) region. The variable regions of each pair of light and heavy chains may form a binding site of an antibody. The VH and VL regions may have a similar general structure, with each region comprising four framework regions, whose sequences are relatively conserved. In some embodiments, the framework regions may be connected by three complementarity determining regions (CDRs). In some embodiments, the three CDRs, known as CDR1, CDR2, and CDR3, form the “hypervariable region” of an antibody, which is responsible for binding.

[0038] As used herein, the term, “chimeric antibody,” refers to an antibody in which a portion of the heavy and / or light chain is derived from a particular source or species, while the remainder of the heavy and / or light chain is derived from a different source or species.

[0039] As used herein, the term, “human antibody,” refers to an antibody comprising an amino acid sequence corresponding to that of an antibody produced by a human or a human cell, or derived from a non-human source that utilizes a human antibody repertoire or human antibodyencoding sequences (e.g., obtained from human sources or designed de novo).

[0040] As used herein, the term, “humanized antibody,” refers to an amino acid sequence thatAtorney Docket No. 220710-705601 differs from the amino acid sequence of an antibody derived from a non-human species by one or more amino acid substitutions, deletions, and / or additions, such that the humanized antibody is less likely to induce an immune response, and / or induces a less severe immune response, as compared to the non-human species antibody, when it is administered to a human subject. In some embodiments, certain amino acids in the framework and constant domains of the heavy and / or light chains of the non-human species antibody are mutated to produce the humanized antibody. In some embodiments, the constant domain(s) from a human antibody are fused to the variable domain(s) of a non-human species. In another embodiment, one or more amino acid residues in one or more CDR sequences of a non-human antibody are changed to reduce the likely immunogenicity of the non-human antibody when it is administered to a human subject, wherein the changed amino acid residues either are not critical for immunospecific binding of the antibody to its target, or the changes to the amino acid sequence that are made are conservative changes, such that the binding of the humanized antibody to the target is not significantly worse than the binding of the non-human antibody to the target. Examples of how to make humanized antibodies can be found in U.S. Pat. Nos. 6,054,297, 5,886,152 and 5,877,293. For further details, see Jones et al., Nature, 1986, 321 :522-525; Riechmann et al., Nature, 1988, 332:323-329; and Presta, Curr. Op. Struct. BioL, 1992, 2:593-596, each of which is incorporated by reference in its entirety.

[0041] As used herein, the term, “epitope,” means a portion of a target that specifically binds to an antibody. Epitopes frequently consist of surface-accessible amino acid residues and / or sugar side chains and may have specific three-dimensional structural characteristics, as well as specific charge characteristics. Conformational and non-conformational epitopes are distinguished in that the binding to the former but not the latter may be lost in the presence of denaturing solvents. An epitope may comprise amino acid residues that are directly involved in the binding, and other amino acid residues, which are not directly involved in the binding. The epitope to which an antibody binds can be determined using known techniques for epitope determination such as, for example, testing for antibody binding to TL1 A, a variant thereof or a fragment thereof.

[0042] As used herein, the term, "Complementarity Determining Regions" (CDRs, i.e., CDR1, CDR2, and CDR3), refers to the amino acid residues of an antibody variable domain the presence of which are necessary for binding. Each variable domain typically has three CDR regions identified as CDR1, CDR2 and CDR3. The CDRs of variable heavy chain can be CDR-H1, CDR- H2 and CDR-H3. The CDRs of variable light chain can be CDR-L1, CDR-L2 and CDR-L3. Exemplary hypervariable loops occur at amino acid residues 26-32 (LI), 50-52 (L2), 91-96 (L3), 26-32 (Hl), 53-55 (H2), and 96-101 (H3). Exemplary CDRs (CDR-L1, CDR-L2, CDR-L3, CDR- Hl, CDR-H2, and CDR-H3) occur at amino acid residues 24-34 of LI, 50-56 of L2, 89-97 of L3, 31-35B of Hl, 50-65 of H2, and 95-102 of H3. Thus, the HVs may be comprised within theAtorney Docket No. 220710-705601 corresponding CDRs and references herein to the "hypervariable loops" of VH and VL domains should be interpreted as also encompassing the corresponding CDRs, and vice versa, unless otherwise indicated. The more highly conserved regions of variable domains are called the framework region (FR), as defined below. The variable domains of native heavy and light chains each comprise four FRs (FR1, FR2, FR3 and FR4, respectively), largely adopting a [beta]-sheet configuration, connected by the three hypervariable loops. The hypervariable loops in each chain are held together in close proximity by the FRs and, with the hypervariable loops from the other chain, contribute to the formation of the binding site of antibodies. Structural analysis of antibodies revealed the relationship between the sequence and the shape of the binding site formed by the complementarity determining regions. Despite their high sequence variability, five of the six loops adopt just a small repertoire of main-chain conformations, called "canonical structures". These conformations are first of all determined by the length of the loops and secondly by the presence of key residues at certain positions in the loops and in the framework regions that determine the conformation through their packing, hydrogen bonding or the ability to assume unusual main- chain conformations. The engineered antibodies or functional fragment thereof of the present disclosure can comprise a CDR3 region that is a length of at least about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. The engineered antibodies or functional fragment thereof of the present disclosure can comprise a CDR3 region that is at least about 18 amino acids in length.

[0043] As used herein, the term, “variable region,” when used in reference to an antibody, refers to the variable region of the antibody light chain or the variable region of the antibody heavy chain, either alone or in combination. The variable regions of the heavy and light chain each consist of four framework regions (FR) connected by three complementarity determining regions (CDRs) also known as hypervariable regions. The CDRs in each chain are held together in close proximity by the FRs and, with the CDRs from the other chain, contribute to the formation of the targetbinding site of antibodies. There are at least two techniques for determining CDRs: (1) an approach based on cross-species sequence variability; and (2) an approach based on crystallographic studies of target-antibody complexes. A CDR may refer to CDRs defined by either approach or by a combination of both approaches. Six hypervariable loops (three loops each from the Heavy and Light chain) contribute the amino acid residues for target-binding and confer target-binding specificity to the antibody. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for a target) has the ability to recognize and bind target, although at a lower affinity than the entire binding site.

[0044] As used herein, the term, “constant region,” when used in reference to an antibody, refers to the constant region of the antibody light chain (z.e., a light chain constant region) or the constantAtorney Docket No. 220710-705601 region of the antibody heavy chain (z.e., a heavy chain constant region) either alone or in combination. The constant region does not vary with respect to target specificity.

[0045] As used herein, the terms, "heavy chain constant region," includes amino acid sequences derived from the constant domains of an immunoglobulin heavy chain. A polypeptide comprising a heavy chain constant region comprises at least one of: a CHI domain, a hinge (e.g., upper, middle, and / or lower hinge region) domain, a CH2 domain, a CH3 domain, or a variant or fragment thereof. In an embodiment, an antibody or a fragment thereof may comprise the Fc region of an immunoglobulin heavy chain (e.g., a hinge portion, a CH2 domain, and a CH3 domain). In another embodiment, an antibody or a fragment thereof lacks at least a region of a constant domain (e.g., all or part of a CH2 domain). In some embodiments, at least one, and preferably all, of the constant domains are derived from a human immunoglobulin heavy chain. For example, in one preferred embodiment, the heavy chain constant region comprises a fully human hinge domain. In other preferred embodiments, the heavy chain constant region comprising a fully human Fc region (e.g., hinge, CH2 and CH3 domain sequences from a human immunoglobulin). In some embodiments, the constituent constant domains of the heavy chain constant region are from different immunoglobulin molecules.

[0046] As used herein, the term, "hinge region," includes the region of a heavy chain that joins the CHI domain to the CH2 domain. The hinge region can comprise approximately 25 residues and is flexible, thus allowing the two N-terminal binding regions to move independently. Hinge regions can be subdivided into three distinct domains: upper, middle, and lower hinge domains.

[0047] As used herein, the term "Fv" is the minimum antibody fragment that contains a complete target-recognition site and target-binding site. This fragment consists of a dimer of one heavy- and one light-chain variable region domain in tight, non-covalent association. From the folding of these two domains emanate six hypervariable loops (three loops each from the H and L chain) that contribute the amino acid residues for binding and confer binding specificity to the antibody. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for a target) has the ability to recognize and bind target, although at a lower affinity than the entire binding site.

[0048] As used herein, the term, “heavy chain variable region” or “VH,” when used in reference to an antibody, refers to the fragment of the heavy chain that contains three CDRs interposed between flanking stretches known as framework regions, these framework regions are generally more highly conserved than the CDRs and form a scaffold to support the CDRs.

[0049] As used herein, the term, “light chain variable region” or “VL,” when used in reference to an antibody, refers to the fragment of the light heavy chain that contains three CDRs interposed between flanking stretches known as framework regions, these framework regions are generallyAtorney Docket No. 220710-705601 more highly conserved than the CDRs and form a scaffold to support the CDRs.

[0050] As used herein, the term, “framework residues” or “FR,” are those variable domain amino acid residues other than the hypervariable region amino acid residues.

[0051] As used herein, the term, “antibody heavy chain,” refers to the larger of the two types of polypeptide chains present in an antibody in their naturally occurring conformations, and which normally determines the class to which the antibody belongs.

[0052] As used herein, the term, “antibody light chain,” refers to the smaller of the two types of polypeptide chains present in an antibody in their naturally occurring conformations. Kappa (“K”) and lambda (“X”) light chains refer to the two major antibody light chain isotypes.

[0053] As used herein, the phrase, “specifically binds” or “preferentially binds,” refers to an antibody or fragment thereof that binds to a target with greater affinity and / or avidity than it binds to epitopes on unrelated polypeptides. The specificity of an antibody or fragment thereof can be determined based on affinity and / or avidity. Methods to determine such specific binding are also well known in the art.

[0054] As used herein, the term, "binding affinity," refers to the strength of the sum total of noncovalent interactions between a first molecule and a second molecule. Unless indicated otherwise, the binding affinity refers to intrinsic binding affinity reflecting interaction between the first molecule and the second molecule at a ratio of 1 : 1.

[0055] As used herein, the term, “multispecific antibody,” is an antibody that comprises two or more different target-binding domains that collectively specifically bind two or more different epitopes. The two or more different epitopes may be epitopes on the same cell or on different cells. In some embodiments, a multi-specific antibody binds two different epitopes (z.e., a “bispecific antibody”). In some embodiments, a multi-specific antibody binds three different epitopes (z.e., a “trispecific antibody”).

[0056] As used herein a “recombinant antibody” is an antibody that comprises an amino acid sequence derived from two different species, or two different sources, and includes synthetic and / or non-naturally-occurring molecules. By way of non-limiting example, a recombinant antibody may comprise a non-human CDR and a human variable region framework or constant or Fc region, an antibody with binding regions (or domains) from two different monoclonal antibodies, or an antibody comprising a mutation of one or more amino acid residues to increase or decrease biological activity or binding of a part of the antibody. In certain embodiments, recombinant antibodies are produced from a recombinant DNA molecule or synthesized. In certain embodiments, the antibodies described herein are a polypeptide(s) encoded by one or more polynucleotides.Atorney Docket No. 220710-705601

[0057] As used herein, “recognize” or “bind” or “selective for” refers to the association or binding between a binding domain and a target domain.

[0058] As used herein, an “antibody construct” refers to a construct that may contain a binding domain and an Fc region.

[0059] As used herein, a “binding domain” refers to an antibody or non-antibody domain.

[0060] As used herein, an “binding domain” refers to a domain from an antibody or from a nonantibody that can bind to a target domain. Binding domains can be numbered when there is more than one binding domain in a given conjugate or antibody construct (e.g., first binding domain, second binding domain, third binding domain, etc.). Different binding domains in the same conjugate or construct can target the same target or different targets.

[0061] As used herein, an “Fc region” refers to an Fc region from an antibody or from a nonantibody that can bind to an Fc receptor. As used herein, an “Fc region” and an “Fc comprising domain” can be used interchangeably. Fc region comprises two Fc subunits. The two Fc subunits may be identical or non-identical.

[0062] As used herein, a “target binding domain” refers to a construct that contains a binding domain from an antibody or from a non-antibody that can bind to a target (e.g. TL1 A, a variant thereof, or a fragment thereof).

[0063] As used herein, the abbreviations for the natural 1 -enantiomeric amino acids are conventional and can be as follows: alanine (A, Ala); arginine (R, Arg); asparagine (N, Asn); aspartic acid (D, Asp); cysteine (C, Cys); glutamic acid (E, Glu); glutamine (Q, Gin); glycine (G, Gly); histidine (H, His); isoleucine (I, He); leucine (L, Leu); lysine (K, Lys); methionine (M, Met); phenylalanine (F, Phe); proline (P, Pro); serine (S, Ser); threonine (T, Thr); tryptophan (W, Trp); tyrosine (Y, Tyr); valine (V, Vai). Unless otherwise specified, X can indicate any amino acid.

[0064] The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of subjects for instance, human beings and animals, without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio.

[0065] The phrase “pharmaceutically acceptable excipient” or “pharmaceutically acceptable carrier” as used herein means a pharmaceutically acceptable material, composition or vehicle, such as a liquid or solid filler, diluent, excipient, solvent or encapsulating material. Each carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulation and not injurious to the patient. Some examples of materials which can serve as pharmaceutically acceptable carriers include: (1) sugars, such as lactose, glucose and sucrose; (2) starches, such as com starch and potato starch; (3) cellulose, and its derivatives, such as sodium carboxymethylAtorney Docket No. 220710-705601 cellulose, ethyl cellulose and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter and suppository waxes; (9) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; (10) glycols, such as propylene glycol; (11) polyols, such as glycerin, sorbitol, mannitol and polyethylene glycol; (12) esters, such as ethyl oleate and ethyl laurate; (13) agar; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxic compatible substances employed in pharmaceutical formulations.

[0066] The terms “fragment of an antibody,” “antibody fragment,” “functional fragment of an antibody,” “binding domain” or their grammatical equivalents are used interchangeably herein to mean one or more fragments or portions of an antibody that retain the ability to specifically bind to a target. The antibody fragment desirably comprises, for example, one or more CDRs, the variable region (or portions thereof), the constant region (or portions thereof), or combinations thereof. Examples of antibody fragments include, but are not limited to, (i) a Fab fragment, which is a monovalent fragment that may comprise VL, VH, CL, and CHI domains; (ii) a F(ab’)2 fragment, which is a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the stalk region; (iii) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody; (iv) a single chain Fv (scFv), which is a monovalent molecule consisting of the two domains of the Fv fragment (z.e., VL and VH) joined by a synthetic linker which enables the two domains to be synthesized as a single polypeptide chain; and (v) a diabody, which is a dimer of polypeptide chains, wherein each polypeptide chain may comprise a VH connected to a VL by a peptide linker that is too short to allow pairing between the VH and VL on the same polypeptide chain, thereby driving the pairing between the complementary domains on different VH-VL polypeptide chains to generate a dimeric molecule having two functional target binding sites. Antibody fragments are known in the art. Other antibody fragments can include variable fragments of heavy chain antibodies (VHH).

[0067] As used herein, the term, “Fab,” refers to a region of an antibody composed of one constant and one variable domain of each of the heavy and the light chains (monovalent target-binding fragment), but wherein the heavy chain is truncated such that it lacks the CH2 and CH3 domain (z.e., VH, CHI, VL, and CL), and may also lack some or all of the hinge region. It can be produced by digestion of a whole antibody with the enzyme papain. Fab may refer to this region in isolation, or this region in the context of a full-length antibody, immunoglobulin construct or Fab fusion protein. Fab can be obtained by treating a whole antibody with pepsin, followed by reduction, to yield a molecule consisting of an intact light chain and a portion of a heavy chain comprising a VH and a single constant domain. Two Fab' fragments are obtained per antibody treated in thisAtorney Docket No. 220710-705601 manner.

[0068] As used herein, the term, "scFv,” refers to an antibody fragment comprising the VH and VL domains of an antibody, wherein these domains are present in a single polypeptide chain. Generally, the Fv polypeptide further comprises a polypeptide linker between the VH and VL domains that enables the scFv to form the desired structure for target-binding.

[0069] The term, “conservative amino acid substitution” or “conservative mutation,” refers to the replacement of one amino acid by another amino acid with a common property. A functional way to define common properties between individual amino acids is to analyze the normalized frequencies of amino acid changes between corresponding proteins of homologous organisms. According to such analyses, groups of amino acids may be defined where amino acids within a group exchange preferentially with each other, and therefore resemble each other most in their impact on the overall protein structure. Examples of conservative mutations include amino acid substitutions of amino acids within the sub-groups above, for example, lysine for arginine and vice versa such that a positive charge may be maintained; glutamic acid for aspartic acid and vice versa such that a negative charge may be maintained; serine for threonine such that a free -OH can be maintained; and glutamine for asparagine such that a free -NH2 can be maintained. Alternatively or additionally, the therapeutic agents can comprise the amino acid sequence of the reference protein with at least one non-conservative amino acid substitution.

[0070] The terms “non-conservative mutation” or “non-conservative amino acid substitution” involve amino acid substitutions between different groups, for example, lysine for tryptophan, or phenylalanine for serine, etc. In this case, it is preferable for the non-conservative amino acid substitution to not interfere with or inhibit the biological activity of the therapeutic agent. The non-conservative amino acid substitution may enhance the biological activity of the therapeutic agent, such that the biological activity of the therapeutic agent is increased as compared to the wild-type therapeutic agent.

[0071] A “multispecific antibody” is an antibody that can bind simultaneously to at least two targets that are of different structure, e.g., two different target, two different epitopes on the same target, or a hapten and / or an epitope. A “multivalent antibody” is an antibody that can bind simultaneously to at least two targets that are of the same or different structure. Valency indicates how many binding arms or sites the antibody has to a single target or epitope (z.e., monovalent, bivalent, trivalent or multivalent). The multivalency of the antibody means that it can take advantage of multiple interactions in binding to a target, thus increasing the avidity of binding to the target. Specificity indicates how many targets or epitopes an antibody is able to bind (z.e., monospecific, bispecific, trispecific, multispecific). Using these definitions, a natural antibody is bivalent because it has two binding arms but is monospecific because it binds to one epitope.Atorney Docket No. 220710-705601Multispecific, multivalent antibodies are constructs that have more than one binding region of different specificity.

[0072] A “bispecific antibody” is an antibody that can bind simultaneously to two targets which are of different structure. Bispecific antibodies may have at least one arm (or binding domain) that specifically binds to, for example, a first target, and at least one other arm (or binding domain) that specifically binds to a second target. At least one of the first and the second targets may be a target produced by or associated with a diseased cell, tissue, organ or pathogen.

[0073] As used herein, the term, “vector,” refers to a nucleic acid molecule capable of propagating another nucleic acid to which it is linked. The term includes the vector as a selfreplicating nucleic acid structure as well as the vector incorporated into the genome of a host cell into which it has been introduced. Certain vectors are capable of directing the expression of nucleic acids to which they are operatively linked. Such vectors are referred to herein as “expression vectors.”

[0074] As used herein, the terms, “host cell,” “host cell line” and “host cell culture,” are interchangeable and refer to cells into which an exogenous nucleic acid has been introduced, and the progeny of such cells. Host cells include “transformants” (or “transformed cells”) and “transfectants” (or “transfected cells”), which each include the primary transformed or transfected cell and progeny derived therefrom. Such progeny may not be completely identical in nucleic acid content to a parent cell, and may contain mutations.

[0075] An engineered antibody construct, or a composition described herein, is said to be administered in a “therapeutically effective amount” if the amount administered is physiologically significant. An agent is physiologically significant if its presence results in a detectable change in the physiology of a recipient subject. In particular embodiments, an engineered antibody construct disclosed herein is physiologically significant if its presence invokes a response or mitigates the signs and symptoms of an infectious or autoimmune disease state. A physiologically significant effect could also be the evocation of a humoral and / or cellular immune response in the recipient subject.

[0076] The term “linker” is used to denote polypeptides comprising two or more amino acid residues joined by peptide bonds and are used to link one or more binding portions or variable domains.

[0077] An "Fv" or "Fv fragment" may consist of only the light chain variable domain (VL) and heavy chain variable domain (VH) of a "single arm" of an immunoglobulin. Thus an "Fv" is the minimum antibody fragment which contains a complete target-recognition and binding site. A "two-chain" Fv fragment consists of a dimer of one heavy- and one light-chain variable domain in tight, non-covalent association. A single-chain Fv species (scFv) may include a VH and a VLAtorney Docket No. 220710-705601 domain of an immunoglobulin, with these domains being present in a single polypeptide chain in which they are covalently linked to each other by a linker peptide. Typically, in a scFv fragment the variable domains of the light and heavy chain associate in a dimeric structure analogous to that in a two-chain Fv species. In single chain Fv fragments, it is possible to either have the variable domain of the light chain arranged at the N-terminus of the single polypeptide chain, followed by the linker and the variable domain of the heavy chain arranged at the C-terminus of the polypeptide chain or vice versa, having the variable domain of the heavy chain arranged on the N-terminus and the variable domain of the light chain at the C-terminus with the linker peptide arranged in between. The linker peptide can be any flexible linker known in the art, for example, made from glycine and serine residues. It is also possible to additionally stabilize the domain association between the VH and the VL domain by introducing disulfide bonds into conserved framework regions. Such scFv fragments are also known as disulfide-stabilized scFv fragments (ds-scFv).

[0078] As used herein, the term, “treating” (and variations thereof such as “treat” or “treatment”), refers to clinical intervention in an attempt to alter the natural course of a disease or condition in a subject in need thereof. Treatment can be performed during the course of clinical pathology. Desirable effects of treatment include cure (if applicable), delay the onset of, reduce the severity of, alleviate, ameliorate one or more symptoms of the disease, improve the disease, reduce or improve any associated symptoms of the disease or the predisposition toward the development of the disease.

[0079] As used herein, the term, “sufficient amount,” means an amount sufficient to produce a desired effect, e.g., an amount sufficient to modulate an immune response in a subject.

[0080] As used herein, the terms, “modulate” and “modulation,” refer to reducing or inhibiting or, alternatively, activating or increasing, a recited variable.Antibody

[0081] Antibody which recognizes specific epitopes can be generated by known techniques. Antibody comprises antibody fragments. Antibody fragments are binding portions of an antibody, such as, for example, F(ab')2, Fab', F(ab)2, Fab, Fv, scFv and the like. F(ab')2 fragments can be produced by pepsin digestion of the antibody and Fab' fragments can be generated by reducing disulfide bridges of the F(ab')2 fragments. Alternatively, Fab' expression libraries can be constructed to allow rapid and easy identification of monoclonal Fab' fragments with the desired specificity. F(ab)2 fragments may be generated by papain digestion of an antibody.

[0082] A single chain Fv (scFv) may comprise a VL domain and a VH domain. The VL and VH domains associate to form a target binding site. These two domains may be further covalently linked by a peptide linker (L).Atorney Docket No. 220710-705601

[0083] Techniques for producing single domain antibodies (DABs or VHH) are also known in the art, as disclosed for example in Cossins et al. (2006, Prot Express Purif 51 :253-259), incorporated herein by reference. Single domain antibodies may be obtained, for example, from camels, alpacas or llamas by standard immunization techniques. The VHH may have potent target binding capacity and can interact with novel epitopes that are inaccessible to conventional VH-VL pairs. Alpaca serum IgG contains about 50% camelid heavy chain only IgG antibodies (HCAbs). Alpacas may be immunized with known targets, such as TNF-a, and VHHs can be isolated that bind to and neutralize the target. PCR primers that amplify virtually all alpaca VHH coding sequences have been identified and may be used to construct alpaca VHH phage display libraries, which can be used for antibody fragment isolation by standard biopanning techniques well known in the art. In certain embodiments, VHH antibody fragments may be utilized in the claimed compositions and methods.

[0084] An antibody fragment can be prepared by proteolytic hydrolysis of the full-length antibody or by expression in E. coli or another host of the DNA coding for the fragment. An antibody fragment can be obtained by pepsin or papain digestion of full-length antibodies by conventional methods.

[0085] Disclosed herein are engineered antibodies comprising: (a) a first TL1 A binding region that binds an epitope on TL1 A, a variant thereof, or a functional fragment thereof; (b) a second TL1A binding region that binds an epitope on TL1A, a variant thereof, or a functional fragment thereof; and (c) an engineered Fc region that comprises a first and a second subunit capable of stable association. In some embodiments, at least one of the first and second TL1 A binding regions are functionally fused to one of the two subunits of the engineered Fc region. In some embodiments, the first and second TL1A binding regions are functionally fused to each other, optionally, via a linker. In some embodiments, a third TL1 A binding region is functionally fused to the first or second TL1 A binding region. In some embodiments, a third TL1 A binding region is functionally fused to the first TL1 A binding region and a fourth TL1 A binding region fused to the second TL1 A binding region. In some embodiments, a third TL1 A binding region is functionally fused to the first or second subunit of the Fc region. In some embodiments, a third TL1 A binding region is functionally fused to the first subunit of the Fc region and a fourth TL1 A binding region fused to the second subunit of the Fc region.TL1A

[0086] Tumor necrosis factor (TNF)-like cytokine 1A (TL1A; HGNC: 11931, Entrez Gene: 9966, UniProtKB: 095150) is a type 2 transmembrane protein that self-assembles into stable trimers and binds to death receptor 3 (DR3). TL1A can also bind to TNFR2 to produceAtorney Docket No. 220710-705601 proinflammatory cytokines like IL-6, ROS, and then impairs mitochondrial dysfunction. TL1 A is also known as Tumor Necrosis Factor Ligand Superfamily Member 15 TNFSF15), TL1, VEGI, TNLG1B, or VEGI192A. TL1 A is mainly expressed as the membrane-bound form.

[0087] TL1A is constitutive expressed in immune cells (e.g., monocyte, macrophage, dendritic cell, and T cells) and non-immune cells (e.g., endothelial cells and synovial fibroblast cells). TL1 A expression in immune cells (e.g., macrophages and dendritic cells) increased by TLR4, TLR11, or FcgR. In non-immune cells (e.g., endothelial cells), TL1A constitutively expressed and upregulated in response to TNFa stimulation.

[0088] TL1 A is also expressed as soluble form (sTLl A) that is produced by alternative splicing or TNFa converting enzyme (TACCE) cleavage. sTLl A can be detected in serum and body fluids of patients with T cell-mediated inflammatory autoimmune diseases, e.g., rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis. STL1A / DR3 binding promotes proinflammatory cytokine secretion, lymphocyte proliferation and cell apoptosis. For example, sTLIA can bind to DR3 and initiate one of two downstream pathways to cause: (1) inflammation - TRADD is recruited to the cytoplasmic domain of DR3, and then further recruits TRAF2 and RIP1 to initiate and activate MAPKs, NFkB, and PI3K signaling to regulate expression of pro-inflammatory genes; or (2) apoptosis - TRADD is recruited to the cytoplasmic domain of DR3, and TRADD binds to FADD and RIP3 to activate Caspase-8 to form complexes. It, then, induces apoptotic cell death through caspase pathway (-3 and -7). sTLIA can bind to soluble decoy receptor 3 (DcR3). When DcR3 competitively binds to sTLIA, combination of sTLIA and DR3 may be destroyed and results in less lymphocyte activation, less pro-inflammatory cytokine production, and prevents apoptosis. DcR3 can bind to other ligands like FasL and LIGHT.

[0089] TL1A is associated with autoimmune conditions (e.g., rheumatoid arthritis, inflammatory bowel disease, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus, ankylosing spondylitis). The autoimmune conditions and its relationship with the TL1A expression are summarized in TABLE 1.TABLE 1. TL1A Expression and Autoimmune ConditionsAtorney Docket No. 220710-705601

[0090] In some embodiments, serum level of TL1 A is significantly associated with progression of atherosclerotic plaque height in subjects having rheumatoid arthritis. In some embodiments, treatment of collagen-induced arthritis (CIA) mice with anti-TLl A antibody decreases total joint score and clinical inflammation. In some embodiments, TL1 A gene knock-out results in improved clinical profiles for CIA mice relative to wildtype mice.

[0091] In some embodiments, TL1A affects epithelial to mesenchymal transition (EMT) and increases the barrier permeability (reduces tight function protein), resulting in causing colonic fibrosis and inflammatory responses in subjects having inflammatory bowel disease. In some embodiments, TL1A expression is elevated in subjects having Crohn’s disease. In some embodiments, anti-TLIA improves tissue inflammation and inhibited expression of fibrotic pathways.

[0092] In some embodiments, TL1 A is predominantly expressed in psoriatic lesions, particularly in infiltrating inflammatory cells, keratinocytes, and vascular cells. In some embodiments, TL1 A promotes production of IL- 17, which ultimately leads to early inflammation. In some embodiments, anti-TLIA antibody treatment alleviates histopathological changes. In some embodiments, TL1A can synergize with IL-23 to stimulate IL- 17 secretion in peripheral blood mononuclear cells (PBMCs), thereby aggravating the autoimmune condition.

[0093] In some embodiments, serum TL1A levels are higher in subjects having primary biliary cirrhosis (PBS). In some embodiments, TL1 A is expressed in biliary epithelial cells, vascular cells and infiltrating mononuclear cells of PBC liver. In some embodiments, the subjects show decrease in serum TL1 A level after treatment with ursodeoxycholic acid (UDCA).

[0094] In some embodiments, engineered antibodies described herein can bind TL1A protein. In some embodiments, engineered antibodies described herein can bind a mammalian TL1A sequence. In some embodiments, engineered antibodies described herein can bind a human homolog of TL1 A protein. In some embodiments, engineered antibodies described herein can bind a murine homolog of TL1A protein.

[0095] An amino acid sequence of a human TL1 A protein is recited in TABLE 2.TABLE 2. Amino Acid Sequence of human TL1A proteinAtorney Docket No. 220710-705601

[0096] In some embodiments, target binding regions (or domains), engineered antibodies, variants thereof, or functional fragments thereof, as described herein, can bind an epitope on TL1 A protein, a variant thereof, or a function fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of the sequences recited in TABLE 2. In some embodiments, target binding regions (or domains), engineered antibodies, variants thereof, or functional fragments thereof, as described herein, can bind an epitope on TL1 A protein, a variant thereof, or a fragment thereof, wherein the TL1A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to SEQ ID NO: 1

[0097] In some embodiments, epitope in TL1A protein comprises one or more amino acid residues selected from the group consisting of: R103, G124, M196, Y238, T239, K240, E241, Hl 18, 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: 1. In some embodiments, the epitope comprises R103, G124, Y238, T239, E120, V102. In some embodiments, the epitope further comprises one or more amino acid residues selected from the group consisting of M196, K240, E241, Hl 18, H121, E122, L123 and T105. In some embodiments, the epitope comprises amino acid residues R103, G124, M196, Y238, T239, K240, E241, Hl 18, E120, H121, E122, L123, V102, and T105. In some embodiments, the epitope consists of amino acid residues R103, G124, M196, Y238, T239, K240, E241, Hl 18, E120, H121, E122, L123, V102, and T105. In some embodiments, epitope in TL1A protein does not comprise one or more amino acid residues selected from the group consisting of: R103, G124, M196, Y238, T239, K240, E241, Hl 18, 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: 1Atorney Docket No. 220710-705601Target Binding Regions

[0098] Target binding regions (or domains) as described herein can bind a target epitope on TL1A, variants thereof, or fragments thereof. In some embodiments, a target binding region (or domain) comprises a heavy chain variable domain. In some embodiments, a heavy chain variable domain comprises CDR-H1, CDR-H2, and CDR-H3. In some embodiments, a target binding region (or domain) comprises a light chain variable domain. In some embodiments, a light chain variable domain comprises CDR-L1, CDR-L2, and CDR-L3. In some embodiments, a heavy chain variable domain interacts with a light chain variable domain, thereby forming a target binding region. In some embodiments, a target binding region (or domain) comprises a constant region (Fc region). In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof comprise at least one target binding region (or domain) as described herein. In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof comprise two target binding regions (or domains). In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof comprise two target binding regions (or domains), wherein the two target binding regions (or domains) are at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to each other. In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof comprise two target binding regions (or domains), wherein the two target binding regions (or domains) are nonidentical to each other.

[0099] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one of CDR-Hs described in TABLE 3 or a variant thereof, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2. The CDRs are according to the Kabat or IMGT delineation system. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise any one of CDR-H1 described in TABLE 3 or a variant thereof, any one of CDR-H2 described in TABLE 3 or a variant thereof, and any one of CDR-H3 described in TABLE 3 or a variant thereof, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise any one of combinations of CDR-Hs or variants thereofAttorney Docket No. 220710-705601 described in TABLE 3, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1 A protein, a variant thereof, or a fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2. In some embodiments, CDR-H variants described herein comprise at least one, at least two or at least three modifications (e.g., substitutions, deletions, additions or combination thereof) relative to a corresponding parent CDR-H sequence described in TABLE 3. In some embodiments, CDR-Hs or variants thereof comprise amino acid sequences that are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to a corresponding parent CDR-H sequences described in TABLE 3. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one of CDR-Hs described set for in SEQ ID NOS: 89-91, 98-103, 116-118, 135- 137, 141-143, 147-149, 154-155, 161, 167, 170-172, 256-295, 327 or a variant thereof, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2, wherein the CDRs are according to the Kabat delineation system.TABLE 3. Exemplary CDR-H sequences of antibodies for binding to TL1AAtorney Docket No. 220710-705601Atorney Docket No. 220710-705601

[0100] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the CDR-Hs described in TABLE 3. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise 0, 1, 2, 3 or 4 modifications (e.g., addition, substitution, deletion or a combination thereof) within any one of the CDR-Hs described in TABLE 3. In some embodiments, a CDR-H1, a CDR-H2, and a CDR-H3 independently comprise amino acid sequences according to amino acid sequences recited in TABLE 3 or variants thereof, wherein said variants comprise at least one amino acid substitution, at least one amino acid deletion, at least one amino acid addition, or combinations thereof relative to a corresponding amino acid sequence recited in TABLE 3. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the CDR-Hs described in TABLE 3, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. Alternatively, in some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g, addition, substitution, deletion or a combination thereof) within any one of framework regions. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as describedAttorney Docket No. 220710-705601 herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the at least one modification provides a pH-dependent binding activity to the target binding regions (or domains), the variants thereof, or the functional fragments thereof. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have a binding affinity of at least 60%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100% in neutral pH condition of a corresponding binding affinity prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope in neutral pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope at pH 7.4 relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease in binding affinity for the target epitope in acidic pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease in binding affinity for the target epitope at pH 5.8 relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, a ratio of the binding affinities of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, for an epitope present on TL1A, a variant thereof, or a fragment thereof at neutral pH and acidic pH, respective, is at least 1.2, at least 10, at least 100, at least 200, or more relative to binding affinity of a corresponding engineered antibody, a variantAttorney Docket No. 220710-705601 thereof or a functional fragment thereof prior to the at least one modification.

[0101] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise amino acid sequences that are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to any one of VH sequences described in TABLE 4, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequence recited in TABLE 2. In some embodiments, TL1A binding VH domains, variants thereof or functional fragments thereof, as described herein, comprise amino acid sequences that are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to any one of amino acid sequences described in SEQ ID NO: 104, 168, 178-254 and 323-326, wherein the TL1A binding VH domains, the variants thereof or the functional fragments thereof can bind TL1 A protein, a variant thereof, or a fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequence recited in TABLE 2.TABLE 4. Exemplary VH sequence sequences of antibodies for binding to TL1AAtorney Docket No. 220710-705601Atorney Docket No. 220710-705601Atorney Docket No. 220710-705601Atorney Docket No. 220710-705601Atorney Docket No. 220710-705601Atorney Docket No. 220710-705601Attorney Docket No. 220710-705601

[0102] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the VH sequences described in TABLE 4. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the VH sequences described in TABLE 4, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. Alternatively, in some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise atAttorney Docket No. 220710-705601 least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the at least one modification provides a pH- dependent binding activity to the target binding regions (or domains), the variants thereof, or the functional fragments thereof. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have a binding affinity of at least 60%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100% in neutral pH condition of a corresponding binding affinity prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope in neutral pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope at pH 7.4 relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease in binding affinity for the target epitope in acidic pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease in binding affinity for the target epitope at pH 5.8 relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the at least one modification in CDR-H3. In some embodiments, the at least one modification is a substitution in CDR-H3. In some embodiments,Attorney Docket No. 220710-705601 the at least one modification comprises a substitution of an uncharged amino acid with a charged amino acid in CDR-H3. The uncharged amino acid can be an amino acid with a hydrophobic side chain (e.g., glycine, alanine, valine, cysteine, proline, leucine, isoleucine, methionine, tryptophan, phenylalanine). Alternatively, the uncharged amino acid can be a polar uncharged amino acid (e.g., serine, threonine, tyrosine, asparagine, glutamine). The charged amino acid can be a negatively charged amino acid (e.g., aspartic acid, glutamic acid). Alternatively, the charged amino acid can be a positively charged amino acid (e.g., lysine, arginine, histidine). In some embodiments, the at least one modification is a substitution of a positively charged amino acid residue with a negatively charged amino acid residue in CDR-H3. In some embodiments, the at least one modification is a substitution of a negatively charged amino acid residue with a positively charged amino acid residue in CDR-H3. In some embodiments, a ratio of the binding affinities of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, for an epitope present on TL1 A, a variant thereof, or a fragment thereof at neutral pH and acidic pH, respective, is at least 1.2, at least 10, at least 100, at least 200, or more. In some embodiments, the VH sequence comprises an amino acid sequence of SEQ ID NO: 104. In some embodiments, the VH sequence comprises at least one modification at positions selected from S30, T69, L83, N84, T104 and F107 relative to SEQ ID NO: 104. Alternatively, in some embodiments, the VH sequence comprises at least one modification at positions selected from 31, 77, 89, 90, 104 and 112A relative to SEQ ID NO: 104, numbering according to IMGT numbering scheme. In some embodiments, the VH sequence comprises at least one modification comprises a substitution selected from a group consisting of S30T, T69I, L83V, N84K, T104D, F107N and F107D relative to SEQ ID NO: 104.

[0103] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one of CDR-Ls described in TABLE 5 or a variant thereof, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2. The CDRs are according to the Kabat or IMGT delineation system. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise any one of CDR-L1 described in TABLE 5 or a variant thereof, any one of CDR-L2 described in TABLE 5 or a variant thereof, and any one of CDR-L3 described in TABLE 5 or a variant thereof, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1 A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequence recited in TABLE 2. In someAtorney Docket No. 220710-705601 embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise any one of combinations of CDR-Ls or variants thereof described in TABLE 5, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof, as described herein, can bind TL1 A protein, a variant thereof, or a fragment thereof, wherein the TL1A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2. In some embodiments, CDR-L variants described herein comprise at least one, at least two or at least three substitutions, deletions, additions, or combination thereof relative to a corresponding parent CDR-L sequence described in TABLE 5. In some embodiments, CDR-Ls or variants thereof comprises an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to a corresponding parent CDR-L sequence described in TABLE 5.TABLE 5. Exemplary CDR-L sequences of antibodies for binding to TL1A

[0104] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the CDR-Ls described in TABLE 5. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise 0, 1, 2, 3 or 4 modifications (e.g.,Attorney Docket No. 220710-705601 addition, substitution, deletion or a combination thereof) within any one of the CDR-Ls described in TABLE 5. In some embodiments, a CDR-L1, a CDR-L2, and a CDR-L3 independently comprise amino acid sequences according to amino acid sequences recited in TABLE 5 or variants thereof, wherein said variants comprise at least one amino acid substitution, at least one amino acid deletion, at least one amino acid addition, or combinations thereof relative to a corresponding amino acid sequence recited in TABLE 5. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the CDR-Ls described in TABLE 5, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. Alternatively, in some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the at least one modification provides a pH-dependent binding activity to the target binding regions (or domains), the variants thereof, or the functional fragments thereof. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have a binding affinity of at least 60%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100% in neutral pH condition of a corresponding binding affinity prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope in neutral pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease inAtorney Docket No. 220710-705601 binding affinity for the target epitope in acidic pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, a ratio of the binding affinities of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, for an epitope present on TL1 A, a variant thereof, or a fragment thereof at neutral pH and acidic pH, respective, is at least 1.2, at least 10, at least 100, at least 200, or more relative to binding affinity of a corresponding engineered antibody, a variant thereof or a functional fragment thereof prior to the at least one modification.

[0105] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise a combination of CDRs, wherein the CDRs comprises a CDR-H1 or a variant thereof, a CDR-H2 or a variant thereof, a CDR-H3 or a variant thereof, a CDR-L1 or a variant thereof, a CDR-L2 or a variant thereof, and a CDR-L3 or a variant thereof, and wherein the combination is according to any one of the combinations provided in TABLE 6TABLE 6. Exemplary CDR sequences of antibodies for binding to TL1AAtorney Docket No. 220710-705601

[0106] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to any one of VL sequences described in TABLE 7, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof can bind TL1A protein, a variant thereof, or a fragment thereof, wherein the TL1A protein comprises an amino acid sequence that is at least 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100% identical to any one of sequences recited in TABLE 2.TABLE 7. Exemplary VL sequence sequences of antibodies for binding to TL1AAttorney Docket No. 220710-705601

[0107] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the VL sequences described in TABLE 7. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of the VL sequences described in TABLE 7, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. Alternatively, in some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions. In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise at least one modification (e.g., addition, substitution, deletion or a combination thereof) within any one of framework regions, wherein the at least one modification changes isoelectric point (pl) of the target binding regions (or domains), variants thereof or functional fragments thereof relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the at least one modification provides a pH- dependent binding activity to the target binding regions (or domains), the variants thereof, or the functional fragments thereof. In some embodiments, the target binding regions (or domains), theAtorney Docket No. 220710-705601 variants thereof, or the functional fragments thereof comprising the at least one modification have a binding affinity of at least 60%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100% in neutral pH condition of a corresponding binding affinity prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope in neutral pH condition relative to a corresponding target binding region (or domain), a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope in neutral pH condition relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more increase in binding affinity for the target epitope at pH 7.4 relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease in binding affinity for the target epitope in acidic pH condition relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions, the variants thereof, or the functional fragments thereof comprising the at least one modification have at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more decrease in binding affinity for the target epitope at pH 5.8 relative to a corresponding target binding region, a variant thereof or a functional fragment thereof prior to the at least one modification. In some embodiments, a ratio of the binding affinities of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, for an epitope present on TL1 A, a variant thereof, or a fragment thereof at neutral pH and acidic pH, respective, is at least 1.1, at least 1.2, at least 1.5, at least 2, at least 3, at least 5, at least 8, at least 10, at least 100, at least 200, or more relative to binding affinity of a corresponding engineered antibody, a variant thereof or a functional fragment thereof prior to the at least one modification.

[0108] In some embodiments, engineered antibodies described herein comprise a TL1 A bindingAtorney Docket No. 220710-705601 region, wherein the TL1 A binding region comprises a TL1 A binding heavy chain variable domain and, optionally, a TL1A binding light chain variable domain. In some embodiments, the engineered antibodies disclosed herein are bispecific antibodies comprising a TL1A binding region. In some embodiments, antibodies described herein comprise a binding affinity for TL1A, a variant thereof or a functional fragment thereof is higher under neutral pH condition relative to the binding affinity under acidic pH condition. In some embodiments, antibodies described herein comprise a binding affinity for TL1 A, a variant thereof or a functional fragment thereof is higher at about pH 7.4 relative to the binding affinity at about pH 5.8.

[0109] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise: (a) a VH sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to any one of amino acid sequences described in TABLE 4; and (b) a VL sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to any one of amino acid sequences described in TABLE 7, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof comprise the VH sequence and the VL sequence according to any one of the combinations described in TABLE 8.TABLE 8. Exemplary VH and VL sequences of antibodies for binding to TL1AFc Regions

[0110] There are five major classes of antibodies: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g., IgGl, IgG2, IgG3, IgG4, IgAl, and IgA2. Fc region that corresponds to the different classes of immunoglobulins are called a, 5, a, y, and p, respectively. Accordingly, engineered antibodies described herein comprise kappa FcAttorney Docket No. 220710-705601 region, lambda Fc region, alpha Fc region, gamma Fc region, delta Fc region, epsilon Fc region, mu Fc region, a functional fragment thereof, or a combination thereof.[oni] A class of antibody or immunoglobulin refers to the type of Fc region possessed by its heavy chain. In some embodiment, the heavy chain is an IgA. In some embodiment, the heavy chain is an IgD. In some embodiment, the heavy chain is an IgE. In some embodiment, the heavy chain is an IgG. In some embodiment, the heavy chain is an IgM. In some embodiment, the heavy chain is an IgGl. In some embodiment, the heavy chain is an IgG2. In some embodiment, the heavy chain is an IgG3. In some embodiments, the heavy chain is an IgG4. In some embodiment, the heavy chain is an IgAl. In some embodiment, the heavy chain is an IgA2. In some embodiments, an antibody is an IgGl antibody. In some embodiments, an antibody is an IgG3 antibody. In some embodiments, an antibody is an IgG2 antibody. In some embodiments, an antibody is an IgG4 antibody.

[0112] In some embodiments, a Fc region described herein is derived from an IgG heavy chain constant domain or an IgA heavy constant domain. In some embodiments, the IgG heavy chain constant domain comprises an IgGl heavy chain constant domain. In some embodiments, the IgGl heavy chain constant domain comprises a human IgGl heavy chain constant domain. An amino acid sequence of wildtype human IgGl heavy chain constant domain is provided in TABLE 9. In some embodiments, the Fc region is engineered to not bind to Fc gamma receptor (FcyR). In some embodiments, the FcyR comprises FcyRI, FcyRII and FcyRIII.TABLE 9. Amino acid sequence of Fc region of human IgGlAtorney Docket No. 220710-705601

[0113] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprises an Fc region. In some embodiments, a subunit of an Fc region comprises any one of the sequences recited in TABLE 9. In some embodiments, a subunit of an Fc region can comprise one or more modifications. In some embodiments, a subunit of an Fc region comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen, at least fifteen or more modifications relative to any one of the sequences recited in TABLE 9. In some embodiments, a subunit of an Fc region comprises at least one modification relative to any one of the sequences recited in TABLE 9. In some embodiments, a subunit of an Fc region comprises an amino acid sequence that is at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 97%, or 100% identical relative to any one of the sequences recited in TABLE 9.

[0114] The FcRn receptor can specifically bind to the Fc region of monoclonal antibodies and Fc fusion proteins, but this binding ability is regulated by pH value. Fc fusion proteins and antibody molecules can be taken up by cells through pinocytosis. Once the protein is endocytosed, the FcRn receptor binds to the antibody or Fc fusion protein with high affinity under acidic pH conditions,Atorney Docket No. 220710-705601 and then the antibody or Fc fusion protein is released into the blood circulation system through exocytosis. Alternatively, the FcRn receptor bound antibody or Fc fusion protein remains present on the surface of the cell. The pH during exocytosis is consistent with the blood circulation system. At this time, the affinity of the antibody or Fc fusion protein to FcRn is greatly reduced, so it can be successfully released from the cell membrane. During the endocytosis process, some antibodies or Fc fusion proteins fail to bind to FcRn or fall off during the binding process, and are then taken into lysosomes and degraded. Accordingly, in some embodiments, the engineered antibodies described herein have high affinity in serum. However, once the antigen-antibody complex is endocytosed into the cell and enters under acidic condition in endosomes, the binding affinity decreases significantly, allowing the antigen to be quickly released and subsequently degraded in lysosomes. Meanwhile, the released engineered antibody will bind the FcRn receptor and re-enter into blood circulation to play its role. Alternatively, the FcRn receptor bound engineered antibody can remain on cell surface. pH-dependent TL1 A binding activity also accelerates the clearance of TL1A antigen in lysosomes, thereby reducing the level of TL1A in circulation and increasing the effective exposure of the engineered TL1A binding antibodies.

[0115] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprising a subunit of an Fc region having at least one modification, wherein the Fc region has increased binding affinity for a neonatal fragment crystallizable receptor (FcRn) in acidic pH condition relative to a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof comprises an Fc region described herein have at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more increase in binding affinity for a neonatal fragment crystallizable receptor (FcRn) in acidic pH condition relative to a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof comprising an Fc region described herein have less than 5%, less than 10%, less than 15%, less than 20%, less than 25%, less than 30%, less than 50% change in binding affinity for a neonatal fragment crystallizable receptor (FcRn) in neutral pH condition relative to binding affinity for a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof have binding affinity for a neonatal fragment crystallizable receptor (FcRn) in neutral pH condition that remains within 5%, 10%, 15%, 20%, 25%, 30%, or 50% relative to binding affinity for a corresponding target bindingAtorney Docket No. 220710-705601 region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof have altered pharmacokinetics (e.g., decreased plasma clearance (CL), increased plasma retention time, and / or increased plasma half-life (t’ )) relative to binding affinity for a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification.

[0116] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprising a modified Fc region have increased binding affinity for a neonatal fragment crystallizable receptor (FcRn) in neutral pH condition relative to binding affinity for a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof have increase in binding affinity by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more for a neonatal fragment crystallizable receptor (FcRn) in neutral pH condition relative to binding affinity for a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof have less than 5%, less than 10%, less than 15%, less than 20%, less than 25%, less than 30%, less than 50% change in binding affinity for a neonatal fragment crystallizable receptor (FcRn) in acidic pH condition relative to binding affinity for a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof have binding affinity for a neonatal fragment crystallizable receptor (FcRn) in acidic pH condition that remains within 5%, 10%, 15%, 20%, 25%, 30%, or 50% relative to binding affinity for a corresponding target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification. In some embodiments, the target binding regions (or domains), the variants thereof or the functional fragments thereof have increased ability of antigen e.g., TL1A, a variant thereof, or a functional fragment thereof) plasma clearance relative to a corresponding clearance of a reference target binding region (or domain), variant thereof or functional fragment thereof prior to the at least one modification prior to the at least one modification.

[0117] In some embodiments, a binding affinity of the Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in acidic pH condition, and wherein a binding affinity of the Fc region for the FcRn in neutral pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to the amino acid modification. In someAtorney Docket No. 220710-705601 embodiments, the binding affinity for the FcRn is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more in acidic pH condition. In some embodiments, at least one amino acid modification in Fc region decreases plasma clearance (CL), increases plasma retention time, or increases plasma half-life (t’ ) of the TL1 A binding engineered antibody, compared to a corresponding antibody prior to the amino acid modification

[0118] In some embodiments, a binding affinity of the Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in neutral pH condition, and wherein a binding affinity of the Fc region for the FcRn in acidic pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to the amino acid modification. In some embodiments, the binding affinity for the FcRn in neutral pH condition is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more. In some embodiments, at least one amino acid modification in Fc region increases antigen plasma clearance by the TL1A binding engineered antibody, compared to a corresponding antibody prior to the amino acid modification

[0119] In some embodiments, an Fc region described herein comprises one or more modifications that increase Fc dimerization, enhance antibody stability, extend antibody half-life, reduce effector function, reduce the immunogenicity of the antibody, reduce post-translational modifications of the antibody or combinations thereof. In some embodiments, one or more modifications enhance binding to FcRn and / or effector function-silencing mutations.

[0120] In some embodiments, an Fc subunit described herein comprises an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to a corresponding parent amino acid sequence of the Fc subunit of IgGl (SEQ ID NO: 86). In some embodiments, an Fc subunit described herein comprises one or more modifications relative to a corresponding parent amino acid sequence of the Fc subunit of IgGl (SEQ ID NO: 86). In some embodiments, the Fc subunit of IgGl comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen modifications relative to a corresponding parent amino acid sequence of SEQ ID NO: 86. In some embodiments, the Fc subunit described herein comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen deletions, substitutions, additions or combinations thereof relative to a corresponding parent amino acid sequence of SEQ ID NO: 86. In some embodiments, the Fc subunit described herein comprises at least one, at least two, at least three, at least four, at least five, at least six, at leastAtorney Docket No. 220710-705601 seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen substitutions relative to a corresponding parent amino acid sequence of SEQ ID NO: 86.

[0121] In some embodiments, an Fc subunit described herein is derived from a human IgGl heavy chain constant region (or domain). In some embodiments, the Fc subunit comprises at least one substitution, at least two substitutions, at least three substitutions, at least four substitutions, at least five substitutions, at least six substitutions or at least seven substitutions relative to the human IgGl heavy chain constant region (or domain). In some embodiments, the at least one substitution is selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265, V266, S267, H268,E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281, V282, E283, V284,H285, N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297, S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323, S324, N325, K326, A327,L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the at least two substitutions are selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265, V266, S267, H268, E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281, V282, E283, V284, H285, N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297, S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323, S324, N325, K326, A327, L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the at least three substitutions are selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265,V266, S267, H268, E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281,V282, E283, V284, H285, N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297,S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323,S324, N325, K326, A327, L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the at least four substitutions are selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265, V266, S267, H268, E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281, V282, E283, V284, H285,Attorney Docket No. 220710-705601N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297, S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323, S324, N325, K326, A327, L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the at least five substitutions are selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265, V266, S267, H268, E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281, V282, E283, V284, H285, N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297, S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323, S324, N325, K326, A327, L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the at least six substitutions are selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265,V266, S267, H268, E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281,V282, E283, V284, H285, N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297,S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323,S324, N325, K326, A327, L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the at least seven substitutions are selected from positions D221, K222, T223, H224, T225, C226, P227, P228, C229, P230, A231, P232, E233, L234, L235, G236, G237, P238, S239, V240, F241, F243, P244, P245, K246, P247, D249, M252, S254, R255, T256, E258, T260, V262, V263, V264, D265, V266, S267, H268, E269, D270, P271, E272, V273, K274, F275, N276, Y278, D280, G281, V282, E283, V284, H285, N286, K288, K290, P291, R292, E293, E294, Q295, Y296, N297, S298, T299, Y300, R301, V302, V303, S304, V305, W313, K317, E318, K320, K322, V323, S324, N325, K326, A327, L328, P329, A330, P331, 1332, E333, K334, T335, 1336, S337, P396, and N297, per EU numbering. In some embodiments, the substitution at position D221 comprise D221K, and D221 Y substitutions. In some embodiments, the substitution at position K222 comprises K222E, and K222Y substitutions. In some embodiments, the substitution at position T223 comprises T223E, and T223K substitutions. In some embodiments, the substitution at position H224 comprises H224E, and H224Y substitutions. In some embodiments, the substitution at position T225 comprises T225E, T225K, and T225W substitutions. In some embodiments, the substitution at position C226 comprise C226S substitution. In some embodiments, the substitution at position P227 comprises P227E, P227G, P227K, and P227Y substitutions. In some embodiments, the substitution at position P228 comprises P228E, P228G, P228K, and P228Y substitutions. In some embodiments,Attorney Docket No. 220710-705601 the substitution at position C229 comprises C229S substitution. In some embodiments, the substitution at position P230 comprises P230A, P230E, P230G, and P230Y substitutions. In some embodiments, the substitution at position A231 comprises A231E, A231G, A231K, A231P, and A231Y substitutions. In some embodiments, the substitution at position P232 comprises P232E, P232G, P232K, and P232Y substitutions. In some embodiments, the substitution at position E233 comprises E233A, E233D, E233F, E233G, E233H, E233I, E233K, E233L, E233M, E233N, E233Q, E233R, E233P, E233S, E233T, E233V, E233W, and E233Y substitutions. In some embodiments, the substitution at position L234 comprises L234A, L234D, L234E, L234F, L234G, L234H, L234I, L234K, L234M, L234N, L234P, L234Q, L234R, L234S, L234T, L234V, L234W, and L234Y substitutions. In some embodiments, the substitution at position L235 comprises L235A, L235D, L235E, L235F, L235G, L235H, L235I, L235K, L235M, L235N, L235P, L235Q, L235R, L235S, L235T, L235V, L235W, and L235Y substitutions. In some embodiments, the substitution at position G236 comprises G236A, G236D, G236E, G236F, G236H, G236I, G236K, G236L, G236M, G236N, G236P, G236Q, G236R, G236S, G236T, G236V, G236W, and G236Y substitutions. In some embodiments, the substitution at position G237 comprises G237A, G237D, G237E, G237F, G237H, G237I, G237K, G237L, G237M, G237N, G237P, G237Q, G237R, G237S, G237T, G237V, G237W, and G237Y substitutions. In some embodiments, the substitution at position P238 comprises P238A, P238D, P238E, P238F, P238G, P238H, P238I, P238K, P238L, P238M, P238N, P238Q, P238R, P238S, P238T, P238V, P238W, and P238Y substitutions. In some embodiments, the substitution at position S239 comprises S239D, S239E, S239F, S239G, S239H, S239I, S239K, S239L, S239M, S239N, S239P, S239Q, S239R, S239T, S239V, S239W, and S239Y substitutions. In some embodiments, the substitution at position V240 comprises V240A, V240I, V240M, and V240T substitutions. In some embodiments, the substitution at position F241 comprises F24 ID, F241E, F241L, F241R, F241S, F241W, and F241Y substitutions. In some embodiments, the substitution at position F243 comprises F243E, F243H, F243L, F243Q, F243R, F243W, and F243 Y substitutions. In some embodiments, the substitution at position P244 comprises P244H substitution. In some embodiments, the substitution at position P245 comprises P245A substitution. In some embodiments, the substitution at position K246 comprises K246D, K246E, K246H, and K246Y substitutions. In some embodiments, the substitution at position P247 comprises P247G, and P247V substitutions. In some embodiments, the substitution at position D249 comprises D249H, D249Q, and D249Y substitutions. In some embodiments, the substitution at position M252 comprises M252Y substitution. In some embodiments, the substitution at position S254 comprises S254T substitution. In some embodiments, the substitution at position R255 comprises R255E, and R255Y substitutions. In some embodiments, the substitution at position T256 comprises T256E substitution. In some embodiments, the substitution at positionAttorney Docket No. 220710-705601E258 comprises E258H, E258S, and E258Y substitutions. In some embodiments, the substitution at position T260 comprises T260D, T260E, T260H, and T260Y substitutions. In some embodiments, the substitution at position V262 comprises V262A, V262E, V262F, V262I, and V262T substitutions. In some embodiments, the substitution at position V263 comprises V263 A, V263I, V263M, and V263T substitutions. In some embodiments, the substitution at position V264 comprises V264A, V264D, V264E, V264F, V264G, V264H, V264I, V264K, V264L, V264M, V264N, V264P, V264Q, V264R, V264S, V264T, V264W, and V264Y substitutions. In some embodiments, the substitution at position D265 comprises D265A, D265F, D265G, D265H, D265I, D265K, D265L, D265M, D265N, D265P, D265Q, D265R, D265S, D265T, D265V, D265W, and D265Y substitutions. In some embodiments, the substitution at position V266 comprises V266A, V266I, V266M, and V266T substitutions. In some embodiments, the substitution at position S267 comprises S267D, S267E, S267F, S267H, S267I, S267K, S267L, S267M, S267N, S267P, S267Q, S267R, S267T, S267V, S267W, and S267Y substitutions. In some embodiments, the substitution at position H268 comprises H268A, H268D, H268E, H268F, H268G, H268I, H268K, H268L, H268M, H268P, H268Q, H268R, H268T, H268V, and H268W substitutions. In some embodiments, the substitution at position E269 comprises E269F, E269G, E269H, E269I, E269K, E269L, E269M, E269N, E269P, E269R, E269S, E269T, E269V, E269W, and E269Y substitutions. In some embodiments, the substitution at position D270 comprises D270A, D270F, D270G, D270H, D270I, D270L, D270M, D270P, D270Q, D270R, D270S, D270T, D270W, and D270Y substitutions. In some embodiments, the substitution at position P271 comprises P271 A, P271D, P271E, P271F, P271G, P271H, P271I, P271K, P271L, P271M, P271N, P271Q, P271R, P271S, P271T, P271V, P271W, and P271Y substitutions. In some embodiments, the substitution at position E272 comprises E272D, E272F, E272G, E272H, E272I, E272K, E272L, E272M, E272P, E272R, E272S, E272T, E272V, E272W, and E272Y substitutions. In some embodiments, the substitution at position V273 comprises V273I substitution. In some embodiments, the substitution at position K274 comprises K274D, K274E, K274F, K274G, K274H, K274I, K274L, K274M, K274N, K274P, K274R, K274T, K274V, K274W, and K274Y substitutions. In some embodiments, the substitution at position F275 comprises F275L, and F275W substitutions. In some embodiments, the substitution at position N276 comprises N276D, N276E, N276F, N276G, N276H, N276I, N276L, N276M, N276P, N276R, N276S, N276T, N276V, N276W, and N276Y substitutions. In some embodiments, the substitution at position Y278 comprises Y278D, Y278E, Y278G, Y278H, Y278I, Y278K, Y278L, Y278M, Y278N, Y278P, Y278Q, Y278R, Y278S, Y278T, Y278V, and Y278W substitutions. In some embodiments, the substitution at position D280 comprises D280G, D280K, D280L, D280P, and D280W substitutions. In some embodiments, the substitution at position G281 comprises G281D,Attorney Docket No. 220710-705601G281E, G281K, G281N, G281P, G281Q, and G281Y substitutions. In some embodiments, the substitution at position V282 comprises V282E, V282G, V282K, V282P, and V282Y substitutions. In some embodiments, the substitution at position E283 comprises E283G, E283H, E283K, E283L, E283P, E283R, and E283 Y substitutions. In some embodiments, the substitution at position V284 comprises V284D, V284E, V284L, V284N, V284Q, V284T, and V284Y substitutions. In some embodiments, the substitution at position H285 comprises H285D, H285E, H285K, H285Q, H285W, and H285Y substitutions. In some embodiments, the substitution at position N286 comprises N286E, N286G, N286P, and N286Y substitutions. In some embodiments, the substitution at position K288 comprises K288D, K288E, and K288Y substitutions. In some embodiments, the substitution at position K290 comprises K290D, K290H, K290L, K290N, and K290W substitutions. In some embodiments, the substitution at position P291 comprises P291D, P291E, P291G, P291H, P291I, P291Q, and P291T substitutions. In some embodiments, the substitution at position R292 comprises R292D, R292E, R292P, R292T, and R292Y substitutions. In some embodiments, the substitution at position E293 comprises E293F, E293G, E293H, E293I, E293L, E293M, E293N, E293P, E293R, E293S, E293T, E293V, E293W, and E293Y substitutions. In some embodiments, the substitution at position E294 comprises E294F, E294G, E294H, E294I, E294K, E294L, E294M, E294P, E294R, E294S, E294T, E294V, E294W, and E294Y substitutions. In some embodiments, the substitution at position Q295 comprises Q295D, Q295E, Q295F, Q295G, Q295H, Q295I, Q295M, Q295N, Q295P, Q295R, Q295S, Q295T, Q295V, Q295W, and Q295Y substitutions. In some embodiments, the substitution at position Y296 comprises Y296A, Y296D, Y296E, Y296G, Y296H, Y296I, Y296K, Y296L, Y296M, Y296N, Y296Q, Y296R, Y296S, Y296T, and Y296V substitutions. In some embodiments, the substitution at position N297 comprises N297A, N297D, N297E, N297F, N297G, N297H, N297I, N297K, N297L, N297M, N297P, N297Q, N297R, N297S, N297T, N297V, N297W, and N297Y substitutions. In some embodiments, the substitution at position S298 comprises S298D, S298E, S298F, S298H, S298I, S298K, S298M, S298N, S298Q, S298R, S298T, S298W, and S298Y substitutions. In some embodiments, the substitution at position T299 comprises T299A, T299D, T299E, T299F, T299G, T299H, T299I, T299K, T299L, T299M, T299N, T299P, T299Q, T299R, T299S, T299V, T299W, and T299Y substitutions. In some embodiments, the substitution at position Y300 comprises Y300A, Y300D, Y300E, Y300G, Y300H, Y300K, Y300L, Y300M, Y300N, Y300P, Y300Q, Y300R, Y300S, Y300T, Y300V, and Y300W substitutions. In some embodiments, the substitution at position R301 comprises R301D, R301E, R301H, and R301 Y substitutions. In some embodiments, the substitution at position V302 comprises V302I substitution. In some embodiments, the substitution at position V303 comprises V303D, V303E, and V303 Y substitutions. In some embodiments, the substitution at position S304Attorney Docket No. 220710-705601 comprises S304D, S304H, S304L, S304N, and S304T substitutions. In some embodiments, the substitution at position V305 comprises V305E, V305T, and V305Y substitutions. In some embodiments, the substitution at position W313 comprises W313F substitution. In some embodiments, the substitution at position K317 comprises K317E, and K317Q substitutions. In some embodiments, the substitution at position E318 comprises E318H, E318L, E318Q, E318R, and E318Y substitutions. In some embodiments, the substitution at position K320 comprises K320D, K320F, K320G, K320H, K320I, K320L, K320N, K320P, K320S, K320T, K320V, K320W, and K320Y substitutions. In some embodiments, the substitution at position K322 comprises K322A, K322D, K322F, K322G, K322H, K322I, K322P, K322Q, K322S, K322T, K322V, K322W, and K322Y substitutions. In some embodiments, the substitution at position V323 comprises V323I substitution. In some embodiments, the substitution at position S324 comprises S324D, S324F, S324G, S324H, S324I, S324L, S324M, S324P, S324R, S324T, S324V, S324W, and S324Y substitutions. In some embodiments, the substitution at position N325 comprises N325A, N325D, N325E, N325F, N325G, N325H, N325I, N325K, N325L, N325M, N325P, N325Q, N325R, N325S, N325T, N325V, N325W, and N325Y substitutions. In some embodiments, the substitution at position K326 comprises K326I, K326L, K326P, and K326T substitutions. In some embodiments, the substitution at position A327 comprises A327D, A327E, A327Q, A327G, A327H, A327I, A327K, A327L, A327M, A327N, A327P, A327R, A327S, A327T, A327V, A327W, and A327Y substitutions. In some embodiments, the substitution at position L328 comprises L328A, L328D, L328E, L328F, L328G, L328H, L328I, L328K, L328M, L328N, L328P, L328Q, L328R, L328S, L328T, L328V, L328W, and L328Y substitutions. In some embodiments, the substitution at position P329 comprises P329A, P329D, P329E, P329F, P329G, P329H, P329I, P329K, P329L, P329M, P329N, P329Q, P329R, P329S, P329T, P329V, P329W, and P329Y substitutions. In some embodiments, the substitution at position A330 comprises A330E, A330F, A330G, A330H, A330I, A330L, A330M, A330N, A330P, A330R, A330S, A330T, A330V, A330W, and A330Y substitutions. In some embodiments, the substitution at position P331 comprises P33 ID, P33 IF, P331H, P33 II, P33 IL, P33 IM, P33 IQ, P331R, P331 S, P331T, P331V, P331W, and P331Y substitutions. In some embodiments, the substitution at position 1332 comprises I332A, I332D, I332E, I332F, 1332H, 1332K, I332L, I332M, I332N, I332P, I332Q, I332R, I332S, I332T, I332V, I332W, and I332Y substitutions. In some embodiments, the substitution at position E333 comprises E333F, E333H, E333I, E333L, E333M, E333P, E333T, and E333 Y substitutions. In some embodiments, the substitution at position K334 comprises K334F, K334I, K334L, K334P, and K334T substitutions. In some embodiments, the substitution at position T335 comprises T335D, T335F, T335G, T335H, T335I, T335L, T335M, T335N, T335P, T335R, T335S, T335V, T335W, and T335Y substitutions. In some embodiments,Atorney Docket No. 220710-705601 the substitution at position 1336 comprises I336E, I336K, and I336Y substitutions. In some embodiments, the substitution at position S337 comprises S337E, S337H, and S337N substitutions. In some embodiments, the substitution at position P396 comprises P396L substitution.

[0122] In some embodiments, a human IgGl Fc subunit (or domain) described herein comprises two substitutions. In some embodiments, the two substitutions are located at positions L234 and L235, per EU numbering. In some embodiments, the two substitutions are L234A and L235A substitutions.

[0123] In some embodiments, a human IgGl Fc subunit (or domain) described herein comprises three substitutions. In some embodiments, the three substitutions are located at positions L234, L235 and P329, per EU numbering. In some embodiments, the three substitutions are L234A, L235A and P329A substitutions, per EU numbering. In some embodiments, the three substitutions are L234A, L235A and P329G substitutions, per EU numbering. In some embodiments, the three substitutions are located at positions M252, S254 and T256, per EU numbering. In some embodiments, the three substitutions are M252Y, S254T and T256E substitutions, per EU numbering.

[0124] In some embodiments, a human IgGl Fc subunit (or domain) described herein comprises one or more substitutions according to at least one group selected from: (1) L234A, L235A and P329A; (2) M252Y, S254T and T256E; (3) N287A; and (4) D265A, per EU numbering. Accordingly, in some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, can comprise: (1) one or modifications of amino acids that can result in pH-dependent target binding activity; and (2) one or more substitutions in a human IgGl Fc subunit (or domain) of the target binding regions (or domains), the variants thereof or the functional fragments thereof according to at least one group selected from: (a) L234A, L235A and P329G; (b) M252Y, S254T and T256E; (c) N287A; and (d) D265A, per EU numbering.

[0125] In some embodiments, a human IgGl Fc subunit (or domain) described herein comprises one or more substitutions according to at least one group selected from: (1) L234A, L235A and P329G; (2) M252Y, S254T and T256E; (3) N287A; and (4) D265A, per EU numbering. Accordingly, in some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, can comprise: (1) one or more modifications of amino acids that can result in pH-dependent target binding activity; and (2) one or more substitutions in a human IgGl Fc subunit (or domain) of the target binding regions (or domains), the variants thereof or the functional fragments thereof according to at least one group selected from: (a) L234A, L235A and P329G; (b) M252Y, S254T and T256E; (c) N287A; and (d) D265A,Atorney Docket No. 220710-705601 per EU numbering.

[0126] In some embodiments, a human IgGl Fc subunit (or domain) described herein comprises one or more substitutions according to at least one group selected from: (1) S239D, A330L, I332E, S239D, A330Y, I332E, L234I, S239D, A330Y, I332E, and V266I; (2) S239D, D265F, N297D, and I332E; (3) S239D, D265H, N297D, and I332E; (4) S239D, D265I, N297D, and I332E; (5) S239D, D265L, N297D, and I332E; (6) S239D, D265T, N297D, and I332E; (7) S239D, D265Y, N297D, and I332E; (8) S239D, E272I, A330L, and I332E; (9) S239D, E272I, and I332E; (10) S239D, E272K, A330L, and I332E; (11) S239D, E272K, and I332E; (12) S239D, E272S, A330L, and I332E; (13) S239D, E272S, and I332E; (14) S239D, E272Y, A330L, and I332E; (15) S239D, E272Y, and I332E; (16) S239D, F241S, F243H, V262T, V264T, N297D, A330Y, and I332E; (17) S239D, and H268D; (18) S239D, and H268E; (19) S239D, and I332D; (20) S239D, and I332E; (21) S239D, I332E, and A327D; (22) S239D, I332E, and A330I; (23) S239D, I332E, and A330Y; (24) S239D, I332E, and E272H; (25) S239D, I332E, and E272R; (26) S239D, I332E, and E283H; (27) S239D, I332E, and E283L; (28) S239D, I332E, and G236A; (29) S239D, I332E, and G236S; (30) S239D, I332E, and H268D; (31) S239D, I332E, and H268E; (32) S239D, I332E, and K246H; (33) S239D, I332E, and R255Y; (34) S239D, I332E, and S267E; (35) S239D, I332E, and V264I; (36) S239D, I332E, V264I, and A330L; (37) S239D, I332E, V264I, and S298A; (38) S239D, I332E, and V284D; (39) S239D, I332E, and V284E; (40) S239D, I332E, and V284E; (41) S239D, and I332N; (42) S239D, and I332Q; (43) S239D, K274E, A330L, and I332E; (44) S239D, K274E, and I332E; (45) S239D, K326E, A330L, and I332E; (46) S239D, K326E, A330Y, and I332E; (47) S239D, K326E, and I332E; (48) S239D, K326T, A330Y, and I332E; (49) S239D, K326T, and I332E; (50) S239D, N297D, A330Y, and I332E; (51) S239D, N297D, and I332E; (52) S239D, N297D, K326E, and I332E; (53) S239D, S267E, A330L, and I332E; (54) S239D, S267E, and I332E; (55) S239D, S298A, K326E, and I332E; (56) S239D, S298A, K326T, and I332E; (57) S239D, V240I, A330Y, and I332E; (58) S239D, V264T, A330Y, and I332E; (59) S239D, Y278T, A330L, and I332E; (60) S239D, Y278T, and I332E; (61) S239E, and D265G; (62) S239E, and D265N; (63) S239E, and D265Q; (64) S239E, and I332E; (65) S239E, and I332N; (66) S239E, and I332Q; (67) S239E, N297D, and I332E; (68) S239E, V264I, A330Y, and I332E; (69) S239E, V264I, and I332E; (70) S239E, V264I, S298A, A330Y, and I332E; (71) S239N, and I332D; (72) S239N, and I332E; (73) S239N, I332E, and A330L; (74) S239N, I332E, and A330Y; (75) S239N, and I332N; (76) S239N, and I332Q; (77) S239Q, and I332D; (78) S239Q, and I332E; (79) S239Q, and I332N; (80) S239Q, and I332Q; (81) S239Q, V264I, and I332E; (82) F241E, F243Q, V262T, V264E, and I332E; (83) F241E, F243Q, V262T, and V264E; (84) F241E, F243R, V262E, V264R, and I332E; (85) F241E, F243R, V262E, and V264R; (86) F241E, F243Y, V262T, V264R, and I332E; (87) F241E, F243Y, V262T, and V264R; (88) F241L, F243L, V262I, and V264I; (89)Attorney Docket No. 220710-705601F241L, and V262I; (90) F241R, F243Q, V262T, V264R, and I332E; (91) F241R, F243Q, V262T, and V264R; (92) F241W, and F243W; (93) F241W, F243W, V262A, and V264A; (94) F241Y, F243 Y, V262T, V264T, N297D, and I332E; (95) F241 Y, F243 Y, V262T, and V264T; (96) F243L, V262I, and V264W; (97) F243L, and V264I; (98) P244H, P245A, and P247V; (99) V264E, N297D, and I332E; (100) V264I, A330L, and I332E; (101) V264I, A330Y, and I332E; (102) V264I, and I332E; (103) D265Y, N297D, and I332E; (104) D265Y, N297D, T299L, and I332E; (105) S267E, and A327D; (106) S267E, and P331D; (107) S267E, and S324I; (108) S267E, and V282G; (109) S267L, and A327S; (110) S267Q, and A327S; (111) Y278W, E283R, and V302I; (112) G281D, and V282G; (113) V282G, and P331D; (114) E283R, V302I, Y278W, and E283R; (115) N297D, and I332E; (116) N297D, I332E, S239D, and D265V; (117) N297D, I332E, and T299E; (118) N297D, I332E, and T299F; (119) N297D, I332E, and T299H; (120) N297D, I332E, and T299I; (121) N297D, I332E, and T299L; (122) N297D, I332E, and T299V; (123) N297D, I332E, and Y296D; (124) N297D, I332E, and Y296E; (125) N297D, I332E, and Y296H; (126) N297D, I332E, and Y296N; (127) N297D, I332E, and Y296Q; (128) N297D, I332E, and Y296T; (129) N297E, and I332E; (130) N297S, and I332E; (131) S298A, and I332E; (132) S298A, and K326E; (133) S298A, K326E, and K334L; (134) S298A, and K334L; (135) S324I, and A327D; (136) L328D, and I332E; (137) L328E, and I332E; (138) L328H, and I332E; (139) L328I, and I332E; (140) L328I, and I332E; (141) L328M, and I332E; (142) L328N, and I332E; (143) L328Q, and I332E; (144) L328Q, and I332E; (145) L328T, and I332E; (146) L328V, and I332E; (147) A330L, and I332E; (148) A330Y, and I332E; (149) I332E, and G281D; (150) I332E, and H268D; (151) I332E, and H268E; (152) I332E, S239D, and S298A; (153) I332E, S239N, and S298A; (154) I332E, V264I, and S298A; (155) I332E, and V284E; (156) S239E, and I332D; (157) Y278W, and V302I; (158) N297D, I332E, and A330Y; (159) N297D, I332E, S239D, and A330L; and (160) N297D, I332E, S298A, and A330Y, per EU numbering.

[0127] In some embodiments, the Fc subunit comprises an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to a corresponding parent sequence of the Fc subunit of IgG2 (SEQ ID NO: 87).

[0128] In some embodiments, the Fc subunit described herein comprises one or more modifications relative to a corresponding parent sequence of the Fc subunit of IgG2 (SEQ ID NO: 87). In some embodiments, the Fc subunit of IgG2 comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen modifications relative to a corresponding parent sequence of SEQ ID NO: 87. In some embodiments, the Fc subunit described herein comprises at least one, at least two, at least three, at least four, at leastAtorney Docket No. 220710-705601 five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen deletions, substitutions, additions or combinations thereof relative to a corresponding parent sequence of SEQ ID NO: 87. In some embodiments, the Fc subunit described herein comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen substitutions relative to a corresponding parent sequence of SEQ ID NO: 87.

[0129] In some embodiments, a Fc subunit described herein is derived from a human IgG2 Fc subunit (or domain). In some embodiments, the Fc subunit comprises at least one substitution, at least two substitutions, at least three substitutions, at least four substitutions, at least five substitutions, at least six substitutions or at least seven substitutions relative to the human IgG2 Fc subunit (or domain). In some embodiments, the at least one substitution is selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, perEU numbering. In some embodiments, the at least two substitutions are selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, per EU numbering. In some embodiments, the at least three substitutions are selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, per EU numbering. In some embodiments, the at least four substitutions are selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, per EU numbering. In some embodiments, the at least five substitutions are selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, per EU numbering. In some embodiments, the at least six substitutions are selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, per EU numbering. In some embodiments, the at least seven substitutions are selected from positions C232, C233, V234, G237, P238, M252, S254, T256, H268, N297, V309, A330, and P331, perEU numbering. In some embodiments, the substitution at position C232 comprises C232S substitution. In some embodiments, the substitution at position C233 comprises C233S substitution. In some embodiments, the substitution at position V234 comprises V234A substitution. In some embodiments, the substitution at position G237 comprises G237A substitution. In some embodiments, the substitution at position P238 comprises P238S substitution. In some embodiments, the substitution at position M252 comprises M252Y substitution. In some embodiments, the substitution at position S254 comprises S254T substitution. In some embodiments, the substitution at position T256 comprises T256E substitution. In some embodiments, the substitution at position H268 comprises H268A, H268E and H268Q substitutions. In some embodiments, the substitution at position N297 comprise N297A andAtorney Docket No. 220710-705601N297Q substitutions. In some embodiments, the substitution at position N297 comprises N297A substitution. In some embodiments, the substitution at position V309 comprises V309L substitution. In some embodiments, the substitution at position A330 comprises A330S substitution. In some embodiments, the substitution at position P331 comprises P331S substitution.

[0130] In some embodiments, the Fc subunit comprises an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to a corresponding parent sequence of the Fc subunit of IgG4 (SEQ ID NO: 88).

[0131] In some embodiments, the Fc subunit described herein comprises one or more modifications relative to a corresponding parent sequence of the Fc subunit of IgG4 (SEQ ID NO: 88). In some embodiments, the Fc subunit of IgG4 comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen modifications relative to a corresponding parent sequence of SEQ ID NO: 88. In some embodiments, the Fc subunit described herein comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen deletions, substitutions, additions or combinations thereof relative to a corresponding parent sequence of SEQ ID NO: 88. In some embodiments, the Fc subunit described herein comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen or at least fifteen substitutions relative to a corresponding parent sequence of SEQ ID NO: 88.

[0132] In some embodiments, a Fc subunit described herein is derived from a human IgG4 Fc subunit (or domain). In some embodiments, the Fc subunit comprises at least one substitution, at least two substitutions, at least three substitutions, at least four substitutions, at least five substitutions, at least six substitutions or at least seven substitutions relative to the human IgG4 Fc subunit (or domain). In some embodiments, the at least one substitution is selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, and T394, per EU numbering. In some embodiments, the at least two substitutions are selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, and T394, per EU numbering. In some embodiments, the at least three substitutions are selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, and T394, per EU numbering. In some embodiments, the at least four substitutions are selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, andAttorney Docket No. 220710-705601T394, per EU numbering. In some embodiments, the at least five substitutions are selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, and T394, per EU numbering. In some embodiments, the at least six substitutions are selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, and T394, per EU numbering. In some embodiments, the at least seven substitutions are selected from positions S228, E233, F234, L235, L236, G237, S241, L248, M252, S254, T256, N297, E318, and T394, per EU numbering. In some embodiments, the substitution at position S228 comprises S228P substitution. In some embodiments, the substitution at position E233 comprises E233P substitution. In some embodiments, the substitution at position F234 comprises F234V substitution. In some embodiments, the substitution at position L235 comprises L235A substitution. In some embodiments, the substitution at position G237 comprises G237A substitution. In some embodiments, the substitution at position S241 comprises S241P substitution. In some embodiments, the substitution at position L248 comprises L248E substitution. In some embodiments, the substitution at position M252 comprises M252Y substitution. In some embodiments, the substitution at position S254 comprises S254T substitution. In some embodiments, the substitution at position T256 comprises T256E substitution. In some embodiments, the substitution at position N297 comprises N297A and N297Q substitutions. In some embodiments, the substitution at position N297 comprises N297A substitution. In some embodiments, the substitution at position E318 comprises E318A substitution. In some embodiments, the substitution at position T394 comprises T394D substitution.

[0133] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprising a modified Fc region has a longer half-life relative to the target binding regions (or domains), the variants thereof or the functional fragments thereof comprising unmodified Fc region. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more modifications at M252, S254, and T256 positions, wherein the modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit comprises one or more of M252Y, S254T, and T256E modifications relative to corresponding wildtype Fc subunit, wherein the modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of M428L and N434S modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regionsAttorney Docket No. 220710-705601(or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of T307A, E380A, and N434A modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of T250Q and M428L modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of T307Q, Q311V, and A378V modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of T256D, H286D, T307R, Q311V, and A378V modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of H285D, T307Q, and A378V modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of T256D, Q311V, and A378V modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of H285N, T307Q, and N315D modifications relative to corresponding wildtype Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof. In some embodiments, a modified Fc subunit of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise one or more of L235A and G237A modifications relative to corresponding wildtypeAtorney Docket No. 220710-705601Fc subunit, wherein the one or more modifications extend half-life of the target binding regions (or domains), the variants thereof or the functional fragments thereof.

[0134] In some embodiments, an engineered antibody or the functional fragment thereof described herein comprises Fc region. In some embodiments, the Fc region is derived from a human IgGl Fc region. In some embodiments, the Fc region comprises a first Fc subunit and a second Fc subunit. In some embodiments, the first Fc subunit is engineered to comprise a knob, and the second Fc subunit is engineered to comprise a hole. Accordingly, in some embodiments, the first Fc subunit comprises a modification at position T366, per EU numbering, and the second Fc subunit comprises a modification at position Y407, per EU numbering. In some embodiments, the first Fc subunit comprises a modification at position T366, per EU numbering, and the second Fc subunit comprises modifications at positions T366 and Y407, per EU numbering. In some embodiments, the first Fc subunit comprises a modification at position T366, per EU numbering, and the second Fc subunit comprises modifications at positions T366, L368 and Y407, per EU numbering. In some embodiments, the first Fc subunit comprises S354C substitution, T366W substitution, or a combination thereof, per EU numbering, and the second Fc subunit comprises Y349C substitution, T366S substitution, Y407V substitution, or a combination thereof, per EU numbering. In some embodiments, a human IgGl Fc subunit described herein comprises substitutions that are located at positions L234, L235 and P329, per EU numbering. In some embodiments, a human IgGl Fc subunit described herein comprises L234A, L235A and P329G substitutions, per EU numbering. In some embodiments, a human IgGl Fc subunit described herein comprises substitutions that are located at positions M252, S254 and T256, per EU numbering. In some embodiments, a human IgGl Fc subunit described herein comprises M252Y, S254T and T256E substitutions, per EU numbering. In some embodiments, in some embodiments, the first and second Fc subunits comprise L234A, L235A, M252Y, S254C, T256E, and P329G substitutions, per EU numbering, In some embodiments, in some embodiments, the first Fc subunit comprises L234A, L235A, M252Y, S254C, T256E, P329G, S354C, and T366W substitutions, per EU numbering. In some embodiments, the first Fc subunit comprises L234A, L235A, M252Y, S254T, T256E, P329G, Y349C, T366S, and Y407V substitutions, per EU numbering.

[0135] In some embodiments, an engineered antibody or the functional fragment thereof described herein comprises Fc region. In some embodiments, the Fc region is derived from a human IgGl Fc region. In some embodiments, the Fc region comprises a first Fc subunit and a second Fc subunit. In some embodiments, the first Fc subunit comprises at least two modifications and the second Fc subunit comprises at least one modification. For example, in some embodiments, the first Fc subunit comprises at least two modifications selected fromAtorney Docket No. 220710-705601 modifications at positions L351, F405 and Y407, per EU numbering, and the second Fc subunit comprises at least one modification selected from modifications at positions T366, K392 and T394, per EU numbering. In some embodiments, the modification at position L351 comprises L351Y and L351A substitutions. In some embodiments, the modification at position F405 comprises F405A, F405S, F405T and F405V substitutions. In some embodiments, the modification at position Y407 comprises Y407A, Y407V, Y407S and Y407I substitutions. In some embodiments, the modification at position T366 comprises T366L, T366M, T366V and T366I substitutions. In some embodiments, the modification at position K392 comprises K392C, K392M, K392L, K392I, K392E, K392D and K392F substitutions. In some embodiments, the modification at position T394 comprises T394D, T394W, T394V and T394S substitutions. In some embodiments, the at least two modifications of the first Fc subunit further comprise one or more modifications at positions Q347, Y349, T350, K370, G371, D399 and / or S400, per EU numbering. In some embodiments, the modification at position Q347 comprises Q347R, Q347E and Q347K substitutions. In some embodiments, the modification at position Y349 comprises Y349C substitution. In some embodiments, the modification at position T350 comprises T350V substitution. In some embodiments, the modification at position K370 comprises K370T substitution. In some embodiments, the modification at position G371 comprises G371D and G371S substitutions. In some embodiments, the modification at position D399 comprises D399C, D399R and D399K substitutions. In some embodiments, the modification at position S400 comprises S400D, S400K, S400E and S400R substitutions. In some embodiments, the at least two modifications of the second Fc subunit further comprises one or more modifications at positions T350, S354, E357, K360, Q362E, S364, N390, K409 and T411, perEU numbering. In some embodiments, the modification at position T350 comprises T350V substitution. In some embodiments, the modification at position S354 comprises S354C substitution. In some embodiments, the modification at position E357 comprises E357Q substitution. In some embodiments, the modification at position K360 comprises K360D and K360E substitutions. In some embodiments, the modification at position Q362 comprises Q362E substitution. In some embodiments, the modification at position S364 comprises S364R substitution. In some embodiments, the modification at position N390 comprises N390K, N390R, N390D and N390E substitutions. In some embodiments, the modification at position K409 comprises K409L, K409M, K409F and K409W substitutions. In some embodiments, the modification at position T411 comprises T411R, T411D, T411I, T411K, T411E, T411N, T411S and T411L substitutions.

[0136] Alternatively, in some embodiments, an engineered antibody or a functional fragment thereof described herein comprises Fc region that are derived from a human IgGl Fc region,Atorney Docket No. 220710-705601 wherein the Fc region comprise a first Fc subunit and a second Fc subunit, wherein the first Fc subunit and the second Fc subunit are engineered to electrostatically interact with each other. In some embodiments, the first Fc subunit comprises a substitution at K370, per EU numbering, with a negatively charged amino acid residue (e.g., aspartic acid, glutamic acid), and the second Fc subunit comprises a substitution at E357, per EU numbering, with a positively charged amino acid residue (e.g., arginine, lysine, histidine). In some embodiments, the first Fc subunit comprises a substitution at K392 or K409, per EU numbering, with a negatively charged amino acid residue (e.g., aspartic acid, glutamic acid), and the second Fc subunit comprises a substitution at D399, per EU numbering, with a positively charged amino acid residue (e.g., arginine, lysine, histidine). In some embodiments, the first Fc subunit comprises a substitution at K439, per EU numbering, with a negatively charged amino acid residue (e.g., aspartic acid, glutamic acid), and the second Fc subunit comprises a substitution at D356, per EU numbering, with a positively charged amino acid residue (e.g., arginine, lysine, histidine).

[0137] In some embodiments, target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, can be used for subcutaneous administration. In some embodiments, a modified Fc region of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, comprise a deletion of c-terminal lysine relative to corresponding wild-type Fc region. In some embodiments, a deletion of c-terminal lysine of an Fc region of target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, improve subcutaneous bioavailability of the target binding regions (or domains), the variants thereof or the functional fragments thereof. Accordingly, in some embodiments, subcutaneous administration of an effective amount of a composition comprising target binding regions (or domains), variants thereof or functional fragments thereof, as described herein, to a subject in need thereof results in treatment of a disease or condition, wherein the target binding regions (or domains), the variants thereof or the functional fragments thereof comprise a modified Fc region, wherein the modified Fc region comprises a deletion of a c-terminal lysine relative to corresponding wild-type Fc region.Engineered Antibodies

[0138] Described herein are engineered antibodies, variants thereof, or functional fragments thereof can bind TL1 A, a variant thereof or a fragment thereof. In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof can bind one or more epitopes on TL1A, a variant thereof or a fragment thereof. In some embodiments, engineered antibodies can bind at least one epitope on TL1 A, a variant thereof or a fragment thereof. In some embodiments, engineered antibodies can bind at least two different epitopes of TL1A, a variant thereof or aAtorney Docket No. 220710-705601 fragment thereof. In some embodiments, engineered antibodies can bind the same epitope on TL1 A, a variant thereof or a fragment thereof.

[0139] There are five major classes of antibodies: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g., IgGl, IgG2, IgG3, IgG4, IgAl, and IgA2. The heavy chain constant domains that correspond to the different classes of immunoglobulins are called a, 5, a, y, and p, respectively. Accordingly, engineered antibodies described herein comprise kappa constant region, lambda constant region, alpha constant region, gamma constant region, delta constant region, epsilon constant region, mu constant region, a functional fragment thereof, or a combination thereof.

[0140] A class of antibody or immunoglobulin refers to the type of constant domain or constant region possessed by its heavy chain. In some embodiment, the heavy chain is an IgA. In some embodiment, the heavy chain is an IgD. In some embodiment, the heavy chain is an IgE. In some embodiment, the heavy chain is an IgG. In some embodiment, the heavy chain is an IgM. In some embodiment, the heavy chain is an IgGl. In some embodiment, the heavy chain is an IgG2. In some embodiment, the heavy chain is an IgG3. In some embodiments, the heavy chain is an IgG4. In some embodiment, the heavy chain is an IgAl. In some embodiment, the heavy chain is an IgA2. In some embodiments, an antibody is an IgGl antibody.

[0141] In some embodiments, an antibody is an IgG3 antibody. In some embodiments, an antibody is an IgG2 antibody. In some embodiments, an antibody is an IgG4 antibody.

[0142] In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof as described herein comprise two target binding regions (or domains). Accordingly, in some embodiments, engineered antibodies, variants thereof, or functional fragments thereof as described comprise two heavy chains. In some embodiments, the two heavy chains are at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 97% or 100% identical to each other. In some embodiments, the two heavy chains are nonidentical to each other. In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof as described comprise two light chains. In some embodiments, the two light chains are at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 97% or 100% identical to each other. In some embodiments, the two light chains are nonidentical to each other. In some embodiments, the two TL1A binding heavy chain variable domains are fused to each other by a linker comprising an amino acid sequence of GGGGSGGGGS (SEQ ID NO: 173). In some embodiments, the TL1 A binding heavy chain variable domain is fused to an Fc subunit by a linker comprising an amino acid sequence of GGGGSGGGGS (SEQ ID NO: 173). In some embodiments, the engineered antibodies described herein comprise histidine free CDRs. In some embodiments, the engineeredAtorney Docket No. 220710-705601 antibodies described herein comprise common light chain variable domain. In some embodiments, the common light chain variable domain does not interact with TL1 A.

[0143] In some embodiments, light chains described herein comprise kappa light chain or lambda light chain. Engineered antibodies such as kappa or lambda antibodies can be made using any of a variety of art-recognized techniques. In some embodiments, engineered antibodies, variants thereof, or functional fragments thereof as described comprise two constant regions. In some embodiments, the two constant regions are at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 97% or 100% identical to each other. In some embodiments, the two constant regions are nonidentical to each other.

[0144] Various techniques for making and isolating engineered antibody functional fragments directly from recombinant cell culture have also been described. For example, engineered antibodies have been produced using leucine zippers. The leucine zipper peptides from the Fos and Jun proteins can be linked to the Fab' portions of two different antibodies by gene fusion. Antibody homodimers can be reduced at the hinge region to form monomers and then re-oxidized to form antibody heterodimers. FIG. 1A shows an exemplary structure of a dimer that has a disulfide linkage in the hinge region. This method can also be utilized for producing antibody homodimers. “Diabody” technology provides an alternative mechanism for making engineered antibody functional fragments. Functional fragments of engineered antibodies comprise a heavychain variable domain (VH) connected to a light-chain variable domain (VL) by a linker which is too short to allow pairing between the two domains on the same chain. Accordingly, VH and VL domains of one functional fragment can be forced to pair with complementary VL and VH domains of another functional fragment, thereby forming two target-binding sites. Another strategy for making engineered antibody functional fragments includes the use of single-chain Fv (sFv) dimers.

[0145] In some embodiments, an interface between a pair of target binding regions (or domains) described herein is engineered to maximize percentage of heterodimers which are recovered from recombinant cell culture. In this method, one or more small amino acid side chains from the interface of the first target binding region (or domain) are replaced with larger side chains to form a protuberance or knob (e.g., tyrosine or tryptophan). Compensatory cavities or holes of identical or similar size to large side chain(s) are created on interface of the second target binding region (or domain) by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine). This provides a mechanism for increasing yield of the heterodimers over other unwanted end-products such as homodimers.

[0146] In some embodiments, antibodies described herein a binding affinity for TL1 A, a variant thereof or a functional fragment thereof that is at least 10%, at least 20%, at least 30%, at leastAtorney Docket No. 220710-70560150%, at least 80%, at least 100%, at least 200% or more higher under neutral pH condition relative to the binding affinity under acidic pH condition. In some embodiments, antibodies described herein comprise a ratio of binding affinities for TL1A, a variant thereof or a functional fragment under neutral pH condition and acidic pH condition is at least 1.1, 1.5, 2, 3, 5, 8, 10, 100 or more. In some embodiments, antibodies described herein comprise a binding affinity for TL1 A, a variant thereof or a functional fragment thereof that is at least 10%, at least 20%, at least 30%, at least 50%, at least 80%, at least 100%, at least 200% or more higher at about pH 7.4 relative to the binding affinity at about pH 5.8. In some embodiments, antibodies described herein comprise a ratio of binding affinities for TL1 A, a variant thereof or a functional fragment at about pH 7.4 and about pH 5.8 is at least 1.1, 1.5, 2, 3, 5, 8, 10, 100 or more. In some embodiments, at least one amino acid modification in TL1A binding heavy chain variable region increases half-life of antibodies described herein by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to half-life of a corresponding antibody prior to said at least one amino acid modification. In some embodiments, antibodies described herein comprise a binding affinity for trimeric TL1 A is at least 10%, at least 20%, at least 30%, at least 50%, at least 80%, at least 100%, at least 200% or more higher than the binding affinity for monomeric TL1 A under neutral pH condition. In some embodiments, antibodies described herein comprise a binding affinity for trimeric TL1 A is at least 10%, at least 20%, at least 30%, at least 50%, at least 80%, at least 100%, at least 200% or more higher than the binding affinity for monomeric TL1 A at about pH 7.4.

[0147] Provided herein are compositions comprising a TL1A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1A binding engineered antibody comprises: (a) at least three TL1A binding regions, each comprising a TL1 A binding heavy chain variable (VH) domain; and (b) an engineered Fc region that comprises a first and a second subunit capable of stable association. In some embodiments, two of the at least three heavy chain variable regions are directly or indirectly linked to the first subunit of an Fc region of the TL1 A binding engineered antibody. In some embodiments, at least one of the at least three TL1 A binding regions comprise at least one amino acid modification that changes an isoelectric point (pl) of the TL1A binding engineered antibody relative to a pl of a corresponding antibody prior to the amino acid modification, thereby resulting in pH-dependent binding activity in said TL1A binding engineered antibody, as measured by surface plasmon resonance spectroscopy.

[0148] In some embodiments, engineered antibodies described herein comprise three TL1A binding regions. In some embodiments, at least two of the three TL1A binding regions (e.g., two TL1 A binding regions, three TL1 A binding regions) target different epitopes of the TL1 A protein.Atorney Docket No. 220710-705601In some embodiments, at least two of the three TL1A binding regions (e.g., two TL1A binding regions, three TL1A binding regions) target the same epitope of the TL1A protein. In some embodiments, a first TL1 A Fab fragment of a First TL1 A binding region and a second TL1 A Fab fragment of a second TL1 A binding region are fused to N-terminal end of a Fc region, wherein N- terminal end of the first TL1A Fab fragment is fused to C-terminal end of a third TL1A Fab fragment of a third TL1 A binding region (FIG. IB). In some embodiments, C-terminal end of a first TL1A Fab fragment of a first TL1A binding region and a second TL1A Fab fragment of a second TL1 A binding region are fused to N-terminal end of an Fc region, wherein N-terminal end of a third TL1 A Fab fragment of a third TL1 A binding region is fused to C-terminal end of the Fc region (FIG. ID)

[0149] In some embodiments, engineered antibodies described herein comprise four TL1A binding regions. In some embodiments, at least two of the four TL1A binding regions (e.g., two TL1A binding regions, three TL1A binding regions, four TL1A binding regions) target different epitopes of the TL1 A protein. In some embodiments, at least two of the four TL1 A binding regions (e.g., two TL1A binding regions, three TL1A binding regions, four TL1A binding regions) target same epitope of the TL1A protein. In some embodiments, C-terminal end of a first TL1A Fab fragment of a First TL1A binding region and a second TL1A Fab fragment of a second TL1A binding region are fused to N-terminal end of a Fc region, wherein N-terminal end of the first TL1A Fab fragment is fused to C-terminal end of a third TL1A Fab fragment of a third TL1A binding region, and wherein N-terminal end of the second TL1A Fab fragment is fused to C- terminal end of a fourth TL1 A Fab fragment of a fourth TL1 A binding region. (FIG. 1C). In some embodiments, C-terminal end of a first TL1A fragment of a First TL1A binding region and a second TL1A Fab fragment of a second TL1A binding region are fused to N-terminal end of an Fc region, wherein N-terminal end of a third TL1 A Fab fragment of a third TL1 A binding region and a fourth TL1 A Fab fragment of a fourth TL1 A binding region are fused to C-terminal end of the Fc region (FIG. IE).

[0150] In some embodiments, engineered antibodies described herein comprise two TL1 A binding regions, and an engineered Fc region that comprises a first and a second subunit capable of stable association. In some embodiments, the two heavy chain variable regions are directly or indirectly linked to the engineered Fc region of the TL1A binding engineered antibody. In some embodiments, the two TL1A binding regions comprise a first VH domain and a second VH domain. In some embodiments, the first VH domain and the second VH domain are directly or indirectly linked to the first subunit of the engineered FC region. In some embodiments, the first VH domain and the second VH domain are directly or indirectly linked to the first subunit and the second subunit of the engineered FC region, respectively. In some embodiments, at least one TL1 AAtorney Docket No. 220710-705601 binding region further comprises a light chain variable (VL) domain. In some embodiments, the two TL1A binding regions further comprise two VL domains, wherein the two VL domains are identical. In some embodiments, the two TL1 A binding regions further comprise two VL domains, wherein the two VL domains are distinct.

[0151] In some embodiments, engineered antibodies described herein comprise three TL1A binding regions, and an engineered Fc region that comprises a first and a second subunit capable of stable association. In some embodiments, at least two of the three TL1 A binding regions target different epitopes of the TL1A protein. In some embodiments, at least two of the three TL1A binding regions target the same epitope of the TL1A protein. In some embodiments, the three TL1 A binding regions comprise a first VH domain, a second VH domain and a third VH domain. In some embodiments, a C-terminus of the first VH domain is linked to a N-terminus of the second VH domain, and wherein a C-terminus of the second VH domain is linked to a N-terminus of the first subunit of the engineered Fc region. In some embodiments, a C-terminus of the first VH domain is linked to a N-terminus of the first subunit of the engineered Fc region, and a N-terminus of the second VH domain is linked to a C-terminus of the first subunit of the engineered Fc region. In some embodiments, at least two of the first VH domain, the second VH domain and the third VH domain are identical. In some embodiments, the first VH domain, the second VH domain and the third VH domain are identical. In some embodiments, the first VH domain, the second VH domain and the third VH domain are distinct. In some embodiments, at least one TL1A binding region further comprises a light chain variable (VL) domain. In some embodiments, at least two of the three TL1 A binding regions further comprise two VL domains, wherein the two VL domains are identical. In some embodiments, at least two of the three TL1A binding regions further comprise two VL domains, wherein the two VL domains are distinct. In some embodiments, the three TL1A binding regions further comprise three VL domains, wherein the three VL domains are identical.

[0152] In some embodiments, engineered antibodies described herein comprise four TL1A binding regions, and an engineered Fc region that comprises a first and a second subunit capable of stable association. In some embodiments, the four TL1 A binding regions comprises a first VH domain, a second heavy variable region, a third VH domain and a fourth VH domain. In some embodiments, a C-terminus of the first VH domain is linked to a N-terminus of the VH domain, a C-terminus of the second VH domain is linked to a N-terminus of the first subunit of the engineered Fc region, a C-terminus of the third VH domain is linked to a N-terminus of the fourth VH domain, and a C-terminus of the fourth VH domain is linked to a N-terminus of the second subunit of the engineered Fc region. In some embodiments, a C-terminus of the first VH domain is linked to a N-terminus of the second VH domain, a C-terminus of the second VH domain is linked to a N-Atorney Docket No. 220710-705601 terminus of the first subunit of the engineered Fc region, a C-terminus of the third VH domain is linked to a N-terminus of the fourth VH domain, and a C-terminus of the fourth VH domain is linked to a N-terminus of the second subunit of the engineered Fc region. In some embodiments, at least two of the first VH domain, the second VH domain, the third VH domain and the fourth VH domain are identical. In some embodiments, the first VH domain, the second VH domain, the third VH domain and the fourth VH domain are identical. In some embodiments, the first VH domain, the second VH domain, the third VH domain and the fourth VH domain are distinct. In some embodiments, at least one TL1 A binding region further comprises a light chain variable (VL) domain. In some embodiments, at least two of the four TL1A binding regions further comprise two VL domains, wherein the two VL domains are identical. In some embodiments, at least two of the four TL1 A binding regions further comprise two VL domains, wherein the two VL domains are distinct. In some embodiments, the four TL1A binding regions further comprise four VL domains, wherein the four VL domains are identical.

[0153] In some embodiments, engineered antibodies described herein comprise at least one modification in one or more TL1 A binding regions. In some embodiments, the at least one amino acid modification changes an isoelectric point (pl) of the engineered antibody relative to a pl of a corresponding antibody prior to the amino acid modification, thereby resulting in pH-dependent binding activity in the engineered antibody. In some embodiments, a binding affinity of the engineered antibody to TL1 A epitope is at least 75%, at least 85%, at least 95%, at least 100%, at least 110%, at least 120%, at least 130%, at least 150%, at least 200% or more of the binding affinity of a corresponding antibody prior to the amino acid modification. In some embodiments, the at least one amino acid modification increases a binding affinity of the engineered antibody for TL1 A epitope in neutral pH condition relative to a corresponding antibody prior to the amino acid modification. In some embodiments, the at least one amino acid modification increases the binding affinity by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to a corresponding antibody prior to the amino acid modification un neutral pH. In some embodiments, the at least one amino acid modification reduces binding affinity of the TL1 A binding engineered antibody for TL1 A epitope in acidic pH condition by at least 5%, at least 10%, at least 20%, at least 30% or more relative to a corresponding antibody prior to the amino acid modification. In some embodiments, the at least one amino acid modification increases a binding affinity of the TL1 A binding engineered antibody for the epitope in trimeric TL1 A in neutral pH condition relative to a corresponding antibody prior to the amino acid modification. In some embodiments, the amino acid modification increases a binding affinity of the TL1A binding engineered antibody for the epitope in monomeric TL1A in neutral pH condition relative to a corresponding antibody prior to the amino acid modification. In someAtorney Docket No. 220710-705601 embodiments, the binding affinity is measured by surface plasmon resonance spectroscopy.Modifications for homodimer or heterodimer

[0154] Methods for making antibodies are known in the art. Traditionally, the recombinant production of antibodies is based on the co-expression of two target binding regions (or domains), each comprising an immunoglobulin heavy-chain / light-chain pair. The purification of the correct region (or domain) is usually accomplished by affinity chromatography steps.

[0155] Described herein are engineered antibodies or a functional fragment thereof comprise a kappa light chain constant region. In some embodiments, an engineered antibody or a functional fragment thereof comprises a light chain variable region. In some embodiments, an engineered antibody or a functional fragment thereof comprises a heavy chain variable region. In some embodiments, an engineered antibody or a functional fragment thereof comprises a light chain variable region and an IgG heavy chain variable region. In some embodiments, an engineered antibody or a functional fragment thereof can be a humanized antibody or a functional fragment thereof. In some embodiments, an engineered antibody or a functional fragment thereof can be a chimeric antibody or a functional fragment thereof. In some embodiments, an engineered antibody or a functional fragment thereof can be a human antibody or a functional fragment thereof. In some embodiments, an engineered antibody or a functional fragment thereof comprises a common light chain (L chain). In some embodiments, the L chain acts against a specific target. The use of a common light chain can prioritize heterodimerization in an Fc region. In some embodiments, the L chain comprises a knob mutation. In some embodiments, the L chain comprises a hole mutation. In some embodiments, preferential heterodimer formation is preferred upon binding of an engineered antibody or a functional fragment thereof comprising a common L chain. In some embodiments, the formations of heterodimeric pairs are assembled using glutathione disulfide exchange.

[0156] The Fc region can interact with FcRn. The circulating half-life of an antibody can be affected by modulating the Fc region-FcRn interaction. An increase in the circulating half-life of an antibody may be achieved through increased binding to FcRn and result in improved efficacy, reduced dosage or frequency of administration, or improved delivery to the target. US7371826, which is incorporated herein by reference, discloses that one or more amino acid modifications at positions 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434 of the Fc region, wherein the numbering of the residues in the Fc region is that of the EU index as in Kabat, can increase binding of the Fc region to FcRn, and, thereby, increase circulating / effective half-life of an antibody comprising the Fc region.

[0157] In some embodiments, an engineered antibody or the functional fragment thereof describedAtorney Docket No. 220710-705601 herein comprises one or more amino acid modifications that can result in pH-dependent target binding activity. In some embodiments, an engineered antibody or the functional fragment thereof described herein can exhibit pH-dependent target binding activity for a target epitope on TL1 A, a variant thereof and a fragment thereof. In some embodiments, an engineered antibody or a functional fragment thereof as described herein can readily bind to a target peptide at a neutral pH and dissociates from the target peptide at an acidic pH. Accordingly, upon administration to a subject the engineered antibody or the functional fragment thereof can bind the target peptide in plasma on account of its neutral pH, while remaining dissociated from the target peptide in endosomes which have an acidic pH. Dissociation of the engineered antibody or the functional fragment thereof from the target peptide in endosomes can facilitate recycling of the engineered antibody or the functional fragment thereof into plasma through FcRn, whereas the target peptide can be trafficked to lysosome and degraded. Such characteristics of the engineered antibody or the functional fragment thereof can allow sweeping of a target peptide from the plasma. Accordingly, in some embodiments, the engineered antibody or the functional fragment thereof can comprise a target peptide sweeping activity for a target peptide that is selected from TL1 A, a variant thereof and a fragment thereof.

[0158] In some embodiments, an engineered antibody or the functional fragment thereof described herein comprises one or more modifications of amino acids that can result in increased FcRn binding at neutral pH. In such embodiments, the engineered antibody or the functional fragment thereof can have increased ability to repeatedly bind to FcRn and remove target peptide from plasma. Alternatively, in some embodiments, an engineered antibody or the functional fragment thereof described herein comprises one or more modifications of amino acids that can result in increased FcRn binding at acidic pH. In such embodiments, the engineered antibody or the functional fragment thereof can have increased recycling efficiency from endosomes to plasma resulting in improving plasma retention of the engineered antibody or the functional fragment thereof. Accordingly, in some embodiments, a constant region (or domain) of an engineered antibody or the functional fragment thereof as described herein can be further modified for increasing FcRn binding activity at neutral pH and / or acidic pH.

[0159] In some embodiments, an engineered antibody or a functional fragment thereof described herein comprises one or more modifications of amino acids that can result in a change of isoelectric point of the engineered antibody or the functional fragment thereof. In some embodiments, the one or more modifications of amino acids can result in change of isoelectric point of a VH sequence of the engineered antibody or the functional fragment thereof. In some embodiments, the one or more modifications of amino acids can result in change of isoelectric point of a VL sequence of the engineered antibody or the functional fragment thereof. In some embodiments, the one or moreAtorney Docket No. 220710-705601 amino acid modifications can increase isoelectric point of the engineered antibody or the functional fragment thereof. In some embodiments, increased isoelectric point can results in increased elimination rate of target peptides from plasma.

[0160] In some embodiments, an engineered antibody or the functional fragment thereof comprises one or more modifications of amino acids that can result in pH-dependent target binding activity and / or increased FcRn binding activity. In some embodiments, the one or more modifications of amino acids comprise at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen, or at least fifteen amino acid modifications. In some embodiments, the one or more modifications of amino acids are in at least one of a Fab region, a scFv region, and a Fc region. In some embodiments, one or more modifications of amino acids of an engineered antibody or a functional fragment thereof are in a VL sequence, a VH sequence, or a combination thereof. In some embodiments, a modification of an amino acid is a deletion, a substitution, or an addition of the amino acid.

[0161] In some embodiments, engineered antibodies described herein have higher binding affinity for TL1A trimer relative to TL1A monomer. In some embodiments, engineered antibodies described herein comprising two or more TL1A binding regions (e.g., two, three, or four) have enhanced antibody recycling ability relative to their counterpart parent antibody having one TL1 A binding region. In some embodiments, the engineered antibodies can bind more than one TL1A molecule per antibody molecule. In some embodiments, the engineered antibodies comprising two TL1A binding regions can bind more TL1A molecules per antibody molecule relative to corresponding antibody having one TL1A binding region. In some embodiments, engineered antibodies described herein bind more TL1 A relative to corresponding antibody having one TL1 A binding region, wherein the engineered antibodies have lower binding affinity for TL1 A relative to the corresponding antibody having one TL1 A binding region.

[0162] Moreover, TL1A binding engineered antibodies can avoid forming Ab-Ag complexes, a known adverse effect of targeting INF-family members. Accordingly, in some embodiments, engineered antibodies described herein have enhanced immunogenicity profile (e.g., reduced immunogenicity). In some embodiments, engineered antibodies described herein have reduced aggregation, relative to their counterpart parent antibody having one TL1A binding region. In some embodiments, engineered antibodies comprising one or more modifications have reduced aggregation, relative to their counterpart parent antibody having higher affinity TL1A binders. Accordingly, engineered antibodies described herein comprise affinity tuned antibodies that limit immunogenicity and toxicity by preventing large antibody-antigen aggregate formation. In some embodiments, engineered antibodies comprise affinity-tuned aTLIA that ensures 1 :1Atorney Docket No. 220710-705601 stoichiometry. In some embodiments, engineered antibodies provided herein comprise antibodies with conditional binding affinity, which limits antibody-associated TMDD, thereby increasing antibody half-life. In some embodiments, the engineered antibody comprises conditional aTLIA that facilitates TL1 A degradation and antibody recycling.

[0163] In some embodiments, the engineered antibody provided herein reduces the induction of anti-drug antibodies. TL1 A, as with all I F-family members, is a self-assembling trimeric protein complex and because TNF-family members have three identical epitopes per complex, antibodyantigen aggregate formation and ADA frequency increase. In some embodiments, the engineered antibody provided herein comprises identical affinity-tuned TL1A binding arms that mandate a 1 : 1 drug-TLl A trimer relationship.

[0164] Disclosed herein are trivalent TL1A binding antibodies. In some embodiments, the trivalent TL1A binding antibodies comprise three TL1A binding regions, as described herein. In some embodiments, at least two of the three TL1A binding regions target the same epitope of TL1 A. In some embodiments, each of the three TL1 A binding regions target different epitope of TL1 A. Also disclosed herein are tetravalent TL1 A binding antibodies. In some embodiments, the tetravalent TL1 A binding antibodies comprise four TL1 A binding regions, as described herein. In some embodiments, at least two of the four TL1A binding regions target the same epitope of TL1A. In some embodiments, each of the four TL1A binding regions target different epitope of TL1A.Common light chain

[0165] In some embodiments, engineered multivalent antibodies disclosed herein comprise a common light chain. Accordingly, in some embodiments, the common light chain does not interact with target epitope. In some embodiments, the common light chain, which forms an antigen binding region with heavy chain that can interact with epitope of a target antigen, does not interact with epitope of the target antigen. In some embodiments, a common light chain, as described herein, comprises a common light chain variable domain. In some embodiments, common light chain variable domains, variants thereof or functional fragments thereof, as described herein, comprise at least one of CDR-Ls described in TABLE 5 or a variant thereof. In some embodiments, common light chain variable domains, variants thereof or functional fragments thereof, as described herein, comprise any one of CDR-L1 described in TABLE 12 or a variant thereof, any one of CDR-L2 described in TABLE 5 or a variant thereof, and any one of CDR-L3 described in TABLE 5 or a variant thereof. In some embodiments, common light chain variable domains, variants thereof or functional fragments thereof, as described herein, comprise any one of combinations of CDR-Ls or variants thereof described in TABLE 5. In some embodiments,Atorney Docket No. 220710-705601CDR-L variants described herein comprise at least one, at least two or at least three substitutions, deletions, additions, or combination thereof relative to a corresponding parent CDR-L sequence described in TABLE 5. In some embodiments, CDR-Ls or variants thereof comprises an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to a corresponding parent CDR-L sequence described in TABLE 5. In some embodiments, CDR-Ls or variants thereof comprise amino acid sequences that have at least 1, at least 2, at least 3, at least 4, or at least 5 amino acid modifications relative to a corresponding parent CDR-L sequences described in TABLE 5.

[0166] In some embodiments, common light chain variable domains, variants thereof or functional fragments thereof, as described herein, comprise an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to the VL sequence described in TABLE 7.

[0167] In some embodiments, engineered antibodies described herein comprises two light chains, wherein neither of the two light chains interact with epitope of target antigen (e.g. , TL 1 A). In some embodiments, the two light chains are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical relative to each other. In some embodiments, the two light chains are non-identical relative to each other. In some embodiments, engineered antibodies described herein comprises two light chains variable domains, wherein neither of the two light chain variable domains interact with epitope of target antigen (e.g, TL1 A). In some embodiments, the two light chain variable domains are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical relative to each other. In some embodiments, the two light chain domains are nonidentical relative to each other.

[0168] In some embodiments, engineered antibodies described herein comprises three light chains, wherein none of the three light chains interact with epitope of target antigen (e.g, TL1 A). In some embodiments, at least two of the three light chains are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical relative to each other. In some embodiments, at least two of the three light chains are non-identical relative to each other. In some embodiments, engineered antibodies described herein comprise three light chains variable domains, wherein none of the three light chain variable domains interact with epitope of target antigen (e.g., TL1A). In some embodiments, at least two of the three light chain variable domains are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical relative to each other. In some embodiments, at least two of the three light chain domains are non-identical relative to each other.

[0169] In some embodiments, engineered antibodies described herein comprise four light chains,Atorney Docket No. 220710-705601 wherein none of the four light chains interact with epitope of target antigen (e.g., TL1 A). In some embodiments, at least two of the four light chains are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical relative to each other. In some embodiments, at least two of the four light chains are non-identical relative to each other. In some embodiments, engineered antibodies described herein comprises four light chains variable domains, wherein none of the four light chain variable domains interact with epitope of target antigen (e.g., TL1A). In some embodiments, at least two of the four light chain variable domains are at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100% identical relative to each other. In some embodiments, at least two of the four light chain domains are non-identical relative to each other.

[0170] In some embodiments, an engineered antibody described herein has TL1 A binding affinity of about 0.1 nM, about 1 nm, about 10 nM, about 50 nM, about 100 nM at pH 7.4. In some embodiments, an engineered antibody described herein has TL1A binding affinity that is more than 10 times weaker at pH 5.8 than at pH 7.4. In some embodiments, an engineered antibody described herein has TL1 A binding with faster off-rate at low pH than at neutral pH.

[0171] In some embodiments, an engineered antibody or the functional fragment thereof described herein comprises two constant subunits (or domains). In some embodiments, the two constant subunits (or domains) are derived from a human IgGl heavy constant region (or domain). In some embodiments, the two constant subunits (or domains) are a first constant subunit (or domain) and a second constant subunit (or domain). In some embodiments, the first constant subunit (or domain) is engineered to comprise a knob, and the second constant subunit (or domain) is engineered to comprise a hole. Accordingly, in some embodiments, the first constant subunit (or domain) comprises a modification at position T366, per EU numbering, and the second constant subunit (or domain) comprises a modification at position Y407, per EU numbering. In some embodiments, the first constant subunit (or domain) comprises a modification at position T366, per EU numbering, and the second constant subunit (or domain) comprises modifications at positions T366 and Y407, per EU numbering. In some embodiments, the first constant subunit (or domain) comprises a modification at position T366, per EU numbering, and the second constant subunit (or domain) comprises modifications at positions T366, L368 and Y407, per EU numbering. In some embodiments, the first constant subunit (or domain) comprises S354C substitution, T366W substitution, or a combination thereof, per EU numbering, and the second constant subunit (or domain) comprises Y349C substitution, T366S substitution, Y407V substitution, or a combination thereof, per EU numbering.

[0172] Alternatively, in some embodiments, an engineered antibody or a functional fragment thereof described herein comprises two constant domains (or subunits) that are derived from aAtorney Docket No. 220710-705601 human IgGl heavy chain constant subunit (or domain), wherein the two constant domains (or subunits) comprise a first constant domain (or subunit) and a second constant domain (or subunit), wherein the first constant domain (or subunit) and the second constant domain (or subunit) are engineered to electrostatically interact with each other. In some embodiments, the first constant subunit (or domain) comprises a substitution at K370, per EU numbering, with a negatively charged amino acid residue (e.g., aspartic acid, glutamic acid), and the second constant subunit (or domain) comprises a substitution at E357, per EU numbering, with a positively charged amino acid residue (e.g., arginine, lysine, histidine). In some embodiments, the first constant subunit (or domain) comprises a substitution at K392 or K409, per EU numbering, with a negatively charged amino acid residue (e.g., aspartic acid, glutamic acid), and the second constant subunit (or domain) comprises a substitution at D399, per EU numbering, with a positively charged amino acid residue (e.g., arginine, lysine, histidine). In some embodiments, the first constant subunit (or domain) comprises a substitution at K439, per EU numbering, with a negatively charged amino acid residue (e.g., aspartic acid, glutamic acid), and the second constant subunit (or domain) comprises a substitution at D356, per EU numbering, with a positively charged amino acid residue (e.g., arginine, lysine, histidine).BiTE antibody

[0173] In some embodiments, the antibodies described herein comprises a bi-specific T-cell engager (BiTE) antibody construct and may be referred to herein as a “BiTE domain”. A BiTE antibody construct is a type of fusion protein. In some embodiments, the BiTE domain activates T-cell activity. In some embodiments, the BiTE domain comprises two single-chain variable functional fragments. In some embodiments, the BiTE domain comprises two target binding regions (or domains). In some embodiments, at least one of the two target binding regions (or domains) is a TL1A binding domain. In some embodiments, the BiTE domain comprises two identical binding regions (or domains). Accordingly, in some embodiments, the BiTE domain comprises two TL1A binding regions (or domains). In some embodiments, the BiTE domain comprises two non-identical target binding regions (or domains). Accordingly, in some embodiments, the BiTE domain comprises two nonidentical TL1 A binding regions (or domains), wherein each TL1 A binding domain targets different target epitope.Recombinant multispecific antibodies

[0174] Recombinant multispecific antibodies described herein comprise two nonidentical target binding regions (or domains). In some embodiments, at least one of the two nonidentical target binding regions (or domains) can be a TL1A binding region (or domain). In some embodiments,Atorney Docket No. 220710-705601 both nonidentical target binding regions (or domains) of multispecific antibodies described herein are TL1 A binding regions (or domains), wherein each TL1 A binding region (or domain) targets a different TL1 A specific epitope. In some embodiments, one of the two nonidentical target binding regions (or domains) of multispecific antibodies described herein is a TL1A binding region (or domain).

[0175] The majority of multispecific antibody formats can be generated by genetic engineering techniques using antibody functional fragments, such as scFv or Fab fragments, as building blocks connected via polypeptide linkers. Formats based on linked antibody functional fragments include tandem scFv (BiTE), diabodies and tandem-diabodies. These formats include diabody-Fc, tandem diabody-Fc, tandem diabody-CH3, (scFv)4-Fc and DVD-Ig. In some embodiments, the multispecific antibody is a Fab2 antibody, a bis-scFv antibody, a diabody, a DVD-Ig, a TandAb, a tandem scFv-Fc, a one-armed tandem scFv-Fc, a DART, a DART-Fc, or a functional fragment thereof.

[0176] Strategies based on forcing the heterodimerization of two heavy chains have been explored. A first approach coined 'knob into hole' aims at forcing the pairing of two different IgG heavy chains by introducing mutations into the CH3 domains to modify the contact interface. On one chain amino acids with large side chains were introduced, to create a 'knob'. Conversely, bulky amino acids were replaced by amino acids with short side chains to create a 'hole' into the other CH3 domain. By co-expressing these two heavy chains, more than 90% heterodimer formation was observed ('knob- hole') versus homodimers formation ('hole -hole' or 'knob-knob'). A similar concept was developed using strand- exchange engineered domain (SEED) human CH3 domains based on human IgG and human IgA sequences. These engineered domains lead to the formation of heterodimeric domains that can carry two different specificities.

[0177] Recently an improvement over the 'knob into hole' approach; "CrossMab" has been described in WO 2009 / 080253 Al. This method involves the exchange of some of the light chain and heavy chain domains in addition to the 'knob into hole' mutations.Chemical Cross-Linking.

[0178] The use of chemical cross-linking reagents to covalently link two antibodies is known in the art. Antibody functional fragments generated from their respective parent antibodies by enzymatic digestion or generated through recombinant technologies may be conjugated using bifunctional.Atorney Docket No. 220710-705601Single domain antibodies

[0179] The immune systems of camelids (lamas and camels) and cartilaginous fish (nurse sharks) use single V-domains fused to a Fc demonstrating that a single domain can confer high affinity binding to a target. Camelid, shark and even human V domains represent alternatives to antibodies, but they also be used for multispecific antibody generation. They can be reformatted into an IgG antibody in which each arm has the potential to bind two targets either via its VH or VL domain. Engineered target binding domains, engineered antibodies, variants thereof, or functional fragments thereof as described herein can be made by any process disclosed in the application or otherwise known in the art.Dual variable domain Immunoglobulin

[0180] Exemplary biparatopic antibodies can comprise individually encoded peptides or "segments" which, in a single continuous chain, would comprise a compact tertiary structure. The component peptides are chosen so as to be asymmetric in their assumed structure, so as not to self- associate to form homo- multimers, but rather to associate in a complementary fashion, adopting a stable complex which resembles the parent tertiary structure. On the genetic level, these segments may be encoded by interchangeable cassettes with suitable restriction sites. These standardized cassettes may be fused C- or N-terminally to different recombinant proteins via a linker or hinge in a suitable expression vector system. Polypeptide segments which do not have the ability to assemble as homodimers are derived by cutting a parental polypeptide which has a compact tertiary structure. These polypeptide segments can then be fused to one or more different functional domains at the genetic level. These distinct polypeptide segments which are now fused to one or more functional domains can be, for example, co-expressed resulting in the formation of a native like parental structure attached to functional domains. This parental structure is formed by the dimerization of the polypeptide segments which were derived from the original parental polypeptide. The resulting multifunctional construct would appear as a compact tertiary structure attached to the one or more functional domains. Once structural sub-domains are identified, the protein is dissected in such a way these sub-domains remain intact. As part of this disclosure, DNA sequences, vectors, preferably bicistronic vectors, vector cassettes, can be made and characterized in that they comprise a DNA sequence encoding an amino acid sequence and optionally at least one further (poly)peptide comprised in the multifunctional polypeptide of the invention, and additionally at least one, preferably singular cloning sites for inserting the DNA encoding at least one further functional domain or that they comprise DNA sequences encoding the amino acid sequences, and optionally the further (poly)peptide(s) comprised in the multifunctional polypeptide of the invention and suitable restriction sites for the cloning of DNA sequencesAttorney Docket No. 220710-705601 encoding the functional domains, such that upon expression of the DNA sequences after the insertion of the DNA sequences encoding the functional domains into said restriction sites, in a suitable host the multifunctional polypeptide of the invention may be formed. Said vector cassette is characterized in that it comprises the inserted DNA sequence(s) encoding said functional domain(s) and host cells transformed with at least one vector or vector cassette of the invention which can be used for the preparation of said biparatopic or multi-functional polypeptides. The host cell may be a mammalian, preferably human, yeast, insect, plant or bacterial, preferably E. coli cell. The biparatopic antibodies can be prepared by a method which comprises culturing at least two host cells of the invention in a suitable medium, said host cells each producing only one of said first and said second amino acid sequences attached to at least one further functional domain, recovering the amino acid sequences, mixing thereof under mildly denaturing conditions and allowing in vitro folding of the multifunctional polypeptide of the invention from said amino acid sequences. The method may be characterized in that the further amino acid sequences attached to at least one further functional domain are / is produced by at least one further host cell not producing said first or second amino acid sequence. Additionally, the method may be characterized in that at least one further amino acid sequence attached to at least one further functional domain is produced by the host cell of the invention producing said first or second amino acid sequence.

[0181] When either the second or the first portion of an engineered antibody described herein comprises at least one TL1A binding variable domain. In some embodiments, the at least one TL1A binding domain comprises a VH- and VL-domain. In some instances, the VH- and VL- domain are directly or indirectly linked. In some cases, the engineered antibody described herein comprises the at least one TL1 A binding region, and a binding region that binds to a second target. Thus, in some instances, the engineered antibodies disclosed herein can comprise two antibody variable domains. In some embodiments, the two antibody variable domains can comprise an scFv fragment. In other cases, an engineered antibody disclosed herein can comprise a construct with a three variable antibody domains. In some cases, one of the three antibody variable domain specifically and independently binds (a) either to a human immune effector cell by specifically binding to an effector on the human immune effector cell or to a target cell, while the remaining two antibody of the three variable domains together specifically bind (b) either to the target on the target cell or to a human immune effector cell by specifically binding to an effector on the human immune effector cell, respectively. In some cases, the presence of three variable antibody domains in the engineered antibody entails unique advantages. Often, an scFv exhibiting the desired binding specificity for a target is already known and optimized, and omitting one of its two antibody variable domains would abolish or at least attenuate its binding characteristics. Such an scFv may make up part of an antibody construct described herein. Specifically, such a three-domain antibodyAtorney Docket No. 220710-705601 may advantageously comprise an entire scFv as either its effector or target conferring portion. In some cases, the first and second portions of the engineered antibody may be separated from one another by a synthetic polypeptide spacer moiety, which covalently links either the C-terminus of the first portion with the N-terminus of the second portion, or the C-terminus of the second portion with the N-terminus of the first portion. As such, the portions of these engineered antibodies may be arranged, as either N-(first portion)-(second portion)-C or N- (second portion)-(first portion)- C. In some embodiments, binding sites of a second specificity are fused to the N- or C-terminus of the heavy or light chain, e.g., in the form of an scFv fragment or a variable single domain, resulting in biparatopic, tetravalent domains. Thus, in some embodiments, the engineered antibodies disclosed herein are biparatopic antibodies that comprise at least one TL1A binding domain. Biparatopic antibody formats, such as those generated by fusing an scFv fragment to a monoclonal antibody (mAb), offer significant design flexibility. ScFv domains can be attached to either the N- or C-terminus of the heavy or light chain variable regions, typically without affecting expression levels or antigen-binding functionality. This category includes formats like DVD-Igs, which incorporate tandem VH and VL domains on each chain; two-in-one antibodies, which are engineered to recognize two distinct epitopes within a single antigen-binding site; and Fc- engineered bispecifics (sometimes referred to as mAb2), where additional binding domains are introduced into the Fc region. A common structural feature across these formats is the inherent symmetry resulting from the dimeric assembly of identical heavy chains.

[0182] Heavy chain heterodimerization can be achieved by engineering a charged CH3 interface to introduce an electrostatic steering effect or using the strand-exchange engineered domain technology (SEEDbody) with CH3 sequences composed of alternating segments from human IgA and IgG. In contrast to the biparatopic IgG-like domains, these biparatopic antibodies are bivalent with a size basically identical to that of IgG. In some cases, Fc heterodimerization was used to generate a multivalent, biparatopic construct that comprises a VH and a VL domain to the C- termini of the engineered heavy chains (HA-TF Fc variant.) Biparatopic antibodies with a molecular mass in the range of 50 -100 kDa can be generated by combining the variable domains of two antibodies. For example, two scFv have been connected by a more or less flexible peptide linker in a tandem orientation (tandem scFv, taFv, tascFv), which can be extended further by additional scFv, e.g., generating bivalent, trivalent, tetraval ent bodies (sctb). Diabodies are heterodimeric domains composed of the variable domains of two antibodies arranged either in the order VHA- VLB and VHB-VLA (VH-VL orientation) or in the order VLA-VHB and VLB- VHA (VL-VH orientation). The linker connecting the two domains within one chain is approximately 5 residues leading, after co- expression of the two chains within one cell, to a head-to-tail assembly and hence formation of a compact domain with two functional binding sites. The diabody (Db)Atorney Docket No. 220710-705601 format was further stabilized by introducing interchain disulfide bonds (dsDb, DART domains) or by generating a single-chain derivative (scDb). ScDbs can be converted into tetravalent domains by reducing the middle linker, resulting in homodimerzation of two chains. Small biparatopic domains have also been produced by fusing a scFv to the heavy or light chain of a Fab fragment. Furthermore, tandem scFv, diabodies and scDb have been fused to the Fc or a CH3 domain to generate tetraval ent derivatives. A different approach for the generation of biparatopic antibodies of the present invention is the dock-and-lock method (DNL). Many of the established biparatopic antibody formats can also be combined with additional proteins and components, e.g., drugs, toxins, enzymes and cytokines, enabling dual targeting and delivery of a fusion partner. In addition, fusion to plasma proteins such as serum albumin or albumin-binding moieties can be applied to extend the plasma half- life of biparatopic antibodies.Structure of Engineered Antibodies

[0183] In some embodiments, an engineered antibody may be a target binding protein comprising a polypeptide chain, wherein the polypeptide chain comprises VHl-(Xl)n-VH2-C— (X2)n, wherein VH1 is a first heavy chain variable domain, VH2 is a second heavy chain variable domain, C is a constant domain, XI represents a polypeptide linker, X2 represents an Fc region and n is 0 or 1. In some embodiments, the VH1 and VH2 in the target binding protein may be heavy chain variable domains selected from the group consisting of a murine heavy chain variable domain, a human heavy chain variable domain, a CDR grafted heavy chain variable domain, and a humanized heavy chain variable domain. VH1 and VH2 may be capable of binding different targets. C may be a heavy chain constant domain. For example, XI is a linker peptide. For example, XI is a linker listed herein. In an embodiment, X2 is an Fc region. In another embodiment, X2 is a variant Fc region. In some embodiments, VH1 is capable of binding a first target and VH2 is capable of binding a second target. In some embodiments, VH1 is capable of binding a second target and VH2 is capable of binding a first target. In some cases, the first and / or the second target is TL1A.

[0184] In some embodiments, an engineered antibody may be a target binding protein comprising a polypeptide chain, wherein the polypeptide chain comprises VLl-(Xl)n-VL2-C— (X2)n, wherein VL1 is a first light chain variable domain, VL2 is a second light chain variable domain, C is a constant domain, XI represents a polypeptide linker, X2 represents an Fc region and n is 0 or 1. In some embodiments The VL1 and VL2 in the binding protein may be light chain variable domains selected from the group consisting of a murine light chain variable domain, a human light chain variable domain, a CDR grafted light chain variable domain, and a humanized light chain variable domain. VL1 and VL2 may be capable of binding different targets. C may be a heavyAtorney Docket No. 220710-705601 chain constant domain. For example, XI is a linker peptide. For example, XI is a linker listed herein. In an embodiment, X2 is an Fc region. In another embodiment, X2 is a variant Fc region. In some embodiments, VL1 is capable of binding a first target and VL2 is capable of binding a second target. In some embodiments, VL1 is capable of binding a first target and VL2 is capable of binding a second target. In some cases, the first and / or the second target is TL1 A.

[0185] In some embodiments, an engineered antibody construct is a biparatopic antibody construct, wherein the biparatopic antibody construct comprises two polypeptide chains, each bind to a different target relative to each other. The biparatopic antibodies of the present disclosure can be a dual-variable domain immunoglobulin (DVD-Ig) that comprises two target binding domains linked by flexible naturally occurring linkers, thereby yielding a tetravalent IgG-like domain.

[0186] The present disclosure additionally provides a method of making a DVD-Ig binding protein by preselecting the parent antibodies against a first target and a second target. A method of making a Dual Variable Domain Immunoglobulin that binds two targets comprises the steps of a) obtaining a first parent antibody, or functional fragment thereof, that binds a first target; b) obtaining a second parent antibody or functional fragment thereof, that binds a second target; c) constructing two copies of a first polypeptide chains, each of which comprises VHl-(Xl)n-VH2-C-(X2)n, wherein, VH1 is a first heavy chain variable domain obtained from said first parent antibody, or functional fragment thereof; VH2 is a second heavy chain variable domain obtained from said second parent antibody or functional fragment thereof, which can be the same as or different from the first parent antibody; C is a heavy chain constant domain; (Xl)n is a linker wherein said (Xl)n is either present or absent; and (X2)n is an Fc region, d) constructing two copies of a second polypeptide chains each of which comprises VLl-(Xl)n-VL2-C-(X2)n, wherein, VL1 is a first light chain variable domain obtained from said first parent antibody, or functional fragment thereof; VL2 is a second light chain variable domain obtained from said second parent antibody, or functional fragment thereof, which can be the same as or different from the first parent antibody; C is a light chain constant domain; (Xl)n is a linker, wherein said (Xl)n is either present or absent; and (X2)n does not comprise an Fc region, wherein said (X2)n is either present or absent; and e) expressing two copies of said first and second polypeptide chains; such that a DVD-Ig binds said first target and said second target is generated.

[0187] The variable domains of the DVD binding protein can be obtained from parent antibodies, including polyclonal and mAbs that bind targets of interest. These antibodies may be naturally occurring or may be generated by recombinant technology, or can be designed de novo. MAbs can be prepared using a wide variety of techniques known in the art including the use of hybridoma, recombinant, and phage display technologies, or a combination thereof. Monoclonal antibodies can be prepared by methods disclosed herein.Atorney Docket No. 220710-705601

[0188] The dual variable domain immunoglobulin (DVD-Ig) domain is designed such that two different light chain variable domains (VL) from the two different parent monoclonal antibodies are linked in tandem directly or via a short linker by recombinant DNA techniques, followed by the light chain constant domain, and optionally, anFc region. Similarly, the heavy chain comprises two different heavy chain variable domains (VH) linked in tandem, followed by the constant domain CHI and Fc region. The variable domains can be obtained using recombinant DNA techniques from a parent antibody generated by any one of the methods described herein. The variable domain may be a murine heavy or light chain variable domain, a CDR a human heavy or light chain variable domain. The first and second variable domains may be linked directly to each other using recombinant DNA techniques, linked via a linker sequence, or the two variable domains are linked. The variable domains may bind the same target or may bind different targets. The constant domain may be linked to the two linked variable domains using recombinant DNA techniques. Sequence comprising linked heavy chain variable domains may be linked to a heavy chain constant domain and sequence comprising linked light chain variable domains is linked to a light chain constant domain. The constant domains may also be human heavy chain constant domain and human light chain constant domain respectively. The DVD heavy chain may be further linked to an Fc region. The Fc region may be a native sequence Fc region, or a variant Fc region, or a human Fc region. Two heavy chain DVD polypeptides and two light chain DVD polypeptides may be combined to form a DVD-Ig domain.

[0189] The design of the “dual-specific multivalent full length binding proteins” of the present disclosure leads to a dual variable domain light chain and a dual variable domain heavy chain which assemble primarily to the desired “dual-specific multivalent full length binding proteins”.Construction of DVD Domains

[0190] The dual variable domain immunoglobulin (DVD-Ig) domain is designed such that two different light chain variable domains (VL) from the two parent monoclonal antibodies, which can be the same or different, are linked in tandem directly or via a short linker by recombinant DNA techniques, followed by the light chain constant domain, and optionally, an Fc region. Similarly, the heavy chain comprises two different heavy chain variable domains (VH) linked in tandem, followed by the constant domain CHI and Fc region

[0191] The variable domains can be obtained using recombinant DNA techniques from a parent antibody generated by any one of the methods described herein. In an embodiment, the variable domain is a murine heavy or light chain variable domain. In another embodiment, the variable domain is a CDR grafted or a humanized variable heavy or light chain domain. In an embodiment, the variable domain is a human heavy or light chain variable domain.Atorney Docket No. 220710-705601

[0192] In one embodiment the first and second variable domains are linked directly to each other using recombinant DNA techniques. In another embodiment the variable domains are linked via a linker sequence. In an embodiment, two variable domains are linked. Three or more variable domains may also be linked directly or via a linker sequence. The variable domains may bind the same target or may bind different targets. DVD-Ig domains of the invention may include one immunoglobulin variable domain and one non-immunoglobulin variable domain, such as ligand binding domain of a receptor, or an active domain of an enzyme. DVD-Ig domains may also comprise two or more non-Ig domains.

[0193] In an embodiment a constant domain is linked to the two linked variable domains using recombinant DNA techniques. In some embodiments, sequences comprising linked heavy chain variable domains are linked to a heavy chain constant domain and sequences comprising linked light chain variable domains are linked to a light chain constant domain. In an embodiment, the constant domains are human heavy chain constant domain and human light chain constant domain respectively, some embodiments, the DVD heavy chain is further linked to an Fc region. The Fc region may be a native sequence Fc region, or a variant Fc region. In another embodiment, the Fc region is a human.

[0194] In another embodiment two heavy chain DVD polypeptides and two light chain DVD polypeptides are combined to form a DVD-Ig domain.

[0195] Binding proteins of the present invention may be produced by any of a number of techniques known in the art. For example, expression from host cells, wherein expression vector(s) encoding the DVD heavy and DVD light chains is (are) transfected into a host cell by standard techniques. The various forms of the term “transfection” are intended to encompass a wide variety of techniques commonly used for the introduction of exogenous DNA into a prokaryotic or eukaryotic host cell, e.g., electroporation, calcium-phosphate precipitation, DEAE-dextran transfection and the like. Although it is possible to express the DVD proteins of the invention in either prokaryotic or eukaryotic host cells, DVD proteins are expressed in eukaryotic cells, for example, mammalian host cells, because such eukaryotic cells (and in particular mammalian cells) are more likely than prokaryotic cells to assemble and secrete a properly folded and immunologically active DVD protein.

[0196] Exemplary mammalian host cells for expressing the recombinant antibodies of the invention include Chinese Hamster Ovary (CHO cells including dhfr-CHO cells), NS0 myeloma cells, COS cells, SP2 and PER.C6 cells. When recombinant expression vectors encoding DVD proteins are introduced into mammalian host cells, the DVD proteins are produced by culturing the host cells for a period of time sufficient to allow for expression of the DVD proteins in the host cells or secretion of the DVD proteins into the culture medium in which the host cells are grown.Atorney Docket No. 220710-705601DVD proteins can be recovered from the culture medium using standard protein purification methods.

[0197] In an exemplary system for recombinant expression of DVD proteins in constructs described herein, a recombinant expression vector encoding both the DVD heavy chain and the DVD light chain is introduced into dhfr-CHO cells by calcium phosphate-mediated transfection. Within the recombinant expression vector, the DVD heavy and light chain genes are each operatively linked to CMV enhancer / AdMLP promoter regulatory elements to drive high levels of transcription of the genes. The recombinant expression vector also carries a DHFR gene, which allows for selection of CHO cells that have been transfected with the vector using methotrexate selection / amplification. The selected transformant host cells are cultured to allow for expression of the DVD heavy and light chains and intact DVD protein is recovered from the culture medium. Standard molecular biology techniques are used to prepare the recombinant expression vector, transfect the host cells, select for transformants, culture the host cells and recover the DVD protein from the culture medium. Still further the invention provides a method of synthesizing a DVD protein of the invention by culturing a host cell of the invention in a suitable culture medium until a DVD protein of the invention is synthesized. The method can further comprise isolating the DVD protein from the culture medium.

[0198] An important feature of DVD-Ig is that it can be produced and purified in a similar way as a conventional antibody. The production of DVD-Ig results in a homogeneous, single major product with desired dual-specific activity, without any sequence modification of the constant region or chemical modifications of any kind. Other previously described methods to generate “bispecific”, “multi-specific”, and “multi-specific multivalent” full length binding proteins do not lead to a single primary product but instead lead to the intracellular or secreted production of a mixture of assembled inactive, mono-specific, multi-specific, multivalent, full length binding proteins, and multivalent full length binding proteins with combination of different binding sites.

[0199] The design of the “dual-specific multivalent full length binding proteins” for use in constructs described herein leads to a dual variable domain light chain and a dual variable domain heavy chain which assemble primarily to the desired “dual-specific multivalent full length binding proteins”.

[0200] In some embodiments, at least 50%, at least 75% and at least 90% of the assembled, and expressed dual variable domain immunoglobulin domains are the desired dual-specific tetravalent protein. This aspect of the invention particularly enhances the commercial utility of the invention. Therefore, the present invention includes a method to express a dual variable domain light chain and a dual variable domain heavy chain in a single cell leading to a single primary product of a “dual-specific tetraval ent full length binding protein”.Atorney Docket No. 220710-705601

[0201] Provided herein are methods of expressing a dual variable domain light chain and a dual variable domain heavy chain in a single cell leading to a “primary product” of a “dual-specific tetravalent full length binding protein,” where the “primary product” is more than 50% of all assembled protein, comprising a dual variable domain light chain and a dual variable domain heavy chain.

[0202] Provided herein are methods of expressing a dual variable domain light chain and a dual variable domain heavy chain in a single cell leading to a single “primary product” of a “dualspecific tetravalent full length binding protein,” where the “primary product” is more than 75% of all assembled protein, comprising a dual variable domain light chain and a dual variable domain heavy chain.

[0203] Provided herein are methods of expressing a dual variable domain light chain and a dual variable domain heavy chain in a single cell leading to a single “primary product” of a “dualspecific tetravalent full length binding protein,” where the “primary product” is more than 90% of all assembled protein, comprising a dual variable domain light chain and a dual variable domain heavy chain.Kappa-lambda antibodies

[0204] In some embodiments, provided herein are antibodies in the kappa -lambda antibody format. The antibodies provided herein have a common heavy chain, two light chains - one Kappa (K), one Lambda (X) - that each has a different specificity (ie., two light chains, two specificities). The methods provided herein produce domains having specific binding where diversity is restricted to the VL region. These methods produce the antibodies through controlled coexpression of the three chains (one VH chains, two VL chains), and purification of the antibody.

[0205] This type of domain is composed of two copies of a unique heavy chain polypeptide, a first light chain variable region fused to a constant Kappa domain and second light chain variable region fused to a constant Lambda domain. Each combining site displays a different target specificity to which both the heavy and light chain contribute. The light chain variable regions can be of the Lambda or Kappa family and are preferably fused to a Lambda and Kappa constant domains, respectively. This is preferred in order to avoid the generation of non-natural polypeptide junctions. However, it is also possible to obtain biparatopic antibodies of the invention by fusing a Kappa light chain variable domain to a constant Lambda domain for a first specificity and fusing a Lambda light chain variable domain to a constant Kappa domain for the second specificity.

[0206] An essential step of exemplary methods is the identification of two antibody Fv regions (each composed by a variable light chain and variable heavy chain domain) having different target specificities that share the same heavy chain variable domain. Numerous methods have beenAtorney Docket No. 220710-705601 described for the generation of monoclonal antibodies and functional fragments thereof. Fully human antibodies are antibody domains in which the sequence of both the light chain and the heavy chain, including the CDRs 1 and 2, arise from human genes. The CDR3 region can be of human origin or designed by synthetic means. Such antibodies are termed “human antibodies,” or “fully human antibodies.” Human monoclonal antibodies can be prepared by using the trioma technique; the human B-cell hybridoma technique; and the EBV hybridoma technique to produce human monoclonal antibodies. In some cases, human monoclonal antibodies are utilized and are produced using human hybridomas or by transforming human B-cells with Epstein Barr Virus.

[0207] Monoclonal antibodies may be generated, e.g., by immunizing an animal with a target or an immunogenic functional fragment, derivative or variant thereof. Alternatively, the animal is immunized with cells transfected with a vector containing a nucleic acid domain encoding the target, such that the target is expressed and associated with the surface of the transfected cells. A variety of techniques are well-known in the art for producing xenogenic non-human animals. For example, see U.S. Pat. No. 6,075,181 and No. 6,150,584, which is hereby incorporated by reference in its entirety.

[0208] Alternatively, antibodies may be obtained by screening a library that contains antibody or binding domain sequences for binding to the target peptide. This library may be prepared, e.g., in bacteriophage as protein or peptide fusions to a bacteriophage coat protein that is expressed on the surface of assembled phage particles and the encoding DNA sequences contained within the phage particles (z.e., "phage displayed library").

[0209] Hybridomas resulting from myeloma / B cell fusions are then screened for reactivity to the target. Monoclonal antibodies may be prepared, for example, using hybridoma methods. In a hybridoma method, a mouse, hamster, or other appropriate host animal, is typically immunized with an immunizing agent to elicit lymphocytes that produce or are capable of producing antibodies that will specifically bind to the immunizing agent. Alternatively, the lymphocytes can be immunized in vitro.

[0210] Kappa-lambda antibodies having the same heavy chain variable domain can be generated by the use of antibody libraries in which the heavy chain variable domain is the same for all the library members and thus the diversity is confined to the light chain variable domain. However, as the light chain variable domain is expressed in conjunction with the heavy variable domain, both domains can contribute to binding. To further facilitate the process, antibody libraries containing the same heavy chain variable domain and either a diversity of Lambda variable light chains or Kappa variable light chains can be used in parallel for in vitro selection of antibodies against different targets. This approach enables the identification of two antibodies having a common heavy chain but one carrying a Lambda light chain variable domain and the other a Kappa lightAtorney Docket No. 220710-705601 chain variable domain that can be used as building blocks for the generation of a biparatopic antibody in the full immunoglobulin format of the invention. Numerous methods for the modification of the Fc portion have been described and are applicable to antibodies of the invention.

[0211] Another step of exemplary embodiments is the optimization of co-expression of the common heavy chain and two different light chains into a single cell to allow for the assembly of a biparatopic antibody of the invention. If all the polypeptides get expressed at the same level and get assembled equally well to form an immunoglobulin domain then the ratio of monospecific (same light chains) and biparatopic (two different light chains) should be 50%.

[0212] The co-expression of the heavy chain and two light chains generates a mixture of three different antibodies into the cell culture supernatant: two monospecific bivalent antibodies and one biparatopic bivalent antibody. The latter has to be purified from the mixture to obtain the domain of interest. The method described herein greatly facilitates this purification procedure by the use of affinity chromatography media that specifically interact with the Kappa or Lambda light chain constant domains such as the CaptureSelect Fab Kappa and CaptureSelect Fab Lambda affinity matrices (BAC BV, Holland). This multi-step affinity chromatography purification approach is efficient and generally applicable to antibodies of the invention. This is in sharp contrast to specific purification methods that have to be developed and optimized for each biparatopic antibodies derived from quadromas or other cell lines expressing antibody mixtures. Indeed, if the biochemical characteristics of the different antibodies in the mixtures are similar, their separation using standard chromatography technique such as ion exchange chromatography can be challenging or not possible at all.

[0213] To avoid the requirement of having access to two antibodies having light chain variable domains of the Kappa and Lambda type being perceived as a limitation to the instant invention, the methods described herein allow for the generation of hybrid light chain in which a Lambda variable domain can be fused to a Kappa constant domain and conversely a Kappa variable domain can be fused to a Lambda constant domain. In some embodiments, the methods of generating engineered antibodies use a complete serum- free chemically defined process. These methods incorporate the most widely used mammalian cell line in pharmaceutical industry, the Chinese Hamster Ovary (CHO) cell line. The methods described therein are used to generate both semistable and stable cell lines. The methods can be used to manufacture the engineered antibodies of the invention at small scale (e.g., in an Erlenmeyer flask) and at mid-scale (e.g., in 25L Wave bag). The methods are also readily adaptable for larger scale production of the engineered antibodies, as well as antibody mixtures of the invention.Atorney Docket No. 220710-705601Binding Affinity

[0214] Binding affinity is generally represented by the dissociation constant (KD). KD values for antibodies can be determined by any of the methods known in the art. Exemplary methods for determining KD includes by using surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), spectroscopic assays, biolayer interferometry (BLI), radioimmunoassay (RIA), equilibrium dialysis, fluorescence resonance energy transfer (FRET), co-immunoprecipitation (Co-IP), protein chip technology and grating-coupled interferometry (GCI).

[0215] In some embodiments, engineered antibodies described herein have a binding affinity in a range of from 1 pM to 1 pM, from 10 pM to 1 pM, from 100 pM to 1 pM, from 1 nM to 1 pM, from 10 nM to 1 pM, from 100 nM to 1 pM, from 500 nM to 1 pM, from 1 pM to 500 nM, from 10 pM to 500 nM, from 100 pM to 500 nM, from 1 nM to 500 nM, from 10 nM to 500 nM, from 100 nM to 500 nM, from 1 pM to 100 nM, from 10 pM to 100 nM, from 100 pM to 100 nM, from 1 nM to 100 nM, from 10 nM to 100 nM, from 1 pM to 10 nM, from 10 pM to 10 nM, from 100 pM to 10 nM, from 1 nM to 10 nM, from 1 pM to 1 nM, from 10 pM to 1 nM, from 100 pM to 1 nM, from 1 pM to 100 pM, or from 10 pM to 100 pM.

[0216] In some embodiments, engineered antibodies described herein have an average binding affinity for target antigen is in a range of from 1 pM to 1 pM, from 10 pM to 1 pM, from 100 pM to 1 pM, from 1 nM to 1 pM, from 10 nM to 1 pM, from 100 nM to 1 pM, from 500 nM to 1 pM, from 1 pM to 500 nM, from 10 pM to 500 nM, from 100 pM to 500 nM, from 1 nM to 500 nM, from 10 nM to 500 nM, from 100 nM to 500 nM, from 1 pM to 100 nM, from 10 pM to 100 nM, from 100 pM to 100 nM, from 1 nM to 100 nM, from 10 nM to 100 nM, from 1 pM to 10 nM, from 10 pM to 10 nM, from 100 pM to 10 nM, from 1 nM to 10 nM, from 1 pM to 1 nM, from 10 pM to 1 nM, from 100 pM to 1 nM, from 1 pM to 100 pM, or from 10 pM to 100 pM.

[0217] In some embodiments, engineered antibodies described herein comprise at least two binding regions (or domains). In some embodiments, the first and second binding regions (or domains) bind TL1 A protein, a variant thereof, or a functional fragment thereof, wherein the first and second binding region (or domain) targets different epitopes of the TL1A protein. In some embodiments, a binding affinity of first and second binding regions (or domains) of an engineered antibody are different for TL1 A protein. In some embodiments, an engineered antibody comprises a first and second binding affinities for TL1 A protein, a variant thereof, or a functional fragment thereof, wherein the first binding affinity is at least two times, at least three time, at least four times, at least five times, at least ten times, at least fifteen times, at least twenty times, at least forty times, at least sixty times, at least eight times, or at least hundred times higher than the second binding affinity.

[0218] Alternatively, in some embodiments, engineered antibodies described herein undergoAtorney Docket No. 220710-705601 cooperative binding event. In some embodiments, engineered antibodies undergo positive cooperative binding upon sequential binding to a first and second epitopes of TL1A protein, a variant thereof, or a function fragment thereof, wherein binding of the engineered antibody to the first epitope results in increase in binding affinity for the second epitope. Alternatively, in some embodiments, engineered antibodies undergo negative cooperative binding to a first and second epitopes of TL1A protein, a variant thereof, or a functional fragment thereof, wherein binding of the engineered antibody to the first epitope results in decrease in binding affinity for the second epitope.

[0219] In some embodiments, engineered antibodies described herein comprise two TL1 A binding regions linked to each other by a disulfide linkage in a hinge region (FIG. 1A). In some embodiments, the TL1A binding regions target different epitopes of the TL1A protein. In some embodiments, the TL1A binding regions target the same epitope of the TL1A protein. In some embodiments, a binding affinity of the first and second TL1A binding regions are different for TL1A protein relative to each other. In some embodiments, a binding affinity of the first TL1A binding region for TL1A protein is at least two times, at least three time, at least four times, at least five times, at least ten times, at least fifteen times, at least twenty times, at least forty times, at least sixty times, at least eight times, or at least hundred times higher than the binding affinity of the second TL1 A binding region for TL1 A protein.

[0220] In some embodiments, engineered antibodies described herein comprise three TL1A binding regions. In some embodiments, at least two of the three TL1A binding regions (e.g., two TL1 A binding regions, three TL1 A binding regions) target different epitopes of the TL1 A protein. In some embodiments, at least two of the three TL1A binding regions (e.g., two TL1A binding regions, three TL1A binding regions) target the same epitope of the TL1A protein. In some embodiments, a first TL1 A Fab fragment of a First TL1 A binding region and a second TL1 A Fab fragment of a second TL1 A binding region are fused to N-terminal end of a Fc region, wherein N- terminal end of the first TL1A Fab fragment is fused to C-terminal end of a third TL1A Fab fragment of a third TL1 A binding region (FIG. IB). In some embodiments, C-terminal end of a first TL1A Fab fragment of a first TL1A binding region and a second TL1A Fab fragment of a second TL1 A binding region are fused to N-terminal end of an Fc region, wherein N-terminal end of a third TL1 A Fab fragment of a third TL1 A binding region is fused to C-terminal end of the Fc region (FIG. ID) In some embodiments, a binding affinity of at least two of the three TL1A binding regions (e.g., two TL1A binding regions, three TL1A binding regions) are different for TL1 A protein relative to each other. In some embodiments, a binding affinity of at least one TL1 A binding region (e.g., one TL1 A binding region, two TL1 A binding regions) for TL1 A protein is at least two times, at least three time, at least four times, at least five times, at least ten times, at leastAtorney Docket No. 220710-705601 fifteen times, at least twenty times, at least forty times, at least sixty times, at least eight times, or at least hundred times higher than the binding affinity of the remaining TL1 A binding region(s).

[0221] In some embodiments, engineered antibodies described herein comprise four TL1A binding regions. In some embodiments, at least two of the four TL1A binding regions (e.g., two TL1A binding regions, three TL1A binding regions, four TL1A binding regions) target different epitopes of the TL1 A protein. In some embodiments, at least two of the four TL1 A binding regions (e.g., two TL1A binding regions, three TL1A binding regions, four TL1A binding regions) target same epitope of the TL1A protein. In some embodiments, C-terminal end of a first TL1A Fab fragment of a First TL1A binding region and a second TL1A Fab fragment of a second TL1A binding region are fused to N-terminal end of a Fc region, wherein N-terminal end of the first TL1A Fab fragment is fused to C-terminal end of a third TL1A Fab fragment of a third TL1A binding region, and wherein N-terminal end of the second TL1A Fab fragment is fused to C- terminal end of a fourth TL1 A Fab fragment of a fourth TL1 A binding region. (FIG. 1C). In some embodiments, C-terminal end of a first TL1A fragment of a First TL1A binding region and a second TL1A Fab fragment of a second TL1A binding region are fused to N-terminal end of an Fc region, wherein N-terminal end of a third TL1 A Fab fragment of a third TL1 A binding region and a fourth TL1 A Fab fragment of a fourth TL1 A binding region are fused to C-terminal end of the Fc region (FIG. IE). In some embodiments, a binding affinity of at least two of the four TL1 A binding regions (e.g., two TL1 A binding regions, three TL1 A binding regions, four TL1 A binding regions) are different for TL1A protein relative to each other. In some embodiments, a binding affinity of at least one TL1A binding region (e.g., one TL1A binding region, two TL1A binding regions, three TL1 A binding regions) for TL1 A protein is at least two times, at least three time, at least four times, at least five times, at least ten times, at least fifteen times, at least twenty times, at least forty times, at least sixty times, at least eight times, or at least hundred times higher than the binding affinity of the remaining TL1 A binding region(s).Compositions

[0222] Disclosed herein, in some embodiments, are compositions comprising at least one TL1 A binding region (or domain). In some embodiments, a TL1 A binding region (or domain) comprises a heavy chain variable region. In some embodiments, a TL1A binding region (or domain) comprises a heavy chain constant region. In some embodiments, a TL1A binding region (or domain) comprises a light chain variable region. In some embodiments, a TL1A binding region (or domain), as described herein, comprises at least one modification that changes isoelectric point (pl) relative to a corresponding TL1 A binding region (or domain) prior to the at least one modification. In some embodiments, a TL1A binding region (or domain) comprises at least oneAtorney Docket No. 220710-705601 amino acid modification within a heavy chain variable region and / or a light chain variable region, wherein the at least one modification changes isoelectric point (pl) of the TL1 A binding region (or domain) and / or provides a pH-dependent binding activity to the TL1 A binding region (or domain). In some embodiments, a heavy chain variable region, as described herein, comprises CDR-H1, CDR-H2 and CDR-H3, and a light chain variable region, as described herein, comprises CDR-L1, CDR-L2 and CDR-L3. In some embodiments, a binding affinity of the TL1A binding region (or domain) to the target epitope increases under neutral pH condition relative to a corresponding TL1A binding region (or domain) prior to modifications. In some embodiments, a binding affinity of the TL1A binding region (or domain) to the target epitope decreases under acidic pH condition relative to a corresponding TL1A binding region (or domain) prior to modifications.

[0223] Also, disclosed herein are compositions comprising an engineered polypeptide. In some embodiments, engineered polypeptide described herein comprise two target binding regions. In some embodiments, at least one of the two target binding regions binds an epitope of TL1A protein, a variant thereof, or a fragment thereof. In some embodiments, the two target binding regions bind an epitope of TL1A protein, a variant thereof, or a fragment thereof. In some embodiments, the two target binding regions are linked to each other by a covalent linkage. In some embodiments, the two target binding regions are linked to each other by a linker described herein. In some embodiments, an N-terminus of one target binding region is linked to C-terminus of another target binding region by a linker there between. In some embodiments, the two target binding regions (or domains) are linked to each other by an Fc subunit described herein there between. In some embodiments, a C-terminus of one target binding region is linked to N- terminus of an Fc subunit and N-terminus of the other target binding region is linked to the C- terminus of the Fc subunit. In some embodiments, the target binding region is linked to an Fc subunit by a linker described herein. An exemplary linker comprises an amino acid sequence of GGGGSGGGGS (SEQ ID NO: 173). In some embodiments, the target binding region comprises a VH domain. In some embodiments, the target binding region comprises a TL1A binding VH domain.

[0224] Also, disclosed herein are compositions comprising engineered antibodies or functional fragments thereof. In some embodiments, engineered antibodies described herein comprise two target binding regions (or domains). In some embodiments, at least one of the two target binding regions (or domains) binds an epitope of TL1A protein, a variant thereof, or a fragment thereof. In some embodiments, two target binding regions (or domains) are linked to each other by a covalent linkage. In some embodiments, two target binding regions (or domains) form dimer by chemical linkage to each other. In some embodiments, two target binding regions (or domains)Atorney Docket No. 220710-705601 form dimer by disulfide linkage to each other. In some embodiments, two target binding regions (or domains) form dimer by knobs-into-holes approach as described herein.

[0225] Disclosed herein are compositions comprising engineered antibodies or functional fragments thereof. In some embodiments, engineered antibodies described herein comprise at least two TL1 A binding regions (e.g., two TL1 A binding regions, three TL1 A binding regions, four TL1 A binding regions). In some embodiments, at least two TL1 A binding regions (e.g., two TL1 A binding regions, three TL1 A binding regions, four binding regions) bind same or different TL1A epitopes. In some embodiments, at least two TL1A binding regions (e.g., two TL1A binding regions, three TL1A binding regions, four binding regions) comprise identical or nonidentical TL1A binding VH domains. In some embodiments, at least two TL1A binding VH domains (e.g., two TL1 A binding VH domains, three TL1A binding VH domains, four binding VH domains) are linked to each other by a linker. In some embodiments, the two TL1 A binding VH domains are linked to each other by a linker. In some embodiments, the C-terminus of the TL1A binding VH domain is linked to the N-terminus of the TL1A binding VH domain by a linker. In some embodiments, N-terminus of at least one TL1A binding VH domain (e.g., one TL1A binding VH domain, two TL1A binding VH domains) is linked to C-terminus of an Fc region of the engineered antibody described herein. In some embodiments, C-terminus of at least one TL1A binding VH domain (e.g., one TL1A binding VH domain, two TL1A binding VH domains) is linked to N-terminus of an Fc region of the engineered antibody described herein. In some embodiments, C-terminus of a TL1A binding VH domain and / or N-terminus of a TL1A binding VH domain are linked to N-terminus and C-terminus of an Fc subunit of the engineered antibody described herein.

[0226] In some embodiments, the compositions described herein have low immunogenicity. In some embodiments, the compositions described herein have high safety profiles. In some embodiments, the compositions described herein can accelerate the clearance of TL1A in lysosomes, thereby reducing the level of TL1A in the body. In some embodiments, the compositions described herein have increased blood circulation level. In some embodiments, the compositions described herein have extended half-lifes. In some embodiments, the compositions described herein can inhibit T cell activation by exogenous TL1A. In some embodiments, the compositions described herein can inhibit the activation of immune cells by endogenous TL1 A.Methods of making engineered antibody

[0160] Disclosed herein are methods of making recombinant monospecific engineered antibodies described herein. In some embodiments, the method comprises expressing and purifying two peptides, wherein one of the two peptides is heavy chain, and the other peptide is a light chain.Atorney Docket No. 220710-705601Next, both peptides are mixed together under reducing condition. Gradual removal of reducing agent results in formation of engineered antibody complex, which can then be purified. Exemplary heavy chains are provided in TABLE 4. In some embodiments, heavy chain of engineered antibodies described herein comprise an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of SEQ ID NO: 36-56, 92, 104-111, 115, 168, 178-254 and 323-326 Exemplary light chains are provided in TABLE 5. In some embodiments, light chain of engineered antibodies described herein comprise an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of SEQ ID NO: 76-85, 96-97 and 317-322

[0161] Disclosed herein are methods of making recombinant monospecific engineered antibodies described herein. In some embodiments, the method comprises expressing and purifying three peptides, wherein two of the three peptides are heavy chains, and the remaining peptide is a light chain. Amongst the two heavy chains, one comprises a first VH domain and a knob mutation, and the other heavy chain comprises a second VH domain and a hole mutation. Next, all three peptides are mixed together under reducing condition. The first VH domain and the second VH domain may be identical or non-identical. Gradual removal of reducing agent results in formation of engineered antibody complex, which can then be purified. Exemplary heavy chains are provided in TABLE 4. In some embodiments, heavy chain of engineered antibodies described herein comprise an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of SEQ ID NO: 36-56, 92, 104-111, 115, 168, 178-254 and 323-326. Exemplary light chains are provided in TABLE 5. In some embodiments, light chain of engineered antibodies described herein comprise an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of SEQ ID NO: 76-85, 96- 97 and 317-322

[0162] Disclosed herein are methods of making recombinant trivalent engineered antibodies described herein. In some embodiments, the recombinant trivalent engineered antibodies described herein are biparatopic trivalent engineered antibodies. In some embodiments, the method comprises expressing and purifying three peptides, wherein two of the three peptides are heavy chains, and the remaining peptide is a common light chain. Amongst the two heavy chains, one comprises two VH domains and a knob mutation, and the other heavy chain comprises one VH domain and a hole mutation. Alternatively, in some embodiments, amongst the two heavy chains, one comprises one VH domain and a knob mutation, and the other heavy chain comprises two VH domains and a hole mutation. Next, all three peptides are mixed together under reducing condition.Atorney Docket No. 220710-705601Gradual removal of reducing agent results in formation of engineered antibody complex, which can then be purified. Exemplary heavy chains are provided in TABLE 23. In some embodiments, heavy chain of engineered antibodies described herein comprise an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of SEQ ID NO: 296-311.

[0162] Also, disclosed herein are methods of making recombinant tetravalent engineered antibodies described herein. In some embodiments, the recombinant trivalent engineered antibodies described herein are biparatopic tetravalent engineered antibodies. In some embodiments, the method comprises expressing and purifying two peptides, wherein one of the two peptides are heavy chains, and the remaining peptide is a common light chain. The heavy chain peptide comprises two VH domains each targeting non-identical epitope. Next, both peptides are mixed together under reducing condition. Gradual removal of reducing agent results in formation of engineered antibody complex, which can then be purified. Exemplary heavy chains are provided in TABLE 24. In some embodiments, heavy chain of engineered antibodies described herein comprise an amino acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99% or 100% identical to any one of SEQ ID NO: 312-315Methods of introducing pH dependent binding activity

[0227] Disclosed herein, in some embodiments, are methods of making a TL1A binding region (or domain) with a binding affinity for a target epitope that is derived from TL1 A protein, a variant thereof or a fragment thereof, wherein the TL1A binding region (or domain) comprises a pH dependent epitope binding activity. In some embodiments, the methods comprise identifying a histidine rich epitope in the target epitope; constructing an antibody that comprises said heavy chain variable region and said light chain variable region; and modifying at least one amino acid of said heavy chain variable region and / or said light chain variable region to make said TL1A binding engineered antibody. In some embodiments, a binding affinity of the TL1 A binding region (or domain) for the target epitope in neutral pH is increased by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to a corresponding binding affinity prior to the at least one modification. In some embodiments, a binding affinity of the TL1 A binding region (or domain) for the target epitope in acidic pH is less than 5%, less than 10%, less than 15%, less than 20%, or less than 25% higher than a binding affinity of the corresponding TL1A binding region (or domain) prior to the at least one modification. In some embodiments, a binding affinity of the TL1 A binding region (or domain) for the target epitope in acidic pH is reduced by at least 2%, at least 5%, at least 10%, at least 15%,Atorney Docket No. 220710-705601 at least 20%, at least 30%, at least 40%, at least 50% or more relative to a binding affinity of the corresponding TL1A binding region (or domain) prior to the at least one modification. In some embodiments, the methods further comprise modifying constant regions of the TL1A binding region (or domain). In some embodiments, a modified constant region decreases plasma clearance (CL), increases plasma retention time, or increases plasma half-life (f / 2) of the TL1A binding region (or domain), compared to plasma clearance (CL), plasma retention time, or plasma half-life (t’A) of the corresponding TL1 A binding region (or domain) prior to modification of the constant region. In some embodiments, a modified constant region increases antigen clearance (CL) by the TL1 A binding region (or domain), compared to a corresponding TL1 A binding region (or domain) prior to modification of the constant region.Methods of Treatment

[0228] Disclosed herein, in some embodiments, are methods of treating a subject in need thereof, comprising administering to the subject, a dose in an effective amount of an engineered antibody or a functional fragment thereof, or a pharmaceutical composition comprising the engineered antibody or the functional fragment thereof. In some embodiments, a subject has a TL1A- mediated disease. In some embodiments, a subject has a disease associated with TL1A expression. In some embodiments, a subject has a disease associated with DR3 expression. In some embodiments, a subject has a disease associated with DcR3 expression. In some embodiments, a subject has a disease associated with the TL1 A / DR3 signaling pathway. In some embodiments, a subject has a disease or condition that is related to impaired mitochondrial dysfunction. In some embodiments, the subject has a disease or condition selected from the group consisting of: an infectious disease, an inflammatory disease or an autoimmune disease. In some embodiments, the subject has an autoimmune disease selected from a group consisting of psoriasis and dermatitis (e.g., atopic dermatitis); systemic scleroderma and sclerosis; responses associated with inflammatory bowel disease (such as 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 infiltration of T cells and chronic inflammatory responses; atherosclerosis; leukocyte adhesion deficiency; rheumatoid arthritis; systemic lupus erythematosus (SLE); diabetes mellitus (e.g., Type I diabetes mellitus or insulin dependent diabetes mellitis); multiple sclerosis; Reynaud's syndrome; autoimmune thyroiditis; allergic encephalomyelitis; Sjorgen's syndrome; juvenile onset diabetes; and immune responses associated with acute and delayed hypersensitivity mediated by cytokines and T- lymphocytes typically found in tuberculosis, sarcoidosis, polymyositis, inflammatory myopathies, interstitialAtorney Docket No. 220710-705601 lung disease, granulomatosis and vasculitis; pernicious anemia (Addison's disease); diseases involving leukocyte diapedesis; central nervous system (CNS) inflammatory disorder; multiple organ injury syndrome; hemolytic anemia (including, but not limited to cryoglobinemia or Coombs positive anemia); myasthenia gravis; antigen-antibody complex mediated diseases; anti -glomerular basement membrane disease; antiphospholipid syndrome; allergic neuritis; Graves' disease; Lambert-Eaton myasthenic syndrome; pemphigoid bullous; pemphigus; autoimmune polyendocrinopathies; Reiter's disease; stiff- man syndrome; Behcet disease; giant cell arteritis; immune complex nephritis; IgA nephropathy; IgM polyneuropathies; immune thrombocytopenic purpura (ITP) or autoimmune thrombocytopenia. In some embodiments, the subject has an inflammatory disease that is characterized by one or more of the signs of pain (dolor, from the generation of noxious substances and the stimulation of nerves), heat (calor, from vasodilatation), redness (rubor, from vasodilatation and increased blood flow), swelling (tumor, from excessive inflow or restricted outflow of fluid), and loss of function (functio laesa, which may be partial or complete, temporary or permanent). Inflammatory disease (e.g., chronic inflammatory disease) may contribute to various 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 diseases and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, etc.). Symptoms associated with inflammatory disease that are not necessarily limiting may include one or more of the following: acute, adhesive, atrophic, catarrhal, chronic, cirrhotic, diffuse, disseminated, exudative, fibrinous, fibrosing, focal, granulomatous, hyperplastic, hypertrophic, interstitial, metastatic, necrotic, obliterative, parenchymatous, plastic, productive, proliferous, pseudomembranous, purulent, sclerosing, seroplastic, serous, simple, specific, subacute, suppurative, toxic, traumatic, and / or ulcerative. In some embodiments, the subject has: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

[0229] In some embodiments, a subject has a disease or condition that is related to gastric inflammatory disease or condition. In some embodiments, the subject has inflammatory bowel disease (c.g, Crohn's Disease (CD), ulcerative colitis (UC)). In some embodiments, a subject has a disease or condition that is related to rheumatoid disease or condition.

[0230] Provided herein are engineered TL1A binding antibodies that may be useful in the treatment, prevention, suppression and amelioration of TL1A related diseases. Also, provided herein are methods for treating a condition / disease associated with TL1A expression. In some embodiments, the disease / condition is selected from the group consisting of inflammatory bowelAtorney Docket No. 220710-705601 disease (I BD), Crohn's disease, ulcerative colitis, fibrostenosing Crohn's disease, irritable bowel syndrome, allergies, ankylosing spondylitis, alopecia areata, arthritis, asthma, atherosclerosis, atopic dermatitis, autoimmune hepatitis, autoimmune thyroiditis, Behcet’s disease, bladder syndrome / intersticial cystitis, cutaneous lupus erythematosus, diabetes mellitus, eczematous dermatitis, encephalomyelitis, eosinophilic esophagitis, eosinophilic gastroenteritis, graft-versus- host disease (GVHD), idiopathic pulmonary fibrosis, juvenile rheumatoid arthritis, multiple sclerosis, myasthenia gravis, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, non- responsive celiac disease, osteoarthritis, primar...

Claims

Attorney Docket No. 220710-705601CLAIMSWhat is claimed is:

1. A composition comprising a TL1 A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises:(a) a heavy chain complementarity determining region 1 (CDR-H1) amino acid sequence as set forth in SEQ ID NO: 256; a CDR-H2 amino acid sequence as set forth in SEQ ID NO: 117 or 257 with up to three amino acid substitution; a CDR-H3 amino acid sequence as set forth in SEQ ID NO: 327 with up to three amino acid substitution; a light chain complementarity determining region 1 (CDR-L1) amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to two amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution; or(b) a CDR-H1 amino acid sequence as set forth in SEQ ID NO: 116 with up to one amino acid substitution; a CDR-H2 amino acid sequence as set forth in any one of SEQ ID NOS: 257-270; a CDR-H3 amino acid sequence as set forth in SEQ ID NO: 327 with up to three amino acid substitution; a CDR-L1 amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to two amino acid substitution; and a CDR- L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution.

2. A composition comprising a TL1 A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises:(a) a CDR-H1 amino acid sequence as set forth in SEQ ID NO: 98 with up to two amino acid substitution; a CDR-H2 amino acid sequence as set forth in SEQ ID NO: 99 with up to three amino acid substitution; a CDR-H3 amino acid sequence as set forth in any one of SEQ ID NOS: 100-103 with up to three amino acid substitution; a CDR-L1 amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to two amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution; orAttorney Docket No. 220710-705601(b) a CDR-H1 amino acid sequence as set forth in SEQ ID NO: 116 with up to one amino acid substitution; a CDR-H2 amino acid sequence as set forth in SEQ ID NO: 117 with up to three amino acid substitution; a CDR-H3 amino acid sequence as set forth in any one of SEQ ID NOS: 118, 170-172 and 327 with up to three amino acid substitution; a CDR-L1 amino acid sequence as set forth in SEQ ID NO: 112 with up to three amino acid substitution; a CDR-L2 amino acid sequence as set forth in SEQ ID NO: 113 with up to three amino acid substitution; and a CDR-L3 amino acid sequence as set forth in SEQ ID NO: 114 with up to three amino acid substitution.

3. A composition comprising a TL1 A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises:(a) a heavy chain variable domain comprising an amino acid sequence that is at least 80% identical to any one of SEQ ID NOS: 168, 178-254 and 323-326; and(b) a light chain variable domain comprising an amino acid sequence that is at least 80% identical to any one of SEQ ID NOS: 97 and 316-322.

4. The composition of any one of claims 1-3, wherein the TL1A binding engineered antibody comprises a binding affinity that is at least about 10-fold higher at pH 7.4 than a binding affinity at pH 5.8.

5. A composition comprising a TL1 A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises:(a) two TL1A binding regions, each comprising a heavy chain variable (VH) domain, wherein at least one of the two TL1 A binding regions comprise at least one amino acid modification that changes an isoelectric point (pl) of said TL1 A binding engineered antibody relative to a pl of a corresponding antibody prior to said amino acid modification, thereby resulting in pH-dependent binding activity in said TL1A binding engineered antibody, as measured by surface plasmon resonance spectroscopy; and(b) an engineered Fc region that comprises a first and a second subunit capable of stable association, wherein said two heavy chain variable regions are directly or indirectly linked to the engineered Fc region of the TL1 A binding engineered antibody.Atorney Docket No. 220710-7056016. The composition of claim 5, wherein the two TL1A binding regions comprise a first VH domain and a second VH domain, wherein the first VH domain and the second VH domain are directly or indirectly linked to the first subunit of the engineered Fc region.

7. The composition of claim 5, wherein the two TL1A binding regions comprise a first VH domain and a second VH domain, wherein the first VH domain and the second VH domain are directly or indirect linked to the first subunit and the second subunit of the engineered Fc region, respectively.

8. The composition of any one of claims 5-7, wherein the first VH domain and the second VH domain are identical.

9. The composition of any one of claims 5-7, wherein the first VH domain and the second VH domain are distinct.

10. A composition comprising a TL1 A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein the TL1 A binding engineered antibody comprises:(a) at least three TL1A binding regions, each comprising a heavy chain variable (VH) domain, wherein at least one of the at least three TL1 A binding regions comprise at least one amino acid modification that changes an isoelectric point (pl) of said TL1A binding engineered antibody relative to a pl of a corresponding antibody prior to said amino acid modification, thereby resulting in pH-dependent binding activity in said TL1 A binding engineered antibody, as measured by surface plasmon resonance spectroscopy; and(b) an engineered Fc region that comprises a first and a second subunit capable of stable association, wherein two of said at least three heavy chain variable regions are directly or indirectly linked to the first subunit of the engineered Fc region of the TL1A binding engineered antibody.

11. The composition of claim 10, wherein the TL1A binding engineered antibody comprises three TL1A binding regions each comprising a TL1A binding heavy chain variable (VH) domain.

12. The composition of claim 11, wherein the three TL1 A binding regions comprise a first VH domain, a second VH domain and a third VH domain, wherein a C-terminus of said first VH domain is linked to a N-terminus of said second VH domain, and wherein a C-terminus of said second VH domain is linked to a N-terminus of said first subunit of said engineered Fc region.Atorney Docket No. 220710-70560113. The composition of claim 11, wherein the three TL1 A binding regions comprises a first VH domain, a second VH domain and a third VH domain, a C-terminus of said first VH domain is linked to a N-terminus of said first subunit of said engineered Fc region, and a N-terminus of said second VH domain is linked to a C-terminus of said first subunit of said engineered Fc region.

14. The composition of any one of claims claim 11-13, wherein at least two of said first VH domain, said second VH domain and said third VH domain are identical.

15. The composition of any one of claims claim 11-14, wherein said first VH domain, said second VH domain and said third VH domain are identical.

16. The composition of any one of claims claim 11-14, wherein said first VH domain, said second VH domain and said third VH domain are distinct.

17. The composition of claim 10, wherein the composition comprises four TL1A binding regions.

18. The composition of claim 17, wherein said four TL1A binding regions comprise a first VH domain, a second heavy variable region, a third VH domain and a fourth VH domain, and wherein a C-terminus of said first VH domain is linked to a N-terminus of said VH domain, wherein a C-terminus of said second VH domain is linked to a N-terminus of said first subunit of said engineered Fc region, wherein a C-terminus of said third VH domain is linked to a N-terminus of said fourth VH domain, and wherein a C-terminus of said fourth VH domain is linked to a N-terminus of said second subunit of said engineered Fc region.

19. The composition of claim 17, wherein said four TL1 A binding regions comprises a first VH domain, a second VH domain, a third VH domain and a fourth VH domain, wherein a C- terminus of said first VH domain is linked to a N-terminus of said second VH domain, wherein a C-terminus of said second VH domain is linked to a N-terminus of said first subunit of said engineered Fc region, wherein a C-terminus of said third VH domain is linked to a N-terminus of said fourth VH domain, and wherein a C-terminus of said fourth VH domain is linked to a N-terminus of said second subunit of said engineered Fc region.

20. The composition of any one of claims claim 17-19, wherein at least two of said first VH domain, said second VH domain, said third VH domain and said fourth VH domain are identical.

21. The composition of any one of claims claim 17-20, wherein said first VH domain, said second VH domain, said third VH domain and said fourth VH domain are identical.

22. The composition of any one of claims claim 17-20, wherein said first VH domain, said second VH domain, said third VH domain and said fourth VH domain are distinct.Atorney Docket No. 220710-70560123. The composition of any one of claims 5-22, wherein each TL1A binding region further comprises a light chain variable (VL) domain.

24. The composition of any one of claims 5-23, wherein a binding affinity of said TL1 A binding engineered antibody to said epitope is at least 75% of the binding affinity of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy.

25. The composition of any one if claims 5-24, wherein said amino acid modification increases a binding affinity of said TL1 A binding engineered antibody for said epitope in neutral pH condition relative to a corresponding antibody prior to said amino acid modification.

26. The composition of claim 25, wherein said amino acid modification increases said binding affinity by at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50% or more relative to a corresponding antibody prior to said amino acid modification.

27. The composition of any one of claims 5-26, wherein said amino acid modification reduces a binding affinity of said TL1A binding engineered antibody for said epitope in acidic pH condition by at least 10% relative to a corresponding antibody prior to said amino acid modification.

28. The composition of any one if claims 5-27, wherein said amino acid modification increases a binding affinity of said TL1A binding engineered antibody for said epitope in trimeric TL1 A in neutral pH condition relative to a corresponding antibody prior to said amino acid modification.

29. The composition of any one if claims 5-27, wherein said amino acid modification increases a binding affinity of said TL1 A binding engineered antibody for said epitope in monomeric TL1 A in neutral pH condition relative to a corresponding antibody prior to said amino acid modification.

30. The composition of any one of claims 5-29 comprising two identical light chain variable regions.

31. The composition of any one of claims 5-29 comprising two nonidentical light chain variable regions.

32. A composition comprising a TL1 A binding engineered antibody that binds to an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, wherein: said TL1 A binding engineered antibody comprises at least three heavy chain variable regions, each comprising a TL1A binding heavy chain variable (VH) domain and a TL1 A binding light chain variable (VL) domain; andAtorney Docket No. 220710-705601 an engineered Fc region that comprises a first and a second subunit capable of stable association, wherein two of said at least three heavy chain variable regions are directly or indirectly linked to said first subunit of the engineered Fc region of the TL1 A binding engineered antibody.

33. The composition of claim 32, wherein the TL1A binding engineered antibody comprises at least one amino acid modification in said heavy chain variable region that increases binding affinity of said TL1 A binding engineered antibody for said epitope at pH 7.4 by at least 10% to that of a corresponding antibody prior to said amino acid modification as measured by surface plasmon resonance spectroscopy.

34. The composition of claim 32, wherein the TL1 A binding engineered antibody comprises at least one amino acid modification in said heavy chain variable region that decreases binding affinity at pH 5.8 of said TL1 A binding engineered antibody for said epitope by at least 10% to that of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy.

35. The composition of claim 32-34, wherein said light chain variable region comprises at least one amino acid modification that increases said binding affinity of said TL1A binding engineered antibody for said epitope at pH 7.4 by at least 10% to that of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy.

36. The composition of any one of claims 32-34, wherein said light chain variable region comprises at least one amino acid modification that decreases binding affinity at pH 5.8 of said TL1A binding engineered antibody for said epitope by at least 10% to that of a corresponding antibody prior to said amino acid modification, as measured by surface plasmon resonance spectroscopy.

37. The composition of claim 35 or 36, wherein a ratio of the binding affinity at pH 7.4 and the binding affinity for trimeric TL1A at pH 5.8 is at least 1.2.

38. The composition of claim 35 or 36, wherein a ratio of the binding affinity at pH 7.4 and the binding affinity for monomeric TL1A at pH 5.8 is at least 1.2.

39. The composition of any one of claims 32-38, comprising two identical TL1 A binding heavy chain variable domains.

40. The composition of any one of claims 32-38, comprising two nonidentical TL1A binding heavy chain variable domains.

41. The composition of any one of claims 32-40, wherein said at least one amino acid modification is within said TL1A binding VH domain that comprises CDR-H1, CDR-H2 and CDR-H3.Atorney Docket No. 220710-70560142. The composition of claim 41, wherein said at least one amino acid modification is within at least one of said CDR-H1, said CDR-H2 and said CDR-H3.

43. The composition of claim 42, wherein said at least one amino acid modification is within said CDR-H3.

44. The composition of claim 43, wherein said at least one amino acid modification in said CDR- H3 is a substitution of an uncharged amino acid residue with a charged amino acid residue.

45. The composition of claim 44, wherein said at least one amino acid modification in said CDR- H3 is a substitution of an uncharged amino acid residue with an aspartic acid residue.

46. The composition of any one of claims 10-29 and 33-45, wherein said at least one amino acid modification is within at least one framework region of said TL1 A binding VH domain.

47. The composition of any one of claims 23-29 and 33-46, wherein said at least one amino acid modification is within said light chain variable region that comprises CDR-L1, CDR-L2 and CDR-L3.

48. The composition of claim 47, wherein said at least one amino acid modification is within at least one of said CDR-L1, said CDR-L2 and said CDR-L3.

49. The composition of claim 47 or 48, wherein said at least one amino acid modification is within at least one framework region of said light chain variable region.

50. The composition of any one of claims 10-49, wherein said first and second Fc subunit comprises at least one amino acid modification relative to any one of amino acid sequences recited in TABLE 9.

51. The composition of claim 50, wherein a binding affinity of said engineered Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in acidic pH condition, and wherein a binding affinity of said engineered Fc region for said FcRn in neutral pH condition remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to said amino acid modification.

52. The composition of claim 51, wherein said binding affinity for said FcRn is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more in acidic pH condition.

53. The composition of any one of claims 50-52, wherein said at least one amino acid modification decreases plasma clearance (CL), increases plasma retention time, or increases plasma half-life (t’ ) of said TL1A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification.

54. The composition of claim 50, wherein a binding affinity of said engineered Fc region for a neonatal fragment crystallizable receptor (FcRn) is increased in neutral pH condition, and wherein a binding affinity of said engineered Fc region for said FcRn in acidic pH conditionAtorney Docket No. 220710-705601 remains within 20% of a binding affinity, each relative to a corresponding Fc region prior to said amino acid modification.

55. The composition of claim 54, wherein said binding affinity for said FcRn in neutral pH condition is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 50%, at least 70% or more.

56. The composition of any one of claims 50 and 54-55, wherein said at least one amino acid modification increases antigen plasma clearance by said TL1 A binding engineered antibody, compared to a corresponding antibody prior to said amino acid modification.

57. The composition of any one of claims 32-56, wherein said light chain variable domain comprises an amino acid sequence that is at least 90% identical to any one of amino acid sequences recited in TABLE 7.

58. The composition of any one of claims 32-57, wherein said CDR-H1, said CDR-H2, and said CDR-H3 independently comprise amino acid sequences according to amino acid sequences recited in TABLE 3 or variants thereof, wherein said variants comprise at least one amino acid substitution, at least one amino acid deletion, at least one amino acid addition, or combinations thereof relative to a corresponding amino acid sequence recited in TABLE 3.

59. The composition of any one of claims 32-58, wherein said heavy chain variable region comprises an amino acid sequence that is at least 90% identical to any one of amino acid sequences recited in TABLE 4.

60. The composition of any one of claims 32-59, wherein said heavy chain variable region comprises an amino acid sequence that is at least 90% identical to SEQ ID NO: 104.

61. The composition of claim 60, wherein said heavy chain variable region comprises an amino acid sequence that comprises one or more modification relative to SEQ ID NO: 104, wherein the one or more modifications are substitutions at positions selected from the group consisting of S30, T69, L83, N84, T104, and F107.

62. The composition of claim 60, wherein said heavy chain variable region comprises an amino acid sequence that comprises one or more modification relative to SEQ ID NO: 104, wherein the one or more modifications are selected from the group consisting of S30T, T69I, L83V, N84K, T104D, F107N and F107D.

63. The composition of any one of claims 32-62 comprising two identical light chain variable regions.

64. The composition of any one of claims 32-62 comprising two nonidentical light chain variable regions.

65. The composition of any one of claims 1-64, for use in treating a disease or condition.

66. The composition of claim 65, wherein said disease is gastric inflammatory disease.Atorney Docket No. 220710-70560167. The composition of claim 65, wherein said disease or condition is selected from the group consisting of: rheumatoid arthritis, Crohn's Disease (CD), ulcerative colitis (UC), psoriatic arthritis, ankylosing spondylitis, psoriasis, primary biliary cirrhosis, systemic lupus erythematosus or combinations thereof.

68. A pharmaceutical composition comprising the composition of any one of claims 1-67, and a pharmaceutically acceptable carrier.

69. A method of treating a disease or condition in a subj ect, the method comprising administering to the subject an effective amount of the composition of any one of claims 1-67, or the pharmaceutical composition of claim 68, thereby treating said disease or condition.

70. The method of claim 69, wherein the method comprises administering to the subject the effective amount of the composition of any one of claims 1-67, or the pharmaceutical composition of claim 68 in an induction dosing regimen sufficient to improve signs and symptoms of said disease or condition by at least 12 weeks after the start of treatment, said induction dosing regimen comprising a plurality of individual induction doses, wherein the method further comprises administering to the subject a subsequent maintenance dosing regimen after completion of the induction dosing regimen, said maintenance dosing regimen comprising a plurality of individual maintenance doses separated from each other by at least 2 weeks.

71. A method of making a TL1A binding engineered antibody with a binding affinity for an epitope on TL1 A protein, a variant thereof or a functional fragment thereof, the method comprising: identifying a histidine rich binding pocket within said epitope; constructing an antibody that comprises a heavy chain variable region and a light chain variable region; and modifying at least one amino acid of said heavy chain variable region and / or said light chain variable region to make said TL1 A binding engineered antibody, wherein: said amino acid modification changes an isoelectric point (pl) of said TL1A binding engineered antibody relative to a pl of a corresponding antibody prior to said at least one amino acid modification, thereby resulting in pH-dependent binding activity in said TL1 A binding engineered antibody, a binding affinity of said TL1 A binding engineered antibody for said epitope in neutral pH is at least 10% higher than a corresponding binding affinity prior to said at least one amino acid modification, andAttorney Docket No. 220710-705601 a binding affinity of said TL1 A engineered antibody for said epitope in acidic pH is less than 25% higher than a corresponding binding affinity prior to said at least one amino acid modification, and wherein said heavy chain variable region comprises two heavy chain variable domains that are directly or indirectly linked to a subunit of an engineered Fc region of the TL1 A binding engineered antibody.

72. The method of claim 71 further comprising modifying the engineered Fc region of said heavy chain variable region, wherein said Fc region comprises at least one modification relative to any one of amino acid sequences recited in TABLE 9.

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