Anti-Stem Cell Factor Antibody in Renal Diseases and Methods of Using the Same

Abstract

The present disclosure relates to methods of using antibodies and antigen-binding fragments thereof that bind stem cell factor (SCF) in renal diseases and disorders. The antibodies and antigen-binding fragments thereof specifically bind to SCF248 and are useful for treating inflammatory and fibrotic renal disorders.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority of U.S. Provisional Patent Application No. 62 / 900,927, filed on September 16, 2019, the entire content of which is incorporated herein by reference.

[0002] Description of Electronically Submitted Text File The content of the text file submitted electronically with this specification is incorporated herein by reference in its entirety: Sequence Listing in computer - readable form copy (filename: OPSL_001_02WO_SeqList_ST25, data record date: September 16, 2020, file size 58 kilobytes)

Background Art

[0003] Inflammatory diseases are a major cause of morbidity and mortality worldwide. Some types of chronic inflammation can lead to fibrosis, which is the formation or development of excessive fibrous connective tissue in an organ or tissue as a reparative or reactive process, as opposed to the formation of fibrous tissue as a normal component of the organ or tissue. Chronic inflammation and fibrosis can affect almost all tissues and organ systems, and fibrous tissue remodeling can affect cancer metastasis in transplant recipients and accelerate chronic graft rejection. Chronic inflammation of the kidney can lead to a fibrotic disease with high mortality.

[0004] Stem cell factor (SCF) and its receptor c-Kit are important factors in the persistence of chronic inflammation and fibrotic diseases (El-Koraie, et al., Kidney Int. 60:167 (2001), Powell, et al., Am. J. Physiol. 289:G2 (2005), El Kossi, et al., Am. J. Kidney Dis. 41:785 (2003), Powell, et al., Am. J. Physiol. 277:C183 (1999) Ding et al J Pathol. 2013 Jun;230(2):205-14., Berlin et al Lab Invest. 2006 Jun;86(6):557-65, Rasky et al Am J Physiol Lung Cell Mol Physiol. 2020 Jan 1;318(1):L200-L211). c-Kit is a type III receptor-tyrosine kinase present in many cell types (Orr-Urtreger et al., Development 109:911 (1990). Immune cells such as mast cells, eosinophils, and innate lymphoid cells 2 and 3 (ILC2 and ILC3) are all c-Kit+ cells that can drive the chronic inflammatory process depending on the associated disease and organ. At the onset of the inflammatory response, various mediators including SCF activate c-Kit+ immune cells, which in turn produce cytokines and convert fibroblasts into activated myofibroblasts. Myofibroblasts secrete extracellular matrix proteins, collagen, and fibronectin, leading to tissue fibrosis. Activated myofibroblasts, activated epithelium, endothelium, macrophages, eosinophils, mast cells, monocytes, and other cells also express SCF on the cell surface, which activates more c-Kit+ immune cells, resulting in more cytokine release and sustaining inflammation. There is a need in the art for more efficient and specific treatments for inflammatory and fibrotic diseases of the kidney. The present disclosure addresses this need and other needs.

PRIOR ART DOCUMENTS

NON-PATENT DOCUMENTS

[0005] [Non-Patent Document 1] El-Koraie, et al., Kidney Int. 60:167 (2001) [Non-Patent Document 2] Powell, et al., Am. J. Physiol. 289:G2 (2005) [Non-Patent Document 3] El Kossi, et al., Am. J. Kidney Dis. 41:785 (2003) [Non-Patent Document 4] Powell, et al., Am. J. Physiol. 277:C183 (1999) [Non-Patent Document 5] Ding et al J Pathol. 2013 Jun;230(2):205-14. [Non-Patent Document 6] Berlin et al Lab Invest. 2006 Jun;86(6):557-65 [Non-Patent Document 7] Rasky et al Am J Physiol Lung Cell Mol Physiol. 2020 Jan 1;318(1):L200-L211 [Non-Patent Document 8] Orr-Urtreger et al., Development 109:911 (1990) [Summary of the Invention] [Means for Solving the Problems]

[0006] In one aspect, the present disclosure provides a method for treating renal diseases and disorders, comprising administering to a patient having a renal disease or disorder an antibody or fragment thereof that specifically binds to stem cell factor (SCF). In embodiments, the renal disease or disorder is an inflammatory renal disease, a fibrotic renal disease, and / or a tissue remodeling renal disease. In embodiments, the antibodies and fragments thereof for use in the methods provided herein specifically bind to the SCF isoform SCF248. In some embodiments, the antibodies and fragments thereof for use in the methods provided herein comprise heavy chain complementarity determining regions (CDRs), and heavy chain CDR1, CDR2, and CDR3 comprise SEQ ID NO: 1, 2, and 3, respectively. In some embodiments, the antibodies and fragments thereof for use in the methods provided herein comprise light chain CDRs, and light chain CDR1, CDR2, and CDR3 comprise SEQ ID NO: 4, 5, and 6, respectively. In some embodiments, the antibodies and fragments thereof for use in the methods provided herein comprise heavy chain CDR1, CDR2, and CDR3 comprising SEQ ID NO: 1, 37, and 3, respectively. In some embodiments, the antibody and fragment thereof comprise a heavy chain variable region having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to a sequence selected from the group consisting of SEQ ID NO: 7, 8, 9, 10, 11, and 12. In some embodiments, the antibody and fragment thereof comprise a light chain variable region having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to a sequence selected from the group consisting of SEQ ID NO: 13, 14, 15, 16, and 17. In some embodiments, the antibody and fragment thereof comprise a heavy chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 7, 8, 9, 10, 11, and 12 and a light chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 13, 14, 15, 16, and 17.

[0007] In some embodiments, the present disclosure provides a method for treating an inflammatory disease and / or a fibrotic disease of the kidney, which includes administering an antibody or a fragment thereof that includes the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 7 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the antibody or the fragment thereof is the antibody or the fragment thereof according to claim 1, which includes the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 8 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the antibody or the fragment thereof includes the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 9 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the antibody or the fragment thereof includes the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 10 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the antibody or the fragment thereof includes the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 11 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the antibody or the fragment thereof includes the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 12 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16.

[0008] In some embodiments, the antibody or the fragment thereof is humanized. In some embodiments, the antibody is a monoclonal antibody. In some embodiments, the antibody includes a human IgG1 domain or a human IgG4 domain. In some embodiments, the antibody is an antigen-binding fragment, and this fragment is selected from Fab, F(ab’)2, Fab’, scFv, and single domain antibody (sdAb).

[0009] In some embodiments, the antibody or the fragment thereof blocks the interaction between SCF (e.g., SCF248) and c-kit. In some embodiments, the antibody specifically binds to SCF248. In some embodiments, the antibody does not bind to SCF220. In some embodiments, the antibody causes the internalization of SCF and makes it unavailable on the cell surface, thereby preventing the interaction between SCF248 and c-kit.

[0010] In one aspect, the present disclosure provides a pharmaceutical composition comprising an antibody or a fragment thereof provided herein. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable carrier, diluent, or excipient.

[0011] In some embodiments, the present disclosure provides an isolated nucleic acid molecule encoding an antibody or a fragment thereof provided herein. In some embodiments, the present disclosure provides an expression vector comprising a nucleic acid encoding an antibody or a fragment thereof. In some embodiments, the present disclosure provides a recombinant host cell comprising the expression vector.

[0012] In one aspect, the present disclosure provides a method for producing an antibody that specifically binds to stem cell factor isoform 248 (SCF248), comprising immunizing a host animal with a peptide comprising SEQ ID NO: 30 (ASSLRNDSSSSNRKAKNPPGD) or a fragment thereof, and obtaining an antibody from the immunized host animal. In some embodiments, the host animal is non-human. In some embodiments, the fragment of SEQ ID NO: 30 comprises at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, or 20 consecutive amino acids of SEQ ID NO: 30. In some embodiments, the fragment of SEQ ID NO: 30 comprises 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 consecutive amino acids of SEQ ID NO: 30. In some embodiments, the N-terminal amino acid of the fragment of SEQ ID NO: 30 is the alanine at position 1 at the N-terminus of SEQ ID NO: 30. In some embodiments, the method comprises immunizing the host animal with a peptide consisting of SEQ ID NO: 30. In some embodiments, the antibody from the immunized host animal is obtained from immune cells isolated from the host animal. In some embodiments, the method further comprises generating hybridomas using the immune cells. Thus, in some embodiments, the present disclosure provides hybridomas that produce the monoclonal antibodies described herein.

[0013] In one aspect, the present disclosure provides an antibody or a fragment thereof that specifically binds to SCF248, wherein the antibody or the fragment thereof binds to an epitope comprising at least 8, at least 9, at least 10, at least 11, at least 12, or at least 13 consecutive amino acids of SEQ ID NO: 33, and the antibody inhibits the interaction between SCF248 and c-Kit. In further embodiments, the epitope comprises SEQ ID NO: 33 or SEQ ID NO: 36. In yet another embodiment, the epitope consists of SEQ ID NO: 33 or SEQ ID NO: 36.

[0014] In one aspect, the present disclosure provides compositions and methods for inhibiting the interaction between SCF and c-Kit. C-kit is expressed on immune cells, hematopoietic stem cells, and several stromal cells. The ligand of C-kit, SCF248, can be upregulated in myofibroblasts, activated epithelium, endothelium, macrophages, eosinophils, mast cells, monocytes, and the like. In some embodiments, the compositions and methods specifically inhibit the interaction between SCF248 and c-Kit. For example, in some embodiments, the compositions and methods specifically inhibit the interaction between SCF248 on myofibroblasts and c-Kit on immune cells. As another example, in some embodiments, the compositions and methods provided herein specifically inhibit the interaction between SCF248 on myofibroblasts, activated epithelium, endothelium, macrophages, eosinophils, mast cells, and / or monocytes and c-Kit on immune cells and / or stromal cells. In some embodiments, the method includes contacting SCF248 on myofibroblasts with an antibody or a fragment thereof provided herein. In some embodiments, the antibody or a fragment thereof provided herein blocks the binding of SCF248 to c-Kit. In some embodiments, the blocking is via steric hindrance. In some embodiments, the antibody or a fragment thereof provided herein internalizes SCF248.

[0015] In some embodiments, the present disclosure provides a method for inhibiting inflammation in a subject in need of inhibiting inflammation, comprising administering to the subject an antibody or a fragment thereof provided herein. In some embodiments, the present disclosure provides a method for inhibiting an inflammatory disease in a subject in need of inhibiting an inflammatory disease, comprising administering to the subject an antibody or a fragment thereof provided herein. In further embodiments, the inflammatory disease is a chronic inflammatory disease. In some embodiments, the present disclosure provides a method for treating inflammation and / or a chronic inflammatory disease in a subject in need of treating inflammation and / or a chronic inflammatory disease, comprising administering to the subject an antibody or a fragment thereof provided herein.

[0016] In some embodiments, the present disclosure provides a method for inhibiting fibrosis in a subject in need of inhibiting fibrosis, comprising administering to the subject an antibody or a fragment thereof provided herein. In some embodiments, the present disclosure provides a method for treating a fibrotic disease in a subject in need of treating a fibrotic disease, comprising administering to the subject an antibody or a fragment thereof provided herein. In an embodiment, the method further comprises administering one or more additional therapies and / or therapeutic agents.

[0017] In some embodiments, the inflammatory kidney disease or fibrotic kidney disease is selected from the group consisting of renal fibrosis of the kidney, interstitial fibrosis and tubular atrophy (IFTA), chronic kidney disease, end-stage renal disease (ESRD), glomerulonephritis, chronic kidney allograft rejection, nephrogenic systemic fibrosis, and nephrosis (e.g., IgA nephropathy, focal segmental glomerulosclerosis, rapidly progressive glomerulonephritis, crescentic glomerulonephritis, lupus nephritis, hypertensive nephropathy, or diabetic nephropathy). BRIEF DESCRIPTION OF THE DRAWINGS

[0018]

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Mode for Carrying Out the Invention

[0019] Stem cell factor (SCF) is an important mediator of acute and chronic inflammation, fibrotic diseases, and tissue remodeling diseases. The interaction between SCF and c-Kit on immune cells initiates and sustains inflammation and fibrosis. The present disclosure provides compositions and methods for treating inflammatory and fibrotic kidney diseases by inhibiting the interaction between SCF and c-Kit. Accordingly, the present disclosure provides a method for treating fibrotic kidney diseases such as chronic inflammatory kidney diseases and chronic kidney diseases. The method includes administering to a patient suffering from an inflammatory and / or fibrotic kidney disease an antibody or a fragment thereof that specifically binds to SCF. In embodiments, the antibodies and fragments thereof provided herein specifically bind to SCF248 and do not bind to SCF220. Accordingly, the present disclosure provides a specific and effective method for inhibiting inflammation and fibrosis in kidney diseases and disorders and for treating inflammatory and fibrotic kidney diseases.

[0020] Definitions As used herein, the term "antibody" refers to a binding protein having at least one antigen-binding domain. The antibodies and fragments thereof of the present invention can be whole antibodies or any fragment thereof. Thus, the antibodies and fragments of the present invention include monoclonal antibodies or fragments thereof, and antibody variants or fragments thereof, as well as immune complexes. Antigen-binding fragments include Fab fragments, Fab' fragments, F(ab')2 fragments, bispecific Fab dimers (Fab2), trispecific Fab trimers (Fab3), Fv, single-chain Fv proteins ("scFv"), bis-scFv, (scFv)2, minibodies, diabodies, triabodies, tetra-bodies, disulfide-stabilized Fv proteins ("dsFv"), single-domain antibodies (sdAb, nanobodies), heavy-chain-only antibodies (e.g., camelid VHH, camelid nanobodies, shark Ig NAR), and portions of full-length antibodies that are responsible for antigen binding. An isolated antibody or antigen-binding fragment thereof is one that has been identified and separated and / or recovered from the components of its natural environment.

[0021] In some embodiments, the antibodies and antigen-binding fragments thereof are isolated antibodies and fragments thereof, and thus the present invention provides isolated antibodies and antigen-binding fragments thereof, and nucleic acids encoding such antibodies and fragments, and compositions comprising such isolated antibodies, fragments, and nucleic acids. The term "isolated" refers to a compound of interest (e.g., an antibody or nucleic acid) that has been separated from the components of its natural environment. The present invention further provides a pharmaceutical composition comprising an isolated antibody or fragment thereof, or a nucleic acid encoding such an antibody or fragment, further comprising one or more pharmaceutically acceptable carriers. Pharmaceutically acceptable carriers include, for example, excipients, diluents, encapsulating materials, fillers, buffers, or other agents.

[0022] As used herein, the term "derived," when used to refer to a molecule or polypeptide in comparison to a reference antibody or other binding protein, means a molecule or polypeptide that is specific for and binds to the same epitope as the reference antibody or other binding protein.

[0023] As used herein, the phrase "specific for" can mean that an antibody does not bind to a target solely by non-specific interactions, and this property can be determined by comparison with an isotype control or the like. Specific binding can include, but is not necessarily limited to, exclusive binding to a single target. In embodiments, the antibodies provided herein specifically bind to SCF248 and do not bind to SCF220.

[0024] The term "host cell" means a cell that has been transformed or is capable of being transformed with a nucleic acid sequence, whereby the cell expresses a gene of interest. The term includes progeny of the parent cell, whether or not the progeny are morphologically identical to the original parent cell or have the same genetic composition as the original parent cell, so long as the gene of interest is present.

[0025] A "variant" of a polypeptide (e.g., an antigen-binding protein or an antibody) includes an amino acid sequence in which one or more amino acid residues have been inserted into, deleted from, and / or substituted in the amino acid sequence as compared to another polypeptide sequence. Variants include antibodies or fragments provided herein, or antibodies and fragments thereof having a listed percent identity to a listed DNA or amino acid sequence of an antibody or fragment having the listed DNA or amino acid sequence.

[0026] The term "identity" refers to the relationship between the sequences of two or more polypeptide molecules or two or more nucleic acid molecules, determined by aligning and comparing the sequences. "Percent identity", "percent homology", "sequence identity", or "sequence homology", etc., mean the percent of identical residues between amino acids or nucleotides in the molecules being compared, and are calculated based on the smallest size of the molecules being compared. For these calculations, gaps (if any) in the alignment are preferably treated by a particular mathematical model or computer program (i.e., "algorithm"). Methods that can be used to calculate the identity of aligned nucleic acids or polypeptides include those described in Computational Molecular Biology, (Lesk, A.M., ed.), 1988, New York: Oxford University Press, Biocomputing Informatics and Genome Projects, (Smith, D.W., ed.), 1993, New York: Academic Press, Computer Analysis of Sequence Data, Part I, (Griffin, A.M., and Griffin, H.G., eds.), 1994, New Jersey: Humana Press, von Heinje, G., 1987, Sequence Analysis in Molecular Biology, New York: Academic Press, Sequence Analysis Primer, (Gribskov, M. and Devereux, J., eds.), 1991, New York: M. Stockton Press, and Carillo et al., 1988, SIAM J. Applied Math. 48:1073. In calculating percent identity, the sequences being compared are typically aligned in a way that gives the maximum match between the sequences.

[0027] The term "light chain" includes full-length light chains and fragments thereof that have a variable region sequence sufficient to confer binding specificity. A full-length light chain includes a variable region domain and a constant region domain. The variable region domain of the light chain is at the amino terminus of the polypeptide. Light chains include kappa chains and lambda chains.

[0028] The term "heavy chain" includes full-length heavy chains and fragments thereof that have a variable region sequence sufficient to confer binding specificity. A full-length heavy chain includes a variable region domain, three constant region domains, C H 1, C H 2, and C H 3. The variable heavy chain domain is at the amino terminus of the polypeptide, and the C H domain is at the carboxyl terminus, with CH3 being closest to the carboxyl terminus of the polypeptide. Heavy chains can be any isotype including IgG (including IgG1, IgG2, IgG3, and IgG4 subtypes), IgA (including IgA1 and IgA2 subtypes), IgM, and IgE. The term "isotype" refers to the antibody class encoded by the heavy chain constant region gene. In some embodiments, the antibodies provided herein have an IgG4 heavy chain, or an IgG4 heavy chain containing specific amino acid mutations. For example, in some embodiments, IgG4 contains a mutation at position 228 (EU numbering scheme, Kabat et al. Sequence of proteins of immunologic interest, 5th ed Bethesda, MD, NIH 1991) to inhibit Fab arm exchange. For example, in some embodiments, the IgG4 heavy chain is an IgG4 S228P heavy chain. In some embodiments, the heavy chain contains one or more amino acid mutations that reduce binding to Fc receptors, thereby reducing or eliminating the effector function of the antibody. For example, the heavy chain can contain a mutation at one or more of positions 233, 234, 235, 236, 237, 265, 309, 331, and 409 (EU numbering).

[0029] The term "variable region" or "variable domain" refers to a portion of the light and / or heavy chains of an antibody, and typically includes approximately 120-130 amino acids at the amino terminus in the heavy chain, and approximately 100-110 amino terminal amino acids in the light chain. In certain embodiments, the variable regions of different antibodies can vary widely in amino acid sequence, even among antibodies of the same species. The variable region of an antibody typically determines the specificity of that antibody for its target. The term "target", as used herein, refers to a molecule or a portion of a molecule that can be bound by an antigen-binding protein. In certain embodiments, the target can have one or more epitopes. In certain embodiments, the target is an antigen. The use of the term "antigen" in the phrase "antigen-binding protein" simply indicates that a protein sequence containing the antigen can be bound by an antibody. In this context, it is not required that the protein be foreign or capable of inducing an immune response.

[0030] The term "epitope" includes any determinant that can be bound by an antigen-binding protein such as an antibody or by a T cell receptor. An epitope is the region of an antigen that is bound by an antigen-binding protein that targets that antigen, and when the antigen is a protein, includes specific amino acids that come into direct contact with the antigen-binding protein. More frequently, epitopes are present on proteins, but in some cases can be present on other types of molecules such as nucleic acids. Epitope determinants can include chemically active surface arrangements of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and can have specific three-dimensional structural characteristics and / or specific charge characteristics. Generally, an antibody specific for a particular target antigen selectively recognizes the epitope on the target antigen in a complex mixture of proteins and / or macromolecules. Antibody epitopes can be linear or conformational. In embodiments, the epitopes provided herein are linear epitopes.

[0031] The use of the singular form includes the plural unless otherwise expressly stated. The words "a" or "an" mean "at least one" unless otherwise expressly stated. The use of "or" means "and / or" unless otherwise stated. The meaning of the phrase "at least one" corresponds to the meaning of the phrase "one or more". Further, the term "including", as well as the use of other forms such as "includes" and "included", is not limiting. Also, terms such as "element" or "component" include both elements and components that include one unit and elements and components that include more than one unit unless otherwise expressly stated. As used herein, the term "about" refers to an amount that is more or less than the recited parameter value, e.g., plus or minus 5 or 10% of the object being modified by "about", or what would be recognized by one of ordinary skill in the art from the context (e.g., about 50% of the interval between values). The term "about" includes the value being referred to.

[0032] Stem cell factor In humans, there are at least two forms of SCF with different structures and activities. SCF220 functions in several homeostatic functions including hematopoiesis and spermatogenesis and is found in the bone marrow, testis, as well as other tissues and organs. SCF220 is slowly cleavable and is sometimes called "membrane SCF". In contrast, SCF248 is rapidly cleavable and contains a cleavage site within exon 6 located between the N-terminal c-kit binding domain and the transmembrane domain. SCF248 can be termed "soluble SCF". Exon 6 is excluded from SCF220 via alternative splicing and thus SCF220 lacks this cleavage site. The monomeric extracellular domain (SCF165) is a cleavage product and functions as a biomarker in the plasma of chronic inflammatory diseases. Plasma may also contain detectable levels of the SCF extracellular domain derived from SCF220, but most of the detectable extracellular domain is expected to be SCF165. SCF248 is an isoform found in myofibroblasts, activated epithelial cells, and other cells, which activates immune cells during inflammation and contributes to the persistence of fibrosis. More specifically, SCF248 binds to c-Kit on immune cells and initiates the production of cytokines that activate fibroblasts to become myofibroblasts, which secrete extracellular matrix proteins, collagen, and fibronectin. Activated myofibroblasts, as well as activated epithelial, endothelial, macrophage, eosinophil, mast cell, monocyte, and other cells also express SCF on the cell surface, activating more c-Kit+ immune cells and resulting in further cytokine release and immune activation and fibrotic responses.

[0033] The antibodies and antigen-binding fragments thereof disclosed herein are specific for SCF. In some embodiments, the antibodies and fragments thereof are specific for human SCF. In some embodiments, the antibodies and fragments thereof are specific for SCF248. In some embodiments, the antibody binds to SCF248 and does not bind to other isoforms of SCF. In some embodiments, the antibody binds to SCF248 and does not bind to SCF220. In some embodiments, the present disclosure provides methods for making an antibody or fragment thereof that is specific for SCF248. Exemplary antibodies and fragments specific for SCF248, as well as methods for making and using the antibodies and fragments, are provided in the present disclosure. In some embodiments, the antibodies and fragments thereof provided herein bind to SCF248 and disrupt the positive feedback loop between SCF248 and c-Kit+ immune cells expressed on various cell types by blocking the interaction between SCF248 and c-Kit.

[0034] Antibodies and fragments The present disclosure provides antibodies, including monoclonal antibodies, and fragments thereof. As used herein, antibody fragments provided herein that are specific for SCF (e.g., SCF248) may be referred to herein as antigen-binding fragments, which means that they contain a portion of the parent antibody capable of binding to a target antigen (SCF, e.g., SCF248). "Antibody fragment", "antigen-binding fragment", etc. are used interchangeably herein. Examples of antigen-binding fragments include Fab fragments, Fab' fragments, F(ab') fragments, Fv fragments, isolated CDR regions, bispecific Fab dimers (Fab2), trispecific Fab trimers (Fab3), single-chain Fv proteins ("scFv"), bis-scFv, (scFv)2, minibodies, diabodies, triabodies, tetrabodies, disulfide-stabilized Fv proteins ("dsFv"), single-domain antibodies (sdAb, nanobodies), heavy-chain-only antibodies (e.g., camelid VHH, camelid nanobodies, shark Ig NAR), and portions of full-length antibodies that are responsible for antigen binding.

[0035] The "Fab fragment" contains one light chain, as well as the C of one heavy chain H 1 and the variable region. The heavy chain of the Fab molecule cannot form a disulfide bond with another heavy chain molecule. The "Fab' fragment" contains one light chain, as well as a portion of one heavy chain containing the VH domain and C H 1 domain, and also the region between the C H 1 domain and the C H 2 domains, such that an interchain disulfide bond can be formed between the two heavy chains of two Fab' fragments to form an F(ab')2 molecule. The "F(ab')2 fragment" contains two heavy chains and the C H 1 domain and a portion of the constant region between the C H 2 domains, such that an interchain disulfide bond is formed between the two heavy chains. Thus, the F(ab')2 fragment consists of two Fab' fragments held together by a disulfide bond between the two heavy chains. The "Fv fragment" contains the variable regions from both the heavy and light chains, but lacks the constant regions. The "scFv" is an Fv molecule in which the heavy and light chain variable regions are connected by a flexible linker to form a single polypeptide chain that forms the antigen-binding region.

[0036] In some embodiments, the antibodies and fragments thereof provided herein are defined by their complementarity-determining regions (CDRs). The CDRs are part of the variable chains in an antibody, and each of the light and heavy chain variable regions contains three CDRs, CDR1, CDR2, and CDR3. The CDRs of an antibody determine antigen specificity. In certain embodiments, the precise delineation of the CDRs and the identification of the residues that comprise the binding site of the antibody are achieved by elucidating the structure of the antibody and / or the structure of the antibody-ligand complex. In certain embodiments, this can be achieved by any of a variety of techniques known to those of skill in the art, such as X-ray crystallography. In certain embodiments, various analytical methods can be used to identify or estimate the CDR regions. Examples of such methods include, but are not limited to, the Kabat definition, the Chothia definition, the AbM definition, and the contact definition.

[0037] The Kabat definition is a standard for numbering the residues of an antibody and is typically used to identify CDR regions. See, for example, Johnson & Wu, Nucleic Acids Res., 28:214-8 (2000). The Chothia definition is similar to the Kabat definition, but the Chothia definition takes into account the positions of certain structural loop regions. See, for example, Chothia et al., J. Mol. Biol., 196:901-17 (1986), Chothia et al., Nature, 342:877-83 (1989). The AbM definition uses an integrated suite of computer programs generated by Oxford Molecular Group to model antibody structures. See, for example, Martin et al., Proc Natl Acad Sci (USA), 86:9268-9272 (1989); “AbM (trademark, A Computer Program for Modeling Variable Regions of Antibodies,” Oxford, UK; Oxford Molecular, Ltd. The AbM definition models the tertiary structure of an antibody from its primary sequence using a combination of knowledge databases and ab initio methods, such as those described in Samudrala et al., ”Ab Initio Protein Structure Prediction Using a Combined Hierarchical Approach,” in PROTEINS, Structure, Function and Genetics, Suppl. 3;194-198, (1999). The contact definition is based on the analysis of achievable complex crystal structures. See, for example, MacCallum et al., J. Mol. Biol., 5:732-45 (1996).

[0038] Antibodies and fragments thereof can also include recombinant polypeptides, fusion proteins, and bispecific antibodies. The anti-SCF antibodies and fragments thereof disclosed herein can be of the IgG1, IgG2, IgG3, or IgG4 isotype. In one embodiment, the anti-SCF antibodies and fragments thereof disclosed herein are of the IgG1 or IgG4 isotype. The anti-SCF antibodies and fragments thereof of the present invention can be derived from any species including, but not limited to, mouse, rat, rabbit, primate, llama, camel, goat, shark, chicken, and human. The SCF antibodies and fragments thereof can be chimeric antibodies, humanized antibodies, or fully human antibodies. In one embodiment, the anti-SCF antibody is a mouse antibody. In another embodiment, the anti-SCF antibody is a chimeric antibody. In a further embodiment, the chimeric antibody is a mouse-human chimeric antibody. In another embodiment, the antibody is derived from a mouse and humanized.

[0039] A "chimeric antibody" is an antibody that has at least a portion of the heavy chain variable region and at least a portion of the light chain variable region derived from one species, and at least a portion of the constant region derived from another species. For example, in one embodiment, a chimeric antibody can include a mouse variable region and a human constant region.

[0040] A "humanized antibody" is an antibody that contains complementarity determining regions (CDRs) derived from a non-human antibody, as well as framework regions and constant regions derived from a human antibody. For example, the anti-SCF antibodies provided herein can include CDRs derived from one or more mouse antibodies, as well as human framework regions and constant regions. Thus, in one embodiment, the humanized antibodies provided herein bind to the same SCF epitope as the mouse antibody from which the CDRs of the antibody are derived.

[0041] In some embodiments, the antibodies and fragments thereof provided herein include a heavy chain and a light chain, each of which includes three CDRs. The amino acid sequences of exemplary heavy chain CDR1, CDR2, and CDR3 (HCDR1, HCDR2, and HCDR3, respectively), and light chain CDR1, CDR2, and CDR3 (LCDR1, LCDR2, and LCDR3, respectively) are provided in Table 1 below. Table 1 also provides the amino acid sequences of exemplary heavy and light chain variable regions. In some embodiments, the present disclosure provides antibodies referred to herein as "5H10" and "2G8". The heavy chain variable regions of humanized 5H10 or 2G8 are referred to herein as VH1, VH2, VH3, VH4, and VH5. 5H10 VH0 is the variable heavy chain of a mouse parental antibody generated via the methods described herein. VH1, VH2, VH3, VH4, and VH5 are humanized heavy chain variable regions derived from 5H10 VH0 or 2G8 VH0, respectively. The 5H10 antibody includes a kappa light chain. The mouse parental antibody variable light chain is referred to herein as 5H10 VK0. VK1, VK2, VK3, and VK4 are humanized light chain variable regions derived from VK0, respectively. The 2G8 antibody includes a lambda light chain. The mouse parental antibody variable light chain is referred to herein as 2G8 VL0. VL1, VL2, VL3, and VL4 are humanized light chain variable regions derived from VL0, respectively.

Table 1-1

Table 1-2

[0042] One of ordinary skill in the art will understand that the variable heavy and variable light chains can be independently selected from the antibodies provided herein or can be mixed and matched. Thus, in some embodiments, the antibodies and fragments thereof provided herein include combinations of heavy and light chains selected from the group consisting of VH0 / VK0, VH0 / VK1, VH0 / VK2, VH0 / VK3, VH0 / VK4, VH1 / VK0, VH1 / VK1, VH1 / VK2, VH1 / VK3, VH1 / VK4, VH2 / VK0, VH2 / VK1, VH2 / VK2, VH2 / VK3, VH2 / VK4, VH3 / VK0, VH3 / VK1, VH3 / VK2, VH3 / VK3, VH3 / VK4, VH4 / VK0, VH4 / VK1, VH4 / VK2, VH4 / VK3, VH4 / VK4, VH5 / VK0, VH5 / VK1, VH5 / VK2, VH5 / VK3, and VH5 / VK4.

[0043] In some embodiments, the present disclosure provides an antibody or fragment thereof comprising an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 90%, at least 95%, or at least 99% homology to an amino acid sequence selected from the group consisting of SEQ ID NOs: 7-12. In some embodiments, the present disclosure provides an antibody or fragment thereof comprising a heavy chain variable region as set forth in a sequence selected from the group consisting of SEQ ID NOs: 7-12. In some embodiments, the present disclosure provides an antibody or fragment thereof comprising an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% homology to an amino acid sequence selected from the group consisting of SEQ ID NOs: 7-11, and the antibody or fragment comprises heavy chain CDR1, CDR2, and CDR3 that are identical to SEQ ID NOs: 1, 2, and 3, respectively. In some embodiments, the present disclosure provides an antibody or fragment thereof comprising an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% homology to the amino acid sequence of SEQ ID NO: 12, and the antibody or fragment comprises heavy chain CDR1, CDR2, and CDR3 that are identical to SEQ ID NOs: 1, 37, and 3, respectively.

[0044] In some embodiments, the present disclosure provides an antibody or fragment thereof that has at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% homology to an amino acid sequence selected from the group consisting of SEQ ID NOs: 13-17. In some embodiments, the present disclosure provides an antibody or fragment thereof that comprises a light chain variable region as set forth in a sequence selected from the group consisting of SEQ ID NOs: 13-17. In some embodiments, the present disclosure provides an antibody or fragment thereof that has at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% homology to an amino acid sequence selected from the group consisting of SEQ ID NOs: 13-17, and the antibody or fragment thereof comprises light chain CDR1, CDR2, and CDR3 that are identical to SEQ ID NOs: 4, 5, and 6, respectively.

[0045] In some embodiments, the present disclosure provides an antibody or fragment thereof comprising an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% homology to SEQ ID NO:7 and SEQ ID NO:13, SEQ ID NO:7 and SEQ ID NO:14, SEQ ID NO:7 and SEQ ID NO:15, SEQ ID NO:7 and SEQ ID NO:16, SEQ ID NO:7 and SEQ ID NO:17, SEQ ID NO:8 and SEQ ID NO:13, SEQ ID NO:8 and SEQ ID NO:14, SEQ ID NO:8 and SEQ ID NO:15, SEQ ID NO:8 and SEQ ID NO:16, SEQ ID NO:8 and SEQ ID NO:17, SEQ ID NO:9 and SEQ ID NO:13, SEQ ID NO:9 and SEQ ID NO:14, SEQ ID NO:9 and SEQ ID NO:15, SEQ ID NO:9 and SEQ ID NO:16, SEQ ID NO:9 and SEQ ID NO:17, SEQ ID NO:10 and SEQ ID NO:13, SEQ ID NO:10 and SEQ ID NO:14, SEQ ID NO:10 and SEQ ID NO:15, SEQ ID NO:10 and SEQ ID NO:16, SEQ ID NO:10 and SEQ ID NO:17, SEQ ID NO:11 and SEQ ID NO:13, SEQ ID NO:11 and SEQ ID NO:14, SEQ ID NO:11 and SEQ ID NO:15, SEQ ID NO:11 and SEQ ID NO:16, SEQ ID NO:11 and SEQ ID NO:17, SEQ ID NO:12 and SEQ ID NO:13, SEQ ID NO:12 and SEQ ID NO:14, SEQ ID NO:12 and SEQ ID NO:15, SEQ ID NO:12 and SEQ ID NO:16, or SEQ ID NO:12 and SEQ ID NO:17.

[0046] In certain embodiments, the antibody and its fragments comprise a combination of heavy and light chains selected from the group consisting of VH1 / VK1, VH1 / VK2, VH1 / VK3, VH2 / VK1, VH2 / VK2, VH2 / VK3, VH3 / VK1, VH3 / VK2, VH3 / VK3, VH4 / VK1, VH4 / VK2, VH4 / VK3, VH5 / VK1, VH5 / VK2, and VH5 / VK3. In some embodiments, the antibody comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% sequence identity to SEQ ID NO: 8 or SEQ ID NO: 9, and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% sequence identity to SEQ ID NO: 16. In some embodiments, the antibody or its fragment comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% sequence identity to SEQ ID NO: 8 or SEQ ID NO: 9, and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% sequence identity to SEQ ID NO: 16, and the antibody or fragment comprises heavy chain CDR1, CDR2, and CDR3 identical to SEQ ID NOs: 1, 2, and 3, respectively, and light chain CDR1, CDR2, and CDR3 identical to SEQ ID NOs: 4, 5, and 6, respectively. In some embodiments, the antibody or its fragment comprises an amino acid sequence having at least 95% or at least 99% sequence identity to SEQ ID NO: 8 or SEQ ID NO: 9, and an amino acid sequence having at least 95% or at least 99% sequence identity to SEQ ID NO: 16, and the antibody or fragment comprises heavy chain CDR1, CDR2, and CDR3 identical to SEQ ID NOs: 1, 2, and 3, respectively, and light chain CDR1, CDR2, and CDR3 identical to SEQ ID NOs: 4, 5, and 6, respectively. The antibody or its fragment can specifically bind to SCF248 but cannot bind to SCF220. In some embodiments, the antibody comprises the heavy chain variable region set forth in SEQ ID NO: 8 and the light chain variable region set forth in SEQ ID NO: 16. In some embodiments, the antibody comprises the heavy chain variable region set forth in SEQ ID NO: 9 and the light chain variable region set forth in SEQ ID NO: 16.

[0047] In some embodiments, the antibodies and fragments provided herein include the heavy chain variable region amino acid sequences set forth in SEQ ID NO: 7, 8, 9, 10, 11, or 12 or variants thereof, and / or the light chain variable region amino acid sequences set forth in SEQ ID NO: 13, 14, 15, 16, or 17 or variants thereof. Variants can include 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions or deletions, or combinations thereof. In some embodiments, the amino acid substitutions are conservative substitutions. An anti-SCF antibody disclosed herein having one or more amino acid substitutions, insertions, deletions, or combinations thereof in a CDR or variable light or heavy chain region retains the biological activity of the corresponding anti-SCF antibody having no amino acid substitutions, insertions, or deletions as compared to the sequences provided herein. Accordingly, the variant anti-SCF antibodies provided herein retain specific binding to SCF248. Terms such as percent homology, sequence identity, sequence homology are used interchangeably herein and refer to dividing the number of identical amino acid sequences shared by two reference sequences by the total number of amino acid positions and multiplying by 100.

[0048] In some embodiments, the invention provides an antibody that binds to the same epitope as any one of the exemplary antibodies disclosed herein. Thus, in some embodiments, the invention provides an antibody that competes with the exemplary antibodies provided herein for binding to SCF. For example, in some embodiments, the present disclosure provides an antibody that specifically binds to a region of the amino acid sequence provided herein as SEQ ID NO: 29. In some embodiments, the antibodies provided herein specifically bind to an epitope comprising the amino acid sequence of SEQ ID NO: 33 (ASSLRNDSSSSNRK) or SEQ ID NO: 36 (ASSLRNDSSSSNR). In some embodiments, the present disclosure provides an antibody that specifically binds to an epitope consisting of the amino acid sequence set forth in SEQ ID NO: 33 or SEQ ID NO: 36. In some embodiments, the present disclosure provides an antibody that specifically binds to an epitope comprising at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 consecutive amino acids of SEQ ID NO: 33.

[0049] In some embodiments, the antibodies and fragments thereof provided herein comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and / or LCDR3 of the heavy and light chain variable regions provided herein, or variants thereof. Thus, in some embodiments, the antibodies and fragments thereof provided herein comprise antibodies wherein the HCDRs are the HCDRs of SEQ ID NOs: 7, 8, 9, 10, 11, or 12, and / or the LCDRs are the LCDRs of SEQ ID NOs: 13, 14, 15, 16, or 17. For example, in some embodiments, the antibody and fragments thereof comprise amino acids 31-35, 50-65, and 95-102 of any one of the heavy chain variable regions provided herein, as defined by the Kabat numbering scheme. In some embodiments, the antibody and fragments thereof comprise amino acids 24-34, 50-56, and 89-97 of any one of the light chain variable regions provided herein, as defined by the Kabat numbering scheme.

[0050] Exemplary humanized antibodies are provided herein. Additional anti-SCF antibodies that include the heavy and light chain CDRs provided herein, or variants thereof, can be generated using any human framework sequence and are also encompassed by the present invention. In one embodiment, framework sequences suitable for use in the present invention include framework sequences that are structurally similar to the framework sequences provided herein. Further modifications in the framework region can be made to improve the properties of the antibodies provided herein. Such further framework modifications can include chemical modifications, point mutations to reduce immunogenicity or remove T cell epitopes, or back mutations to residues within the original germline sequence.

[0051] In some embodiments, such framework modifications include those corresponding to the mutations exemplified herein, including back mutations to the germline sequence. For example, in one embodiment, one or more amino acids within the human framework region of the VH and / or VL of the humanized antibody provided herein are back mutated to the corresponding amino acids in the parental mouse antibody. The present invention also encompasses humanized antibodies that bind to SCF (e.g., SCF248) and include framework modifications corresponding to the exemplary modifications described herein with respect to any suitable framework sequence, as well as other framework modifications that otherwise improve the properties of the antibody. In other embodiments, the antibodies provided herein include one or more mutations for improving stability, solubility, altering glycosylation, and / or reducing immunogenicity, such as targeted amino acid changes that reduce deamidation or oxidation, reduce isomerization, optimize hydrophobic core and / or charge cluster residues, remove hydrophobic surface residues, optimize residues involved in the interface between the variable heavy chain and the variable light chain, and / or modify the isoelectric point.

[0052] The anti-SCF antibodies and fragments thereof provided herein may further comprise Fc region modifications for modifying effector function. The Fc modifications can be amino acid insertions, deletions, or substitutions, or chemical modifications. For example, the Fc region modifications can be made to increase or decrease complement binding, to increase or decrease antibody-dependent cellular cytotoxicity, or to increase or decrease the half-life of the antibody. Some Fc modifications increase or decrease the affinity of the antibody for Fcγ receptors such as FcγRI, FcγRII, FcγRIII, or FcRn. Various Fc modifications are described in the art, for example, in Shields et al., J Biol.Chem 276;6591(2001), Tai et al. Blood 119;2074(2012), Spiekermann et al. J Exp.Med 196;303(2002), Moore et al. mAbs 2:2;181(2010), Medzihradsky Methods in Molecular Biology 446;293(2008), Mannan et al. Drug Metabolism and Disposition 35;86(2007), and Idusogie et al. J Immunol 164;4178(2000). In some embodiments, the Fc region glycosylation pattern is modified. In other embodiments, the Fc region is modified by pegylation (e.g., by reacting the antibody or fragment thereof with polyethylene glycol (PEG)). Exemplary Fc modifications include modifications at one or more amino acid positions selected from the group consisting of 228, 233, 234, 235, 236, 241, 248, 265, 297, 309, 331, and 409 (Kabat numbering; Kabat et al., Sequences of Immunological Interest, Fifth Edition, National Institute of Health, Bethesda, Md. (1991)). In embodiments, the antibody has a modification for reducing or abolishing effector function.In embodiments, the antibody is an IgG1 antibody having one or more Fc modifications selected from the group consisting of E233P, L234V, L234A, L235V, L235A, G236 (deletion), D265A, D270A, N297A, and N297Q. In embodiments, the antibody is an IgG4 antibody having one or more Fc modifications selected from the group consisting of S228P, E233P, F234A, F234V, L235A, L235V, S241P, L248E, D265A, D265T, L309L, and R409K. In embodiments, the anti-SCF antibodies provided herein include the S241P mutation and the L248E mutation.

[0053] In embodiments, the present disclosure provides the antibodies provided herein that include the human IgG4 constant regions set forth in SEQ ID NOs: 40 and 41. In embodiments, the present disclosure provides antibodies having at least about 80%, at least about 85%, at least about 90%, at least about 95%, or about 99% sequence identity to SEQ ID NO: 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 40 and the light chain set forth in SEQ ID NO: 41. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 42, 43, 44, 45, or 46 and the light chain set forth in SEQ ID NO: 47, 48, 49, or 50. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 42 and the light chain set forth in SEQ ID NO: 49. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 43 and the light chain set forth in SEQ ID NO: 49. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 44 and the light chain set forth in SEQ ID NO: 49. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 45 and the light chain set forth in SEQ ID NO: 49. In embodiments, the present disclosure provides an antibody that includes the heavy chain set forth in SEQ ID NO: 46 and the light chain set forth in SEQ ID NO: 49.

[0054] In some embodiments, the antibodies provided herein are specific for SCF248 and do not bind to SCF220. Accordingly, the antibodies provided herein are capable of specifically inhibiting the interaction between SCF248 and c-Kit, which induces and sustains chronic inflammatory responses and fibrosis in inflammatory and fibrotic kidney diseases. Further, the antibodies provided herein are capable of specifically inducing internalization of SCF, thereby reducing the interaction between SCF248 and c-Kit. Accordingly, in some embodiments, the present disclosure provides a method for treating inflammatory and fibrotic kidney diseases, the method comprising administering to a patient in need thereof an antibody that is specific for SCF248, is discussed herein, and is safe and effective in various inflammatory and fibrotic kidney diseases well-known in the art.

[0055] For the preparation of monoclonal antibodies, any technique that provides for the production of antibody molecules by continuous cell lines in culture can be used (e.g., Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.). These include, but are not limited to, the hybridoma technique first developed by Kohler and Milstein, and the trioma technique, human B-cell hybridoma technique (see, e.g., Kozbor et al., Immunol. Today, 4:72 (1983)), and EBV-hybridoma technique for producing human monoclonal antibodies (Cole et al., in Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96 (1985)). Alternatively, antibodies can be made by recombinant DNA methods. In some embodiments, the antibodies according to the present disclosure can be made by isolating monoclonal antibodies from phage display libraries using, for example, the techniques described in Clackson et al., Nature 352:624-28 (1991) and Marks et al., J. Mol. Biol. 222(3):581-97 (1991). In some embodiments, the antibodies are fully human antibodies constructed by combining Fv clone variable domain sequence(s) selected from a human-derived phage display or yeast display library with known human constant domain sequence(s).

[0056] In some embodiments provided herein, the antibody is prepared from a hybridoma. Using the hybridoma method, a mouse, hamster, or other suitable host animal is immunized by injecting an immunizing peptide to induce the production of lymphocytes that produce antibodies that specifically bind to the immunizing antigen. Alternatively, the lymphocytes can be immunized in vitro. After immunization, the lymphocytes are isolated and fused, for example, using polyethylene glycol, with a suitable myeloma cell line to form hybridoma cells that can then be selected away from unfused lymphocytes and myeloma cells. Then, hybridomas that produce monoclonal antibodies that are specifically directed against the selected antigen, as determined by in vitro binding assays such as immunoprecipitation, immunoblotting, or radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA), can be propagated in vitro (e.g., in culture) or as ascites tumors in animals using standard methods (Goding, Monoclonal Antibodies: Principles and Practice, Academic Press, 1986). The monoclonal antibodies can then be purified from the culture medium or ascites, as described for the polyclonal antibodies above.

[0057] In some embodiments, the antibodies provided herein are generated using a mouse hybridoma system. Hybridoma production in mice is an established procedure. Immunization protocols and techniques for the isolation of immunized spleen cells for fusion are known in the art. The fusion partner (e.g., mouse myeloma cells) and the fusion procedure are also known. Embodiments of the techniques herein provide antibodies (e.g., monoclonal antibodies) generated from hybridomas prepared by immunizing a mouse with a peptide that is a portion or fragment of the SCF protein.

[0058] In some embodiments, the antibodies specific for SCF248 provided herein are generated by immunizing mice with a peptide having an amino acid sequence that is mostly or exclusive within exon 6. For example, the immunizing peptide includes any extension of 5 or more amino acids within SEQ ID NO: 34. As another example, the immunizing peptide includes any extension of 5 or more amino acids starting from amino acid position 20 of SEQ ID NO: 29. As another example, the immunizing peptide includes an extension of 5 or more amino acids starting from amino acid position 20 of SEQ ID NO: 29 and ending at any one of positions 25-38 of SEQ ID NO: 29. Thus, in some embodiments, the immunizing peptide includes the amino acid sequence of exon 6 after the cleavage site and is either fully contained within exon 6 or includes only 1, 2, 3, 4, or 5 amino acids of exon 7. In some embodiments, the immunizing peptide includes or consists of SEQ ID NO: 30. In some embodiments, the immunizing peptide includes any one of the peptides or conservative variants thereof provided herein. Conservative variants can include 1, 2, 3, 4, or 5 amino acid substitutions or deletions, or combinations thereof. As provided above, in some embodiments, the antibodies generated using the immunizing peptides provided herein have epitopes that are fully or mostly contained within exon 6. "Mostly within" means that at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of the peptide is contained within exon 6. In some embodiments, the epitope starts at the cleavage site of exon 6 (i.e., between alanines at amino acid positions 19 and 20 of SEQ ID NO: 29) and extends to the end of exon 6. In some embodiments, the epitope starts at the cleavage site of exon 6 and extends to the first, second, third, fourth, or fifth n-terminal amino acid of the transmembrane domain. In some embodiments, the epitope includes or consists of SEQ ID NO: 33. In some embodiments, the antibody referred to herein as 5H10 (including mouse, chimeric, and humanized 5H10 antibodies) binds to an epitope of SCF that includes or consists of SEQ ID NO: 33.

[0059] In some embodiments, the methods provided herein were used to generate an antibody referred to herein as 5H10. In some embodiments, the antibody “5H10” is also referred to herein as “OpSCF”. Antibody 5H10 binds preferably to SCF248 with high specificity and does not bind to SCF220. The amino acid sequences of the murine parent antibody 5H10, as well as its humanized variants, are provided herein (see Table 1).

[0060] In one embodiment, the invention provides methods of using bispecific or multispecific antibodies specific for SCF and at least one other antigen or epitope. The anti-SCF antibodies and fragments thereof provided herein can be tested for binding to SCF using the binding assays provided herein or any other binding assay known in the art.

[0061] Unless otherwise described, the practice of the present invention uses conventional molecular biology, cell biology, biochemistry, and immunology techniques that are well known in the art, for example, as described in Methods in Molecular Biology, Humana Press, Molecular Cloning: A Laboratory Manual, second edition (Sambrook et al., 1989), Current Protocols in Immunology (J.E. Coligan et al., eds., 1991), Immunobiology (C.A. Janeway and P. Travers, 1997), Antibodies (P. Finch, 1997), Antibodies: a practical approach (D. Catty., ed., IRL Press, 1988 - 1989), Monoclonal antibodies: a practical approach (P. Shepherd and C. Dean, eds., Oxford University Press, 2000), Phage display: a laboratory manual (C. Barbas III et al, Cold Spring Harbor Laboratory Press, 2001), and Using antibodies: a laboratory manual (E. Harlow and D. Lane (Cold Spring Harbor Laboratory Press, 1999).

[0062] Method of treatment As used herein, the terms "treating" or "treatment" refer to both therapeutic and prophylactic or preventive measures. Subjects in need of treatment include subjects already having a disease or condition, as well as subjects who may develop a disease or condition, and the treatment prevents, delays, or reduces the disease or condition. As used herein, the term "subject" refers to mammals such as rodents, cats, dogs, and primates. Preferably, the subject according to the present invention is a human. As used herein, the term "therapeutically effective amount" refers to the amount of a compound or composition necessary to provide a therapeutic and / or prophylactic benefit to a subject.

[0063] In one aspect, the present invention provides a method for treating a subject with an inflammatory and / or fibrotic kidney disease. In one aspect, the present disclosure provides an antibody for use as a medicament useful for treating kidney diseases such as inflammatory and / or fibrotic kidney diseases. In one aspect, the present disclosure provides an antibody for use in a method for treating kidney diseases such as inflammatory and / or fibrotic kidney diseases. In some embodiments, the inflammatory kidney disease is a chronic inflammatory kidney disease. Exemplary inflammatory and / or fibrotic kidney diseases include, for example, renal fibrosis of the kidney, cirrhosis of the kidney, interstitial fibrosis and tubular atrophy (IFTA), chronic kidney disease, end-stage renal disease (ESRD), Goodpasture syndrome, glomerulonephritis, membranoproliferative glomerulonephritis (MPGN), chronic renal allograft rejection, nephrogenic systemic fibrosis, and nephrosis (e.g., IgA nephropathy, focal segmental glomerulosclerosis, rapidly progressive glomerulonephritis, crescentic glomerulonephritis, lupus nephritis, hypertensive nephropathy, or diabetic nephropathy).

[0064] In some embodiments, the antibodies and fragments thereof disclosed herein can be administered to a subject by at least one route selected from parenteral, subcutaneous, intramuscular, intravenous, intra-articular, intra-bronchial, intraperitoneal, intra-capsular, intra-cartilaginous, intra-cavity, intracelial, intra-cerebellar, intra-ventricular, intra-colonic, intra-cervical, intra-gastric, intra-hepatic, intra-myocardial, intra-osteal, intra-pelvic, intra-pericardial, intra-peritoneal, intra-pleural, intra-prostatic, intra-pulmonary, intra-rectal, intra-renal, intra-retinal, intra-spinal, intra-synovial, intra-thoracic, intra-tympanic, intra-uterine, intra-vesical, intra-vitreal, bolus, sub-conjunctival, oral, vaginal, rectal, buccal, sub-lingual, intra-nasal, intra-tumoral, and transdermal.

[0065] In embodiments, the antibodies and fragments thereof disclosed herein can be administered to a subject in need thereof in combination with one or more additional therapies. The one or more additional therapies can be a procedure such as a surgical procedure or dialysis, or a therapeutic agent such as a drug designed to alleviate or reduce the symptoms of a disease or disorder associated with renal fibrosis and / or inflammation.

[0066] The present invention is further illustrated by reference to the following examples. However, it should be noted that these examples, like the above embodiments, are illustrative and should not be construed as limiting the scope of the present invention in any way.

Examples

[0067] The following examples are provided for the purpose of illustrating various embodiments of the present disclosure and are not meant to limit the present disclosure in any way. Modifications and other uses of the present examples that are within the spirit of the present disclosure, as defined by the claims, will be recognized by those skilled in the art.

[0068] The overview of the tissue injury / disease process is summarized in Figure 1. The disease process initiates inflammation. c-Kit+ immune cells produce cytokines and transform fibroblasts into activated myofibroblasts that express SCF248 on their surface. The expression of SCF248 on the surface of myofibroblasts and other cells activates more immune cells, resulting in cytokine release of IL-4, IL-9, IL-13, IL-25, TGFβ, and other cytokines, and sustaining inflammation. Myofibroblasts secrete extracellular matrix proteins, collagen, and fibronectin, causing fibrotic diseases such as chronic kidney disease. An exemplary mechanism of the disclosed antibodies targeting SCF248 in glomerulonephritis (GN), an exemplary kidney disease (the antibody is referred to herein as OpSCF and / or 5H10), is summarized in Figure 2.

[0069] As provided above, SCF has two isoforms resulting from alternative splicing: SCF248 and SCF220. SCF248 and SCF220 differ by exon 6. SCF220 is associated with a constitutive function, and SCF248 is associated with inflammation and fibrosis. SCF248 activates immune cells during inflammation and may be called "soluble SCF". SCF248 is expressed in various cell types including myofibroblasts, activated epithelium, endothelium, macrophages, eosinophils, mast cells, and monocytes (Figure 3). The SCF248 isoform results in cleavage of a monomeric truncated extracellular domain called SCF165. The amino acid sequence of exon 6 is provided herein as SEQ ID NO: 34.

[0070] Example 1: Generation of anti-SCF mAb Using Hybridoma Technology Antibodies that bind to SCF248 were generated using a peptide comprising ASSLRNDSSSSNRKAKNPPGD (SEQ ID NO: 30). The immunizing peptide included a portion of exon 6, namely the SCF248 isoform of stem cell factor. In particular, the immunizing peptide included a portion of exon 6 that starts after the cleavage site as defined herein. Mice were immunized with the peptide described in SEQ ID NO: 30 using a standard protocol. Determination of high-titer serum antibodies indicated that appropriate immunization and fusion hybridomas had been performed. Culture supernatants were analyzed for SCF-specific antibodies from individual clones and selected based on specificity. Hybridomas producing specific monoclonal antibodies against the peptide were grown, and then the monoclonal with the highest titer was tested in biologically relevant cultures. Antibody 5H10 had high specificity for SCF248 and no cross-reactivity with SCF220. Other monoclonal antibodies produced by the hybridomas did not have high specificity for SCF248 without cross-reactivity with SCF220. Therefore, 5H10 was selected for further characterization, generation, and chimerization, and subsequent humanization.

[0071] Example 2. Binding of 5H10 to the complete extracellular domain of SCF248 The mouse 5H10 antibody obtained as described in Example 1 was directly conjugated to a fluorescent marker, and the labeled antibody was incubated with Sl / Sl4 hSCF248 cells expressing SCF248, Sl / Sl4 hSCF220 cells expressing SCF220, or control cells not expressing SCF. Binding of the labeled antibody to the cells was evaluated by flow cytometry. Specificity of 5H10 for SCF248 and lack of cross-reactivity with SCF220 are shown in Figure 4A.

[0072] The binding of the mouse 5H10 antibody to the truncated extracellular domain (ECD) containing only amino acids 1 - 165 of SCF was evaluated by ELISA against the full-length ECD containing amino acids 1 - 194 of SCF. The antibody bound to the full-length SCF ECD but not to the truncated SCF ECD (Figure 4B). This demonstrated that the antibody is specific for the full-length extracellular domain and does not bind to the monomeric truncated ECD circulating in the blood.

[0073] To evaluate the ability of the 2G8 and 5H10 antibodies to internalize SCF248 on myofibroblasts, the antibodies were labeled with pHrodo Red. This is colorless at neutral pH and fluoresces red at the low pH within endosomes. The labeled antibodies were incubated with cultured human IPF myofibroblasts for 45 minutes, and the red fluorescence was visualized by microscopy. As shown in Figure 5, the dye-labeled antibodies, but not the control IgG, were rapidly internalized. 5H10 was internalized more rapidly, resulting in higher fluorescence compared to 2G8.

[0074] SCF induces c-kit to signal through two different pathways, the MEK / ERK pathway and the P13K / AKT pathway. The mouse 5H10 antibody was studied to determine whether it inhibits intracellular signaling in c-kit positive cells in either or both of these pathways. Eosinophils were incubated with the SCF248-expressing cell line in the presence of either 5H10 or an IgG control, and the expression of phospho-proteins was measured using the BioRad Bio-Plex assay system. 5H10 significantly decreased the phospho-MEK and phospho-AKT levels, indicating that the antibody significantly inhibited c-kit-mediated intracellular signaling (Figure 6).

[0075] Collectively, the results of these studies showed that the antibody 5H10 specifically binds to SCF248, internalizes, and does not cross-react with the SCF220 isoform or the truncated ECD. Furthermore, 5H10 significantly inhibits the intracellular signaling pathway of c-kit positive cells that sustains inflammation.

[0076] Example 3. Humanized 5H10 Chimeric antibodies derived from 5H10 were produced by subcloning the variable domains of the heavy and light chains into a vector having a human IgG4 backbone. The chimeric antibodies were expressed and purified using standard protocols. 2G8 is an antibody developed previously that binds to SCF248 and SCF220 and contains a lambda light chain. The chimeric heavy and light chains of 2G8 were designated VH0 and VL0, respectively. 5H10, an SCF248-specific antibody provided herein, contains a kappa light chain. The chimeric heavy and light chains of 5H10 were designated VH0 and VK0, respectively.

[0077] The chimeric antibodies were humanized. The humanized heavy chains retained the same complementarity-determining regions (CDRs) but retained more "human-like" framework regions, and several humanized variants of each of the 2G8 and 5H10 variable heavy chains, designated VH1, VH2, VH3, VH4, and VH5 herein, were generated. Humanized kappa light chain variants of 5H10, designated VK1, VK2, VK3, and VK4 herein, were also generated. The humanized lambda light chain of 2G8 was designated VL1, VL2, VL3, and VL4. Combinations of the chimeric and humanized light and heavy chains of 2G8 and 5H10 tested are shown in Tables 2 and 3, respectively. As shown in Table 2, certain heavy and light chain combinations of the 5H10 antibody variants resulted in high binding to hSCF248. [Table 2] [Table 3]

[0078] Binding affinity was also evaluated using BiaCore analysis. BiaCore data showed that the affinity of all humanized 5H10 antibodies with VK1, VK2, or VK3 light chains for the immobilized SCF248 peptide antigen was very similar to the binding affinity of the parental mouse 5H10 using this assay. The humanized 5H10 antibody with VK4 light chain did not bind to the peptide.

Table 4

[0079] The 5H10 clones VH1 / VK3, VH2 / VK3, VH3 / VK3, VH4 / VK3, and VH5 / VK3 were evaluated by flow cytometry for binding to the SCF248-expressing cell line. As shown in Figures 7A and 7B, VH1 / VK3 and VH2 / VK3 showed high binding, which was maximized at 1 μg / mL. The negative control was secondary antibody only. Binding to the control SCF220-expressing cell line was not observed (not shown).

[0080] Example 4. In Vitro Inhibition of the Interaction between SCF and c-kit Humanized 5H10 antibodies were tested for their ability to inhibit the SCF-c-kit interaction and the inflammatory feed-forward loop in vitro. Cultured human IPF myofibroblasts (Mfb) expressing surface SCF248 were overlaid with the SCF-responsive cell line, LAD2 mast cells. In the absence of other interventions, Mfb stimulate LAD2 cells, and LAD2 cells stimulate Mfb to produce additional cytokines and extracellular matrix proteins. In this assay, the inflammatory readouts and feed-forward loop are the mRNAs for CCL11, collagen 1 and 3, and fibronectin.

[0081] Mouse 5H10 and humanized (VH1 / VK3, VH2 / VK3, VH3 / VK3, VH4 / VK3, and VH5 / VK3) 5H10 antibodies were pre-incubated with Mfb at concentrations of 1 μg / mL and 10 μg / mL, and their ability to inhibit the feed-forward loop was evaluated. These results are shown in FIGS. 8A-8D. The humanized VH1 / VK3 antibody consistently demonstrated inhibition of the SCF-c-kit interaction even at low concentrations.

[0082] Example 5. Correlation between SCF248 and disease progression in renal biopsy RNAseq was performed to quantify SCF248 mRNA from renal biopsies of patients with focal segmental glomerulosclerosis (FSGS). As shown in FIG. 9A, a significant inverse correlation between SCF248 mRNA and glomerular filtration rate was observed. As shown in FIG. 9B, a positive correlation between SCF248 mRNA and the proportion of interstitial fibrosis was also observed. Furthermore, as shown in FIG. 9C, a positive correlation between SCF248 mRNA and the percentage of mononuclear leukocytes in renal biopsy was identified. Collectively, these data suggest an association between SCF248 and markers of inflammation and progressive renal insufficiency.

[0083] Furthermore, SCF165, the cleavage stem cell factor extracellular domain of plasma levels in subjects with chronic kidney disease, was significantly inversely correlated with estimated glomerular filtration rate (eGFR) (FIG. 10) and correlated with urinary albumin / creatinine ratio (UACR) in chronic kidney disease (FIG. 11).

[0084] Example 6. 5H10 effectively treats diseases in a chronic kidney disease model. In the area of human renal fibrosis, SCF248 is expressed. Samples stained with control IgG by immunohistochemistry (FIG. 12A) were compared with samples stained with mouse 5H10 antibody, which were strongly positive for SCF248 in the tubulointerstitium (FIGS. 12B and 12C). Furthermore, staining for mast cell tryptase showed the presence of mast cells in the kidneys of patients with diabetic nephropathy and IgA nephropathy (FIGS. 13B and 13C), but not in the kidneys of healthy patients. (FIG. 13A).

[0085] Using a mouse model of chronic kidney disease (CKD), the effect of 5H10 on disease progression and survival was investigated. C57 / black 6 TGFβ1 transgenic mice (TGFβ mice) overexpress TGFβ1 in the liver under the control of the albumin promoter, resulting in an increase in circulating TGFβ that promotes tissue fibrosis. TGFβ mice experience progressive glomerular and mesangial expansion, as well as a decrease in podocyte density. Progressive interstitial fibrosis leads to a decrease in kidney weight and death.

[0086] TGFβ mice were administered either 5H10 or a control antibody at a dose of 20 mg / kg twice a week from 2 weeks of age for 4 weeks. This experiment was terminated because the mice died at week 6. Mice treated with 5H10 had significantly improved survival (p = 0.03) and a decrease in kidney weight loss (p = 0.03) compared to mice treated with a control IgG antibody (Figures 14A and 14B). Kidneys were masked and scored by an experienced renal pathologist, and the kidneys in the 5H10 treatment group had significantly less fibrosis (Figure 14C).

[0087] To evaluate kidney histology during disease progression, TGFβ mice were administered 5H10 or control antibody twice weekly at 5 mg / kg from 2 weeks of age and sacrificed 2 weeks after the onset of CKD disease progression. Compared to control IgG, glomerular volume and mesangial volume did not increase much with 5H10 treatment, suggesting a decrease in tissue damage. In the early stages of CKD, glomerular volume and mesangial volume increase with the influx of inflammatory cells and extracellular matrix. Podocyte density was maintained using 5H10 therapy, showing less podocyte dropout and less glomerular swelling (Figures 15A, 15B, 15C). RNA sequencing showed a statistically significant decrease in type III collagen alpha 1 chain (Figure 16A), type VI collagen alpha 3 chain (Figure 16B), type XV collagen alpha 1 chain (Figure 16C), fibronectin type III domain containing 1 (Figure 16D), fibrin 1 (Figure 16E), and microfibril-associated protein 4 (Figure 16F) in animals treated with m5H10. Therefore, administration of the 5H10 antibody in a chronic kidney disease model significantly reduced renal fibrosis and improved survival, indicating that the antibody is useful as a treatment for kidney disease.

[0088] Publications, patents, and patent applications cited herein are specifically incorporated by reference in their entirety. Although the described invention has been explained with reference to its specific embodiments, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many changes may be made to adopt specific situations, materials, compositions of substances, processes, process steps (s) with respect to the objective spirit and scope of the described invention. All such modifications are intended to be within the scope of the claims. The present invention provides, for example, the following items. (Item 1) A method for treating an inflammatory or fibrotic kidney disease in a subject in need of treatment for the inflammatory or fibrotic kidney disease, the method comprising administering to the subject an antibody or an antigen-binding fragment thereof that specifically binds to stem cell factor (SCF), wherein the antibody or the antigen-binding fragment thereof comprises a heavy-chain CDR1, CDR2, and CDR3 comprising SEQ ID NOs: 1, 2, and 3, respectively, and a light-chain CDR1, CDR2, and CDR3 according to SEQ ID NOs: 4, 5, and 6, respectively. (Item 2) The method according to item 1, wherein the antibody or the fragment thereof comprises a heavy-chain variable region having at least 80% identity to a sequence selected from SEQ ID NOs: 7, 8, 9, 10, and 11. (Item 3) The method according to item 1 or item 2, wherein the antibody or the fragment thereof comprises a heavy-chain variable region having at least 90% identity to a sequence selected from SEQ ID NOs: 7, 8, 9, 10, and 11. (Item 4) The method according to any one of items 1 to 3, wherein the antibody or the fragment thereof comprises a light-chain variable region having at least 80% identity to a sequence selected from SEQ ID NOs: 13, 14, 15, and 16. (Item 5) The method according to any one of items 1 to 4, wherein the antibody or the fragment thereof comprises a light-chain variable region having at least 90% identity to a sequence selected from SEQ ID NOs: 13, 14, 15, and 16. (Item 6) The method according to any one of items 1 to 5, wherein the antibody or the fragment thereof comprises a heavy-chain variable region amino acid sequence selected from SEQ ID NOs: 7, 8, 9, 10, and 11 and a light-chain variable region amino acid sequence selected from SEQ ID NOs: 13, 14, 15, and 16. (Item 7) The method according to any one of items 1 to 6, wherein the antibody or the fragment thereof comprises the heavy-chain variable region amino acid sequence set forth in SEQ ID NO: 7 and the light-chain variable region amino acid sequence set forth in SEQ ID NO: 16. (Item 8) The method according to any one of items 1 to 6, wherein the antibody or a fragment thereof comprises the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 8 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. (Item 9) The method according to any one of items 1 to 6, wherein the antibody or a fragment thereof comprises the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 9 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. (Item 10) The method according to any one of items 1 to 6, wherein the antibody or a fragment thereof comprises the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 10 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. (Item 11) The method according to any one of items 1 to 6, wherein the antibody or a fragment thereof comprises the heavy chain variable region amino acid sequence set forth in SEQ ID NO: 11 and the light chain variable region amino acid sequence set forth in SEQ ID NO: 16. (Item 12) The method according to item 1, wherein the antibody or a fragment thereof is humanized. (Item 13) The method according to any one of items 1 to 12, wherein the antibody is a monoclonal antibody. (Item 14) The method according to item 13, wherein the antibody comprises a human IgG4 domain. (Item 15) The method according to item 14, wherein the IgG4 domain comprises an S241P mutation at amino acid residue 241 and an L248E mutation at amino acid residue 248, and the numbering of the residues is according to the Kabat numbering system. (Item 16) The method according to any one of items 13 to 15, wherein the antibody comprises the heavy chain set forth in SEQ ID NO: 42 and the light chain set forth in SEQ ID NO: 49. (Item 17) The method according to any one of items 13 to 15, wherein the antibody comprises the heavy chain set forth in SEQ ID NO: 43 and the light chain set forth in SEQ ID NO: 49. (Item 18) The method according to any one of items 1 to 17, wherein the antibody or a fragment thereof specifically binds to SCF248. (Item 19) The method according to any one of items 1 to 18, wherein the antibody does not bind to SCF220. (Item 20) The method according to any one of items 1 to 19, wherein the inflammatory or fibrotic kidney disease is selected from the group consisting of chronic kidney disease (CKD), end-stage renal disease (ERSD), renal fibrosis, glomerulonephritis, and nephrosis. (Item 21) The method according to item 20, wherein the nephrosis or glomerulonephritis is IgA nephropathy, diabetic nephropathy, focal segmental glomerulosclerosis, rapidly progressive glomerulonephritis, crescentic glomerulonephritis, lupus nephritis, hypertensive nephropathy, or diabetic nephropathy.

Claims

**Claim 1** A composition for treating an inflammatory or fibrotic kidney disease in a subject in need of treatment for an inflammatory or fibrotic kidney disease, comprising an antibody that specifically binds to stem cell factor 248 (SCF248), wherein the antibody comprises, respectively, heavy chain CDR1, CDR2, and CDR3 comprising SEQ ID NOs: 1, 2, and 3, and light chain CDR1, CDR2, and CDR3 according to SEQ ID NOs: 4, 5, and 6, and the antibody (a) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 8, (b) a light chain variable region having the amino acid sequence of SEQ ID NO: 16, the composition. **Claim 2** The composition according to claim 1, wherein the antibody is humanized. **Claim 3** The composition according to claim 1, wherein the antibody is a monoclonal antibody. **Claim 4** The composition according to claim 3, wherein the antibody comprises a human IgG4 domain. **Claim 5** The composition according to claim 4, wherein the IgG4 domain comprises an S241P mutation at amino acid residue 241 and an L248E mutation at amino acid residue 248, and the numbering of the residues is according to the Kabat numbering system. **Claim 6** The composition according to any one of claims 2 to 5, wherein the antibody comprises a heavy chain as set forth in SEQ ID NO: 42 and a light chain as set forth in SEQ ID NO:

49. **Claim 7** The composition according to any one of claims 1 to 6, wherein the antibody does not bind to SCF220. **Claim 8** The composition according to any one of claims 1 to 7, wherein the inflammatory or fibrotic kidney disease is selected from the group consisting of chronic kidney disease (CKD), end-stage renal disease (ERSD), renal fibrosis, glomerulonephritis, and nephrosis. **Claim 9** The composition according to claim 8, wherein the nephrosis or glomerulonephritis is IgA nephropathy, diabetic nephropathy, focal segmental glomerulosclerosis, rapidly progressive glomerulonephritis, crescentic glomerulonephritis, lupus nephritis, hypertensive nephropathy, or diabetic nephropathy.

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