Anti-KIT antibody preparations and methods

Abstract

Provided herein are pharmaceutical compositions comprising antibodies that immunospecifically bind to the receptor tyrosine kinase KIT, and uses thereof. Also provided are kits and methods for producing such pharmaceutical compositions. KIT (or c-Kit) is a type III receptor tyrosine kinase encoded by the c-kit gene. KIT contains five extracellular immunoglobulin (ig)-like domains, a single transmembrane region, an inhibitory cytoplasmic juxtamembrane domain, and a split cytoplasmic kinase domain separated by a kinase insert segment.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 369,644, filed July 27, 2022, which is incorporated herein by reference in its entirety.

[0002] Reference to an electronically submitted sequence listing This application incorporates by reference the Sequence Listing submitted with this application as an xml file entitled "12638-172-228_SeqListing.XML", created on July 20, 2023, and having a size of 56,314 bytes.

[0003] 1. Field Provided herein are pharmaceutical compositions comprising antibodies that immunospecifically bind to the receptor tyrosine kinase KIT, and uses thereof. Also provided are kits and methods for producing such pharmaceutical compositions. [Background technology]

[0004] 2.Background KIT (or c-kit) is a type III receptor tyrosine kinase encoded by the c-kit gene. KIT contains five extracellular immunoglobulin (Ig)-like domains, a single transmembrane region, an inhibitory cytoplasmic juxtamembrane domain, and a split cytoplasmic kinase domain separated by a kinase insert segment (see, e.g., Yarden et al., Nature, 1986, 323:226-232; Ullrich and Schlessinger, Cell, 1990, 61:203-212; Clifford et al., J. Biol. Chem., 2003, 278:31461-31464). The human c-kit gene encoding the KIT receptor was cloned as reported by Yarden et al., EMBO J., 1987, 6:3341-3351. KIT is also known as CD117 or stem cell factor receptor ("SCFR") because it is the receptor for stem cell factor ("SCF") ligand (also known as Steel factor or Kit ligand). SCF ligand binding to the first three extracellular Ig-like domains of KIT induces receptor dimerization, thereby activating intrinsic tyrosine kinase activity through phosphorylation of specific tyrosine residues within the juxtamembrane and kinase domains (see, e.g., Weiss and Schlessinger, Cell, 1998, 94:277-280; Clifford et al., J. Biol. Chem., 2003, 278:31461-31464). Members of the Stat, Src, ERK, and AKT signaling pathways have been shown to be downstream signal transducers of KIT signaling.

[0005] The fourth (D4) and fifth (D5) extracellular Ig-like domains of KIT are thought to mediate receptor dimerization (see, e.g., International Patent Application Publication No. WO2008 / 153926; Yuzawa et al., Cell, 2007, 130:323-334).

[0006] KIT expression has been detected in various cell types, including mast cells, stem cells, brain cells, melanoma cells, ovarian cells, and cancer cells (e.g., leukemia cells) (see, e.g., Besmer, P. Curr. Opin. Cell Biol, 1991, 3:939-946; Lyman et al., Blood, 1998, 91:1101-1134; Ashman, LK, Int. J. Biochem. Cell Biol, 1999, 31:1037-1051; Kitamura et al., Mutat. Res., 2001, 477:165-171; Mol et al., J. Biol. Chem., 2003, 278:31461-31464). Furthermore, KIT plays an important role in hematopoiesis, melanogenesis, and gametogenesis (see Ueda et al., Blood, 2002, 99:3342-3349).

[0007] Antibodies that immunospecifically bind to human KIT are known, for example, from International Patent Publication No. WO2014018625A1, which is incorporated herein by reference in its entirety.

[0008] There is a need to provide suitable formulations for antibodies against human KIT. Summary of the Invention

[0009] 3. Overview In one aspect, provided herein is a pharmaceutical composition comprising: (i) an antibody, or antigen-binding fragment thereof, that immunospecifically binds to human KIT; (ii) a buffering agent; (iii) a salt; and (iv) an excipient.

[0010] In certain embodiments, the pharmaceutical composition has a pH of about 4 to about 7. In certain embodiments, the pharmaceutical composition has a pH of about 5 to about 6. In certain embodiments, the pharmaceutical composition has a pH of about 5.5.

[0011] In certain embodiments, the salt is an alkali metal salt. In certain embodiments, the alkali metal salt is sodium chloride. In certain embodiments, the sodium chloride is at a concentration of about 25 mM to about 100 mM. In one embodiment, the sodium chloride is at a concentration of about 50 mM.

[0012] In certain embodiments, the buffering agent is an alkali metal acetate. In certain embodiments, the alkali metal acetate is sodium acetate. In certain embodiments, the sodium acetate is at a concentration of about 1 mM to about 50 mM. In one embodiment, the sodium acetate is at a concentration of about 25 mM.

[0013] In certain embodiments, the excipient is a sugar, sugar alcohol, or amino acid. In certain embodiments, the excipient is mannitol, sorbitol, sucrose, trehalose, glycine, arginine, alanine, histidine, or any combination thereof. In certain embodiments, the excipient is mannitol, sorbitol, sucrose, trehalose, glycine, arginine, histidine, or any combination thereof. In certain embodiments, the excipient is mannitol, sucrose, arginine, histidine, or any combination thereof. In certain embodiments, the excipient is mannitol. In certain embodiments, the mannitol is at a concentration of about 1% to about 10%. In one embodiment, the mannitol is at a concentration of about 3%.

[0014] In certain embodiments, the antibody or antigen-binding fragment thereof is at a concentration of about 50 mg / ml to about 500 mg / ml. In certain embodiments, the antibody or antigen-binding fragment thereof is at a concentration of about 100 mg / ml to about 400 mg / ml. In one embodiment, the antibody or antigen-binding fragment thereof is at a concentration of about 150 mg / ml.

[0015] In another aspect, provided herein is a pharmaceutical composition comprising: (i) an antibody that immunospecifically binds to human KIT, or an antigen-binding fragment thereof, at a concentration of about 50 mg / ml to about 500 mg / ml; (ii) an alkali metal acetate at a concentration of about 1 mM to about 50 mM; (iii) an alkali metal chloride at a concentration of about 25 mM to about 100 mM; and (iv) mannitol at a concentration of about 1% to about 10%, wherein the pharmaceutical composition has a pH of about 5 to about 6.

[0016] In another aspect, provided herein is a pharmaceutical composition comprising: (i) an antibody that immunospecifically binds to human KIT, or an antigen-binding fragment thereof, at a concentration of about 50 mg / ml to 500 mg / ml; (ii) sodium acetate at a concentration of about 1 mM to about 50 mM; (iii) sodium chloride at a concentration of about 25 mM to about 100 mM; and (iv) mannitol at a concentration of about 1% to about 10%, wherein the pharmaceutical composition has a pH of about 5 to about 6.

[0017] In another aspect, provided herein is a pharmaceutical composition comprising: (i) an antibody, or antigen-binding fragment thereof, that immunospecifically binds to human KIT at a concentration of about 150 mg / ml; (ii) sodium acetate at a concentration of about 25 mM; (iii) sodium chloride at a concentration of about 50 mM; and (iv) mannitol at a concentration of about 3%, wherein the pharmaceutical composition has a pH of about 5.5.

[0018] In certain embodiments, the antibody or antigen-binding fragment thereof (A)(i) a light chain variable region (“VL”) comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; and (ii) a heavy chain variable region (“VH”) comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:7, respectively; (B)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 25, SEQ ID NO: 26, and SEQ ID NO: 27, respectively; (C)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 28, SEQ ID NO: 29, and SEQ ID NO: 30, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 25, SEQ ID NO: 31, and SEQ ID NO: 32, respectively; (D)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 33, SEQ ID NO: 34, and SEQ ID NO: 27, respectively; or (E)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 35, SEQ ID NO: 36, and SEQ ID NO: 37, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 38, SEQ ID NO: 39, and SEQ ID NO: 40, respectively.

[0019] In certain embodiments, the antibody or antigen-binding fragment thereof comprises a VL comprising VL CDR1 to 3 comprising the amino acid sequences of SEQ ID NOs: 2 to 4, respectively, and a VH comprising VH CDR1 to 3 comprising the amino acid sequences of SEQ ID NOs: 5 to 7, respectively.

[0020] In certain embodiments, the antibody or antigen-binding fragment thereof has (i) the amino acid sequence: DIVMTQSPSX K1 LSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKX K2 LIYSASYRYSGVPDRFX K3 GSGSGTDFTLTISSLQX K4 EDFAX K5 YX K6CQQYNSYPRTFGGGTKVEIK (SEQ ID NO: 17), wherein X K1 is an amino acid having an aromatic or aliphatic hydroxyl side chain, and X K2 is an amino acid having an aliphatic or aliphatic hydroxyl side chain, and X K3 is an amino acid having an aliphatic hydroxyl side chain, and X K4 is an amino acid having an aliphatic hydroxyl side chain or is P, and X K5 is an amino acid having a charged or acidic side chain, and X K6 is an amino acid having an aromatic side chain; and (ii) the amino acid sequence: QVQLVQSGAEX. H1 KKPGASVKX H2 SCKASGYTFTDYYINWVX H3 QAPGKGLEWIARIYPGSGNTYYNEKFKGRX H4 TX H5 TAX H6 KSTSTAYMX H7 LSSLRSEDX H8 AVYFCARGVYYFDYWGQGTTVTVSS (SEQ ID NO: 18), wherein X H1 is an amino acid having an aliphatic side chain, and X H2 is an amino acid having an aliphatic side chain, and X H3 is an amino acid with a polar or basic side chain, and X H4 is an amino acid having an aliphatic side chain, and X H5 is an amino acid having an aliphatic side chain, and X H6 is an amino acid with an acidic side chain, and X H7 is an amino acid having an acidic or amide derivative side chain, and X H8 is an amino acid having an aliphatic hydroxyl side chain. K1 is the amino acid F or S, and X K2 is the amino acid A or S, and X K3 is the amino acid T or S, and X K4 is the amino acid S or P, and X K5is the amino acid D or T, and X K6 is the amino acid F or Y, and X H1 is an amino acid L or V, and X H2 is an amino acid L or V, and X H3 is the amino acid K or R, and X H4 is the amino acid V or A, and X H5 is an amino acid L or I, and X H6 is the amino acid E or D, and X H7 is the amino acid Q or E, and X H8 is the amino acid S or T.

[0021] In certain embodiments, the antibody or antigen-binding fragment thereof comprises a VL comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 13, 14, 15, and 16, and a VH comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 9, 10, 11, and 12.

[0022] In certain embodiments, the antibody comprises a human heavy chain constant region, wherein the human heavy chain constant region is a human IgG1 constant region.

[0023] In certain embodiments, the antibody comprises a modified human Fc region or domain.

[0024] In certain embodiments, the antibody comprises a modified human IgG1 Fc region or domain. In certain embodiments, the modified human IgG1 Fc region or domain comprises the non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat. In another specific embodiment, the modified human IgG1 Fc region or domain further comprises the non-naturally occurring amino acids 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat.

[0025] In certain embodiments, the antibody comprises (i) a VL comprising the amino acid sequence of SEQ ID NO: 14; (ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; and (iii) a modified human IgG1 Fc region or domain comprising non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat.

[0026] In certain embodiments, the antibody comprises (i) a VL comprising the amino acid sequence of SEQ ID NO: 14; (ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; and (iii) a modified human IgG1 Fc region or domain comprising the non-naturally occurring amino acids 234A, 235Q, 322Q, 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat.

[0027] In certain embodiments, the antibody has the amino acid sequence: QVQLVQSGAEVKKPGASVKLSCKASGYTFTDYYINWVRQAPGKGLEWIARIYPGSGNTYYNEKFKGRATLTADKSTSTAYMQLSSLRSEDTAVYFCARGVYYFDYWGQGTTVTVS SASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAP EAQGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCQVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 21).

[0028] In certain embodiments, the antibody has the amino acid sequence: and a light chain comprising DIVMTQSPSSLSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKALIYSASYRYSGVPDRFTGSGSGTDFTLTISSLQPEDFADYFCQQYNSYPRTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 22).

[0029] In another aspect, provided herein are kits comprising the pharmaceutical compositions described herein.

[0030] In another aspect, provided herein are methods for protecting against, treating, or managing a KIT-associated disorder, the methods comprising administering to a subject in need thereof a therapeutically effective amount of a pharmaceutical composition described herein.

[0031] In certain embodiments, KIT-related disorder is mast cell-related disorder, eosinophil-related disorder, cancer, asthma, inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, gastrointestinal disorder or fibrosis.In certain embodiments, KIT-related disorder is mast cell-related disorder.In another embodiment, KIT-related disorder is eosinophil-related disorder.

[0032] In certain embodiments, the methods provided herein further comprise administering to the subject a second therapeutic agent, hi certain embodiments, the second therapeutic agent is a chemotherapeutic agent, a histone deacetylase inhibitor, an antibody, a cytokine, a tyrosine kinase inhibitor, an antihistamine, a leukotriene receptor antagonist, an immunomodulatory agent, or an anti-inflammatory agent.

[0033] In certain embodiments, the subject is a human.

[0034] In certain embodiments, 1.5 mg / kg or more of the antibody or antigen-binding fragment thereof is administered to the subject per dose. In certain embodiments, about 1.5 mg / kg to about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose. In certain embodiments, about 1.5 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose. In certain embodiments, about 3.0 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose. In certain embodiments, about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose.

[0035] In certain embodiments, two doses of the antibody or antigen-binding fragment thereof are administered to the subject. In certain embodiments, three doses of the antibody or antigen-binding fragment thereof are administered to the subject.

[0036] In certain embodiments, the antibody or antigen-binding fragment thereof is administered to the subject every four weeks. In certain embodiments, the antibody or antigen-binding fragment thereof is administered to the subject every eight weeks.

[0037] In a specific embodiment, about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to a subject every 4 weeks for 3 doses. In another specific embodiment, about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to a subject every 8 weeks for 2 doses. In another specific embodiment, about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to a subject every 8 weeks for 2 doses.

[0038] In another aspect, provided herein is a method for producing a pharmaceutical composition described herein, the method comprising combining an antibody or antigen-binding fragment thereof with a buffer, salt, and excipient. 3.1 Exemplary Embodiments 1. A pharmaceutical composition comprising: (i) an antibody, or antigen-binding fragment thereof, that immunospecifically binds to human KIT; (ii) a buffering agent; (iii) a salt; and (iv) an excipient. 2. The pharmaceutical composition of embodiment 1, having a pH of about 4 to about 7. 3. The pharmaceutical composition of embodiment 2, having a pH of about 5 to about 6. 4. The pharmaceutical composition of embodiment 3, having a pH of about 5.5. 5. The pharmaceutical composition of any one of the preceding embodiments, wherein said salt is an alkali metal salt. 6. The pharmaceutical composition of embodiment 5, wherein the alkali metal salt is sodium chloride. 7. The pharmaceutical composition of embodiment 6, wherein the sodium chloride is at a concentration of about 25 mM to about 100 mM. 8. The pharmaceutical composition of embodiment 7, wherein the sodium chloride is at a concentration of about 50 mM. 9. The pharmaceutical composition of any one of the preceding embodiments, wherein the buffering agent is an alkali metal acetate. 10. The pharmaceutical composition of embodiment 9, wherein the alkali metal acetate is sodium acetate. 11. The pharmaceutical composition of embodiment 10, wherein the sodium acetate is at a concentration of about 1 mM to about 50 mM. 12. The pharmaceutical composition of embodiment 11, wherein the sodium acetate is at a concentration of about 25 mM. 13. The pharmaceutical composition of any one of the preceding embodiments, wherein said excipient is a sugar, a sugar alcohol, an amino acid, or any combination thereof. 14. The pharmaceutical composition of embodiment 13, wherein the excipient is mannitol, sorbitol, sucrose, trehalose, glycine, arginine, alanine, histidine, or any combination thereof. 15. The pharmaceutical composition of embodiment 13, wherein the excipient is mannitol, sorbitol, sucrose, trehalose, glycine, arginine, histidine, or any combination thereof. 16. The pharmaceutical composition of embodiment 14 or 15, wherein the excipient is mannitol, sucrose, arginine, histidine, or any combination thereof. 17. The pharmaceutical composition of any one of embodiments 13-16, wherein the excipient is mannitol. 18. The pharmaceutical composition of embodiment 17, wherein the mannitol is in a concentration of about 1% to about 10%. 19. The pharmaceutical composition of embodiment 18, wherein the mannitol is in a concentration of about 3%. 20. The pharmaceutical composition of any one of the preceding embodiments, wherein the antibody or antigen-binding fragment thereof is at a concentration of about 50 mg / ml to about 500 mg / ml. 21. The pharmaceutical composition of embodiment 20, wherein the antibody or antigen-binding fragment thereof is at a concentration of about 100 mg / ml to about 400 mg / ml. 22. The pharmaceutical composition of embodiment 21, wherein the antibody or antigen-binding fragment thereof is at a concentration of about 150 mg / ml. 23. A pharmaceutical composition comprising: (i) an antibody or antigen-binding fragment thereof that immunospecifically binds to human KIT at a concentration of about 50 mg / ml to about 500 mg / ml; (ii) an alkali metal acetate at a concentration of about 1 mM to about 50 mM; (iii) an alkali metal chloride at a concentration of about 25 mM to about 100 mM; and (iv) mannitol at a concentration of about 1% to about 10%, wherein the pharmaceutical composition has a pH of about 5 to about 6. 24. A pharmaceutical composition comprising: (i) an antibody or antigen-binding fragment thereof that immunospecifically binds to human KIT at a concentration of about 50 mg / ml to 500 mg / ml; (ii) sodium acetate at a concentration of about 1 mM to about 50 mM; (iii) sodium chloride at a concentration of about 25 mM to about 100 mM; and (iv) mannitol at a concentration of about 1% to about 10%, wherein the pharmaceutical composition has a pH of about 5 to about 6. 25. A pharmaceutical composition comprising: (i) an antibody or antigen-binding fragment thereof that immunospecifically binds to human KIT at a concentration of about 150 mg / ml; (ii) sodium acetate at a concentration of about 25 mM; (iii) sodium chloride at a concentration of about 50 mM; and (iv) mannitol at a concentration of about 3%, wherein the pharmaceutical composition has a pH of about 5.5. 26. The antibody or antigen-binding fragment thereof (A)(i) a light chain variable region (“VL”) comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; and (ii) a heavy chain variable region (“VH”) comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:7, respectively; (B)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 25, SEQ ID NO: 26, and SEQ ID NO: 27, respectively; (C)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 28, SEQ ID NO: 29, and SEQ ID NO: 30, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 25, SEQ ID NO: 31, and SEQ ID NO: 32, respectively; (D)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 33, SEQ ID NO: 34, and SEQ ID NO: 27, respectively; or (E)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 35, SEQ ID NO: 36, and SEQ ID NO: 37, respectively; and (ii) A VH comprising VH CDR1, VH CDR2, and VH CDR3 comprising the amino acid sequences of SEQ ID NO: 38, SEQ ID NO: 39, and SEQ ID NO: 40, respectively. 27. The pharmaceutical composition of any one of the preceding embodiments, wherein the antibody or antigen-binding fragment thereof comprises a VL comprising VL CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 2-4, respectively, and a VH comprising VH CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 5-7, respectively. 28. The antibody or antigen-binding fragment thereof (i) Amino acid sequence: DIVMTQSPSX K1 LSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKX K2 LIYSASYRYSGVPDRFX K3 GSGSGTDFTLTISSLQX K4 EDFAX K5 YX K6 CQQYNSYPRTFGGGTKVEIK (SEQ ID NO: 17), wherein X K1 is an amino acid having an aromatic or aliphatic hydroxyl side chain, and X K2 is an amino acid having an aliphatic or aliphatic hydroxyl side chain, and X K3 is an amino acid having an aliphatic hydroxyl side chain, and X K4 is an amino acid having an aliphatic hydroxyl side chain or is P, and X K5 is an amino acid having a charged or acidic side chain, and X K6 is an amino acid having an aromatic side chain; (ii) Amino acid sequence: QVQLVQSGAEX H1 KKPGASVKX H2 SCKASGYTFTDYYINWVX H3 QAPGKGLEWIARIYPGSGNTYYNEKFKGRX H4 TX H5 TAX H6 KSTSTAYMX H7 LSSLRSEDX H8 AVYFCARGVYYFDYWGQGTTVTVSS (SEQ ID NO: 18), wherein X H1 is an amino acid having an aliphatic side chain, and X H2is an amino acid having an aliphatic side chain, and X H3 is an amino acid with a polar or basic side chain, and X H4 is an amino acid having an aliphatic side chain, and X H5 is an amino acid having an aliphatic side chain, and X H6 is an amino acid with an acidic side chain, and X H7 is an amino acid having an acidic or amide derivative side chain, and X H8 is an amino acid having an aliphatic hydroxyl side chain. 29.X K1 is an amino acid F or S, and X K2 is an amino acid A or S, and X K3 is the amino acid T or S, and X K4 is the amino acid S or P, and X K5 is the amino acid D or T, and X K6 is amino acid F or Y, and X H1 is an amino acid L or V, and X H2 is an amino acid L or V, and X H3 is the amino acid K or R, and X H4 is an amino acid V or A, and X H5 is an amino acid L or I, and X H6 is amino acid E or D, and X H7 is an amino acid Q or E, and X H8 is the amino acid S or T. 30. The pharmaceutical composition of any one of the preceding embodiments, wherein the antibody or antigen-binding fragment thereof comprises a VL comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 13, 14, 15, and 16, and a VH comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 9, 10, 11, and 12. 31. The pharmaceutical composition of any one of the preceding embodiments, wherein the antibody comprises a human heavy chain constant region, and the human heavy chain constant region is a human IgG1 constant region. 32. The pharmaceutical composition of any one of the preceding embodiments, wherein the antibody comprises a modified human Fc region or domain. 33. The pharmaceutical composition of any one of the preceding embodiments, wherein said antibody comprises a modified human IgG1 Fc region or domain. 34. The pharmaceutical composition of embodiment 33, wherein said modified human IgG1 Fc region or domain comprises the non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat. 35. The pharmaceutical composition of embodiment 34, wherein said modified human IgG1 Fc region or domain further comprises the non-naturally occurring amino acids 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat. 36. The antibody, (i) a VL comprising the amino acid sequence of SEQ ID NO: 14; (ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; (iii) a modified human IgG1 Fc region or domain comprising non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat. 37. The antibody, (i) a VL comprising the amino acid sequence of SEQ ID NO: 14; (ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; (iii) a modified human IgG1 Fc region or domain comprising the non-naturally occurring amino acids 234A, 235Q, 322Q, 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat. 38. The antibody has the amino acid sequence: QVQLVQSGAEVKKPGASVKLSCKASGYTFTDYYINWVRQAPGKGLEWIARIYPGSGNTYYNEKFKGRATLTADKSTSTAYMQLSSLRSEDTAVYFCARGVYYFDYWGQGTTVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEAQGGPSVFLFP PKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCQVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 21). 39. The antibody has the amino acid sequence: 10. The pharmaceutical composition of any one of the preceding embodiments, comprising a light chain comprising DIVMTQSPSSLSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKALIYSASYRYSGVPDRFTGSGSGTDFTLTISSLQPEDFADYFCQQYNSYPRTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 22). 40. A kit comprising the pharmaceutical composition of any one of the preceding embodiments. 41. A method for protecting against, treating, or managing a KIT-associated disorder, comprising administering to a subject in need thereof a therapeutically effective amount of a pharmaceutical composition of any one of embodiments 1-39. 42. The method of embodiment 41, wherein the pharmaceutical composition is administered subcutaneously to the subject. 43. The method of embodiment 41 or 42, wherein the KIT-associated disorder is a mast cell-associated disorder, an eosinophil-associated disorder, cancer, asthma, an inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, a gastrointestinal disorder, or fibrosis. 44. The method of embodiment 43, wherein the KIT-associated disorder is a mast cell-associated disorder. 45. The method of embodiment 43, wherein the KIT-associated disorder is an eosinophil-associated disorder. 46. ​​The method of any one of embodiments 41-45, further comprising administering to the subject a second therapeutic agent. 47. The method of embodiment 46, wherein the second therapeutic agent is a chemotherapeutic agent, a histone deacetylase inhibitor, an antibody, a cytokine, a tyrosine kinase inhibitor, an antihistamine, a leukotriene receptor antagonist, an immunomodulatory agent, or an anti-inflammatory agent. 48. The method of any one of embodiments 41 to 47, wherein the subject is a human. 49. The method of any one of embodiments 41-48, wherein 1.5 mg / kg or more of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 50. The method of any one of embodiments 41-48, wherein about 1.5 mg / kg to about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose. 51. The method of any one of embodiments 41-48, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 52. The method of any one of embodiments 41-48, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 53. The method of any one of embodiments 41-48, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 54. The method of any one of embodiments 41-53, wherein two doses of the antibody or antigen-binding fragment thereof are administered to the subject. 55. The method of any one of embodiments 41-53, wherein three doses of the antibody or antigen-binding fragment thereof are administered to the subject. 56. The method of any one of embodiments 41-55, wherein the antibody or antigen-binding fragment thereof is administered to the subject every four weeks. 57. The method of any one of embodiments 41-55, wherein the antibody or antigen-binding fragment thereof is administered to the subject every 8 weeks. 58. The method of any one of embodiments 41-48, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 4 weeks for 3 doses. 59. The method of any one of embodiments 41-48, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses. 60. The method of any one of embodiments 41-48, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses. 61. Use of a pharmaceutical composition according to any one of embodiments 1 to 39 for the manufacture of a medicament for protecting against, treating or managing a KIT-associated disorder in a subject. 62. The use according to embodiment 61, wherein the pharmaceutical composition is formulated for subcutaneous administration. 63. The use of embodiment 61 or 62, wherein the KIT-associated disorder is a mast cell-associated disorder, an eosinophil-associated disorder, cancer, asthma, an inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, a gastrointestinal disorder, or fibrosis. 64. The use according to embodiment 63, wherein the KIT-associated disorder is a mast cell-associated disorder. 65. The use according to embodiment 63, wherein the KIT-associated disorder is an eosinophil-associated disorder. 66. The use of any one of embodiments 61 to 65, wherein the medicament is manufactured to be administered to the subject in combination with a second therapeutic agent. 67. The use of embodiment 66, wherein the second therapeutic agent is a chemotherapeutic agent, a histone deacetylase inhibitor, an antibody, a cytokine, a tyrosine kinase inhibitor, an antihistamine, a leukotriene receptor antagonist, an immunomodulatory agent, or an anti-inflammatory agent. 68. The use according to any one of embodiments 61 to 67, wherein the subject is a human. 69. The use according to any one of embodiments 61 to 68, wherein 1.5 mg / kg or more of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 70. The use of any one of embodiments 61 to 68, wherein about 1.5 mg / kg to about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose. 71. The use according to any one of embodiments 61 to 68, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 72. The use of any one of embodiments 61 to 68, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 73. The use of any one of embodiments 61 to 68, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 74. The use of any one of embodiments 61-73, wherein two doses of the antibody or antigen-binding fragment thereof are administered to the subject. 75. The use of any one of embodiments 61-73, wherein three doses of the antibody or antigen-binding fragment thereof are administered to the subject. 76. The use according to any one of embodiments 61 to 75, wherein the antibody or antigen-binding fragment thereof is administered to the subject every 4 weeks. 77. The use according to any one of embodiments 61 to 75, wherein the antibody or antigen-binding fragment thereof is administered to the subject every 8 weeks. 78. The use of any one of embodiments 61 to 68, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 4 weeks for 3 doses. 79. The use of any one of embodiments 61 to 68, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses. 80. The use of any one of embodiments 61 to 68, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses. 81. A pharmaceutical composition according to any one of embodiments 1 to 39, for use in a method for protecting against, treating or managing a KIT-associated disorder in a subject. 82. The pharmaceutical composition for use according to embodiment 81, wherein the pharmaceutical composition is to be administered subcutaneously to the subject. 83. The pharmaceutical composition for use according to embodiment 81 or 82, wherein the KIT-associated disorder is a mast cell-associated disorder, an eosinophil-associated disorder, cancer, asthma, an inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, a gastrointestinal disorder, or fibrosis. 84. The pharmaceutical composition for use according to embodiment 83, wherein the KIT-associated disorder is a mast cell-associated disorder. 85. The pharmaceutical composition for use according to embodiment 83, wherein the KIT-associated disorder is an eosinophil-associated disorder. 86. The pharmaceutical composition for use according to any one of embodiments 81 to 85, wherein the method further comprises administering to the subject a second therapeutic agent. 87. The pharmaceutical composition for use according to embodiment 86, wherein the second therapeutic agent is a chemotherapeutic agent, a histone deacetylase inhibitor, an antibody, a cytokine, a tyrosine kinase inhibitor, an antihistamine, a leukotriene receptor antagonist, an immunomodulatory agent, or an anti-inflammatory agent. 88. The pharmaceutical composition for use according to any one of embodiments 81 to 87, wherein the subject is a human. 89. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein 1.5 mg / kg or more of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 90. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 1.5 mg / kg to about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered to the subject per dose. 91. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 92. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 93. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject. 94. The pharmaceutical composition for use according to any one of embodiments 81 to 93, wherein two doses of the antibody or antigen-binding fragment thereof are administered to the subject. 95. The pharmaceutical composition for use according to any one of embodiments 81 to 93, wherein three doses of the antibody or antigen-binding fragment thereof are administered to the subject. 96. The pharmaceutical composition for use according to any one of embodiments 81 to 95, wherein the antibody or antigen-binding fragment thereof is administered to the subject every four weeks. 97. The pharmaceutical composition for use according to any one of embodiments 81 to 95, wherein the antibody or antigen-binding fragment thereof is administered to the subject every 8 weeks. 98. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 4 weeks for 3 doses. 99. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses. 100. The pharmaceutical composition for use according to any one of embodiments 81 to 88, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses. 101. A method for producing a pharmaceutical composition according to any one of embodiments 1 to 39, comprising combining the antibody or antigen-binding fragment thereof with the buffer, the salt, and the excipient. [Brief explanation of the drawings]

[0039] 4. Brief description of the drawings [Figure 1] 1 shows the amino acid sequence of full-length human KIT (SEQ ID NO:1), GenBank™ Accession No. AAC50969. The first through fifth extracellular Ig-like domains (i.e., D1, D2, D3, D4, and D5) are shown, with "{" indicating the amino-terminal residue of each domain and "}" indicating the carboxyl-terminal residue of each domain. The D1 domain is located at P34 to R112, the D2 domain is located at D113 to P206, the D3 domain is located at A207 to D309, the D4 domain is located at K310 to N410, the hinge region between D4 and D5 is located at V409 to N410, and the D5 domain is located at T411 to K509. The D1 / D2 hinge region is located at D113 to L117, the D2 / D3 hinge region is located at P206 to A210, and the D3 / D4 hinge region is located at D309 to G311. The D4 / D5 region includes K310 to K509. The transmembrane domain includes residues F525 to Q545, and the kinase domain includes residues K589 to S933.

[0040] [Figure 2] AE show the effect of mAb1, a specific anti-KIT antibody according to the invention, on plasma tryptase levels.

[0041] [Figure 3] A and B show the additional effect of mAb1, a specific anti-KIT antibody according to the invention, on plasma tryptase levels.

[0042] [Figure 4] 1 shows the effect of mAb1, a specific anti-KIT antibody according to the invention, on plasma stem cell factor (SCF) levels.

[0043] [Figure 5] 1 shows the effect of a particular anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, with the same variable region sequence but with non-mutated (wild-type) human IgG1 sequence, on SCF-induced activation of wild-type KIT and downstream intracellular signaling pathways.

[0044] [Figure 6] 1 shows the effect of a particular anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, with the same variable region sequence but with unmutated (wild-type) human IgG1 sequence, on SCF-dependent cell proliferation.

[0045] [Figure 7] 1 shows the binding affinity of a particular anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, with the same variable region sequence but with unmutated (wild-type) human IgG1 sequence, to recombinant human Fc-gamma receptors (FcγR) and human neonatal Fc receptors (FcRn).

[0046] [Figure 8A] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAb1 to FcγRI is shown. [Figure 8B] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). 1 shows the binding curve of mAb1 to FcγRIIa. [Figure 8C] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAb1 to FcγRIIb is shown. [Figure 8D] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAb1 to FcγRIIIa is shown. [Figure 8E] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAb1 to FcγRIIIb is shown. [Figure 8F] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but an unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAb1 to FcRn is shown (pH 6.0). [Figure 8G] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but an unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAb1 to FcRn is shown (pH 7.2). [Figure 8H]1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, with the same variable region sequence but with unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAbc to FcγRI is shown. [Figure 8I] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but non-mutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). 1 shows the binding curve of mAbc to FcγRIIa. [Figure 8J] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but non-mutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). 1 shows the binding curve of mAbc to FcγRIIb. [Figure 8K] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but non-mutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). 1 shows the binding curve of mAbc to FcγRIIIa. [Figure 8L] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but non-mutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAbc to FcγRIIIb is shown. [Figure 8M]1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but an unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAbc to FcRn is shown (pH 6.0). [Figure 8N] 1 shows the binding curves of a specific anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, having the same variable region sequence but an unmutated (wild-type) human IgG1 sequence, to recombinant human Fc gamma receptor (FcγR) and human neonatal Fc receptor (FcRn). The binding curve of mAbc to FcRn is shown (pH 7.2).

[0047] [Figure 9] 1 shows the effect of a particular anti-KIT antibody according to the invention, mAb1, and a corresponding antibody, mAbc, with the same variable region sequence but with unmutated (wild-type) human IgG1 sequence, on antibody-dependent cellular cytotoxicity (ADCC) activity.

[0048] [Figure 10] 1 shows the effect of mAb1, a specific anti-KIT antibody according to the present invention, on the production of specific cytokines. The conditions shown in each bar graph, from left to right, are PHA, LPS, huIgG1 (soluble), 0.02 nM mAb1 (soluble), 0.2 nM mAb1 (soluble), 40 nM mAb1 (soluble), 0.02 nM mAb1 (dry coating), 0.2 nM mAb1 (dry coating), and 40 nM mAb1 (dry coating).

[0049] [Figure 11] FIG. 1 shows a schematic illustrating the role of KIT signaling in mast cells and the effect of mAb1 on the KIT receptor.

[0050] [Figure 12A]Figure 12 shows that a single dose of mAb1 resulted in rapid and sustained responses in patients with chronically inducible urticaria (CIndU), with a complete response (CR) rate of 95%. 10 / 10 cold urticaria (ColdU) patients achieved CR (Figure 12A). 8 / 9 symptomatic dermatographism (SD) patients achieved CR, and 1 / 9 SD patient achieved partial response (PR) (Figure 12B). CR = 4°C or higher or negative provocation test with 0 pins; PR = 4°C or improvement with 2 pins or higher; maximum response for each patient is shown. TempTest® results over time in ColdU patients are shown in Figure 12C. Among ColdU patients (n=8) who completed, CR was maintained for a median duration of 77 days (Figure 12C). FricTest® results over time in SD patients are shown in Figure 12D. Among patients with completed SD (n=6), CR was maintained for a median duration of 57 days (FIG. 12D). [Figure 12B] Figure 12 shows that a single dose of mAb1 resulted in rapid and sustained responses in patients with chronically inducible urticaria (CIndU), with a complete response (CR) rate of 95%. 10 / 10 cold urticaria (ColdU) patients achieved CR (Figure 12A). 8 / 9 symptomatic dermatographism (SD) patients achieved CR, and 1 / 9 SD patient achieved partial response (PR) (Figure 12B). CR = 4°C or higher or negative provocation test with 0 pins; PR = 4°C or improvement with 2 pins or higher; maximum response for each patient is shown. TempTest® results over time in ColdU patients are shown in Figure 12C. Among ColdU patients (n=8) who completed, CR was maintained for a median duration of 77 days (Figure 12C). FricTest® results over time in SD patients are shown in Figure 12D. Among patients with completed SD (n=6), CR was maintained for a median duration of 57 days (FIG. 12D). [Figure 12C]Figure 12 shows that a single dose of mAb1 resulted in rapid and sustained responses in patients with chronically inducible urticaria (CIndU), with a complete response (CR) rate of 95%. 10 / 10 cold urticaria (ColdU) patients achieved CR (Figure 12A). 8 / 9 symptomatic dermatographism (SD) patients achieved CR, and 1 / 9 SD patient achieved partial response (PR) (Figure 12B). CR = 4°C or higher or negative provocation test with 0 pins; PR = 4°C or improvement with 2 pins or higher; maximum response for each patient is shown. TempTest® results over time in ColdU patients are shown in Figure 12C. Among ColdU patients (n=8) who completed, CR was maintained for a median duration of 77 days (Figure 12C). FricTest® results over time in SD patients are shown in Figure 12D. Among patients with completed SD (n=6), CR was maintained for a median duration of 57 days (FIG. 12D). [Figure 12D] Figure 12 shows that a single dose of mAb1 resulted in rapid and sustained responses in patients with chronically inducible urticaria (CIndU), with a complete response (CR) rate of 95%. 10 / 10 cold urticaria (ColdU) patients achieved CR (Figure 12A). 8 / 9 symptomatic dermatographism (SD) patients achieved CR, and 1 / 9 SD patient achieved partial response (PR) (Figure 12B). CR = 4°C or higher or negative provocation test with 0 pins; PR = 4°C or improvement with 2 pins or higher; maximum response for each patient is shown. TempTest® results over time in ColdU patients are shown in Figure 12C. Among ColdU patients (n=8) who completed, CR was maintained for a median duration of 77 days (Figure 12C). FricTest® results over time in SD patients are shown in Figure 12D. Among patients with completed SD (n=6), CR was maintained for a median duration of 57 days (FIG. 12D).

[0051] [Figure 13]A-B indicate overall disease improvement as evidenced by the Physician's Global Assessment (Phys-GA) and Patient's Global Assessment (Pat-GA). Phys-GA and Pat-GA assess disease severity using a Likert scale of 0-3, with 0 being none and 3 being severe.

[0052] [Figure 14A] Figure 1 shows that mAb1 treatment significantly depleted skin mast cells and serum tryptase. Figure 1 shows that mAb1 reduced the number of skin mast cells (n=14, * means p<0.05, ** means p<0.01, *** means p<0.001, **** means p<0.0001). [Figure 14B] Figure 1 shows that mAb1 treatment significantly depleted skin mast cells and serum tryptase. Figure 2 shows that mAb1 reduced serum tryptase to below detection in all patients (tryptase values ​​below the assay limit of quantitation (LLoQ = 1 ng / mL) were normalized to 0). [Figure 14C] Figure 1 shows that mAb1 treatment significantly depleted skin mast cells and serum tryptase. Figure 2 shows the dynamics of mast cells and tryptase. [Figure 14D] Figure 1 shows that mAb1 treatment significantly depleted skin mast cells and serum tryptase. Skin mast cell numbers correlated with serum tryptase levels (p<0.0001, R2=0.45).

[0053] [Figure 15A] Figure 1 shows the kinetics of skin mast cells and tryptase depletion reflected a decrease in provocation threshold. Figure 2 shows mast cell kinetics and TempTest® results over time in ColdU patients. [Figure 15B] Figure 1 shows the kinetics of skin mast cells and tryptase depletion reflected a decrease in provocation threshold. Figure 2 shows mast cell kinetics and FricTest® results over time in SD patients. [Figure 15C]Figure 1 shows the kinetics of skin mast cells and tryptase depletion reflected a decrease in the elicitation threshold. Figure 2 shows tryptase kinetics over time and TempTest® results in ColdU patients (tryptase values ​​below the LLoQ were normalized to 0, and a critical temperature threshold below 4°C (negative test) was assigned a value of 3°C). [Figure 15D] Figure 1 shows the kinetics of skin mast cells and tryptase depletion reflected a decrease in provocation threshold. Figure 2 shows tryptase kinetics and FricTest® results over time in SD patients.

[0054] [Figure 16A] Hematologic parameters generally remained within normal ranges, with mild, transient, asymptomatic declines in hemoglobin and white blood cell (WBC) parameters. Hemoglobin (HgB) levels over time are shown. [Figure 16B] Figure 1 shows that hematological parameters generally remained within normal ranges, with mild, transient, asymptomatic declines in hemoglobin and white blood cell (WBC) parameters. WBC counts over time are shown. [Figure 16C] Figure 1 shows that hematological parameters generally remained within normal ranges, with mild, transient, asymptomatic declines in hemoglobin and white blood cell (WBC) parameters. Platelet counts over time are shown. [Figure 16D] Figure 1 shows that hematological parameters generally remained within normal ranges, with mild, transient, asymptomatic declines in hemoglobin and white blood cell (WBC) parameters. Neutrophil count (ANC) over time is shown. In each graph, the shaded area represents the corresponding normal range.

[0055] [Figure 17]Figures 17A-B show that a single 3 mg / kg dose of mAb1 resulted in rapid and sustained improvement in urticaria control in patients with cold urticaria (ColdU) (n=10, see Figure 17A) and symptomatic dermatographia (SD) (n=10, see Figure 17B). A urticaria control test (UCT) score of 16 indicates complete urticaria control, a UCT score of ≥12 indicates well-controlled urticaria, and a UCT score <12 indicates poorly controlled urticaria. Each graph displays the mean UCT score ± SEM.

[0056] [Figure 18] Figures 18A-B show that a single 3 mg / kg dose of mAb1 resulted in rapid and sustained improvement in urticaria control in ColdU and SD patients. Figure 18A shows that 100% of patients achieved "well controlled" status (UCT score ≥ 12) by week 8. Figure 18B shows that 63% of patients achieved "complete control" status (UCT score = 16) by week 8.

[0057] [Figure 19] A-B show that mAb1 significantly reduced the impact of the disease on quality of life in patients with cold urticaria (ColdU, n=10, see FIG. 19A) and symptomatic dermatographia (SD, n=10, see FIG. 19B). Mean DLQI scores ± SEM are shown.

[0058] [Figure 20] Figures 20A-B show that mAb1 significantly reduced the impact of the disease on quality of life in patients with cold urticaria (ColdU) and symptomatic dermatographia (SD). Figure 20A shows that 93% of patients achieved a clinically significant improvement in quality of life by week 4. †: A decrease in DLQI of ≥ 4 points is the minimal clinically important difference (MCID). *: Only patients with a baseline DLQI score of ≥ 4 were included. Figure 20B shows that 58% of patients reported no impact of the disease on quality of life by week 4. T: All responses provided at each week were included.

[0059] [Figure 21A] Figure 1 shows that a single 3 mg / kg dose of mAb1 produced rapid and sustained improvement in provocation testing, with a 95% complete response (CR) and significant tryptase reduction. Figure 1 shows that mAb1 produced rapid and sustained improvement in provocation testing, with a 95% complete response. Disease activity was assessed by the critical temperature threshold (CTT) with the TempTest® for cold urticaria (ColdU) and the critical friction threshold (CFT) with the FricTest® for symptomatic dermatographism (SD). *: A critical temperature threshold below 4°C (negative test) was assigned a value of 3°C. 10 / 10 ColdU patients and 9 / 10 SD patients experienced a CR on the test. CR = negative provocation test below 4°C (for ColdU) or 0 pin (for SD). Graphs show mean ± SEM. [Figure 21B] Figure 1 shows that a single 3 mg / kg dose of mAb1 produced rapid and sustained improvement in provocation testing with a 95% complete response (CR) and significant tryptase reduction. Figure 2 shows that mAb1 produced rapid, sustained, and significant tryptase reduction. Tryptase values ​​below the lower limit of quantitation (1 ng / mL) were normalized to 0. Graphs show mean ± SEM.

[0060] [Figure 22] Figure 1 shows the study design for a Phase 1 study in adults with moderate to severe chronic spontaneous urticaria (CSU).

[0061] [Figure 23] Figures 23A-C show that mAb1 induced rapid and sustained symptom improvement in patients with antihistamine-refractory CSU. Data presented are mean ± SE. Figure 23A shows data for UAS7 (weekly urticaria activity score). Figure 23B shows data for ISS7 (weekly itch severity score). Figure 23C shows data for HSS (weekly urticaria severity score).

[0062] [Figure 24]Figures 24A-B show that mAb1 produced durable responses at doses of 1.5 mg / kg or higher with UAS7. Figure 24A shows data for % of patients with UAS7≦6. Figure 24B shows data for % of patients with UAS7=0.

[0063] [Figure 25] Figures 25A-B show that prolonged mAb1 exposure and tryptase inhibition were achieved at doses of 1.5 mg / kg and above. Figure 25A shows pharmacokinetic data (data presented are geometric means ± geometric SD). Figure 25B shows serum tryptase data (data presented are means ± SE; tryptase values ​​below the lower limit of detection are normalized to 0).

[0064] [Figure 26] A-B show that greater urticaria disease control (UCT≧12) was achieved with mAb1 at doses ≧1.5 mg / kg. Figure 26A shows the mean UCT scores (data presented are mean±SE). Figure 26B shows the % of patients with a UCT≧12. UCT=16: complete control. UCT≧12: well-controlled disease.

[0065] [Figure 27] Figures 27A-B show that robust clinical activity was observed in both omalizumab-experienced and naive patients. Figure 27A shows mean UAS7. Figure 27B shows mean UCT. Data presented are means ± SE.

[0066] [Figure 28A] Key hematological parameters over time: Hemoglobin. [Figure 28B] Key hematological parameters are shown over time: White blood cells. [Figure 28C] Key hematological parameters are shown over time: Neutrophils. [Figure 28D] Key hematological parameters are shown over time: Platelets. Data presented are means ± SE. DETAILED DESCRIPTION OF THE INVENTION

[0067] 5. MODE FOR CARRYING OUT THE INVENTION Provided herein are anti-KIT antibody formulations. Specifically, provided herein are pharmaceutical compositions comprising (i) an antibody or antigen-binding fragment thereof that immunospecifically binds to human KIT, (ii) a buffering agent, (iii) a salt, and (iv) an excipient. Also provided are methods for making such pharmaceutical compositions. Also provided herein are methods and uses for protecting against, treating, or managing KIT-associated disorders or diseases, comprising administering the pharmaceutical compositions described herein. Also provided herein are kits comprising the pharmaceutical compositions described herein.

[0068] As used herein, "administering" or "administration" refers to the act of injecting or otherwise physically delivering a substance (e.g., a humanized anti-KIT antibody or antigen-binding fragment thereof provided herein or a pharmaceutical composition described herein) to a subject or patient (e.g., a human), such as by mucosal, topical, intradermal, parenteral, intravenous, intramuscular delivery and / or any other method of physical delivery described herein or known in the art.

[0069] As used herein, the term "effective amount" or "therapeutically effective amount" refers to an amount of a therapy (e.g., an antibody or pharmaceutical composition provided herein) sufficient to reduce and / or ameliorate the severity and / or duration of a given disease and / or its associated symptoms. These terms also encompass the amount necessary to reduce, delay, or ameliorate the development or progression of a given disease, reduce, delay, or ameliorate the recurrence, onset, or onset of a given disease, and / or improve or enhance the prophylactic or therapeutic effect(s) of another therapy (e.g., a therapy other than an anti-KIT antibody or pharmaceutical composition provided herein). In some embodiments, "effective amount" as used herein also refers to the amount of an antibody or pharmaceutical composition described herein to achieve a particular result, such as a reduction in the number and / or activity of mast cells, a reduction in the number and / or activity of eosinophils, inhibition (e.g., partial inhibition) of cellular KIT biological activity, such as inhibition of cell proliferation or cell survival, or enhancement or induction of apoptosis or cell differentiation.

[0070] As used herein, the term "D4 or D5 region" or "D4 / D5 domain" refers to the region within the KIT polypeptide spanning the fourth Ig-like extracellular ("D4") domain, the fifth Ig-like extracellular ("D5") domain, and the hinge region between the D4 and D5 domains (the "D4-D5 hinge region") of KIT, in the following order from amino-terminus to carboxyl-terminus: D4, D4-D5 hinge region, and D5. As used herein, amino acids V308 to H515 of Figure 1 are considered an example of a D4 / D5 region or domain.

[0071] As used herein, the term "KIT" or "KIT receptor" or "KIT polypeptide" refers to any form of full-length KIT, including, but not limited to, native KIT, an isoform of KIT, an interspecies KIT homolog, or a KIT variant, e.g., a naturally occurring (e.g., an allelic or splice variant, or a mutant, e.g., a somatic mutant) or an artificially constructed variant (e.g., a recombinant or chemically modified variant). KIT is a type III receptor tyrosine kinase encoded by the c-kit gene (see, e.g., Yarden et al., Nature, 1986, 323:226-232; Ullrich and Schlessinger, Cell, 1990, 61:203-212; Clifford et al., J. Biol. Chem., 2003, 278:31461-31464; Yarden et al., EMBO J., 1987, 6:3341-3351; Mol et al., J. Biol. Chem., 2003, 278:31461-31464). GenBank™ Accession No. NM000222 provides an exemplary human KIT nucleic acid sequence. GenBank™ Accession Nos. NP001087241, PI0721, and AAC50969 provide exemplary human KIT amino acid sequences. GenBank™ Accession No. AAH75716 provides an exemplary murine KIT amino acid sequence. Native KIT contains five extracellular immunoglobulin (Ig)-like domains (D1, D2, D3, D4, D5), a single transmembrane region, an inhibitory cytoplasmic juxtamembrane domain, and a split cytoplasmic kinase domain separated by a kinase insert segment (see, e.g., Yarden et al., Nature, 1986, 323:226-232; Ullrich and Schlessinger, Cell, 1990, 61:203-212; Clifford et al., J. Biol. Chem., 2003, 278:31461-31464). An exemplary amino acid sequence of the D4 / D5 region of human KIT is provided in Figure 1, from amino acid residues V308 to H515. In certain embodiments, the KIT is human KIT.In certain embodiments, KIT can exist as a monomer, dimer, multimer, native form, or denatured form.

[0072] As used herein, the term "combination" in the context of administering other therapies refers to the use of two or more therapies. The use of the term "combined" does not restrict the order in which the therapies are administered. The therapies can be administered, for example, sequentially, sequentially, simultaneously, or concomitantly.

[0073] As used herein, the terms "KIT-associated disorder" or "KIT-associated disease" are used interchangeably and refer to any disease caused, associated, or resulting in whole or in part from KIT expression and / or activity or a lack thereof. In preferred embodiments, the KIT-associated disorder or disease is a disease caused, associated, or resulting in whole or in part from KIT expression and / or activity (e.g., overexpression of KIT, gain-of-function KIT activity, and / or an increase in KIT activity). In certain embodiments, the KIT-associated disease or disorder is a disease associated with KIT expression and / or activity, e.g., involving cells that express KIT and / or exhibit KIT activity, but is not caused by or results from KIT expression or activity. In one aspect, the KIT-associated disorder or disease can be known to or ascertained by one of skill in the art. In certain embodiments, the KIT-associated disease or disorder is associated with KIT expression and / or activity. For example, KIT expression and / or activity, in combination with one or more other factors (e.g., mutations or the expression and / or activity of another gene), may contribute to the development and / or progression of a KIT-associated disease or disorder. In certain embodiments, a KIT-associated disease or disorder is associated with one or more mutations in KIT.

[0074] In certain embodiments, the KIT-related disorder is a mast cell-related disorder, an eosinophil-related disorder, cancer, asthma, an inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, a gastrointestinal disorder, or fibrosis. In certain embodiments, the KIT-related disorder is a fibrosis or inflammatory disorder, for example, an inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). In other embodiments, the KIT-related disorder is a cancer such as lung cancer (e.g., small cell lung cancer), leukemia, neuroblastoma, melanoma, sarcoma (e.g., Ewing's sarcoma), or gastrointestinal stromal tumor (GIST). In certain embodiments, the KIT-related disorder is a mast cell-related disorder. In certain embodiments, the KIT-related disorder is an eosinophil-related disorder such as eosinophilic esophagitis (EoE).

[0075] As used herein, the term "chronic prurigo" refers to a disease characterized by both chronic pruritus (itch) and the presence of multiple localized or generalized pruritic lesions.

[0076] As used herein, the term "prurigo nodularis" refers to a disease characterized by chronic pruritus and the presence of both multiple localized or generalized, elevated, indurated, and nodular lesions.

[0077] As used herein, the terms "treat," "treatment," and "treating" refer to the reduction or amelioration of the progression, severity, and / or duration of a KIT-associated disease (e.g., cancer, inflammatory disorder, or fibrosis) resulting from the administration of one or more therapies (including, but not limited to, the administration of one or more prophylactic or therapeutic agents, such as antibodies or pharmaceutical compositions provided herein).

[0078] As used herein, the terms "manage," "managing," and "management" refer to the beneficial effect a subject derives from a therapy (e.g., a prophylactic or therapeutic agent), which does not result in a cure. In certain embodiments, a subject is administered one or more therapies (e.g., a prophylactic or therapeutic agent, such as an antibody or pharmaceutical composition described herein) to "manage" a disorder, or one or more symptoms thereof, such that the progression or worsening of the disorder is prevented.

[0079] As used herein, the terms "protect against," "prevent," or "preventing" in the context of a disorder refer to a complete or partial inhibition (e.g., less than 100%, 95%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or 5%) or blockage of the onset, recurrence, development, or spread of a disorder, and / or symptoms associated therewith, resulting from the administration of a therapy or combination of therapies provided herein (e.g., a combination of prophylactic or therapeutic agents, such as an antibody or pharmaceutical composition described herein).

[0080] As used herein, the term "prophylactic agent" refers to any agent that can completely or partially inhibit the onset, recurrence, progression, or spread of a disorder and / or its associated symptoms in a subject. In certain embodiments, the term "prophylactic agent" refers to an antibody or pharmaceutical composition described herein. In certain other embodiments, the term "prophylactic agent" refers to an agent other than an antibody or pharmaceutical composition described herein. Generally, a prophylactic agent is an agent that is known to be useful, has been used, or is currently being used, to prevent a disorder and / or its associated symptoms, or to hinder the onset, development, progression, and / or severity of a disorder and / or its associated symptoms. In certain embodiments, a prophylactic agent is a human anti-KIT antibody, such as a humanized or fully human anti-KIT monoclonal antibody, or a pharmaceutical composition thereof.

[0081] As used herein, the term "side effect" or "adverse effect" encompasses unwanted and adverse effects of a therapy (e.g., a prophylactic or therapeutic agent). Unwanted effects are not necessarily harmful. Adverse effects from a therapy (e.g., a prophylactic or therapeutic agent) can be harmful or uncomfortable or dangerous. Examples of side effects include diarrhea, cough, gastroenteritis, wheezing, nausea, vomiting, loss of appetite, abdominal cramps, fever, pain, weight loss, dehydration, hair loss, difficulty breathing, insomnia, dizziness, mucositis, nerve and muscle effects, fatigue, dry mouth, and loss of appetite, rash or swelling at the site of administration, flu-like symptoms such as fever, chills, and fatigue, gastrointestinal problems, and allergic reactions. Additional unwanted effects experienced by patients are numerous and known in the art. Many are described in the Physician's Desk Reference (71 st ed., 2017).

[0082] As used herein, the terms "subject" and "patient" are used interchangeably. As used herein, a subject is a mammal, e.g., a human, such as a non-primate (e.g., cow, pig, horse, cat, dog, goat, rabbit, rat, mouse, etc.) or a primate (e.g., monkey and human). In one embodiment, the subject is a mammal, e.g., a human, diagnosed with a disorder. In another embodiment, the subject is a mammal, e.g., a human, at risk of developing a KIT-associated disorder. In another embodiment, the subject is a non-human primate. In certain embodiments, the subject is a human adult. In certain embodiments, the subject is an adult human subject at least 18 years of age. In certain embodiments, the subject is a human child. In certain embodiments, the subject is a human child aged 1 to 18 years. In certain embodiments, the subject is a human aged 1 to 3 years. In certain embodiments, the subject is a human aged 3 to 12 years or 12 to 18 years.

[0083] As used herein, the terms "therapies" and "therapy" can refer to any protocol(s), method(s), composition(s), formulation(s), and / or agent(s) that can be used to prevent, protect against, treat, manage, or ameliorate a condition or disorder or its symptoms or one or more symptoms or conditions associated therewith. In certain embodiments, the terms "therapies" and "therapy" refer to drug therapy, adjunctive therapy, radiation therapy, surgery, biological therapy, supportive therapy, and / or other therapies useful for protecting against, treating, managing, preventing, or ameliorating a condition or disorder or one or more symptoms thereof or one or more symptoms or conditions associated therewith. In certain embodiments, the term "therapy" refers to a therapy other than an anti-KIT antibody described herein or a pharmaceutical composition described herein. In certain embodiments, "additional therapy" and "additional therapies" refer to a therapy other than treatment using an anti-KIT antibody described herein or a pharmaceutical composition described herein. In certain embodiments, the therapy includes use of an anti-KIT antibody or pharmaceutical composition described herein as adjuvant therapy. For example, the anti-KIT antibodies or pharmaceutical compositions described herein are used in combination with drug therapy, biological therapy, surgery, and / or supportive care.

[0084] As used herein, the term "therapeutic agent" refers to any agent that can be used to protect against, treat, manage, or ameliorate a disorder and / or its associated symptoms. In certain embodiments, the term "therapeutic agent" refers to an anti-KIT antibody or antigen-binding fragment thereof described herein or a pharmaceutical composition described herein. In certain other embodiments, the term "therapeutic agent" refers to an agent other than an antibody or pharmaceutical composition described herein. In certain embodiments, a therapeutic agent is an agent that is known to be useful, or has been used, or is currently being used, for the protection against, treatment, management, or amelioration of a disorder or one or more symptoms associated therewith.

[0085] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The terms "a" (or "an"), as well as "one or more," and "at least one," can be used interchangeably herein.

[0086] Whenever an embodiment is described herein with the term "comprising," it is understood that analogous embodiments described with the terms "consisting of" and / or "consisting essentially of" are also provided.

[0087] As used herein, unless otherwise specified, the terms "about" and "approximately" are intended to allow for normal variation as determined by one of ordinary skill in the art, such as, for example, variation within 20%, or 10%, or 5%. In certain embodiments, the terms "about" and "approximately" encompass the exact value recited.

[0088] 5.1 Antibodies Provided herein are antibodies (e.g., anti-KIT antibodies) that specifically bind to a KIT receptor (e.g., the extracellular domain of the human KIT receptor shown, for example, in SEQ ID NO: 1 or FIG. 1), or an antigen-binding fragment thereof.

[0089] As used herein, the terms "antibody" and "immunoglobulin" and "Ig" are terms of the art and may be used interchangeably herein to refer to a molecule having an antigen-binding site that immunospecifically binds to an antigen. The term "antibody" includes antigen-binding fragments.

[0090] Antibodies include, for example, monoclonal antibodies, recombinantly produced antibodies, monospecific antibodies, multispecific antibodies (including bispecific antibodies), human antibodies, humanized antibodies, chimeric antibodies, synthetic antibodies, tetrameric antibodies comprising two heavy chain molecules and two light chain molecules, antibody light chain-antibody heavy chain pairs, heteroconjugate antibodies, single domain antibodies, monovalent antibodies, single-chain antibodies, single-chain variable fragments (scFv), camelized antibodies, affibodies, Fab fragments, F(ab') fragments, disulfide-linked variable fragments (dsFv), and antigen-binding fragments of any of the above. In certain embodiments, antibodies described herein refer to polyclonal antibody populations. Antibodies can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, or IgY), any class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, or IgA2), or any subclass (e.g., IgG2a or IgG2b) of immunoglobulin molecule. In certain embodiments, the antibodies described herein are IgG antibodies, or a class (eg, human IgG1 or IgG4) or subclass thereof.

[0091] As used herein, an "antigen" is a moiety or molecule that contains an epitope and is therefore specifically bound by an antibody. In certain embodiments, the antigen bound by the antibodies described herein is KIT (e.g., human KIT), or a fragment thereof, such as the extracellular domain of KIT (e.g., human KIT) or the D4 region of KIT (e.g., human KIT).

[0092] As used herein, the terms "antigen-binding domain," "antigen-binding region," "antigen-binding fragment," and similar terms refer to a portion of an antibody molecule that contains amino acid residues (e.g., complementarity-determining regions (CDRs)) that interact with an antigen and confer on the antibody molecule its specificity for the antigen. The antigen-binding region can be derived from any animal species, including rodents (e.g., mice, rats, or hamsters) and humans. The CDRs of an antibody molecule can be determined by any method known to those skilled in the art. In particular, CDRs can be determined according to the Kabat numbering system (Kabat et al. (1991) Sequences of Proteins of Immunological Interest. (USDapartment of Health and Human Services, Washington, DC) 5). thed.). In certain embodiments, the CDRs of the antibody are numbered according to (i) the Chothia numbering scheme, which is referred to herein as "Chothia CDRs" (see, e.g., Chothia and Lesk, 1987, J. Mol. Biol, 196:901-917; Al-Lazikani et al., 1997, J. Mol. Biol, 273:927-948; and U.S. Patent No. 7,709,226), (ii) the IMGT numbering system, e.g., as described in Lefranc, M.-P., 1999, The Immunologist, 7:132-136; and Lefranc, M.-P. et al., 1999, Nucleic Acids Res., 27:209-212, (iii) the AbM numbering system, e.g., as described in MacCallum et al. al., 1996, J. Mol. Biol., 262:732-745 and Martin, A., "Protein Sequence and Structure Analysis of Antibody Variable Domains," in Antibody Engineering, Kontermann and Dubel, eds., Chapter 31, pp. 422-439, Springer-Verlag, Berlin (2001), or (iv) the Contact numbering system, which is based on analysis of available complex crystal structures (bioinf.org.uk / abs) (see, e.g., MacCallum et al., (1996) J. Mol. Biol. 5:732-745). In preferred embodiments, the antigen-binding fragments described herein comprise a full-length heavy chain Fc region or domain (e.g., a full-length human IgG1, human IgG2, human IgG3, or human IgG4 Fc region or domain) or a partial heavy chain Fc region or domain (e.g., a partial human IgG1, human IgG2, human IgG3, or human IgG4 Fc region or domain).

[0093] As used herein, the term "constant region" or "constant domain" refers to the portion of an antibody, e.g., the carboxyl-terminal portions of the light and / or heavy chains, that are not directly involved in binding the antibody to an antigen, but which exhibit or contribute to various effector functions, such as interaction with Fc receptors. The term refers to a portion of an immunoglobulin molecule that generally has a more conserved amino acid sequence compared to the immunoglobulin variable domain.

[0094] As used herein, "epitope" is a term used in the art and refers to a localized region of an antigen to which an antibody can specifically bind. The region or polypeptide contributing to an epitope can be contiguous amino acids of a polypeptide, or an epitope can be comprised of two or more non-contiguous regions of a polypeptide.

[0095] As used herein, the term "heavy chain," when used in reference to an antibody, refers to any of the different types, e.g., alpha (a), delta (δ), epsilon (ε), gamma (γ), and mu (μ), based on the amino acid sequence of the constant domain, which give rise to antibodies of the IgA, IgD, IgE, IgG, and IgM classes, respectively, and include the subclasses of IgG, e.g., IgGi, IgG2, IgG3, and IgG4. In certain embodiments, the heavy chain is a human heavy chain.

[0096] As used herein, the terms "immunospecifically bind," "immunospecifically recognize," "specifically bind," and "specifically recognize" are similar terms in the context of antibodies, and such binding refers to a molecule that binds to an antigen (e.g., an epitope or immune complex) as understood by one of skill in the art. For example, a molecule that specifically binds to an antigen may generally bind with low affinity to other peptides or polypeptides as determined, for example, by immunoassay, Biacore™, KinExA 3000 instrument (Sapidyne Instruments, Boise, ID), or other assays known in the art. In certain embodiments, a molecule that immunospecifically binds to an antigen is one that binds to another antigen with a K a At least 2, 2.5, 3, or 4 logs higher than a In another specific embodiment, a molecule that immunospecifically binds to an antigen does not cross-react with other proteins. In another specific embodiment, a molecule that immunospecifically binds to an antigen does not cross-react with other non-KIT proteins.

[0097] As used herein, an "isolated" or "purified" antibody is substantially free of cellular material or other contaminating proteins from the cell or tissue source from which it is derived, or substantially free of chemical precursors or other chemicals when chemically synthesized. In certain embodiments, the antibodies or antigen-binding fragments described herein are isolated.

[0098] The term "Kabat numbering" and similar terms are art-recognized and refer to a system for numbering amino acid residues in the heavy and light chain variable regions, or antigen-binding portions thereof, of an antibody (Kabat et al. (1971) Ann. NY Acad. Sci. 190:382-391 and Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242). Using the Kabat numbering system, the CDRs within an antibody heavy chain molecule are typically located at amino acid positions 31-35 ("CDR1"), amino acid positions 50-65 ("CDR2"), and amino acid positions 95-102 ("CDR3"). Using the Kabat numbering system, the CDRs in an antibody light chain molecule are typically located at amino acid positions 24-34 (CDR1), amino acid positions 50-56 (CDR2), and amino acid positions 89-97 (CDR3).

[0099] As used herein, the term "light chain," when used in reference to an antibody, refers to any of the different types, e.g., lambda (λ) or kappa (κ), based on the amino acid sequence of the constant domain. Light chain amino acid sequences are well known in the art. In certain embodiments, the light chain is a human light chain.

[0100] As used herein, the term "monoclonal antibody" refers to an antibody obtained from a homogeneous or substantially homogeneous population of antibodies, with each monoclonal antibody typically recognizing a single epitope on an antigen. The term "monoclonal" is not limited to any particular method for producing the antibody. Generally, a population of monoclonal antibodies can be produced by a cell, a group of cells, or a cell line. In certain embodiments, a "monoclonal antibody," as used herein, is an antibody produced by a single hybridoma or other cell (e.g., a host cell producing a recombinant antibody), which immunospecifically binds to a KIT epitope (e.g., an epitope of D4 of human KIT) as determined, for example, by ELISA or other antigen-binding or competitive binding assays known in the art or in the examples provided herein. The monoclonal antibodies described herein can be produced, for example, by hybridoma methods such as those described in Kohler et al., Nature, 256:495 (1975), or isolated from phage libraries, for example, using techniques such as those described herein. Other methods for the preparation of clonal cell lines and the monoclonal antibodies expressed thereby are well known in the art (see, e.g., Chapter 11 in Short Protocols in Molecular Biology, (2002) 5th Ed., Ausubel et al., eds., John Wiley and Sons, New York). In certain embodiments, monoclonal antibodies are monospecific, in that their antigen-binding regions are specific for the same epitope. In further specific embodiments, monoclonal monospecific antibodies can be monovalent (having one antigen-binding region) or multivalent (having two or more antigen-binding regions), e.g., bivalent (having two antigen-binding regions).

[0101] As used herein, the term "naked antibody" refers to an antibody that is not linked, fused, or conjugated to another agent or molecule (e.g., a label or drug), peptide, or polypeptide. In certain embodiments, a naked antibody expressed by a mammalian host cell may be glycosylated by the host cell's glycosylation machinery, e.g., glycosylation enzymes. In certain embodiments, a naked antibody is not glycosylated if it is expressed by a host cell that does not itself possess the glycosylation machinery, e.g., glycosylation enzymes. In certain embodiments, a naked antibody is a whole antibody; in other embodiments, a naked antibody is an antigen-binding fragment of a whole antibody, such as a Fab antibody.

[0102] As used herein, the term "polyclonal antibody" refers to an antibody population containing a variety of different antibodies directed against the same and different epitopes within an antigen or antigens. Methods for producing polyclonal antibodies are known in the art (see, for example, Chapter 11 in Short Protocols in Molecular Biology, (2002) 5th Ed., Ausubel et al., eds., John Wiley and Sons, New York).

[0103] As used herein, the term "recombinant human antibody" includes human antibodies isolated, prepared, expressed, or generated by recombinant means, such as antibodies expressed using a recombinant expression vector transfected into a host cell, antibodies isolated from a recombinant combinatorial human antibody library, antibodies isolated from an animal (e.g., a mouse, rabbit, goat, or cow) that is transgenic and / or transchromosomal for human immunoglobulin genes (see, e.g., Taylor, LD et al. (1992) Nucl. Acids Res. 20:6287-6295), or antibodies prepared, expressed, generated, or isolated by any other means involving, for example, synthesis, genetic engineering of DNA sequences encoding human immunoglobulin sequences, or splicing of human immunoglobulin-encoding sequences, e.g., human immunoglobulin gene sequences, into other such sequences. Such recombinant human antibodies can have variable and constant regions derived from human germline immunoglobulin sequences. In certain embodiments, the amino acid sequences of such recombinant human antibodies have therefore been modified such that the amino acid sequences of the VH and / or VL regions of the recombinant antibody are derived from and related to human germline VH and VL sequences, but are sequences that do not naturally occur within the human antibody germline repertoire in vivo. As a non-limiting example, a recombinant human antibody can be obtained by assembling several human sequence fragments into the composite human sequence of a recombinant human antibody.

[0104] As used herein, the term "variable region" or "variable domain" refers to a portion of an antibody, generally a portion of either the light or heavy chain, typically the amino-terminal 110-120 amino acids in the mature heavy chain and approximately 90-100 amino acids in the mature light chain, which vary significantly in sequence among antibodies and are used for the binding and specificity of a particular antibody for its particular antigen. The variability in sequence is concentrated in these regions called complementarity-determining regions (CDRs), while the more highly conserved regions in variable domains are called framework regions (FRs).

[0105] Without wishing to be bound by any particular mechanism or theory, it is believed that the CDRs of the light and heavy chains are primarily involved in the interaction of the antibody with the antigen. In certain embodiments, the numbering of the amino acid positions of the antibodies described herein is according to the EU index, as in Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242 ("Kabat et al."). In certain embodiments, the CDRs of the antibody may be numbered according to: (i) the Chothia numbering scheme, which is referred to herein as "Chothia CDRs" (see, e.g., Chothia and Lesk, 1987, J. Mol. Biol, 196:901-917; Al-Lazikani et al., 1997, J. Mol. Biol, 273:927-948; and U.S. Patent No. 7,709,226); (ii) the IMGT numbering system, e.g., as described in Lefranc, M.-P., 1999, The Immunologist, 7:132-136; and Lefranc, M.-P. et al., 1999, Nucleic Acids Res., 27:209-212; or (iii) the AbM numbering system, e.g., as described in MacCallum et al. al., 1996, J. Mol. Biol., 262:732-745 and Martin, A., "Protein Sequence and Structure Analysis of Antibody Variable Domains," in Antibody Engineering, Kontermann and Dubel, eds., Chapter 31, pp. 422-439, Springer-Verlag, Berlin (2001), or (iv) the Contact numbering system, which is based on analysis of available complex crystal structures (bioinf.org.uk / abs) (see, e.g., MacCallum et al., (1996) J. Mol. Biol. 5:732-745).In certain embodiments, the variable region is a human variable region. In certain embodiments, the variable region comprises rodent or murine CDRs and human framework regions (FRs). In certain embodiments, the variable region is a primate (e.g., non-human primate) variable region. In certain embodiments, the variable region comprises rodent or murine CDRs and primate (e.g., non-human primate) framework regions (FRs). As a non-limiting example, the variable regions described herein are obtained from assembling two or more fragments of human sequences into a composite human sequence.

[0106] In certain embodiments, anti-KIT antibodies (e.g., humanized antibodies) provided herein comprise a light chain variable region ("VL") comprising VL CDRs 1-3 and a heavy chain variable region ("VH") comprising VH CDRs 1-3 as set forth in Table 1. In certain embodiments, anti-KIT antibodies (e.g., humanized antibodies) provided herein comprise a light chain variable region ("VL") comprising VL CDRs 1-3 and a heavy chain variable region ("VH") comprising VH CDRs 1-3 as set forth in Table 2 (Set 1 or Set 2). In certain embodiments, anti-KIT antibodies (e.g., humanized antibodies) provided herein comprise a light chain variable region ("VL") comprising VL CDRs 1-3 and a heavy chain variable region ("VH") comprising VH CDRs 1-3 as set forth in Table 3 (AbM CDRs or Contact CDRs).

[0107] In certain aspects, anti-KIT antibodies (e.g., humanized antibodies) provided herein comprise a VL comprising VL CDRs 1-3 (SEQ ID NOS: 2-4) set forth in Table 1 and a VH comprising VH CDRs 1-3 (SEQ ID NOS: 5-7) set forth in Table 1. In certain embodiments, such anti-KIT antibodies are naked antibodies. In certain embodiments, such anti-KIT antibodies are bivalent monospecific antibodies. In certain embodiments, such anti-KIT antibodies are bispecific antibodies. In certain embodiments, such anti-KIT antibodies are not bispecific antibodies.

[0108] [Table 1]

[0109] [Table 2]

[0110] [Table 3]

[0111] In certain aspects, the anti-KIT antibodies (e.g., humanized antibodies) provided herein are (i) Amino acid sequence: DIVMTQSPSX K1 LSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKX K2 LIYSASYRYSGVPDRFX K3 GSGSGTDFTLTISSLQX K4 EDFAX K5 YX K6 CQQYNSYPRTFGGGTKVEIK (SEQ ID NO: 17), wherein X K1 ~X K6 is any amino acid; and (ii) Amino acid sequence: QVQLVQSGAEX H1 KKPGASVKX H2 SCKASGYTFTDYYINWVX H3 QAPGKGLEWIARIYPGSGNTYYNEKFKGRX H4 TX H5 TAX H6 KSTSTAYMX H7 LSSLRSEDX H8 AVYFCARGVYYFDYWGQGTTVTVSS (SEQ ID NO: 18), wherein X H1 ~X H8 is any amino acid, and VH.

[0112] In certain embodiments, X κ1 is an amino acid with an aromatic or aliphatic hydroxyl side chain, and X κ2 is an amino acid with an aliphatic or aliphatic hydroxyl side chain, and Xκ3 is an amino acid with an aliphatic hydroxyl side chain, and X K4 is an amino acid with an aliphatic hydroxyl side chain or is P, and X K5 is an amino acid with a charged or acidic side chain, and X K6 is an amino acid with an aromatic side chain, and X H1 is an amino acid with an aliphatic side chain, and X H2 is an amino acid with an aliphatic side chain, and X H3 is an amino acid with a polar or basic side chain, and X H4 is an amino acid with an aliphatic side chain, and X H5 is an amino acid with an aliphatic side chain, and X H6 is an amino acid with an acidic side chain, and X H7 is an amino acid having an acidic or amide derivative side chain, and X H8 is an amino acid with an aliphatic hydroxyl side chain.

[0113] In certain embodiments, X K1 is the amino acid F or S, and X K2 is the amino acid A or S, and X K3 is the amino acid T or S, and X K4 is the amino acid S or P, and X K5 is the amino acid D or T, and X K6 is the amino acid F or Y, and X H1 is an amino acid L or V, and X H2 is an amino acid L or V, and X H3 is the amino acid K or R, and X H4 is the amino acid V or A, and X H5 is an amino acid L or I, and X H6 is the amino acid E or D, and X H7 is the amino acid Q or E, and X H8 is the amino acid S or T.

[0114] In certain aspects, the anti-KIT antibodies (e.g., humanized antibodies) provided herein are (i) Amino acid sequence: DIVMTQSPSXK1 LSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKX K2 LIYSASYRYSGVPDRFX K3 GSGSGTDFTLTISSLQX K4 EDFAX K5 YX K6 CQQYNSYPRTFGGGTKVEIK (SEQ ID NO: 17), wherein X K1 ~X K6 is any amino acid; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:7, respectively.

[0115] In certain embodiments, X κ1 is an amino acid with an aromatic or aliphatic hydroxyl side chain, and X κ2 is an amino acid with an aliphatic or aliphatic hydroxyl side chain, and X κ3 is an amino acid with an aliphatic hydroxyl side chain, and X K4 is an amino acid with an aliphatic hydroxyl side chain or is P, and X K5 is an amino acid with a charged or acidic side chain, and X K6 is an amino acid with an aromatic side chain.

[0116] In certain embodiments, X K1 is the amino acid F or S, and Χ κ2 is the amino acid A or S, and X K3 is the amino acid T or S, and Χ K4 is the amino acid S or P, and X K5 is the amino acid D or T, and Χ K6 is the amino acid F or Y.

[0117] In certain aspects, the anti-KIT antibodies (e.g., humanized antibodies) provided herein are (i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 having the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; (ii) Amino acid sequence: QVQLVQSGAEX H1 KKPGASVKX H2 SCKASGYTFTDYYINWVX H3 QAPGKGLEWIARIYPGSGNTYYNEKFKGRX H4 TX H5 TAX H6 KSTSTAYMX H7 LSSLRSEDX H8 AVYFCARGVYYFDYWGQGTTVTVSS (SEQ ID NO: 18), wherein X H1 ~X H8 is any amino acid, and VH.

[0118] In certain embodiments, X H1 is an amino acid with an aliphatic side chain, and X H2 is an amino acid with an aliphatic side chain, and X H3 is an amino acid with a polar or basic side chain, and X H4 is an amino acid with an aliphatic side chain, and X H5 is an amino acid with an aliphatic side chain, and X H6 is an amino acid with an acidic side chain, and X H7 is an amino acid having an acidic or amide derivative side chain, and X H8 is an amino acid with an aliphatic hydroxyl side chain.

[0119] In certain embodiments, X H1 is an amino acid L or V, and X H2 is an amino acid L or V, and X H3 is the amino acid K or R, and X H4は、アミノ酸 V or A, X H5 is the amino acid L or I, and χ H6 is the amino acid E or D, and X H7 is the amino acid Q or E, and X H8 is the amino acid S or T.

[0120] In certain aspects, anti-KIT antibodies (e.g., humanized antibodies) provided herein comprise a heavy chain variable region ("VH") comprising an amino acid sequence selected from Table 4 (SEQ ID NOS: 8-12), and / or a light chain variable region ("VL") comprising an amino acid sequence selected from Table 5 (SEQ ID NOS: 13-16). In certain embodiments, such anti-KIT antibodies are naked antibodies. In certain embodiments, such anti-KIT antibodies are bivalent monospecific antibodies. In certain embodiments, such anti-KIT antibodies are bispecific antibodies. In certain embodiments, such anti-KIT antibodies are not bispecific antibodies.

[0121] [Table 4]

[0122] [Table 5]

[0123] In certain aspects, the anti-KIT antibodies (e.g., humanized antibodies) provided herein comprise a VH comprising the amino acid sequence of SEQ ID NO: 8 and / or a VL comprising the amino acid sequence of SEQ ID NO: 13. In one embodiment, the anti-KIT antibodies provided herein comprise a VH comprising the amino acid sequence of SEQ ID NO: 8 and / or a VL comprising the amino acid sequence of SEQ ID NO: 14. In one embodiment, the anti-KIT antibodies provided herein comprise a VH comprising the amino acid sequence of SEQ ID NO: 8 and / or a VL comprising the amino acid sequence of SEQ ID NO: 15. In one embodiment, the anti-KIT antibodies provided herein comprise a VH comprising the amino acid sequence of SEQ ID NO: 8 and / or a VL comprising the amino acid sequence of SEQ ID NO: 16.

[0124] In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 9 and / or a VL comprising the amino acid sequence of SEQ ID NO: 13. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 9 and / or a VL comprising the amino acid sequence of SEQ ID NO: 14. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 9 and / or a VL comprising the amino acid sequence of SEQ ID NO: 15. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 9 and / or a VL comprising the amino acid sequence of SEQ ID NO: 16.

[0125] In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 10 and / or a VL comprising the amino acid sequence of SEQ ID NO: 13. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 10 and / or a VL comprising the amino acid sequence of SEQ ID NO: 14. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 10 and a VL comprising the amino acid sequence of SEQ ID NO: 14. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 10 and / or a VL comprising the amino acid sequence of SEQ ID NO: 15. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 10 and / or a VL comprising the amino acid sequence of SEQ ID NO: 16.

[0126] In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 11 and / or a VL comprising the amino acid sequence of SEQ ID NO: 13. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 11 and / or a VL comprising the amino acid sequence of SEQ ID NO: 14. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 11 and / or a VL comprising the amino acid sequence of SEQ ID NO: 15. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 11 and / or a VL comprising the amino acid sequence of SEQ ID NO: 16.

[0127] In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 12 and / or a VL comprising the amino acid sequence of SEQ ID NO: 13. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 12 and / or a VL comprising the amino acid sequence of SEQ ID NO: 14. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 12 and / or a VL comprising the amino acid sequence of SEQ ID NO: 15. In one embodiment, an anti-KIT antibody provided herein comprises a VH comprising the amino acid sequence of SEQ ID NO: 12 and / or a VL comprising the amino acid sequence of SEQ ID NO: 16.

[0128] In certain aspects, the anti-KIT antibodies (e.g., humanized antibodies) provided herein are (i) a VL comprising an amino acid sequence that is at least 90% identical to SEQ ID NO: 13, at least 88% identical to SEQ ID NO: 14, at least 87% identical to SEQ ID NO: 15, or at least 84% identical to SEQ ID NO: 16; (ii) a VH comprising an amino acid sequence that is at least 93% identical to SEQ ID NO:8, at least 92% identical to SEQ ID NO:9, at least 90% identical to SEQ ID NO:10, at least 87% identical to SEQ ID NO:11, or at least 86% identical to SEQ ID NO:12.

[0129] Previous anti-KIT antibodies have been found to induce degranulation of FcgRI-expressing human mast cells and / or exhibit Fc receptor-dependent KIT agonist activity, which can cause undesirable infusion-related reactions (IRRs), among other adverse effects.

[0130] In various embodiments, the anti-KIT antibodies or antigen-binding fragments described herein comprise an altered (e.g., mutated) Fc region or domain (e.g., an altered (e.g., mutated) human IgG Fc region or domain, e.g., an altered (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 Fc region or domain). Preferably, the anti-KIT antibodies or antigen-binding fragments described herein have reduced Fc receptor binding activity (particularly reduced FcγR binding activity), do not induce degranulation of FcgRI-expressing human mast cells, and / or do not exhibit Fc receptor-dependent KIT agonist activity. In certain embodiments, one or more of these properties of the anti-KIT antibodies or antigen-binding fragments result from the altered (e.g., mutated) Fc region or domain.

[0131] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein have reduced Fc receptor binding activity (particularly reduced FcγR binding activity). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein do not have significant Fc receptor (particularly FcγR) binding activity. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein have no detectable Fc receptor (particularly FcγR) binding activity. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein have at least 10% less, at least 20% less, at least 30% less, at least 40% less, at least 50% less, at least 60% less, at least 70% less, at least 80% less, at least 90% less, at least 95% less, or at least 99% less Fc receptor (particularly FcγR) binding activity compared to a suitable control antibody or antigen-binding fragment. Where an anti-KIT antibody or antigen-binding fragment described herein comprises an altered (e.g., mutated) Fc region or domain (e.g., an altered (e.g., mutated) human IgG Fc region or domain, such as an altered (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 Fc region or domain), in a preferred embodiment, a suitable control antibody or antigen-binding fragment is an antibody or antigen-binding fragment having the same VH and VL but with a wild-type (unmodified) Fc region or domain of the same isotype. In specific embodiments, the anti-KIT antibodies or antigen-binding fragments described herein comprise an altered (e.g., mutated) human IgG1 Fc region or domain and have at least 10% less, at least 20% less, at least 30% less, at least 40% less, at least 50% less, at least 60% less, at least 70% less, at least 80% less, at least 90% less, at least 95% less, or at least 99% less Fc receptor (particularly FcγR) binding activity compared to a corresponding antibody or antigen-binding fragment having the same VH and VL but a wild-type (unmodified) human IgG1 Fc region or domain.

[0132] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein do not induce significant degranulation of FcgRI-expressing human mast cells (e.g., as determined, for example, by the % release of beta-hexosaminidase from human mast cells in culture (e.g., in the presence of IFN-gamma)). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein do not induce detectable degranulation of FcgRI-expressing human mast cells (e.g., as determined, for example, by the % release of beta-hexosaminidase from human mast cells in culture (e.g., in the presence of IFN-gamma)). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein induce degranulation (e.g., as determined by % release of beta-hexosaminidase from human mast cells in culture (e.g., in the presence of IFN-gamma) of FcgRI-expressing human mast cells by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% compared to a suitable control antibody or antigen-binding fragment. In certain embodiments, the release of beta-hexosaminidase from human mast cells in culture in the presence of IFN-gamma is reduced by more than 50% using the anti-KIT antibodies or antigen-binding fragments described herein compared to a suitable control antibody or antigen-binding fragment. In certain embodiments, the release of beta-hexosaminidase from human mast cells in culture in the presence of IFN-gamma is reduced by more than 60%, more than 70%, or more than 80% using an anti-KIT antibody or antigen-binding fragment described herein compared to a suitable control antibody or antigen-binding fragment.Where an anti-KIT antibody or antigen-binding fragment described herein comprises an altered (e.g., mutated) Fc region or domain (e.g., an altered (e.g., mutated) human IgG Fc region or domain, such as an altered (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 Fc region or domain, in a preferred embodiment, a suitable control antibody or antigen-binding fragment is an antibody or antigen-binding fragment having the same VH and VL but with a wild-type (unmodified) Fc region or domain of the same isotype. In a specific embodiment, an anti-KIT antibody or antigen-binding fragment described herein comprises an altered (e.g., mutated) human IgG1 Fc region or domain and has the same VH and VL but with a wild-type (unmodified) human IgG1 Induce degranulation of FcgRI-expressing human mast cells (e.g., as determined by the % release of beta-hexosaminidase from human mast cells in culture (e.g., in the presence of IFN-gamma) by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% compared to a corresponding antibody or antigen-binding fragment having an Fc region or domain. In a specific embodiment, the release of beta-hexosaminidase from human mast cells in culture in the presence of IFN-gamma is greater than or equal to 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% compared to a corresponding antibody or antigen-binding fragment having the same VH and VL but with a wild-type (unmodified) human IgG1 Fc region or domain. The release of beta-hexosaminidase from human mast cells in culture in the presence of IFN-gamma is reduced by more than 50% using an anti-KIT antibody or antigen-binding fragment described herein that comprises an Fc region or domain. In certain embodiments, the release of beta-hexosaminidase from human mast cells in culture in the presence of IFN-gamma is reduced by more than 60%, more than 70%, or more than 80% using an anti-KIT antibody or antigen-binding fragment described herein that comprises an altered (e.g., mutated) human IgG1 Fc region or domain, compared to a corresponding antibody or antigen-binding fragment having the same VH and VL but with a wild-type (unmodified) human IgG1 Fc region or domain.

[0133] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein do not exhibit significant Fc receptor-dependent KIT agonist activity (e.g., as determined, for example, by KIT phosphorylation). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein do not exhibit detectable Fc receptor-dependent KIT agonist activity (e.g., as determined, for example, by KIT phosphorylation). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein induce at least 10% less, at least 20% less, at least 30% less, at least 40% less, at least 50% less, at least 60% less, at least 70% less, at least 80% less, at least 90% less, at least 95% less, or at least 99% less Fc receptor-dependent KIT activity (e.g., as determined, for example, by KIT phosphorylation) compared to a suitable control antibody or antigen-binding fragment. In certain embodiments, Fc receptor-dependent KIT agonist activity (as determined by KIT phosphorylation using cross-linked Fc receptors) is reduced by more than 50% using an anti-KIT antibody or antigen-binding fragment described herein compared to a suitable control antibody or antigen-binding fragment. In certain embodiments, Fc receptor-dependent KIT agonist activity (as determined by KIT phosphorylation using cross-linked Fc receptors) is reduced by more than 60%, more than 70%, or more than 80% using an anti-KIT antibody or antigen-binding fragment described herein compared to a suitable control antibody or antigen-binding fragment. When an anti-KIT antibody or antigen-binding fragment described herein comprises an altered (e.g., mutated) Fc region or domain (e.g., an altered (e.g., mutated) human IgG Fc region or domain, such as an altered (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 Fc region or domain), in a preferred embodiment, a suitable control antibody or antigen-binding fragment is an antibody or antigen-binding fragment having the same VH and VL but a wild-type (unmodified) Fc region or domain of the same isotype.In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein comprise an engineered (e.g., mutated) human IgG1 Fc region or domain and induce at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% of the Fc receptor-dependent KIT activity (e.g., as determined by, for example, KIT phosphorylation) compared to a corresponding antibody or antigen-binding fragment having the same VH and VL but a wild-type (unmodified) human IgG1 Fc region or domain. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein do not exhibit significant or detectable Fc receptor-dependent KIT agonist activity as described herein, even when cross-linked in THP-1 cells. In certain embodiments, Fc receptor-dependent KIT agonist activity (as determined by KIT phosphorylation using a cross-linked Fc receptor) is reduced by more than 50% using an anti-KIT antibody or antigen-binding fragment described herein that comprises an engineered (e.g., mutated) human IgG1 Fc region or domain, compared to a corresponding antibody or antigen-binding fragment having the same VH and VL but with a wild-type (unmodified) human IgG1 Fc region or domain. In certain embodiments, Fc receptor-dependent KIT agonist activity (as determined by KIT phosphorylation using a cross-linked Fc receptor) is reduced by more than 60%, more than 70%, or 80% using an anti-KIT antibody or antigen-binding fragment described herein that comprises an engineered (e.g., mutated) human IgG1 Fc region or domain, compared to a corresponding antibody or antigen-binding fragment having the same VH and VL but with a wild-type (unmodified) human IgG1 Fc region or domain.

[0134] In various embodiments, the anti-KIT antibodies or antigen-binding fragments described herein (1) reduce disease activity in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (2) reduce skin mast cell numbers in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (3) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (4) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (5) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (6) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (7) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (8) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (9) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (10) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (11) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CIndU are refractory to antihistamine treatment), (12) reduce tryptase levels in CIndU patients (e.g., CIndU patients whose CInd (4) improve urticaria control in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment), (5) improve quality of life in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment), and / or (6) maintain hematological parameters (e.g., hemoglobin (HgB) levels, white blood cell count (WBC), platelet count, and / or absolute neutrophil count (ANC)) within the normal range in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment).

[0135] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly reduce the critical temperature threshold in the TempTest® for CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) compared to pre-treatment values. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can reduce the critical temperature threshold in the TempTest® for a CIndU patient (e.g., a CIndU patient whose CIndU is refractory to antihistamine treatment) by at least 5°C, at least 6°C, at least 7°C, at least 8°C, at least 9°C, at least 10°C, at least 11°C, at least 12°C, at least 13°C, at least 14°C, at least 15°C, at least 16°C, at least 17°C, at least 18°C, at least 19°C, or at least 20°C (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment) compared to the pre-treatment value. In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment is sustained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0136] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly reduce the number of pins on the FricTest® in a CIndU patient (e.g., a CIndU patient whose CIndU is refractory to antihistamine treatment) compared to the number of pins before treatment. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can reduce the number of pins on the FricTest® in a CIndU patient (e.g., a CIndU patient whose CIndU is refractory to antihistamine treatment) by at least one, at least two, at least three, or at least four (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment) compared to the number of pins before treatment. In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment is sustained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0137] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly improve the Physician's Global Assessment (Phys-GA) and / or Patient's Global Assessment (Pat-GA) compared to pre-treatment levels. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can improve the Physician's Global Assessment (Phys-GA) and / or Patient's Global Assessment (Pat-GA) by reducing the Likert scale (0 to 3, where 0 is none and 3 is severe) by at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, or at least 1.3 compared to pre-treatment levels (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment). In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment lasts for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0138] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly reduce the number of skin mast cells in a CIndU patient (e.g., a CIndU patient whose CIndU is refractory to antihistamine treatment) compared to the number before treatment. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can reduce the number of skin mast cells in a CIndU patient (e.g., a CIndU patient whose CIndU is refractory to antihistamine treatment) by at least 20%, at least 40%, at least 60%, or at least 80% compared to the number before treatment (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment). In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment is sustained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0139] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly reduce serum tryptase in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) compared to pre-treatment levels. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can reduce serum tryptase in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) by at least 50%, at least 70%, or at least 90% compared to pre-treatment levels (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment). In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment is sustained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0140] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly improve urticaria control in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) compared to pre-treatment levels. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can improve urticaria control in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) by increasing the Urticaria Control Test (UCT) score by at least 2, at least 3, at least 4, 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, or 16 compared to pre-treatment levels, or by increasing the UCT score by at least 12, at least 13, at least 14, at least 15, or 16 (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment). In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment is sustained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0141] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can significantly improve quality of life in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) compared to pre-treatment levels. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein can improve quality of life in CIndU patients (e.g., CIndU patients whose CIndU is refractory to antihistamine treatment) by reducing the Dermatology Life Quality Index (DLQI) by at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 12, at least 14, at least 16, at least 18, at least 20, or at least 25 compared to pre-treatment levels, or by reducing the DLQI by up to 5, up to 4, up to 3, up to 2, up to 1, or 0 (e.g., at 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, or 12 weeks after treatment with the anti-KIT antibody or antigen-binding fragment). In certain embodiments, the effect of the anti-KIT antibody or antigen-binding fragment is sustained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0142] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein maintain a patient's hematological parameters (e.g., hemoglobin (HgB) levels, white blood cell (WBC) count, platelet count, and / or absolute neutrophil count (ANC)) within the normal range. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments described herein maintain a hematological parameter (e.g., hemoglobin (HgB) levels, white blood cell (WBC) count, platelet count, and / or absolute neutrophil count (ANC)) within the normal range in a CIndU patient (e.g., a CIndU patient whose CIndU is refractory to antihistamine treatment). In certain embodiments, the hematological parameter is maintained for at least 2 weeks, at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, or at least 12 weeks.

[0143] In various embodiments, the anti-KIT antibodies described herein have one or more of the properties described herein. In various embodiments, the antigen-binding fragments of the anti-KIT antibodies described herein have one or more of the properties described herein.

[0144] In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain comprises at least one (e.g., one, two, three, four, five, or six) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., one, two, three, four, five, or six) non-naturally occurring amino acid residue.

[0145] In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is a human IgG1 Fc region or domain, as numbered by the EU index as set forth in Kabat, is as follows: 234A, 234D, 234E, 234N, 234Q, 234T, 234H, 234Y, 234I, 234V, 234F, 235A, 235D, 235R, 235W, 235P, 235S, 235N, 235Q, 235T, 235H, 235Y, 235I, 235V, 235F, 236E, 239D, 239E, 239N, 239Q, 239F, 239T, 239H, 239Y, 240I, 240A, 240T, 240M, 241W, 241L, 24 1Y, 241E, 241R, 243W, 243L, 243Y, 243R, 243Q, 244H, 245A, 247V, 247G, 252Y , 254T, 256E, 2621, 262A, 262T, 262E, 2631, 263A, 263T, 263M, 264L, 2641, 2 64W, 264T, 264R, 264F, 264M, 264Y, 264E, 265G, 265N, 265Q, 265Y, 265F, 265V , 2651, 265L, 265H, 265T, 2661, 266A, 266T, 266M, 267Q, 267L, 269H, 269Y, 2 69F, 269R, 296E, 296Q, 296D, 296N, 296S, 296T, 296L, 296I, 296H, 269G, 297 S, 297D, 297E, 298H, 298I, 298T, 298F, 299I, 299L, 299A, 299S, 299V, 299H, 299F, 299E, 313F, 322Q, 325Q, 325L, 325I, 325D, 325E, 325A, 325T, 325V, 32 At least one (e.g., one, two, three, four, five, or more) selected from the group consisting of 5H, 327G, 327W, 327N, 327L, 328S, 328M, 328D, 328E, 328N, 328Q, 328F, 3281, 328V, 328T, 328H, 328A, 329F, 329H, 329Q, 330K, 330G, 330T, 330C, 330L, 330Y, 330V, 3301, 330F, 330R, 330H, 332D, 332S, 332W, 332F, 332E, 332N, 332Q, 332T, 332H, 332Y, and 332A.or six) amino acid modifications (e.g., substitutions, deletions, or additions), or at least one non-naturally occurring amino acid residue (e.g., one, two, three, four, five, or six). Optionally, the Fc region or domain can include additional and / or alternative non-naturally occurring amino acid residues known to those of skill in the art (see, e.g., U.S. Patent Nos. 5,624,821, 6,277,375, 6,737,056, PCT Patent Publication Nos. WO01 / 58957, WO04 / 016750, WO04 / 029207, WO04 / 035752, and WO05 / 040217). In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is a human IgG2 Fc region or domain and comprises at least one (e.g., 1, 2, 3, 4, 5, or 6) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., 1, 2, 3, 4, 5, or 6) non-naturally occurring amino acid residue, which is equivalent to the amino acid residue(s) described herein for a human IgG1 Fc region or domain, and can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is that of a human IgG3 and comprises at least one (e.g., one, two, three, four, five, or six) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., one, two, three, four, five, or six) non-naturally occurring amino acid residue, which is equivalent to the amino acid residue(s) described herein for a human IgG1 Fc region or domain and can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is that of a human IgG4 and comprises at least one (e.g., one, two, three, four, five, or six) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., one, two, three, four, five, or six) non-naturally occurring amino acid residue,These are equivalent to the amino acid residue(s) described herein for the human IgG1 Fc region or domain and can be determined by one of skill in the art.

[0146] In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is a human IgG1 Fc region or domain, as numbered by the EU index as set forth in Kabat, including 234A, 234D, 234E, 234N, 234Q, 234T, 234H, 234Y, 234I, 234V, 234F, 235A, 235D, 235R, 235W, 235P, 235S, 235N, 235Q, 235T, 235H, 235Y, 235I, 235V, 235F, 236E, 239D, 239E, 239F, 239G, 239H, 239I ... 9N, 239Q, 239F, 239T, 239H, 239Y, 240I, 240A, 240T, 240M, 241W, 241L, 241Y , 241E, 241R, 243W, 243L, 243Y, 243R, 243Q, 244H, 245A, 247V, 247G, 252Y, 2 54T, 256E, 2621, 262A, 262T, 262E, 2631, 263A, 263T, 263M, 264L, 2641, 264 W, 264T, 264R, 264F, 264M, 264Y, 264E, 265G, 265N, 265Q, 265Y, 265F, 265V, 2651, 265L, 265H, 265T, 2661, 266A, 266T, 266M, 267Q, 267L, 269H, 269Y, 26 9F, 269R, 296E, 296Q, 296D, 296N, 296S, 296T, 296L, 296I, 296H, 269G, 297S , 297D, 297E, 298H, 298I, 298T, 298F, 299I, 299L, 299A, 299S, 299V, 299H, 2 99F, 299E, 313F, 322Q, 325Q, 325L, 325I, 325D, 325E, 325A, 325T, 325V, 325 At least one (e.g., one, two, three, four, five, or more) selected from the group consisting of H, 327G, 327W, 327N, 327L, 328S, 328M, 328D, 328E, 328N, 328Q, 328F, 3281, 328V, 328T, 328H, 328A, 329F, 329H, 329Q, 330K, 330G, 330T, 330C, 330L, 330Y, 330V, 3301, 330F, 330R, 330H, 332D, 332S, 332W, 332F, 332E, 332N, 332Q, 332T, 332H, 332Y, and 332A.or six) amino acid modifications (e.g., substitutions, deletions, or additions), or at least one non-naturally occurring amino acid residue (e.g., one, two, three, four, five, or six). Optionally, the Fc region or domain can include additional and / or alternative non-naturally occurring amino acid residues known to those of skill in the art (see, e.g., U.S. Patent Nos. 5,624,821, 6,277,375, 6,737,056, PCT Patent Publication Nos. WO01 / 58957, WO04 / 016750, WO04 / 029207, WO04 / 035752, and WO05 / 040217). In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is a human IgG2 Fc region or domain and comprises at least one (e.g., 1, 2, 3, 4, 5, or 6) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., 1, 2, 3, 4, 5, or 6) non-naturally occurring amino acid residue, which is equivalent to the amino acid residue(s) described herein for a human IgG1 Fc region or domain, and can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is that of a human IgG3 and comprises at least one (e.g., one, two, three, four, five, or six) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., one, two, three, four, five, or six) non-naturally occurring amino acid residue, which is equivalent to the amino acid residue(s) described herein for a human IgG1 Fc region or domain and can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise a modified Fc region or domain, wherein the Fc region or domain is that of a human IgG4 and comprises at least one (e.g., one, two, three, four, five, or six) amino acid modification (e.g., substitution, deletion, or addition) or at least one (e.g., one, two, three, four, five, or six) non-naturally occurring amino acid residue,These are equivalent to the amino acid residue(s) described herein for the human IgG1 Fc region or domain and can be determined by one of skill in the art.

[0147] In certain aspects, provided herein are antibodies comprising an Fc region or domain, wherein the Fc region or domain is that of a human IgG1 and comprises at least one non-naturally occurring amino acid at one or more positions selected from the group consisting of 239, 330, and 332, as numbered by the EU index as set forth in Kabat. In certain embodiments, provided herein are antibodies comprising an Fc region or domain, wherein the Fc region or domain is that of a human IgG1 and comprises at least one non-naturally occurring amino acid selected from the group consisting of 239D, 330L, and 332E, as numbered by the EU index as set forth in Kabat. Optionally, the Fc region or domain may further comprise an additional non-naturally occurring amino acid at one or more positions selected from the group consisting of 252, 254, and 256, as numbered by the EU index as set forth in Kabat. In certain embodiments, provided herein are antibodies comprising an Fc region or domain, wherein the Fc region or domain is that of a human IgG1 and comprises at least one non-naturally occurring amino acid selected from the group consisting of 239D, 330L, and 332E, as numbered by the EU index as set forth in Kabat, and wherein at least one non-naturally occurring amino acid at one or more positions is selected from the group consisting of 252Y, 254T, and 256E, as numbered by the EU index as set forth in Kabat. In certain embodiments, provided herein are antibodies comprising an Fc region or domain, wherein the Fc region or domain is that of a human IgG2, IgG3, or IgG4 and comprises at least one non-naturally occurring amino acid residue that is equivalent(s) to the amino acid residue(s) described herein for a human IgG1 Fc region or domain, as can be determined by one of skill in the art.In certain embodiments, provided herein are antibodies comprising an Fc region or domain, wherein the Fc region or domain is an Fc region or domain of human IgG2, IgG3, or IgG4, and comprises at least one non-naturally occurring amino acid residue at one or more positions that are equivalent(s) to the positions described herein for a human IgG1 Fc region or domain, as can be determined by one of skill in the art. In one embodiment, an Fc region or domain comprising such a sequence exhibits one or more Fc activities, e.g., binding affinity to an Fc receptor or an effector function such as ADCC or CDC. In certain embodiments, an Fc region or domain comprising such a sequence exhibits reduced Fc activity, e.g., reduced binding affinity to an Fc receptor or reduced effector function such as ADCC or CDC. In certain embodiments, an Fc region or domain comprising such a sequence exhibits enhanced FcRn activity, e.g., enhanced half-life.

[0148] Non-limiting examples of additional Fc region or domain modifications are described in Ghetie et al., 1997, Nat Biotech. 15:637-40, Duncan et al., 1988, Nature 332:563-564, Lund et al., 1991, J. Immunol 147:2657-2662, Lund et al., 1992, Mol Immunol 29:53-59, Alegre et al., 1994, Transplantation 57:1537-1543, Hutchins et al., 1995, Proc Natl. Acad Sci U S A 92:11980-11984, Jefferis et al., 1995, Immunol Lett. 44:111-117, Lund et al., 1995, Faseb J 9:115-119, Jefferis et al., 1996, Immunol Lett 54:101-104, Lund et al., 1996, J Immunol 157:4963-4969, Armour et al., 1999, Eur J Immunol 29:2613-2624, Idusogie et al., 2000, J Immunol 164:4178-4184, Reddy et al., 2000, J Immunol 164:1925-1933, Xu et al., 2000, Cell Immunol 200:16-26, Idusogie et al., 2001, J Immunol 166:2571-2575, Shields et al., 2001, J Biol Chem 276:6591-6604, Jefferis et al., 2002, Immunol Lett 82:57-65, Presta et al.,2002,Biochem Soc Trans 30:487-490), U.S. Patent No. 5,624,821, U.S. Pat. 5,624,821, 5,648,260, 6,528,624, 6,194,551, 6,737,056, 6,821,505, 6,277,375, 8,163,882, 7,35 Nos. 5,008, 7,960,512, 8,039,592, 8,039,359, 8,101,720, 7,214,775, 7,682,610, 7,741,442, U.S. Patent Publication No. 2004 / 0002587, and PCT Publication Nos. WO94 / 29351, WO99 / 58572, WO00 / 42072, WO04 / 029207, WO04 / 099249, and WO04 / 063351.

[0149] In certain embodiments, the antibodies described herein comprise a modified (e.g., mutated) human IgG1 Fc region or domain that comprises the non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat. In certain embodiments, the modified (e.g., mutated) human IgG1 Fc region or domain further comprises the non-naturally occurring amino acids 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat.

[0150] In certain embodiments, the antibodies described herein comprise modified (e.g., mutated) human IgG2 Fc regions or domains, which contain non-naturally occurring amino acids equivalent to 234A, 235Q, and 322Q when numbered by the EU index as set forth in Kabat for a human IgG1 Fc region or domain, as can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise modified (e.g., mutated) human IgG2 Fc regions or domains, which contain non-naturally occurring amino acids equivalent to 234A, 235Q, 322Q, 252Y, 254T, and 256E when numbered by the EU index as set forth in Kabat for an IgG1 Fc region or domain, as can be determined by one of skill in the art.

[0151] In certain embodiments, the antibodies described herein comprise modified (e.g., mutated) human IgG3 Fc regions or domains, which contain non-naturally occurring amino acids equivalent to 234A, 235Q, and 322Q when numbered by the EU index as set forth in Kabat for a human IgG1 Fc region or domain, as can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise modified (e.g., mutated) human IgG3 Fc regions or domains, which contain non-naturally occurring amino acids equivalent to 234A, 235Q, 322Q, 252Y, 254T, and 256E when numbered by the EU index as set forth in Kabat for a human IgG1 Fc region or domain, as can be determined by one of skill in the art.

[0152] In certain embodiments, the antibodies described herein comprise modified (e.g., mutated) human IgG4 Fc regions or domains, which include non-naturally occurring amino acids equivalent to 234A, 235Q, and 322Q when numbered by the EU index as set forth in Kabat for a human IgG1 Fc region or domain, as can be determined by one of skill in the art. In certain embodiments, the antibodies described herein comprise modified (e.g., mutated) human IgG4 Fc regions or domains, which include non-naturally occurring amino acids equivalent to 234A, 235Q, 322Q, 252Y, 254T, and 256E when numbered by the EU index as set forth in Kabat for a human IgG1 Fc region or domain, as can be determined by one of skill in the art.

[0153] In certain embodiments, the antibodies described herein comprise the VL and VH CDR sequences set forth in Table 1 and an engineered (e.g., mutated) human IgG1 Fc region or domain, wherein the engineered (e.g., mutated) human IgG1 Fc region or domain comprises non-naturally occurring amino acids 234A, 235Q, and 322Q when numbered by the EU index as set forth in Kabat.

[0154] In a preferred embodiment, the antibodies described herein comprise the VL and VH CDR sequences shown in Table 1 and a modified (e.g., mutated) human IgG1 Fc region or domain, wherein the modified (e.g., mutated) human IgG1 Fc region or domain comprises the non-naturally occurring amino acids 234A, 235Q, 322Q, 252Y, 254T, and 256E when numbered by the EU index as set forth in Kabat.

[0155] Thus, in one aspect, there is provided herein an antibody that immunospecifically binds to human KIT, the antibody comprising: (i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 having the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 having the amino acid sequences of SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:7, respectively; and (iii) a human IgG1 Fc region or domain comprising non-naturally occurring amino acids 234A, 235Q, and 322Q when numbered according to the EU index as set forth in Kabat.

[0156] Accordingly, in a further aspect, there is provided herein an antibody that immunospecifically binds to human KIT, the antibody comprising: (i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 having the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 having the amino acid sequences of SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:7, respectively; and (iii) a human IgG1 Fc region or domain comprising the non-naturally occurring amino acids 234A, 235Q, 322Q, 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat.

[0157] In a further aspect, there is provided herein an antibody that immunospecifically binds to human KIT, the antibody comprising: (i) the amino acid sequence: DIVMTQSPSX K1 LSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKX K2 LIYSASYRYSGVPDRFX K3 GSGSGTDFTLTISSLQX K4 EDFAX K5 YX K6 CQQYNSYPRTFGGGTKVEIK (SEQ ID NO: 17), wherein X K1 is an amino acid having an aromatic or aliphatic hydroxyl side chain, and X K2 is an amino acid having an aliphatic or aliphatic hydroxyl side chain, and X K3is an amino acid having an aliphatic hydroxyl side chain, and X K4 is an amino acid having an aliphatic hydroxyl side chain or is P, and X K5 is an amino acid having a charged or acidic side chain, and X K6 is an amino acid having an aromatic side chain; and (ii) the amino acid sequence: QVQLVQSGAEX. H1 KKPGASVKX H2 SCKASGYTFTDYYINWVX H3 QAPGKGLEWIARIYPGSGNTYYNEKFKGRX H4 TX H5 TAX H6 KSTSTAYMX H7 LSSLRSEDX H8 AVYFCARGVYYFDYWGQGTTVTVSS (SEQ ID NO: 18), wherein X H1 is an amino acid having an aliphatic side chain, and X H2 is an amino acid having an aliphatic side chain, and X H3 is an amino acid with a polar or basic side chain, and X H4 is an amino acid having an aliphatic side chain, and X H5 is an amino acid having an aliphatic side chain, and X H6 is an amino acid with an acidic side chain, and X H7 is an amino acid having an acidic or amide derivative side chain, and X H8 is an amino acid having an aliphatic hydroxyl side chain; and (iii) a modified (e.g., mutated) human IgG1 Fc region or domain comprising the non-naturally occurring amino acids 234A, 235Q, 322Q, and preferably also 252Y, 254T, and 256E, as numbered by the EU index as set forth in Kabat.

[0158] In a further aspect, provided herein is an antibody that immunospecifically binds to human KIT, the antibody comprising: i) a VL comprising the amino acid sequence of SEQ ID NO: 13, 14, 15, or 16; ii) a VH comprising the amino acid sequence of SEQ ID NO: 8, 9, 10, 11, or 12; and (iii) a modified (e.g., mutated) human IgG1 Fc region or domain comprising non-naturally occurring amino acids 234A, 235Q, 322Q, and preferably also 252Y, 254T, and 256E, as numbered by the EU index as set forth in Kabat.

[0159] In a further aspect, provided herein is an antibody that immunospecifically binds to human KIT, the antibody comprising i) a VL comprising the amino acid sequence of SEQ ID NO: 14; ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; and (iii) a modified (e.g., mutated) human IgG1 Fc region or domain comprising non-naturally occurring amino acids 234A, 235Q, 322Q, and preferably also 252Y, 254T, and 256E, as numbered by the EU index as set forth in Kabat.

[0160] In certain embodiments, the antibodies provided herein have the following amino acid sequence: QVQLVQSGAEVKKPGASVKLSCKASGYTFTDYYINWVRQAPGKGLEWIARIYPGSGNTYYNEKFKGRATLTADKSTSTAYMQLSSLRSEDTAVYFCARGVYYFDYWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKV EPKSCDKTHTCPPCPAPEAQGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCQVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 21).

[0161] In certain embodiments, the antibodies provided herein comprise a light chain comprising the following amino acid sequence: DIVMTQSPSSLSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKALIYSASYRYSGVPDRFTGSGSGTDFTLTISSLQPEDFADYFCQQYNSYPRTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 22).

[0162] In certain embodiments, the antibodies provided herein have the following amino acid sequence: QVQLVQSGAEVKKPGASVKLSCKASGYTFTDYYINWVRQAPGKGLEWIARIYPGSGNTYYNEKFKGRATLTADKSTSTAYMQLSSLRSEDTAVYFCARGVYYFDYWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEAQGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCQVSNKALPAPIEKTI and a light chain comprising the following amino acid sequence: DIVMTQSPSSLSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKALIYSASYRYSGVPDRFTGSGSGTDFTLTISSLQPEDFADYFCQQYNSYPRTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 22).

[0163] In certain embodiments, reference is made herein to a polypeptide comprising (i) the amino acid sequence: [ka] wherein the leader sequence is shown in bold italics, the variable region (VH) is shown in italics, and the constant region is underlined. Additionally, mutations in the constant region (compared to wild-type human IgG1) are double underlined, (ii) Amino acid sequence: [ka] wherein the leader sequence is shown in bold italics, the variable region (VL) is shown in italics, and the constant region is underlined.

[0164] In certain embodiments, the anti-KIT antibodies described herein do not bind (e.g., have no detectable binding to) any human Fc-gamma receptor (FcγR receptor). In certain embodiments, the anti-KIT antibodies described herein do not bind (e.g., have no detectable binding to) human FcγRI. In certain embodiments, the anti-KIT antibodies described herein do not bind (e.g., have no detectable binding to) human FcγRIIa. In certain embodiments, the anti-KIT antibodies described herein do not bind (e.g., have no detectable binding to) human FcγRIIb. In certain embodiments, the anti-KIT antibodies described herein do not bind (e.g., have no detectable binding to) human FcγRIIIa. In certain embodiments, the anti-KIT antibodies described herein do not bind (e.g., have no detectable binding to) human FcγRIIIb.

[0165] In certain embodiments, the anti-KIT antibodies described herein comprise an engineered (e.g., mutated) human IgG constant region (e.g., an engineered (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 constant region) and have enhanced binding (e.g., at least 2-fold, 5-fold, 10-fold, 50-fold, 100-fold, 500-fold, 1000-fold, 5000-fold, or 10,000-fold higher binding affinity) to human neonatal Fc receptor (FcRn) compared to a corresponding antibody having the same variable region sequence but an unmodified (wild-type) human IgG constant region. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 20 nM at pH 6.0. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 2 nM at pH 6.0. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 1 nM at pH 6.0. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 500 nM at pH 6.0. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 400 pM at pH 6.0. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 200 nM at pH 7.2. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 150 nM at pH 7.2. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 100 nM at pH 7.2. In certain embodiments, the anti-KIT antibodies described herein bind to FcRn with a KD of less than 80 nM at pH 7.2.

[0166] In certain embodiments, the anti-KIT antibodies described herein comprise a modified (e.g., mutated) human IgG constant region (e.g., a modified (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 constant region) and do not exhibit antibody-dependent cellular cytotoxicity (ADCC). In certain embodiments, the anti-KIT antibodies described herein comprise a modified (e.g., mutated) human IgG constant region (e.g., a modified (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 constant region) and exhibit reduced ADCC (e.g., at least 10% less, at least 20% less, at least 30% less, at least 40% less, at least 50% less, at least 60% less, at least 70% less, at least 80% less, at least 90% less, at least 95% less, or at least 99% less) compared to a corresponding antibody having the same variable region sequence but an unmodified (wild-type) human IgG constant region.

[0167] In certain embodiments, the anti-KIT antibodies described herein comprise an engineered (e.g., mutated) human IgG constant region (e.g., an engineered (e.g., mutated) human IgG1, IgG2, IgG3, or IgG4 constant region) and exhibit reduced (e.g., at least 10% less, at least 20% less, at least 30% less, at least 40% less, at least 50% less, at least 60% less, at least 70% less, at least 80% less, at least 90% less, at least 95% less, or at least 99% less) cytokine (e.g., IFN-γ, IL-1β, IL-2, IL-6, IL-8, IL-10, and / or TNF-α) production compared to a corresponding antibody having the same variable region sequence but an unmodified (wild-type) human IgG constant region.

[0168] Certain embodiments also provide antigen-binding fragments of the antibodies described herein, preferably antigen-binding fragments comprising a full-length heavy chain Fc region or domain (e.g., a full-length human IgG1, human IgG2, human IgG3, or human IgG4 Fc region or domain). Certain embodiments also provide antigen-binding fragments of the antibodies described herein comprising a partial heavy chain Fc region or domain (e.g., a partial human IgG1, human IgG2, human IgG3, or human IgG4 Fc region or domain).

[0169] In certain embodiments, anti-KIT antibodies or antigen-binding fragments thereof can be obtained using methods known in the art, see, eg, Section 5.4 below.

[0170] In certain aspects, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to the D4 domain of human KIT and to the D5 region of KIT, e.g., human KIT. In another specific embodiment, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to the D5 domain of KIT, e.g., human KIT, with lower affinity than to the D4 domain of KIT, e.g., human KIT. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to the D4 domain of KIT, e.g., human KIT, with higher affinity than to the D5 domain of KIT, e.g., human KIT, e.g., the higher affinity is at least 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20-fold, 50-fold, 100-fold, 500-fold, or 1000-fold, as determined by methods known in the art, e.g., by ELISA or Biacore assay.

[0171] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein specifically bind to the D4 or D4 / D5 region of KIT, e.g., human KIT, and have at least 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, or 10-fold higher affinity for a KIT antigen consisting essentially of only the D4 domain than for a KIT antigen consisting essentially of only the D5 domain.

[0172] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein have an EC50 of about 50 nM, 10 nM, 500 pM, 300 pM, 200 pM, 100 pM, or 50 pM or less as determined by an assay described in the art, such as ELISA. 50 (half the maximal effective concentration) value.

[0173] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein have an EC of about 200 pM or 150 pM or less as determined by assays described in the art, such as ELISA or FAC using CHO-WT-KIT cells (CHO cells engineered to recombinantly express wild-type human KIT). 50 The antibody specifically binds to a KIT polypeptide (e.g., the D4 region of human KIT) at a specific binding site.

[0174] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein have an IC of about 600 pM or less. 50 It is possible to block KIT phosphorylation at a value (50% inhibitory concentration).

[0175] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor internalization, e.g., by at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99%, when compared to internalization in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT), as assessed by methods described herein or known to those of skill in the art. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor internalization, e.g., by at least about 25% or 35%, optionally about 75%, when compared to internalization in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT), as assessed by methods described herein or known to those of skill in the art. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor internalization, e.g., by at least 1-fold, 1.2-fold, 1.3-fold, 1.4-fold, 1.5-fold, 2-fold, 2.5-fold, 3-fold, 3.5-fold, 4-fold, 4.5-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 15-fold, 20-fold, 30-fold, 40-fold, 50-fold, 60-fold, 70-fold, 80-fold, 90-fold, or 100-fold, compared to internalization in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT), as assessed by methods described herein or known to those of skill in the art. Techniques for quantifying or visualizing cell surface receptors are well known in the art and include various fluorescent and radioactive techniques. For example, one method involves incubating cells with a radiolabeled anti-receptor antibody. Alternatively, the receptor's natural ligand can be conjugated to a fluorescent molecule or radioactive label and incubated with the cells.Additional receptor internalization assays are well known in the art and are described, for example, in Jimenez et al., Biochemical Pharmacology, 1999, 57:1125-1131, Bernhagen et al., Nature Medicine, 2007, 13:587-596, and Conway et al., J. Cell Physiol., 2001, 189:341-55.

[0176] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor turnover by, e.g., at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99%, as assessed by methods described herein or known to those of skill in the art (e.g., pulse-chase assays) compared to turnover in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor turnover, e.g., by at least about 25% or 35%, optionally about 75%, as assessed by methods described herein or known to those of skill in the art, compared to turnover in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor turnover, for example, by at least 1-fold, 1.2-fold, 1.3-fold, 1.4-fold, 1.5-fold, 2-fold, 2.5-fold, 3-fold, 3.5-fold, 4-fold, 4.5-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 15-fold, 20-fold, 30-fold, 40-fold, 50-fold, 60-fold, 70-fold, 80-fold, 90-fold, or 100-fold, as assessed by methods described herein or known to those skilled in the art (e.g., pulse-chase assays), compared to turnover in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT). Methods for determining receptor turnover are well known in the art. For example, cells expressing KIT can be 35After pulse-labeling with S-EXPRESS protein labeling mixture (NEG772, NEN Life Science Products), washing, and chasing with unlabeled medium for a period, protein lysates from labeled cells can be immunoprecipitated with anti-KIT antibodies, resolved by SDS-PAGE, visualized (e.g., exposed to a PhosphoImager screen (Molecular Dynamics) and scanned using a Typhoon 8600 scanner (Amersham)) and analyzed using ImageQuant software (Molecular Dynamics) (see, e.g., Chan et al., Development, 2004, 131:5551-5560).

[0177] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor degradation, e.g., by at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99%, when assessed by methods described herein or known to those of skill in the art (e.g., pulse-chase assays) compared to degradation in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor degradation, e.g., by at least about 25% or 35%, optionally about 75%, when assessed by methods described herein or known to those of skill in the art, compared to degradation in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can induce or enhance KIT receptor degradation, e.g., by at least 1-fold, 1.2-fold, 1.3-fold, 1.4-fold, 1.5-fold, 2-fold, 2.5-fold, 3-fold, 3.5-fold, 4-fold, 4.5-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 15-fold, 20-fold, 30-fold, 40-fold, 50-fold, 60-fold, 70-fold, 80-fold, 90-fold, or 100-fold, as assessed by methods described herein or known to those of skill in the art (e.g., pulse-chase assays) compared to degradation in the presence of an unrelated antibody (e.g., an antibody that does not immunospecifically bind to KIT). Techniques for quantifying or monitoring the ubiquitination and / or degradation (e.g., kinetics or degradation rate) of cell surface receptors are well known in the art and include a variety of fluorescent and radioactive techniques (see, e.g., International Patent Application Publication No. WO 2008 / 153926 A2). For example, 125 Pulse-chase experiments or experiments using radiolabeled ligands such as I-SCF can be performed to quantitatively measure the degradation of KIT.

[0178] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein do not bind to the extracellular ligand-binding site of KIT, e.g., the SCF-binding site of KIT. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein do not inhibit ligand binding to KIT, e.g., do not inhibit KIT ligand (e.g., SCF) binding to KIT, as determined by methods described in the art, e.g., ELISA. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein do not completely or partially inhibit ligand binding to KIT, e.g., do not completely or partially inhibit KIT ligand (e.g., SCF) binding to KIT, as determined by methods described in the art, e.g., ELISA or FACS (fluorescence-activated cell sorting).

[0179] In certain aspects, the anti-KIT antibodies (e.g., human or humanized antibodies) provided herein are inhibitory antibodies, i.e., antibodies that inhibit (e.g., partially inhibit) KIT activity, i.e., one or more KIT activities. In certain embodiments, partial inhibition of KIT activity results in, for example, about 25% to about 65% or 75% inhibition. In certain embodiments, partial inhibition of KIT activity results in, for example, about 35% to about 85% or 95% inhibition. Non-limiting examples of KIT activities include KIT dimerization, KIT phosphorylation (e.g., tyrosine phosphorylation), signaling downstream of KIT (e.g., Stat, AKT, MAPK, or Ras signaling), induction or enhancement of gene transcription (e.g., c-Myc), and induction or enhancement of cell proliferation or cell survival. In certain embodiments, the antibodies described herein inhibit KIT phosphorylation (e.g., ligand-induced phosphorylation).

[0180] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit KIT tyrosine phosphorylation in the KIT cytoplasmic domain.

[0181] In another specific embodiment, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit cell proliferation, e.g., mast cell proliferation or eosinophil proliferation. In yet another specific embodiment, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit cell survival, e.g., mast cell survival or eosinophil cell survival. In certain aspects, inhibition of cell proliferation, e.g., mast cell proliferation or eosinophil proliferation, is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0182] In another specific embodiment, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit mast cell activation or eosinophil activation. In certain aspects, inhibition of mast cell activation or activity or eosinophil activation or activity is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0183] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit eosinophil or mast cell degranulation (see, e.g., Staats et al., 2012, Med. Chem. Commun., 2013, 4:88-94, and Ochkur et al., 2012, J. Immunol. Methods, 384:10-20). In certain aspects, inhibition of eosinophil or mast cell degranulation is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0184] In another specific embodiment, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit mast cell mediator release. In certain aspects, mast cell mediator release is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%. Assays for measuring mast cell activity, such as mediator release from mast cell cultures, including rodent and human mast cell cultures, have been described (see, e.g., Kuehn et al., "Measuring Mast Cell Mediator Release," in Current Protocols in Immunology, Unite 7.38.1-7.38.9, November 2010 (John Wiley & Sons, Inc.)). For example, certain assays are designed to monitor mast cell degranulation through measuring the release of the granule component β-hexosaminidase, determining the production of products of phospholipid metabolism such as eicosanoids, leukotriene C4 (LTC4), and prostaglandin D2 (PGD2), or determining the production of multiple cytokines. In certain embodiments, measurement of mast cell culture release of cytokines can be performed by enzyme-linked immunosorbent assay (ELISA). In certain embodiments, CD34 peripheral blood progenitor cells or mast cell lines such as HMC-1 or human LAD2 mast cell lines can be used in these assays to confirm the effect of anti-KIT antibodies on mast cells.

[0185] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein induce apoptosis, e.g., mast cell apoptosis or eosinophil apoptosis. In another specific embodiment, the anti-KIT antibodies or antigen-binding fragments thereof provided herein induce cell differentiation, e.g., mast cell differentiation.

[0186] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein can achieve any one of the following: a reduction in eosinophil numbers and / or activity, a reduction in mast cell proliferation, a reduction in plasma tryptase levels, a reduction in plasma SCF levels, a reduction in mast cell numbers or amounts, an inhibition or reduction in mast cell activity, a reduction in mast cell-induced production or release of inflammatory factors, a reduction in the release of inflammatory factors, restoration of mast cell homeostasis, reduced mast cell migration, reduced mast cell adhesion, an inhibition or reduction in mast cell recruitment of eosinophils, and an inhibition or reduction in antigen-mediated degranulation of mast cells.

[0187] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit KIT activity but do not inhibit KIT dimerization. In another specific embodiment, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit KIT activity but do not inhibit ligand binding to KIT, for example, do not inhibit KIT ligand (e.g., SCF) binding to KIT, but inhibit KIT dimerization.

[0188] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit KIT activity, such as ligand-induced tyrosine phosphorylation of the KIT cytoplasmic domain, by about 25% to about 65% or 75%, as determined by a cell-based phosphorylation assay well known in the art, e.g., the cell-based phosphorylation assay described herein. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit KIT activity, such as ligand-induced tyrosine phosphorylation of the KIT cytoplasmic domain, by about 35% to about 85% or 95%, as determined by a cell-based phosphorylation assay well known in the art, e.g., the cell-based phosphorylation assay described herein.

[0189] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein inhibit KIT activity, such as ligand-induced tyrosine phosphorylation of the KIT cytoplasmic domain, at a 50% inhibitory concentration (IC) of less than about 600 pM, or less than about 500 pM, or less than about 250 pM, as determined by a cell-based phosphorylation assay well known in the art, such as a cell-based phosphorylation assay described herein. 50 In certain embodiments, IC 50 is less than about 550 pM or 200 pM. In certain embodiments, the IC 50 In certain embodiments, the IC is in the range of about 50 pM to about 225 pM, or in the range of 100 pM to about 600 pM. 50 is in the range of about 50 pM to about 550 pM, or about 50 pM to about 600 pM, or about 150 pM to about 550 pM.

[0190] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein (i) immunospecifically bind to a KIT polypeptide comprising the D4 and / or D5 region of human KIT, (ii) inhibit KIT phosphorylation (e.g., tyrosine phosphorylation), and (iii) do not completely inhibit or partially inhibit KIT ligand (e.g., SCF) binding to KIT. In yet another specific embodiment, such antibodies do not inhibit KIT dimerization. In yet another specific embodiment, such antibodies can be recombinantly expressed by CHO cells at an average titer of at least 0.5 μg / mL, e.g., at least 1.0 μg / mL. In a further specific embodiment, such antibodies comprise VH and VL domains that are non-immunogenic, e.g., the VH and VL domains do not comprise T-cell epitopes.

[0191] In other specific embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein immunospecifically bind to the monomeric form of KIT (e.g., human KIT). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to the monomeric form of KIT (e.g., human KIT). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to the dimeric form of KIT (e.g., human KIT).

[0192] In certain embodiments, the anti-KIT antibody or its antigen-binding fragment provided herein does not bind to KIT in monomeric form, but specifically binds to KIT in dimeric form or KIT in multimeric form.In certain embodiments, the antibody has a higher affinity for KIT monomer than for KIT dimer.In certain embodiments, the antibody has a higher affinity for KIT monomer than for KIT multimer.

[0193] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein specifically bind to a native isoform or native variant of KIT (i.e., a naturally occurring isoform or variant of KIT in an animal (e.g., monkey, mouse, goat, donkey, dog, cat, rabbit, pig, rat, human, frog, or bird) that can be isolated from an animal, preferably a human). In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein specifically bind to human KIT or a fragment thereof. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein specifically bind to human KIT or a fragment thereof and do not specifically bind to non-human KIT (e.g., monkey, mouse, goat, donkey, dog, cat, rabbit, pig, rat, or bird) or a fragment thereof. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to human KIT or a fragment thereof and do not specifically bind to murine KIT. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to human KIT or a fragment thereof (e.g., the D4 region of human KIT), as well as canine (dog) and non-human primate (e.g., monkey) KIT. In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to human KIT or a fragment thereof (e.g., the D4 region of human KIT), as well as canine (dog) and non-human primate (e.g., monkey) KIT, but do not specifically bind to murine or rat KIT or a fragment thereof (e.g., the D4 region of murine KIT).

[0194] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments provided herein specifically bind to human KIT or a fragment thereof (e.g., the D4 region of human KIT), as well as canine (dog), feline (cat), and cynomolgus KIT, but do not specifically bind to mouse or rat KIT or a fragment thereof (e.g., the D4 region of mouse KIT).

[0195] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein specifically bind to human KIT or a fragment thereof (e.g., the D4 region of human KIT), as well as canine (dog), feline (cat), and cynomolgus KIT, with higher affinity (e.g., at least 0.5-fold, 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, or 10-fold) than to murine or rat KIT or a fragment thereof (e.g., the D4 region of murine KIT).

[0196] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein specifically bind to the extracellular domain of human KIT containing a mutation, e.g., a somatic mutation, such as a mutation in exon 9 of human KIT in which the Ala and Tyr residues at positions 502 and 503 are duplicated (see, e.g., Marcia et al., (2000) Am. J. Pathol. 156(3):791-795, and Debiec-Rychter et al., (2004) European Journal of Cancer. 40:689-695, both of which are incorporated herein by reference in their entireties and describe KIT mutations).

[0197] In certain embodiments, the anti-KIT antibody or antigen-binding fragment thereof provided herein specifically binds to the extracellular domain of glycosylated human KIT. In certain embodiments, the antibody or antigen-binding fragment thereof described herein binds to the extracellular domain of two different glycosylated forms of human KIT. For example, two forms of human KIT with different molecular weights and different glycosylation patterns have been observed by immunoblotting.

[0198] In certain embodiments, the antibodies described herein can specifically bind to both of these forms of human KIT, which have different glycosylation patterns, e.g., one form is more glycosylated than the other. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein bind to the unglycosylated extracellular domain of human KIT.

[0199] In certain embodiments, the anti-KIT antibodies or antigen-binding fragments thereof provided herein are bivalent, monospecific antibodies, which have two antigen-binding regions (e.g., two identical antigen-binding regions), both of which specifically bind to the same antigen, KIT (e.g., human KIT). In certain embodiments, the antigen-binding regions comprise the VH and VL CDRs set forth in Table 1. In certain embodiments, the antigen-binding regions comprise a VH comprising the amino acid sequence of any one of SEQ ID NOs: 8-12 and / or a VL comprising the amino acid sequence of any one of SEQ ID NOs: 13-16. In certain aspects, the anti-KIT antibodies or antigen-binding fragments thereof provided herein are not bispecific antibodies.

[0200] In certain embodiments, the antibodies described herein are monoclonal antibodies or isolated monoclonal antibodies. In another specific embodiment, the antibodies described herein are humanized monoclonal antibodies. In certain embodiments, the antibodies described herein are recombinant antibodies, such as recombinant human antibodies, recombinant humanized antibodies, or recombinant monoclonal antibodies. In certain embodiments, the antibodies described herein comprise non-human amino acid sequences, such as non-human CDRs or non-human (e.g., non-human primate) framework residues.

[0201] In certain embodiments provided herein, recombinant antibodies can be isolated, prepared, expressed, or produced by recombinant means, such as antibodies expressed using a recombinant expression vector transfected into a host cell, antibodies isolated from a recombinant combinatorial antibody library, or antibodies prepared, expressed, produced, or isolated by any other means, including, for example, synthesis, genetic engineering of DNA sequences encoding human immunoglobulin sequences, or production of human immunoglobulins, e.g., via splicing of sequences encoding human immunoglobulin gene sequences, into other such sequences. In certain embodiments, the amino acid sequences of such recombinant antibodies have been modified such that the amino acid sequences of such antibodies, e.g., the VH and / or VL regions, are sequences that do not naturally occur within the antibody germline repertoire of an organism in vivo, e.g., a murine or human germline repertoire. In certain embodiments, recombinant antibodies can be obtained by assembling several sequence fragments that naturally occur in an organism (e.g., a primate, such as a human) into a composite sequence of the recombinant antibody, where the composite sequence does not naturally occur within the organism (e.g., a primate, such as a human).

[0202] Antibodies provided herein include immunoglobulin molecules of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or subclass of immunoglobulin molecule. In certain embodiments, antibodies provided herein are IgG antibodies (e.g., human IgG antibodies), or a class (e.g., human IgG1 or IgG4) or subclass thereof. In another specific embodiment, an antibody described herein is an IgG1 (e.g., human IgG1 (isotype a, z, or f)) or IgG4 antibody. In certain embodiments, an antibody described herein is a whole or fully humanized antibody, a human antibody, or a composite human antibody.

[0203] In certain aspects, the antibodies provided herein comprise antibody light and heavy chains, e.g., separate light and heavy chains. With respect to the light chain, in certain embodiments, the light chain of an antibody described herein is a kappa light chain. In another specific embodiment, the light chain of an antibody described herein is a lambda light chain. In yet another specific embodiment, the light chain of an antibody described herein is a human kappa light chain or a human lambda light chain. In certain embodiments, the antibodies described herein comprise a human light chain constant region. Non-limiting examples of human light chain constant region sequences are described in the art, see, for example, U.S. Patent No. 5,693,780 and Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242.

[0204] With respect to the heavy chain, in certain embodiments, the heavy chain of an antibody described herein can be an alpha (α), delta (δ), epsilon (ε), gamma (γ), or mu (μ) heavy chain. In another specific embodiment, the heavy chain of a described antibody can comprise a human alpha (α), delta (δ), epsilon (ε), gamma (γ), or mu (μ) heavy chain. In certain embodiments, an antibody described herein comprises a human heavy chain constant region (e.g., a human IgG constant region, e.g., a human IgG1, IgG2, IgG3, or IgG4 constant region). Non-limiting examples of human heavy chain constant region sequences are described in the art; see, for example, U.S. Patent No. 5,693,780 and Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242. In certain embodiments, the antibodies described herein comprise an altered (e.g., mutated) human Fc region or domain (e.g., an altered (e.g., mutated) human IgG1 Fc region or domain, an altered (e.g., mutated) human IgG2 Fc region or domain, an altered (e.g., mutated) human IgG3 Fc region or domain, or an altered (e.g., mutated) human IgG4 Fc region or domain).

[0205] In certain embodiments, the anti-KIT antibodies described herein are human, bihuman, or humanized monoclonal antibodies. In certain embodiments, the antibodies described herein are engineered antibodies, e.g., antibodies produced by recombinant methods. In certain embodiments, the antibodies described herein are humanized antibodies comprising one or more non-human (e.g., rodent or murine) CDRs, one or more human framework regions (FRs), and, optionally, human heavy chain constant regions and / or light chain constant regions. In certain embodiments, the antibodies described herein comprise one or more primate (or non-human primate) framework regions. In certain embodiments, the antibodies described herein do not comprise non-human primate framework regions.

[0206] The antibodies provided herein can include antibodies that contain chemical modifications, e.g., antibodies that have been chemically modified, e.g., by the covalent attachment of any type of molecule to the antibody. For example, but not limited to, an anti-KIT antibody can be glycosylated, acetylated, pegylated, phosphorylated, or amidated, can be derivatized via a protecting / blocking group, or can further comprise a cellular ligand and / or other protein or peptide (e.g., a heterologous protein or peptide), etc. For example, the antibodies provided herein can be chemically modified, e.g., by glycosylation, acetylation, pegylation, phosphorylation, amidation, derivatization with known protecting / blocking groups, proteolytic cleavage, conjugation with a cellular ligand or other protein, etc. Additionally, the anti-KIT antibodies described herein can contain one or more non-classical amino acids.

[0207] In one embodiment, the anti-KIT antibodies provided herein are naked antibodies that are not linked, fused, or conjugated (e.g., artificially linked, fused, or conjugated) to another molecule, peptide, or polypeptide (e.g., a heterologous polypeptide). In certain embodiments, the anti-KIT antibodies provided herein are not antibody-drug conjugates. In certain embodiments, the anti-KIT antibodies provided herein are not fusion proteins. In certain embodiments, the anti-KIT antibodies described herein do not comprise any non-classical amino acids.

[0208] 5.1.1 Antibody conjugates In some embodiments, provided herein are antibodies (e.g., humanized antibodies) or antigen-binding fragments thereof conjugated or recombinantly fused to a diagnostic, detectable, or therapeutic agent, or any other molecule. The conjugated or recombinantly fused antibodies can be useful, for example, as part of a clinical testing procedure, for monitoring or prognosing the onset, development, progression, and / or severity of a KIT-associated disorder or disease, such as determining the efficacy of a particular therapy. The conjugated or recombinantly fused antibodies can be useful, for example, for protecting against, treating, or managing a KIT-associated disorder, or for protecting against, treating, or managing the effects of a KIT-associated disorder. The antibodies described herein can also be conjugated to a molecule (e.g., polyethylene glycol) that can affect one or more biological and / or molecular properties of the antibody, such as stability (e.g., in serum), half-life, solubility, and antigenicity.

[0209] In certain aspects, provided herein are conjugates comprising an agent (e.g., a therapeutic agent) conjugated to an antibody (or antigen-binding fragment thereof) described herein. In certain embodiments, the conjugate comprises an antibody described herein and a molecule (e.g., a therapeutic or drug moiety), where the antibody is directly conjugated to the molecule or is conjugated via one or more linkers. In certain embodiments, the antibody is covalently conjugated to the molecule. In certain embodiments, the antibody is non-covalently conjugated to the molecule. In certain embodiments, the antibody described herein, e.g., the antibody conjugated to an agent, binds to wild-type human KIT. In certain embodiments, the antibody described herein, e.g., the antibody conjugated to an agent, binds to the extracellular domain of human KIT containing a mutation, e.g., a somatic mutation associated with cancer (e.g., GIST), such as a mutation in exon 9 of human KIT where the Ala and Tyr residues at positions 502 and 503 are duplicated.

[0210] Such diagnosis and detection can be accomplished, for example, by conjugating the antibody to a detectable molecule or substance, including various enzymes such as, but not limited to, horseradish peroxidase, alkaline phosphatase, beta-galactosidase, or acetylcholinesterase; conjugated groups such as, but not limited to, streptavidin / biotin and avidin / biotin; fluorescent materials such as, but not limited to, umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansyl chloride, or phycoerythrin; luminescent materials such as, but not limited to, luminol; bioluminescent substances such as, but not limited to, luciferase, luciferin, and aecolin; iodine ( 131 I, 125 I, 123 I, and 121 I), carbon ( 14 C), sulfur ( 35 S), tritium ( 3 H), indium ( 115 In, 113 In, 112 In, and111 In,), technetium ( 99 Tc), thallium ( 201 Ti), Gallium ( 68 Ga, 67 Ga), palladium ( 103 Pd), molybdenum ( 99 Mo), xenon ( 133 Xe), fluorine ( 18 F), 153 Sm, 177 Lu, 159 Gd, 149 Pm, 140 La, 175 Yb, 166 Ho, 90 Y, 47 Sc, 186 Re, 188 Re, 142 Pr, 105 Rh, 97 Ru, 68 Ge, 57 Co, 65 Zn, 85 Sr, 32 P, 153 Gd, 169 Yb, 51 Cr, 54 Mn, 75 Se, 113 Sn, and 117 These include, but are not limited to, radioactive materials such as, but not limited to, Sn; as well as positron-emitting metals using various positron emission tomography techniques, and non-radioactive paramagnetic metal ions.

[0211] Provided are antibodies, or antigen-binding fragments thereof, described herein conjugated or recombinantly fused to a therapeutic moiety (or one or more therapeutic moieties), and uses of such antibodies. The antibodies can be conjugated or recombinantly fused to a therapeutic moiety, e.g., a cytotoxin such as a cell inhibitor or cytocidal agent, a therapeutic agent, or a radioactive metal ion, e.g., an alpha emitter. A cytotoxin or cytotoxic agent includes any agent that is detrimental to cells. Therapeutic moieties include auristatin or a derivative thereof, e.g., monomethyl auristatin E (MMAE), monomethyl auristatin F (MMAF), auristatin PYE, and auristatin E (AE) (see, e.g., U.S. Pat. No. 7,662,387 and U.S. Patent Application Publication Nos. 2008 / 0300192 and 2008 / 0025989, each of which is incorporated herein by reference); microtubule disrupting agents, e.g., maytansine or a derivative thereof, e.g., maytansinoid DM1 (see, e.g., U.S. Pat. Nos. 7,851,432, 7,575,748, and 5,416,064, each of which is incorporated herein by reference); prodrugs, e.g., prodrugs of CC-1065 (racermycin) analogs; antimetabolites (e.g., , methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, 5-fluorouracil decarbazine); alkylating agents (e.g., mechlorethamine, thioepachlorambucil, melphalan, carmustine (BCNU) and lumustine (CCNU), cyclophosphamide, busulfan, dibromomannitol, streptozotocin, mitomycin C, and cis-dichlorodiamine platinum(II) (DDP), and cisplatin); minor groove-binding alkylating agents; anthracyclines (e.g., daunorubicin (formerly daunomycin) and doxorubicin); antibiotics (e.g., d-actinomycin (formerly actinomycin), bleomycin, mithramycin, and anthramycin (AMC)); auristatin molecules (e.g., auristatin PHE, bryostatin 1, solastatin 10;Woyke et al., Antimicrob.Agents Chemother.46:3802-8(2002), Woyke et al., Antimicrob.Agents Chemother.45:3580-4(2001), Mohammad et al., Anticancer Drugs 12:735-40(2001), Wall et al. al.,Biochem.Biophys.Res.Commun.266:76-80(1999), Mohammad et al. al., Int. J. Oncol. 15:367-72 (1999), all of which are incorporated herein by reference; hormones (e.g., glucocorticoids, progestins, androgens, and estrogens), DNA repair enzyme inhibitors (e.g., etoposide or topotecan), kinase inhibitors (e.g., compound ST1571, imatinib mesylate (Kantarjian et al., Clin Cancer Res. 8(7):2167-76 (2002));Cytotoxic agents (e.g., paclitaxel, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxyanthracin dione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucorticoids, procaine, tetracaine, lidocaine, propranolol, and puromycin, and analogs or homologs thereof, and those disclosed in U.S. Patent Nos. 6,245,759, 6,399,633, 6,383,790, 6,399,63 ... No. 335,156, No. 6,271,242, No. 6,242,196, No. 6,218,410, No. 6,218,372, No. 6,057,3 00, 6,034,053, 5,985,877, 5,958,769, 5,925,376, 5,922,844, those compounds disclosed in US Pat. Nos. 5,911,995, 5,872,223, 5,863,904, 5,840,745, 5,728,868, 5,648,239, and 5,587,459, each of which is incorporated herein by reference for its disclosure of such compounds;Farnesyltransferase inhibitors (e.g., R115777, BMS-214662, and compounds described in, for example, U.S. Patent Nos. 6,458,935, 6,451,812, 6,440,974, 6,436,960, 6,432,959, 6,420,387, 6,414,145, 6,410,541, 6,410,539, 6,403,581, 6,399,615, 6,387,905, 6,372,747, 6,369,034, 6,362,188, 6,3 No. 42,765, No. 6,342,487, No. 6,300,501, No. 6,268,363, No. 6,265,422, No. No. 6,248,756, No. 6,239,140, ​​No. 6,232,338, No. 6,228,865, No. 6,228,856, No. 6,225,322, No. 6,218,406, No. 6,211,193, No. 6,187,786, No. 6,169,09 No. 6, No. 6,159,984, No. 6,143,766, No. 6,133,303, No. 6,127,366, No. 6,124, 465, 6,124,295, 6,103,723, 6,093,737, 6,090,948, 6,080,870, 6,077,853, 6,071,935, 6,066,738, 6,063,930, 6,054,466, 6,051,582, 6,051,574, and 6,040,305, each of which is incorporated herein by reference for its disclosure of such inhibitors; topoisomerase inhibitors (e.g., camptothecin, ibuprofen, Rinotecan, SN-38, topotecan, 9-aminocamptothecin, GG-211 (GI147211); DX-8951f; IST-622; rubitecan; pyrazoloacridine; XR-5000; saintpin; UCE6; UCE1022; TAN-1518A; TAN1518B; KT6006; KT6528; ED-110; NB-506; ED-110; NB-506; and rebeccamycin); vulgarein; DNA minor groove binders such as Hoechst dye 33342 and Hoechst dye 33258; nitidine; fagaronine; epiberberine; coraline;beta-lapachone; BC-4-1; bisphosphonates (e.g., alendronate, cimadronate, clodronate, tiludronate, etidronate, ibandronate, neridronate, olpandronate, risedronate, piridronate, pamidronate, zolendronate); HMG-CoA reductase inhibitors (e.g., lovastatin, simvastatin, atorvastatin, pravastatin, fluvastatin, statins, cerivastatin, lescol, lupitor, rosuvastatin, and atorvastatin); antisense oligonucleotides (e.g., U.S. Pat. No. 6, 277,832, 5,998,596, 5,885,834, 5,734,033, and 5,618,709, each of which is incorporated herein by reference with respect to such oligonucleotides); adenosine deaminase inhibitors (e.g., fludarabine phosphate and 2-chlorodeoxyadenosine); ibritumomab tiuxetan (Zevalin®); tositumomab (Bexxar®), and pharmaceutically acceptable salts, solvates, clathrates, and prodrugs thereof.

[0212] In certain embodiments, the therapeutic or drug moiety is an antitubulin drug, such as an auristatin or a derivative thereof. Non-limiting examples of auristatins include monomethyl auristatin E (MMAE), monomethyl auristatin F (MMAF), auristatin PYE, and auristatin E (AE) (see, e.g., U.S. Patent No. 7,662,387 and U.S. Patent Application Publication Nos. 2008 / 0300192 and 2008 / 0025989, each of which is incorporated herein by reference). In certain embodiments, the therapeutic or drug moiety is a microtubule-disrupting agent, such as maytansine or a derivative thereof, e.g., maytansinoid DM1 or DM4 (see, e.g., U.S. Patent Nos. 7,851,432, 7,575,748, and 5,416,064, each of which is incorporated herein by reference). In certain embodiments, the therapeutic moiety or drug moiety is a prodrug, e.g., a prodrug of a CC-1065 (rachelmycin) analog (see, e.g., U.S. Patent Application Publication No. 2008 / 0279868, and PCT International Patent Application Publication Nos. WO2009 / 017394, WO2010 / 062171, and WO2007 / 089149, each of which is incorporated herein by reference).

[0213] In certain embodiments, the antibody and therapeutic / drug agent are conjugated by one or more linkers. In another particular embodiment, the antibody and therapeutic / drug agent are directly conjugated.

[0214] In certain embodiments, non-limiting examples of therapeutic or drug moieties for conjugation to the antibodies described herein include calicheamicin (e.g., LL-E33288 conjugates, e.g., gamma-calicheamicin, see, e.g., U.S. Pat. No. 4,970,198) and derivatives thereof (e.g., gamma-calicheamicin hydrazide derivatives), ozogaimicin, duocarmycin and derivatives thereof (e.g., CC-1065 (NSC298223)), or achiral analogs of duocarmycin (e.g., AS-1-145 or Centanamycin). isine), taxanes and their derivatives, and enediynes and their derivatives (see, e.g., PCT International Patent Application Publication Nos. WO2009 / 017394, WO2010 / 062171, WO2007 / 089149, WO2011 / 021146, WO2008 / 150261, WO2006 / 031653, WO2005 / 089809, WO2005 / 089807, and WO2005 / 089808, each of which is incorporated by reference in its entirety).

[0215] Non-limiting examples of calicheamicins suitable for conjugation to the antibodies described herein are disclosed in, e.g., U.S. Pat. Nos. 4,671,958, 5,053,394, 5,037,651, 5,079,233, and 5,108,912, and PCT International Patent Application Publication Nos. WO2011 / 021146, WO2008 / 150261, WO2006 / 031653, WO2005 / 089809, WO2005 / 089807, and WO2005 / 089808, each of which is incorporated herein by reference for such calicheamicin disclosure. In certain embodiments, these compounds may contain a methyl trisulfide that reacts with an appropriate thiol to form a disulfide, while simultaneously introducing a functional group such as a hydrazide or other functional group that may be useful for conjugating calicheamicin to an antibody described herein. In certain embodiments, stabilizing the disulfide bond present in a calicheamicin conjugate by adding a dimethyl substituent may result in an improved antibody / drug conjugate. In certain embodiments, the calicheamicin derivative is N-acetyl gamma calicheamicin dimethyl hydrazide, or NAc-gamma DMH (CL-184,538), as one of the derivatives optimized for conjugation. Disulfide analogs of calicheamicin that can be conjugated to the antibodies described herein are described, for example, in U.S. Patent Nos. 5,606,040 and 5,770,710, each of which is incorporated herein by reference for its disclosure of such compounds. In certain embodiments, a moiety (e.g., calicheamicin or a derivative thereof) is conjugated to an antibody by a linker. In certain embodiments, the moiety (e.g., calicheamicin or a derivative thereof) is hydrolyzed at the linker from the antibody-drug conjugate. In one embodiment, the moiety (e.g., calicheamicin or a derivative thereof) is hydrolyzed at the linker from the antibody conjugate at a pH of about 3.0 to pH 4.0, at a temperature of 20 to 50°C, preferably at 37°C, for 1 to 24 hours.

[0216] In certain embodiments, non-limiting examples of therapeutic or drug moieties for conjugation to the antibodies described herein include pyrrolobenzodiazepines (PBDs) and derivatives thereof, such as PBD dimers (e.g., SJG-136 or SG2000), C2 unsaturated PBD dimers, pyrrolobenzodiazepine dimers with C2 aryl substitutions (e.g., SG2285), hydrolytically activated PBD dimer prodrugs (e.g., SG22 85), and polypyrrole-PBD (e.g., SG2274) (see, e.g., PCT International Patent Application Publication Nos. WO2000 / 012507, WO2007 / 039752, WO2005 / 110423, WO2005 / 085251, and WO2005 / 040170, and U.S. Pat. No. 7,612,062, each of which is incorporated herein by reference for its disclosure of such compounds).

[0217] In addition, the antibodies described herein can be coupled to a therapeutic moiety such as a radioactive metal ion, e.g. 213 Alpha emitters such as Bi, or 131 In, 131 LU, 131 Y, 131 Ho, 131 Radioactive metal ions, including but not limited to Sm, can be conjugated to macrocyclic chelators useful for conjugating to polypeptides. In certain embodiments, the macrocyclic chelator is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA), which can be attached to the antibody via a linker molecule. Such linker molecules are generally known in the art and are described in Denardo et al., 1998, Clin Cancer Res. 4(10):2483-90; Peterson et al., 1999, Bioconjug. Chem. 10(4):553-7; and Zimmerman et al., 1999, Nucl. Med. Biol. 26(8):943-50, each of which is incorporated herein by reference.

[0218] In certain embodiments, an antibody, or antigen-binding fragment thereof, described herein is conjugated to one or more molecules (e.g., therapeutic or drug moieties) directly or indirectly via one or more linker molecules. In certain embodiments, the linker is an enzyme-cleavable linker or a disulfide linker. In certain embodiments, the cleavable linker is cleavable via an enzyme such as an aminopeptidase, aminoesterase, dipeptidyl carboxypeptidase, or a protease of the blood coagulation cascade. In certain embodiments, the linker comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 20 amino acid residues. In certain embodiments, the linker consists of 1 to 10 amino acid residues, 1 to 15 amino acid residues, 5 to 20 amino acid residues, 10 to 25 amino acid residues, 10 to 30 amino acid residues, or 10 to 50 amino acid residues.

[0219] In certain embodiments, the moiety is conjugated to the antibody via one or more linkers. In certain embodiments, the moiety is hydrolyzed at the linker from the antibody-drug conjugate. In one embodiment, the moiety is hydrolyzed at the linker from the antibody conjugate at a pH of about 3.0 to pH 4.0 for about 1 to 24 hours at a temperature of about 20 to 50°C, preferably 37°C. In certain embodiments, the linker is stable in the bloodstream but releases the conjugated moiety once it is in target cells. In certain embodiments, the moiety is conjugated to the antibody described herein via one or more triazole-containing linkers (see, e.g., International Patent Application Publication No. WO 2007 / 018431, incorporated herein by reference). Non-limiting examples of linkers and spacers for incorporation into the antibody-drug conjugates described herein are disclosed in PCT International Patent Application Publication Nos. WO2007 / 018431, WO2004 / 043493, and WO2002 / 083180.

[0220] Additionally, the antibodies described herein can be fused to a marker sequence, such as a peptide, that facilitates purification. In a preferred embodiment, the marker amino acid sequence is a hexa-histidine peptide, such as the tag provided in the pQE vector (QIAGEN, Inc.), many of which are commercially available. For example, hexa-histidine provides for convenient purification of the fusion protein, as described by Gentz ​​et al., 1989, Proc. Natl. Acad. Sci. USA 86:821-824. Other peptide tags useful for purification include, but are not limited to, the hemagglutinin ("HA") tag, which corresponds to an epitope derived from the influenza hemagglutinin protein (Wilson et al., 1984, Cell 37:767), and the "FLAG" tag.

[0221] Methods for fusing or conjugating therapeutic moieties (including polypeptides) to antibodies are well known, and include, for example, Arnon et al., "Monoclonal Antibodies For Immunotargeting Of Drugs In Cancer Therapy," in Monoclonal Antibodies And Cancer Therapy, Reisfeld et al. (eds.), pp. 243-56 (Alan R. Liss, Inc. 1985); Hellstrom et al., "Antibodies For Drug Delivery," in Controlled Drug Delivery (2nd Ed.), Robinson et al. (eds.), pp. 623-53 (Marcel Dekker, Inc. 1987); Thorpe, "Antibody Carriers Of Cytotoxic Agents In Cancer Therapy: A Review," in Monoclonal Antibodies 84: Biological And Clinical Applications, Pinchera et al. (eds.), pp. 475-506 (1985); "Analysis, Results, And Future Prospective Of The Therapeutic Use Of Radiolabeled Antibody In Cancer Therapy”, in Monoclonal Antibodies For Cancer Detection And Therapy, Baldwin et al. (eds.), pp. 303-16 (Academic Press 1985), Thorpe et al., 1982, Immunol. Rev.62:119-58, U.S. Patent Nos. 5,336,603, 5,622,929, 5,359,046, 5,349,053, 5,447,851, 5,723,125, 5,783,181, 5,908,626, 5,844,095, and 5,112,946, EP 307,434, EP 367,166, EP 394,827, PCT Publication Nos. WO 91 / 06570, WO 96 / 04388, WO 96 / 22024, WO 97 / 34631, and WO 99 / 04813, Ashkenazi et al. al., Proc. Natl. Acad. Sci. USA, 88:10535-10539, 1991; Traunecker et al., Nature, 331:84-86, 1988; Zheng et al., J. Immunol., 154:5590-5600, 1995; Vil et al., Proc. Natl. Acad. Sci. USA, 89:11337-11341, 1992, which are incorporated herein by reference in their entireties.

[0222] The antibodies described herein can also be attached to solid supports, which are particularly useful for immunoassays or purification of target antigens. Such solid supports include, but are not limited to, glass, cellulose, polyacrylamide, nylon, polystyrene, polyvinyl chloride, or polypropylene.

[0223] In certain embodiments, the antibodies or antigen-binding fragments thereof described herein are extracellular drug conjugates (ECDs) comprising an antibody bound to a drug, optionally via a linker (see, e.g., PCT International Patent Application Publication No. WO2011 / 031870). The drug can act outside the cell, and therefore, internalization of the conjugate is not required. After the ECD binds to the target cell, the drug sends a signal to the cell.

[0224] In one embodiment, the linker of the ECD is a non-cleavable linker. Examples of non-cleavable linkers include linkers containing polyethylene glycol or polyethylene chains that are not acid- or base-sensitive (e.g., hydrazone-containing linkers), not sensitive to reducing or oxidizing agents (e.g., those containing disulfide bonds), and not sensitive to enzymes that may be found in cells or the circulatory system. Specific examples of non-cleavable linkers include the SMCC linker (U.S. Patent Application No. 20090202536). For illustrative purposes, examples of cleavable linkers include linkers containing unhindered glutathione-sensitive disulfides, esters, peptide sequences sensitive to peptidases such as cathepsin or plasmin, pH-sensitive hydrazones (see Bioconjugate Chem., 2010, 21(1), pp. 5-13), and the unhindered disulfide linker SPP (U.S. Patent Application No. 20090202536).

[0225] In certain aspects, the ECD comprises a drug or agent that is a cardiac glycoside, such as proscillaridin or sugar-enriched proscillaridin. In one embodiment, the agent is composed of a cardiac glycoside that lacks sugar. In various embodiments, the cardiac glycoside is a compound identified in PCT Publication No. WO2010 / 017480 (PCT / US2009 / 053159).

[0226] 5.2 Polynucleotides In certain aspects, provided herein are polynucleotides and polynucleotide combinations comprising a nucleotide sequence(s) encoding an antibody (e.g., a human or humanized antibody) or fragment thereof (e.g., a variable light chain region and / or a variable heavy chain region) described herein that immunospecifically binds to a KIT antigen. Also provided herein are polynucleotides encoding KIT antigens for generating anti-KIT antibodies described herein.

[0227] As used herein, an "isolated" polynucleotide or nucleic acid molecule is one that is separated from other nucleic acid molecules that are present in the nucleic acid molecule's natural source (e.g., humans). Furthermore, an "isolated" nucleic acid molecule, such as a cDNA molecule, can be substantially free of other cellular material or culture medium if produced by recombinant techniques, or substantially free of chemical precursors or other chemicals if chemically synthesized. For example, the phrase "substantially free" includes preparations of polynucleotides or nucleic acid molecules that have less than about 15%, 10%, 5%, 2%, 1%, 0.5%, or 0.1% (particularly less than about 10%) of other materials, e.g., cellular material, culture medium, other nucleic acid molecules, chemical precursors, and / or other chemicals. In certain embodiments, the nucleic acid molecule(s) encoding the antibodies described herein are isolated or purified.

[0228] In certain aspects, provided herein is a polynucleotide or combination of polynucleotides comprising a nucleotide sequence encoding an antibody or antigen-binding fragment thereof described herein, or the VH and VL or antigen-binding fragment thereof of the antibody. In certain embodiments, provided herein is a polynucleotide comprising a nucleotide sequence encoding the VH or antigen-binding fragment thereof of the antibody described herein. In certain embodiments, provided herein is a polynucleotide comprising a nucleotide sequence encoding the VL or antigen-binding fragment thereof of the antibody described herein. In certain embodiments, provided herein is a polynucleotide comprising a first nucleotide sequence encoding the VH or antigen-binding fragment thereof of the antibody described herein and a second nucleotide sequence encoding the VL or antigen-binding fragment thereof of the antibody. In certain embodiments, provided herein is a combination of two polynucleotides, wherein the first polynucleotide of the combination comprises a first nucleotide sequence encoding the VH or antigen-binding fragment thereof of the antibody described herein and the second polynucleotide of the combination comprises a second nucleotide sequence encoding the VL or antigen-binding fragment thereof of the antibody. In certain embodiments, provided herein is a polynucleotide comprising a nucleotide sequence encoding the heavy chain of the antibody described herein. In certain embodiments, provided herein is a polynucleotide comprising a nucleotide sequence encoding the light chain of an antibody described herein. In certain embodiments, provided herein is a polynucleotide comprising a first nucleotide sequence encoding the heavy chain of an antibody described herein and a second nucleotide sequence encoding the light chain of the antibody. In certain embodiments, provided herein is a combination of two polynucleotides, wherein a first polynucleotide of the combination comprises a first nucleotide sequence encoding the heavy chain of an antibody described herein and a second polynucleotide of the combination comprises a second nucleotide sequence encoding the light chain of the antibody.

[0229] In certain embodiments, the polynucleotides provided herein comprise the nucleotide sequence of SEQ ID NO: 23. In certain embodiments, the polynucleotides provided herein comprise the nucleotide sequence of SEQ ID NO: 24. In certain embodiments, the polynucleotides provided herein comprise the nucleotide sequence of SEQ ID NO: 23 and the nucleotide sequence of SEQ ID NO: 24. In certain embodiments, the combination of polynucleotides provided herein comprises a first polynucleotide comprising the nucleotide sequence of SEQ ID NO: 23 and a second polynucleotide comprising the nucleotide sequence of SEQ ID NO: 24.

[0230] Also provided herein are polynucleotides encoding anti-KIT antibodies or fragments thereof that have been optimized, for example, by codon / RNA optimization, substitution with a heterologous signal sequence, and removal of mRNA instability elements. Thus, methods for generating optimized nucleic acids encoding anti-KIT antibodies or fragments thereof (e.g., light chain, heavy chain, VH domain, or VL domain) for recombinant expression by introducing codon changes in the mRNA and / or removing inhibitory regions can be performed by adapting the optimization methods described in, for example, U.S. Patent Nos. 5,965,726, 6,174,666, 6,291,664, 6,414,132, and 6,794,498. For example, potential splice sites and instability elements (e.g., A / T or A / U-rich elements) within the RNA can be mutated without changing the amino acid encoded by the nucleic acid sequence to increase the stability of the RNA for recombinant expression. Alterations can take advantage of the degeneracy of the genetic code, for example, by using alternative codons for the same amino acid. In some embodiments, it may be desirable to alter one or more codons to encode a conservative mutation, e.g., a similar amino acid having a similar chemical structure and properties and / or function as the original amino acid. Such methods can increase expression of an anti-KIT antibody or fragment thereof by at least 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold, 60-fold, 70-fold, 80-fold, 90-fold, or 100-fold or more compared to expression of an anti-KIT antibody encoded by a non-optimized polynucleotide.

[0231] In certain embodiments, an optimized polynucleotide sequence encoding an anti-KIT antibody or fragment thereof (e.g., VL domain and / or VH domain) described herein can hybridize to an antisense (e.g., complementary) polynucleotide of an unoptimized polynucleotide sequence encoding an anti-KIT antibody or fragment thereof (e.g., VL domain and / or VH domain) described herein. In certain embodiments, an optimized nucleotide sequence encoding an anti-KIT antibody or fragment thereof described herein hybridizes to an antisense polynucleotide of an unoptimized polynucleotide sequence encoding an anti-KIT antibody or fragment thereof described herein under high stringency conditions. In certain embodiments, an optimized nucleotide sequence encoding an anti-KIT antibody or fragment thereof described herein hybridizes to an antisense polynucleotide of an unoptimized nucleotide sequence encoding an anti-KIT antibody or fragment thereof described herein under high stringency, medium stringency, or low stringency hybridization conditions. Information regarding hybridization conditions is provided in U.S. Patent Application Publication No. US 2005 / 0048549 (e.g., paragraphs 72-73), which is incorporated herein by reference.

[0232] In certain embodiments, optimized polynucleotide sequences encoding the VL regions of the antibodies described herein are at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 98% identical to the nucleotide sequence of SEQ ID NO: 23. In certain embodiments, optimized polynucleotide sequences encoding the VH regions of the antibodies described herein are at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 98% identical to the nucleotide sequence of SEQ ID NO: 24.

[0233] Polynucleotides can be obtained by any method known in the art, and the nucleotide sequence of the polynucleotides can be determined thereby. Nucleotide sequences encoding the antibodies and variants of these antibodies described herein can be determined using methods well known in the art, i.e., nucleotide codons known to encode specific amino acids are assembled in such a way to generate a nucleic acid encoding the antibody. Such polynucleotides encoding antibodies can be assembled from chemically synthesized oligonucleotides (e.g., as described in Kutmeier et al., 1994, BioTechniques 17:242), which briefly involves synthesizing overlapping oligonucleotides containing portions of the antibody-encoding sequence, annealing and ligating these oligonucleotides, and then amplifying the ligated oligonucleotides by PCR.

[0234] Alternatively, polynucleotides encoding the antibodies described herein can be generated from nucleic acid from a suitable source (e.g., a hybridoma) using methods well known in the art (e.g., PCR and other molecular cloning methods). For example, PCR amplification using synthetic primers capable of hybridizing to the 3' and 5' ends of a known sequence can be performed using genomic DNA obtained from hybridoma cells producing the antibody of interest. Such PCR amplification methods can be used to obtain nucleic acids containing sequences encoding the light and / or heavy chains of the antibody. Such PCR amplification methods can be used to obtain nucleic acids containing sequences encoding the variable light and / or variable heavy chain regions of the antibody. Amplified nucleic acids can be cloned into vectors for expression in host cells and for further cloning, e.g., to generate chimeric and humanized antibodies.

[0235] If a clone containing nucleic acid encoding a particular antibody is not available but the sequence of the antibody molecule is known, nucleic acid encoding the immunoglobulin can be chemically synthesized or obtained from a suitable source (e.g., an antibody cDNA library or a cDNA library generated, or isolated nucleic acid, preferably polyA+ RNA, from any tissue or cell that expresses the antibody, such as hybridoma cells selected to express an antibody described herein) by PCR amplification using synthetic primers capable of hybridizing to the 3' and 5' ends of the sequence, or by cloning using oligonucleotide probes specific for the particular gene sequence to identify a cDNA clone from a cDNA library that encodes the antibody. Amplified nucleic acids generated by PCR can then be cloned into a replicable cloning vector using any method well known in the art.

[0236] DNA encoding the anti-KIT antibodies described herein can be readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes capable of specifically binding to genes encoding the heavy and light chains of the anti-KIT antibody). Hybridoma cells can serve as a source of such DNA. Once isolated, the DNA can be placed into an expression vector and then transfected into host cells such as E. coli cells, monkey COS cells, Chinese hamster ovary (CHO) cells (e.g., CHO cells from the CHO GS System™ (Lonza)), or myeloma cells that do not otherwise produce immunoglobulin protein, to obtain the synthesis of the anti-KIT antibody in the recombinant host cells.

[0237] To generate whole antibodies, the VH or VL sequences in scFv clones can be amplified using PCR primers containing the VH or VL nucleotide sequence, restriction sites, and flanking sequences to protect the restriction sites. Using cloning techniques known to those skilled in the art, the PCR-amplified VH domain can be cloned into a vector expressing a heavy chain constant region, such as a human gamma 1 or gamma 4 constant region, and the PCR-amplified VL domain can be cloned into a vector expressing a light chain constant region, such as a human kappa or lambda constant region. In certain embodiments, the vector for expressing the VH or VL domain contains an EF-1α promoter, a secretion signal, cloning sites for the variable domain, a constant domain, and a selection marker such as neomycin. The VH and VL domains can also be cloned into a vector expressing the necessary constant regions. The heavy chain conversion vector and the light chain conversion vector are then co-transfected into cell lines to generate stable or transient cell lines expressing full-length antibodies, such as IgG, using techniques known to those skilled in the art.

[0238] The DNA can also be modified, for example, by substituting the coding sequence for human heavy and light chain constant domains in place of the murine sequences, or by covalently linking all or part of the coding sequence for a non-immunoglobulin polypeptide to the immunoglobulin coding sequence.

[0239] 5.3 Host Cells and Recombinant Expression of Antibodies In certain aspects, provided herein are host cells and associated expression vectors that recombinantly express the antibodies (or antigen-binding fragments thereof) described herein. Provided herein are vectors and vector combinations (e.g., expression vectors) that include a polynucleotide comprising a nucleotide sequence encoding an anti-KIT antibody or antigen-binding fragment for recombinant expression in a host cell, preferably a mammalian cell. Also provided herein are host cells that include such vectors or vector combinations for recombinantly expressing an anti-KIT antibody (e.g., a human or humanized antibody) described herein.

[0240] Recombinant expression of an antibody described herein that immunospecifically binds to the KIT antigen (e.g., a full-length antibody, an antibody heavy and / or light chain, or a single-chain antibody described herein) involves construction of an expression vector(s) containing polynucleotide(s) encoding the antibody. Once a polynucleotide encoding an antibody molecule described herein, the antibody heavy and / or light chain, or a fragment thereof (preferably, but not necessarily containing the heavy and / or light chain variable domains), has been obtained, the vector(s) for the production of the antibody molecule can be produced by recombinant DNA technology using techniques well known in the art. Thus, methods for preparing a protein by expressing a polynucleotide containing an antibody (or VH / VL or heavy / light chain)-encoding nucleotide sequence are described herein. Methods well known to those skilled in the art can be used to construct expression vectors containing antibody coding sequences and appropriate transcriptional and translational control signals. These methods include, for example, in vitro recombinant DNA techniques, synthetic techniques, and in vivo genetic recombination. Also provided are replicable vectors containing a nucleotide sequence encoding an antibody molecule described herein, an antibody heavy or light chain, an antibody heavy or light chain variable domain or fragment thereof, or a heavy or light chain CDR, operably linked to a promoter. Such vectors can include, for example, nucleotide sequences encoding the constant region of an antibody molecule (see, e.g., International Publication Nos. WO 86 / 05807 and WO 89 / 01036 and U.S. Patent No. 5,122,464), and antibody variable domains can be cloned into such vectors for expression of the complete heavy chain, the complete light chain, or both the complete heavy and light chains.

[0241] In certain embodiments, provided herein are vectors comprising a polynucleotide encoding the VH, or antigen-binding fragment thereof, of an antibody described herein. In certain embodiments, provided herein are vectors comprising a polynucleotide encoding the VL, or antigen-binding fragment thereof, of an antibody described herein. In certain embodiments, provided herein are vectors comprising polynucleotides encoding the VH and VL, or antigen-binding fragment thereof, of an antibody described herein. In certain embodiments, provided herein are vectors comprising a first polynucleotide encoding the VH, or antigen-binding fragment thereof, of an antibody described herein, and a second polynucleotide encoding the VL or antigen-binding fragment thereof. In certain embodiments, provided herein are combinations of two vectors, wherein the first vector of the combination comprises a first polynucleotide encoding the VH, or antigen-binding fragment thereof, of an antibody described herein, and the second vector of the combination comprises a second polynucleotide encoding the VL or antigen-binding fragment thereof. In certain embodiments, provided herein are vectors comprising a polynucleotide encoding the heavy chain of an antibody described herein. In certain embodiments, provided herein are vectors comprising a polynucleotide encoding the light chain of an antibody described herein. In certain embodiments, provided herein are vectors comprising polynucleotides encoding the heavy and light chains of an antibody described herein. In certain embodiments, provided herein are vectors comprising a first polynucleotide encoding the VH of an antibody described herein and a second polynucleotide encoding the VL of the antibody. In certain embodiments, provided herein are combinations of two vectors, a first vector of the combination comprising a first polynucleotide encoding the VH of an antibody described herein and a second vector of the combination comprising a second polynucleotide encoding the VL of the antibody.

[0242] The expression vector or combination of expression vectors can be transferred into cells (e.g., host cells) by conventional techniques, and the resulting cells can then be cultured by conventional techniques to produce an antibody or fragment thereof described herein. Accordingly, provided herein are host cells containing a polynucleotide or combination of polynucleotides encoding an antibody or fragment thereof described herein, or a heavy or light chain thereof, or fragment thereof, or a single-chain antibody described herein, operably linked to a promoter for expression of such sequences in the host cell. In certain embodiments, for expression of double-chain antibodies, as described in more detail below, vectors encoding both the heavy and light chains can be individually co-expressed in a host cell for expression of a complete immunoglobulin molecule. In certain embodiments, a host cell contains vectors comprising polynucleotides encoding both the heavy and light chains (or both the VH and VL) of an antibody described herein, or a fragment thereof. In certain embodiments, a host cell contains two different vectors: a first vector comprising a polynucleotide encoding the heavy chain (or VH) or fragment thereof of an antibody described herein, and a second vector comprising a polynucleotide encoding the light chain (or VL) or fragment thereof of an antibody described herein. In other embodiments, the first host cell comprises a first vector comprising a polynucleotide encoding the heavy chain (or VH) or fragment thereof of an antibody described herein, and the second host cell comprises a second vector comprising a polynucleotide encoding the light chain (or VL) or fragment thereof of an antibody described herein.

[0243] A variety of host-expression vector systems can be utilized to express the antibody molecules described herein (see, e.g., U.S. Pat. No. 5,807,715). Such host-expression systems represent vehicles in which a coding sequence of interest can be produced and subsequently purified, but also represent cells which, when transformed or transfected with the appropriate nucleotide coding sequence, are capable of expressing the antibody molecules described herein in situ. These include microorganisms such as bacteria (e.g., E. coli and B. subtilis) transformed with recombinant bacteriophage DNA, plasmid DNA, or cosmid DNA expression vectors containing the antibody coding sequences; yeast (e.g., Saccharomyces Pichia) transformed with recombinant yeast expression vectors containing the antibody coding sequences; insect cell systems infected with recombinant viral expression vectors (e.g., baculovirus) containing the antibody coding sequences; and plant cell systems (e.g., Chlamydomonas sp.) infected with recombinant viral expression vectors (e.g., cauliflower mosaic virus, CaMV; tobacco mosaic virus, TMV) or transformed with recombinant plasmid expression vectors (e.g., Ti plasmid) containing the antibody coding sequences. reinhardtii); or mammalian cell systems (e.g., COS, CHO, BHK, MDCK, HEK293, NS0, PER.C6, VERO, CRL7030, HsS78Bst, HeLa, and NIH3T3 cells) harboring a recombinant expression construct containing a promoter derived from the genome of a mammalian cell (e.g., a metallothionein promoter) or from a mammalian virus (e.g., an adenovirus late promoter, a vaccinia virus 7.5K promoter). In certain embodiments, the cells for expressing the antibodies or antigen-binding fragments thereof described herein are CHO cells, e.g., CHO cells from CHO GS System™ (Lonza). In certain embodiments, the mammalian expression vector is pOptiVEC™ or pcDNA3.3.Preferably, bacterial cells such as Escherichia coli, and more preferably eukaryotic cells, are used for the expression of recombinant antibody molecules, particularly for the expression of whole recombinant antibody molecules. For example, mammalian cells such as Chinese hamster ovary (CHO) cells, in conjunction with vectors such as the major intermediate-early gene promoter element from human cytomegalovirus, are effective expression systems for antibodies (Foecking et al., 1986, Gene 45:101, and Cockett et al., 1990, Bio / Technology 8:2). In certain embodiments, the antibodies described herein are produced by CHO cells or NSO cells. In certain embodiments, expression of the nucleotide sequence encoding the antibodies described herein that immunospecifically bind to the KIT antigen is regulated by a constitutive promoter, an inducible promoter, or a tissue-specific promoter.

[0244] In bacterial systems, several expression vectors can be advantageously selected depending on the intended use of the expressed antibody molecule. For example, if large quantities of such antibody are to be produced, a vector directing the expression of high-level fusion protein products that are easily purified for the generation of pharmaceutical compositions of the antibody molecule may be desirable. Such vectors include, but are not limited to, the E. coli expression vector pUR278 (Ruther et al., 1983, EMBO 12:1791), pIN vectors (Inouye & Inouye, 1985, Nucleic Acids Res. 13:3101-3109; Van Heeke & Schuster, 1989, J. Biol. Chem. 24:5503-5509), and the like, in which antibody coding sequences can be individually ligated in frame with the lacZ coding region to produce a fusion protein. pGEX vectors can also be used to express foreign polypeptides as fusion proteins with glutathione 5-transferase (GST). In general, such fusion proteins are soluble and can easily be purified from lysed cells by adsorption and binding to a matrix of glutathione-agarose beads followed by elution in the presence of free glutathione. The pGEX vectors are designed to contain thrombin or factor Xa protease cleavage sites so that the cloned target gene product can be released from the GST moiety.

[0245] In an insect system, Autographa californica nuclear polyhedrosis virus (AcNPV) is used as a vector to express foreign genes. The virus is grown in Spodoptera frugiperda cells. The antibody coding sequence can be cloned individually into non-essential regions (e.g., the polyhedrin gene) of the virus and placed under control of an AcNPV promoter (e.g., the polyhedrin promoter).

[0246] Several viral-based expression systems are available for mammalian host cells. When adenovirus is used as an expression vector, the antibody coding sequence of interest can be ligated to an adenovirus transcription / translation control complex, e.g., the late promoter and tripartite leader sequence. This chimeric gene can then be inserted into the adenovirus genome by in vitro or in vivo recombination. Insertion into a non-essential region of the viral genome (e.g., region E1 or E3) results in recombinant virus that is viable and capable of expressing the antibody molecule in infected hosts (see, e.g., Logan & Shenk, 1984, Proc. Natl. Acad. Sci. USA 8 1:355-359). Specific initiation signals may also be required for efficient translation of the inserted antibody coding sequence. These signals include the ATG initiation codon and adjacent sequences. Furthermore, the initiation codon must be in phase with the reading frame of the desired coding sequence to ensure translation of the entire insert. These exogenous translational control signals and initiation codons can be of a variety of origins, both natural and synthetic. The efficiency of expression may be enhanced by the inclusion of appropriate transcription elements, transcription terminators, etc. (see, eg, Bittner et al., 1987, Methods in Enzymol. 153:51-544).

[0247] In addition, a host cell strain can be selected that modulates the expression of the inserted sequences, or modifies and processes the gene product in the specific fashion desired. Such modifications (e.g., glycosylation) and processing (e.g., cleavage) of protein products can be important for the function of the protein. Different host cells have characteristic and specific mechanisms for the post-translational processing and modification of proteins and gene products. Appropriate cell lines or host systems can be selected to ensure the correct modification and processing of the expressed foreign protein. To this end, eukaryotic host cells that possess the cellular machinery for proper processing of the primary transcript, glycosylation, and phosphorylation of the gene product can be used. Such mammalian host cells include, but are not limited to, CHO, VERO, BHK, Hela, COS, MDCK, HEK293, NIH3T3, W138, BT483, Hs578T, HTB2, BT2O and T47D, NS0 (a murine myeloma cell line that does not endogenously produce any immunoglobulin chains), CRL7O3O, and HsS78Bst cells. In certain embodiments, the humanized monoclonal anti-KIT antibodies described herein are produced in mammalian cells, such as CHO cells.

[0248] For long-term, high-yield production of recombinant proteins, stable expression is preferred. For example, cell lines that stably express an antibody molecule can be engineered. Rather than using expression vectors containing viral origins of replication, host cells can be transformed with DNA controlled by appropriate expression control elements (e.g., promoter, enhancer, sequences, transcription termination, polyadenylation sites, etc.) and a selectable marker. After introduction of the foreign DNA, engineered cells can be grown in an enriched medium for 1-2 days and then switched to a selective medium. The selectable marker in the recombinant plasmid confers resistance to selection, allowing the cells to stably integrate the plasmid into their chromosomes and grow to form aggregates that can then be cloned and expanded into cell lines. This method can be advantageously used to engineer cell lines that express an antibody molecule. Such engineered cell lines can be particularly useful for screening and evaluating compositions that interact directly or indirectly with the antibody molecule.

[0249] Several selection systems can be used, including, but not limited to, herpes simplex virus thymidine kinase (Wigler et al., 1977, Cell 11:223), hypoxanthine guanine phosphoribosyltransferase (Szybalska & Szybalski, 1992, Proc. Natl. Acad. Sci. USA 48:202), and adenine phosphoribosyltransferase (Lowy et al., 1980, Cell 22:8-17), genes that can be used to select tk-, hgprt-, or aprt- cells, respectively.Additionally, antimetabolite resistance is mediated by the following genes: dhfr, which confers resistance to methotrexate (Wigler et al., 1980, Natl. Acad. Sci. USA 77:357; O'Hare et al., 1981, Proc. Natl. Acad. Sci. USA 78:1527), gpt, which confers resistance to mycophenolic acid (Mulligan & Berg, 1981, Proc. Natl. Acad. Sci. USA 78:2072), and neo, which confers resistance to the aminoglycoside G-418 (Wu and Wu, 1991, Biotherapy 3:87-95; Tolstoshev, 1993, Ann. Rev. Pharmacol. Toxicol. 32:573-596; Mulligan, 1993, Science 260:926-932, and Morgan and Anderson, 1993, Ann. Rev. Biochem. 62:191-217, May, 1993, TIB TECH 11(5):155-215), and hygro, which confers resistance to hygromycin (Santerre et al., 1984, Gene 30:147). Methods commonly known in the field of recombinant DNA technology can be routinely applied to select the desired recombinant clones, and such methods are described, for example, in Ausubel et al. (eds.), Current Protocols in Molecular Biology, John Wiley & Sons, NY (1993); Kriegler, Gene Transfer and Expression, A Laboratory Manual, Stockton Press, NY (1990), and Chapters 12 and 13, Dracopoli et al. (eds.), Current Protocols in Human Genetics, John Wiley & Sons, NY (1990). Sons, NY (1994), Colberre-Garapin et al., 1981, J. Mol. Biol. 150:1, which are incorporated herein by reference in their entireties.

[0250] The expression level of an antibody molecule can be increased by vector amplification (for a review, see Bebbington and Hentschel, "The use of vectors based on gene amplification for the expression of cloned genes in mammalian cells in DNA cloning," Vol. 3 (Academic Press, New York, 1987)). If the marker in the antibody expression vector system is amplifiable, an increase in the level of inhibitor present in the host cell culture will increase the copy number of the marker gene. Because the amplified region is associated with the antibody gene, antibody production will also increase (Crouse et al., 1983, Mol. Cell. Biol. 3:257).

[0251] Host cells can be co-transfected with two or more expression vectors described herein, where one vector encodes a heavy chain-derived polypeptide and the second vector encodes a light chain-derived polypeptide. The two vectors can contain identical selectable markers that enable equal expression of heavy and light chain polypeptides. Host cells can be co-transfected with different amounts of two or more expression vectors. For example, host cells can be transfected with any one of the following ratios of the first expression vector to the second expression vector: 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:12, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, or 1:50.

[0252] Alternatively, a single vector capable of encoding and expressing both heavy and light chain polypeptides can be used. In such situations, the light chain should be placed before the heavy chain to avoid an excess of toxic free heavy chain (Proudfoot, 1986, Nature 322:52, and Kohler, 1980, Proc. Natl. Acad. Sci. USA 77:2197-2199). The coding sequences for the heavy and light chains can comprise cDNA or genomic DNA. Expression vectors can be monocistronic or multicistronic. Multicistronic nucleic acid constructs can encode 2, 3, 4, 5, 6, 7, 8, 9, 10 or more genes / nucleotide sequences, or between 2 and 5, 5 and 10, or 10 and 20 genes / nucleotide sequences. For example, a bicistronic nucleic acid construct can contain, in this order: a promoter, a first gene (e.g., the heavy chain of an antibody described herein), and a second gene (e.g., the light chain of an antibody described herein). In such an expression vector, transcription of both genes can be driven by a promoter, but translation of mRNA from the first gene can be by a cap-dependent scanning mechanism, and translation of mRNA from the second gene can be by a cap-independent mechanism, e.g., an IRES.

[0253] Once an antibody molecule described herein has been produced by recombinant expression, it can be purified by any method known in the art for the purification of immunoglobulin molecules, such as, for example, chromatography (e.g., ion exchange, affinity (particularly by affinity for a particular antigen after Protein A), and sizing column chromatography), centrifugation, differential solubility, or any other standard technique for the purification of proteins. Furthermore, the antibodies described herein can be fused to heterologous polypeptide sequences described herein or otherwise known in the art to facilitate purification.

[0254] In certain embodiments, the antibodies described herein are isolated or purified. Generally, an isolated antibody is substantially free of other antibodies having antigenic specificities different from the isolated antibody. For example, in certain embodiments, preparations of antibodies described herein are substantially free of cellular material and / or chemical precursors. The phrase "substantially free of cellular material" includes preparations of antibodies in which the antibody is separated from cellular components of the cells from which it is isolated or recombinantly produced. Thus, antibodies that are substantially free of cellular material include preparations of antibodies having less than about 30%, 20%, 10%, 5%, 2%, 1%, 0.5%, or 0.1% (by dry weight) of heterologous proteins (also referred to herein as "contaminating proteins") and / or antibody variants, e.g., different post-translationally modified forms of antibodies or other different forms of antibodies (e.g., antibody fragments). When an antibody is recombinantly produced, it is also generally substantially free of culture medium, i.e., culture medium represents less than about 20%, 10%, 2%, 1%, 0.5%, or 0.1% of the volume of the protein preparation. When an antibody is produced by chemical synthesis, the antibody is generally substantially free of chemical precursors or other chemicals, i.e., it is separated from chemical precursors or other chemicals involved in the synthesis of the protein. Thus, such antibody preparations have less than about 30%, 20%, 10%, or 5% (by dry weight) of chemical precursors or compounds other than the antibody of interest. In certain embodiments, the antibodies described herein are isolated or purified.

[0255] 5.4 Antibody production Antibodies (e.g., human or humanized antibodies) (or antigen-binding fragments thereof) described herein that immunospecifically bind to the KIT antigen can be produced by any method known in the art for synthesizing antibodies, for example, by chemical synthesis or by recombinant expression techniques. In certain aspects, provided herein are methods for making the antibodies described herein, the methods comprising culturing and / or expressing such antibodies using a host cell described herein, and optionally further comprising purifying the antibody obtained from the host cell. The methods described herein employ, unless otherwise indicated, conventional techniques of molecular biology, microbiology, genetic analysis, recombinant DNA, organic chemistry, biochemistry, PCR, oligonucleotide synthesis and modification, nucleic acid hybridization, and related arts within the art. These techniques are described in the references cited herein and are explained more fully therein.For example, see Maniatis et al. (1982) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press; Sambrook et al. (1989), Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press, Sambrook et al. (2001) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons (1987 and annual updates), Current Protocols in Immunology, John Wiley & Sons (1987 and annual updates) Gait (ed.) (1984) Oligonucleotide Synthesis: A Practical Approach, IRL Press, Eckstein (ed.) (1991) Oligonucleotides and Analogues: A Practical Approach, IRL Press, Birren et al. (eds.) (1999) Genome Analysis: A Laboratory Manual, Cold Spring Harbor Laboratory Press.

[0256] For example, humanized antibodies can be produced by techniques such as CDR grafting (EP 239,400, WO 91 / 09967, and U.S. Pat. Nos. 5,225,539, 5,530,101, and 5,585,089), veneering, or resurfacing (EP 592,106 and EP 519,596; Padlan, 1991, Molecular Immunology 28(4 / 5):489-498; Studnicka et al., 1994, Protein Engineering 7(6):805-814; and Roguska et al., 1994, PNAS 91:969-973), chain shuffling (U.S. Pat. No. 5,565,332), as well as methods such as, for example, U.S. Pat. No. 6,407,213, U.S. Pat. No. 5,766,886, WO9317105, Tan et al., J. Immunol 169:1119 25(2002), Caldas et al., Protein Eng. 13(5):353-60(2000), Morea et al., Methods 20(3):267 79(2000), Baca et al., J. Biol. Chem. 272(16):10678-84(1997), Roguska et al., Protein Eng. 9(10):895 904(1996), Couto et al., Cancer Res. 55(23 Supp):5973s-5977s (1995), Couto et al., Cancer Res. 55(8):1717-22 (1995), Sandhu JS, Gene 150(2):409-10 (1994), and Pedersen et al., J. Mol. Biol. 235(3):959-73 (1994). See also U.S. Patent Publication No. US2005 / 0042664A1 (February 24, 2005), which is incorporated herein by reference.

[0257] Monoclonal antibodies can be prepared using a variety of techniques known in the art, including the use of hybridoma, recombinant, and phage display technologies, or a combination thereof. For example, monoclonal antibodies can be produced using hybridoma techniques, including those known in the art, as taught, for example, in Harlow et al., Antibodies: A Laboratory Manual, (Cold Spring Harbor Laboratory Press, 2nd ed. 1988) and Hammerling et al., in: Monoclonal Antibodies and T-Cell Hybridomas 563 681 (Elsevier, NY, 1981). The term "monoclonal antibody" as used herein is not limited to antibodies produced by hybridoma technology. For example, monoclonal antibodies can be produced by recombinant techniques, e.g., recombinant monoclonal antibodies expressed by host cells, such as mammalian host cells.

[0258] Methods for producing and screening for specific antibodies using hybridoma technology are routine and well known in the art. For example, in the hybridoma method, mice or other suitable host animals, such as sheep, goats, rabbits, rats, hamsters, or monkeys, are immunized to induce lymphocytes that produce or can produce antibodies that specifically bind to the protein used for immunization (e.g., the extracellular domain of human KIT). Alternatively, lymphocytes can be immunized in vitro. The lymphocytes are then fused with myeloma cells using a suitable fusing agent, such as polyethylene glycol, to form hybridoma cells (Goding, Monoclonal Antibodies: Principles and Practice, pp. 59-103 (Academic Press, 1986)). In addition, animals can be immunized using the RIMMS (repeated immunization multiple site) technique (Kilptrack et al., 1997 Hybridoma 16:381-9, which is incorporated herein by reference).

[0259] Non-limiting examples of myeloma cell lines include those derived from MOPC-21 and MPC-11 mouse tumors, available from the Salk Institute Cell Distribution Center, San Diego, CA, USA, and murine myeloma cell lines such as SP-2 or X63-Ag8.653 cells, available from the American Type Culture Collection, Rockville, MD, USA. Human myeloma and mouse-human heteromyeloma cell lines have also been described for the production of human monoclonal antibodies (Kozbor, J. Immunol., 133:3001 (1984); Brodeur et al., Monoclonal Antibody Production Techniques and Applications, pp. 51-63 (Marcel Dekker, Inc., New York, 1987)).

[0260] The antibodies described herein include antibody fragments that recognize specific KIT antigens and can be produced by any technique known to those skilled in the art. For example, the Fab and F(ab')2 fragments described herein can be produced by proteolytic cleavage of immunoglobulin molecules using enzymes such as papain (to produce Fab fragments) or pepsin (to produce F(ab')2 fragments). The Fab fragment corresponds to one of the two identical arms of an antibody molecule and contains an intact light chain paired with the VH and CH1 domains of the heavy chain. The F(ab')2 fragment contains the two antigen-binding arms of an antibody molecule linked by disulfide bonds in the hinge region.

[0261] In one embodiment, to generate whole antibodies, PCR primers containing the VH or VL nucleotide sequence, restriction sites, and flanking sequences to protect the restriction sites can be used to amplify the VH or VL sequence from a template, e.g., an scFv clone. Using cloning techniques known to those skilled in the art, the PCR-amplified VH domain can be cloned into a vector expressing a VH constant region, and the PCR-amplified VL domain can be cloned into a vector expressing a VL constant region, e.g., a human kappa or lambda constant region. The VH and VL domains can also be cloned into a vector expressing the necessary constant regions. The heavy chain conversion vector and the light chain conversion vector are then co-transfected into cell lines to generate stable or transient cell lines expressing full-length antibodies, e.g., IgG, using techniques known to those skilled in the art.

[0262] Single domain antibodies, e.g., antibodies lacking light chains, can be produced by methods well known in the art (see Riechmann et al., 1999, J. Immunol. 231:25-38; Nuttall et al., 2000, Curr. Pharm. Biotechnol. 1(3):253-263; Muylderman, 2001, J. Biotechnol. 74(4):277-302; U.S. Patent No. 6,005,079; and International Publication Nos. WO 94 / 04678, WO 94 / 25591, and WO 01 / 44301).

[0263] 5.5 Methods of Treatment and Medical Use Provided herein are methods for interfering with, preventing, protecting against, treating, and / or managing a KIT-associated disorder or disease. Such methods comprise administering to a subject in need thereof a therapeutically effective amount of an anti-KIT antibody (e.g., a humanized antibody), antigen-binding fragment thereof, conjugate thereof, or pharmaceutical composition described herein. In certain aspects, also provided herein are methods for preventing, interfering with, protecting against, treating, or managing one or more symptoms of a KIT-associated disorder or disease.

[0264] In certain embodiments, the methods described herein for treating a KIT-associated disorder or disease provide for a reduction or amelioration of the progression, severity, and / or duration of the KIT-associated disorder or disease resulting from the administration of one or more therapies (including, but not limited to, the administration of one or more prophylactic or therapeutic agents, such as an anti-KIT antibody described herein or a pharmaceutical composition described herein). In further particular embodiments, the methods described herein for treating a KIT-associated disorder or disease relate to reducing one or more symptoms of the KIT-associated disorder or disease. In certain embodiments, the antibodies, or antigen-binding fragments thereof, or conjugates thereof, or pharmaceutical compositions described herein are for use in protecting against, treating, or managing a KIT-associated disorder. In certain embodiments, the KIT-related disease or disorder treated, managed, or protected against by an anti-KIT antibody, or antigen-binding fragment thereof, or conjugate thereof, described herein, or a pharmaceutical composition described herein, is associated with KIT expression and / or activity, e.g., involves cells that express KIT and / or exhibit KIT activity, but is not caused by or is not a result of KIT expression or activity.

[0265] In certain embodiments, the antibody used in the methods described herein is internalized by the cells to which it binds. In certain embodiments, a conjugate is used in the methods described herein, and the conjugate comprises an antibody described herein (e.g., a humanized anti-KIT antibody), or a KIT-binding fragment thereof. In certain embodiments, the conjugate comprises an antibody described herein (e.g., a humanized anti-KIT antibody), or a KIT-binding fragment thereof, covalently or non-covalently bound to a therapeutic agent, such as a toxin. In certain embodiments, the conjugate used in the methods described herein is internalized into the cells to which it binds.

[0266] In certain embodiments, KIT is abnormally (e.g., highly) expressed by the cell, e.g., KIT is overexpressed. In certain embodiments, KIT expression (e.g., on the cell surface) is at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% higher than KIT expression on the surface of a control cell (e.g., a cell expressing normal levels of KIT, e.g., a normal, e.g., human, mast cell, stem cell, brain cell, melanocyte, or ovarian cell). In certain embodiments, KIT expression results in cell surface KIT expression that is at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% higher than the average KIT expression on the surface of a control cell population (e.g., a cell population expressing normal levels of KIT, e.g., a normal, e.g., human, mast cell population, stem cell population, brain cell population, melanoma blast population, or ovarian cell population). In certain embodiments, such control cells can be obtained or derived from a healthy individual (e.g., a healthy human). In some embodiments, KIT can be aberrantly upregulated in a particular cell type regardless of whether KIT is aberrantly expressed on the cell surface. In certain embodiments, KIT signaling or activity can be aberrantly upregulated in a particular cell type regardless of whether KIT is aberrantly expressed on the cell surface. In certain embodiments, KIT signaling is at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% higher than KIT signaling in control cells (e.g., cells comprising normal KIT signaling, e.g., mast cells, stem cells, brain cells, melanocytes, or ovarian cells). In certain embodiments, KIT signaling is at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% higher than the average KIT signaling in a control cell population (e.g., a cell population exhibiting normal KIT signaling, e.g., a normal, e.g., human, mast cell population, stem cell population, brain cell population, melanocytes, or ovarian cell population). In certain embodiments, the normal, abnormal, or excessive cell signaling is caused by binding of KIT to a KIT ligand.In other embodiments, the aberrant or excessive cell signaling occurs independent of binding of KIT to a KIT ligand.

[0267] In certain aspects, KIT-related disorders or diseases can be characterized by gain-of-function KIT activity, increased KIT activity, or overexpression of KIT. In one embodiment, KIT-related disorders or diseases are caused completely or partially by or result from gain-of-function KIT activity or expression, e.g., overexpression of KIT. In certain embodiments, gain-of-function KIT activity can occur independently of KIT ligand (e.g., SCF)-binding KIT receptor. In certain aspects, high or overexpression of KIT in cells refers to an expression level that is at least about 35%, 45%, 55%, or 65% higher than the expression level of a reference cell known to have normal KIT expression or KIT activity, or the average expression level of KIT in a population of cells or samples known to have normal KIT expression or KIT activity. The expression level of KIT can be assessed by methods described herein or known to those skilled in the art (e.g., Western blotting or immunohistochemistry). In certain embodiments, KIT-associated disorders or diseases are characterized by higher than normal KIT activity, which is involved in cell transformation, neoplasia, and tumorigenesis. In certain aspects, high KIT activity or increased KIT activity in a cell refers to a KIT activity level that is at least about 35%, 45%, 55%, or 65% higher than the expression level of a reference cell known to have normal KIT activity, or the average expression level of KIT activity in a population of cells or samples known to have normal KIT activity. Non-limiting examples of KIT activity include tyrosine phosphorylation of the cytoplasmic domain of KIT and downstream signaling of KIT, such as Stat or Akt signaling.

[0268] In certain embodiments, the KIT-related disorder is a mast cell-related disorder, an eosinophil-related disorder, cancer, asthma, an inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, a gastrointestinal disorder, or fibrosis. In certain embodiments, the KIT-related disorder is a fibrosis or inflammatory disorder, for example, an inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). In other embodiments, the KIT-related disorder is a cancer such as lung cancer (e.g., small cell lung cancer), leukemia, neuroblastoma, melanoma, sarcoma (e.g., Ewing's sarcoma), or gastrointestinal stromal tumor (GIST). In other embodiments, the KIT-related disorder is a systemic mast cell disorder (e.g., mastocytosis), a blood disorder, fibrosis (e.g., idiopathic pulmonary fibrosis (TPF), scleroderma, or myelofibrosis), or an inflammatory condition such as asthma, rheumatoid arthritis, inflammatory bowel disease, or allergic inflammation.

[0269] In certain embodiments, the KIT-associated disorder is a mast cell-associated disorder. In certain embodiments, the KIT-associated disorder is an eosinophil-associated disorder, such as eosinophilic esophagitis (EoE).

[0270] Mast cells, derived from bone marrow precursor cells, are large cells found in connective tissues throughout the body, most commonly in the submucosa and dermis. They contain large granules that store various mediator molecules, including the vasoactive amine histamine, and possess high-affinity Fes receptors (FcsRI), which enable them to bind IgE monomers. Antigen binding to mast cell-bound IgE induces mast cell degranulation and activation, resulting in immediate local or systemic hypersensitivity reactions. Thus, mast cells play an important role in inflammatory and allergic responses. However, without proper balance and regulation, mast cells can also contribute to the harmful, exacerbated responses to antigens observed in disorders such as anaphylaxis, atopy, and rhinitis.

[0271] KIT signaling is important for mast cell development and homeostasis, such as the proliferation of mast cells from their precursor cells and their subsequent maturation and survival in their resident tissues, the homing of mast cells to their resident sites in vivo, and promoting the adhesion of mast cells to extracellular matrix proteins. Activating mutations in KIT, such as those at amino acid residues 816 or 560, are associated with mastocytosis, which is characterized by mast cell overproduction and gastrointestinal stromal cell tumors (GISTs).

[0272] In certain embodiments, the methods described herein for protecting against, treating, or managing a KIT-mediated disorder, e.g., a fibrotic or inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation), in a subject in need thereof, involve administering a therapeutically effective amount of an anti-KIT antibody described herein or a pharmaceutical composition described herein, to the subject, which results in one of the following effects: (i) a reduction in the fibrotic or inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation) and / or (ii) a reduction in the fibrotic or inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation). or one or more symptoms associated therewith; (ii) a reduction in the duration of one or more symptoms associated with fibrosis or an inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation); (iii) prevention of recurrence of fibrosis or an inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation); (iv) a reduction in hospitalization of a subject; (v) a reduction in the length of hospitalization; (vi) a reduction in the severity of a fibrosis or inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation); (vii) inhibiting (e.g., partially inhibiting) the progression of a fibrotic or inflammatory condition (e.g., inflammatory bowel disease, allergic inflammation, and / or one or more symptoms associated therewith); (vii) enhancing or improving the therapeutic efficacy of another therapy (e.g., anti-inflammatory therapy, such as a steroid); (viii) increasing the number of patients in remission (i.e., a period characterized by the absence or minimal symptoms associated with the inflammatory condition); (ix) increasing the duration of remission in patients; (x) reducing hospitalization rates; (xi) reducing the progression of a fibrotic or inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation); (xii) a reduction in the concentration of one or more inflammatory mediators (e.g., cytokines or interleukins) in a biological specimen (e.g., plasma, serum, cerebrospinal fluid, urine, or any other biological fluid) of a subject with a fibrotic or inflammatory condition (e.g., asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation); and (xiii) an improvement in quality of life as assessed by methods well known in the art, e.g., questionnaires.

[0273] Other non-limiting examples of KIT-associated disorders or diseases include systemic mast cell disorders (e.g., mastocytosis), hematological disorders, fibrosis (e.g., idiopathic pulmonary fibrosis (TPF), scleroderma, or myelofibrosis), and inflammatory conditions such as asthma, rheumatoid arthritis, inflammatory bowel disease, and allergic inflammation.

[0274] As used herein, the term "mast cell-associated disorder" or "mast cell-associated disorders" refers to disorders in which mast cell activity is involved in the pathology and / or in which mast cells are found in abnormal, such as above-normal or below-normal, amounts in various parts of the body. For example, a mast cell-associated disorder can potentially manifest as a pathological accumulation of mast cells in any or all organs and tissues and / or an abnormal release of one or more mast cell mediators, such as inflammatory mediators. Non-limiting examples of inflammatory mediators released by mast cells include any of: (i) granule-associated mediators, including histamine, serotonin (5-hydroxytryptamine), and various proteases and peptidases; (ii) eicosanoids, such as prostaglandin D2 (PGD2) and leukotriene C4 (LTC4); and (iii) cytokines, including interleukin-2 (IL-2), IL-3, IL-4, IL-5, IL-6, IL-10, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor α (TNFα), and chemokines, including CCL-2, CCL-3, CCL-5, and CXCL8.

[0275] In certain embodiments, the mast cell-associated disorder is a mast cell-associated disorder of the central nervous system, such as nervous system, e.g., NMO, NMOSD, MS, or NF (e.g., NF type 1 (NF1), NF type 2 (NF2), or schwannomatosis).

[0276] MS is a chronic inflammatory demyelinating disorder of the central nervous system (brain and spinal cord) involving episodes of inflammation of the white matter within the brain or spinal cord, which is then damaged by the individual's own immune system. These inflamed areas result in scarring within the brain and spinal cord. The damage disrupts the ability of parts of the nervous system to communicate, resulting in a variety of symptoms, including physical, mental, and / or psychiatric problems. Forms of MS include, but are not limited to, relapsing forms, in which symptoms occur in a single attack, and progressive forms, in which symptoms accumulate over time. Guidelines for diagnosing MS have been described; see, for example, National Collaborating Centre for Chronic Conditions (UK), "Multiple Sclerosis: National Clinical Guideline for Diagnosis and Management in Primary and Secondary Care," London: Royal College of Physicians (UK), 2004, (NICE Clinical Guidelines, No. 8), available at http: / / www.ncbi.nlm.nih.gov / books / NBK48919 / . Symptoms of MS can manifest as any neurological symptom or sign, such as autonomic, visual, motor, and sensory problems. Non-limiting examples of symptoms of MS include changes in sensation, such as loss of sensitivity or tingling, pins and needles, or numbness, muscle weakness, very pronounced reflexes, muscle spasms, or difficulty moving, difficulty with coordination and balance (ataxia), problems speaking or swallowing, vision problems (nystagmus, optic neuritis, or double vision), fatigue, acute or chronic pain, bladder and bowel difficulties, emotional problems, such as depression or mood instability, Uthoff's phenomenon (worsening symptoms with exposure to higher than normal temperatures), and Lhermitte's sign (a sensation of electricity running down the back when bending the neck).In certain aspects, provided herein are methods of protecting against, treating, alleviating, or managing one or more of these symptoms of MS by administering to a subject in need thereof a therapeutically effective amount of an antibody that specifically binds to KIT (e.g., human KIT) or an antigen-binding fragment thereof.

[0277] Neuromyelitis optica (NMO), or Devic's disease, is an autoimmune inflammatory disorder of the central nervous system that primarily affects the optic nerve and spinal cord, and occasionally the brain. NMO can lead to paralysis and blindness. The majority of patients with NMO are seropositive for immunoglobulin autoantibodies against aquaporin-4 (AQP4), a water channel widely expressed in the optic nerve, spinal cord, and periventricular region (AQP4-IgG or NMO-IgG). A small percentage of NMO patients are NMO-IgG negative.

[0278] NMOSD refers to various disorders related to NMO, but may not fully meet the clinical diagnostic criteria for definite NMO. Non-limiting examples of disorders typically included in this NMOSD classification include NMO-IgG seropositive limited NMO (e.g., transverse myelitis (LETM) with single or recurrent long spinal cord lesions [e.g., 3 or more intervertebral disc segment spinal cord lesions seen on MRI], recurrent or simultaneous bilateral optic neuritis (ON)), Asian optic nerve MS (OSMS), optic neuritis or LETM associated with systemic autoimmune disease, and optic neuritis or osteomyelitis associated with brain lesions typical of NMO (e.g., hypothalamic or brainstem lesions) (see, e.g., Oh et al., Neurology Research International, vol. 2012, Article ID 460825, 13 pages, 2012).

[0279] In certain aspects, diagnostic criteria for NMO include, but are not limited to, the presence of osteomyelitis and optic neuritis, and any two of the following: (i) extensive myelitis on spinal cord MRI, (ii) normal brain MRI at presentation, and (iii) positive anti-AQP4 antibodies (see, e.g., Collongues et al., Ther. Adv. Neurol. Disord., 2011, 4:111-121).

[0280] Non-limiting examples of symptoms of NMO or NMOSD include acute optic neuritis (e.g., bilateral), transverse osteomyelitis (e.g., with long lesions), unilateral or bilateral vision loss, ocular pain, severe paraplegia, asymmetric sensory level, bladder dysfunction, paroxysmal tonic convulsions of the trunk and limbs, and Lhermitte's phenomenon. In certain embodiments, cephalad extension of cervical spinal cord lesions to the cervicomedullary junction can cause symptoms such as acute respiratory decompensation, nausea, intractable vomiting, and hiccups. In some embodiments, hypothalamic-pituitary axis dysfunction associated with NMO can manifest as hypersomnia, hyponatremia, hypothermia, hypothyroidism, and hyperprolactinemia. In addition, confusion, abrupt changes in level of consciousness, cortical blindness, and imaging findings suggestive of reversible leukoencephalopathy syndrome (PRES) may also be associated with NMO.

[0281] NF is a genetic disorder of the nervous system that primarily affects the development and growth of nervous (nerve) tissue, causing tumors called neurofibromas to grow along nerves throughout the body. NF is generally an inherited disease, but new cases can arise spontaneously due to genetic mutations. NF is commonly diagnosed in childhood, approximately 3 to 16 years of age, and sometimes in infancy (in children with severe cases).

[0282] Non-limiting types of NF include NF1 type (NF1), NF2 type (NF2), and schwannomatosis. NF1 is also known as Recklinghausen's disease. Phenotypic signs of NF1 include the presence of light-brown skin patches at birth or in childhood, neurofibromas (tumors that grow along nerves under the skin, also referred to as cutaneous neurofibromas), plexiform neurofibromas (tumors involving multiple nerves), spinal and optic nerve tumors, and learning disabilities. In certain aspects, individuals with NF1 may have a higher probability of developing gastrointestinal stromal tumors (GISTs) than the general population. Neurofibromas can be considered external neurofibromas, e.g., cutaneous or dermal neurofibromas, or internal neurofibromas, e.g., plexiform neurofibromas.

[0283] NF2 is an autosomal dominant genetic disorder associated with neurological, ophthalmological, and skin abnormalities. Non-limiting examples of NF2 symptoms include hearing loss, tinnitus, visual disturbances, imbalance, and painful skin lesions. In certain embodiments, skull base tumors (including vestibular schwannomas (VS) and meningiomas) in NF2 patients can lead to lower cranial nerve dysfunction and death.

[0284] A diagnosis of NF2 can be established by the presence of bilateral vestibular schwannomas (VS) or unilateral VS, in conjunction with the presence of NF2-associated tumors (e.g., meningiomas, schwannomas, ependymomas, gliomas, or neurofibromas), secondary cataracts, or a family history of other NF2-associated tumors. In addition to the morbidity associated with hearing loss and vestibular deficits, patients may experience other neurological dysfunctions associated with VS growth (e.g., due to compression of other cranial nerves).

[0285] Schwannomatosis shares many characteristics with the more familiar forms of NF. Multiple schwannomas, or tumors of the nerve sheath, are seen in schwannomatosis but not in the characteristic vestibular (oto-nerve) tumors seen in NF2. In certain embodiments, patients with schwannomatosis develop tumors in the sheaths or coverings of their nerves (see, e.g., MacCollin et al., Neurology, 2005, 64:1838-1845).

[0286] Other non-limiting examples of mast cell-related disorders include, for example, anaphylaxis, atopic disease, mast cell activation syndrome, allergic rhinitis, food- and venom-related allergies (e.g., nut, shellfish, fish, hymenopteran venom, or bee sting allergies), psoriasis, atopic dermatitis, rosacea, eczema, tubulointerstitial nephritis, glomerulonephritis, diabetic nephropathy, allograft rejection, amyloidosis, renovascular ischemia, reflux nephropathy, polycystic kidney disease, drug-induced nephropathy, post-transplant fibrosis, and liver fibrosis (e.g., due to alcohol consumption, viral hepatitis B and C, and non-alcoholic steatohepatitis (NASH)), parasitic infections (e.g., schistosomiasis, amebiasis, echinococcosis), and non-IgE mast cell-mediated activation such as angioedema and anaphylaxis.

[0287] Alternatively, the mast cell-related disorder can be urticaria, particularly chronic urticaria, including chronic spontaneous urticaria (CSU), chronic idiopathic urticaria, and chronic inducible urticaria (i.e., chronic inducible urticaria (CIndU). In certain embodiments, the mast cell-related disorder is chronic spontaneous urticaria. In certain embodiments, the mast cell-related disorder is moderate to severe chronic spontaneous urticaria. Chronic spontaneous urticaria is characterized by the occurrence of hives or wheals for six weeks or more without an identifiable specific trigger or cause. In certain embodiments, obesity The cell-related disorder is chronically triggered urticaria. Chronic triggered urticaria is a form of urticaria that has a trigger that can cause it, and typically results in wheals (hives) or angioedema. In a specific embodiment, the chronically triggered urticaria is cold urticaria (ColdU). People suffering from cold urticaria experience symptoms such as itching, severe wheals, and angioedema when their skin is exposed to temperatures lower than their skin temperature. In another specific embodiment, the chronically triggered urticaria is symptomatic dermatographism (SD). Symptomatic dermatographia is characterized by the development of a wheal and flare response in response to stroking, scratching, or rubbing of the skin, usually occurring within minutes of the triggering stimulus. In another specific embodiment, the chronically triggered urticaria is cholinergic urticaria. Cholinergic urticaria is caused by the body's sweating response to active or passive increases in body temperature and is characterized by small (1-4 mm) wheals surrounded by bright red redness. Common triggers include exercise, hot baths / showers, fever, occlusive dressings, ingestion of spicy foods, and emotional stress. In another specific embodiment, the chronically induced urticaria is heat urticaria. In another specific embodiment, the chronically induced urticaria is delayed pressure urticaria. In another specific embodiment, the chronically induced urticaria is solar urticaria. In another specific embodiment, the chronically induced urticaria is vibratory urticaria. In another specific embodiment, the chronically induced urticaria is contact urticaria. In another specific embodiment, the chronically induced urticaria is water urticaria. Antihistamines are an approved treatment for chronically induced urticaria.

[0288] The mast cell-related disorder may also be chronic prurigo. In certain embodiments, the chronic prurigo is prurigo nodularis. In certain embodiments, the chronic prurigo is common prurigo. In certain embodiments, the chronic prurigo is nodular prurigo. In certain embodiments, the chronic prurigo is plaque prurigo. In certain embodiments, the chronic prurigo is pitted prurigo. In certain embodiments, the chronic prurigo is linear prurigo. In some embodiments, the patient exhibits a monomorphic phenotype of lesions. In other embodiments, the patient exhibits a polymorphic phenotype of lesions.

[0289] In various embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed one or more previous treatments for the disorder. In certain embodiments, the one or more previous treatments include at least one standard of care therapy for the disorder. In certain embodiments, the one or more previous treatments are all standard of care therapies for the disorder. In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed one or more antihistamine treatments for the disorder. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed one or more H1-antihistamine treatments for the disorder. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed one or more H2-antihistamine treatments for the disorder. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed both H1- and H2-antihistamine treatments for the disorder. In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed treatment(s) for the disorder with one or more leukotriene receptor antagonists. In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed treatment(s) for the disorder with one or more immunomodulatory or anti-inflammatory agents.In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with an anti-IgE antibody, e.g., an IgE inhibitor such as omalizumab (Xolair®) or ligelizumab. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®). In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®). In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with an anti-IL-5 antibody, e.g., an IL-5 inhibitor such as mepolizumab. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with a Siglec 8 inhibitor such as an anti-Siglec 8 antibody, e.g., lirentelimab. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with a TSLP or TSLPR inhibitor such as an anti-TSLP or anti-TSLPR antibody, e.g., tezepelumab (Tezspire™).In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with an anti-C5aR antibody, e.g., a C5aR inhibitor such as avdoralimab. In certain embodiments, a patient with a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis has failed treatment for their disorder with an anti-CD200R antibody, e.g., a CD200R inhibitor such as LY3454738. In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed treatment(s) for the disorder with one or more Bruton's tyrosine kinase (BTK) inhibitors, e.g., remibrutinib and / or rilzabrutinib.In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, may be treated with one or more of the following: (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment); (2) treatment(s) with one or more leukotriene receptor antagonists; (3) one or more immunomodulatory or anti-inflammatory agents (e.g., an anti-IgE antibody, e.g., an IgE inhibitor such as omalizumab (Xolair®) or ligelizumab; an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®); an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®); an anti-IL-5 antibody, e.g., an IL-5 inhibitor such as mepolizumab; an anti-Siglec and / or (3) have failed treatment(s) with one or more BTK inhibitors, e.g., a Siglec 8 antibody, e.g., a Siglec 8 inhibitor such as lirentelimab, an anti-TSLP or anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor such as tezepelumab (Tezspire™), an anti-C5aR antibody, e.g., a C5aR inhibitor such as abdularimab, and / or an anti-CD200R antibody, e.g., a CD200R inhibitor such as LY3454738, and / or (4) have failed treatment(s) with one or more BTK inhibitors, e.g., remibrutinib and / or rilzabrutinib.In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, may be treated with (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), and (2) one or more immunomodulatory or anti-inflammatory agents (e.g., an anti-IgE antibody, e.g., an IgE inhibitor such as omalizumab (Xolair®) or ligelizumab, an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®), an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®), an anti-IL-5 antibody, e.g., an IL-5 inhibitor such as mepolizumab, or an anti-Siglec 8 antibody, e.g., lilentelimab) for the disorder. have failed treatment(s) with an anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor such as tezepelumab (Tezspire™), an anti-C5aR antibody, e.g., a C5aR inhibitor such as abdularimab, and / or an anti-CD200R antibody, e.g., a CD200R inhibitor such as LY3454738. In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed treatment for their disorder with: (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment); (2) an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab; and (3) an IL-4R inhibitor, such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed treatment for their disorder with (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), and (2) an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab.In certain embodiments, a patient with a mast cell-related disorder, such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, has failed treatment for the disorder with (1) an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab, and (2) an IL-4R inhibitor, such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed treatment with an IL-4R inhibitor, such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed treatment with an IL-31 receptor alpha inhibitor, such as an anti-IL-31 receptor alpha antibody, e.g., nemolizumab. In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed treatment with a Janus kinase 1 inhibitor, e.g., INCB054707 or abrocitinib. In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed treatment with a neurokinin-1 (NK1) receptor antagonist, e.g., serlopitant. In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed treatment with a PDE4 and / or TNF-α inhibitor, e.g., apremilast. In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed treatment with an OSMRβ inhibitor, such as an anti-OSMRβ antibody, e.g., vixarelimab. In certain embodiments, the mast cell-related disorder is chronic prurigo, and the patient has failed one, two, three, or more of the treatments described above for chronic prurigo.

[0290] A patient is considered to have failed treatment for a disorder if the disorder is refractory to treatment, is resistant to treatment, recurs after treatment, and / or the patient discontinues treatment due to intolerance to the treatment.

[0291] In various embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to one or more previous treatments for the disorder. In certain embodiments, the one or more previous treatments include at least one standard of care therapy for the disorder. In certain embodiments, the one or more previous treatments are all standard of care therapies for the disorder. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to H1-antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to H2-antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to both H1- and H2-antihistamine treatment. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment(s) with one or more leukotriene receptor antagonists. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment(s) with one or more immunomodulatory or anti-inflammatory agents. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment with an IgE inhibitor such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab.In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment with an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment with an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®). In certain embodiments, mast cell-related disorders such as urticaria (e.g., chronically induced urticaria or chronic spontaneous urticaria) or eosinophil-related disorders such as eosinophilic esophagitis are refractory to treatment with an IL-5 inhibitor such as an anti-IL-5 antibody, e.g., mepolizumab. In certain embodiments, mast cell-related disorders such as urticaria (e.g., chronically induced urticaria or chronic spontaneous urticaria) or eosinophil-related disorders such as eosinophilic esophagitis are refractory to treatment with a Siglec 8 inhibitor such as an anti-Siglec 8 antibody, e.g., lirentelimab. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronically provoked urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment with an anti-TSLP or anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor, such as tezepelumab (Tezspire™). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronically provoked urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to treatment with an anti-C5aR antibody, e.g., a C5aR inhibitor, such as abdolalimab. In certain embodiments, the mast cell-associated disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or the eosinophil-associated disorder, such as eosinophilic esophagitis, is refractory to treatment with a CD200R inhibitor, such as an anti-CD200R antibody, e.g., LY3454738.In certain embodiments, a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, is refractory to treatment(s) with one or more BTK inhibitors, e.g., remibrutinib and / or rilzabrutinib. In certain embodiments, mast cell-related disorders, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria) or eosinophil-related disorders, such as eosinophilic esophagitis, are treated with (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), (2) treatment(s) with one or more leukotriene receptor antagonists, (3) one or more immunomodulatory or anti-inflammatory agents (e.g., anti-IgE antibodies, e.g., IgE inhibitors such as omalizumab (Xolair®) or ligelizumab, anti-IL-4R antibodies, e.g., IL-4R inhibitors such as dupilumab (Dupixent®), anti-IL-5R antibodies, e.g., IL-5R inhibitors such as benralizumab (Fasenra®), anti-IL-5 antibodies, e.g., IL-5 inhibitors such as mepolizumab, anti-Siglec and / or (3) the patient is refractory to treatment(s) with one or more BTK inhibitors, e.g., a Siglec 8 antibody, e.g., a Siglec 8 inhibitor such as lilenterimab, an anti-TSLP or anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor such as tezepelumab (Tezspire™), an anti-C5aR antibody, e.g., a C5aR inhibitor such as abdularimab, and / or an anti-CD200R antibody, e.g., a CD200R inhibitor such as LY3454738, and / or (4) one or more BTK inhibitors, e.g., remibrutinib and / or rilzabrutinib.In certain embodiments, mast cell-related disorders such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria) or eosinophil-related disorders such as eosinophilic esophagitis are treated with (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), and (2) one or more immunomodulatory or anti-inflammatory agents (e.g., an anti-IgE antibody, e.g., an IgE inhibitor such as omalizumab (Xolair®) or ligelizumab, an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®), an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®), an anti-IL-5 antibody, e.g., an IL-5 inhibitor such as mepolizumab, an anti-Siglec 8 antibody, e.g., lilentelimab, or an anti-Siglec 8 antibody). the patient is refractory to treatment(s) with an anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor such as tezepelumab (Tezspire™), an anti-C5aR antibody, e.g., a C5aR inhibitor such as abduralimab, and / or an anti-CD200R antibody, e.g., a CD200R inhibitor such as LY3454738. In certain embodiments, a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, is refractory to (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), (2) treatment with an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab, and (3) treatment with an IL-4R inhibitor, such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, is refractory to (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), and (2) treatment with an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab.In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is refractory to (1) treatment with an IgE inhibitor such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab, and (2) treatment with an IL-4R inhibitor such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, the mast cell-related disorder is chronic prurigo and is refractory to treatment with an IL-4R inhibitor such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, the mast cell-related disorder is chronic prurigo and is refractory to treatment with an IL-31 receptor alpha inhibitor such as an anti-IL-31 receptor alpha antibody, e.g., nemolizumab. In certain embodiments, the mast cell-related disorder is chronic prurigo and is refractory to treatment with a Janus kinase 1 inhibitor, e.g., INCB054707 or abrocitinib. In certain embodiments, the mast cell-related disorder is chronic prurigo and is refractory to treatment with a neurokinin-1 (NK1) receptor antagonist, e.g., serlopitant. In certain embodiments, the chronic prurigo is refractory to treatment with a PDE4 and / or TNF-α inhibitor, e.g., apremilast. In certain embodiments, the mast cell-related disorder is chronic prurigo and is refractory to treatment with an OSMRβ inhibitor, such as an anti-OSMRβ antibody, e.g., bixarelimab. In certain embodiments, the mast cell-related disorder is chronic prurigo and is refractory to one, two, three, or more of the treatments described above for chronic prurigo.

[0292] In various embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to one or more previous treatments for the disorder. In certain embodiments, the one or more previous treatments include at least one standard of care therapy for the disorder. In certain embodiments, the one or more previous treatments are all standard of care therapies for the disorder. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to H1-antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to H2-antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to both H1- and H2-antihistamine treatment. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment(s) with one or more leukotriene receptor antagonists. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment(s) with one or more immunomodulatory or anti-inflammatory agents. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment with an IgE inhibitor such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab.In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment with an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment with an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®). In certain embodiments, mast cell-related disorders such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or eosinophil-related disorders such as eosinophilic esophagitis are resistant to treatment with an anti-IL-5 antibody, e.g., an IL-5 inhibitor such as mepolizumab. In certain embodiments, mast cell-related disorders such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or eosinophil-related disorders such as eosinophilic esophagitis are resistant to treatment with an anti-Siglec 8 antibody, e.g., a Siglec 8 inhibitor such as lirentelimab. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronically provoked urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment with an anti-TSLP or anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor such as tezepelumab (Tezspire™). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronically provoked urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to treatment with an anti-C5aR antibody, e.g., a C5aR inhibitor such as abdolalimab. In certain embodiments, the mast cell-associated disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or the eosinophil-associated disorder, such as eosinophilic esophagitis, is resistant to treatment with a CD200R inhibitor, such as an anti-CD200R antibody, e.g., LY3454738.In certain embodiments, a mast cell-associated disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-associated disorder, such as eosinophilic esophagitis, is resistant to treatment(s) with one or more BTK inhibitors, e.g., remibrutinib and / or rilzabrutinib. In certain embodiments, mast cell-related disorders, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria) or eosinophil-related disorders, such as eosinophilic esophagitis, are treated with (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), (2) treatment(s) with one or more leukotriene receptor antagonists, (3) one or more immunomodulatory or anti-inflammatory agents (e.g., anti-IgE antibodies, e.g., IgE inhibitors such as omalizumab (Xolair®) or ligelizumab, anti-IL-4R antibodies, e.g., IL-4R inhibitors such as dupilumab (Dupixent®), anti-IL-5R antibodies, e.g., IL-5R inhibitors such as benralizumab (Fasenra®), anti-IL-5 antibodies, e.g., IL-5 inhibitors such as mepolizumab, anti-Siglec and / or (3) the patient is resistant to treatment(s) with one or more BTK inhibitors, e.g., a Siglec 8 antibody, e.g., a Siglec 8 inhibitor such as lirentelimab, an anti-TSLP or anti-TSLPR antibody, e.g., a TSLP or TSLPR inhibitor such as tezepelumab (Tezspire™), an anti-C5aR antibody, e.g., a C5aR inhibitor such as abdularimab, and / or an anti-CD200R antibody, e.g., a CD200R inhibitor such as LY3454738, and / or (4) the patient is resistant to treatment(s) with one or more BTK inhibitors, e.g., remibrutinib and / or rilzabrutinib.In certain embodiments, mast cell-related disorders such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria) or eosinophil-related disorders such as eosinophilic esophagitis are treated with (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), and (2) one or more immunomodulatory or anti-inflammatory agents (e.g., an anti-IgE antibody, e.g., an IgE inhibitor such as omalizumab (Xolair®) or ligelizumab, an anti-IL-4R antibody, e.g., an IL-4R inhibitor such as dupilumab (Dupixent®), an anti-IL-5R antibody, e.g., an IL-5R inhibitor such as benralizumab (Fasenra®), an anti-IL-5 antibody, e.g., an IL-5 inhibitor such as mepolizumab, an anti-Siglec 8 antibody, e.g., lilentelimab, or an anti-Siglec 8 antibody). or a CD200R inhibitor such as LY3454738). In certain embodiments, a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, is resistant to (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), (2) treatment with an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab, and (3) treatment with an IL-4R inhibitor, such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, a mast cell-related disorder, such as urticaria (e.g., chronic provoked urticaria or chronic spontaneous urticaria), or an eosinophil-related disorder, such as eosinophilic esophagitis, is resistant to (1) antihistamine treatment(s) (e.g., H1- and / or H2-antihistamine treatment), and (2) treatment with an IgE inhibitor, such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab.In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is resistant to (1) treatment with an IgE inhibitor such as an anti-IgE antibody, e.g., omalizumab (Xolair®) or ligelizumab, and (2) treatment with an IL-4R inhibitor such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to treatment with an IL-4R inhibitor such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to treatment with an IL-31 receptor alpha inhibitor such as an anti-IL-31 receptor alpha antibody, e.g., nemolizumab. In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to treatment with a Janus kinase 1 inhibitor, e.g., INCB054707 or abrocitinib. In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to treatment with a neurokinin-1 (NK1) receptor antagonist, e.g., serlopitant. In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to treatment with a PDE4 and / or TNF-α inhibitor, e.g., apremilast. In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to treatment with an OSMRβ inhibitor, such as an anti-OSMRβ antibody, e.g., bixarelimab. In certain embodiments, the mast cell-related disorder is chronic prurigo and is resistant to one, two, three, or more of the treatments described above for chronic prurigo.

[0293] In various embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to one or more previous treatments for the disorder. In certain embodiments, the one or more previous treatments include at least one standard of care therapy for the disorder. In certain embodiments, the one or more previous treatments are all standard of care therapies for the disorder. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to H1-antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to H2-antihistamine treatment(s). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to both H1- and H2-antihistamine treatment. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to treatment(s) with one or more leukotriene receptor antagonists. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to treatment(s) with one or more immunomodulatory or anti-inflammatory agents.In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to treatment with an anti-IgE antibody, e.g., an IgE inhibitor such as omalizumab (Xolair®) or ligelizumab. In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to treatment with an IL-4R inhibitor such as an anti-IL-4R antibody, e.g., dupilumab (Dupixent®). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to treatment with an IL-5R inhibitor such as an anti-IL-5R antibody, e.g., benralizumab (Fasenra®). In certain embodiments, a mast cell-related disorder such as urticaria (e.g., chronic inducible urticaria or chronic spontaneous urticaria) or an eosinophil-related disorder such as eosinophilic esophagitis is both refractory and resistant to ...

Claims

1. A pharmaceutical composition comprising: (i) an antibody or antigen-binding fragment thereof that immunospecifically binds to human KIT; (ii) a buffering agent; (iii) a salt; and (iv) an excipient.

2. 10. The pharmaceutical composition of claim 1, having a pH of about 4 to about 7.

3. 3. The pharmaceutical composition of claim 2, having a pH of about 5 to about 6.

4. 4. The pharmaceutical composition of claim 3, having a pH of about 5.

5.

5. 10. The pharmaceutical composition of any one of the preceding claims, wherein the salt is an alkali metal salt.

6. 6. The pharmaceutical composition of claim 5, wherein the alkali metal salt is sodium chloride.

7. 7. The pharmaceutical composition of claim 6, wherein the sodium chloride is at a concentration of about 25 mM to about 100 mM.

8. 8. The pharmaceutical composition of claim 7, wherein the sodium chloride is at a concentration of about 50 mM.

9. 10. The pharmaceutical composition of any one of the preceding claims, wherein the buffering agent is an alkali metal acetate.

10. 10. The pharmaceutical composition of claim 9, wherein the alkali metal acetate is sodium acetate.

11. 11. The pharmaceutical composition of claim 10, wherein the sodium acetate is at a concentration of about 1 mM to about 50 mM.

12. 12. The pharmaceutical composition of claim 11, wherein the sodium acetate is at a concentration of about 25 mM.

13. 10. The pharmaceutical composition of any one of the preceding claims, wherein the excipient is a sugar, a sugar alcohol, an amino acid, or any combination thereof.

14. 14. The pharmaceutical composition of claim 13, wherein the excipient is mannitol, sorbitol, sucrose, trehalose, glycine, arginine, alanine, histidine, or any combination thereof.

15. 14. The pharmaceutical composition of claim 13, wherein the excipient is mannitol, sorbitol, sucrose, trehalose, glycine, arginine, histidine, or any combination thereof.

16. 16. The pharmaceutical composition of claim 14 or 15, wherein the excipient is mannitol, sucrose, arginine, histidine, or any combination thereof.

17. The pharmaceutical composition according to any one of claims 13 to 16, wherein the excipient is mannitol.

18. 18. The pharmaceutical composition of claim 17, wherein the mannitol is at a concentration of about 1% to about 10%.

19. 19. The pharmaceutical composition of claim 18, wherein the mannitol is at a concentration of about 3%.

20. 10. The pharmaceutical composition of any one of the preceding claims, wherein the antibody or antigen-binding fragment thereof is at a concentration of about 50 mg / ml to about 500 mg / ml.

21. 21. The pharmaceutical composition of claim 20, wherein the antibody or antigen-binding fragment thereof is at a concentration of about 100 mg / ml to about 400 mg / ml.

22. 22. The pharmaceutical composition of claim 21, wherein the antibody or antigen-binding fragment thereof is at a concentration of about 150 mg / ml.

23. 1. A pharmaceutical composition comprising: (i) an antibody, or antigen-binding fragment thereof, that immunospecifically binds to human KIT at a concentration of about 50 mg / ml to about 500 mg / ml; (ii) an alkali metal acetate at a concentration of about 1 mM to about 50 mM; (iii) an alkali metal chloride at a concentration of about 25 mM to about 100 mM; and (iv) mannitol at a concentration of about 1% to about 10%, wherein the pharmaceutical composition has a pH of about 5 to about 6.

24. 1. A pharmaceutical composition comprising: (i) an antibody, or antigen-binding fragment thereof, that immunospecifically binds to human KIT at a concentration of about 50 mg / ml to 500 mg / ml; (ii) sodium acetate at a concentration of about 1 mM to about 50 mM; (iii) sodium chloride at a concentration of about 25 mM to about 100 mM; and (iv) mannitol at a concentration of about 1% to about 10%, wherein the pharmaceutical composition has a pH of about 5 to about 6.

25. A pharmaceutical composition comprising: (i) an antibody, or antigen-binding fragment thereof, that immunospecifically binds to human KIT at a concentration of about 150 mg / ml; (ii) sodium acetate at a concentration of about 25 mM; (iii) sodium chloride at a concentration of about 50 mM; and (iv) mannitol at a concentration of about 3%, wherein the pharmaceutical composition has a pH of about 5.

5.

26. the antibody or antigen-binding fragment thereof (A)(i) a light chain variable region (“VL”) comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; and (ii) a heavy chain variable region (“VH”) comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO:5, SEQ ID NO:6, and SEQ ID NO:7, respectively; (B) (i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO:25, SEQ ID NO:26, and SEQ ID NO:27, respectively; (C) (i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 28, SEQ ID NO: 29, and SEQ ID NO: 30, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO:25, SEQ ID NO:31, and SEQ ID NO:32, respectively; (D)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively; and (ii) a VH comprising a VH CDR1, a VH CDR2, and a VH CDR3 comprising the amino acid sequences of SEQ ID NO: 33, SEQ ID NO: 34, and SEQ ID NO: 27, respectively; or (E)(i) a VL comprising a VL CDR1, a VL CDR2, and a VL CDR3 comprising the amino acid sequences of SEQ ID NO: 35, SEQ ID NO: 36, and SEQ ID NO: 37, respectively; and (ii) a VH comprising VH CDR1, VH CDR2, and VH CDR3 comprising the amino acid sequences of SEQ ID NO: 38, SEQ ID NO: 39, and SEQ ID NO: 40, respectively.

27. 10. The pharmaceutical composition of any one of the preceding claims, wherein the antibody or antigen-binding fragment thereof comprises a VL comprising VL CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 2-4, respectively, and a VH comprising VH CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 5-7, respectively.

28. the antibody or antigen-binding fragment thereof (i) Amino acid sequence: DIVMTQSPSX Ｋ１ LSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKX Ｋ２ LIYSASYRYSGVPDRFX Ｋ３ GSGSGTDFTLISSLQX Ｋ４ EDFAX Ｋ５ YX Ｋ６ CQQYNSYPRTFGGGTKVEIK (SEQ ID NO: 17), wherein X Ｋ１ is an amino acid having an aromatic or aliphatic hydroxyl side chain, and X Ｋ２ is an amino acid having an aliphatic or aliphatic hydroxyl side chain, and X Ｋ３ is an amino acid having an aliphatic hydroxyl side chain, and X Ｋ４ is an amino acid having an aliphatic hydroxyl side chain or is P, and X Ｋ５ is an amino acid having a charged or acidic side chain, and X Ｋ６ is an amino acid having an aromatic side chain; (ii) Amino acid sequence: QVQLVQSGAEX Ｈ１ KKPGASVKX Ｈ２ SCKASGYTFTDYYINWVX Ｈ３ QAPGKGLEWIARIYPGSGNTYNEKFKGRX Ｈ４ TX Ｈ５ TAX Ｈ６ KST STAYMX Ｈ７ LSSLRSEDX Ｈ８ AVYFCARGVYYFDYWGQGTTVTVSS (SEQ ID NO: 18), wherein X Ｈ１ is an amino acid having an aliphatic side chain, and X Ｈ２ is an amino acid having an aliphatic side chain, and X Ｈ３ is an amino acid with a polar or basic side chain, and X Ｈ４ is an amino acid having an aliphatic side chain, and X Ｈ５ is an amino acid having an aliphatic side chain, and X Ｈ６ is an amino acid having an acidic side chain, and X Ｈ７ is an amino acid having an acidic or amide derivative side chain, and X Ｈ８ 6. The pharmaceutical composition of claim 1, comprising: a VH comprising the amino acid sequence wherein is an amino acid having an aliphatic hydroxyl side chain.

29. X Ｋ１ is an amino acid F or S, and X Ｋ２ is an amino acid A or S, and X Ｋ３ is the amino acid T or S, and X Ｋ４ is an amino acid S or P, and X Ｋ５ is the amino acid D or T, and X Ｋ６ is an amino acid F or Y, and X Ｈ１ is an amino acid L or V, and X Ｈ２ is an amino acid L or V, and X Ｈ３ is an amino acid K or R, and X Ｈ４ is an amino acid V or A, and X Ｈ５ is an amino acid L or I, and X Ｈ６ is amino acid E or D, and X Ｈ７ is an amino acid Q or E, and X Ｈ８ is the amino acid S or T.

30. 10. The pharmaceutical composition of any one of the preceding claims, wherein the antibody or antigen-binding fragment thereof comprises a VL comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 13, 14, 15, and 16, and a VH comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 9, 10, 11, and 12.

31. 2. The pharmaceutical composition of any one of the preceding claims, wherein the antibody comprises a human heavy chain constant region, and the human heavy chain constant region is a human IgG1 constant region.

32. 10. The pharmaceutical composition of any one of the preceding claims, wherein the antibody comprises a modified human Fc region or domain.

33. 10. The pharmaceutical composition of any one of the preceding claims, wherein the antibody comprises a modified human IgG1 Fc region or domain.

34. 34. The pharmaceutical composition of claim 33, wherein the modified human IgGl Fc region or domain comprises non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat.

35. 35. The pharmaceutical composition of claim 34, wherein the modified human IgGl Fc region or domain further comprises non-naturally occurring amino acids 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat.

36. The antibody (i) a VL comprising the amino acid sequence of SEQ ID NO: 14; and (ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; and (iii) a modified human IgG1 Fc region or domain comprising the non-naturally occurring amino acids 234A, 235Q, and 322Q as numbered by the EU index as set forth in Kabat.

37. The antibody (i) a VL comprising the amino acid sequence of SEQ ID NO: 14; and (ii) a VH comprising the amino acid sequence of SEQ ID NO: 10; and (iii) a modified human IgG1 Fc region or domain comprising the non-naturally occurring amino acids 234A, 235Q, 322Q, 252Y, 254T, and 256E as numbered by the EU index as set forth in Kabat.

38. The antibody has the amino acid sequence: QVQLVQSGAEVKKPGASVKLSCKASGYTFTDYYINWVRQAPGKGLEWIARIYPGSGNTYY NEKFKGRATLTADKSTSTAYMQLSSLRSEDTAVYFCARGVYYFDYWGQGTTVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSL SSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEAQGGPSVFLF 10. The pharmaceutical composition of any one of the preceding claims, comprising a heavy chain comprising: PPKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCQVSNKALPAPIEKTISKAKGQPREPQVYTLPPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 21).

39. The antibody has the amino acid sequence:

10. The pharmaceutical composition of any one of the preceding claims, comprising a light chain comprising DIVMTQSPSSLSASVGDRVTITCKASQNVRTNVAWYQQKPGKAPKALIYSASYRYSGVPDRFTGSGSGTDFTLTISSLQPEDFADYFCQQYNSYPRTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 22).

40. A kit comprising a pharmaceutical composition according to any one of the preceding claims.

41. 40. A method for protecting against, treating, or managing a KIT-associated disorder, comprising administering to a subject in need thereof a therapeutically effective amount of the pharmaceutical composition of any one of claims 1 to 39.

42. 42. The method of claim 41, wherein the pharmaceutical composition is administered subcutaneously to the subject.

43. 43. The method of claim 41 or 42, wherein the KIT-associated disorder is a mast cell-associated disorder, an eosinophil-associated disorder, cancer, asthma, an inflammatory condition, rheumatoid arthritis, allergic inflammation, inflammatory bowel disease, a gastrointestinal disorder, or fibrosis.

44. 44. The method of claim 43, wherein the KIT-associated disorder is a mast cell-associated disorder.

45. 44. The method of claim 43, wherein the KIT-associated disorder is an eosinophil-associated disorder.

46. 46. ​​The method of any one of claims 41 to 45, further comprising administering to the subject a second therapeutic agent.

47. 47. The method of claim 46, wherein the second therapeutic agent is a chemotherapeutic agent, a histone deacetylase inhibitor, an antibody, a cytokine, a tyrosine kinase inhibitor, an antihistamine, a leukotriene receptor antagonist, an immunomodulatory agent, or an anti-inflammatory agent.

48. The method of any one of claims 41 to 47, wherein the subject is a human.

49. 49. The method of any one of claims 41 to 48, wherein 1.5 mg / kg or more of the antibody or antigen-binding fragment thereof per dose is administered to the subject.

50. 49. The method of any one of claims 41 to 48, wherein about 1.5 mg / kg to about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered per dose to the subject.

51. 49. The method of any one of claims 41 to 48, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject.

52. 49. The method of any one of claims 41 to 48, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject.

53. 49. The method of any one of claims 41 to 48, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof is administered per dose to the subject.

54. 54. The method of any one of claims 41 to 53, wherein two doses of the antibody or antigen-binding fragment thereof are administered to the subject.

55. 54. The method of any one of claims 41 to 53, wherein three doses of the antibody or antigen-binding fragment thereof are administered to the subject.

56. 56. The method of any one of claims 41 to 55, wherein the antibody or antigen-binding fragment thereof is administered to the subject every four weeks.

57. 56. The method of any one of claims 41 to 55, wherein the antibody or antigen-binding fragment thereof is administered to the subject every 8 weeks.

58. 49. The method of any one of claims 41-48, wherein about 1.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every four weeks for three doses.

59. 49. The method of any one of claims 41-48, wherein about 3.0 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses.

60. 49. The method of any one of claims 41-48, wherein about 4.5 mg / kg of the antibody or antigen-binding fragment thereof per dose is administered to the subject every 8 weeks for two doses.

61. 40. A method for producing the pharmaceutical composition of any one of claims 1 to 39, comprising combining the antibody or antigen-binding fragment thereof with the buffer, the salt, and the excipient.

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