Bone marrow conditioning method

Abstract

The present disclosure relates to a method of conditioning a subject and / or depleting a population of cells in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT), comprising administering an antibody that binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject, in a preferred embodiment, the target is CD117 (c-kit).

Description

[Technical field]

[0001] Related Application Data This application claims priority to Australian Patent Application No. 2022900484 entitled "Methods of Bone Marrow Conditioning" filed on March 1, 2022, the entire contents of which are incorporated herein by reference.

[0002] Sequence Listing This application has been filed with a Sequence Listing in electronic format, the entire contents of which are incorporated herein by reference.

[0003] The present disclosure relates to a method of conditioning a subject and / or depleting a population of cells in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT), comprising administering an antibody that binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject. [Background technology]

[0004] Hematopoietic cell transplantation (HCT) is the administration of hematopoietic stem and progenitor cells to patients with a variety of acquired and inherited malignant and non-malignant disorders to establish bone marrow and immune function. These disorders include hematological malignancies (e.g., leukemia, lymphoma, and myeloma), non-malignant acquired bone marrow disorders (e.g., aplastic anemia), and genetic diseases associated with abnormal hematopoiesis and function (e.g., thalassemia, sickle cell anemia, and severe combined immunodeficiency). HCT can also be used to support patients undergoing high-dose chemotherapy for the treatment of certain solid tumors (e.g., germ cell tumors, soft tissue sarcomas, and neuroblastomas) where hematological toxicity would otherwise limit drug administration.

[0005] Prior to HCT, conditioning regimens are used to reduce disease burden, create room for engraftment, and immunosuppression. Currently, conditioning regimens are myeloablative or non-myeloablative. Myeloablative regimens include high-dose chemotherapy (e.g., cyclophosphamide, busulfan, and etoposide) and / or radiation therapy (e.g., total body irradiation) combined with immunosuppressive components. While these regimens are designed to suppress the immune system, they can also adversely affect multiple organ systems, frequently resulting in life-threatening complications. Non-myeloablative regimens (or reduced-intensity regimens) use doses of chemotherapy and radiation that are too low to eradicate all of the patient's bone marrow cells, and thus patients have a reduced risk of infection and transplant-related mortality. However, relapse remains a major problem after reduced-intensity conditioning regimens.

[0006] More recently, non-myeloablative regimens have been combined with other immunotherapy conditioning regimens, including chimeric antigen receptor (CAR)-modified T cells against hematopoietic stem cell markers. However, a major limitation of this regimen is the complete elimination of all CAR-modified infused T cells prior to donor cell transplantation.

[0007] Thus, there is a need to develop conditioning regimens that avoid unwanted toxicities and minimize the frequency of serious adverse reactions while also reducing the patient's risk of relapse. Summary of the Invention

[0008] In creating the present invention, the inventors have identified antibodies useful in conditioning regimens for patients preparing for hematopoietic cell transplantation (HCT). The inventors have found that antibodies that bind targets (e.g., CD117) on endogenous hematopoietic stem cells (HSCs) successfully deplete and / or reduce HSCs. Advantageously, the inventors have identified that depletion of HSCs is improved using antibodies that mediate antibody-dependent cellular trogocytosis (ADCT) and antibodies that include an IgA2 heavy chain.

[0009] Thus, the inventors' findings provide the basis for a method of conditioning a subject in need of HCT. In particular, the findings provide the basis for a method of conditioning a subject in need of HCT, comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject.

[0010] The inventors' findings also provide the basis for a method of reducing, depleting and / or reducing a population of cells in the bone marrow of a subject in need of HCT. In particular, the findings provide the basis for a method of reducing, depleting and / or reducing a population of cells in the bone marrow of a subject in need of HCT, comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject.

[0011] In one example, the antibody mediates antibody-dependent cell-mediated cytotoxicity (ADCC), and / or antibody-dependent cell-mediated phagocytosis (ADCP), and / or ADCT, and / or complement-dependent cytotoxicity (CDC), and combinations thereof. For example, the antibody mediates ADCC. In another example, the antibody mediates ADCP. In a further example, the antibody mediates ADCT. In one example, the antibody mediates CDC. In one example, the antibody mediates ADCC and ADCP. In another example, the antibody mediates ADCC and ADCT. In a further example, the antibody mediates ADCC and CDC. In one example, the antibody mediates ADCP and ADCT. In another example, the antibody mediates ADCP and CDC. In a further example, the antibody mediates ADCT and CDC. In one example, the antibody mediates ADCC, ADCP and ADCT. In another example, the antibody mediates ADCC, ADCP and CDC. In a further example, the antibody mediates ADCC, ADCT and CDC. In one example, the antibody mediates ADCP, ADCT and CDC. In one example, the antibody mediates ADCC, ADCP, ADCT and CDC.

[0012] The present disclosure provides a method of conditioning a subject in need of HCT, the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0013] The disclosure also provides a method for reducing, depleting and / or attenuating a population of cells in the bone marrow of a subject in need of HCT, the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0014] The disclosure provides a method of conditioning a subject in need of HCT, the method comprising administering to the subject an antibody that comprises a modified hinge region.

[0015] The disclosure also provides a method of reducing, depleting and / or attenuating a population of cells in the bone marrow of a subject in need of HCT, comprising administering to the subject an antibody that includes a modified hinge region, e.g., an extended hinge region, e.g., an extended hinge region that includes a portion of an IgG3 hinge region inserted into an IgA2 hinge region after the first proline.

[0016] In one example, an antigen-binding site of an antibody of the present disclosure that comprises an extended hinge region can bind its epitope better than an antigen-binding site of an antibody that does not have the extended hinge region.

[0017] The present disclosure provides a method of conditioning a subject in need of HCT, the method comprising administering to the subject an antibody that includes an extended hinge region, wherein the antigen-binding site of the antibody is able to bind to its epitope better than an antibody that does not have the extended hinge region.

[0018] The disclosure also provides a method of reducing, depleting and / or attenuating a population of cells in the bone marrow of a subject in need of HCT, comprising administering to the subject an antibody that includes an extended hinge region, wherein the antigen-binding site of the antibody has better access to its epitope compared to an antibody that does not have the extended hinge region.

[0019] In one example, the antibody comprises an IgA antibody heavy chain. For example, the IgA antibody heavy chain is an IgA2 heavy chain.

[0020] In one example, the antibody comprises an antibody light chain. For example, the antibody comprises a lambda or kappa light chain. In one example, the antibody comprises a lambda light chain. In another example, the antibody comprises a kappa light chain.

[0021] In one example, the antibody comprises an IgA2 heavy chain and a lambda or kappa light chain.

[0022] In one example, the IgA2 heavy chain is a modified IgA2 heavy chain. For example, the IgA2 heavy chain is (i) an N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) scheme; (ii) a P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) scheme; (iii) a C to S mutation at position 311 according to the myeloma IgA1 protein (Bur) scheme; (iv) a NIT to TLS mutation at positions 337–339 according to the myeloma IgA1 protein (Bur) scheme; (v) deletion of a C residue at position 472 according to the myeloma IgA1 protein (Bur) scheme; and (vi) deletion of a Y residue at position 473 according to the myeloma IgA1 protein (Bur) scheme; The compound comprises one or more modifications selected from the group consisting of:

[0023] In one example, the IgA2 heavy chain contains an N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) scheme. For example, IgA2 contains an N to G mutation at the residue corresponding to amino acid 47 of SEQ ID NO:32.

[0024] In one example, the IgA2 heavy chain comprises a P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) scheme. For example, the IgA2 comprises a P to R mutation at a residue corresponding to amino acid 102 of SEQ ID NO: 32. In one example, the IgA2 comprises the sequence shown in SEQ ID NO: 33.

[0025] In one example, the IgA2 heavy chain contains a C to S mutation at position 311 according to the myeloma IgA1 protein (Bur) scheme. For example, IgA2 contains a C to S mutation at a residue corresponding to amino acid 179 of SEQ ID NO:32.

[0026] In one example, the IgA2 heavy chain contains a NIT to TLS mutation at positions 337-339 according to the myeloma IgA1 protein (Bur) scheme. For example, IgA2 contains a NIT to TLS mutation at residues corresponding to amino acids 205-207 of SEQ ID NO:32.

[0027] In one example, the IgA2 heavy chain contains a deletion of a C residue at position 472 according to the myeloma IgA1 protein (Bur) scheme. For example, IgA2 contains a deletion of a C residue corresponding to amino acid 339 of SEQ ID NO:32.

[0028] In one example, the IgA2 heavy chain comprises a deletion of a Y residue at position 473 according to the myeloma IgA1 protein (Bur) scheme. For example, the IgA2 comprises a deletion of a Y residue corresponding to amino acid 340 of SEQ ID NO:32.

[0029] In one example, the IgA2 heavy chain comprises (i) an N to G mutation at position 166 according to the Myeloma IgA1 Protein (Bur) scheme; and (ii) a P to R mutation at position 221 according to the Myeloma IgA1 Protein (Bur) scheme; and (iii) a C to S mutation at position 311 according to the Myeloma IgA1 Protein (Bur) scheme; and (iv) an NIT to TLS mutation at positions 337-339 according to the Myeloma IgA1 Protein (Bur) scheme; and (v) a deletion of a C residue at position 472 according to the Myeloma IgA1 Protein (Bur) scheme; and (vi) a deletion of a Y residue at position 473 according to the Myeloma IgA1 Protein (Bur) scheme.

[0030] In one example, the IgA2 heavy chain comprises (i) an N to G mutation at a residue corresponding to amino acid 47 of SEQ ID NO:32; and (ii) a P to R mutation at a residue corresponding to amino acid 102 of SEQ ID NO:32; and (iii) a C to S mutation at a residue corresponding to amino acid 179 of SEQ ID NO:32; and (iv) an NIT to TLS mutation at residues corresponding to amino acids 205-207 of SEQ ID NO:32; and (v) a deletion of a C residue corresponding to amino acid 339 of SEQ ID NO:32; and (vi) a deletion of a Y residue corresponding to amino acid 340 of SEQ ID NO:32.

[0031] In one example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO: 33 or SEQ ID NO: 34 or SEQ ID NO: 66. For example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO: 33. In another example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO: 34. In a further example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO: 66.

[0032] In one example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO:66, wherein the amino acid sequence comprises an asparagine (N) or glycine (G) at position 47 and / or a proline (P) or arginine (R) at position 102 and / or a cysteine ​​(C) or serine (S) at position 179 and / or an asparagine (N) or threonine (T) at position 205 and / or an isoleucine (I) or leucine (L) at position 206 and / or a threonine (T) or serine (S) at position 207 and / or a cysteine ​​(C) or absent at position 339 and / or a tyrosine (Y) or absent at position 340.

[0033] In one example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO:66, the amino acid sequence comprising an asparagine (N) at position 47, and an arginine (R) at position 102, and a cysteine ​​(C) at position 179, and an asparagine (N) at position 205, and an isoleucine (I) at position 206, and a threonine (T) at position 207, and a cysteine ​​(C) at position 339, and a tyrosine (Y) at position 340. For example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO:33.

[0034] In one example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO:66, the amino acid sequence comprising a glycine (G) at position 47, an arginine (R) at position 102, a serine (S) at position 179, a threonine (T) at position 205, a leucine (L) at position 206, a serine (S) at position 207, an absent at position 339, and an absent at position 340. For example, the IgA2 heavy chain comprises the sequence set forth in SEQ ID NO:34.

[0035] In one example, an antibody comprising an extended hinge region comprises a C-terminal CH1 sequence from IgA, an upper hinge sequence from IgG3, a middle hinge sequence from IgG3, a lower hinge sequence from IgG3, and / or a sequence past the lower hinge sequence from IgA and combinations thereof. In one example, an antibody comprising an extended hinge region comprises a C-terminal CH1 sequence from IgA. In one example, an antibody comprising an extended hinge region comprises an upper hinge sequence from IgG3. In one example, an antibody comprising an extended hinge region comprises a middle hinge sequence from IgG3. In one example, an antibody comprising an extended hinge region comprises a lower hinge sequence from IgG3. In one example, an antibody comprising an extended hinge region comprises a sequence past the lower hinge sequence from IgA.

[0036] In one example, an antibody comprising an extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and / or a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 127, and combinations thereof. In one example, an antibody comprising an extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123. In one example, an antibody comprising an extended hinge region comprises an upper hinge comprising the sequence set forth in SEQ ID NO: 124. In one example, an antibody comprising an extended hinge region comprises a middle hinge comprising the sequence set forth in SEQ ID NO: 125. In one example, an antibody comprising an extended hinge region comprises an upper hinge comprising a lower hinge comprising the sequence set forth in SEQ ID NO: 126. In one example, an antibody comprising an extended hinge region comprises a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 127.

[0037] In one example, an antibody comprising an extended hinge region comprises an a-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and / or a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 128, and combinations thereof. In one example, an antibody comprising an extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123. In one example, an antibody comprising an extended hinge region comprises an upper hinge comprising the sequence set forth in SEQ ID NO: 124. In one example, an antibody comprising an extended hinge region comprises a middle hinge comprising the sequence set forth in SEQ ID NO: 125. In one example, an antibody comprising an extended hinge region comprises an upper hinge comprising a lower hinge comprising the sequence set forth in SEQ ID NO: 126. In one example, an antibody comprising an extended hinge region comprises a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 128.

[0038] In one example of any of the methods described herein, the antibody binds or specifically binds to a target on endogenous HSCs in the subject. In one example, the target on endogenous HSCs is CD2, CD5, CD7, CD11a, CDw12, CD13, CD15, CD18, CD19, CD21, CD22, CD29, CD30, CD33, CD34, CD36, CD38, CD40, CD41, CD42a, CD42b, CD42c, CD42d, CD43, CD45, CD45RA, CD45RB, CD45RC, CD45RO, CD48, CD49b, CD49d (VLA-4) , CD49e, CD49f(VLA-6), CD50, CD51, CD53, CD55, CD58, CD64a, CD68, CD71, CD72, CD73, CD81, CD82, CD84, CD85A, CD85K, CD90, CD97, CD99, CD104, CD105, CD109, CD110, CD111, CD112, CD114, CD115, CD117(c-kit), CD123, CD124, CD126, CD12 7, CD130, CD131, CD133, CD134, CD135, CD137, CD138, CD151, CD157, CD162, CD164, CD166, CD168, CD172a, CD173, CD174 , CD175, CD175s, CD176, CD183, CD184(CXCR4), CD191, CD200, CD201, CD205, CD217, CD220, CD221, CD222, CD223, CD224 , CD225, CD226, CD227, CD228, CD229, CD230, CD235a, CD235b, CD236, CD236R, CD238, CD240, CD242, CD243, CD277, CD292, CDw293, CD295, CD298, CD309, CD318, CD324, CD325, CD338, CD344, CD349, CD350, CD361 and combinations thereof.

[0039] In one example, the target on endogenous HSC is CD2. In one example, the target on endogenous HSC is CD5. In one example, the target on endogenous HSC is CD7. In one example, the target on endogenous HSC is CD11a. In one example, the target on endogenous HSC is CDw12. In one example, the target on endogenous HSC is CD13. In one example, the target on endogenous HSC is CD15. In one example, the target on endogenous HSC is CD18. In one example, the target on endogenous HSC is CD19. In one example, the target on endogenous HSC is CD21. In one example, the target on endogenous HSC is CD22. In one example, the target on endogenous HSC is CD29. In one example, the target on endogenous HSC is CD30. In one example, the target on endogenous HSC is CD33. In one example, the target on endogenous HSCs is CD34. In one example, the target on endogenous HSCs is CD36. In one example, the target on endogenous HSCs is CD38. In one example, the target on endogenous HSCs is CD40. In one example, the target on endogenous HSCs is CD41. In one example, the target on endogenous HSCs is CD42a. In one example, the target on endogenous HSCs is CD42b. In one example, the target on endogenous HSCs is CD42c. In one example, the target on endogenous HSCs is CD42d. In one example, the target on endogenous HSCs is CD43. In one example, the target on endogenous HSCs is CD45. In one example, the target on endogenous HSCs is CD45RA. In one example, the target on endogenous HSCs is CD45RB. In one example, the target on endogenous HSCs is CD45RC. In one example, the target on endogenous HSCs is CD45RO. In one example, the target on endogenous HSCs is CD48. In one example, the target on endogenous HSCs is CD49b. In one example, the target on endogenous HSCs is CD49d (VLA-4). In one example, the target on endogenous HSCs is CD49e. In one example, the target on endogenous HSCs is CD49f (VLA-6). In one example, the target on endogenous HSCs is CD50. In one example, the target on endogenous HSCs is CD51. In one example, the target on endogenous HSCs is CD53. In one example, the target on endogenous HSCs is CD55.In one example, the target on endogenous HSCs is CD58. In one example, the target on endogenous HSCs is CD64a. In one example, the target on endogenous HSCs is CD68. In one example, the target on endogenous HSCs is CD71. In one example, the target on endogenous HSCs is CD72. In one example, the target on endogenous HSCs is CD73. In one example, the target on endogenous HSCs is CD81. In one example, the target on endogenous HSCs is CD82. In one example, the target on endogenous HSCs is CD84. In one example, the target on endogenous HSCs is CD85A. In one example, the target on endogenous HSCs is CD85K. In one example, the target on endogenous HSCs is CD90. In one example, the target on endogenous HSCs is CD97. In one example, the target on endogenous HSCs is CD99. In one example, the target on endogenous HSCs is CD104. In one example, the target on endogenous HSCs is CD105. In one example, the target on endogenous HSCs is CD109. In one example, the target on endogenous HSCs is CD110. In one example, the target on endogenous HSCs is CD111. In one example, the target on endogenous HSCs is CD112. In one example, the target on endogenous HSCs is CD114. In one example, the target on endogenous HSCs is CD115. In one example, the target on endogenous HSCs is CD117 (c-kit). In one example, the target on endogenous HSCs is CD123. In one example, the target on endogenous HSCs is CD124. In one example, the target on endogenous HSCs is CD126. In one example, the target on endogenous HSCs is CD127. In one example, the target on endogenous HSCs is CD130. In one example, the target on endogenous HSCs is CD131. In one example, the target on endogenous HSCs is CD133. In one example, the target on endogenous HSCs is CD134. In one example, the target on endogenous HSCs is CD135. In one example, the target on endogenous HSCs is CD137. In one example, the target on endogenous HSCs is CD138. In one example, the target on endogenous HSCs is CD151. In one example, the target on endogenous HSCs is CD157. In one example, the target on endogenous HSCs is CD162. In one example, the target on endogenous HSCs is CD164.In one example, the target on endogenous HSCs is CD166. In one example, the target on endogenous HSCs is CD168. In one example, the target on endogenous HSCs is CD172a. In one example, the target on endogenous HSCs is CD173. In one example, the target on endogenous HSCs is CD174. In one example, the target on endogenous HSCs is CD175. In one example, the target on endogenous HSCs is CD175s. In one example, the target on endogenous HSCs is CD176. In one example, the target on endogenous HSCs is CD183. In one example, the target on endogenous HSCs is CD184 (CXCR4). In one example, the target on endogenous HSCs is CD191. In one example, the target on endogenous HSCs is CD200. In one example, the target on endogenous HSCs is CD201. In one example, the target on endogenous HSCs is CD205. In one example, the target on endogenous HSCs is CD217. In one example, the target on endogenous HSCs is CD220. In one example, the target on endogenous HSCs is CD221. In one example, the target on endogenous HSCs is CD222. In one example, the target on endogenous HSCs is CD223. In one example, the target on endogenous HSCs is CD224. In one example, the target on endogenous HSCs is CD225. In one example, the target on endogenous HSCs is CD226. In one example, the target on endogenous HSCs is CD227. In one example, the target on endogenous HSCs is CD228. In one example, the target on endogenous HSCs is CD229. In one example, the target on endogenous HSCs is CD230. In one example, the target on endogenous HSCs is CD235a. In one example, the target on endogenous HSCs is CD235b. In one example, the target on endogenous HSCs is CD236. In one example, the target on endogenous HSCs is CD236R. In one example, the target on endogenous HSCs is CD238. In one example, the target on endogenous HSCs is CD240. In one example, the target on endogenous HSCs is CD242. In one example, the target on endogenous HSCs is CD243. In one example, the target on endogenous HSCs is CD277. In one example, the target on endogenous HSCs is CD292. In one example, the target on endogenous HSCs is CDw293. In one example, the target on endogenous HSCs is CD295.In one example, the target on endogenous HSCs is CD298. In one example, the target on endogenous HSCs is CD309. In one example, the target on endogenous HSCs is CD318. In one example, the target on endogenous HSCs is CD324. In one example, the target on endogenous HSCs is CD325. In one example, the target on endogenous HSCs is CD338. In one example, the target on endogenous HSCs is CD344. In one example, the target on endogenous HSCs is CD349. In one example, the target on endogenous HSCs is CD350. In one example, the target on endogenous HSCs is CD361.

[0040] In one example, the antibody is (i) blocking the binding of CD117 by stem cell factor (SCF); and / or (ii) inhibiting activation of CD117 by SCF; and / or (iii) inhibiting SCF-mediated CD117+ cell proliferation; and / or (iv) depleting the population of CD117+ cells in the subject; The drug is administered in an amount sufficient to

[0041] In one example, the antibody is administered in an amount sufficient to block the binding of CD117 by SCF. For example, the antibody is administered in an amount sufficient to inhibit the binding of CD117 by SCF. It will be clear to those skilled in the art that the antibody does not need to completely block or inhibit the binding of CD117 by SCF, but rather only needs to reduce it by a statistically significant amount, for example, at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. In one example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 10%. In another example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 20%. In a further example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 30%. In one example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 40%. In another example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 50%. In a further example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 60%. In one example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 70%. In another example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 80%. In a further example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 90%. In one example, the antibody blocks or inhibits the binding of CD117 by SCF by at least about 95%. In one example, the antibody completely blocks or inhibits the binding of CD117 by SCF.

[0042] Methods for determining blocking or inhibition of binding are known in the art and / or described herein. In one example, the antibody blocks or inhibits binding of CD117 by SCF as determined in a TF-1 proliferation assay.

[0043] In one example, the antibody is administered in an amount sufficient to inhibit the activation of CD117 by SCF. It will be clear to those skilled in the art that the antibody need not completely inhibit the activation of CD117 by SCF, but rather only need to reduce it by a statistically significant amount, for example, at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. In one example, the antibody inhibits the activation of CD117 by SCF by at least about 10%. In another example, the antibody inhibits the activation of CD117 by SCF by at least about 20%. In a further example, the antibody inhibits the activation of CD117 by SCF by at least about 30%. In one example, the antibody inhibits the activation of CD117 by SCF by at least about 40%. In another example, the antibody inhibits the activation of CD117 by SCF by at least about 50%. In a further example, the antibody inhibits activation of CD117 by SCF by at least about 60%. In one example, the antibody inhibits activation of CD117 by SCF by at least about 70%. In another example, the antibody inhibits activation of CD117 by SCF by at least about 80%. In a further example, the antibody inhibits activation of CD117 by SCF by at least about 90%. In one example, the antibody inhibits activation of CD117 by SCF by at least about 95%. In one example, the antibody completely inhibits activation of CD117 by SCF.

[0044] Methods for determining inhibition of activation are known in the art and / or described herein. In one example, the antibody inhibits activation of CD117 by SCF as determined in a TF-1 proliferation assay.

[0045] In one example, the antibody is administered in an amount sufficient to inhibit CD117+ cell proliferation mediated by SCF. It will be clear to those skilled in the art that the antibody does not need to completely inhibit CD117+ cell proliferation by SCF, but rather only needs to reduce it by a statistically significant amount, for example, at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. In one example, the antibody inhibits CD117+ cell proliferation by SCF at least about 10%. In another example, the antibody inhibits CD117+ cell proliferation by SCF at least about 20%. In a further example, the antibody inhibits CD117+ cell proliferation by SCF at least about 30%. In one example, the antibody inhibits CD117+ cell proliferation by SCF at least about 40%. In another example, the antibody inhibits CD117+ cell proliferation by SCF at least about 50%. In a further example, the antibody inhibits SCF-induced CD117+ cell proliferation by at least about 60%. In one example, the antibody inhibits SCF-induced CD117+ cell proliferation by at least about 70%. In another example, the antibody inhibits SCF-induced CD117+ cell proliferation by at least about 80%. In a further example, the antibody inhibits SCF-induced CD117+ cell proliferation by at least about 90%. In one example, the antibody inhibits SCF-induced CD117+ cell proliferation by at least about 95%. In one example, the antibody completely inhibits SCF-induced CD117+ cell proliferation.

[0046] Methods for determining SCF-induced CD117+ cell proliferation inhibition are known in the art and / or described herein. In one example, the antibody inhibits SCF-induced CD117+ cell proliferation as determined in a TF-1 proliferation assay.

[0047] In one example, the antibody is administered in an amount sufficient to deplete the population of CD117+ cells in the subject. It will be clear to those skilled in the art that the antibody does not need to completely deplete the population of CD117+ cells, but rather only needs to reduce it by a statistically significant amount, for example, at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. In one example, the antibody depletes the population of CD117+ cells by at least about 10%. In another example, the antibody depletes the population of CD117+ cells by at least about 20%. In a further example, the antibody depletes the population of CD117+ cells by at least about 30%. In one example, the antibody depletes the population of CD117+ cells by at least about 40%. In another example, the antibody depletes the population of CD117+ cells by at least about 50%. In a further example, the antibody depletes the population of CD117+ cells by at least about 60%. In one example, the antibody depletes the population of CD117+ cells by at least about 70%. In another example, the antibody depletes the population of CD117+ cells by at least about 80%. In a further example, the antibody depletes the population of CD117+ cells by at least about 90%. In one example, the antibody depletes the population of CD117+ cells by at least about 95%. In one example, the antibody completely depletes the population of CD117+ cells.

[0048] Methods for determining CD117+ cell depletion are known in the art and / or described herein. For example, CD117+ cell depletion is determined using flow cytometry of CD89Tg positive bone marrow cells (e.g., neutrophils and / or macrophages) cultured in the presence of an antibody.

[0049] In one example, the antibody is an anti-CD117 antibody.

[0050] In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 and / or the C-terminus of human CD117 and / or full-length human CD117.

[0051] In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117. For example, the antibody has an affinity dissociation constant (K D For example, the antibody may have a K of 1 μM or less, e.g., 900 nM or less, or about 800 nM or less, or 700 nM or less, or 600 nM or less, or 500 nM or less, or 400 nM or less, or 300 nM or less, or 200 nM or less, or 100 nM or less, etc. D In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K of 100 nM or less, e.g., 90 nM or less, or 80 nM or less, or 70 nM or less, or 60 nM or less, or 50 nM or less, or 40 nM or less, or 30 nM or less, or 20 nM or less, etc. D For example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K D In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K D In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K of 20 nM or less, e.g., 18 nM or less, e.g., 15 nM or less, or 12 nM or less, or 10 nM or less. D For example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K D In another example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K D In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K of 10 nM or less, or 8 nM or less, or 5 nM or less, or 3 nM or less, or 2 nM or less, or 1 nM or less, or 0.5 nM or less. D For example, the antibody may have a K of 10 nM to 1 nM. D For example, the antibody binds to or specifically binds to the soluble N-terminus of human CD117 with a K of about 10 nM to 8 nM, for example, about 8.6 nM or about 9 nM. DK D In one example, the antibody has a K of 2 nM to 3 nM. D , e.g., a K of about 2.5 nM D In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K of about 0.5 nM. D It binds or specifically binds to the soluble N-terminus of human CD117 at

[0052] In one example, the antibody binds or specifically binds to the C-terminus of human CD117. For example, the antibody has a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D In one example, the antibody binds or specifically binds to the soluble N-terminus of human CD117 with a K of 200 nM or less, e.g., 175 nM or less, or 150 nM or less, or 125 nM or less, or 100 nM or less, or 90 nM or less, or 80 nM or less, or 70 nM or less, or 60 nM or less, etc. D In one example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody may have a K of 60 nM or less, e.g., 50 nM or less, or 40 nM or less, or 30 nM or less, or 20 nM or less, or 10 nM or less, etc. D For example, the antibody may have a K of 40 nM or less and specifically bind to the C-terminus of human CD117. D , e.g., a K of about 35 nM D For example, the antibody may have a K of 20 nM or less and specifically bind to the C-terminus of human CD117. D , e.g., a K of about 18 nM D For example, the antibody may have a K of 10 nM or less and specifically bind to the C-terminus of human CD117. D , e.g., a K of about 9 nM D For example, the antibody may have a K of 5 nM or less and specifically bind to the C-terminus of human CD117. D , e.g., a K of about 2.5 nM Dand the like, and binds or specifically binds to the C-terminus of human CD117.

[0053] In one example, the antibody binds or specifically binds to full-length human CD117. For example, the antibody has a K D For example, the antibody may have a K of 60 nM or less and specifically bind to the C-terminus of human CD117. D , e.g., 55 nM or less, or 50 nM or less, or 45 nM or less, or 40 nM or less, or 35 nM or less, or 30 nM or less, etc. D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D In one example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D , e.g., a K of 25 nM or less, or 20 nM or less, or 15 nM or less, or 10 nM or less, etc. D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D In one example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K of about 5 nM or less, or 4 nM or less, or 3 nM or less, or 2 nM or less, or 1 nM or less. D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a K D For example, the antibody binds or specifically binds to the C-terminus of human CD117 with a KD It binds to or specifically binds to the C-terminus of human CD117 at

[0054] In one example, the anti-CD117 antibody is (i) an affinity dissociation constant (K D ) the soluble N-terminus of human CD117; and / or (ii) K of 200 nM or less D at the C-terminus of human CD117; and / or (iii) K of 60 nM or less D Full-length human CD117 Combine the above.

[0055] In one example, the anti-CD117 antibody is (i) an affinity dissociation constant (K D ) the soluble N-terminus of human CD117; and / or (ii) K of 15 nM or less D at the C-terminus of human CD117; and / or (iii) K of 60 nM or less D Full-length human CD117 Combine the above.

[0056] In one example, the anti-CD117 antibody inhibits SCF-mediated proliferation of TF-1 cells. For example, the anti-CD117 antibody has an IC of at least 1 nM. 50 inhibits SCF-mediated proliferation of TF-1 cells at IC 50 is at least 1 nM, or 0.9 nM, or 0.8 nM, or 0.7 nM, or 0.6 nM, or 0.5 nM, or 0.4 nM, or 0.3 nM, or 0.2 nM, or 0.1 nM. For example, 50 For example, IC 50 In one example, the anti-CD117 antibody has an IC of at least 100 μM. 50 inhibits SCF-mediated proliferation of TF-1 cells at IC 50is at least 90 μM, or 80 μM, or 70 μM, or 60 μM, or 50 μM, or 40 μM, or 30 μM, or 20 μM, or 10 μM. For example, 50 For example, IC 50 For example, IC 50 For example, IC 50 is 18 μM.

[0057] I C 50 Methods for determining the number of cells that can be expressed are described herein and involve culturing TF-1 cells (e.g., approximately 2x10 cells) in the presence of an antibody (e.g., an anti-CD117 antibody) prior to the addition of human SCF. 5 The method includes culturing TF-1 cells (e.g., for at least about 48 hours or at least about 72 hours or at least about 96 hours, e.g., for about 72 hours) and then determining cell proliferation. Cell proliferation can be determined by using a commercially available kit, such as a Vialight Plus kit. By determining proliferation at various concentrations of antibody, the IC 50 can be determined.

[0058] In one example, anti-CD117 antibodies have been shown to increase normalized maximal membrane uptake (B) of at least 50% as determined by mean fluorescence intensity (MFI) of DILC18 on neutrophils. max ) mediates ADCT. For example, the antibody mediates a normalized B of 51% max In one example, the antibody mediates ADCT with at least 60% normalized B max For example, the antibody mediates ADCT with a normalized B max For example, the antibody mediates ADCT with 68% normalized B max In one example, the antibody mediates ADCT with at least 70% normalized B max For example, the antibody mediates ADCT with a normalized B max In one example, the antibody mediates ADCT with at least 80% normalized B max In one example, the antibody mediates ADCT with at least 90% normalized B maxFor example, an antibody mediates ADCT with 95% normalized B max Mediates ADCT.

[0059] I C 50 Methods for determining DILC18 are described herein and include, for example, flow cytometry. For example, a method includes culturing a cell line transfected with a target (e.g., human CD117) and labeled with the membrane dye DILC18 (1,1″-dioctadecyl-3,3,3″,3″-tetramethylindocarbacyanine perchlorate) in the presence of peripheral blood neutrophils. Viable neutrophils can be identified by forward and side scatter followed by viable CD66b positive cells. Membrane uptake by neutrophils can be measured by an increase in DILC18 mean fluorescence intensity (MFI). DILC18 MFI is normalized to the maximum MFI per donor neutrophil. In one example, normalized maximum membrane uptake (B) promoted by an antibody that induces trogocytosis by peripheral blood neutrophils is measured. max ) (percentage) is determined.

[0060] In one example, the anti-CD117 antibody has an EC 50 In one example, EC 50 is 20 nM or less, or 15 nM or less, or 10 nM or less, or 5 nM or less. 50 is 1 nM or less, or 0.5 nM or less, or 0.4 nM or less, or 0.3 nM or less, or 0.2 nM or less.

[0061] In one example, the anti-CD117 antibody competitively inhibits the binding of any one or more of the following antibodies to CD117: (i) a heavy chain variable region (V) comprising the sequence shown in SEQ ID NO: 4 or SEQ ID NO: 13 H ); and a light chain variable region (V L ) an antibody comprising; (ii) V comprising the sequence shown in SEQ ID NO:7 H and V comprising the sequence shown in SEQ ID NO:10 L an antibody comprising (iii) V comprising the sequence shown in SEQ ID NO: 13 H and V comprising the sequence shown in SEQ ID NO:16 L an antibody comprising (iv) V comprising the sequence shown in SEQ ID NO: 19 H and V comprising the sequence shown in SEQ ID NO:22 L an antibody comprising (v) V comprising the sequence shown in SEQ ID NO: 25 H and V comprising the sequence shown in SEQ ID NO:28 L 4. An antibody comprising:

[0062] In one example, the anti-CD117 antibody is a VDG comprising the sequence shown in SEQ ID NO:4 or SEQ ID NO:13 to CD117. H and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 L The compound competitively inhibits the binding of an antibody comprising the compound.

[0063] In one example, the anti-CD117 antibody is a VVL antibody to CD117 comprising the sequences shown in SEQ ID NO:4 and SEQ ID NO:5. H The compound competitively inhibits the binding of an antibody comprising the compound.

[0064] In one example, the anti-CD117 antibody is a VVL antibody comprising the sequences set forth in SEQ ID NO:4 and SEQ ID NO:28 to CD117. H The compound competitively inhibits the binding of an antibody comprising the compound.

[0065] In one example, the anti-CD117 antibody is a V polypeptide comprising the sequence set forth in SEQ ID NO: 13 to CD117. H and V comprising the sequence shown in SEQ ID NO:5 L The compound competitively inhibits the binding of an antibody comprising the compound.

[0066] In one example, the anti-CD117 antibody is a V polypeptide comprising the sequence set forth in SEQ ID NO:7 to CD117. H and V comprising the sequence shown in SEQ ID NO:10 LThe compound competitively inhibits the binding of an antibody comprising the compound.

[0067] In one example, the anti-CD117 antibody is a V polypeptide comprising the sequence set forth in SEQ ID NO: 13 to CD117. H and V comprising the sequence shown in SEQ ID NO:16 L The compound competitively inhibits the binding of an antibody comprising the compound.

[0068] In one example, the anti-CD117 antibody is a VVLK antibody to CD117 comprising the sequence set forth in SEQ ID NO:19. H and V comprising the sequence shown in SEQ ID NO:22 L The compound competitively inhibits the binding of an antibody comprising the compound.

[0069] In one example, the anti-CD117 antibody is a VVLK antibody to CD117 comprising the sequence set forth in SEQ ID NO:25. H and V comprising the sequence shown in SEQ ID NO:28 L The compound competitively inhibits the binding of an antibody comprising the compound.

[0070] In one example, the anti-CD117 antibody is (i) V comprising the sequence shown in SEQ ID NO: 4 or SEQ ID NO: 13 H and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 L ;or a. V comprising the sequence shown in SEQ ID NO:4 or SEQ ID NO:13 H V containing three complementarity determining regions (CDRs) H and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 L V containing the three CDRs L Includes.

[0071] In one example, the anti-CD117 antibody comprises a V H and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 L Includes.

[0072] In one example, the anti-CD117 antibody comprises a V Hand V comprising the sequence shown in SEQ ID NO:5 L Includes.

[0073] In one example, the anti-CD117 antibody comprises a V H and V comprising the sequence shown in SEQ ID NO:28 L Includes.

[0074] In one example, the anti-CD117 antibody comprises a V H and V comprising the sequence shown in SEQ ID NO:5 L Includes.

[0075] In one example, the anti-CD117 antibody comprises a V H V containing three complementarity determining regions (CDRs) H and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 L V containing the three CDRs L Includes.

[0076] In one example, the anti-CD117 antibody is (a)V H And, (i) CDR1 comprising the sequence set forth in amino acids 31 to 35 of SEQ ID NO: 4 or SEQ ID NO: 13; (ii) CDR2 comprising the sequence set forth in amino acids 50 to 66 of SEQ ID NO: 4 or SEQ ID NO: 13; and (c) a CDR3 comprising the sequence set forth in amino acids 99 to 110 of SEQ ID NO: 4 or SEQ ID NO: 13; Including, V H and (ii) V L And, (a) CDR1 comprising the sequence set forth in amino acids 23 to 33 of SEQ ID NO: 5 or SEQ ID NO: 28; (b) CDR2 comprising the sequence set forth in amino acids 49 to 55 of SEQ ID NO: 5 or SEQ ID NO: 28; and (c) CDR3 comprising the sequence shown in amino acids 88 to 98 of SEQ ID NO: 5 or SEQ ID NO: 28 Including, V L Includes.

[0077] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:5 L V containing the three CDRs L Includes.

[0078] In one example, the anti-CD117 antibody is (a)V H And, (i) CDR1 comprising a sequence as set forth in amino acids 31 to 35 of SEQ ID NO:4, wherein the amino acid sequence comprises serine (S) or aspartic acid (D) at position 31 and / or alanine (A) or glycine (G) at position 33 and / or serine (S) or histidine (H) at position 35; (ii) a CDR2 comprising a sequence as set forth in amino acids 50 to 66 of SEQ ID NO: 4, the amino acid sequence comprising an alanine (A) or valine (V) at position 50, and / or a serine (S) or absence or glycine (G) at position 52, and / or a glycine (G) or tyrosine (Y) at position 53, and / or a serine (S) or glycine (G) at position 54, and / or a serine (S) or glycine (G) at position 57, and / or a threonine (T) or lysine (K) at position 58; and (c) a CDR3 comprising a sequence as set forth in amino acids 99 to 110 of SEQ ID NO: 4, the amino acid sequence comprising leucine (L) or serine (S) or threonine (T) at position 100, and / or arginine (R) or serine (S) or tryptophan (W) at position 101, and / or valine (V) or glycine (G) or tryptophan (W) at position 102, and / or tyrosine (Y) or leucine (L) at position 103, and / or alanine (A) or arginine (R) at position 104, and / or methionine (M) or glycine (G) at position 105, and / or glutamic acid (E) or aspartic acid (D) or leucine (L) at position 106, and / or alanine (A) or absent at position 107, and / or isoleucine (I) or tyrosine (Y) at position 110; Including, V H and (ii) V L And, (a) CDR1 comprising a sequence as set forth in amino acids 23 to 33 of SEQ ID NO:5, wherein the amino acid sequence comprises glutamine (Q) or serine (S) at position 23, and / or serine (S) or lysine (K) at position 26, and / or leucine (L) or valine (V) at position 27, and / or arginine (R) or glycine (G) at position 28, and / or aspartic acid (D) or glutamic acid (E) or alanine (A) at position 29, and / or tyrosine (Y) or threonine (T) or lysine (K) at position 30, and / or alanine (A) or valine (V) at position 32, and / or asparagine (N) or histidine (H) or phenylalanine (F) at position 33; (b) a CDR2 comprising a sequence set forth in amino acids 49 to 55 of SEQ ID NO:5, the amino acid sequence comprising a tyrosine (Y) or glutamine (Q) at position 49 and / or a serine (S) or a phenylalanine (F) or an asparagine (N) at position 51 and / or an aspartic acid (D) or a lysine (K) at position 52; and (c) a CDR3 comprising a sequence as set forth in amino acids 88 to 98 of SEQ ID NO:5, the amino acid sequence comprising serine (S) or threonine (T) at position 94 and / or aspartic acid (D) or alanine (A) at position 95 and / or histidine (H) or valine (V) or leucine (L) at position 96 and / or tryptophan (W) or tyrosine (Y) or absent at position 97 and / or valine (V) or absent at position 98. Including, V L Includes.

[0079] In one example, the anti-CD117 antibody is (a)V H And, (i) CDR1 comprising a sequence as set forth in amino acids 31 to 35 of SEQ ID NO: 4, wherein the amino acid sequence comprises a serine (S) at position 31 and / or an alanine (A) at position 33 and / or a serine (S) at position 35; (ii) CDR2 comprising a sequence set forth in amino acids 50 to 66 of SEQ ID NO:4, the amino acid sequence comprising an alanine (A) at position 50, a serine (S) at position 52, a glycine (G) at position 53, a serine (S) at position 54, a serine (S) at position 57, and a threonine (T) at position 58; and (c) a CDR3 comprising a sequence shown in amino acids 99 to 110 of SEQ ID NO: 4, the amino acid sequence comprising leucine (L) at position 100, arginine (R) at position 101, valine (V) at position 102, tyrosine (Y) at position 103, alanine (A) at position 104, methionine (M) at position 105, glutamic acid (E) at position 106, alanine (A) at position 107, and isoleucine (I) at position 110; Including, V H and (ii) V L And, (a) CDR1 comprising a sequence as set forth in amino acids 23 to 33 of SEQ ID NO:5, the amino acid sequence comprising: glutamine (Q) at position 23, and serine (S) at position 26, and leucine (L) at position 27, and arginine (R) at position 28, and aspartic acid (D) at position 29, and tyrosine (Y) at position 30, and alanine (A) at position 32, and asparagine (N) at position 33; (b) CDR2 comprising the sequence set forth in amino acids 49 to 55 of SEQ ID NO:5, wherein the amino acid sequence comprises a tyrosine (Y) at position 49, a serine (S) at position 51, and an aspartic acid (D) at position 52; and (c) a CDR3 comprising a sequence as set forth in amino acids 88 to 98 of SEQ ID NO:5, the amino acid sequence comprising a serine (S) at position 94, an aspartic acid (D) at position 95, a histidine (H) at position 96, a tryptophan (W) at position 97, and a valine (V) at position 98; Including, V L Includes.

[0080] In one example, the anti-CD117 antibody is (a)V H And, (i) CDR1 comprising a sequence as set forth in amino acids 31 to 35 of SEQ ID NO:4, wherein the amino acid sequence comprises a serine (S) at position 31 and / or an alanine (A) at position 33 and / or a histidine (H) at position 35; (ii) CDR2 comprising a sequence as set forth in amino acids 50 to 66 of SEQ ID NO:4, the amino acid sequence comprising a valine (V) at position 50 and an absent amino acid at position 52 and a tyrosine (Y) at position 53 and a serine (S) at position 54 and a serine (S) at position 57 and a threonine (T) at position 58; and (c) a CDR3 comprising a sequence as set forth in amino acids 99 to 110 of SEQ ID NO: 4, the amino acid sequence comprising serine (S) at position 100, serine (S) at position 101, glycine (G) at position 102, tyrosine (Y) at position 103, arginine (R) at position 104, glycine (G) at position 105, aspartic acid (D) at position 106, absent at position 107, and tyrosine (Y) at position 110; Including, V H and (ii) V L And, (a) CDR1 comprising a sequence as set forth in amino acids 23 to 33 of SEQ ID NO:5, the amino acid sequence comprising a serine (S) at position 23, a lysine (K) at position 26, a valine (V) at position 27, a glycine (G) at position 28, an alanine (A) at position 29, a lysine (K) at position 30, a valine (V) at position 32, and a phenylalanine (F) at position 33; (b) a CDR2 comprising a sequence set forth in amino acids 49 to 55 of SEQ ID NO:5, the amino acid sequence comprising a glutamine (Q) at position 49, an asparagine (N) at position 51, and a lysine (K) at position 52; and (c) a CDR3 comprising a sequence as set forth in amino acids 88 to 98 of SEQ ID NO:5, the amino acid sequence comprising threonine (T) at position 94, alanine (A) at position 95, leucine (L) at position 96, tyrosine (Y) at position 97, and valine (V) at position 98; Including, V L Includes.

[0081] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:28 L V containing the three CDRs L Includes.

[0082] In one example, the anti-CD117 antibody is (a)V H And, (i) CDR1 comprising a sequence as set forth in amino acids 31 to 35 of SEQ ID NO: 4, wherein the amino acid sequence comprises an aspartic acid (D) at position 31 and / or a glycine (G) at position 33 and / or a serine (S) at position 35; (ii) CDR2 comprising a sequence as set forth in amino acids 50 to 66 of SEQ ID NO:4, the amino acid sequence comprising an alanine (A) at position 50, a glycine (G) at position 52, a tyrosine (Y) at position 53, a glycine (G) at position 54, a glycine (G) at position 57, and a lysine (K) at position 58; and (c) a CDR3 comprising a sequence as set forth in amino acids 99 to 110 of SEQ ID NO: 4, the amino acid sequence comprising a threonine (T) at position 100, a tryptophan (W) at position 101, a tryptophan (W) at position 102, a leucine (L) at position 103, an alanine (A) at position 104, a glycine (G) at position 105, a leucine (L) at position 106, an absent amino acid at position 107, and a tyrosine (Y) at position 110; Including, V H and (ii) V L And, (a) CDR1 comprising the sequence set forth in amino acids 23 to 33 of SEQ ID NO:28; (b) CDR2 comprising the sequence set forth in amino acids 49 to 55 of SEQ ID NO: 28; and (c) CDR3 comprising the sequence shown in amino acids 88 to 98 of SEQ ID NO: 28 Including, V L Includes.

[0083] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:5 L V containing the three CDRs L Includes.

[0084] In one example, the anti-CD117 antibody is (a)V H And, (i) CDR1 comprising the sequence set forth in amino acids 31 to 35 of SEQ ID NO: 13; (ii) CDR2 comprising the sequence set forth in amino acids 50 to 66 of SEQ ID NO: 13; and (c) CDR3 comprising the sequence shown in amino acids 99 to 110 of SEQ ID NO: 13 Including, V H and (a) CDR1 comprising a sequence as set forth in amino acids 23 to 33 of SEQ ID NO:5, the amino acid sequence comprising a serine (S) at position 23, a lysine (K) at position 26, a leucine (L) at position 27, a glycine (G) at position 28, a glutamic acid (E) at position 29, a threonine (T) at position 30, a valine (V) at position 32, and a histidine (H) at position 33; (b) CDR2 comprising the sequence set forth in amino acids 49 to 55 of SEQ ID NO:5, wherein the amino acid sequence comprises a glutamine (Q) at position 49, a phenylalanine (F) at position 51, and a lysine (K) at position 52; and (c) a CDR3 comprising a sequence as set forth in amino acids 88 to 98 of SEQ ID NO:5, the amino acid sequence comprising a threonine (T) at position 94, an alanine (A) at position 95, a valine (V) at position 96, an absent amino acid at position 97, and an absent amino acid at position 98; Includes.

[0085] In one example, the amino acid sequence of SEQ ID NO:4 contains an alanine (A) or valine (V) or leucine (L) at position 5 and / or an aspartic acid (D) or glycine (G) at position 10 and / or a leucine (L) or valine (V) at position 11 and / or a glycine (G) or arginine (R) at position 16 and / or a serine (S) or aspartic acid (D) at position 31 and / or an alanine (A) or glycine (G) at position 33 and / or or serine (S) or histidine (H) at position 35 and / or alanine (A) or valine (V) at position 50 and / or serine (S) or absent or glycine (G) at position 52 and / or glycine (G) or tyrosine (Y) at position 53 and / or serine (S) or glycine (G) at position 54 and / or serine (S) or glycine (G) at position 57 and / or threonine (T) or lysine (K) at position 58 and / or at position 93 isoleucine (I) or valine (V) and / or at position 98 arginine (R) or lysine (K) and / or at position 100 leucine (L) or serine (S) or threonine (T) and / or at position 101 arginine (R) or serine (S) or tryptophan (W) and / or at position 102 valine (V) or glycine (G) or tryptophan (W) and / or at position 103 tyrosine (Y) or leucine (L) and / or at position 104 an alanine (A) or arginine (R) and / or at position 105 an methionine (M) or glycine (G) and / or at position 106 an glutamic acid (E) or aspartic acid (D) or leucine (L) and / or at position 107 an alanine (A) or absent and / or at position 110 an isoleucine (I) or tyrosine (Y) and / or at position 116 an methionine (M) or leucine (L).

[0086] In one example, the amino acid sequence of SEQ ID NO:4 has an alanine (A) at position 5 and an aspartic acid (D) at position 10 and an aspartic acid (L) at position 11 and an glycine (G) at position 16 and an alanine (A) at position 31 and an alanine (A) at position 33 and an alanine (S) at position 35 and an alanine (A) at position 50 and an alanine (S) at position 52 and an alanine (G) at position 53 and an alanine (S) at position 54 and an alanine (S) at position 57 and an alanine (A) at position 58. (T) and isoleucine (I) at position 93 and arginine (R) at position 98 and leucine (L) at position 100 and arginine (R) at position 101 and valine (V) at position 102 and tyrosine (Y) at position 103 and alanine (A) at position 104 and methionine (M) at position 105 and glutamic acid (E) at position 106 and alanine (A) at position 107 and isoleucine (I) at position 110 and methionine (M) at position 116.

[0087] In one example, the amino acid sequence of SEQ ID NO:4 contains a valine (V) at position 5, a glycine (G) at position 10, a valine (V) at position 11, an arginine (R) at position 16, a serine (S) at position 31, an alanine (A) at position 33, a histidine (H) at position 35, a valine (V) at position 50, an absent at position 52, a tyrosine (Y) at position 53, a serine (S) at position 54, a serine (S) at position 57, and a tyrosine (Y) at position 58. at position 98, and serine (S) at position 100, and serine (S) at position 101, and glycine (G) at position 102, and tyrosine (Y) at position 103, and arginine (R) at position 104, and glycine (G) at position 105, and aspartic acid (D) at position 106, and absent at position 107, and tyrosine (Y) at position 110, and leucine (L) at position 116.

[0088] In one example, the amino acid sequence of SEQ ID NO:4 has leucine (L) at position 5 and glycine (G) at position 10 and leucine (L) at position 11 and glycine (G) at position 16 and aspartic acid (D) at position 31 and glycine (G) at position 33 and serine (S) at position 35 and alanine (A) at position 50 and glycine (G) at position 52 and tyrosine (Y) at position 53 and glycine (G) at position 54 and glycine (G) at position 57 and glycine (G) at position 58 and glycine (G) at position 59 and glycine (G) at position 60 and glycine (G) at position 61 and glycine (G) at position 62 and glycine (G) at position 63 and glycine (G) at position 64 and glycine (G) at position 65 and glycine (G) at position 66 and glycine (G) at position 67 and glycine (G) at position 68 and glycine (G) at position 69 and glycine (G) at position 70 and glycine (G) at position 71 and glycine (G) at position 72 and glycine (G) at position 73 and glycine (G) at position 74 and glycine (G) at position 75 and glycine (G) at position 76 and glycine (G) at position 77 and glycine (G) at position 78 and glycine (G) at position 79 and glycine (G) at position 80 and glycine (G) at position 81 and glycine (G) at position 82 and glycine (G) at position 83 and glycine (G) at position 84 and glycine (G) at position 85 and glycine (G) at position 86 and at position 8, lysine (K) and at position 93, valine (V) and at position 98, lysine (K) and at position 100, threonine (T) and at position 101, tryptophan (W) and at position 102, tryptophan (W) and at position 103, leucine (L) and at position 104, alanine (A) and at position 105, glycine (G) and at position 106, leucine (L) and at position 107, absent and at position 110, tyrosine (Y) and at position 116, leucine (L).

[0089]

[0090] In one example, the amino acid sequence of SEQ ID NO:5 includes an aspartic acid (D) at position 7 and an alanine (A) at position 9 and an alanine (A) at position 13 and a leucine (L) at position 14 and a valine (V) at position 18 and an arginine (R) at position 19 and a glutamine (Q) at position 26 and a serine (S) and a leucine (L) at position 27 and an arginine (R) at position 28 and an aspartic acid (D) at position 29 and a tyrosine (Y) at position 30 and an alanine (A) at position 32 and an asparagine (N) at position 33 and a phenylalanine (F) at position 35 and a glutamine (Q) at position 37 and a lysine (K) at position 38 and a proline (A) at position 39. and phenylalanine (F) at position 49 and tyrosine (Y) at position 49 and serine (S) at position 51 and aspartic acid (D) at position 52 and arginine (R) at position 76 and valine (V) at position 77 and glutamic acid (E) at position 78 and glycine (G) at position 80 and serine (S) at position 94 and aspartic acid (D) at position 95 and histidine (H) at position 96 and tryptophan (W) at position 97 and valine (V) at position 98 and glycine (G) at position 101 and leucine (L) at position 105.

[0091] In one example, the amino acid sequence of SEQ ID NO:5 includes a proline (P) at position 7 and a serine (S) at position 9 and a serine (S) at position 13 and a proline (P) at position 14 and an alanine (A) at position 18 and a threonine (T) at position 19 and a serine (S) at position 23 and a lysine (K) at position 26 and a leucine (L) at position 27 and a glycine (G) at position 28 and a glutamic acid (E) at position 29 and a threonine (T) at position 30 and a valine (V) at position 32 and a histidine (H) at position 33 and a tyrosine (Y) at position 35 and a histidine (H) at position 37 and a glutamine (Q) at position 38 and a threonine (T) at position 39 and a valine (V) at position 40 and a histidine (H) at position 41 and a tyrosine (Y) at position 42 and a histidine (H) at position 43 and a glutamine (Q) at position 44 and a threonine (T) at position 45 and a valine (V) at position 46 and a histidine (H) at position 47 and a tyrosine (Y) at position 48 and a histidine (H) at position 49 and a glutamine (Q) at position 50 and a threonine (T) at position 51 and a threonine (T) at position 52 and a threonine (T) at position 53 and a threonine (T) at position 54 and a threonine (T) at position 55 and a histidine (H) at position 56 and a glutamine (Q) at position 57 and a threonine (T) at position 58 It includes serine (S) and serine (S) at position 42 and isoleucine (I) at position 44 and valine (V) at position 47 and tyrosine (Y) at position 48 and glutamine (Q) at position 49 and phenylalanine (F) at position 51 and lysine (K) at position 52 and glycine (G) at position 76 and threonine (T) at position 77 and glutamine (Q) at position 78 and methionine (M) at position 80 and threonine (T) at position 94 and alanine (A) at position 95 and valine (V) at position 96 and absent at position 97 and absent at position 98 and glycine (G) at position 101 and leucine (L) at position 105.

[0092] In one example, the amino acid sequence of SEQ ID NO:5 contains proline (P) at position 7 and serine (S) at position 9 and serine (S) at position 13 and proline (P) at position 14 and alanine (A) at position 18 and serine (S) at position 19 and serine (S) at position 23 and lysine (K) at position 26 and valine (V) at position 27 and glycine (G) at position 28 and alanine (A) at position 29 and lysine (K) at position 30 and valine (V) at position 32 and phenylalanine (F) at position 33 and tyrosine (Y) at position 35 and glutamine (Q) at position 37 and lysine (K) at position 38 and proline ( and serine (S) at position 42 and valine (V) at position 44 and valine (V) at position 47 and tyrosine (Y) at position 48 and glutamine (Q) at position 49 and asparagine (N) at position 51 and lysine (K) at position 52 and glycine (G) at position 76 and threonine (T) at position 77 and glutamine (Q) at position 78 and methionine (M) at position 80 and threonine (T) at position 94 and alanine (A) at position 95 and leucine (L) at position 96 and tyrosine (Y) at position 97 and valine (V) at position 98 and threonine (T) at position 101 and valine (V) at position 105.

[0093] In one example, the anti-CD117 antibody is (i) V comprising the sequence shown in SEQ ID NO: 7 H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:10 L V containing the three CDRs L ; (ii) V comprising the sequence shown in SEQ ID NO: 13 H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:16 L V containing the three CDRs L ; (iii) V comprising the sequence shown in SEQ ID NO: 19 H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:22 L V containing the three CDRs L ;or (iv) V comprising the sequence shown in SEQ ID NO: 25H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:28 L V containing the three CDRs L ;or (v) V comprising a CDR1 having the sequence shown in SEQ ID NO: 42, a CDR2 having the sequence shown in SEQ ID NO: 43, and a CDR3 having the sequence shown in SEQ ID NO: 44 H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:45, a CDR2 comprising the sequence set forth in SEQ ID NO:46, and a CDR3 comprising the sequence set forth in SEQ ID NO:47. L ;or (vi) a V comprising a CDR1 having the sequence shown in SEQ ID NO: 48, a CDR2 having the sequence shown in SEQ ID NO: 49, and a CDR3 having the sequence shown in SEQ ID NO: 50 H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:51, a CDR2 comprising the sequence set forth in SEQ ID NO:52, and a CDR3 comprising the sequence set forth in SEQ ID NO:53. L ;or (vii) a V comprising a CDR1 having the sequence shown in SEQ ID NO: 54, a CDR2 having the sequence shown in SEQ ID NO: 55, and a CDR3 having the sequence shown in SEQ ID NO: 56 H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:57, a CDR2 comprising the sequence set forth in SEQ ID NO:58, and a CDR3 comprising the sequence set forth in SEQ ID NO:59. L ;or (viii) V comprising CDR1 having the sequence shown in SEQ ID NO: 60, CDR2 having the sequence shown in SEQ ID NO: 61, and CDR3 having the sequence shown in SEQ ID NO: 62 H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:63, a CDR2 comprising the sequence set forth in SEQ ID NO:64, and a CDR3 comprising the sequence set forth in SEQ ID NO:65. L Includes.

[0094] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:10 L V containing the three CDRsL Includes.

[0095] In one example, the anti-CD117 antibody comprises a CDR1 comprising amino acids 31-35 of SEQ ID NO:7, a CDR2 comprising amino acids 50-66 of SEQ ID NO:7, and a CDR3 comprising amino acids 99-110 of SEQ ID NO:7. H and V comprising CDR1 comprising amino acids 23 to 33 of SEQ ID NO:10, CDR2 comprising amino acids 49 to 55 of SEQ ID NO:10, and CDR3 comprising amino acids 88 to 98 of SEQ ID NO:10. L Includes.

[0096] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:16 L V containing the three CDRs L Includes.

[0097] In one example, the anti-CD117 antibody comprises a CDR1 comprising amino acids 31-36 of SEQ ID NO:13, a CDR2 comprising amino acids 51-66 of SEQ ID NO:13, and a CDR3 comprising amino acids 99-114 of SEQ ID NO:13. H and V comprising CDR1 comprising amino acids 23 to 33 of SEQ ID NO:16, CDR2 comprising amino acids 49 to 55 of SEQ ID NO:16, and CDR3 comprising amino acids 88 to 96 of SEQ ID NO:16. L Includes.

[0098] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:22 L V containing the three CDRs L Includes.

[0099] In one example, the anti-CD117 antibody comprises a CDR1 comprising amino acids 31-35 of SEQ ID NO:19, a CDR2 comprising amino acids 50-65 of SEQ ID NO:19, and a CDR3 comprising amino acids 98-108 of SEQ ID NO:19. Hand V comprising CDR1 comprising amino acids 23 to 33 of SEQ ID NO:22, CDR2 comprising amino acids 49 to 55 of SEQ ID NO:22, and CDR3 comprising amino acids 88 to 98 of SEQ ID NO:22. L Includes.

[0100] In one example, the anti-CD117 antibody comprises a V H V containing the three CDRs H and V comprising the sequence shown in SEQ ID NO:28 L V containing the three CDRs L Includes.

[0101] In one example, the anti-CD117 antibody comprises a CDR1 comprising amino acids 31-35 of SEQ ID NO:25, a CDR2 comprising amino acids 50-66 of SEQ ID NO:25, and a CDR3 comprising amino acids 99-109 of SEQ ID NO:25. H and V comprising CDR1 comprising amino acids 24 to 35 of SEQ ID NO:28, CDR2 comprising amino acids 51 to 57 of SEQ ID NO:28, and CDR3 comprising amino acids 90 to 98 of SEQ ID NO:28. L Includes.

[0102] In one example, the anti-CD117 antibody comprises a CDR1 comprising the sequence set forth in SEQ ID NO: 42, a CDR2 comprising the sequence set forth in SEQ ID NO: 43, and a CDR3 comprising the sequence set forth in SEQ ID NO: 44. H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:45, a CDR2 comprising the sequence set forth in SEQ ID NO:46, and a CDR3 comprising the sequence set forth in SEQ ID NO:47. L Includes.

[0103] In one example, the anti-CD117 antibody comprises a CDR1 comprising the sequence set forth in SEQ ID NO: 48, a CDR2 comprising the sequence set forth in SEQ ID NO: 49, and a CDR3 comprising the sequence set forth in SEQ ID NO: 50. H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:51, a CDR2 comprising the sequence set forth in SEQ ID NO:52, and a CDR3 comprising the sequence set forth in SEQ ID NO:53. L Includes.

[0104] In one example, the anti-CD117 antibody comprises a CDR1 comprising the sequence set forth in SEQ ID NO:54, a CDR2 comprising the sequence set forth in SEQ ID NO:55, and a CDR3 comprising the sequence set forth in SEQ ID NO:56. H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:57, a CDR2 comprising the sequence set forth in SEQ ID NO:58, and a CDR3 comprising the sequence set forth in SEQ ID NO:59. L Includes.

[0105] In one example, the anti-CD117 antibody comprises a CDR1 comprising the sequence set forth in SEQ ID NO: 60, a CDR2 comprising the sequence set forth in SEQ ID NO: 61, and a CDR3 comprising the sequence set forth in SEQ ID NO: 62. H and V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:63, a CDR2 comprising the sequence set forth in SEQ ID NO:64, and a CDR3 comprising the sequence set forth in SEQ ID NO:65. L Includes.

[0106] In one example, the anti-CD117 antibody is (i) V comprising the sequence shown in SEQ ID NO: 7 H and V comprising the sequence shown in SEQ ID NO:10 L ; (ii) V comprising the sequence shown in SEQ ID NO: 13 H and V comprising the sequence shown in SEQ ID NO:16 L ; (iii) V comprising the sequence shown in SEQ ID NO: 19 H and V comprising the sequence shown in SEQ ID NO:22 L ;or (iv) V comprising the sequence shown in SEQ ID NO: 25 H and V comprising the sequence shown in SEQ ID NO:28 L Includes.

[0107] In one example, the anti-CD117 antibody comprises a V H and V comprising the sequence shown in SEQ ID NO:10 L Includes.

[0108] In one example, the anti-CD117 antibody comprises a V Hand V comprising the sequence shown in SEQ ID NO:16 L Includes.

[0109] In one example, the anti-CD117 antibody comprises a V H and V comprising the sequence shown in SEQ ID NO:22 L Includes.

[0110] In one example, the anti-CD117 antibody comprises a V H and V comprising the sequence shown in SEQ ID NO:28 L Includes.

[0111] In one example, the anti-CD117 antibody is (i) V comprising the sequence shown in SEQ ID NO: 7 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:10. L lambda light chains, including; (ii) V comprising the sequence shown in SEQ ID NO: 13 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO: 16. L lambda light chains, including; (iii) V comprising the sequence shown in SEQ ID NO: 19 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:22. L a lambda light chain comprising (iv) V comprising the sequence shown in SEQ ID NO: 25 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:28. L Kappa light chains, including Includes.

[0112] In one example, the anti-CD117 antibody comprises a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:10. L The lambda light chain comprises

[0113] In one example, the anti-CD117 antibody comprises a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO: 16.L The lambda light chain comprises

[0114] In one example, the anti-CD117 antibody comprises a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:22. L The lambda light chain comprises

[0115] In one example, the anti-CD117 antibody comprises a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:28. L The kappa light chains include

[0116] In one example, the anti-CD117 antibody is (i) a heavy chain comprising the sequence set forth in SEQ ID NO:6; and a light chain comprising the sequence set forth in SEQ ID NO:9; (ii) a heavy chain comprising the sequence set forth in SEQ ID NO: 12; and a light chain comprising the sequence set forth in SEQ ID NO: 15; (iii) a heavy chain comprising the sequence set forth in SEQ ID NO: 18; and a light chain comprising the sequence set forth in SEQ ID NO: 21; (iv) a heavy chain comprising the sequence set forth in SEQ ID NO:24; and a light chain comprising the sequence set forth in SEQ ID NO:27; (v) a heavy chain comprising the sequence set forth in SEQ ID NO:67; and a light chain comprising the sequence set forth in SEQ ID NO:69; (vi) a heavy chain comprising the sequence set forth in SEQ ID NO: 71; and a light chain comprising the sequence set forth in SEQ ID NO: 73; (vii) a heavy chain comprising the sequence set forth in SEQ ID NO: 75; and a light chain comprising the sequence set forth in SEQ ID NO: 77; (viii) a heavy chain comprising the sequence set forth in SEQ ID NO: 79; and a light chain comprising the sequence set forth in SEQ ID NO: 81; (ix) a heavy chain comprising the sequence set forth in SEQ ID NO: 83; and a light chain comprising the sequence set forth in SEQ ID NO: 85; (x) a heavy chain comprising the sequence set forth in SEQ ID NO: 87; and a light chain comprising the sequence set forth in SEQ ID NO: 89; (xi) a heavy chain comprising the sequence set forth in SEQ ID NO: 91; and a light chain comprising the sequence set forth in SEQ ID NO: 93; (xii) a heavy chain comprising the sequence set forth in SEQ ID NO: 95; and a light chain comprising the sequence set forth in SEQ ID NO: 97; (xiii) a heavy chain comprising the sequence set forth in SEQ ID NO: 99; and a light chain comprising the sequence set forth in SEQ ID NO: 101; (xiv) a heavy chain comprising the sequence set forth in SEQ ID NO: 103; and a light chain comprising the sequence set forth in SEQ ID NO: 105; or (xv) a heavy chain comprising the sequence set forth in SEQ ID NO: 107; and a light chain comprising the sequence set forth in SEQ ID NO: 109; or (xvi) a heavy chain comprising the sequence set forth in SEQ ID NO: 113; and a light chain comprising the sequence set forth in SEQ ID NO: 111; or (xvii) a heavy chain comprising the sequence set forth in SEQ ID NO: 115; and a light chain comprising the sequence set forth in SEQ ID NO: 111. Includes.

[0117] In one example, the anti-CD117 antibody is (i) a heavy chain comprising amino acids 20 to 467 of SEQ ID NO: 6; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 9; (ii) a heavy chain comprising amino acids 20 to 471 of SEQ ID NO: 12; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 15; (iii) a heavy chain comprising amino acids 20 to 465 of SEQ ID NO: 18; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 21; or (iv) a heavy chain comprising amino acids 20 to 466 of SEQ ID NO: 24; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 27; or (v) a heavy chain comprising amino acids 20 to 470 of SEQ ID NO: 67; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 69; (vi) a heavy chain comprising amino acids 20 to 480 of SEQ ID NO: 71; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 73; (vii) a heavy chain comprising amino acids 20 to 478 of SEQ ID NO: 75; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 77; (viii) a heavy chain comprising amino acids 20 to 474 of SEQ ID NO: 79; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 81; (ix) a heavy chain comprising amino acids 20 to 484 of SEQ ID NO: 83; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 85; (x) a heavy chain comprising amino acids 20 to 468 of SEQ ID NO: 87; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 89; (xi) a heavy chain comprising amino acids 20 to 478 of SEQ ID NO: 91; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 93; (xii) a heavy chain comprising amino acids 20 to 476 of SEQ ID NO: 95; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 97; (xiii) a heavy chain comprising amino acids 20 to 469 of SEQ ID NO: 99; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 101; (xiv) a heavy chain comprising amino acids 20 to 479 of SEQ ID NO: 103; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 105; or (xv) a heavy chain comprising amino acids 20 to 477 of SEQ ID NO: 107; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 109. Includes.

[0118] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 6; and a light chain comprising the sequence set forth in SEQ ID NO: 9. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 467 of SEQ ID NO: 6; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 9.

[0119] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 12; and a light chain comprising the sequence set forth in SEQ ID NO: 15. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 471 of SEQ ID NO: 12; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 15.

[0120] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 18; and a light chain comprising the sequence set forth in SEQ ID NO: 21. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 465 of SEQ ID NO: 18; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 21.

[0121] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 24; and a light chain comprising the sequence set forth in SEQ ID NO: 27. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 466 of SEQ ID NO: 24; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 27.

[0122] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 67; and a light chain comprising the sequence set forth in SEQ ID NO: 69. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 470 of SEQ ID NO: 67; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 69.

[0123] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 71; and a light chain comprising the sequence set forth in SEQ ID NO: 73. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 480 of SEQ ID NO: 71; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 73.

[0124] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 75; and a light chain comprising the sequence set forth in SEQ ID NO: 77. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 478 of SEQ ID NO: 75; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 77.

[0125] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 79; and a light chain comprising the sequence set forth in SEQ ID NO: 81. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 474 of SEQ ID NO: 79; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 81.

[0126] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 83; and a light chain comprising the sequence set forth in SEQ ID NO: 85. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 484 of SEQ ID NO: 83; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 85.

[0127] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 87; and a light chain comprising the sequence set forth in SEQ ID NO: 89. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 468 of SEQ ID NO: 87; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 89.

[0128] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 91; and a light chain comprising the sequence set forth in SEQ ID NO: 93. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 478 of SEQ ID NO: 91; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 93.

[0129] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 95; and a light chain comprising the sequence set forth in SEQ ID NO: 97. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 476 of SEQ ID NO: 95; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 97.

[0130] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 99; and a light chain comprising the sequence set forth in SEQ ID NO: 101. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 469 of SEQ ID NO: 99; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 101.

[0131] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 103; and a light chain comprising the sequence set forth in SEQ ID NO: 105. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 479 of SEQ ID NO: 103; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 105.

[0132] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 107; and a light chain comprising the sequence set forth in SEQ ID NO: 109. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 477 of SEQ ID NO: 107; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 109.

[0133] In one example, the subject suffers from a disease or condition that requires treatment with HCT. For example, the subject suffers from cancer, hemoglobin disorder, myelodysplastic disorder, primary immune deficiency (PID), autoimmune disorder, immunodeficiency disorder, or metabolic disorder.

[0134] In one example, the subject suffers from cancer. For example, the cancer is a hematological (or blood) cancer. In one example, the hematological / blood cell cancer is leukemia, lymphoma or other blood cancer. For example, the leukemia is acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, or hairy cell leukemia. In one example, the lymphoma is AIDS-related lymphoma, cutaneous T-cell lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma mycosis fungoides, Sezary syndrome, Waldenstrom's macroglobulinemia, or primary central nervous system lymphoma. In one example, the other hematological cancer is chronic myeloproliferative disorder, multiple myeloma / plasma cell neoplasm, myelodysplastic syndrome, myelodysplastic / myeloproliferative disorder, neuroblastoma, or Ewing's sarcoma.

[0135] In one example, the subject is afflicted with a myelodysplastic disorder.

[0136] In one example, the subject suffers from a hemoglobin disorder, such as sickle cell anemia, thalassemia, Fanconi anemia, or aplastic anemia.

[0137] In one example, the subject suffers from a primary immune deficiency (PID). For example, PIDs include activated PI3K delta syndrome (APDS), X-linked agammaglobulinemia (XLA), ataxia telangiectasia, chronic granulomatous disease (CGD) and other phagocytic disorders, common variable immunodeficiency (CVID), complement deficiencies, DiGeorge syndrome, hemophagocytic lymphohistiocytosis (HLH), hyper-IgE syndrome, hyper-IgM syndrome, IgG subclass deficiencies, innate immune defects, Toll-like receptor (TLR) deficiencies (MyD88 deficiency, IRAK4 deficiency, UNC9 deficiency, and others). 3B deficiency and TLR3 mutations), human natural killer cell deficiency, defects in interferon-gamma (IFN-γ) and interleukin-12 (IL-12) signaling, leukocyte adhesion deficiency (LAD), NEMO deficiency syndrome, selective IgA deficiency, selective IgM deficiency, severe combined immunodeficiency (SCID) and combined immunodeficiency, specific antibody deficiencies, transient hypogammaglobulinemia of infancy, WHIM syndrome (warts, hypogammaglobulinemia, infections, and and myeloid cellular pooling), Wiskott-Aldrich syndrome, antibody deficiency with normal or elevated immunoglobulins, immunodeficiency with thymoma (Good's syndrome), transcobalamin II deficiency, kappa chain deficiency, heavy chain deficiency, postmeiotic segregation (PMS2) disorder, hypogammaglobulinemia not otherwise specified, chronic mucocutaneous candidiasis (CMC), cartilage-hair hypoplasia (CHH), X-linked lymphoproliferative (XLP) syndromes 1 and 2, X-linked immune dysregulation with polyendocrinopathy (I-linked immune dysregulation with polyendocrinopathy (PID) syndromes 2 and 3, and X-linked immune dysregulation with polyendocrinopathy (PID) syndromes 4 and 5. These include PEX (prostate cancer exacerbation) syndrome, veno-occlusive disease (VODI), Hoyeral-Freidarsson syndrome (dyskeratosis congenita), immunodeficiency with centromere instability and facial anomalies (ICF), Schimke syndrome, Kommerl-Netherton syndrome, Diamond-Blackfan anemia, Schwachman-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen instability syndrome, or graft-versus-host disease (GvHD).In some instances, the PID is Wiskott-Aldrich syndrome, X-linked agammaglobulinemia (XLA), Diamond-Blackfan anemia, Schwachman-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen instability syndrome, or graft-versus-host disease (GvHD).

[0138] In one example, the subject suffers from an autoimmune disorder.For example, the autoimmune disorder is multiple sclerosis or diabetes.For example, the diabetes is type I diabetes.

[0139] In one example, the subject suffers from an immunodeficiency disorder, for example, the immunodeficiency disorder is human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS).

[0140] In one example, the subject is suffering from a metabolic disorder, for example, the metabolic disorder is glycogen storage disease, mucopolysaccharidoses, Gaucher disease, Hurler disease, sphingolipidosis, or metachromatic leukodystrophy.

[0141] In one example, the subject has undergone, is undergoing, or will undergo an additional conditioning regimen. For example, the subject has undergone an additional conditioning regimen. In one example, the subject is undergoing an additional conditioning regimen. In a further example, the subject is going to undergo an additional conditioning regimen.

[0142] In one example, the additional conditioning regimen is a non-myeloablative or reduced intensity conditioning regimen. For example, the additional conditioning regimen is a non-myeloablative conditioning regimen. In one example, the additional conditioning regimen is a reduced intensity conditioning regimen.

[0143] Suitable non-myeloablative and reduced intensity conditioning regimens for use in the present disclosure will be apparent to those of skill in the art and / or are described herein.

[0144] In one example of any of the methods described herein, the subject further undergoes HCT following administration of the antibody.

[0145] The present disclosure provides methods of HCT in a subject in need of HCT, where the subject has already received treatment with an antibody that binds or specifically binds to a target on endogenous HSCs in the subject.

[0146] The present disclosure also provides a method of HCT in a subject in need of HCT, where the subject has already received treatment with an antibody that binds or specifically binds to a target on endogenous HSCs in the subject, and the antibody mediates ADCT.

[0147] The present disclosure provides a method of HCT in a subject in need thereof, the method comprising: (i) conditioning the patient with an antibody that binds or specifically binds to a target on endogenous HSCs in the subject; and (ii) administering a hematopoietic cell transplant to the subject; The present invention further provides a method comprising:

[0148] The disclosure also provides a method of reducing a side effect of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject.

[0149] The present disclosure also further provides a method of reducing a side effect of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0150] The present disclosure also provides a method of reducing a side effect of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody comprising an extended hinge region.

[0151] The present disclosure also further provides a method of reducing a side effect of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody comprising an extended hinge region.

[0152] The present disclosure provides an anti-CD117 antibody, the antibody comprising: (i) V comprising the sequence shown in SEQ ID NO: 7 H and V comprising the sequence shown in SEQ ID NO:10 L ; (ii) V comprising the sequence shown in SEQ ID NO: 13 H and V comprising the sequence shown in SEQ ID NO:16 L ; (iii) V comprising the sequence shown in SEQ ID NO: 19 H and V comprising the sequence shown in SEQ ID NO:22 L ;or (iv) V comprising the sequence shown in SEQ ID NO: 25 H and V comprising the sequence shown in SEQ ID NO:28 L The present invention provides an anti-CD117 antibody comprising:

[0153] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and V comprising the sequence shown in SEQ ID NO:10 L The present invention provides an anti-CD117 antibody comprising:

[0154] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and V comprising the sequence shown in SEQ ID NO:16 L The present invention provides an anti-CD117 antibody comprising:

[0155] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and V comprising the sequence shown in SEQ ID NO:22 L The present invention provides an anti-CD117 antibody comprising:

[0156] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and V comprising the sequence shown in SEQ ID NO:28 L The present invention provides an anti-CD117 antibody comprising:

[0157] The present disclosure provides an anti-CD117 antibody, the antibody comprising: (i) V comprising the sequence shown in SEQ ID NO: 7 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:10. L lambda light chains, including; (ii) V comprising the sequence shown in SEQ ID NO: 13 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO: 16. L lambda light chains, including; (iii) V comprising the sequence shown in SEQ ID NO: 19 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:22. L a lambda light chain comprising (iv) V comprising the sequence shown in SEQ ID NO: 25 H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:28. L Kappa light chains, including The present invention further provides an anti-CD117 antibody, comprising:

[0158] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:10. L The present invention provides an anti-CD117 antibody comprising a lambda light chain comprising:

[0159] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO: 16. L The present invention provides an anti-CD117 antibody comprising a lambda light chain comprising:

[0160] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V Hand an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:22. L The present invention provides an anti-CD117 antibody comprising a lambda light chain comprising:

[0161] The present disclosure relates to an anti-CD117 antibody, the antibody comprising a V H and an IgA2 heavy chain comprising the sequence shown in SEQ ID NO:28. L The present invention provides an anti-CD117 antibody comprising a kappa light chain comprising:

[0162] The present disclosure also provides an anti-CD117 antibody, the antibody comprising: (i) a heavy chain comprising the sequence set forth in SEQ ID NO:6; and a light chain comprising the sequence set forth in SEQ ID NO:9; (ii) a heavy chain comprising the sequence set forth in SEQ ID NO: 12; and a light chain comprising the sequence set forth in SEQ ID NO: 15; (iii) a heavy chain comprising the sequence set forth in SEQ ID NO: 18; and a light chain comprising the sequence set forth in SEQ ID NO: 21; (iv) a heavy chain comprising the sequence set forth in SEQ ID NO:24; and a light chain comprising the sequence set forth in SEQ ID NO:27; (v) a heavy chain comprising the sequence set forth in SEQ ID NO:67; and a light chain comprising the sequence set forth in SEQ ID NO:69; (vi) a heavy chain comprising the sequence set forth in SEQ ID NO: 71; and a light chain comprising the sequence set forth in SEQ ID NO: 73; (vii) a heavy chain comprising the sequence set forth in SEQ ID NO: 75; and a light chain comprising the sequence set forth in SEQ ID NO: 77; (viii) a heavy chain comprising the sequence set forth in SEQ ID NO: 79; and a light chain comprising the sequence set forth in SEQ ID NO: 81; (ix) a heavy chain comprising the sequence set forth in SEQ ID NO: 83; and a light chain comprising the sequence set forth in SEQ ID NO: 85; (x) a heavy chain comprising the sequence set forth in SEQ ID NO: 87; and a light chain comprising the sequence set forth in SEQ ID NO: 89; (xi) a heavy chain comprising the sequence set forth in SEQ ID NO: 91; and a light chain comprising the sequence set forth in SEQ ID NO: 93; (xii) a heavy chain comprising the sequence set forth in SEQ ID NO: 95; and a light chain comprising the sequence set forth in SEQ ID NO: 97; (xiii) a heavy chain comprising the sequence set forth in SEQ ID NO: 99; and a light chain comprising the sequence set forth in SEQ ID NO: 101; (xiv) a heavy chain comprising the sequence set forth in SEQ ID NO: 103; and a light chain comprising the sequence set forth in SEQ ID NO: 105; or (xv) a heavy chain comprising the sequence set forth in SEQ ID NO: 107; and a light chain comprising the sequence set forth in SEQ ID NO: 109. The present invention provides an anti-CD117 antibody comprising:

[0163] In one example, the heavy and / or light chain sequences do not include a signal sequence.

[0164] The present disclosure also provides an anti-CD117 antibody, the antibody comprising: (i) a heavy chain comprising amino acids 20 to 467 of SEQ ID NO: 6; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 9; (ii) a heavy chain comprising amino acids 20 to 471 of SEQ ID NO: 12; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 15; (iii) a heavy chain comprising amino acids 20 to 465 of SEQ ID NO: 18; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 21; or (iv) a heavy chain comprising amino acids 20 to 466 of SEQ ID NO: 24; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 27; or (v) a heavy chain comprising amino acids 20 to 470 of SEQ ID NO: 67; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 69; (vi) a heavy chain comprising amino acids 20 to 480 of SEQ ID NO: 71; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 73; (vii) a heavy chain comprising amino acids 20 to 478 of SEQ ID NO: 75; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 77; (viii) a heavy chain comprising amino acids 20 to 474 of SEQ ID NO: 79; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 81; (ix) a heavy chain comprising amino acids 20 to 484 of SEQ ID NO: 83; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 85; (x) a heavy chain comprising amino acids 20 to 468 of SEQ ID NO: 87; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 89; (xi) a heavy chain comprising amino acids 20 to 478 of SEQ ID NO: 91; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 93; (xii) a heavy chain comprising amino acids 20 to 476 of SEQ ID NO: 95; and a light chain comprising amino acids 20 to 233 of SEQ ID NO: 97; (xiii) a heavy chain comprising amino acids 20 to 469 of SEQ ID NO: 99; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 101; (xiv) a heavy chain comprising amino acids 20 to 479 of SEQ ID NO: 103; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 105; or (xv) a heavy chain comprising amino acids 20 to 477 of SEQ ID NO: 107; and a light chain comprising amino acids 20 to 234 of SEQ ID NO: 109. Includes.

[0165] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 6; and a light chain comprising the sequence set forth in SEQ ID NO: 9. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-467 of SEQ ID NO: 6; and a light chain comprising amino acids 20-233 of SEQ ID NO: 9.

[0166] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 12; and a light chain comprising the sequence set forth in SEQ ID NO: 15. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-471 of SEQ ID NO: 12; and a light chain comprising amino acids 20-231 of SEQ ID NO: 15.

[0167] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 18; and a light chain comprising the sequence set forth in SEQ ID NO: 21. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-465 of SEQ ID NO: 18; and a light chain comprising amino acids 20-233 of SEQ ID NO: 21.

[0168] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 24; and a light chain comprising the sequence set forth in SEQ ID NO: 27. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-466 of SEQ ID NO: 24; and a light chain comprising amino acids 20-233 of SEQ ID NO: 27.

[0169] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 67; and a light chain comprising the sequence set forth in SEQ ID NO: 69. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-470 of SEQ ID NO: 67; and a light chain comprising amino acids 20-233 of SEQ ID NO: 69.

[0170] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 71; and a light chain comprising the sequence set forth in SEQ ID NO: 73. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-480 of SEQ ID NO: 71; and a light chain comprising amino acids 20-233 of SEQ ID NO: 73.

[0171] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 75; and a light chain comprising the sequence set forth in SEQ ID NO: 77. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-478 of SEQ ID NO: 75; and a light chain comprising amino acids 20-233 of SEQ ID NO: 77.

[0172] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 79; and a light chain comprising the sequence set forth in SEQ ID NO: 81. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20 to 474 of SEQ ID NO: 79; and a light chain comprising amino acids 20 to 231 of SEQ ID NO: 81.

[0173] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 83; and a light chain comprising the sequence set forth in SEQ ID NO: 85. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-484 of SEQ ID NO: 83; and a light chain comprising amino acids 20-231 of SEQ ID NO: 85.

[0174] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 87; and a light chain comprising the sequence set forth in SEQ ID NO: 89. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-468 of SEQ ID NO: 87; and a light chain comprising amino acids 20-233 of SEQ ID NO: 89.

[0175] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 91; and a light chain comprising the sequence set forth in SEQ ID NO: 93. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-478 of SEQ ID NO: 91; and a light chain comprising amino acids 20-233 of SEQ ID NO: 93.

[0176] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 95; and a light chain comprising the sequence set forth in SEQ ID NO: 97. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-476 of SEQ ID NO: 95; and a light chain comprising amino acids 20-233 of SEQ ID NO: 97.

[0177] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 99; and a light chain comprising the sequence set forth in SEQ ID NO: 101. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-469 of SEQ ID NO: 99; and a light chain comprising amino acids 20-234 of SEQ ID NO: 101.

[0178] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence set forth in SEQ ID NO: 103; and a light chain comprising the sequence set forth in SEQ ID NO: 105. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-479 of SEQ ID NO: 103; and a light chain comprising amino acids 20-234 of SEQ ID NO: 105.

[0179] The present disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO: 107; and a light chain comprising the sequence set forth in SEQ ID NO: 109. For example, the anti-CD117 antibody comprises a heavy chain comprising amino acids 20-477 of SEQ ID NO: 107; and a light chain comprising amino acids 20-234 of SEQ ID NO: 109.

[0180] The present disclosure also provides an anti-CD117 antibody, the antibody comprising: (i) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:8; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:11; (ii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:14; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:17; (iii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:20; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:23; (iv) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:26; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:29; (v) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:68; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:70; (vi) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:72; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:74; (vii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:76; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:78; (viii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 80; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 82; (ix) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 84; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 86; (x) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:88; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:90; (xi) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:92; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:94; (xii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 96; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 98; (xiii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:100; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:102; (xiv) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 104; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 106; or (xv) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 108; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 110; or (xvi) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:114; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:112; or (xvii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:116; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:112. Includes.

[0181] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:8; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:11.

[0182] In one example, the disclosure provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:8; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:11, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:11.

[0183] In one example, the disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:14; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:17.

[0184] In one example, the disclosure provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:14; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:17, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:17.

[0185] In one example, the disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:20; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:23.

[0186] In one example, the disclosure provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:20; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:23, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:23.

[0187] In one example, the disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:26; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:29.

[0188] In one example, the disclosure provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:26; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:29, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:29.

[0189] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:68; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:70.

[0190] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:68; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:70, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:70.

[0191] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:72; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:74.

[0192] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:72; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:74, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:74.

[0193] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:76; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:78.

[0194] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:76; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:78, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:78.

[0195] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:80; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:82.

[0196] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:80; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:82, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:82.

[0197] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:84; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:86.

[0198] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:84; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:86, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:86.

[0199] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:88; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:90.

[0200] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:88; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:90, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:90.

[0201] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:92; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:94.

[0202] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:92; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:94, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:94.

[0203] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:96; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:98.

[0204] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:96; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:98, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:98.

[0205] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:100; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:102.

[0206] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:100; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:102, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:102.

[0207] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:104; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:106.

[0208] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:104; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:106, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:106.

[0209] The disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:108; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:110.

[0210] The disclosure also provides an anti-CD117 antibody, the antibody comprising a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:108; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:110, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46-128 of SEQ ID NO:110.

[0211] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, the anti-CD117 antibody comprising: a heavy chain comprising the sequence set forth in SEQ ID NO:113; and a light chain comprising the sequence set forth in SEQ ID NO:111.

[0212] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, the anti-CD117 antibody comprising: a heavy chain comprising the sequence set forth in SEQ ID NO:115; and a light chain comprising the sequence set forth in SEQ ID NO:111.

[0213] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, the antibody comprising: a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:114; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:112.

[0214] The disclosure also provides an anti-CD117 antibody extended hinge region, wherein the antibody comprises a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:116; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:112.

[0215] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, (i) a C-terminal CH1 sequence from IgA, an upper hinge sequence from IgG3, a middle hinge sequence from IgG3, a lower hinge sequence from IgG3, and past the lower hinge sequence from IgA; or (ii) a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 127; or (iii) a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 128. The present invention provides an anti-CD117 antibody comprising:

[0216] In one example, an anti-CD117 antibody comprising an extended hinge region comprises a C-terminal CH1 sequence from IgA, an upper hinge sequence from IgG3, a middle hinge sequence from IgG3, a lower hinge sequence from IgG3, and a sequence past the lower hinge sequence from IgA. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a C-terminal CH1 sequence from IgA. In one example, an anti-CD117 antibody comprising an extended hinge region comprises an upper hinge sequence from IgG3. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a middle hinge sequence from IgG3. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a lower hinge sequence from IgG3. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a sequence past the lower hinge sequence from IgA.

[0217] In one example, an anti-CD117 antibody comprising an extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and / or a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 127, and combinations thereof. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123. In one example, an anti-CD117 antibody comprising an extended hinge region comprises an upper hinge comprising the sequence set forth in SEQ ID NO: 124. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a middle hinge comprising the sequence set forth in SEQ ID NO: 125. In one example, an anti-CD117 antibody comprising an extended hinge region comprises an upper hinge comprising a lower hinge comprising the sequence set forth in SEQ ID NO: 126. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a sequence past the lower hinge that comprises the sequence set forth in SEQ ID NO:127.

[0218] In one example, an anti-CD117 antibody comprising an extended hinge region comprises an a-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and / or a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 128, and combinations thereof. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123. In one example, an anti-CD117 antibody comprising an extended hinge region comprises an upper hinge comprising the sequence set forth in SEQ ID NO: 124. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a middle hinge comprising the sequence set forth in SEQ ID NO: 125. In one example, an anti-CD117 antibody comprising an extended hinge region comprises an upper hinge comprising a lower hinge comprising the sequence set forth in SEQ ID NO: 126. In one example, an anti-CD117 antibody comprising an extended hinge region comprises a sequence past the lower hinge that comprises the sequence set forth in SEQ ID NO:128.

[0219] In one example, the level of effector function induced by the anti-CD117 antibody comprising the extended hinge region is improved compared to the antibody without the extended hinge region. In one example, the anti-CD117 antibody comprising the extended hinge region improves the pharmacokinetic properties of the antibody compared to the antibody without the extended hinge region. In one example, the anti-CD117 antibody comprising the extended hinge region increases the half-life of the antibody compared to the anti-CD117 antibody comprising the extended hinge region. In one example, the anti-CD117 antibody comprising the extended hinge region improves the stability of the anti-CD117 antibody comprising the extended hinge region compared to the antibody without the extended hinge region. In one example, the anti-CD117 antibody comprising the extended hinge region increases the affinity of the hinge region to the fetal Fc region (FcRn) compared to the antibody without the extended hinge region. In one example, the anti-CD117 antibody comprising the extended hinge region has better access to its epitope compared to the antibody without the extended hinge region.

[0220] The present disclosure further provides a method of modifying the hinge region of an antibody of the present disclosure, the method comprising replacing the hinge region of the antibody with an extended hinge region.

[0221] In one example, the hinge region is modified by inserting an additional hinge region into the hinge region of the antibody.

[0222] In another example, the hinge region is modified by inserting at least a portion of an additional hinge region into the antibody hinge region after the first proline, hi another example, the hinge region is modified by inserting at least a portion of an IgG3 hinge region into the antibody IgA2 hinge region after the first proline.

[0223] In one example, the modified hinge region is an extended hinge region.

[0224] In one example, the extended hinge region is capable of inducing enhanced levels of effector function.

[0225] In one example, the level of effector function induced by the extended hinge region is improved compared to an antibody that does not have the extended hinge region. In one example, the extended hinge region improves the pharmacokinetic properties of the antibody compared to an antibody that does not have the extended hinge region. In one example, the extended hinge region increases the half-life of the antibody compared to an antibody that does not have the extended hinge region. In one example, the extended hinge region improves the stability of the antibody compared to an antibody that does not have the extended hinge region. In one example, the extended hinge region increases the affinity of the hinge region for the fetal Fc region (FcRn) compared to an antibody that does not have the extended hinge region. In one example, the extended hinge region provides better access to its epitope compared to an antibody that does not have the extended hinge region.

[0226] In one example, the extended hinge region comprises a C-terminal CH1 sequence from IgA, an upper hinge sequence from IgG3, a middle hinge sequence from IgG3, a lower hinge sequence from IgG3, and / or a sequence past the lower hinge sequence from IgA and combinations thereof. In one example, the extended hinge region comprises a C-terminal CH1 sequence from IgA. In one example, the extended hinge region comprises an upper hinge sequence from IgG3. In one example, the extended hinge region comprises a middle hinge sequence from IgG3. In one example, the extended hinge region comprises a lower hinge sequence from IgG3. In one example, the extended hinge region comprises a sequence past the lower hinge sequence from IgA.

[0227] In one example, the extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and / or a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 127, and combinations thereof. In one example, the extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123. In one example, the extended hinge region comprises an upper hinge comprising the sequence set forth in SEQ ID NO: 124. In one example, the extended hinge region comprises a middle hinge comprising the sequence set forth in SEQ ID NO: 125. In one example, the extended hinge region comprises an upper hinge comprising a lower hinge comprising the sequence set forth in SEQ ID NO: 126. In one example, the extended hinge region comprises a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 127.

[0228] In one example, the extended hinge region comprises an a-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123, an upper hinge comprising the sequence set forth in SEQ ID NO: 124, a middle hinge comprising the sequence set forth in SEQ ID NO: 125, a lower hinge comprising the sequence set forth in SEQ ID NO: 126, and / or a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 128, and combinations thereof. In one example, the extended hinge region comprises a C-terminal CH1 comprising the sequence set forth in SEQ ID NO: 123. In one example, the extended hinge region comprises an upper hinge comprising the sequence set forth in SEQ ID NO: 124. In one example, the extended hinge region comprises a middle hinge comprising the sequence set forth in SEQ ID NO: 125. In one example, the extended hinge region comprises an upper hinge comprising a lower hinge comprising the sequence set forth in SEQ ID NO: 126. In one example, the extended hinge region comprises a sequence past the lower hinge comprising the sequence set forth in SEQ ID NO: 128.

[0229] The present disclosure further provides a polynucleotide encoding an anti-CD117 as disclosed herein. In one example, the polynucleotide is operably linked to a heterologous promoter.

[0230] The present disclosure additionally provides an expression construct comprising a nucleic acid of the present disclosure operably linked to a promoter. Such an expression construct may be a vector, for example, a plasmid.

[0231] In one example, the expression construct of the present disclosure comprises one of the polypeptides (e.g., V H ) and another of the polypeptides operably linked to another promoter (e.g., V L The nucleic acid encoding the

[0232] In another example, the expression construct is a bicistronic expression construct that includes, for example, the following operably linked components in 5' to 3' order: (i) Promoter (ii) a nucleic acid encoding a first polypeptide; (iii) an internal ribosome entry site; and (iv) a nucleic acid encoding a second polypeptide.

[0233] For example, the first polypeptide may be H and the second polypeptide comprises V L or the first polypeptide comprises V L and the second polypeptide comprises V H Includes.

[0234] The present disclosure also contemplates separate expression constructs, one of which expresses a first polypeptide (e.g., V H ) and another encodes a second polypeptide (e.g., V L For example, the present disclosure also provides a composition comprising: (i) (e.g., a V H a first expression construct comprising a nucleic acid encoding a polypeptide comprising: (ii) (e.g., a V LA second expression construct comprising a nucleic acid encoding a polypeptide comprising wherein the first and second polypeptides associate to form the antibody of the present disclosure.

[0235] The present disclosure additionally provides an isolated cell expressing an antibody of the present disclosure or a recombinant cell genetically modified to express an antibody of the present disclosure. For example, the present disclosure provides the use of an isolated cell for preparing an antibody of the present disclosure. In one example, the cell is an isolated hybridoma. In another example, the cell is a nucleic acid of the present disclosure or an expression construct of the present disclosure, or: (i) a polypeptide operably linked to a promoter (e.g., V H a first expression construct comprising a nucleic acid encoding (ii) a polypeptide operably linked to a promoter (e.g., V L a second expression construct comprising a nucleic acid encoding wherein the first and second polypeptides associate to form the antibody of the disclosure.

[0236] The present disclosure additionally provides a pharmaceutical composition comprising an antibody or a nucleic acid or an expression construct or a cell of the present disclosure and a suitable carrier. In one example, the pharmaceutical composition comprises an antibody of the present disclosure.

[0237] In one example, the carrier is pharma- ceutically acceptable.

[0238] The disclosure additionally provides an antibody or a nucleic acid or an expression construct or a cell or a composition of the disclosure for use as a medicament.

[0239] The disclosure also provides an antibody or a nucleic acid or an expression construct or a cell or a composition of the disclosure for use in conditioning a subject in need of HCT.

[0240] The disclosure also provides for the use of an antibody that binds or specifically binds to a target on endogenous HSCs in the manufacture of a medicament for conditioning a subject in need of HCT.

[0241] The disclosure also provides for the use of an antibody that binds or specifically binds to a target on endogenous HSCs, where the antibody mediates ADCT, in the manufacture of a medicament for conditioning a subject in need of HCT.

[0242] The disclosure further provides an antibody or nucleic acid or expression construct or cell or composition of the disclosure for use in depleting a population of cells in the bone marrow of a subject in need of HCT.

[0243] The disclosure also provides for the use of an antibody that binds or specifically binds to a target on endogenous HSCs in the manufacture of a medicament for depleting a population of cells in the bone marrow of a subject in need of HCT.

[0244] The disclosure also provides for the use of an antibody that binds or specifically binds to a target on endogenous HSCs, where the antibody mediates antibody-dependent cellular trogocytosis (ADCT), in the manufacture of a medicament for depleting a population of cells in the bone marrow of a subject in need of HCT.

[0245] The disclosure further provides an antibody or a nucleic acid or an expression construct or a cell or a composition of the disclosure for use in a method of HCT.

[0246] The disclosure further provides an antibody or nucleic acid or expression construct or cell or composition of the disclosure for use in reducing the side effects of a myeloablative conditioning regimen.

[0247] The disclosure also provides the use of an antibody that binds or specifically binds to a target on endogenous HSCs in the manufacture of a medicament for reducing a side effect of a myeloablative conditioning regimen in a subject.

[0248] The disclosure also provides the use of an antibody that binds or specifically binds to a target on endogenous HSCs, where the antibody mediates ADCT, in the manufacture of a medicament for reducing side effects of a myeloablative conditioning regimen in a subject.

[0249] The disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for conditioning a subject in need of HCT.

[0250] The disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for conditioning a subject in need of HCT, wherein the antibody mediates ADCT.

[0251] The disclosure also provides for the use of an antibody comprising an extended hinge region in the manufacture of a medicament for depleting a population of cells in the bone marrow of a subject in need of HCT.

[0252] The disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for depleting a population of cells in the bone marrow of a subject in need of HCT, wherein the antibody mediates antibody-dependent cellular trogocytosis (ADCT).

[0253] The disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for reducing a side effect of a myeloablative conditioning regimen in a subject.

[0254] The disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for reducing a side effect of a myeloablative conditioning regimen in a subject, wherein the antibody mediates ADCT.

[0255] The present disclosure provides antibodies comprising an extended hinge region, wherein the antigen-binding site of an antibody of the present disclosure comprising an extended hinge region is able to bind its epitope better than the antigen-binding site of an antibody that does not have the extended hinge region.

[0256] The present disclosure additionally provides an anti-CD117 antibody that comprises an extended hinge region. In one example, the antigen-binding site of an antibody of the present disclosure that comprises an extended hinge region can bind to its epitope better than the antigen-binding site of an antibody that does not have the extended hinge region.

[0257] The present disclosure additionally provides a method for improving the ability of an antigen-binding site of an antibody to bind to its epitope, the method comprising replacing the hinge region of the antibody with an extended hinge region.

[0258] Exemplary extended hinge regions and antibodies are described herein and shall be construed as applying equally to the foregoing examples of this disclosure.

[0259] The disclosure also provides kits comprising the antibodies or nucleic acids or expression constructs or cells or compositions of the disclosure packaged with instructions for use in any of the methods described herein (e.g., methods of HCT or methods of depleting a population of cells in a subject's bone marrow).

[0260] In one example, the subject is a mammal, such as a primate, such as a human. [Brief description of the drawings]

[0261] [Figure 1]

[0036] Figure 1 is a series of graphs showing binding of anti-CD117 antibodies to cells expressing human, cynomolgus and mouse CD117. (A) Binding curves of various concentrations of anti-CD117-IgG1 antibodies to cell surface CD117 on TF-1 cells. (B) EC50 (nM) data from a single representative experiment. Specific binding curves of anti-CD117-IgG1 antibodies to HEK293FS cells stably expressing (C) human CD117, (D) cynomolgus CD117 and (E) mouse CD117, generated by subtracting non-specific binding observed on parental HEK293FS cells. (F) EC50 (nM) data from a representative experiment of anti-CD117-IgG1 antibodies to HEK293FS cells stably expressing human CD117, (G) cynomolgus CD117 and (H) mouse CD117 (* indicates that the EC50 value could not be determined). [Diagram 2] FIG. 2 is a graph showing inhibition of human stem cell factor-mediated proliferation on TF-1 cells by anti-CD117-IgG1 antibody. [Diagram 3] FIG. 1 is a series of graphs showing internalization of selected anti-CD117-IgG1 antibodies using (A) anti-AF488 quenching antibody assay and (B) IncuCyte® live cell analysis. [Figure 4] FIG. 2 is a graph showing that anti-CD117-IgG1 antibody is unable to activate the CD117 receptor and induce proliferation of TF-1 cells in the absence of stem cell factor. [Figure 5-1] A series of graphs showing the screening of anti-human CD117 antibodies against soluble N-terminal (HuCD1171-307) and C-terminal (HuCD117308-524) fragments of the human CD117 receptor. (A) Positive binding reactions are indicated by shaded bars. Global distribution of binding affinities of anti-human CD117 antibodies (dark circles) tested against (B) soluble N-terminal (HuCD1171-307) and (C) C-terminal (HuCD117308-524) fragments of the human CD117 receptor. Shaded areas indicate isophilic regions. [Figure 5-2] Continued from Figure 5-1. [Figure 6]FIG. 1 is a series of graphs showing SPR screening of anti-human CD117 antibodies against soluble (A) human CD117 and (B) cynoCD117 receptors. Antibody ligands were prepared in IgG1 (black bars), IgG4 (white bars) or IgA2 (grey bars) formats. [Figure 7-1]

[0023] Figure 1 is a series of graphs showing that anti-CD117-IgA2 antibodies induce antibody-dependent cellular cytotoxic trogocytosis (ADCT): (A) normalized DILC18 MFI±SD, (B) EC50 and (C) Bmax from n=5 donors pooled from 3 experiments. [Figure 7-2] Continued from Figure 7-1.

[0262] [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0263] Overview Throughout this specification, unless specifically stated otherwise or the context requires otherwise, references to a single step, composition of matter, group of steps or group of compositions of matter shall be interpreted as encompassing one and more (i.e., one or more) of that step, composition of matter, group of steps or group of compositions of matter.

[0264] Those skilled in the art will understand that the present disclosure is susceptible to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The present disclosure also includes all of the steps, features, compositions and compounds referred to or shown in this specification, individually or collectively, and any combination or any two or more of said steps or features.

[0265] The present disclosure should not be limited in scope by the specific examples described herein, which are intended for illustrative purposes only. Functionally equivalent products, compositions and methods are clearly within the scope of the present disclosure.

[0266] Any example of the present disclosure herein shall be construed to apply mutatis mutandis to any other example of the present disclosure, unless specifically stated otherwise.

[0267] Unless specifically defined otherwise, all technical and scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art (e.g., cell culture, molecular genetics, immunology, immunohistochemistry, protein chemistry, and biochemistry).

[0268] Unless otherwise indicated, the recombinant protein, cell culture, and immunological techniques utilized in this disclosure are standard procedures, well known to those skilled in the art. Such techniques are described in J. Perbal, A Practical Guide to Molecular Cloning, John Wiley and Sons (1984), J. Sambrook et al. Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1989), TA Brown (editor), Essential Molecular Biology: A Practical Approach, Volumes 1 and 2, IRL Press (1991), DMG Lover and BDHames (editors), DNA Cloning: A Practical Approach, Volumes 1-4, IRL Press (1995 and 1996), and FM Ausubel et al. (editors), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988 (including all updates to date)), Ed Harlow and David Lane (editors), Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, (1988), and JE Coligan et al. al. (editors) Current Protocols in Immunology, John Wiley & Sons (including all updates to date), and other sources.

[0269] The descriptions and definitions of variable regions and portions thereof, immunoglobulins, antibodies and fragments thereof herein may be further clarified by the discussion in Kabat Sequences of Proteins of Immunological Interest, National Institutes of Health, Bethesda, Md., 1987 and 1991, Bork et al., J Mol. Biol. 242, 309-320, 1994, Chothia and Lesk J. Mol Biol. 196:901-917, 1987, Chothia et al. Nature 342, 877-883, 1989, Al-Lazikani et al., J Mol Biol 273, 927-948, 1997, and / or Lohse et al., Cancer Research 76(2); 403-17, 2015.

[0270] Any discussion of a protein or antibody herein will be understood to include any variant of the protein or antibody produced during production and / or storage. For example, during production and / or storage, an antibody may be deamidated (e.g., at asparagine or glutamine residues), and / or have altered glycosylation, and / or have glutamine residues converted to pyroglutamic acid, and / or have N- or C-terminal residues removed or "truncated," and / or have part or all of a signal sequence that is incompletely processed, resulting in the antibody remaining at its terminus. It is understood that a composition comprising a particular amino acid sequence may be a heterogeneous mixture of the described or encoded sequence and / or variants of the described or encoded sequence.

[0271] The term "and / or," e.g., "X and / or Y," shall be understood to mean either "X and Y" or "X or Y," and shall be interpreted as providing explicit support for both meanings or either meaning.

[0272] Throughout this specification, the word "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0273] As used herein, the term "derived from" shall be construed to indicate that the identified completion may be obtained from a particular source, but not necessarily directly from that source.

[0274] Selected Definitions The term "antibody-dependent cellular trogocytosis" or "antibody-dependent cell-mediated trogocytosis" (ADCT) refers to the rapid cell-to-cell transfer of membrane fragments and their associated molecules from donor cells to acceptor cells (e.g., effector cells) during cell-to-cell contact or via the release of vesicles. Exemplary acceptor cells include T and B cells, monocytes / macrophages, dendritic cells, neutrophils, and natural killer (NK) cells. In the context of the present disclosure, trogocytosis-mediated transfer of cell surface molecules, such as CD117, from donor cells to acceptor cells results in the transfer of antibody-antigen complexes, i.e., antibody-antigen complexes in which the antibody is bound to the cell surface molecule (e.g., antibody-CD117 complexes), from donor cells to acceptor cells. A specialized form of trogocytosis can occur when the acceptor cells are Fc-gamma-receptor (FcγR)-expressing effector cells; these acceptor cells take up and internalize donor cell-associated immune complexes, typically composed of specific antibodies bound to target antigens on the donor cells, following binding of the FcγR to the Fc region of the antibody.

[0275] The term "reduce" or "reducing," as used herein, refers to administering an antibody described herein to stop or prevent differentiation and / or maturation of cells in a subject, with respect to a population of cells in the bone marrow.

[0276] The terms "deplete" or "depleting," as used herein, with respect to a population of cells in bone marrow, refer to the administration of an antibody described herein to stop or prevent survival of bone marrow cells in a subject.

[0277] As used herein, the terms "deplete" and "depletion" refer to partial or complete removal of a population of cells (e.g., HSCs) from a target tissue (e.g., bone marrow). It will be apparent to one of skill in the art that depletion includes complete removal or depletion of such cells from a target tissue. Alternatively, depletion is partial removal or depletion of such cells (e.g., HSCs) from a target tissue (i.e., bone marrow). For example, the methods disclosed herein result in at least about 5%, 10%, 12.5%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92.5%, 95%, 97.5%, 98% or 99% depletion of cells (e.g., HSCs) in a target tissue (e.g., bone marrow).

[0278] For nomenclature purposes only and not for limitation purposes, an exemplary sequence of Cluster of Differentiation (CD117) (also known as c-kit or stem cell factor receptor (SCFR)) is set forth in NCBI Reference Sequence NP_000213.1 and RefSeq Accession NM_000222.3 and SEQ ID NO: 1. The sequence of CD117 from other species can be determined using the sequences provided herein and / or in publicly available databases and / or determined using standard techniques (e.g., as described in Ausubel et al., (editors), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988 (including all updates to date)) or Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1989)). For nomenclature purposes only and not for limitation purposes, an exemplary sequence of cynomolgus CD117 is set forth in RefSeq Accession XP_005555330 and SEQ ID NO: 2. For nomenclature and non-limiting purposes only, an exemplary sequence of murine CD117 is set forth in NCBI reference sequence NP_001116205.1 and SEQ ID NO: 3. Reference to human CD117 may be abbreviated as hCD117. Reference herein to CD117 includes all isoforms thereof.

[0279] As used herein, the term "subject" shall be taken to mean any animal, including humans, e.g., mammals. Exemplary subjects include, but are not limited to, humans and non-human primates. In one example, the subject is a human.

[0280] The term "protein" shall be taken to include a single polypeptide chain, i.e., a series of consecutive amino acids linked by peptide bonds, or a series of polypeptide chains covalently or non-covalently linked to each other (i.e., a polypeptide complex). For example, a series of polypeptide chains may be covalently linked using suitable chemical or disulfide bonds. Examples of non-covalent bonds include hydrogen bonds, ionic bonds, van der Waals forces, and hydrophobic interactions.

[0281] It will be understood from the previous paragraph that the term "polypeptide" or "polypeptide chain" means a series of consecutive amino acids linked by peptide bonds.

[0282] The term "isolated protein" or "isolated polypeptide" is a protein or polypeptide that is not associated with naturally associated components with which it is associated in its native state by its origin or source, i.e., is substantially free from other proteins from the same source. A protein can be rendered substantially free of naturally associated components by isolation, or substantially purified, using protein purification techniques known in the art. "Substantially purified" means that the protein is substantially free of contaminants, e.g., at least about 70% or 75% or 80% or 85% or 90% or 95% or 96% or 97% or 98% or 99% free of contaminants.

[0283] The term "recombinant" shall be understood to mean a product of artificial genetic recombination. Thus, in the context of a recombinant protein containing an antibody antigen-binding domain, this term does not encompass naturally occurring antibodies in the subject's body that are products of natural recombination occurring during B-cell maturation. However, when such an antibody is isolated, it should be considered an isolated protein that contains an antibody antigen-binding domain. Similarly, when a nucleic acid encoding a protein is isolated and expressed using recombinant means, the resulting protein is a recombinant protein that contains an antibody antigen-binding domain. Recombinant protein also encompasses proteins expressed by artificial recombinant means, for example, when it is within the cell, tissue, or subject in which it was expressed.

[0284] As used herein, the term "antigen-binding site" shall be taken to mean a structure formed by a protein that is capable of binding or specifically binding to an antigen. An antigen-binding site does not necessarily have to be a series of contiguous amino acids, or even amino acids in a single polypeptide chain. For example, in an Fv generated from two different polypeptide chains, the antigen-binding site is the V domain that interacts with the antigen and is usually (but not always) located in one or more of the CDRs in each variable region. L and V H In some instances, the antigen binding site is composed of a series of amino acids, V H or V L or Fv. In some examples, the antigen-binding site comprises one or more CDRs of an antibody. The antigen-binding site need not be in the context of a whole antibody, for example, it can be disaggregated (e.g., a domain antibody) or in another form as described herein, such as, for example, an scFv.

[0285] Those skilled in the art will recognize that an "antibody" typically comprises multiple polypeptide chains, e.g., V L Polypeptides comprising V HIt will be known that an antibody is considered to be a protein that includes a variable region composed of a polypeptide including a constant domain, a portion of which may be located within the constant domain, including, in the case of the heavy chain, the constant fragment or fragment crystallizable (Fc). H and V L interact to form an Fv comprising an antigen-binding region, which is capable of specifically binding to one or several closely related antigens. Usually, the light chain from a mammal is either a kappa or lambda light chain, and the heavy chain from a mammal is an alpha, delta, epsilon, gamma, or mu. The antibody can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or subclass. The term "antibody" also encompasses humanized antibodies, primatized antibodies, human antibodies, and chimeric antibodies. In one example, the antibody is an IgA antibody. For example, the IgA antibody is a class IgA2 antibody.

[0286] The terms "full length antibody," "intact antibody," or "complete antibody" are used interchangeably to refer to an antibody in its substantially intact form, as opposed to an antigen-binding fragment of an antibody. Specifically, complete antibodies include those having heavy and light chains, including the Fc region. The constant domains may be wild-type sequence constant domains (e.g., human wild-type sequence constant domains) or amino acid sequence variants thereof.

[0287] The term "hinge region" as used herein refers to the proline-rich portion of the antibody heavy chain constant region that links the Fc and Fab regions and confers flexibility to the two Fab arms of an antibody defined herein.

[0288] As used herein, "variable region" refers to a portion of the light and / or heavy chain of an antibody defined herein capable of specifically binding to an antigen, and includes the amino acid sequences of the complementarity determining regions (CDRs); i.e., CDR1, CDR2, and CDR3, and framework regions (FRs). An exemplary variable region includes three or four FRs (e.g., FR1, FR2, FR3, and optionally FR4) together with three CDRs. In the case of a protein derived from an IgNAR, the protein may lack CDR2. H refers to the variable region of the heavy chain. L refers to the variable region of the light chain.

[0289] As used herein, the term "complementarity determining region" (synonym CDR; i.e., CDR1, CDR2, and CDR3) refers to amino acid residues of an antibody variable region, the presence of which is necessary for antigen binding. Each variable region typically has three CDR regions identified as CDR1, CDR2, and CDR3. The amino acid positions assigned to CDRs and FRs may be defined according to Kabat Sequences of Proteins of Immunological Interest, National Institutes of Health, Bethesda, Md., 1987 and 1991, or other numbering systems in the practice of this disclosure, such as the standard numbering system of Chothia and Lesk J. Mol Biol. 196:901-917, 1987; Chothia et al. Nature 342, 877-883, 1989; and / or Al-Lazikani et al., J Mol Biol 273:927-948, 1997; the IMGT numbering system of Lefranc et al., Devel. And Compar. Immunol., 27:55-77, 2003; or the AHO numbering system of Honnegher and Plukthun J. Mol. Biol., 309:657-670, 2001. For example, according to the Kabat numbering system, HThe framework regions (FRs) and CDRs are arranged as follows: residues 1-30 (FR1), 31-35 (CDR1), 36-49 (FR2), 50-65 (CDR2), 66-94 (FR3), 95-102 (CDR3), and 103-113 (FR4). L The FRs and CDRs of are arranged as follows: residues 1-23 (FR1), 24-34 (CDR1), 35-49 (FR2), 50-56 (CDR2), 57-88 (FR3), 89-97 (CDR3) and 98-107 (FR4). The present disclosure is not limited to FRs and CDRs defined by the Kabat numbering system, but includes all numbering systems, including those discussed above. In one example, references herein to CDRs (or FRs) refer to those regions according to the Kabat numbering system.

[0290] As used herein, the term "Fv" refers to a V polypeptide, regardless of whether it comprises multiple polypeptides or a single polypeptide. L and V H The term "antigen-binding site" should be taken to mean any protein with which V associates to form a complex having an antigen-binding site, i.e., capable of specifically binding to an antigen. H and V L The fragments may be in a single polypeptide chain or in different polypeptide chains. Furthermore, an Fv of this disclosure (as well as any protein of this disclosure) may have multiple antigen-binding sites that may or may not bind the same antigen. It is to be understood that the term encompasses fragments derived directly from antibodies as well as proteins corresponding to such fragments produced using recombinant means.

[0291] As used herein, the term "specifically binds" or "binds specifically" shall be taken to mean that an antibody of the present disclosure reacts or associates more frequently, more rapidly, for longer duration, and / or with higher affinity with a particular antigen or cell expressing it than with alternative antigens or cells. For example, a protein binds to CD117 with substantially higher affinity (e.g., 20-fold or 40-fold or 60-fold or 80-fold to 100-fold or 150-fold or 200-fold higher affinity) avidity, more readily, and / or for longer duration than it binds to other antigens or antigens commonly recognized by polyreactive natural antibodies (i.e., by naturally occurring antibodies known to bind a variety of antigens naturally found in humans). Usually, but not necessarily, reference to binding shall mean specifically binding, and each term shall be understood to provide explicit support for the other term.

[0292] The antibody is directed against another polypeptide. D is less than the dissociation constant (K D ) can be considered to "preferentially bind" to a polypeptide. In one example, an antibody can be considered to "preferentially bind" to a polypeptide if it binds the polypeptide at a K D at least about 20-fold, 40-fold, 60-fold, 80-fold, 100-fold, 120-fold, 140-fold, or 160-fold higher affinity (i.e., K D ) is considered to preferentially bind to the polypeptide.

[0293] For purposes of clarity, and as will be apparent to those of skill in the art based on the exemplified subject matter herein, references herein to "affinity" refer to the K D This is a reference to.

[0294] For purposes of clarity, and as will be apparent to one of ordinary skill in the art based on the description herein, “K DThe reference to " D It will be understood that a value of K nM means that the value is equal to or lower than XnM. D A lower value corresponds to a higher (i.e., stronger) affinity, i.e., an affinity of 2 nM is stronger than an affinity of 3 nM.

[0295] "At least IC 50 " is an IC 50 is equal to or exceeds the stated value (i.e., IC 50 (the value described as "lower"), i.e., an IC of 2 nM 50 has an IC of 3 nM 50 It will be understood that this means "greater than X." In other words, this term means "an IC less than or equal to X." 50 " where X is a value described herein.

[0296] The term "competitively inhibit" shall be understood to mean that an antibody of the present disclosure (i.e., an anti-CD117 antibody) reduces or prevents, for example, the binding of the described antibody or protein to CD117. This may be due to antibodies binding to the same or overlapping epitopes. It will be clear from the foregoing that an antibody need not completely inhibit the binding of the antibody, but rather only need to reduce binding by a statistically significant amount, for example, at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. Preferably, the antibody reduces, for example, the binding of the antibody to CD117 by at least about 30%, more preferably at least about 50%, more preferably at least about 70%, also more preferably at least about 75%, even more preferably at least about 80% or 85% and even more preferably at least about 90%. Methods for determining competitive inhibition of binding are known in the art and / or described herein. For example, antibody is exposed to CD117 either in the presence or absence of compound.If less antibody binds in the presence of antibody than in the absence of antibody, the antibody is considered to competitively inhibit the binding of antibody.In one example, competitive inhibition is not caused by steric hindrance.

[0297] As used herein, the term "blocking" shall be taken to mean that the antibody that binds CD117 is capable of blocking, reducing or preventing CD117-mediated signaling in cells by SCF. It will be clear from the above that the antibody need not completely block CD117-mediated signaling by SCF, but rather only reduce it by a statistically significant amount, e.g., at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. Methods for determining blocking are known in the art and / or described herein.

[0298] The term "inhibit" with respect to CD117 activation and / or CD117 cell proliferation shall be understood to mean that the antibodies of the present disclosure (i.e., anti-CD117 antibodies) reduce or prevent CD117 activation and / or CD117 cell proliferation. It will be apparent from the foregoing that the antibody need not completely inhibit activation or cell proliferation, but rather only reduce it by a statistically significant amount, e.g., at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. Methods for determining CD117 activation and / or CD117 cell proliferation are known in the art and / or described herein.

[0299] Bone marrow conditioning method The methods described herein provide methods of conditioning a subject and / or depleting a population of cells in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT), comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject.

[0300] The methods herein also provide a method of reducing side effects of a method of HCT and / or a myeloablative conditioning regimen in a subject, comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous HSCs in the subject.

[0301] Hematopoietic cell transplantation (HCT) As used herein, the term "hematopoietic cell transplantation" or "HCT" refers to the infusion, engraftment, or transplantation of hematopoietic stem cells (HSCs) and progenitor cells into a subject. It will be apparent to one of skill in the art that this term is used interchangeably with "bone marrow transplantation," "stem cell transplantation," and "hematopoietic stem cell transplantation."

[0302] In one example of any of the methods described herein, the subject requires HCT. For example, the subject has not yet undergone HCT. For example, the antibody is administered to the subject before he undergoes HCT.

[0303] In one example, the subject is undergoing HCT. For example, an antibody is administered to a subject undergoing HCT. In one example, the antibody and HCT are administered to the subject sequentially (i.e., one after the other). In another example, the antibody and HCT are administered to the subject simultaneously (i.e., at the same time).

[0304] In one example of any of the methods described herein, administering the antibody enhances or improves the engraftment efficiency of HCT. As used herein, the phrases "engraftment efficiency" and "engraftment efficiency" refer to the efficiency with which an administered stem / progenitor cell population (i.e., HSC transplant) engrafts in the subject's conditioned target tissue (i.e., bone marrow). In certain embodiments, the engraftment efficiency is increased by at least about 5%, 7.5%, 10%, 12.5%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 75%, 80%, 90%, 95%, 100% or more. It will be apparent to one of skill in the art that the determination of engraftment efficiency is evaluated relative to the engraftment efficiency of a method in which HSC engraftment is performed without the methods disclosed herein.

[0305] In one example, engraftment efficiency is monitored by determining chimerism in a subject. As used herein, the term "chimerism" refers to the percentage of HSCs in a subject that are of donor origin. It will be clear to one of skill in the art that "donor" chimerism means that 100% of the bone marrow and blood cells in a subject are of donor origin, whereas "mixed" or "partial" chimerism means that cells of the subject are also present. Methods for determining chimerism will be clear to one of skill in the art and / or described herein. For example, chimerism is determined using real-time quantitative PCR, fluorescent in situ hybridization (FISH) and chromosomal markers.

[0306] In one example of any of the methods described herein, administration of the antibody induces chimerism in the subject.

[0307] In one example, administration of an antibody comprising an extended hinge region promotes or enables at least partial depletion, substantial depletion or elimination of cells expressing a target (eg, cells expressing CD117).

[0308] In one example, administration of an antibody that comprises an extended hinge region.

[0309] In one example, administration of an antibody comprising a heavy chain comprising the sequence set forth in SEQ ID NO:113; and a light chain comprising the sequence set forth in SEQ ID NO:111.

[0310] In one example, an anti-CD117 antibody comprising: a heavy chain comprising the sequence set forth in SEQ ID NO:115; and a light chain comprising the sequence set forth in SEQ ID NO:111.

[0311] In one example, administration of the antibody induces HSC transplant tolerance, e.g., inducing chimerism in a subject induces HSC transplant tolerance.

[0312] In one example, the subject is undergoing or will undergo autologous HCT. The term "autologous" with respect to HCT refers to HCT with cells collected or obtained from the subject (i.e., the same individual) being treated or to be treated.

[0313] In one example, the subject is undergoing or will undergo allogeneic HCT. The term "allogeneic" with respect to HCT refers to HCT with cells collected or obtained from another person (i.e., a different individual) than the subject being treated or undergoing treatment.

[0314] Subjects in need of HCT will be apparent to those of skill in the art and / or described herein, for example, a subject in need of HCT is a subject having a disease or condition that would benefit from HCT.

[0315] In one example, the subject suffers from a disease or condition that requires treatment with HCT. For example, the subject suffers from cancer, hemoglobin disorder, myelodysplastic disorder, primary immune deficiency (PID), autoimmune disorder, immunodeficiency disorder, or metabolic disorder.

[0316] In one example, the subject suffers from cancer.The term "cancer" refers to or represents a physiological condition in mammals that is typically characterized by uncontrolled cell growth / proliferation.For example, the cancer is hematological (or blood) cancer. Hematological / blood cell cancers include, but are not limited to, leukemias (e.g., acute lymphoblastic leukemia in adults and children; acute myeloid leukemia in adults and children; chronic lymphocytic leukemia; chronic myelogenous leukemia; and hairy cell leukemia); lymphomas (e.g., AIDS-related lymphoma; cutaneous T-cell lymphoma; Hodgkin's lymphoma, including Hodgkin's lymphoma, in adults and children; Hodgkin's lymphoma during pregnancy; non-Hodgkin's lymphoma, including non-Hodgkin's lymphoma, in adults and children; non-Hodgkin's lymphoma during pregnancy; mycosis fungoides; Sezary syndrome; Waldenstrom's macroglobulinemia; and primary central nervous system lymphoma); and other hematological cancers (e.g., chronic myeloproliferative disorders; multiple myeloma / plasma cell neoplasms; myelodysplastic syndromes; myelodysplastic / myeloproliferative disorders, neuroblastoma, and Ewing's sarcoma).

[0317] In one example, the subject is afflicted with a myelodysplastic disorder.

[0318] In one example, the subject suffers from a hemoglobin disorder, such as sickle cell anemia, thalassemia, Fanconi anemia, or aplastic anemia.

[0319] In one example, the subject suffers from a primary immune deficiency (PID). For example, PIDs include activated PI3K delta syndrome (APDS), X-linked agammaglobulinemia (XLA), ataxia telangiectasia, chronic granulomatous disease (CGD) and other phagocytic disorders, common variable immunodeficiency (CVID), complement deficiencies, DiGeorge syndrome, hemophagocytic lymphohistiocytosis (HLH), hyper-IgE syndrome, hyper-IgM syndrome, IgG subclass deficiencies, innate immune defects, Toll-like receptor (TLR) deficiencies (MyD88 deficiency, IRAK4 deficiency, UNC9 deficiency, and others). 3B deficiency and TLR3 mutations), human natural killer cell deficiency, defects in interferon-gamma (IFN-γ) and interleukin-12 (IL-12) signaling, leukocyte adhesion deficiency (LAD), NEMO deficiency syndrome, selective IgA deficiency, selective IgM deficiency, severe combined immunodeficiency (SCID) and combined immunodeficiency, specific antibody deficiencies, transient hypogammaglobulinemia of infancy, WHIM syndrome (warts, hypogammaglobulinemia, infections, and and myeloid cellular pooling), Wiskott-Aldrich syndrome, antibody deficiency with normal or elevated immunoglobulins, immunodeficiency with thymoma (Good's syndrome), transcobalamin II deficiency, kappa chain deficiency, heavy chain deficiency, postmeiotic segregation (PMS2) disorder, hypogammaglobulinemia not otherwise specified, chronic mucocutaneous candidiasis (CMC), cartilage-hair hypoplasia (CHH), X-linked lymphoproliferative (XLP) syndromes 1 and 2, X-linked immune dysregulation with polyendocrinopathy (I-linked immune dysregulation with polyendocrinopathy (PID) syndromes 2 and 3, and X-linked immune dysregulation with polyendocrinopathy (PID) syndromes 4 and 5. These include PEX (prostate cancer exacerbation) syndrome, veno-occlusive disease (VODI), Hoyeral-Freidarsson syndrome (dyskeratosis congenita), immunodeficiency with centromere instability and facial anomalies (ICF), Schimke syndrome, Kommerl-Netherton syndrome, Diamond-Blackfan anemia, Schwachman-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen instability syndrome, or graft-versus-host disease (GvHD).In some instances, the PID is Wiskott-Aldrich syndrome (WAS), X-linked agammaglobulinemia (XLA), Diamond-Blackfan anemia, Schwachman-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen instability syndrome, or graft-versus-host disease (GvHD).

[0320] In one example, the subject suffers from an autoimmune disorder.For example, the autoimmune disorder is multiple sclerosis or diabetes.For example, the diabetes is type I diabetes.

[0321] In one example, the subject suffers from an immunodeficiency disorder, for example, the immunodeficiency disorder is human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS).

[0322] In one example, the subject is suffering from a metabolic disorder, for example, the metabolic disorder is glycogen storage disease, mucopolysaccharidoses, Gaucher disease, Hurler disease, sphingolipidosis, or metachromatic leukodystrophy.

[0323] Targeting endogenous hematopoietic stem cells As described herein, the present disclosure relates to targeting, reducing, diminishing, and / or depleting a population of hematopoietic stem cells (HSCs) present in a target tissue (e.g., bone marrow or peripheral blood) of a subject. For example, the methods described herein relate to targeting, reducing, diminishing, and / or depleting an endogenous HSC population in the bone marrow of a subject to conditions for engraftment of a transplanted HSC population.

[0324] As used herein, the term "hematopoietic stem cell" (HSC) refers to an immature cell that can differentiate into all types of hematopoietic cells (i.e., blood cells), including white blood cells, red blood cells (including bone marrow (e.g., monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes / platelets, dendritic cells), and lymphoid (e.g., T cells, B cells, NK cells), and platelets. Hematopoietic stem cells are found in peripheral blood and bone marrow.

[0325] The term "endogenous," as used herein with respect to HSCs, refers to HSCs that originate within a subject (i.e., within the blood and / or bone marrow of a subject).

[0326] In one example of any method described herein, the method comprises administering to the subject an antibody that binds or specifically binds to a target on endogenous HSC in the subject.It will be clear to those skilled in the art that the reference to "target" on endogenous HSC refers to any protein, receptor, antigen, carbohydrate, lipid or other site that is located or expressed on the surface of HSC and can be used to distinguish cell populations.For example, the target is selectively expressed on the surface of the target cell population (i.e., HSC).In one example, the target is expressed only on the cell population that is targeted (i.e., endogenous HSC population), thereby limiting or avoiding "off-target" effects.

[0327] In one example, the selection of targets can be based on comparing the detected expression of such targets (e.g., cell surface markers) on HSCs compared to the expression of such targets on a control population of cells. For example, the expression of a target on HSCs or progenitor cells is compared to the average expression of the same target on other cells (i.e., non-HSCs or progenitor cells).

[0328] In one example, targets on endogenous HSCs include CD2, CD5, CD7, CD11a, CDw12, CD13, CD15, CD18, CD19, CD21, CD22, CD29, CD30, CD33, CD34, CD36, CD38, CD40, CD41, CD42a, CD42b, CD42c, CD42d, CD43, CD45, CD45RA, CD45RB, CD45RC, CD45RO, CD48, CD49b, CD49d ( VLA-4), CD49e, CD49f(VLA-6), CD50, CD51, CD53, CD55, CD58, CD64a, CD68, CD71, CD72, CD73, CD81, CD82, CD84, CD8 5A, CD85K, CD90, CD97, CD99, CD104, CD105, CD109, CD110, CD111, CD112, CD114, CD115, CD117, CD123, CD124, CD126 , CD127, CD130, CD131, CD133, CD135, CD137, CD138, CD151, CD157, CD162, CD164, CD166, CD168, CD172a, CD173, CD1 74, CD175, CD175s, CD176, CD183, CD184(CXCR4), CD191, CD200, CD201, CD205, CD217, CD220, CD221, CD222, CD223, Selected from the group consisting of CD224, CD225, CD226, CD227, CD228, CD229, CD230, CD235a, CD235b, CD236, CD236R, CD238, CD240, CD242, CD243, CD277, CD292, CDw293, CD295, CD298, CD309, CD318, CD324, CD325, CD338, CD344, CD349, CD350 and CD361.

[0329] In one example, the target on endogenous HSCs is selected from the group consisting of CD11a, CD18, CD34, CD37, CD45, CD47, CD52, CD58, CD62L, CD69, CD74, CD97, CD103, CD117, CD132, CD156a, CD179a, CD179b, CD184, CD232, CD244, CD252, CD302, CD305, CD317, and CD361.

[0330] In one example, the target on endogenous HSCs is CD117.

[0331] Antibodies that bind to targets on HSCs The present disclosure provides an antibody that binds or specifically binds to a target on endogenous HSCs in a subject. In one example of any of the methods described herein, the antibody mediates antibody-dependent cellular trogocytosis (ADCT).

[0332] Methods for generating antibodies are known in the art and / or described in Harlow and Lane (editors) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, (1988). Typically, in such methods, CD117 or a region thereof (e.g., the extracellular domain) or an immunogenic fragment or epitope thereof or a cell expressing and presenting it (i.e., immunogen), optionally formulated with any suitable or desired carrier, adjuvant, or pharma- ceutically acceptable excipient, is administered to a non-human animal, such as a mouse, chicken, rat, rabbit, guinea pig, dog, horse, cow, goat, or pig. The immunogen may be administered intranasally, intramuscularly, subcutaneously, intravenously, intradermally, intraperitoneally, or by other known routes.

[0333] Monoclonal antibody is one exemplary form of antibody contemplated by the present disclosure. The term "monoclonal antibody" or "mAb" refers to a homogeneous antibody population that can bind to the same antigen(s), for example, the same epitope within the antigen. This term is not intended to be limited with respect to the source of the antibody or the method by which it is made.

[0334] For the production of mAbs, any one of a number of known techniques can be used, for example the procedures exemplified in US 4,196,265 or Harlow and Lane (1988) supra.

[0335] Alternatively, ABL-MYC technology (NeoClone, Madison WI 53713, USA) is used to generate cell lines secreting MAbs (e.g., as described in Largaespada et al, J. Immunol. Methods. 197:85-95, 1996).

[0336] Antibodies can also be generated or isolated by screening display libraries, such as phage display libraries, e.g., as described in US6300064 and / or US5885793. For example, the present inventors have isolated fully human antibodies from phage display libraries.

[0337] The antibody of the present disclosure can be a synthetic antibody, e.g., the antibody is a chimeric antibody, a humanized antibody, a human antibody, or a deimmunized antibody.

[0338] In one example, the antibody described herein is a chimeric antibody. The term "chimeric antibody" refers to an antibody in which a portion of the heavy and / or light chain is identical or homologous to a corresponding sequence in an antibody from a particular species (e.g., murine, e.g., mouse) or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical or homologous to a corresponding sequence in an antibody from another species (e.g., primate) or belonging to another antibody class or subclass. Methods for producing chimeric antibodies are described, for example, in US4816567; and US5807715.

[0339] The antibodies of the present disclosure may be humanized or human.

[0340] The term "humanized antibody" shall be understood to refer to a subclass of chimeric antibodies that have an antigen-binding site or variable region derived from an antibody from a non-human species and the remaining antibody structure based on the structure and / or sequence of a human antibody. In a humanized antibody, the antigen-binding site usually comprises the complementarity determining regions (CDRs) from a non-human antibody grafted onto the appropriate FRs in the variable regions of the human antibody and the remaining regions from the human antibody. The antigen-binding site may be wild-type (i.e., identical to that of the non-human antibody) or modified by one or more amino acid substitutions. In some instances, FR residues of a human antibody are replaced by corresponding non-human residues.

[0341] Methods for humanizing non-human antibodies or parts thereof (e.g., variable regions) are known in the art. Humanization can be carried out according to the methods of US5225539, or US5585089. Other methods for humanizing antibodies are not excluded.

[0342] The term "human antibody," as used herein, refers to an antibody that is H , V L ) and, optionally, having a constant region derived from or corresponding to sequences found in a human, e.g., in human germline or somatic cells.

[0343] mutation The present disclosure also contemplates variant forms of the antibodies of the present disclosure. For example, such variant antibodies contain one or more conservative amino acid substitutions compared to the sequences shown herein. In some examples, the antibody contains 30 or less, or 20 or less, or 10 or less, e.g., 9 or 8 or 7 or 6 or 5 or 4 or 3 or 2 conservative amino acid substitutions. A "conservative amino acid substitution" is one in which an amino acid residue is replaced with an amino acid residue having a similar side chain and / or hydropathy and / or hydrophilicity.

[0344] In one example of any of the antibodies described herein, the antibody comprises amino acid modifications numbered according to the Myeloma IgA1 protein (Bur) scheme, e.g., the Myeloma IgA1 protein (Bur) scheme described in Lohse et al., Cancer Research 76(2);403-17,2015.

[0345] In one example, a variant antibody has only 1 or 2 or 3 or 4 or 5 or 6 or less conservative amino acid changes compared to a naturally occurring antibody. Details of conservative amino acid changes are provided below. As one skilled in the art will realize, for example, from the present disclosure herein, such small changes can be reasonably expected not to alter the activity of the antibody.

[0346] Families of amino acid residues have been defined in the art that have similar side chains, including basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), β-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine).

[0347] The present disclosure also contemplates non-conservative amino acid changes (e.g., substitutions) in the antibodies of the present disclosure, e.g., in the CDRs, e.g., CDR3. In one example, the antibody contains less than 6 or 5 or 4 or 3 or 2 or 1 non-conservative amino acid substitutions, e.g., in the CDR3, e.g., CDR3.

[0348] In one example, the mutation(s) occur within a FR of the antigen-binding domain of an antibody of the disclosure. In another example, the mutation(s) occur within a CDR of an antibody of the disclosure.

[0349] Exemplary methods for generating mutant forms of antibodies include: DNA mutagenesis (Thie et al., Methods Mol. Biol. 525:309-322, 2009) or RNA mutagenesis (Kopsidas et al., Immunol. Lett. 107:163-168, 2006; Kopsidas et al. BMC Biotechnology, 7:18, 2007; and WO1999 / 058661); introducing a nucleic acid encoding the polypeptide into a mutator cell, such as XL-1Red, XL-mutS and XL-mutS-Kanr bacterial cell (Stratagene); DNA shuffling, as disclosed, for example, in Stemmer, Nature 370:389-91, 1994; and - For example, site-directed mutagenesis as described in Dieffenbach (ed) and Dveksler (ed) (In: PCR Primer: A Laboratory Manual, Cold Spring Harbor Laboratories, NY, 1995).

[0350] The present disclosure also contemplates one or more insertions or deletions compared to the sequences shown herein, in some examples, the antibodies contain 10 or fewer insertions and / or deletions, e.g., 9 or 8 or 7 or 6 or 5 or 4 or 3 or 2 insertions and / or deletions.

[0351] Constant region The present disclosure encompasses proteins and / or antibodies described herein that comprise an antibody constant region, including an antigen-binding fragment of an antibody fused to Fc.

[0352] The sequences of constant regions useful for generating the proteins of the present disclosure can be obtained from a number of different sources. In some examples, the constant region of the protein or a portion thereof is derived from a human antibody. The constant domain or a portion thereof can be derived from any antibody class, including IgM, IgG, IgD, IgA and IgE, as well as any antibody isotype. In one example, the human antibody class IgA is used. In another example, the human isotype IgA2 is used.

[0353] In one example, the Fc region of the constant region has or exhibits an effector function that promotes or enables at least partial depletion, substantial depletion or elimination of target-expressing cells (e.g., cells expressing CD117). Such effector function can be improved binding affinity to an Fc receptor, and / or antibody-dependent cell-mediated cytotoxicity (ADCC), and / or antibody-dependent cell-mediated phagocytosis (ADCP), and / or antibody-dependent cellular trogocytosis (ADCT), and / or complement-dependent cytotoxicity (CDC), and combinations thereof. Methods for assessing the level of effector function of an Fc region-containing protein are known in the art and / or described herein.

[0354] In one example, the antibodies of the disclosure are capable of inducing enhanced levels of effector function.

[0355] In one example, the level of effector function induced by the constant region is enhanced compared to a wild-type Fc region of an IgG1 antibody or a wild-type Fc region of an IgG4 antibody.

[0356] In another example, the constant region is modified to increase the level of effector function it is able to induce compared to a constant region not having the modification. Such modifications can be at the amino acid level and / or at the secondary structure level and / or at the tertiary structure level and / or to the glycosylation of the Fc region.

[0357] One of skill in the art will appreciate that greater effector function can be manifested in any of a number of ways, for example, as a higher level of effect, a more sustained effect, or a faster rate of effect.

[0358] Exemplary constant region modifications include amino acid substitutions, such as the N166G mutation, the P221R mutation, the C311S mutation, the NIT337-339TLS mutation, delC472, and delY473, numbered according to the myeloma IgA1 protein (Bur) scheme.

[0359] It will be apparent to one of skill in the art that the antibodies described herein according to any of the examples may be further modified to improve the pharmacokinetic properties of the antibody. For example, the antibody may be further modified to increase the half-life and / or stability of the antibody.

[0360] In one example, the antibody comprises one or more amino acid modifications that increase the half-life of the antibody. For example, the antibody comprises an Fc region that comprises one or more amino acid substitutions that increase the affinity of the Fc region for fetal Fc region (FcRn). These amino acid substitutions are useful for extending the half-life of the protein by reducing clearance from the blood.

[0361] In one example, the antibody comprises one or more amino acid modifications that increase the stability of the antibody, for example, the antibody comprises amino acid modifications at asparagine and / or glutamine residues that are prone to deamidation and / or glutamine residues that are prone to pyroglutamic acid formation.

[0362] In one example, the antibody is conjugated to a compound that increases the half-life of the antibody, e.g., the antibody is conjugated to a half-life extender, such as polyethylene glycol (PEG), glycerol, glucose, and / or albumin.

[0363] Hinge Area The present disclosure includes proteins and / or antibodies described herein that comprise a modified hinge region.

[0364] The sequences of hinges useful in the proteins of the present disclosure can be obtained from a number of different sources. In some examples, the hinge region of the protein is derived from a human antibody. The hinge region can be derived from any antibody class, including IgM, IgG, IgD, IgA, and IgE, as well as any antibody isotype. In one example, the human antibody class IgA is used. In another example, the human isotype IgA2 is used. In a further example, the human isotype IgG is used. For example, the human isotype IgG is IgG1, IgG2, IgG3, or IgG4. In one example, the human isotype IgG is IgG1. In one example, the human isotype IgG is IgG2. In one example, the human isotype IgG is IgG3. In one example, the human isotype IgG is IgG4.

[0365] In one example, the hinge region is modified to increase the level of effector function it can induce compared to a hinge region not having the modification. Such modifications may be to substitutions and / or insertions at the amino acid level and / or at the secondary structure level and / or at the tertiary structure level and / or to the glycosylation of the hinge region.

[0366] In one example, an antibody comprising a modified hinge region has or exhibits an effector function that promotes or enables at least partial depletion, substantial depletion or elimination of target-expressing cells (e.g., cells expressing CD117). Such effector function may be improved binding affinity to an Fc receptor, and / or antibody-dependent cell-mediated cytotoxicity (ADCC), and / or antibody-dependent cell-mediated phagocytosis (ADCP), and / or antibody-dependent cellular trogocytosis (ADCT), and / or complement-dependent cytotoxicity (CDC) and combinations thereof. Methods for assessing the level of effector function of an antibody are known in the art and / or described herein.

[0367] In one example, an antibody of the disclosure that comprises a modified hinge region is capable of inducing improved levels of effector function.

[0368] In one example, the level of effector function induced by an antibody comprising a modified hinge region is increased compared to a wild-type IgA2 antibody or a wild-type IgG3 antibody.

[0369] One of skill in the art will appreciate that greater effector function can be manifested in any of a number of ways, for example, as a higher level of effect, a more sustained effect, or a faster rate of effect.

[0370] It will be apparent to one of skill in the art that the hinge region according to any of the examples described herein may be modified or further modified to improve the pharmacokinetic properties of the antibody. For example, the hinge region may be modified to increase the half-life and / or stability of the antibody.

[0371] In one example, the hinge region comprises one or more amino acid modifications and / or insertions that increase the half-life of the antibody. For example, the antibody comprises a hinge region comprising one or more amino acid substitutions and / or insertions that increase the affinity of the hinge region for fetal Fc region (FcRn). These amino acid substitutions and / or insertions are useful for extending the half-life of the protein and / or antibody by reducing clearance from the blood.

[0372] In one example, the hinge region contains one or more amino acid modifications and / or insertions that increase the stability of the antibody.

[0373] In one example, the hinge region is modified by inserting one or more amino acids to generate an extended hinge region, e.g., the hinge region is modified by inserting another hinge region to generate an extended hinge region.

[0374] In one example, an antibody that includes an extended hinge region has better access to its epitope compared to a wild-type antibody. In one example, an antibody that includes an extended hinge region has better access to its epitope compared to an antibody that does not have an extended hinge region.

[0375] In one example, the IgA2 hinge region is modified by inserting at least a portion of an IgG3 hinge region after the first proline in the IgA2 hinge region, e.g., the modified hinge region comprises a chimeric IgA2 / IgG3 hinge region.

[0376] In one example, the IgA2 hinge region is modified by inserting at least a portion of the IgA1 hinge region after the first proline in the IgA2 hinge region, e.g., the modified hinge region comprises a chimeric IgA2 / IgA1 hinge region.

[0377] Molecular cloning techniques to achieve these goals are known in the art and are described, for example, in Senior et al., Cleavage of a Recombinant Human Immunoglobulin A2 (IgA2)-IgA1 Hybrid Antibody by Certain Bacterial IgA1 Proteases (2000) or Woof & Kerr. err. The function of immunoglobulin A in immunity (2006).

[0378] Protein production In one example, an antibody described herein according to any of the examples is produced by culturing a hybridoma under conditions sufficient to produce the protein, e.g., as described herein and / or known in the art.

[0379] Recombinant expression In another example, the antibodies described herein according to any of the examples are recombinant.

[0380] In the case of a recombinant antibody, the nucleic acid encoding it can be cloned into an expression construct or vector, which is then transfected into a host cell, such as an E. coli cell, a yeast cell, an insect cell, or a mammalian cell, such as a Simian COS cell, a Chinese hamster ovary (CHO) cell, a human embryonic kidney (HEK) cell, or a myeloma cell (which does not otherwise produce the protein). Exemplary cells used to express the protein are CHO cells, myeloma cells, or HEK cells. Molecular cloning techniques to achieve these goals are known in the art and are described, for example, in Ausubel et al., (editors), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988 (including all updates to date) or Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1989). A variety of cloning and in vitro amplification methods are suitable for the construction of recombinant nucleic acids. Methods for producing recombinant antibodies are also known in the art. See, for example, US4816567 or US5530101.

[0381] Once isolated, the nucleic acid is inserted into an expression construct or vector and operably linked to a promoter for further cloning (amplification of the DNA) or for expression in a cell-free system or in a cell.

[0382] As used herein, the term "promoter" should be interpreted in its broadest context and includes, for example, the transcriptional control sequences of a genomic gene, including the TATA box or initiation elements required for accurate transcription initiation, with or without additional control elements (e.g., upstream activating sequences, transcription factor binding sites, enhancers and silencers) that modify expression of the nucleic acid in response to developmental and / or external stimuli or in a tissue-specific manner. In this context, the term "promoter" is also used to refer to a recombinant, synthetic or fusion nucleic acid, or derivative, that confers, activates or enhances expression of an operably linked nucleic acid. Exemplary promoters may contain additional copies of one or more specific control elements to further enhance expression and / or modify spatial and / or temporal expression of said nucleic acid.

[0383] As used herein, the term "operably linked to" refers to positioning a promoter relative to a nucleic acid such that expression of the nucleic acid is controlled by the promoter.

[0384] Many vectors are available for expression in cells. Vector components typically include, but are not limited to, one or more of the following: signal sequence, protein coding sequence (e.g., from the information provided herein), enhancer element, promoter, and transcription termination sequence. Those skilled in the art will know suitable sequences for protein expression. Exemplary signal sequences include prokaryotic secretion signals (e.g., pelB, alkaline phosphatase, penicillinase, Ipp, or heat-stable enterotoxin II), yeast secretion signals (e.g., invertase leader, alpha-factor leader, or acid phosphatase leader) or mammalian secretion signals (e.g., herpes simplex gD signal).

[0385] Exemplary promoters active in mammalian cells include the cytomegalovirus immediate early promoter (CMV-IE), human elongation factor 1-alpha promoter (EF1), small nuclear RNA promoters (U1a and U1b), alpha-myosin heavy chain promoter, simian virus 40 promoter (SV40), Rous sarcoma virus promoter (RSV), adenovirus major late promoter, beta-actin promoter; hybrid control elements including the CMV enhancer / beta-actin promoter or immunoglobulin promoter or active fragments thereof. Examples of useful mammalian host cell lines are monkey kidney CV1 line transformed by SV40 (COS-7, ATCC CRL1651); human embryonic kidney line (293 cells or 293 cells subcloned for growth in suspension culture; baby hamster kidney cells (BHK, ATCC CCL10); or Chinese hamster ovary cells (CHO).

[0386] Exemplary promoters suitable for expression in yeast cells, such as yeast cells selected from the group including Pichia pastoris, Saccharomyces cerevisiae, and S. pombe, include, but are not limited to, the ADH1 promoter, the GAL1 promoter, the GAL4 promoter, the CUP1 promoter, the PHO5 promoter, the nmt promoter, the RPR1 promoter, or the TEF1 promoter.

[0387] Means for introducing isolated nucleic acids or expression constructs containing same into cells for expression are known to those skilled in the art. The technique used for a given cell depends on known successful techniques. Means for introducing recombinant DNA into cells include, inter alia, microinjection, DEAE-dextran mediated transfection, liposome mediated transfection, e.g., by using Lipofectamine (Gibco, MD, USA) and / or Cellfectin (Gibco, MD, USA), PEG-mediated DNA uptake, electroporation, and microparticle bombardment, e.g., by using DNA-coated tungsten or gold particles (Agracetus Inc., WI, USA).

[0388] Host cells used to produce proteins may be cultured in a variety of media depending on the cell type used. Commercially available media, such as Ham's F10 (Sigma), Minimum Essential Medium ((MEM), (Sigma), RPM1-1640 (Sigma), and Dulbecco's Modified Eagle's Medium ((DMEM), Sigma) are suitable for culturing mammalian cells. Media for culturing the other cell types discussed herein are known in the art.

[0389] Protein isolation Methods for isolating proteins are known in the art and / or described herein.

[0390] If the protein is secreted into the medium, the supernatant from such an expression system may first be concentrated using a commercially available protein concentration filter, e.g., an Amicon or Millipore Pellicon ultrafiltration unit. A protease inhibitor, e.g., PMSF, may be included in any of the preceding steps to inhibit proteolysis, and antibiotics may be included to prevent the growth of adventitious contaminants. Alternatively, or in addition, the supernatant may be filtered and / or separated from the cells expressing the protein, e.g., using continuous centrifugation.

[0391] Proteins prepared from cells can be purified using, for example, ion exchange, hydroxyapatite chromatography, hydrophobic interaction chromatography, gel electrophoresis, dialysis, affinity chromatography (e.g., protein A affinity chromatography or protein G chromatography), or any combination of the above. These methods are known in the art and described, for example, in WO1999 / 57134 or Harlow and David Lane (editors) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, (1988).

[0392] Those skilled in the art will also know that proteins can be modified to include tags for facilitating purification or detection, such as poly-histidine tags, such as hexa-histidine tags, or influenza virus hemagglutinin (HA) tags, or simian virus 5 (V5) tags, or FLAG tags, or glutathione S-transferase (GST) tags. The resulting proteins are then purified using methods known in the art, such as affinity purification. For example, proteins that include hexa-his tags are purified by contacting a sample containing the protein with nickel-nitrilotriacetic acid (Ni-NTA), which specifically binds the hexa-his tags immobilized on a solid or semi-solid support, washing the sample to remove unbound proteins, and then eluting the bound proteins. Alternatively, or in addition, a ligand or antibody that binds to the tag is used in the affinity purification method.

[0393] Activity assay Binding assays Methods for evaluating the binding of candidate antibodies to target proteins (e.g., CD117) are known in the art, for example as described in Scopes (In: Protein purification: principles and practice, Third Edition, Springer Verlag, 1994). Such methods usually involve labeling a protein and contacting it with an immobilized antibody. After washing to remove non-specifically bound proteins, the amount of label and, as a result, bound proteins are detected. Of course, the protein can be immobilized and the antibody can be labeled. Panning-type assays can also be used. Alternatively, or additionally, surface plasmon resonance assays can be used. The level of binding can also be conveniently determined using a biosensor.

[0394] Affinity assays Optionally, for example, the dissociation constant (Kd) or association constant (Ka) or binding constant (K D The Kd value (i.e., Ka / Kd) is determined. For example, the "Kd" or "Kd value" for a compound that binds to CD117 is measured in one example by a radioactive or fluorescently labeled CD117 binding assay. This assay equilibrates the antibody with a minimal concentration of labeled CD117 in the presence of a titration series of unlabeled CD117. After washing to remove unbound CD117, the amount of label is determined, which indicates the Kd of the protein.

[0395] According to another example, the Kd or Kd value is measured by using a surface plasmon resonance assay, for example, using BIAcore surface plasmon resonance (BIAcore, Inc., Piscataway, NJ) with immobilized CD117 or a region thereof.

[0396] Competitive binding determination The assay for determining the antibody that competitively inhibits the binding of the antibody described herein will be clear to those skilled in the art. For example, the exemplary antibody is conjugated to a detectable label, such as a fluorescent label or a radioactive label. The labeled antibody and the test protein are then mixed and contacted with, for example, CD117 or a region thereof (e.g., a polypeptide comprising SEQ ID NO: 1) or a cell that expresses it. The level of the labeled antibody is then determined and compared to the level determined when the labeled antibody is contacted with CD117, a region or a cell in the absence of the protein. If the level of labeled CSL117 is reduced in the presence of the test protein compared to the absence of the protein, the protein is considered to competitively inhibit the binding of the antibody to CD117.

[0397] Optionally, the test protein is conjugated to a label different from the antibody, which alternative label allows for detection of the level of binding of the test protein to CD117 or a region or cell thereof.

[0398] In another example, the protein is allowed to bind to CD117 or a region thereof (e.g., a polypeptide comprising SEQ ID NO:1) or a cell expressing it prior to contacting CD117, the region, or the cell with the antibody. A reduction in the amount of bound antibody in the presence of the protein compared to the absence of the protein indicates that the protein competitively inhibits the binding of the antibody to CD117. Reciprocal assays can also be performed using a labeled protein, first binding the antibody to CD117. In this case, a reduced amount of labeled protein bound to CD117 in the presence of the antibody compared to the absence of the antibody indicates that the protein competitively inhibits the binding of the antibody to CD117.

[0399] Internalization assay Assays for assessing internalization of the antibodies of the disclosure will be apparent to one of skill in the art and / or are described herein. Exemplary assays include the anti-AF488 quenched antibody assay and the IncuCyte® live cell high throughput internalization assay.

[0400] In one example, internalization is evaluated using anti-AF488 quenched antibody assay. Briefly, cells are incubated with test antibody precomplexed with AF488-labeled anti-human IgG Fab fragment in the presence or absence of human stem cell factor. After incubation, mean fluorescence intensity (MFI) values ​​are obtained, and the percentage of internalized antibody is calculated by dividing the internalization signal (MFI from anti-AF488 quenched antibody treated sample) by the total cell-bound signal (MFI from non-quenched sample) at each time point.

[0401] In another example, internalization is assessed using the IncuCyte® live cell high-throughput internalization assay. Briefly, TF-1 cells are seeded and allowed to adhere to 96-well plates pre-coated with 0.001% (V / V) poly-ornithine. Test antibodies are pre-complexed with FabFluor-pH Red and added to the cells in the absence and presence of human stem cell factor. Internalized antibodies are immediately captured in an Incucyte® S3 (Sartorius) and analyzed for red fluorescent object area (a measure of FabFluor-labeled internalized antibodies) (any background fluorescent signal is subtracted).

[0402] In one example, the antibodies of the disclosure have slow internalization kinetics in an anti-AF488 quenched antibody assay and / or IncuCyte® live cell analysis.

[0403] Inhibition assay In one example, an antibody that binds or specifically binds to a target on endogenous HSCs blocks binding of CD117 by stem cell factor (SCF) and / or inhibits activation of CD117 by SCF. For example, an antibody of the disclosure is evaluated for its ability to inhibit human stem cell factor-mediated TF-1 proliferation.

[0404] Briefly, TF-1 cells were expanded to 2×10 4The cells are seeded at a density of 1000 cells / well. The antibody of the present disclosure is added to each corresponding well in the presence of human stem cell factor. After incubation, the inhibition of TF-1 cell proliferation is measured using a commercially available kit, for example, Vialight Plus kit.

[0405] Determination of effector functions As discussed herein, the antibodies of the disclosure may have effector function (or improved effector function). Methods for assessing effector function, e.g., ADCC or ADCT activity, are known in the art.

[0406] In one example, the level of ADCC activity can be determined by: 51 Cr release assay, europium release assay or 35 S release assay. In each of these assays, for example, cells expressing CD117 are cultured with one or more of the described compounds (i.e., anti-CD117 antibodies) for a time and under conditions sufficient for the compound to be taken up by the cells. 35 For the S release assay, cells expressing CD117 were incubated for a period of time sufficient for the incorporation of labeled amino acids into newly synthesized proteins. 35 The cells may be cultured with S-labeled methionine and / or cysteine. The cells are then cultured in the presence or absence of anti-CD117 antibodies and in the presence of immune effector cells, such as peripheral blood mononuclear cells (PBMCs) and / or NK cells. 51 Cr, Europium and / or 35The amount of S is detected and little or no change in the presence of anti-CD117 antibody compared to the absence of anti-CD117 antibody indicates that the protein has reduced effector function, while an increased amount compared to the absence of anti-CD117 antibody (or an increase compared to the presence of an anti-CD117 antibody containing an IgG1 Fc region) indicates effector function or improved effector function. Exemplary publications disclosing assays for assessing the level of ADCC induced by a protein include Hellstrom, et al. Proc. Natl Acad. Sci. USA 83:7059-7063, 1986 and Bruggemann, et al., J. Exp. Med. 166:1351-1361, 1987.

[0407] Other assays for assessing the level of ADCC induced by a protein include the ACTI™ Non-Radioactive Cytotoxicity Assay for Flow Cytometry (Cell Technology, Inc. CA, USA) or the CytoTox96® Non-Radioactive Cytotoxicity Assay (Promega, WI, USA).

[0408] In one example, the level of ADCT activity is assessed by flow cytometry. Briefly, human CD117 transfected cell lines are labeled with the membrane dye DILC18 (1,1″-dioctadecyl-3,3,3″,3″-tetramethylindocarbacyanine perchlorate), mixed with freshly isolated peripheral blood neutrophils as effector cells, and incubated with an antibody of the present disclosure or a control antibody. Cells are then stained with Alexa fluor 647-conjugated anti-CD66b and LIVE / DEAD™ Fixable Green Stain, washed, and fixed with formaldehyde. Cells are acquired on a flow cytometer and viable neutrophils are identified by forward and side scatter, followed by identification of viable CD66b positive cells. Membrane uptake by neutrophils is measured by the increase in DILC18 mean fluorescence intensity (MFI). DILC18 MFI is normalized to the maximum MFI per donor neutrophil. In one example, half maximal effective concentration (EC 50 ±SD) [nM] and normalized maximum membrane uptake (B max ) (percentage) is determined.

[0409] Any of the foregoing assays can be performed with any of the targets described herein.

[0410] composition In one example, the antibodies described herein may be administered orally, parenterally, by inhalation spray, adsorption, absorption, topically, rectally, nasally, bucally, vaginally, intracerebroventricularly, via an implanted reservoir in a dosage formulation containing a conventional non-toxic pharmaceutically acceptable carrier, or by any other convenient dosage form. The term "parenteral" as used herein includes subcutaneous, intravenous, intramuscular, intraperitoneal, intrathecal, intraventricular, intrasternal, intrapolyp and intracranial injection or infusion techniques.

[0411] Methods for formulating antibodies into suitable forms (e.g., pharmaceutical compositions) for administration to a subject are known in the art and include, for example, those methods described in Remington's Pharmaceutical Sciences (18th ed., Mack Publishing Co., Easton, Pa., 1990) and the US Pharmacopeia: National Formulary (Mack Publishing Company, Easton, Pa., 1984).

[0412] The pharmaceutical compositions of the present disclosure are particularly useful for parenteral administration, e.g., intravenous administration or administration into a cavity or lumen of an organ or joint. A composition for administration will generally comprise a solution of the antibody dissolved in a pharma- ceutically acceptable carrier, e.g., an aqueous carrier. A variety of aqueous carriers, e.g., buffered saline, and the like, may be used. The composition may contain pharma- ceutically acceptable auxiliary substances, as necessary, to approximate physiological conditions, e.g., pH adjusting and buffering agents, toxicity adjusting agents, and the like, e.g., sodium acetate, sodium chloride, potassium chloride, calcium chloride, sodium lactate, and the like. The concentration of the antibody of the present disclosure in these formulations may vary and will be selected according to the particular mode of administration selected and the needs of the patient, based primarily on the volume, viscosity, weight, and the like of the bodily fluids. Exemplary carriers include water, saline, Ringer's solution, dextrose solution, and 5% human serum albumin. Non-aqueous vehicles, e.g., mixed oils and ethyl oleate, may also be used. Liposomes may also be used as carriers. The vehicle may contain minor amounts of additives that enhance isotonicity and chemical stability, such as buffers and preservatives.

[0413] Once formulated, the antibody of the present disclosure is administered in a manner compatible with the dosage formulation and in a therapeutically / prophylactically effective amount. The formulations are easily administered in a variety of dosage forms, such as injectable solutions of the type described above, but other pharma- ceutically acceptable forms, such as tablets, pills, capsules or other solids for oral administration, suppositories, pessaries, nasal solutions or sprays, aerosols, inhalants, liposomal forms, and the like, are also contemplated. Pharmaceutical "delayed release" capsules or compositions may also be used. Delayed release formulations are typically designed to provide a constant drug level over an extended period of time and may be used to deliver the antibody of the present disclosure.

[0414] WO2002 / 080967 describes compositions and methods for administering aerosolized compositions containing antibodies for the treatment of respiratory conditions, which are also suitable for administration of compounds according to the methods of the present disclosure.

[0415] Combination therapy In one example, the antibody of the disclosure is administered in combination with an additional conditioning regimen, e.g., the subject is undergoing or will undergo an additional conditioning regimen.

[0416] In one example, the additional conditioning regimen is a non-myeloablative or reduced intensity conditioning regimen.

[0417] As used herein, the terms "non-myeloablative conditioning" and "reduced intensity conditioning" refer to conditioning regimens that include low-dose chemotherapy and / or radiation therapy. Non-myeloablative and reduced intensity conditioning regimens differ in their ability to produce cytopenias.

[0418] In one example, the non-myeloablative or reduced intensity conditioning regimen includes low-dose chemotherapy. For example, the low-dose chemotherapy is fludarabine, cyclophosphamide, busulfan, antithymocyte globulin, thiotepa, melphalan, alemtuzumab, cladribine, idarubicin, cytarabine, cisplatin, azacytidine, rituximab, etoposide, and combinations thereof. In one example, the low-dose chemotherapy is busulfan. In another example, the low-dose chemotherapy is busulfan, fludarabine, and rituximab.

[0419] In one example, the non-myeloablative or reduced intensity conditioning regimen includes low-dose radiation therapy, such as low-dose total body irradiation or total body lymphatic irradiation. In one example, the low-dose total body irradiation is a dose of ≦2 Gray (Gy) or 1 Gy.

[0420] In one example, the additional conditioning regimen is total body irradiation at a dose of ≦2 Gy, with or without a purine analog.

[0421] In one example, the additional conditioning regimen is fludarabine and cyclophosphamide, with or without antithymocyte globulin.

[0422] In one example, the additional conditioning regimen is fludarabine, cytarabine and idarubicin.

[0423] In one example, the additional conditioning regimen is cladribine and cytarabine.

[0424] In one example, the additional conditioning regimen is total body lymphatic irradiation and antithymocyte globulin.

[0425] Dosage and timing of administration Suitable dosages of the antibodies of the present disclosure will vary depending on the particular antibody, the condition being treated, and / or the subject being treated. For example, it is within the ability of one of ordinary skill in the art to determine suitable dosages by starting with a suboptimal dosage and then modifying the dosage incrementally to determine an optimal or useful dosage. Alternatively, data from cell culture assays or animal studies can be used to determine appropriate dosages for treatment / prophylaxis, and suitable doses can be determined based on the ED of the active compound with little or no toxicity. 50 The therapeutically or prophylactically effective dose can be estimated initially from cell culture assays. Dosages are within a circulating concentration range that includes the IC 50 The compound may be formulated in animal models to achieve a circulating plasma concentration range (i.e., a concentration or amount of compound that achieves half-maximal inhibition of symptoms) that includes. Such information can be used to more accurately determine useful doses in humans. Levels in plasma can be measured, for example, by high performance liquid chromatography.

[0426] In some examples, the methods of the disclosure comprise administering an effective amount of an antibody described herein.

[0427] The term "effective amount" refers to an amount that, when administered to a subject in need of treatment, improves the condition of the subject's target tissue (e.g., bone marrow) for transplantation. For example, an effective amount is an amount sufficient to reduce or deplete or reduce the endogenous HSC population in the subject. The amount administered to a subject will depend on the particular characteristics of the condition being treated, the type and stage of the condition being treated, the mode of administration, and the characteristics of the subject, such as general health, other diseases, age, sex, genotype, and weight. One of skill in the art will be able to determine appropriate dosages depending on these and other factors. Thus, the term should not be construed to limit the present disclosure to a particular quantity, e.g., weight or amount, of protein, rather, the present disclosure encompasses any amount of antibody sufficient to achieve the described result in a subject.

[0428] In one example, an effective amount of an antibody disclosed herein achieves maximal stem cell depletion, e.g., about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 97.5%, 98%, 99%, 99.5% or more depletion of endogenous HSCs from a target tissue of a subject, e.g., bone marrow.

[0429] For in vivo administration of the antibodies described herein, normal dosages can vary from about 10 ng / kg to about 100 mg / kg (body weight) or more per day. For repeated administration over several days or more, depending on the severity of the disease or disorder being treated, treatment can be continued until a desired suppression of symptoms is achieved.

[0430] In some examples, the antibody is administered at an initial (or loading) dose of about 1 mg / kg to about 30 mg / kg, e.g., about 1 mg / kg to about 10 mg / kg, or about 1 mg / kg or about 2 mg / kg or 5 mg / kg. The antibody may then be administered at a lower maintenance dose of about 0.01 mg / kg to about 2 mg / kg, e.g., about 0.05 mg / kg to about 1 mg / kg, e.g., about 0.1 mg / kg to about 1 mg / kg, e.g., about 0.1 mg / kg or 0.5 mg / kg or 1 mg / kg. The maintenance dose may be administered every 7 to 30 days, e.g., every 10 to 15 days, e.g., every 10 or 11 or 12 or 13 or 14 or 15 days.

[0431] In some examples, the antibody is administered at a dose of about 0.01 mg / kg to about 50 mg / kg, e.g., about 0.05 mg / kg to about 30 mg / kg, e.g., about 0.1 mg / kg to about 20 mg / kg, e.g., about 0.1 mg / kg to about 10 mg / kg, e.g., about 0.1 mg / kg to about 2 mg / kg. For example, the antibody is administered at a dose of about 0.01 mg / kg to about 5 mg / kg, e.g., about 0.1 mg / kg to about 2 mg / kg, e.g., about 0.2 mg / kg or 0.3 mg / kg or 0.5 mg / kg or 1 mg / kg or 1.5 mg / kg (e.g., without a higher loading dose or a lower maintenance dose). In some examples, multiple doses are administered, e.g., every 7-30 days, e.g., every 10-22 days, e.g., every 10-15 days, e.g., every 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 days. For example, the antibody is administered every 7 days or every 14 days or every 21 days.

[0432] In some examples, when therapy is initiated, the subject is administered the antibody for no more than 7 consecutive days, or 6 consecutive days, or 5 consecutive days, or 4 consecutive days.

[0433] For subjects not responding adequately to treatment, multiple doses may be administered per week. Alternatively, or in addition, increasing doses may be administered.

[0434] In another example, for subjects experiencing an adverse reaction, the starting (or loading) dose can be split over multiple days in a week or over multiple consecutive days.

[0435] Administration of antibodies according to the methods of the present disclosure can be continuous or intermittent, depending, for example, on the physiological condition of the recipient and other factors known to those of skill in the art. Administration of antibodies can be essentially continuous over a preselected period of time, or can be in a series of spaced doses, for example, either during or after the progression of a pathological condition.

[0436] kit Another example of the disclosure provides kits containing antibodies useful for the methods of conditioning a subject in need of HCT described herein.

[0437] In one example, the kit includes (a) a container containing an antibody described herein, optionally in a pharma- ceutically acceptable carrier or diluent; and (b) a package insert having instructions for conditioning a subject in need of HCT.

[0438] In one example, the kit includes (a) a container containing an antibody described herein, optionally in a pharma- ceutically acceptable carrier or diluent; and (b) a package insert with instructions for reducing, depleting, and / or attenuating a population of cells in the bone marrow of a subject in need of HCT.

[0439] According to this example of the disclosure, the package insert is on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, and the like. The container can be formed from a variety of materials, for example, glass or plastic. The container holds or contains a composition that is effective for conditioning a subject and can have a sterile access port (for example, the container can be an intravenous solution bag or a vial with a stopper that can be punctured by a hypodermic needle). At least one active agent in the composition is a compound that binds to a target on endogenous HSC. The label or package insert indicates that the composition is to be administered to a subject eligible for treatment, for example, a subject requiring or undergoing HCT, with specific guidance regarding dosage and intervals of the compound and any other medications provided. The kit can further include additional containers containing a pharma-ceutically acceptable diluent buffer, for example, bacteriostatic water for injection (BWFI), phosphate buffered saline, Ringer's solution, and / or dextrose solution. The kit may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, and syringes.

[0440] The present disclosure includes the following non-limiting examples. EXAMPLES

[0441] Example 1: Anti-CD117-IgG1 monoclonal antibody screening To identify antibodies against CD117, an in-house antibody phage display library was panned against recombinant human CD117 (recHuCD117). Three rounds of phage display selection were performed against biotinylated recHuCD117 ECD in solution, where the antigen concentration was kept constant for selections A, C, and D; or decreased with each round of panning for selections B, E, and F. Phage / HuCD117 complexes were collected by incubating them with streptavidin magnetic beads. After each round, the beads were washed and bound phages were amplified and purified to be used as input for the next panning round. At the end of the panning process, individual phage clones from round 3 output were screened by Fab-phage ELISA for binding to recHuCD117 ECD and recombinant murine CD117 ECD (c-Kit Protein, Mouse, Recombinant (His Tag) Sino Biologicals). Sequence analysis of clones reactive to human and mouse CD117 revealed a total of 49 positive unique clones.

[0442] Of the HuCD117 positive clones, 47 could be reformatted into intact human antibodies (IgG1 format).

[0443] Example 2: Anti-CD117-IgG1 antibodies bind to human, mouse and cynoCD117 To evaluate binding of anti-CD117-IgG1 antibodies to cell surface-expressed CD117, TF-1 or HEK293FS cells stably expressing human, mouse or cynomolgus CD117 were resuspended in Dulbecco's PBS (Sigma Aldrich, D8537) containing 1% FCS and incubated with adjusted amounts of anti-CD117-IgG1 antibodies (5.7 pM to 12.5 nM for TF-1 cells; 6.1 pM to 25 nM for HEK293FS). After 1 h of incubation on ice, cells were washed once before fixation.

[0444] Primary anti-CD117-IgG1 antibodies were detected by the addition of secondary anti-human IgG Fab fragments conjugated to Alexa-Fluor 488 (Jackson labs, 109-547-008) (1 hour incubation on ice) and their cell-bound fluorescence was analyzed on an LSRFortessa™ cell analyzer (BD Biosciences). Mean fluorescence intensity (MFI) was obtained using Flowjo v10 and analyzed using GraphPad Prism. Total binding curves for TF-1 cells and specific binding curves for HEK293FS expressing CD117 (generated by subtracting non-specific binding to parental cells) were plotted. EC50 values ​​for each tested anti-CD117-IgG1 antibody were determined using a non-linear regression model.

[0445] Of the 47 anti-CD117-IgG1 antibodies generated, 28 were EC 50 All antibodies bound cell surface CD117 on TF-1 cells at <25 nM (Figure 1A-B). All antibodies bound human and cynomolgus CD117 when expressed on the surface of HEK293FS cells, and four were cross-reactive with murine CD117 when expressed on the surface of HEK293FS cells (Figure 1C-H).

[0446] Example 3: Anti-CD117-IgG1 antibody inhibits human stem cell factor-mediated TF-1 cell proliferation To evaluate antibodies with potential inhibitory activity, inhibition of human stem cell factor (SCF)-mediated TF-1 cell proliferation was evaluated.

[0447] TF-1 cells were cultured in RPMI complete medium (RPMI 1640 (Sigma)) supplemented with 10% FBS, 50 U / ml penicillin and 50 mg / ml streptomycin (Pen-Strep, Gibco #15070-063), 2 mM Glutamax (Gibco #35050)) supplemented with hGM-CSF (5 ng / ml, R&D Systems, #215-GM). Cells were grown in RPMI complete media (#R0883) at 37°C with 5% CO2. Cells were pelleted by centrifugation (1200 rpm, 5 min), resuspended in 5 ml of RPMI complete media, counted using a hemacytometer, and prepared to a final cell density of 2x105 cells / ml. Cells (100ul) were then seeded into 96-well plates to achieve a final cell density of 2x104 cells / well. Antibody clones were prepared in RPMI complete media at 4X concentration (4ug / ml, 26.68nM) and diluted 1 Serial 3-fold dilutions were made for 2 points. The titrated antibodies were then added (50ul) to each corresponding well to provide a final starting concentration of 1ug / ml (6.67nM). Human stem cell factor (hSCF, Peprotech, #300-07) was prepared in RPMI complete media at 4x the EC50 concentration (328pM) and added (50ul) to all wells to achieve a final concentration of 82pM / well. The plates were then incubated for 72 hours in an incubator at 37°C for 12 hours. o C, 5% CO2. Endpoint measurements were performed after 72 h of incubation using the Vialight Plus kit (Lonza, #LT07-121) according to the manufacturer's instructions.

[0448] Of the 47 anti-CD117-IgG1 antibodies generated, 13 inhibited hSCF-induced TF1 cell proliferation (Figure 2).

[0449] Example 4: Internalization of anti-CD117-IgG1 antibody Anti-AF488 quenching antibody assay To assess the internalization of anti-CD117-IgG1 antibodies, an assay based on quenching cell surface-bound fluorescence using anti-AF488 antibodies was established using TF-1 cells. Briefly, cells were incubated with 5 nM of anti-CD117-IgG1 antibodies precomplexed with AF488-labeled anti-human IgG Fab fragments (Jackson labs, 109-547-008) in a 1:3 molar ratio, in the presence or absence of 56 nM human stem cell factor (Genscript, Z02692-1), and incubated at 37°C for 0, 15, 30, 60 and 120 min. Two samples were processed at each time point: one sample was resuspended in PBS containing 1% FCS and the other in PBS containing 1% FCS and 20 μg / mL of anti-AF488 quenching IgG (Thermo-Fisher, A-11094). Cells were incubated on ice for 30 min before analysis on a BD LSRFortessa cytometer. Mean fluorescence intensity (MFI) values ​​were obtained using Flowjo v10, and the percentage of internalized antibody was calculated by dividing the internalized signal (MFI from samples treated with anti-AF488 quenched antibody) by the total cell-associated signal (MFI from non-quenched samples) at each time point.

[0450] As shown in FIG. 3A, the selected anti-CD117-IgG1 antibodies had slow internalization kinetics.

[0451] IncuCyte® Live Cell High Throughput Internalization Assay To compare the internalization of anti-CD117-IgG1 antibodies, an integration assay based on IncuCyte® live cell analysis and pH-sensitive dye-conjugated antibody fragments (IncuCyte® Human FabFluor-pH Red Antibody Labeling Reagent, Sartorius, 4722) was performed using TF-1 cells and according to the manufacturer's instructions. Briefly, TF-1 cells were seeded in wells of a 96-well plate pre-coated with 0.001% (V / V) poly-ornithine (Sigma-Aldrich, A004M) and allowed to adhere for 1 h at 37°C. Anti-CD117 antibodies pre-complexed with FabFluor-pH Red at a molar ratio of 1:3 were added to the cells (serialized dilutions from 25 nM to 3.125 nM). Experiments were performed in the absence or presence of 56 nM human stem cell factor. Images of internalized antibodies were immediately captured using a 20X objective every 10 min for 6 h in an Incucyte® S3 (Sartorius) and analyzed using integrated software for red fluorescent object area (a measure of FabFluor-labeled internalized antibodies). Top Hat subtraction was used to minimize any background fluorescent signal.

[0452] Similar to the anti-AF488 quenched antibody assay, the selected anti-CD117-IgG1 antibodies had slow internalization kinetics in the IncuCyte® live cell analysis (Figure 3B).

[0453] Example 5: Absence of activation of TF-1 cells mediated by anti-CD117-IgG antibodies in the absence of human SCF Anti-CD117-IgG1 antibodies were evaluated for their ability to activate TF-1 proliferation in the absence of human stem cell factor.

[0454] TF-1 cells were grown as described above. Cells were pelleted by centrifugation (1200 rpm, 5 min), resuspended in 5 ml of RPMI complete medium, counted using a hemocytometer, and found to be 2×10 5 The cells (100ul) were then seeded into 96-well plates at a final cell density of 2 x 10 4A final cell density of cells / well was achieved. Antibodies were prepared in RPMI complete media at 4X concentration (400ug / ml, 2668nM) and serially diluted 3-fold for 12 points and added to each corresponding well (50ul) to give a final starting concentration of 100ug / ml (667nM). To prevent early cell death, low level hGM-CSF (R&D Systems, #215-GM) was prepared in RPMI complete media at 4X concentration (0.04ng / ml) and added to all wells (100ul) to provide a final concentration of 0.01ng / ml. Plates were then incubated for 48 hours in an incubator at 37°C. o C, 5% CO2. After incubation, endpoint measurements were performed using the Vialight Plus kit (Lonza, #LT07-121) according to the manufacturer's instructions.

[0455] As shown in Figure 4, none of the 47 anti-CD117-IgG1 antibodies was able to activate the CD117 receptor in the absence of stem cell factor and induce proliferation of TF-1 cells.

[0456] Example 6: Soluble N-Terminal (HuCD117 1-307 ) and C-terminus (HuCD117 308-524 Binding affinity of anti-CD117 antibodies to Biacore4000 was used for all binding analyses. Experiments were performed at pH 7.3, 37° C., and a flow rate of 30 μL / min. Human anti-CD117 antibodies were surface captured using Protein G immobilized directly onto the carboxymethyldextran surface of a CM5 sensor chip to approximately 1,500 RU using standard NHS / EDC chemistry at pH 4.5. The immobilized Protein G surface was preconditioned with 10 injections each of human polyclonal IgG (Pirivigen 60s, 10 μg / mL), followed by a regeneration cycle with 10 mM glycine (pH 1.6).

[0457] A total of 52 anti-CD117 antibodies (2 μg / mL) were incubated with a soluble 8×his-tagged N-terminal fragment of the human CD117 receptor (HuCD117 1-307) and C-terminus (HuCD117 308-524 ) fragment. Between these, 47 candidates were reformatted into an IgG4 scaffold. Four antibodies (huAb249, huAb85, huCK6 and huhzSR1) were reformatted into an IgG1 scaffold and included as benchmark controls. HuhzSR1 was also reformatted into an IgG4 scaffold. BM4 and Pirivigen were used as negative controls.

[0458] HuCD117 fragments were prepared in 3-fold dilutions of 25, 75, and 225 nM. Anti-CD117 antibodies huAb249, huAb85, huCK6, and huhzSR1 were used as positive controls. Association and dissociation were monitored for 120 and 180 seconds. No significant differences were observed from huhzSR1 antibodies prepared in either IgG1 or IgG4 backbones. Anti-CD117 antibodies conjugated either the N-terminal or C-terminal domains (but not both). Positive binding responses to the soluble domains are shown in green, whereas negative responses are shown in white (Figure 5A). Approximate binding affinities were calculated from sensorgrams double-referenced using reference surface and blank buffer injection data collected within each experiment. Rate constants and binding affinities were calculated using a 1:1 kinetic model with local Rmax and null refractive index (RI=0).

[0459] Forty-eight anti-CD117 antibodies bound either domain (but not both) (Figure 5A). The N-terminal domain bound 23 anti-CD117 antibodies with affinities ranging from 8 nM (hu3A7) to 1.5 μM (hu3A12), whereas the C-terminal domain bound the remaining 20 anti-CD117 antibodies with affinities ranging from 12 nM (hu4A8) to 16 μM (hu3A2). The positive control anti-CD117 antibodies huAb249, huAb85, huCK6, and huhzSR1 bound only the N-terminal domain. Four antibodies (hu3A8, hu3B9, hu4A5, and hu4B4) did not bind any of the CD117 domains, suggesting that their epitopes lie at the junction of the N- and C-terminal regions. No reactivity was detected from either BM4 (negative control) or Pirivigen (polyclonal human IgG). The binding affinities of the antibody panel for each domain are shown in FIG. 5A, and the overall distribution of binding affinities is shown in FIGS. 5B and C.

[0460] Four antibodies were shortlisted for further study based on their cell-based activity and cross-reactivity: of these, hu3B3 (9 nM), hu3C2 (14 nM), and hu4A2 (49 nM) bound the N-terminal domain, whereas hu3B2 (191 nM) bound the C-terminal domain of CD117.

[0461] Example 7: Comparative anti-CD117 antibodies prepared in IgG1, IgG4 or IgA2 backbones Biacore4000 was used for all binding analyses. Experiments were performed at pH 7.3, 37°C, and a flow rate of 30 μL / min. Human anti-CD117 antibodies were surface captured using either polyclonal goat anti-human IgG or IgA antibodies directly immobilized onto the carboxymethyldextran surface of a CM5 sensor chip to approximately 13,000 RU using standard NHS / EDC chemistry at pH 5. The immobilized antibody surfaces were preconditioned with 10 injections of human polyclonal IgG (Pirivigen 60s, 10 μg / mL), respectively, followed by a regeneration cycle with 100 mM H3PO4.

[0462] A total of 18 anti-CD117 antibodies (2 μg / mL) were tested against four soluble mammalian CD117 receptor variants: the N-terminal domain of human CD117 (HuCD117 1-308 ), full-length human CD117 (HuCD117 1-524 ), cynoCD117(cynoCD117 1-520 ), and murine CD117 (MuCD117 1-527 The 18 antibodies represented four parental mAbs (hu3B2, hu3B3, hu3C2, and hu4Aa) and four control antibodies (huCK6, huAb249, huAb85, and hzSR1) prepared in either an IgG1 or IgG4 and IgA2 backbone.

[0463] Antibodies were captured at the active spots (1 and 5) of each flow cell for 60 seconds to approximately 2,000 RU, while the inner spots (2 and 4) were left blank and used for reference subtraction. Association and dissociation steps were monitored for 120 and 180 seconds, respectively.

[0464] CD117 protein was prepared in two-fold dilutions ranging from 0.8 to 200 nM. Anti-CD117 antibodies huAb249, huAb85, huCK6 and huhzSR1 were used as positive controls. BM4 was prepared in IgG and IgA2 formats and used as a negative control. Binding affinities were calculated from sensorgrams that were double-referenced using the reference surface and blank buffer injection data collected within each experiment. Rate constants and binding affinities were calculated using a 1:1 kinetic model with local Rmax and null refractive index (RI=0).

[0465] Briefly, human anti-CD117 antibodies bound the N-terminal domain of CD117 with approximately 2-fold higher affinity compared to the full-length protein. Anti-CD117 antibodies bound human and cynomolgus isoforms of CD117 with comparable affinity, which is consistent given the high degree of similarity between these two receptors.

[0466] The overall binding affinity (K D ) of these antibodies to full-length human and cyno receptors can be represented as Hu3B3 (2 - 5 nM) < hu3C2 (10 - 30 nM) < hu4A2 (approx. 3 - 40 nM) < hu3B2 (35 - 59 nM) (Figure 6). Antibodies generated on an IgA2 backbone bound their antigens with increased affinity compared to those prepared with IgG1 or IgG4. Hu4A2 showed the greatest increase in affinity (approx. 2-fold for huCD117 and approx. 10-fold for cynoCD117).

[0467] It was not possible to determine the binding affinity of these antibodies to murine isoforms of CD117. As shown in Table 1, murine CD117 showed weak binding affinity (i.e., KD > 1 μM) to antibodies hu3B2 and hu4A2 and did not bind to the remaining antibodies. Control antibodies huCK6, huAb249, huAb85, and hzSR1 bound human and cyno receptors with low nanomolar affinity (Table 1).

[0468]

Table 2

[0469] Example 8: In vitro antibody-dependent cellular cytotoxicity trogocytosis (ADCT) assay using exemplary candidates The IgA2 anti-CD117 antibody trogocytosis activities of the newly generated clones 3B2, 3B3, 3C2, 4A2, Ab249, and Ab85 were determined by flow cytometry and compared with the previously published clones SR1 and CK6. Briefly, human CD117-transfected 293 target cell line was labeled with the membrane dye DILC18 (1,1”-dioctadecyl-3,3,3”,3”-tetramethylindocarbacyanine perchlorate, Thermo Fisher), mixed 1:10 with freshly isolated peripheral blood neutrophils as effector cells, and incubated with human IgA2 anti-CD117 antibody (0.02–100 nM) or control antibody (100 nM) for 4 h at 37 °C and 5% CO in a total volume of 150 μL. Cells were then stained with Alexa fluor 647-conjugated anti-CD66b and LIVE / DEAD™ Fixable Green Stain (Invitrogen), washed, and dehydrated using formaldehyde (BD Cells were fixed with Cytofix. Cells were acquired on a Fortessa and viable neutrophils were identified by forward and side scatter followed by identification of viable CD66b positive cells. Membrane uptake by neutrophils was measured by the increase in DILC18 mean fluorescence intensity (MFI) with a YG586-15 detector. DILC18 MFI was normalized to the maximum MFI per donor neutrophil (Figure 7A).

[0470] Half-maximal effective concentration (EC 50 ±SD) [nM] and normalized maximum membrane uptake (B max ) (percentage) are shown in Table 1 and Figures B and C. EC50 and normalized Bmax (%) were calculated using Prism 8 Graphphad Software utilizing a four parameter logistic curve based on the experiment shown in Graph 7.1.

[0471] [Table 3]

[0472] Example 9: Modification of the hinge region of an anti-CD117-IgG1 antibody Two IgA2 candidates were prepared with extended IgA2 / IgG3 hinge regions: antibody 3C2 (CDRs were not modified, applicable CDRs are SEQ ID NOs: 42-47) and SR1 (a commercial antibody as a control).

[0473] The IgG3 hinge region was inserted after the first Pro of the IgA2 hinge (Senior et al., 2000 and Woof & Kerr, 2006).

[0474] Two versions of the extended hinge region were generated (see Table 3). Version 1 (V1) had a 5x proline motif in the heavy chain with the first proline from the lower hinge and four additional prolines from the IgA2 sequence, and version 2 (V2) had a 4x proline motif in the heavy chain. For both of these versions, the light chain sequence remained the same.

[0475] [Table 4] [Table 5-1] [Table 5-2] [Table 5-3] [Table 5-4] [Table 5-5] [Table 5-6]

Table 5-7

Table 5-8

Table 5-9

Table 5-10

Table 5-11

Table 5-12

Table 5-13

Table 5-14

Table 5-15

Table 5-16

Table 5-17

Table 5-18

Table 5-19

Table 5-20

Table 5-21

Table 5-22

Table 5-23

Table 5-24

Table 5-25

Table 5-26

Table 5-27

Table 5-28

Table 5-29

Table 5-30

Claims

1. 1. A method of conditioning a subject in need of hematopoietic cell transplantation (HCT), the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject, the antibody mediating antibody-dependent cellular trogocytosis (ADCT).

2. 1. A method for reducing, depleting and / or attenuating a population of cells in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT), the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject, the antibody mediating antibody-dependent cellular trogocytosis (ADCT).

3. The antibody is IgA ２ 3. The method of claim 1 or 2, comprising a heavy chain; and a lambda or kappa light chain.

4. The IgA ２ The heavy chain is (i) an N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) scheme; (ii) a P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) scheme; (iii) a C to S mutation at position 311 according to the myeloma IgA1 protein (Bur) scheme; (iv) a NIT to TLS mutation at positions 337-339 according to the myeloma IgA1 protein (Bur) scheme; (v) deletion of a C residue at position 472 according to the myeloma IgA1 protein (Bur) scheme; and (vi) deletion of a Y residue at position 473 according to the myeloma IgA1 protein (Bur) scheme; The method of claim 3, comprising one or more modifications selected from the group consisting of:

5. The IgA ２ 5. The method of claim 3 or 4, wherein the heavy chain comprises the sequence shown in SEQ ID NO:33 or SEQ ID NO:34 or SEQ ID NO:

66.

6. The targets on the endogenous HSCs are CD2, CD5, CD7, CD11a, CDw12, CD13, CD15, CD18, CD19, CD21, CD22, CD29, CD30, CD33, CD34, CD36, CD38, CD40, CD41, CD42a, CD42b, CD42c, CD42d, CD43, CD45, CD45RA, CD45RB, CD45RC, CD45RO, CD48, CD49b, CD49d (VLA-4), CD49 e, CD49f (VLA-6), CD50, CD51, CD53, CD55, CD58, CD64a, CD68, CD71, CD72, CD73, CD81, CD82, CD84, CD85A, CD85K, CD90, CD 97, CD99, CD104, CD105, CD109, CD110, CD111, CD112, CD114, CD115, CD117 (c-kit), CD123, CD124, CD126, CD127, CD130, CD 131, CD133, CD134, CD135, CD137, CD138, CD151, CD157, CD162, CD164, CD166, CD168, CD172a, CD173, CD174, CD175, CD175 s, CD176, CD183, CD184 (CXCR4), CD191, CD200, CD201, CD205, CD217, CD220, CD221, CD222, CD223, CD224, CD225, CD226, CD 6. The method of any one of claims 1 to 5, wherein the IL-16 polypeptide is selected from the group consisting of CD227, CD228, CD229, CD230, CD235a, CD235b, CD236, CD236R, CD238, CD240, CD242, CD243, CD277, CD292, CDw293, CD295, CD298, CD309, CD318, CD324, CD325, CD338, CD344, CD349, CD350, CD361, and combinations thereof.

7. The method of any one of claims 1 to 6, wherein the target on the endogenous HSC is CD117.

8. The antibody is (i) blocking the binding of CD117 by stem cell factor (SCF); and / or (ii) inhibiting the activation of CD117 by SCF; and / or (iii) inhibiting SCF-mediated CD117+ cell proliferation; and / or (iv) depleting the population of CD117+ cells in the subject. The method of claim 7, wherein the therapeutic agent is administered in an amount sufficient to

9. The method according to any one of claims 1 to 8, wherein the antibody is an anti-CD117 antibody.

10. The anti-CD117 antibody is (i) a K of 20 nM or less Ｄ and / or (ii) a K of 15 nM or less Ｄ at the C-terminus of human CD117; and / or (iii) a K of 60 nM or less Ｄ Full-length human CD117 The method of claim 9, wherein

11. The anti-CD117 antibody has an IC ５０ The method of claim 9 or 10, wherein the method inhibits SCF-mediated proliferation of TF-1 cells expressing CD117 in a mouse model of the present invention.

12. The anti-CD117 antibody has an EC ５０ The method according to any one of claims 9 to 11, wherein the antibody binds to TF-1 cells expressing CD117 at a specific concentration.

13. The anti-CD117 antibody exhibited at least 50% normalized maximum membrane uptake (B) as determined by mean fluorescence intensity (MFI) of DILC18 on neutrophils. ｍａｘ 13. The method according to any one of claims 9 to 12, wherein ADCT is mediated by

14. The method of any one of claims 9 to 13, wherein the anti-CD117 antibody competitively inhibits the binding of any one or more of the following antibodies to CD117: (i) a heavy chain variable region (V Ｈ ); and a light chain variable region (V Ｌ ); (ii) a V comprising the sequence shown in SEQ ID NO:7 Ｈ and V comprising the sequence shown in SEQ ID NO:

10. Ｌ an antibody comprising (iii) a V comprising the sequence shown in SEQ ID NO: 13 Ｈ and V comprising the sequence shown in SEQ ID NO:16 Ｌ an antibody comprising (iv) a V comprising the sequence set forth in SEQ ID NO: 19 Ｈ and V comprising the sequence set forth in SEQ ID NO:22 Ｌ An antibody comprising: (v) V comprising the sequence shown in SEQ ID NO: 25 Ｈ and V comprising the sequence set forth in SEQ ID NO:28 Ｌ An antibody comprising:

15. The anti-CD117 antibody is (i) a V comprising the sequence shown in SEQ ID NO: 4 or SEQ ID NO: 13 Ｈ and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 Ｌ ;or (ii) a V comprising the sequence shown in SEQ ID NO: 4 or SEQ ID NO: 13 Ｈ V comprising three complementarity determining regions (CDRs) Ｈ and V comprising the sequence shown in SEQ ID NO:5 or SEQ ID NO:28 Ｌ V comprising the three CDRs Ｌ The method according to any one of claims 9 to 14, comprising:

16. The anti-CD117 antibody is (i) a V comprising the sequence shown in SEQ ID NO:7 Ｈ V comprising the three CDRs Ｈ and V comprising the sequence shown in SEQ ID NO:

10. Ｌ V comprising the three CDRs Ｌ ; (ii) a V comprising the sequence shown in SEQ ID NO: 13 Ｈ V comprising the three CDRs Ｈ and V comprising the sequence shown in SEQ ID NO:16 Ｌ V comprising the three CDRs Ｌ ; (iii) a V comprising the sequence shown in SEQ ID NO: 19 Ｈ V comprising the three CDRs Ｈ and V comprising the sequence set forth in SEQ ID NO:22 Ｌ V comprising the three CDRs Ｌ ;or (iv) a V comprising the sequence set forth in SEQ ID NO: 25 Ｈ V comprising the three CDRs Ｈ and V comprising the sequence set forth in SEQ ID NO:28 Ｌ V comprising the three CDRs Ｌ ;or (v) a V comprising a CDR1 having the sequence set forth in SEQ ID NO: 42, a CDR2 having the sequence set forth in SEQ ID NO: 43, and a CDR3 having the sequence set forth in SEQ ID NO: 44; Ｈ and a V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:45, a CDR2 comprising the sequence set forth in SEQ ID NO:46, and a CDR3 comprising the sequence set forth in SEQ ID NO:

47. Ｌ ;or (vi) a VDR1 comprising the sequence set forth in SEQ ID NO: 48, a CDR2 comprising the sequence set forth in SEQ ID NO: 49, and a CDR3 comprising the sequence set forth in SEQ ID NO: 50; Ｈ and a V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:51, a CDR2 comprising the sequence set forth in SEQ ID NO:52, and a CDR3 comprising the sequence set forth in SEQ ID NO:

53. Ｌ ;or (vii) a VDR1 comprising the sequence set forth in SEQ ID NO: 54, a CDR2 comprising the sequence set forth in SEQ ID NO: 55, and a CDR3 comprising the sequence set forth in SEQ ID NO: 56; Ｈ and a V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:57, a CDR2 comprising the sequence set forth in SEQ ID NO:58, and a CDR3 comprising the sequence set forth in SEQ ID NO:

59. Ｌ ;or (viii) a VDR1 comprising the sequence set forth in SEQ ID NO: 60, a CDR2 comprising the sequence set forth in SEQ ID NO: 61, and a CDR3 comprising the sequence set forth in SEQ ID NO: 62 Ｈ and a V comprising a CDR1 comprising the sequence set forth in SEQ ID NO:63, a CDR2 comprising the sequence set forth in SEQ ID NO:64, and a CDR3 comprising the sequence set forth in SEQ ID NO:

65. Ｌ The method according to any one of claims 9 to 15, comprising:

17. The anti-CD117 antibody is (i) a V comprising the sequence shown in SEQ ID NO:7 Ｈ and V comprising the sequence shown in SEQ ID NO:

10. Ｌ ; (ii) a V comprising the sequence shown in SEQ ID NO: 13 Ｈ and V comprising the sequence shown in SEQ ID NO:16 Ｌ ; (iii) a V comprising the sequence shown in SEQ ID NO: 19 Ｈ and V comprising the sequence set forth in SEQ ID NO:22 Ｌ ;or (iv) a V comprising the sequence set forth in SEQ ID NO: 25 Ｈ and V comprising the sequence set forth in SEQ ID NO:28 Ｌ The method according to any one of claims 9 to 16, comprising:

18. The anti-CD117 antibody is (i) a V comprising the sequence shown in SEQ ID NO:7 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:10 Ｌ a lambda light chain comprising (ii) a V comprising the sequence shown in SEQ ID NO: 13 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:16 Ｌ a lambda light chain comprising (iii) a V comprising the sequence shown in SEQ ID NO: 19 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:22 Ｌ or a lambda light chain comprising (iv) a V comprising the sequence set forth in SEQ ID NO: 25 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:28 Ｌ Kappa light chains, including The method according to any one of claims 9 to 17, comprising:

19. The anti-CD117 antibody is (i) a heavy chain comprising the sequence set forth in SEQ ID NO:6; and a light chain comprising the sequence set forth in SEQ ID NO:9; (ii) a heavy chain comprising the sequence set forth in SEQ ID NO: 12; and a light chain comprising the sequence set forth in SEQ ID NO: 15; (iii) a heavy chain comprising the sequence set forth in SEQ ID NO: 18; and a light chain comprising the sequence set forth in SEQ ID NO: 21; (iv) a heavy chain comprising the sequence set forth in SEQ ID NO:24; and a light chain comprising the sequence set forth in SEQ ID NO:27; (v) a heavy chain comprising the sequence set forth in SEQ ID NO:67; and a light chain comprising the sequence set forth in SEQ ID NO:69; (vi) a heavy chain comprising the sequence set forth in SEQ ID NO: 71; and a light chain comprising the sequence set forth in SEQ ID NO: 73; (vii) a heavy chain comprising the sequence set forth in SEQ ID NO: 75; and a light chain comprising the sequence set forth in SEQ ID NO: 77; (viii) a heavy chain comprising the sequence set forth in SEQ ID NO: 79; and a light chain comprising the sequence set forth in SEQ ID NO: 81; (ix) a heavy chain comprising the sequence set forth in SEQ ID NO: 83; and a light chain comprising the sequence set forth in SEQ ID NO: 85; (x) a heavy chain comprising the sequence set forth in SEQ ID NO: 87; and a light chain comprising the sequence set forth in SEQ ID NO: 89; (xi) a heavy chain comprising the sequence set forth in SEQ ID NO: 91; and a light chain comprising the sequence set forth in SEQ ID NO: 93; (xii) a heavy chain comprising the sequence set forth in SEQ ID NO: 95; and a light chain comprising the sequence set forth in SEQ ID NO: 97; (xiii) a heavy chain comprising the sequence set forth in SEQ ID NO: 99; and a light chain comprising the sequence set forth in SEQ ID NO: 101; (xiv) a heavy chain comprising the sequence set forth in SEQ ID NO: 103; and a light chain comprising the sequence set forth in SEQ ID NO: 105; or (xv) a heavy chain comprising the sequence set forth in SEQ ID NO: 107; and a light chain comprising the sequence set forth in SEQ ID NO:

109. The method according to any one of claims 9 to 18, comprising:

20. 20. The method of any one of claims 1 to 19, wherein the subject is afflicted with cancer, a hemoglobin disorder, a myelodysplastic disorder, a primary immune deficiency (PID), an autoimmune disorder, an immunodeficiency disorder, or a metabolic disorder.

21. The method of any one of claims 1 to 20, wherein the subject has undergone, is undergoing or will undergo an additional conditioning regimen.

22. 22. The method of claim 21, wherein the additional conditioning regimen is a non-myeloablative or reduced intensity conditioning regimen.

23. The method of any one of claims 1 to 22, wherein the subject further undergoes HCT after administration of the antibody.

24. 1. A method of hematopoietic cell transplantation (HCT) in a subject in need thereof, wherein the subject has already been treated with an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject, and the antibody mediates antibody-dependent cellular trogocytosis (ADCT).

25. 1. A method of hematopoietic cell transplantation (HCT) in a subject in need thereof, the method comprising: (i) conditioning the patient with an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject; and (ii) administering a hematopoietic cell transplant to the subject. The method comprising:

26. 1. A method of reducing a side effect of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject, the antibody mediating antibody-dependent cellular trogocytosis (ADCT).

27. An anti-CD117 antibody, the antibody comprising: (i) a V comprising the sequence shown in SEQ ID NO:7 Ｈ and V comprising the sequence shown in SEQ ID NO:

10. Ｌ ; (ii) a V comprising the sequence shown in SEQ ID NO: 13 Ｈ and V comprising the sequence shown in SEQ ID NO:16 Ｌ ; (iii) a V comprising the sequence shown in SEQ ID NO: 19 Ｈ and V comprising the sequence set forth in SEQ ID NO:22 Ｌ ;or (iv) a V comprising the sequence set forth in SEQ ID NO: 25 Ｈ and V comprising the sequence set forth in SEQ ID NO:28 Ｌ The anti-CD117 antibody comprising:

28. An anti-CD117 antibody, the antibody comprising: (i) a V comprising the sequence shown in SEQ ID NO:7 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:10 Ｌ a lambda light chain comprising (ii) a V comprising the sequence shown in SEQ ID NO: 13 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:16 Ｌ a lambda light chain comprising (iii) a V comprising the sequence shown in SEQ ID NO: 19 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:22 Ｌ or a lambda light chain comprising (iv) a V comprising the sequence set forth in SEQ ID NO: 25 Ｈ IgA containing ２ heavy chain; and V comprising the sequence shown in SEQ ID NO:28 Ｌ Kappa light chains, including The anti-CD117 antibody comprising:

29. An anti-CD117 antibody, the antibody comprising: (i) a heavy chain comprising the sequence set forth in SEQ ID NO:6; and a light chain comprising the sequence set forth in SEQ ID NO:9; (ii) a heavy chain comprising the sequence set forth in SEQ ID NO: 12; and a light chain comprising the sequence set forth in SEQ ID NO: 15; (iii) a heavy chain comprising the sequence set forth in SEQ ID NO: 18; and a light chain comprising the sequence set forth in SEQ ID NO: 21; (iv) a heavy chain comprising the sequence set forth in SEQ ID NO:24; and a light chain comprising the sequence set forth in SEQ ID NO:27; (v) a heavy chain comprising the sequence set forth in SEQ ID NO:67; and a light chain comprising the sequence set forth in SEQ ID NO:69; (vi) a heavy chain comprising the sequence set forth in SEQ ID NO: 71; and a light chain comprising the sequence set forth in SEQ ID NO: 73; (vii) a heavy chain comprising the sequence set forth in SEQ ID NO: 75; and a light chain comprising the sequence set forth in SEQ ID NO: 77; (viii) a heavy chain comprising the sequence set forth in SEQ ID NO: 79; and a light chain comprising the sequence set forth in SEQ ID NO: 81; (ix) a heavy chain comprising the sequence set forth in SEQ ID NO: 83; and a light chain comprising the sequence set forth in SEQ ID NO: 85; (x) a heavy chain comprising the sequence set forth in SEQ ID NO: 87; and a light chain comprising the sequence set forth in SEQ ID NO: 89; (xi) a heavy chain comprising the sequence set forth in SEQ ID NO: 91; and a light chain comprising the sequence set forth in SEQ ID NO: 93; (xii) a heavy chain comprising the sequence set forth in SEQ ID NO: 95; and a light chain comprising the sequence set forth in SEQ ID NO: 97; (xiii) a heavy chain comprising the sequence set forth in SEQ ID NO: 99; and a light chain comprising the sequence set forth in SEQ ID NO: 101; (xiv) a heavy chain comprising the sequence set forth in SEQ ID NO: 103; and a light chain comprising the sequence set forth in SEQ ID NO: 105; or (xv) a heavy chain comprising the sequence set forth in SEQ ID NO: 107; and a light chain comprising the sequence set forth in SEQ ID NO:

109. The anti-CD117 antibody comprising:

30. An anti-CD117 antibody, the antibody comprising: (i) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:8; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:11; (ii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:14; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:17; (iii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:20; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:23; (iv) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:26; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:29; (v) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:68; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:70; (vi) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:72; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:74; (vii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:76; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:78; (viii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 80; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 82; (ix) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:84; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:86; (x) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:88; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:90; (xi) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:92; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:94; (xii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:96; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:98; (xiii) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:100; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:102; (xiv) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 104; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 106; or (xv) a heavy chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO: 108; and a light chain comprising a sequence expressed from or encoded by a nucleic acid comprising SEQ ID NO:

110. The anti-CD117 antibody comprising:

31. A pharmaceutical composition comprising an anti-CD117 antibody according to any one of claims 27 to 30; and a pharma- ceutically acceptable carrier.

32. A polynucleotide encoding the anti-CD117 antibody of any one of claims 27 to 30.

33. 33. The polynucleotide of claim 32, wherein the polynucleotide is operably linked to a heterologous promoter.

34. 34. An expression construct comprising the polynucleotide of claim 32 or 33.

35. A cell comprising the expression construct of claim 34.

36. An anti-CD117 antibody according to any one of claims 27 to 30, or a pharmaceutical composition according to claim 31, for use as a medicament.

37. An anti-CD117 antibody according to any one of claims 27 to 30, or a pharmaceutical composition according to claim 31, for use in conditioning a subject in need of hematopoietic cell transplantation (HCT).

38. 1. Use of an antibody that binds or specifically binds to a target on an endogenous hematopoietic stem cell (HSC) in the manufacture of a medicament for conditioning a subject in need of hematopoietic cell transplantation (HCT), wherein the antibody mediates antibody-dependent cellular trogocytosis (ADCT).

39. An anti-CD117 antibody according to any one of claims 27 to 30, or a pharmaceutical composition according to claim 31, for use in depleting a population of cells in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT).

40. 1. Use of an antibody that binds or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the manufacture of a medicament for depleting a population of cells in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT), wherein the antibody mediates antibody-dependent cellular trogocytosis (ADCT).

41. An anti-CD117 antibody according to any one of claims 27 to 30, or a pharmaceutical composition according to claim 31, for use in a method of hematopoietic cell transplantation (HCT).

42. An anti-CD117 antibody according to any one of claims 27 to 30, or a pharmaceutical composition according to claim 31, for use in reducing the side effects of a myeloablative conditioning regimen.

43. 1. Use of an antibody that binds or specifically binds to a target on an endogenous hematopoietic stem cell (HSC), wherein the antibody mediates antibody-dependent cellular trogocytosis (ADCT), in the manufacture of a medicament for reducing side effects of a myeloablative conditioning regimen in a subject.

44. The method of any one of claims 1 to 26, wherein the antibody comprises a modified hinge region.

45. The modified hinge region is a chimeric IgA ２ / IgG ３ 45. The method of claim 44, comprising a hinge region.

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