Bone marrow conditioning method

Abstract

The present disclosure relates to methods of conditioning and / or depleting cell populations 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 CD 117 (c-kit).

Description

[0001] Related application data

[0002] 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 that patent application are hereby incorporated by reference.

[0003] Sequence Listing

[0004] This application is filed with a sequence listing in electronic form, the entire contents of which are hereby incorporated by reference. Technical Field

[0005] The present disclosure relates to methods of conditioning and / or depleting a cell population in the bone marrow of a subject in need of hematopoietic cell transplantation (HCT), the method comprising administering an antibody that binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject. Background Art

[0006] Hematopoietic cell transplantation (HCT) is to apply hematopoietic stem cells and progenitor cells to establish bone marrow and immune function to patients with multiple acquired and inherited malignant and non-malignant diseases. These diseases include hematological malignancies (e.g., leukemia, lymphoma and myeloma), non-malignant acquired bone marrow diseases (e.g., aplastic anemia) and genetic diseases related to hematopoiesis and dysfunction (e.g., thalassemia, sickle cell anemia and severe combined immunodeficiency). HCT can also be used to support patients who receive high-dose chemotherapy to treat certain solid tumors, and blood toxicity can limit drug administration (e.g., germ cell tumors, soft tissue sarcomas and neuroblastomas) in addition for these patients.

[0007] Before HCT, conditioning therapy is used to reduce the burden of disease, generate space for implantation and immunosuppression. At present, conditioning regimens are myeloablative or non-myeloablative. Myeloablative regimens include a combination of high-dose chemotherapy (e.g., cyclophosphamide, busulfan and etoposide) and / or radiotherapy (e.g., whole body irradiation) with immunosuppressive components. Although these regimens are designed to suppress the immune system, they may also have adverse effects on multiple organ systems, and often lead to life-threatening complications. The chemotherapy and radiotherapy doses used in non-myeloablative regimens (or regimens with reduced intensity) are too low to eradicate all bone marrow cells of the patient, so that the risk of infection and transplant-related death of the patient is reduced. However, relapse is always a major problem after the conditioning regimen with reduced intensity.

[0008] Recently, nonmyeloablative regimens have been used in combination with other immunotherapy conditioning regimens that include T cells modified with chimeric antigen receptors (CARs) targeting hematopoietic stem cell markers. However, a major limitation of this regimen is that all CAR-modified infused T cells are completely eliminated before donor cell transplantation.

[0009] Therefore, there is a need to develop conditioning regimens that avoid undesirable toxicities and minimize the occurrence of severe adverse events while reducing the risk of patient relapse. Summary of the invention

[0010] In the generation of the present invention, the inventors identified antibodies that can be used for conditioning regimens for patients preparing for hematopoietic cell transplantation (HCT). The inventors found that antibodies that bind to targets (e.g., CD117) on endogenous hematopoietic stem cells (HSC) can successfully deplete and / or eliminate HSC. Advantageously, the inventors found that the use of antibodies that mediate antibody-dependent cellular trogocytosis (ADCT) and antibodies comprising IgA2 heavy chains can enhance the depletion of HSC.

[0011] Therefore, the inventors' findings provide a basis for methods of conditioning subjects in need of HCT. Specifically, these findings provide a basis for methods of conditioning subjects in need of HCT, the method comprising administering to the subject an antibody that binds to or specifically binds to a target on an endogenous HSC in the subject.

[0012] The inventor's discovery also provides a basis for methods of reducing, depleting and / or eliminating cell populations in the bone marrow of a subject in need of HCT. Specifically, these discoveries provide a basis for methods of reducing, depleting and / or eliminating cell populations in the bone marrow of a subject in need of HCT, the method comprising administering to the subject an antibody that is bound to or specifically bound to a target on an endogenous HSC in the subject.

[0013] 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 yet another 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 yet another 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 yet another 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 yet another 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.

[0014] 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 to or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0015] The present disclosure also provides a method of reducing, depleting and / or eliminating a cell population in the bone marrow of a subject in need of HCT, the method comprising administering to the subject an antibody that binds to or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0016] The present disclosure provides a method of conditioning a subject in need of HCT, the method comprising administering to the subject an antibody comprising a modified hinge region.

[0017] The present disclosure also provides a method of reducing, depleting and / or eliminating a cell population in the bone marrow of a subject in need of HCT, the method comprising administering to the subject an antibody comprising a modified hinge region (e.g., an extended hinge region). For example, the extended hinge region comprises a portion of an IgG3 hinge region of an IgA2 hinge region inserted after the first proline.

[0018] In one example, an antigen binding site of an antibody of the present disclosure comprising an extended hinge region is better able to bind to its epitope relative to an antigen binding site of an antibody that does not comprise an extended hinge region.

[0019] The present disclosure provides a method of conditioning a subject in need of HCT, the method comprising administering to the subject an antibody comprising an extended hinge region, wherein the antigen binding site of the antibody is better able to bind to an epitope thereof relative to the antibody not comprising the extended hinge region.

[0020] The present disclosure also provides a method for reducing, depleting and / or eliminating a cell population in the bone marrow of a subject in need of HCT, the method comprising administering to the subject an antibody comprising an extended hinge region, wherein the antigen binding site of the antibody has better access to its epitope relative to the antibody not comprising the extended hinge region.

[0021] In one example, the antibody comprises an IgA antibody heavy chain. For example, the IgA antibody heavy chain is an IgA2 heavy chain.

[0022] In one example, the antibody includes an antibody light chain. For example, the antibody includes a lambda light chain or a kappa light chain. In one example, the antibody includes a lambda light chain. In another example, the antibody includes a kappa light chain.

[0023] In one example, the antibody includes an IgA2 heavy chain and a lambda light chain or a kappa light chain.

[0024] In one example, the IgA2 heavy chain is a modified IgA2 heavy chain. For example, the IgA2 heavy chain comprises one or more modifications selected from the group consisting of:

[0025] (i) N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) scheme;

[0026] (ii) P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) scheme;

[0027] (iii) C to S mutation at position 311 according to the myeloma IgA1 protein (Bur) scheme;

[0028] (iv) NIT to TLS mutation at positions 337 to 339 according to the myeloma IgA1 protein (Bur) scheme;

[0029] (v) deletion of the C residue at position 472 according to the myeloma IgA1 protein (Bur) scheme; and

[0030] (vi) Deletion of the Y residue at position 473 according to the myeloma IgA1 protein (Bur) scheme.

[0031] In one example, the IgA2 heavy chain comprises an N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) protocol. For example, IgA2 comprises an N to G mutation at a residue corresponding to amino acid 47 of SEQ ID NO:32.

[0032] In one example, the IgA2 heavy chain comprises a P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) protocol. For example, IgA2 comprises a P to R mutation at a residue corresponding to amino acid 102 of SEQ ID NO: 32. In one example, IgA2 comprises the sequence shown in SEQ ID NO: 33.

[0033] In one example, the IgA2 heavy chain comprises a C to R mutation at position 311 according to the myeloma IgA1 protein (Bur) protocol. For example, IgA2 comprises a C to R mutation at a residue corresponding to amino acid 179 of SEQ ID NO:32.

[0034] In one example, the IgA2 heavy chain comprises a NIT to TLS mutation at positions 337 to 339 according to the myeloma IgA1 protein (Bur) protocol. For example, IgA2 comprises a NIT to TLS mutation at residues corresponding to amino acids 205 to 207 of SEQ ID NO:32.

[0035] In one example, the IgA2 heavy chain comprises a deletion of the C residue at position 472 according to the myeloma IgA1 protein (Bur) scheme. For example, IgA2 comprises a deletion of the C residue corresponding to amino acid 339 of SEQ ID NO:32.

[0036] In one example, the IgA2 heavy chain comprises a deletion of the Y residue at position 473 according to the myeloma IgA1 protein (Bur) scheme. For example, IgA2 comprises a deletion of the Y residue corresponding to amino acid 340 of SEQ ID NO:32.

[0037] In one example, the IgA2 heavy chain comprises (i) an N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) protocol; and (ii) a P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) protocol; and (iii) a C to S mutation at position 311 according to the myeloma IgA1 protein (Bur) protocol; and (iv) a NIT to TLS mutation at positions 337 to 339 according to the myeloma IgA1 protein (Bur) protocol; and (v) a deletion of the C residue at position 472 according to the myeloma IgA1 protein (Bur) protocol; and (vi) a deletion of the Y residue at position 473 according to the myeloma IgA1 protein (Bur) protocol.

[0038] In one example, the IgA2 heavy chain comprises (i) an N to G mutation at the residue corresponding to amino acid 47 of SEQ ID NO:32; and (ii) a P to R mutation at the residue corresponding to amino acid 102 of SEQ ID NO:32; and (iii) a C to S mutation at the residue corresponding to amino acid 179 of SEQ ID NO:32; and (iv) a NIT to TLS mutation at residues corresponding to amino acids 205 to 207 of SEQ ID NO:32; and (v) a deletion of the C residue corresponding to amino acid 339 of SEQ ID NO:32; and (vi) a deletion of the Y residue corresponding to amino acid 340 of SEQ ID NO:32.

[0039] In one example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 33 or SEQ ID NO: 34 or SEQ ID NO: 66. For example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 33. In another example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 34. In yet another example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 66.

[0040] In one example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO:66, wherein the amino acid sequence comprises asparagine (N) or glycine (G) at position 47 and / or proline (P) or arginine (R) at position 102 and / or cysteine ​​(C) or serine (S) at position 179 and / or asparagine (N) or threonine (T) at position 205 and / or isoleucine (I) or leucine (L) at position 206 and / or threonine (T) or serine (S) at position 207 and / or cysteine ​​(C) or the absence of an amino acid at position 339 and / or tyrosine (Y) or the absence of an amino acid at position 340.

[0041] In one example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 66, wherein the amino acid sequence comprises asparagine (N) at position 47, arginine (R) at position 102, cysteine ​​(C) at position 179, asparagine (N) at position 205, isoleucine (I) at position 206, threonine (T) at position 207, cysteine ​​(C) at position 339, and tyrosine (Y) at position 340. For example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 33.

[0042] In one example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 66, wherein the amino acid sequence comprises glycine (G) at position 47, arginine (R) at position 102, serine (S) at position 179, threonine (T) at position 205, leucine (L) at position 206, and serine (S) at position 207, and there is no amino acid at position 339 and there is no amino acid at position 340. For example, the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 34.

[0043] In one example, the antibody comprising an extended hinge region includes 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 after the lower hinge sequence from IgA and a combination thereof. In one example, the antibody comprising an extended hinge region includes a C-terminal CH1 sequence from IgA. In one example, the antibody comprising an extended hinge region includes an upper hinge sequence from IgG3. In one example, the antibody comprising an extended hinge region includes a middle hinge sequence from IgG3. In one example, the antibody comprising an extended hinge region includes a lower hinge sequence from IgG3. In one example, the antibody comprising an extended hinge region includes a sequence after the lower hinge sequence from IgA.

[0044] In one example, the antibody comprising an extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123; an upper hinge comprising the sequence shown in SEQ ID NO: 124; a middle hinge comprising the sequence shown in SEQ ID NO: 125; a lower hinge comprising the sequence shown in SEQ ID NO: 126; and / or a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 127, and combinations thereof. In one example, the antibody comprising an extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123. In one example, the antibody comprising an extended hinge region includes an upper hinge comprising the sequence shown in SEQ ID NO: 124. In one example, the antibody comprising an extended hinge region includes a middle hinge comprising the sequence shown in SEQ ID NO: 125. In one example, the antibody comprising an extended hinge region includes an upper hinge with a lower hinge comprising the sequence shown in SEQ ID NO: 126. In one example, an antibody comprising an extended hinge region includes a sequence after the lower hinge comprising the sequence shown in SEQ ID NO:127.

[0045] In one example, the antibody comprising an extended hinge region includes a terminal CH1 comprising the sequence shown in SEQ ID NO: 123; an upper hinge comprising the sequence shown in SEQ ID NO: 124; a middle hinge comprising the sequence shown in SEQ ID NO: 125; a lower hinge comprising the sequence shown in SEQ ID NO: 126; and / or a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 128, and combinations thereof. In one example, the antibody comprising an extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123. In one example, the antibody comprising an extended hinge region includes an upper hinge comprising the sequence shown in SEQ ID NO: 124. In one example, the antibody comprising an extended hinge region includes a middle hinge comprising the sequence shown in SEQ ID NO: 125. In one example, the antibody comprising an extended hinge region includes an upper hinge having a lower hinge comprising the sequence shown in SEQ ID NO: 126. In one example, an antibody comprising an extended hinge region includes a sequence after the lower hinge comprising the sequence shown in SEQ ID NO:128.

[0046] In one example of any of the methods described herein, the antibody binds to or specifically binds to a target on an endogenous HSC in a subject. In one example, the target on an endogenous HSC is selected from the group consisting of CD2, CD5, CD7, CD11a, CDwl2, 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, CD8 4. CD85A, CD85K, CD90, CD97, CD99, CD104, CD105, CD109, CD110, CD111, CD112, CD114, CD115, CD117(c-kit), CD123, CD 124. CD126, CD127, CD130, CD131, CD133, CD134, CD135, CD137, CD138, CD151, CD157, CD162, CD164, CD166, CD168, CD1 72a, CD173, CD174, CD175, CD175s, CD176, CD183, CD184(CXCR4), CD191, CD200, CD201, CD205, CD217, CD220, CD221, CD 222, 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.

[0047] 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 HSC is CD34. In one example, the target on endogenous HSC is CD36. In one example, the target on endogenous HSC is CD38. In one example, the target on endogenous HSC is CD40. In one example, the target on endogenous HSC is CD41. In one example, the target on endogenous HSC is CD42a. In one example, the target on endogenous HSC is CD42b. In one example, the target on endogenous HSC is CD42c. In one example, the target on endogenous HSC is CD42d. In one example, the target on endogenous HSC is CD43. In one example, the target on endogenous HSC is CD45. In one example, the target on endogenous HSC is CD45RA. In one example, the target on endogenous HSC is CD45RB. In one example, the target on endogenous HSC is CD45RC. In one example, the target on endogenous HSC is CD45RO. In one example, the target on endogenous HSC is CD48. In one example, the target on endogenous HSC is CD49b. In one example, the target on endogenous HSC is CD49d (VLA-4). In one example, the target on endogenous HSC is CD49e. In one example, the target on endogenous HSC is CD49f (VLA-6). In one example, the target on endogenous HSC is CD50. In one example, the target on endogenous HSC is CD51. In one example, the target on endogenous HSC is CD53. In one example, the target on endogenous HSC is CD55. In one example, the target on endogenous HSC is CD58. In one example, the target on endogenous HSC is CD64a. In one example, the target on endogenous HSC is CD68. In one example, the target on endogenous HSC is CD71.In one example, the target on endogenous HSC is CD72. In one example, the target on endogenous HSC is CD73. In one example, the target on endogenous HSC is CD81. In one example, the target on endogenous HSC is CD82. In one example, the target on endogenous HSC is CD84. In one example, the target on endogenous HSC is CD85A. In one example, the target on endogenous HSC is CD85K. In one example, the target on endogenous HSC is CD90. In one example, the target on endogenous HSC is CD97. In one example, the target on endogenous HSC is CD99. In one example, the target on endogenous HSC is CD104. In one example, the target on endogenous HSC is CD105. In one example, the target on endogenous HSC is CD109. In one example, the target on endogenous HSC is CD110. In one example, the target on endogenous HSC is CD111. In one example, the target on endogenous HSC is CD112. In one example, the target on endogenous HSC is CD114. In one example, the target on endogenous HSC is CD115. In one example, the target on endogenous HSC is CD117 (c-kit). In one example, the target on endogenous HSC is CD123. In one example, the target on endogenous HSC is CD124. In one example, the target on endogenous HSC is CD126. In one example, the target on endogenous HSC is CD127. In one example, the target on endogenous HSC is CD130. In one example, the target on endogenous HSC is CD131. In one example, the target on endogenous HSC is CD133. In one example, the target on endogenous HSC is CD134. In one example, the target on endogenous HSC is CD135. In one example, the target on endogenous HSC is CD137. In one example, the target on endogenous HSC is CD138. In one example, the target on endogenous HSC is CD151. In one example, the target on endogenous HSC is CD157. In one example, the target on endogenous HSC is CD162. In one example, the target on endogenous HSC is CD164. In one example, the target on endogenous HSC is CD166. In one example, the target on endogenous HSC is CD168. In one example, the target on endogenous HSC is CD172a. In one example, the target on endogenous HSC is CD173. In one example, the target on endogenous HSC is CD174. In one example, the target on endogenous HSC is CD175. In one example, the target on endogenous HSC is CD175s.In one example, the target on endogenous HSC is CD176. In one example, the target on endogenous HSC is CD183. In one example, the target on endogenous HSC is CD184 (CXCR4). In one example, the target on endogenous HSC is CD191. In one example, the target on endogenous HSC is CD200. In one example, the target on endogenous HSC is CD201. In one example, the target on endogenous HSC is CD205. In one example, the target on endogenous HSC is CD217. In one example, the target on endogenous HSC is CD220. In one example, the target on endogenous HSC is CD221. In one example, the target on endogenous HSC is CD222. In one example, the target on endogenous HSC is CD223. In one example, the target on endogenous HSC is CD224. In one example, the target on endogenous HSC is CD225. In one example, the target on endogenous HSC is CD226. In one example, the target on endogenous HSC is CD227. In one example, the target on endogenous HSC is CD228. In one example, the target on endogenous HSC is CD229. In one example, the target on endogenous HSC is CD230. In one example, the target on endogenous HSC is CD235a. In one example, the target on endogenous HSC is CD235b. In one example, the target on endogenous HSC is CD236. In one example, the target on endogenous HSC is CD236R. In one example, the target on endogenous HSC is CD238. In one example, the target on endogenous HSC is CD240. In one example, the target on endogenous HSC is CD242. In one example, the target on endogenous HSC is CD243. In one example, the target on endogenous HSC is CD277. In one example, the target on endogenous HSC is CD292. In one example, the target on endogenous HSC is CDw293. In one example, the target on endogenous HSC is CD295. In one example, the target on endogenous HSC is CD298. In one example, the target on endogenous HSC is CD309. In one example, the target on endogenous HSC is CD318. In one example, the target on endogenous HSC is CD324. In one example, the target on endogenous HSC is CD325. In one example, the target on endogenous HSC is CD338. In one example, the target on endogenous HSC is CD344. In one example, the target on endogenous HSC is CD349. In one example, the target on endogenous HSC is CD350. In one example, the target on endogenous HSC is CD361.

[0048] In one example, the antibody is administered in an amount sufficient to:

[0049] (i) blocking the binding of stem cell factor (SCF) to CD117; and / or

[0050] (ii) inhibiting the activation of CD117 by SCF; and / or

[0051] (iii) inhibiting SCF-mediated proliferation of CD117+ cells; and / or

[0052] (iv) depleting the CD117+ cell population in the subject.

[0053] In one example, the antibody is administered in an amount sufficient to block the binding of SCF to CD117. For example, the antibody is administered in an amount sufficient to inhibit the binding of SCF to CD117. It will be apparent to the technician that the antibody does not need to completely block or inhibit the binding of SCF to CD117, but only needs to reduce the antibody to a statistically significant amount, for example, a reduction of 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 SCF to CD117 by at least about 10%. In another example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 20%. In yet another example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 30%. In one example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 40%. In another example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 50%. In yet another example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 60%. In one example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 70%. In another example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 80%. In yet another example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 90%. In one example, the antibody blocks or inhibits the binding of SCF to CD117 by at least about 95%. In one example, the antibody completely blocks or inhibits the binding of SCF to CD117.

[0054] Methods for determining blockade or inhibition of binding are known in the art and / or described herein. In one example, the antibody blocks or inhibits binding of SCF to CD117 as determined in a TF-1 proliferation assay.

[0055] In one example, the antibody is administered in an amount sufficient to inhibit the activation of CD117 by SCF. It is apparent to the technician that the antibody does not need to completely inhibit the activation of CD117 by SCF, but only needs to reduce the statistically significant amount of the antibody, for example, reducing 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 another 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 another example, the antibody inhibits the activation of CD117 by SCF by at least about 60%. In one example, the antibody inhibits the activation of CD117 by SCF by at least about 70%. In another example, the antibody inhibits SCF activation of CD117 by at least about 80%. In yet another example, the antibody inhibits SCF activation of CD117 by at least about 90%. In one example, the antibody inhibits SCF activation of CD117 by at least about 95%. In one example, the antibody completely inhibits SCF activation of CD117.

[0056] 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.

[0057] In one example, the antibody is administered in an amount sufficient to inhibit CD117+ cell proliferation mediated by SCF. It is apparent to the technician that the antibody does not need to completely inhibit the CD117+ cell proliferation caused by SCF, but only needs to reduce the antibody to a statistically significant amount, for example, reducing 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 CD117+ cell proliferation caused by SCF by at least about 10%. In another example, the antibody inhibits the CD117+ cell proliferation caused by SCF by at least about 20%. In another example, the antibody inhibits the CD117+ cell proliferation caused by SCF by at least about 30%. In one example, the antibody inhibits the CD117+ cell proliferation caused by SCF by at least about 40%. In another example, the antibody inhibits the CD117+ cell proliferation caused by SCF by at least about 50%. In another example, the antibody inhibits the CD117+ cell proliferation caused by SCF by at least about 60%. In one example, the antibody inhibits the proliferation of CD117+ cells caused by SCF by at least about 70%. In another example, the antibody inhibits the proliferation of CD117+ cells caused by SCF by at least about 80%. In another example, the antibody inhibits the proliferation of CD117+ cells caused by SCF by at least about 90%. In one example, the antibody inhibits the proliferation of CD117+ cells caused by SCF by at least about 95%. In one example, the antibody completely inhibits the proliferation of CD117+ cells caused by SCF.

[0058] Methods for determining inhibition of SCF-induced proliferation of CD117+ cells are known in the art and / or described herein. In one example, the antibody inhibits SCF-induced proliferation of CD117+ cells as determined in a TF-1 proliferation assay.

[0059] In one example, the antibody is administered in an amount sufficient to eliminate the CD117+ cell group in the subject. It is apparent to the technician that the antibody does not need to completely eliminate the CD117+ cell group, but only needs to reduce the antibody to a statistically significant amount, for example, reducing 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 eliminates the CD117+ cell group by at least about 10%. In another example, the antibody eliminates the CD117+ cell group by at least about 20%. In another example, the antibody eliminates the CD117+ cell group by at least about 30%. In one example, the antibody eliminates the CD117+ cell group by at least about 40%. In another example, the antibody eliminates the CD117+ cell group by at least about 50%. In another example, the antibody eliminates the CD117+ cell group by at least about 60%. In one example, the antibody eliminates the CD117+ cell group by at least about 70%. In another example, the antibody depletes the CD117+ cell population by at least about 80%. In yet another example, the antibody depletes the CD117+ cell population by at least about 90%. In one example, the antibody depletes the CD117+ cell population by at least about 95%. In one example, the antibody completely depletes the CD117+ cell population.

[0060] 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 antibodies.

[0061] In one example, the antibody is an anti-CD117 antibody.

[0062] In one example, the antibody binds to 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.

[0063] In one example, the antibody binds to or specifically binds to the soluble N-terminus of human CD117. For example, the antibody binds to or specifically binds to the soluble N-terminus of human CD117 with an affinity dissociation constant (K) of 1.5 μM or less. D ) binds to or specifically binds to the soluble N-terminus of human CD117. For example, the antibody has a K of 1 μM or less, for example, 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. DBinds to or specifically binds to the soluble N-terminus of human CD117. In one example, the antibody has 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. D Binds to or specifically binds to the soluble N-terminus of human CD117. For example, the antibody has a K of about 49 nM. D Binds to or specifically binds to the soluble N-terminus of human CD117. In one example, the antibody has a K of 20 nM or less. D Binds to or specifically binds to the soluble N-terminus of human CD117. In one example, the antibody has a K of 20 nM or less, such as 18 nM or less, for example, 15 nM or less, or 12 nM or less, or 10 nM or less. D Binds to or specifically binds to the soluble N-terminus of human CD117. For example, the antibody has a K of about 14 nM D In another example, the antibody binds to or specifically binds to the soluble N-terminus of human CD117. D Binds to or specifically binds to the soluble N-terminus of human CD117. In one example, the antibody has 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 Binds to or specifically binds to the soluble N-terminus of human CD117. For example, the antibody binds to or specifically binds to the soluble N-terminus of human CD117 with a K between 10 nM and 1 nM. D Binds to or specifically binds to the soluble N-terminus of human CD117. For example, K D Between about 10 nM and 8 nM, such as K D In one example, the antibody has a K between 2 nM and 3 nM. D , for example, a K of about 2.5 nM D Binds to or specifically binds to the soluble N-terminus of human CD117. In one example, the antibody has a K of about 0.5 nM. D Binds to or specifically binds to the soluble N-terminus of human CD117.

[0064] In one example, the antibody binds to or specifically binds to the C-terminus of human CD117. For example, the antibody binds to or specifically binds to the C-terminus of human CD117 with a K of 200 nM or less. D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 191 nM. DBinds to or specifically binds to the soluble N-terminus of human CD117. In one example, the antibody has 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. D Binds to or specifically binds to the C-terminus of human CD117. In one example, the antibody has a K of 60 nM or less. D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has 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. D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of 40 nM or less. D , for example, a K of about 35 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of 20 nM or less. D , for example, a K of about 18 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of 10 nM or less. D , for example, a K of about 9 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of 5 nM or less. D , for example, a K of about 2.5 nM D Binds to or specifically binds to the C-terminus of human CD117.

[0065] In one example, the antibody binds to or specifically binds to full-length human CD117. For example, the antibody binds to or specifically binds to full-length human CD117 with a K of 60 nM or less. D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of 60 nM or less. D , for example, a K of 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 D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 55 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 38 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 36 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 32 nMD Binds to or specifically binds to the C-terminus of human CD117. In one example, the antibody has a K of 30 nM or less. D , for example, a K of 25 nM or less, or 20 nM or less, or 15 nM or less, or 10 nM or less D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 18 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 14 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 9 nM D Binds to or specifically binds to the C-terminus of human CD117. In one example, the antibody has 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 Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 4 nM D Binds to or specifically binds to the C-terminus of human CD117. For example, the antibody has a K of about 2.5 nM D Binds to or specifically binds to the C-terminus of human CD117.

[0066] In one example, an anti-CD117 antibody:

[0067] (i) with an affinity dissociation constant (K) of 1.5 μM or less D ) binds to the soluble N-terminus of human CD117; and / or

[0068] (ii) With a K of 200 nM or less D Bind to the C-terminus of human CD117; and / or

[0069] (iii) with a K of 60 nM or less D Binds full-length human CD117.

[0070] In one example, an anti-CD117 antibody:

[0071] (i) with an affinity dissociation constant (K) of 20 nM or less D ) binds to the soluble N-terminus of human CD117; and / or

[0072] (ii) with a K of 15 nM or less D Bind to the C-terminus of human CD117; and / or

[0073] (iii) with a K of 60 nM or less D Binds full-length human CD117.

[0074] 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 Inhibit SCF-mediated proliferation of TF-1 cells. For example, 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, IC 50 is 0.19nM. For example, IC 50 In one example, the anti-CD117 antibody has an IC of at least 100 μM. 50 Inhibit SCF-mediated proliferation of TF-1 cells. For example, IC 50 is 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, IC 50 is 90 μM. For example, IC 50 is 45 μM. For example, IC 50 is 38 μM. For example, IC 50 is 18μM.

[0075] To determine IC 50 The method is described herein and comprises culturing TF-1 cells (e.g., about 2×10 5 TF-1 cells), then human SCF is added and the cells are cultured (e.g., cultured for at least about 48 hours, or at least about 72 hours, or at least about 96 hours, e.g., cultured for about 72 hours), and then cell proliferation is determined. Cell proliferation can be determined using a commercially available kit (e.g., a Vialight Plus kit). By determining proliferation at different antibody concentrations, the IC 50 .

[0076] In one example, the anti-CD117 antibody is expressed at a normalized maximum membrane uptake (MBI) of at least 50% as measured by the mean fluorescence intensity (MFI) of DILC18 on neutrophils. max ) to mediate ADCT. For example, an antibody with 51% normalized B max In one example, the antibody mediates ADCT with at least 60% of the normalized B max For example, the antibody mediated ADCT with 64% of the normalized B max For example, the antibody mediated ADCT with 68% of the normalized B max In one example, the antibody mediates ADCT with at least 70% of the normalized Bmax For example, the antibody mediated ADCT with 71% of the normalized B max In one example, the antibody mediates ADCT with at least 80% of the normalized B max In one example, the antibody mediates ADCT with at least 90% of the normalized B max Mediate ADCT. For example, an antibody with 95% normalized B max Mediates ADCT.

[0077] To determine IC 50 Methods are described herein and include, for example, flow cytometry. For example, the 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"-tetramethylindocarbocyanine perchlorate) in the presence of peripheral blood neutrophils. Live neutrophils can be identified by forward scatter and side scatter, followed by live CD66b-positive cells. The membrane uptake of neutrophils can be measured by the increase in DILC18 mean fluorescence intensity (MFI). The DILC18 MFI is normalized to the maximum MFI of each donor neutrophil. In one example, the normalized maximum membrane uptake (B) expressed as a percentage of antibody-induced phagocytosis of peripheral blood neutrophils is determined. max ).

[0078] In one example, the anti-CD117 antibody has an EC of 25 nM or less. 50 Binds to cells (e.g., TF-1 cells or HEK293FS cells) expressing CD117 (e.g., human CD117 or cynomolgus CD117). 50 20 nM or less, or 15 nM or less, or 10 nM or less, or 5 nM or less. In one example, EC 50 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.

[0079] In one example, the anti-CD117 antibody competitively inhibits binding of any one or more of the following antibodies to CD117:

[0080] (i) comprising a heavy chain variable region (V H );And a light chain variable region (V L )

[0081] (ii) comprising a V comprising the sequence shown in SEQ ID NO: 7 H ; and V comprising the sequence shown in SEQ ID NO: 10 L Antibodies

[0082] (iii) comprising a V comprising the sequence shown in SEQ ID NO: 13 H and V comprising the sequence shown in SEQ ID NO: 16 L Antibodies

[0083] (iv) comprising a V comprising the sequence shown in SEQ ID NO: 19 H and V comprising the sequence shown in SEQ ID NO: 22 L Antibodies to

[0084] (v) comprising a V comprising the sequence shown in SEQ ID NO: 25 H and V comprising the sequence shown in SEQ ID NO: 28 L of antibodies.

[0085] In one example, the anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, and the antibody comprises: H , which comprises the sequence shown in SEQ ID NO:4 or SEQ ID NO:13; and V L , which comprises the sequence shown in SEQ ID NO:5 or SEQ ID NO:28.

[0086] In one example, an anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, wherein the antibody comprises V H , which comprises the sequences shown in SEQ ID NO:4 and SEQ ID NO:5.

[0087] In one example, an anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, wherein the antibody comprises V H , which comprises the sequences shown in SEQ ID NO:4 and SEQ ID NO:28.

[0088] In one example, the anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, and the antibody comprises: H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:5.

[0089] In one example, the anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, and the antibody comprises:H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10.

[0090] In one example, the anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, and the antibody comprises: H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16.

[0091] In one example, the anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, and the antibody comprises: H , which comprises the sequence shown in SEQ ID NO: 19; and V L , which comprises the sequence shown in SEQ ID NO:22.

[0092] In one example, the anti-CD117 antibody competitively inhibits the binding of an antibody to CD117, and the antibody comprises: H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:28.

[0093] In one example, the anti-CD117 antibody comprises:

[0094] (i)V H , which comprises the sequence shown in SEQ ID NO:4 or SEQ ID NO:13; and V L , which comprises the sequence shown in SEQ ID NO:5 or SEQ ID NO:28; or

[0095] aV H , which includes a V comprising the sequence shown in SEQ ID NO:4 or SEQ ID NO:13 H three complementarity determining regions (CDRs); and V L , which includes a V comprising the sequence shown in SEQ ID NO: 5 or SEQ ID NO: 28 L Three CDRs.

[0096] In one embodiment, the anti-CD117 antibody comprises: H , which comprises the sequence shown in SEQ ID NO:4 or SEQ ID NO:13; and V L , which comprises the sequence shown in SEQ ID NO:5 or SEQ ID NO:28.

[0097] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO:4; and V L , which comprises the sequence shown in SEQ ID NO:5.

[0098] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO:4; and V L , which comprises the sequence shown in SEQ ID NO:28.

[0099] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:5.

[0100] In one embodiment, the anti-CD117 antibody comprises: H , which includes a V comprising the sequence shown in SEQ ID NO:4 or SEQ ID NO:13 H three complementarity determining regions (CDRs); and V L , which includes a V comprising the sequence shown in SEQ ID NO: 5 or SEQ ID NO: 28 L Three CDRs.

[0101] In one example, the anti-CD117 antibody comprises:

[0102] (a)V H , which contains:

[0103] (i) CDR1 comprising the sequence shown in amino acids 31-35 of SEQ ID NO:4 or SEQ ID NO:13;

[0104] (ii) CDR2 comprising the sequence shown in amino acids 50-66 of SEQ ID NO:4 or SEQ ID NO:13; and

[0105] (c) a CDR3 comprising the sequence shown in amino acids 99-110 of SEQ ID NO:4 or SEQ ID NO:13; and

[0106] (ii) V L , which contains:

[0107] (a) CDR1 comprising the sequence shown in amino acids 23-33 of SEQ ID NO:5 or SEQ ID NO:28;

[0108] (b) CDR2 comprising the sequence shown in amino acids 49-55 of SEQ ID NO:5 or SEQ ID NO:28; and

[0109] (c) CDR3 comprising the sequence shown in amino acids 88-98 of SEQ ID NO:5 or SEQ ID NO:28.

[0110] In one embodiment, the anti-CD117 antibody comprises: H , which includes a V comprising the sequence shown in SEQ ID NO:4 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO:5 L Three CDRs.

[0111] In one example, the anti-CD117 antibody comprises:

[0112] (a)V H , which contains:

[0113] (i) a CDR1 comprising the sequence shown in amino acids 31-35 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;

[0114] (ii) a CDR2 comprising the sequence shown in amino acids 50-66 of SEQ ID NO:4, wherein the amino acid sequence comprises alanine (A) or valine (V) at position 50 and / or serine (S) or no amino acid 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

[0115] (c) a CDR3 comprising the sequence shown in amino acids 99-110 of SEQ ID NO:4, wherein the amino acid sequence comprises 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 no amino acid at position 107 and / or isoleucine (I) or tyrosine (Y) at position 110; and

[0116] (ii) V L , which contains:

[0117] (a) a CDR1 comprising the sequence shown in amino acids 23-33 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;

[0118] (b) a CDR2 comprising the sequence shown in amino acids 49-55 of SEQ ID NO:5, wherein the amino acid sequence comprises tyrosine (Y) or glutamine (Q) at position 49 and / or serine (S) or phenylalanine (F) or asparagine (N) at position 51 and / or aspartic acid (D) or lysine (K) at position 52; and

[0119] (c) a CDR3 comprising the sequence shown in amino acids 88-98 of SEQ ID NO:5, wherein the amino acid sequence comprises 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 the absence of an amino acid at position 97 and / or valine (V) or the absence of an amino acid at position 98.

[0120] In one example, the anti-CD117 antibody comprises:

[0121] (a)V H , which contains:

[0122] (i) CDR1 comprising the sequence shown in amino acids 31-35 of SEQ ID NO:4, wherein the amino acid sequence comprises serine (S) at position 31, alanine (A) at position 33, and serine (S) at position 35;

[0123] (ii) CDR2 comprising the sequence shown in amino acids 50-66 of SEQ ID NO:4, wherein the amino acid sequence comprises alanine (A) at position 50, serine (S) at position 52, glycine (G) at position 53, serine (S) at position 54, serine (S) at position 57, and threonine (T) at position 58; and

[0124] (c) a CDR3 comprising the sequence shown in amino acids 99-110 of SEQ ID NO:4, wherein the amino acid sequence comprises 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; and

[0125] (ii) V L , which contains:

[0126] (a) CDR1 comprising the sequence shown in amino acids 23-33 of SEQ ID NO:5, wherein the amino acid sequence comprises glutamine (Q) at position 23, serine (S) at position 26, leucine (L) at position 27, arginine (R) at position 28, aspartic acid (D) at position 29, tyrosine (Y) at position 30, alanine (A) at position 32, and asparagine (N) at position 33;

[0127] (b) CDR2 comprising the sequence shown in amino acids 49-55 of SEQ ID NO:5, wherein the amino acid sequence comprises tyrosine (Y) at position 49, serine (S) at position 51, and aspartic acid (D) at position 52; and

[0128] (c) CDR3 comprising the sequence shown in amino acids 88-98 of SEQ ID NO:5, wherein the amino acid sequence comprises serine (S) at position 94, aspartic acid (D) at position 95, histidine (H) at position 96, tryptophan (W) at position 97, and valine (V) at position 98.

[0129] In one example, the anti-CD117 antibody comprises:

[0130] (a)V H , which contains:

[0131] (i) CDR1 comprising the sequence shown in amino acids 31-35 of SEQ ID NO:4, wherein the amino acid sequence comprises serine (S) at position 31, alanine (A) at position 33, and histidine (H) at position 35;

[0132] (ii) CDR2 comprising the sequence shown in amino acids 50-66 of SEQ ID NO:4, wherein the amino acid sequence comprises valine (V) at position 50, an amino acid not present at position 52, tyrosine (Y) at position 53, serine (S) at position 54, serine (S) at position 57, and threonine (T) at position 58; and

[0133] (c) a CDR3 comprising the sequence shown in amino acids 99-110 of SEQ ID NO:4, wherein the amino acid sequence comprises 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, an amino acid not present at position 107, and tyrosine (Y) at position 110; and

[0134] (ii) V L , which contains:

[0135] (a) CDR1 comprising the sequence shown in amino acids 23-33 of SEQ ID NO:5, wherein the amino acid sequence comprises serine (S) at position 23, lysine (K) at position 26, valine (V) at position 27, glycine (G) at position 28, alanine (A) at position 29, lysine (K) at position 30, valine (V) at position 32, and phenylalanine (F) at position 33;

[0136] (b) CDR2 comprising the sequence shown in amino acids 49-55 of SEQ ID NO:5, wherein the amino acid sequence comprises glutamine (Q) at position 49, asparagine (N) at position 51, and lysine (K) at position 52; and

[0137] (c) CDR3 comprising the sequence shown in amino acids 88-98 of SEQ ID NO:5, wherein the amino acid sequence comprises 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.

[0138] In one embodiment, the anti-CD117 antibody comprises V H , which includes a V comprising the sequence shown in SEQ ID NO:4 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 28 L Three CDRs.

[0139] In one example, the anti-CD117 antibody comprises:

[0140] (a)V H , which contains:

[0141] (i) CDR1 comprising the sequence shown in amino acids 31-35 of SEQ ID NO:4, wherein the amino acid sequence comprises aspartic acid (D) at position 31, glycine (G) at position 33, and serine (S) at position 35;

[0142] (ii) CDR2 comprising the sequence shown in amino acids 50-66 of SEQ ID NO:4, wherein the amino acid sequence comprises amino acid (A) at position 50, glycine (G) at position 52, tyrosine (Y) at position 53, glycine (G) at position 54, glycine (G) at position 57, and lysine (K) at position 58; and

[0143] (c) a CDR3 comprising the sequence shown in amino acids 99-110 of SEQ ID NO:4, wherein the amino acid sequence comprises 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 amino acid not present at position 107, and a tyrosine (Y) at position 110; and

[0144] (ii) V L , which contains:

[0145] (a) CDR1 comprising the sequence shown in amino acids 23-33 of SEQ ID NO:28;

[0146] (b) CDR2 comprising the sequence shown in amino acids 49-55 of SEQ ID NO:28; and

[0147] (c) CDR3 comprising the sequence shown in amino acids 88-98 of SEQ ID NO:28.

[0148] In one embodiment, the anti-CD117 antibody comprises V H , which includes a V comprising the sequence shown in SEQ ID NO: 13 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO:5 L Three CDRs.

[0149] In one example, the anti-CD117 antibody comprises:

[0150] (a)V H , which contains:

[0151] (i) CDR1 comprising the sequence shown in amino acids 31-35 of SEQ ID NO: 13;

[0152] (ii) CDR2 comprising the sequence shown in amino acids 50-66 of SEQ ID NO: 13; and

[0153] (c) CDR3 comprising the sequence shown in amino acids 99-110 of SEQ ID NO: 13; and

[0154] (a) CDR1 comprising the sequence shown in amino acids 23-33 of SEQ ID NO:5, wherein the amino acid sequence comprises serine (S) at position 23, lysine (K) at position 26, leucine (L) at position 27, glycine (G) at position 28, glutamic acid (E) at position 29, threonine (T) at position 30, valine (V) at position 32, and histidine (H) at position 33;

[0155] (b) CDR2 comprising the sequence shown in amino acids 49-55 of SEQ ID NO:5, wherein the amino acid sequence comprises glutamine (Q) at position 49, phenylalanine (F) at position 51, and lysine (K) at position 52; and

[0156] (c) CDR3 comprising the sequence shown in amino acids 88-98 of SEQ ID NO:5, wherein the amino acid sequence comprises threonine (T) at position 94, alanine (A) at position 95, valine (V) at position 96, and no amino acid at position 97 and no amino acid at position 98.

[0157] In one example, the amino acid sequence of SEQ ID NO: 4 comprises 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 a leucine (L) or valine (V) at position 14 and / or a serine (S) or aspartic acid (D) at position 36 and / or a serine (S) or aspartic acid (D) at position 37 and / or a serine (S) or aspartic acid (D) at position 38 and / or a serine (S) or aspartic acid (D) at position 39 and / or a serine (S) or aspartic acid (D) at position 40 and / or a serine (S) or aspartic acid (D) at position 41 and / or a serine (S) or aspartic acid (D) at position 42 and / or a serine (S) or aspartic acid (D) at position 43 and / or a serine (S) or aspartic acid (D) at position 44 and / or a serine (S) or aspartic acid (D) at position 45 and / or a serine (S) or aspartic acid (D) at position 47 and / or a serine (S) or aspartic acid (D) at position 48 and / or a serine (S) or aspartic acid (D) at position 49 and / or a serine (S) or aspartic acid (D) at position 50 and / or a serine (S) or aspartic acid (D) at position 5 35 and / or alanine (A) or valine (V) at position 50 and / or serine (S) or no amino acid 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 isoleucine (I) or valine (V) at position 93 and / or arginine (R) or lysine (K) at position 98 and / or 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 isoleucine (I) or tyrosine (Y) at position 110 and / or methionine (M) or leucine (L) at position 116.

[0158] In one example, the amino acid sequence of SEQ ID NO: 4 comprises an alanine (A) at position 5, an aspartic acid (D) at position 10, a leucine (L) at position 11, a glycine (G) at position 16, a serine (S) at position 31, an alanine (A) at position 33, a serine (S) at position 35, 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 (S) at position 58. 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.

[0159] In one example, the amino acid sequence of SEQ ID NO:4 comprises valine (V) at position 5, glycine (G) at position 10, valine (V) at position 11, arginine (R) at position 16, serine (S) at position 31, alanine (A) at position 33, histidine (H) at position 35, valine (V) at position 50, and no amino acid at position 52, tyrosine (Y) at position 53, serine (S) at position 54, serine (S) at position 57, and arginine (R) at position 16. Threonine (T) and valine (V) at position 93 and arginine (R) 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 the amino acid is absent at position 107 and tyrosine (Y) at position 110 and leucine (L) at position 116.

[0160] In one example, the amino acid sequence of SEQ ID NO:4 comprises a leucine (L) at position 5 and a glycine (G) at position 10 and a leucine (L) at position 11 and a glycine (G) at position 16 and an aspartic acid (D) at position 31 and a glycine (G) at position 33 and a serine (S) at position 35 and an alanine (A) at position 50 and a glycine (G) at position 52 and a tyrosine (Y) at position 53 and a glycine (G) at position 54 and a glycine (G) at position 57 and a serine (S) at position 58. lysine (K) at position 93 and valine (V) at position 93 and lysine (K) at position 98 and threonine (T) at position 100 and tryptophan (W) at position 101 and tryptophan (W) at position 102 and leucine (L) at position 103 and alanine (A) at position 104 and glycine (G) at position 105 and leucine (L) at position 106 and there is no amino acid at position 107 and tyrosine (Y) at position 110 and leucine (L) at position 116.

[0161] In one example, the amino acid sequence of SEQ ID NO:5 comprises aspartic acid (D) or proline (P) at position 7 and / or alanine (A) or serine (S) at position 9 and / or alanine (A) or serine (S) at position 13 and / or leucine (L) or proline (P) at position 14 and / or valine (V) or alanine (A) at position 18 and / or arginine (R) or threonine (T) or serine (S) at position 19 and / or 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 threonine (T) or serine (S) at position 19 and / or 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 threonine (T) or serine (S) at position 28 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 and / or phenylalanine (F) or tyrosine (Y) at position 35 and / or glutamine (Q) or histidine (H) at position 37 and / or glutamine (Q) or lysine (K) at position 38 and / or proline (P) or serine (S) at position 39. ) and / or alanine (A) or serine (S) at position 42 and / or leucine (L) or isoleucine (I) or valine (V) at position 44 and / or isoleucine (I) or valine (V) at position 47 and / or phenylalanine (F) or tyrosine (Y) at position 48 and / or tyrosine (Y) or glutamine (Q) at position 49 and / or serine (S) or phenylalanine (F) or asparagine (N) at position 51 and / or aspartic acid (D) or lysine (K) at position 52 and / or arginine (R) or glycine (G) at position 76 and / or valine (V) or threonine (T) at position 77 ) and / or glutamic acid (E) or glutamine (Q) at position 78 and / or glycine (G) or methionine (M) at position 80 and / or 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) at position 97 or the absence of an amino acid and / or valine (V) at position 98 or the absence of an amino acid and / or glycine (G) or threonine (T) at position 101 and / or leucine (L) or valine (V) at position 105.

[0162] In one example, the amino acid sequence of SEQ ID NO:5 comprises aspartic acid (D) at position 7 and alanine (A) at position 9 and alanine (A) at position 13 and leucine (L) at position 14 and valine (V) at position 18 and arginine (R) at position 19 and glutamine (Q) 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 and phenylalanine (F) at position 35 and glutamine (Q) at position 37 and lysine (K) at position 38 and proline (R) at position 39. 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.

[0163] In one example, the amino acid sequence of SEQ ID NO:5 comprises 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 serine (S) at position 39. ) 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 there is no amino acid at position 97 and there is no amino acid at position 98 and glycine (G) at position 101 and leucine (L) at position 105.

[0164] In one example, the amino acid sequence of SEQ ID NO:5 comprises 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 serine (S) at position 19 and a serine (S) at position 23 and a lysine (K) at position 26 and a valine (V) at position 27 and a glycine (G) at position 28 and an alanine (A) at position 29 and a lysine (K) at position 30 and a valine (V) at position 32 and a phenylalanine (F) at position 33 and a tyrosine (Y) at position 35 and a glutamine (Q) at position 37 and a lysine (K) at position 38 and a proline (V) at position 39 P) 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.

[0165] In one example, the anti-CD117 antibody comprises:

[0166] (i)V H , which includes a V comprising the sequence shown in SEQ ID NO:7 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 10 L The three CDRs of

[0167] (ii) V H , which includes a V comprising the sequence shown in SEQ ID NO: 13 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 16 L The three CDRs of

[0168] (iii)V H , which includes a V comprising the sequence shown in SEQ ID NO: 19 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 22 L or

[0169] (iv)V H , which includes a V comprising the sequence shown in SEQ ID NO: 25 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 28 L or

[0170] (v)V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:42, a CDR2 comprising the sequence shown in SEQ ID NO:43, and a CDR3 comprising the sequence shown in SEQ ID NO:44; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:45, a CDR2 comprising the sequence shown in SEQ ID NO:46, and a CDR3 comprising the sequence shown in SEQ ID NO:47; or

[0171] (vi)V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:48, a CDR2 comprising the sequence shown in SEQ ID NO:49, and a CDR3 comprising the sequence shown in SEQ ID NO:50; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:51, a CDR2 comprising the sequence shown in SEQ ID NO:52, and a CDR3 comprising the sequence shown in SEQ ID NO:53; or

[0172] (vii) V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:54, a CDR2 comprising the sequence shown in SEQ ID NO:55, and a CDR3 comprising the sequence shown in SEQ ID NO:56; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:57, a CDR2 comprising the sequence shown in SEQ ID NO:58, and a CDR3 comprising the sequence shown in SEQ ID NO:59; or

[0173] (viii)V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:60, a CDR2 comprising the sequence shown in SEQ ID NO:61, and a CDR3 comprising the sequence shown in SEQ ID NO:62; and V L, which includes a CDR1 comprising the sequence shown in SEQ ID NO:63, a CDR2 comprising the sequence shown in SEQ ID NO:64, and a CDR3 comprising the sequence shown in SEQ ID NO:65.

[0174] In one embodiment, the anti-CD117 antibody comprises V H , which includes a V comprising the sequence shown in SEQ ID NO:7 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 10 L Three CDRs.

[0175] In one embodiment, the anti-CD117 antibody comprises V H , which includes 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; and V L , which includes a CDR1 comprising amino acids 23-33 of SEQ ID NO:10, a CDR2 comprising amino acids 49-55 of SEQ ID NO:10, and a CDR3 comprising amino acids 88-98 of SEQ ID NO:10.

[0176] In one embodiment, the anti-CD117 antibody comprises V H , which includes a V comprising the sequence shown in SEQ ID NO: 13 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 16 L Three CDRs.

[0177] In one embodiment, the anti-CD117 antibody comprises V H , which includes 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; and V L , which includes a CDR1 comprising amino acids 23-33 of SEQ ID NO:16, a CDR2 comprising amino acids 49-55 of SEQ ID NO:16, and a CDR3 comprising amino acids 88-96 of SEQ ID NO:16.

[0178] In one embodiment, the anti-CD117 antibody comprises V H , which includes a V comprising the sequence shown in SEQ ID NO: 19H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 22 L Three CDRs.

[0179] In one embodiment, the anti-CD117 antibody comprises V H , which includes 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; and V L , which includes a CDR1 comprising amino acids 23-33 of SEQ ID NO:22, a CDR2 comprising amino acids 49-55 of SEQ ID NO:22, and a CDR3 comprising amino acids 88-98 of SEQ ID NO:22.

[0180] In one embodiment, the anti-CD117 antibody comprises V H , which includes a V comprising the sequence shown in SEQ ID NO: 25 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 28 L Three CDRs.

[0181] In one embodiment, the anti-CD117 antibody comprises V H , which includes 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; and V L , which includes a CDR1 comprising amino acids 24-35 of SEQ ID NO:28, a CDR2 comprising amino acids 51-57 of SEQ ID NO:28, and a CDR3 comprising amino acids 90-98 of SEQ ID NO:28.

[0182] In one embodiment, the anti-CD117 antibody comprises V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:42, a CDR2 comprising the sequence shown in SEQ ID NO:43, and a CDR3 comprising the sequence shown in SEQ ID NO:44; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:45, a CDR2 comprising the sequence shown in SEQ ID NO:46, and a CDR3 comprising the sequence shown in SEQ ID NO:47.

[0183] In one embodiment, the anti-CD117 antibody comprises V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:48, a CDR2 comprising the sequence shown in SEQ ID NO:49, and a CDR3 comprising the sequence shown in SEQ ID NO:50; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:51, a CDR2 comprising the sequence shown in SEQ ID NO:52, and a CDR3 comprising the sequence shown in SEQ ID NO:53.

[0184] In one embodiment, the anti-CD117 antibody comprises V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:54, a CDR2 comprising the sequence shown in SEQ ID NO:55, and a CDR3 comprising the sequence shown in SEQ ID NO:56; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:57, a CDR2 comprising the sequence shown in SEQ ID NO:58, and a CDR3 comprising the sequence shown in SEQ ID NO:59.

[0185] In one embodiment, the anti-CD117 antibody comprises V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:60, a CDR2 comprising the sequence shown in SEQ ID NO:61, and a CDR3 comprising the sequence shown in SEQ ID NO:62; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:63, a CDR2 comprising the sequence shown in SEQ ID NO:64, and a CDR3 comprising the sequence shown in SEQ ID NO:65.

[0186] In one example, the anti-CD117 antibody comprises:

[0187] (i)V H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10;

[0188] (ii) V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16;

[0189] (iii)V H, which comprises the sequence shown in SEQ ID NO: 19; and V L , which comprises the sequence shown in SEQ ID NO:22; or

[0190] (iv)V H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:28.

[0191] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10.

[0192] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16.

[0193] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO: 19; and V L , which comprises the sequence shown in SEQ ID NO:22.

[0194] In one embodiment, the anti-CD117 antibody comprises V H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:28.

[0195] In one example, the anti-CD117 antibody comprises:

[0196] (i) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 7 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 10 L ;

[0197] (ii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 13 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 16 L ;

[0198] (iii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 19 Hand a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 22 L ;or

[0199] (iv) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 25 H and a kappa light chain comprising a V comprising the sequence shown in SEQ ID NO: 28 L .

[0200] In one example, an anti-CD117 antibody comprises an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 7. H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 10 L .

[0201] In one example, an anti-CD117 antibody comprises an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 13. H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 16 L .

[0202] In one example, an anti-CD117 antibody comprises an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 19. H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 22 L .

[0203] In one example, an anti-CD117 antibody comprises an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 25. H and a kappa light chain comprising a V comprising the sequence shown in SEQ ID NO: 28 L .

[0204] In one example, the anti-CD117 antibody comprises:

[0205] (i) a heavy chain comprising the sequence shown in SEQ ID NO:6; and a light chain comprising the sequence shown in SEQ ID NO:9;

[0206] (ii) a heavy chain comprising the sequence shown in SEQ ID NO: 12; and a light chain comprising the sequence shown in SEQ ID NO: 15;

[0207] (iii) a heavy chain comprising the sequence shown in SEQ ID NO: 18; and a light chain comprising the sequence shown in SEQ ID NO: 21;

[0208] (iv) a heavy chain comprising the sequence shown in SEQ ID NO: 24; and a light chain comprising the sequence shown in SEQ ID NO: 27;

[0209] (v) a heavy chain comprising the sequence shown in SEQ ID NO:67; and a light chain comprising the sequence shown in SEQ ID NO:69;

[0210] (vi) a heavy chain comprising the sequence shown in SEQ ID NO:71; and a light chain comprising the sequence shown in SEQ ID NO:73;

[0211] (vii) a heavy chain comprising the sequence shown in SEQ ID NO:75; and a light chain comprising the sequence shown in SEQ ID NO:77;

[0212] (viii) a heavy chain comprising the sequence shown in SEQ ID NO:79; and a light chain comprising the sequence shown in SEQ ID NO:81;

[0213] (ix) a heavy chain comprising the sequence shown in SEQ ID NO:83; and a light chain comprising the sequence shown in SEQ ID NO:85;

[0214] (x) a heavy chain comprising the sequence shown in SEQ ID NO:87; and a light chain comprising the sequence shown in SEQ ID NO:89;

[0215] (xi) a heavy chain comprising the sequence shown in SEQ ID NO:91; and a light chain comprising the sequence shown in SEQ ID NO:93;

[0216] (xii) a heavy chain comprising the sequence shown in SEQ ID NO:95; and a light chain comprising the sequence shown in SEQ ID NO:97;

[0217] (xiii) a heavy chain comprising the sequence shown in SEQ ID NO:99; and a light chain comprising the sequence shown in SEQ ID NO:101;

[0218] (xiv) a heavy chain comprising the sequence shown in SEQ ID NO: 103; and a light chain comprising the sequence shown in SEQ ID NO: 105; or

[0219] (xv) a heavy chain comprising the sequence shown in SEQ ID NO: 107; and a light chain comprising the sequence shown in SEQ ID NO: 109; or

[0220] (xvi) a heavy chain comprising the sequence shown in SEQ ID NO: 113; and a light chain comprising the sequence shown in SEQ ID NO: 111; or

[0221] (xvii) a heavy chain comprising the sequence shown in SEQ ID NO:115; and a light chain comprising the sequence shown in SEQ ID NO:111.

[0222] In one example, the anti-CD117 antibody comprises:

[0223] (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;

[0224] (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;

[0225] (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

[0226] (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

[0227] (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;

[0228] (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;

[0229] (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;

[0230] (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;

[0231] (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;

[0232] (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;

[0233] (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;

[0234] (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;

[0235] (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;

[0236] (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

[0237] (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.

[0238] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 6; and a light chain comprising the sequence shown 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.

[0239] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 12; and a light chain comprising the sequence shown 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.

[0240] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 18; and a light chain comprising the sequence shown 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.

[0241] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 24; and a light chain comprising the sequence shown 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.

[0242] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 67; and a light chain comprising the sequence shown 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.

[0243] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 71; and a light chain comprising the sequence shown 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.

[0244] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 75; and a light chain comprising the sequence shown 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.

[0245] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 79; and a light chain comprising the sequence shown 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.

[0246] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 83; and a light chain comprising the sequence shown 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.

[0247] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 87; and a light chain comprising the sequence shown 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.

[0248] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 91; and a light chain comprising the sequence shown 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.

[0249] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 95; and a light chain comprising the sequence shown 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.

[0250] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 99; and a light chain comprising the sequence shown 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.

[0251] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 103; and a light chain comprising the sequence shown 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.

[0252] In one example, the anti-CD117 antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 107; and a light chain comprising the sequence shown 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.

[0253] In one example, the subject has a disease or condition that requires treatment with HCT. For example, the subject has cancer, a hemoglobinopathy disorder, a myelodysplastic disorder, a primary immunodeficiency (PID), an autoimmune disorder, an immunodeficiency disorder, or a metabolic disorder.

[0254] In one example, the subject suffers from cancer. For example, the cancer is a blood cancer (or blood cancer). In one example, the blood cancer / blood cell cancer is a leukemia, a lymphoma or other blood cancers. For example, the leukemia is acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia, chronic myeloid 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, another blood cancer is a chronic myeloproliferative disorder, multiple myeloma / plasma cell neoplasm, myelodysplastic syndrome, myelodysplastic / myeloproliferative disorder, neuroblastoma or Ewing's sarcoma.

[0255] In one example, the subject has a myelodysplastic disorder.

[0256] In one example, the subject has a hemoglobinopathy disorder. For example, the hemoglobinopathy disorder is sickle cell anemia, thalassemia, Fanconi anemia, or aplastic anemia.

[0257] In one example, the subject suffers from a primary immunodeficiency (PID). For example, a PID is PI3Kδ activation syndrome (APDS), X-linked agammaglobulinemia (XLA), ataxia telangiectasia, chronic granulomatous disease (CGD) and other phagocytic disorders, common variable immunodeficiency (CVID), complement deficiency, DiGeorge syndrome, hemophagocytic lymphohistiocytosis (HLH), hyper-IgE syndrome, hyper-IgM syndrome, IgG subclass deficiency, innate immune deficiency, Toll-like receptor (TLR) deficiency (including MyD88 deficiency, IRAK4 deficiency, UNC93B deficiency, and TLR3 mutations), human natural killer cell deficiency, interferon-γ (IFN-γ) and interleukin-12 (IL-12) signaling defects, 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 congenital myeloid granulocyte defects), Wiskott-Aldrich syndrome, antibody deficiency with normal or elevated immunoglobulins, immunodeficiency with thymoma (Good syndrome), cobalamin transfer protein II deficiency, kappa chain deficiency, heavy chain deficiency, postmeiotic segregation (PMS2) disorder, unspecified hypogammaglobulinemia, chronic mucocutaneous candidiasis (CMC), chondro-hair dysplasia (CHH), X-linked lymphoproliferative (XLP) syndrome 1 and 2 , X-linked immunodysregulation with polyendocrine disease (IPEX) syndrome, veno-occlusive disease (VODI), Hoyeraal-Hreidarsson syndrome (dyskeratosis congenita), immunodeficiency with centromere instability and facial anomalies (ICF), Schimke syndrome, Comel-Netherton syndrome, congenital pure red cell aplasia, Schwachmann-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen breakage syndrome, or graft-versus-host disease (GvHD).In one example, the PID is Wiskott-Aldrich syndrome, X-linked agammaglobulinemia (XLA), congenital pure red cell aplasia, Schwachmann-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen breakage syndrome, or graft-versus-host disease (GvHD).

[0258] In one example, the subject suffers from an autoimmune disease. For example, the autoimmune disease is multiple sclerosis or diabetes. For example, the diabetes is type I diabetes.

[0259] In one example, the subject has an immunodeficiency disorder. For example, the immunodeficiency disorder is human immunodeficiency virus (HIV) disease or acquired immunodeficiency syndrome (AIDS).

[0260] In one example, the subject has a metabolic disorder. For example, the metabolic disorder is glycogen storage disease, mucopolysaccharidosis, Gaucher disease, Hurlers disease, sphingolipid storage disease, or metachromatic leukodystrophy.

[0261] In one example, the subject has received, is receiving, or will receive an additional conditioning regimen. For example, the subject has received an additional conditioning regimen. In one example, the subject is receiving an additional conditioning regimen. In another example, the subject will receive an additional conditioning regimen.

[0262] 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.

[0263] Non-myeloablative and reduced intensity conditioning regimens suitable for use in the present disclosure will be apparent to the skilled artisan and / or described herein.

[0264] In one example of any of the methods described herein, the subject further receives HCT following administration of the antibody.

[0265] The present disclosure provides a method of performing HCT in a subject in need thereof, wherein the subject has previously been treated with an antibody that binds to or specifically binds to a target on endogenous HSCs in the subject.

[0266] The present disclosure also provides a method of performing HCT in a subject in need thereof, wherein the subject has previously been treated with an antibody that binds to or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0267] The present disclosure further provides a method of performing HCT in a subject in need thereof, the method comprising:

[0268] (i) conditioning the patient with an antibody that binds to or specifically binds to a target on an endogenous HSC in the subject; and

[0269] (ii) administering to the subject a hematopoietic cell implant.

[0270] The present disclosure also provides a method of reducing the side effects of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody that binds to or specifically binds to a target on an endogenous HSC in the subject.

[0271] The present disclosure further provides a method of reducing side effects of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody that binds to or specifically binds to a target on endogenous HSCs in the subject, wherein the antibody mediates ADCT.

[0272] The present disclosure also provides a method of reducing the side effects of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody comprising an extended hinge region.

[0273] The present disclosure further provides a method of reducing the side effects of a myeloablative conditioning regimen in a subject, the method comprising administering to the subject an antibody comprising an extended hinge region.

[0274] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises:

[0275] (i)V H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10;

[0276] (ii) V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16;

[0277] (iii)V H , which comprises the sequence shown in SEQ ID NO: 19; and V L, which comprises the sequence shown in SEQ ID NO:22; or

[0278] (iv)V H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:28.

[0279] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises V H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10.

[0280] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16.

[0281] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises V H , which comprises the sequence shown in SEQ ID NO: 19; and V L , which comprises the sequence shown in SEQ ID NO:22.

[0282] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises V H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:28.

[0283] The present disclosure further provides an anti-CD117 antibody, wherein the antibody comprises:

[0284] (i) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 7 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 10 L ;

[0285] (ii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 13 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 16 L ;

[0286] (iii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 19 Hand a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 22 L ;or

[0287] (iv) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 25 H and a kappa light chain comprising a V comprising the sequence shown in SEQ ID NO: 28 L .

[0288] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises an IgA2 heavy chain, which comprises a V comprising the sequence shown in SEQ ID NO: 7. H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 10 L .

[0289] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises an IgA2 heavy chain, which comprises a V comprising the sequence shown in SEQ ID NO: 13. H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 16 L .

[0290] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises an IgA2 heavy chain, which comprises a V comprising the sequence shown in SEQ ID NO: 19. H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 22 L .

[0291] The present disclosure provides an anti-CD117 antibody, wherein the antibody comprises an IgA2 heavy chain, which comprises a V comprising the sequence shown in SEQ ID NO: 25. H and a kappa light chain comprising a V comprising the sequence shown in SEQ ID NO: 28 L .

[0292] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises:

[0293] (i) a heavy chain comprising the sequence shown in SEQ ID NO:6; and a light chain comprising the sequence shown in SEQ ID NO:9;

[0294] (ii) a heavy chain comprising the sequence shown in SEQ ID NO: 12; and a light chain comprising the sequence shown in SEQ ID NO: 15;

[0295] (iii) a heavy chain comprising the sequence shown in SEQ ID NO: 18; and a light chain comprising the sequence shown in SEQ ID NO: 21;

[0296] (iv) a heavy chain comprising the sequence shown in SEQ ID NO: 24; and a light chain comprising the sequence shown in SEQ ID NO: 27;

[0297] (v) a heavy chain comprising the sequence shown in SEQ ID NO:67; and a light chain comprising the sequence shown in SEQ ID NO:69;

[0298] (vi) a heavy chain comprising the sequence shown in SEQ ID NO:71; and a light chain comprising the sequence shown in SEQ ID NO:73;

[0299] (vii) a heavy chain comprising the sequence shown in SEQ ID NO:75; and a light chain comprising the sequence shown in SEQ ID NO:77;

[0300] (viii) a heavy chain comprising the sequence shown in SEQ ID NO:79; and a light chain comprising the sequence shown in SEQ ID NO:81;

[0301] (ix) a heavy chain comprising the sequence shown in SEQ ID NO:83; and a light chain comprising the sequence shown in SEQ ID NO:85;

[0302] (x) a heavy chain comprising the sequence shown in SEQ ID NO:87; and a light chain comprising the sequence shown in SEQ ID NO:89;

[0303] (xi) a heavy chain comprising the sequence shown in SEQ ID NO:91; and a light chain comprising the sequence shown in SEQ ID NO:93;

[0304] (xii) a heavy chain comprising the sequence shown in SEQ ID NO:95; and a light chain comprising the sequence shown in SEQ ID NO:97;

[0305] (xiii) a heavy chain comprising the sequence shown in SEQ ID NO:99; and a light chain comprising the sequence shown in SEQ ID NO:101;

[0306] (xiv) a heavy chain comprising the sequence shown in SEQ ID NO: 103; and a light chain comprising the sequence shown in SEQ ID NO: 105; or

[0307] (xv) a heavy chain comprising the sequence shown in SEQ ID NO: 107; and a light chain comprising the sequence shown in SEQ ID NO: 109.

[0308] In one example, the heavy chain sequence and / or the light chain sequence does not comprise a signal sequence.

[0309] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises:

[0310] (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;

[0311] (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;

[0312] (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

[0313] (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

[0314] (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;

[0315] (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;

[0316] (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;

[0317] (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;

[0318] (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;

[0319] (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;

[0320] (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;

[0321] (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;

[0322] (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;

[0323] (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

[0324] (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.

[0325] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 6; and a light chain comprising the sequence shown 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.

[0326] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 12; and a light chain comprising the sequence shown 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.

[0327] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 18; and a light chain comprising the sequence shown 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.

[0328] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 24; and a light chain comprising the sequence shown 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.

[0329] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 67; and a light chain comprising the sequence shown 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.

[0330] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 71; and a light chain comprising the sequence shown 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.

[0331] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 75; and a light chain comprising the sequence shown 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.

[0332] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 79; and a light chain comprising the sequence shown 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.

[0333] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 83; and a light chain comprising the sequence shown 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.

[0334] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 87; and a light chain comprising the sequence shown 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.

[0335] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 91; and a light chain comprising the sequence shown 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.

[0336] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 95; and a light chain comprising the sequence shown 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.

[0337] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 99; and a light chain comprising the sequence shown 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.

[0338] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 103; and a light chain comprising the sequence shown 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.

[0339] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising the sequence shown in SEQ ID NO: 107; and a light chain comprising the sequence shown 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.

[0340] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises:

[0341] (i) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 8; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 11;

[0342] (ii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 14; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 17;

[0343] (iii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 20; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 23;

[0344] (iv) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 26; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 29;

[0345] (v) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 68; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 70;

[0346] (vi) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 72; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 74;

[0347] (vii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 76; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 78;

[0348] (viii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 80; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 82;

[0349] (ix) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 84; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 86;

[0350] (x) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 88; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 90;

[0351] (xi) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 92; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 94;

[0352] (xii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 96; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 98;

[0353] (xiii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 100; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 102;

[0354] (xiv) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 104; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 106; or

[0355] (xv) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 108; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 110; or

[0356] (xvi) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 114; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 112; or

[0357] (xvii) a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO:116; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO:112.

[0358] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 8; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 11.

[0359] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 8; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 11, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 11.

[0360] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 14; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 17.

[0361] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 14; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 17, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 17.

[0362] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 20; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 23.

[0363] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 20; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 23, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 23.

[0364] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 26; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 29.

[0365] In one example, the present disclosure provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 26; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 29, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 29.

[0366] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 68; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 70.

[0367] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 68; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 70, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 70.

[0368] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 72; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 74.

[0369] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 72; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 74, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 74.

[0370] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 76; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 78.

[0371] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 76; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 78, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 78.

[0372] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 80; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 82.

[0373] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 80; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 82, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 82.

[0374] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 84; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 86.

[0375] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 84; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 86, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 86.

[0376] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 88; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 90.

[0377] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 88; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 90, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 90.

[0378] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 92; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 94.

[0379] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 92; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 94, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 94.

[0380] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO:96; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO:98.

[0381] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 96; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 98, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 98.

[0382] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 100; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 102.

[0383] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 100; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 102, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 102.

[0384] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 104; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 106.

[0385] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 104; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 106, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 106.

[0386] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 108; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 110.

[0387] The present disclosure also provides an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 108; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 110, optionally wherein the light chain lacks an intron sequence corresponding to nucleotides 46 to 128 of SEQ ID NO: 110.

[0388] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, which includes a heavy chain comprising the sequence shown in SEQ ID NO: 113; and a light chain comprising the sequence shown in SEQ ID NO: 111.

[0389] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, which includes a heavy chain comprising the sequence shown in SEQ ID NO: 115; and a light chain comprising the sequence shown in SEQ ID NO: 111.

[0390] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 114; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 112.

[0391] The present disclosure also provides an extended hinge region of an anti-CD117 antibody, wherein the antibody comprises a heavy chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 116; and a light chain comprising a sequence expressed or encoded by a nucleic acid comprising SEQ ID NO: 112.

[0392] The present disclosure also provides an anti-CD117 antibody comprising an extended hinge region, comprising:

[0393] (i) the C-terminal CH1 sequence from IgA, the upper hinge sequence from IgG3, the middle hinge sequence from IgG3, the lower hinge sequence from IgG3 and the sequence after the lower hinge sequence from IgA; or

[0394] (ii) a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123, an upper hinge comprising the sequence shown in SEQ ID NO: 124, a middle hinge comprising the sequence shown in SEQ ID NO: 125, a lower hinge comprising the sequence shown in SEQ ID NO: 126, and a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 127; or

[0395] (iii) a C-terminal CH1 comprising the sequence shown in SEQ ID NO:123, an upper hinge comprising the sequence shown in SEQ ID NO:124, a middle hinge comprising the sequence shown in SEQ ID NO:125, a lower hinge comprising the sequence shown in SEQ ID NO:126, and a sequence after the lower hinge comprising the sequence shown in SEQ ID NO:128.

[0396] In one example, the anti-CD117 antibody comprising an extended hinge region includes 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 after the lower hinge sequence from IgA. In one example, the anti-CD117 antibody comprising an extended hinge region includes a C-terminal CH1 sequence from IgA. In one example, the anti-CD117 antibody comprising an extended hinge region includes an upper hinge sequence from IgG3. In one example, the anti-CD117 antibody comprising an extended hinge region includes a middle hinge sequence from IgG3. In one example, the anti-CD117 antibody comprising an extended hinge region includes a lower hinge sequence from IgG3. In one example, the anti-CD117 antibody comprising an extended hinge region includes a sequence after the lower hinge sequence from IgA.

[0397] In one example, an anti-CD117 antibody comprising an extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123; an upper hinge comprising the sequence shown in SEQ ID NO: 124; a middle hinge comprising the sequence shown in SEQ ID NO: 125; a lower hinge comprising the sequence shown in SEQ ID NO: 126; and / or a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 127, and combinations thereof. In one example, an anti-CD117 antibody comprising an extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123. In one example, an anti-CD117 antibody comprising an extended hinge region includes an upper hinge comprising the sequence shown in SEQ ID NO: 124. In one example, an anti-CD117 antibody comprising an extended hinge region includes a middle hinge comprising the sequence shown in SEQ ID NO: 125. In one example, an anti-CD117 antibody comprising an extended hinge region includes an upper hinge with a lower hinge comprising the sequence shown in SEQ ID NO: 126. In one example, an anti-CD117 antibody comprising an extended hinge region includes a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 127.

[0398] In one example, the anti-CD117 antibody comprising an extended hinge region includes a terminal CH1 comprising the sequence shown in SEQ ID NO: 123; an upper hinge comprising the sequence shown in SEQ ID NO: 124; a middle hinge comprising the sequence shown in SEQ ID NO: 125; a lower hinge comprising the sequence shown in SEQ ID NO: 126; and / or a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 128, and combinations thereof. In one example, the anti-CD117 antibody comprising an extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123. In one example, the anti-CD117 antibody comprising an extended hinge region includes an upper hinge comprising the sequence shown in SEQ ID NO: 124. In one example, the anti-CD117 antibody comprising an extended hinge region includes a middle hinge comprising the sequence shown in SEQ ID NO: 125. In one example, the anti-CD117 antibody comprising an extended hinge region includes an upper hinge having a lower hinge comprising the sequence shown in SEQ ID NO: 126. In one example, an anti-CD117 antibody comprising an extended hinge region includes a sequence after the lower hinge comprising the sequence shown in SEQ ID NO:128.

[0399] In one example, the effector function level induced by the anti-CD117 antibody comprising the hinge area of ​​extension is increased relative to the antibody not comprising the hinge area of ​​extension. In one example, the anti-CD117 antibody comprising the hinge area of ​​extension enhances the pharmacokinetic properties of antibody relative to the antibody not comprising the hinge area of ​​extension. In one example, the anti-CD117 antibody comprising the hinge area of ​​extension prolongs the half-life of antibody relative to the anti-CD117 antibody comprising the hinge area of ​​extension. In one example, the anti-CD117 antibody comprising the hinge area of ​​extension enhances the stability of the anti-CD117 antibody comprising the hinge area of ​​extension relative to the antibody not comprising the hinge area of ​​extension. In one example, the anti-CD117 antibody comprising the hinge area of ​​extension increases the affinity of the hinge area to the neonatal Fc region (FcRn) relative to the antibody not comprising the hinge area of ​​extension. In one example, the anti-CD117 antibody comprising the hinge area of ​​extension can be better approached to its epitope relative to the antibody not comprising the hinge area of ​​extension.

[0400] 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.

[0401] In one example, the hinge region is modified by inserting an additional hinge region into the hinge region of an antibody.

[0402] In another example, the hinge region is modified by inserting at least a portion of an additional hinge region into the hinge region of an antibody after the first proline. For example, the hinge region is modified by inserting at least a portion of an IgG3 hinge region into the IgA2 hinge region of an antibody after the first proline.

[0403] In one example, the modified hinge region is an extended hinge region.

[0404] In one example, the extended hinge region is capable of inducing increased levels of effector function.

[0405] In one example, the effector function level induced by the extended hinge region is increased relative to the antibody that does not comprise the extended hinge region. In one example, the extended hinge region enhances the pharmacokinetic properties of the antibody relative to the antibody that does not comprise the extended hinge region. In one example, the extended hinge region prolongs the half-life of the antibody relative to the antibody that does not comprise the extended hinge region. In one example, the extended hinge region enhances the stability of the antibody relative to the antibody that does not comprise the extended hinge region. In one example, the extended hinge region increases the affinity of the hinge region to the neonatal Fc region (FcRn) relative to the antibody that does not comprise the extended hinge region. In one example, the extended hinge region can better approach its epitope relative to the antibody that does not comprise the extended hinge region.

[0406] In one example, the extended hinge region includes 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 after the lower hinge sequence from IgA and a combination thereof. In one example, the extended hinge region includes a C-terminal CH1 sequence from IgA. In one example, the extended hinge region includes an upper hinge sequence from IgG3. In one example, the extended hinge region includes a middle hinge sequence from IgG3. In one example, the extended hinge region includes a lower hinge sequence from IgG3. In one example, the extended hinge region includes a sequence after the lower hinge sequence from IgA.

[0407] In one example, the extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123; an upper hinge comprising the sequence shown in SEQ ID NO: 124; a middle hinge comprising the sequence shown in SEQ ID NO: 125; a lower hinge comprising the sequence shown in SEQ ID NO: 126; and / or a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 127, and combinations thereof. In one example, the extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123. In one example, the extended hinge region includes an upper hinge comprising the sequence shown in SEQ ID NO: 124. In one example, the extended hinge region includes a middle hinge comprising the sequence shown in SEQ ID NO: 125. In one example, the extended hinge region includes an upper hinge having a lower hinge comprising the sequence shown in SEQ ID NO: 126. In one example, the extended hinge region includes a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 127.

[0408] In one example, the extended hinge region includes a terminal CH1 comprising the sequence shown in SEQ ID NO: 123; an upper hinge comprising the sequence shown in SEQ ID NO: 124; a middle hinge comprising the sequence shown in SEQ ID NO: 125; a lower hinge comprising the sequence shown in SEQ ID NO: 126; and / or a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 128, and combinations thereof. In one example, the extended hinge region includes a C-terminal CH1 comprising the sequence shown in SEQ ID NO: 123. In one example, the extended hinge region includes an upper hinge comprising the sequence shown in SEQ ID NO: 124. In one example, the extended hinge region includes a middle hinge comprising the sequence shown in SEQ ID NO: 125. In one example, the extended hinge region includes an upper hinge having a lower hinge comprising the sequence shown in SEQ ID NO: 126. In one example, the extended hinge region includes a sequence after the lower hinge comprising the sequence shown in SEQ ID NO: 128.

[0409] 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.

[0410] The present disclosure further provides an expression construct comprising a nucleic acid of the present disclosure operably linked to a promoter. Such an expression construct can be in the form of a vector (eg, a plasmid).

[0411] In one example, an expression construct of the present disclosure comprises a polypeptide (e.g., comprising V H ) and a nucleic acid encoding another polypeptide operably linked to another promoter (e.g., comprising V L ) nucleic acid.

[0412] In another example, the expression construct is a bicistronic expression construct, for example, comprising the following operably linked components in 5' to 3' order:

[0413] (i) Promoter

[0414] (ii) a nucleic acid encoding a first polypeptide;

[0415] (iii) an internal ribosome entry site; and

[0416] (iv) a nucleic acid encoding a second polypeptide.

[0417] For example, the first polypeptide comprises V H and the second polypeptide comprises V L , or the first polypeptide comprises VL and the second polypeptide comprises V H .

[0418] The present disclosure also contemplates separate expression constructs, wherein one expression construct encodes a first polypeptide (e.g., comprising V H ), and another expression construct encodes a second polypeptide (e.g., comprising V L ). For example, the present disclosure also provides a composition comprising:

[0419] (i) a first expression construct comprising a polypeptide encoding a polypeptide (e.g., comprising a V sequence operably linked to a promoter); H ) nucleic acid; and

[0420] (ii) a second expression construct comprising a polypeptide encoding (e.g., comprising a V sequence operably linked to a promoter) L ),

[0421] wherein the first polypeptide and the second polypeptide associate to form the antibody of the present disclosure.

[0422] The present disclosure further 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 comprises a nucleic acid of the present disclosure or an expression construct of the present disclosure or:

[0423] (i) a first expression construct comprising a polypeptide (e.g., comprising V H ) nucleic acid; and

[0424] (ii) a second expression construct comprising a polypeptide (e.g., comprising V L ),

[0425] wherein the first polypeptide and the second polypeptide associate to form the antibody of the present disclosure.

[0426] The present disclosure further provides a pharmaceutical composition, which comprises the antibody or nucleic acid or expression construct or cell of the present disclosure and a suitable carrier. In one example, the pharmaceutical composition comprises the antibody of the present disclosure.

[0427] In one example, the carrier is pharmaceutically acceptable.

[0428] The present disclosure further provides the antibody or nucleic acid or expression construct or cell or composition of the present disclosure for use as a medicament.

[0429] The present disclosure also provides the antibodies or nucleic acids or expression constructs or cells or compositions of the present disclosure for use in conditioning a subject in need of HCT.

[0430] The present disclosure also provides for the use of an antibody that binds to or specifically binds to a target on an endogenous HSC in the manufacture of a medicament for conditioning a subject in need of HCT.

[0431] The present disclosure also provides for the use of an antibody that binds or specifically binds to a target on an endogenous HSC in the manufacture of a medicament for conditioning a subject in need of HCT, wherein the antibody mediates ADCT.

[0432] The present disclosure further provides an antibody or nucleic acid or expression construct or cell or composition of the present disclosure for use in depleting a cell population in the bone marrow of a subject in need of HCT.

[0433] The present disclosure also provides for the use of an antibody that binds to or specifically binds to a target on endogenous HSC in the manufacture of a medicament for depleting a cell population in the bone marrow of a subject in need of HCT.

[0434] The present disclosure also provides for the use of an antibody that binds to or specifically binds to a target on endogenous HSC in the manufacture of a medicament for depleting a cell population in the bone marrow of a subject in need of HCT, wherein the antibody mediates antibody-dependent cellular phagocytosis (ADCT).

[0435] The present disclosure further provides the antibodies or nucleic acids or expression constructs or cells or compositions of the present disclosure for use in methods of HCT.

[0436] The present disclosure further provides an antibody or nucleic acid or expression construct or cell or composition of the present disclosure for use in reducing the side effects of a myeloablative conditioning regimen.

[0437] The present disclosure also provides for the use of an antibody that binds to or specifically binds to a target on an endogenous HSC in the manufacture of a medicament for reducing the side effects of a myeloablative conditioning regimen in a subject.

[0438] The present disclosure also provides for the use of an antibody that binds to or specifically binds to a target on an endogenous HSC in the manufacture of a medicament for reducing the side effects of a myeloablative conditioning regimen in a subject, wherein the antibody mediates ADCT.

[0439] The present 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.

[0440] The present disclosure also provides 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.

[0441] The present disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for depleting a cell population in the bone marrow of a subject in need of HCT.

[0442] The present disclosure also provides use of an antibody comprising an extended hinge region in the manufacture of a medicament for depleting a cell population in the bone marrow of a subject in need of HCT, wherein the antibody mediates antibody-dependent cellular phagocytosis (ADCT).

[0443] The present disclosure also provides the use of an antibody comprising an extended hinge region in the manufacture of a medicament for reducing the side effects of a myeloablative conditioning regimen in a subject.

[0444] The present disclosure also provides use of an antibody comprising an extended hinge region in the manufacture of a medicament for reducing the side effects of a myeloablative conditioning regimen in a subject, wherein the antibody mediates ADCT.

[0445] The present disclosure further provides an antibody comprising an extended hinge region, wherein the antigen binding site of the antibody of the present disclosure comprising the extended hinge region is better able to bind to its epitope relative to the antigen binding site of the antibody not comprising the extended hinge region.

[0446] The present disclosure further provides an anti-CD117 antibody comprising an extended hinge region. In one example, the antigen binding site of the antibody of the present disclosure comprising an extended hinge region is better able to bind to its epitope relative to the antigen binding site of the antibody not comprising an extended hinge region.

[0447] The present disclosure further 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.

[0448] Exemplary extended hinge regions and antibodies are described herein and should be considered equally applicable to the preceding examples of the present disclosure.

[0449] The present disclosure also provides a kit comprising the antibody or nucleic acid or expression construct or cell or composition of the present disclosure, and instructions for use in any method described herein (e.g., HCT or a method of depleting a cell population in the bone marrow of a subject).

[0450] In one example, the subject is a mammal, eg, a primate, such as a human. BRIEF DESCRIPTION OF THE DRAWINGS

[0451] Figure 1is a series of graphical representations showing the binding of anti-CD117 antibodies to cells expressing human, cynomolgus monkey, and mouse CD117. (A) Binding curves of different concentrations of anti-CD117-IgG1 antibody to cell surface CD117 on TF-1 cells. (B) EC from a single representative experiment 50 Data in nM. Specific binding curves of anti-CD117-IgG1 antibody to HEK293FS cells stably expressing (C) human CD117, (D) cynomolgus monkey CD117, and (E) mouse CD117 were generated by subtracting the nonspecific binding observed on parental HEK293FS cells. EC 50 (nM) Data are from representative experiments with anti-CD117-IgG1 antibody and HEK293FS cells stably expressing (F) human CD117, (G) cynomolgus monkey CD117, and (H) mouse CD117, where * indicates EC 50 The value cannot be determined.

[0452] Figure 2 is a graphical representation showing the inhibition of human stem cell factor-mediated TF-1 cell proliferation by anti-CD117-IgG1 antibody.

[0453] Figure 3 The results are shown using (A) anti-AF488 quenching antibody assay and (B) A series of graphical representations of the internalization of selected anti-CD117-IgG1 antibodies performed by live cell analysis.

[0454] Figure 4 is a graphical representation showing that anti-CD117-IgG1 antibody is unable to activate CD117 receptor and induce proliferation of TF-1 cells in the absence of stem cell factor.

[0455] Figure 5 It is a soluble N-terminal fragment targeting the human CD117 receptor (HuCD117 1-307 ) and C-terminus (HuCD117 308-524 Figure 1 is a series of graphical representations of the screening of anti-human CD117 antibodies against fragments of (A) positive binding reactions are represented by shaded bars. The overall distribution of binding affinities of anti-human CD117 antibodies (black circles) is against (B) the soluble N-terminus of the human CD117 receptor (HuCD117 1-307 ) and (C) C-terminus (HuCD117 308-524 ) fragments were tested. Diagonal lines indicate regions of equal affinity.

[0456] Figure 6Is a series of graphical representations showing SPR screening of anti-human CD117 antibodies against soluble (A) human CD117 and (B) cynomolgus CD117 receptors. Antibody ligands were prepared in IgG1 (black bars), IgG4 (white bars) or IgA2 (grey bars) format.

[0457] Figure 7 Figure 2 is a series of graphical representations showing antibody-dependent cellular cytotoxicity (ADCT) induced by anti-CD117-IgA2 antibody. (A) Normalized DILC18 MFI ± SD (B) EC 50 and (C) Bmax of n = 5 donors pooled from three experiments.

[0458] Sequence Listing Annotations

[0459]

[0460]

[0461]

[0462]

[0463] DETAILED DESCRIPTION

[0464] Overview

[0465] Throughout this specification, references to individual steps, compositions of matter, groups of steps, or groups of compositions of matter shall be considered to encompass both one and multiple (i.e., one or more) of those steps, compositions of matter, groups of steps, or groups of compositions of matter, unless expressly stated otherwise or the context requires otherwise.

[0466] Those skilled in the art will appreciate that the present disclosure is susceptible to variations and modifications other than those specifically described. It should be understood that the present disclosure includes all such variations and modifications. The present disclosure also includes all steps, features, compositions and compounds mentioned or indicated in this specification, either individually or collectively, and any and all combinations or any two or more of the steps or features.

[0467] The present disclosure is not 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.

[0468] Unless expressly stated otherwise, any example of the present disclosure herein should be considered applicable mutatis mutandis to any other example of the present disclosure.

[0469] Unless specifically defined otherwise, all technical and scientific terms used herein should be interpreted as having 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).

[0470] Unless otherwise indicated, the recombinant protein, cell culture, and immunological techniques used in this disclosure are standard procedures well known to those skilled in the art. Such techniques are described and explained in the literature in sources such as, 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 (ed.), Essential Molecular Biology: A Practical Approach, Vols. 1 and 2, IRL Press (1991), DM Glover and BD Hames (eds.), DNA Cloning: A Practical Approach, Vols. 1-4, IRL Press (1995 and 1996), and FM Ausubel et al. (eds.), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988, including all updates to date), Ed Harlow and David Lane (eds.) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1989), TA Brown (ed.), Essential Molecular Biology: A Practical Approach, Vols. 1 and 2, IRL Press (1991), DM Glover and BD Hames (eds.), DNA Cloning: A Practical Approach, Vols. 1-4, IRL Press (1995 and 1996), and FM Ausubel et al. (eds.), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988, including all updates to date), Ed Harlow and David Lane (eds.), Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1991). Harbor Laboratory, (1988), and JE Coligan et al. (eds.) Current Protocols in Immunology, John Wiley & Sons (including all updates to date).

[0471] The description and definition of variable regions and portions thereof, immunoglobulins, antibodies and fragments thereof herein may be further clarified in the discussion of 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.

[0472] Any discussion of proteins or antibodies herein should be understood to include any variants of the proteins or antibodies produced during manufacture and / or storage. For example, during manufacture or storage, the antibody may be deamidated (e.g., at asparagine or glutamine residues) and / or subjected to altered glycosylation and / or conversion of glutamine residues to pyroglutamic acid and / or removal or "clipped" of the N-terminal or C-terminal residues and / or incomplete processing of a portion or all of the signal sequence, thereby remaining at the end of the antibody. It should be understood that a composition comprising a particular amino acid sequence may be a heterogeneous mixture of the stated or encoded sequence and / or variants of the stated or encoded sequence.

[0473] The term "and / or", such as "X and / or Y", should be understood to mean "X and Y" or "X or Y", and should be considered to provide clear support for both or either meanings.

[0474] Throughout this specification, the word "comprise" or variations such as "comprising" or "having" will be understood to mean the inclusion of stated elements, integers or steps, or groups of elements, integers or steps, but not the exclusion of any other elements, integers or steps, or groups of elements, integers or steps.

[0475] As used herein, the term "derived from" is to be understood as meaning that the specified integer may be obtained from a particular source, although not necessarily directly from that source.

[0476] Selected Definitions

[0477] The term "antibody-dependent cellular phagocytosis" or "antibody-dependent cell-mediated phagocytosis" (ADCT) refers to the rapid intercellular transfer of membrane fragments and their associated molecules from donor cells to recipient cells (e.g., effector cells) during cell-to-cell contact or by the release of vesicles. Exemplary recipient cells include T cells and B cells, monocytes / macrophages, dendritic cells, neutrophils, and natural killer (NK) cells. In the context of the present disclosure, the transfer of phagocytic-mediated cell surface molecules (e.g., CD117) from donor cells to recipient cells causes antibody-antigen complexes (i.e., antibody-antigen complexes bound to cell surface molecules (e.g., antibody-CD117 complexes)) to be transferred from donor cells to recipient cells. When the recipient cells are effector cells expressing Fc-γ receptors (FcγRs), a special form of phagocytosis can occur; these recipient cells absorb donor cell-associated immune complexes (composed of specific antibodies bound to target antigens on donor cells) and internalize them, usually after FcγRs bind to the Fc region of the antibody.

[0478] As used herein, when referring to cell populations in the bone marrow, the terms "reduce" or "reducing" refer to administering an antibody described herein to prevent or hinder differentiation and / or maturation of cells in a subject.

[0479] As used herein, the terms "deplete" or "depleting" when referring to cell populations in the bone marrow refer to administering an antibody described herein to prevent or inhibit the survival of bone marrow cells in a subject.

[0480] As used herein, the term "ablate and ablation" refers to the partial or complete removal of a cell population (e.g., HSC) from a target tissue (e.g., bone marrow). It will be apparent to the technician that elimination includes complete removal or elimination of such cells from the target tissue. Alternatively, elimination is the partial removal or elimination of such cells (e.g., HSC) from the target tissue (i.e., bone marrow). For example, the methods disclosed herein reduce the cells (e.g., HSC) of the target tissue (e.g., bone marrow) by 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%.

[0481] For naming purposes only and not for limiting purposes, an exemplary sequence of human differentiation cluster (CD117) (also referred to as c-kit or stem cell factor receptor (SCFR)) is shown in NCBI reference sequence NP_000213.1 and RefSeq accession number NM_000222.3 and SEQ ID NO: 1. The sequence of CD117 from other species can be determined using sequences provided in this article and / or publicly available databases, and / or using standard techniques (e.g., as described in Ausubel et al., (ed.), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988, including all updated versions to date) or Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1989)). For naming purposes only and not for limiting purposes, an exemplary sequence of cynomolgus macaque CD117 is shown in RefSeq accession number XP_005555330 and SEQ ID NO: 2. For nomenclature purposes only and not for limiting purposes, an exemplary sequence of murine CD117 is shown as NCBI reference sequence NP_001116205.1 and SEQ ID NO: 3. References to human CD117 may be abbreviated as hCD117. References to CD117 herein include all isoforms thereof.

[0482] As used herein, the term "subject" should be understood to mean any animal, including humans, such as mammals. Exemplary subjects include, but are not limited to, humans and non-human primates. In one example, the subject is a human.

[0483] The term "protein" should 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 can be covalently linked using suitable chemical bonds or disulfide bonds. Examples of non-covalent bonds include hydrogen bonds, ionic bonds, van der Waals forces, and hydrophobic interactions.

[0484] In accordance with the above paragraph, the term "polypeptide" or "polypeptide chain" is understood to mean a series of consecutive amino acids linked by peptide bonds.

[0485] The term "isolated protein" or "isolated polypeptide" refers to a protein or polypeptide that, by its origin or source of derivation, is not associated with naturally associated components with which it is naturally present; the protein or polypeptide is substantially free of other proteins from the same source. A protein can be rendered substantially free of naturally associated components, or substantially purified by separation using protein purification techniques known in the art. By "substantially purified" is meant that the protein is substantially free of contaminants, for example, 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.

[0486] The term "recombinant" should be understood to mean the product of artificial genetic recombination. Therefore, in the context of a recombinant protein comprising an antibody antigen-binding domain, the term does not encompass antibodies naturally present in a subject, which are the product of natural recombination occurring during B cell maturation. However, if this antibody is separated, it should be considered as a separated protein comprising an antibody antigen-binding domain. Similarly, if the nucleic acid encoding the protein is separated and expressed using a recombinant method, the resulting protein is a recombinant protein comprising an antibody antigen-binding domain. Recombinant protein also encompasses proteins expressed by an artificial recombinant method when located in a cell, tissue or subject (e.g., expressed therein).

[0487] As used herein, the term "antigen binding site" is understood to mean a structure formed by a protein that is capable of binding or specifically binding to an antigen. An antigen binding site need not be a series of consecutive amino acids, or even amino acids in a single polypeptide chain. For example, in an Fv produced by two different polypeptide chains, the antigen binding site consists of V L and V H The VL and VH interact with the antigen and are generally, but not always, present in one or more of the CDRs in each variable region. In some examples, the antigen binding site is or comprises 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 an intact antibody, for example, it can be isolated (e.g., a domain antibody) or in another form, for example, as described herein, such as scFv.

[0488] The skilled artisan will appreciate that an "antibody" is generally considered to be a protein comprising a variable region composed of multiple polypeptide chains, e.g., comprising V L The polypeptide and the polypeptide containing V H Antibodies also typically contain constant domains, some of which may be arranged into a constant region, which, in the case of a heavy chain, comprises a constant fragment or a crystallizable fragment (Fc). Hand V L The interaction forms an Fv comprising an antigen binding region that is capable of specific binding to one or more closely related antigens. Generally speaking, the light chain of a mammal is a kappa light chain or a lambda light chain, and the heavy chain of a mammal is an alpha, delta, epsilon, gamma or mu. Antibodies can belong to any type (e.g., IgG, IgE, IgM, IgD, IgA and IgY), category (e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) or subclass. The term "antibody" also encompasses humanized antibodies, primatogenic antibodies, human antibodies and chimeric antibodies. In an example, the antibody is an IgA antibody. For example, an IgA antibody belongs to the IgA2 antibody category.

[0489] The terms "full-length antibody," "intact antibody," or "whole antibody" are used interchangeably and refer to an antibody in substantially intact form, as opposed to an antigen-binding fragment of an antibody. Specifically, whole antibodies include those having heavy and light chains that include an Fc region. These constant domains may be wild-type sequence constant domains (e.g., human wild-type sequence constant domains) or amino acid sequence variants thereof.

[0490] As used herein, the term "hinge region" refers to the proline-rich portion of the constant region of an antibody heavy chain that connects the Fc region and the Fab region and confers mobility to the two Fab arms of the antibody, as defined herein.

[0491] As used herein, "variable region" refers to a portion of the light chain and / or heavy chain of an antibody as defined herein that specifically binds to an antigen and comprises an amino acid sequence of a complementary determining region (CDR) (i.e., CDR1, CDR2, and CDR3) and a framework region (FR). An exemplary variable region comprises three or four FRs (e.g., FR1, FR2, FR3, and optionally FR4) and three CDRs. In the case of a protein derived from an IgNAR, the protein may lack a CDR2. H V refers to the variable region of the heavy chain. L Refers to the variable region of the light chain.

[0492] As used herein, the term "complementarity determining region" (synonymous CDR; i.e., CDR1, CDR2, and CDR3) refers to the amino acid residues of an antibody variable region whose presence is essential for antigen binding. Each variable region typically has three CDR regions, which are identified as CDR1, CDR2, and CDR3, respectively. The amino acid positions assigned to CDRs and FRs can be defined according to Kabat Sequences of Proteins of Immunological Interest, National Institutes of Health, Bethesda, Md., 1987 and 1991, or other numbering systems used in making this disclosure (e.g., the canonical numbering system of Chothia and Lesk, J. Mol Biol. 196:901-917, 1987; Chothia et al., Nature 342, 877-883, 1989; and / or the canonical numbering system of 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 Plükthun J. Mol. Biol., 309:657-670, 2001). For example, according to Kabat's numbering system, V H The positions of the framework regions (FRs) and CDRs are as follows: residues 1-30 (FR1), residues 31-35 (CDR1), residues 36-49 (FR2), residues 50-65 (CDR2), residues 66-94 (FR3), residues 95-102 (CDR3), and residues 103-113 (FR4). According to the numbering system of Kabat, V L The positions of FRs and CDRs are as follows: residues 1-23 (FR1), residues 24-34 (CDR1), residues 35-49 (FR2), residues 50-56 (CDR2), residues 57-88 (FR3), residues 89-97 (CDR3), and residues 98-107 (FR4). The present disclosure is not limited to FRs and CDRs defined by the Kabat numbering system, but also includes all numbering systems, including the numbering systems discussed above. In one example, references herein to CDRs (or FRs) refer to those regions related to the Kabat numbering system.

[0493] As used herein, the term "Fv" is understood to mean a L and V HAny protein consisting of multiple polypeptides or a single polypeptide that associates and forms a complex with an antigen binding site (i.e., capable of specifically binding to an antigen). H and V L It can be in one polypeptide chain or in different polypeptide chains. In addition, the Fv of the present disclosure (and any protein of the present disclosure) can have multiple antigen binding sites, which may or may not bind to the same antigen. The term should be understood to cover fragments directly derived from antibodies and proteins corresponding to such fragments produced using recombinant means.

[0494] As used herein, the term "specific binding (specifically binds or binds specifically)" should be understood to mean that the antibody of the present disclosure reacts or associates with a specific antigen or a cell expressing the antigen more frequently, more rapidly, more persistently and / or with greater affinity than the antibody reacts or associates with other antigens or cells. For example, the binding of a protein to CD117 is significantly improved (for example, affinity is increased by 20 times or 40 times or 60 times or 80 times to 100 times or 150 times or 200 times) affinity, easier and / or more persistent than the binding of the protein to other antigens or antigens generally recognized by polyreactive natural antibodies (i.e., naturally occurring antibodies known to be able to bind to multiple antigens naturally occurring in the human body), easier and / or more persistent. In general, but not necessarily, reference to binding means specific binding, and each term should be understood as providing clear support for another term.

[0495] If the dissociation constant (K D ) is less than the K of the antibody binding to another polypeptide D , then the antibody can be considered to "preferentially bind" to the one polypeptide. In one example, if the affinity (i.e., K) of the antibody binding to a polypeptide is D ) than the K of the antibody binding to another polypeptide D If the antibody has a binding affinity of at least about 20-fold, 40-fold, 60-fold, 80-fold, 100-fold, 120-fold, 140-fold, or 160-fold greater than that of the one polypeptide, the antibody is considered to bind preferentially to that one polypeptide.

[0496] For clarity, and as will be apparent to the skilled artisan based on the subject matter exemplified herein, references to "affinity" in this specification refer to the K of an antibody. D mentioned.

[0497] For the sake of clarity, and as will be apparent to a skilled person based on the description herein, the term “K D Reference to "X nM or less" should be understood to mean K DThe value of K is equal to X nM or less. The skilled person will understand that K D Smaller values ​​of correspond to higher (ie, stronger) affinity, ie, an affinity of 2 nM is stronger than an affinity of 3 nM.

[0498] “At least some value IC 50 ” will be understood to mean IC 50 is equal to or greater than the value (i.e., IC 50 smaller of the values), i.e., an IC of 2 nM 50 IC greater than 3nM 50 In other words, the term could be "X or smaller IC 50 ”, where X is a value described herein.

[0499] The term "competitive inhibition" is understood to mean that the antibody of the present disclosure (i.e., anti-CD117 antibody) reduces or prevents the combination of the antibody or protein with, for example, CD117. This can be due to the combination of the antibody with the same or overlapping epitopes. It is obvious from the above that the antibody does not need to completely inhibit the combination of the antibody, but only needs to reduce the statistically significant amount of the combination, for example, reducing 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 the combination of the antibody with, for example, CD117 by at least about 30%, more preferably by at least about 50%, more preferably by at least about 70%, more preferably by at least about 75%, even more preferably by at least about 80% or 85%, and even more preferably by at least about 90%. The method for determining the competitive inhibition of binding is known in the art and / or described herein. For example, whether there is a compound, the antibody is exposed to CD117. An antibody is said to competitively inhibit binding of an antibody if binding of the antibody is less in the presence of the antibody than in the absence of the antibody. In one example, competitive inhibition is not due to steric hindrance.

[0500] As used herein, the term "blocking" is understood to mean that an antibody that binds to CD117 is able to block, reduce or prevent CD117-mediated signaling produced by SCF in cells. As is apparent from the above, the antibody need not completely block CD117-mediated signaling produced by SCF, but only need to reduce the signaling by a statistically significant amount, for example, by 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.

[0501] When referring to the activation of CD117 and / or CD117 cell proliferation, the term "inhibition" is understood to mean that the antibody of the present disclosure (i.e., anti-CD117 antibody) reduces or prevents CD117 activation and / or CD117 cell proliferation. It is obvious from the above that the antibody does not need to completely inhibit activation or cell proliferation, but only needs to reduce the statistically significant amount of activation or cell proliferation, for example, reducing at least about 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% or 90% or 95%. The method for determining CD117 activation and / or CD117 cell proliferation is known in the art and / or described herein.

[0502] Bone marrow conditioning methods

[0503] The methods described herein provide methods for conditioning a subject in need of hematopoietic cell transplantation (HCT) and / or methods for depleting a cell population in the bone marrow of the subject, the method comprising administering to the subject an antibody that binds to or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject.

[0504] The methods herein also provide methods of HCT and / or methods of reducing the side effects of a myeloablative conditioning regimen in a subject, the methods comprising administering to the subject an antibody that binds to or specifically binds to a target on endogenous HSCs in the subject.

[0505] Hematopoietic cell transplantation (HCT)

[0506] As used herein, the term "hematopoietic cell transplantation" or "HCT" refers to the infusion, implantation or transplantation of hematopoietic stem cells (HSC) and progenitor cells into a subject. It will be apparent to the skilled person that the term can be used interchangeably with "bone marrow transplantation," "stem cell transplantation," and "hematopoietic stem cell transplantation."

[0507] In an example of any of the methods described herein, the subject requires HCT. For example, the subject has not yet received HCT. For example, the antibody is administered before the subject receives HCT.

[0508] In one example, the subject is receiving HCT. For example, the antibody is administered to a subject receiving HCT. In one example, the antibody and HCT are administered to the subject in sequence (i.e., one by one). In another example, the antibody and HCT are administered to the subject simultaneously (i.e., at the same time).

[0509] In an example of any method described herein, antibody is used to increase or improve the implantation efficiency of HCT. As used herein, phrase "implantation efficiency (engraftment efficiency and efficiency of engraftment)" refers to the efficiency of the conditioned target tissue (i.e., bone marrow) of the subject implanted by the stem cell group / progenitor cell group (i.e., HSC implant) administered. In certain embodiments, implantation efficiency improves 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 is obvious to the technician that the implantation efficiency is determined relative to the implantation efficiency of the method for HSC implantation not using the method disclosed herein to be evaluated.

[0510] In one example, the implantation efficiency is monitored by determining the chimerism of the subject. As used herein, the term "chimerism" refers to the percentage of HSC in a subject derived from a donor. It will be apparent to the technician that "donor" chimerism means that 100% of the bone marrow and blood cells in the subject are derived from the donor, while "mixed" or "partial" chimerism means that there are also cells of the subject. The method for determining chimerism is apparent to the technician and / or described herein. For example, real-time quantitative PCT, fluorescence in situ hybridization (FISH) and chromosome markers are used to determine chimerism.

[0511] In one example of any of the methods described herein, administration of the antibody induces chimerism in the subject.

[0512] In one example, administration of an antibody comprising an extended hinge region facilitates or enables at least partial depletion, substantial depletion, or elimination of cells expressing a target (eg, cells expressing CD117).

[0513] In one example, an antibody comprising an extended hinge region is administered

[0514] In one example, an antibody comprising a heavy chain comprising the sequence shown in SEQ ID NO:113; and a light chain comprising the sequence shown in SEQ ID NO:111 is administered.

[0515] In one example, the anti-CD117 antibody includes a heavy chain comprising the sequence shown in SEQ ID NO:115; and a light chain comprising the sequence shown in SEQ ID NO:111.

[0516] In one example, administration of the antibody induces HSC transplantation tolerance. For example, inducing chimerism in a subject can induce HSC transplantation tolerance.

[0517] In one example, the subject is undergoing or will undergo autologous HCT. When referring to HCT, the term "autologous" means that HCT is performed using cells collected or obtained from the subject who will be treated or is being treated (ie, the same individual).

[0518] In one example, the subject is receiving or will receive allogeneic HCT. When referring to HCT, the term "allogeneic" refers to HCT performed using cells collected or obtained from a different person (ie, a different individual) than the subject who will be treated or is being treated.

[0519] A subject in need of HCT is one that is apparent to a skilled artisan and / or described herein. For example, a subject in need of HCT is one that suffers from a disease or condition that would benefit from HCT.

[0520] In one example, the subject has a disease or condition that requires treatment with HCT. For example, the subject has cancer, a hemoglobinopathy disorder, a myelodysplastic disorder, a primary immunodeficiency (PID), an autoimmune disorder, an immunodeficiency disorder, or a metabolic disorder.

[0521] In one example, the subject has cancer. The term "cancer" refers to or describes the physiological condition in mammals that is typically characterized by unregulated cell growth / proliferation. For example, the cancer is a blood cancer (or blood cancer). Hematologic cancers / blood cell cancers include, but are not limited to, leukemias (e.g., acute lymphoblastic leukemia in adults and children; acute myeloid leukemias, e.g., acute myeloid leukemia in adults and children; chronic lymphocytic leukemia; chronic myeloid leukemia; and hairy cell leukemia); lymphomas (e.g., AIDS-related lymphoma; cutaneous T-cell lymphoma; Hodgkin lymphoma, including adult and childhood Hodgkin lymphoma; Hodgkin lymphoma of pregnancy; non-Hodgkin lymphoma, including adult and childhood non-Hodgkin lymphoma; non-Hodgkin lymphoma of pregnancy; mycosis fungoides; Sezary syndrome; Waldenstrom's macroglobulinemia; and primary central nervous system lymphoma); and other hematologic cancers (e.g., chronic myeloproliferative disorders; multiple myeloma / plasma cell neoplasms; myelodysplastic syndromes; myelodysplastic / myeloproliferative disorders, neuroblastoma, and Ewing's sarcoma).

[0522] In one example, the subject has a myelodysplastic disorder.

[0523] In one example, the subject has a hemoglobinopathy disorder. For example, the hemoglobinopathy disorder is sickle cell anemia, thalassemia, Fanconi anemia, or aplastic anemia.

[0524] In one example, the subject suffers from a primary immunodeficiency (PID). For example, a PID is PI3Kδ activation syndrome (APDS), X-linked agammaglobulinemia (XLA), ataxia telangiectasia, chronic granulomatous disease (CGD) and other phagocytic disorders, common variable immunodeficiency (CVID), complement deficiency, DiGeorge syndrome, hemophagocytic lymphohistiocytosis (HLH), hyper-IgE syndrome, hyper-IgM syndrome, IgG subclass deficiency, innate immune deficiency, Toll-like receptor (TLR) deficiency (including MyD88 deficiency, IRAK4 deficiency, UNC93B deficiency, and TLR3 mutations), human natural killer cell deficiency, interferon-γ (IFN-γ) and interleukin-12 (IL-12) signaling defects, 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 congenital myeloid granulocyte defects), Wiskott-Aldrich syndrome, antibody deficiency with normal or elevated immunoglobulins, immunodeficiency with thymoma (Good syndrome), cobalamin transfer protein II deficiency, kappa chain deficiency, heavy chain deficiency, postmeiotic segregation (PMS2) disorder, unspecified hypogammaglobulinemia, chronic mucocutaneous candidiasis (CMC), chondro-hair dysplasia (CHH), X-linked lymphoproliferative (XLP) syndrome 1 and 2 , X-linked immunodysregulation with polyendocrine disease (IPEX) syndrome, veno-occlusive disease (VODI), Hoyeraal-Hreidarsson syndrome (dyskeratosis congenita), immunodeficiency with centromere instability and facial anomalies (ICF), Schimke syndrome, Comel-Netherton syndrome, congenital pure red cell aplasia, Schwachmann-Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen breakage syndrome, or graft-versus-host disease (GvHD).In one example, the PID is Wiskott-Aldrich syndrome (WAS), X-linked agammaglobulinemia (XLA), congenital pure red cell aplasia, Schwachmann Diamond syndrome, adenosine deaminase 2 deficiency, Krabbe disease (GLD), alpha-mannosidosis, Nijmegen breakage syndrome, or graft-versus-host disease (GvHD).

[0525] In one example, the subject suffers from an autoimmune disease. For example, the autoimmune disease is multiple sclerosis or diabetes. For example, the diabetes is type I diabetes.

[0526] In one example, the subject has an immunodeficiency disorder. For example, the immunodeficiency disorder is human immunodeficiency virus (HIV) disease or acquired immunodeficiency syndrome (AIDS).

[0527] In one example, the subject has a metabolic disorder. For example, the metabolic disorder is glycogen storage disease, mucopolysaccharidosis, Gaucher disease, Hurlers disease, sphingolipid storage disease, or metachromatic leukodystrophy.

[0528] Targeting endogenous hematopoietic stem cells

[0529] As described herein, the disclosure relates to targeting, reducing, eliminating and / or depleting hematopoietic stem cell (HSC) groups residing in a target tissue (e.g., bone marrow or peripheral blood) of a subject. For example, methods described herein relate to targeting, reducing, eliminating and / or depleting endogenous HSC groups in the bone marrow of a subject, to condition the subject for implantation of a transplanted HSC group.

[0530] 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 leukocytes, erythrocytes (including myeloid lineage cells (e.g., monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes / platelets, dendritic cells) and lymphoid lineage cells (e.g., T cells, B cells, NK cells) and platelets. Hematopoietic stem cells are present in peripheral blood and bone marrow.

[0531] As used herein, when referring to HCT, the term "endogenous" refers to HSCs that originate from within a subject (ie, within the blood and / or bone marrow of a subject).

[0532] In one example of any method described herein, the method includes administering to a subject an antibody that is bound to or specifically bound to a target on an endogenous HSC in the subject. It will be apparent to the technician that reference to a "target" on an endogenous HSC refers to reference to any protein, receptor, antigen, carbohydrate, lipid, or other portion that is positioned or expressed on the surface of the HSC and can be used to distinguish a cell population. For example, the target is selectively expressed on the surface of a target cell population (i.e., HSC). In one example, the target is expressed only on a target cell population (i.e., an endogenous HSC population) to limit or avoid "off-target" effects.

[0533] In one example, the selection of a target is based on the detected expression of such a target (e.g., a cell surface marker) on HSCs compared to the expression of such a target on a control cell population. 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).

[0534] In one example, the target on endogenous HSC is selected from the group consisting of: CD2, CD5, CD7, CD11a, CDwl2, 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, C D82, CD84, CD85A, 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, CD17 2a, 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, CD 242, CD243, CD277, CD292, CDw293, CD295, CD298, CD309, CD318, CD324, CD325, CD338, CD344, CD349, CD350 and CD361.

[0535] In one example, the target on endogenous HSC 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.

[0536] In one example, the target on endogenous HSC is CD117.

[0537] Antibodies that bind to targets on HSC

[0538] The present disclosure provides an antibody that binds or specifically binds to a target on an endogenous HSC in a subject.In one example of any of the methods described herein, the antibody mediates antibody-dependent cellular phagocytosis (ADCT).

[0539] Methods for producing antibodies are known in the art and / or described in Harlow and Lane (ed.) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, (1988). Typically, in these methods, CD117 or a region thereof (e.g., an extracellular domain) or an immunogenic fragment thereof or an epitope thereof or a cell expressing and displaying it (i.e., an immunogen) (optionally formulated with any suitable or desired carrier, adjuvant, or pharmaceutically acceptable excipient) is administered to a non-human animal, e.g., mouse, chicken, rat, rabbit, guinea pig, dog, horse, cow, goat, or pig. The immunogen can be administered intranasally, intramuscularly, subcutaneously, intravenously, intradermally, intraperitoneally, or by other known routes.

[0540] Monoclonal antibodies are an exemplary form of antibodies contemplated by the present disclosure. The term "monoclonal antibody" or "mAb" refers to a homogeneous group of antibodies that can bind to the same antigen (e.g., the same epitope within an antigen). The term is not intended to limit the source of the antibody or the manner in which the antibody is prepared.

[0541] For the generation of mAbs, any of a variety of known techniques may be used, for example, US 4196265 or the exemplified procedures of Harlow and Lane (1988), supra.

[0542] Alternatively, ABL-MYC technology (NeoClone, Madison WI 53713, USA) is used to generate MAb-secreting cell lines (eg, as described in Largaespada et al., J. Immunol. Methods. 197:85-95, 1996).

[0543] Antibodies can also be produced or isolated by screening display libraries (e.g., phage display libraries), for example as described in US 6300064 and / or US 5885793. For example, the present inventors isolated fully human antibodies from a phage display library.

[0544] The antibodies of the present disclosure can be synthetic antibodies. For example, the antibodies are chimeric antibodies, humanized antibodies, human antibodies, or deimmunized antibodies.

[0545] In one example, antibody as described herein is a chimeric antibody. The term "chimeric antibody" refers to an antibody in which a portion of a heavy chain and / or a light chain is identical or homologous to a corresponding sequence in an antibody derived from a particular species (e.g., mouse, such as a mouse) or belonging to a particular antibody class or subclass, and the remainder of the chain is identical or homologous to a corresponding sequence in an antibody derived from another species (e.g., primates, such as humans) or belonging to another antibody class or subclass. The method for producing chimeric antibodies is described in, for example, US4816567 and US5807715.

[0546] The antibodies of the disclosure may be humanized or human.

[0547] The term "humanized antibody" should be understood to refer to an antigen binding site or variable region of an antibody derived from a non-human species, and a subclass of a chimeric antibody based on the structure and / or sequence of the remaining antibody structure of a human antibody. In a humanized antibody, the antigen binding site generally comprises a complementary determining region (CDR) (which is implanted into the appropriate FR in the variable region of a human antibody) from a non-human antibody and the remaining regions from a human antibody. The antigen binding site can be a wild type (i.e., identical to the antigen binding site of a non-human antibody) or modified by one or more amino acid replacements. In some cases, the FR residues of a human antibody are replaced by corresponding non-human residues.

[0548] Methods for humanizing non-human antibodies or parts thereof (e.g., variable regions) are known in the art. Humanization can be performed according to the methods of US5225539 or US5585089. Other methods for humanizing antibodies are not excluded.

[0549] As used herein, the term "human antibody" refers to an antibody having variable regions (e.g., V H 、V L ) and, optionally, an antibody whose constant region is derived from or corresponds to a sequence present in a human (e.g., in a human germline or somatic cell).

[0550] mutation

[0551] The present disclosure also contemplates mutant forms of the antibodies of the present disclosure. For example, such mutant antibodies comprise one or more conservative amino acid substitutions compared to the sequences shown herein. In some instances, the antibodies comprise 30 or less, or 20 or less, or 10 or less, for example, 9 or 8 or 7 or 6 or 5 or 4 or 3 or 2 conservative amino acid substitutions. "Conservative amino acid substitutions" are amino acid substitutions in which an amino acid residue is replaced by an amino acid residue having a similar side chain and / or hydrophilicity and / or hydrophilicity.

[0552] 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. For example, the Myeloma IgA1 Protein (Bur) scheme as described in Lohse et al., Cancer Research 76(2); 403-17, 2015.

[0553] In one example, the mutant antibody has only or no more than one or two or three or four or five or six conservative amino acid changes compared to the naturally occurring antibody. Details of the conservative amino acid changes are provided below. The skilled person will appreciate that, for example, based on the disclosure herein, such minor changes can be reasonably predicted to not alter the activity of the antibody.

[0554] Families of amino acid residues having similar side chains have been defined in the art, 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), beta-branched side chains (e.g., threonine, valine, isoleucine), and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine).

[0555] The present disclosure also contemplates non-conservative amino acid changes (e.g., substitutions) in the antibodies of the present disclosure (e.g., CDRs, such as CDR3). In one example, the antibody comprises less than 6 or 5 or 4 or 3 or 2 or 1 non-conservative amino acid substitutions (e.g., in CDR3, such as CDR3).

[0556] In one example, the mutation occurs in the FR of the antigen binding domain of the antibody of the present disclosure. In another example, the mutation occurs in the CDR of the antibody of the present disclosure.

[0557] Exemplary methods for generating mutant forms of antibodies include:

[0558] 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 WO 1999 / 058661);

[0559] Introducing a nucleic acid encoding a polypeptide into a mutator cell, e.g., XL-1 Red, XL-mutS, and XL-mutS-Kanr bacterial cells (Stratagene);

[0560] DNA shuffling, e.g., as disclosed in Stemmer, Nature 370:389-91, 1994; and

[0561] - Site-directed mutagenesis, e.g., as described in Dieffenbach (ed.) and Dveksler (ed.), In: PCR Primer: A Laboratory Manual, Cold Spring Harbor Laboratories, NY, 1995.

[0562] The present disclosure also contemplates one or more insertions or deletions compared to the sequences shown herein. In some examples, the antibody comprises 10 or fewer, e.g., 9 or 8 or 7 or 6 or 5 or 4 or 3 or 2 insertions and / or deletions.

[0563] Constant region

[0564] The present disclosure encompasses proteins and / or antibodies described herein that comprise the constant region of an antibody. This includes antigen binding fragments of an antibody fused to an Fc.

[0565] The sequence of the constant region useful for producing and the protein of the present disclosure can be obtained from a plurality of different sources. In some instances, the constant region of the protein or its portion is derived from a human antibody. The constant domain or its portion can be derived from any antibody class, including IgM, IgG, IgD, IgA and IgE, and any antibody isotype. In one example, the human antibody IgA class is used. In another example, human isotype IgA2 is used.

[0566] In one example, the Fc region of the constant region has or exhibits an effector function that contributes to or can at least partially reduce, substantially reduce or eliminate cells expressing the target (e.g., cells expressing CD117). This effector function can be an enhanced binding affinity to Fc receptors, and / or antibody-dependent cell-mediated cytotoxicity (ADCC), and / or antibody-dependent cell-mediated phagocytosis (ADCP), and / or antibody-dependent cell phagocytosis (ADCT), and / or complement-dependent cytotoxicity (CDC) and combinations thereof. Methods for assessing the effector function levels of proteins containing Fc regions are known in the art and / or described herein.

[0567] In one example, the antibodies of the present disclosure are capable of inducing increased levels of effector function.

[0568] In one example, the level of effector function induced by the constant region is increased relative to a wild-type Fc region of an IgG1 antibody or a wild-type Fc region of an IgG4 antibody.

[0569] In another example, the constant region is modified to increase the level of effector function that can be induced compared to the unmodified constant region. Such modifications may occur at the amino acid level and / or the secondary structure level and / or the tertiary structure level and / or glycosylation of the Fc region.

[0570] The skilled artisan will appreciate that greater effector function may manifest itself in any of a variety of ways, for example, as a higher level of effect, a longer lasting effect, or a faster rate of effect.

[0571] Exemplary constant region modifications include amino acid substitutions such as N166G mutation, P221R mutation, C311S mutation, NIT337-339TLS mutation, delC472, and delY473 numbered according to the myeloma IgAl protein (Bur) scheme.

[0572] It will be apparent to a skilled person that the antibodies described herein according to any example may be further modified to enhance the pharmacokinetic properties of the antibodies. For example, the antibodies may be further modified to enhance the half-life and / or stability of the antibodies.

[0573] 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 to the neonatal Fc region (FcRn). These amino acid substitutions can be used to extend the half-life of the protein by reducing blood clearance.

[0574] 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 residues and / or glutamine residues susceptible to deamidation and / or at glutamine residues susceptible to formation of pyroglutamic acid.

[0575] In one example, the antibody is conjugated to a compound that increases the half-life of the antibody. For example, the antibody is conjugated to a half-life extender such as polyethylene glycol (PEG), glycerol, glucose and / or albumin.

[0576] Hinge area

[0577] The present disclosure encompasses the proteins and / or antibodies described herein comprising a modified hinge region.

[0578] The sequence of the hinge useful for the protein of the present disclosure can be obtained from a plurality of different sources. In some instances, the hinge region of the protein is derived from a human antibody. Its hinge region can be derived from any antibody class, including IgM, IgG, IgD, IgA and IgE, and any antibody isotype. In one example, the human antibody IgA class is used. In another example, human isotype IgA2 is used. In yet another example, human isotype IgG is used. For example, human isotype IgG is IgG1, IgG2, IgG3 or IgG4. In one example, human isotype IgG is IgG1. In one example, human isotype IgG is IgG2. In one example, human isotype IgG is IgG3. In one example, human isotype IgG is IgG4.

[0579] In one example, the hinge region is modified to increase the level of effector function that can be induced compared to the unmodified hinge region. Such modifications can be substitutions and / or insertions at the amino acid level and / or the secondary structure level and / or the tertiary structure level and / or glycosylation of the hinge region.

[0580] In one example, the antibody comprising a modified hinge region has or exhibits an effector function that contributes to or can at least partially reduce, substantially reduce or eliminate cells expressing the target (e.g., cells expressing CD117). This effector function can be an enhanced binding affinity to Fc receptors, and / or antibody-dependent cell-mediated cytotoxicity (ADCC), and / or antibody-dependent cell-mediated phagocytosis (ADCP), and / or antibody-dependent cell phagocytosis (ADCT), and / or complement-dependent cytotoxicity (CDC) and combinations thereof. Methods for assessing the effector function level of an antibody are known in the art and / or described herein.

[0581] In one example, an antibody of the present disclosure comprising a modified hinge region is capable of inducing increased levels of effector function.

[0582] In one example, an antibody comprising a modified hinge region induces an increased level of effector function relative to a wild-type IgA2 antibody or a wild-type IgG3 antibody.

[0583] The skilled artisan will appreciate that greater effector function may manifest itself in any of a variety of ways, such as a higher level of effect, a longer lasting effect, or a faster rate of effect.

[0584] It will be apparent to the skilled person that the hinge region described herein according to any example may be modified or further modified to enhance the pharmacokinetic properties of the antibody. For example, the hinge region may be further modified to enhance the half-life and / or stability of the antibody.

[0585] 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 that comprises one or more amino acid substitutions and / or insertions that increase the affinity of the hinge region to the neonatal Fc region (FcRn). These amino acid substitutions and / or insertions can be used to extend the half-life of a protein and / or antibody by reducing blood clearance.

[0586] In one example, the hinge region contains one or more amino acid modifications and / or insertions that increase the stability of the antibody.

[0587] In one example, the hinge region is modified by inserting one or more amino acids to generate an extended hinge region. For example, the hinge region is modified by inserting another hinge region to generate an extended hinge region.

[0588] In one example, an antibody comprising an extended hinge region can better access its epitope relative to a wild-type antibody. In one example, an antibody comprising an extended hinge region can better access its epitope relative to an antibody not comprising an extended hinge region.

[0589] 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. For example, the modified hinge region comprises a chimeric IgA2 / IgG3 hinge region.

[0590] 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. For example, the modified hinge region comprises a chimeric IgA2 / IgA1 hinge region.

[0591] 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. The function of immunoglobulin A in immunity (2006).

[0592] Protein production

[0593] In one example, an antibody described herein according to any example is produced by culturing a hybridoma under conditions sufficient to produce the protein, e.g., as described herein and / or as known in the art.

[0594] Recombinant expression

[0595] In another example, the antibody described herein according to any example is recombinant.

[0596] For recombinant antibodies, the nucleic acid encoding the recombinant antibody can be cloned into an expression construct or an expression vector, and then the expression construct or expression vector is transfected into a host cell that does not produce protein in addition, such as an Escherichia coli (E. coli) cell, a yeast cell, an insect cell, or a mammalian cell (such as a monkey COS cell, a Chinese hamster ovary (CHO) cell, a human embryonic kidney (HEK) cell, or a myeloma cell). Exemplary cells for expressing proteins are CHO cells, myeloma cells, or HEK cells. Molecular cloning techniques for achieving these purposes are known in the art and are described, for example, in Ausubel et al., (ed.), Current Protocols in Molecular Biology, Greene Pub. Associates and Wiley-Interscience (1988, including all updated versions to date) or Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press (1989). There are a variety of cloning and in vitro amplification methods suitable for constructing recombinant nucleic acids. Methods for producing recombinant antibodies are also known in the art, see, for example, US4816567 or US5530101.

[0597] After isolation, the nucleic acid is inserted operably linked to a promoter in an expression construct or expression vector for further cloning (amplification of the DNA) or for expression in a cell-free system or in cells.

[0598] As used herein, the term "promoter" should be understood in its broadest context and includes a transcriptional regulatory sequence (including a TATA box or initiation element) of a genomic gene, which is necessary for accurate transcription initiation in the presence or absence of additional regulatory elements (e.g., upstream activation sequences, transcription factor binding sites, enhancers, and silencers), which, for example, respond to development and / or external stimuli, or change the expression of nucleic acids in a tissue-specific manner. In the context of the present invention, the term "promoter" is also used to describe a recombinant, synthetic or fusion nucleic acid, or a derivative (operably linked to the nucleic acid) that confers, activates or enhances the expression of a nucleic acid. An exemplary promoter may contain additional copies of one or more specific regulatory elements to further enhance expression and / or change the spatial expression and / or temporal expression of the nucleic acid.

[0599] As used herein, the term "operably linked to" means that a promoter is positioned relative to a nucleic acid such that expression of the nucleic acid is controlled by the promoter.

[0600] There are many vectors that can be used for expression in cells. Vector components generally include, but are not limited to, one or more of the following: a signal sequence, a sequence encoding a protein (e.g., derived from the information provided herein), an enhancer element, a promoter, and a transcription termination sequence. The skilled artisan will appreciate suitable sequences for expressing proteins. 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 virus gD signal).

[0601] Exemplary promoters active in mammalian cells include 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; mixed regulatory elements containing CMV enhancer / beta-actin promoter or immunoglobulin promoter or their active fragments. Examples of mammalian host cell lines that can be used are SV40-transformed monkey kidney CV1 line (COS-7, ATCC CRL 1651); human embryonic kidney cell line (293 or 293 cells, subcloned for growth in suspension culture); baby hamster kidney cells (BHK, ATCC CCL 10); or Chinese hamster ovary cells (CHO).

[0602] Typical promoters suitable for expression in yeast cells (e.g., yeast cells selected from the group consisting of Pichia pastoris, Saccharomyces cerevisiae, and S. pombe) include, but are not limited to, ADH1 promoter, GAL1 promoter, GAL4 promoter, CUP1 promoter, PHO5 promoter, nmt promoter, RPR1 promoter, or TEF1 promoter.

[0603] For the nucleic acid of separation or the expression construct comprising the nucleic acid of separation introduced into the cell to express the method is known to those skilled in the art.The technology for specifying the cell depends on known successful technology.The mode for introducing recombinant DNA into the cell comprises microinjection, DEAE-dextran-mediated transfection, liposome-mediated transfection (such as by using lipofectamine (Gibco, MD, USA) and / or cellfectin (Gibco, MD, USA)), PEG-mediated DNA uptake, electroporation and microparticle bombardment (such as by using tungsten or gold particles (Agracetus Inc., WI, USA) of DNA coating) etc.

[0604] Host cells used to produce proteins can be cultured in a variety of culture media, depending on the cell type used. Commercially available culture media such as Ham's F10 (Sigma), Minimal Essential Medium ((MEM), Sigma), RPMI-1640 (Sigma), and Dulbecco's Modified Eagle's Medium ((DMEM), Sigma) are suitable for culturing mammalian cells. Culture media for culturing other cell types discussed herein are known in the art.

[0605] Protein separation

[0606] Methods for isolating proteins are known in the art and / or described herein.

[0607] When the protein is secreted into the culture medium, the supernatant of such expression system can be concentrated using a commercially available protein concentration filter (e.g., Amicon or Millipore Pellicon ultrafiltration unit). Protease inhibitors (such as PMSF) can be included in any of the aforementioned steps to inhibit proteolysis, and antibiotics can be included to prevent the growth of exogenous contaminants. Alternatively or additionally, the supernatant can be filtered and / or the supernatant can be separated from the cells expressing the protein, e.g., using continuous centrifugation.

[0608] 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 foregoing. These methods are known in the art and are described, for example, in WO 1999 / 57134 or Ed Harlow and David Lane (eds.) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, (1988).

[0609] The skilled artisan will also appreciate that the protein can be modified to include a tag that facilitates purification or detection, for example, a polyhistidine tag (e.g., a hexahistidine tag), or an influenza virus hemagglutinin (HA) tag, or a simian virus 5 (V5) tag, or a FLAG tag, or a glutathione S-transferase (GST) tag. The resulting protein is then purified using methods known in the art, such as affinity purification. For example, a protein containing a hexahistidine tag is purified by contacting a sample containing the protein with nickel-nitrilotriacetic acid (Ni-NTA) that specifically binds to the hexahistidine tag immobilized on a solid or semisolid support, washing the sample to remove unbound protein, and then eluting bound protein. Alternatively or additionally, a ligand or antibody that binds to the tag is used in an affinity purification method.

[0610] Determination of activity

[0611] Binding assay

[0612] 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). This method generally involves labeling the protein and contacting the protein with an immobilized antibody. After washing to remove non-specifically bound proteins, the amount of the marker and the amount of bound protein are detected. Of course, the protein can be immobilized and the antibody can be labeled. A panning assay can also be used. Alternatively or additionally, a surface plasmon resonance assay can be used. The level of binding can also be conveniently determined using a biosensor.

[0613] Affinity determination

[0614] Optionally, the dissociation constant (Kd) or association constant (Ka) or binding constant (Kd) of the antibody to, for example, CD117 or an epitope thereof is determined. D , i.e., Ka / Kd). In one example, the "Kd" or "Kd value" of a compound bound to, for example, CD117 is measured by a radiolabeled or fluorescently labeled CD117 binding assay. The assay equilibrates the antibody with the lowest 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 represents the Kd of the protein.

[0615] According to another example, Kd or Kd value is measured using a surface plasmon resonance assay, for example, BIAcore surface plasmon resonance (BIAcore, Inc., Piscataway, NJ) using immobilized CD117 or a region thereof.

[0616] Determine competitive binding

[0617] The skilled person can see clearly the determination of antibodies for determining the binding of antibodies described herein to competitive inhibition. For example, exemplary antibodies are conjugated to detectable markers (e.g., fluorescent markers or radioactive markers). The labeled antibody and 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 expressing CD117 or a region thereof. The level of the labeled antibody is then determined, and the level is compared with the level determined when the labeled antibody is in contact with CD117, a region or a cell in the absence of protein. If the level of the labeled CSL117 is reduced when the test protein is present compared to when the test protein is not present, it is considered that the test protein competitively inhibits the binding of the antibody to CD117.

[0618] Optionally, the test protein is conjugated to a label different from the antibody. Such an alternative label allows detection of the level of binding of the test protein to CD117 or a region thereof or a cell.

[0619] In another example, before contacting CD117, region or cell with antibody, protein is allowed to bind to CD117 or region thereof (e.g., polypeptide comprising SEQ ID NO: 1) or cell expressing CD117 or region thereof. When protein is present, compared to when protein is not present, the amount of bound antibody is reduced indicating that the protein competitively inhibits the binding of antibody to CD117. Mutual determination can also be performed using labeled protein, and antibody is first allowed to bind to CD117. In this case, when antibody is present, compared to when antibody is not present, the amount of labeled protein bound to CD117 is reduced indicating that the protein competitively inhibits the binding of antibody to CD117.

[0620] Internalization assay

[0621] Assays for evaluating internalization of the antibodies of the present disclosure will be apparent to the skilled artisan and / or described herein. Exemplary assays include anti-AF488 quenching antibody assays and Live cell high-throughput internalization assay.

[0622] In one example, internalization was assessed using an anti-AF488 quenching antibody assay. In brief, cells were incubated with a test antibody pre-complexed with an anti-human IgG Fab fragment labeled with AF488 in the presence or absence of human stem cell factor. After incubation, mean fluorescence intensity (MFI) values ​​were obtained, and the percentage of internalized antibody was calculated by dividing the internalized signal (MFI of samples treated with anti-AF488 quenching antibody) by the total cell binding signal (MFI of unquenched samples) at each time point.

[0623] In another example, internalization uses The results were evaluated by a live cell high-throughput internalization assay. Briefly, TF-1 cells were seeded in 96-well plates pre-coated with 0.001% (v / v) poly-ornithine and allowed to adhere. Test antibodies were pre-complexed with FabFluor-pH Red and added to the cells in the absence and presence of human stem cell factor. In S3 (Sartorius), internalized antibodies were captured immediately and the red fluorescent object area (a measure of FabFluor-labeled internalized antibodies) was analyzed after subtracting any background fluorescent signal.

[0624] In one example, the antibodies of the present disclosure are assayed for anti-AF488 quenching antibody and / or Has slow internalization kinetics in live cell assays.

[0625] Inhibition assay

[0626] In one example, an antibody that binds or specifically binds to a target on endogenous HSC blocks stem cell factor (SCF) binding to CD117 and / or inhibits SCF activation of CD117. For example, the ability of the disclosed antibodies to inhibit human stem cell factor-mediated TF-1 proliferation was evaluated.

[0627] Briefly, TF-1 cells were proliferated and cultured at 2 × 10 4 The cells were plated at a density of 10 cells / well. In the presence of human stem cell factor, the antibodies of the present disclosure were added to each corresponding well. After incubation, inhibition of TF-1 cell proliferation was measured using a commercially available kit (e.g., Vialight Plus kit).

[0628] Determining effector function

[0629] As discussed herein, the antibodies of the present disclosure may have effector function (or enhanced effector function).Methods for assessing effector function (such as ADCC or ADCT activity) are known in the art.

[0630] In one example, using 51 Cr release assay, Europium release assay or 35 S release assays are used to assess the level of ADCC activity. In each of these assays, cells expressing, for example, CD117 are cultured with one or more of the compounds (i.e., anti-CD117 antibodies) for a period of time and under conditions sufficient for the cells to take up the compounds. 35 For S release assay, cells expressing CD117 can be 35 The cells are then cultured with S-labeled methionine and / or cysteine ​​for a time sufficient to allow the labeled amino acids to be incorporated into newly synthesized proteins. The cells are then cultured in the presence or absence of anti-CD117 antibodies and in the presence of immune effector cells (e.g., peripheral blood mononuclear cells (PBMCs) and / or NK cells). 51 Cr, Europium and / or 35 The amount of S, compared with the absence of anti-CD117 antibodies, the change in amount in the presence of anti-CD117 antibodies is very small or no change indicates that the effector function of the protein is reduced, and the increase in amount (or the increase in amount compared with the presence of anti-CD117 antibodies comprising IgG1 Fc regions) indicates that there is effector function or effector function enhancement. Exemplary publications disclosing assays for assessing protein-induced ADCC levels include Hellstrom et al., Proc. Natl Acad. Sci. USA 83: 7059-7063, 1986 and Bruggemann et al., J. Exp. Med. 166: 1351-1361, 1987.

[0631] Other assays for assessing the level of protein-induced ADCC include ACTI for flow cytometry. TM Non-radioactive cytotoxicity assay (Cell Technology, Inc. CA, USA) or CytoTox Non-radioactive cytotoxicity assay (Promega, WI, USA).

[0632] In one example, the level of ADCT activity was assessed by flow cytometry. Briefly, a human CD117 transfected cell line was labeled with a membrane dye DILC18 (1,1"-dioctadecyl-3,3,3",3"-tetramethylindocarbocyanine perchlorate), mixed with freshly isolated peripheral blood neutrophils as effector cells, and incubated with the antibodies of the present disclosure or control antibodies. Subsequently, the cells were incubated with Alexa fluor 647-conjugated anti-CD66b and LIVE / DEAD TMThe cells were stained with a fixable green stain, washed, and fixed with formaldehyde. Cells were acquired on a flow cytometer and live neutrophils were identified by forward and side scatter, followed by live CD66b positive cells. Membrane uptake by neutrophils was measured by the increase in DILC18 mean fluorescence intensity (MFI). DILC18 MFI was normalized to the maximum MFI of each donor neutrophil. In one example, the half maximal effect concentration (EC) expressed in [nM] was determined. 50 ± SD) and the normalized maximum membrane uptake expressed as a percentage of antibody-induced peripheral blood neutrophil phagocytosis (B max ).

[0633] Any of the foregoing assays can be performed with any target as described herein.

[0634] Composition

[0635] In one example, antibodies as described herein can be administered orally, parenterally, by inhalation spray, adsorption, absorption, topically, rectally, nasally, buccally, vaginally, intraventricularly, via implantable reservoirs (dosage formulations containing conventional nontoxic pharmaceutically acceptable carriers), or in any other convenient dosage form. As used herein, the term "parenteral" includes subcutaneous, intravenous, intramuscular, intraperitoneal, intrathecal, intraventricular, intrasternal, intrapolyp and intracranial injection or infusion techniques.

[0636] Methods for preparing antibodies into a form suitable for administration to a subject (e.g., a pharmaceutical composition) are known in the art and include, for example, those described in Remington's Pharmaceutical Sciences (18th ed., Mack Publishing Co., Easton, Pa., 1990) and US Pharmacopeia: National Formulary (Mack Publishing Company, Easton, Pa., 1984).

[0637] The pharmaceutical compositions of the present disclosure are particularly suitable for parenteral administration, such as intravenous administration or administration to the lumen of a body cavity or organ or joint. The composition for administration generally comprises a solution of an antibody dissolved in a pharmaceutically acceptable carrier (e.g., an aqueous carrier). A variety of aqueous carriers can be used, such as buffered saline, etc. The composition may contain pharmaceutically acceptable auxiliary substances required for simulating physiological conditions, such as pH regulators and buffers, toxicity regulators, etc., for example, sodium acetate, sodium chloride, potassium chloride, calcium chloride, sodium lactate, etc. The concentration difference of the antibodies of the present disclosure in these preparations can be very large, and is mainly selected according to the specific mode of administration selected and the needs of the patient, based on the volume of the fluid, viscosity, body weight, etc. Exemplary carriers include water, saline, Ringer's solution, glucose solution, and 5% human serum albumin. Non-aqueous vehicles, such as mixed oils and ethyl oleate, can also be used. Liposomes can also be used as carriers. The vehicle may contain a small amount of additives that enhance isotonicity and chemical stability, for example, buffers and preservatives.

[0638] After formulation, the antibodies of the present disclosure will be administered in a manner compatible with the dosage formulation and in an amount effective for treatment / prevention. The formulations can be conveniently administered in a variety of dosage forms, such as the types of solutions for injection described above, but other pharmaceutically acceptable forms are also contemplated, for example, tablets, pills, capsules or other solids for oral administration, suppositories, vaginal suppositories, nasal solutions or sprays, aerosols, inhalants, liposome forms, etc. Pharmaceutical "slow-release" capsules or compositions can also be used. Sustained-release formulations are generally designed to provide constant drug levels over a long period of time and can be used to deliver antibodies of the present disclosure.

[0639] WO2002 / 080967 describes compositions and methods for administering aerosolized compositions comprising antibodies for treating respiratory disorders, which methods are also suitable for administering compounds according to the methods of the present disclosure.

[0640] Combination therapy

[0641] In one example, an antibody of the present disclosure is administered in combination with an additional conditioning regimen. For example, the subject is receiving or will receive an additional conditioning regimen.

[0642] In one example, the additional conditioning regimen is a non-myeloablative or reduced intensity conditioning regimen.

[0643] As used herein, the terms "nonmyeloablative conditioning" and "reduced intensity conditioning" refer to a conditioning regimen consisting of low-dose chemotherapy and / or low-dose radiation therapy. Nonmyeloablative and reduced intensity conditioning regimens differ in their ability to produce cytopenias.

[0644] In one example, the conditioning regimen of non-myeloablative or reduced intensity includes low-dose chemotherapy. For example, low-dose chemotherapy is fludarabine, cyclophosphamide, busulfan, horse anti-thymocyte globulin, thiopeta, melphalan, alemtuzumab, cladribine, idarubicin, cytarabine, cisplatin, azacitidine, rituximab, etoposide and their combination. In one example, low-dose chemotherapy is busulfan. In another example, low-dose chemotherapy is busulfan, fludarabine and rituximab.

[0645] In one example, the non-myeloablative or reduced intensity conditioning regimen includes low-dose radiation therapy. For example, low-dose whole body irradiation or whole body lymphatic irradiation. In one example, the dose of low-dose whole body irradiation is ≤2 Gray (Gy) or 1 Gy.

[0646] In one example, the additional conditioning regimen is whole body irradiation at a dose of ≤ 2 Gy in the presence or absence of a purine analog.

[0647] In one example, the additional conditioning regimen is fludarabine and cyclophosphamide with or without antithymocyte globulin.

[0648] In one example, the additional conditioning regimen is fludarabine, cytarabine, and idarubicin.

[0649] In one example, the additional conditioning regimen is cladribine and cytarabine.

[0650] In one example, the additional conditioning regimen is whole body lymphoid irradiation and antithymocyte globulin.

[0651] Dosage and administration schedule

[0652] The appropriate dosage of the antibodies of the present disclosure will vary depending on the specific antibody, the condition to be treated, and / or the subject being treated. A skilled physician will be able to determine an appropriate dosage, for example, by starting with a suboptimal dose and gradually modifying the dose to determine an optimal or useful dose. Alternatively, to determine an appropriate dosage for treatment / prevention, data from cell culture assays or animal studies can be used, where an appropriate dosage is within the range of the ED of the active compound with little or no toxicity. 50The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. The therapeutically or prophylactically effective dose can be estimated initially from cell culture assays. The dose can be formulated in animal models to achieve the values ​​determined in cell culture, including the IC 50 (i.e., the concentration or amount of the compound that achieves half-maximal inhibition of symptoms). Such information can be used to more accurately determine useful doses in humans. For example, levels in plasma can be measured by high performance liquid chromatography.

[0653] In some examples, the methods of the present disclosure include administering an effective amount of an antibody described herein.

[0654] The term "effective amount" refers to the amount of the target tissue (e.g., bone marrow) disorder of the transplantation of the subject that is improved when applied to a subject in need of treatment. For example, an effective amount is an amount sufficient to eliminate or reduce or reduce the endogenous HSC population in the subject's body. The amount applied to the subject will depend on the specific characteristics of the disorder treated, the type and stage of the disorder treated, the mode of administration and the characteristics of the subject, such as general health, other diseases, age, sex, genotype and body weight. Those skilled in the art will be able to determine the appropriate dosage based on these and other factors. Therefore, the term should not be interpreted as limiting the disclosure to a specific number, e.g., the weight or amount of protein, on the contrary, the disclosure encompasses any amount of the antibody sufficient to achieve the stated result in the subject.

[0655] In one example, an effective amount of an antibody disclosed herein achieves maximum stem cell depletion. For example, about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 97.5%, 98%, 99%, 99.5% or more of endogenous HSCs are depleted from a target tissue (e.g., bone marrow) of a subject.

[0656] For in vivo administration of the antibodies described herein, normal dosages may vary from about 10 ng / kg body weight of an individual per day to a maximum of about 100 mg / kg body weight of an individual per day or more. For repeated administrations over several days or longer, depending on the severity of the disease or disorder to be treated, treatment may be maintained until the desired symptom suppression is achieved.

[0657] In some instances, the antibody is administered at an initial (or loading) dose of about 1 mg / kg to about 30 mg / kg, such as 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 can then be administered at a lower maintenance dose of about 0.01 mg / kg to about 2 mg / kg, such as about 0.05 mg / kg to about 1 mg / kg, for example, about 0.1 mg / kg to about 1 mg / kg, such as about 0.1 mg / kg or 0.5 mg / kg or 1 mg / kg. The maintenance dose can be administered every 7-30 days, such as every 10-15 days, for example, every 10 or 11 or 12 or 13 or 14 or 15 days.

[0658] In some instances, the antibody is administered at a dosage of about 0.01 mg / kg to about 50 mg / kg, such as about 0.05 mg / kg to about 30 mg / kg, for example, about 0.1 mg / kg to about 20 mg / kg, for example, about 0.1 mg / kg to about 10 mg / kg, such as about 0.1 mg / kg to about 2 mg / kg. For example, the antibody is administered at a dosage of about 0.01 mg / kg to about 5 mg / kg, such as about 0.1 mg / kg to about 2 mg / kg, such as 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 the need for a higher loading dose or a lower maintenance dose). In some examples, multiple doses are administered, e.g., every 7-30 days, such as 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.

[0659] In some examples, at initiation of therapy, 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.

[0660] If the subject does not respond adequately to treatment, multiple doses may be administered within a week. Alternatively or additionally, increased doses may be administered.

[0661] In another example, for subjects who experience adverse effects, the initial (or loading) dose can be divided into administrations on multiple days of the week or on multiple consecutive days.

[0662] Administration of antibodies according to the methods of the present disclosure may be continuous or intermittent, depending, for example, on the physiological condition of the recipient and other factors known to skilled practitioners. Administration of the antibody may be substantially continuous over a preselected period of time, or may be in a series of spaced doses, for example, during or after the development of the condition.

[0663] Reagent test kit

[0664] Another example of the present disclosure provides a kit containing an antibody that can be used in a method of conditioning a subject in need of HCT, as described herein.

[0665] In one example, the kit includes (a) a container comprising an antibody as described herein, optionally in a pharmaceutically acceptable carrier or diluent; and (b) a package insert with instructions for treating a subject in need of HCT.

[0666] In one example, the kit includes (a) a container comprising an antibody as described herein, optionally in a pharmaceutically acceptable carrier or diluent; and (b) a package insert with instructions for reducing, depleting and / or eliminating a cell population in the bone marrow of a subject in need of HCT.

[0667] According to this example of the present disclosure, the package insert is on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, etc. The container can be formed of a variety of materials (such as glass or plastic). The container holds or contains a composition that can effectively condition the 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 pierced by a hypodermic needle). At least one active agent in the composition is a compound that is bound to a target on an endogenous HSC. The label or package insert indicates that the composition can be applied to a subject suitable for treatment, for example, a subject who needs or receives HCT, and provides specific guidance on the dosage and interval of the compound and any other drug. The kit can also include an additional container, which contains a pharmaceutically acceptable dilution buffer, such as antibacterial water for injection (BWFI), phosphate-buffered saline, Ringer's solution and / or glucose solution. The kit can further include other materials required from a commercial and user perspective, including other buffers, diluents, filters, needles and syringes.

[0668] The present disclosure includes the following non-limiting examples.

[0669] Example

[0670] Example 1: Screening of anti-CD117-IgG1 monoclonal antibodies

[0671] In order to identify antibodies for CD117, panning for recombinant human CD117 (recHuCD117) was performed on the internal antibody phage display library. The biotinylated recHuCD117 ECD in the solution was subjected to three rounds of phage display selection, wherein for selection A, selection C and selection D, the antigen concentration remained constant; or for selection B, selection E and selection F, the antigen concentration decreased with each round of panning. These complexes were collected by incubating the phage / HuCD117 complex with streptavidin magnetic beads. After each round of screening, the beads were washed, and the bound phages were amplified and purified to be used as input for the next round of panning. At the end of the panning process, the binding of single phage clones from the 3rd round of output to recHuCD117 ECD and recombinant mouse CD117 ECD (c-Kit protein, mouse, recombinant (His tag) SinoBiologicals) was screened by Fab-phage ELISA. Sequence analysis of clones reactive to human and mouse CD117 revealed a total of 49 positive unique clones.

[0672] Forty-seven HuCD117 positive clones could be reformatted into fully human antibodies (IgG1 format).

[0673] Example 2: Anti-CD117-IgG1 antibody binds to human, mouse and cynomolgus monkey CD117

[0674] To evaluate the binding of anti-CD117-IgG1 antibodies to CD117 expressed on the cell surface, TF-1 or HEK293FS stably expressing human, mouse or cynomolgus CD117 were resuspended in Dulbecco's PBS (SigmaAldrich, D8537) containing 1% FCS and incubated with titrated anti-CD117-IgG1 antibodies (5.7pM-12.5nM for TF-1 cells; 6.1pM-25nM for HEK293FS). After incubation on ice for one hour, the cells were washed once and then fixed.

[0675] The primary anti-CD117-IgG1 antibody was detected by adding a secondary anti-human IgG Fab fragment conjugated to Alexa-Fluor 488 (Jacksonlabs, 109-547-008), incubated on ice for one hour, and then analyzed on an LSRFortessaTM cell analyzer (BD Biosciences) for their cell binding fluorescence. Flowjov10 was used to obtain the mean fluorescence intensity (MFI) and analyzed using GraphPad Prism. The total binding curve of TF-1 cells and the specific binding curve of HEK293FS expressing CD117 (generated by subtracting nonspecific binding to parental cells) were plotted. The EC50 value of each anti-CD117-IgG1 antibody tested was determined using a nonlinear regression model.

[0676] Of the 47 anti-CD117-IgG1 antibodies generated, 28 bound to cell surface CD117 on TF-1 cells, EC 50 <25nM( Figure 1 All antibodies bound to human and cynomolgus macaque CD117 when expressed on the surface of HEK293FS cells, with 4 antibodies cross-reacting with mouse CD117 when expressed on the surface of HEK293FS cells ( Figure 1 CH).

[0677] Example 3: Anti-CD117-IgG1 antibody inhibits human stem cell factor-mediated TF-1 cell proliferation

[0678] To evaluate antibodies with potential inhibitory activity, inhibition of human stem cell factor (SCF)-mediated proliferation of TF-1 cells was assessed.

[0679] TF-1 cells were propagated in RPMI complete medium (RPMI 1640 (Sigma #R0883), 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) at 37°C, 5% CO2. Cells were pelleted by centrifugation (1200 rpm, 5 minutes) and resuspended in 5 ml of RPMI complete medium, counted using a hemocytometer, and prepared to a final cell density of 2×105 cells / ml. Cells (100 μl) were then plated in 96-well plates to achieve a final cell density of 2×104 cells / well. Antibody clones were prepared at 4× concentrations (4 μg / ml, 26.68 nM) in RPMI complete medium and serially diluted 3 times to obtain 12 points. The titrated antibody was then added to each corresponding well (50 μl) to obtain a final starting concentration of 1 μg / ml (6.67 nM). Human stem cell factor (hSCF, Peprotech, #300-07) was prepared at 4×EC50 concentrations (328 pM) in RPMI complete medium and added to all wells (50 μl) to achieve a final concentration of 82 pM / well. The plate was then placed in an incubator and cultured at 37°C 5% CO2 for 72 hours. Endpoint measurements were performed using a Vialight Plus kit (Lonza, #LT07-121) after 72 hours of incubation, according to the manufacturer's instructions.

[0680] Of the 47 anti-CD117-IgG1 antibodies generated, 13 inhibited hSCF-induced proliferation of TF1 cells ( Figure 2 ).

[0681] Example 4: Internalization of anti-CD117-IgG1 antibody

[0682] Anti-AF488 quenching antibody assay

[0683] In order to evaluate the internalization of anti-CD117-IgG1 antibodies, TF-1 cells were used to establish an assay based on the quenching of cell surface binding fluorescence using anti-AF488 antibodies. In short, in the presence or absence of 56nM human stem cell factor (Genscript, Z02692-1), cells were incubated with 5nM anti-CD117-IgG1 antibodies (pre-compounded with anti-human IgG Fab fragments (Jackson labs, 109-547-008) labeled with AF488) at a molar ratio of 1:3, and incubated at 37°C for 0, 15, 30, 60 and 120 minutes. Two samples were processed at each time point: one sample was resuspended in PBS containing 1% FCS, and the other sample was resuspended in PBS containing 1% FCS and 20μg / mL anti-AF488 quenching IgG (Thermo-Fisher, A-11094). The cells were incubated on ice for 30 minutes and then analyzed with a BD LSRFortessa flow cytometer. Mean fluorescence intensity (MFI) values ​​were acquired using Flowjo v10, and the percentage of internalized antibody was calculated by dividing the internalized signal (MFI of samples treated with anti-AF488 quenching antibody) by the total cell-bound signal (MFI of unquenched samples) at each time point.

[0684] like Figure 3 As shown in A, the selected anti-CD117-IgG1 antibodies have slow internalization kinetics.

[0685] Live cell high-throughput internalization assay

[0686] To compare the internalization of anti-CD117-IgG1 antibody, TF-1 cells were used and the manufacturer's instructions were followed. Live cell analysis and pH-sensitive dye-conjugated antibody fragments ( Human FabFluor-pHRed antibody labeling reagent, Sartoriu, 4722). Briefly, TF-1 cells were seeded in wells of a 96-well plate pre-coated with 0.001% (V / V) polyornithine (Sigma-Aldrich, A004M) and allowed to adhere for 1 hour at 37°C. Anti-CD117 antibodies pre-complexed with FabFluor-pH Red were added to the cells at a molar ratio of 1:3 (serial dilutions from 25nM to 3.125nM). The experiments were performed in the absence and presence of 56nM human stem cell factor. Images of internalized antibodies were captured immediately every 10 minutes for 6 hours using a 20× objective in 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.

[0687] Similar to the anti-AF488 quenching antibody assay, the selected anti-CD117-IgG1 antibody was Slow internalization kinetics in live cell assays ( Figure 3 B).

[0688] Example 5: Anti-CD117-IgG antibody-mediated TF-1 cell activation is not possible in the absence of human SCF

[0689] The ability of anti-CD117-IgG1 antibody to activate TF-1 proliferation in the absence of human stem cell factor was evaluated.

[0690] TF-1 cells were propagated as described above. The cells were pelleted by centrifugation (1200 rpm, 5 min) and resuspended in 5 ml of RPMI complete medium, counted using a hemocytometer, and prepared into 2 × 10 5 The cells (100 μl) were then plated in 96-well plates to achieve a final cell density of 2×10 4 The final cell density of cells / well was 4 cells / well. The antibody was prepared at a 4× concentration (400 μg / ml, 2668 nM) in RPMI complete medium and serially diluted 3 times to obtain 12 points and added to each corresponding well (50 μl) to obtain a final starting concentration of 100 μg / ml (667 nM). To prevent initial cell death, a low level of hGM-CSF (R&D Systems, #215-GM) was prepared at a 4× concentration (0.04 ng / ml) in RPMI complete medium and added to all wells (100 μl) to obtain a final concentration of 0.01 ng / ml. The plate was then placed in an incubator and cultured at 37°C 5% CO2 for 48 hours. Endpoint measurements were performed using a Vialight Plus kit (Lonza, #LT07-121) after incubation according to the manufacturer's instructions.

[0691] like Figure 4 As shown, in the absence of stem cell factor, 47 anti-CD117-IgG1 antibodies were unable to activate the CD117 receptor and induce TF-1 cell proliferation.

[0692] Example 6: Anti-CD117 Antibody and Soluble N-Terminus (HuCD117 1-307) and C-terminus (HuCD117 308-524 )

[0693] All binding analyses were performed using Biacore 4000. Experiments were performed at pH 7.3, 37°C, and 30 μL / min flow rates. Surface capture of human anti-CD117 antibodies was performed using protein G, which was directly fixed to the carboxymethyl dextran surface of a CM5 sensor chip at pH 4.5 using standard NHS / EDC chemistry to approximately 1,500 RU. The fixed protein G surface was preconditioned with ten injections of human polyclonal IgG (Privigen 60s, 10 μg / mL), with regeneration cycles after each injection using 10 mM glycine pH 1.6.

[0694] A total of 52 anti-CD117 antibodies (2 μg / mL) were used as soluble 8×his-tagged N-terminus of human CD117 receptor (HuCD117 1-307 ) and C-terminus (HuCD117 308-524 ) fragments were tested (N=1). Of these, 47 candidates were reformatted into an IgG4 backbone. Four antibodies (huAb249, huAb85, huCK6, and huhzSR1) were reformatted into an IgG1 backbone and included as a benchmark control. HuhzSR1 was also reformatted into an IgG4 backbone. BM4 and Privigen were used as negative controls.

[0695] HuCD117 fragments were prepared in three-fold dilutions of 25nM, 75nM, and 225nM. Anti-CD117 antibodies huAb249, huAb85, huCK6, and huhzSR1 were used as positive controls. Association and dissociation were monitored for 120 seconds and 180 seconds. No significant differences were observed for huhzSR1 antibodies prepared on an IgG1 backbone or an IgG4 backbone. Anti-CD117 antibodies only bind to the N-terminal domain or the C-terminal domain, not both at the same time. Positive binding reactions to the soluble domain are indicated in green, while negative reactions are indicated in white ( Figure 5 A). Approximate binding affinities were obtained from doubly referenced sensorgrams using reference surface and blank buffer injection data collected in each experiment. Rate constants and binding affinities were calculated using a 1:1 kinetic model with local Rmax and zero refractive index (RI=0).

[0696] 48 anti-CD117 antibodies bind to either domain but not both domains simultaneously ( Figure 5A). The N-terminal domain bound 23 anti-CD117 antibodies with affinities ranging from 8nM (hu3A7) to 1.5μM (hu3A12), while the C-terminal domain bound the remaining 20 anti-CD117 antibodies with affinities ranging from 12nM (hu4A8) to 16μM (hu3A2). The positive control anti-CD117 antibodies huAb249, huAb85, huCK6, and huhzSR1 only bound to the N-terminal domain. Four antibodies (hu3A8, hu3B9, hu4A5, and hu4B4) did not bind to any of the CD117 domains, indicating that their epitopes are located at the junction of the N-terminal and C-terminal regions. No reaction was detected with either BM4 (negative control) or Privigen (polyclonal human IgG). The binding affinity of the antibody panels to each domain is shown in Figure 2. Figure 5 The overall distribution of binding affinities is shown in A. Figure 5 As shown in B and C.

[0697] Based on cell-based activity and cross-reactivity, four antibodies were shortlisted for further study. Of these, hu3B3 (9 nM), hu3C2 (14 nM), and hu4A2 (49 nM) bind to the N-terminal domain of CD117, while hu3B2 (191 nM) binds to the C-terminal domain.

[0698] Example 7: Comparison of anti-CD117 antibodies prepared on IgG1, IgG4 or IgA2 backbones

[0699] All binding analyses were performed using Biacore 4000. The experiment was performed at pH 7.3, 37°C and 30 μL / min flow rate. Human anti-CD117 antibodies were surface captured using polyclonal goat anti-human IgG or IgA antibodies, which were directly fixed to the carboxymethyl dextran surface of a CM5 sensor chip at pH 5 using standard NHS / EDC chemistry to approximately 13,000 RU. The fixed antibody surface was preconditioned using ten injections of human polyclonal IgG (Privigen 60s, 10 μg / mL), with 100 mM H3PO4 regeneration cycles after each injection.

[0700] A total of 18 anti-CD117 antibodies (2 μg / mL) were tested as capture ligands against four soluble mammalian CD117 receptor variants: the N-terminal domain of human CD117 (HuCD117 1-308 ), full-length human CD117 (HuCD117 1-524 ), cynomolgus macaque CD117 (cynoCD117 1-520 ) and mouse CD117 (MuCD117 1-527These 18 antibodies correspond to four parental mAbs (hu3B2, hu3B3, hu3C2, and hu4Aa) and four control antibodies (huCK6, huAb249, huAb85, and hzSR1), which were prepared on IgG1 or IgG4 and IgA2 backbones.

[0701] Antibodies were captured at active spots (1 and 5) of each flow cell for 60 seconds to approximately 2,000 RU, while interior spots (2 and 4) were left empty and used for reference subtraction. The association and dissociation phases were monitored for 120 and 180 seconds, respectively.

[0702] CD117 protein was prepared with two-fold dilution ranging from 0.8nM to 200nM. Anti-CD117 antibodies huAb249, huAb85, huCK6 and huhzSR1 were used as positive controls. BM4 was prepared in IgG and IgA2 forms and used as negative controls. Using the reference surface and blank buffer injection data collected in each experiment, the binding affinity was calculated from the sensorgram of the double reference. The 1:1 kinetic model with local Rmax and zero refractive index (RI=0) was used to calculate rate constants and binding affinity.

[0703] In brief, human anti-CD117 antibodies bind to the N-terminal domain of CD117 with approximately 2-fold higher affinity than the full-length protein. Anti-CD117 antibodies bind to human and cynomolgus macaque isoforms of CD117 with comparable affinities, which is consistent given the high similarity between the two receptors.

[0704] The total binding affinity (K) of these antibodies to the full-length human and cynomolgus macaque receptors D ) can be expressed as Hu3B3 (2-5nM) <hu3C2(10-30nM)<hu4A2(~3-40nM)<hu3B2(35-59nM)( Figure 6 Antibodies produced on an IgA2 backbone showed increased binding affinity to their antigens compared to antibodies produced on IgG1 or IgG4. Hu4A2 showed the greatest increase in affinity (approximately 2-fold increase relative to huCD117 and approximately 10-fold increase relative to cynoCD117).

[0705] The binding affinity of these antibodies to the murine isoform of CD117 could not be determined. 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 to human and cynomolgus macaque receptors with low nanomolar affinity (Table 1).

[0706] Table 1: Soluble human, cynomolgus monkey and mouse CD117 and human IgG1 / IgG4 or human IgA2 (hLhA2 P221R ) The binding affinity (K D ).

[0707]

[0708]

[0709] Binding values ​​were calculated from sensorgram data fitted to a 1:1 binding model. Values ​​shown in nanomolar are the average of at least two experimental replicates. WB: weak binding; NB: no binding.

[0710] Example 8: In vitro antibody-dependent cellular cytotoxicity (ADCT) assay of exemplary candidates

[0711] The IgA2-anti-CD117 antibody phagocytic activity of the newly generated clones 3B2, 3B3, 3C2, 4A2, Ab249, and Ab85 was determined by flow cytometry and compared with previously published clones SR1 and CK6. Briefly, the human CD117-transfected 293-target cell line was labeled with the membrane dye DILC18 (1,1"-dioctadecyl-3,3,3",3"-tetramethylindocarbocyanine perchlorate, Thermo Fisher), mixed 1:10 with freshly isolated peripheral blood neutrophils as effector cells, and incubated with human IgA2 anti-CD117 antibody (0.02-100nM) or control antibody (100nM) in a total volume of 150μL for 4 hours at 37°C, 5% CO2. Subsequently, the cells were incubated with Alexa fluor 647-conjugated anti-CD66b and LIVE / DEAD TM Cells were stained with fixable green stain (Invitrogen), washed, and fixed with formaldehyde (BD Cytofix). Cells were acquired on a Fortessa and live neutrophils were identified by forward and side scatter, followed by live CD66b-positive cells. Neutrophil membrane uptake was measured on a YG586-15 detector by the increase in DILC18 mean fluorescence intensity (MFI). DILC18 MFI was normalized to the maximum MFI of each donor neutrophil ( Figure 7 A).

[0712] The half-maximal effect concentration (EC) is expressed in [nM] 50 ± SD) and the normalized maximum membrane uptake expressed as a percentage of peripheral blood neutrophil phagocytosis induced by IgA2 anti-CD117 antibody from n = 5 donors (B max) are shown in Table 1 and Figures B and C. EC50 and normalized Bmax (%) were calculated using Prism 8 Graphphad software using a 4-parameter logistic curve based on the experiment shown in Graph 7.1.

[0713] Table 2: ECs generated by phagocytosis of peripheral blood neutrophils induced by anti-CD117-IgA2 antibody 50 and B max

[0714]

[0715] Example 9: Modification of the hinge region of anti-CD117-IgG1 antibody

[0716] Two IgA2 candidates were prepared using an extended IgA2 / IgG3 hinge region: antibody 3C2 (unmodified CDRs, applicable CDRs are SEQ ID Nos. 42-47) and SR1 (a commercial antibody as a control).

[0717] The IgG3 hinge region is inserted after the first proline of the IgA2 hinge (Senior et al., 2000 and Woof & Kerr, 2006).

[0718] Two forms of extended hinge regions were generated (see Table 3). Form 1 (V1) has a 5× proline motif in the heavy chain, where the first proline comes from the lower hinge and the other 4 prolines come from the IgA2 sequence, and form 2 (V2) has a 4× proline motif in the heavy chain. For both forms, the light chain sequence remains the same.

[0719] Table 3: Annotated IgA2 / IgG3 extended hinge version 1 (V1) and version 2 (V2)

[0720]

[0721] *R Corresponding to the stabilizing P221R mutation

[0722] Table 4: Sequence

[0723]

[0724]

[0725]

[0726]

[0727]

[0728]

[0729]

[0730]

[0731]

[0732]

[0733]

[0734]

[0735]

[0736]

[0737]

[0738]

[0739]

[0740]

[0741]

[0742]

[0743]

[0744]

[0745]

[0746]

[0747]

[0748]

[0749]

[0750]

[0751]

[0752]

[0753]

[0754]

[0755]

[0756]

[0757]

Claims

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

2. A method for reducing, depleting and / or eliminating a cell population 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 to or specifically binds to a target on endogenous hematopoietic stem cells (HSCs) in the subject, wherein the antibody mediates antibody-dependent cellular phagocytosis (ADCT).

3. The method of claim 1 or 2, wherein the antibody comprises an IgA2 heavy chain; and a λ light chain or a κ light chain.

4. The method of claim 3, wherein the IgA2 heavy chain comprises one or more modifications selected from the group consisting of: (i) N to G mutation at position 166 according to the myeloma IgA1 protein (Bur) scheme; (ii) P to R mutation at position 221 according to the myeloma IgA1 protein (Bur) scheme; (iii) C to S mutation at position 311 according to the myeloma IgA1 protein (Bur) scheme; (iv) NIT to TLS mutation at positions 337 to 339 according to the myeloma IgA1 protein (Bur) scheme; (v) deletion of the C residue at position 472 according to the myeloma IgA1 protein (Bur) scheme; and (vi) Deletion of the Y residue at position 473 according to the myeloma IgA1 protein (Bur) scheme.

5. The method of claim 3 or 4, wherein the IgA2 heavy chain comprises the sequence shown in SEQ ID NO: 33 or SEQ ID NO: 34 or SEQ ID NO:

66.

6. The method of any one of claims 1 to 5, wherein the target on the endogenous HSC is selected from the group consisting of CD2, CD5, CD7, CD11a, CDwl2, CD13, CD15, CD18, CD19, CD21, CD22, CD29, CD30, CD33, CD34, CD36, CD38, CD40, CD41, CD42a, CD42b, CD42c, CD42d, CD43, CD45, CD45RA, CD45RB, CD45RC, CD 45RO, CD48, CD49b, CD49d (VLA-4), CD49e, CD49f (VLA-6), CD50, CD51, CD53, CD55, CD58, CD64a, CD68, CD71, CD72, CD73, C D81, CD82, CD84, CD85A, CD85K, CD90, CD97, CD99, CD104, CD105, CD109, CD110, CD111, CD112, CD114, CD115, CD117 (c-kit ), CD123, CD124, CD126, CD127, CD130, CD131, CD133, CD134, CD135, CD137, CD138, CD151, CD157, CD162, CD164, CD166, CD 168. CD172a, CD173, CD174, CD175, CD175s, CD176, CD183, CD184(CXCR4), CD191, CD200, CD201, CD205, CD217, CD220, CD2 21. 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.

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

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

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

10. The method of claim 9, wherein the anti-CD117 antibody: (i) With a K of 20 nM or less D Binds to the soluble N-terminus of human CD117; and / or (ii) with a K of 15 nM or less D Bind to the C-terminus of human CD117; and / or (iii) with a K of 60 nM or less D Binds full-length human CD117.

11. The method of claim 9 or 10, wherein the anti-CD117 antibody is expressed at an IC of at least 1 nM. 50 Inhibits SCF-mediated proliferation of TF-1 cells expressing CD117.

12. The method of any one of claims 9 to 11, wherein the anti-CD117 antibody has an EC of 25 nM or less. 50 Binds to TF-1 cells expressing CD117.

13. The method of any one of claims 9 to 12, wherein the anti-CD117 antibody is expressed at a normalized maximum membrane uptake (MBI) of at least 50% as measured by the mean fluorescence intensity (MFI) of DILC18 on neutrophils. max ) to mediate ADCT.

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) comprising a heavy chain variable region (V H );And a light chain variable region (V L ) (ii) comprising a V comprising the sequence shown in SEQ ID NO: 7 H ; and V comprising the sequence shown in SEQ ID NO: 10 L Antibodies (iii) comprising a V comprising the sequence shown in SEQ ID NO: 13 H and V comprising the sequence shown in SEQ ID NO: 16L Antibodies (iv) comprising a V comprising the sequence shown in SEQ ID NO: 19 H and V comprising the sequence shown in SEQ ID NO: 22 L Antibodies to (v) comprising a V comprising the sequence shown in SEQ ID NO: 25 H and V comprising the sequence shown in SEQ ID NO: 28 L of antibodies.

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

16. The method of any one of claims 9 to 15, wherein the anti-CD117 antibody comprises: (i)V H , which includes a V comprising the sequence shown in SEQ ID NO:7 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 10 L The three CDRs of (ii) V H , which includes a V comprising the sequence shown in SEQ ID NO: 13 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 16 L The three CDRs of (iii)V H , which includes a V comprising the sequence shown in SEQ ID NO: 19 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 22 L three CDRs of (iv)V H , which includes a V comprising the sequence shown in SEQ ID NO: 25 H The three CDRs of V L , which includes a V comprising the sequence shown in SEQ ID NO: 28 L three CDRs of (v)V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:42, a CDR2 comprising the sequence shown in SEQ ID NO:43, and a CDR3 comprising the sequence shown in SEQ ID NO:44; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:45, a CDR2 comprising the sequence shown in SEQ ID NO:46, and a CDR3 comprising the sequence shown in SEQ ID NO:47; or (vi)V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:48, a CDR2 comprising the sequence shown in SEQ ID NO:49, and a CDR3 comprising the sequence shown in SEQ ID NO:50; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:51, a CDR2 comprising the sequence shown in SEQ ID NO:52, and a CDR3 comprising the sequence shown in SEQ ID NO:53; or (vii) V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:54, a CDR2 comprising the sequence shown in SEQ ID NO:55, and a CDR3 comprising the sequence shown in SEQ ID NO:56; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:57, a CDR2 comprising the sequence shown in SEQ ID NO:58, and a CDR3 comprising the sequence shown in SEQ ID NO:59; or (viii)V H , which includes a CDR1 comprising the sequence shown in SEQ ID NO:60, a CDR2 comprising the sequence shown in SEQ ID NO:61, and a CDR3 comprising the sequence shown in SEQ ID NO:62; and V L , which includes a CDR1 comprising the sequence shown in SEQ ID NO:63, a CDR2 comprising the sequence shown in SEQ ID NO:64, and a CDR3 comprising the sequence shown in SEQ ID NO:

65.

17. The method of any one of claims 9 to 16, wherein the anti-CD117 antibody comprises: (i)V H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10; (ii) V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16; (iii)V H , which comprises the sequence shown in SEQ ID NO: 19; and V L , which comprises the sequence shown in SEQ ID NO:22; or (iv)V H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:

28.

18. The method of any one of claims 9 to 17, wherein the anti-CD117 antibody comprises: (i) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 7 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 10 L ; (ii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 13 H ; and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 16 L ; (iii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 19 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 22 L ;or (iv) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 25 H and a kappa light chain comprising a V comprising the sequence shown in SEQ ID NO: 28 L .

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

109.

20. The method of any one of claims 1 to 19, wherein the subject has cancer, a hemoglobinopathy disorder, a myelodysplastic disorder, a primary immunodeficiency (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 received, is receiving, or will receive an additional conditioning regimen.

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

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

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

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

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

27. An anti-CD117 antibody, wherein the antibody comprises: (i)V H , which comprises the sequence shown in SEQ ID NO:7; and V L , which comprises the sequence shown in SEQ ID NO:10; (ii) V H , which comprises the sequence shown in SEQ ID NO: 13; and V L , which comprises the sequence shown in SEQ ID NO:16; (iii)V H , which comprises the sequence shown in SEQ ID NO: 19; and V L , which comprises the sequence shown in SEQ ID NO:22; or (iv)V H , which comprises the sequence shown in SEQ ID NO:25; and V L , which comprises the sequence shown in SEQ ID NO:

28.

28. An anti-CD117 antibody, wherein the antibody comprises: (i) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 7 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 10 L ; (ii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 13 H ; and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 16 L ; (iii) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 19 H and a lambda light chain comprising a V comprising the sequence shown in SEQ ID NO: 22 L ;or (iv) an IgA2 heavy chain comprising a V comprising the sequence shown in SEQ ID NO: 25 H and a kappa light chain comprising a V comprising the sequence shown in SEQ ID NO: 28 L .

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

109.

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

110.

31. A pharmaceutical composition comprising the anti-CD117 according to any one of claims 27 to 30; and a pharmaceutically acceptable carrier.

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

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

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

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

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

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

38. 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 phagocytosis (ADCT).

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

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

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

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

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

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

45. The method of claim 44, wherein the modified hinge region comprises a chimeric IgA2 / IgG3 hinge region.

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