Anti-GPRC5D antibody and its applications

Abstract

The present invention provides an anti-G protein-coupled receptor family C group 5 member D (GPRC5D) antibody or a fragment thereof, further provides an application of the antibody or a fragment thereof as an active ingredient for treating tumors or cancer, and further provides a bispecific antibody against GPRC5D and CD3, comprising the antibody or a fragment thereof.

Description

[Technical field]

[0001] CROSS-CIRCUMSTANCES OF RELATED APPLICATIONS This application claims priority to a Chinese patent application filed on December 31, 2021, bearing application number CN202111663745.2, the entire contents of which are incorporated herein by reference. The present invention belongs to the field of biomedicine and relates to a novel anti-GPRC5D antibody or a functional fragment thereof. The present invention further relates to applications of the antibody or the functional fragment thereof. [Background technology]

[0002] G protein-coupled receptor family C group 5 member D (GPRC5D) is a retinoic acid-induced 40 kDa protein with seven transmembrane segments and one short N-terminal extracellular domain, and is expressed in keratinocytes, pancreas, kidney, small intestine, spleen, and testis. In March 2019, a research paper on GPRC5D CAR-T targeting multiple myeloma was published in the journal Science Translational Medicine, which initially demonstrated the potential of GPRC5D as a new target for the treatment of multiple myeloma. Research on tissue expression profiles found that GPRC5D was specifically and highly expressed in plasma cells of multiple myeloma. It was also proposed that diseases related to GPRC5D include chromosome 13Q14 deletion syndrome. Given the prominent role of GPRC5D in diseases including multiple myeloma, there is a need for more antibodies that recognize GPRC5D. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides an anti-G protein-coupled receptor family C group 5 member D (GPRC5D) antibody or a fragment thereof, and uses of the antibody or a fragment thereof. Here, the present invention further provides a bispecific antibody against GPRC5D and CD3, which is the antibody or a fragment thereof. The present invention provides the following: According to one aspect, the present invention provides an antibody or a fragment thereof capable of specifically binding to GPRC5D, in particular human GPRC5D. Specifically, the antibody or fragment thereof provided by the present invention comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) comprise a combination of CDRs (complementary determining regions) (HCDR-1, HCDR-2, HCDR-3; LCDR-1, LCDR-2, LCDR-3) selected from the following: (1) HCDR-1 including the amino acid sequence (SDYAWN) shown in SEQ ID NO: 28, HCDR-2 including the amino acid sequence (YISYSGSATYNPSLKS) shown in SEQ ID NO: 29, and HCDR-3 including the amino acid sequence (GGIAGRGRWGAMDY) shown in SEQ ID NO: 30; and LCDR-1 including the amino acid sequence (KASQNVGTNVA) shown in SEQ ID NO: 31, LCDR-2 including the amino acid sequence (SASYRDS) shown in SEQ ID NO: 32, and LCDR-3 including the amino acid sequence (QQYKSYPLT) shown in SEQ ID NO: 33; (2) HCDR-1 including the amino acid sequence (SDYAWN) shown in SEQ ID NO: 28, HCDR-2 including the amino acid sequence (YISYSGSATYSPSLKS) shown in SEQ ID NO: 34, and HCDR-3 including the amino acid sequence (GGIAGRGRWGAMDY) shown in SEQ ID NO: 30; and LCDR-1 including the amino acid sequence (KASQNVGTNVA) shown in SEQ ID NO: 31, LCDR-2 including the amino acid sequence (SASYRDS) shown in SEQ ID NO: 32, and LCDR-3 including the amino acid sequence (QQYKSYPLT) shown in SEQ ID NO: 33; (3) HCDR-1 containing the amino acid sequence (SYTIQ) shown in SEQ ID NO: 35, HCDR-2 containing the amino acid sequence (YIIPSSGYTNYNQKFKD) shown in SEQ ID NO: 36, and HCDR-3 containing the amino acid sequence (NYGNWGFTY) shown in SEQ ID NO: 37; and LCDR-1 containing the amino acid sequence (KASQNVGSAVT) shown in SEQ ID NO: 38, LCDR-2 containing the amino acid sequence (SASNRYT) shown in SEQ ID NO: 39, and LCDR-3 containing the amino acid sequence (QQYSNYPLT) shown in SEQ ID NO: 40; (4) HCDR-1 comprising the amino acid sequence (YYVMH) shown in SEQ ID NO: 41, HCDR-2 comprising the amino acid sequence (YINPYNDGTKYNEKFKG) shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence (GGVRRYFDY) shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence (RASQDIGSNLN) shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence (ATSSLDS) shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence (LQYATFPYT) shown in SEQ ID NO: 46; (5) HCDR-1 comprising the amino acid sequence (YYVIH) shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence (YINPYNDGTKYNEKFKG) shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence (GGVRRYFDY) shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence (RASQDIGSNLN) shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence (ATSSLDS) shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence (LQYATFPYT) shown in SEQ ID NO: 46; and (6) HCDR-1 comprising the amino acid sequence (YYVIH) shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence (YINPYNAGTKYNEKFKG) shown in SEQ ID NO: 48, HCDR-3 comprising the amino acid sequence (GGVRRYFDY) shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence (RASQDIGSNLN) shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence (ATSSLDS) shown in SEQ ID NO: 45, and LCDR-3 comprising the amino acid sequence (LQYATFPYT) shown in SEQ ID NO: 46. Any combination of light and heavy chain CDRs provided in the context of the present invention is derived from an antibody or a fragment thereof of the present invention, and a person skilled in the art can generally determine the CDRs contained therein based on the amino acid sequence of the variable region contained in a given antibody or a fragment thereof. For example, according to a specific embodiment of the present invention, the CDRs in the amino acid sequence of the variable region are defined using the KABAT definition method. In the antibody or fragment thereof provided by the present invention, preferably, the heavy chain variable region comprises a sequence selected from the amino acid sequence set forth in SEQ ID NO:5, SEQ ID NO:13, SEQ ID NO:7, SEQ ID NO:15, SEQ ID NO:9, SEQ ID NO:17, SEQ ID NO:11 or SEQ ID NO:19, or an amino acid sequence having at least 75% identity to said amino acid sequence; and / or the light chain variable region comprises a sequence selected from the amino acid sequence set forth in SEQ ID NO:6, SEQ ID NO:14, SEQ ID NO:8, SEQ ID NO:16, SEQ ID NO:10, SEQ ID NO:18, SEQ ID NO:12 or SEQ ID NO:20, or an amino acid sequence having at least 75% identity to said amino acid sequence. More preferably, the heavy chain variable region and the light chain variable region comprised in the antibody or fragment thereof comprise a combination of sequences selected from the following: (1) an amino acid sequence shown in SEQ ID NO:5 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:5; and an amino acid sequence shown in SEQ ID NO:6 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:6; (2) an amino acid sequence shown in SEQ ID NO: 13 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 13; and an amino acid sequence shown in SEQ ID NO: 14 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 14; (3) an amino acid sequence shown in SEQ ID NO: 7 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 7; and an amino acid sequence shown in SEQ ID NO: 8 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 8; (4) an amino acid sequence shown in SEQ ID NO: 15 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 15; and an amino acid sequence shown in SEQ ID NO: 16 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 16; (5) an amino acid sequence shown in SEQ ID NO: 9 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 9; and an amino acid sequence shown in SEQ ID NO: 10 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 10; (6) an amino acid sequence shown in SEQ ID NO: 17 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 17; and an amino acid sequence shown in SEQ ID NO: 18 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 18; (7) an amino acid sequence shown in SEQ ID NO: 11 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 11; and an amino acid sequence shown in SEQ ID NO: 12 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 12; and (8) An amino acid sequence shown in SEQ ID NO: 19 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO: 19; and an amino acid sequence shown in SEQ ID NO: 20 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO: 20. In the context of the present invention, "at least 75% identity" refers to any percentage between 75% and 100%, such as 75%, 80%, 85%, 90%, or even 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity. In particular, the antibody or fragment thereof of the present invention comprises at least a heavy chain variable region and a light chain variable region, both of which comprise the above-mentioned CDRs and framework regions at intervals, and the arrangement of each domain is FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4. Furthermore, optionally, the difference of up to 25% in the amino acid sequence according to the "at least 75% identity" may be present in any framework region in the heavy chain variable region or the light chain variable region, or may be present in any domain or sequence other than the heavy chain variable region and the light chain variable region in the antibody or fragment thereof of the present invention. The difference may be caused by deletion, addition or substitution of amino acids at any position. For antigens, the antibody or fragment thereof of the present invention is an anti-GPRC5D antibody or fragment thereof; preferably, the antibody is in any form, such as a mouse antibody, a rabbit antibody, a monoclonal antibody, a chimeric antibody, a partially or fully humanized antibody, or the fragment is a half antibody or an antigen-binding fragment of an antibody or half antibody, such as scFv, BsFv, dsFv, (dsFv)2, Fab, Fab, F(ab')2 or Fv; more preferably, the antibody is an IgG. According to a specific embodiment of the present invention, the present invention provides an isolated and structurally characterized human antibody, such as a human monoclonal antibody, that specifically binds to GPRC5D (e.g., human GPRC5D). The antibodies or fragments thereof provided by the present invention comprise, in addition to the variable regions, a constant region, e.g. a human or murine constant region, preferably a human or murine heavy chain constant region (CH) and / or a light chain constant region (CL); preferably, said antibodies or fragments thereof comprise a heavy chain and a light chain; more preferably, said antibodies or fragments thereof comprise an IgG, IgA, IgM, IgD or IgE heavy chain constant region and / or a κ- or λ-type light chain constant region. According to a specific embodiment of the invention, the antibody is a monoclonal antibody, preferably a murine, chimeric or humanized monoclonal antibody. Preferably, the heavy chain constant region of the monoclonal antibody is of IgG1 or IgG4 subtype, and the light chain constant region is of κ type. Preferably, the heavy chain constant region of the monoclonal antibody comprises the amino acid sequence shown in SEQ ID NO: 23 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 23; and the light chain constant region of the monoclonal antibody comprises the amino acid sequence shown in SEQ ID NO: 24 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 24. According to a specific embodiment of the present invention, the anti-human GPRC5D antibody of the present invention is a monoclonal antibody. Preferably, the anti-human GPRC5D antibody provided by the present invention is an immunoglobulin, for example, the immunoglobulin type is human IgA, IgD, IgE, IgG or IgM. More preferably, the antibody is a human IgG1 or IgG4 subtype. The antibodies or fragments thereof provided by the present invention may also be used to construct anti-GPRC5DxCD3 bispecific antibodies. To this end, as described below, the present invention further provides bispecific antibody constructs such as: The present invention provides a bispecific antibody construct, the antibody construct comprising a first binding domain that binds to G protein-coupled receptor family C group 5 member D (GPRC5D) and a second binding domain that binds to CD3 on the surface of T cells. In the bispecific antibody construct provided by the present invention, the first binding domain comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) comprise a combination of CDRs (HCDR-1, HCDR-2, HCDR-3; LCDR-1, LCDR-2, LCDR-3) selected from the following: (1) HCDR-1 including the amino acid sequence (SDYAWN) shown in SEQ ID NO: 28, HCDR-2 including the amino acid sequence (YISYSGSATYNPSLKS) shown in SEQ ID NO: 29, and HCDR-3 including the amino acid sequence (GGIAGRGRWGAMDY) shown in SEQ ID NO: 30; and LCDR-1 including the amino acid sequence (KASQNVGTNVA) shown in SEQ ID NO: 31, LCDR-2 including the amino acid sequence (SASYRDS) shown in SEQ ID NO: 32, and LCDR-3 including the amino acid sequence (QQYKSYPLT) shown in SEQ ID NO: 33; (2) HCDR-1 including the amino acid sequence (SDYAWN) shown in SEQ ID NO: 28, HCDR-2 including the amino acid sequence (YISYSGSATYSPSLKS) shown in SEQ ID NO: 34, and HCDR-3 including the amino acid sequence (GGIAGRGRWGAMDY) shown in SEQ ID NO: 30; and LCDR-1 including the amino acid sequence (KASQNVGTNVA) shown in SEQ ID NO: 31, LCDR-2 including the amino acid sequence (SASYRDS) shown in SEQ ID NO: 32, and LCDR-3 including the amino acid sequence (QQYKSYPLT) shown in SEQ ID NO: 33; (3) HCDR-1 containing the amino acid sequence (SYTIQ) shown in SEQ ID NO: 35, HCDR-2 containing the amino acid sequence (YIIPSSGYTNYNQKFKD) shown in SEQ ID NO: 36, and HCDR-3 containing the amino acid sequence (NYGNWGFTY) shown in SEQ ID NO: 37; and LCDR-1 containing the amino acid sequence (KASQNVGSAVT) shown in SEQ ID NO: 38, LCDR-2 containing the amino acid sequence (SASNRYT) shown in SEQ ID NO: 39, and LCDR-3 containing the amino acid sequence (QQYSNYPLT) shown in SEQ ID NO: 40; (4) HCDR-1 comprising the amino acid sequence (YYVMH) shown in SEQ ID NO: 41, HCDR-2 comprising the amino acid sequence (YINPYNDGTKYNEKFKG) shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence (GGVRRYFDY) shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence (RASQDIGSNLN) shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence (ATSSLDS) shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence (LQYATFPYT) shown in SEQ ID NO: 46; (5) HCDR-1 comprising the amino acid sequence (YYVIH) shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence (YINPYNDGTKYNEKFKG) shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence (GGVRRYFDY) shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence (RASQDIGSNLN) shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence (ATSSLDS) shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence (LQYATFPYT) shown in SEQ ID NO: 46; and (6) HCDR-1 comprising the amino acid sequence (YYVIH) shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence (YINPYNAGTKYNEKFKG) shown in SEQ ID NO: 48, HCDR-3 comprising the amino acid sequence (GGVRRYFDY) shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence (RASQDIGSNLN) shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence (ATSSLDS) shown in SEQ ID NO: 45, and LCDR-3 comprising the amino acid sequence (LQYATFPYT) shown in SEQ ID NO: 46. Preferably, in the first binding domain, the heavy chain variable region comprises a sequence selected from the amino acid sequence set forth in SEQ ID NO:5, SEQ ID NO:13, SEQ ID NO:7, SEQ ID NO:15, SEQ ID NO:9, SEQ ID NO:17, SEQ ID NO:11 or SEQ ID NO:19, or an amino acid sequence having at least 75% identity to said amino acid sequence; and / or the light chain variable region comprises a sequence selected from the amino acid sequence set forth in SEQ ID NO:6, SEQ ID NO:14, SEQ ID NO:8, SEQ ID NO:16, SEQ ID NO:10, SEQ ID NO:18, SEQ ID NO:12 or SEQ ID NO:20, or an amino acid sequence having at least 75% identity to said amino acid sequence. More preferably, the heavy chain variable region and the light chain variable region comprised in the first binding domain comprise a combination of sequences selected from the following: (1) an amino acid sequence shown in SEQ ID NO:5 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:5; and an amino acid sequence shown in SEQ ID NO:6 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:6; (2) an amino acid sequence shown in SEQ ID NO: 13 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 13; and an amino acid sequence shown in SEQ ID NO: 14 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 14; (3) an amino acid sequence shown in SEQ ID NO: 7 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 7; and an amino acid sequence shown in SEQ ID NO: 8 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 8; (4) an amino acid sequence shown in SEQ ID NO: 15 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 15; and an amino acid sequence shown in SEQ ID NO: 16 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 16; (5) an amino acid sequence shown in SEQ ID NO: 9 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 9; and an amino acid sequence shown in SEQ ID NO: 10 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 10; (6) an amino acid sequence shown in SEQ ID NO: 17 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 17; and an amino acid sequence shown in SEQ ID NO: 18 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 18; (7) an amino acid sequence shown in SEQ ID NO: 11 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 11; and an amino acid sequence shown in SEQ ID NO: 12 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 12; or (8) An amino acid sequence shown in SEQ ID NO: 19 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO: 19; and an amino acid sequence shown in SEQ ID NO: 20 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO: 20. In the bispecific antibody construct provided by the present invention, said second binding domain comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein said heavy chain variable region (VH) and light chain variable region (VL) comprise a combination of CDRs (HCDR-1, HCDR-2, HCDR-3; LCDR-1, LCDR-2, LCDR-3) selected from the following: HCDR-1 having the amino acid sequence (TYAMN) shown in SEQ ID NO: 49, HCDR-2 having the amino acid sequence (RIRSKYNNYATYYADSVKD) shown in SEQ ID NO: 50, HCDR-3 having the amino acid sequence (HGNFGNSYVSYFAY) shown in SEQ ID NO: 51; and LCDR-1 having the amino acid sequence (RSSTGAVTTSNYAN) shown in SEQ ID NO: 52, LCDR-2 having the amino acid sequence (GTNKRAP) shown in SEQ ID NO: 53, and LCDR-3 having the amino acid sequence (ALWYSNLWV) shown in SEQ ID NO: 54. Preferably, in the second binding domain, the heavy chain variable region comprises the amino acid sequence set forth in SEQ ID NO: 21 or an amino acid sequence having at least 75% identity thereto; and the light chain variable region comprises the amino acid sequence set forth in SEQ ID NO: 22 or an amino acid sequence having at least 75% identity thereto. More preferably, the bispecific antibody construct provided by the present invention comprises four polypeptide chains: 1) heavy chain 1, which contains domains arranged from N-terminus to C-terminus according to VH-CH1-CH2-CH3; 2) heavy chain 2, which contains domains arranged from the N-terminus to the C-terminus according to VL-CH1-CH2-CH3; 3) light chain 1, which contains domains arranged according to VL-CL from the N-terminus to the C-terminus; 4) light chain 2, which contains domains arranged according to VH-CL from the N-terminus to the C-terminus; Here, the VH and VL contained in heavy chain 1 and light chain 1 pair to form a first binding domain that binds to the GPRC5D, and the VL and VH contained in heavy chain 2 and light chain 2 pair to form a second binding domain that binds to the CD3. A schematic diagram of the structure of the bispecific antibody construct provided by the present invention is shown in Figure 1. According to specific embodiments of the invention, in the bispecific antibody construct provided by the invention, the CH1-CH2-CH3 domain in heavy chain 1 comprises the amino acid sequence as shown in SEQ ID NO: 25 or an amino acid sequence having at least 75% identity to said amino acid sequence; the CH1-CH2-CH3 domain in heavy chain 2 comprises the amino acid sequence as shown in SEQ ID NO: 26 or an amino acid sequence having at least 75% identity to said amino acid sequence; the CL domain in light chain 1 comprises the amino acid sequence as shown in SEQ ID NO: 24 or an amino acid sequence having at least 75% identity to said amino acid sequence; and the CL domain in light chain 2 comprises the amino acid sequence as shown in SEQ ID NO: 27 or an amino acid sequence having at least 75% identity to said amino acid sequence. According to another aspect, the present invention further provides a nucleic acid molecule comprising a nucleotide sequence encoding the heavy chain CDR, the light chain CDR, the light chain variable region, the heavy chain variable region, the heavy chain or the light chain comprised in the antibody or fragment thereof provided by the present invention or the bispecific antibody construct provided by the present invention. The nucleic acid molecule of the present invention may be cloned into a vector and further transformed or transfected into a host cell. Thus, according to yet another aspect, the present invention further provides a vector comprising the nucleic acid molecule of the present invention. The vector may be a eukaryotic expression vector, a prokaryotic expression vector, an artificial chromosome and a phagemid vector, etc. The vector or nucleic acid molecule of the present invention may be used to transform or transfect a host cell. Thus, according to yet another aspect, the present invention provides a host cell, the host cell comprising the nucleic acid molecule and / or vector of the present invention or the host cell transformed or transfected with the nucleic acid molecule and / or vector of the present invention. The host cell may be any prokaryotic or eukaryotic cell, such as a bacterial or insect, fungal, plant or animal cell. The antibodies or fragments thereof and bispecific antibody constructs provided by the present invention may be obtained by any method known in the art, for example by culturing a host cell provided by the present invention, where the heavy and light chains of said antibodies are allowed to be expressed in said host cell. Optionally, said method further comprises the step of recovering the antibodies produced. The antibodies or fragments thereof, bispecific antibody constructs, nucleic acid molecules, vectors and / or host cells provided by the present invention may be comprised in a composition, more particularly in a pharmaceutical composition, e.g. a pharmaceutical formulation, and thus used for various purposes according to practical needs.Thus, according to yet another aspect, the present invention further provides a composition, e.g. a pharmaceutical composition, comprising an antibody or fragment thereof, bispecific antibody construct, nucleic acid molecule, vector and / or host cell according to the present invention, and any pharma- ceutical acceptable auxiliary. According to yet another aspect, the present invention further provides the use of said antibody or fragment thereof, bispecific antibody construct, nucleic acid molecule, vector, host cell and / or composition in the manufacture of a medicament for treating a disease, said disease being a tumor or cancer. Preferably, said disease is a tumor or cancer associated with GPRC5D expression (e.g. high expression), such as lymphoma or myeloma, in particular multiple myeloma. Therefore, accordingly, the present invention further provides a method of treating a disease, said method comprising administering to a subject in need thereof the antibody or fragment thereof, bispecific antibody construct, nucleic acid molecule, vector, host cell and / or composition of the present invention, said disease being a tumor or cancer. Preferably, said disease is a tumor or cancer associated with GPRC5D expression (e.g. high expression), such as lymphoma or myeloma; said disease is in particular multiple myeloma. Preferably, said subject is a mammal; more preferably, said subject is a human. According to yet another aspect, the present invention further provides the use of said antibody or fragment thereof, bispecific antibody construct, nucleic acid molecule, vector, host cell and / or composition in the manufacture of a reagent for use in the diagnosis of a disease or for detecting the presence of the antigen GPRC5D, said disease being a tumour or cancer. Preferably, said disease is a tumour or cancer associated with GPRC5D expression (e.g. high expression), such as lymphoma or myeloma, in particular multiple myeloma. In yet another aspect, the present invention provides a kit comprising the antibody or fragment thereof, bispecific antibody construct, nucleic acid molecule, vector, host cell and / or composition of the present invention. The kit may be used for the above-mentioned treatment or for diagnosis or antigen detection. Depending on the intended application, the kit further comprises other reagents used for treatment, diagnosis or detection. For example, the kit is a kit for detecting the presence of GPRC5D in any biological sample by ELISA. [Brief description of the drawings]

[0004] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. [Figure 1] FIG. 1 is a schematic diagram of the structure of an anti-human GPRC5D×CD3 bispecific antibody. [Diagram 2] 1 shows the results of FACS detection of binding between the supernatant of hybridoma cells and different cells. [Diagram 3] 1 shows the results of FACS detection of binding between the supernatant of hybridoma cells and different cells. [Figure 4] The FACS detection results of the binding of the hybridoma cell supernatant to different cells are shown, among which: 4-1: MM1R cells; 4-2: Nalm6 cells; 4-3: OPM2 cells; 4-4: NCI-H929 cells. [Diagram 5] 4 shows the FACS detection results of the binding of humanized antibodies to cells expressing human GPRC5D, among which: 5-1: 9D7(hz); 5-2: 26D1(hz); 5-3: 24F5(hz); 5-4: 6E97(hz). [Figure 6]The FACS detection results of the binding of humanized antibodies to cells expressing monkey GPRC5D are shown, among which: 6-1: 9D7(hz); 6-2: 26D1(hz); 6-3: 24F5(hz); 6-4: 6E97(hz). [Figure 7] 1 shows the FACS detection results of the binding of humanized antibodies to different tumor cell lines, where 7-1: MM.1R cells; 7-2: MOLP8 cells. [Figure 8] The results of the detection of the affinity of humanized antibodies to GPRC5D are shown, among which: 8-1: GPRC5D×CD3 JNJ; 8-2: 9D7(hz); 8-3: 26D1(hz); 8-4: 24F5(hz); 8-5: 6E97(hz). [Figure 9] The results of humanized antibody-mediated ADCC detection are shown, where 9-1: wild-type NCI-H929; 9-2: GPRC5D knockout NCI-H929. [Figure 10] The results of detection of bispecific antibody-mediated T cell cytotoxicity are shown, where 10-1: co-culture experiment 1; 10-2: co-culture experiment 2; 10-3: co-culture experiment 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] The present invention will be described below with reference to specific examples. It should be understood by those skilled in the art that these examples are only used to illustrate the present invention, and are not intended to limit the scope of the present invention in any manner. Unless otherwise specified, the experimental methods in the following examples are all conventional methods. Unless otherwise specified, the raw materials, reagents, etc. used in the following examples are all commercially available products. Human GPRC5D protein: Genbank Accession No. NM_018654; Monkey GPRC5D protein: Genbank Accession No. XM_005570193.2. Example 1 Production of hybridoma cells and acquisition of antibody protein Human GPRC5D-expressing cells (Kyinno, Catalog No. KC-1583) were cultured at a cell concentration of 1 × 10 in PBS containing 2% FBS. 7 The cells were prepared as a cell suspension at 100 / mL. Mice were immunized with this cell suspension as an immunogen, 5 mice were immunized subcutaneously, and 5 mice were immunized intramuscularly. Quick antibody 5W water-soluble adjuvant was used as the adjuvant. Antibody titers were measured 2 weeks after booster immunization, and 2 mice with high antibody titers were selected and subjected to immune shock. Serum was collected 3 days later, and the spleens were collected after dissection. The isolated splenocytes and cultured myeloma cells were fused in a 96-well plate, and screening was performed by adding selective medium at the same time. The culture medium was replaced after 7 days, and ELISA detection was performed using cells after 10 days. ELISA detection was performed using 293T cells (Kyinno, catalog number KC-1723) expressing human GPRC5D, and cells with OD values ​​10 times or more higher than the negative control (normal mouse serum) were selected and further detected by flow cytometry. For flow cytometry, 293T cells (Kyinno, catalog number KC-1723) expressing human GPRC5D were used. Cells that were positive in both ELISA and FACS were selected, and subcloning was performed by limiting dilution to select monoclonal cells. Culture supernatants were taken from the selected monoclonal cells, and double-positive cells were selected and expanded. The culture supernatant of the obtained hybridoma cells was collected, centrifuged, concentrated, and purified with a G protein affinity column. The purified sample was then diluted 10 times with a buffer solution (20 mM citric acid + 100 mM NaCl, pH 5.5) and concentrated to an appropriate volume using an ultrafiltration concentration tube, then dispensed into 1.5 mL EP tubes at 200 μL / tube and stored at -80°C. At the same time, a portion of the sample was taken out and subjected to SDS-PAG and FACS identification to verify the purity and activity of the protein. Example 2 ELISA detection of binding of hybridoma cell culture supernatant to human GPRC5D BXPC-3 cells expressing human GPRC5D (Kyinno, Catalog No. KC-1717) were cultured at a cell concentration of 1 × 10 in PBS containing 2% FBS. 5 The cells were prepared as a cell suspension of 100 μL / well and added to a 96-well plate at 37°C overnight. The liquid in the wells was discarded, and the wells were washed three times with washing solution. 80 μL of 4% tissue fixative (Beyotime, Catalog No. P0099) was added to each well, fixed at room temperature for 15 min, washed twice with PBS, dried, 250 μL of blocking solution containing 2% BSA was added to each well, incubated at 37°C for 1 h, and the plate was washed three times with PBS. 50 to 100 μL of culture supernatant of the hybridoma cells to be tested was added to each well, and a positive control (with serum of fused mice added), a negative control (with serum of normal mice added), and a blank control (with medium added) were also placed at the same time. The wells were incubated at 37°C for 1 to 2 hours, washed, and dried. Then, the enzyme-labeled secondary antibody, horseradish peroxidase-labeled sheep anti-mouse IgG (SIGMA, Catalog No. A9044-2mL) diluted 1:10000 was added to each well, 50-100μL was added to each well, incubated at 37℃ for 1-2 hours, washed, and dried. Freshly prepared substrate color solution TMB was added to each well, 50-100μL was added, and incubated at 37℃ for 10-30 minutes. The reaction was stopped by adding 2 mol / L H2SO4, and the OD value was read using an ELISA (enzyme-linked immunosorbent assay) reader. Judgment of results: P / N>2:1 (P represents the positive value, and N represents the value of normal mouse serum) was considered positive. If the negative control wells were colorless or nearly colorless and the positive control wells were clearly colored, the results could be directly observed by visual inspection. The results are shown in Table 1.

[0006] [Table 1] Example 3 Construction of anti-human GPRC5D×CD3 bispecific antibody We constructed an anti-human GPRC5D×CD3 bispecific antibody using the GPRC5D-targeting domain and the CD3-targeting domain of Johnson & Johnson's Talquetamab (JNJ-64407564). A schematic diagram of the structure of this bispecific antibody is shown in Figure 1, in which the domains contained in each chain are as follows, from the N-terminus to the C-terminus: Heavy chain 1: VH-CH1-CH2-CH3. >VH (SEQ ID NO: 1) QVQLVQSGAEVKKPGASVKVSCKASGYSFTGYTMNWVRQAPGQGLEWMGLINPYNSDTNYAQKLQGRVTMTTDTSTSTAYMELRSLRSDDTAVYYCARVALRVALDYWGQGTLVTVSS >CH1-CH2-CH3 (SEQ ID NO: 25) ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPPAAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALAAPIEKTISKAKGQPREPQVYTLPPCREEMTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFLLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK Heavy chain 2: VL-CH1-CH2-CH3 >VL (SEQ ID NO: 2) QTVVTQEPSLTVSPGGTVTLTCRSSTGAVTTSNYANWVQQKPGQAPRGLIGGTNKRAPGTPARFSGSLLGGKAALTLSGVQPEDEAEYYCALWYSNLWVFGGGTKLTVL >CH1-CH2-CH3 (SEQ ID NO:26) SSASTKGPSVFPLAPSSKSTSGGTAALGCLVEDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDDRVEPKSCDKTHTCPPCPAPPAAGPSVFLFPPKPKDTLMISRTPEVTCVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREE QYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALAAPIEKTISKAKGQPREPQVCTLPPSREEMTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSRLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK Light chain 1: VL-CL >VL (SEQ ID NO: 3) DIQMTQSPSSLSASVGDRVTITCKASQNVATHVGWYQQKPGKAPKRLIYSASYRYSGVPSRFSGSGSGTEFTLTISNLQPEDFATYYCQQYNRYPYTFGQGTKLEIK >CL (SEQ ID NO: 24) RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC Light chain 2: VH-CL >VH (SEQ ID NO: 4) EVQLVESGGGLVQPGGSLRLSCAASGFTFNTYAMNWVRQAPGKGLEWVARIRSKYNNYATYYAASVKGRFTISRDDSKNSLYLQMNSLKTEDTAVYYCARHGNFGNSYVSWFAYWGQGTLVTVSS >CL (SEQ ID NO: 27) GQPKAAPSVTLFPPSSEELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTECS Primers were designed for the above four polypeptide chains, the corresponding coding genes were synthesized and introduced into a eukaryotic expression plasmid, and the resulting four recombinant expression plasmids were co-transfected into HEK293F cells. After culturing the cells for 5-7 days, the secreted antibody supernatant was obtained. The bispecific antibodies were purified from the cell culture supernatant using MabSelectSure affinity chromatography technology and SP cation exchange chromatography technology. The resulting bispecific antibody was named "GPRC5DxCD3 JNJ." Example 4 FACS detection of binding between culture supernatant of hybridoma cells and human GPRC5D 293T cells expressing human GPRC5D as described above were cultured in PBS containing 2% FBS at a cell concentration of 1 × 10 5 The cells were prepared as a cell suspension at 100 / mL. 50μL of cell suspension was placed in each flow tube (sample tube), and then 50μL of culture supernatant of the hybridoma cells to be tested and anti-human GPRC5D×CD3 bispecific antibody GPRC5D×CD3 JNJ as a positive control antibody were added, and incubated at 4℃ for 60 minutes. 1mL of flow buffer was added to each flow tube, centrifuged at 1200rpm for 5 minutes, the supernatant was discarded, and washed three times. At the same time, control tube 1 (no culture supernatant and secondary antibody below were added, only cell suspension was added) and control tube 2 (no culture supernatant was added, only cell suspension and secondary antibody below were added) were installed. Then, 100 μL of flow buffer was added to each flow tube to resuspend the cells, and 5 μL of anti-mouse Fc-tagged secondary antibody (Biolegend, catalog number 409304) labeled with PE according to the experimental requirements was added, and the cells were incubated at 4°C in the dark for 30 minutes, after which 1 mL of flow buffer was added, and the cells were centrifuged at 1200 rpm at room temperature for 5 minutes, the supernatant was discarded, and the cells were washed three times. Again, 250 μL of flow buffer was added to each flow tube, and the mixture was resuspended and mixed uniformly, and detection was performed using the device. The detection results are shown in Tables 2-1 to 2-4 and 2-1 to 2-4 in FIG.

[0007] [Table 2-1]

[0008] [Table 2-2]

[0009] [Table 2-3]

[0010] [Table 2-4] Example 5 FACS detection of binding between hybridoma cell supernatant and monkey GPRC5D According to the procedure described in Example 4, cells expressing human GPRC5D were replaced with 293T cells expressing monkey GPRC5D (Kyinno, catalog number KC-1586), and the binding between the culture supernatant of the hybridoma cells of the present invention and monkey GPRC5D was detected. The results of FACS binding detection are shown in Tables 3-1 to 3-3 and 3-1 to 3-3 in FIG. 3, and the positive control antibody was GPRC5D×CD3 JNJ.

[0011] [Table 3-1]

[0012] [Table 3-2]

[0013] [Table 3-3] Example 6 FACS detection of binding between the supernatant of hybridoma cells and different cells According to the procedures described in Example 4, cells expressing human GPRC5D were replaced with other cells, such as NALM6 (Kyinno, catalog number KC-0626), NCI-H929 (Kyinno, catalog number KC-0629), MM1R (Kyinno, catalog number KC-0619), and OPM2 (Kyinno, catalog number KC-0631), and the binding between the culture supernatant of the hybridoma cells of the present invention and human GPRC5D was detected. The results of FACS binding detection are shown in Table 4 and 4-1 to 4-4 in FIG. 4, and the positive control antibody was GPRC5D×CD3 JNJ.

[0014] [Table 4] Example 7 Identification of the sequences of the murine antibodies of the invention Screened hybridoma cell lines were selected, and RNA was extracted from the monoclonal cells, reverse transcribed into cDNA, the cDNA was amplified, recovered from the gel, and then introduced into a sequencing vector for sequencing analysis. The sequences of the heavy and light chain variable regions of an exemplary mouse antibody obtained from hybridoma cells are as follows, in which the bold underlined parts indicate the CDRs (as defined by the KABAT method): A1: >9D7-H (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 5 / 28 / 29 / 30)

[0015] [ka] >9D7-L (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 6 / 31 / 32 / 33)

[0016] [ka] A2: >26D1-H (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 7 / 35 / 36 / 37)

[0017] [ka] >26D1-L (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 8 / 38 / 39 / 40)

[0018] [ka] A3 >24F5-H (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 9 / 41 / 42 / 43)

[0019] [ka] TLTVSS >24F5-L (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 10 / 44 / 45 / 46)

[0020] [ka] A4 >6E97-H (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 11 / 47 / 42 / 43 / )

[0021] [ka] >6E97-L (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 12 / 44 / 45 / 46)

[0022] [ka] Example 8 Production of chimeric and humanized antibodies using mouse antibodies For the A1 antibody (mouse antibody 9D7), the following human germline sequences were selected as templates for the heavy and light chains: IGHV4-39 and IGKV1-39, respectively. Homology modeling was performed on the A1 antibody, and a structural simulation of the Fab region was performed. The final predicted Fab structure of the A1 antibody was obtained by calculation using homology modeling. By comparing and analyzing the predicted Fab structure and heavy chain with the IGHV4-39 sequence, in this VH, except for the CDR regions and 2V, 49M, 68I, and 72R, which were the original mouse amino acids, all other mouse amino acids were replaced with the corresponding human amino acids using IGHV4-39 as a template. By comparing and analyzing the predicted Fab structure and light chain with the IGKV1-39 sequence, except for the CDR regions and 42Q, 43S, 46A, and 60D in this VL, the original mouse amino acids were retained, and all other mouse amino acids were replaced with the corresponding human amino acids using IGKV1-39 as the template. The resulting humanized sequences are as follows (heavy and light chain CDRs are shown in bold and underlined, and were obtained by the KABAT definition method): The sequence of the humanized antibody is as follows: >9D7-H humanized sequence (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 13 / 28 / 34 / 30)

[0023] [ka] [ka] >9D7-L humanized sequence (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 14 / 31 / 32 / 33)

[0024] [ka] For the A2 antibody (mouse antibody 26D1), the following human germline sequences were selected as templates for the heavy and light chains: IGHV1-46 and IGKV1-5, respectively. Homology modeling was performed on the A2 antibody, and a structural simulation of the Fab region was performed. The final predicted Fab structure of the A2 antibody was obtained by calculation using homology modeling. By comparing and analyzing the predicted Fab structure and heavy chain with the IGHV1-46 sequence, in this VH, except for the CDR regions and 37I, 38K, 48I, 67R, 68A, 70L, 72A, 74K, 76S, 77N, 79A, and 98N, which were the original mouse amino acids, all other mouse amino acids were replaced with the corresponding human amino acids using IGHV1-46 as a template. By comparing and analyzing the predicted Fab structure and light chain with the IGKV1-5 sequence, except for the CDR regions and 45R, 60D, and 87F in this VL, the original mouse amino acids were retained, and all other mouse amino acids were replaced with the corresponding human amino acids using IGKV1-5 as the template. The resulting humanized sequences are as follows (heavy and light chain CDRs are shown in bold and underlined, and were obtained by the KABAT definition method): The sequence of the humanized antibody is as follows: >26D1-H humanized sequence (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 15 / 35 / 36 / 37)

[0025] [ka] >26D1-L humanized sequence (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 16 / 38 / 39 / 40)

[0026] [ka] For the A3 antibody (mouse antibody 24F5), the following human germline sequences were selected as templates for the heavy and light chains: IGHV1-46 and IGKV1-15, respectively. Homology modeling was performed on the A3 antibody, and a structural simulation of the Fab region was performed. The final predicted Fab structure of the A3 antibody was obtained by calculation using homology modeling. By comparing and analyzing the predicted Fab structure and heavy chain with the IGHV1-46 sequence, in this VH, except for the CDR regions and 48I, 68A, 70L, 72S, 74K, and 79A, which were the original mouse amino acids, all other mouse amino acids were replaced with the corresponding human amino acids using IGHV1-46 as a template. By comparing and analyzing the predicted Fab structure and light chain with the IGKV1-15 sequence, in this VL, except for the CDR regions and 36L, 42G, 43T, 44I, 46R, 66R, 69S, 71Y, which retained the original mouse amino acids, all other mouse amino acids were replaced with the corresponding human amino acids using IGKV1-15 as the template. The resulting humanized sequence is as follows (heavy and light chain CDRs are shown in bold and underlined, obtained by the KABAT definition method): The sequence of the humanized antibody is as follows: >24F5-H humanized sequence (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 17 / 41 / 42 / 43)

[0027] [ka] >24F5-L humanized sequence (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 18 / 44 / 45 / 46)

[0028] [ka] For the A4 antibody (mouse antibody 6E97), the following human germline sequences were selected as templates for the heavy and light chains: IGHV1-46 and IGKV1-15, respectively. Homology modeling was performed on the A4 antibody, and a structural simulation of the Fab region was performed. The final predicted Fab structure of the A4 antibody was obtained by calculation using homology modeling. By comparing and analyzing the predicted Fab structure and heavy chain with the IGHV1-46 sequence, in this VH, except for the CDR regions and 48I, 68A, 70L, 72S, 74K, and 79A, which were the original mouse amino acids, all other mouse amino acids were replaced with the corresponding human amino acids using IGHV1-46 as a template. By comparing and analyzing the predicted Fab structure and light chain with the IGKV1-15 sequence, in this VL, except for the CDR regions and 4L, 36L, 42G, 43T, 44I, 46R, 66R, 69S, 71Y, which retained the original mouse amino acids, all other mouse amino acids were replaced with the corresponding human amino acids using IGKV1-15 as the template. The resulting humanized sequence is as follows (heavy and light chain CDRs are shown in bold and underlined, obtained by the KABAT definition method): The sequence of the humanized antibody is as follows: >6E97-H humanized sequence (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 19 / 47 / 48 / 43)

[0029] [ka] >6E97-L humanized sequence (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 20 / 44 / 45 / 46)

[0030] [ka] The sequence shown in SEQ ID NO: 23 was used as the heavy chain constant region, and the sequence shown in SEQ ID NO: 24 was used as the light chain constant region. Primers were redesigned for the antibody DNA sequence against the GRRC5D target obtained by sequencing, and the corresponding chimeric antibody and humanized antibody genes were synthesized and introduced into eukaryotic expression vectors, transformed into DH5alpha competent cells, incubated overnight in a constant temperature incubator at 37°C, and a monoclonal strain was selected and identified by sequencing. A strain with the correct sequence was selected, shaken, and a large amount of plasmid was extracted, transfected into mammalian expression cells 293F, and cultured in an incubator at 37°C and 5% CO2 for 7 days to express the gene. The supernatant was taken, centrifuged, filtered, and purified by selecting a protein G affinity chromatography column, the purity of the purified antibody was detected by SDS-PAGE electrophoresis, and the antibody concentration was detected by a BCA protein detection kit, and the antibody was dispensed and stored in a refrigerator at -80°C. Here, the chimeric antibody was named "mouse antibody abbreviation (chi)" and the humanized antibody was named "mouse antibody abbreviation (hz)". >CH1-CH3 heavy chain constant region (SEQ ID NO: 23) ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSS SLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEY KCKVSNKALAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK >CL1 light chain constant region (SEQ ID NO: 24) RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC Example 9 FACS detection of binding of humanized antibodies to human GPRC5D The experimental procedure was as shown in Example 4, using 293T cells expressing human GPRC5D (Kyinno, catalog number KC-1584), and adding the test antibody, positive control antibody GPRC5D×CD3 JNJ or negative control antibody (hIgG1), the concentrations of which are shown in Figure 4. At the same time, control tube 1 (no antibody or secondary antibody, only cell suspension) and control tube 2 (no antibody, only cell suspension and secondary antibody) were set up. The results are shown in Table 5 and 5-1 to 5-4 in FIG.

[0031] [Table 5] Example 10 FACS detection of binding of humanized antibodies to monkey GPRC5D The experimental procedure was as shown in Example 4, using 293T cells expressing monkey (cyno) GPRC5D (Kyinno, catalog number KC-1586), and adding the test antibody, positive control antibody GPRC5D×CD3 JNJ, or negative control antibody (hIgG1), with the concentrations shown in Figure 6. At the same time, control tube 1 (no antibody or secondary antibody, only cell suspension) and control tube 2 (no antibody, only cell suspension and secondary antibody) were set up. The results are shown in Table 6 and 6-1 to 6-4 in FIG.

[0032] [Table 6] Example 11 FACS detection of binding of humanized antibodies to GPRC5A / B / C The experimental procedure was the same as in Example 4, and cells expressing other members of the G protein-coupled receptor family C group 5 were used: 293T cells expressing human GPRC5A 293T-GPRC5A (Kyinno, Catalog No. KC-1888), 293T cells expressing human GPRC5B 293T-GPRC5B (Kyinno, Catalog No. KC-1854), and 293T cells expressing human GPRC5C 293T-GPRC5C (Kyinno, Catalog No. KC-1889). The test antibody, positive control antibody GPRC5D×CD3 JNJ, or negative control antibody (hIgG1) were added at a concentration of 2 μg / mL. At the same time, control tube 1 (no antibody or secondary antibody was added, only cell suspension was added) and control tube 2 (no antibody was added, only cell suspension and secondary antibody were added) were set up. The results are shown in Table 7.

[0033] [Table 7] Example 12 FACS detection of binding of humanized antibodies to tumor cell lines The experimental procedure was the same as in Example 4, except that the cells used were replaced with multiple myeloma cells MM.1R (Kyinno, Catalog No. KC-0619) and MOLP8 (Kyinno, Catalog No. KC-0622), and the test antibody, positive control antibody GPRC5D×CD3 JNJ, or negative control antibody (hIgG1) were added. At the same time, control tube 1 (no antibody or secondary antibody, only cell suspension) and control tube 2 (no antibody, only cell suspension and secondary antibody) were set up. The results are shown in Table 8 and in 7-1 and 7-2 in FIG.

[0034] [Table 8] Example 13 Detection of affinity between humanized antibodies and GPRC5D protein The test antibody was prepared as a solution with a concentration of 10 μg / mL using PBS buffer, and the antibody was captured using an AHC chip according to the Fortebio instructions. Human GPRC5D protein (Kactus Biosystems, catalog number GPR-HM05P) (protein was diluted 2-fold in six steps to a maximum concentration of 200 nM) prepared in advance was passed through the chip, and the specific conditions were a flow rate of 30 μL / min, an antigen-antibody binding time of 200 seconds, and a dissociation time of 500 seconds. The affinity between the antibody and the antigen was analyzed by fitting the measured results with the dedicated software for the device. The results are shown in Table 9 and 8-1 to 8-5 in Figure 8.

[0035] [Table 9] Example 14 Detection of humanized antibody-mediated ADCC In a U-bottom 96-well plate, 20,000 reporter cells Jurkat-NFAT-luc-CD16-V158 (Kyinno, Catalog No. KC-1507), 20,000 wild-type NCI-H929 cells (CFSE-H929, Kyinno, Catalog No. KC-0629) or GPRC5D knockout NCI-H929 cells (CFSE-H929GPRC5DKO, Kyinno, Catalog No. KC-2203) and different concentrations of antibodies (10 μg / mL, 3.16 μg / mL, 1 μg / mL, 0.316 μg / mL, 0.1 μg / mL, 0.0316 μg / mL, 0.01 μg / mL, 0.00316 μg / mL) were added to each well. After co-culture for 6 hours, the luciferase signal was detected. The results are shown in Table 10 and 9-1 to 9-2 in FIG. 9, and the positive control antibody was GPRC5D×CD3 JNJ.

[0036] [Table 10] Example 15 Obtaining anti-CD3 antibodies and detecting their affinity to targets The heavy chain variable region sequence SEQ ID NO.10 and the light chain variable region sequence SEQ ID NO.5 of a mouse-derived antibody were obtained from patent US10066015B2. The antibody sequence was humanized for this antibody, and the humanized sequence obtained is as follows (heavy and light chain CDRs are shown in bold and underlined, and obtained according to the KABAT definition method): >VH humanized sequence (VH / HCDR-1 / HCDR-2 / HCDR-3: SEQ ID NO: 21 / 49 / 50 / 51)

[0037] [ka] >VL humanized sequence (VL / LCDR-1 / LCDR-2 / LCDR-3: SEQ ID NO: 22 / 52 / 53 / 54)

[0038] [ka] As described in Example 8, an antibody containing the above humanized sequence was obtained and named SP34V1(hz). Similarly, a chimeric antibody was obtained using the heavy and light chain variable region sequences of the above mouse-derived antibody in patent US10066015B2 and named SP34(chi). The humanized and chimeric antibodies were prepared in PBS buffer at a concentration of 10 μg / mL, and the antibodies were captured using an AHC chip according to the Fortebio instructions. Human CD3 protein (Kactus Biosystems, catalog number GPR-HM05P) (protein was diluted 2-fold in six steps to a maximum concentration of 200 nM) was passed through the chip under the following specific conditions: flow rate 30 μL / min, antigen-antibody binding time 200 seconds, and dissociation time 500 seconds. The affinity between the antibody and the antigen was analyzed by fitting the measured results with the dedicated software for the device. The results are shown in Table 1.

[0039] [Table 11] Example 16 Construction of bispecific antibodies of the present invention A bispecific antibody of the present invention was constructed as described in Example 3, with the difference that the VH in heavy chain 1 and the VL in light chain 1 were replaced with the VH and VL of the humanized antibodies 9D7(hz), 26D1(hz), 24F5(hz) and 6E97(hz), respectively, of the present invention, and the VL in heavy chain 2 and the VH in light chain 2 were replaced with the humanized sequences against CD3 obtained in Example 15, respectively. The VH and VL containing the humanized antibodies 9D7(hz), 26D1(hz), 24F5(hz) and 6E97(hz) of the present invention, respectively, and the anti-human GPRC5D×CD3 bispecific antibody having the above-mentioned sequences were named "GPRC5D×CD3 9D7(hz)," "GPRC5D×CD3 26D1(hz)," "GPRC5D×CD3 24F5(hz)," and "GPRC5D×CD3 26D1(hz)," respectively. Example 17 GPRC5D-CD3 double antibody-mediated T cell toxicity experiment PBMCs and CD3 / CD28 magnetic beads were mixed in a quantitative ratio of 2:1 in RPMI1640 containing 10 ng / mL IL-2 and 10% FBS, and cultured for 7 days to expand and activate the T cells. Co-culture experiment 1: 293T LDHA-Hibit-GPRC5D cells (Kyinno, Cat. No. KC-2151) were plated (96-well plate) one day prior to the start of the experiment, and then 10,000 of the above T cells were added to each well. In addition, different concentrations of the positive control antibody GPRC5D×CD3 JNJ and the bispecific antibody of the present invention (1 μg / mL, 0.1 μg / mL, 0.01 μg / mL, 0.001 μg / mL, 0.0001 μg / mL, 0.00001 μg / mL, 0.000001 μg / mL, 0.0000001 μg / mL) were added, and the cells were co-cultured for 18 hours in RPMI1640 containing 10 ng / mL IL-2 and 10% FBS. The proportion of injured cells was detected by detecting LDHA-HIBIT released from dead cells in the supernatant using Nano-Glo® HiBiT Extracellular Reagent (Promega, Cat. No. N2420). In this experiment, two sets of controls were set up for each of the two antibodies: one in which 293T LDHA-Hibit-GPRC5D cells and antibodies were added but no T cells were added; and one in which non-antibody-mediated injury and antibody-mediated non-T cell injury were eliminated by adding 293T LDHA-Hibit cells (Kyinno), T cells and antibodies. The results are shown in 10-1 in Figure 10. Co-culture experiment 2: NCI-H929 (expressing GPRC5D) and K562 cells (not expressing GPRC5D) were stained with CFSE and named CFSE-H929 and CFSE-K562, respectively. In a U-bottom 96-well plate, 10,000 activated T cells and 3,000 CFSE-H929 were added to each well, and different concentrations of the positive control antibody GPRC5D×CD3 JNJ and the bispecific antibody of the present invention (1 μg / mL, 0.1 μg / mL, 0.01 μg / mL, 0.001 μg / mL, 0.0001 μg / mL, 0.00001 μg / mL, 0.000001 μg / mL, 0.000001 μg / mL) were added, respectively, and co-cultured for 18 hours in RPMI1640 containing 10 ng / mL IL-2 and 10% FBS. Then, the cells were stained with 7-AAD and detected by flow cytometry, and the percentage of CFSE+7-AAD+ cells in CSFE+ cells was counted as the percentage of cytotoxicity. In this experiment, two sets of controls were set up for each of the two antibodies: one in which CFSE-H929 cells and antibodies were added but no T cells were added; and one in which non-antibody-mediated toxicity and antibody-mediated non-T cell toxicity were eliminated by adding CFSE-K562, T cells and antibodies. The results are shown in 10-2 in Figure 10. Co-culture experiment 3: Wild-type NCI-H929 (Kyinno, catalog number KC-0629) and GPRC5D knockout NCI-H929 cells (Kyinno, catalog number KC-2203) were stained with CFSE and named CFSE-H929 and CFSE-H929GPRC5DKO, respectively. In a U-bottom 96-well plate, 10,000 activated T cells and 3,000 CFSE-H929 were added to each well, and different concentrations of the positive control antibody GPRC5D×CD3 JNJ and the bispecific antibody of the present invention (1 μg / mL, 0.1 μg / mL, 0.01 μg / mL, 0.001 μg / mL, 0.0001 μg / mL, 0.00001 μg / mL, 0.000001 μg / mL, 0.0000001 μg / mL) were added, respectively, and co-cultured in RPMI1640 containing 10 ng / mL IL-2 and 10% FBS for 18 hours. Then, stained with 7-AAD and detected by flow cytometry, the percentage of CFSE+7-AAD+ cells in CSFE+ cells was counted as the percentage of cytotoxicity. In this experiment, two sets of controls were set up for each of the four antibodies: CFSE-H929 cells and antibodies were added but no T cells were added; CFSE-H929GPRC5DKO, T cells and antibodies were added to eliminate non-antibody mediated injury and antibody mediated non-T cell injury. The results are shown in 10-3 in Figure 10. The above describes the specific embodiments of the present invention, but does not limit the present invention. Those skilled in the art may make various changes and modifications based on the present invention without departing from the spirit of the present invention, and all such corresponding changes and modifications should fall within the scope of protection of the claims attached to the present invention.

Claims

1. The heavy chain variable region (VH) and the light chain variable region (VL) each include a combination of CDRs selected from the following: HCDR-1, HCDR-2, HCDR-3; LCDR-1, LCDR-2, LCDR-3. An antibody or fragment thereof, characterized in that: (1) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 28, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 29, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 30; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 31, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 32, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 33; (2) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 28, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 34, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 30; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 31, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 32, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 33; (3) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 35, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 36, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 37; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 38, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 39, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 40; (4) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 41, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 46; (5) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 46; and (6) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 48, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO:

46.

2. the heavy chain variable region comprises an amino acid sequence selected from the amino acid sequence set forth in SEQ ID NO:5, SEQ ID NO:13, SEQ ID NO:7, SEQ ID NO:15, SEQ ID NO:9, SEQ ID NO:17, SEQ ID NO:11, or SEQ ID NO:19, or an amino acid sequence having at least 75% identity to said amino acid sequence; and / or The light chain variable region comprises an amino acid sequence selected from the amino acid sequence set forth in SEQ ID NO:6, SEQ ID NO:14, SEQ ID NO:8, SEQ ID NO:16, SEQ ID NO:10, SEQ ID NO:18, SEQ ID NO:12, or SEQ ID NO:20, or an amino acid sequence having at least 75% identity to the amino acid sequence. The antibody or fragment thereof according to claim 1 .

3. The heavy chain variable region and the light chain variable region contained in the antibody or fragment thereof include a combination of sequences selected from the following: The antibody or fragment thereof according to claim 1 or 2, (1) an amino acid sequence shown in SEQ ID NO:5 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:5; and an amino acid sequence shown in SEQ ID NO:6 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:6; (2) an amino acid sequence shown in SEQ ID NO: 13 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 13; and an amino acid sequence shown in SEQ ID NO: 14 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 14; (3) an amino acid sequence shown in SEQ ID NO: 7 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 7; and an amino acid sequence shown in SEQ ID NO: 8 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 8; (4) an amino acid sequence shown in SEQ ID NO: 15 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 15; and an amino acid sequence shown in SEQ ID NO: 16 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 16; (5) an amino acid sequence shown in SEQ ID NO: 9 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 9; and an amino acid sequence shown in SEQ ID NO: 10 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 10; (6) an amino acid sequence shown in SEQ ID NO: 17 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 17; and an amino acid sequence shown in SEQ ID NO: 18 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 18; (7) An amino acid sequence as set forth in SEQ ID NO: 11 or an amino acid sequence having at least 75% identity with the amino acid sequence as set forth in SEQ ID NO: 11; and an amino acid sequence as set forth in SEQ ID NO: 12 or an amino acid sequence having at least 75% identity with the amino acid sequence as set forth in SEQ ID NO: 12; and (8) An amino acid sequence shown in SEQ ID NO: 19 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO: 19; and an amino acid sequence shown in SEQ ID NO: 20 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO:

20.

4. The antibody or fragment thereof is an anti-GPRC5D antibody or fragment thereof; Preferably, the antibody is in any form, such as a mouse antibody, rabbit antibody, monoclonal antibody, chimeric antibody, partially or fully humanized antibody; or the fragment is a half antibody or an antigen-binding fragment of an antibody or half antibody, such as scFv, BsFv, dsFv, (dsFv) ２ , Fab, Fab', F(ab') ２ or Fv; More preferably, the antibody is an IgG. An antibody or a fragment thereof according to any one of claims 1 to 3.

5. The antibody or fragment thereof further comprises a constant region; Preferably, the antibody or fragment thereof comprises a heavy chain and a light chain; More preferably, said antibody or fragment thereof comprises an IgG, IgA, IgM, IgD or IgE heavy chain constant region and / or a kappa or lambda type light chain constant region. An antibody or a fragment thereof according to any one of claims 1 to 4.

6. a first binding domain that binds to G protein-coupled receptor family C group 5 member D (GPRC5D) and a second binding domain that binds to CD3 on the surface of a T cell; The first binding domain comprises a heavy chain variable region (VH) and a light chain variable region (VL); The heavy chain variable region (VH) and the light chain variable region (VL) each comprise a combination of CDRs selected from the following: HCDR-1, HCDR-2, HCDR-3; LCDR-1, LCDR-2, LCDR-3. A bispecific antibody construct characterized in that: (1) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 28, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 29, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 30; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 31, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 32, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 33; (2) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 28, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 34, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 30; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 31, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 32, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 33; (3) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 35, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 36, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 37; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 38, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 39, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 40; (4) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 41, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 46; (5) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 47, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 42, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 43; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO: 45, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO: 46; and (6) HCDR-1 comprising the amino acid sequence shown in SEQ ID NO:47, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO:48, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO:43; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO:44, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO:45, LCDR-3 comprising the amino acid sequence shown in SEQ ID NO:

46.

7. In the first binding domain, the heavy chain variable region comprises a sequence selected from the amino acid sequence set forth in SEQ ID NO:5, SEQ ID NO:13, SEQ ID NO:7, SEQ ID NO:15, SEQ ID NO:9, SEQ ID NO:17, SEQ ID NO:11, or SEQ ID NO:19, or an amino acid sequence having at least 75% identity thereto; and / or the light chain variable region comprises a sequence selected from the amino acid sequence set forth in SEQ ID NO:6, SEQ ID NO:14, SEQ ID NO:8, SEQ ID NO:16, SEQ ID NO:10, SEQ ID NO:18, SEQ ID NO:12, or SEQ ID NO:20, or an amino acid sequence having at least 75% identity thereto.

7. The bispecific antibody construct of claim 6.

8. The heavy chain variable region and the light chain variable region contained in the first binding domain include a combination of sequences selected from the following:

8. A bispecific antibody construct according to claim 6 or 7, (1) an amino acid sequence shown in SEQ ID NO:5 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:5; and an amino acid sequence shown in SEQ ID NO:6 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:6; (2) an amino acid sequence shown in SEQ ID NO: 13 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 13; and an amino acid sequence shown in SEQ ID NO: 14 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 14; (3) an amino acid sequence shown in SEQ ID NO: 7 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 7; and an amino acid sequence shown in SEQ ID NO: 8 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 8; (4) an amino acid sequence shown in SEQ ID NO: 15 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 15; and an amino acid sequence shown in SEQ ID NO: 16 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 16; (5) an amino acid sequence shown in SEQ ID NO: 9 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 9; and an amino acid sequence shown in SEQ ID NO: 10 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 10; (6) an amino acid sequence shown in SEQ ID NO: 17 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 17; and an amino acid sequence shown in SEQ ID NO: 18 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO: 18; (7) an amino acid sequence as set forth in SEQ ID NO: 11 or an amino acid sequence having at least 75% identity with the amino acid sequence as set forth in SEQ ID NO: 11; and an amino acid sequence as set forth in SEQ ID NO: 12 or an amino acid sequence having at least 75% identity with the amino acid sequence as set forth in SEQ ID NO: 12; or (8) An amino acid sequence shown in SEQ ID NO: 19 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO: 19; and an amino acid sequence shown in SEQ ID NO: 20 or an amino acid sequence having at least 75% identity to the amino acid sequence shown in SEQ ID NO:

20.

9. The second binding domain comprises a heavy chain variable region (VH) and a light chain variable region (VL), and the heavy chain variable region (VH) and the light chain variable region (VL) comprise a combination of CDRs selected from the following: HCDR-1, HCDR-2, HCDR-3; LCDR-1, LCDR-2, LCDR-3. A bispecific antibody construct according to any one of claims 6 to 8, HCDR-1 comprising the amino acid sequence shown in SEQ ID NO:49, HCDR-2 comprising the amino acid sequence shown in SEQ ID NO:50, HCDR-3 comprising the amino acid sequence shown in SEQ ID NO:51; and LCDR-1 comprising the amino acid sequence shown in SEQ ID NO:52, LCDR-2 comprising the amino acid sequence shown in SEQ ID NO:53, and LCDR-3 comprising the amino acid sequence shown in SEQ ID NO:

54.

10. In the second binding domain, the heavy chain variable region comprises the amino acid sequence set forth in SEQ ID NO:21 or an amino acid sequence having at least 75% identity thereto; and the light chain variable region comprises the amino acid sequence set forth in SEQ ID NO:22 or an amino acid sequence having at least 75% identity thereto. A bispecific antibody construct according to any one of claims 6 to 9.

11. The bispecific antibody construct comprises four polypeptide chains. A bispecific antibody construct according to any one of claims 6 to 10, 1) heavy chain 1, which comprises domains arranged from N-terminus to C-terminus according to VH-CH1-CH2-CH3; 2) heavy chain 2, which comprises domains arranged from N-terminus to C-terminus according to VL-CH1-CH2-CH3; 3) light chain 1, which comprises domains arranged according to VL-CL from the N-terminus to the C-terminus; 4) a light chain 2 comprising domains arranged according to VH-CL from the N-terminus to the C-terminus; The VH and VL contained in heavy chain 1 and light chain 1 pair together to form a first binding domain that binds to the GPRC5D; the VL and VH contained in heavy chain 2 and light chain 2 pair together to form a second binding domain that binds to the CD3.

12. The antibody or fragment thereof of any one of claims 1 to 5 or the bispecific antibody construct of any one of claims 6 to 11 comprises a nucleotide sequence encoding a heavy chain CDR, a light chain CDR, a light chain variable region, a heavy chain variable region, a heavy chain or a light chain. A nucleic acid molecule comprising:

13. The nucleic acid molecule of claim 12 A vector characterized in that

14. Comprising a nucleic acid molecule according to claim 12 and / or a vector according to claim 13 A host cell characterized in that

15. 15. A method for the preparation of a method for the preparation of a bispecific antibody comprising the steps of: Preferably, it is a pharmaceutical composition, further comprising any pharma- ceutically acceptable auxiliary agent. A composition comprising:

16. Use of an antibody or fragment thereof according to any one of claims 1 to 5, a bispecific antibody construct according to any one of claims 6 to 11, a nucleic acid molecule according to claim 12, a vector according to claim 13, a host cell according to claim 14 and / or a composition according to claim 15 in the manufacture of a medicament for treating a disease, comprising the disease is a tumor or cancer, Preferably, the disease is a tumor or cancer associated with GPRC5D expression (e.g. high expression), such as lymphoma or myeloma, in particular multiple myeloma.

2. The use according to claim 1 ,

17. administering to a subject in need thereof an antibody or fragment thereof according to any one of claims 1 to 5, a bispecific antibody construct according to any one of claims 6 to 11, a nucleic acid molecule according to claim 12, a vector according to claim 13, a host cell according to claim 14 and / or a composition according to claim 15, the disease is a tumor or cancer; Preferably, the disease is a tumor or cancer associated with GPRC5D expression (e.g. high expression), such as a lymphoma or myeloma, in particular multiple myeloma; Preferably, the subject is a mammal; more preferably, the subject is a human. A method for treating a disease characterized by

18. Use of an antibody or fragment thereof according to any one of claims 1 to 5, a bispecific antibody construct according to any one of claims 6 to 11, a nucleic acid molecule according to claim 12, a vector according to claim 13, a host cell according to claim 14 and / or a composition according to claim 15 in the manufacture of a reagent for use in the diagnosis of a disease or for detecting the presence of the antigen GPRC5D, comprising the disease is a tumor or cancer; Preferably, the disease is a tumor or cancer associated with GPRC5D expression (e.g. high expression), such as lymphoma or myeloma, in particular multiple myeloma.

2. The use according to claim 1 ,

19. The antibody or fragment thereof according to any one of claims 1 to 5, the bispecific antibody construct according to any one of claims 6 to 11, the nucleic acid molecule according to claim 12, the vector according to claim 13, the host cell according to claim 14 and / or the composition according to claim 15. A kit characterized by:

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