Antibodies that bind to GPRC5D

Abstract

The present invention generally relates to antibodies that bind to GPRC5D, including bispecific antigen binding molecules, for example for activating T cells. In addition, the present invention relates to polynucleotides encoding such antibodies, as well as vectors and host cells comprising such polynucleotides. The present invention further relates to methods for generating the antibodies, and methods of using them in the treatment of diseases.

Description

Field of the Invention

[0001] The present invention generally relates to antibodies that bind to GPRC5D, including bispecific antigen-binding molecules, for use, for example, in activating T cells. Furthermore, the present invention relates to polynucleotides encoding such antibodies, as well as vectors and host cells comprising such polynucleotides. The present invention further relates to methods for producing such antibodies and methods of using such antibodies in the treatment of diseases. Background of the Invention

[0003] Affecting approximately 75,000 new patients annually in the EU and US, multiple myeloma (MM) is one of the most common hematologic malignancies, representing a significant unmet medical need. MM is characterized by terminally differentiated plasma cells that secrete nonfunctional monoclonal immunoglobulins. In the short term, immunomodulatory drugs such as lenalidomide and pomalidomide, and proteasome inhibitors such as carfilzomib or bortezomib, are likely to remain the backbone of first-line therapy for MM (Moreau, P. and SV Rajkumar, Multiple Myeloma-Translation of Trial Results into Reality. Lancet, 2016. 388(10040): p. 111-3). However, these drugs do not specifically target diseased tumor cells, such as diseased plasma cells (PCs). Efforts have been made to selectively deplete plasma cells in MM. The lack of surface proteins that specifically mark plasma cells has hindered the development of antibody or cell therapies for MM. To date, there have been few successful biologics, such as daratumumab (anti-CD38) and elotuzumab (anti-CD319), but it is important to note that these two molecules are not exclusively expressed by plasma cells. Therefore, RNA sequencing was used to identify novel targets from plasma cells in multiple myeloma, such as G protein-coupled receptor class C group 5 member D (GPRC5D). GPRC5D is a specific surface protein expressed by plasma cells in multiple myeloma. GPRC5D has been reported to be associated with prognosis and tumor burden in patients with multiple myeloma (Atamaniuk, J., et al., Overexpression of G protein-coupled receptor 5D in the bone marrow is associated with poor prognosis in patients with multiple myeloma. Eur J Clin Invest, 2012. 42(9): p. 953-60; and Cohen, Y., et al., GPRC5D is a promising marker for monitoring the tumor load and to target multiple myeloma cells. Hematology, 2013. 18(6): p. 348-51).

[0004] GPRC5D is an orphan receptor with no known ligand or function in humans or human cancers. The gene encoding GPRC5D, located on chromosome 12p13.3, contains three exons and spans approximately 9.6 kb (Brauner-Osborne, H., et al., Cloning and characterization of a human orphan family C G-protein coupled receptor GPRC5D. Biochim Biophys Acta, 2001. 1518(3): p. 237-48). The larger first exon encodes seven transmembrane domains. However, the biology of GPRC5D is largely unknown. GPRC5D has been shown to be involved in keratin formation in hair follicles in animals (Gao, Y., et al., Comparative Transcriptome Analysis of Fetal Skin Reveals Key Genes Related to Hair Follicle Morphogenesis in Cashmere Goats. PLoS One, 2016. 11(3): p. e0151118; and Inoue, S., T. Nambu, and T. Shimomura, The RAIG family member, GPRC5D, is associated with hard-keratinized structures. J Invest Dermatol, 2004. 122(3): p. 565-73).

[0005] WO 2018 / 017786A2 discloses GPRC5D-specific antibodies or antigen-binding fragments.

[0006] There is a need for additional drugs to treat cancer, particularly multiple myeloma. Particularly useful drugs for this purpose include antibodies that bind to GPRC5D, particularly bispecific antibodies that bind to GPRC5D on target cells and to an activating T cell antigen, such as CD3, on T cells. Simultaneous binding of such antibodies to their two targets forces a transient interaction between the target cell and the T cell, leading to activation of any cytotoxic T cells and subsequent lysis of the target cell.

[0007] The present invention provides novel antibodies that specifically bind to human GPRC5D, including bispecific antibodies. In particular, the T cell bispecific antibodies targeting GPRC5D according to the present invention have the efficacy of treating multiple myeloma. SUMMARY OF THE INVENTION

[0009] The present inventors have developed novel antibodies that bind to GPRC5D with unexpected, improved properties. Furthermore, the inventors have developed bispecific antigen-binding molecules that bind to GPRC5D and an activating T cell antigen and incorporate the novel GPRC5D antibodies.

[0010] In a first aspect, the present invention provides an antibody that binds to GPRC5D, wherein the antibody comprises (i) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89; and (ii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89. NO:88 LCDR 2 and SEQ ID NO:89 LCDR 3, (iii) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:91, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO:94, LCDR 2 of SEQ ID NO:95, and LCDR 3 of SEQ ID NO:97; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:91, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising NO:94, LCDR 2 of SEQ ID NO:96, and LCDR 3 of SEQ ID NO:97; or (v) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:92, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO:94, LCDR 2 of SEQ ID NO:95, and LCDR 3 of SEQ ID NO:97.Alternatively, the antibody may comprise (I) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6; or (II) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12. 3.In one embodiment, (i) the VH comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) the VH comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) the VH comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 48, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: NO:53; or (iv) the VH comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:52; or (v) the VH comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64; or (vi) the VH comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: NO:58, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63.In another embodiment, (i) the VH comprises the amino acid sequence of SEQ ID NO: 13, and the VL comprises the amino acid sequence of SEQ ID NO: 14; or (ii) the VH comprises the amino acid sequence of SEQ ID NO: 15, and the VL comprises the amino acid sequence of SEQ ID NO: 16; or (iii) the VH comprises the amino acid sequence of SEQ ID NO: 48, and the VL comprises the amino acid sequence of SEQ ID NO: 53; or (iv) the VH comprises the amino acid sequence of SEQ ID NO: 49, and the VL comprises the amino acid sequence of SEQ ID NO: 52; or (v) the VH comprises the amino acid sequence of SEQ ID NO: 57, and the VL comprises the amino acid sequence of SEQ ID NO: 64; or (vi) the VH comprises the amino acid sequence of SEQ ID NO: 58, and the VL comprises the amino acid sequence of SEQ ID NO: 63. In another embodiment, the antibody is an IgG, particularly an IgG1, antibody. In one embodiment, the antibody is a full-length antibody. In another embodiment, the antibody is an antibody fragment selected from the group consisting of an Fv molecule, a scFv molecule, a Fab molecule, and a F(ab')2 molecule. In one embodiment, the antibody is a multispecific antibody.

[0011] In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises (i) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89; and (ii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89; 3, the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89; (iii) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97 NO:93, the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO:94, LCDR 2 of SEQ ID NO:96 and LCDR 3 of SEQ ID NO:97; or (v) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:92, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO:94, LCDR 2 of SEQ ID NO:95 and LCDR 3 of SEQ ID NO:97.Alternatively, the first antigen binding moiety may comprise (I) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 1, HCDR2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6; or (II) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12. 3; and (b) a second antigen binding moiety that specifically binds to a second antigen.In one embodiment, (i) the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 13, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 15, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: NO:48, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:53; or (iv) the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO:49, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:52; or (v) the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: NO:57, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64; or (vi) the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO:58, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63.In one embodiment, (i) the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 13, and the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 14; or (ii) the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 15, and the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 16; or (iii) the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 48, and the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 53; or (iv) the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 49, and the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 52; or (v) the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 57, and the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 64; or (vi) the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: NO:58, and the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO:63. In another embodiment, the second antigen is CD3, particularly CD3ε. In one embodiment, the second antigen binding moiety comprises a VH comprising HCDR 1 of SEQ ID NO:29, HCDR 2 of SEQ ID NO:30, and HCDR 3 of SEQ ID NO:31, and a VL comprising LCDR 1 of SEQ ID NO:32, LCDR 2 of SEQ ID NO:33, and LCDR 3 of SEQ ID NO:34. In another embodiment, the VH of the second antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO:35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO:36. In another embodiment, the VH of the second antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 36.

[0012] In one embodiment, the first and / or the second antigen binding moiety is a Fab molecule. This means that either the first antigen binding moiety can be a Fab molecule, the second antigen binding moiety can be a Fab molecule, or the first antigen binding moiety and the second antigen binding moiety can be Fab molecules. In another embodiment, the second antigen binding moiety is a Fab molecule, wherein the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain, in particular the variable domains VL and VH, are replaced with each other. In another embodiment, the first antigen binding moiety is a Fab molecule in which the amino acid at position 124 in the constant domain is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index). In another embodiment, the first and second antigen binding moieties are fused to each other, optionally via a peptide linker. In another embodiment, the first and second antigen binding moieties are each a Fab molecule and wherein either (i) the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety, or (ii) the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety. In another embodiment, the bispecific antigen binding molecule comprises a third antigen binding moiety. In another embodiment, the third antigen binding moiety is the same as the first antigen binding moiety. In another embodiment, the bispecific antigen binding molecule comprises an Fc domain composed of a first and a second subunit. In another embodiment, the first, second, and, if present, third antigen binding moieties are each a Fab molecule; and wherein either (i) the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety and the C-terminus of the Fab heavy chain of the first antigen binding moiety is fused to the N-terminus of the first subunit of the Fc domain, or (ii) the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety and the C-terminus of the Fab heavy chain of the second antigen binding moiety is fused to the N-terminus of the first subunit of the Fc domain; and wherein the third antigen binding moiety, if present, is fused at the C-terminus of the Fab heavy chain to the N-terminus of the second subunit of the Fc domain. In another embodiment, the Fc domain is an IgG, particularly an IgG1, Fc domain. In yet another embodiment, the Fc domain is a human Fc domain.In another embodiment, amino acid residues in the CH3 domain of the first subunit of the Fc domain are replaced with amino acid residues having a larger side chain volume, thereby generating a protuberance within the CH3 domain of the first subunit that can be positioned within a cavity within the CH3 domain of the second subunit, and amino acid residues in the CH3 domain of the second subunit of the Fc domain are replaced with amino acid residues having a smaller side chain volume, thereby generating a cavity within the CH3 domain of the second subunit that can be positioned within the protuberance within the CH3 domain of the first subunit. In another embodiment, the Fc domain comprises one or more amino acid substitutions that reduce binding to an Fc receptor and / or effector function. This means that binding to an Fc receptor can be reduced, effector function can be reduced, or both binding to an Fc receptor and effector function can be reduced.

[0013] In another aspect, the present invention provides one or more isolated polynucleotides encoding an antibody or bispecific antigen-binding molecule as described herein. In yet another aspect, the present invention provides one or more vectors, particularly expression vectors, comprising one or more polynucleotides as described herein. In another aspect, the present invention provides a host cell comprising one or more polynucleotides as described herein or one or more vectors as described herein. In some embodiments, the host cell is a eukaryotic cell, particularly a mammalian cell.

[0014] In another aspect of the present invention, a method for producing an antibody that binds GPRC5D is provided, comprising the steps of: a) culturing a host cell as described herein under conditions suitable for expression of the antibody and b) optionally recovering the antibody. In another aspect, the present invention provides an antibody that binds GPRC5D produced by the method as described herein. Another aspect of the present invention relates to a pharmaceutical composition comprising an antibody or bispecific antigen-binding molecule as described herein and a pharmaceutically acceptable carrier. Another aspect of the present invention relates to an antibody or bispecific antigen-binding molecule as described herein, or a pharmaceutical composition as described herein, for use as a medicament. Another aspect of the present invention relates to an antibody or bispecific antigen-binding molecule as described herein, or a pharmaceutical composition as described herein, for use in the treatment of a disease. In one embodiment, the disease is cancer, particularly multiple myeloma. Alternatively, the disease is an autoimmune disease, such as systemic lupus erythematosus and / or rheumatoid arthritis.

[0015] The present invention further provides the use of an antibody or bispecific antigen-binding molecule as described herein in the manufacture of a medicament for treating a disease, particularly cancer, more particularly multiple myeloma. Alternatively, the disease is an autoimmune disease, such as systemic lupus erythematosus and / or rheumatoid arthritis.

[0016] In another aspect, the present invention relates to a method for treating a disease, particularly cancer, and more particularly multiple myeloma, in a subject, comprising administering to the subject a therapeutically effective amount of a composition comprising an antibody or bispecific antigen binding molecule as described herein in a pharmaceutically acceptable form. Alternatively, the disease is an autoimmune disease, such as systemic lupus erythematosus and / or rheumatoid arthritis. In any of the above embodiments, the subject is preferably a mammal, particularly a human. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 AZ. Exemplary configurations of bispecific antigen-binding molecules of the present invention. ( Figure 1 A, Figure 2 D) Schematic representation of the “1+1 CrossMab” molecule. ( Figure 1 B, Figure 1 E) Schematic representation of a "2+1 IgG Crossfab" molecule with an alternative order of Crossfab and Fab components ("inverted"). Figure 1 C, Figure 1 F) Schematic representation of the "2+1 IgG Crossfab" molecule. Figure 1 G, Figure 1 K) Schematic representation of a "1+1 IgG Crossfab" molecule with an alternative order of Crossfab and Fab components ("inverted"). Figure 1 H, Figure 1 L) Schematic representation of the "1+1 IgG Crossfab" molecule. Figure 1 I, Figure 1 M) Schematic representation of a "2+1 IgG Crossfab" molecule, which has two CrossFabs. ( Figure 1 J, Figure 1 N) Schematic representation of a "2+1 IgG CrossFab" molecule with two CrossFabs and an alternative order of CrossFab and Fab components ("inverted"). Figure 1 O, Figure 1 S) Schematic representation of a "Fab-Crossfab" molecule. ( Figure 1 P, Figure 1 T) Schematic representation of a "Crossfab-Fab" molecule. ( Figure 1 Q, Figure 1 U) Schematic representation of a "(Fab)2-Crossfab" molecule. Figure 1 R, Figure 1 V) Schematic representation of a "Crossfab-(Fab)2" molecule. Figure 1 W, Figure 1Y) Schematic representation of a "Fab-(Crossfab)2" molecule. Figure 1 X, Figure 1 Z) Schematic representation of a "(Crossfab)2-Fab" molecule. Black dots: optional Fc domain modifications promoting heterodimerization. ++, --: optional introduction of oppositely charged amino acids in the CH1 and CL domains. The Crossfab molecule is depicted as including VH and VL domain swaps, but can alternatively include CH1 and CL domain swaps in embodiments where charge modifications are not introduced in the CH1 and CL domains.

[0019] Figure 2 Analysis of gene expression of tumor targets on plasma cells and B cells by RNAseq.

[0020] Figure 3 Exemplary configurations of the 5E11 bispecific antigen-binding molecules of the present invention. Black dots: Optional Fc domain modifications promoting heterodimerization. ++,--: Optional introduction of oppositely charged amino acids into the CH1 and CL domains.

[0021] Figure 4 AC. Bispecific antigen binding molecule 5F11-TCB ( Figure 4 A) and 5E11-TCB ( Figure 4 B) and control antibody ET150-5-TCB ( Figure 4 C) Binding analysis on multiple myeloma cell lines AMO-1, L636, NCI-H929, RPMI-8226, OPM-2 and WSU-DLCL2.

[0022] Figure 5 AE. GPRC5D-TCB-mediated inhibition of multiple myeloma cell line AMO-1 ( Figure 5 A),NCI-H929( Figure 5 B), RPMI-8226( Figure 5 C) and L363( Figure 5 D) T cell cytotoxicity analysis. The control cell line was WSU-DL CL2 ( Figure 5 E). Test molecules: 5E11-TCB, 5F11-TCB. Control molecules: DP47-TCB (non-targeting) and ET150-5-TCB.

[0023] Figure 6 Analysis of GPRC5D-TCB-activated T cells that upregulate CD25 and CD69 in the multiple myeloma cell line NCI-H929 and the negative control cell line WSU-DLCL2.

[0024] Figure 7 AJ. Upregulation of cell line AMO-1 ( Figure 7 A),NCI-H929( Figure 7 B), RPMI-8226( Figure 7 C),L363( Figure 7 D) and WSU-DLCL2( Figure 7 E) CD25 and up-regulated in the cell line AMO-1 ( Figure 7 F),NCI-H929( Figure 7 G), RPMI-8226( Figure 7 H),L363( Figure 7 I) and WSU-DLCL2( Figure 7 J) Analysis of CD69-GPRC5D-TCB-activated T cells engaging multiple myeloma.

[0025] Figure 8 AB. Visualization of antibody localization and internalization by fluorescence confocal microscopy ( Figure 8 A) and analysis of membrane to cytoplasmic signal intensity ( Figure 8 B).

[0026] Figure 9 Binding of different anti-GPRC5D antibodies to human, cynomolgus monkey, and mouse GPRC5D was assessed by ELISA using stably transfected CHO clones expressing human GPRC5D (clone 12) or cynomolgus monkey GPRC5D (clone 13), mouse GPRC5D (clone 4), or human GPRC5A (clone 30).

[0027] Figure 10 AG. T cell-mediated lysis of various multiple myeloma (MM) cell lines induced by different GPRC5D- or BCMA-targeting T cell bispecific molecules during 20 hours of co-incubation (E:T = 10:1, human pan T cells). Depicted are duplicates and SD.

[0028] Figure 11 AF. Allogeneic pan-human T cells and unprocessed bone marrow cells from healthy donors (E:T = 10:1, human pan-T cells) were co-cultured for approximately 20 hours with different GPRC5D or BCMA-targeting T cell bispecific molecules ( Figure 11 A in 5E11-TCB; Figure 11 5F11-TCB in B; Figure 11 10B10-TCB in C; Figure 11 BCMA-TCB in D; Figure 11 BCMA-TCB in E; Figure 11T cell activation induced by DP47-TCB (in F). Depicted are FACS dot plots from a representative donor showing upregulation of the activation marker CD69 on CD4 (upper row) or CD8 T cells (lower row) as the percentage of positive cells among all CD4 or CD8 T cells.

[0029] Figure 12 AB. T cell activation induced by different GPRC5D- or BCMA-targeting T cell bispecific molecules during approximately 20 hours of co-incubation of allogeneic pan-human T cells with unprocessed bone marrow cells from healthy donors (E:T = 10:1, human pan-T cells). Depicted is a summary of all four evaluated donors, showing activation at the selected fixed dose of 50 nM ( Figure 12 A) or 5 nM ( Figure 12 B) Upregulation of the activation marker CD69 on CD8 T cells during TCB.

[0030] Figure 13 AD. Different GPRC5D-targeting T cell bispecific molecules ( Figure 13 5F11-TCB in A; Figure 13 BCMA-TCB in B; Figure 13 B72-TCB in C; Figure 13 Figure 3. In vivo efficacy of HER2-induced cytotoxicity (VEGEN-D) as depicted by tumor growth kinetics over time in a humanized NSG mouse model implanted with NCI-H929 tumor cells. Spider plots are drawn, with each line representing one mouse.

[0031] Figure 14 AD. Different GPRC5D-targeting T cell bispecific molecules ( Figure 14 5F11-TCB in A; Figure 14 5E11-TCB in B; Figure 14 B72-TCB in C; Figure 14 (D)-induced in vivo efficacy, as depicted by tumor growth kinetics over time in a humanized NSG mouse model implanted with OPM-2 tumor cells. Spider plots are drawn, with each line representing one mouse.

[0032] Figure 15 AB. PGLALA-CAR-J activation after approximately 16 hours of incubation, as measured by luminescence. The latter was activated in the presence of GPRC5D IgG ( Figure 15 5F11-IgG in A; Figure 15In B, 5E11-IgG was induced upon simultaneous binding of the GPRC5D-expressing multiple myeloma cell line L-363 and the PGLALA-modified Fc domain to Jurkat-NFAT reporter cells genetically engineered to express a TCR targeting the PGLALA mutation in the Fc portion of these IgG molecules. Depicted are duplicates and SD. Detailed Description of the Invention

[0034] definition

[0035] Unless otherwise defined below, terms are used herein as commonly used in the art.

[0036] As used herein, the term "antigen binding molecule" refers in its broadest sense to a molecule that specifically binds to an antigenic determinant. Examples of antigen binding molecules are immunoglobulins and their derivatives, such as fragments.

[0037] The term "bispecific" refers to an antigen-binding molecule that is capable of specifically binding to at least two different antigenic determinants. Typically, a bispecific antigen-binding molecule comprises two antigen-binding sites, each specific for a different antigenic determinant. In certain embodiments, the bispecific antigen-binding molecule is capable of simultaneously binding to two antigenic determinants, particularly two antigenic determinants expressed on two different cells.

[0038] As used herein, the term "valent" refers to the presence of a specified number of antigen-binding sites in an antigen-binding molecule. Thus, the term "monovalent binding to an antigen" refers to the presence of one (and no more than one) antigen-binding site in an antigen-binding molecule that is specific for the antigen.

[0039] An "antigen-binding site" refers to the site, or one or more amino acid residues, on an antigen-binding molecule that interacts with an antigen. For example, the antigen-binding site of an antibody comprises amino acid residues from the complementarity-determining regions (CDRs). Natural immunoglobulin molecules typically have two antigen-binding sites, while Fab molecules typically have a single antigen-binding site.

[0040] As used herein, the term "antigen binding moiety" refers to a polypeptide molecule that specifically binds to an antigenic determinant. In one embodiment, the antigen binding moiety is capable of directing an entity to which it is attached (e.g., a second antigen binding moiety) to a target site, such as a specific type of tumor cell bearing the antigenic determinant. In another embodiment, the antigen binding moiety is capable of activating signaling via its target antigen, such as a T-cell receptor complex antigen. Antigen binding moieties include antibodies and fragments thereof as further defined herein. Specific antigen binding moieties include the antigen binding domain of an antibody, which comprises an antibody heavy chain variable region and an antibody light chain variable region. In certain embodiments, the antigen binding moiety may comprise an antibody constant region, as further defined herein and known in the art. Available heavy chain constant regions include any of the following five isotypes: α, δ, ε, γ, or μ. Available light chain constant regions include any of the following two isotypes: κ and λ.

[0041] As used herein, the term "antigenic determinant" is synonymous with "antigen" and "epitope" and refers to a site on a polypeptide macromolecule (e.g., a continuous stretch of amino acids or a conformational configuration consisting of distinct regions of discontinuous amino acids) to which an antigen-binding moiety binds, thereby forming an antigen-binding moiety-antigen complex. Useful antigenic determinants can be found, for example, on the surface of tumor cells, on the surface of virus-infected cells, on the surface of other diseased cells, on the surface of immune cells, free in blood serum, and / or in the extracellular matrix (ECM). Unless otherwise indicated, proteins referred to herein as antigens (e.g., GPRC5D, CD3) can be any native form of the protein from any vertebrate source, including mammals such as primates (e.g., humans), non-human primates (e.g., cynomolgus monkeys), and rodents (e.g., mice and rats). In a specific embodiment, the antigen is a human protein. Where reference is made to a specific protein herein, the term encompasses the "full-length," unprocessed protein as well as any form of the protein resulting from processing in the cell. The term also encompasses naturally occurring variants of the protein, such as splice variants or allelic variants. An exemplary human protein that can be used as an antigen is CD3, in particular the epsilon subunit of CD3 (for the human sequence, see UniProt no. P07766 (Release 185), NCBI RefSeq no. NP_000724.1, SEQ ID NO: 40; or for the cynomolgus monkey [Macaca fascicularis] sequence, see UniProt no. Q95LI5 (Release 69), NCBI GenBank no. BAB71849.1, SEQ ID NO: 41), or GPRC5D (for the human sequence, see UniProt no. Q9NZD1 (Release 115); NCBI RefSeq no. NP_061124.1, SEQ ID NO: 45). In certain embodiments, the antibodies or bispecific antigen-binding molecules of the invention bind to an epitope of CD3 or GPRC5D that is conserved between CD3 or GPRC5D antigens from different species. In specific embodiments, the antibodies or bispecific antigen-binding molecules of the invention bind to human GPRC5D.

[0042] "Specific binding" means that the binding is selective for the antigen and can be distinguished from unwanted or non-specific interactions. The ability of an antigen-binding moiety to bind to a specific antigenic determinant can be measured by enzyme-linked immunosorbent assay (ELISA) or other techniques known to those skilled in the art, such as surface plasmon resonance (SPR) technology (e.g., analysis on a BIAcore instrument) (Liljeblad et al., Glyco J 17, 323-329 (2000)), and traditional binding assays (Heeley, Endocr Res 28, 217-229 (2002)). In one embodiment, the extent of binding of an antigen-binding moiety to an unrelated protein is less than about 10% of the binding of the antigen-binding moiety to the antigen, as measured, for example, by SPR. In certain embodiments, an antigen binding moiety that binds to an antigen, or an antigen binding molecule comprising the antigen binding moiety, has a C-terminal affinity of ≤1 μM, ≤100 nM, ≤10 nM, ≤1 nM, ≤0.1 nM, ≤0.01 nM, or ≤0.001 nM (e.g., 10 -8 M or less, such as 10 -8 M to 10 -13 M, for example 10 -9 M to 10 -13 The dissociation constant (K D ).

[0043] "Affinity" refers to the strength of the sum of non-covalent interactions between a single binding site of a molecule (e.g., a receptor) and its binding partner (e.g., a ligand). Unless otherwise indicated, as used herein, "binding affinity" refers to the intrinsic binding affinity that reflects a 1:1 interaction between members of a binding pair (e.g., an antigen binding moiety and an antigen, or a receptor and its ligand). The affinity of a molecule X for its partner Y can generally be expressed in terms of the dissociation constant (K D ) are expressed as the dissociation and association rate constants (K 解离 and K 结合 ). Thus, equal affinities may comprise different rate constants, as long as the ratio of the rate constants remains the same. Affinity can be measured by established methods known in the art, including those described herein. One specific method for measuring affinity is surface plasmon resonance (SPR).

[0044] "Decreased binding," e.g., reduced binding to an Fc receptor, refers to a decrease in the affinity of the corresponding interaction, as measured, e.g., by SPR. For clarity, the term also encompasses a decrease in affinity to zero (or below the detection limit of the analytical method), i.e., complete abolition of the interaction. Conversely, "increased binding" refers to an increase in the binding affinity of the corresponding interaction.

[0045] As used herein, "activating T cell antigen" refers to an antigenic determinant expressed on the surface of T lymphocytes, particularly cytotoxic T lymphocytes, which can induce T cell activation after interacting with an antigen binding molecule. Specifically, the interaction of an antigen binding molecule with an activating T cell antigen can induce T cell activation by triggering the signaling cascade of the T cell receptor complex. In a specific embodiment, the activating T cell antigen is CD3, particularly the epsilon subunit of CD3 (for human sequences, see UniProt no. P07766 (Release 144), NCBI RefSeq no. NP_000724.1, SEQ ID NO: 40; or for cynomolgus monkey [Macaca fascicularis] sequences, see UniProt no. Q95LI5 (Release 49), NCBI GenBank no. BAB71849.1, SEQ ID NO: 41).

[0046] As used herein, "T cell activation" refers to one or more cellular responses of T lymphocytes, particularly cytotoxic T lymphocytes, selected from the group consisting of proliferation, differentiation, cytokine secretion, cytotoxic effector molecule release, cytotoxic activity, and expression of activation markers. Suitable assays for measuring T cell activation are known in the art and described herein.

[0047] As used herein, "target cell antigen" refers to an antigenic determinant presented on the surface of a target cell, such as a cell in a tumor, such as a cancer cell or a cell of the tumor stroma. In a particular embodiment, the target cell antigen is GPRC5D, in particular human GPRC5D according to SEQ ID NO: 45.

[0048] As used herein, the terms "first," "second," or "third" are used with respect to Fab molecules, etc., to facilitate differentiation when there is more than one of each type of module. Unless explicitly stated otherwise, the use of these terms is not intended to confer a particular order or orientation on the bispecific antigen-binding molecules.

[0049] "Fusion" means that the building blocks (eg, a Fab molecule and an Fc domain subunit) are linked by peptide bonds, either directly or via one or more peptide linkers.

[0050] "Fab molecule" refers to a protein composed of the VH and CH1 domains of an immunoglobulin heavy chain ("Fab heavy chain") and the VL and CL domains of a light chain ("Fab light chain").

[0051] "Exchange" Fab molecules (also referred to as "Crossfab") refer to Fab molecules in which the variable or constant domains of the Fab heavy and light chains are exchanged (i.e., replaced with each other), i.e., the exchange Fab molecules comprise a peptide chain (VL-CH1, N to C-terminal direction) consisting of the light chain variable domain VL and the heavy chain constant domain 1CH1, and a peptide chain (VH-CL, N to C-terminal direction) consisting of the heavy chain variable domain VH and the light chain constant domain CL. For clarity, in exchange Fab molecules in which the variable domains of the Fab light chain and the Fab heavy chain are exchanged, the peptide chain comprising the heavy chain constant domain 1CH1 is referred to herein as the "heavy chain" of the (exchange) Fab molecule. Conversely, in exchange Fab molecules in which the constant domains of the Fab light chain and the Fab heavy chain are exchanged, the peptide chain comprising the heavy chain variable domain VH is referred to herein as the "heavy chain" of the (exchange) Fab molecule.

[0052] In contrast, a "conventional" Fab molecule is intended to be a Fab molecule in its natural form, i.e., comprising a heavy chain consisting of the heavy chain variable and constant domains (VH-CH1, in N to C-terminal direction), and a light chain consisting of the light chain variable and constant domains (VL-CL, in N to C-terminal direction).

[0053] The term "immunoglobulin molecule" refers to a protein with the structure of a naturally occurring antibody. For example, immunoglobulins of the IgG class are heterotetrameric glycoproteins of approximately 150,000 daltons, composed of two light chains and two heavy chains connected by disulfide bonds. From N-terminus to C-terminus, each heavy chain has a variable domain (VH), also called a variable heavy domain or heavy chain variable region, followed by three constant domains (CH1, CH2, and CH3), also called heavy chain constant regions. Similarly, from N-terminus to C-terminus, each light chain has a variable domain (VL), also called a variable light domain or light chain variable region, followed by a constant light (CL) domain (also called a light chain constant region). Immunoglobulin heavy chains can be assigned to one of five classes, designated α (IgA), δ (IgD), ε (IgE), γ (IgG), or μ (IgM), some of which can be further divided into subclasses, such as γ1 (IgG1), γ2 (IgG2), γ3 (IgG3), γ4 (IgG4), α1 (IgA1), and α2 (IgA2). Immunoglobulin light chains can be assigned to one of two classes, designated kappa (κ) and lambda (λ), based on the amino acid sequence of their constant domains. Immunoglobulins are essentially composed of two Fab molecules and an Fc domain connected by an immunoglobulin hinge region.

[0054] The term "antibody" is used herein in the broadest sense and encompasses various antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments, so long as they exhibit the desired antigen-binding activity.

[0055] As used herein, the term "monoclonal antibody" refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies contained in the population are identical and / or bind to the same epitope, except for possible variant antibodies containing, for example, naturally occurring mutations or arising during the production of the monoclonal antibody preparation, such variants generally being present in minimal amounts. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a single determinant on the antigen. Thus, the modifier "monoclonal" indicates the characteristic of the antibody being obtained from a population of substantially homogeneous antibodies and should not be construed as requiring production of the antibody by any particular method. For example, monoclonal antibodies to be used in accordance with the present invention can be produced by a variety of techniques, including, but not limited to, hybridoma methods, recombinant DNA methods, phage display methods, and methods utilizing transgenic animals containing all or part of the human immunoglobulin loci. Such methods and other exemplary methods for producing monoclonal antibodies are described herein.

[0056] An "isolated" antibody is one that has been separated from components of its natural environment, i.e., is not in its natural environment. No particular level of purification is required. For example, an isolated antibody can be removed from its natural or native environment. For the purposes of the present invention, recombinantly produced antibodies expressed in host cells are considered isolated, as are natural or recombinant antibodies that have been separated, fractionated, or partially or substantially purified by any suitable technique. Thus, the antibodies and bispecific antigen-binding molecules of the present invention are isolated. In some embodiments, the antibodies are purified to a purity greater than 95% or 99% as determined by, for example, electrophoresis (e.g., SDS-PAGE, isoelectric focusing (IEF), capillary electrophoresis) or chromatography (e.g., ion exchange or reverse-phase HPLC). For a review of methods for assessing antibody purity, see, for example, Flatman et al., J. Chromatogr. B 848:79-87 (2007).

[0057] The terms "full-length antibody," "intact antibody," and "whole antibody" are used interchangeably herein to refer to an antibody that has a structure substantially similar to a native antibody structure.

[0058] "Antibody fragment" refers to a molecule other than an intact antibody that contains a portion of an intact antibody that binds to the antigen to which the intact antibody binds. Examples of antibody fragments include, but are not limited to, Fv, Fab, Fab', Fab'-SH, F(ab')2, diabodies, linear antibodies, single-chain antibody molecules (e.g., scFv), and single-domain antibodies. For a review of certain antibody fragments, see Hudson et al., Nat Med 9, 129-134 (2003). For a review of scFv fragments, see, for example, Plückthun, in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore, eds., Springer-Verlag, New York, pp. 269-315 (1994); see also WO 93 / 16185; and U.S. Patent Nos. 5,571,894 and 5,587,458. For a discussion of Fab and F(ab')2 fragments comprising salvage receptor binding epitope residues and having extended in vivo half-lives, see U.S. Patent No. 5,869,046. Diabodies are antibody fragments with two antigen-binding sites that can be bivalent or bispecific. See, for example, EP 404,097; WO 1993 / 01161; Hudson et al., Nat Med 9, 129-134 (2003); and Hollinger et al., Proc Natl Acad Sci USA 90, 6444-6448 (1993). Triabodies and tetrabodies are also described in Hudson et al., Nat Med 9, 129-134 (2003). Single-domain antibodies are antibody fragments that comprise all or part of the heavy chain variable domain, or all or part of the light chain variable domain, of an antibody. In certain embodiments, the single-domain antibody is a human single-domain antibody (Domantis, Inc., Waltham, MA; see, e.g., U.S. Patent No. 6,248,516 Bl). Antibody fragments can be prepared by various techniques, including but not limited to proteolytic digestion of intact antibodies and production by recombinant host cells (e.g., E. coli or phage), as described herein.

[0059] The term "antigen-binding domain" refers to the portion of an antibody that contains the region that specifically binds to part or all of an antigen and is complementary to it. An antigen-binding domain can be provided, for example, by one or more antibody variable domains (also referred to as antibody variable regions). Specifically, an antigen-binding domain comprises an antibody light chain variable domain (VL) and an antibody heavy chain variable domain (VH).

[0060] The term "variable region" or "variable domain" refers to the domain of an antibody heavy or light chain that is involved in binding the antibody to an antigen. The variable domains of the heavy and light chains of natural antibodies (VH and VL, respectively) generally have similar structures, with each domain comprising four conserved framework regions (FRs) and three hypervariable regions (HVRs). See, for example, Kindt et al., Kuby Immunology, 6th ed., WH Freeman and Co., p. 91 (2007). A single VH or VL domain may be sufficient to confer antigen-binding specificity. As used herein in connection with variable region sequences, "Kabat numbering" refers to the numbering system proposed by Kabat et al., Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD (1991).

[0061] As used herein, the amino acid positions of the constant regions and domains of all heavy and light chains are numbered according to the Kabat numbering system described in Kabat, et al., Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD (1991), referred to herein as "numbering according to Kabat" or "Kabat numbering." Specifically, the Kabat numbering system (see pages 647-660 of Kabat et al., Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD (1991)) is used for the light chain constant domains CL of the kappa and lambda isotypes and the Kabat EU index numbering system (see pages 661-723) is used for the heavy chain constant domains (CH1, hinge, CH2 and CH3), in which case this is further clarified herein by reference to "numbering according to the Kabat EU index."

[0062] As used herein, the term "hypervariable region" or "HVR" refers to each region of an antibody variable domain that is hypervariable in sequence ("complementarity determining region" or "CDR"; CDRs of the heavy chain variable region / domain are abbreviated as, for example, HCDR1, HCDR2, and HCDR3; CDRs of the light chain variable region / domain are abbreviated as, for example, LCDR1, LCDR2, and LCDR3) and / or form structurally defined loops ("hypervariable loops") and / or contain antigen-contacting residues ("antigen contacts"). Generally, antibodies comprise six HVRs: three in VH (H1, H2, H3) and three in VL (L1, L2, L3). Exemplary HVRs herein include:

[0063] (a) Hypervariable loops, present at amino acid residues 26-32 (L1), 50-52 (L2), 91-96 (L3), 26-32 (H1), 53-55 (H2), and 96-101 (H3) (Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987));

[0064] (b) CDRs, present at amino acid residues 24-34 (L1), 50-56 (L2), 89-97 (L3), 31-35b (H1), 50-65 (H2), and 95-102 (H3) (Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD (1991));

[0065] (c) antigenic contacts, present at amino acid residues 27c-36 (L1), 46-55 (L2), 89-96 (L3), 30-35b (H1), 47-58 (H2), and 93-101 (H3) (MacCallum et al. J. Mol. Biol. 262:732-745 (1996)); and

[0066] (d) a combination of (a), (b), and / or (c), including HVR amino acid residues 46-56 (L2), 47-56 (L2), 48-56 (L2), 49-56 (L2), 26-35 (H1), 26-35b (H1), 49-65 (H2), 93-102 (H3), and 94-102 (H3).

[0067] Unless otherwise indicated, HVR residues and other residues in the variable domain (eg, FR residues) are numbered herein according to Kabat et al., supra.

[0068] "Framework" or "FR" refers to variable domain residues excluding hypervariable region (HVR) residues. The variable domain FR generally consists of four FR domains: FR1, FR2, FR3, and FR4. Thus, HVR and FR sequences generally appear in the following order in VH (or VL): FR1-H1(L1)-FR2-H2(L2)-FR3-H3(L3)-FR4.

[0069] A "humanized" antibody refers to a chimeric antibody that comprises amino acid residues from non-human HVRs and amino acid residues from human FRs. In certain embodiments, a humanized antibody will comprise at least one, and typically two, substantially entire variable domains, in which all or substantially all of the HVRs (e.g., CDRs) correspond to those of a non-human antibody, and all or substantially all of the FRs correspond to those of a human antibody. Such variable domains are referred to herein as "humanized variable regions." Optionally, a humanized antibody may comprise at least a portion of an antibody constant region derived from a human antibody. In some embodiments, some FR residues in a humanized antibody are replaced with corresponding residues from a non-human antibody (e.g., the antibody from which the HVR residues are derived), for example, to restore or improve antibody specificity or affinity. A "humanized form" of an antibody (e.g., a non-human antibody) refers to an antibody that has undergone humanization. Other forms of "humanized antibodies" encompassed by the present invention are those in which the constant region has been modified or altered from that of the original antibody to generate the properties according to the present invention (particularly with respect to C1q binding and / or Fc receptor (FcR) binding).

[0070] A "human antibody" refers to an antibody that possesses an amino acid sequence that corresponds to the amino acid sequence of an antibody produced by a human or human cell, or derived from a non-human source using a human antibody repertoire or other human antibody coding sequence. This definition of a human antibody specifically excludes humanized antibodies that contain non-human antigen-binding residues. In certain embodiments, human antibodies are derived from non-human transgenic mammals, such as mice, rats, or rabbits. In certain embodiments, human antibodies are derived from hybridoma cell lines. Antibodies or antibody fragments isolated from human antibody libraries are also considered human antibodies or human antibody fragments herein.

[0071] The "class" of an antibody or immunoglobulin refers to the type of constant domain or region possessed by its heavy chain. There are five major classes of antibodies: IgA, IgD, IgE, IgG, and IgM, and several of these can be further divided into subclasses (isotypes), such as IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. The heavy chain constant domains corresponding to the different immunoglobulin classes are called α, δ, ε, γ, and μ, respectively.

[0072] The term "Fc domain" or "Fc region" is used herein to define the C-terminal region of an immunoglobulin heavy chain that contains at least a portion of the constant region. This term encompasses both native-sequence Fc regions and variant Fc regions. Although the boundaries of the Fc region of an IgG heavy chain can vary slightly, the human IgG heavy chain Fc region is typically defined as extending from Cys226 or Pro230 to the carboxyl terminus of the heavy chain. However, antibodies produced by host cells may undergo post-translational cleavage, which removes one or more, particularly one or two, amino acids from the C-terminus of the heavy chain. Thus, an antibody produced by a host cell by expressing a specific nucleic acid molecule encoding a full-length heavy chain may include a full-length heavy chain, or it may include a cleaved variant of the full-length heavy chain (also referred to herein as a "cleaved variant heavy chain"). This may be the case when the final two C-terminal amino acids of the heavy chain are glycine (G446) and lysine (K447, numbering according to the Kabat EU index). Thus, the C-terminal lysine (Lys447), or both the C-terminal glycine (Gly446) and the lysine (K447), of the Fc region may be present or absent. Unless otherwise indicated, the amino acid sequence of a heavy chain comprising an Fc domain (or a subunit of an Fc domain as defined herein) is herein expressed without the C-terminal glycine-lysine dipeptide. In one embodiment of the present invention, the heavy chain comprising a subunit of an Fc domain as defined herein, contained in an antibody or bispecific antigen-binding molecule according to the present invention, comprises an additional C-terminal glycine-lysine dipeptide (G446 and K447, numbering according to the EU index as defined by Kabat). In one embodiment of the present invention, the heavy chain comprising a subunit of an Fc domain as defined herein, contained in an antibody or bispecific antigen-binding molecule according to the present invention, comprises an additional C-terminal glycine residue (G446, numbering according to the EU index as defined by Kabat). Compositions of the present invention, such as the pharmaceutical compositions described herein, comprise a population of antibodies or bispecific antigen-binding molecules of the present invention. A population of antibodies or bispecific antigen-binding molecules may comprise molecules having full-length heavy chains and molecules having cleaved variant heavy chains. A population of antibodies or bispecific antigen-binding molecules can be composed of a mixture of molecules with full-length heavy chains and molecules with cleavage variant heavy chains, wherein at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the antibodies or bispecific antigen-binding molecules have cleavage variant heavy chains. In one embodiment of the invention, a composition comprising a population of antibodies or bispecific antigen-binding molecules of the invention comprises an antibody or bispecific antigen-binding molecule comprising a heavy chain comprising one subunit of the Fc domain as defined herein and additionally a C-terminal glycine-lysine dipeptide (G446 and K447, numbering according to the EU index as in Kabat).In one embodiment of the invention, a composition comprising a population of antibodies or bispecific antigen-binding molecules of the invention comprises an antibody or bispecific antigen-binding molecule comprising a heavy chain comprising one subunit of an Fc domain as specified herein and an additional C-terminal glycine residue (G446, numbering according to the EU index as of Kabat). In one embodiment of the invention, such a composition comprises a population of antibodies or bispecific antigen-binding molecules composed of molecules comprising a heavy chain comprising one subunit of an Fc domain as specified herein; molecules comprising a heavy chain comprising one subunit of an Fc domain as specified herein and an additional C-terminal glycine residue (G446, numbering according to the EU index as of Kabat), and molecules comprising a heavy chain comprising one subunit of an Fc domain as specified herein and an additional C-terminal glycine-lysine dipeptide (G446 and K447, numbering according to the EU index as of Kabat). Unless otherwise specified herein, the numbering of amino acid residues in the Fc region or constant region is in accordance with the EU numbering system, also known as the EU index, as described in Kabat et al., Sequences of Proteins of Immunological Interest, 5th ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991 (see also above). As used herein, a "subunit" of an Fc domain refers to one of the two polypeptides that form a dimeric Fc domain, i.e., a polypeptide comprising the C-terminal constant region of an immunoglobulin heavy chain that is capable of stabilizing its own association. For example, a subunit of an IgG Fc domain comprises the IgG CH2 and IgG CH3 constant domains.

[0073] A "modification that promotes association of the first and second Fc domain subunits" is a peptide backbone manipulation or post-translational modification of an Fc domain subunit that reduces or prevents a polypeptide comprising an Fc domain subunit from associating with an identical polypeptide to form a homodimer. As used herein, a modification that promotes association specifically includes separate modifications made to each of the two Fc domain subunits (i.e., the first and second Fc domain subunits) for which association is desired, wherein the modifications are complementary to each other, thereby promoting association of the two Fc domain subunits. For example, a modification that promotes association may alter the structure or charge of one or both Fc domain subunits, thereby promoting their association sterically or electrostatically, respectively. Thus, (hetero)dimerization occurs between a polypeptide comprising the first Fc domain subunit and a polypeptide comprising the second Fc domain subunit, which may differ in that the additional components (e.g., antigen-binding moieties) fused to each subunit are different. In some embodiments, the modification that promotes association comprises an amino acid mutation, specifically an amino acid substitution, in the Fc domain. In a specific embodiment, the modification that promotes association comprises a separate amino acid mutation, specifically an amino acid substitution, in each of the two Fc domain subunits.

[0074] The term "effector function" refers to those biological activities attributable to the Fc region of an antibody and which vary with the antibody isotype. Examples of antibody effector functions include: C1q binding and complement-dependent cytotoxicity (CDC), Fc receptor binding, antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), cytokine secretion, immune complex-mediated antigen uptake by antigen-presenting cells, downregulation of cell surface receptors (e.g., B cell receptor), and B cell activation.

[0075] As used herein, the term "engineering" is considered to include any manipulation of the peptide backbone or post-translational modification of a naturally occurring or recombinant polypeptide or fragment thereof. Engineering includes modifications to the amino acid sequence, glycosylation pattern, or individual amino acid side chain groups, as well as combinations of these approaches.

[0076] As used herein, the term "amino acid mutation" is intended to encompass amino acid substitutions, deletions, insertions, and modifications. Any combination of substitutions, deletions, insertions, and modifications can be performed to achieve the final construct, as long as the final construct possesses the desired properties, such as reduced binding to Fc receptors or increased binding to another peptide. Amino acid sequence deletions and insertions include amino- and / or carboxyl-terminal deletions and amino acid insertions. A specific amino acid mutation is an amino acid substitution. To alter, for example, the binding characteristics of the Fc region, non-conservative amino acid substitutions are particularly preferred, i.e., replacing one amino acid with another with different structural and / or chemical properties. Amino acid substitutions include replacement with non-naturally occurring amino acids or with naturally occurring amino acid derivatives of the 20 standard amino acids (e.g., 4-hydroxyproline, 3-methylhistidine, ornithine, homoserine, 5-hydroxylysine). Amino acid mutations can be generated using genetic or chemical methods known in the art. Genetic methods can include site-directed mutagenesis, PCR, gene synthesis, and the like. It is also contemplated that methods other than genetic engineering, such as chemical modification, to alter amino acid side chain groups may also be useful. Various names may be used herein to refer to the same amino acid mutation. For example, a substitution from proline at position 329 of the Fc domain to glycine can be indicated as 329G, G329, G 329 ,P329G or Pro329Gly.

[0077] "Percent (%) amino acid sequence identity" with respect to a reference polypeptide sequence is defined as the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in the reference polypeptide sequence, after aligning the sequences and introducing gaps, if necessary, to achieve maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for the purpose of determining percent amino acid sequence identity can be performed in a variety of ways within the skill in the art, for example, using publicly available computer software such as BLAST, BLAST-2, Clustal W, Megalign (DNASTAR) software, or the FASTA package. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. However, for purposes herein, % amino acid sequence identity values ​​are generated using the ggsearch program in the FASTA package, version 36.3.8c or later, and the BLOSUM50 comparison matrix. The FASTA program package was written by W.R. Pearson and DJ Lipman (1988) "Improved Tools for Biological Sequence Analysis", PNAS 85:2444-2448; W.R. Pearson (1996) "Effective protein sequence comparison", Meth. Enzymol. 266:227-258; and Pearson et al. (1997) Genomics 46:24-36 and is publicly available at http: / / fasta.bioch.virginia.edu / fasta_www2 / fasta_down.shtml. Alternatively, sequences can be compared using the public server available at http: / / fasta.bioch.virginia.edu / fasta_www2 / index.cgi using the ggsearch (global protein:protein) program and default options (BLOSUM50; open: -10; extend: -2; Ktup = 2) to ensure a global rather than local alignment. The percent amino acid identity is given in the output alignment header.

[0078] The term "polynucleotide" refers to an isolated nucleic acid molecule or construct, such as messenger RNA (mRNA), virally derived RNA, or plasmid DNA (pDNA). A polynucleotide can contain conventional phosphodiester bonds or unconventional bonds (e.g., amide bonds, as found in peptide nucleic acids (PNA)). The term "nucleic acid molecule" refers to any one or more nucleic acid segments, such as DNA or RNA fragments, present in a polynucleotide.

[0079] An "isolated" nucleic acid molecule or polynucleotide means a nucleic acid molecule, DNA or RNA, that has been removed from its natural environment. For example, a recombinant polynucleotide encoding a polypeptide contained in a vector is considered isolated for the purposes of the present invention. Other examples of isolated polynucleotides include recombinant polynucleotides maintained in heterologous host cells or purified (partially or substantially) polynucleotides in solution. An isolated polynucleotide includes a polynucleotide molecule contained in a cell that normally contains the polynucleotide molecule, but the polynucleotide molecule is present extrachromosomally or at a chromosomal location that is different from its natural chromosomal location. Isolated RNA molecules include in vivo or in vitro RNA transcripts of the present invention, as well as positive and negative strand forms, and double-stranded forms. Isolated polynucleotides or nucleic acids according to the present invention also include such molecules produced synthetically. In addition, a polynucleotide or nucleic acid can be or can include regulatory elements such as a promoter, a ribosome binding site, or a transcription terminator.

[0080] An "isolated polynucleotide (or nucleic acid) encoding [e.g., an antibody or bispecific antigen-binding molecule of the invention]" refers to one or more polynucleotide molecules encoding the heavy and light chains of an antibody (or fragments thereof), including such polynucleotide molecules in a single vector or separate vectors, and such nucleic acid molecules present at one or more locations in a host cell.

[0081] The term "expression cassette" refers to a recombinantly or synthetically generated polynucleotide comprising a series of defined nucleic acid elements that permit transcription of a specific nucleic acid in a target cell. Recombinant expression cassettes can be incorporated into plasmids, chromosomes, mitochondrial DNA, plastid DNA, viruses, or nucleic acid fragments. Typically, the recombinant expression cassette portion of an expression vector comprises, among other things, the nucleic acid sequence to be transcribed and a promoter. In certain embodiments, the expression cassette comprises a polynucleotide sequence encoding an antibody or bispecific antigen-binding molecule of the present invention, or a fragment thereof.

[0082] The term "vector" or "expression vector" refers to a DNA molecule used to introduce a specific gene into a cell and direct its expression. The term includes vectors that are autonomously replicating nucleic acid structures as well as vectors that are incorporated into the genome of a host cell into which they have been introduced. The expression vectors of the present invention comprise an expression cassette. Expression vectors allow for the transcription of large amounts of stable mRNA. Once the expression vector is within the cell, the cellular transcription and / or translation machinery produces the RNA molecule or protein encoded by the gene. In one embodiment, the expression vector of the present invention comprises an expression cassette comprising a polynucleotide sequence encoding an antibody or bispecific antigen-binding molecule of the present invention, or a fragment thereof.

[0083] The terms "host cell," "host cell line," and "host cell culture" are used interchangeably to refer to cells into which exogenous nucleic acid has been introduced, including the progeny of such cells. Host cells include "transformants" and "transformed cells," which include the initially transformed cell and its progeny (regardless of the number of passages). Progeny may not be completely identical to the parent cell in terms of nucleic acid content, but may contain mutations. Mutant progeny that have the same function or biological activity as screened or selected for in the originally transformed cell are included herein. A host cell is any type of cell system that can be used to produce the antibodies or bispecific antigen-binding molecules of the present invention. Host cells include cultured cells, for example, cultured mammalian cells such as HEK cells, CHO cells, BHK cells, NSO cells, SP2 / 0 cells, YO myeloma cells, P3X63 mouse myeloma cells, PER cells, PER.C6 cells, or hybridoma cells, yeast cells, insect cells, and plant cells, among others, and also include cells contained in transgenic animals, transgenic plants, or cultured plant or animal tissues.

[0084] An "activating Fc receptor" is an Fc receptor that, upon engagement by the Fc domain of an antibody, triggers signaling events that stimulate cells bearing the receptor to carry out effector functions. Human activating Fc receptors include FcγRIIIa (CD16a), FcγRI (CD64), FcγRIIa (CD32), and FcαRI (CD89).

[0085] Antibody-dependent cell-mediated cytotoxicity (ADCC) is an immune mechanism that results in the lysis of antibody-coated target cells by immune effector cells. Target cells are cells to which an antibody or derivative comprising an Fc region specifically binds, typically via the protein portion at the N-terminus of the Fc region. As used herein, the term "reduced ADCC" is defined as a reduction in the number of target cells lysed in a given time period at a given concentration of antibody in the medium surrounding the target cells via the ADCC mechanism defined above, and / or an increase in the concentration of antibody in the medium surrounding the target cells required to achieve the lysis of a given number of target cells in a given time period via the ADCC mechanism. The reduction in ADCC is relative to the ADCC mediated by the same antibody produced by the same host cell type using the same standard production, purification, formulation, and storage methods (which are known to those skilled in the art), but which has not been engineered. For example, the reduction in ADCC mediated by an antibody containing an amino acid substitution in its Fc domain that reduces ADCC is relative to the ADCC mediated by the same antibody without such amino acid substitution in the Fc domain. Suitable assays to measure ADCC are well known in the art (see, eg, PCT Publication No. WO 2006 / 082515 or PCT Publication No. WO 2012 / 130831).

[0086] An "effective amount" of an agent is that amount necessary to effect a physiological change in the cell or tissue to which it is administered.

[0087] A "therapeutically effective amount" of an agent, such as a pharmaceutical composition, is an amount effective (at the necessary dosage and for the necessary period of time) to achieve the desired therapeutic or preventive result. A therapeutically effective amount of an agent, for example, eliminates, reduces, delays, minimizes, or prevents the adverse effects of a disease.

[0088] An "individual" or "subject" is a mammal. Mammals include, but are not limited to, domesticated animals (e.g., cattle, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates such as monkeys), rabbits, and rodents (e.g., mice and rats). In particular, the individual or subject is a human.

[0089] The term "pharmaceutical composition" refers to a preparation that is in such form as to permit the biological activity of the active ingredient contained therein to be effective, and that contains no additional ingredients that would be unacceptably toxic to a subject to which the composition would be administered.

[0090] "Pharmaceutically acceptable carrier" refers to a component other than the active ingredient in a pharmaceutical composition that is non-toxic to the subject. Pharmaceutically acceptable carriers include, but are not limited to, buffers, excipients, stabilizers, or preservatives.

[0091] As used herein, "treatment" (and grammatical variations thereof) refers to an attempt to alter the natural course of a disease in a treated individual and can be a clinical intervention performed for prevention or during the course of clinical pathology. Desirable effects of treatment include, but are not limited to, preventing the onset or recurrence of the disease, alleviating symptoms, reducing any direct or indirect pathological consequences of the disease, preventing metastasis, slowing the rate of disease progression, ameliorating or palliating the disease state, and regression or improved prognosis. In some embodiments, the antibodies or bispecific antigen-binding molecules of the invention are used to delay the development of a disease or slow the progression of a disease.

[0092] The term "package insert" is used to refer to instructions customarily included in commercial packages of therapeutic products, that contain information about the indications, usage, dosage, administration, combination therapy, contraindications and / or warnings concerning the use of such therapeutic products.

[0093] Detailed description of the implementation plan

[0094] The present invention provides antibodies and bispecific antigen-binding molecules that bind to GPRC5D, in particular human GPRC5D. In addition, the molecules have other properties that are advantageous for therapeutic applications, for example in terms of efficacy and / or safety and productivity.

[0095] GPRC5D antibody

[0096] In a first aspect, the present invention provides an antibody that binds to GPRC5D, wherein the antibody comprises (i) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89; and (ii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89. NO:88 LCDR 2 and SEQ ID NO:89 LCDR 3; (iii) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:91, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO:94, LCDR 2 of SEQ ID NO:95, and LCDR 3 of SEQ ID NO:97; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:91, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising NO:94, LCDR 2 of SEQ ID NO:96, and LCDR 3 of SEQ ID NO:97; or (v) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 of SEQ ID NO:90, HCDR 2 of SEQ ID NO:92, and HCDR 3 of SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 of SEQ ID NO:94, LCDR 2 of SEQ ID NO:95, and LCDR 3 of SEQ ID NO:97.

[0097] In some embodiments, the antibody is a humanized antibody. In one embodiment, the VH is a humanized VH and / or the VL is a humanized VL. In one embodiment, the antibody comprises the CDRs as in any of the above embodiments and further comprises an acceptor human framework, such as a human immunoglobulin framework or a human consensus framework.

[0098] In a specific embodiment, (i) the VH comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) the VH comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) the VH comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 48, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: or (v) the VH comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64; or (vi) the VH comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:52. NO:58, and the VL comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63.

[0099] In a specific embodiment, the antibody comprises (i) a VH that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 13, and a VL that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) a VH that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 15, and a VL that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) a VH that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 48, and a VL that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: NO:53; or (iv) a VH at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:49, and a VL at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:52; or (v) a VH at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO:57, and a VL at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64; or (vi) a VH at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: NO:58 has an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the VH of SEQ ID NO:58, and a VL that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63.

[0100] In another embodiment, the antibody is an IgG, particularly an IgG1, antibody. In one embodiment, the antibody is a full-length antibody. In another embodiment, the antibody is an antibody fragment selected from the group consisting of an Fv molecule, a scFv molecule, a Fab molecule, and a F(ab')2 molecule. In one embodiment, the antibody is a multispecific antibody.

[0101] In certain embodiments, a VH or VL sequence having at least 95%, 96%, 97%, 98%, or 99% identity contains substitutions (e.g., conservative substitutions), insertions, or deletions relative to the reference sequence, but an antibody comprising the sequence retains the ability to bind to GPRC5D. In certain embodiments, a total of 1 to 10 amino acids are substituted, inserted and / or deleted in SEQ ID NO: 13 and / or a total of 1 to 10 amino acids are substituted in SEQ ID NO: 14 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 15 and / or a total of 1 to 10 amino acids are substituted, inserted and / or deleted in SEQ ID NO: 16 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 48 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 53 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 49 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 52 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 57 and / or a total of 1 to 10 amino acids are substituted, inserted and / or deleted in SEQ ID NO: 58 and / or a total of 1 to 10 amino acids are inserted and / or deleted in SEQ ID NO: 59. NO:64 by substitution, insertion and / or deletion of a total of 1 to 10 amino acids and / or SEQ ID NO:58 by substitution, insertion and / or deletion of a total of 1 to 10 amino acids and / or SEQ ID NO:63 by substitution, insertion and / or deletion of a total of 1 to 10 amino acids.

[0102] In certain embodiments, substitutions, insertions, or deletions occur in regions outside of the HVRs (i.e., in the FRs). Optionally, the antibody comprises the VH sequence of SEQ ID NO: 13 and / or the VL sequence of SEQ ID NO: 14, including post-translational modifications of such sequences. Optionally, the antibody comprises the VH sequence of SEQ ID NO: 15 and / or the VL sequence of SEQ ID NO: 16, including post-translational modifications of such sequences. Optionally, the antibody comprises the VH sequence of SEQ ID NO: 48 and / or the VL sequence of SEQ ID NO: 53, including post-translational modifications of such sequences. Optionally, the antibody comprises the VH sequence of SEQ ID NO: 49 and / or the VL sequence of SEQ ID NO: 52, including post-translational modifications of such sequences. Optionally, the antibody comprises the VH sequence of SEQ ID NO: 57 and / or the VL sequence of SEQ ID NO: 64, including post-translational modifications of such sequences. Optionally, the antibody comprises the VH sequence in SEQ ID NO: 58 and / or the VL sequence in SEQ ID NO: 63, including post-translational modifications of that sequence.

[0103] In one embodiment, the antibody comprises a VH comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 13 and SEQ ID NO: 15, and a VL comprising the amino acid sequence of SEQ ID NO: 14.

[0104] In one embodiment, the antibody comprises a VH sequence selected from the group of SEQ ID NO: 13 and SEQ ID NO: 12, and a VL sequence of SEQ ID NO: 16.

[0105] In a specific embodiment, the antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 13 and a VL comprising the amino acid sequence of SEQ ID NO: 14. In a specific embodiment, the antibody comprises the VH sequence of SEQ ID NO: 13 and the VL sequence of SEQ ID NO: 14.

[0106] In a specific embodiment, the antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 15 and a VL comprising the amino acid sequence of SEQ ID NO: 16. In a specific embodiment, the antibody comprises the VH sequence of SEQ ID NO: 15 and the VL sequence of SEQ ID NO: 16.

[0107] In a specific embodiment, the antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 48 and a VL comprising the amino acid sequence of SEQ ID NO: 53. In a specific embodiment, the antibody comprises the VH sequence of SEQ ID NO: 48 and the VL sequence of SEQ ID NO: 53.

[0108] In a specific embodiment, the antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 49 and a VL comprising the amino acid sequence of SEQ ID NO: 52. In a specific embodiment, the antibody comprises the VH sequence of SEQ ID NO: 49 and the VL sequence of SEQ ID NO: 52.

[0109] In a specific embodiment, the antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 57 and a VL comprising the amino acid sequence of SEQ ID NO: 64. In a specific embodiment, the antibody comprises the VH sequence of SEQ ID NO: 57 and the VL sequence of SEQ ID NO: 64.

[0110] In a specific embodiment, the antibody comprises a VH comprising the amino acid sequence of SEQ ID NO: 58 and a VL comprising the amino acid sequence of SEQ ID NO: 63. In a specific embodiment, the antibody comprises the VH sequence of SEQ ID NO: 58 and the VL sequence of SEQ ID NO: 63.

[0111] In one embodiment, the antibody comprises a human constant region. In one embodiment, the antibody is an immunoglobulin molecule comprising a human constant region, particularly an IgG class immunoglobulin molecule comprising a human CH1, CH2, CH3, and / or CL domain. Exemplary sequences of human constant domains are set forth in SEQ ID NOs: 37 and 38 (human kappa and lambda CL domains, respectively) and SEQ ID NO: 39 (human IgG1 heavy chain constant domain CH1-CH2-CH3). In some embodiments, the antibody comprises a light chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 37 or SEQ ID NO: 39, particularly the amino acid sequence of SEQ ID NO: 38. In some embodiments, the antibody comprises a heavy chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 39. In particular, the heavy chain constant region may comprise amino acid mutations in the Fc domain as described herein.

[0112] In one embodiment, the antibody is a monoclonal antibody.

[0113] In one embodiment, the antibody is an IgG, particularly an IgG1, antibody. In one embodiment, the antibody is a full-length antibody.

[0114] In one embodiment, the antibody comprises an Fc domain, particularly an IgG Fc domain, more particularly an IgG1 Fc domain. In one embodiment, the Fc domain is a human Fc domain. The Fc domain of the antibody may incorporate any of the features described herein for the Fc domains of the bispecific antigen-binding molecules of the invention, either singly or in combination.

[0115] In another embodiment, the antibody is an antibody fragment selected from the group consisting of an Fv molecule, a scFv molecule, a Fab molecule, and a F(ab')2 molecule; in particular, a Fab molecule. In another embodiment, the antibody fragment is a diabody, a triabody, or a tetrabody.

[0116] In yet another aspect, the antibody according to any of the above embodiments may incorporate any of the features as described in the following sections, singly or in combination.

[0117] Glycosylation variants

[0118] In certain embodiments, the antibodies provided herein are altered to increase or decrease the degree of antibody glycosylation. Addition or deletion of glycosylation sites of an antibody can be conveniently achieved by altering the amino acid sequence such that one or more glycosylation sites are created or eliminated.

[0119] Where an antibody comprises an Fc region, the oligosaccharides attached thereto may be modified. Natural antibodies produced by mammalian cells typically contain branched, biantennary oligosaccharides, which are generally attached to Asn297 of the CH2 domain of the Fc region via an N-linkage. See, for example, Wright et al., TIBTECH 15:26-32 (1997). Oligosaccharides may include various carbohydrates, such as mannose, N-acetylglucosamine (GlcNAc), galactose, and sialic acid, as well as fucose attached to the GlcNAc in the "backbone" of the biantennary oligosaccharide structure. In some embodiments, the oligosaccharides in the antibodies of the invention may be modified to create antibody variants with certain improved properties.

[0120] In one embodiment, antibody variants are provided that have non-fucosylated oligosaccharides, i.e., oligosaccharide structures lacking fucose, attached (directly or indirectly) to the Fc region. Such non-fucosylated oligosaccharides (also referred to as "afucosylated" oligosaccharides) are, in particular, N-linked oligosaccharides that lack the fucose residue attached to the first GlcNAc in the backbone of the biantennary oligosaccharide structure. In one embodiment, antibody variants are provided that have an increased proportion of non-fucosylated oligosaccharides in the Fc region compared to a native or parent antibody. For example, the proportion of non-fucosylated oligosaccharides can be at least about 20%, at least about 40%, at least about 60%, at least about 80%, or even about 100% (i.e., the absence of fucosylated oligosaccharides). The percentage of non-fucosylated oligosaccharides is the (average) amount of oligosaccharides lacking a fucose residue relative to the sum of all oligosaccharides attached to Asn297 (e.g., complex, hybrid, and high-mannose structures), as measured by MALDI-TOF mass spectrometry, as described, for example, in WO2006 / 082515. Asn297 refers to the asparagine residue located at approximately position 297 (EU numbering of Fc region residues) in the Fc region; however, Asn297 may also be located approximately ±3 amino acids upstream or downstream of position 297, i.e., between positions 294 and 300, due to minor sequence variation within antibodies. Such antibodies with an increased proportion of non-fucosylated oligosaccharides in the Fc region may have improved FcRγIIIa receptor binding and / or improved effector function, particularly improved ADCC function. See, for example, US 2003 / 0157108; US 2004 / 0093621.

[0121] Examples of cell lines capable of producing antibodies with reduced fucosylation include protein fucosylation-deficient Lec13 CHO cells (Ripka et al., Arch. Biochem. Biophys. 249:533-545 (1986); US 2003 / 0157108; and WO 2004 / 056312, particularly in Example 11), and knockout cell lines, such as α-1,6-fucosyltransferase gene FUT8 knockout CHO cells (see, e.g., Yamane-Ohnuki et al., Biotech. Bioeng. 87:614-622 (2004); Kanda, Y. et al., Biotechnol. Bioeng., 94(4):680-688 (2006); and WO 2004 / 056312). 2003 / 085107), or cells in which GDP-fucose synthesis or transporter activity is reduced or abolished (see, for example, US2004259150, US2005031613, US2004132140, US2004110282).

[0122] In another embodiment, antibody variants are provided having bisected oligosaccharides, for example, wherein the biantennary oligosaccharide attached to the Fc region of the antibody is bisected by GlcNAc. Such antibody variants may have reduced fucosylation and / or improved ADCC function as described above. Examples of such antibody variants are described, for example, in Umana et al., Nat Biotechnol 17, 176-180 (1999); Ferrara et al., Biotechn Bioeng 93, 851-861 (2006); WO 99 / 54342; WO 2004 / 065540, and WO 2003 / 011878.

[0123] Also provided are antibody variants having at least one galactose residue in the oligosaccharide attached to the Fc region. Such antibody variants may have improved CDC function. Such antibody variants are described, for example, in WO 1997 / 30087; WO 1998 / 58964; and WO 1999 / 22764.

[0124] Cysteine-engineered antibody variants

[0125] In certain embodiments, it may be desirable to create cysteine-engineered antibodies, e.g., "thioMAbs," in which one or more residues of an antibody are replaced with cysteine ​​residues. In specific embodiments, the replaced residues are present at accessible sites of the antibody. By replacing those residues with cysteine, reactive thiol groups are thereby located at accessible sites of the antibody and can be used to conjugate the antibody to other moieties, such as drug moieties or linker-drug moieties, to create immunoconjugates, as further described herein. Cysteine-engineered antibodies can be generated as described, for example, in U.S. Patent Nos. 7,521,541, 8,30,930, 7,855,275, 9,000,130, or WO2016040856.

[0126] Antibody derivatives

[0127] In certain embodiments, the antibodies provided herein can be further modified to contain additional non-proteinaceous moieties known in the art and readily available. Suitable moieties for antibody derivatization include, but are not limited to, water-soluble polymers. Non-limiting examples of water-soluble polymers include, but are not limited to, polyethylene glycol (PEG), ethylene glycol / propylene glycol copolymers, carboxymethylcellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone, poly-1,3-dioxolane, poly-1,3,6-trioxane, ethylene / maleic anhydride copolymers, polyamino acids (homopolymers or random copolymers), and dextran or poly(n-vinyl pyrrolidone) polyethylene glycol, propylene glycol homopolymers, propylene oxide / ethylene oxide copolymers, polyoxyethylated polyols (e.g., glycerol), polyvinyl alcohol, and mixtures thereof. Polyethylene glycol propionaldehyde may have advantages in production due to its stability in water. The polymer can be of any molecular weight and can be branched or unbranched. The number of polymers attached to the antibody can vary, and if more than one polymer is attached, they can be the same or different molecules. In general, the number and / or type of polymers used for derivatization can be determined based on considerations including, but not limited to, the specific property or function of the antibody to be improved, whether the antibody derivative will be used therapeutically for a given condition, etc.

[0128] In another embodiment, a conjugate of an antibody and a non-proteinaceous moiety that can be selectively heated by exposure to radiation is provided. In one embodiment, the non-proteinaceous moiety is a carbon nanotube (Kam et al., Proc. Natl. Acad. Sci. USA 102:11600-11605 (2005)). The radiation can be of any wavelength, including but not limited to wavelengths that are harmless to normal cells but heat the non-proteinaceous moiety to a temperature that kills cells in the vicinity of the antibody-non-proteinaceous moiety.

[0129] Immunoconjugates

[0130] The invention also provides immunoconjugates comprising an anti-GPRC5D antibody as described herein conjugated (chemically bonded) to one or more therapeutic agents, such as a cytotoxic agent, a chemotherapeutic agent, a drug, a growth inhibitory agent, a toxin (e.g., a protein toxin, an enzymatically active toxin of bacterial, fungal, plant or animal origin, or a fragment thereof), or a radioactive isotope.

[0131] In one embodiment, the immunoconjugate is an antibody-drug conjugate (ADC), in which the antibody is conjugated to one or more of the therapeutic agents mentioned above. A linker is typically used to connect the antibody to the one or more therapeutic agents. For a review of ADC technology (including examples of therapeutic agents, drugs, and linkers), see Pharmacol Review 68:3-19 (2016).

[0132] In another embodiment, the immunoconjugate comprises an antibody as described herein conjugated to an enzymatically active toxin or fragment thereof, including but not limited to diphtheria A chain, non-binding active fragments of diphtheria toxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain, abrin A chain, modeccin A chain, α-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII and PAP-S), Momordica charantia inhibitor, curcin, crotin, sapaonaria officinalis toxin, scutellaria baicalensis toxin, scutellaria serrata ... officinalis inhibitors, gelonin, mitogellin, restrictocin, phenomycin, enomycin, and the tricothecenes.

[0133] In another embodiment, the immunoconjugate comprises an antibody as described herein conjugated to a radioactive atom to form a radioconjugate. A variety of radioactive isotopes can be used to generate radioconjugates. Examples include At 211 ,I 131 ,I 125 ,Y 90 ,Re 186 ,Re 188 ,Sm 153 ,Bi212 ,P 32 ,Pb 212 When a radioconjugate is used for detection, it may contain a radioactive atom such as tc99m or 1123 for scintigraphic studies, or a spin label such as iodine-123, iodine-131, indium-111, fluorine-19, carbon-13, nitrogen-15, oxygen-17, gadolinium, manganese, or iron for nuclear magnetic resonance (NMR) imaging (also known as magnetic resonance imaging, MRI).

[0134] Conjugates of antibodies and cytotoxic agents can be made using a variety of bifunctional protein coupling agents, such as N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP), succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC), iminothiolane (IT), bifunctional derivatives of imidoesters (such as dimethyl adipimidate hydrochloride), active esters (such as disuccinimidyl suberate), aldehydes (such as glutaraldehyde), bis-azido compounds (such as bis(p-azidobenzoyl)hexanediamine), bis-diazonium derivatives (such as bis(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such as toluene 2,6-diisocyanate), and bis-active fluorine compounds (such as 1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin can be prepared as described in Vitetta et al., Science 238:1098 (1987). Carbon-14 labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent for conjugating radionucleotides to antibodies. See WO 94 / 11026. The linker can be a "cleavable linker" that facilitates release of the cytotoxic drug in the cell. For example, an acid-labile linker, a peptidase-sensitive linker, a photolabile linker, a dimethyl linker, or a disulfide-containing linker can be used (Chari et al., Cancer Res 52:127-131 (1992); U.S. Patent No. 5,208,020).

[0135] The immunoconjugates or ADCs herein specifically encompass, but are not limited to, such conjugates prepared with cross-linking reagents including, but not limited to, BMPS, EMCS, GMBS, HBVS, LC-SMCC, MBS, MPBH, SBAP, SIA, SIAB, SMCC, SMPB, SMPH, sulfo-EMCS, sulfo-GMBS, sulfo-KMUS, sulfo-MBS, sulfo-SIAB, sulfo-SMCC, and sulfo-SMPB, and SVSB (succinimidyl-(4-vinylsulfone)benzoate), which are commercially available (e.g., from Pierce Biotechnology, Inc., Rockford, IL., USA).

[0136] Multispecific antibodies

[0137] In certain embodiments, the antibodies provided herein are multispecific antibodies, such as bispecific antibodies. Multispecific antibodies are monoclonal antibodies that have binding specificities for at least two different sites (i.e., different epitopes on different antigens or different epitopes on the same antigen). In certain embodiments, multispecific antibodies have three or more binding specificities. In certain embodiments, one of the binding specificities is for GPRC5D, while the other (two or more) specificities are for any other antigen. In certain embodiments, bispecific antibodies can bind to two (or more) different epitopes of GPRC5D. Multispecific (e.g., bispecific) antibodies can also be used to localize cytotoxic agents or cells to cells expressing GPRC5D. Multispecific antibodies can be prepared as full-length antibodies or antibody fragments.

[0138] Techniques for producing multispecific antibodies include, but are not limited to, recombinant co-expression of two immunoglobulin heavy chain-light chain pairs with different specificities (see Milstein and Cuello, Nature, 305:537 (1983)), and “knob-into-hole” engineering (see, e.g., U.S. Patent No. 5,731,168 and Atwell et al., J. Mol. Biol., 270:26 (1997)). It is also possible to engineer electrostatic manipulation effects for generating antibody Fc-heterodimer molecules (see, e.g., WO 2009 / 089004); cross-link two or more antibodies or fragments (see, e.g., U.S. Patent No. 4,676,980, and Brennan et al., Science, 229:81 (1985)); use of leucine zippers to generate bispecific antibodies (see, e.g., Kostelny et al., J. Immunol., 148(5):1547-1553 (1992) and WO 2011 / 034605); use of common light chain technology to circumvent the light chain mispairing problem (see, e.g., WO 98 / 50431); use of "diabody" technology for generating bispecific antibody fragments (see, e.g., Hollinger et al., J. Immunol., 148(5):1547-1553 (1992) and WO 2011 / 034605). al., Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993)); and using single-chain Fv (sFv) dimers (see, e.g., Gruber et al., J. Immunol., 152:5368 (1994)); and preparing trispecific antibodies as described, e.g., in Tutt et al. J. Immunol. 147:60 (1991). Multispecific antibodies are generated.

[0139] Also included herein are engineered antibodies with three or more antigen-binding sites, including, for example, "octopus antibodies" or DVD-Igs (see, for example, WO 2001 / 77342 and WO 2008 / 024715). Other examples of multispecific antibodies with three or more antigen-binding sites can be found in WO 2010 / 115589, WO 2010 / 112193, WO 2010 / 136172, WO 2010 / 145792, and WO 2013 / 026831. Bispecific antibodies or antigen-binding fragments thereof also include "dual-acting FAbs" or "DAFs" comprising antigen-binding sites that bind to GPRC5D and another, different antigen, or two different epitopes of GPRC5D (see, for example, US 2008 / 0069820 and WO 2015 / 095539).

[0140] Multispecific antibodies can also be provided in an asymmetric format, having one or more domains swapped in the binding arms with the same antigen specificity, i.e., by swapping the VH / VL domains (see, e.g., WO 2009 / 080252 and WO 2015 / 150447), the CH1 / CL domains (see, e.g., WO 2009 / 080253), or the entire Fab arm (see, e.g., WO 2009 / 080251, WO 2016 / 016299, also see Schaefer et al., PNAS, 108 (2011) 1187-1191, and Klein et al., MAbs 8 (2016) 1010-20). Asymmetric Fab arms can also be engineered by introducing charged or uncharged amino acid mutations into the domain interfaces to direct correct Fab pairing. See, e.g., WO 2016 / 172485.

[0141] Various additional molecular formats of multispecific antibodies are known in the art and are encompassed herein (see, eg, Spiess et al., Mol Immunol 67 (2015) 95-106).

[0142] A particular type of multispecific antibody also encompassed herein is a bispecific antibody designed to simultaneously bind to a surface antigen on a target cell, such as a tumor cell, and to an activating, invariant component of the T cell receptor (TCR) complex, such as CD3, thereby retargeting the T cell to kill the target cell. Thus, in certain embodiments, the antibodies provided herein are multispecific antibodies, particularly bispecific antibodies, in which one of the binding specificities is for GPRC5D and the other is for CD3.

[0143] Examples of bispecific antibody formats that may be useful for this purpose include, but are not limited to, so-called "BiTE" (bispecific T cell engager) molecules in which two scFv molecules are fused via a flexible linker (see, e.g., WO 2004 / 106381, WO 2005 / 061547, WO 2007 / 042261, and WO 2008 / 119567, Nagorsen and Exp Cell Res 317, 1255-1260 (2011)); diabodies (Holliger et al., Prot Eng 9, 299-305 (1996)) and their derivatives, such as tandem diabodies ("TandAb"; Kipriyanov et al., J Mol Biol 293, 41-56 (1999)); "DART" (dual affinity retargeting) molecules, which are based on the diabody format but feature a C-terminal disulfide bridge for additional stabilization (Johnson et al., J Mol Biol 399, 436-449 (2010)), and so-called triomabs, which are full hybrid mouse / rat IgG molecules (reviewed in Seimetz et al., Cancer Treat Rev 36, 458-467 (2010)). Specific T cell bispecific antibody formats encompassed herein are described in WO 2013 / 026833, WO 2013 / 026839, WO 2016 / 020309; Bacac et al., Oncoimmunology 5(8) (2016)e1203498.

[0144] Bispecific antigen-binding molecules that bind GPRC5D and a second antigen

[0145] The present invention also provides a bispecific antigen-binding molecule, i.e., an antigen-binding molecule comprising at least two antigen-binding modules capable of specifically binding to two distinct antigenic determinants (a first and a second antigen).

[0146] According to specific embodiments of the present invention, the antigen-binding moieties contained in the bispecific antigen-binding molecule are Fab molecules (i.e., antigen-binding domains composed of heavy and light chains, each comprising a variable and constant domain). In one embodiment, the first and / or second antigen-binding moieties are Fab molecules. In one embodiment, the Fab molecules are human. In a specific embodiment, the Fab molecules are humanized. In yet another embodiment, the Fab molecules comprise human heavy and light chain constant domains.

[0147] Preferably, at least one of the antigen-binding moieties is a crossover Fab molecule. This modification reduces mispairing of heavy and light chains from different Fab molecules, thereby improving the yield and purity of the bispecific antigen-binding molecules of the present invention during recombinant production. In one specific crossover Fab molecule useful in the bispecific antigen-binding molecules of the present invention, the variable domains (VL and VH, respectively) of the Fab light chain and Fab heavy chain are exchanged. However, even with this domain swap, preparations of bispecific antigen-binding molecules may contain certain byproducts due to so-called Bence Jones-type interactions between the mispaired heavy and light chains (see Schaefer et al, PNAS, 108 (2011) 11187-11191). In order to further reduce the mispairing of heavy and light chains from different Fab molecules and thereby improve the purity and yield of the desired bispecific antigen-binding molecule, charged amino acids with opposite charges can be introduced at specific amino acid positions in the CH1 and CL domains of the Fab molecule that binds the first antigen (i.e., GPRC5D) or the Fab molecule that binds the second antigen (e.g., an activating T cell antigen, such as CD3), as further described herein. Figure 1 AC, GJ) or in a VH / VL exchange Fab molecule comprised in a bispecific antigen binding molecule (such as e.g. Figure 1 DF, KN) (but not both). In a specific embodiment, the conventional Fab molecule (which binds the first antigen, i.e., GPRC5D, in a specific embodiment) included in the bispecific antigen-binding molecule is charge-modified.

[0148] In a specific embodiment according to the present invention, a bispecific antigen-binding molecule is capable of simultaneously binding to a first antigen (i.e., GPRC5D) and a second antigen (e.g., an activating T cell antigen, particularly CD3). In one embodiment, the bispecific antigen-binding molecule is capable of cross-linking T cells and target cells by simultaneously binding to GPRC5D and the activating T cell antigen. In an even more specific embodiment, such simultaneous binding results in lysis of target cells (particularly GPRC5D-expressing tumor cells). In one embodiment, such simultaneous binding results in activation of T cells. In other embodiments, such simultaneous binding results in a cellular response of T lymphocytes (particularly cytotoxic T lymphocytes) selected from the group consisting of proliferation, differentiation, cytokine secretion, release of cytotoxic effector molecules, cytotoxic activity, and expression of activation markers. In one embodiment, binding of the bispecific antigen-binding molecule to an activating T cell antigen, particularly CD3, in the absence of simultaneous binding to GPRC5D does not result in T cell activation.

[0149] In one embodiment, the bispecific antigen binding molecule is capable of redirecting the cytotoxic activity of T cells to target cells. In a specific embodiment, the redirection is independent of MHC-mediated peptide antigen presentation by the target cell and / or the specificity of the T cell.

[0150] In particular, the T cells according to any embodiment of the present invention are cytotoxic T cells. In some embodiments, the T cells are CD4 + or CD8 + T cells, especially CD8 + T cells.

[0151] First antigen binding moiety

[0152] The bispecific antigen-binding molecules of the present invention comprise at least one antigen-binding moiety, particularly a Fab molecule, that binds GPRC5D (a first antigen). In certain embodiments, the bispecific antigen-binding molecules comprise two antigen-binding moieties, particularly Fab molecules, that bind GPRC5D. In a specific such embodiment, each of these antigen-binding moieties binds to the same antigenic determinant. In an even more specific embodiment, all of these antigen-binding moieties are identical, i.e., they comprise the same amino acid sequence, including the same amino acid substitutions in the CH1 and CL domains (if any) as described herein. In one embodiment, the bispecific antigen-binding molecule comprises no more than two antigen-binding moieties, particularly Fab molecules, that bind GPRC5D.

[0153] In certain embodiments, the antigen binding moiety that binds to GPRC5D is a conventional Fab molecule. In such embodiments, the antigen binding moiety that binds to the second antigen is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CH1 and CL of the Fab heavy and light chains are exchanged / replaced with each other.

[0154] In alternative embodiments, the antigen binding moiety that binds to GPRC5D is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CH1 and CL of the Fab heavy and light chains are exchanged / replaced with each other. In such embodiments, the antigen binding moiety that binds to the second antigen is a conventional Fab molecule.

[0155] The GPRC5D binding module is capable of directing the bispecific antigen-binding molecule to a target site, such as a specific type of tumor cell expressing GPRC5D.

[0156] The first antigen binding moiety of the bispecific antigen binding molecule may incorporate any of the features described herein in relation to antibodies that bind GPRC5D, singly or in combination, unless clearly scientifically unreasonable or impossible.

[0157] Thus, in one aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89, and (b) a second antigen binding moiety that binds to a second antigen. In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89, and (b) a second antigen binding moiety that binds to a second antigen. In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97, and (b) a second antigen binding moiety that binds to a second antigen.In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97, and (b) a second antigen binding moiety that binds to a second antigen. In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97, and (b) a second antigen binding moiety that binds to a second antigen. In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6, and (b) a second antigen binding moiety that binds to a second antigen.In another aspect, the present invention provides a bispecific antigen binding molecule comprising (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety comprises a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12, and (b) a second antigen binding moiety that binds to a second antigen.

[0158] In some embodiments, the first antigen binding moiety is (derived from) a humanized antibody. In one embodiment, the VH is a humanized VH and / or the VL is a humanized VL. In one embodiment, the first antigen binding moiety comprises the CDRs as in any of the above embodiments, and further comprises an acceptor human framework, such as a human immunoglobulin framework or a human consensus framework.

[0159] In one embodiment, the VH of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and the VL of the first antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0160] In one embodiment, the first antigen binding moiety comprises a VH sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and a VL sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0161] In one embodiment, the first antigen binding moiety comprises a VH comprising an amino acid sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and a VL comprising an amino acid sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0162] In one embodiment, the first antigen binding moiety comprises a VH sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and a VL sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0163] In a specific embodiment, the first antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 13 and a VL comprising the amino acid sequence of SEQ ID NO: 14. In a specific embodiment, the first antigen binding moiety comprises the VH sequence of SEQ ID NO: 13 and the VL sequence of SEQ ID NO: 14.

[0164] In a specific embodiment, the first antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 15 and a VL comprising the amino acid sequence of SEQ ID NO: 16. In a specific embodiment, the first antigen binding moiety comprises the VH sequence of SEQ ID NO: 15 and the VL sequence of SEQ ID NO: 16.

[0165] In a specific embodiment, the first antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 48 and a VL comprising the amino acid sequence of SEQ ID NO: 53. In a specific embodiment, the first antigen binding moiety comprises the VH sequence of SEQ ID NO: 48 and the VL sequence of SEQ ID NO: 53.

[0166] In a specific embodiment, the first antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 49 and a VL comprising the amino acid sequence of SEQ ID NO: 52. In a specific embodiment, the first antigen binding moiety comprises the VH sequence of SEQ ID NO: 49 and the VL sequence of SEQ ID NO: 52.

[0167] In a specific embodiment, the first antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 57 and a VL comprising the amino acid sequence of SEQ ID NO: 64. In a specific embodiment, the first antigen binding moiety comprises the VH sequence of SEQ ID NO: 57 and the VL sequence of SEQ ID NO: 64.

[0168] In a specific embodiment, the first antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 58 and a VL comprising the amino acid sequence of SEQ ID NO: 63. In a specific embodiment, the first antigen binding moiety comprises the VH sequence of SEQ ID NO: 58 and the VL sequence of SEQ ID NO: 63.

[0169] In one embodiment, the first antigen-binding moiety comprises a human constant region. In one embodiment, the first antigen-binding moiety is a Fab molecule comprising a human constant region, particularly a human CH1 and / or CL domain. Exemplary sequences of human constant domains are set forth in SEQ ID NOs: 37 and 38 (human kappa and lambda CL domains, respectively) and SEQ ID NO: 39 (human IgG1 heavy chain constant domain CH1-CH2-CH3). In some embodiments, the first antigen-binding moiety comprises a light chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 37 or SEQ ID NO: 38, particularly the amino acid sequence of SEQ ID NO: 37. In particular, the light chain constant region may comprise amino acid mutations as described herein under "Charge Modification" and / or may comprise a deletion or substitution of one or more (particularly two) N-terminal amino acids, if present in a crossover Fab molecule. In some embodiments, the first antigen binding moiety comprises a heavy chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the CH1 domain sequence contained in the amino acid sequence of SEQ ID NO: 39. In particular, the heavy chain constant region (particularly the CH1 domain) may comprise amino acid mutations as described herein under "Charge Modification".

[0170] Second antigen binding moiety

[0171] The bispecific antigen-binding molecule of the present invention comprises at least one antigen-binding moiety, in particular a Fab molecule, that binds to a second antigen (different from GPRC5D).

[0172] In certain embodiments, the antigen-binding moiety that binds to the second antigen is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CH1 and CL of the Fab heavy and light chains are exchanged / replaced with each other. In such embodiments, the antigen-binding moiety that binds to the first antigen (i.e., GPRC5D) is preferably a conventional Fab molecule. In embodiments in which the bispecific antigen-binding molecule comprises more than one antigen-binding moiety that binds to GPRC5D, particularly a Fab molecule, the antigen-binding moiety that binds to the second antigen is preferably a crossover Fab molecule and the antigen-binding moiety that binds to GPRC5D is a conventional Fab molecule.

[0173] In alternative embodiments, the antigen-binding moiety that binds to the second antigen is a conventional Fab molecule. In such embodiments, the antigen-binding moiety that binds to the first antigen (i.e., GPRC5D) is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CH1 and CL of the Fab heavy and light chains are exchanged / replaced with each other. In embodiments in which the bispecific antigen-binding molecule comprises more than one antigen-binding moiety that binds to a second antigen, particularly a Fab molecule, the antigen-binding moiety that binds to GPRC5D is preferably a crossover Fab molecule and the antigen-binding moiety that binds to the second antigen is a conventional Fab molecule.

[0174] In some embodiments, the second antigen is an activating T cell antigen (also referred to herein as an "activating T cell antigen binding moiety, or an activating T cell antigen binding Fab molecule"). In a specific embodiment, the bispecific antigen binding molecule comprises no more than one antigen binding moiety that is capable of specifically binding to an activating T cell antigen. In one embodiment, the bispecific antigen binding molecule provides monovalent binding to an activating T cell antigen.

[0175] In certain embodiments, the second antigen is CD3, particularly human CD3 (SEQ ID NO: 40) or cynomolgus CD3 (SEQ ID NO: 41), most particularly human CD3. In one embodiment, the second antigen binding moiety is cross-reactive (i.e., specifically binds) to human and cynomolgus CD3. In some embodiments, the second antigen is the epsilon subunit of CD3 (CD3ε).

[0176] In one embodiment, the second antigen binding moiety comprises HCDR 1 of SEQ ID NO: 29, HCDR 2 of SEQ ID NO: 30, HCDR 3 of SEQ ID NO: 31, LCDR 1 of SEQ ID NO: 32, LCDR 2 of SEQ ID NO: 33, and LCDR 3 of SEQ ID NO: 34.

[0177] In one embodiment, the second antigen binding moiety comprises a VH comprising HCDR 1 of SEQ ID NO: 29, HCDR 2 of SEQ ID NO: 30, and HCDR 3 of SEQ ID NO: 31, and a VL comprising LCDR 1 of SEQ ID NO: 32, LCDR 2 of SEQ ID NO: 33, and LCDR 3 of SEQ ID NO: 34.

[0178] In some embodiments, the second antigen binding moiety is (derived from) a humanized antibody. In one embodiment, the VH is a humanized VH and / or the VL is a humanized VL. In one embodiment, the second antigen binding moiety comprises the CDRs as in any of the above embodiments, and further comprises an acceptor human framework, such as a human immunoglobulin framework or a human consensus framework.

[0179] In one embodiment, the second antigen binding moiety comprises a VH sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 35. In one embodiment, the second antigen binding moiety comprises a VL sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 36.

[0180] In one embodiment, the second antigen binding moiety comprises a VH sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 35, and a VL sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 36.

[0181] In one embodiment, the VH of the second antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 36.

[0182] In one embodiment, the second antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 35, and a VL comprising the amino acid sequence of SEQ ID NO: 36.

[0183] In one embodiment, the second antigen binding moiety comprises the VH sequence of SEQ ID NO: 35, and the VL sequence of SEQ ID NO: 36.

[0184] In one embodiment, the second antigen-binding moiety comprises a human constant region. In one embodiment, the second antigen-binding moiety is a Fab molecule comprising a human constant region, particularly a human CH1 and / or CL domain. Exemplary sequences of human constant domains are set forth in SEQ ID NOs: 37 and 38 (human kappa and lambda CL domains, respectively) and SEQ ID NO: 39 (human IgG1 heavy chain constant domain CH1-CH2-CH3). In some embodiments, the second antigen-binding moiety comprises a light chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 37 or SEQ ID NO: 38, particularly the amino acid sequence of SEQ ID NO: 37. In particular, the light chain constant region may comprise amino acid mutations as described herein under "Charge Modification" and / or may comprise a deletion or substitution of one or more (particularly two) N-terminal amino acids, if present in a crossover Fab molecule. In some embodiments, the second antigen binding moiety comprises a heavy chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the CH1 domain sequence contained in the amino acid sequence of SEQ ID NO: 39. In particular, the heavy chain constant region (particularly the CH1 domain) may comprise amino acid mutations as described herein under "Charge Modification".

[0185] In some embodiments, the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain, in particular the variable domains VL and VH, are replaced with each other (i.e., according to such embodiments, the second antigen binding moiety is a crossover Fab molecule in which the variable or constant domains of the Fab light chain and the Fab heavy chain are exchanged). In one such embodiment, the first (and third, if any) antigen binding moiety is a conventional Fab molecule.

[0186] In one embodiment, no more than one antigen binding moiety that binds a second antigen (e.g., an activating T cell antigen such as CD3) is present in the bispecific antigen binding molecule (ie, the bispecific antigen binding molecule provides monovalent binding to the second antigen).

[0187] Charge modification

[0188] The bispecific antigen-binding molecules of the present invention may include the following amino acid substitutions in the Fab molecules contained therein that are particularly effective in reducing mispairing of the light chain with an unmatched heavy chain (Bence-Jones-type byproducts), which can occur during the production of Fab-based bi- / multispecific antigen-binding molecules with VH / VL exchange in one (or more, if the molecule comprises more than two antigen-binding Fab molecules) of their binding arms (see also PCT Publication No. WO 2015 / 150447, particularly the Examples therein, incorporated herein by reference in its entirety). The ratio of desired bispecific antigen-binding molecules to unwanted byproducts, particularly Bence-Jones-type byproducts, that occurs in bispecific antigen-binding molecules with VH / VL domain exchange in one of their binding arms can be improved by introducing charged amino acids with opposite charges at specific amino acid positions in the CH1 and CL domains (sometimes referred to herein as "charge modification").

[0189] Thus, in some embodiments in which the first and second antigen binding moieties of the bispecific antigen binding molecule are both Fab molecules, and in one of the antigen binding moieties (particularly the second antigen binding moiety) the variable domains VL and VH of the Fab light chain and Fab heavy chain are replaced with each other,

[0190] i) the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is substituted with a positively charged amino acid (numbering according to Kabat), and wherein the amino acid at position 147 or the amino acid at position 213 in the constant domain CH1 of the first antigen binding moiety is substituted with a negatively charged amino acid (numbering according to the Kabat EU index); or

[0191] ii) the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is substituted with a positively charged amino acid (numbering according to Kabat), and wherein the amino acid at position 147 or the amino acid at position 213 in the constant domain CH1 of the second antigen binding moiety is substituted with a negatively charged amino acid (numbering according to the Kabat EU index).

[0192] The bispecific antigen binding molecule does not contain the modifications mentioned under i) and ii) at the same time. The constant domains CL and CH1 of the antigen binding moiety with VH / VL exchange are not replaced with each other (ie remain unexchanged).

[0193] In a more specific embodiment,

[0194] i) the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 or the amino acid at position 213 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index); or

[0195] ii) the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 or the amino acid at position 213 in the constant domain CH1 of the second antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0196] In one such embodiment, the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 or the amino acid at position 213 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0197] In a further embodiment, the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E), or aspartic acid (D) (numbering according to the Kabat EU index).

[0198] In a specific embodiment, the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index).

[0199] In a more specific embodiment, the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is substituted with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is substituted with lysine (K) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is substituted with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is substituted with glutamic acid (E) (numbering according to Kabat EU index).

[0200] In an even more specific embodiment, the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is substituted with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is substituted with arginine (R) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is substituted with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is substituted with glutamic acid (E) (numbering according to Kabat EU index).

[0201] In a specific embodiment, if amino acid substitutions according to the above embodiments are made in the constant domain CL and constant domain CH1 of the first antigen binding moiety, the constant domain CL of the first antigen binding moiety is of the kappa isotype.

[0202] Alternatively, the amino acid substitutions according to the above embodiments can be made in the constant domain CL and constant domain CH1 of the second antigen binding moiety instead of in the constant domain CL and constant domain CH1 of the first antigen binding moiety. In specific such embodiments, the constant domain CL of the second antigen binding moiety is of the kappa isotype.

[0203] Thus, in one embodiment, the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 or the amino acid at position 213 in the constant domain CH1 of the second antigen binding moiety is independently substituted with glutamic acid (E), or aspartic acid (D) (numbering according to the Kabat EU index).

[0204] In a further embodiment, the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the second antigen binding moiety is independently substituted with glutamic acid (E), or aspartic acid (D) (numbering according to the Kabat EU index).

[0205] In yet another embodiment, the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the second antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to Kabat EU index).

[0206] In one embodiment, the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is substituted with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is substituted with lysine (K) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the second antigen binding moiety is substituted with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is substituted with glutamic acid (E) (numbering according to Kabat EU index).

[0207] In another embodiment, the amino acid at position 124 in the constant domain CL of the second antigen binding moiety is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with arginine (R) (numbering according to Kabat), and the amino acid at position 147 in the constant domain CH1 of the second antigen binding moiety is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index).

[0208] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0209] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89, and

[0210] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0211] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0212] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0213] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89, and

[0214] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0215] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0216] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0217] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97, and

[0218] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0219] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0220] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0221] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97, and

[0222] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0223] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0224] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0225] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97, and

[0226] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0227] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0228] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0229] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6, and

[0230] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0231] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0232] In a specific embodiment, the bispecific antigen binding molecule of the invention comprises

[0233] (a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12, and

[0234] (b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0235] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)) and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H) (numbering according to Kabat) (in a specific embodiment, independently substituted with lysine (K) or arginine (R)), and the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index) and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D) (numbering according to the Kabat EU index).

[0236] Bispecific antigen-binding molecule format

[0237] The components of the bispecific antigen binding molecules according to the present invention can be fused to each other in a variety of configurations. Figure 1 AZ.

[0238] In a specific embodiment, the antigen binding moieties contained in the bispecific antigen binding molecule are Fab molecules. In such embodiments, the first, second, third, etc. antigen binding moieties may be referred to herein as first, second, third, etc. Fab molecules, respectively.

[0239] In one embodiment, the first and second antigen-binding moieties of the bispecific antigen-binding molecule are fused to each other, optionally via a peptide linker. In a specific embodiment, the first and second antigen-binding moieties are each Fab molecules. In one such embodiment, the second antigen-binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen-binding moiety. In another such embodiment, the first antigen-binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen-binding moiety. In embodiments where either (i) the second antigen-binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen-binding moiety or (ii) the first antigen-binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen-binding moiety, the Fab light chain of the first antigen-binding moiety and the Fab light chain of the second antigen-binding moiety may additionally be fused to each other, optionally via a peptide linker.

[0240] A bispecific antigen binding molecule (e.g., a Fab molecule) having a single antigen binding moiety (e.g., a Fab molecule) that is capable of specifically binding to a target cell antigen such as GPRC5D Figure 1 A, 1D, 1G, 1H, 1K, 1L) are useful, particularly in cases where the target cell antigen is expected to be internalized following binding of the high-affinity antigen binding moiety. In such cases, the presence of more than one antigen binding moiety specific for the target cell antigen may enhance internalization of the target cell antigen, thereby reducing its availability.

[0241] However, in other cases, bispecific antigen binding molecules comprising two or more antigen binding moieties specific for a target cell antigen, such as Fab molecules, may be advantageous (see Figure 1 B, 1C, 1E, 1F, 1I, 1J, 1M or 1N), for example to optimize targeting to a target site or to allow cross-linking of target cell antigens.

[0242] Thus, in certain embodiments, the bispecific antigen binding molecule according to the invention comprises a third antigen binding moiety.

[0243] In one embodiment, the third antigen binding moiety binds to the first antigen, i.e., GPRC5D. In one embodiment, the third antigen binding moiety is a Fab molecule.

[0244] In one embodiment, the third antigen binding moiety is identical to the first antigen binding moiety.

[0245] The third antigen binding moiety of the bispecific antigen binding molecule may incorporate any of the features described herein in relation to the first antigen binding moiety and / or the antibody that binds GPRC5D, singly or in combination, unless clearly scientifically unreasonable or impossible.

[0246] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89.

[0247] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89.

[0248] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97.

[0249] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97.

[0250] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97.

[0251] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 4, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 5, LCDR 2 of SEQ ID NO: 6, and LCDR 3 of SEQ ID NO: 7.

[0252] In one embodiment, the third antigen binding moiety comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12.

[0253] In some embodiments, the third antigen binding moiety is (derived from) a humanized antibody. In one embodiment, the VH is a humanized VH and / or the VL is a humanized VL. In one embodiment, the third antigen binding moiety comprises the CDRs as in any of the above embodiments, and further comprises an acceptor human framework, such as a human immunoglobulin framework or a human consensus framework.

[0254] In one embodiment, the VH of the third antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and the VL of the third antigen binding moiety comprises an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0255] In one embodiment, the third antigen binding moiety comprises a VH sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and a VL sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0256] In one embodiment, the third antigen binding moiety comprises a VH comprising an amino acid sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and a VL comprising an amino acid sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0257] In one embodiment, the third antigen binding moiety comprises a VH sequence selected from the group of SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 57 and SEQ ID NO: 58, and a VL sequence selected from the group of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 63 and SEQ ID NO: 64.

[0258] In a specific embodiment, the third antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 13 and a VL comprising the amino acid sequence of SEQ ID NO: 14. In a specific embodiment, the third antigen binding moiety comprises the VH sequence of SEQ ID NO: 13 and the VL sequence of SEQ ID NO: 14.

[0259] In a specific embodiment, the third antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 15 and a VL comprising the amino acid sequence of SEQ ID NO: 16. In a specific embodiment, the third antigen binding moiety comprises the VH sequence of SEQ ID NO: 15 and the VL sequence of SEQ ID NO: 16.

[0260] In a specific embodiment, the third antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 48 and a VL comprising the amino acid sequence of SEQ ID NO: 53. In a specific embodiment, the third antigen binding moiety comprises the VH sequence of SEQ ID NO: 48 and the VL sequence of SEQ ID NO: 53.

[0261] In a specific embodiment, the third antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 49 and a VL comprising the amino acid sequence of SEQ ID NO: 52. In a specific embodiment, the third antigen binding moiety comprises the VH sequence of SEQ ID NO: 49 and the VL sequence of SEQ ID NO: 52.

[0262] In a specific embodiment, the third antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 57 and a VL comprising the amino acid sequence of SEQ ID NO: 64. In a specific embodiment, the third antigen binding moiety comprises the VH sequence of SEQ ID NO: 57 and the VL sequence of SEQ ID NO: 64.

[0263] In a specific embodiment, the third antigen binding moiety comprises a VH comprising the amino acid sequence of SEQ ID NO: 58 and a VL comprising the amino acid sequence of SEQ ID NO: 63. In a specific embodiment, the third antigen binding moiety comprises the VH sequence of SEQ ID NO: 58 and the VL sequence of SEQ ID NO: 63.

[0264] In one embodiment, the third antigen-binding moiety comprises a human constant region. In one embodiment, the third antigen-binding moiety is a Fab molecule comprising a human constant region, particularly a human CH1 and / or CL domain. Exemplary sequences of human constant domains are set forth in SEQ ID NOs: 37 and 38 (human kappa and lambda CL domains, respectively) and SEQ ID NO: 39 (human IgG1 heavy chain constant domain CH1-CH2-CH3). In some embodiments, the third antigen-binding moiety comprises a light chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 37 or SEQ ID NO: 38, particularly the amino acid sequence of SEQ ID NO: 37. In particular, the light chain constant region may comprise amino acid mutations as described herein under "Charge Modification" and / or may comprise a deletion or substitution of one or more (particularly two) N-terminal amino acids, if present in a crossover Fab molecule. In some embodiments, the third antigen binding moiety comprises a heavy chain constant region comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the CH1 domain sequence contained in the amino acid sequence of SEQ ID NO: 39. In particular, the heavy chain constant region (particularly the CH1 domain) may comprise amino acid mutations as described herein under "Charge Modification".

[0265] In certain embodiments, the third and first antigen-binding moieties are each a Fab molecule, and the third antigen-binding moiety is identical to the first antigen-binding moiety. Thus, in these embodiments, the first and third antigen-binding moieties comprise the same heavy and light chain amino acid sequences and have the same domain arrangement (i.e., conventional or swapped). Furthermore, in these embodiments, the third antigen-binding moiety comprises the same amino acid substitutions, if any, as the first antigen-binding moiety. For example, amino acid substitutions described herein as "charge modifications" may be made in the constant domains CL and CH1 of each of the first and third antigen-binding moieties. Alternatively, these amino acid substitutions may be made in the constant domains CL and CH1 of the second antigen-binding moiety (which, in certain embodiments, is also a Fab molecule), but not in the constant domains CL and CH1 of the first and third antigen-binding moieties.

[0266] Like the first antigen-binding moiety, the third antigen-binding moiety is particularly a conventional Fab molecule. However, embodiments are also contemplated in which the first and third antigen-binding moieties are crossover Fab molecules (and the second antigen-binding moiety is a conventional Fab molecule). Thus, in specific embodiments, the first and third antigen-binding moieties are each a conventional Fab molecule, and the second antigen-binding moiety is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CL and CH1 of the Fab heavy and light chains are exchanged / replaced with each other. In other embodiments, the first and third antigen-binding moieties are each a crossover Fab molecule, and the second antigen-binding moiety is a conventional Fab molecule.

[0267] If a third antigen binding moiety is present, in a particular embodiment the first and third antigen binding moieties bind GPRC5D and the second antigen binding moiety binds a second antigen, particularly an activating T cell antigen, more particularly CD3, most particularly CD3ε.

[0268] In certain embodiments, the bispecific antigen-binding molecule comprises an Fc domain composed of a first and a second subunit. The first and second subunits of the Fc domain are capable of stably associating.

[0269] The bispecific antigen-binding molecules according to the present invention can have different configurations, i.e., the first, second (and optionally third) antigen-binding moieties can be fused to each other and to the Fc domain in different ways. The components can be fused to each other directly or preferably via one or more suitable peptide linkers. In the case of Fab molecules fused to the N-terminus of a subunit of the Fc domain, it is typically via the immunoglobulin hinge region.

[0270] In some embodiments, the first and second antigen-binding moieties are each Fab molecules, and the second antigen-binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first or second subunit of the Fc domain. In such embodiments, the first antigen-binding moiety can be fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen-binding moiety or to the N-terminus of another subunit of the Fc domain. In certain such embodiments, the first antigen-binding moiety is a conventional Fab molecule, and the second antigen-binding moiety is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CL and CH1 of the Fab heavy and light chains are exchanged / replaced with each other. In other such embodiments, the first Fab molecule is a crossover Fab molecule, and the second Fab molecule is a conventional Fab molecule.

[0271] In one embodiment, the first and second antigen binding moieties are each a Fab molecule, the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first or second subunit of the Fc domain, and the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety. In a specific embodiment, the bispecific antigen binding molecule consists essentially of the first and second Fab molecules, the Fc domain consisting of the first and second subunits, and optionally one or more peptide linkers, wherein the first Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second Fab molecule, and the second Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first or second subunit of the Fc domain. Such a construction is schematically shown in Figure 1 G and 1K (the second antigen binding domain in these examples is a VH / VL swapped Fab molecule). Optionally, the Fab light chain of the first Fab molecule and the Fab light chain of the second Fab molecule can additionally be fused to each other.

[0272] In another embodiment, the first and second antigen binding moieties are each Fab molecules and the first and second antigen binding moieties are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain. In a specific embodiment, the bispecific antigen binding molecule consists essentially of the first and second Fab molecules, the Fc domain consisting of the first and second subunits, and optionally one or more peptide linkers, wherein the first and second Fab molecules are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain. Such a configuration is schematically shown in Figure 1 A and 1D (in these examples, the second antigen-binding domain is a VH / VL-swapped Fab molecule and the first antigen-binding moiety is a conventional Fab molecule). The first and second Fab molecules can be fused to the Fc domain directly or via a peptide linker. In a specific embodiment, the first and second Fab molecules are each fused to the Fc domain via an immunoglobulin hinge region. In a specific embodiment, the immunoglobulin hinge region is a human IgG1 hinge region, particularly when the Fc domain is an IgG1 Fc domain.

[0273] In some embodiments, the first and second antigen-binding moieties are each Fab molecules, and the first antigen-binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first or second subunit of the Fc domain. In such embodiments, the second antigen-binding moiety can be fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen-binding moiety or to the N-terminus of another subunit of the Fc domain (as described above). In specific such embodiments, the first antigen-binding moiety is a conventional Fab molecule, and the second antigen-binding moiety is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CL and CH1 of the Fab heavy and light chains are exchanged / replaced with each other. In other such embodiments, the first Fab molecule is a crossover Fab molecule and the second Fab molecule is a conventional Fab molecule.

[0274] In one embodiment, the first and second antigen binding moieties are each a Fab molecule, the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first or second subunit of the Fc domain, and the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety. In a specific embodiment, the bispecific antigen binding molecule consists essentially of the first and second Fab molecules, the Fc domain consisting of the first and second subunits, and optionally one or more peptide linkers, wherein the second Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first Fab molecule, and the first Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first or second subunit of the Fc domain. Such a construction is schematically shown in Figure 1 H and 1 L (in these examples the second antigen binding domain is a VH / VL exchange Fab molecule and the first antigen binding moiety is a conventional Fab molecule). Optionally, the Fab light chain of the first Fab molecule and the Fab light chain of the second Fab molecule can additionally be fused to each other.

[0275] In some embodiments, the third antigen-binding moiety, particularly the third Fab molecule, is fused to the N-terminus of the first or second subunit of the Fc domain at the C-terminus of the Fab heavy chain. In certain such embodiments, the first and third Fab molecules are each a conventional Fab molecule, and the second Fab molecule is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CL and CH1 of the Fab heavy and light chains are exchanged / replaced with each other. In other such embodiments, the first and third Fab molecules are each a crossover Fab molecule, and the second Fab molecule is a conventional Fab molecule.

[0276] In a specific such embodiment, the second and third antigen binding moieties are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain, and the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second Fab molecule. In a specific embodiment, the bispecific antigen binding molecule consists essentially of a first, a second and a third Fab molecule, an Fc domain consisting of a first and a second subunit, and optionally one or more peptide linkers, wherein the first Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second Fab molecule, and the second Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first subunit of the Fc domain, and wherein the third Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the second subunit of the Fc domain. Such a configuration is schematically shown in Figure 1 B and IE (in these examples the second antigen binding moiety is a VH / VL exchange Fab molecule, and the first and third antigen binding moieties are conventional Fab molecules), and Figure 1 J and 1N (in these examples, the second antigen-binding moiety is a conventional Fab molecule, and the first and third antigen-binding moieties are VH / VL swapped Fab molecules). The second and third Fab molecules can be fused to the Fc domain directly or via a peptide linker. In a specific embodiment, the second and third Fab molecules are each fused to the Fc domain via an immunoglobulin hinge region. In a specific embodiment, the immunoglobulin hinge region is a human IgG1 hinge region, particularly when the Fc domain is an IgG1 Fc domain. Optionally, the Fab light chain of the first Fab molecule and the Fab light chain of the second Fab molecule can also be fused to each other.

[0277] In another such embodiment, the first and third antigen binding moieties are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain, and the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety. In a specific embodiment, the bispecific antigen binding molecule consists essentially of the first, second and third Fab molecules, an Fc domain composed of the first and second subunits, and optionally one or more peptide linkers, wherein the second Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first Fab molecule, and the first Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the first subunit of the Fc domain, and wherein the third Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the second subunit of the Fc domain. Such a construction is schematically shown in Figure 1 C and 1F (in these examples the second antigen binding moiety is a VH / VL exchange Fab molecule, and the first and third antigen binding moieties are conventional Fab molecules) and Figure 11 and 1M (in these examples, the second antigen-binding moiety is a conventional Fab molecule, and the first and third antigen-binding moieties are VH / VL swapped Fab molecules). The first and third Fab molecules can be fused to the Fc domain directly or via a peptide linker. In a specific embodiment, the first and third Fab molecules are each fused to the Fc domain via an immunoglobulin hinge region. In a specific embodiment, the immunoglobulin hinge region is a human IgG1 hinge region, particularly when the Fc domain is an IgG1 Fc domain. Optionally, the Fab light chain of the first Fab molecule and the Fab light chain of the second Fab molecule can also be fused to each other.

[0278] In a bispecific antigen-binding molecule configuration in which a Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of each subunit of the Fc domain via an immunoglobulin hinge region, the two Fab molecules, the hinge region, and the Fc domain essentially form an immunoglobulin molecule. In a specific embodiment, the immunoglobulin molecule is an IgG class immunoglobulin. In an even more specific embodiment, the immunoglobulin is an IgG1 subclass immunoglobulin. In another embodiment, the immunoglobulin is an IgG4 subclass immunoglobulin. In yet another specific embodiment, the immunoglobulin is a human immunoglobulin. In other embodiments, the immunoglobulin is a chimeric immunoglobulin or a humanized immunoglobulin. In one embodiment, the immunoglobulin comprises a human constant region, particularly a human Fc region.

[0279] In some bispecific antigen-binding molecules of the present invention, the Fab light chain of a first Fab molecule and the Fab light chain of a second Fab molecule are fused to each other, optionally via a peptide linker. Depending on the configuration of the first and second Fab molecules, the Fab light chain of the first Fab molecule can be fused at its C-terminus to the N-terminus of the Fab light chain of the second Fab molecule, or the Fab light chain of the second Fab molecule can be fused at its C-terminus to the N-terminus of the Fab light chain of the first Fab molecule. Fusion of the Fab light chains of the first and second Fab molecules further reduces mispairing of mismatched Fab heavy and light chains and reduces the number of plasmids required to express some bispecific antigen-binding molecules of the present invention.

[0280] The antigen binding moieties can be fused to the Fc domain or to each other directly or via a peptide linker comprising one or more amino acids, typically about 2-20 amino acids. Peptide linkers are known in the art and described herein. Suitable, non-immunogenic peptide linkers include, for example, (G4S) n ,(SG4) n ,(G4S) n or G4 (SG4) nPeptide linker. "n" is generally an integer from 1 to 10, usually from 2 to 4. In one embodiment, the peptide linker has a length of at least 5 amino acids, in one embodiment from 5 to 100 amino acids, in another embodiment from 10 to 50 amino acids. In one embodiment, the peptide linker is (GxS) n or (GxS) n G m , wherein G = glycine, S = serine, and (x = 3, n = 3, 4, 5 or 6, and m = 0, 1, 2 or 3) or (x = 4, n = 2, 3, 4 or 5 and m = 0, 1, 2 or 3), in one embodiment, x = 4 and n = 2 or 3, in yet another embodiment, x = 4 and n = 2. In one embodiment, the peptide linker is (G4S)2. A particularly suitable peptide linker for fusing the Fab light chains of the first and second Fab molecules to each other is (G4S)2. An exemplary peptide linker suitable for connecting the Fab heavy chains of the first and second Fab fragments comprises the sequence (D)-(G4S)2 (SEQ ID NOs: 43 and 44). Another suitable such linker comprises the sequence (G4S)4. Additionally, the linker may comprise (a portion of) an immunoglobulin hinge region. In particular, when the Fab molecule is fused to the N-terminus of an Fc domain subunit, it may be fused via the immunoglobulin hinge region or a portion thereof, with or without an additional peptide linker.

[0281] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond (VL) with the Fc domain subunit. (2) -CH1 (2) -CH2-CH3(-CH4)), and a polypeptide wherein the Fab heavy chain of the first Fab molecule shares a carboxyl-terminal peptide bond with the Fc domain subunit (VH (1) -CH1 (1) -CH2-CH3(-CH4)). In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VH (2) -CL (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) In certain embodiments, the polypeptides are covalently linked, for example, via disulfide bonds.

[0282] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises an exchange Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with the Fc domain subunit (VH (2) -CL (2) -CH2-CH3(-CH4)), and a polypeptide wherein the Fab heavy chain of the first Fab molecule shares a carboxyl-terminal peptide bond with the Fc domain subunit (VH (1) -CH1 (1) -CH2-CH3(-CH4)). In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VL (2) -CH1 (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) In certain embodiments, the polypeptides are covalently linked, for example, via disulfide bonds.

[0283] In some embodiments, the bispecific antigen binding molecule comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxy-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxy-terminal peptide bond with the Fab heavy chain of the first Fab molecule, which in turn shares a carboxy-terminal peptide bond with the Fc domain subunit (VL (2) -CH1 (2) -VH (1) -CH1 (1) -CH2-CH3(-CH4)). In other embodiments, the bispecific antigen-binding molecule comprises a polypeptide wherein the Fab heavy chain of a first Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain variable region of a second Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond with an Fc domain subunit (VH (1) -CH1 (1) -VL (2) -CH1 (2) -CH2-CH3(-CH4)).

[0284] In some of these embodiments, the bispecific antigen binding molecule further comprises a crossover Fab light chain polypeptide of a second Fab molecule, wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxy-terminal peptide bond (VH (2) -CL (2) ), and the Fab light chain polypeptide (VL (1) -CL (1) In other of these embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxy-terminal peptide bond with the Fab light chain constant region of the second Fab molecule, which in turn shares a carboxy-terminal peptide bond (VH) with the Fab light chain polypeptide of the first Fab molecule. (2) -CL (2) -VL (1) -CL (1) ), or a polypeptide wherein the Fab light chain polypeptide of a first Fab molecule shares a carboxy-terminal peptide bond with the Fab heavy chain variable region of a second Fab molecule, which in turn shares a carboxy-terminal peptide bond (VL (1) -CL (1) -VH (2) -CL (2) ), when appropriate.

[0285] The bispecific antigen binding molecule according to these embodiments may further comprise (i) an Fc domain subunit polypeptide (CH2-CH3(-CH4)), or (ii) a polypeptide wherein the Fab heavy chain of the third Fab molecule shares a carboxyl-terminal peptide bond (VH) with the Fc domain subunit. (3) -CH1 (3) -CH2-CH3(-CH4)) and the Fab light chain polypeptide (VL (3) -CL (3) In certain embodiments, the polypeptides are covalently linked, for example, via disulfide bonds.

[0286] In some embodiments, the bispecific antigen binding molecule comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises an exchange Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fc domain subunit (VH (2) -CL (2) -VH (1) -CH1 (1)-CH2-CH3(-CH4)). In other embodiments, the bispecific antigen-binding molecule comprises a polypeptide wherein the Fab heavy chain of the first Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain variable region of the second Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with an Fc domain subunit (VH (1) -CH1 (1) -VH (2) -CL (2) -CH2-CH3(-CH4)).

[0287] In some of these embodiments, the bispecific antigen binding molecule further comprises a crossover Fab light chain polypeptide of a second Fab molecule, wherein the Fab light chain variable region of the second Fab molecule shares a carboxy-terminal peptide bond (VL (2) -CH1 (2) ), and the Fab light chain polypeptide (VL (1) -CL (1) In other of these embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxy-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule, which in turn shares a carboxy-terminal peptide bond (VL) with the Fab light chain polypeptide of the first Fab molecule. (2) -CH1 (2) -VL (1) -CL (1) ), or a polypeptide wherein the Fab light chain polypeptide of a first Fab molecule shares a carboxy-terminal peptide bond with the Fab heavy chain variable region of a second Fab molecule, which in turn shares a carboxy-terminal peptide bond (VL (1) -CL (1) -VL (2) -CH1 (2) ), when appropriate.

[0288] The bispecific antigen binding molecule according to these embodiments may further comprise (i) an Fc domain subunit polypeptide (CH2-CH3(-CH4)), or (ii) a polypeptide wherein the Fab heavy chain of the third Fab molecule shares a carboxyl-terminal peptide bond (VH) with the Fc domain subunit. (3) -CH1 (3) -CH2-CH3(-CH4)) and the Fab light chain polypeptide (VL (3) -CL (3) In certain embodiments, the polypeptides are covalently linked, for example, via disulfide bonds.

[0289] In certain embodiments, the bispecific antigen-binding molecule does not comprise an Fc domain. In certain such embodiments, the first and, if present, the third Fab molecule are each a conventional Fab molecule, and the second Fab molecule is a crossover Fab molecule as described herein, i.e., a Fab molecule in which the variable domains VH and VL or the constant domains CL and CH1 of the Fab heavy and light chains are exchanged / replaced with one another. In other such embodiments, the first and, if present, the third Fab molecule are each a crossover Fab molecule, and the second Fab molecule is a conventional Fab molecule.

[0290] In one such embodiment, the bispecific antigen binding molecule consists essentially of a first and a second antigen binding moiety, and optionally one or more peptide linkers, wherein the first and second antigen binding moieties are both Fab molecules and the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety. Such a configuration is schematically shown in Figure 1 O and 1S (in these examples the second antigen binding domain is a VH / VL exchange Fab molecule and the first antigen binding moiety is a conventional Fab molecule).

[0291] In another such embodiment, the bispecific antigen binding molecule consists essentially of a first and a second antigen binding moiety, and optionally one or more peptide linkers, wherein the first and second antigen binding moieties are both Fab molecules and the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety. Such a configuration is schematically shown in Figure 1 P and IT (in these examples the second antigen binding domain is a VH / VL exchange Fab molecule and the first antigen binding moiety is a conventional Fab molecule).

[0292] In some embodiments, the first Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second Fab molecule, and the bispecific antigen binding molecule further comprises a third antigen binding moiety, in particular a third Fab molecule, wherein the third Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first Fab molecule. In certain such embodiments, the bispecific antigen binding molecule consists essentially of the first, second and third Fab molecules, and optionally one or more peptide linkers, wherein the first Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second Fab molecule, and the third Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first Fab molecule. Such a construction is schematically shown in Figure 1 Q and 1U (in these examples the second antigen binding domain is a VH / VL exchange Fab molecule and the first and third antigen binding moieties are each conventional Fab molecules), or Figure 1 X and 1Z (in these examples the second antigen binding domain is a conventional Fab molecule and the first and third antigen binding moieties are each VH / VL swapped Fab molecules).

[0293] In some embodiments, the second Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first Fab molecule, and the bispecific antigen binding molecule further comprises a third antigen binding moiety, in particular a third Fab molecule, wherein the third Fab molecule is fused at the N-terminus of the Fab heavy chain to the C-terminus of the Fab heavy chain of the first Fab molecule. In certain such embodiments, the bispecific antigen binding molecule consists essentially of the first, second and third Fab molecules, and optionally one or more peptide linkers, wherein the second Fab molecule is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first Fab molecule, and the third Fab molecule is fused at the N-terminus of the Fab heavy chain to the C-terminus of the Fab heavy chain of the first Fab molecule. Such a construction is schematically shown in Figure 1 R and IV (in these examples the second antigen binding domain is a VH / VL exchange Fab molecule and the first and third antigen binding moieties are each conventional Fab molecules), or Figure 1 W and 1Y (in these examples the second antigen binding domain is a conventional Fab molecule and the first and third antigen binding moieties are each VH / VL swapped Fab molecules).

[0294] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain of a first Fab molecule shares a carboxy-terminal peptide bond with the Fab light chain variable region of a second Fab molecule, which in turn shares a carboxy-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region) (VH (1) -CH1 (1) -VL (2) -CH1 (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VH (2) -CL (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) ).

[0295] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond (VL) with the Fab heavy chain of the first Fab molecule. (2) -CH1 (2) -VH (1) -CH1 (1) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VH (2) -CL (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) ).

[0296] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises an exchange Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond (VH) with the Fab heavy chain of the first Fab molecule. (2) -CL (2) -VH (1) -CH1 (1) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VL (2) -CH1 (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) ).

[0297] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond (VL) with the Fab heavy chain of the first Fab molecule. (2) -CH1 (2) -VH (1) -CH1 (1)In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VH (2) -CL (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) ).

[0298] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain of the third Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab light chain variable region of the second Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region) (VH (3) -CH1 (3) -VH (1) -CH1 (1) -VL (2) -CH1 (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VH (2) -CL (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) In some embodiments, the bispecific antigen binding molecule further comprises a Fab light chain polypeptide (VL (3) -CL (3) ).

[0299] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain of the third Fab molecule shares a carboxy-terminal peptide bond with the Fab heavy chain of the first Fab molecule, which in turn shares a carboxy-terminal peptide bond with the Fab heavy chain variable region of the second Fab molecule, which in turn shares a carboxy-terminal peptide bond with the Fab light chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises a crossover Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region) (VH (3) -CH1 (3) -VH (1) -CH1 (1) -VH (2) -CL (2)In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VL (2) -CH1 (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) In some embodiments, the bispecific antigen binding molecule further comprises a Fab light chain polypeptide (VL (3) -CL (3) ).

[0300] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises an exchange Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the third Fab molecule (VL (2) -CH1 (2) -VH (1) -CH1 (1) -VH (3) -CH1 (3) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VH (2) -CL (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) In some embodiments, the bispecific antigen binding molecule further comprises a Fab light chain polypeptide (VL (3) -CL (3) ).

[0301] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the second Fab molecule (i.e., the second Fab molecule comprises an exchange Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the third Fab molecule (VH (2) -CL (2) -VH (1) -CH1 (1)-VH (3) -CH1 (3) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the second Fab molecule shares a carboxyl-terminal peptide bond (VL (2) -CH1 (2) ) and the Fab light chain polypeptide (VL (1) -CL (1) In some embodiments, the bispecific antigen binding molecule further comprises a Fab light chain polypeptide (VL (3) -CL (3) ).

[0302] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain variable region of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the first Fab molecule (i.e., the first Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond with the Fab light chain variable region of the third Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the third Fab molecule (i.e., the third Fab molecule comprises a crossover Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region). (2) -CH1 (2) -VL (1) -CH1 (1) -VL (3) -CH1 (3) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the first Fab molecule shares a carboxyl-terminal peptide bond (VH (1) -CL (1) ) and the Fab light chain polypeptide (VL) of the second Fab molecule (2) -CL (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the third Fab molecule shares a carboxyl-terminal peptide bond (VH (3) -CL (3) ).

[0303] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain of the second Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain variable region of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the first Fab molecule (i.e., the first Fab molecule comprises a crossover Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain variable region of the third Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the third Fab molecule (i.e., the third Fab molecule comprises a crossover Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region) (VH (2) -CH1 (2) -VH (1) -CL (1) -VH (3) -CL (3) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the first Fab molecule shares a carboxyl-terminal peptide bond (VL (1) -CH1 (1) ) and the Fab light chain polypeptide (VL) of the second Fab molecule (2) -CL (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the third Fab molecule shares a carboxyl-terminal peptide bond (VL (3) -CH1 (3) ).

[0304] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab light chain variable region of the third Fab molecule shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the third Fab molecule (i.e., the third Fab molecule comprises an exchange Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond with the Fab light chain variable region of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain constant region of the first Fab molecule (i.e., the first Fab molecule comprises an exchange Fab heavy chain in which the heavy chain variable region is replaced with a light chain variable region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the second Fab molecule (VL (3) -CH1 (3) -VL (1) -CH1 (1) -VH (2) -CH1 (2)In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the first Fab molecule shares a carboxyl-terminal peptide bond (VH (1) -CL (1) ) and the Fab light chain polypeptide (VL) of the second Fab molecule (2) -CL (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab heavy chain variable region of the third Fab molecule shares a carboxyl-terminal peptide bond (VH (3) -CL (3) ).

[0305] In certain embodiments, the bispecific antigen binding molecule according to the present invention comprises a polypeptide wherein the Fab heavy chain variable region of the third Fab molecule shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the third Fab molecule (i.e., the third Fab molecule comprises a crossover Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain variable region of the first Fab molecule, which in turn shares a carboxyl-terminal peptide bond with the Fab light chain constant region of the first Fab molecule (i.e., the first Fab molecule comprises a crossover Fab heavy chain in which the heavy chain constant region is replaced with a light chain constant region), which in turn shares a carboxyl-terminal peptide bond with the Fab heavy chain of the second Fab molecule (VH (3) -CL (3) -VH (1) -CL (1) -VH (2) -CH1 (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the first Fab molecule shares a carboxyl-terminal peptide bond (VL (1) -CH1 (1) ) and the Fab light chain polypeptide (VL) of the second Fab molecule (2) -CL (2) In some embodiments, the bispecific antigen binding molecule further comprises a polypeptide wherein the Fab light chain variable region of the third Fab molecule shares a carboxyl-terminal peptide bond (VL (3) -CH1 (3) ).

[0306] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0307] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0308] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0309] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0310] d) an Fc domain composed of a first and a second subunit;

[0311] in

[0312] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0313] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0314] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0315] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0316] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0317] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0318] d) an Fc domain composed of a first and a second subunit;

[0319] in

[0320] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0321] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0322] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0323] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0324] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0325] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0326] d) an Fc domain composed of a first and a second subunit;

[0327] in

[0328] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0329] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0330] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0331] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97;

[0332] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0333] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0334] d) an Fc domain composed of a first and a second subunit;

[0335] in

[0336] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0337] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0338] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0339] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0340] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0341] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0342] d) an Fc domain composed of a first and a second subunit;

[0343] in

[0344] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0345] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0346] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0347] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6;

[0348] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0349] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0350] d) an Fc domain composed of a first and a second subunit;

[0351] in

[0352] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0353] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0354] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0355] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12;

[0356] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0357] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0358] d) an Fc domain composed of a first and a second subunit;

[0359] in

[0360] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0361] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0362] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0363] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0364] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0365] c) an Fc domain composed of a first and a second subunit;

[0366] in

[0367] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0368] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0369] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0370] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0371] c) an Fc domain composed of a first and a second subunit;

[0372] in

[0373] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0374] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0375] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0376] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0377] c) an Fc domain composed of a first and a second subunit;

[0378] in

[0379] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0380] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0381] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97;

[0382] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0383] c) an Fc domain composed of a first and a second subunit;

[0384] in

[0385] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0386] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0387] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0388] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0389] c) an Fc domain composed of a first and a second subunit;

[0390] in

[0391] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0392] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0393] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6;

[0394] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0395] c) an Fc domain composed of a first and a second subunit;

[0396] in

[0397] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0398] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0399] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12;

[0400] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other;

[0401] c) an Fc domain composed of a first and a second subunit;

[0402] in

[0403] (i) The first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0404] In all the different configurations of the bispecific antigen-binding molecules according to the present invention, the amino acid substitutions described herein, if any, can be made in the CH1 and CL domains of the first and (if any) third antigen-binding moiety / Fab molecule, or in the CH1 and CL domains of the second antigen-binding moiety / Fab molecule. Preferably, they are made in the CH1 and CL domains of the first and (if any) third antigen-binding moiety / Fab molecule. According to the concepts of the present invention, if amino acid substitutions as described herein are made in the first (and, if any, third) antigen-binding moiety / Fab molecule, such amino acid substitutions are not made in the second antigen-binding moiety / Fab molecule. Conversely, if amino acid substitutions as described herein are made in the second antigen-binding moiety / Fab molecule, such amino acid substitutions are not made in the first (and, if any, third) antigen-binding moiety / Fab molecule. In particular, amino acid substitutions are made in bispecific antigen-binding molecules comprising Fab molecules in which the variable domains VL and VH1 of the Fab light chain and Fab heavy chain are replaced with each other.

[0405] In certain embodiments of the bispecific antigen binding molecules according to the invention, in particular wherein amino acid substitutions as described herein are made in the first (and, if present, third) antigen binding moiety / Fab molecule, the constant domain CL of the first (and, if present, third) Fab molecule is of the kappa isotype. In other embodiments of the bispecific antigen binding molecules according to the invention, in particular wherein amino acid substitutions as described herein are made in the second antigen binding moiety / Fab molecule, the constant domain CL of the second antigen binding moiety / Fab molecule is of the kappa isotype. In some embodiments, the constant domain CL of the first (and, if present, third) antigen binding moiety / Fab molecule and the constant domain CL of the second antigen binding moiety / Fab molecule are of the kappa isotype.

[0406] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0407] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0408] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0409] c) an Fc domain composed of a first and a second subunit;

[0410] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0411] in

[0412] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or

[0413] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0414] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0415] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0416] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0417] c) an Fc domain composed of a first and a second subunit;

[0418] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0419] in

[0420] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or

[0421] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0422] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0423] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0424] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0425] c) an Fc domain composed of a first and a second subunit;

[0426] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0427] in

[0428] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or

[0429] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0430] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0431] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97;

[0432] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0433] c) an Fc domain composed of a first and a second subunit;

[0434] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0435] in

[0436] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or

[0437] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0438] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0439] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0440] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0441] c) an Fc domain composed of a first and a second subunit;

[0442] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0443] in

[0444] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0445] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0446] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6;

[0447] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0448] c) an Fc domain composed of a first and a second subunit;

[0449] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0450] in

[0451] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or

[0452] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0453] In one embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0454] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12;

[0455] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0456] c) an Fc domain composed of a first and a second subunit;

[0457] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0458] in

[0459] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c), or

[0460] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0461] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0462] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0463] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0464] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0465] d) an Fc domain composed of a first and a second subunit;

[0466] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0467] in

[0468] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0469] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0470] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0471] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0472] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0473] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0474] d) an Fc domain composed of a first and a second subunit;

[0475] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0476] in

[0477] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0478] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0479] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0480] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0481] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0482] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0483] d) an Fc domain composed of a first and a second subunit;

[0484] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0485] in

[0486] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0487] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0488] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0489] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97;

[0490] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0491] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0492] d) an Fc domain composed of a first and a second subunit;

[0493] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0494] in

[0495] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0496] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0497] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0498] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0499] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0500] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0501] d) an Fc domain composed of a first and a second subunit;

[0502] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0503] in

[0504] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0505] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0506] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0507] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6;

[0508] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0509] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0510] d) an Fc domain composed of a first and a second subunit;

[0511] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0512] in

[0513] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0514] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0515] In a specific embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0516] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12;

[0517] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0518] c) a third antigen binding moiety that binds to the first antigen and is identical to the first antigen binding moiety; and

[0519] d) an Fc domain composed of a first and a second subunit;

[0520] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) and the third antigen binding moiety under c) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0521] in

[0522] (i) the first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d), or

[0523] (ii) the second antigen binding moiety under b) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety under a), and the first antigen binding moiety under a) and the third antigen binding moiety under c) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under d).

[0524] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 84, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0525] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0526] c) an Fc domain composed of a first and a second subunit;

[0527] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0528] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0529] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 83, HCDR 2 of SEQ ID NO: 85, and HCDR 3 of SEQ ID NO: 86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 87, LCDR 2 of SEQ ID NO: 88, and LCDR 3 of SEQ ID NO: 89;

[0530] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0531] c) an Fc domain composed of a first and a second subunit;

[0532] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0533] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0534] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0535] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0536] c) an Fc domain composed of a first and a second subunit;

[0537] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0538] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0539] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0540] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 91, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 96, and LCDR 3 of SEQ ID NO: 97;

[0541] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0542] c) an Fc domain composed of a first and a second subunit;

[0543] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0544] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0545] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0546] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 90, HCDR 2 of SEQ ID NO: 92, and HCDR 3 of SEQ ID NO: 93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 94, LCDR 2 of SEQ ID NO: 95, and LCDR 3 of SEQ ID NO: 97;

[0547] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0548] c) an Fc domain composed of a first and a second subunit;

[0549] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0550] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0551] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0552] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 1, HCDR 2 of SEQ ID NO: 2, and HCDR 3 of SEQ ID NO: 3, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 4, LCDR 2 of SEQ ID NO: 5, and LCDR 3 of SEQ ID NO: 6;

[0553] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0554] c) an Fc domain composed of a first and a second subunit;

[0555] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0556] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0557] In another embodiment, the present invention provides a bispecific antigen binding molecule comprising

[0558] a) a first antigen binding moiety that binds to a first antigen, wherein the first antigen is GPRC5D and the first antigen binding moiety is a Fab molecule comprising a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO: 7, HCDR 2 of SEQ ID NO: 8, and HCDR 3 of SEQ ID NO: 9, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 of SEQ ID NO: 10, LCDR 2 of SEQ ID NO: 11, and LCDR 3 of SEQ ID NO: 12;

[0559] b) a second antigen binding moiety that binds to a second antigen, wherein the second antigen is an activating T cell antigen, particularly CD3, more particularly CD3ε, and the second antigen binding moiety is a Fab molecule in which the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0560] c) an Fc domain composed of a first and a second subunit;

[0561] wherein the amino acid at position 124 in the constant domain CL of the first antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index); and

[0562] wherein the first antigen binding moiety under a) and the second antigen binding moiety under b) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0563] According to any of the above embodiments, the components of the bispecific antigen binding molecule (e.g., Fab molecule, Fc domain) can be fused directly or via various linkers described herein or known in the art (particularly peptide linkers comprising one or more amino acids, typically about 2-20 amino acids). Suitable, non-immunogenic peptide linkers include, for example, (G4S) n ,(SG4) n ,(G4S) n or G4 (SG4) n Peptide linkers, wherein n is generally an integer from 1 to 10, typically 2 to 4.

[0564] In one specific aspect, the present invention provides a bispecific antigen binding molecule comprising

[0565] a) a first and a third antigen binding moiety that bind to a first antigen; wherein the first antigen is GPRC5D and wherein the first and the second antigen binding moiety are each a (conventional) Fab molecule comprising a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 13 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14;

[0566] b) a second antigen binding moiety that binds to a second antigen; wherein the second antigen is CD3 and wherein the second antigen binding moiety is a Fab molecule comprising a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 36, wherein the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0567] c) an Fc domain composed of a first and a second subunit;

[0568] in

[0569] the amino acid at position 124 in the constant domain CL of the first and the third antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first and the third antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0570] And further

[0571] The first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under a) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0572] In one specific aspect, the present invention provides a bispecific antigen binding molecule comprising

[0573] a) a first and a third antigen binding moiety that bind to a first antigen; wherein the first antigen is GPRC5D and wherein the first and the second antigen binding moiety are each a (conventional) Fab molecule comprising a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16;

[0574] b) a second antigen binding moiety that binds to a second antigen; wherein the second antigen is CD3 and wherein the second antigen binding moiety is a Fab molecule comprising a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 36, wherein the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other;

[0575] c) an Fc domain composed of a first and a second subunit;

[0576] in

[0577] the amino acid at position 124 in the constant domain CL of the first and the third antigen binding moiety under a) is replaced with lysine (K) (numbering according to Kabat) and the amino acid at position 123 is replaced with lysine (K) or arginine (R) (numbering according to Kabat) (most particularly by arginine (R)), and wherein the amino acid at position 147 in the constant domain CH1 of the first and the third antigen binding moiety under a) is replaced with glutamic acid (E) (numbering according to Kabat EU index) and the amino acid at position 213 is replaced with glutamic acid (E) (numbering according to Kabat EU index);

[0578] And further

[0579] The first antigen binding moiety under a) is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety under b), and the second antigen binding moiety under b) and the third antigen binding moiety under a) are each fused at the C-terminus of the Fab heavy chain to the N-terminus of one of the subunits of the Fc domain under c).

[0580] In one embodiment, according to this aspect of the invention, the threonine residue at position 366 in the first subunit of the Fc domain is replaced with a tryptophan residue (T366W), and the tyrosine residue at position 407 in the second subunit of the Fc domain is replaced with a valine residue (Y407V) and optionally the threonine residue at position 366 is replaced with a serine residue (T366S) and the leucine residue at position 368 is replaced with an alanine residue (L368A) (numbering is according to the Kabat EU index).

[0581] In a further embodiment, according to this aspect of the invention, additionally the serine residue at position 354 is replaced with a cysteine ​​residue (S354C) or the glutamic acid residue at position 356 is replaced with a cysteine ​​residue (E356C) (in particular the serine residue at position 354 is replaced with a cysteine ​​residue), and additionally the tyrosine residue at position 349 is replaced with a cysteine ​​residue (Y349C) in the second subunit of the Fc domain (numbering according to the Kabat EU index).

[0582] In still another embodiment according to this aspect of the invention, the leucine residue at position 234 is replaced with an alanine residue (L234A), the leucine residue at position 235 is replaced with an alanine residue (L235A) and the proline residue at position 329 is replaced with a glycine residue (P329G) in each of the first and second subunits of the Fc domain (numbering is according to the Kabat EU index).

[0583] In yet a further embodiment according to this aspect of the invention, the Fc domain is a human IgG1 Fc domain.

[0584] In a specific embodiment, the bispecific antigen-binding molecule comprises a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 17, a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 18, a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 19, and a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 20. In yet another specific embodiment, the bispecific antigen-binding molecule comprises a polypeptide comprising the amino acid sequence of SEQ ID NO: 17, a polypeptide comprising the amino acid sequence of SEQ ID NO: 18, a polypeptide comprising the amino acid sequence of SEQ ID NO: 19, and a polypeptide comprising the amino acid sequence of SEQ ID NO: 20.

[0585] In another specific embodiment, the bispecific antigen-binding molecule comprises a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 21, a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 22, a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 23, and a polypeptide comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to the sequence of SEQ ID NO: 24. In yet another specific embodiment, the bispecific antigen-binding molecule comprises a polypeptide comprising the amino acid sequence of SEQ ID NO: 21, a polypeptide comprising the amino acid sequence of SEQ ID NO: 22, a polypeptide comprising the amino acid sequence of SEQ ID NO: 23, and a polypeptide comprising the amino acid sequence of SEQ ID NO: 24.

[0586] Fc domain

[0587] In certain embodiments, the bispecific antigen-binding molecules of the present invention comprise an Fc domain composed of a first and a second subunit. It is understood that the features of the Fc domain described herein with respect to the bispecific antigen-binding molecules are equally applicable to the Fc domain contained in the antibodies of the present invention.

[0588] The Fc domain of a bispecific antigen-binding molecule is composed of a pair of polypeptide chains that contain the heavy chain domains of an immunoglobulin molecule. For example, the Fc domain of an immunoglobulin G (IgG) molecule is a dimer, each subunit of which contains the CH2 and CH3 IgG heavy chain constant domains. The two subunits of the Fc domain are capable of stably associating with each other. In one embodiment, the bispecific antigen-binding molecule of the present invention comprises no more than one Fc domain.

[0589] In one embodiment, the Fc domain of the bispecific antigen-binding molecule is an IgG Fc domain. In a specific embodiment, the Fc domain is an IgG1 Fc domain. In another embodiment, the Fc domain is an IgG4 Fc domain. In a more specific embodiment, the Fc domain is an IgG4 Fc domain comprising an amino acid substitution at position S228 (Kabat EU index numbering), particularly the amino acid substitution S228P. This amino acid substitution reduces Fab arm exchange in vivo in IgG4 antibodies (see Stubenrauch et al., Drug Metabolism and Disposition 38, 84-91 (2010)). In yet another specific embodiment, the Fc domain is a human Fc domain. In an even more specific embodiment, the Fc domain is a human IgG1 Fc domain. An exemplary sequence of a human IgG1 Fc region is set forth in SEQ ID NO:42.

[0590] Fc domain modifications that promote heterodimerization

[0591] The bispecific antigen-binding molecules according to the present invention comprise different antigen-binding moieties, which can be fused to one or the other of the two subunits of the Fc domain, whereby the two subunits of the Fc domain are typically contained in two different polypeptide chains. Recombinant co-expression and subsequent dimerization of these polypeptides results in several possible combinations of the two polypeptides. In order to improve the yield and purity of bispecific antigen-binding molecules during recombinant production, it would be advantageous to introduce modifications into the Fc domain of the bispecific antigen-binding molecule that promote the association of the desired polypeptides.

[0592] Thus, in specific embodiments, the Fc domain of the bispecific antigen-binding molecule according to the present invention comprises modifications that promote association of the first and second subunits of the Fc domain. The site of the most extensive protein-protein interaction between the two subunits of the human IgG Fc domain is in the CH3 domain of the Fc domain. Thus, in one embodiment, the modifications are in the CH3 domain of the Fc domain.

[0593] There are several approaches to modify the CH3 domain of the Fc domain to enhance heterodimerization, which are described in detail in, for example, WO 96 / 27011, WO 98 / 050431, EP 1870459, WO 2007 / 110205, WO 2007 / 147901, WO 2009 / 089004, WO 2010 / 129304, WO 2011 / 90754, WO 2011 / 143545, WO 2012058768, WO 2013157954, and WO 2013096291. Typically, in all such approaches, the CH3 domain of the first subunit of the Fc domain and the CH3 domain of the second subunit of the Fc domain are engineered in a complementary manner such that each CH3 domain (or the heavy chain comprising it) is no longer able to homodimerize with itself but is forced to heterodimerize with the other complementary engineered CH3 domain (such that the first and second CH3 domains heterodimerize and homodimers are not formed between the two first CH3 domains or the two second CH3 domains). These different approaches for improving heavy chain heterodimerization are contemplated as various alternatives in combination with heavy-light chain modifications in bispecific antigen-binding molecules that reduce heavy / light chain mispairing and Bence Jones-type byproducts (e.g., VH and VL exchange / replacement in one binding arm and introduction of oppositely charged amino acids at the CH1 / CL interface).

[0594] In a specific embodiment, the modification that promotes the association of the first subunit and the second subunit of the Fc domain is a so-called "knob-into-hole" modification, which comprises a "knob" modification in one of the two subunits of the Fc domain and a "hole" modification in the other of the two subunits of the Fc domain.

[0595] The knob-into-hole technique is described in, for example, US Pat. No. 5,731,168; US Pat. No. 7,695,936; Ridgway et al., Prot Eng 9, 617-621 (1996) and Carter, J Immunol Meth 248, 7-15 (2001). Generally, the method involves introducing a protuberance ("knob") at the interface of a first polypeptide and a corresponding cavity ("hole") at the interface of a second polypeptide, so that the protuberance can be placed in the cavity, thereby promoting heterodimer formation and hindering homodimer formation. The protuberance is constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g., tyrosine or tryptophan). A complementary cavity of the same or similar size as the protuberance is created in the interface of the second polypeptide by replacing the large amino acid side chains with smaller amino acid side chains (e.g., alanine or threonine).

[0596] Thus, in a specific embodiment, in the CH3 domain of the first subunit of the Fc domain of the bispecific antigen binding molecule, one amino acid residue is replaced with an amino acid residue having a larger side chain volume, thereby generating a protuberance within the CH3 domain of the first subunit which can be positioned within a cavity within the CH3 domain of the second subunit, and in the CH3 domain of the second subunit of the Fc domain, one amino acid residue is replaced with an amino acid residue having a smaller side chain volume, thereby generating a cavity within the CH3 domain of the seco...

Claims

1. An antibody that binds to GPRC5D, wherein the antibody comprises (i) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO: 1, HCDR 2 as shown in SEQ ID NO: 2, and HCDR 3 as shown in SEQ ID NO: 3, and the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO: 4, LCDR 2 as shown in SEQ ID NO: 5, and LCDR 3 as shown in SEQ ID NO: 6; (ii) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO: 1, a HCDR 2 as shown in STGGVNTYYADSVKG, and a HCDR 3 as shown in SEQ ID NO: 3, and the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO: 4, a LCDR 2 as shown in SEQ ID NO: 5, and a LCDR 3 as shown in SEQ ID NO: 6; (iii) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:7, HCDR 2 as shown in SEQ ID NO:8, and HCDR3 as shown in SEQ ID NO:9, and the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:10, LCDR 2 as shown in SEQ ID NO:11, and LCDR 3 as shown in SEQ ID NO:12; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:7, HCDR 2 as shown in SEQ ID NO:8, and HCDR3 as shown in SEQ ID NO:9, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:10, LCDR 2 as shown in SEQ ID NO:96, and LCDR 3 as shown in SEQ ID NO:12; or (v) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:7, HCDR2 as shown in STGGGNTYYADSVKG, and HCDR3 as shown in SEQ ID NO:9, and the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:10, LCDR 2 as shown in SEQ ID NO:11, and LCDR 3 as shown in SEQ ID NO:

12.

2. An antibody that binds to GPRC5D, wherein the antibody comprises (i) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:83, HCDR 2 as shown in SEQ ID NO:84, and HCDR3 as shown in SEQ ID NO:86, and the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:87, LCDR 2 as shown in SEQ ID NO:88, and LCDR 3 as shown in SEQ ID NO:89; (ii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:83, HCDR 2 as shown in SEQ ID NO:85, and HCDR3 as shown in SEQ ID NO:86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:87, LCDR 2 as shown in SEQ ID NO:88, and LCDR 3 as shown in SEQ ID NO:89; (iii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:90, HCDR 2 as shown in SEQ ID NO:91, and HCDR 3 as shown in SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:94, LCDR 2 as shown in SEQ ID NO:95, and LCDR 3 as shown in SEQ ID NO:97; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:90, HCDR 2 as shown in SEQ ID NO:91, and HCDR3 as shown in SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:94, LCDR 2 as shown in SEQ ID NO:96, and LCDR 3 as shown in SEQ ID NO:97; or (v) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:90, HCDR 2 as shown in SEQ ID NO:92, and HCDR3 as shown in SEQ ID NO:93, and the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:94, LCDR 2 as shown in SEQ ID NO:95, and LCDR 3 as shown in SEQ ID NO:

97.

3. The antibody according to claim 1 or 2, (i) wherein the VH comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:48, and the VL comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:53; or (iv) wherein the VH comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:52; or (v) wherein the VH comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:64; or (vi) wherein the VH comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:58, and the VL comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:

63.

4. The antibody according to claim 1 or 2, (i) wherein the VH comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:48, and the VL comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:53; or (iv) wherein the VH comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:52; or (v) wherein the VH comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:64; or (vi) wherein the VH comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:58, and the VL comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:

63.

5. The antibody according to claim 1 or 2, (i) wherein the VH comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:48, and the VL comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:53; or (iv) wherein the VH comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:52; or (v) wherein the VH comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:64; or (vi) wherein the VH comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:58, and the VL comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:

63.

6. The antibody according to claim 1 or 2, (i) wherein the VH comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:48, and the VL comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:53; or (iv) wherein the VH comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:52; or (v) wherein the VH comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:64; or (vi) wherein the VH comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:58, and the VL comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:

63.

7. The antibody according to claim 1 or 2, (i) wherein the VH comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 13, and the VL comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 15, and the VL comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:48, and the VL comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:53; or (iv) wherein the VH comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:49, and the VL comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:52; or (v) wherein the VH comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:57, and the VL comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:64; or (vi) wherein the VH comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:58, and the VL comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:

63.

8. The antibody according to claim 1 or 2, (i) wherein the VH comprises the amino acid sequence of SEQ ID NO: 13, and the VL comprises the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH comprises the amino acid sequence of SEQ ID NO: 15, and the VL comprises the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH comprises the amino acid sequence of SEQ ID NO:48, and the VL comprises the amino acid sequence of SEQ ID NO:53; or (iv) wherein the VH comprises the amino acid sequence of SEQ ID NO:49, and the VL comprises the amino acid sequence of SEQ ID NO:52; or (v) wherein the VH comprises the amino acid sequence of SEQ ID NO:57, and the VL comprises the amino acid sequence of SEQ ID NO:64; or (vi) wherein the VH comprises the amino acid sequence of SEQ ID NO:58, and the VL comprises the amino acid sequence of SEQ ID NO:

63.

9. The antibody of claim 1 or 2, wherein the antibody is an IgG antibody.

10. The antibody of claim 9, wherein the antibody is an IgG1 antibody.

11. The antibody of claim 1 or 2, wherein the antibody is a full-length antibody.

12. The antibody of claim 1 or 2, wherein the antibody is an antibody fragment selected from the group consisting of an Fv molecule, a scFv molecule, a Fab molecule, and a F(ab')2 molecule.

13. The antibody of claim 1 or 2, wherein the antibody is a multispecific antibody.

14. A bispecific antigen binding molecule comprising (a) a first antigen-binding moiety that binds to a first antigen, Wherein the first antigen is GPRC5D and the first antigen binding moiety comprises (i) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO: 1, HCDR 2 as shown in SEQ ID NO: 2, and HCDR 3 as shown in SEQ ID NO: 3, and the light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO: 4, LCDR 2 as shown in SEQ ID NO: 5, and LCDR 3 as shown in SEQ ID NO: 6; (ii) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO: 1, a HCDR2 as shown in STGGVNTYYADSVKG, and a HCDR 3 as shown in SEQ ID NO: 3, and the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO: 4, a LCDR 2 as shown in SEQ ID NO: 5, and a LCDR 3 as shown in SEQ ID NO: 6; (iii) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:7, HCDR 2 as shown in SEQ ID NO:8, and HCDR3 as shown in SEQ ID NO:9, and the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:10, LCDR 2 as shown in SEQ ID NO:11, and LCDR 3 as shown in SEQ ID NO:12; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:7, HCDR 2 as shown in SEQ ID NO:8, and HCDR3 as shown in SEQ ID NO:9, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:10, LCDR 2 as shown in SEQ ID NO:96, and LCDR 3 as shown in SEQ ID NO:12; or (v) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:7, a HCDR2 as shown in STGGGNTYYADSVKG, and a HCDR3 as shown in SEQ ID NO:9, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:10, a LCDR 2 as shown in SEQ ID NO:11, and a LCDR 3 as shown in SEQ ID NO:12; and (b) a second antigen-binding moiety that specifically binds to a second antigen.

15. A bispecific antigen binding molecule comprising (a) a first antigen-binding moiety that binds to a first antigen, Wherein the first antigen is GPRC5D and the first antigen binding moiety comprises (i) a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:83, HCDR 2 as shown in SEQ ID NO:84, and HCDR3 as shown in SEQ ID NO:86, and the light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:87, LCDR 2 as shown in SEQ ID NO:88, and LCDR 3 as shown in SEQ ID NO:89; (ii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:83, HCDR 2 as shown in SEQ ID NO:85, and HCDR3 as shown in SEQ ID NO:86, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:87, LCDR 2 as shown in SEQ ID NO:88, and LCDR 3 as shown in SEQ ID NO:89; (iii) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:90, HCDR 2 as shown in SEQ ID NO:91, and HCDR 3 as shown in SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:94, LCDR 2 as shown in SEQ ID NO:95, and LCDR 3 as shown in SEQ ID NO:97; (iv) a heavy chain variable region (VH) comprising a heavy chain complementary determining region (HCDR) 1 as shown in SEQ ID NO:90, HCDR 2 as shown in SEQ ID NO:91, and HCDR3 as shown in SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementary determining region (LCDR) 1 as shown in SEQ ID NO:94, LCDR 2 as shown in SEQ ID NO:96, and LCDR 3 as shown in SEQ ID NO:97; or (v) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region (HCDR) 1 as shown in SEQ ID NO:90, HCDR 2 as shown in SEQ ID NO:92, and HCDR3 as shown in SEQ ID NO:93, and a light chain variable region (VL) comprising a light chain complementarity determining region (LCDR) 1 as shown in SEQ ID NO:94, LCDR 2 as shown in SEQ ID NO:95, and LCDR 3 as shown in SEQ ID NO:97; and (b) a second antigen-binding moiety that specifically binds to a second antigen.

16. The bispecific antigen binding molecule of claim 14 or 15, (i) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 13, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 15, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 48, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 53; or (iv) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 49, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 52; or (v) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 57, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 64; or (vi) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 58, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:

63.

17. The bispecific antigen binding molecule of claim 14 or 15, (i) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 13, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 15, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 48, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 53; or (iv) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 49, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 52; or (v) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 57, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 64; or (vi) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 58, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:

63.

18. The bispecific antigen binding molecule of claim 14 or 15, (i) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 13, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 15, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 48, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 53; or (iv) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 49, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 52; or (v) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 57, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 64; or (vi) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 58, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:

63.

19. The bispecific antigen binding molecule of claim 14 or 15, (i) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 13, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 15, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 48, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 53; or (iv) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 49, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 52; or (v) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 57, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 64; or (vi) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 58, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:

63.

20. The bispecific antigen binding molecule of claim 14 or 15, (i) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 13, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 15, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 48, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 53; or (iv) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 49, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 52; or (v) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 57, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 64; or (vi) wherein the VH of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 58, and wherein the VL of the first antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:

63.

21. The bispecific antigen binding molecule of claim 14 or 15, (i) wherein the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 13, and wherein the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 14; or (ii) wherein the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 15, and wherein the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 16; or (iii) wherein the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 48, and wherein the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 53; or (iv) wherein the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 49, and wherein the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 52; or (v) wherein the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 57, and wherein the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 64; or (vi) wherein the VH of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 58, and wherein the VL of the first antigen binding moiety comprises the amino acid sequence of SEQ ID NO:

63.

22. The bispecific antigen binding molecule of claim 14 or 15, wherein the second antigen is CD3.

23. The bispecific antigen binding molecule of claim 22, wherein the second antigen is CD3ε.

24. The bispecific antigen binding molecule of claim 22, wherein the second antigen binding moiety comprises a VH and a VL, the VH comprising a HCDR 1 as shown in SEQ ID NO: 29, a HCDR 2 as shown in SEQ ID NO: 30, and a HCDR 3 as shown in SEQ ID NO: 31, and the VL comprising a LCDR 1 as shown in SEQ ID NO: 32, a LCDR 2 as shown in SEQ ID NO: 33, and a LCDR 3 as shown in SEQ ID NO:

34.

25. The bispecific antigen binding molecule of claim 24, wherein the VH of the second antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:

36.

26. The bispecific antigen binding molecule of claim 24, wherein the VH of the second antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO:

36.

27. The bispecific antigen binding molecule of claim 24, wherein the VH of the second antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO:

36.

28. The bispecific antigen binding molecule of claim 24, wherein the VH of the second antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:

36.

29. The bispecific antigen binding molecule of claim 24, wherein the VH of the second antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:

36.

30. The bispecific antigen binding molecule of claim 24, wherein the VH of the second antigen binding moiety comprises the amino acid sequence of SEQ ID NO: 35, and the VL of the second antigen binding moiety comprises the amino acid sequence of SEQ ID NO:

36.

31. The bispecific antigen binding molecule of claim 14 or 15, wherein the first and / or the second antigen binding moiety is a Fab molecule.

32. The bispecific antigen binding molecule of claim 14 or 15, wherein the second antigen binding moiety is a Fab molecule, wherein the variable domains VL and VH or the constant domains CL and CH1 of the Fab light chain and the Fab heavy chain are replaced with each other.

33. The bispecific antigen binding molecule of claim 32, wherein the second antigen binding moiety is a Fab molecule, wherein the variable domains VL and VH of the Fab light chain and the Fab heavy chain are replaced with each other.

34. The bispecific antigen binding molecule of claim 14 or 15, wherein the first antigen binding moiety is a Fab molecule wherein the amino acid at position 124 in the constant domain is independently substituted with lysine (K), arginine (R) or histidine (H), numbering according to Kabat, and the amino acid at position 123 is independently substituted with lysine (K), arginine (R) or histidine (H), numbering according to Kabat, and the amino acid at position 147 in the constant domain CH1 is independently substituted with glutamic acid (E) or aspartic acid (D), numbering according to the Kabat EU index, and the amino acid at position 213 is independently substituted with glutamic acid (E) or aspartic acid (D), numbering according to the Kabat EU index.

35. The bispecific antigen binding molecule of claim 14 or 15, wherein the first and the second antigen binding moiety are fused to each other, optionally via a peptide linker.

36. The bispecific antigen binding molecule of claim 14 or 15, wherein the first and the second antigen binding moiety are each a Fab molecule and wherein either (i) the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety, or (ii) the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety.

37. The bispecific antigen binding molecule of claim 14 or 15, comprising a third antigen binding moiety.

38. The bispecific antigen binding molecule of claim 37, wherein the third antigen binding moiety is identical to the first antigen binding moiety.

39. The bispecific antigen binding molecule of claim 14 or 15, comprising an Fc domain composed of a first and a second subunit.

40. The bispecific antigen binding molecule of claim 39, wherein the first, the second and, when present, the third antigen binding moiety are each a Fab molecule; and wherein either (i) the second antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the first antigen binding moiety and the C-terminus of the Fab heavy chain of the first antigen binding moiety is fused to the N-terminus of the first subunit of the Fc domain, or (ii) the first antigen binding moiety is fused at the C-terminus of the Fab heavy chain to the N-terminus of the Fab heavy chain of the second antigen binding moiety and the C-terminus of the Fab heavy chain of the second antigen binding moiety is fused to the N-terminus of the first subunit of the Fc domain; And wherein the third antigen binding module, when present, is fused at the C-terminus of the Fab heavy chain to the N-terminus of the second subunit of the Fc domain.

41. The bispecific antigen binding molecule of claim 39, wherein the Fc domain is an IgG Fc domain.

42. The bispecific antigen binding molecule of claim 41, wherein the Fc domain is an IgG1 Fc domain.

43. The bispecific antigen binding molecule of claim 42, wherein the Fc domain is a human IgG1 Fc domain.

44. The bispecific antigen binding molecule of claim 43, wherein the amino acid residues in the CH3 domain of the first subunit of the Fc domain are replaced with amino acid residues having a larger side chain volume, thereby generating a protuberance in the CH3 domain of the first subunit, which can be placed in a cavity in the CH3 domain of the second subunit, and the amino acid residues in the CH3 domain of the second subunit of the Fc domain are replaced with amino acid residues having a smaller side chain volume, thereby generating a cavity in the CH3 domain of the second subunit, in which the protuberance in the CH3 domain of the first subunit can be placed.

45. The bispecific antigen binding molecule of claim 39, wherein the Fc domain comprises one or more amino acid substitutions that reduce binding to an Fc receptor and / or effector function.

46. ​​One or more isolated polynucleotides encoding the antibody or bispecific antigen binding molecule of any one of claims 1 to 45.

47. One or more vectors comprising one or more polynucleotides of claim 46.

48. The vector of claim 47, which is an expression vector.

49. A host cell comprising one or more polynucleotides of claim 46 or one or more vectors of claim 47 or 48.

50. A method for producing an antibody that binds GPRC5D, comprising the steps of: a) culturing the host cell of claim 49 under conditions suitable for expression of the antibody and b) optionally recovering the antibody.

51. An antibody that binds GPRC5D produced by the method of claim 50.

52. A pharmaceutical composition comprising the antibody or bispecific antigen binding molecule of any one of claims 1 to 45 or 51 and a pharmaceutically acceptable carrier.

53. The antibody or bispecific antigen binding molecule of any one of claims 1, 2, 14, 15 and 51 or the pharmaceutical composition of claim 52, characterized in that , used as medicine.

54. The antibody or bispecific antigen binding molecule of any one of claims 1, 2, 14, 15 and 51 or the pharmaceutical composition of claim 52, characterized in that , used in the treatment of diseases.

55. The antibody or bispecific antigen binding molecule of any one of claims 1, 2, 14, 15 and 51 or the pharmaceutical composition of claim 52, characterized in that , used in the treatment of a disease, wherein the disease is cancer or an autoimmune disease.

56. The antibody or bispecific antigen binding molecule of any one of claims 1, 2, 14, 15 and 51 or the pharmaceutical composition of claim 52, characterized in that , for use in the treatment of a disease, wherein the disease is multiple myeloma.

57. Use of the antibody or bispecific antigen binding molecule of any one of claims 1 to 45 or 51 or the pharmaceutical composition of claim 52 in the manufacture of a medicament for treating a disease, wherein the disease is multiple myeloma.

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