B cell maturation antigen (BCMA) chimeric antigen receptor invariant natural killer T cells and uses thereof

Abstract

The present disclosure is based, at least in part, on the discovery of novel BCMA antibodies or antigen-binding fragments thereof, and genetically modified cells (e.g., iNKT cells, CAR T cells, etc.) expressing chimeric antigen receptors comprising anti-BCMA antibodies or antigen-binding fragments thereof exhibit improved properties, including increased binding to BCMA, in vitro and in vivo killing of cancer cells expressing BCMA; and enhanced persistence in a subject receiving therapy.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 422,916, filed November 4, 2022, pursuant to 35U.SC119(e), the entire contents of which are incorporated herein by reference.

[0003] Reference to electronic sequence listing

[0004] The contents of the electronic serial number (A132770003WO00-SEQ-LJG.xml; size: 202,613 bytes; and creation date: November 3, 2023) are incorporated herein by reference in their entirety. Background Technology

[0005] B-cell maturation antigen (BCMA) is a member of the tumor necrosis factor receptor (TNFR) expressed on the surface of B-cell lineage cells. BCMA expression is associated with many cancers, autoimmune diseases, and infectious diseases. Cancers with increased BCMA expression include several hematologic malignancies such as multiple myeloma (MM), Hodgkin's and non-Hodgkin's lymphomas, various leukemias, and glioblastoma. Chimeric antigen receptor (CAR) proteins and CAR cells (e.g., CAR T cells or CARiNKT cells) targeting BCMA have been previously described. Summary of the Invention

[0006] This disclosure is based, at least in part, on novel BCMA antibodies or antigen-binding fragments thereof, and genetically modified cells (e.g., iNKT cells, CAR T cells, etc.) expressing chimeric antigen receptors comprising anti-BCMA antibodies or antigen-binding fragments thereof. In some embodiments, the compositions described herein exhibit improved properties, including increased binding to BCMA relative to previously described anti-BCMA binding molecules, in vitro and in vivo killing of BCMA-expressing cancer cells, and enhanced persistence in subjects receiving the compositions. Various aspects of this disclosure relate to methods of treating certain cancers (e.g., BCMA-expressing cancers) by administering the compositions described herein to subjects in need of them.

[0007] In some aspects, this disclosure provides an invariant natural killer T (iNKT) cell engineered to express a chimeric antigen receptor comprising a B cell maturation antigen (BCMA) binding moiety and IL-15.

[0008] In some embodiments, IL-15 is soluble IL-15. In some embodiments, IL-15 is human IL-15.

[0009] In some embodiments, iNKT cells kill cells expressing BCMA. In some embodiments, iNKT cells directly kill cells expressing BCMA. In some embodiments, iNKT cells indirectly kill cells expressing BCMA.

[0010] In some embodiments, iNKT cells retain responses to CD1d and / or NK receptor ligands.

[0011] In some embodiments, iNKT cells contain a CAR containing any of the anti-BCMA antibodies listed in Table 3. In some embodiments, iNKT cells contain a CAR containing any of the CARs listed in Table 4.

[0012] In some aspects, this disclosure provides a method for killing cells, the method comprising contacting the cell with iNKT cells engineered to express a chimeric antigen receptor comprising a B cell maturation antigen (BCMA) binding moiety and IL-15.

[0013] In some aspects, this disclosure provides a method for treating a tumor in a subject, the method comprising administering iNKT cells to a subject who has or is suspected of having cancer, the iNKT cells being engineered to express a chimeric antigen receptor comprising a B-cell maturation antigen (BCMA) binding moiety and IL-15.

[0014] In some aspects, this disclosure provides a method for reducing tumor growth, the method comprising contacting a subject’s tumor with iNKT cells engineered to express a chimeric antigen receptor comprising a B-cell maturation antigen (BCMA) binding moiety and IL-15.

[0015] In some embodiments, tumor cells express BCMA. In some embodiments, administration of iNKT cells results in a reduction in tumor burden relative to the subject's tumor burden prior to administration. In some embodiments, administration of iNKT cells results in resistance to T cell exhaustion, enhanced tissue homing of anti-BCMA iNKT cells, selective cytotoxicity to M2 macrophages, and / or stimulation of dendritic cell maturation.

[0016] In some embodiments, the subject does not experience lymphocyte depletion prior to administration of iNKT cells engineered to express a chimeric antigen receptor comprising a B-cell maturation antigen (BCMA) binding moiety and IL-15.

[0017] In some respects, this disclosure provides an antibody or antigen-binding fragment that specifically binds to an amino acid sequence having at least 85% identity with SEQ ID NO:38 to 48.

[0018] In some embodiments, the antibody specifically binds to the amino acid sequence listed in SEQ ID NO:38 to 48.

[0019] In some aspects, this disclosure provides an antibody or antigen-binding fragment comprising a heavy chain variable region having a sequence listed in any of SEQ ID NO:7, 12, 19 or 21.

[0020] In some embodiments, the antibody comprises a heavy chain variable region having a sequence as listed in SEQ ID NO:7, 12, 19 or 21 and a light chain variable region having a sequence as listed in SEQ ID NO:8, 10, 13, 15 or 22.

[0021] In some embodiments, the antibody comprises: (i) a heavy chain variable region having the sequence listed in SEQ ID NO:7 and a light chain variable region having the sequence listed in SEQ ID NO:8; (ii) a heavy chain variable region having the sequence listed in SEQ ID NO:7 and a light chain variable region having the sequence listed in SEQ ID NO:10; (iii) a heavy chain variable region having the sequence listed in SEQ ID NO:12 and a light chain variable region having the sequence listed in SEQ ID NO:13; (iv) a heavy chain variable region having the sequence listed in SEQ ID NO:12 and a light chain variable region having the sequence listed in SEQ ID NO:15; (v) a heavy chain variable region having the sequence listed in SEQ ID NO:7 and a light chain variable region having the sequence listed in SEQ ID NO:13; (vi) a heavy chain variable region having the sequence listed in SEQ ID NO:7 and a light chain variable region having the sequence listed in SEQ ID NO:15; (vii) a heavy chain variable region having the sequence listed in SEQ ID NO:19 and a light chain variable region having the sequence listed in SEQ ID NO:10. The light chain variable region of the sequence listed in NO:10; or (viii) the heavy chain variable region of the sequence listed in SEQ ID NO:21 and the light chain variable region of the sequence listed in SEQ ID NO:22.

[0022] In some aspects, this disclosure provides an antibody or antigen-binding fragment comprising a variable heavy chain region having a complementarity-determining region 3 (CDRH3) having the sequence listed in SEQ ID NO:3 or 33.

[0023] In some embodiments, the antibody or antigen-binding fragment further includes a variable light chain region comprising a complementarity-determining region 3 (CDRL3) having a sequence listed in SEQ ID NO: 6, 29, 30 or 36.

[0024] In some aspects, this disclosure provides an antibody or antigen-binding fragment comprising six complementarity-determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3, wherein (i) CDRH1 comprises the sequence listed in SEQ ID NO:1, CDRH2 comprises the sequence listed in SEQ ID NO:2, CDRH3 comprises the sequence listed in SEQ ID NO:3, CDRL1 comprises the sequence listed in SEQ ID NO:4, CDRL2 comprises the sequence listed in SEQ ID NO:5, and CDRL3 comprises the sequence listed in SEQ ID NO:6; (ii) CDRH1 comprises the sequence listed in SEQ ID NO:1, CDRH2 comprises the sequence listed in SEQ ID NO:2, CDRH3 comprises the sequence listed in SEQ ID NO:3, CDRL1 comprises the sequence listed in SEQ ID NO:4, CDRL2 comprises the sequence listed in SEQ ID NO:5, and CDRL3 comprises the sequence listed in SEQ ID NO:6; (iii) CDRH1 comprises the sequence listed in SEQ ID NO:6, CDRH2 comprises the sequence listed in SEQ ID NO:2, CDRH3 comprises the sequence listed in SEQ ID NO:3, CDRL1 comprises the sequence listed in SEQ ID NO:4, CDRL2 comprises the sequence listed in SEQ ID NO:5, and CDRL3 comprises the sequence listed in SEQ ID NO:6; The sequences listed in SEQ ID NO:25, CDRH2 contains the sequence listed in SEQ ID NO:27, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:30; (iv) CDRH1 contains the sequence listed in SEQ ID NO:25, CDRH2 contains the sequence listed in SEQ ID NO:27, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:29; (v) CDRH1 contains the sequence listed in SEQ ID NO:1, CDRH2 contains the sequence listed in SEQ ID NO:2, CDRH3 contains the sequence listed in SEQ ID NO:3, and CDRL1 contains the sequence listed in SEQ ID NO:20. The sequences listed in NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:30;(vi) CDRH1 contains the sequence listed in SEQ ID NO:1, CDRH2 contains the sequence listed in SEQ ID NO:2, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:29; (vii) CDRH1 contains the sequence listed in SEQ ID NO:26, CDRH2 contains the sequence listed in SEQ ID NO:28, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:6; or (viii) CDRH1 contains the sequence listed in SEQ ID NO:31, CDRH2 contains the sequence listed in SEQ ID NO:32, and CDRH3 contains the sequence listed in SEQ ID NO:39. The sequences listed in NO:33, CDRL1 contains the sequence listed in SEQ ID NO:34, CDRL2 contains the sequence listed in SEQ ID NO:35, and CDRL3 contains the sequence listed in SEQ ID NO:36.

[0025] In some embodiments, the antibody or antigen-binding fragment is chimeric.

[0026] In some embodiments, the antibody or antigen-binding fragment is humanized.

[0027] In some embodiments, the antibody or antigen-binding fragment is a single-chain variable fragment (scFv). In some embodiments, the scFv comprises the amino acid sequence listed in any one of SEQ ID NO: 9, 11, 14, 16, 17, 18, 20, or 23.

[0028] In some respects, this disclosure provides an isolated nucleic acid that encodes the antibody or antigen-binding fragment described herein.

[0029] In some embodiments, the isolated nucleic acid comprises the sequence listed in any of SEQ ID NO:49 to 64. In some embodiments, the isolated nucleic acid comprises the sequence listed in any of SEQ ID NO:65 to 72.

[0030] In some aspects, this disclosure provides a vector comprising the isolated nucleic acid described herein. In some embodiments, the vector is a viral vector. In some embodiments, the viral vector is a lentiviral vector. In some embodiments, the lentiviral vector comprises the sequence listed in any of SEQ ID NO:73 to 80.

[0031] In some aspects, this disclosure provides a host cell comprising the antibody or antigen-binding fragment, isolated nucleic acid, or vector described herein. In some embodiments, the cell is a mammalian cell, bacterial cell, yeast cell, or insect cell. In some embodiments, the cell is a hybridoma cell.

[0032] In some aspects, this disclosure provides a chimeric antigen receptor (CAR) comprising the anti-BCMA antigen-binding fragment described herein (e.g., anti-BCMA scFv).

[0033] In some embodiments, the CAR further includes a hinge region. In some embodiments, the hinge region contains an amino acid sequence that is at least 80% identical to that of SEQ ID NO:82.

[0034] In some embodiments, the CAR further comprises a transmembrane domain. In some embodiments, the transmembrane domain comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:83.

[0035] In some embodiments, the CAR further comprises a cytoplasmic domain. In some embodiments, the cytoplasmic domain comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:84.

[0036] In some embodiments, the CAR further comprises a co-stimulatory domain. In some embodiments, the co-stimulatory domain comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:85.

[0037] In some embodiments, CAR comprises the amino acid sequence of any one of SEQ ID NO:86 to 93.

[0038] In some aspects, this disclosure provides an immune cell comprising the anti-BCMACAR described herein. In some embodiments, the immune cell is a natural killer (NK) cell or a T cell. In some embodiments, the immune cell is an invariant natural killer T (iNKT) cell.

[0039] In some embodiments, immune cells are engineered to express one or more immunomodulatory gene products. In some embodiments, one or more immunomodulatory gene products include IL-15, IL-12, CD40L, or 4-1BB.

[0040] In some aspects, this disclosure provides a pharmaceutical composition comprising an anti-BCMA antibody or antigen-binding fragment as described herein, or an immune cell, and a pharmaceutically acceptable excipient.

[0041] In some aspects, this disclosure provides a method for killing cells, the method comprising contacting cells with an anti-BCMA antibody or antigen-binding fragment, immune cells, or a pharmaceutical composition described herein.

[0042] In some aspects, this disclosure provides a method for treating a subject with cancer, the method comprising administering the immune cell or pharmaceutical composition described herein to a subject who has or is suspected of having cancer.

[0043] In some aspects, this disclosure provides a method for reducing tumor growth, the method comprising contacting a subject’s tumor with an anti-BCMA antibody or antigen-binding fragment, immune cells, or a pharmaceutical composition described herein.

[0044] In some embodiments, the cell is a mammalian cell. In some embodiments, the cell is a human cell. In some embodiments, the cell is a cancer cell. In some embodiments, the cancer is a blood cancer. In some embodiments, the blood cancer is leukemia or lymphoma. In some embodiments, the cancer is multiple myeloma.

[0045] In some embodiments, administration is performed via injection.

[0046] In some embodiments, the subject does not experience lymphocyte depletion prior to the administration of iNKT cells. Attached Figure Description

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain embodiments and, together with the written description, serve to provide non-limiting examples of certain aspects of the compositions and methods disclosed herein.

[0048] Figure 1 This diagram illustrates how iNKT cells target tumor cells via direct or indirect mechanisms.

[0049] Figure 2 A schematic diagram of exemplary anti-BCMA-CAR-iNKT cells is shown. The anti-BCMA-CAR iNKT cells shown are engineered to secrete IL-15.

[0050] Figure 3 A schematic diagram showing an overview of the screening process for anti-BCMACARiNKT cells.

[0051] Figure 4 A schematic diagram of conventional phage motility used to select BCMA conjugates is shown.

[0052] Figure 5 A schematic diagram of a mammalian screening strategy for identifying high-functionality BCMACAR is shown.

[0053] Figure 6 Representative data on the binding affinity of exemplary anti-BCMA scFv F6 and F1 are shown.

[0054] Figures 7A to 7B Representative data for epitope plotting of BCMACAR candidates are shown. Figure 7A The results show the loss of binding with BCMA mutants (where the accessible amino acid is mutated to alanine to map the epitopes against BCMACAR candidates) compared to wild-type BCMA via Biacore. Figure 7B Display based on Figure 7A 3D structure of the binding sites of F6G-Var2 to BCMA (Asp15, Leu17, Leu18 at the top, Arg27, Thr32 and Leu35 at the bottom).

[0055] Figures 8A to 8I Representative data from the anti-BCMA-CAR iNKT cell-mediated cytotoxicity assay are presented. Figure 8A A schematic diagram of a cytotoxicity assay mediated by iNKT cells transiently transfected with BCMA-CAR is shown. Figures 8B to 8H This study demonstrates the killing effect of iNKT cells on target cells by expressing different BCMA-CAR candidates or the clinical benchmark bb2121. Figure 8B The legend is applicable Figures 8B to 8H . Figure 8I The endogenous BCMA expression level for each tumor line, as assessed by flow cytometry, is shown (bottom right). Wild-type or K562 cells stably transduced with BCMA were also included in the assay.

[0056] Figures 9A to 9C An example of achieving affinity maturation of F6G using an accelerated drug discovery (ADD) approach is shown. Figure 9A This diagram illustrates the formation of the CDR position through a mutation. Figure 9B The affinity KD(M) values ​​for the mutant scFv that binds to the BCMA antigen are shown. The sequences shown are GYYMH (SEQ ID NO:1), NPNSGN (SEQ ID NO:105), QWEPL (SEQ ID NO:106), DALPKKYTY (SEQ ID NO:107), EDTKRPS (SEQ ID NO:5), and LSTDPTGQ (SEQ ID NO:108). Figure 9CThe single Biacore sensor map with E to Y substitutions in position 49 of CDRL2 is shown.

[0057] Figures 10A to 10D Representative data on affinity maturation of F6G via phage libraries are presented. Figure 10A This diagram illustrates the phage-display affinity maturation library strategy. CDR amino acids marked "x" are mutated to any other amino acid to form the library. Figure 10B The library was shown for phage screening, followed by a mammalian display. Figure 10C Representative data on target cell killing by iNKT cells expressing different BCMA-CAR candidates or clinical benchmark (bb2121) are presented. Figure 10D Representative data were shown, indicating negligible cytotoxicity to BCMA-negative K562 cells, similar to bb2121, and negligible activation for most test candidates, similar to bb2121.

[0058] Figure 11 Representative data on the binding kinetics of the F6 variant are shown. The affinity-mature clones showed a 10-fold increase in affinity compared to the original F6 clones and a nearly 50-fold increase in affinity compared to germline F6G.

[0059] Figure 12 Representative data on the kinetics of other known anti-BCMACAR agents are shown compared to F6G-Var2.

[0060] Figures 13A to 13G Representative data on anti-BCMA-CAR iNKT cell-mediated tumor cell killing are presented. 13A to Figure 13C Flow cytometry analysis of RFP expression was shown to demonstrate CAR expression in BCMA-CARiNKT from two iNKT donors and antigen binding to BCMA-APC. Figure 13D The BCMA expression levels on each tumor cell line are shown as assessed by flow cytometry. The left peak shows isotype staining, and the right peak shows BCMA expression. Figure 13E Showing Figure 13A The percentage of target cells that died after 24 hours of co-culturing iNKT cells with tumor cell lines endogenously expressing BCMA or K562 at three different effector cell to target cell ratios. Figure 13F The percentage of iNKT cells co-expressing CD69 / CD25 after co-culturing with target cells expressing BCMA or K562 cells is shown. Figure 13G The percentage of iNKT cells expressing 4-1BB after co-culturing with BCMA-expressing target cells or K562 cells is shown.

[0061] Figure 14 Sequence alignments of the variable regions of the F6G modified heavy chain and light chain are shown. The heavy chain sequences shown are: F6G-Var5 (SEQ ID NO:7); F6G-Var3 (SEQ ID NO:12); F6G-Var2 (SEQ ID NO:12); F6G-Var6 (SEQ ID NO:19); F6G-Var4 (SEQ ID NO:7); and F6G-Var1 (SEQ ID NO:7). The light chain sequences shown are: F6G-Var6 (SEQ ID NO:109); F6G-Var1 (SEQ ID NO:109); F6G-Var5 (SEQ ID NO:110); F6G-Var3 (SEQ ID NO:110); F6G-Var2 (SEQ ID NO:111); and F6G-Var4 (SEQ ID NO:111).

[0062] Figure 15 Representative data predicting the immunogenicity of the F6G variant are shown.

[0063] Figure 16 An overview of the stable CAR-iNKT generation process is shown (left panel), and flow cytometry is used to assess the purity and quantity of BCMA CAR-iNKT cells (right panel).

[0064] Figure 17 Flow cytometry analysis of anti-BCMACAR IL-15iNKT cells generated by lentiviral transduction and antigen-mediated CAR enrichment is shown.

[0065] Figures 18A to 18L Representative data from an in vitro cytotoxicity assay of BCMA-CARiNKT cells attacked with BCMA-expressing multiple myeloma tumor lines, with or without IL-15 armor, are presented. bb2121 IL-15iNKT cells and anti-CD19 CAR IL-15iNKT cells, as well as untransduced iNKT cells, were used as controls. Figures 18A to 18F The results of the cytotoxicity assay from iNKT cells from donor 1 are shown. Figures 18G to 18L Representative cytotoxicity assay data from iNKT cells from donor 2 are shown. Sample legend is shown. Figure 18A and Figure 18B between.

[0066] Figures 19A to 19D Representative data on antigen-specific activation of BCMA-CAR-IL-15iNKT cells are presented. Figures 19A to 19BAntigen-specific activation of BCMA-CAR-IL-15iNKT cells from donor 1 was demonstrated. Figures 19C to 19D Antigen-specific activation of BCMA-CAR-IL-15iNKT cells from donor 2 was demonstrated.

[0067] Figures 20A to 20B Representative data show increased IFN-γ production by BCMA-CAR-IL-15iNKT cells when challenged with BCMA-expressing tumor lines. Figure 20A This study demonstrated that IFN-γ was produced by BCMA-CAR-IL-15iNKT cells from donor 1 when challenged with a tumor line expressing BCMA. Figure 20B The study showed that IFN-γ was produced by BCMA-CAR-IL-15iNKT cells from donor 1 when challenged with a tumor line expressing BCMA.

[0068] Figures 21A to 21E It showed that IL-15 production increases anti-BCMACAR iNKT cells in the blood ( Figure 21A ),marrow( Figure 21B ),liver( Figure 21C ),spleen( Figure 21D ) and lungs ( Figure 21E Representative data on in vivo persistence in )

[0069] Figures 22A to 22H This study presents representative data on how adoptive cell transfer, which indicates BCMA-CAR-IL-15iNKT cells, delayed the implantation of multiple myeloma MM1.s tumors in xenograft mice. Figures 22A to 22B The study showed that BCMA-CAR-IL-15iNKT cells exhibited delayed tumor implantation 3 weeks after adoptive transfer. Figure 22C The Kaplan-Meier survival graph shows that mice treated with BCMA-CAR-IL-15iNKT cells had a significant survival benefit compared to the CD19-IL-15CAR iNKT cell group and the untreated mouse group. Figure 22D Mice treated with BCMA-CAR-IL-15iNKT cells did not show multiple myeloma-related or IL-15-related (F6G-Var2 IL-15iNKT cell versus F6G-Var2 iNKT cell group) toxicity or weight loss. Figures 22E to 22F Flow cytometry analysis and quantification of bone marrow tissue from all mice showed that at both harvest time points, the samples showed very little / no GFP-positive MM1.s, indicating significant tumor control. Figures 22G to 22HFlow cytometry analysis of bone marrow was shown, indicating that BCMA-CAR-IL-15 persisted at both harvest time points. IL-15 expression in F6G-Var2 IL-15, compared to its non-IL-15 counterpart F6G-Var2, indicated that IL-15 expression was beneficial for iNKT persistence at earlier time points. Detailed Implementation

[0070] This disclosure is based, at least in part, on novel BCMA antibodies or antigen-binding fragments thereof. In some aspects, this disclosure also relates to chimeric antigen receptors (CARs) comprising the anti-BCMA antibodies or antigen-binding fragments described herein, and immune cells (e.g., iNKT cells, T cells, NK cells, etc.) expressing such CARs. In some embodiments, immune cells (e.g., iNKT cells, T cells, NK cells, etc.) are engineered to secrete IL-15, and this has been observed to promote persistence of immune cells in a subject. Use of anti-BCMA antibodies or antigen-binding fragments, and / or immune cells expressing anti-BCMA antigen-binding fragments, is also provided for killing cancer cells (e.g., BCMA-expressing cancer cells) and / or treating cancer (e.g., BCMA-positive cancers). As further described in the examples, anti-BCMA antibodies, and / or cells expressing CARs comprising the anti-BCMA antibodies described herein, exhibit improved properties, including increased binding to BCMA, in vitro and in vivo killing of BCMA-expressing cancer cells, and enhanced persistence in subjects receiving the composition (e.g., relative to subjects receiving other CAR T-cell therapies or anti-BCMA antibody therapies).

[0071] The foregoing and other aspects, implementations, functions, features, and embodiments of this teaching can be more fully understood through the following description taken in conjunction with the accompanying drawings.

[0072] I. Definition

[0073] For convenience, chapter headings have been provided, but should not be construed as limiting the content to be disclosed. For example, terms are defined throughout the entire specification, not just in chapters titled "Definitions".

[0074] Administration: As described herein, the terms “administering” or “administration” mean providing a subject with a therapeutic agent or a combination thereof in a manner that is physiologically and / or pharmacologically useful (e.g., to treat the subject’s condition).

[0075] Affinity-matured antibodies: “Affinity-matured antibody” is used herein to refer to an antibody having one or more alterations in one or more CDRs that result in an increased affinity (i.e., KD, kd, or ka) for the target antigen compared to a parent antibody without such alterations. In some embodiments, the affinity-matured antibody will have nanomolar or even picomolar affinity for the target antigen. Various procedures for generating affinity-matured antibodies are known in the art, including screening combinatorial antibody libraries already prepared using biodisplay. For example, Marks et al., BioTechnology, 10:779-783 (1992) describe affinity maturation achieved through VH and VL domain shuffling. Random mutations of CDRs and / or framework residues are described in: Barbas et al., Proc. Nat. Acad. Sci. USA, 91:3809-3813 (1994); Schier et al., Gene, 169:147-155 (1995); Yelton et al., J. Immunol., 155:1994-2004 (1995); Jackson et al., J. Immunol., 154(7):3310-3319 (1995); and Hawkins et al., J. Mol. Biol., 226:889-896 (1992). Selective mutations at the site of selective mutation formation and at contact or hypermutation sites using amino acid residues that enhance activity are described in U.S. Patent No. 6,914,128B1.

[0076] Antibody: As used herein, the term “antibody” or “antibodies” refers to a polypeptide containing at least one immunoglobulin variable domain or at least one antigenic determinant (e.g., a complementary site that binds specifically to an antigen). Examples of antibodies include monoclonal antibodies, recombinant antibodies, monospecific antibodies, multispecific antibodies (including bispecific antibodies), human antibodies, humanized antibodies, chimeric antibodies, immunoglobulins, synthetic antibodies, tetrameric antibodies comprising two heavy chain molecules and two light chain molecules, antibody light chain monomers, antibody heavy chain monomers, antibody light chain dimers, antibody heavy chain dimers, antibody light chain-antibody heavy chain pairs, intracellular antibodies, heteroconjugate antibodies, antibody-drug conjugates, single-domain antibodies, monovalent antibodies, single-chain antibodies or single-chain Fv (scFv), camelified antibodies, affinity molecules, Fab fragments, F(ab')2 fragments, disulfide-linked Fv (sdFv), anti-idiotype (anti-Id) antibodies (including, for example, anti-anti-Id antibodies), and antigen-binding fragments of any of the above antibodies. In some embodiments, the antibody is a full-length antibody that further comprises constant regions of the immunoglobulin heavy and light chains. In some embodiments, the antibody is a chimeric antibody. In some embodiments, the antibody is a humanized antibody. However, in some embodiments, the antibody is a Fab fragment, an F(ab')2 fragment, an Fv fragment, or a scFv fragment. In some embodiments, the antibody is a nanobody derived from a camel antibody or a nanobody derived from a shark antibody. In some embodiments, the antibody is a bisomatic antibody. In some embodiments, the antibody comprises a framework having a germline sequence from a species (e.g., a human germline sequence). In some embodiments, the antibody comprises a heavy (H) chain variable region (abbreviated herein as VH) and / or a light (L) chain variable region (abbreviated herein as VL). In some embodiments, the VH comprises an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or at least 99% identical to any of the heavy chain variable domains provided herein. In some embodiments, the VL comprises an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or at least 99% identical to any of the light chain variable domains provided herein. In some embodiments, the antibody comprises a constant domain, such as an Fc region. Immunoglobulin constant domains refer to heavy chain or light chain constant domains. The amino acid sequences of the human IgG heavy and light chain constant domains, as well as their functional variations, are known. In another embodiment, the antibody comprises a heavy chain constant domain selected from the group consisting of: IgG, IgG1, IgG2, IgG2A, IgG2B, IgG2C, IgG3, IgG4, IgA1, IgA2, IgD, IgM, and IgE constant domains. Regarding the heavy chain, in some embodiments, the heavy chain of the antibody described herein may be an α (α), δ (Δ), ε (ε), γ (γ), or μ (μ) heavy chain.In some embodiments, the heavy chain of the antibody described herein may comprise a human α (α), δ (Δ), ε (ε), γ (γ), or μ (μ) heavy chain. In a particular embodiment, the antibody described herein comprises human γ1CH1, CH2, and / or CH3 domains. In some embodiments, V. H The amino acid sequence of the domain includes the amino acid sequence of the human γ (γ) heavy chain constant domain, such as any sequence known in the art. Non-limiting examples of human constant region sequences have been described in the art, see, for example, U.S. Patent No. 5,693,780 and Kabat EA et al., (1991), ibid. In some embodiments, the antibody is modified, for example, via glycosylation, phosphorylation, SUMOylation, and / or methylation. In some embodiments, the antibody is a glycosylated antibody coupled to one or more sugar or carbohydrate molecules. In some embodiments, one or more sugar or carbohydrate molecules are coupled to the antibody via N-glycosylation, O-glycosylation, C-glycosylation, glycosylphosphatidylinositylation (GPI anchoring), and / or phosphorylated glycosylation. In some embodiments, one or more sugar or carbohydrate molecules are monosaccharides, disaccharides, oligosaccharides, or glycans. In some embodiments, one or more sugar or carbohydrate molecules are branched oligosaccharides or branched glycans. In some embodiments, one or more sugar or carbohydrate molecules comprise mannose units, glucose units, N-acetylglucosamine units, or phospholipid units.

[0077] Approximately: As used herein, the term “approximately” or “about”, when applied to one or more target values, refers to a value similar to the stated reference value. In some embodiments, the term “approximately” or “about” refers to a range of values ​​falling within (greater than or less than) 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less of the stated reference value in any direction, unless otherwise stated or otherwise apparent from the context (unless such a number exceeds 100% of the possible value).

[0078] B cell maturation antigen (BCMA): Human BCMA is a 184-amino acid protein encoded by the TNFRSF17 gene and is a member of the TNF receptor superfamily. BCMA is expressed in mature B lymphocytes and is likely important for B cell development and autoimmune responses. This receptor has been shown to specifically bind to tumor necrosis factor (ligand) superfamily member 13b (TNFSF13B / TALL-1 / BAFF), leading to NF-κB and MAPK8 / JNK activation. This receptor also binds to various TRAF family members and can therefore transduce signals for cell survival and proliferation.

[0079] Binding affinity: As used herein, the term “binding affinity” refers to the total strength of the non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an epitope). Unless otherwise stated, as used herein, “binding affinity” refers to intrinsic binding affinity, which reflects the 1:1 interaction between members of a binding pair. The affinity of molecule X for its partner Y can generally be determined by the dissociation constant (K0). D Affinity can be expressed in a variety of ways known in the art, including but not limited to the equilibrium dissociation constant (K). D ) and equilibrium association constant (K A K D It is based on k off / k on The quotient is calculated from K. A It is based on k on / k off The quotient is calculated from k. on This refers to, for example, the rate constant of antibody-epitope binding, while k... off This refers to, for example, the dissociation rate constant between an antibody and an epitope.

[0080] Binding affinity (or binding specificity) can be determined using various methods, including equilibrium dialysis, equilibrium binding, gel filtration, ELISA, surface plasmon resonance (SPR), fluorescence activated cell sorting (FACS), or spectroscopic methods (e.g., using fluorescence assays). Exemplary conditions for assessing binding affinity are in HBS-P buffer (10 mM HEPES pH 7.4, 150 mM NaCl, 0.005% (v / v) surfactant P20) and PBS buffer (10 mM PO4-3, 137 mM NaCl, and 2.7 mM KCl). These techniques can be used to measure the concentration of bound protein as a function of target protein concentration. The concentration of bound protein ([bound]) is generally correlated with the concentration of free target protein ([free]) by the following equation:

[0081] [Binding] = [Free] / (Kd + [Free])

[0082] However, it is not always necessary to target K. A Precise determination is necessary because sometimes, for example, activity in a functional assay (e.g., in vitro or in vivo assay) is sufficient to obtain a quantitative measurement of affinity, a qualitative measurement of affinity, or an inference of affinity, which is determined, for example, using methods such as ELISA or FACS analysis, with K A Proportional, and therefore can be used for comparisons, such as determining whether a higher affinity is, for example, 2 times higher.

[0083] CDR: As used herein, the term "CDR" refers to the complementarity-determining region within the variable sequence of an antibody. A typical antibody molecule contains a heavy chain variable region (VH) and a light chain variable region (VL), which are typically involved in antigen binding. The VH and VL regions can be further subdivided into hypervariable regions, also known as "complementarity-determining regions" ("CDRs"), interspersed with more conserved regions called "framework regions" ("FRs"). Each VH and VL typically consists of three CDRs and four FRs, arranged in the following order from the amino terminus to the carboxyl terminus: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The extent of the framework regions and CDRs can be precisely identified using methods known in the art, such as the Kabat definition, IMGT definition, Chothia definition, AbM definition, and / or contact definition, all of which are well-known in the art. See, for example, Kabat, E.A. et al. (1991), Sequences of Proteins of Immunological Interest, 5th ed., Department of Health and Human Services, NIH Publication No. 91-3242; the international ImMunoGeneTics information http: / / www.imgt.org, Lefranc, M.-P. et al., Nucleic Acids Res., 27:209-212 (1999); Ruiz, M. et al., Nucleic Acids Res., 28:219-221 (2000); Lefranc, M.-P., Nucleic Acids Res., 29:207-209 (2001); Lefranc, M.-P., Nucleic Acids Res., 31:307-310 (2003); Lefranc, M.-P. et al., In Silico Biol., 5,0006 (2004) [ebook], 5:45-60 (2005); Lefranc, M.-P. et al., Nucleic Acids Res., 33:D593-597 (2005); Lefranc, M.-P. et al., Nucleic Acids Res., 37:D1006-1012 (2009); Lefranc, M.-P. et al., Nucleic Acids Res., 43:D413-422 (2015); Chothia et al., (1989) Nature 342:877; Chothia, C. et al. (1987) J. Mol. Biol. 196:901-917, Al-lazikani et al. (1997) J. Molec. Biol. 273:927-948; and Almagro, J. Mol. Recognit. 17:132-143 (2004). Please see hgmp.mrc.ac.uk and bioinf.org.uk / abs. As described herein, a CDR can refer to a CDR defined by any method known in the art. Two antibodies having the same CDR means that the two antibodies have the same amino acid sequence of that CDR as determined by the same method (e.g., as defined by Kabat).

[0084] Typically, each variable region of the heavy and light chains contains three CDRs, designated CDR1, CDR2, and CDR3 for each variable region. As used herein, the term "CDR group" refers to a group of three CDRs capable of binding the antigen that appear within a single variable region. The exact boundaries of these CDRs have been defined differently depending on the system. The system described by Kabat (Kabat et al., Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987) and (1991)) not only provides a definitive residue numbering system applicable to any variable region of an antibody, but also provides precise residue boundaries defining three CDRs. These CDRs can be referred to as Kabat CDRs. Sub-regions of a CDR can be designated as L1, L2, and L3 or H1, H2, and H3, where “L” and “H” designate the light chain and heavy chain regions, respectively. These regions can be referred to as Chothia CDRs, which have boundaries that overlap with Kabat CDRs. Padlan (FASEB J.9:133-139 (1995)) and MacCallum (J Mol Biol 262(5):732-45 (1996)) have described other boundaries defining CDRs that overlap with Kabat CDRs. Other CDR boundary definitions may not strictly follow one of the systems described above, but still relate to Kabat. CDR overlap, although it can be shortened or lengthened based on predictions or experimental findings that specific residues or groups of residues, or even the entire CDR, do not significantly affect antigen binding. The method used in this paper utilizes CDRs defined according to any of these systems.

[0085] When different definition systems are used (e.g., IMGT definition, Kabat definition, or Chothia definition), the CDR of an antibody can have different amino acid sequences. Definition systems annotate each amino acid in a given antibody sequence (e.g., the VH or VL sequence of any of the anti-BCMA antibodies described in Table 3), and Table 1 provides numbers corresponding to the heavy and light chain CDRs. The CDRs of the anti-BCMA antibodies provided herein (e.g., the CDRs of any of the anti-BCMA antibodies listed in Table 3) are defined according to the Kabat definition. Those skilled in the art can deduce the CDR sequences using the different numbering systems for the anti-BCMA antibodies provided in Table 3.

[0086] Table 1. Definition of CDR

[0087]

[0088] 1 imgt.org, Lefranc, M.-P. et al., Nucleic Acids Res., 27:209-212 (1999)

[0089] 2 Kabat et al. (1991), Sequences of Proteins of Immunological Interest, 5th Edition, Department of Health and Human Services, NIH Publication No. 91-3242

[0090] 3 Chothia et al., J.Mol.Biol.196:901-917 (1987)

[0091] Chimeric antigen receptor: As used herein, a “chimeric antigen receptor” or “CAR” refers to an engineered receptor that specifically binds to an antigen (e.g., BCMA) or other ligand or molecule onto immune effector cells (e.g., T cells, NK cells, NKT cells, iNKT cells). Chimeric antigen receptors typically contain at least an extracellular ligand-binding domain or portion thereof capable of specifically binding to an antigen, and an intracellular domain comprising one or more signal transduction domains and / or co-stimulatory domains.

[0092] In some embodiments, the extracellular ligand-binding domain of the CAR may be in the form of a binding protein, a small molecule, a peptide, a target, an agonist, or an antagonist. In some embodiments, the binding protein is an antibody, an antigen-binding fragment of an antibody (e.g., an scFv), a ligand, a cytokine, or a receptor. In some embodiments, the antigen-binding fragment is an scFv (e.g., an scFv targeting BCMA).

[0093] In some embodiments, the extracellular ligand-binding domain is in the form of a single-chain variable fragment (scFv) derived from an antibody (e.g., a monoclonal antibody) that provides specificity for a particular epitope or antigen (e.g., an epitope or antigen that is preferentially present on the cell surface, such as an epitope or antigen of a cancer cell or other pathogenic cell or particle).

[0094] In some embodiments, the CAR includes an intracellular signaling domain. The intracellular signaling domain is a cytoplasmic domain that, upon binding to an extracellular domain, transmits an activation signal to the cell. The intracellular signaling domain can be any intracellular signaling domain of interest known in the art. Such cytoplasmic signaling domains may include, but are not limited to, CD3ζ. In some embodiments, the intracellular domain further includes one or more intracellular co-stimulatory domains, such as those described herein, which, upon binding to an extracellular domain, transmit co-stimulatory signals that promote cell proliferation, cell survival, and / or cytokine secretion. Such intracellular co-stimulatory domains may include, but are not limited to, any co-stimulatory domains disclosed herein or those known in the art, such as CD27, CD28, CD8, 4-1BB (CD137), OX40, CD30, CD40, CD127, PD-1, ICOS, lymphocyte function-associated antigen-1 (LFA-1), CD2, CD7, LIGHT, NKG2C, B7-H3, and ligands that specifically bind to CD83, N1, N6, or any combination thereof. Another suitable co-stimulatory domain is described in PCT international application number PCT / US2017 / 055133, which is incorporated herein by reference in its entirety. In some embodiments, the co-stimulatory domain is 4-1BB (CD137). In some embodiments, the chimeric antigen receptor further includes additional structural elements, including a transmembrane domain attached to an extracellular ligand-binding domain via a hinge or conjugation sequence. The transmembrane domain may be derived from any membrane-binding or transmembrane protein. For example, a transmembrane polypeptide may be a subunit of a T-cell receptor, an IL2 receptor p55 (a chain), p75 (β chain), or a γ chain (i.e., an α, β, γ, or ζ polypeptide constituting the CD3 complex), a subunit chain of an Fc receptor (e.g., an Fcy receptor III), or a CD protein such as a CD8α chain. Alternatively, the transmembrane domain may be synthetic and may primarily contain hydrophobic residues such as leucine and valine. In some embodiments, the CAR comprises a CD8 transmembrane domain. A hinge region refers to any oligopeptide or polypeptide that functions to connect a transmembrane domain and an extracellular ligand-binding domain. For example, a hinge region may contain up to 300 amino acids, 10 to 100 amino acids, and 25 to 50 amino acids. The hinge region may be derived from all or part of a naturally occurring molecule, such as all or part of the extracellular region of CD8, CD4, or CD28, or all or part of an antibody constant region. Alternatively, the hinge region may be a synthetic sequence corresponding to a naturally occurring hinge sequence, or it may be a fully synthetic hinge sequence. In some embodiments, the hinge domain may comprise a portion of the human CD8α chain, the FcγRIIIa receptor, or IgG1. In some embodiments, the CAR comprises a CD8 hinge region.

[0095] CDR-grafted antibody: The term “CDR-grafted antibody” refers to an antibody that contains heavy and light chain variable region sequences from one species, but in which one or more CDR regions of VH and / or VL are replaced by CDR sequences from another species, such as antibodies having mouse heavy and light chain variable regions in which one or more mouse CDRs (e.g., CDR3) have been replaced by human CDR sequences.

[0096] Chimeric antibody: The term "chimeric antibody" refers to an antibody that contains heavy and light chain variable region sequences from one species and constant region sequences from another species, such as antibodies with mouse heavy and light chain variable regions linked to human constant regions.

[0097] Complementarity: As used herein, the term “complementarity” refers to the ability to precisely pair between two nucleotides or groups of nucleotides. In particular, complementarity is a term characterizing the extent to which hydrogen-bonded pairing results in binding between two nucleotides or groups of nucleotides. For example, if a base at a position of an oligonucleotide is able to hydrogen bond with a base at a corresponding position of a target nucleic acid (e.g., mRNA), the bases at that position are considered complementary to each other. Base pairing can include both canonical Watson-Crick base pairing and non-Watson-Crick base pairing (e.g., Wobble base pairing and Hoogsteen base pairing). For example, in some embodiments, for complementary base pairing, an adenosine base (A) is complementary to a thymidine base (T) or a uracil base (U), a cytosine base (C) is complementary to a guanosine base (G), and universal bases such as 3-nitropyrrole or 5-nitroindole can hybridize with any A, C, U, or T and are considered complementary to any A, C, U, or T. Inosine (I) is also considered a universal base in the art and is considered complementary to any A, C, U or T.

[0098] Conservative amino acid substitution: As used herein, “conservative amino acid substitution” refers to an amino acid substitution that does not alter the relative charge or size characteristics of the protein to which the substitution is made. Variants can be prepared according to methods known to those skilled in the art for altering polypeptide sequences, such methods can be found, for example, in compilations of such methods: Molecular Cloning: A Laboratory Manual, edited by J. Sambrook et al., 4th ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 2012 or Current Protocols in Molecular Biology, edited by F. MAusubel et al., John Wiley & Sons, Inc., New York. Conservative substitution of amino acids includes substitutions between amino acids within the following group: (a) M, I, L, V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g) E, D.

[0099] Costimulatory domain: As used herein, a “costimulatory domain” refers to a polypeptide domain that, upon activation, transmits signals for intracellular proliferation and / or cell survival. Activation of a costimulatory domain can occur after homodimerization of two costimulatory domain polypeptides. Activation can also occur after activation of a construct, for example, that includes a costimulatory domain (e.g., a chimeric antigen receptor or an inducible regulatory construct). Typically, costimulatory domains can be derived from transmembrane costimulatory receptors, particularly from the intracellular portion of the costimulatory receptor. Non-limiting examples of costimulatory polypeptides include, but are not limited to, 4-1BB, CD28, ICOS, OX-40, and CD27, as well as any other costimulatory domains further described herein. In some embodiments, the CAR described herein includes a 4-1BB costimulatory domain.

[0100] Co-stimulatory signal: As used herein, "co-stimulatory signal" refers to an intracellular signal induced by a co-stimulatory domain that promotes cell proliferation, expansion of cell populations in vitro and / or in vivo, promotes cell survival, regulates (e.g., upregulates or downregulates) the secretion of cytokines, and / or regulates the production and / or secretion of other immunomodulatory molecules. In some embodiments, the co-stimulatory signal is induced following homodimerization of peptides containing two co-stimulatory domains. In some embodiments, the co-stimulatory signal is induced following activation of a construct comprising a co-stimulatory domain (e.g., a chimeric antigen receptor or an inducible regulatory construct).

[0101] Cross-reactivity: As used herein and in the context of a target agent (e.g., an antibody), the term "cross-reactivity" refers to the property of an agent to specifically bind with more than one antigen of similar type or class (e.g., multiple homologs, paralogs, or orthologs) with similar affinity or coherence. For example, in some embodiments, antibodies that are cross-reactive to similar types or classes of human and non-human primate antigens (e.g., human BCMA and non-human primate BCMA) are capable of binding to human and non-human primate antigens with similar affinity or coherence. In some embodiments, antibodies are cross-reactive to similar types or classes of human and rodent antigens. In some embodiments, antibodies are cross-reactive to similar types or classes of rodent and non-human primate antigens. In some embodiments, antibodies are cross-reactive to similar types or classes of human, non-human primate, and rodent antigens.

[0102] Effective amount: As used herein, "effective amount" means the amount of each active agent (e.g., anti-BCMA antibody) required, alone or in combination with one or more other active agents, to produce a therapeutic effect on a subject. In some embodiments, the therapeutic effect includes, but is not limited to, reducing tumor size, eliminating tumor, or alleviating tumor-related symptoms.

[0103] Epitope: As used herein, “epitope” is a term in the art and refers to a localized region of an antigen (e.g., a peptide or peptide-MHC complex) that an antibody or chimeric antigen receptor can bind to. In some embodiments, epitopes that the antibody or chimeric antigen receptor binds to can be determined by, for example, NMR spectroscopy, X-ray diffraction crystallography, ELISA assays, hydrogen / deuterium exchange coupled mass spectrometry (e.g., liquid chromatography-electrospray ionization mass spectrometry), flow cytometry analysis, mutation formation mapping (e.g., site-directed mutagenesis mapping), and / or structural modeling. For X-ray crystallography, crystallization can be accomplished using any method known in the art (e.g., Giegé R et al., (1994) Acta Crystallogr D Biol Crystallogr 50 (Pt 4):339-350; McPherson A (1990) Eur J Biochem 189:1-23; Chayen NE (1997) Structure 5:1269-1274; McPherson A (1976) J Biol Chem 251:6300-6303, each of which is incorporated herein by reference in its entirety). Antibody: Antigen crystals can be studied using well-known X-ray diffraction techniques and computer software such as X-PLOR (Yale University, 1992, distributed by Molecular Simulations, Inc.; see, for example, Meth Enzymol (1985) Vols. 114 and 115, edited by Wyckoff HW et al.; US2004 / 0014194) and BUSTER (Bricogne G (1993) Acta Crystallogr D Biol Crystallogr 49 (Pt 1):37-60; Bricogne G (1997) Meth Enzymol 276A:361-423, edited by Carter CW; Roversi P et al., (2000) Acta Crystallogr D Biol Crystallogr 56 (Pt 1) The following references (10):1316-1323) are refined and are incorporated herein by reference in their entirety. Mutagenesis mapping studies can be performed using any method known to those skilled in the art. See, for example, Champe M et al., (1995) J BiolChem 270:1388-1394 and Cunningham BC & Wells JA (1989) Science 244:1081-1085, each of which describes mutagenesis techniques (including alanine scanning mutagenesis techniques) and is incorporated herein by reference in its entirety.In a specific embodiment, alanine scanning mutagenesis was used to determine the epitopes of the antigen. In a specific embodiment, hydrogen / deuterium exchange coupled mass spectrometry was used to determine the epitopes of the antigen.

[0104] Frame: As used herein, the term “frame” or “frame sequence” refers to the sequence remaining after subtracting the CDR from the variable region. Because the exact definition of a CDR sequence can be determined by different systems, the meaning of a frame sequence can be interpreted accordingly. The six CDRs (CDR-L1, CDR-L2, and CDR-L3 for the light chain and CDR-H1, CDR-H2, and CDR-H3 for the heavy chain) also divide the frames on both the light and heavy chains into four subregions (FR1, FR2, FR3, and FR4) on each chain, where CDR1 is located between FR1 and FR2, CDR2 between FR2 and FR3, and CDR3 between FR3 and FR4. Where no specific subregion is designated as FR1, FR2, FR3, or FR4, other references to frame regions refer to combinations of FRs within the variable region of a single naturally occurring immunoglobulin chain. As used herein, FR represents one of the four subregions, and FRs represent two or more of the four subregions that constitute a frame region. Human heavy and light chain receptor sequences are known in the art. In one embodiment, a receptor sequence known in the art may be used in the antibody disclosed herein.

[0105] Human Antibody: As used herein, the term "human antibody" is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. Human antibodies of this disclosure may contain amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations formed through random or site-specific mutations in vitro or introduced through somatic mutations in vivo), such as in CDRs, and particularly in CDR3. However, as used herein, the term "human antibody" is not intended to include antibodies in which a germline CDR sequence derived from another mammalian species (e.g., mouse) has been grafted onto a human scaffold region sequence.

[0106] Humanized antibody: The term "humanized antibody" refers to an antibody that contains variable region sequences of both heavy and light chains derived from a non-human species (e.g., mouse), but in which V... H and / or V LAt least a portion of the sequence has been altered to be more "human-like" (i.e., more similar to human germline variable sequences) antibody. One type of humanized antibody is a CDR-grafted antibody, in which a human CDR sequence is introduced into non-human VH and VL sequences to replace the corresponding non-human CDR sequences. In one embodiment, a humanized anti-BCMA antibody and its antigen-binding fragment are provided. Such antibodies can be produced by obtaining mouse anti-BCMA monoclonal antibodies using conventional hybridoma techniques, followed by humanization using in vitro genetic engineering, such as those disclosed in PCT publication WO 2005 / 123126A2 by Kasaian et al. In some embodiments, the humanized antibody comprises a human immunoglobulin (recipient antibody), wherein residues from the recipient's complementarity-determining region (CDR) are replaced by residues from a non-human species (donor antibody) having the desired specificity, affinity, and capacity, such as a mouse, rat, or rabbit CDR. In some embodiments, Fv framework region (FR) residues of the human immunoglobulin are replaced by corresponding non-human residues. In addition, humanized antibodies may include residues not found in the receptor antibody or in the introduced CDR or frame sequence but included to further refine and optimize antibody performance. Typically, humanized antibodies will include at least one, and typically two, variable domains, of substantially all of the variable domains, wherein all or substantially all of the CDR regions correspond to regions of non-human immunoglobulins, and all or substantially all of the FR regions are regions of human immunoglobulin common sequences. Humanized antibodies will also preferably include at least a portion of an immunoglobulin constant region or domain (Fc), typically at least a portion of a human immunoglobulin. The antibody may have a modified Fc region as described in WO 99 / 58572. Other forms of humanized antibodies have one or more CDRs (one, two, three, four, five, six) modified with respect to the original antibody, also referred to as one or more CDRs derived from one or more CDRs of the original antibody. Humanized antibodies may also involve affinity maturation.

[0107] Invariant Natural Killer Cells (iNKT): As used herein, the terms “invariant natural killer T cells” or “invariant NKT cells”, “iNKT cells” or “type I NKT cells” refer to a population of T lymphocytes that express a conserved semi-invariant TCR specific to a lipid antigen (Ag) and are limited to a singlet MHC class I-associated molecule CD1d. Natural killer T cells (NKT cells) were initially characterized in mice as T cells that express both TCR and NK1.1 (NKR-P1a-c or CD161) (type C lectin NK receptor). Invariant NKT (iNKT) cells express a semi-invariant αβ TCR (e.g., formed by the invariant TRAV11-TRAJ18(4) rearrangement in mice or the homologous invariant TRAV10-TRAJ18 in humans) paired with a limited and diverse set of Vβ chains, predominantly TRBV1, TRBV29 or TRBV13(6) in mice and predominantly TRBV25 in humans (see, for example, Dellabona et al., An The invariant Valpha 24-J alpha Q / V beta 11T cell receptor is expressed in all individuals by clonally expanded CD4-8-T cells. J Exp Med. (1994) 180: 1171–6.10.1084. In some embodiments, the semi-invariant TCR recognizes exogenous and endogenous lipid Ag presented by the singlet MHC class I-associated molecule CD1d (see, e.g., Brennan et al., Invariant naturalkiller T cells: an innate activation scheme linked to diverse effector functions. Nat Rev Immunol. (2013) 13: 101–17.10.1038). In some embodiments, the exogenous lipid Ag includes the prototype α-galactosylceramide (α-GalCer) (Kawano et al., CD1d-restricted and TCR-mediated activation of valpha14 NKT cells by (glycosylceramides. Science. (1997) 278: 1626–9.10.1126) and many bacterial Ags can activate iNKT cells.

[0108] Compared to T cells, iNKT cells undergo a unique developmental pathway, resulting in the acquisition of innate effector functions in the thymus. Thymic iNKT cells do express markers typically upregulated by peripheral effector / memory T cells, such as CD44 and CD69, as well as unique NK differentiation markers, such as NK1.1 (CD161 in humans in some mouse genetic backgrounds), CD122 (IL-2R / IL-15Rβ chain), CD94 / NKG2, and Ly49 (AJ), and a broad spectrum of TH1 / 2 / 17 effector cytokines. In some embodiments, upon migration to the surrounding environment, iNKT cells form tissue-resident populations that investigate cellular integrity and rapidly respond to local injury and inflammation, thereby initiating cellular responses to both innate and adaptive immune responses. In some embodiments, anti-BCMACAR iNKT cells are Th1 iNKT cells, Th2 iNKT cells, Th17 iNKT cells, or a combination thereof.

[0109] In some respects, iNKT cells have been found to play a role in various diseases by establishing Th1- or Th2-based immune responses, due to their rapid production of IFNγ, IL-4, or both. In bacterial and viral infections, iNKT cells often help control pathogens early by establishing an effective Th1 response. The role of iNKT cells in diseases associated with excessive Th1 responses, such as type 1 diabetes and chronic obstructive pulmonary disease, has been described in small and human studies. The role of iNKT cells in helping to suppress Th1 responses and drive tolerance responses to grafts has also been described. For example, the presence of iNKT cells after hematopoietic stem cell transplantation has predicted survival rates in patients and preclinical models, as well as a reduction in graft-versus-host disease (GvHD).

[0110] In some respects, iNKT cells infiltrate tumors and play an important role in immune surveillance against tumors (e.g., solid and / or hematologic malignancies) (see, for example, Wolf et al., Novel Approaches to Exploiting Invariant NKT Cells in Cancer Immunotherapy, FrontImmunol. 2018 Mar 2; 9:384). In some cases, iNKT cells can serve as an attractive platform for adoptive cellular immunotherapy for cancer compared to conventional T cells. In some embodiments, iNKT cells can directly kill cancer cells (e.g., cancer cells expressing CD1d). In some embodiments, iNKT cells can restrict immunosuppressive myeloid mononuclear cell populations in the tumor microenvironment (TME) (e.g., via CD1d homologous recognition), promoting antitumor responses (e.g., regardless of whether cancer cells express CD1d). In some embodiments, iNKT cells can be adopted across the MHC barrier without the risk of alloreactivity because CD1d molecules are identical in all individuals, and they also possess the ability to suppress graft-versus-host disease (GvHD) without impairing antitumor responses. In other embodiments, iNKT cells can be engineered to acquire secondary antigen specificity by expressing recombinant TCRs and / or chimeric antigen receptors (CARs) specific to tumor-associated antigens, thereby enabling direct targeting of cancer cells expressing the antigens while maintaining their CD1d-dependent function. In some embodiments, iNKT cells can be used for off-the-shelf adoptive cell therapy without donor limitations, thereby enabling simultaneous targeting of cancer cells and suppression of the tumor microenvironment. Compared to conventional αβT cells, iNKT cell adoptive immunotherapy offers advantages including, but not limited to, the following: (i) control of the tumor microenvironment (TME); (ii) the ability to combat cancer cells through engineered tumor-specific CARs and / or TCRs while maintaining their intrinsic control over the TME; and (iii) the absence of alloreactivity, limited to singlet CD1d molecules, thus allowing them to be used directly without donor limitations.

[0111] Isolated antibody: As used herein, “isolated antibody” is intended to refer to an antibody that is substantially free of other antibodies with different antigen specificities (e.g., an isolated antibody that specifically binds to BCMA is substantially free of antibodies that specifically bind to antigens other than BCMA). Furthermore, isolated antibodies may be substantially free of other cellular material and / or chemicals.

[0112] Percentage Identity: Mathematical algorithms can be used to determine the "percentage identity" or "percentage similarity" between two sequences (e.g., amino acid sequences or nucleic acid sequences). Specific, non-limiting examples of mathematical algorithms used to compare two sequences are those of Karlin S and Altschul SF (1990) PNAS 87:2264-2268, modified as in Karlin S and Altschul SF (1993) PNAS 90:5873-5877, each of which is incorporated herein by reference in its entirety. Such algorithms are incorporated in the NBLAST and XBLAST procedures of Altschul SF et al., (1990) J Mol Biol 215:403, which is also incorporated herein by reference in its entirety. A BLAST nucleotide search can be performed using the NBLAST nucleotide procedure parameter set (e.g., fraction = 100, word length = 12) to obtain nucleotide sequences homologous to the nucleic acid molecules described herein. A BLAST protein search can be performed using the XBLAST procedure parameter set (e.g., fraction = 50, word length = 3) to obtain amino acid sequences homologous to the protein molecules described herein. For gap alignments to be performed for comparative purposes, gap BLAST as described in Altschul SF et al., (1997) Nuc Acids Res 25:3389-3402, which is incorporated herein by reference in its entirety. Alternatively, PSIBLAST can be used to perform an iterative search to detect distance relationships between molecules. Ibid. When using the BLAST, gap BLAST, and PSIBlast procedures, the default parameters of the corresponding procedures (e.g., XBLAST and NBLAST) can be used (see, for example, the National Center for Biotechnology Information (NCBI) on the World Wide Web, ncbi.nlm.nih.gov). Another specific, non-limiting example of a mathematical algorithm for sequence comparison is the algorithm of Myers and Miller, 1988, CABIOS 4:11-17, which is incorporated herein by reference in its entirety. This algorithm has been incorporated into the ALIGN program (version 2.0), which is part of the GCG sequence alignment software package. When comparing amino acid sequences using the ALIGN program, the PAM120 weighted residue table, vacancy length penalty of 12, and vacancy penalty of 4 can be used.

[0113] Whether or not gaps are allowed, techniques similar to those described above can be used to determine the percentage of identity between two sequences. When calculating the percentage of identity, typically only exact matches are counted.

[0114] Recombinant Antibody: As used herein, the term “recombinant human antibody” is intended to include all human antibodies prepared, expressed, generated, or isolated in a recombinant manner, such as antibodies expressed using recombinant expression vectors transfected into host cells (described in more detail in this disclosure), antibodies isolated from recombinant, combinatorial human antibody libraries (Hoogenboom HR, (1997) TIBTech. 15:62-70; Azzazy H. and Highsmith WE, (2002) Clin. Biochem. 35:425-445; Gavilondo JV and Larrick JW (2002) BioTechniques 29:128-145; Hoogenboom H. and Chames P. (2000) Immunology Today 21:371-378), and antibodies isolated from animals (e.g., mice) transgenic with human immunoglobulin genes (see, e.g., Taylor, LD et al. (1992) Nucl. Acids Res. 20:6287-6295; Kellermann SA. and Green LL (2002) Current Opinion in Biotechnology 13:593-597; Little M. et al. (2000) Immunology Today 21:364-370), or antibodies prepared, expressed, generated, or isolated by any other means involving splicing human immunoglobulin gene sequences into other DNA sequences. Such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences. However, in some embodiments, such recombinant human antibodies undergo in vitro mutagenesis (or, when using animals with transgenic human Ig sequences, in vivo somatic mutagenesis), and therefore the V of the recombinant antibody... H District and V L The amino acid sequence of the region is as follows: Although it is derived from human lineage V H Sequence and V L The sequence is associated with, but may not be naturally present in the human antibody germline library in vivo. One embodiment of this disclosure provides a fully human antibody capable of binding to human BCMA, which can be generated using techniques well known in the art, such as, but not limited to, using human Ig phage libraries, such as those disclosed in PCT Publication No. WO 2005 / 007699A2 by Jermutus et al.

[0115] Single-chain variable fragment (scFv): As used herein, the term "single-chain variable fragment (scFv)" refers to a fusion protein in which the variable regions of the heavy chain (VH) and light chain (VL) of an immunoglobulin are linked by short linker peptides. A linker is a peptide or short oligopeptide sequence used to assemble two subunits into a single polypeptide. Linkers may have sequences found in native proteins or may be artificial sequences not found in any native protein. Linkers may be flexible and lack secondary structure, or may tend to form a specific three-dimensional structure under physiological conditions. In some embodiments, the linker is a glycine-rich linker. In some embodiments, the linker is serine- or threonine-rich. In some embodiments, scFv is a fusion protein in which the N-terminus of VH is linked to the C-terminus of VL. In some embodiments, scFv is a fusion protein in which the N-terminus of VL is linked to the C-terminus of VH. scFv retains the specificity of the original immunoglobulin, although the constant region is removed and a linker is introduced. In some embodiments, scFv may be generated to facilitate phage display. In some embodiments, scFv can be generated directly from the heavy and light chains of a subclone derived from a hybridoma. ScFv has many uses, such as flow cytometry, immunohistochemistry, and as an antigen-binding domain for chimeric antigen receptors.

[0116] Specific binding: As used herein, the term "specific binding" or "specific binding" refers to the ability of a molecule to bind to a binding partner with a degree of affinity or affinity that allows the molecule to be used to distinguish the binding partner from a suitable control in a binding assay or other binding setting. Regarding antibodies, the term "specific binding" refers to the ability of an antibody to bind to a specific antigen with a degree of affinity or affinity compared to one or more suitable reference antigens that allows the antibody to be used to distinguish the specific antigen from other antigens, for example, to the extent that it allows preferential targeting of certain cells (e.g., muscle cells) by binding to antigens as described herein. In some embodiments, if the antibody binds to the target K D For at least about 10 -4 M, 10 -5 M, 10 -6 M, 10 -7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13 If M is smaller, the antibody binds specifically to the target. In some embodiments, the antibody binds specifically to BCMA.

[0117] Subject: As used herein, the term "subject" refers to a mammal. In some embodiments, the subject is a non-human primate or rodent. In some embodiments, the subject is a human. In some embodiments, the subject is a patient, such as a person who has or is suspected of having a disease. In some embodiments, the subject is a person who has or is suspected of having a muscle disease (e.g., cancer expressing BCMA) or other conditions associated with abnormal BCMA expression or activity.

[0118] Treatment: As used herein, the term "treating" or "treatment" refers to the administration or application of a composition comprising one or more active agents (e.g., anti-BCMA antibody) to a subject who has a target disease or symptom (e.g., cancer), symptoms of the disease / symptom (e.g., tumor growth, tumor metastasis, fatigue, weight changes (including unexpected loss or gain), pain, fever, non-healing sores, persistent cough or hoarseness, abnormal bleeding, or anemia), or susceptibility to the disease / symptom (e.g., cancer), with the aim of curing, healing, alleviating, reducing, altering, remedying, improving, or influencing the patient's condition (e.g., cancer), symptoms of the disease (e.g., tumor growth, tumor metastasis, fatigue, weight changes (including unexpected loss or gain), pain, fever, non-healing sores, persistent cough or hoarseness, abnormal bleeding, or anemia), or susceptibility to the disease or symptom. Alleviating a target disease / symptom includes delaying or preventing the development or progression of the disease, or reducing the severity of the disease.

[0119] II. Anti-BCMA antibody or its antigen-binding fragment

[0120] In some aspects, this disclosure provides antibodies or antigen-binding fragments specific to B cell maturation antigen (BCMA). In some embodiments, the anti-BCMA antibodies or antigen-binding fragments provided herein are antibodies that bind to BCMA with high specificity and affinity. In some embodiments, the antigen-binding fragments of the anti-BCMA antibodies described herein specifically bind to extracellular epitopes of BCMA or epitopes that become exposed to the antibody. In some embodiments, the antigen-binding fragments of the anti-BCMA antibodies provided herein specifically bind to BCMA from humans, non-human primates, mice, rats, etc. In some embodiments, the antigen-binding fragments of the anti-BCMA antibodies provided herein bind to human BCMA. In some embodiments, the anti-BCMA antibodies described herein or their antigen-binding fragments specifically bind to epitopes on human BCMA (e.g., human BCMA listed in SEQ ID NO: 103 or 104). In some embodiments, the anti-BCMA antibodies or their antigen-binding fragments bind to fragments of human BCMA (e.g., human BCMA listed in SEQ ID NO: 103 or 104). In some embodiments, the anti-BCMA antibody described herein or its antigen-binding fragment binds to fragments of BCMA (e.g., human BCMA as listed in SEQ ID NO: 103 or 104) of length between about 5 and about 184 amino acids, between about 10 and about 184 amino acids, between about 20 and about 184 amino acids, between about 30 and about 150 amino acids, between about 30 and about 120 amino acids, between about 30 and about 100 amino acids, between about 30 and about 90 amino acids, between about 30 and about 80 amino acids, between about 30 and about 60 amino acids, between about 30 and about 50 amino acids, between about 40 and about 80 amino acids, or between about 40 and about 60 amino acids. In some embodiments, the anti-BCMA antibody described herein or its antigen-binding fragment binds to fragments comprising a consecutive number of amino acids from human BCMA protein (e.g., human BCMA as listed in SEQ ID NO: 103 or 104). In some embodiments, the anti-BCMA antibody described herein or its antigen-binding fragment binds to a fragment comprising at least 5, at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, at least 100, at least 110, at least 120, at least 130, at least 140, at least 150, at least 160, at least 170, or at least 180 consecutive amino acids of human BCMA protein (e.g., human BCMA listed in SEQ ID NO: 103 or 104).In some embodiments, the anti-BCMA antibody described herein, or its antigen-binding fragment, binds to a fragment having an amino acid sequence that differs from a fragment of human BCMA protein (e.g., human BCMA listed in SEQ ID NO: 103 or 104) by up to five, four, three, two, or one amino acid. Exemplary human BCMA amino acid sequences are listed in NP_001183 (SEQ ID NO: 103) or BAB60895 (SEQ ID NO: 104).

[0121] An exemplary BCMA amino acid sequence is listed in SEQ ID NO:103(NP_001183):

[0122] MLQMAGQCSQNEYFDSLLHACIPCQLRCSSNTPPLTCQRYCNASVTNSVKGTNAILWTCLGLSLIISLAVFVLMFLLRKINSEPLKDEFKNTGSGLLGMANIDLEKSRTGDEIILPRGLEYTVEECTCEDCIKSKPKVDSDHCFPLPAMEEGATILVTTKTNDYCKSLPAALSATEIEKSISAR

[0123] An exemplary BCMA amino acid sequence is listed in SEQ ID NO:104 (BAB60895):

[0124] MLQMAGQCSQNEYFDSLLHACIPCQLRCSSNTPPLTCQRYCNASVTNSVKGTNAILWTCLGLSLIISLAVFVLMFLLRKISSEPLKDEFKNTGSGLLGMANIDLEKSRTGDEIILPRGLEYTVEECTCEDCIKSKPKVDSDHCFPLPAMEEGATILVTTKTNDYCKSLPAALSATEIEKSISAR

[0125] Exemplary BCMA epitopes are listed in Table 2. In some embodiments, the anti-BCMA antibody described herein or its antigen-binding fragment binds to an epitope having an amino acid sequence that is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to any of SEQ ID NO:38 to 48. In some embodiments, the anti-BCMA antibody described herein or its antigen-binding fragment binds to an epitope having an amino acid sequence that differs from any of SEQ ID NO:38 to 48 by at most one, at most two, at most three, at most four, at most five, at most six, at most seven, at most eight, at most nine, or at most ten amino acids.

[0126] Table 2: BCMA Tabletops

[0127]

[0128] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment is at least about 10 -4 M, 10 -5 M, 10 -6 M, 10 - 7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13 M or less binding affinity (e.g., as by K) D(Indication) Specific binding to BCMA. For example, the anti-BCMA antibody or its antigen-binding fragment disclosed herein can be between 5 pM and 500 nM, between 10 pM and 450 nM, between 20 pM and 400 nM, between 30 pM and 350 nM, between 40 pM and 300 nM, between 50 pM and 250 nM, between 60 pM and 200 nM, between 70 pM and 150 nM, between 80 pM and 100 nM, between 80 pM and 90 nM. Affinities between M, between 90 pM and 80 nM, between 100 pM and 70 nM, between 200 pM and 60 nM, between 300 pM and 50 nM, between 400 pM and 40 nM, between 500 pM and 30 nM, between 600 pM and 20 nM, between 700 pM and 10 nM, between 800 pM and 5 nM, or between 900 pM and 2 nM bind to BCMA proteins (e.g., human BCMA epitopes listed in any of SEQ ID NO: 38 to 48).

[0129] This disclosure also includes antibodies that compete with any of the antibodies described herein for binding to BCMA proteins (e.g., human BCMA epitopes listed in any of SEQ ID NO:38 to 48) and have an affinity of 100 nM or less (e.g., 80 nM or less, 50 nM or less, 20 nM or less, 10 nM or less, 500 pM or less, 50 pM or less, or 5 pM or less). The affinity and binding kinetics of the anti-BCMA antibody or its antigen-binding fragment can be tested using any suitable method (including, but not limited to, biosensor technologies) (e.g., OCTET or BIACORE). In some embodiments, the anti-BCMA antibody or its antigen-binding fragment described herein is in the sub-nanomolar range of Kc. D Combined with BCMA.

[0130] Table 3 provides unrestricted examples of anti-BCMA antibodies.

[0131] Table 3. Exemplary anti-BCMA antibodies (CDRs as defined by Kabat; CDR sequences in VH / VL / ScFv sequences are bolded; VH / VL sequences in scFv are underlined)

[0132]

[0133]

[0134]

[0135]

[0136]

[0137] In some embodiments, the anti-BCMA antibody or antigen-binding fragment thereof disclosed herein comprises one or more of the heavy chain CDR (e.g., CDRH1, CDRH2, or CDRH3) amino acid sequences selected from any of the anti-BCMA antibodies listed in Table 3. In some embodiments, the anti-BCMA antibody or antigen-binding fragment thereof disclosed herein comprises CDRH1, CDRH2, and CDRH3 as provided by any of the antibodies selected in Table 3. In some embodiments, the anti-BCMA antibody or antigen-binding fragment thereof disclosed herein comprises one or more of the light chain CDR (e.g., CDRL1, CDRL2, or CDRL3) amino acid sequences selected from any of the anti-BCMA antibodies selected in Table 3. In some embodiments, the anti-BCMA antibody or antigen-binding fragment thereof disclosed herein comprises CDRL1, CDRL2, and CDRL3 as provided by any of the anti-BCMA antibodies selected in Table 3.

[0138] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 as provided by any of the anti-BCMA antibodies selected from Table 3. In some embodiments, the CDR3 domains of the antibody heavy and light chains may play a particularly important role in the antibody's binding specificity / affinity to the antigen. Therefore, the anti-BCMA antibody or its antigen-binding fragment may at least comprise the heavy chain and / or light chain CDR3 of any of the anti-BCMA antibodies selected from Table 3.

[0139] Functional variants of the exemplary anti-BCMA antibodies or their antigen-binding fragments disclosed herein are also within the scope of this disclosure. Functional variants may contain a V relative to the reference antibody. H and / or V L In, or one or more amino acid residue variations in one or more heavy chain CDRs and / or one or more light chain CDRs, while retaining substantially similar binding and biological activities to the reference antibody (e.g., substantially similar binding affinity, binding specificity, inhibitory activity, anti-inflammatory activity, or combinations thereof).

[0140] In some embodiments, any of the anti-BCMA antibodies or antigen-binding fragments thereof disclosed herein have one or more CDR (e.g., heavy chain CDRs or light chain CDRs) sequences that are substantially similar to any one of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 sequences selected from the anti-BCMA antibodies in Table 3. In some embodiments, the positions of one or more CDRs of the antibodies described herein along the VH (e.g., CDRH1, CDRH2 or CDRH3) and / or VL (e.g., CDRL1, CDRL2 or CDRL3) regions may vary by one, two, three, four, five or six amino acid positions, as long as specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintaining the binding of the original antibody from which it is derived, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%). For example, in some embodiments, the position of the CDR defining any antibody described herein can be altered by shifting the N-terminal and / or C-terminal boundary of the CDR by one, two, three, four, five, or six amino acids relative to the CDR position of any of the antibodies described herein, as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintaining the binding of the original antibody derived therefrom, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%). In another embodiment, the length of one or more CDRs of the antibody described herein along the VH (e.g., CDRH1, CDRH2, or CDRH3) and / or VL (e.g., CDRL1, CDRL2, or CDRL3) may be varied (e.g., become shorter or longer) by one, two, three, four, five, or more amino acids, as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintaining the binding of the original antibody from which it is derived, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%).

[0141] Therefore, in some embodiments, the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 of the anti-BCMA antibody or its antigen-binding fragment may be one, two, three, four, five or more amino acids shorter than one or more CDRs described herein (e.g., CDRs selected from any of the anti-BCMA antibodies in Table 3), as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding to the original antibody from which it is derived. In some embodiments, the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 of the anti-BCMA antibody or its antigen-binding fragment may be one, two, three, four, five or more amino acids longer than one or more CDRs described herein (e.g., CDRs selected from any of the anti-BCMA antibodies in Table 3), as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding to the original antibody from which it is derived. In some embodiments, compared to one or more CDRs described herein (e.g., CDRs selected from any of the anti-BCMA antibodies in Table 3), the amino moiety of CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 of the anti-BCMA antibody or its antigen-binding fragment may be extended by one, two, three, four, five or more amino acids, as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the carboxyl moiety of CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 of an anti-BCMA antibody or its antigen-binding fragment may be extended by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs selected from any of the anti-BCMA antibodies in Table 3), as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding to the original antibody from which it is derived.In some embodiments, compared to one or more CDRs described herein (e.g., CDRs selected from any of the anti-BCMA antibodies in Table 3), the amino groups of CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 of the anti-BCMA antibody or its antigen-binding fragment may be shortened by one, two, three, four, five or more amino acids, as long as the specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding to the original antibody from which it is derived. In some embodiments, the carboxyl moiety of CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and / or CDRL3 of an anti-BCMA antibody or its antigen-binding fragment may be shortened by one, two, three, four, five, or more amino acids compared to one or more CDRs described herein (e.g., CDRs selected from any of the anti-BCMA antibodies in Table 3), as long as specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. Any method may be used to determine whether specific binding to BCMA (e.g., human BCMA) is maintained, such as using binding assays and conditions described in the art.

[0142] In some instances, the anti-BCMA antibody or its antigen-binding fragment comprises one or more CDR (e.g., heavy chain CDR or light chain CDR) sequences substantially similar to any of the anti-BCMA antibodies selected from Table 3. For example, an antibody may comprise one or more CDR sequences selected from any of the anti-BCMA antibodies in Table 3, containing at most 5, 4, 3, 2, or 1 amino acid residue variations compared to the corresponding CDR region in any of the CDRs provided herein (e.g., CDRs of any of the anti-BCMA antibodies in Table 3), provided that specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, any of the amino acid variations in any of the CDRs provided herein may be conserved variations. Conserved variations may be introduced into the CDR at locations where residues are unlikely to be involved in interacting with the BCMA protein (e.g., human BCMA) (e.g., as determined based on crystal structure).

[0143] Some aspects of this disclosure provide anti-BCMA antibodies comprising one or more of the heavy chain variable (VH) and / or light chain variable (VL) domains provided herein. In some embodiments, each of the VH domains provided herein comprises one or more of the CDR sequences (e.g., CDRH1, CDRH2, and CDRH3) provided herein, such as any of the heavy chain CDR sequences provided in any of the anti-BCMA antibodies listed in Table 3. In some embodiments, each of the VL domains provided herein comprises one or more of the CDR-L sequences (e.g., CDRL1, CDRL2, and CDRL3) provided herein, such as any of the light chain CDR sequences provided in any of the anti-BCMA antibodies listed in Table 3.

[0144] In some embodiments, an anti-BCMA antibody or its antigen-binding fragment comprises any antibody containing a heavy chain variable domain and / or a light chain variable domain selected from any of the anti-BCMA antibodies and their variants in Table 3. In some embodiments, an anti-BCMA antibody or its antigen-binding fragment comprises any antibody containing a heavy chain variable and light chain variable pair selected from any of the anti-BCMA antibodies in Table 3.

[0145] Various aspects of this disclosure provide anti-BCMA antibodies or antigen-binding fragments thereof comprising amino acid sequences of heavy chain variable (VH) and / or light chain variable (VL) domains homologous to any of those described herein. In some embodiments, the anti-BCMA antibody or antigen-binding fragment thereof comprises a VH or VL that is at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the VH and / or any VL selected from any of the anti-BCMA antibodies in Table 3. In some embodiments, the homologous VH and / or VL amino acid sequences remain unchanged within any of the CDR sequences provided herein. For example, in some embodiments, the degree of sequence variation (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) may occur within the VH and / or VL sequences, excluding any of the CDR sequences provided herein. In some embodiments, any of the anti-BCMA antibodies or their antigen-binding fragments provided herein comprises VH and VL sequences that contain a frame sequence that is at least 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to the frame sequence of any anti-BCMA antibody selected from Table 3. In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH of any of the anti-BCMA antibodies listed in Table 3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL of any of the anti-BCMA antibodies listed in Table 3.

[0146] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment is a humanized antibody (e.g., a humanized variant containing one or more of the CDRs listed in Table 3). In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises the same CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 as shown in Table 3, and comprises a humanized VH and / or a humanized VL. In some embodiments, the anti-BCMA antibody or its antigen-binding fragment is a humanized variant comprising one or more amino acid substitutions (e.g., in the VH frame region) compared to any of the VHs listed in Table 3, and / or one or more amino acid substitutions (e.g., in the VL frame region) compared to any of the VLs listed in Table 3.

[0147] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:8.

[0148] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0149] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. As used anywhere in this disclosure, “common” means that the total number of amino acid variations in all three heavy chain CDRs is within the defined range. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0150] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0151] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:5; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0152] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises VL containing the amino acid sequence of SEQ ID NO:8.

[0153] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:8.

[0154] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:8.

[0155] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:10.

[0156] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0157] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0158] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0159] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0160] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:10.

[0161] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:10.

[0162] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:10.

[0163] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:13.

[0164] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0165] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which, compared to CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3, contains a total of no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which, compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30, contains a total of no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0166] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0167] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:27; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0168] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:13.

[0169] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO: 12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO: 13.

[0170] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:13.

[0171] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:15.

[0172] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0173] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0174] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0175] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:27; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0176] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:15.

[0177] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO: 12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO: 15.

[0178] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:12. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:15.

[0179] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:13.

[0180] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0181] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0182] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0183] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0184] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:13.

[0185] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:13.

[0186] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:13.

[0187] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:15.

[0188] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0189] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0190] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0191] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0192] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:15.

[0193] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:15.

[0194] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:15.

[0195] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:19. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:10.

[0196] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0197] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0198] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0199] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:26; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:28; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0200] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:19. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:10.

[0201] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO: 19. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO: 10.

[0202] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:19. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:10.

[0203] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:21. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:22.

[0204] In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH3 having the amino acid sequence of SEQ ID NO:33. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRH3 having the amino acid sequence of SEQ ID NO:33. In some embodiments, according to the Kabat definition system, an anti-BCMA antibody or its antigen-binding fragment comprises CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, CDRH3 having the amino acid sequence of SEQ ID NO:33, CDRL1 having the amino acid sequence of SEQ ID NO:34, CDRL2 having the amino acid sequence of SEQ ID NO:35, and CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0205] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRH3 having the amino acid sequence of SEQ ID NO:33. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:34, CDRL2 having the amino acid sequence of SEQ ID NO:35, and CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0206] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRH3 having the amino acid sequence of SEQ ID NO:33. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises CDRL1, CDRL2, and CDRL3, which together are at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to CDRL1 having the amino acid sequence of SEQ ID NO:34, CDRL2 having the amino acid sequence of SEQ ID NO:35, and CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0207] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:31; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:32; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:33. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:34; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:35; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0208] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing the amino acid sequence of SEQ ID NO:21. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing the amino acid sequence of SEQ ID NO:22.

[0209] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:21. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:22.

[0210] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:21. Alternatively or additionally, the anti-BCMA antibody or its antigen-binding fragment comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:22.

[0211] The anti-BCMA antibodies or antigen-binding fragments thereof described herein may be in any antibody form, including but not limited to full-length antibodies, their antigen-binding fragments (such as Fab, F(ab'), F(ab')2, Fv), single-chain antibodies (e.g., scFv), bispecific antibodies, or nanobodies. In some embodiments, the anti-BCMA antibodies or antigen-binding fragments thereof described herein are single-chain variable fragments (scFv). In some embodiments, the anti-BCMA antibodies or antigen-binding fragments thereof described herein are scFv-Fab (e.g., scFv fused with a portion of a constant region).

[0212] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment is selected from the VL and / or VH domains of any of the anti-BCMA antibodies listed in Table 3, and includes a constant region comprising the amino acid sequence of the constant region of an IgG, IgE, IgM, IgD, IgA, or IgY immunoglobulin molecule, any class of immunoglobulin molecules (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or any subclass (e.g., IgG2a and IgG2b). Non-limiting examples of human constant regions are described in the art, for example, see Kabat EA et al., (1991), ibid. Other antibody heavy and light chain constant regions are well known in the art, for example, those available in the IMGT database (imgt.org) or vbase2.org / vbstat.php, both of which are incorporated herein by reference.

[0213] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment is a single-chain variable fragment (scFv). In some embodiments, the anti-BCMA scFv comprises VH and VL selected from any of the anti-BCMA antibodies in Table 3. In some embodiments, the VH and VL of the anti-BCMA scFv are joined together by a linker. In some embodiments, the linker may have a length of about 2 to 10 amino acids, 5 to 20 amino acids, 10 to 30 amino acids, 20 to 50 amino acids, 40 to 60 amino acids, 60 to 80 amino acids, or more than 80 amino acids. In some embodiments, the linker may comprise a sequence substantially comprising glycine and serine. An exemplary linker sequence is GGGGSGGGGSGGGAS (SEQ ID NO: 81). In some embodiments, the linker may include, but is not limited to, any linker covered by U.S. Patent Nos. 8,445,251 and 9,434,931. In some embodiments, anti-BCMA comprises a linker between VH and VL, and the linker comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99%, or 100% identical to that of SEQ ID NO:81.

[0214] In some embodiments, the anti-BCMA scFv comprises VH and VL, and the C-terminus of VH is engaged with the N-terminus of VL via a connector (e.g., a connector listed in SEQ ID NO:81). In some embodiments, the anti-BCMA scFv comprises VH and VL, and the C-terminus of VL is engaged with the N-terminus of VH via a connector (e.g., a connector listed in SEQ ID NO:81).

[0215] In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH of any of the anti-BCMA antibodies listed in Table 3. Alternatively or additionally, the anti-BCMA scFv comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH of any of the anti-BCMA antibodies listed in Table 3. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) of the VH of any of the anti-BCMA antibodies listed in Table 3. Alternatively or additionally, the anti-BCMA scFv comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH of any of the anti-BCMA antibodies listed in Table 3.

[0216] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to any of the anti-BCMA scFvs listed in Table 3. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) the same as any of the anti-BCMA scFvs listed in Table 3.

[0217] In some embodiments, anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:8. In some embodiments, anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VH listed in SEQ ID NO:7 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO:8. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) of the same amino acid sequence as VH listed in SEQ ID NO:7 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the same amino acid sequence as VL listed in SEQ ID NO:8.

[0218] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:9. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:9. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:9.

[0219] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:10. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:10. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) of the same amino acid sequence as VH listed in SEQ ID NO:7 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the same amino acid sequence as VL listed in SEQ ID NO:10.

[0220] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:11. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:11. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:11.

[0221] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:12 and / or a VL containing the amino acid sequence of SEQ ID NO:13. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VH listed in SEQ ID NO:12 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO:13. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) of the same amino acid sequence as VH listed in SEQ ID NO:12 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the same amino acid sequence as VL listed in SEQ ID NO:13.

[0222] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:14. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:14. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:14.

[0223] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:12 and / or a VL containing the amino acid sequence of SEQ ID NO:15. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VH listed in SEQ ID NO:12 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO:15. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) of the same amino acid sequence as VH listed in SEQ ID NO:12 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the same amino acid sequence as VL listed in SEQ ID NO:15.

[0224] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:16. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:16. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:16.

[0225] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:13. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VH listed in SEQ ID NO:7 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO:13. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:13.

[0226] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:17. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:17. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:17.

[0227] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:15. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VH listed in SEQ ID NO:7 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO:15. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:15.

[0228] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:18. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:18. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:18.

[0229] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:19 and / or a VL containing the amino acid sequence of SEQ ID NO:10. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VH listed in SEQ ID NO:19 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to a VL listed in SEQ ID NO:10. In one embodiment, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO:19 and / or a VL containing at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) of the amino acid sequence listed in SEQ ID NO:10.

[0230] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:20. In one embodiment, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to the scFv amino acid sequence listed in SEQ ID NO:20. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:20.

[0231] In some embodiments, the anti-BCMA scFv comprises a VH containing the amino acid sequence of SEQ ID NO:21 and / or a VL containing the amino acid sequence of SEQ ID NO:22. In some embodiments, the anti-BCMA scFv comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:21 and / or a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:22. In some embodiments, the anti-BCMA scFv comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:21 and / or a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:22.

[0232] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:23. In some embodiments, the anti-BCMA scFv comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the scFv amino acid sequence listed in SEQ ID NO:23. In some embodiments, the anti-BCMA scFv comprises the amino acid sequence of SEQ ID NO:23.

[0233] In some embodiments, any of the anti-BCMA antibody or antigen-binding fragments described herein are modified, for example via glycosylation, phosphorylation, SUMOylation, and / or methylation. In some embodiments, the anti-BCMA antibody or antigen-binding fragment is a glycosylated antibody coupled to one or more sugar or carbohydrate molecules. In some embodiments, one or more sugar or carbohydrate molecules are coupled to the antibody via N-glycosylation, O-glycosylation, C-glycosylation, glypiation (GPI anchoring), and / or phosphorylated glycosylation. In some embodiments, one or more sugar or carbohydrate molecules are monosaccharides, disaccharides, oligosaccharides, or polysaccharides. In some embodiments, one or more sugar or carbohydrate molecules are branched oligosaccharides or branched polysaccharides. In some embodiments, one or more sugar or carbohydrate molecules comprise mannose units, glucose units, N-acetylglucosamine units, N-acetylgalactosamine units, galactose units, fucose units, or phospholipid units. In some embodiments, about 1 to 10, about 1 to 5, about 5 to 10, about 1 to 4, about 1 to 3, or about 2 sugar molecules are present. In some embodiments, the glycosylated antibody is fully or partially glycosylated. In some embodiments, the antibody is glycosylated by a chemical reaction or by an enzymatic method. In some embodiments, the antibody is glycosylated in vitro or intracellularly, optionally lacking enzymes in the N-glycosylation or O-glycosylation pathway, such as glycosyltransferases. In some embodiments, the antibody is functionalized with sugar or carbohydrate molecules, as described in International Patent Application Publication WO2014065661, published May 1, 2014, entitled "Modified antibody, antibody-conjugate and process for the preparation thereof".

[0234] In some embodiments, a conserved mutation may be introduced into an antibody sequence (e.g., a CDR or frame sequence) at a location where the residues are unlikely to interact with the target antigen (e.g., BCMA) (e.g., as determined based on the crystal structure).

[0235] In some embodiments, any of the anti-BCMA antibodies or antigen-binding fragments described herein may include a signal peptide (e.g., an N-terminal signal peptide) in the heavy chain and / or light chain sequence. In some embodiments, the anti-BCMA antibodies or antigen-binding fragments described herein include any of the VH and VL sequences described herein, any of the IgG heavy chain and light chain sequences, or any of the scFv sequences (e.g., any of the scFvs listed in SEQ ID NO: 9, 11, 14, 16, 17, 18, 20, or 23) and further include a signal peptide (e.g., an N-terminal signal peptide).

[0236] II. Anti-BCMA chimeric antigen receptor

[0237] This disclosure also provides, at least in part, a chimeric antigen receptor (CAR) comprising an extracellular ligand-binding domain. In some embodiments, the selection of the ligand-binding domain depends on the type and number of ligands defining the surface of the target cell. For example, the ligand-binding domain may be selected to identify one or more ligands that act as cell surface markers on target cells associated with a particular disease state. Thus, examples of cell surface markers that may act as ligands for the ligand-binding domain in the CAR of this disclosure may include those associated with viral, bacterial and parasitic infections, autoimmune diseases, and more preferably cancer cells. In some embodiments, the CAR of this disclosure is engineered to target one or more tumor antigens of interest by means of engineering desired ligand-binding portions that specifically bind to one or more antigens on tumor cells. In the context of this disclosure, “tumor antigen” refers to an antigen common to or specific to a particular proliferative disease, such as cancer. Typically, the CAR of this disclosure (e.g., anti-BCMACAR) will comprise at least an extracellular domain and an intracellular domain. In some embodiments, the extracellular domain comprises a target-specific binding element (e.g., an scFv that specifically binds to BCMA), otherwise referred to herein as a ligand-binding domain (also referred to herein as an antigen-binding domain). In some embodiments, the extracellular domain is an antigen-binding domain or a portion thereof. In some embodiments, the extracellular ligand-binding domain is Fab. In some embodiments, the extracellular ligand-binding domain is scFv. In some embodiments, the extracellular ligand-binding domain of the CAR described herein comprises an antigen-binding fragment that specifically binds to BCMA (e.g., human BCMA). In some embodiments, the extracellular ligand-binding domain of the CAR described herein comprises either a BCMA antibody or an antigen-binding fragment thereof (e.g., anti-BCMA scFv).

[0238] In some embodiments, the anti-BCMACAR of this disclosure comprises at least about 10 -4 M, 10 -5 M, 10 -6 M, 10 -7 M, 10 - 8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13 M or less binding affinity (e.g., as by K) D(Indication) Specifically binds to the extracellular ligand-binding domain of BCMA. For example, the anti-BCMACAR of this disclosure can bind in the ranges of 5 pM to 500 nM, 10 pM to 450 nM, 20 pM to 400 nM, 30 pM to 350 nM, 40 pM to 300 nM, 50 pM to 250 nM, 60 pM to 200 nM, 70 pM to 150 nM, 80 pM to 100 nM, and 80 pM to 90 nM. Affinities between 90 pM and 80 nM, between 100 pM and 70 nM, between 200 pM and 60 nM, between 300 pM and 50 nM, between 400 pM and 40 nM, between 500 pM and 30 nM, between 600 pM and 20 nM, between 700 pM and 10 nM, between 800 pM and 5 nM, or between 900 pM and 2 nM bind to BCMA proteins (e.g., human BCMA epitopes listed in any of SEQ ID NO: 38 to 48).

[0239] This disclosure also includes CARs that compete with any of the CARs described herein for binding to BCMA proteins (e.g., human cell surface BCMA epitopes listed in any of SEQ ID NO:38 to 48) and have an affinity of 100 nM or less (e.g., 80 nM or less, 50 nM or less, 20 nM or less, 10 nM or less, 500 pM or less, 50 pM or less, or 5 pM or less). The affinity and binding kinetics of anti-BCMACAR can be tested using any suitable method (including, but not limited to, biosensor technologies) (e.g., OCTET or BIACORE). In some embodiments, the anti-BCMACAR described herein is expressed in sub-nanomolar Kc. D Combined with BCMA.

[0240] In some embodiments, the anti-BCMA CAR of this disclosure comprises one or more of the heavy chain CDR (e.g., CDRH1, CDRH2, or CDRH3) amino acid sequences from any of the anti-BCMA antibodies selected from Table 3. In some embodiments, the anti-BCMACAR of this disclosure comprises CDRH1, CDRH2, and CDRH3 as provided by any of the antibodies selected from Table 3. In some embodiments, the anti-BCMACAR of this disclosure comprises one or more of the light chain CDR (e.g., CDRL1, CDRL2, or CDRL3) amino acid sequences from any of the anti-BCMA antibodies selected from Table 3. In some embodiments, the anti-BCMACAR of this disclosure comprises CDRL1, CDRL2, and CDRL3 as provided by any of the anti-BCMA antibodies selected from Table 3.

[0241] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 provided by any of the anti-BCMA antibodies selected from Table 3. In some embodiments, the CDR3 domains of the antibody heavy and light chains may play a particularly important role in the antibody's binding specificity / affinity to the antigen. Therefore, the anti-BCMA CAR may at least comprise the heavy chain and / or light chain CDR3 of any of the anti-BCMA antibodies selected from Table 3.

[0242] In some embodiments, any of the anti-BCMA antibodies of this disclosure has one or more CDR (e.g., heavy chain CDR or light chain CDR) sequences that are substantially similar to any one of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2 and / or CDRL3 sequences selected from the anti-BCMA antibodies in Table 3. In some embodiments, the position of one or more CDRs of the chimeric antigen receptor described herein along the VH (e.g., CDRH1, CDRH2 or CDRH3) and / or VL (e.g., CDRL1, CDRL2 or CDRL3) regions may vary by one, two, three, four, five or six amino acid positions, as long as specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintaining binding to the original antibody derived therefrom, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%).

[0243] In some instances, anti-BCMACAR comprises one or more CDR (e.g., heavy chain CDR or light chain CDR) sequences that are substantially similar to any of the anti-BCMA antibodies selected from Table 3. For example, anti-BCMACAR may comprise one or more CDR sequences selected from any of the anti-BCMA antibodies in Table 3, containing at most 5, 4, 3, 2, or 1 amino acid residue variations compared to the corresponding CDR region in any of the CDRs provided herein (e.g., CDRs of any of the anti-BCMA antibodies in Table 3), provided that specific binding to BCMA (e.g., human BCMA) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived.

[0244] Some aspects of this disclosure provide anti-BCMA antibodies comprising one or more of the heavy chain variable (VH) and / or light chain variable (VL) domains provided herein. In some embodiments, each of the VH domains provided herein comprises one or more of the CDR sequences (e.g., CDRH1, CDRH2, and CDRH3) provided herein, such as any of the heavy chain CDR sequences provided in any of the anti-BCMA antibodies listed in Table 3. In some embodiments, each of the VL domains provided herein comprises one or more of the CDR-L sequences (e.g., CDRL1, CDRL2, and CDRL3) provided herein, such as any of the light chain CDR sequences provided in any of the anti-BCMA antibodies listed in Table 3.

[0245] In some embodiments, the anti-BCMA CAR comprises a heavy chain variable domain and / or a light chain variable domain selected from any of the anti-BCMA antibodies and their variants in Table 3. In some embodiments, the anti-BCMA CAR comprises a heavy chain variable and light chain variable pair of any anti-BCMA antibody selected from Table 3.

[0246] Various aspects of this disclosure provide anti-BCMACAR containing heavy chain variable (VH) and / or light chain variable (VL) amino acid sequences homologous to any of those described herein. In some embodiments, anti-BCMACAR contains at least 75% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) VH or VL identical to any of the anti-BCMA antibodies selected from Table 3. In some embodiments, the homologous VH and / or VL amino acid sequences of anti-BCMACAR are unchanged within any of the CDR sequences provided herein. For example, in some embodiments, the degree of sequence variation (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) may occur within the VH and / or VL sequences of the anti-BCMACARs provided herein, excluding any of the CDR sequences. In some embodiments, any of the anti-BCMACARs provided herein comprises a VH and a VL sequence containing a frame sequence that is at least 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to the frame sequence of any anti-BCMA antibody selected from Table 3. In some embodiments, the anti-BCMACAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH of any of the anti-BCMA antibodies listed in Table 3. Alternatively or additionally, anti-BCMACAR contains a VL with no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to any of the anti-BCMA antibodies listed in Table 3.

[0247] In some embodiments, the anti-BCMA CAR comprises the same CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 as shown in Table 3, and comprises a humanized VH and / or a humanized VL. In some embodiments, the anti-BCMA CAR is a humanized variant comprising one or more amino acid substitutions (e.g., in the VH framework region) compared to any of the VHs listed in Table 3, and / or one or more amino acid substitutions (e.g., in the VL framework region) compared to any of the VLs listed in Table 3.

[0248] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:8.

[0249] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0250] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0251] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical with at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0252] In some embodiments, anti-BCMACAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, its anti-BCMACAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:5; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0253] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:8.

[0254] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:8.

[0255] In some embodiments, the anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:8.

[0256] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:10.

[0257] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0258] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0259] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical with at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0260] In some embodiments, anti-BCMACAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA CAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0261] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:10.

[0262] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:10.

[0263] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:10.

[0264] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:13.

[0265] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0266] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0267] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0268] In some embodiments, the anti-BCMA CAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:27; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0269] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:13.

[0270] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO: 12. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO: 13.

[0271] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:12. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:13.

[0272] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:15.

[0273] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0274] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0275] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical with at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0276] In some embodiments, the anti-BCMA CAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:25; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:27; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0277] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:12. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:15.

[0278] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO: 12. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO: 15.

[0279] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:12. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:15.

[0280] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:13.

[0281] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0282] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0283] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0284] In some embodiments, anti-BCMACAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA CAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:30.

[0285] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:13.

[0286] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:13.

[0287] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:13.

[0288] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:15.

[0289] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0290] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0291] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical with at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0292] In some embodiments, anti-BCMACAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:1; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:2; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, the anti-BCMA CAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:29.

[0293] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:15.

[0294] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:7. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:15.

[0295] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:7. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:15.

[0296] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:19. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:10.

[0297] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, and CDRH3 having the amino acid sequence of SEQ ID NO:3. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0298] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0299] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, and CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical with at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0300] In some embodiments, the anti-BCMA CAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:26; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:28; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:3. Alternatively or additionally, anti-BCMACAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:4; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:24; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:6.

[0301] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:19. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:10.

[0302] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO: 19. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO: 10.

[0303] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:19. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:10.

[0304] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having the amino acid sequence of SEQ ID NO:21. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having the amino acid sequence of SEQ ID NO:22.

[0305] In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH3 having the amino acid sequence of SEQ ID NO:33. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRH3 having the amino acid sequence of SEQ ID NO:33. In some embodiments, according to the Kabat definition system, anti-BCMACAR comprises CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, CDRH3 having the amino acid sequence of SEQ ID NO:33, CDRL1 having the amino acid sequence of SEQ ID NO:34, CDRL2 having the amino acid sequence of SEQ ID NO:35, and CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0306] In some embodiments, anti-BCMACAR comprises CDRH1, CDRH2, and CDRH3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRH3 having the amino acid sequence of SEQ ID NO:33. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:34, CDRL2 having the amino acid sequence of SEQ ID NO:35, and CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0307] In some embodiments, the anti-BCMA CAR comprises CDRH1, CDRH2, and CDRH3, which are collectively identical to at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRH3 having the amino acid sequence of SEQ ID NO:33. Alternatively or additionally, anti-BCMACAR comprises CDRL1, CDRL2, and CDRL3, which are collectively identical with at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of CDRL1 having the amino acid sequence of SEQ ID NO:34, CDRL2 having the amino acid sequence of SEQ ID NO:35, and CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0308] In some embodiments, the anti-BCMA CAR comprises: CDRH1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH1 having the amino acid sequence of SEQ ID NO:31; CDRH2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH2 having the amino acid sequence of SEQ ID NO:32; and / or CDRH3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRH3 having the amino acid sequence of SEQ ID NO:33. Alternatively or additionally, anti-BCMACAR comprises: CDRL1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL1 having the amino acid sequence of SEQ ID NO:34; CDRL2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL2 having the amino acid sequence of SEQ ID NO:35; and / or CDRL3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDRL3 having the amino acid sequence of SEQ ID NO:36.

[0309] In some embodiments, anti-BCMACAR comprises VH containing the amino acid sequence of SEQ ID NO:21. Alternatively or additionally, anti-BCMACAR comprises VL containing the amino acid sequence of SEQ ID NO:22.

[0310] In some embodiments, the anti-BCMA CAR comprises a VH containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH listed in SEQ ID NO:21. Alternatively or additionally, the anti-BCMA CAR comprises a VL containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL listed in SEQ ID NO:22.

[0311] In some embodiments, anti-BCMACAR comprises a VH containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH listed in SEQ ID NO:21. Alternatively or additionally, anti-BCMACAR comprises a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VL listed in SEQ ID NO:22.

[0312] The anti-BCMA antibodies or their antigen-binding fragments described herein can be grafted onto chimeric antigen receptors, including but not limited to their antigen-binding fragments (such as Fab, F(ab'), F(ab')2, Fv), single-chain antibodies (e.g., scFv), bispecific antibodies, or nanobodies. In some embodiments, the anti-BCMA antibodies described herein include a single-chain variable fragment (scFv) as an extracellular ligand-binding domain.

[0313] In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising a single-stranded variable fragment (scFv). In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising VH and VL selected from any of the anti-BCMA scFvs in Table 3. In some embodiments, the VH and VL of anti-BCMACAR are joined together by a linker. In some embodiments, the linker may have a length of about 2 to 10 amino acids, 5 to 20 amino acids, 10 to 30 amino acids, 20 to 50 amino acids, 40 to 60 amino acids, 60 to 80 amino acids, or more than 80 amino acids. In some embodiments, the linker may comprise a sequence substantially comprising glycine and serine. An exemplary linker sequence is GGGGSGGGGSGGGAS (SEQ ID NO: 81). In some embodiments, the linker may include, but is not limited to, any linker covered by U.S. Patent Nos. 8,445,251 and 9,434,931. In some embodiments, anti-BCMACAR comprises a linker between VH and VL, and the linker comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99%, or 100% identical to that of SEQ ID NO:81.

[0314] In some embodiments, the anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing VH and VL, wherein the C-terminus of VH is coupled to the N-terminus of VL via a connector (e.g., a connector listed in SEQ ID NO: 81). In some embodiments, the anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing VH and VL, wherein the C-terminus of VL is coupled to the N-terminus of VH via a connector (e.g., a connector listed in SEQ ID NO: 81).

[0315] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing a VH with no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH of any of the anti-BCMA antibodies listed in Table 3. Alternatively or additionally, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing a VL with no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH of any of the anti-BCMA antibodies listed in Table 3. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing a VH, the VH comprising at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH of any of the anti-BCMA antibodies listed in Table 3. Alternatively or additionally, anti-BCMACAR includes an extracellular ligand-binding domain containing an scFv with a VL containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the VH of any of the anti-BCMA antibodies listed in Table 3.

[0316] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to any of the anti-BCMA scFvs listed in Table 3. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the same amino acid sequence as any of the anti-BCMA scFvs listed in Table 3.

[0317] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:9. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO:9. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:9.

[0318] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO: 11. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO: 11. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:11.

[0319] In some embodiments, the anti-BCMA scFv comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:14. In some embodiments, the anti-BCMA scFv comprises an extracellular ligand-binding domain containing an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO:14. In some embodiments, the anti-BCMA CAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:14.

[0320] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO: 16. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO: 16. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:16.

[0321] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO: 17. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO: 17. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:17.

[0322] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO: 18. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO: 18. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:18.

[0323] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO: 20. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO: 20. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:20.

[0324] In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing an amino acid sequence having no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the scFv amino acid sequence listed in SEQ ID NO:23. In some embodiments, anti-BCMACAR comprises an extracellular ligand-binding domain comprising an scFv containing at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) of the amino acid sequence listed in SEQ ID NO:23. In some embodiments, anti-BCMACAR includes an extracellular ligand-binding domain comprising an scFv containing the amino acid sequence of SEQ ID NO:23.

[0325] In some embodiments, anti-BCMACAR further comprises a hinge region. In some embodiments, the hinge region is a CD8 hinge region. An exemplary amino acid sequence of the CD8 hinge region is listed in SEQ ID NO:82:

[0326] TTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACD

[0327] In some embodiments, anti-BCMACAR comprises a CD8 hinge region having an amino acid sequence as listed in SEQ ID NO:82 or a variant thereof. In some embodiments, anti-BCMACAR comprises a hinge region containing at least 70%, at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99%, or 100% of the same amino acid sequence as SEQ ID NO:82. In some embodiments, the hinge region may be any suitable hinge region known in the art, such as the hinge region described in Guedan et al., Engineering and Design of Chimeric Antigen Receptors, MolTherMethods Clin Dev. March 15, 2019; 12:145–156, such as hinge regions derived from IgG1, IgG2, IgG4, CD28, CD8, or hybrids thereof.

[0328] In some embodiments, the anti-BCMACAR further comprises a transmembrane domain that links an extracellular ligand-binding domain to an intracellular signaling and co-stimulatory domain. Regarding the transmembrane domain, the CAR may be designed to include a transmembrane domain fused to an extracellular domain of the CAR (e.g., an antigen-binding domain). Any transmembrane domain is considered for use herein, provided that the domain is capable of anchoring the CAR containing that domain to the cell membrane. In some embodiments, a transmembrane domain naturally associated with one of the domains in the CAR is used. In some cases, transmembrane domains may be selected or modified by amino acid substitutions to prevent such domains from binding to transmembrane domains of the same or different surface membrane proteins, thereby minimizing interactions with other members of the receptor complex. Those skilled in the art will appreciate that a complete transmembrane domain or a portion thereof is implemented together with a cytoplasmic domain or a portion thereof. The transmembrane domain may be derived from a natural or synthetic source. In the case of a natural source, the domain may be derived from any membrane-binding or transmembrane protein. In some embodiments, the transmembrane domain may be synthetic, in which case the transmembrane domain will primarily comprise hydrophobic residues such as leucine and valine. Preferably, a triplet of phenylalanine, tryptophan, and valine is found at each end of the synthetic transmembrane domain. Optionally, short oligopeptide or polypeptide linkers, preferably 2 to 10 amino acids in length, can form a link between the transmembrane domain and the cytoplasmic signaling domain of the CAR. Glycine-serine duplexes provide particularly suitable linkers.

[0329] In some embodiments, the transmembrane domain is a CD8 transmembrane domain. An exemplary amino acid sequence of the CD8 transmembrane domain is listed in SEQ ID NO:83:

[0330] IYIWAPLAGTCGVLLLSLVITLYC

[0331] In some embodiments, anti-BCMACAR comprises a CD8 transmembrane domain having an amino acid sequence as listed in SEQ ID NO:83 or a variant thereof. In some embodiments, anti-BCMACAR comprises a transmembrane domain containing at least 70%, at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99%, or 100% of the same amino acid sequence as SEQ ID NO:83. In some embodiments, the transmembrane domain may be any suitable transmembrane domain known in the art, such as a transmembrane domain derived from TCRα, TCRβ, TCRζ, CD3ζ, CD3ε, CD3γ, CD3δ, CD4, CD5, CD8, CD9, CD16, CD22, CD28, CD32, CD33, CD34, CD37, CD45, CD64, CD80, CD86, CD134, CD137, CD154, or induced T cell co-stimulation (ICOS). However, any transmembrane domain is considered for use herein, provided that the domain is capable of anchoring a CAR containing that extracellular domain to the cell membrane. Transmembrane domains can be identified using any method known in the art or described herein, such as by using the UniProt database.

[0332] In some embodiments, anti-BCMACAR further comprises an intracellular (or cytoplasmic) domain. In some embodiments, the intracellular domain of the CAR is responsible for activating at least one normal effector function of the immune cell in which the CAR is located. The term "effector function" refers to a specific function of a cell (e.g., iNKT cells). An effector function of a cell (e.g., iNKT cells) may be, for example, cytolytic activity or helper activity, including the secretion of cytokines. Thus, the term "intracellular signaling domain" refers to a portion of a protein that transduces effector function signals and directs the cell to perform a specific function. While the entire intracellular signaling domain can generally be used, it is not necessary to use the entire domain in many cases. With regard to the use of a truncated portion of an intracellular signaling domain, such a truncated portion can be used instead of the complete domain as long as it transduces effector function signals. Therefore, the term intracellular signaling domain is intended to include any truncated portion of an intracellular signaling domain sufficient to transduce effector function signals. The intracellular (or cytoplasmic) domains of chimeric antigen receptors disclosed herein may include, but are not limited to, the 4-1BB intracellular domain, the OX40 intracellular domain, the CD30 intracellular domain, the CD40 intracellular domain, the ICOS intracellular domain, the LFA-1 intracellular domain, the CD2 intracellular domain, the CD3ζ intracellular domain, the CD3γ intracellular domain, the CD3δ intracellular domain, the CD3ε intracellular domain, and the CD7 and CD22 intracellular domains. In some embodiments, anti-BCMACAR comprises a CD3ζ intracellular domain. An exemplary amino acid sequence of the CD3ζ intracellular domain is listed in SEQ ID NO:84: RVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEG LYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR

[0333] In some embodiments, anti-BCMACAR comprises an intracellular domain having an amino acid sequence as listed in SEQ ID NO:84 or a variant thereof. In some embodiments, anti-BCMACAR comprises an intracellular domain containing an amino acid sequence that is at least 70%, at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99%, or 100% identical to that in SEQ ID NO:84.

[0334] In some embodiments, the intracellular domain further includes one or more intracellular co-stimulatory domains, such as those described herein, which, upon binding to the extracellular domain, deliver co-stimulatory signals that promote cell proliferation, cell survival, and / or cytokine secretion. In some embodiments, such intracellular co-stimulatory domains include, but are not limited to, any co-stimulatory domains disclosed herein or those known in the art, including but not limited to CD28, ICOS, 4-1BB, OX40, or CD27. In some embodiments, anti-BCMACAR comprises a 4-1BB co-stimulatory domain. An exemplary amino acid sequence of the 4-1BB co-stimulatory domain is listed in SEQ ID NO:85:

[0335] KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL

[0336] In some embodiments, anti-BCMACAR comprises a 4-1BB co-stimulatory domain having an amino acid sequence as listed in SEQ ID NO:85 or a variant thereof. In some embodiments, anti-BCMACAR comprises a 4-1BB co-stimulatory domain containing at least 70%, at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99%, or 100% of the same amino acid sequence as SEQ ID NO:85.

[0337] The intracellular signal transduction domain of the chimeric antigen receptor disclosed herein is responsible for activating at least one normal effector function and / or activating proliferation and cell survival pathways in the cell where the CAR is located.

[0338] It should be understood that the chimeric antigen receptors disclosed herein may include domains (e.g., extracellular domains, transmembrane domains, intracellular (cytoplasmic) domains, costimulatory domains, signal transduction domains, or any combination thereof) of sequences or variants thereof or fragments thereof as listed herein (e.g., variants and / or fragments that retain the functions required for chimeric antigen receptor activity) having any one or more of the domains disclosed herein.

[0339] In some embodiments, exemplary anti-BCMACAR amino acid sequences are listed in Table 4.

[0340] Table 4. Anti-BCMACAR amino acid sequence

[0341]

[0342]

[0343]

[0344]

[0345]

[0346] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:86. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:86. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:86.

[0347] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:87. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:87. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:87.

[0348] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:88. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:88. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:88.

[0349] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:89. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:89. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:89.

[0350] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO: 90. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO: 90. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO: 90.

[0351] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:91. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:91. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:91.

[0352] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:92. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:92. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:92.

[0353] In some embodiments, anti-BCMACAR comprises an amino acid sequence containing no more than 20 amino acid variations (e.g., no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:93. In some embodiments, anti-BCMACAR comprises an amino acid sequence that is at least 80% (e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the anti-BCMACAR amino acid sequence listed in SEQ ID NO:93. In some embodiments, anti-BCMACAR comprises the amino acid sequence of SEQ ID NO:93.

[0354] III. Genetically modified cells expressing anti-BCMA chimeric antigen receptor and their production methods

[0355] This disclosure also provides genetically modified cells containing at least one anti-BCMA antibody or its antigen-binding fragment, or at least one anti-BCMA antibody as disclosed herein.

[0356] In some embodiments, cells may be genetically modified to express any of the chimeric antigen receptors described herein. In some embodiments, the genetically modified cells described herein are eukaryotic cells. In some embodiments, genetically modified cells containing a CAR as described herein (e.g., anti-BCMA CAR) are human cells. In some embodiments, genetically modified cells containing a CAR as described herein (e.g., anti-BCMACAR) are immune cells. In some embodiments, genetically modified cells containing a CAR (e.g., anti-BCMACAR) are immune cells (e.g., T cells such as cytotoxic T lymphocytes, regulatory T cells, NK cells, NKT cells such as invariant NKT cells, macrophages, monocytes, neutrophils, eosinophils, or any combination thereof). In some embodiments, the genetically modified immune cells are iNKT cells modified to express one or more of the anti-BCMACARs described herein.

[0357] In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) comprising the anti-BCMACAR described herein. In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) comprising anti-BCMACAR comprising CDRH1, CDRH2, and CDRH3 having a heavy chain variable domain (VH) having an amino acid sequence of any one of SEQ ID NO: 7, 12, 19, or 21, and / or CDRL1, CDRL2, and CDRL3 having a light chain variable domain (VL) having an amino acid sequence of any one of SEQ ID NO: 8, 10, 13, 15, or 22.

[0358] In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) comprising: (i) anti-BCMACAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:5, and CDRL3 having the amino acid sequence of SEQ ID NO:6; (ii) anti-BCMACAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6; (iii) anti-BCMACAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:25, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6; (iv) Anti-BCMACAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:27, CDRH2 having the amino acid sequence of SEQ ID NO:3, CDRH1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:30; (v) Anti-BCMA CAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:27, CDRH2 having the amino acid sequence of SEQ ID NO:3, CDRH3 having the amino acid sequence of SEQ ID NO:4, CDRL1 having the amino acid sequence of SEQ ID NO:24, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29; (v) Anti-BCMA CAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:25, CDRH2 having the amino acid sequence of SEQ ID NO:27, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29; CDRL2 with amino acid sequence NO:24 and CDRL3 with amino acid sequence NO:30;(vi) Anti-BCMA CAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:1, CDRH2 having the amino acid sequence of SEQ ID NO:2, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:29; (vii) Anti-BCMA CAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:26, CDRH2 having the amino acid sequence of SEQ ID NO:28, CDRH3 having the amino acid sequence of SEQ ID NO:3, CDRL1 having the amino acid sequence of SEQ ID NO:4, CDRL2 having the amino acid sequence of SEQ ID NO:24, and CDRL3 having the amino acid sequence of SEQ ID NO:6; or (viii) Anti-BCMA CAR comprising CDRH1 having the amino acid sequence of SEQ ID NO:31, CDRH2 having the amino acid sequence of SEQ ID NO:32, and CDRL3 having the amino acid sequence of SEQ ID NO:29; CDRH3 with amino acid sequence NO:33, CDRL1 with amino acid sequence NO:34, CDRL2 with amino acid sequence NO:35, and CDRL3 with amino acid sequence NO:36.

[0359] In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) comprising: (i) anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:8; (ii) anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:10; (iii) anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:12 and / or a VL containing the amino acid sequence of SEQ ID NO:13; (iv) anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:12 and / or a VL containing the amino acid sequence of SEQ ID NO:15; (v) anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:13; (vi) anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:13; (vii) Anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:7 and / or a VL containing the amino acid sequence of SEQ ID NO:15; or (viii) Anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:19 and / or a VL containing the amino acid sequence of SEQ ID NO:10; or (viii) Anti-BCMACAR, comprising a VH containing the amino acid sequence of SEQ ID NO:21 and / or a VL containing the amino acid sequence of SEQ ID NO:22.

[0360] In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) containing anti-BCMACAR, wherein the anti-BCMACAR contains scFv as an extracellular ligand-binding domain comprising an amino acid sequence comprising any one of SEQ ID NO: 9, 11, 14, 16, 17, 18, 20 or 23.

[0361] In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) containing anti-BCMACAR, wherein the anti-BCMACAR contains scFv as an extracellular ligand-binding domain comprising an amino acid sequence comprising any one of SEQ ID NO: 9, 11, 14, 16, 17, 18, 20 or 23.

[0362] In some embodiments, this disclosure provides a population of genetically modified immune cells (e.g., iNKT cells) containing an anti-BCMACAR, the anti-BCMACAR containing an amino acid sequence of any one of SEQ ID NO: 86 to 93.

[0363] In some embodiments, the genetically modified cells (e.g., iNKT cells) are armored CAR-expressing cells engineered to express another molecule (e.g., cytokines or ligands) that can enhance one or more properties of the genetically modified cells (e.g., survival / persistence, immune interactions with other cells such as macrophages and / or dendritic cells, disruption of the immunosuppressive tumor microenvironment). Genetically modified cells (e.g., iNKT cells) can be engineered to express any suitable armored molecule known in the art, such as those described in Yeku et al., Armored CAR T-cells:utilizing cytokines and pro-inflammatory ligands to enhance CAR T-cell anti-tumour efficacy, Biochem Soc Trans. 2016 Apr 15; 44(2):412–418; Hawkins et al., Armored CAR T-Cells:The Next Chapter in T-Cell Cancer Immunotherapy, Biologics. 2021; 15:95–105). Unrestricted examples of armor molecules include IL-15, IL-2, IL-12, CD40L, 4-1BBL, IL-18, IL-7, IL-33, dominant-negative TGF-β receptor II (dnTGF-βRII), constitutively active Akt (caAkt), mixed IL-4 / IL-7 receptors, checkpoint inhibitors (such as anti-PD1 antibodies), nanobodies targeting CD47, or bispecific T-cell binders (BiTE).

[0364] In some embodiments, cells engineered to express the gene-modified CAR described herein (e.g., anti-BCMA CAR) are also engineered to express IL-15. In some embodiments, cells engineered to express the gene-modified CAR described herein (e.g., anti-BCMA CAR) are also engineered to express secreted IL-15 (sIL-15). The role of IL-15 in enhancing the expansion and function of T cells and natural killer T cells (e.g., iNKT cells) has been previously described (see, for example, Lin et al., Interleukin-15 enhances the expansion and function of natural killer T cells from adult peripheral and umbilical cord blood, Cytokine. Dec 2015; 76(2):348-355; Battram et al., IL-15 enhances the persistence and function of BCMA-Targeting CAR-T Cells Compared to IL-2 or IL-15 / IL-7 by Limiting CAR-T Cell Dysfunction and Differentiation; Cancers (Basel). Julius 2021; 13(14):3534). Evidence suggests that multiple cell types, including macrophages and dendritic cells (DCs), are responsible for producing IL-15, and once released, IL-15 stimulates CD8+ T cells and NK cells, thereby increasing their proliferative and cytotoxic capabilities. Administration of IL-15 to mice has been shown to enhance the antitumor activity of adoptively transferred CD8+ tumor-reactive T cells, suggesting that IL-15 may also enhance the antitumor activity of CAR T cell therapy. Further engineering of IL-15-secreting CAR T cells has been shown to enhance tumor cytotoxicity compared to CAR T cells alone in vitro and in vivo, and to increase antigen-recognizing T cell expansion in vitro. Furthermore, IL-15 increases antigen-independent T cell proliferation while allowing T cells to persist after tumor clearance. It is also known that IL-15-secreting CAR T cells provide stronger protection against tumor re-attack in vivo than IL-15-non-secreting CAR T cells. Some previous studies have used a membrane-tethered form of IL-15 and found that this promotes the development of a memory phenotype in CAR T cells. These data suggest that IL-15 can provide long-term CAR T cell-mediated immunity against cancer antigens while enhancing CAR T cell function in the tumor microenvironment.

[0365] In some embodiments, this disclosure is based, at least in part, on the discovery of the use of secreted IL-15 as an “armor molecule” for genetically modified immune cells (e.g., iNKT cells) that express anti-BCMACAR. In some embodiments, secreted IL-15 enhances the persistence of genetically modified immune cells (e.g., iNKT cells) in the tumor microenvironment (e.g., persistence relative to other modified cells that do not produce armor molecules such as IL-15).

[0366] In some embodiments, the nucleic acid encoding the CAR (e.g., anti-BCMA CAR) is a polycistronic vector that also encodes secreted IL-15 in addition to the CAR. An exemplary IL-15 coding sequence is listed in SEQ ID NO:94: ATGCGGATCTCCAAGCCCCACCTCCGAAGCATCAGTATCCAGTGTTATCTGTGCCTTCTTCTGAATTCCCATTTTTTGACAGAGGCAGGAATTCATGTATTCATATTGGGTTGTTTCTCCGCGGGGCTTCCTAAAACCGAAGCTAACTGGGTTAATGTCATTTCAGATCTGAAGAAAATTGAAGATCTTATTCAATCAATGCATATCGACGCGACCTTGTACACGGAGAGTGATGTCC ACCCGAGCTGCAAGGTAACGGCCATGAAATGCTTCTTGCTGGAATTGCAGGTAATTAGTCTTGAGAGTGGAGATGCGTCTATACACGACACCGTAGAGAATCTCATTATTTTGGCGAACAATTCTCTCAGCAGTAACGGCAATGTTACTGAATCAGGATGTAAGGAGTGTGAAGAGCTGGAAGAAAAGAACATTAAGGAATTTTTGCAGAGCTTCGTACATATCGTCCAAATGTTCATAAAATACAAGC

[0367] In some embodiments, the nucleic acid encoding CAR (e.g., anti-BCMACAR) further comprises a nucleic acid sequence that is at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the nucleic acid sequence of SEQ ID NO:94.

[0368] In some embodiments, the polycistronic vector contains two or more expression cassettes encoding one or more anti-BCMACAR and sIL-15.

[0369] In some embodiments, the multicistronic expression construct includes expression cassettes positioned in different ways. For example, in some embodiments, a multicistronic expression construct is provided in which a first expression cassette (e.g., an expression cassette encoding anti-BCMACAR or a portion thereof) is positioned adjacent to a second expression cassette (e.g., an expression cassette encoding sIL-15). In some embodiments, the first expression cassette (e.g., an expression cassette encoding anti-BCMACAR or a portion thereof) is positioned at 5' of the second expression cassette (e.g., an expression cassette encoding sIL-15). In some embodiments, the first expression cassette (e.g., an expression cassette encoding anti-BCMACAR or a portion thereof) is positioned at 3' of the second expression cassette (e.g., an expression cassette encoding sIL-15). Multicistronic vectors have been previously described, for example, by Shaimardanova et al., Production and Application of Multicistronic Constructs for Various Human Disease Therapies, Pharmaceutics 2019, 11, 580. In some embodiments, the polycistronic vector comprises a nucleic acid sequence encoding a self-cleaving 2A peptide between a first expression cassette (e.g., an expression cassette encoding anti-BCMACAR or a portion thereof) and a second expression cassette (e.g., an expression cassette encoding sIL-15). In some embodiments, the self-cleaving 2A peptide is a P2A peptide. In some embodiments, the self-cleaving 2A peptide is a T2A peptide. In some embodiments, the polycistronic vector comprises a nucleic acid sequence encoding an internal ribosome entry site (IRES) between a first expression cassette (e.g., an expression cassette encoding anti-BCMACAR or a portion thereof) and a second expression cassette (e.g., an expression cassette encoding sIL-15).

[0370] In some embodiments, a nucleic acid sequence encoding sIL-15 (e.g., the sIL-15 coding sequence listed in SEQ ID NO:94) is delivered to cells in a construct separate from the construct encoding a CAR. In some embodiments, the cells have already expressed secreted IL-15 (e.g., engineered to express sIL-15) prior to receiving the nucleic acid construct encoding a CAR (e.g., anti-BCMACAR).

[0371] This document also provides cells (e.g., iNKT cells) that contain nucleic acid molecules encoding chimeric antigen receptors as disclosed herein. In some embodiments, the nucleic acid molecule encoding a CAR (e.g., anti-BCMACAR) as described herein is present (i.e., integrated) within the genome of the genetically modified cell, or is not integrated into the cell's genome. In some embodiments, where the nucleic acid molecule encoding a CAR (e.g., anti-BCMACAR) is not integrated into the genome, the nucleic acid molecule is present in the genetically modified cell within the recombinant DNA construct, in mRNA, in the viral genome, or in another nucleic acid not integrated into the cell's genome.

[0372] In one embodiment, the genetically modified cell (e.g., iNKT cell) contains a nucleic acid molecule located within the cell's genome that encodes a chimeric antigen receptor (e.g., anti-BCMACAR) as disclosed herein. In other embodiments, the genetically modified cell (e.g., iNKT cell) contains a nucleic acid molecule located within the cell's endogenous T cell receptor α gene that encodes a chimeric antigen receptor (e.g., anti-BCMACAR) as disclosed herein.

[0373] In some embodiments, the invention covers isolated nucleic acids comprising a sequence of a CAR (e.g., anti-BCMACAR), wherein the sequence comprises an extracellular ligand-binding domain of a nucleic acid sequence operatively linked to a transmembrane domain and a cytoplasmic domain. The nucleic acid sequence encoding the desired molecule can be obtained using recombination methods known in the art, such as screening libraries from cells expressing the gene using standard techniques, by gene derivation from a vector known to contain the gene, or by direct isolation from cells and tissues containing the gene. Alternatively, the gene of interest can be synthesized rather than cloned. The invention also provides vectors into which the DNA of the invention is inserted. Vectors derived from retroviruses (such as lentiviruses) are suitable tools for achieving long-term gene transfer because they allow for long-term, stable integration of the transgene and its propagation in daughter cells. Lentiviral vectors have additional advantages over vectors derived from tumor retroviruses (such as murine leukemia virus) because they can transduce non-proliferating cells, such as hepatocytes. They also have the additional advantage of low immunogenicity. In another embodiment, the desired CAR can be expressed in cells by means of a transposon.

[0374] In short, the expression of a natural or synthetic nucleic acid encoding a CAR is typically achieved by operatively linking a nucleic acid encoding a CAR polypeptide (e.g., anti-BCMACAR) or a portion thereof to a promoter and incorporating the construct into an expression vector (e.g., a lentiviral vector). The vector is suitable for replication and integration into eukaryotes. Typical cloning vectors contain transcription and translation terminators, a start sequence, and a promoter for regulating the expression of the desired nucleic acid sequence. The expression constructs of the present invention can also be used for nucleic acid immunotherapy and gene therapy, using standard gene delivery protocols. Methods of gene delivery are known in the art. See, for example, U.S. Patent Nos. 5,399,346, 5,580,859, and 5,589,466, which are incorporated herein by reference in their entirety.

[0375] Nucleic acids can be cloned into various types of vectors. For example, nucleic acids can be cloned into vectors, including but not limited to plasmids, viral vectors, phage particles, phage derivatives, animal viruses, and entrapments. Vectors of particular interest include expression vectors, replication vectors, probe generation vectors, and sequencing vectors.

[0376] Furthermore, the expression vector can be provided to cells in the form of a viral vector. Viral vector technology is well known in the art and described, for example, in Sambrook et al. (2001, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, New York) and other virology and molecular biology manuals. Viruses that can be used as vectors include, but are not limited to, retroviruses, adenoviruses, adeno-associated viruses, herpesviruses, and lentiviruses. Typically, a suitable vector contains an origin of replication that is functional in at least one organism, a promoter sequence, a convenient restriction endonuclease site, and one or more optional markers (e.g., WO 01 / 96584; WO 01 / 29058; and U.S. Patent No. 6,326,193).

[0377] Numerous virus-based systems have been developed for transferring genes into mammalian cells. Lentivirals, for example, provide a convenient platform for gene delivery systems. Selected genes can be inserted into vectors and packaged into lentiviral particles using techniques known in the art. The recombinant virus can then be isolated and delivered to the cells of a subject, either in vivo or in vitro. Many lentiviral systems are known in the art.

[0378] In some embodiments, the vector described herein further comprises a promoter operatively linked to a nucleic acid encoding the CAR described herein (e.g., anti-BCMACAR). Non-limiting examples of suitable promoters include cytomegalovirus (CMV) promoters, elongation factor-1a (EF-1a) promoters, simian virus 40 (SV40) early promoters, mouse mammary tumor virus (MMTV), human immunodeficiency virus (HIV) long terminal repeat (LTR) promoters, MoMuLV promoters, avian leukosis virus promoters, Epstein-Barr virus immediate early promoters, Roussarcoma virus promoters, and human gene promoters, such as, but not limited to, actin promoters, myosin promoters, hemoglobin promoters, and creatine kinase promoters. In some embodiments, the promoter is the EF-1a promoter. Furthermore, the use of inducible promoters is also contemplated in this disclosure. The use of inducible promoters provides a molecular switch that can turn on the expression of a polynucleotide sequence operably linked to it when such expression is needed, or turn off such expression when it is not needed. Examples of inducible promoters include, but are not limited to, metallothionein promoters, glucocorticoid promoters, progesterone promoters, and tetracycline promoters.

[0379] To assess the expression of a CAR peptide or a portion thereof, the expression vector to be introduced into cells may also contain a selective marker gene or a reporter gene, or both, to facilitate the identification and selection of expressing cells from a population of cells seeking transfection or infection via a viral vector. In other respects, the optional marker may be carried on a separate DNA fragment and used in a co-transfection procedure. Both the optional marker and the reporter gene may be side-mounted with appropriate regulatory sequences to enable expression in host cells. Useful optional markers include, for example, antibiotic resistance genes, such as kanamycin resistance genes, and fluorescent genes, such as GFP, YFP, RFP, etc. In some embodiments, the reporter gene or optional marker gene is excluded from the CAR peptide used in the therapy described herein.

[0380] Methods for introducing and expressing genes into cells are known in the art. In the context of expression vectors, vectors can be readily introduced into host cells, such as mammalian, bacterial, yeast, or insect cells, by any method in the art. For example, expression vectors can be transferred into host cells by physical, chemical, or biological methods. Physical methods for introducing polynucleotides into host cells include calcium phosphate precipitation, lipid transfection, particle bombardment, microinjection, electroporation, etc. Methods for generating cells containing vectors and / or exogenous nucleic acids are well known in the art. See, for example, Sambrook et al. (2001, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, New York). A preferred method for introducing polynucleotides into host cells is calcium phosphate transfection. Biological methods for introducing polynucleotides of interest into host cells include the use of DNA and RNA vectors. Viral vectors, especially retroviral vectors, have become the most widely used method for inserting genes into mammalian (e.g., human cells). Other viral vectors can be derived from lentiviruses, poxviruses, herpes simplex virus I, adenoviruses, and adeno-associated viruses, etc. See, for example, U.S. Patent Nos. 5,350,674 and 5,585,362.

[0381] Chemical methods for introducing polynucleotides into host cells include colloidal dispersion systems, such as macromolecular complexes, nanocapsules, microspheres, beads, and lipid-based systems, including oil-in-water emulsions, micelles, mixed micelles, and liposomes. An exemplary colloidal system used as a delivery medium in vitro and in vivo is a liposome (e.g., an artificial membrane vesicle). In the case of using non-viral delivery systems, an exemplary delivery medium is a liposome. Consider using lipid formulations to introduce nucleic acids into host cells (in vitro, ex vivo, or in vivo). Alternatively, nucleic acids can associate with lipids. Lipid-associated nucleic acids can be encapsulated within the aqueous interior of liposomes, dispersed in a lipid bilayer of liposomes, linked to liposomes via linkers associated with both liposomes and oligonucleotides, captured in liposomes, complexed with liposomes, dispersed in a solution containing lipids, mixed with lipids, incorporated with lipids, contained as a suspension in lipids, contained in or complexed with microparticles, or otherwise associated with lipids. Compositions associated with lipids, lipid / DNA, or lipid / expression vectors are not limited to any specific structure in solution. For example, they can exist as bilayers, microclusters, or “collapsed” structures. They can also simply be dispersed in solution, possibly forming aggregates that are not uniform in size or shape. Lipids are fatty substances that can be naturally occurring lipids or synthetic lipids. For example, lipids include naturally occurring fat droplets in the cytoplasm, as well as compounds containing long-chain aliphatic hydrocarbons and their derivatives (such as fatty acids, alcohols, amines, amino alcohols, and aldehydes).

[0382] Regardless of the method used to introduce exogenous nucleic acids into host cells or otherwise expose cells to the inhibitors of the present invention, a variety of assays can be performed to confirm the presence of recombinant DNA sequences in host cells. Such assays include, for example, "molecular biology" assays well known to those skilled in the art, such as Southern Blotting and Northern Blotting, RT-PCR, and PCR; and "biochemical" assays, such as detecting the presence or absence of a specific peptide, for example by immunological means (ELISA and Western blotting) or by assays described herein to identify agents falling within the scope of this disclosure.

[0383] In some embodiments, the nucleic acid sequence encoding the anti-BCMA antibody or its antigen-binding fragment, the BCMACAR, and the lentiviral vector sequence are listed in Table 5.

[0384] Table 5. Nucleic acid sequences encoding anti-BCMA antibody, anti-BCMACAR and lentiviral vector sequences.

[0385]

[0386]

[0387]

[0388]

[0389]

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[0445] In some embodiments, single-chain antibodies (e.g., anti-BCMA scFv) can be prepared via recombinant technology by linking a nucleotide sequence encoding a heavy chain variable region and a nucleotide sequence encoding a light chain variable region. Preferably, a flexible linker is incorporated between the two variable regions.

[0446] In some embodiments, the anti-BCMA antibody or its antigen-binding fragment is generated by expressing: (i) a nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:49, and / or a nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:57; (ii) a nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:49; NO:50 contains at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:58, and / or at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:58; (iii) the same as SEQ ID NO:58. IDNO:51 contains at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:59, and / or at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:59; (iv) the same as SEQ ID NO:59. NO:52 is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:60, and / or at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:60;(v) Nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) the same as SEQ ID NO:53, and / or nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) the same as SEQ ID NO:61; (vi) Nucleic acid that is the same as SEQ ID NO:53. NO:54 Nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:62, and / or nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:62; (vii) nucleic acid that is identical to SEQ ID NO:62. NO:55 is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:63, and / or at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:63; or (viii) is the same as SEQ ID NO:63. SEQ ID NO:56 contains at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:64, and / or at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as SEQ ID NO:64.

[0447] In some embodiments, anti-BCMA scFv is generated by expressing at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid as any of SEQ ID NO:66 to 72.

[0448] In some embodiments, anti-BCMACAR is expressed by cells (e.g., iNKT cells) by delivering to the cells a nucleic acid that is at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to any of SEQ ID NO: 95 to 102.

[0449] In some embodiments, this disclosure also provides a vector (e.g., a lentiviral vector) for expressing anti-BCMACAR in cells (e.g., iNKT cells). In some embodiments, the lentiviral vector comprises at least 60% (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) of the same nucleic acid sequence as any of SEQ ID NO:73 to 80.

[0450] In some aspects, this disclosure also provides methods for preparing a population of immune cells (e.g., iNKT cells) expressing a CAR (e.g., anti-BCMACAR). The initial population of immune cells can be obtained from any source, such as peripheral blood mononuclear cells (PBMCs), bone marrow, or tissues such as the spleen, lymph nodes, thymus, or tumor tissue. Suitable sources for obtaining the desired host cell type will be apparent to those skilled in the art. In some embodiments, the population of immune cells (e.g., iNKT cells) is derived from PBMCs. In some embodiments, a blood sample or apheresis blood is taken from a generally healthy subject. In some embodiments, a blood sample or apheresis blood is taken from a generally healthy subject at risk of developing a disease but who has not yet developed a disease, and the cells of interest are isolated and frozen for later use. In some embodiments, iNKT cells may be expanded, frozen, and used later. In some embodiments, samples are collected from the patient shortly after diagnosis of a specific disease as described herein but before any treatment. In another embodiment, prior to any number of relevant treatment modalities, cells are isolated from a blood sample or apheresis of the subject, including but not limited to agents such as natalizumab, efalizumab, antiviral agents, chemotherapy, radiotherapy, immunosuppressants (such as cyclosporine, azathioprine, methotrexate, mycophenolate, and FK506), antibodies, or other immunoablation agents (such as...). Treatment options include anti-CD3 antibodies, Cytoxan, fludarabine, cyclosporine, FK506, rapamycin, mycophenolic acid, steroids, FR901228, and radiation. These drugs inhibit the calcium-dependent phosphatase calcineurin (cyclosporine and FK506) or inhibit p70S6 kinase (rapamycin), which is crucial for growth factor-induced signaling (Liu et al., Cell 66:807-815, 1991; Henderson et al., Immun. 73:316-321, 1991; Bierer et al., Curr. Opin. Immun. 5:763-773, 1993). In another embodiment, cells are isolated from the patient and frozen for later use with bone marrow or stem cell transplantation, T-cell ablation therapy using chemotherapeutic agents (such as fludarabine), external beam radiation therapy (XRT), cyclophosphamide, or antibodies (such as OKT3 or...). (e.g., before, during, or after). In some embodiments, blood samples or apheresis are collected from a healthy donor, and iNKT cells isolated from a third-party healthy donor can be used "off the spot," for example, as described by Li et al., Off-the-shelf third-party HSC-engineered iNKT cells for ameliorating GvHD while preserving GvL effect in the treatment of bloodcancers, iScience. 2022 Sep 16; 25(9):104859.

[0451] In some embodiments, an initial population of iNKT cells is purified from PBMCs using any suitable method known in the art (e.g., FACS or MACS). In some embodiments, the initial population of iNKT cells is stimulated with α-galactosylceramide (α-GalCer) or any modified glycolipid thereof to activate and expand, for example, as described in Zhang et al., α-GalCer and iNKT Cell-Based Cancer Immunotherapy: Realizing the Therapeutic Potentials, FrontImmunol. 2019 6 / J; 10:1126; Schafer et al., iNKT cellstimulation by glycolipid ligands modified from α-galactosylceramide results in differential interleukin-2 secretion profiles, JImmunol 1 / May 2019, 202(1 Supplement) 177.1). In some embodiments, iNKT cells are transduced with any of the lentiviral vectors described herein to express anti-BCMACAR (e.g., any of the anti-BCMACARs described herein). In some embodiments, after transduction, more than 1%, more than 2%, more than 5%, more than 8%, more than 10%, more than 12%, or more than 15%, more than 18%, more than 20%, more than 22%, more than 25%, more than 28%, or more than 30% of the iNKT cells express anti-BCMACAR. In some embodiments, after transduction, the iNKT cells are further stimulated and expanded. In some embodiments, further stimulation and expansion includes stimulating the iNKT cells expressing anti-BCMACAR with feeder cells carrying BCMA. Feeder cells can be any suitable feeder cells known in the art, such as feeder cells or cell-derived membrane vesicles (Ukrainskaya et al., Antigen-Specific Stimulation and Expansion of CAR-T Cells Using Membrane Vesicles as Target Cell Surrogates, Small. November 2021; 17(45):e2102643). In some embodiments, feeder cells are feeder cells (e.g., K562 feeder cells), major histocompatibility complex class I chain-associated protein A (MICA) feeder cells, or artificially fed (221-mIL-21) cells based on the membrane-bound human B lymphoblast line 721.221 (hereinafter referred to as 221).In some embodiments, the feeder cells are K562 feeder cells. The use of genetically engineered K562 feeder cells to expand NK cells has been previously described; see, for example, Phan et al., Expansion of NK Cells Using Genetically Engineered K562 Feeder Cells, Natural Killer Cells, pp. 167–174. In some embodiments, the K562 cells are irradiated prior to co-culturing with iNKT cells expressing anti-BCMACAR. In some embodiments, the engineered K562 cells express BCMA on their cell surface. In some embodiments, after co-culturing with feeder cells, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 98%, at least 99% or more of the iNKT cells express anti-BCMACAR.

[0452] IV. Therapeutic Applications

[0453] In some embodiments, this disclosure covers cells (e.g., iNKT cells) modified to express CARs that bind antigen recognition domains (e.g., anti-BCMAscFv), transmembrane domains (e.g., CD8 transmembrane domains), and cytoplasmic domains (e.g., intracellular domains of CD3-ζ, CD28, OX40, 4-1BB, or any combination thereof). Therefore, in some embodiments, the transduced immune cells (e.g., iNKT cells) elicit CAR-mediated immune responses (e.g., T cell responses) and / or innate immune responses (e.g., NK cell responses) in a subject. In some embodiments, this disclosure provides the use of CARs to specifically redirect primary iNKT cells to tumor antigens. Therefore, in some embodiments, the present invention also provides a method for stimulating an iNKT cell-mediated immune response against a target cell population or tissue in a mammal, the method comprising the step of administering to the mammal a plurality of iNKT cells expressing a CAR (e.g., anti-BCMA CAR), wherein the CAR comprises a binding portion that specifically interacts with a predetermined target (e.g., BCMA), a ζ-chain portion comprising, for example, an intracellular domain of human CD3ζ, and a co-stimulatory signaling region. In some embodiments, this disclosure includes a type of cell therapy in which iNKT cells are genetically modified to express a CAR, and iNKT cells expressing a CAR (e.g., anti-BCMACAR) are infused into a recipient in need. The injected cells are capable of killing tumor cells in the recipient's body. Unlike antibody therapy, CAR iNKT cells are capable of replicating in vivo, thereby achieving long-term persistence and sustained tumor control. In some embodiments, unlike CAR T therapy, subjects receiving the iNKT cell composition do not experience lymphocyte depletion prior to receiving the iNKT cells.

[0454] In some embodiments, this disclosure provides cells (e.g., iNKT cells) modified to express a CAR (e.g., anti-BCMA CAR) and cytokines (e.g., sIL-15). In some embodiments, IL-15 secreted by iNKT cells expressing anti-BCMA CAR enhances iNKT cell persistence in a subject (e.g., relative to a subject administered a CAR that does not express an armor molecule (such as IL-15).

[0455] Without being bound by any particular theory, the anti-tumor immune response induced by CAR-modified iNKT cells may be an innate or adaptive immune response. In some embodiments, the CAR-mediated immune response may be part of an adoptive immunotherapy approach, wherein CAR-modified iNKT cells induce an immune response specific to the antigen-binding portion of the CAR. For example, BCMA-specific CARiNKT cells elicit a specific immune response against cells expressing BCMA. In some embodiments, the BCMA-specific CAR iNKT cells described herein kill cancer cells. In some embodiments, the BCMA-specific CARiNKT cells described herein reduce tumor burden. In some embodiments, the BCMA-specific CARiNKT cells described herein recruit other immune cells into the tumor microenvironment to kill cancer. In some embodiments, the antigen-binding domain in the CAR of this disclosure targets tumor antigens (e.g., BCMA) to achieve the purpose of treating cancer. In some embodiments, the antigen-binding portion of the CAR of the present invention is designed to treat specific cancers (e.g., cancers expressing BCMA), such as multiple myeloma.

[0456] The CAR-modified iNKT cells disclosed herein can also be used as a vaccine type for mammalian in vitro immunization and / or in vivo therapy. Preferably, the mammal is a human.

[0457] In some embodiments, iNKT cells as described herein can be used to treat and prevent diseases (e.g., cancer) in immunocompromised individuals, such as individuals with cancer. Specifically, iNKT cells expressing the anti-BCMA CAR of this disclosure are used to treat multiple myeloma. In some embodiments, iNKT cells expressing the anti-BCMA CAR of this disclosure are used to treat patients at risk of developing multiple myeloma.

[0458] In some embodiments, iNKT cells expressing the anti-BCMACAR of this disclosure or compositions comprising such cells may be used or administered to subjects in need to provide anti-tumor immunity; treat or prevent cancer; treat or prevent autoimmune diseases; or treat or prevent allergic diseases. In some embodiments, the cancer is a cancer expressing BCMA. In some embodiments, the cancer is multiple myeloma, Hodgkin lymphoma, non-Hodgkin lymphoma, leukemia, or glioblastoma. In some embodiments, the autoimmune disease is myasthenia gravis, systemic lupus erythematosus, rheumatoid arthritis, pemphigus, psoriasis, inflammatory bowel disease, celiac disease, pernicious anemia, idiopathic thrombocytopenic purpura, scleroderma, Graves' disease, Sjögren's syndrome ( Allergic conditions include anaphylactic shock, asthma, food allergy, stinging insect allergy, drug allergy, allergic rhinitis, urticaria, angioedema, eczema, atopic dermatitis, contact dermatitis, and eosinophilic esophagitis. In some embodiments, allergic conditions include anaphylactic shock, asthma, food allergy, stinging insect allergy, drug allergy, allergic rhinitis, urticaria, angioedema, eczema, atopic dermatitis, contact dermatitis, and eosinophilic esophagitis.

[0459] In some embodiments, iNKT cells expressing the anti-BCMACAR of this disclosure may be administered alone or as a composition (e.g., a pharmaceutical composition) in combination with diluents and / or other components (such as IL-2 or other cytokines or cell populations). In short, the pharmaceutical compositions of the present invention may comprise target cell populations as described herein and one or more pharmaceutically or physiologically acceptable loads, diluents, or excipients. Such compositions may comprise buffers, such as neutral buffered saline, phosphate buffered saline, etc.; carbohydrates, such as glucose, mannose, sucrose, or dextran, mannitol; proteins; peptides or amino acids, such as glycine; antioxidants; chelating agents, such as EDTA or glutathione; adjuvants (e.g., aluminum hydroxide); and preservatives.

[0460] The pharmaceutical compositions of the present invention can be administered in a manner suitable for treating (or preventing) a disease. The amount and frequency of administration will be determined by factors such as the patient's condition and the type and severity of the patient's disease, but an appropriate dosage can be determined through clinical trials. In some embodiments, the compositions of the present disclosure are formulated for intravenous administration.

[0461] When specifying "immunely effective dose," "antitumor effective dose," "tumor-suppressive effective dose," or "therapeutic dose," the precise amount of the composition of the invention to be administered can be determined by a physician taking into account individual differences in the patient's (subject's) condition, such as age, weight, tumor size, degree of infection or metastasis, and other factors. Cells can be administered using infusion techniques known in immunotherapy (see, for example, Rosenberg et al., New Eng. J. of Med. 319:1676, 1988). Those skilled in the medical field can readily determine the optimal dosage and treatment regimen for a specific patient by monitoring for signs of disease and adjusting treatment accordingly.

[0462] The compositions of this invention can be administered in any convenient manner, including by aerosol inhalation, injection, ingestion, infusion, implantation, or transplantation. The compositions described herein can be administered to patients subcutaneously, intradermally, intratumorally, intranodally, intramedullary, intramuscularly, intravenously (iv), or intraperitoneally. In some embodiments, the immune cell (e.g., iNKT cell) compositions of this invention are administered to patients via intradermal or subcutaneous injection. In another embodiment, the immune cell (e.g., iNKT cell) compositions of this invention are preferably administered via intravenous injection. The immune cell (e.g., iNKT cell) compositions can be injected directly into the tumor, lymph node, or disease site.

[0463] In some embodiments of this disclosure, cells activated and expanded using the methods described herein or other methods known in the art for expanding iNKT cells to therapeutic levels are administered to a patient in combination with any number of relevant treatment modalities (e.g., before, during, or after). These modalities include, but are not limited to, treatment with antiviral therapies, agents of cidofovir and interleukin-2, cytarabine (also known as ARA-C), nastatinumab for MS patients, efalizumab for psoriasis patients, or other treatments for PML patients. In other embodiments, the iNKT cells of this disclosure may be used in combination with chemotherapy, radiation, immunosuppressants (such as cyclosporine, azathioprine, methotrexate, mycophenolate mofetil, and FK506), antibodies, or other immunoablation agents (such as CAMPATH, anti-CD3 antibodies or other antibody therapies, cytotoxins, fludarebrine, cyclosporine, FK506, rapamycin, mycophenolate mofetil, steroids, FR901228, cytokines, and radiation). In another embodiment, the cell composition of this disclosure is administered to the patient in conjunction with bone marrow transplantation, T-cell ablation therapy using chemotherapeutic agents (such as fludarabine), external beam radiation therapy (XRT), cyclophosphamide, or antibodies (such as OKT3 or CAMPATH) (e.g., before, simultaneously with, or after). In another embodiment, the cell composition of this disclosure is administered after B-cell ablation therapy (such as an agent that responds to CD20 (e.g., Rituxan)). For example, in some embodiments, the subject may undergo standard treatment with high-dose chemotherapy followed by peripheral blood stem cell transplantation. In some embodiments, after transplantation, the subject receives an infusion of expanded immune cells (e.g., iNKT cells) of this disclosure. In other embodiments, iNKT cells are administered before or after surgery.

[0464] The scaling of the dosage for human administration can be done according to practices accepted in the art. For example, for adult patients, the dosage of CAMPATH is typically in the range of 1 mg to about 100 mg, usually administered daily for a period of 1 to 30 days. The preferred daily dose is 1 mg to 10 mg daily, but in some cases larger doses of up to 40 mg daily may be used (as described in U.S. Patent No. 6,120,766). Strategies for CAR-T cell administration and timing have been discussed (Ertl et al., 2011, Cancer Res, 71:3175-81; Junghans, 2010, Journal of Translational Medicine, 8:55).

[0465] Without further elaboration, it is believed that those skilled in the art can utilize this disclosure to the fullest extent based on the foregoing description. Therefore, the following specific embodiments should be interpreted as illustrative only and do not limit the remainder of this disclosure in any way. All disclosures referenced herein are incorporated by way of reference for the purposes or subject matter of this document.

[0466] Example

[0467] The following examples are provided for illustrative purposes and are not intended to limit the scope of the invention.

[0468] Example 1: Development and evaluation of anti-BCMACARiNKT cells

[0469] Invariant natural killer T (iNKT) cells act as an anti-cancer mechanism by lysing tumors via T cell receptor (TCR)-dependent and TCR-independent mechanisms. Figure 1 In the direct pathway, iNKT cells are activated upon recognizing the lipid-CD1d complex on the surface of tumor cells via their invariant T cell receptors (iTCRs), leading to subsequent tumor cell lysis. Similarly, iNKT cell-mediated killing can be triggered when stress molecules on tumor cells are recognized by natural killer (NK) cell activation receptors (e.g., NKG2DL and DNAM) expressed by iNKT cells. In the indirect activation pathway, iNKT cells recognize the lipid-CD1d complex on the surface of tumor microenvironment (TME) antigen-presenting cells (APCs) or tissue-associated macrophages (TAMs). This interaction leads to iNKT cell-mediated killing of immunosuppressive TAMs, thereby allowing NK cells to function better. In the presence of CD1d expressed by APCs, iNKT cells can activate APCs and stimulate IL-12 production, thereby helping resident effector cells such as NK cells overcome the immunosuppressive TME.

[0470] This disclosure at least partially describes anti-BCMACAR iNKT cells and their uses (e.g., cancer immunotherapy). Typically, the CAR iNKT cells of this disclosure contain chimeric antigen receptors and are capable of secreting IL-15 (…). Figure 2 Typically, iNKT cells are transduced with lentivirus to express a second-generation CAR that specifically recognizes BCMA via its fully human scFv (1). Following the scFv are the CD8 transmembrane domain, the 4-1bb signaling domain, and the CD3z activation domain (2). CAR-iNKT cells also secrete soluble IL-15 because the lentiviral cassette also contains the IL-15 gene (3).

[0471] Figure 3 This provides an overview of the screening process for anti-BCMACAR. (CARDIS) TM The platform is a two-stage high-throughput discovery method in which highly diverse scFv libraries are screened via phage display, followed by functional activity screening of mammalian display libraries in CAR format. Promising candidates are transiently transfected into iNKT cells and tested in functional assays such as cytotoxicity and activation, and then the most potent CAR is stably transfected into iNKT cells for more comprehensive and long-term assays, such as repeated stimulation.

[0472] Figure 4 This illustrates conventional phage motility when selecting BCMA conjugates, and is a schematic diagram of the early BCMA phage motility funnel. Containing higher than 10 10 A highly diverse, immature human scFv phage display library of different scFv clones was used for screening against the BCMA antigen. After two rounds of selection, 219 selected single colonies were tested by ELISA, and 57 conjugates were identified. The ELISA conjugates were then further tested in Biacore. Of these conjugates, 25 clones with good kinetics were selected, and further cell binding assays narrowed the candidate pool to 11. Of these 11, 7 remained CAR conjugates, but none showed the functionality measured by BCMA-positive target cell killing.

[0473] Figure 5A mammalian screening strategy for identifying highly functional CARs is presented. Phage selection output was converted into a CAR expression library and transduced into AKD mammalian cells for functional screening. Binding assays in the mammalian cell library showed that only 20%–25% of CAR-expressing cells bound the BCMA antigen in the CAR format. Single-cell sorting of the BCMA binders confirmed that 85% of clones were bound. A series of activation assays performed on the single-sorted cells yielded only 4% specific activators, while over 9% were nonspecific tetanic activators. The majority of clones were binders but not activators (71%). This highlights the importance of screening CAR functionality in a format as close as possible to the final application. Following mammalian screening, several candidates (e.g., F1, F6) were selected for further development.

[0474] The affinity of F6 and F1 scFv for BCMA was measured using a Biacore T200. Figure 6 BCMA-Fc antigen was immobilized on a protein A chip, and BCMA clones expressed in scFv form were flowed through the chip at concentrations of 0 nM, 1 nM, 10 nM, 100 nM, and 1000 nM. Experiments were performed on a Biacore T200. Both F1 and F6 bound to BCMA, with F6 exhibiting higher affinity.

[0475] To map the epitopes of anti-BCMACAR candidates, the accessible BCMA amino acid was mutated to alanine, and the loss of binding compared to wild-type was quantified via Biacore. Figure 7A The study showed the loss of binding between various anti-BCMACAR antibodies and various BCMA antigen mutants. Figure 7B The 3D structure showing the binding sites of A-based F6G (germline F6) with BCMA (Asp15, Leu17, Leu18 at the top, Arg27, Thr32, and Leu35 at the bottom) is displayed.

[0476] The candidate anti-BCMA scFv was transiently expressed as anti-BCMA CAR in iNKT cells and tested in a cytotoxicity assay. Figure 8A This diagram illustrates a cytotoxicity assay mediated by iNKT cells transiently transfected with BCMA-CAR. iNKT cells expressing different BCMA-CAR candidates or the clinical baseline (bb2121) were co-cultured with BCMA-expressing tumor cell lines at three different effector-to-target ratios for 24 hours. The percentage of dead tumor cells was assessed by flow cytometry. Wild-type or stably transduced K562 cells with BCMA were also included in the assay. Figures 8B to 8H Endogenous BCMA expression levels in each tumor lineage were assessed by flow cytometry. Figure 8IThe results showed that bb2121 outperformed the three candidates in Raji and T2 cells, while the three candidates performed similarly to bb2121 in RPMI, U266, H929, and K562 cells. These results indicate that further improvements to the candidate drugs are needed to enhance the function of the BCMA conjugate. F6 was selected for further development.

[0477] In addition, affinity maturation of germline versions of F6 (F6G) was performed using a combination of two methods: accelerated drug discovery (ADD) and affinity maturation of phage libraries. Figures 9A to 9C The ADD method is described. Figure 9A This is a schematic diagram illustrating the formation of CDR positions through mutation. Each amino acid in the heavy and light chain CDRs is replaced by eight different amino acids: Tyr, Ser, Pro, Leu, his, Gly, Asp, and Asn. PCR is performed to generate fragments containing single amino acid substitutions. These PCR fragments are then used as templates to express scFv in a cell-free system. The KD(M) value shows the affinity of the mutant scFv for binding to the BCMA antigen. The experiment was run in a Biacore 4000. The dashed line indicates binding to the parental F6G clone. The KD below the dashed line indicates increased affinity. The E to Y substitution at position 49 of the light chain CDRL2 is significantly more effective than other positions. Figure 9B The image shows a single Biacore sensor map with E to Y substitutions at position 49 of CDRL2. Figure 9C ).

[0478] F6G also achieved affinity maturation through phage libraries. Figure 10A This diagram illustrates a phage display affinity maturation library strategy. The CDR amino acid labeled x is mutated to any other amino acid, and the library is used for phage panning, followed by mammalian display. Figure 10B ).

[0479] Based on the combination results of ADD substitution and affinity maturation libraries, several combinations were designed and their cytotoxicity and activation were tested in functional assays, and the results are as follows: Figures 10C to 10DAs shown in the figure. iNKT cells expressing different BCMA-CAR candidates or the clinical baseline (bb2121) were co-cultured with T2 cells expressing endogenous BCMA at three different effector-to-target ratios for 24 hours. The percentage of dead target cells and activation markers 4-1BB, CD25, and CD69 were assessed by flow cytometry. The F6G variants showed similar cytotoxicity and activation activity to the reference baseline bb2121. Cytotoxicity to BCMA-negative K562 cells was negligible and similar to the reference clinical candidate. Activation after co-culturing with BCMA-negative K562 cells was negligible and similar to bb2121 for most F6G variants. Figure 10D ).

[0480] To test the affinity of BCMA F6G variants, their binding domains were expressed as IgG and captured onto a protein A chip. BCMA antigen was flowed through the chip at concentrations of 400 mM, 100 mM, 25 mM, 6.25 mM, 1.25 mM, and 0 mM. Experiments were run on a Biacore T200. Affinity-mature clones showed a 10-fold increase in affinity compared to the original F6 clone and nearly a 50-fold increase compared to germline F6G. Figure 11 ). Figure 12 The affinity of F6G-Var2 for two known anti-BCMA CARide-cel and cilta-cel was demonstrated. CAR was expressed as IgG and captured onto a protein A chip. BCMA antigen was flowed through the chip at concentrations of 400 mM, 100 mM, 25 mM, 6.25 mM, 1.25 mM, and 0. Experiments were run on a Biacore T200.

[0481] INKT cells from two donors were temporarily transfected with the F6G variant, and their killing of tumor cells mediated by anti-BCMA-CAR iNKT cells was tested. Flow cytometry analysis of RFP expression was used to demonstrate CAR expression in BCMA-CAR iNKT cells and their binding to the BCMA-APC antigen. Figures 13A to 13C ). BCMA expression levels on each tumor cell line were assessed by flow cytometry, with the left peak indicating isomorphic staining and the right peak indicating BCMA expression. Figure 13D ). iNKT cells expressing anti-BCMACAR (e.g. Figure 13A (As shown) Tumor cell lines endogenously expressing BCMA or K562 were co-cultured with the target cell line for 24 hours at three different effector-to-target ratios. After 24 hours of co-culture, the percentage of dead target cells was determined by flow cytometry assay. Figure 13E The percentage of iNKT cells co-expressing CD69 / CD25 ( Figure 13F The percentage of 4-1BB cells expressing iNKT () and Figure 13G ).

[0482] Sequence alignment of the variable regions of the F6G variable heavy chain and light chain is as follows: Figure 14 As shown in the figure. The immunogenicity of the F6G variant was analyzed. The risk of candidate BCMACARs against other biological therapeutics was ranked using an internal computer immunogenicity scoring algorithm based on NetMHCpanIIv.4. Protein sequences were evaluated based on overlapping 9-mer peptides, and cumulative scores were calculated. The calculated score values ​​are only relevant when compared with values ​​in a representative reference set. In this case, a set of 420 Fvs (variable domains) from the therapeutic antibody Thera-SabDab was used. The 420 Fv sequences were divided into 4 groups [human (hu), humanized (zu), and mouse / chimeric (mu / xi), all (total)]. The computer-simulated immunogenicity scores were then plotted on the X-axis, and the ...

Claims

1. An invariant natural killer T (iNKT) cell engineered to express a chimeric antigen receptor comprising a B cell maturation antigen (BCMA) binding moiety and IL-15.

2. The iNKT cells according to claim 1, wherein the IL-15 is soluble IL-15.

3. The iNKT cells according to claim 1 or 2, wherein the IL-15 is human IL-15.

4. The iNKT cells according to any one of claims 1 to 3, wherein the iNKT cells kill cells expressing BCMA.

5. The iNKT cell according to claim 4, wherein the iNKT cell directly kills cells expressing BCMA.

6. The iNKT cell according to claim 4, wherein the iNKT cell indirectly kills cells expressing BCMA.

7. The iNKT cells according to any one of claims 1 to 6, wherein the iNKT cells retain a response to CD1d and / or NK receptor ligands.

8. The iNKT cell according to any one of claims 1 to 7, wherein the iNKT cell comprises a CAR containing any one of the anti-BCMA antibodies listed in Table 3.

9. The iNKT cell according to any one of claims 1 to 8, wherein the iNKT cell comprises a CAR containing any one of the CARs listed in Table 4.

10. A method for killing cells, the method comprising contacting the cells with iNKT cells according to any one of claims 1 to 9.

11. A method for treating a tumor in a subject, the method comprising administering iNKT cells according to any one of claims 1 to 9 to a subject who has or is suspected of having cancer.

12. A method for reducing tumor growth, the method comprising contacting a subject's tumor with iNKT cells according to any one of claims 1 to 9.

13. The method of claim 11 or 12, wherein the tumor cells express BCMA.

14. The method according to any one of claims 11 to 13, wherein the administration of the iNKT cells results in a reduction in tumor burden relative to the tumor burden of the subject prior to the administration.

15. The method according to any one of claims 11 to 14, wherein the administration of the iNKT cells results in resistance to T cell exhaustion, enhanced tissue homing of anti-BCMA iNKT cells, selective cytotoxicity to M2 macrophages, and / or stimulation of dendritic cell maturation.

16. The method according to any one of claims 11 to 15, wherein the subject does not experience lymphocyte depletion prior to administration of the iNKT cells.

17. An antibody or antigen-binding fragment that specifically binds to an amino acid sequence, said amino acid sequence having at least 85% identity with SEQ ID NO: 38 to 48.

18. The antibody or antigen-binding fragment of claim 17, wherein the antibody specifically binds to the amino acid sequence listed in SEQ ID NO: 38 to 48.

19. An antibody or antigen-binding fragment comprising a heavy chain variable region having a sequence listed in any one of SEQ ID NO:7, 12, 19 or 21.

20. The antibody or antigen-binding fragment of claim 19, wherein the antibody comprises a heavy chain variable region having a sequence as listed in SEQ ID NO:7, 12, 19 or 21 and a light chain variable region having a sequence as listed in SEQ ID NO:8, 10, 13, 15 or 22.

21. The antibody or antigen-binding fragment according to any one of claims 17 to 20, wherein the antibody comprises: (i) having a heavy chain variable region of the sequence listed in SEQ ID NO:7 and a light chain variable region of the sequence listed in SEQ ID NO:8; (ii) Having a heavy chain variable region of the sequence listed in SEQ ID NO:7 and a light chain variable region of the sequence listed in SEQ ID NO:10; (iii) Having a heavy chain variable region of the sequence listed in SEQ ID NO:12 and a light chain variable region of the sequence listed in SEQ ID NO:13; (iv) A heavy chain variable region having the sequence listed in SEQ ID NO:12 and a light chain variable region having the sequence listed in SEQ ID NO:15; (v) Having a heavy chain variable region of the sequence listed in SEQ ID NO:7 and a light chain variable region of the sequence listed in SEQ ID NO:13; (vi) Having a heavy chain variable region of the sequence listed in SEQ ID NO:7 and a light chain variable region of the sequence listed in SEQ ID NO:15; (vii) Having a heavy chain variable region of the sequence listed in SEQ ID NO:19 and a light chain variable region of the sequence listed in SEQ ID NO:10; or (viii) Having a heavy chain variable region of the sequence listed in SEQ ID NO:21 and a light chain variable region of the sequence listed in SEQ ID NO:

22.

22. An antibody or antigen-binding fragment comprising a variable heavy chain region, said variable heavy chain region comprising a complementarity-determining region 3 (CDRH3) having the sequence listed in SEQ ID NO: 3 or 33.

23. The antibody or antigen-binding fragment of claim 22, further comprising a variable light chain region, said variable light chain region comprising a complementarity-determining region 3 (CDRL3) having a sequence listed in any one of SEQ ID NO: 6, 29, 30 or 36.

24. An antibody or antigen-binding fragment comprising six complementarity-determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3. in (i) CDRH1 contains the sequence listed in SEQ ID NO:1, CDRH2 contains the sequence listed in SEQ ID NO:2, CDRH3 contains the sequence listed in SEQ ID NO:3, and CDRL1 contains the sequence listed in SEQ ID NO: The sequences listed in 4, CDRL2 contains the sequence listed in SEQ ID NO:5, and CDRL3 contains the sequence listed in SEQ ID NO:6; (ii) CDRH1 contains the sequence listed in SEQ ID NO:1, CDRH2 contains the sequence listed in SEQ ID NO:2, CDRH3 contains the sequence listed in SEQ ID NO:3, and CDRL1 contains the sequence listed in SEQ ID NO: The sequences listed in 4, CDRL2 contains the sequence listed in SEQ ID NO:5, and CDRL3 contains the sequence listed in SEQ ID NO:6; (iii) CDRH1 contains the sequence listed in SEQ ID NO:25, CDRH2 contains the sequence listed in SEQ ID NO:27, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:30; (iv) CDRH1 contains the sequence listed in SEQ ID NO:25, CDRH2 contains the sequence listed in SEQ ID NO:27, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:29; (v) CDRH1 contains the sequence listed in SEQ ID NO:1, CDRH2 contains the sequence listed in SEQ ID NO:2, CDRH3 contains the sequence listed in SEQ ID NO:3, and CDRL1 contains the sequence listed in SEQ ID NO: The sequences listed in 4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:30; (vi) CDRH1 contains the sequence listed in SEQ ID NO:1, CDRH2 contains the sequence listed in SEQ ID NO:2, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:

29. (vii) CDRH1 contains the sequence listed in SEQ ID NO:26, and CDRH2 contains the sequence listed in SEQ ID NO: The sequences listed in SEQ ID NO:28, CDRH3 contains the sequence listed in SEQ ID NO:3, CDRL1 contains the sequence listed in SEQ ID NO:4, CDRL2 contains the sequence listed in SEQ ID NO:24, and CDRL3 contains the sequence listed in SEQ ID NO:6; or (viii) CDRH1 contains the sequence listed in SEQ ID NO:31, and CDRH2 contains the sequence listed in SEQ ID NO: The sequences listed in SEQ ID NO:32, CDRH3 contains the sequence listed in SEQ ID NO:33, CDRL1 contains the sequence listed in SEQ ID NO:34, CDRL2 contains the sequence listed in SEQ ID NO:35, and CDRL3 contains the sequence listed in SEQ ID NO:

36.

25. The antibody or antigen-binding fragment according to any one of claims 17 to 24, wherein the antibody or antigen-binding fragment is chimeric.

26. The antibody or antigen-binding fragment according to any one of claims 17 to 25, wherein the antibody or antigen-binding fragment is humanized.

27. The antibody or antigen-binding fragment according to any one of claims 17 to 26, wherein the antibody or antigen-binding fragment is a single-chain variable fragment (scFv).

28. The antibody or antigen-binding fragment of claim 27, wherein the scFv comprises the amino acid sequence listed in any one of SEQ ID NO: 9, 11, 14, 16, 17, 18, 20 or 23.

29. An isolated nucleic acid encoding an antibody or antigen-binding fragment according to any one of claims 17 to 28.

30. The isolated nucleic acid according to claim 29, comprising the sequence listed in any one of SEQ ID NO:49-64.

31. The isolated nucleic acid according to claim 29, comprising the sequence listed in any one of SEQ ID NO:65-72.

32. A vector comprising the isolated nucleic acid according to any one of claims 29 to 31.

33. The vector according to claim 32, wherein the vector is a viral vector.

34. The vector according to claim 33, wherein the viral vector is a lentiviral vector.

35. The vector of claim 34, wherein the lentiviral vector comprises the sequence listed in any one of SEQ ID NO:73-80.

36. A host cell comprising an antibody or antigen-binding fragment according to any one of claims 17 to 28, or an isolated nucleic acid according to any one of claims 29 to 31, or a vector according to any one of claims 32 to 35.

37. The host cell according to claim 36, wherein the cell is a mammalian cell, a bacterial cell, a yeast cell, or an insect cell.

38. The host cell according to claim 36 or 37, wherein the cell is a hybridoma cell.

39. A chimeric antigen receptor (CAR) comprising an antigen-binding fragment according to any one of claims 17 to 28.

40. The CAR of claim 39, wherein the CAR further comprises a hinge region.

41. The CAR of claim 40, wherein the hinge region comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:

82.

42. The CAR according to any one of claims 39 to 41, wherein the CAR further comprises a transmembrane domain.

43. The CAR according to claim 39 or 40, wherein the transmembrane domain comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:

83.

44. The CAR according to any one of claims 39 to 43, wherein the CAR further comprises a cytoplasmic domain.

45. The CAR of claim 44, wherein the cytoplasmic domain comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:

84.

46. ​​The CAR according to any one of claims 39 to 45, wherein the CAR further comprises a co-stimulatory domain.

47. The CAR of claim 46, wherein the co-stimulatory domain comprises an amino acid sequence that is at least 80% identical to that of SEQ ID NO:

85.

48. The CAR of claim 47, wherein the CAR comprises the amino acid sequence of any one of SEQ ID NO: 86 to 93.

49. An immune cell comprising the CAR according to any one of claims 39 to 48.

50. The immune cell of claim 49, wherein the immune cell is a natural killer (NK) cell or a T cell.

51. The immune cell of claim 50, wherein the immune cell is an invariant natural killer T (iNKT) cell.

52. The immune cell according to any one of claims 49 to 51, wherein the immune cell is engineered to express one or more immune regulatory gene products.

53. The immune cell of claim 52, wherein the one or more immunomodulatory gene products comprise IL-15, IL-12, CD40L, or 4-1BB.

54. A pharmaceutical composition comprising an antibody or antigen-binding fragment according to any one of claims 17 to 28 or an immune cell according to any one of claims 49 to 53, and a pharmaceutically acceptable excipient.

55. A method for killing cells, the method comprising contacting the cells with an antibody or antigen-binding fragment according to any one of claims 17 to 28, an immune cell according to any one of claims 49 to 53, or a pharmaceutical composition according to claim 54.

56. The method of claim 55, wherein the cell is a mammalian cell.

57. The method according to claim 55 or 56, wherein the cell is a human cell.

58. The method according to any one of claims 55 to 57, wherein the cell is a cancer cell.

59. The method of claim 58, wherein the cancer is a blood cancer.

60. The method of claim 59, wherein the blood cancer is leukemia or lymphoma.

61. The method according to any one of claims 55 to 60, wherein the cancer is multiple myeloma.

62. A method for treating a subject with cancer, the method comprising administering to a subject who has or is suspected of having cancer immune cells according to any one of claims 49 to 53 or a pharmaceutical composition according to claim 54.

63. A method for reducing tumor growth, the method comprising contacting the tumor of a subject with an antibody or antigen-binding fragment according to any one of claims 17 to 28, an immune cell according to any one of claims 49 to 53, or a pharmaceutical composition according to claim 54.

64. The method according to claim 62 or 63, wherein the subject is a human being.

65. The method according to any one of claims 62 to 64, wherein the cancer is a blood cancer.

66. The method of claim 65, wherein the cancer is leukemia or lymphoma.

67. The method according to any one of claims 62 to 66, wherein the cancer is multiple myeloma.

68. The method according to any one of claims 62 to 67, wherein the application is performed via injection.

69. The method according to any one of claims 62 to 68, wherein the subject does not experience lymphocyte depletion prior to administration of the iNKT cells.

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