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WO2025191260A1 - Treatment of autoimmune disease by co-expression of cd19-car and bcma-car - Google Patents

Treatment of autoimmune disease by co-expression of cd19-car and bcma-car

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Publication number
WO2025191260A1
WO2025191260A1 PCT/GB2025/050497 GB2025050497W WO2025191260A1 WO 2025191260 A1 WO2025191260 A1 WO 2025191260A1 GB 2025050497 W GB2025050497 W GB 2025050497W WO 2025191260 A1 WO2025191260 A1 WO 2025191260A1
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WIPO (PCT)
Prior art keywords
car
cells
seq
bcma
cell
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French (fr)
Inventor
Wolfram Brugger
Martin PULÉ
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Autolus Ltd
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Autolus Ltd
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K40/00—Cellular immunotherapy
    • A61K40/10—Cellular immunotherapy characterised by the cell type used
    • A61K40/11—T-cells, e.g. tumour infiltrating lymphocytes [TIL] or regulatory T [Treg] cells; Lymphokine-activated killer [LAK] cells
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K40/00—Cellular immunotherapy
    • A61K40/30—Cellular immunotherapy characterised by the recombinant expression of specific molecules in the cells of the immune system
    • A61K40/31—Chimeric antigen receptors [CAR]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K40/00—Cellular immunotherapy
    • A61K40/40—Cellular immunotherapy characterised by antigens that are targeted or presented by cells of the immune system
    • A61K40/41—Vertebrate antigens
    • A61K40/416—Antigens related to auto-immune diseases; Preparations to induce self-tolerance
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K40/00—Cellular immunotherapy
    • A61K40/40—Cellular immunotherapy characterised by antigens that are targeted or presented by cells of the immune system
    • A61K40/41—Vertebrate antigens
    • A61K40/42—Cancer antigens
    • A61K40/4202—Receptors, cell surface antigens or cell surface determinants
    • A61K40/421—Immunoglobulin superfamily
    • A61K40/4211—CD19 or B4
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K40/00—Cellular immunotherapy
    • A61K40/40—Cellular immunotherapy characterised by antigens that are targeted or presented by cells of the immune system
    • A61K40/41—Vertebrate antigens
    • A61K40/42—Cancer antigens
    • A61K40/4202—Receptors, cell surface antigens or cell surface determinants
    • A61K40/4214—Receptors for cytokines
    • A61K40/4215—Receptors for tumor necrosis factors [TNF], e.g. lymphotoxin receptor [LTR], CD30
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2239/00—Indexing codes associated with cellular immunotherapy of group A61K40/00
    • A61K2239/10—Indexing codes associated with cellular immunotherapy of group A61K40/00 characterized by the structure of the chimeric antigen receptor [CAR]
    • A61K2239/11—Antigen recognition domain
    • A61K2239/13—Antibody-based
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2239/00—Indexing codes associated with cellular immunotherapy of group A61K40/00
    • A61K2239/27—Indexing codes associated with cellular immunotherapy of group A61K40/00 characterized by targeting or presenting multiple antigens
    • A61K2239/28—Expressing multiple CARs, TCRs or antigens
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2239/00—Indexing codes associated with cellular immunotherapy of group A61K40/00
    • A61K2239/46—Indexing codes associated with cellular immunotherapy of group A61K40/00 characterised by the cancer treated
    • A61K2239/48—Blood cells, e.g. leukemia or lymphoma

Definitions

  • the present invention relates to method for treating an autoimmune disease using a cell composition comprising cells which co-express an anti-CD19 chimeric antigen receptor (CAR) and an anti-B-cell maturation antigen (BCMA) CAR.
  • CAR anti-CD19 chimeric antigen receptor
  • BCMA anti-B-cell maturation antigen
  • autoimmune diseases include rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, multiple sclerosis, Type I diabetes, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, psoriasis, Graves’ disease, Hashimoto’s thyroiditis, myasthenia gravis, scleroderma, vasculitis and pemphigus vulgaris.
  • Autoimmune diseases affect millions of individuals world-wide and the cost of these diseases, in terms of actual treatment expenditures and lost productivity, is measured in billions of dollars annually.
  • Current standard approaches to treating autoimmune diseases focus on managing the disease rather than offering a cure.
  • the main concept to treat autoimmune disease is to prevent autoreactive immune cells from attacking host tissues by broad (and mostly non-targeted) immunosuppressive agents such as glucocorticoids and non-steroidal anti-inflammatory drugs.
  • Autoreactive immune cells can be more specifically blocked using therapeutic antibodies which target B cells via for example, CD20 (Rituximab) or BAFF (Belimumab), T cells via, for example, CD52 (alemtuzumab) or by small molecules that mainly act of B and T cell signalling and function by blocking intracellular pathways (e.g. cyclosporine A).
  • Chimeric Antigen Receptors are proteins which, in their usual format, graft the specificity of a monoclonal antibody (mAb) to the effector function of a T-cell.
  • mAb monoclonal antibody
  • Their usual form is that of a type I transmembrane domain protein with an antigen recognizing amino terminus, a spacer, a transmembrane domain all connected to a compound endodomain which transmits T-cell survival and activation signals.
  • the most common form of these molecules use single-chain variable fragments (scFv) derived from monoclonal antibodies to recognize a target antigen.
  • the scFv is fused via a spacer and a transmembrane domain to a signaling endodomain.
  • T cells When T cells express such a CAR, they recognize and kill target cells that express the target antigen.
  • CARs have been developed against tumour associated antigens, and adoptive transfer approaches using such CAR-expressing T cells are currently in clinical trial for the treatment of various cancers.
  • the CD19 antigen expressed by B-cell malignancies was the first clinically applicable target for cancer therapy using autologous CAR T cells. Treatment with T cells genetically equipped with anti-CD19 CARs has led to impressive remission rates in patients with relapsed/refractory B cell malignancies.
  • SLE Systemic lupus erythematosus
  • B cells which lead to progressive tissue destruction due to the deposition of immune complexes.
  • anti-CD19 CAR-T cells deplete B-cells, their use has been suggested as a potential treatment approach for SLE. Tolerability and efficacy were initially tested in a single SLE patient treated with a CD19 CAR (Mougiakakos et al. (2021). N Engl J Med 385(6):567-9).
  • CAR T cell therapy in a small series of seriously ill and treatment-resistant patients with SLE.
  • autologous T cells from five patients with SLE were transduced with a lentiviral anti-CD19 CAR vector, expanded and reinfused at a dose of 1 ⁇ 10 6 CAR T cells per kg body weight into the patients after lymphodepletion with fludarabine and cyclophosphamide.
  • CAR T cells were expanded in vivo and led to deep depletion of B cells with improvement of clinical symptoms and normalization of laboratory parameters including seroconversion of anti-ds DNA antibodies.
  • Plasma cells are the antibody secretors of the immune system. Continuous antibody secretion over years can provide long-term immune protection but can also be responsible for long-lasting autoimmunity in case of self-reactive plasma cells. While CD19 CAR T cell therapy as discussed in the previous section has been shown to improve outcomes in mouse models of lupus, it was found that autoreactive antibodies were eliminated only when CAR-T cells were given at an early course of disease. Later in the disease course, long-lived plasma cells accumulate and lead to persistent autoantibody production despite B-cell depletion.
  • FIGURES Figure 1 - Schematic diagram showing a classical chimeric antigen receptor (a) Basic schema of a chimeric antigen receptor; (b) First generation receptors; (c) Second generation receptors; (d) Third generation receptors.
  • Figure 2 (a) D8-41BB- ⁇ Architecture is a standard CAR.
  • Binding domain is in a scFv format with CD8 stalk as a spacer. This is expressed as a single protein.
  • D8Fab- 41BB- ⁇ architecture is in FabCAR format.
  • two separate proteins comprise the CAR with the VL andKappa common chain as one protein and VH, CH1 and signaling endodomains as the second protein. Both are expressed from a single open reading frame but translated as two separate proteins by use of a foot-and-mouth 2A-like peptide (denoted by scissors).
  • the resulting product will be a mixture of cells which are singly and combinatorially transduced (bottom figure – purple and green gene products).
  • the transduced cells will be a mixture of cells expressing A alone; B alone; and cell expressing both A and B.
  • Figure 4 - (a) Double transduction of normal donor T cells with separate vectors encoding D8Fab-41BB- ⁇ and CAT-41BB- ⁇ .
  • CAR expression on live CD3+ cells were detected by staining with CAT19 anti-idiotype plus anti-Rat-Fc-PE for detection of CAT-41BB- ⁇ , and with BCMA-AviTag + streptavidin-APC for detection of D8Fab- 41BB- ⁇ .
  • Flow cytometry plots from a representative transduction are shown, with mock-transduced (NT) control, D8 single transduction, CAT single transduction, and D8/CAT dual transduction.
  • Right graph shows percentages of D8-CAT-, D8+CAT- , D8+CAT+ and D8-CAT+ cells within the CD3+ population of the transduced PBMCs for 9 donors, with mean + SD shown.
  • FIG. 5 Cytotoxicity and cytokine production of D8, CAT and D8/CAT CAR T cells against target cells which express neither, one or both BCMA and CD19.
  • Viable targets recovered from co-cultures with CAR-transduced T cells were normalised to that recovered from co-cultures with mock-transduced (NT) T cells (%).
  • CTV CellTrace Violet
  • the present inventors have developed a cell composition for the treatment of autoimmune diseases which comprises cells co-expressing two CARs, one which targets CD19 and one which targets B cell maturation antigen (BCMA). Since the cells co-express an anti-CD19 CAR and an anti-BCMA CAR, they target both B cells (via CD19) and plasma cells (via BCMA). This dual targeting is more successful that cells expressing a CD19 CAR alone in removing autoantibody producing cells for the treatment of autoimmune diseases, particularly later in the disease course where autoantibody-secreting plasma cells may exist and predominate.
  • BCMA B cell maturation antigen
  • the present invention provides a method of treating an autoimmune disease in a patient comprising administering to the patient a cell composition made by transducing cells with a mixture of vectors, the mixture comprising: (i) a first vector which expresses a first chimeric antigen receptor (CAR) which binds CD19; and (ii) a second vector which expresses a second CAR which binds B cell maturation antigen (BCMA).
  • a cell composition made by transducing cells with a mixture of vectors, the mixture comprising: (i) a first vector which expresses a first chimeric antigen receptor (CAR) which binds CD19; and (ii) a second vector which expresses a second CAR which binds B cell maturation antigen (BCMA).
  • CAR chimeric antigen receptor
  • BCMA B cell maturation antigen
  • the cell composition comprises a mixture of a) cells transduced with the first vector alone which cells express the anti-CD19 CAR; b) cells transduced with the second vector alone which cells express the anti-BCMA CAR; and c) cells transduced with both the first and second vectors, which cells co-express anti-CD19 and anti-BCMA CARs.
  • the autoimmune disease may be driven by autoantibodies.
  • the cell once administered to the patient, may kill auto-antibody-producing B cells and plasma cells in the patient.
  • the first CAR may comprise a CD19-binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6).
  • VH heavy chain variable region
  • CDRs complementarity determining regions
  • the second CAR may comprise a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12).
  • BCMA B cell maturation antigen
  • the CD19-binding domain of the first CAR may comprise a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14.
  • the first CAR may comprise the sequence shown as 15.
  • the BCMA-binding domain of the second CAR may comprise a VH domain having the sequence shown as SEQ ID No. 16; and a VL domain having the sequence shown as SEQ ID No. 17.
  • the second CAR may comprise the sequence shown as SEQ ID No.18.
  • the autoimmune disease may be selected from the following group: systemic lupus erythematosus (SLE), rheumatoid arthritis, idiopathic inflammatory myopathy (IIM, myositis), ANCA-associated vasculitis, inflammatory bowel disease (IBD), multiple sclerosis (MS), Type I diabetes, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Graves’ disease, Hashimoto’s thyroiditis or Hashimoto’s disease, myasthenia gravis, neuromyelitis optica, N-methyl-D-aspartate receptor (NMDAR) encephalitis, Lambert-Eaton syndrome, scleroderma, vasculitis, pemphigus vulgaris, pemphigus foliaceus, epidermolysis bullosa acquisita, bullous pemphigoid, lupus nephritis, membranous nephropathy, Goodpas
  • the autoimmune disease may be selected from: systemic lupus erythematosus (SLE); lupus nephritis; and membranous nephropathy.
  • the autoimmune disease may be membranous nephropathy.
  • the second vector may comprise a nucleic acid expressing a suicide gene.
  • the first vector may not comprise a nucleic acid expressing a suicide gene, i.e. only the second vector may comprise a nucleic acid expressing a suicide gene.
  • both the first and second vector may comprise a nucleic acid expressing a suicide gene.
  • the suicide gene expressed by the first vector may be the same as, or differed from, the suicide gene expressed by the second vector. Where the suicide genes are different, they may be activated by different agent. For example, one suicide gene may be RQR8 which is activated by rituximab; and the other suicide gene may be RapCsp9, which is activated with rapamycin.
  • a method for selectively deleting anti-BCMA CAR-expressing cells in a patient comprises the step of administering an agent to patient, wherein the patient has previously been administered a CAR- expressing cell composition as defined above, and wherein the agent activates the suicide gene expressed by the second vector.
  • a method for restoring the plasma cell compartment in a patient which has been treated according to the first aspect of the invention comprises the step of administering an agent to the patient which agent activates the suicide gene expressed by the second vector, thereby killing cells in the patient which express the second CAR but sparing cells in the patient which express the first CAR alone.
  • the present invention relates to a method of treating a disease using a cell composition made by transducing cells with a mixture of vectors. When cells are transduced with multiple vectors simultaneously, the resulting product will be a mixture of cells which are singly and combinatorially transduced.
  • the transduced cells will be a mixture of cells expressing A alone; B alone; and cell expressing both A and B.
  • the present invention involves using such a mixture as a therapeutic CAR-T-cell product.
  • the use of a combinatorial product gives in-built flexibility which enhances the product's capacity to adapt to differences in target cell populations in the patient.
  • FURTHER ASPECTS OF THE INVENTION The present invention also relates to further aspects which are summarised in the following numbered paragraphs.
  • CAR first chimeric antigen receptor
  • BCMA B cell maturation antigen
  • the first CAR comprises a CD19-binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6).
  • VH heavy chain variable region
  • CDRs complementarity determining regions
  • the second CAR comprises a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12).
  • BCMA B cell maturation antigen
  • CD19-binding domain of the first CAR comprises a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14.
  • a method according to any preceding paragraph wherein the first CAR comprises the sequence shown as SEQ ID No.15.
  • a method according to any preceding paragraph wherein the BCMA-binding domain of the second CAR comprises a VH domain having the sequence shown as SEQ ID No.16; and a VL domain having the sequence shown as SEQ ID No.17.
  • the second CAR comprises the sequence shown as SEQ ID No.18. A8.
  • the cell comprises a suicide gene.
  • B1 A method of treating an autoimmune disease in a patient by administering to the patient a cell comprising a first chimeric antigen receptor (CAR) and a second CAR, wherein the first CAR targets CD19 and the second CAR has a Fab-type antigen binding domain which binds B cell maturation antigen (BCMA).
  • CAR chimeric antigen receptor
  • B2 B cell maturation antigen
  • the first CAR comprises a CD19-binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6).
  • VH heavy chain variable region
  • CDRs complementarity determining regions
  • the second CAR comprises a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12).
  • BCMA B cell maturation antigen
  • CD19-binding domain of the first CAR comprises a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14. B5.
  • the first CAR comprises the sequence shown as SEQ ID No.15.
  • the BCMA-binding domain of the second CAR comprises a VH domain having the sequence shown as SEQ ID No.16; and a VL domain having the sequence shown as SEQ ID No.17. B7.
  • the second CAR comprises the sequence shown as SEQ ID No.18. B8.
  • the autoimmune disease is selected from: systemic lupus erythematosus (SLE), rheumatoid arthritis, idiopathic inflammatory myopathy (IIM, myositis), ANCA-associated vasculitis, inflammatory bowel disease (IBD), multiple sclerosis (MS), Type I diabetes, Guillain- Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Graves’ disease, Hashimoto’s thyroiditis or Hashimoto’s disease, myasthenia gravis, neuromyelitis optica, N-methyl-D-aspartate receptor (NMDAR) encephalitis, Lambert- Eaton syndrome, scleroderma, vasculitis, pemphigus vulgaris, pemphigus foliaceus, epidermolysis bullosa acquisita, bullous pemphigoid, lupus nephritis, membranous ne
  • SLE systemic lupus
  • autoimmune disease is selected from: systemic lupus erythematosus (SLE); lupus nephritis; and membranous nephropathy.
  • SLE systemic lupus erythematosus
  • lupus nephritis lupus nephritis
  • membranous nephropathy B10.
  • the autoimmune disease is membranous nephropathy.
  • the second vector comprises a nucleic acid expressing a suicide gene.
  • the cell is made by transduction of a cell with a nucleic acid construct which comprises a first nucleic acid sequence encoding the first CAR and a second nucleic acid sequence encoding the second CAR.
  • kit comprises (i) a first vector which comprises a nucleic acid sequence encoding the first CAR; and (ii) a second vector which comprises a nucleic acid sequence encoding the second CAR.
  • the cell comprises a suicide gene.
  • CARS DETAILED DESCRIPTION CHIMERIC ANTIGEN RECEPTORS
  • a classical chimeric antigen receptor is a chimeric type I trans-membrane protein which connects an extracellular antigen-binding domain to an intracellular signaling domain (endodomain).
  • the antigen-binding domain is typically a single- chain variable fragment (scFv) derived from a monoclonal antibody (mAb), but it can be based on other formats which comprise an antibody fragment or an antibody-like antigen-binding site.
  • a natural ligand of the target antigen a peptide with sufficient affinity for the target, a F(ab) fragment, a F(ab’)2 fragment, a F(ab’) fragment, a single domain antibody (sdAb), a domain antibody (dAb), a VHH antigen-binding domain or nanobody, an artificial single binder such as a DARPin (designed ankyrin repeat protein), an affibody, a fibronectin artificial antibody scaffold, an anticalin, an affilin, a VNAR, an iBody, an affimer, a fynomer, an abdurin/ nanoantibody, a centyrin, an alphabody, a nanofitin, or a single- chain derived from a T-cell receptor which is capable of binding the target antigen.
  • DARPin designed ankyrin repeat protein
  • a spacer is usually necessary to isolate the antigen-binding domain from the membrane and to allow it a suitable orientation.
  • a common spacer used is the Fc of IgG1. More compact spacers can suffice, e.g., the stalk from CD8 ⁇ and even just the IgG1 hinge alone, depending on the antigen.
  • a transmembrane domain anchors the protein in the cell membrane and connects the spacer to the endodomain.
  • Early CAR designs had endodomains derived from the intracellular parts of either the ⁇ chain of the Fc ⁇ R1 or CD3 ⁇ ( Figure 1a). These first generation receptors transmitted immunological signal 1, which was sufficient to trigger T-cell killing of cognate target cells but failed to fully activate the T-cell to proliferate and survive.
  • compound endodomains have been constructed: fusion of the intracellular part of a T-cell co-stimulatory molecule to that of CD3 ⁇ results in second generation receptors which can transmit an activating and co-stimulatory signal simultaneously after antigen recognition.
  • One common co-stimulatory domain is that of CD28. This supplies the most potent co-stimulatory signal - namely immunological signal 2, which triggers T-cell proliferation.
  • Some receptors have also been described which include TNF receptor family endodomains, such as the closely related OX40 and 41BB which transmit survival signals (Figure 1b). Even more potent third generation CARs have now been described which have endodomains capable of transmitting activation, proliferation and survival signals (Figure 1c).
  • an activating signal is transmitted to the T- cell on which the CAR is expressed thereby directing the specificity and cytotoxicity of the T cell towards cells expressing the target antigen.
  • CAR-encoding nucleic acids may be transferred to T cells using, for example, retroviral or lentiviral vectors to generate antigen-specific T cells for adoptive cell transfer.
  • the CAR binds the target-antigen, this results in the transmission of an activating signal to the T-cell it is expressed on.
  • the CAR directs the specificity and cytotoxicity of the T cell towards cells expressing the targeted antigen.
  • ANTIGEN BINDING DOMAIN The antigen binding domain is the portion of CAR which recognizes antigen.
  • the antigen-binding domain may comprise: a single-chain variable fragment (scFv) derived from a monoclonal antibody; a natural ligand of the target antigen; a peptide with sufficient affinity for the target; a single domain antibody; an artificial single binder such as a Darpin (designed ankyrin repeat protein); or a single-chain derived from a T-cell receptor.
  • the antigen-binding domain comprises: a single-chain variable fragment (scFv) derived from a monoclonal antibody ( Figure 2a).
  • a FabCAR comprises two chains: one having an antibody-like light chain variable region (VL) and constant region (CL); and one having a heavy chain variable region (VH) and constant region (CH).
  • VL antibody-like light chain variable region
  • CL constant region
  • CH constant region
  • One chain also comprises a transmembrane domain and an intracellular signalling domain. Association between the CL and CH causes assembly of the receptor.
  • the two chains of a Fab CAR may have the general structure: VH - CH - spacer - transmembrane domain - intracellular signalling domain; and VL - CL or VL - CL - spacer- transmembrane domain - intracellular signalling domain; and VH - CH
  • the antigen binding domain is made up of a VH from one polypeptide chain and a VL from another polypeptide chain.
  • the polypeptide chains may comprise a linker between the VH/VL domain and the CH/CL domains. The linker may be flexible and serve to spatially separate the VH/VL domain from the CH/CL domain.
  • Target antigens are an entity which is specifically recognized and bound by the antigen-binding domains of a chimeric receptor provided herein.
  • the target antigen may be an antigen present on an auto-antibody-producing cell, for example, an antigen expressed on B cells and/or plasma cells.
  • BCMA and CD19 are target antigens contemplated herein. Binding domains specific for BCMA target antigen
  • the B cell maturation target also known as BCMA; TR17_HUMAN, TNFRSF17 (UniProt Accession No.
  • BCMA transmembrane protein that is expressed in mature lymphocytes, e.g., memory B cells, plasmablasts and bone marrow plasma cells. BCMA is also expressed on myeloma cells. BCMA is a non- glycosylated type III transmembrane protein, which is involved in B cell maturation, growth and survival. An antigen binding domain of a CAR which binds to BCMA may be any domain which is capable of binding BCMA.
  • the VH and VL sequences for fourteen anti-BCMA antibodies are given below with CDR sequences in bold and underlined. The sequence of BCMA is depicted under UniProt Accession No.
  • BCMA is an excellent MM target since it is expressed on practically all cases of MM and expression is otherwise restricted to normal plasma cells. However, it is a low- density antigen, so a key consideration in selecting a BCMA CAR was sensitivity to low antigen density.
  • a number of BCMA-targeted CARs are in clinical development, including bb2121, LCAR-B38M, MCARH171, JCARH125, P-BCMA-101, FCARH143, bb21217 and CT053.
  • WO2015/052538 describes a BCMA targeted CAR in which the antigen-binding domain is derived from APRIL, which is a natural ligand for BCMA.
  • WO2020/065330 which is incorporated herein by reference, describes the VH and VL domains for 14 BCMA binding domains and their use in CARs.
  • the BCMA antigen-binding domain may comprise: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 - GFIFSDYN (SEQ ID NO: 7) CDR2 - IIYDGSST (SEQ ID NO: 8) CDR3 - ATRPGPFAY (SEQ ID NO: 9); and b) a light chain variable region (VL) having complementarity determining regions (CDRs) with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID NO: 10) CDR2 - LVS (SEQ ID NO: 11) CDR3 - VHGTHAWT (SEQ ID NO: 12).
  • the BCMA antigen-binding domain may comprise the following VH domain.
  • D8 VH domain (SEQ ID NO: 16) EVQLVESGGGLVQPGRSLKLSCAASGFIFSDYNMAWVRQAPKKGLEWVATIIYDGS STNHGDSVKGRFTISRDNAKSTLYLQMDSLRSEDTATYYCATRPGPFAYWGQGTLV TVS
  • the BCMA antigen-binding domain may comprise the following VL domain.
  • the BCMA antigen-binding domain may comprise an anti-BCMA Fab CAR.
  • the BCMA antigen-binding domain may comprise the following heavy chain (VH- CH1) sequence: D8 heavy chain (SEQ ID NO: 19) EVQLVESGGGLVQPGRSLKLSCAASGFIFSDYNMAWVRQAPKKGLEWVATIIYDGS STNHGDSVKGRFTISRDNAKSTLYLQMDSLRSEDTATYYCATRPGPFAYWGQGTLV TVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHT FPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRV
  • the BCMA antigen-binding domain may comprise the following light chain (VL- Ckappa) sequence: D8 light chain (SEQ ID NO: 20) DVVLTQTPPTLSATIGQSVSISCRSSQSLLHSNGNTYLHWLLQRPGQSPQFLIYLVS GLGSGVPNRFSGSGSGTDFTLKISGVEAEDLGIYYCVHG
  • the BCMA antigen-binding domain may be any domain which is capable of binding BCMA.
  • the VH and VL sequences for twelve anti-BCMA antibodies are given below with CDR sequences in bold and underlined.
  • SEQ ID NO: 23 (anti-BCMA Ab1 VH) QIQLVQSGPELVKPGSSVKLSCKTSGFTFSDSYMSWLKQVPGQSIEWIGNIYAGDG ATHYHQKFKGKATLTVDTSSSTAYMDLSSLTSEDSALYFCARPLYTTAYYYVGGFA YWGQGTLVTVSS
  • SEQ ID NO: 24 (anti-BCMA Ab1 VL) DIVMTQSPSSLAVSAGETVTINCKSSQSLLSSGNQKNYLAWYQQKPGQSPKLLIYW ASTRQSGVPDRFIGSGSGTDFTLTISSVQAEDLAIYYCQQYYDTPLTFGSGTKLEIK
  • SEQ ID NO: 25 (anti-BCMA Ab2 VH) EVK
  • the BCMA binder may have a kinetic affinity (KD) of 10nM or less, or 5nM or less, or 1nM or less, or 0.5nM or less, or 0.1nM or less.
  • KD kinetic affinity
  • the CAR may be used in a combination with one or more other activating or inhibitory chimeric antigen receptors. For example, they may be used in combination with one or more other CARs in a “logic-gate”, a CAR combination which, when expressed by a cell, such as a T cell, are capable of detecting a particular pattern of expression of at least two target antigens.
  • the three possible options are as follows: “OR GATE” – T cell triggers when either antigen A or antigen B is present on the target cell “AND GATE” – T cell triggers only when both antigens A and B are present on the target cell “AND NOT GATE” – T cell triggers if antigen A is present alone on the target cell, but not if both antigens A and B are present on the target cell.
  • Engineered T cells expressing these CAR combinations can be tailored to be adequately specific for target cells, based on their particular expression (or lack of expression) of two or more markers.
  • An “OR Gate” comprises two or more activatory CARs each directed to a distinct target antigen expressed by a target cell.
  • the advantage of an OR gate is that the effective targetable antigen is increased on the target cell, as it is effectively antigen A + antigen B. This is especially important for antigens expressed at variable or low density on the target cell, as the level of a single antigen may be below the threshold needed for effective targeting by a CAR-T cell. Also, it avoids the phenomenon of antigen escape.
  • some diseases may become BCMA negative after BCMA targeting: using an OR gate which targets BCMA in combination with another antigen provides a “back-up” antigen, should this occur.
  • the OR gate may comprise a CAR against a second antigen expressed in the same or different target cells, such as CD19.
  • the second CAR may have any suitable antigen binding domain, for example a binding domain based on an scFv, a domain antibody (dAb) or a Fab.
  • the antigen-binding domains of the first and second CARs bind to different antigens and both CARs may comprise an activating endodomain.
  • the two CARs may comprise spacer domains which may be the same, or sufficiently different to prevent cross-pairing of the two different receptors.
  • a cell can hence be engineered to activate upon recognition of either or both BCMA and CD19.
  • the first and second CAR of the T cell may be produced as a polypeptide comprising both CARs, together with a cleavage site.
  • Binding domains specific for CD19 target antigen The human CD19 antigen is a 95 kd transmembrane glycoprotein belonging to the immunoglobulin superfamily.
  • CD19 is classified as a type I transmembrane protein, with a single transmembrane domain, a cytoplasmic C-terminus, and extracellular N- terminus. CD19 is expressed very early in B-cell differentiation and is only lost at terminal B-cell differentiation into plasma cells.
  • CD19 is a biomarker for normal B cells as well as follicular dendritic cells.
  • CD19 primarily acts as a B cell co-receptor in conjunction with CD21 and CD81.
  • the cytoplasmic tail of CD19 becomes phosphorylated, which leads to binding by Src-family kinases and recruitment of PI-3 kinase.
  • CD19 is also expressed on all B-cells but not plasma cells. It is not expressed on other haematopoietic populations or non-haematopoietic cells and therefore targeting this antigen should not lead to toxicity to the bone marrow or non-haematopoietic organs.
  • CD19 CAR Loss of the normal B-cell compartment is considered an acceptable toxicity when treating lymphoid malignancies, because although effective CD19 CAR T cell therapy will result in B cell aplasia, the consequent hypogammaglobulinaemia can be treated with pooled immunoglobulin.
  • Different designs of CARs have been tested against CD19 in various clinical trials, as outlined in the following Table 2.
  • Table 2 As shown above, most of the studies conducted to date have used an scFv derived from the hybridoma fmc63 as part of the binding domain to recognize CD19.
  • the antigen-binding domain of a CAR which binds to CD19 (referred to as a CD19 CAR herein) may be any domain which is capable of binding CD19.
  • the antigen-binding domain may comprise a CD19 antigen-binding domain as described in Table 3.
  • Table 3 The gene encoding CD19 comprises ten exons: exons 1 to 4 encode the extracellular domain; exon 5 encodes the transmembrane domain; and exons 6 to 10 encode the cytoplasmic domain.
  • the antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 1 of the CD19 gene.
  • the antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 2 of the CD19 gene.
  • the antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 3 of the CD19 gene.
  • the antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 4 of the CD19 gene.
  • a CD19-binding domain exemplified herein comprises variable regions with complementarity determining regions (CDRs) from an antibody referred to as CAT19, a) a heavy chain variable region (VH) having CAT19 CDRs with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1); CDR2 – YPGDED (SEQ ID NO: 2) CDR3 – SLLYGDYLDY (SEQ ID NO: 3); and b) a light chain variable region (VL) having CAT 19 CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4); CDR2 – DTSKLAS (SEQ ID NO: 5) CDR3 – QQWNINPLT (SEQ ID NO: 6).
  • CDRs complementarity determining regions
  • the CAT19 antibody is described in WO2016/139487. It is contemplated that one or more mutations (substitutions, additions or deletions) can be introduced into one or more CDRs without negatively affecting CD19-binding activity.
  • Each CDR may, for example, have one, two or three amino acid mutations.
  • the CDRs may be in the format of a single-chain variable fragment (scFv), which is a fusion protein of the heavy variable region (VH) and light chain variable region (VL) of an antibody, connected with a short linker peptide of ten to about 25 amino acids.
  • scFv single-chain variable fragment
  • VH heavy variable region
  • VL light chain variable region
  • the scFv may be in the orientation VH-VL, i.e., the VH is at the amino-terminus of the CAR molecule and the VL domain is linked to the spacer and, in turn the transmembrane domain and endodomain.
  • the CDRs may be grafted on to the framework of a human antibody or scFv.
  • the CAR may comprise a CD19-binding domain consisting or comprising one of the following sequences.
  • the CD19 CAR may comprise the following VH sequence.
  • CD19 CAR may comprise the following VL sequence.
  • CD19 CAR may comprise the following scFv sequence.
  • the CAR may consist of or comprise one of the following sequences.
  • the CAR provided herein may comprise a variant of the polypeptide of SEQ ID NO: 1-6, 13-15 or 47 having at least 80, 85, 90, 95, 98 or 99% sequence identity, provided that the variant sequence retain the capacity to bind CD19 (when in conjunction with a complementary VL or VH domain, if appropriate).
  • the percentage identity between two polypeptide sequences may be readily determined by programs such as BLAST which is freely available at http://blast.ncbi.nlm.nih.gov.
  • the CD19 CAR exemplified herein i.e., the CAT19 CAR, SEQ ID NO: 15
  • the CAT19 CAR exemplified herein effects killing of target cells expressing CD19 and proliferates in response to CD19 expressing targets, but releases less Interferon-gamma.
  • a small animal model of an aggressive B-cell lymphoma showed equal efficacy and equal engraftment between the fmc63- and CAT19-based CAR-T cells, but surprisingly, less of the CAT19 CAR T-cells were exhausted than fmc63 CAR T-cells. See, Examples 2 and 3 of US Publication No.: 2018-0044417.
  • the CAT19 CAR provided herein may cause 25, 50, 70 or 90% lower IFN ⁇ release in a comparative assay involving bringing CAR T cells into contact with target cells.
  • the CAT19 CAR provided herein may result in a smaller proportion of CAR T cells becoming exhausted than equivalent fmc63 CAR T cells. T cell exhaustion may be assessed using methods known in the art, such as analysis of PD-1 expression.
  • the CAR may cause 20, 30, 40, 50, 60 of 70% fewer CAR T cells to express PD-1 that fmc63 CAR T cells in a comparative assay involving bringing CAR T cells into contact with target cells.
  • CD19 antigen-binding domain is based on the CD19 antigen-binding domain CD19ALAb (described in WO2016/102965) and comprises: a) a heavy chain variable region (VH) having CDRs with the following sequences: CDR1 – SYWMN (SEQ ID NO: 48); CDR2 – QIWPGDGDTNYNGKFK (SEQ ID NO: 49) CDR3 – RETTTVGRYYYAMDY (SEQ ID NO: 50); and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – KASQSVDYDGDSYLN (SEQ ID NO: 51); CDR2 – DASNLVS (SEQ ID NO: 52) CDR3 – QQSTEDPWT (SEQ ID NO: 53).
  • VH heavy chain variable region
  • VL light chain variable region having CDRs with the following sequences: CDR1 – KASQSVDYDGDSYLN (SEQ ID NO
  • Each CDR may, for example, have one, two or three amino acid mutations.
  • the CAR may comprise one of the following amino acid sequences.
  • SEQ ID NO: 54 Murine CD19ALAb scFv sequence QVQLQQSGAELVRPGSSVKISCKASGYAFSSYWMNWVKQRPGQGLEWIGQIWPG DGDTNYNGKFKGKATLTADESSSTAYMQLSSLASEDSAVYFCARRETTTVGRYYYA MDYWGQGTTVTVSSDIQLTQSPASLAVSLGQRATISCKASQSVDYDGDSYLNWYQ QIPGQPPKLLIYDASNLVSGIPPRFSGSGSGTDFTLNIHPVEKVDAATYHCQQSTEDP WTFGGGTKLEIK SEQ ID NO: 55 – Humanized CD19ALAb scFv sequence – Heavy 19, Kappa 16 QVQLVQSGAEVKKPGASVKLSCKASGYAFSSYWMNWVRQAPGQSLEWIGQIWPG DGDTNYNGKFKGRATLTADESARTAYMELSSLRSGDTAVYFCARRETTTVGRYY
  • the CAR may comprise one of the following VH sequences: SEQ ID NO: 57 – Murine CD19ALAb VH sequence QVQLQQSGAELVRPGSSVKISCKASGYAFSSYWMNWVKQRPGQGLEWIGQIWPG DGDTNYNGKFKGKATLTADESSSTAYMQLSSLASEDSAVYFCARRETTTVGRYYYA MDYWGQGTTVTVSS SEQ ID NO: 58 – Humanized CD19ALAb VH sequence QVQLVQSGAEVKKPGASVKLSCKASGYAFSSYWMNWVRQAPGQSLEWIGQIWPG DGDTNYNGKFKGRATLTADESARTAYMELSSLRSGDTAVYFCARRETTTVGRYYYA MDYWGKGTLVTVSS
  • the CAR may comprise one of the following VL sequences: SEQ ID NO: 59 – Murine CD19ALAb VL sequence DIQLTQSPASLAVSLGQRATISCKASQSVDYDGDSYL
  • the percentage identity between two polypeptide sequences may be readily determined by programs such as BLAST which is freely available at blast.ncbi.nlm.nih.gov.
  • SIGNAL PEPTIDES The CARs of the cell may comprise a signal peptide so that when the CAR is expressed inside a cell, such as a T-cell, the nascent protein is directed to the endoplasmic reticulum and subsequently to the cell surface, where it is expressed.
  • the core of the signal peptide may contain a long stretch of hydrophobic amino acids that has a tendency to form a single alpha-helix.
  • the signal peptide may begin with a short positively charged stretch of amino acids, which helps to enforce proper topology of the polypeptide during translocation.
  • signal peptide there is typically a stretch of amino acids that is recognized and cleaved by signal peptidase.
  • Signal peptidase may cleave either during or after completion of translocation to generate a free signal peptide and a mature protein.
  • the free signal peptides are then digested by specific proteases.
  • the signal peptide may be at the amino terminus of the molecule.
  • the signal peptide may comprise the amino acid sequence of any of SEQ ID NO: 62- 67 or a variant thereof having 5, 4, 3, 2 or 1 amino acid mutations (insertions, substitutions or additions) provided that the signal peptide still functions to cause cell surface expression of the CAR.
  • the signal peptide of SEQ ID NO: 62 is compact and highly efficient.
  • SEQ ID NO: 62 MGTSLLCWMALCLLGADHADA
  • the signal peptide of SEQ ID NO: 63 follows. METDTLLLWVLLLLVPGSTG
  • the signal peptide of SEQ ID NO: 64 follows.
  • the signal peptide of SEQ ID NO: 65 follows.
  • the signal peptide of SEQ ID NO: 66 is derived from IgG1.
  • the signal peptide of SEQ ID NO: 67 is derived from CD8.
  • SEQ ID NO: 67 MAVPTQVLGLLLLWLTDARC
  • the signal peptide for the first CAR may have a different sequence from the signal peptide of the second CAR.
  • SPACERS CARs comprise a spacer to connect the antigen-binding domain with the transmembrane domain and spatially separate the antigen-binding domain from the endodomain.
  • a flexible spacer allows the antigen-binding domain to orient in different directions to facilitate binding.
  • the spacer may, for example, comprise an IgG1 Fc region, an IgG1 hinge or a CD8 stalk, or a combination thereof.
  • the spacer may alternatively comprise an alternative sequence which has similar length and/or domain spacing properties as an IgG1 Fc region, an IgG1 hinge or a CD8 stalk.
  • the first and second CARs may comprise different spacer molecules.
  • the spacer may, for example, comprise an IgG1 Fc region, an IgG1 hinge or a human CD8 stalk or the mouse CD8 stalk.
  • the spacer may alternatively comprise an alternative linker which has similar length and/or domain spacing properties as an IgG1 Fc region, an IgG1 hinge or a CD8 stalk.
  • a human IgG1 spacer may be altered to remove Fc binding motifs.
  • the spacer for the CD19 CAR may comprise a CD8 stalk spacer, or a spacer having a length equivalent to a CD8 stalk spacer.
  • the spacer for the CD19 CAR may have at least 30 amino acids or at least 40 amino acids. It may have between 35-55 amino acids, for example between 40-50 amino acids. It may have about 46 amino acids.
  • the spacer for the BCMA CAR may comprise an IgG1 hinge spacer, or a spacer having a length equivalent to an IgG1 hinge spacer.
  • the spacer for the BCMA CAR may have fewer than 30 amino acids or fewer than 25 amino acids. It may have between 15-25 amino acids, for example between 18-22 amino acids. It may have about 20 amino acids.
  • SEQ ID NO: 68 (hinge-CH2CH3 of human IgG1) AEPKSPDKTHTCPPCPAPPVAGPSVFLFPPKPKDTLMIARTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKA LPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESN GQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGKKD
  • SEQ ID NO: 69 (human CD8 stalk): TTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACD
  • SEQ ID NO: 70 (human IgG1 hinge): AEPKSPDKTHTCPPCPKDPK SEQ ID NO: 71 (human IgG1 hinge): AEPKSPDKTHT
  • SEQ ID NO: 74 (CD2 ectodomain) KEITNALETWGALGQDINLDIPSFQMSDDIDDIKWEKTSDKKKIAQFRKEKETFKEKD TYKLFKNGTLKIKHLKTDDQDIYKVSIYDTKGKNVLEKIFDLKIQERVSKPKISWTCINT TLTCEVMNGTDPELNLYQDGKHLKLSQRVITHKWTTSLSAKFKCTAGNKVSKESSV EPVSCPEKGLD SEQ ID NO: 75 (CD34 ectodomain) SLDNNGTATPELPTQGTFSNVSTNVSYQETTTPSTLGSTSLHPVSQHGNEATTNITE TTVKFTSTSVITSVYGNTNSSVQSQTSVISTVFTTPANVSTPETTLKPSLSPGNVSDL STTSTSLATSPTKPYTSSSPILSDIKAEIKCSGIREVKLTQGICLEQNKTSSCAEFKKD RGEGLARVLCGEEQADADAGAQVC
  • the epitope may not be at the same “level” on the target cell so that a cross-paired CAR may only be able to bind to one antigen; (2) the VH and VL from the two different scFv could swap over and either fail to recognize target or worse recognize an unexpected and unpredicted antigen.
  • the spacer of the first CAR may be sufficiently different from the spacer of the second CAR in order to avoid cross- pairing.
  • the amino acid sequence of the first spacer may share less than 50%, 40%, 30% or 20% identity at the amino acid level with the second spacer.
  • TRANSMEMBRANE DOMAINS The transmembrane domain is the domain of the CAR that spans the membrane.
  • a transmembrane domain may be any protein structure which is thermodynamically stable in a membrane. This is typically an alpha helix comprising of several hydrophobic residues.
  • the transmembrane domain of any transmembrane protein can be used to supply the transmembrane portion provided herein.
  • the presence and span of a transmembrane domain of a protein can be determined by those skilled in the art using the TMHMM algorithm (http://www.cbs.dtu.dk/services/TMHMM-2.0/).
  • transmembrane domain of a protein is a relatively simple structure, i.e, a polypeptide predicted to form a hydrophobic alpha helix of sufficient length to span the membrane
  • an artificially designed transmembrane domain may also be used (US 7052906 B1 describes synthetic transmembrane components).
  • the transmembrane domain may be derived from CD28, which gives good receptor stability.
  • the CD28 transmembrane domain sequence is shown as SEQ ID NO: 76 SEQ ID NO: 76 FWVLVVVGGVLACYSLLVTVAFIIFWV
  • the transmembrane domain may be derived from human Tyrp-1.
  • the tyrp-1 transmembrane domain sequence is shown as SEQ ID NO: 77.
  • the transmembrane domain may be derived from CD8A.
  • the CD8A transmembrane domain sequence is shown as SEQ ID NO: 78.
  • SEQ ID NO: 78 IYIWAPLAGTCGVLLLSLVITLYC ENDODOMAINS
  • the endodomain is the signal-transmission portion of the CAR. After antigen recognition, receptors cluster, native CD45 and CD148 are excluded from the synapse and a signal is transmitted to the cell.
  • the most commonly used endodomain component is that of CD3-zeta which contains three ITAMs. This transmits an activation signal to the T cell after antigen is bound.
  • CD3-zeta may not provide a fully competent activation signal and additional co-stimulatory signaling may be needed.
  • chimeric CD28 and OX40 can be used with CD3-Zeta to transmit a proliferative / survival signal, or all three can be used together.
  • the cells provided herein comprise two CARs, each with an endodomain.
  • the endodomain of the first CAR and the endodomain of the second CAR may comprise: (i) an ITAM-containing endodomain, such as the endodomain from CD3 zeta; and/or (ii) a co-stimulatory domain, such as the endodomain from CD28; and/or (iii) a domain which transmits a survival signal, for example a TNF receptor family endodomain such as OX-40 or 4-1BB.
  • the endodomain of the CAR of the present disclosure may comprise combinations of one or more of the CD3-Zeta endodomain, the 41BB endodomain, the OX40 endodomain or the CD28 endodomain.
  • the intracellular T-cell signalling domain (endodomain) of the CAR of the present disclosure may comprise the sequence shown as any of SEQ ID NO: 79-86 or a variant thereof having at least 80% sequence identity.
  • SEQ ID NO: 79 CD3 zeta endodomain
  • SEQ ID NO: 80 (41BB endodomain) KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL
  • SEQ ID NO: 81 OX40 endodomain
  • SEQ ID NO: 82 CD28 endodomain
  • SEQ ID NO: 83 (41BB-Zeta endodomain fusion) KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCELRVKFSRSADAPAYQ QGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMA EAYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR SEQ ID NO: 84 (OX40-Zeta endodomain fusion) RRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKIRVKFSRSADAPAYQQGQN QLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAEAYS EIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR SEQ ID NO: 85 (CD28Zeta endodomain fusion) KRSRLLHSDY
  • nucleic acid(s) provided herein encode a BCMA CAR and a CD19 CAR of the disclosure.
  • polynucleotide As used herein, the terms “polynucleotide”, “nucleotide”, and “nucleic acid” are intended to be synonymous with each other.
  • the nucleic acid may be, for example, an RNA, a DNA or a cDNA.
  • Nucleic acids may comprise DNA or RNA. They may be single-stranded or double-stranded. They may also be polynucleotides which include within them synthetic or modified nucleotides. A number of different types of modification to oligonucleotides are known in the art.
  • polynucleotides may be modified by any method available in the art. Such modifications may be carried out in order to enhance the in vivo activity or life span of polynucleotides of interest.
  • Alternative codons may be used in regions of sequence encoding the same or similar amino acid sequences, in order to avoid homologous recombination when the both CARs are encoded by the same vector. Due to the degeneracy of the genetic code, it is possible to use alternative codons which encode the same amino acid sequence.
  • RNA codons “ccg” and “cca” both encode the amino acid proline, so using “ccg” may be exchanged for “cca” without affecting the amino acid in this position in the sequence of the translated protein.
  • Table 4 Alternative codons may be used in the portions of nucleic acid which encode the spacer of the first CAR and the spacer of the second CAR, especially if the same or similar spacers are used in the first and second CARs.
  • Alternative codons may be used in the portions of nucleic acid which encode the transmembrane domain of the first CAR and the transmembrane of the second CAR, especially if the same or similar transmembrane domains are used in the first and second CARs.
  • Alternative codons may be used in one or more nucleic acids which encode co- stimulatory domains, such as the CD28 endodomain.
  • Alternative codons may be used in one or more domains which transmit survival signals, such as OX40 and 41BB endodomains.
  • nucleic acid encoding a CD3zeta endodomain and/or the portions of nucleic acid encoding one or more costimulatory domain(s) and/or the portions of nucleic acid encoding one or more domain(s) which transmit survival signals.
  • NUCLEIC ACID CONSTRUCT The present disclosure also provides a nucleic acid construct encoding a chimeric receptor of the disclosure.
  • a nucleic acid construct encoding a FabCAR may have the structure: VH-CH-spacer-TM-endo-coexpr-VL-CL or VL-CL-spacer-TM-endo-coexpr-VH-CH in which: VH is a nucleic acid sequence encoding a heavy chain variable region; CH is a nucleic acid sequence encoding a heavy chain constant region spacer is a nucleic acid encoding a spacer; TM is a a nucleic acid sequence encoding a transmembrane domain; endo is a nucleic acid sequence encoding an endodomain; coexpr is a nucleic acid sequence enabling co-expression of the first and second polypeptides; VL is a nucleic acid sequence encoding a light chain variable region; and CL is a nucleic acid sequence encoding a light chain constant region.
  • nucleic acid sequences encoding the two polypeptides may be in either order in the construct.
  • nucleic acid construct encoding an OR gate which comprises two of more CARs, one of which may be a FabCAR according to the present disclosure.
  • a nucleic acid construct encoding a double OR gate may have the structure: VH-CH-spacer1-TM1-endo1-coexpr1-VL-CL-coexpr2-AgBD-spacer2-TM2-endo2; or VL-CL-spacer-TM1-endo1-coexpr1-VH-CH-coexpr2-AgBD-spacer2-TM2-endo2 in which: VH is a nucleic acid sequence encoding a heavy chain variable region of the first CAR; CH is a nucleic acid sequence encoding a heavy chain constant region of the first CAR; Spacer 1 is a nucleic acid sequence encoding a spacer of the first CAR; TM1 is a a nucleic acid sequence encoding a transmembrane domain of the first CAR; Endo1 is a nucleic acid sequence encoding an endodomain of the first CAR; Coexpr1 and coexpr2, which my be the same
  • the antigen-binding domain of the second CAR may, for example, be an scFv or a domain antibody or single domain antibody dAb.
  • nucleic acid sequences encoding the two polypeptides of the first CAR; and the nucleic acid sequences encoding the first and second CARs may be in any order in the construct.
  • a nucleic acid construct encoding a double FabCAR OR gate may have the structure: VH1-CH1-spacer1-TM1-endo1-coexpr1-VL1-CL1-coexpr2-VH2-CH2-spacer2-TM2- endo2-coexpr3-VL2-CL2; VH1-CH1-spacer1-TM1-endo1-coexpr1-VL1-CL1-coexpr2-VL2-CL2-spacer2-TM2- endo2-coexpr3-VH2-CH2; VL1-CL1-spacer1-TM1-endo1-coexpr1-VH1-CH1-coexpr2-VL2-CL2-spacer2-TM2- endo2-coexpr3-VH2-CH2; or VL1-CL1-spacer1-TM1-endo1-coexpr1-VH1-CH1-coexpr2-VH2-CH2-spacer2-TM2- end
  • nucleic acids As used herein, the terms “polynucleotide”, “nucleotide”, and “nucleic acid” are intended to be synonymous with each other. It will be understood by a skilled person that numerous different polynucleotides and nucleic acids can encode the same polypeptide as a result of the degeneracy of the genetic code. In addition, it is to be understood that skilled persons may, using routine techniques, make nucleotide substitutions that do not affect the polypeptide sequence encoded by the polynucleotides described here to reflect the codon usage of any particular host organism in which the polypeptides are to be expressed. Nucleic acids according to the disclosure may comprise DNA or RNA. They may be single-stranded or double-stranded.
  • polynucleotides which include within them synthetic or modified nucleotides.
  • a number of different types of modification to oligonucleotides are known in the art. These include methylphosphonate and phosphorothioate backbones, addition of acridine or polylysine chains at the 3’ and/or 5’ ends of the molecule.
  • the polynucleotides may be modified by any method available in the art. Such modifications may be carried out in order to enhance the in vivo activity or life span of polynucleotides of interest.
  • variant in relation to a nucleotide sequence include any substitution of, variation of, modification of, replacement of, deletion of or addition of one (or more) nucleic acid from or to the sequence.
  • coexpr is a nucleic acid sequence enabling co-expression of two polypeptides as separate entities. It may be a sequence encoding a cleavage site, such that the nucleic acid construct produces both polypeptides, joined by a cleavage site(s). The cleavage site may be self-cleaving, such that when the polypeptide is produced, it is immediately cleaved into individual peptides without the need for any external cleavage activity.
  • the cleavage site may be any sequence which enables the two polypeptides to become separated.
  • the term “cleavage” is used herein for convenience, but the cleavage site may cause the peptides to separate into individual entities by a mechanism other than classical cleavage.
  • FMDV Foot-and-Mouth disease virus
  • various models have been proposed for to account for the “cleavage” activity: proteolysis by a host-cell proteinase, autoproteolysis or a translational effect (Donnelly et al (2001) J. Gen. Virol. 82:1027-1041).
  • cleavage refers to a peptide which functions such that when the polypeptide comprising the proteins and the self-cleaving peptide is produced, it is immediately “cleaved” or separated into distinct and discrete first and second polypeptides without the need for any external cleavage activity.
  • the self-cleaving peptide may be a 2A self-cleaving peptide from an aphtho- or a cardiovirus.
  • the primary 2A/2B cleavage of the aptho- and cardioviruses is mediated by 2A “cleaving” at its own C-terminus.
  • apthoviruses such as foot-and-mouth disease viruses (FMDV) and equine rhinitis A virus
  • the 2A region is a short section of about 18 amino acids, which, together with the N-terminal residue of protein 2B (a conserved proline residue) represents an autonomous element capable of mediating “cleavage” at its own C-terminus (Donelly et al (2001) as above).
  • a nucleic acid construct may also comprise a nucleic acid encoding a suicide gene.
  • HSV-TK Herpes Virus Thymidine Kinase
  • iCasp9 is activated by an otherwise inert small molecular chemical inducer of dimerization (CID).
  • CID small molecular chemical inducer of dimerization
  • iCasp9 has been recently tested in the setting of haploidentical HSCT and can abort GvHD.
  • Both iCasp9 and HSV-TK are intracellular proteins, so when used as the sole transgene, they have been co-expressed with a marker gene to allow selection of transduced cells.
  • WO2016/135470 describes a suicide gene which also comprises Caspase 9 but can be induced to dimerise using rapamycin or a rapamycin analog. This suicide gene, sometimes termed Rapcasp9 or Rapacasp9, has the amino acid sequence shown as SEQ ID No.89.
  • the sort/suicide gene RQR8 has the amino acid sequence shown as SEQ ID No.79.
  • SEQ ID No.79 (RQR8) CPYSNPSLCSGGGGSELPTQGTFSNVSTNVSPAKPTTTACPYSNPSLCSGGGGSP APRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACDIYIWAPLAGTCGVLLLS LVITLYCNHRNRRRVCKCPRPVVV
  • Including a suicide gene in one or more of the vectors in the viral vector composition of the invention enables the selective ablation of a proportion of transduced cells within the subject.
  • transduced cells will be a mixture of cells transduced with vector A alone, cells transduced with vector B alone, and cells transduced with both vectors A and B.
  • vector A expresses or co-expresses a suicide gene
  • activating the suicide gene will cause the deletion of cells transduced with vector A alone, or with vectors A and B, but cells transduced with vector B alone will be spared.
  • This is particularly useful in the treatment of autoantibody-driven autoimmune diseases as it may desirable avoid a long-lasting complete absence of plasma cells.
  • antibody secretion by plasma cells is the corner-stone of long- term immune protection resulting from previous antigen exposure and immunisation.
  • both the vector expressing the CD19 CAR and the BCMA CAR may comprise a nucleic acid encoding a suicide gene, which may be the same or different.
  • the present disclosure also provides a vector, or kit of vectors which comprises one or more CAR-encoding nucleic acid(s).
  • a vector may be used to introduce the nucleic acid(s) into a host cell so that it expresses the first and second CARs.
  • the vector may, for example, be a plasmid or a viral vector, such as a retroviral vector or a lentiviral vector, or a transposon-based vector or synthetic mRNA.
  • the vector may be capable of transfecting or transducing a T cell.
  • a viral vector composition which comprises two vectors: a first vector which comprises a nucleic acid sequence encoding an anti-CD19 CAR and a second vector which comprises a nucleic acid sequence encoding an anti-BCMA CAR.
  • Transduction of cells with the viral vector composition will produce a combinatorially transduced cell product which comprises the following cell subpopulations: a) cell which express the anti-CD19 CAR alone; b) cells which express the anti-BCMA CAR alone; and c) cells which co-express the anti-CD19 CAR and anti-BCMA CAR.
  • CELLS Cells are provided herein which co-express a first CAR and a second CAR, wherein one CAR binds BCMA and the other CAR binds CD19, such that the cell recognizes a target cell expressing either of these markers.
  • a combinatorial CAR-expressing cell product is also provided which comprise cells which co-express a BCMA CAR and a CD19 CAR, as well as cells that express the BCMA CAR alone and cells that express the CD19 CAR alone. Dual targeting of two antigens has various advantages: 1. In the treatment of autoimmune diseases, the CAR-expressing cells will target both B cells and plasma cells, leading to more efficient cessation of the production of autoantibodies. 2.
  • Dual targeting enables “piggybacking” of BCMA specificity onto long persisting CD19 CAR T cells.
  • CAT19 CAR T-cell persistence is well demonstrated.
  • Reported BCMA CAR T-cell persistence is typically short-lived which is likely to be due to reduced signaling due to low BCMA target density.
  • Cells which co-express CD19 and BCMA CARS are more likely to survive and persist in vivo than cells which express BCMA-CAR alone due to the prevalence of the CD19 antigen.
  • Using a mixed population of cells which comprises cells which co-express a BCMA CAR and a CD19 CAR, as well as cells that express the BCMA CAR alone and cells that express the CD19 CAR alone is also associated with various advantages: 1.
  • a suicide gene can be used on one vector, or different suicide genes on the two vectors, facilitating selective removal of a sub-population of CAR-expressing cells without killing all CAR-expressing cells 2. Flexibility in CAR expression and/or stoichiometry enables in vivo evolution to occur, meaning that cells with the optimal ratio of expression or co-expression for CAR-T persistence and engraftment will win out. 3. Immune response against the transgene products may be reduced. If two potentially immunogenic binders are encoded in the same expression cassette, the probability of triggering and immune response doubles. With double transduction the probability that at least one population will persist increases.
  • the cell may be any eukaryotic cell capable of expressing a CAR at the cell surface, such as an immunological cell.
  • the cell may be an immune effector cell such as a T cell or a natural killer (NK) cell.
  • T cells or T lymphocytes are a type of lymphocyte that play a central role in cell- mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells (NK cells), by the presence of a T-cell receptor (TCR) on the cell surface.
  • TCR T-cell receptor
  • T cell There are various types of T cell, as summarized below.
  • Helper T helper cells TH cells
  • helper T helper cells assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages.
  • TH cells express CD4 on their surface.
  • TH cells become activated when they are presented with peptide antigens by MHC class II molecules on the surface of antigen presenting cells (APCs). These cells can differentiate into one of several subtypes, including TH1, TH2, TH3, TH17, Th9, or TFH, which secrete different cytokines to facilitate different types of immune responses. Cytotoxic T cells (TC cells, or CTLs) destroy virally infected cells and tumor cells, and are also implicated in transplant rejection. CTLs express the CD8 at their surface. These cells recognize their targets by binding to antigen associated with MHC class I, which is present on the surface of all nucleated cells.
  • APCs antigen presenting cells
  • Memory T cells are a subset of antigen-specific T cells that persist long-term after an infection has resolved. They quickly expand to large numbers of effector T cells upon re-exposure to their cognate antigen, thus providing the immune system with “memory” against past infections.
  • Memory T cells comprise three subtypes: central memory T cells (TCM cells) and two types of effector memory T cells (TEM cells and TEMRA cells). Memory cells may be either CD4+ or CD8+. Memory T cells typically express the cell surface protein CD45RO.
  • Treg cells Regulatory T cells
  • TSLP Regulatory T cells
  • Naturally occurring Treg cells can be distinguished from other T cells by the presence of an intracellular molecule called FoxP3. Mutations of the FOXP3 gene can prevent regulatory T cell development, causing the fatal autoimmune disease IPEX.
  • Adaptive Treg cells also known as Tr1 cells or Th3 cells
  • the T cell provided herein may be any of the T cell types mentioned above, in particular a CTL.
  • Natural killer (NK) cells are a type of cytolytic cell which forms part of the innate immune system. NK cells provide rapid responses to innate signals from virally infected cells in an MHC independent manner.
  • NK cells (belonging to the group of innate lymphoid cells) are defined as large granular lymphocytes (LGL) and constitute the third kind of cells differentiated from the common lymphoid progenitor generating B and T lymphocytes. NK cells are known to differentiate and mature in the bone marrow, lymph node, spleen, tonsils and thymus where they then enter into the circulation.
  • the CAR-expressing cells provided herein may be any of the cell types mentioned above.
  • CAR-expressing cells such as CAR-expressing T or NK cells may either be created ex vivo either from a patient’s own peripheral blood (1 st party), or in the setting of a haematopoietic stem cell transplant from donor peripheral blood (2 nd party), or peripheral blood from an unconnected donor (3 rd party).
  • T or NK cells provided herein may be derived from ex vivo differentiation of inducible progenitor cells or embryonic progenitor cells to T or NK cells.
  • an immortalized T-cell line which retains its lytic function and could act as a therapeutic may be used.
  • the CAR cells are generated by introducing DNA or RNA coding for the CARs by one of many means including, but not limited to, transduction with a viral vector, transfection with DNA or RNA. Cells may be activated and/or expanded prior to being transduced with CAR-encoding nucleic acid, for example by treatment with an anti- CD3 monoclonal antibody.
  • the T or NK cells provided herein may be made by: (i) isolation of a T or NK cell- containing sample from a subject or other sources listed above, and (ii) transduction or transfection of the T or NK cells with one or more a nucleic acid(s) encoding the CD19 and BCMA CARs.
  • the T or NK cells may then by purified, for example, selected on the basis of expression of the antigen-binding domain of the antigen-binding polypeptide.
  • the present disclosure also provides a cell composition comprising CAR-expressing T cells and/or CAR-expressing NK cells, which cells co-express a CAR that binds CD19 and another CAR that binds BCMA, such that the cells can recognize a target cell expressing either of these markers.
  • the cell composition may be made by transducing a blood-sample ex vivo with a nucleic acid according to the present disclosure.
  • CD19/BCMA CAR T-cell composition refers herein to a cell composition comprising a mixture of untransduced cells, cells expressing a CD19 CAR alone, cells expressing a BCMA CAR alone, and cells expressing both the CD19 and BCMA CARs.
  • PHARMACEUTICAL COMPOSITIONS The present disclosure also relates to a pharmaceutical composition containing a plurality of CAR-expressing cells, such as T cells or NK cells provided herein.
  • Pharmaceutical compositions comprising the BCMA/CD19 CAR T-cell product described in the examples are provided.
  • the pharmaceutical composition may additionally comprise a pharmaceutically acceptable carrier, diluent or excipient.
  • the pharmaceutical composition may optionally comprise one or more further pharmaceutically active polypeptides and/or compounds.
  • Such a formulation may, for example, be in a form suitable for intravenous infusion.
  • the cell compositions of the present disclosure are capable of killing cells recognizable by expression of BCMA or CD19, such as B cells and plasma cells.
  • CAR-expressing cells, such as T cells may either be created ex vivo either from a patient’s own peripheral blood (1 st party), or in the setting of a haematopoietic stem cell transplant from donor peripheral blood (2 nd party), or peripheral blood from an unconnected donor (3 rd party).
  • CAR T-cells may be derived from ex-vivo differentiation of inducible progenitor cells or embryonic progenitor cells to T-cells.
  • CAR T-cells are generated by introducing DNA or RNA coding for the CAR by one of many means including transduction with a viral vector, transfection with DNA or RNA.
  • the disease may be an autoantibody-driven autoimmune disease and/or an autoimmune disease associated with particularly high autoantibody titers.
  • the disease may be systemic lupus erythematosus (SLE), lupus nephritis or membranous nephropathy (MN).
  • SLE systemic lupus erythematosus
  • MN membranous nephropathy
  • Treatment with the T cells provided herein may kill autoantibody producing B-cell, plasma cell, and/or precursor cells.
  • the methods provided herein slow or prevent progression of the autoimmune disease, diminish the extent of the autoimmune disease, result in remission (partial or total) of the autoimmune disease, and/or prolong survival of the patient.
  • the patient may be administered a single dose of between 1 x 10 6 and 1x10 7 CAR T- cells, such as BCMA/CD19 CAR T-cell product described in the Examples.
  • the patient may be administered a single dose of about 1 x 10 6 , 5 x 10 6 , 50 x 10 6 , 100 x 10 6 , 150 x 10 6 or about 4x10 7 CAR T-cells, such as BCMA/CD19 CAR T- cell product described in the Examples.
  • the administration may be an intravenous injection through a Hickman line or peripherally inserted central catheter (PICC line).
  • PICC line peripherally inserted central catheter
  • the patient may be administered conditioning chemotherapy or lymphodepletion prior to receiving the CAR T-cells.
  • the conditioning chemotherapy or lymphodepletion may include cyclophosphamide and fludarabine, such as 300mg/m 2 cyclophosphamide x 3 doses on Day -5 and Day -3 and 30mg/m 2 fludarabine for 3 doses over Day -5 to Day -3 prior to BCMA/CD19 CAR T-cell product infusion on Day 0.
  • An alternative lymphodepleting regimen may include 60mg/kg cyclophosphamide on Day -6, and and 30mg/m 2 fludarabine for 3 doses over Day -5 to Day -3 prior to BCMA/CD19 CAR T-cell product infusion on Day 0. These doses may be adjusted to renal function and serum Fludarabine levels.
  • SLE Systemic lupus erythematosus
  • SLE is an autoimmune disease that can involve almost all body organs. Lupus may be classified into several subtypes according to the clinical features including systemic lupus erythematosus, cutaneous lupus erythematosus, drug-induced lupus, and neonatal lupus.
  • the progression of SLE involves the immune system. Almost all of the pathological manifestations of SLE are due to antibody formation and deposition of immune complexes in different organs of the body. When the immune complexes are formed, they deposit in different body tissues and vessels, which may lead to complement activation and more organ damage.
  • systemic lupus erythematosus Without treatment, the patient will develop symptoms of end organ damage, which eventually leads to death in most cases.
  • Common complications of systemic lupus erythematosus include dermatitis, nephritis, and arthritis. Most of these complications occur in chronic cases and lead to significant debilitation.
  • the prognosis of systemic lupus erythematosus can vary. SLE can range from a benign illness to an extremely rapidly progressive disease that can lead to fulminant organ failure and death. Without treatment, systemic lupus erythematosus results in very high mortality rate. During the mid-20th century, the mortality rate of SLE was reported to be higher than 60%. SLE can be diagnosed based on SLICC criteria.
  • the patient may have a positive history of familial lupus, skin rashes (especially photosensitive skin rashes), arthritis, and fatigue, which may be suggestive of systemic lupus erythematosus.
  • the most common symptoms of SLE include constitutional symptoms such as fatigue, fever, myalgia, and weight changes. Other, organ-specific symptoms mostly occur with disease progression. SLE may show a variety of symptoms in different organs depending on the complications of the disease.
  • the therapy for systemic lupus erythematosus (SLE) is targeted towards controlling disease activity and preventing organ damage.
  • the choice of treatment for systemic lupus erythematosus (SLE) varies based on the severity of the disease and symptoms.
  • SLE patients are commonly treated with hydroxychloroquine.
  • Other pharmacologic medical therapies for SLE include glucocorticoids like oral prednisone or intravenous methylprednisolone, NSAIDs like celecoxib, and immunosuppressive therapy with mycophenolate, cyclophosphamide, or, particularly in severe cases, rituximab.
  • Cutaneous lupus erythematosus (CLE) if present without the involvement of any other organ system, can be treated with topical corticosteroids.
  • Patients to be treated may have a diagnosis of SLE fulfilling the 2019 European League against Rheumatism (EULAR)/American College of Rheumatology (ACR) Classification Criteria for Systemic Lupus Erythematosus; may be positive for at least one of the following autoantibodies: antinuclear antibodies (ANA) at a titer of ⁇ 1:80, or anti-dsDNA ( ⁇ 30 IU/mL) or anti-Sm (> ULN), anti-histone or anti-chromatin (> ULN); may have severe SLE defined as a) a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of ⁇ 8 points (of which 4 are non-laboratory items and with the exclusion of points associated with neurological findings [SLEDAI 2K items 1-7]) and b) at least one of the following significant SLE-related organ involvements: i) renal (ongoing active, biopsy-proven lupus nephritis), i
  • refractory SLE defined as lack of response, insufficient response or lack of sustained response or intolerance to: a) hydroxychloroquine treatment in combination with corticosteroids, and b) ⁇ 2 of the following treatment groups used for at least 3 months each or less if intolerant: i) Immunosuppressive drugs (e.g., methotrexate, azathioprine, mycophenolate mofetil, mycophenolic acid, tacrolimus, leflunomide, cyclosporine, voclosporin or cyclophosphamide), ii) B cell-targeting agents (e.g., belimumab, anti-CD20 mAb), and iii) cytokine inhibitors (e.g., anifrolumab).
  • Immunosuppressive drugs e.g., methotrexate, azathioprine, mycophenolate mofetil, mycophenolic acid, tacrolimus, leflunomide, cyclospor
  • Patients may be subject to a pre-conditioning chemotherapy such as lymphodepletion chemotherapy prior to CD19/BCMA CAR treatment.
  • the lymphodepletion chemotherapy may comprise treatment with fludarabine and cyclophosphamide.
  • the patients may receive three doses of fludarabine 25 mg/m 2 /d intravenous administration on Day -5, Day -4, and Day -3 relative to CD19/BCMA CAR treatment and one dose of cyclophosphamide 1000 mg/m 2 intravenous administration on Day -3 relative to CD19/BCMA CAR treatment.
  • an autoimmune disease such as SLE
  • the patients may be administered a single dose of 50 x 10 6 ( ⁇ 20%) transduced cells.
  • Alternative doses contemplated are an escalated (100 x 10 6 [ ⁇ 20%]) or a de- escalated (30 x 10 6 [ ⁇ 20%]) CAR-T cell dose.
  • the administration may be, for example, an intravenous injection through a Hickman line or peripherally inserted central catheter (PICC line).
  • LUPUS NEPHRITIS Lupus nephritis is an inflammation of the kidneys caused by systemic lupus erythematosus (SLE), as discussed above. It is a type of glomerulonephritis in which the glomeruli become inflamed. Since it is a result of SLE, this type of glomerulonephritis is said to be secondary, and has a different pattern and outcome from conditions with a primary cause originating in the kidney. The diagnosis of lupus nephritis depends on blood tests, urinalysis, X-rays, ultrasound scans of the kidneys, and a kidney biopsy.
  • MN MEMBRANOUS NEPHROPATHY
  • MN Membranous nephropathy
  • MGN membranous glomerulonephritis
  • MN is generally classified as primary (idiopathic) or secondary to other systemic disease, such as infections, malignancies, vasculitides etc.
  • Kidney biopsy remains the gold standard for the diagnosis of MN, showing subepithelial deposits with capillary wall thickening and IgG deposition under immunofluorescence. While MN is widely considered a chronic condition with a waxing and waning course, it is usually self-limited in the majority of the cases. Heavy proteinuria, a significant marker of prognosis, indicates the need for intervention. Treatment efficacy may be assessed by measuring anti-PLA2R antibody levels.
  • Standard treatment is with corticosteroids, cyclophosphamide and calcineurin inhibitors. More recently B-cell depleting therapeutic antibodies like Rituximab are used. These induce responses in 60% of patients by 12 months; however, randomized studies have not yet shown clear improvement in long-term outcomes. Furthermore, loss of autoantibodies can take months, increasing risk of chronic kidney disease (CKD), as well as cardiovascular complications due to uncontrolled nephrotic syndrome. MN patients frequently relapse and managing the episodic nature of this disease is burdensome. Ultimately many patients require renal replacement (35% at 10 years and 41% at 15 years). Notably, disease recurrence is common (30-40%) following renal transplant.
  • CKD chronic kidney disease
  • CAR T cells were generated by transducing normal donor PBMCs with two lentiviral vectors: One which encodes an anti-BCMA CAR having a Fab-type antigen binding domain (known as “D8”) and a second generation endodomain comprising 4-1BB and CD3z; and one which encodes an anti-CD19 CAR having an scFv antigen binding domain (known as “CAT” or “CAT19” and a second generation endodomain comprising 4-1BB and CD3z ( Figure 2).
  • D8 Fab-type antigen binding domain
  • CAT19 scFv antigen binding domain
  • Transduction of cells with a mixture of two vectors produces a combinatorial product, as some cells are untransduced; some cells express the BCMA-CAR alone; some cells express the CD19 CAR alone; and some cell co-express the two CARs (Figure 3).
  • Cells were transduced with a mixture of two vectors at a multiplicity of infection (MOI) of 2.5 for each vector.
  • D8/CAT CAR T cells In vitro function of D8/CAT CAR T cells to demonstrate the cytotoxicity of D8/CAT CAR T cells against BCMA-expressing and CD19-expressing targets, co-cultures with different targets and effectors were performed. Effectors were D8 CAR T cells, CAT CAR T cells and D8/CAT CAR T cells. Targets were SupT1 cells (negative for both BCMA and CD19), SupT.BCMAlow, SupT1.CD19 (SupT1 cells engineered to express CD19) and SupT1 BCMAlow.CD19 (SupT1.BCMAlow additionally engineered to express CD19). After a 96-hour incubation period, killing was determined by flow-cytometry.
  • SupT1 BCMAlow targets were killed by D8 and D8/CAT CAR T cells but not by CAT CAR T cells.
  • SupT1 CD19 targets were killed by CAT and D8/CAT CAR T cells but not by D8 CAR T cells.
  • SupT1.BCMAlow.CD19 targets were killed by D8, CAT and D8/CAT CAR T cells.
  • CAR T cells were cultured with antigen-negative SupT1 NT cells, BCMA- expressing SupT1-BCMAlow and MM1.S cells and BCMA/CD19 dual positive Raji and Jeko-1 cells.
  • CAT CAR T cells only showed cytokine production against CD19-expressing Raji and Jeko-1 cells
  • D8 CAR T cells demonstrated cytokine production against BCMA-expressing cells lines
  • D8/CAT dual CAR- expressing T cells demonstrated cytokine secretion against all BCMA-expressing lines regardless of the presence or absence of CD19.
  • Proliferation of D8/CAT CAR T cells in response to target cells was also tested.
  • CAR- transduced T cells were labelled with a proliferation tracker dye CTV before co- culturing with target cell lines expressing either BCMA or CD19 alone or co- expressing both antigens. JeKo-1 cells are CD19+.
  • D8/CAT CAR T cells showed significant proliferation against target cell lines which express BCMA (SupT1 BCMAlow, SupT1 BCMAlow CD19, JeKo-1 and MM.1s) which were comparable to that seen with D8 CAR T cells (Figure 6). Furthermore, D8/CAT CAR T cells were capable of proliferating against SupT1 which are expressing CD19 alone whereas D8 single transduced T cells did not, indicative of the proliferative function of CAT19 CAR against CD19 antigen.
  • Example 2 In vivo testing of D8/CAT CAR T cells in a xenogeneic murine myeloma model
  • D8/CAT CAR T cells were used in an NSG mouse model.
  • Figure 7 shows the summary of the experimental design and the results. Briefly, NSG mice were injected with 1x10 6 Fluc expressing JeKo-1 cells at D0 and were allowed to engraft in the mice for the following 10 days. T cells were transduced at a total MOI of 5 and in the presence of 2.5uM AKTi VIII and 5x10 6 CAR expressing T cells were subsequently injected into the mice at D10. Mice were then imaged 3 times a week and then sacrificed at D30.

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Abstract

There is provided a method of treating an autoimmune disease comprising administering to a patient a cell composition made by transducing cells with a mixture of vectors, the mixture comprising: (i) a first vector which expresses a first chimeric antigen receptor (CAR) which binds CD19; and (ii) a second vector which expresses a second CAR which binds B cell maturation antigen (BCMA). There is also provided a method for selectively deleting anti-BCMA CAR-expressing cells and a method for restoring the plasma cell compartment in a patient who has received such a treatment.

Description

METHOD FIELD OF THE INVENTION The present invention relates to method for treating an autoimmune disease using a cell composition comprising cells which co-express an anti-CD19 chimeric antigen receptor (CAR) and an anti-B-cell maturation antigen (BCMA) CAR. BACKGROUND TO THE INVENTION Autoimmune Diseases Autoimmune disorders arise when the body’s own immune cells, specifically autoreactive B cells and T cells, initiate aberrant attacks on the body’s own tissues through various effector mechanisms. Common autoimmune diseases include rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, multiple sclerosis, Type I diabetes, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, psoriasis, Graves’ disease, Hashimoto’s thyroiditis, myasthenia gravis, scleroderma, vasculitis and pemphigus vulgaris. Autoimmune diseases affect millions of individuals world-wide and the cost of these diseases, in terms of actual treatment expenditures and lost productivity, is measured in billions of dollars annually. Current standard approaches to treating autoimmune diseases focus on managing the disease rather than offering a cure. The main concept to treat autoimmune disease is to prevent autoreactive immune cells from attacking host tissues by broad (and mostly non-targeted) immunosuppressive agents such as glucocorticoids and non-steroidal anti-inflammatory drugs. Autoreactive immune cells can be more specifically blocked using therapeutic antibodies which target B cells via for example, CD20 (Rituximab) or BAFF (Belimumab), T cells via, for example, CD52 (alemtuzumab) or by small molecules that mainly act of B and T cell signalling and function by blocking intracellular pathways (e.g. cyclosporine A). To date, for many autoimmune diseases there is no definitive cure available and new treatment options are needed. Chimeric Antigen Receptors (CARs) Chimeric antigen receptors are proteins which, in their usual format, graft the specificity of a monoclonal antibody (mAb) to the effector function of a T-cell. Their usual form is that of a type I transmembrane domain protein with an antigen recognizing amino terminus, a spacer, a transmembrane domain all connected to a compound endodomain which transmits T-cell survival and activation signals. The most common form of these molecules use single-chain variable fragments (scFv) derived from monoclonal antibodies to recognize a target antigen. The scFv is fused via a spacer and a transmembrane domain to a signaling endodomain. Such molecules result in activation of the T-cell in response to recognition by the scFv of its target. When T cells express such a CAR, they recognize and kill target cells that express the target antigen. Several CARs have been developed against tumour associated antigens, and adoptive transfer approaches using such CAR-expressing T cells are currently in clinical trial for the treatment of various cancers. The CD19 antigen expressed by B-cell malignancies was the first clinically applicable target for cancer therapy using autologous CAR T cells. Treatment with T cells genetically equipped with anti-CD19 CARs has led to impressive remission rates in patients with relapsed/refractory B cell malignancies. CARs and autoimmune disease CD19-targeting CAR-T cells have also been considered as a potentially curative approach for the treatment of autoimmune diseases. Systemic lupus erythematosus (SLE) is a severe and potentially life-threatening disease with central involvement of autoantibody-producing B cells, which lead to progressive tissue destruction due to the deposition of immune complexes. Since anti-CD19 CAR-T cells deplete B-cells, their use has been suggested as a potential treatment approach for SLE. Tolerability and efficacy were initially tested in a single SLE patient treated with a CD19 CAR (Mougiakakos et al. (2021). N Engl J Med 385(6):567-9). The same research group further assessed tolerability and efficacy of CD19 CAR T cell therapy in a small series of seriously ill and treatment-resistant patients with SLE. In this series, autologous T cells from five patients with SLE were transduced with a lentiviral anti-CD19 CAR vector, expanded and reinfused at a dose of 1×106 CAR T cells per kg body weight into the patients after lymphodepletion with fludarabine and cyclophosphamide. CAR T cells were expanded in vivo and led to deep depletion of B cells with improvement of clinical symptoms and normalization of laboratory parameters including seroconversion of anti-ds DNA antibodies. Remission of SLE according to DORIS criteria was achieved in all five patients after 3 months, and drug- free remission was maintained during longer follow-up after CAR T cell administration. Plasma cells Plasma cells are the antibody secretors of the immune system. Continuous antibody secretion over years can provide long-term immune protection but can also be responsible for long-lasting autoimmunity in case of self-reactive plasma cells. While CD19 CAR T cell therapy as discussed in the previous section has been shown to improve outcomes in mouse models of lupus, it was found that autoreactive antibodies were eliminated only when CAR-T cells were given at an early course of disease. Later in the disease course, long-lived plasma cells accumulate and lead to persistent autoantibody production despite B-cell depletion. While early CD19-based therapy may prevent accumulation of these autoreactive plasma cells, administration of CD19 CAR T cells later in disease course would be ineffective at removing already formed plasma cells. As clinical therapy would likely begin later in disease course when there is a substantial autoreactive plasma population, CD19 CAR T cell therapy may be ineffective. There is therefore a need for alternative approaches to treat autoantibody-driven autoimmune diseases. DESCRIPTION OF THE FIGURES Figure 1 - Schematic diagram showing a classical chimeric antigen receptor (a) Basic schema of a chimeric antigen receptor; (b) First generation receptors; (c) Second generation receptors; (d) Third generation receptors. Figure 2 - (a) D8-41BB-ζ Architecture is a standard CAR. Binding domain is in a scFv format with CD8 stalk as a spacer. This is expressed as a single protein. (b) D8Fab- 41BB-ζ architecture is in FabCAR format. Here, two separate proteins comprise the CAR with the VL andKappa common chain as one protein and VH, CH1 and signaling endodomains as the second protein. Both are expressed from a single open reading frame but translated as two separate proteins by use of a foot-and-mouth 2A-like peptide (denoted by scissors). Figure 3 – Production of a dual targeting CAR by co-transduction When cells are transduced with a single vector, all transduced cells will express the same gene product (top figure – green gene product). However, when cells are transduced with two of vectors simultaneously, the resulting product will be a mixture of cells which are singly and combinatorially transduced (bottom figure – purple and green gene products). For example, if cells are transduced with two vectors, one comprising transgene A and one comprising transgene B, the transduced cells will be a mixture of cells expressing A alone; B alone; and cell expressing both A and B. Figure 4 - (a) Double transduction of normal donor T cells with separate vectors encoding D8Fab-41BB-ζ and CAT-41BB-ζ. CAR expression on live CD3+ cells were detected by staining with CAT19 anti-idiotype plus anti-Rat-Fc-PE for detection of CAT-41BB-ζ, and with BCMA-AviTag + streptavidin-APC for detection of D8Fab- 41BB-ζ. Flow cytometry plots from a representative transduction are shown, with mock-transduced (NT) control, D8 single transduction, CAT single transduction, and D8/CAT dual transduction. (b) Right graph shows percentages of D8-CAT-, D8+CAT- , D8+CAT+ and D8-CAT+ cells within the CD3+ population of the transduced PBMCs for 9 donors, with mean + SD shown. Figure 5 - Cytotoxicity and cytokine production of D8, CAT and D8/CAT CAR T cells against target cells which express neither, one or both BCMA and CD19. A) For cytotoxicity assessment CAR-transduced T cells were co-cultured with antigen- negative SupT1 NT, SupT1.BCMAlow, SupT1.CD19 or SupT1 BCMAlow.CD19 targets at effector:target ratio of 1:1 for 96 hours, before target cells were enumerated for as a measure of CAR cytotoxicity. Viable targets recovered from co-cultures with CAR-transduced T cells were normalised to that recovered from co-cultures with mock-transduced (NT) T cells (%). Mean ± SD shown; Two-way ANOVA with post hoc Dunnett’s test was used, **p<0.01, ***p<0.001, ns = not significant; n=6. B) For measurement of cytokine production CAR-Transduced T cells were co-cultured with the indicated target cells for 24 hours at an effector target ratio of 1:4. Figure 6 - Proliferation of D8, CAT and D8/CAT CAR T cells in response to different targets expressing neither, one or both of target antigens BCMA and CD19. Proliferation of different CAR T cells were compared by co-culturing CellTrace Violet (CTV)-labelled CAR T cells with SupT1 cells, SupT1.BCMAlow, SupT1.CD19, SupT1.BCMAlow.CD19, JeKo-1 and MM.1s target cells at an effector:target ratio of 1:1 for 96 hours, before acquisition by flow cytometry and analysis of CTV dilution as a measure of proliferation. Note: JeKo-1 cells express both BCMA and CD19; MM.1s cells express BCMA, but not CD19. Proliferation of CD8+ or (bottom graph) CD8- CAR populations, where CTV-diluted CAR T cells were gated as proliferated cells and expressed as percentages (%). Mean ± SD shown; Two-way ANOVA with post hoc Dunnett’s test was used, **p<0.01, ***p<0.001, ****p<0.0001, ns = not signifcant; n=6. Figure 7 - Top panel, summary of experimental design, Bottom panel: bioluminescence of different cohorts (media alone, N=6; NT, n=5; D8 CAR. N=4; D8/CAT CAR, n=5) following injection with CAR T cells. Figure 8 - Annotated amino acid sequence (SEQ ID NO: 15) of the CD19 CATCAR (AUTO1). Figure 9 - Annotated amino acid sequence (SEQ ID NO: 18) of the BCMA CAR (D8 FabCAR). SUMMARY OF ASPECTS OF THE INVENTION The present inventors have developed a cell composition for the treatment of autoimmune diseases which comprises cells co-expressing two CARs, one which targets CD19 and one which targets B cell maturation antigen (BCMA). Since the cells co-express an anti-CD19 CAR and an anti-BCMA CAR, they target both B cells (via CD19) and plasma cells (via BCMA). This dual targeting is more successful that cells expressing a CD19 CAR alone in removing autoantibody producing cells for the treatment of autoimmune diseases, particularly later in the disease course where autoantibody-secreting plasma cells may exist and predominate. Thus, in a first aspect, the present invention provides a method of treating an autoimmune disease in a patient comprising administering to the patient a cell composition made by transducing cells with a mixture of vectors, the mixture comprising: (i) a first vector which expresses a first chimeric antigen receptor (CAR) which binds CD19; and (ii) a second vector which expresses a second CAR which binds B cell maturation antigen (BCMA). The cell composition comprises a mixture of a) cells transduced with the first vector alone which cells express the anti-CD19 CAR; b) cells transduced with the second vector alone which cells express the anti-BCMA CAR; and c) cells transduced with both the first and second vectors, which cells co-express anti-CD19 and anti-BCMA CARs. The autoimmune disease may be driven by autoantibodies. The cell, once administered to the patient, may kill auto-antibody-producing B cells and plasma cells in the patient. The first CAR may comprise a CD19-binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6). The second CAR may comprise a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12). The CD19-binding domain of the first CAR may comprise a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14. The first CAR may comprise the sequence shown as 15. The BCMA-binding domain of the second CAR may comprise a VH domain having the sequence shown as SEQ ID No. 16; and a VL domain having the sequence shown as SEQ ID No. 17. The second CAR may comprise the sequence shown as SEQ ID No.18. The autoimmune disease may be selected from the following group: systemic lupus erythematosus (SLE), rheumatoid arthritis, idiopathic inflammatory myopathy (IIM, myositis), ANCA-associated vasculitis, inflammatory bowel disease (IBD), multiple sclerosis (MS), Type I diabetes, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Graves’ disease, Hashimoto’s thyroiditis or Hashimoto’s disease, myasthenia gravis, neuromyelitis optica, N-methyl-D-aspartate receptor (NMDAR) encephalitis, Lambert-Eaton syndrome, scleroderma, vasculitis, pemphigus vulgaris, pemphigus foliaceus, epidermolysis bullosa acquisita, bullous pemphigoid, lupus nephritis, membranous nephropathy, Goodpasture’s syndrome, immune thrombocytopenic purpura, thrombotic thrombocytopenic purpura, primary antiphospholipid syndrome, autoimmune haemolytic anaemia, and acquired haemophilia. The autoimmune disease may be selected from: systemic lupus erythematosus (SLE); lupus nephritis; and membranous nephropathy. The autoimmune disease may be membranous nephropathy. In order to facilitate the depletion or removal of cells expressing the second CAR in vivo, the second vector may comprise a nucleic acid expressing a suicide gene. The first vector may not comprise a nucleic acid expressing a suicide gene, i.e. only the second vector may comprise a nucleic acid expressing a suicide gene. Alternatively, both the first and second vector may comprise a nucleic acid expressing a suicide gene. The suicide gene expressed by the first vector may be the same as, or differed from, the suicide gene expressed by the second vector. Where the suicide genes are different, they may be activated by different agent. For example, one suicide gene may be RQR8 which is activated by rituximab; and the other suicide gene may be RapCsp9, which is activated with rapamycin. In a second aspect there is provided a method for selectively deleting anti-BCMA CAR-expressing cells in a patient, which method comprises the step of administering an agent to patient, wherein the patient has previously been administered a CAR- expressing cell composition as defined above, and wherein the agent activates the suicide gene expressed by the second vector. In a third aspect there is provided a method for restoring the plasma cell compartment in a patient which has been treated according to the first aspect of the invention, which method comprises the step of administering an agent to the patient which agent activates the suicide gene expressed by the second vector, thereby killing cells in the patient which express the second CAR but sparing cells in the patient which express the first CAR alone. The present invention relates to a method of treating a disease using a cell composition made by transducing cells with a mixture of vectors. When cells are transduced with multiple vectors simultaneously, the resulting product will be a mixture of cells which are singly and combinatorially transduced. For example, if cells are transduced with two vectors, one comprising transgene A and one comprising transgene B, the transduced cells will be a mixture of cells expressing A alone; B alone; and cell expressing both A and B. The present invention involves using such a mixture as a therapeutic CAR-T-cell product. The use of a combinatorial product gives in-built flexibility which enhances the product's capacity to adapt to differences in target cell populations in the patient. FURTHER ASPECTS OF THE INVENTION The present invention also relates to further aspects which are summarised in the following numbered paragraphs. A1 A method for treating membranous nephropathy (MN) in a patient by administering to the patient a cell comprising a first chimeric antigen receptor (CAR) which targets CD19 and a second CAR which targets B cell maturation antigen (BCMA). A2. A method according to paragraph A1, wherein the first CAR comprises a CD19-binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6). A3. A method according to paragraph A1 or A2, wherein the second CAR comprises a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12). A4. A method according to any preceding paragraph wherein the CD19-binding domain of the first CAR comprises a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14. A5. A method according to any preceding paragraph wherein the first CAR comprises the sequence shown as SEQ ID No.15. A6. A method according to any preceding paragraph wherein the BCMA-binding domain of the second CAR comprises a VH domain having the sequence shown as SEQ ID No.16; and a VL domain having the sequence shown as SEQ ID No.17. A7. A method according to any preceding paragraph wherein the second CAR comprises the sequence shown as SEQ ID No.18. A8. A method according to any preceding paragraph, wherein the cell is made by transduction of a cell with a nucleic acid construct which comprises a first nucleic acid sequence encoding the first CAR and a second nucleic acid sequence encoding the second CAR. A9. A method according to any of paragraphs A1 to A7, wherein the cell is made by transduction of a cell with a kit of vectors which kit comprises (i) a first vector which comprises a nucleic acid sequence encoding the first CAR; and (ii) a second vector which comprises a nucleic acid sequence encoding the second CAR. A10. A method according to any preceding paragraph, wherein the cell comprises a suicide gene. Yet further aspects are summarised in the following numbered paragraphs: B1 A method of treating an autoimmune disease in a patient by administering to the patient a cell comprising a first chimeric antigen receptor (CAR) and a second CAR, wherein the first CAR targets CD19 and the second CAR has a Fab-type antigen binding domain which binds B cell maturation antigen (BCMA). B2. A method according to paragraph B1, wherein the first CAR comprises a CD19-binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6). B3. A method according to paragraph B1 or B2, wherein the second CAR comprises a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12). B4. A method according to any preceding paragraph wherein the CD19-binding domain of the first CAR comprises a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14. B5. A method according to any preceding paragraph wherein the first CAR comprises the sequence shown as SEQ ID No.15. B6. A method according to any preceding paragraph wherein the BCMA-binding domain of the second CAR comprises a VH domain having the sequence shown as SEQ ID No.16; and a VL domain having the sequence shown as SEQ ID No.17. B7. A method according to any preceding paragraph wherein the second CAR comprises the sequence shown as SEQ ID No.18. B8. A method according to any preceding paragraph, wherein the autoimmune disease is selected from: systemic lupus erythematosus (SLE), rheumatoid arthritis, idiopathic inflammatory myopathy (IIM, myositis), ANCA-associated vasculitis, inflammatory bowel disease (IBD), multiple sclerosis (MS), Type I diabetes, Guillain- Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Graves’ disease, Hashimoto’s thyroiditis or Hashimoto’s disease, myasthenia gravis, neuromyelitis optica, N-methyl-D-aspartate receptor (NMDAR) encephalitis, Lambert- Eaton syndrome, scleroderma, vasculitis, pemphigus vulgaris, pemphigus foliaceus, epidermolysis bullosa acquisita, bullous pemphigoid, lupus nephritis, membranous nephropathy, Goodpasture’s syndrome, immune thrombocytopenic purpura, thrombotic thrombocytopenic purpura, primary antiphospholipid syndrome, autoimmune haemolytic anaemia, and acquired haemophilia. B9. A method according to any preceding paragraph, wherein the autoimmune disease is selected from: systemic lupus erythematosus (SLE); lupus nephritis; and membranous nephropathy. B10. A method according to any preceding paragraph, wherein the autoimmune disease is membranous nephropathy. B11. A method according to any preceding paragraph, wherein the second vector comprises a nucleic acid expressing a suicide gene. B12. A method according to any preceding paragraph, wherein the cell is made by transduction of a cell with a nucleic acid construct which comprises a first nucleic acid sequence encoding the first CAR and a second nucleic acid sequence encoding the second CAR. B13. A method according to any of paragraphs A1 to A11, wherein the cell is made by transduction of a cell with a kit of vectors which kit comprises (i) a first vector which comprises a nucleic acid sequence encoding the first CAR; and (ii) a second vector which comprises a nucleic acid sequence encoding the second CAR. B14. A method according to any preceding paragraph, wherein the cell comprises a suicide gene. The following detailed description, as it relates to cells, methods of treatment, nucleic acid and polypeptide sequences, vectors, methods of manufacture etc applies equally to the aspects laid out in the above paragraphs as to the aspects of the invention in the claims. DETAILED DESCRIPTION CHIMERIC ANTIGEN RECEPTORS (CARS) A classical chimeric antigen receptor (CAR) is a chimeric type I trans-membrane protein which connects an extracellular antigen-binding domain to an intracellular signaling domain (endodomain). The antigen-binding domain is typically a single- chain variable fragment (scFv) derived from a monoclonal antibody (mAb), but it can be based on other formats which comprise an antibody fragment or an antibody-like antigen-binding site. Other examples include, but are not limited to: a natural ligand of the target antigen, a peptide with sufficient affinity for the target, a F(ab) fragment, a F(ab’)2 fragment, a F(ab’) fragment, a single domain antibody (sdAb), a domain antibody (dAb), a VHH antigen-binding domain or nanobody, an artificial single binder such as a DARPin (designed ankyrin repeat protein), an affibody, a fibronectin artificial antibody scaffold, an anticalin, an affilin, a VNAR, an iBody, an affimer, a fynomer, an abdurin/ nanoantibody, a centyrin, an alphabody, a nanofitin, or a single- chain derived from a T-cell receptor which is capable of binding the target antigen. A spacer is usually necessary to isolate the antigen-binding domain from the membrane and to allow it a suitable orientation. A common spacer used is the Fc of IgG1. More compact spacers can suffice, e.g., the stalk from CD8α and even just the IgG1 hinge alone, depending on the antigen. A transmembrane domain anchors the protein in the cell membrane and connects the spacer to the endodomain. Early CAR designs had endodomains derived from the intracellular parts of either the γ chain of the FcεR1 or CD3ζ (Figure 1a). These first generation receptors transmitted immunological signal 1, which was sufficient to trigger T-cell killing of cognate target cells but failed to fully activate the T-cell to proliferate and survive. To overcome this limitation, compound endodomains have been constructed: fusion of the intracellular part of a T-cell co-stimulatory molecule to that of CD3ζ results in second generation receptors which can transmit an activating and co-stimulatory signal simultaneously after antigen recognition. One common co-stimulatory domain is that of CD28. This supplies the most potent co-stimulatory signal - namely immunological signal 2, which triggers T-cell proliferation. Some receptors have also been described which include TNF receptor family endodomains, such as the closely related OX40 and 41BB which transmit survival signals (Figure 1b). Even more potent third generation CARs have now been described which have endodomains capable of transmitting activation, proliferation and survival signals (Figure 1c). When the CAR binds the target antigen, an activating signal is transmitted to the T- cell on which the CAR is expressed thereby directing the specificity and cytotoxicity of the T cell towards cells expressing the target antigen. CAR-encoding nucleic acids may be transferred to T cells using, for example, retroviral or lentiviral vectors to generate antigen-specific T cells for adoptive cell transfer. When the CAR binds the target-antigen, this results in the transmission of an activating signal to the T-cell it is expressed on. Thus, the CAR directs the specificity and cytotoxicity of the T cell towards cells expressing the targeted antigen. ANTIGEN BINDING DOMAIN The antigen binding domain is the portion of CAR which recognizes antigen. Numerous antigen-binding domains are known in the art, including those based on the antigen binding site of an antibody, antibody mimetics, and T-cell receptors. For example, the antigen-binding domain may comprise: a single-chain variable fragment (scFv) derived from a monoclonal antibody; a natural ligand of the target antigen; a peptide with sufficient affinity for the target; a single domain antibody; an artificial single binder such as a Darpin (designed ankyrin repeat protein); or a single-chain derived from a T-cell receptor. In a classical CAR, the antigen-binding domain comprises: a single-chain variable fragment (scFv) derived from a monoclonal antibody (Figure 2a). CARs have also been produced with domain antibody (dAb) or VHH antigen binding domains or which comprise a Fab fragment of, for example, a monoclonal antibody (Figure 2b). A FabCAR comprises two chains: one having an antibody-like light chain variable region (VL) and constant region (CL); and one having a heavy chain variable region (VH) and constant region (CH). One chain also comprises a transmembrane domain and an intracellular signalling domain. Association between the CL and CH causes assembly of the receptor. The two chains of a Fab CAR may have the general structure: VH - CH - spacer - transmembrane domain - intracellular signalling domain; and VL - CL or VL - CL - spacer- transmembrane domain - intracellular signalling domain; and VH - CH For Fab-type chimeric receptors, the antigen binding domain is made up of a VH from one polypeptide chain and a VL from another polypeptide chain. The polypeptide chains may comprise a linker between the VH/VL domain and the CH/CL domains. The linker may be flexible and serve to spatially separate the VH/VL domain from the CH/CL domain. Target antigens A ‘target antigen’ is an entity which is specifically recognized and bound by the antigen-binding domains of a chimeric receptor provided herein. The target antigen may be an antigen present on an auto-antibody-producing cell, for example, an antigen expressed on B cells and/or plasma cells. BCMA and CD19 are target antigens contemplated herein. Binding domains specific for BCMA target antigen The B cell maturation target, also known as BCMA; TR17_HUMAN, TNFRSF17 (UniProt Accession No. Q02223, entry version 200, https://www.uniprot.org/uniprot/Q02223) is a transmembrane protein that is expressed in mature lymphocytes, e.g., memory B cells, plasmablasts and bone marrow plasma cells. BCMA is also expressed on myeloma cells. BCMA is a non- glycosylated type III transmembrane protein, which is involved in B cell maturation, growth and survival. An antigen binding domain of a CAR which binds to BCMA may be any domain which is capable of binding BCMA. The VH and VL sequences for fourteen anti-BCMA antibodies are given below with CDR sequences in bold and underlined. The sequence of BCMA is depicted under UniProt Accession No. Q02223, entry version 200 (https://www.uniprot.org/uniprot/Q02223). BCMA is an excellent MM target since it is expressed on practically all cases of MM and expression is otherwise restricted to normal plasma cells. However, it is a low- density antigen, so a key consideration in selecting a BCMA CAR was sensitivity to low antigen density. A number of BCMA-targeted CARs are in clinical development, including bb2121, LCAR-B38M, MCARH171, JCARH125, P-BCMA-101, FCARH143, bb21217 and CT053. WO2015/052538 describes a BCMA targeted CAR in which the antigen-binding domain is derived from APRIL, which is a natural ligand for BCMA. WO2020/065330, which is incorporated herein by reference, describes the VH and VL domains for 14 BCMA binding domains and their use in CARs. The BCMA antigen-binding domain may comprise: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 - GFIFSDYN (SEQ ID NO: 7) CDR2 - IIYDGSST (SEQ ID NO: 8) CDR3 - ATRPGPFAY (SEQ ID NO: 9); and b) a light chain variable region (VL) having complementarity determining regions (CDRs) with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID NO: 10) CDR2 - LVS (SEQ ID NO: 11) CDR3 - VHGTHAWT (SEQ ID NO: 12). It is contemplated that it is possible to introduce one or more mutations (substitutions, additions or deletions) into one or more CDRs without negatively affecting BCMA- binding activity. Each CDR may, for example, have one, two or three amino acid mutations. The BCMA antigen-binding domain may comprise the following VH domain. D8 VH domain (SEQ ID NO: 16) EVQLVESGGGLVQPGRSLKLSCAASGFIFSDYNMAWVRQAPKKGLEWVATIIYDGS STNHGDSVKGRFTISRDNAKSTLYLQMDSLRSEDTATYYCATRPGPFAYWGQGTLV TVS The BCMA antigen-binding domain may comprise the following VL domain. D8 VL domain (SEQ ID NO: 17) DVVLTQTPPTLSATIGQSVSISCRSSQSLLHSNGNTYLHWLLQRPGQSPQFLIYLVS GLGSGVPNRFSGSGSGTDFTLKISGVEAEDLGIYYCVHGTHAWTVGGGTKLELK The BCMA antigen-binding domain may comprise an anti-BCMA Fab CAR. The BCMA antigen-binding domain may comprise the following heavy chain (VH- CH1) sequence: D8 heavy chain (SEQ ID NO: 19) EVQLVESGGGLVQPGRSLKLSCAASGFIFSDYNMAWVRQAPKKGLEWVATIIYDGS STNHGDSVKGRFTISRDNAKSTLYLQMDSLRSEDTATYYCATRPGPFAYWGQGTLV TVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHT FPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRV The BCMA antigen-binding domain may comprise the following light chain (VL- Ckappa) sequence: D8 light chain (SEQ ID NO: 20) DVVLTQTPPTLSATIGQSVSISCRSSQSLLHSNGNTYLHWLLQRPGQSPQFLIYLVS GLGSGVPNRFSGSGSGTDFTLKISGVEAEDLGIYYCVHGTHAWTVGGGTKLELKRT VAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTE QDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC The CAR may comprise the following sequences: SEQ ID NO: 21 (CAR light chain: D8 VL-Ckappa) DVVLTQTPPTLSATIGQSVSISCRSSQSLLHSNGNTYLHWLLQRPGQSPQFLIYLVS GLGSGVPNRFSGSGSGTDFTLKISGVEAEDLGIYYCVHGTHAWTVGGGTKLELKRT VAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTE QDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC SEQ ID NO: 22 (CAR heavy chain: D8 VH-CH1-IgG1 hinge-CD28TM-41BB-CD3z) EVQLVESGGGLVQPGRSLKLSCAASGFIFSDYNMAWVRQAPKKGLEWVATIIYDGS STNHGDSVKGRFTISRDNAKSTLYLQMDSLRSEDTATYYCATRPGPFAYWGQGTLV TVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHT FPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTC PPCPKDPKFWVLVVVGGVLACYSLLVTVAFIIFWVKRGRKKLLYIFKQPFMRPVQTT QEEDGCSCRFPEEEEGGCELRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVL DKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGL YQGLSTATKDTYDALHMQALPPR The CAR provided herein may comprise a variant of the sequence shown as any of SEQ ID NO: 7 to 12 and 16 to 22 having at least 80, 85, 90, 95, 98 or 99% sequence identity, provided that the variant sequence retains the capacity to bind BCMA (when in conjunction with a complementary VL or VH domain, if appropriate). The BCMA antigen-binding domain may be any domain which is capable of binding BCMA. The VH and VL sequences for twelve anti-BCMA antibodies are given below with CDR sequences in bold and underlined. SEQ ID NO: 23 (anti-BCMA Ab1 VH) QIQLVQSGPELVKPGSSVKLSCKTSGFTFSDSYMSWLKQVPGQSIEWIGNIYAGDG ATHYHQKFKGKATLTVDTSSSTAYMDLSSLTSEDSALYFCARPLYTTAYYYVGGFA YWGQGTLVTVSS SEQ ID NO: 24 (anti-BCMA Ab1 VL) DIVMTQSPSSLAVSAGETVTINCKSSQSLLSSGNQKNYLAWYQQKPGQSPKLLIYW ASTRQSGVPDRFIGSGSGTDFTLTISSVQAEDLAIYYCQQYYDTPLTFGSGTKLEIK SEQ ID NO: 25 (anti-BCMA Ab2 VH) EVKLVESGGGLVQPGRSLKLSCTASGFTFSNYDMAWVRQAPTKGLEWVASISTSG DTIYYRDSVKGRFTVSRDKAKSTLYLQMDSLRSEDTATYYCARHDYYDGYQSFAY WGQGTLVTVSS SEQ ID NO: 26 (anti-BCMA Ab2 VL) NTVMTQSPTSMSISVGDRVTMNCKASQNVGNNIAWYQQKPGQSPKLLIYYASNRYT GVPDRFTGSGSGTDFTLTINSVQAEDAAFYYCQRIYNSALTFGSGTKLEIK SEQ ID NO: 27 (anti-BCMA Ab3 VH) QVQLQQSGAALVKPGASVKMSCKASGYTFTDYWVSWVKQSHGKSLEWIGEIYPNS GPTNFNKKFKGKATLTVDKSTSTAYMELSRLTSEDSAIYYCTPRTVAPYNWFAYWG QGTLVTVSS SEQ ID NO: 28 (anti-BCMA Ab3 VL) DIVLTQSPALAVSPGERVSISCRASESVSTRMHWYQQKPGQQPKLLIYGASNLESG VPARFSGSGSGTDFTLTIDPVEADDTATYFCQQSWNDPYTFGAGTKLELK SEQ ID NO: 29 (anti-BCMA Ab4 VH) EVQLVESGGGLVQPGRSLKLSCSASGFIFSNFDMAWVRQAPRKGLEWVASITTSG GDTHYRDSVKGRFTVSRHNAKSTLYLQMDSLRSEDTATYYCARHVYYGLFWFFDF WGPGTMVTVSS SEQ ID NO: 30 (anti-BCMA Ab4 VL) NTVMTQSPKSIFISVGDRVTVNCKASQNVGTNVDWYQQKTGQSPKLLIYGASNRYT GVPDRFTGSGSGTDFTFTISNMQAEDLAVYYCMQSNTNPFTFGAGTKLELKR SEQ ID NO: 31 (anti-BCMA Ab5 VH) EVQLVESGGGLVQPGRSLKLSCTASGFTFSNYDMAWVRQAPTKGLEWVASISTSG DTIYYRDSVKGRFTVSRDKAKSTLYLQMDSLRSEDTATYYCARHDYYDGYQSFAY WGQGTLVTVSS SEQ ID NO: 32 (anti-BCMA Ab5 VL) DIVMTQSPSTLPASLGERVTISCRASQSISNYLNWYQQKPDGTIKPLIYYTSNLQSGV PSRFSGSGSGTDYSLTISSLEPEDFAMYYCQQDASFPWTFGGGTKLELKR SEQ ID NO: 33 (anti-BCMA Ab6 VH) EVQLQESGPGLVKPSQSLSLTCSVTGYPITNNYDWSWIRQFPGNKMEWMGYISDS GNTNYNPSLKSRISITRDTSKNQFFLQLNSVTTEDTATYYCASGYISYIPFAFWGQGT LVTVSS SEQ ID NO: 34 (anti-BCMA Ab6 VL) DIVLTQSPALAVSLGQRATISCRASQSVSISSYNLMQWYQQKPGQQPKLLIYDASNL ASGIPARFSGSGSGTDFTLTIDPVQADDIATYYCQQSKDDPNTFGAGTKLEIKR SEQ ID NO: 35 (anti-BCMA Ab7 VH) EVQLQESGPGLVQPSQTLSLTCSVTGYPITNNYDWSWIRKFPGNKMEWMGYISDS GSTNYNPSLKSRISITRDTSKNQFFLQLNSVTTEDTATYYCASGYISYIPFGFWGQGT LVTVSS SEQ ID NO: 36 (anti-BCMA Ab7 VL) DIVLTQSPALAVSPGERVTISCRASESVSTRMHWYQQKPGQQPKLLIYGASNLESG VPARFSGSGSGTDFTLTIDPVEADDTATYFCQQSWNDPPTFGSGTKLEIK SEQ ID NO: 37 (anti-BCMA Ab8 VH) EVQLVESGGGLVQPGRSLKLSCTASGFTFSNYDMAWVRQAPTKGLEWVASISTSG DTIYYRDSVKGRFTVSRDKAKSTLYLQMDSLRSEDTATYYCARHDYYDGYQSFAY WGQGTLVTVSS SEQ ID NO: 38 (anti-BCMA Ab8 VL) DIVMTQSPASQAVSAGEKVTMSCKSSQSLLYSGDQKNYLAWYQQKPGQSPKLLIYL ASTRESGVPDRFIGSGSGTDFTLTISSVQAEDLADYYCQQHYSYPLTFGSGTKLEIK SEQ ID NO: 39 (anti-BCMA Ab9 VH) EVQLVESGGGLVQPGRSLKLSCAASGFTFSNYDMAWVRQAPTKGLEWVASISTSG DTIYYRDSVKGRFTVSRDNAKSTLYLQMDSLRSEDTATYYCTRHGYYDGYQSFDY WGQGTLVTVSS SEQ ID NO: 40 (anti-BCMA Ab9 VL) NTVMTQSPKSMSISVGDRVTMNCKASQNVGNNIAWYQQKPGQSPKLLIYYASNRY TGVPDRFTGGGYGTDFTLTINSVQAEDAATYYCQQWNYPSITFGSGTKLEIK SEQ ID NO: 41 (anti-BCMA Ab10 VH) EVQLVESGGGLVQPGRSMKLSCAASGFTFSNYDMAWVRQAPTKGLEWVASISPSG GSTYYRDSVKGRFTVSRDNAKSSLYLQMDSLRSEDTATYYCTRGDYGYNYAYWFA YWGQGTLVTVSS SEQ ID NO: 42 (anti-BCMA Ab10 VL) DIVMTQAPSSMPASLGERVTISCRASQGISNYLNWYQQKPDGTIKPLIYYTSNLQSG VPSRFSGSGSGTDYSLTISSLEPEDFAMYYCQQYDSSPLTFGAGTKLELK SEQ ID NO: 43 (anti-BCMA Ab11 VH) EVQLVESGGGLVQPGRSLKLSCEASGFTFSNYDMAWVRQAPTKGLEWVASISTSG DSIYYRDSVKGRFTVSRDNVKSTLYLQMDSLRSEDTATYYCARHGYYDGYQSFDY WGQGTLVTVSS SEQ ID NO: 44 (anti-BCMA Ab12 VL) DIVMTQSPSSLPASLGERVTISCRASQGISNNLNWYQQKPDGTIKPLIYYTSNLQSGV PSRFSGSGSGTDYSLTISSLEPEDFATYYCQQDETFPYTFGAGTKLELK SEQ ID NO: 45 (anti-BCMA Ab13 VH) EVQLVESGGGLVQPGRSLKLSCAASGFTFSNYDMAWVRQAPTKGLEWVASISPSG GSTYYRDSVKGRFTISRDNAKSTLYLQMDSLRSEDTATYYCATHNYYDGSSLFAYW GQGTLVTVSS SEQ ID NO: 46 (anti-BCMA Ab13 VL) DIVLTQSPALAVSPGERVTISCGANETVSTLVHWYQQKPGQQPKLLIYLASHLESGV PARFSGSGSGTDFTLTIDPVEADDTATYYCQQSWNDPPTFGGGTKLELK The percentage identity between two polypeptide sequences may be readily determined by programs such as BLAST which is freely available at blast.ncbi.nlm.nih.gov. The BCMA binder may have a kinetic affinity (KD) of 10nM or less, or 5nM or less, or 1nM or less, or 0.5nM or less, or 0.1nM or less. OR GATES The CAR may be used in a combination with one or more other activating or inhibitory chimeric antigen receptors. For example, they may be used in combination with one or more other CARs in a “logic-gate”, a CAR combination which, when expressed by a cell, such as a T cell, are capable of detecting a particular pattern of expression of at least two target antigens. If the at least two target antigens are arbitrarily denoted as antigen A and antigen B, the three possible options are as follows: “OR GATE” – T cell triggers when either antigen A or antigen B is present on the target cell “AND GATE” – T cell triggers only when both antigens A and B are present on the target cell “AND NOT GATE” – T cell triggers if antigen A is present alone on the target cell, but not if both antigens A and B are present on the target cell. Engineered T cells expressing these CAR combinations can be tailored to be exquisitely specific for target cells, based on their particular expression (or lack of expression) of two or more markers. Such “Logic Gates” are described, for example, in WO2015/075469, WO2015/075470 and WO2015/075470. An “OR Gate” comprises two or more activatory CARs each directed to a distinct target antigen expressed by a target cell. The advantage of an OR gate is that the effective targetable antigen is increased on the target cell, as it is effectively antigen A + antigen B. This is especially important for antigens expressed at variable or low density on the target cell, as the level of a single antigen may be below the threshold needed for effective targeting by a CAR-T cell. Also, it avoids the phenomenon of antigen escape. For example, some diseases may become BCMA negative after BCMA targeting: using an OR gate which targets BCMA in combination with another antigen provides a “back-up” antigen, should this occur. The OR gate may comprise a CAR against a second antigen expressed in the same or different target cells, such as CD19. The second CAR may have any suitable antigen binding domain, for example a binding domain based on an scFv, a domain antibody (dAb) or a Fab. Thus, the antigen-binding domains of the first and second CARs bind to different antigens and both CARs may comprise an activating endodomain. The two CARs may comprise spacer domains which may be the same, or sufficiently different to prevent cross-pairing of the two different receptors. As contemplated herein a cell can hence be engineered to activate upon recognition of either or both BCMA and CD19. The first and second CAR of the T cell may be produced as a polypeptide comprising both CARs, together with a cleavage site. Binding domains specific for CD19 target antigen The human CD19 antigen is a 95 kd transmembrane glycoprotein belonging to the immunoglobulin superfamily. CD19 is classified as a type I transmembrane protein, with a single transmembrane domain, a cytoplasmic C-terminus, and extracellular N- terminus. CD19 is expressed very early in B-cell differentiation and is only lost at terminal B-cell differentiation into plasma cells. CD19 is a biomarker for normal B cells as well as follicular dendritic cells. CD19 primarily acts as a B cell co-receptor in conjunction with CD21 and CD81. Upon activation, the cytoplasmic tail of CD19 becomes phosphorylated, which leads to binding by Src-family kinases and recruitment of PI-3 kinase. CD19 is also expressed on all B-cells but not plasma cells. It is not expressed on other haematopoietic populations or non-haematopoietic cells and therefore targeting this antigen should not lead to toxicity to the bone marrow or non-haematopoietic organs. Loss of the normal B-cell compartment is considered an acceptable toxicity when treating lymphoid malignancies, because although effective CD19 CAR T cell therapy will result in B cell aplasia, the consequent hypogammaglobulinaemia can be treated with pooled immunoglobulin. Different designs of CARs have been tested against CD19 in various clinical trials, as outlined in the following Table 2. Table 2 As shown above, most of the studies conducted to date have used an scFv derived from the hybridoma fmc63 as part of the binding domain to recognize CD19. The antigen-binding domain of a CAR which binds to CD19 (referred to as a CD19 CAR herein) may be any domain which is capable of binding CD19. For example, the antigen-binding domain may comprise a CD19 antigen-binding domain as described in Table 3. Table 3 The gene encoding CD19 comprises ten exons: exons 1 to 4 encode the extracellular domain; exon 5 encodes the transmembrane domain; and exons 6 to 10 encode the cytoplasmic domain. The antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 1 of the CD19 gene. The antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 2 of the CD19 gene. The antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 3 of the CD19 gene. The antigen-binding domain of a CD19 CAR herein may bind an epitope of CD19 encoded by exon 4 of the CD19 gene. A CD19-binding domain exemplified herein comprises variable regions with complementarity determining regions (CDRs) from an antibody referred to as CAT19, a) a heavy chain variable region (VH) having CAT19 CDRs with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1); CDR2 – YPGDED (SEQ ID NO: 2) CDR3 – SLLYGDYLDY (SEQ ID NO: 3); and b) a light chain variable region (VL) having CAT 19 CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4); CDR2 – DTSKLAS (SEQ ID NO: 5) CDR3 – QQWNINPLT (SEQ ID NO: 6). The CAT19 antibody is described in WO2016/139487. It is contemplated that one or more mutations (substitutions, additions or deletions) can be introduced into one or more CDRs without negatively affecting CD19-binding activity. Each CDR may, for example, have one, two or three amino acid mutations. The CDRs may be in the format of a single-chain variable fragment (scFv), which is a fusion protein of the heavy variable region (VH) and light chain variable region (VL) of an antibody, connected with a short linker peptide of ten to about 25 amino acids. The scFv may be in the orientation VH-VL, i.e., the VH is at the amino-terminus of the CAR molecule and the VL domain is linked to the spacer and, in turn the transmembrane domain and endodomain. The CDRs may be grafted on to the framework of a human antibody or scFv. For example, the CAR may comprise a CD19-binding domain consisting or comprising one of the following sequences. The CD19 CAR may comprise the following VH sequence. SEQ ID NO: 13 – VH sequence from CAT19 murine monoclonal antibody QVQLQQSGPELVKPGASVKISCKASGYAFSSSWMNWVKQRPGKGLEWIGRIYPGD EDTNYSGKFKDKATLTADKSSTTAYMQLSSLTSEDSAVYFCARSLLYGDYLDYWGQ GTTLTVSS The CD19 CAR may comprise the following VL sequence. SEQ ID NO: 14 – VL sequence from CAT19 murine monoclonal antibody QIVLTQSPAIMSASPGEKVTMTCSASSSVSYMHWYQQKSGTSPKRWIYDTSKLASG VPDRFSGSGSGTSYFLTINNMEAEDAATYYCQQWNINPLTFGAGTKLELKR The CD19 CAR may comprise the following scFv sequence. SEQ ID NO: 47 – VH-VL scFv sequence from murine monoclonal antibody QVQLQQSGPELVKPGASVKISCKASGYAFSSSWMNWVKQRPGKGLEWIGRIYPGD EDTNYSGKFKDKATLTADKSSTTAYMQLSSLTSEDSAVYFCARSLLYGDYLDYWGQ GTTLTVSSGGGGSGGGGSGGGGSQIVLTQSPAIMSASPGEKVTMTCSASSSVSYM HWYQQKSGTSPKRWIYDTSKLASGVPDRFSGSGSGTSYFLTINNMEAEDAATYYC QQWNINPLTFGAGTKLELKR The CAR may consist of or comprise one of the following sequences. SEQ ID NO: 15 – CAT19 CAR MGTSLLCWMALCLLGADHADAQVQLQQSGPELVKPGASVKISCKASGYAFSSSWM NWVKQRPGKGLEWIGRIYPGDEDTNYSGKFKDKATLTADKSSTTAYMQLSSLTSED SAVYFCARSLLYGDYLDYWGQGTTLTVSSGGGGSGGGGSGGGGSQIVLTQSPAIM SASPGEKVTMTCSASSSVSYMHWYQQKSGTSPKRWIYDTSKLASGVPDRFSGSGS GTSYFLTINNMEAEDAATYYCQQWNINPLTFGAGTKLELKRSDPTTTPAPRPPTPAP TIASQPLSLRPEACRPAAGGAVHTRGLDFACDIYIWAPLAGTCGVLLLSLVITLYCKR GRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCELRVKFSRSADAPAYQQ GQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAE AYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR The CAT19 CAR has a CD8a spacer and transmembrane domain, 4-1BB endodomain and TCR CD3z endodomain. The CAR provided herein may comprise a variant of the polypeptide of SEQ ID NO: 1-6, 13-15 or 47 having at least 80, 85, 90, 95, 98 or 99% sequence identity, provided that the variant sequence retain the capacity to bind CD19 (when in conjunction with a complementary VL or VH domain, if appropriate). The percentage identity between two polypeptide sequences may be readily determined by programs such as BLAST which is freely available at http://blast.ncbi.nlm.nih.gov. The CD19 CAR exemplified herein (i.e., the CAT19 CAR, SEQ ID NO: 15) has properties which result in lower toxicity and better efficacy in treated patients. When compared with an fmc63 CAR having the same spacer and endodomains, the CAT19 CAR exemplified herein effects killing of target cells expressing CD19 and proliferates in response to CD19 expressing targets, but releases less Interferon-gamma. Further, a small animal model of an aggressive B-cell lymphoma showed equal efficacy and equal engraftment between the fmc63- and CAT19-based CAR-T cells, but surprisingly, less of the CAT19 CAR T-cells were exhausted than fmc63 CAR T-cells. See, Examples 2 and 3 of US Publication No.: 2018-0044417. The CAT19 CAR provided herein may cause 25, 50, 70 or 90% lower IFNγ release in a comparative assay involving bringing CAR T cells into contact with target cells. The CAT19 CAR provided herein may result in a smaller proportion of CAR T cells becoming exhausted than equivalent fmc63 CAR T cells. T cell exhaustion may be assessed using methods known in the art, such as analysis of PD-1 expression. The CAR may cause 20, 30, 40, 50, 60 of 70% fewer CAR T cells to express PD-1 that fmc63 CAR T cells in a comparative assay involving bringing CAR T cells into contact with target cells. Another exemplary CD19 antigen-binding domain contemplated by the disclosure is based on the CD19 antigen-binding domain CD19ALAb (described in WO2016/102965) and comprises: a) a heavy chain variable region (VH) having CDRs with the following sequences: CDR1 – SYWMN (SEQ ID NO: 48); CDR2 – QIWPGDGDTNYNGKFK (SEQ ID NO: 49) CDR3 – RETTTVGRYYYAMDY (SEQ ID NO: 50); and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – KASQSVDYDGDSYLN (SEQ ID NO: 51); CDR2 – DASNLVS (SEQ ID NO: 52) CDR3 – QQSTEDPWT (SEQ ID NO: 53). It is contemplated that it is possible to introduce one or more mutations (substitutions, additions or deletions) into one or more CDRs without negatively affecting CD19- binding activity. Each CDR may, for example, have one, two or three amino acid mutations. The CAR may comprise one of the following amino acid sequences. SEQ ID NO: 54 – Murine CD19ALAb scFv sequence QVQLQQSGAELVRPGSSVKISCKASGYAFSSYWMNWVKQRPGQGLEWIGQIWPG DGDTNYNGKFKGKATLTADESSSTAYMQLSSLASEDSAVYFCARRETTTVGRYYYA MDYWGQGTTVTVSSDIQLTQSPASLAVSLGQRATISCKASQSVDYDGDSYLNWYQ QIPGQPPKLLIYDASNLVSGIPPRFSGSGSGTDFTLNIHPVEKVDAATYHCQQSTEDP WTFGGGTKLEIK SEQ ID NO: 55 – Humanized CD19ALAb scFv sequence – Heavy 19, Kappa 16 QVQLVQSGAEVKKPGASVKLSCKASGYAFSSYWMNWVRQAPGQSLEWIGQIWPG DGDTNYNGKFKGRATLTADESARTAYMELSSLRSGDTAVYFCARRETTTVGRYYYA MDYWGKGTLVTVSSDIQLTQSPDSLAVSLGERATINCKASQSVDYDGDSYLNWYQ QKPGQPPKLLIYDASNLVSGVPDRFSGSGSGTDFTLTISSLQAADVAVYHCQQSTED PWTFGQGTKVEIKR SEQ ID NO: 56 (Humanized CD19ALAb scFv sequence – Heavy 19, Kappa 7) QVQLVQSGAEVKKPGASVKLSCKASGYAFSSYWMNWVRQAPGQSLEWIGQIWPG DGDTNYNGKFKGRATLTADESARTAYMELSSLRSGDTAVYFCARRETTTVGRYYYA MDYWGKGTLVTVSSDIQLTQSPDSLAVSLGERATINCKASQSVDYDGDSYLNWYQ QKPGQPPKVLIYDASNLVSGVPDRFSGSGSGTDFTLTISSLQAADVAVYYCQQSTE DPWTFGQGTKVEIKR The scFv may be in a VH-VL orientation or a VL-VH orientation. The CAR may comprise one of the following VH sequences: SEQ ID NO: 57 – Murine CD19ALAb VH sequence QVQLQQSGAELVRPGSSVKISCKASGYAFSSYWMNWVKQRPGQGLEWIGQIWPG DGDTNYNGKFKGKATLTADESSSTAYMQLSSLASEDSAVYFCARRETTTVGRYYYA MDYWGQGTTVTVSS SEQ ID NO: 58 – Humanized CD19ALAb VH sequence QVQLVQSGAEVKKPGASVKLSCKASGYAFSSYWMNWVRQAPGQSLEWIGQIWPG DGDTNYNGKFKGRATLTADESARTAYMELSSLRSGDTAVYFCARRETTTVGRYYYA MDYWGKGTLVTVSS The CAR may comprise one of the following VL sequences: SEQ ID NO: 59 – Murine CD19ALAb VL sequence DIQLTQSPASLAVSLGQRATISCKASQSVDYDGDSYLNWYQQIPGQPPKLLIYDASN LVSGIPPRFSGSGSGTDFTLNIHPVEKVDAATYHCQQSTEDPWTFGGGTKLEIK SEQ ID NO: 60 (Humanized CD19ALAb VL sequence, Kappa 16) DIQLTQSPDSLAVSLGERATINCKASQSVDYDGDSYLNWYQQKPGQPPKLLIYDASN LVSGVPDRFSGSGSGTDFTLTISSLQAADVAVYHCQQSTEDPWTFGQGTKVEIKR SEQ ID NO: 61 – Humanized CD19ALAb VL sequence, Kappa 7 DIQLTQSPDSLAVSLGERATINCKASQSVDYDGDSYLNWYQQKPGQPPKVLIYDAS NLVSGVPDRFSGSGSGTDFTLTISSLQAADVAVYYCQQSTEDPWTFGQGTKVEIKR The CAR provided herein may comprise a variant of the sequence shown as any of SEQ ID NO: 48-61 having at least 80, 85, 90, 95, 98 or 99% sequence identity, provided that the variant sequence retain the capacity to bind CD19 (when in conjunction with a complementary VL or VH domain, if appropriate). The percentage identity between two polypeptide sequences may be readily determined by programs such as BLAST which is freely available at blast.ncbi.nlm.nih.gov. SIGNAL PEPTIDES The CARs of the cell may comprise a signal peptide so that when the CAR is expressed inside a cell, such as a T-cell, the nascent protein is directed to the endoplasmic reticulum and subsequently to the cell surface, where it is expressed. The core of the signal peptide may contain a long stretch of hydrophobic amino acids that has a tendency to form a single alpha-helix. The signal peptide may begin with a short positively charged stretch of amino acids, which helps to enforce proper topology of the polypeptide during translocation. At the end of the signal peptide there is typically a stretch of amino acids that is recognized and cleaved by signal peptidase. Signal peptidase may cleave either during or after completion of translocation to generate a free signal peptide and a mature protein. The free signal peptides are then digested by specific proteases. The signal peptide may be at the amino terminus of the molecule. The signal peptide may comprise the amino acid sequence of any of SEQ ID NO: 62- 67 or a variant thereof having 5, 4, 3, 2 or 1 amino acid mutations (insertions, substitutions or additions) provided that the signal peptide still functions to cause cell surface expression of the CAR. The signal peptide of SEQ ID NO: 62 is compact and highly efficient. It is predicted to give about 95% cleavage after the terminal glycine, giving efficient removal by signal peptidase. SEQ ID NO: 62 MGTSLLCWMALCLLGADHADA The signal peptide of SEQ ID NO: 63 follows. METDTLLLWVLLLLVPGSTG The signal peptide of SEQ ID NO: 64 follows. METDTLILWVLLLLVPGSTG The signal peptide of SEQ ID NO: 65 follows. MGWSCIILFLVATATGVHS The signal peptide of SEQ ID NO: 66 is derived from IgG1. SEQ ID NO: 66: MSLPVTALLLPLALLLHAARP The signal peptide of SEQ ID NO: 67 is derived from CD8. SEQ ID NO: 67: MAVPTQVLGLLLLWLTDARC The signal peptide for the first CAR may have a different sequence from the signal peptide of the second CAR. SPACERS CARs comprise a spacer to connect the antigen-binding domain with the transmembrane domain and spatially separate the antigen-binding domain from the endodomain. A flexible spacer allows the antigen-binding domain to orient in different directions to facilitate binding. The spacer may, for example, comprise an IgG1 Fc region, an IgG1 hinge or a CD8 stalk, or a combination thereof. The spacer may alternatively comprise an alternative sequence which has similar length and/or domain spacing properties as an IgG1 Fc region, an IgG1 hinge or a CD8 stalk. In the cells provided herein, the first and second CARs may comprise different spacer molecules. For example, the spacer may, for example, comprise an IgG1 Fc region, an IgG1 hinge or a human CD8 stalk or the mouse CD8 stalk. The spacer may alternatively comprise an alternative linker which has similar length and/or domain spacing properties as an IgG1 Fc region, an IgG1 hinge or a CD8 stalk. A human IgG1 spacer may be altered to remove Fc binding motifs. The spacer for the CD19 CAR may comprise a CD8 stalk spacer, or a spacer having a length equivalent to a CD8 stalk spacer. The spacer for the CD19 CAR may have at least 30 amino acids or at least 40 amino acids. It may have between 35-55 amino acids, for example between 40-50 amino acids. It may have about 46 amino acids. The spacer for the BCMA CAR may comprise an IgG1 hinge spacer, or a spacer having a length equivalent to an IgG1 hinge spacer. The spacer for the BCMA CAR may have fewer than 30 amino acids or fewer than 25 amino acids. It may have between 15-25 amino acids, for example between 18-22 amino acids. It may have about 20 amino acids. Examples of amino acid sequences for these spacers are given below: SEQ ID NO: 68 (hinge-CH2CH3 of human IgG1) AEPKSPDKTHTCPPCPAPPVAGPSVFLFPPKPKDTLMIARTPEVTCVVVDVSHEDPE VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKA LPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESN GQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGKKD SEQ ID NO: 69 (human CD8 stalk): TTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACD SEQ ID NO: 70 (human IgG1 hinge): AEPKSPDKTHTCPPCPKDPK SEQ ID NO: 71 (human IgG1 hinge variation) EPKSCDKTHTCPPCP SEQ ID NO: 72 (IgG1 Hinge-Fc) AEPKSPDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESN GQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGKKDPK SEQ ID NO: 73 (IgG1 Hinge – Fc modified to remove Fc receptor recognition motifs) AEPKSPDKTHTCPPCPAPPVA*GPSVFLFPPKPKDTLMIARTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESN GQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGKKDPK Modified residues are underlined; * denotes a deletion. SEQ ID NO: 74 (CD2 ectodomain) KEITNALETWGALGQDINLDIPSFQMSDDIDDIKWEKTSDKKKIAQFRKEKETFKEKD TYKLFKNGTLKIKHLKTDDQDIYKVSIYDTKGKNVLEKIFDLKIQERVSKPKISWTCINT TLTCEVMNGTDPELNLYQDGKHLKLSQRVITHKWTTSLSAKFKCTAGNKVSKESSV EPVSCPEKGLD SEQ ID NO: 75 (CD34 ectodomain) SLDNNGTATPELPTQGTFSNVSTNVSYQETTTPSTLGSTSLHPVSQHGNEATTNITE TTVKFTSTSVITSVYGNTNSSVQSQTSVISTVFTTPANVSTPETTLKPSLSPGNVSDL STTSTSLATSPTKPYTSSSPILSDIKAEIKCSGIREVKLTQGICLEQNKTSSCAEFKKD RGEGLARVLCGEEQADADAGAQVCSLLLAQSEVRPQCLLLVLANRTEISSKLQLMK KHQSDLKKLGILDFTEQDVASHQSYSQKT Since CARs are typically homodimers (see Figure 1A), cross-pairing may result in a heterodimeric chimeric antigen receptor. This is undesirable for various reasons, for example: (1) the epitope may not be at the same “level” on the target cell so that a cross-paired CAR may only be able to bind to one antigen; (2) the VH and VL from the two different scFv could swap over and either fail to recognize target or worse recognize an unexpected and unpredicted antigen. The spacer of the first CAR may be sufficiently different from the spacer of the second CAR in order to avoid cross- pairing. The amino acid sequence of the first spacer may share less than 50%, 40%, 30% or 20% identity at the amino acid level with the second spacer. TRANSMEMBRANE DOMAINS The transmembrane domain is the domain of the CAR that spans the membrane. A transmembrane domain may be any protein structure which is thermodynamically stable in a membrane. This is typically an alpha helix comprising of several hydrophobic residues. The transmembrane domain of any transmembrane protein can be used to supply the transmembrane portion provided herein. The presence and span of a transmembrane domain of a protein can be determined by those skilled in the art using the TMHMM algorithm (http://www.cbs.dtu.dk/services/TMHMM-2.0/). Further, given that the transmembrane domain of a protein is a relatively simple structure, i.e, a polypeptide predicted to form a hydrophobic alpha helix of sufficient length to span the membrane, an artificially designed transmembrane domain may also be used (US 7052906 B1 describes synthetic transmembrane components). The transmembrane domain may be derived from CD28, which gives good receptor stability. The CD28 transmembrane domain sequence is shown as SEQ ID NO: 76 SEQ ID NO: 76 FWVLVVVGGVLACYSLLVTVAFIIFWV The transmembrane domain may be derived from human Tyrp-1. The tyrp-1 transmembrane domain sequence is shown as SEQ ID NO: 77. SEQ ID NO: 77 IIAIAVVGALLLVALIFGTASYLI The transmembrane domain may be derived from CD8A. The CD8A transmembrane domain sequence is shown as SEQ ID NO: 78. SEQ ID NO: 78 IYIWAPLAGTCGVLLLSLVITLYC ENDODOMAINS As noted above, the endodomain is the signal-transmission portion of the CAR. After antigen recognition, receptors cluster, native CD45 and CD148 are excluded from the synapse and a signal is transmitted to the cell. The most commonly used endodomain component is that of CD3-zeta which contains three ITAMs. This transmits an activation signal to the T cell after antigen is bound. CD3-zeta may not provide a fully competent activation signal and additional co-stimulatory signaling may be needed. For example, chimeric CD28 and OX40 can be used with CD3-Zeta to transmit a proliferative / survival signal, or all three can be used together. The cells provided herein comprise two CARs, each with an endodomain. The endodomain of the first CAR and the endodomain of the second CAR may comprise: (i) an ITAM-containing endodomain, such as the endodomain from CD3 zeta; and/or (ii) a co-stimulatory domain, such as the endodomain from CD28; and/or (iii) a domain which transmits a survival signal, for example a TNF receptor family endodomain such as OX-40 or 4-1BB. Thus, the endodomain of the CAR of the present disclosure may comprise combinations of one or more of the CD3-Zeta endodomain, the 41BB endodomain, the OX40 endodomain or the CD28 endodomain. The intracellular T-cell signalling domain (endodomain) of the CAR of the present disclosure may comprise the sequence shown as any of SEQ ID NO: 79-86 or a variant thereof having at least 80% sequence identity. SEQ ID NO: 79 (CD3 zeta endodomain) RSRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRK NPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQ ALPPR SEQ ID NO: 80 (41BB endodomain) KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL SEQ ID NO: 81 (OX40 endodomain) RRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKI SEQ ID NO: 82 (CD28 endodomain) KRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAY Examples of combinations of such endodomains include 41BB-Zeta, OX40-Zeta, CD28-Zeta and CD28-OX40-Zeta. SEQ ID NO: 83 (41BB-Zeta endodomain fusion) KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCELRVKFSRSADAPAYQ QGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMA EAYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR SEQ ID NO: 84 (OX40-Zeta endodomain fusion) RRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKIRVKFSRSADAPAYQQGQN QLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAEAYS EIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR SEQ ID NO: 85 (CD28Zeta endodomain fusion) KRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRSRVKFSRSADAPAYQQG QNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAEA YSEIGMKGERRRGKGHDGLYQGLSTATKDTYDALHMQALPPR SEQ ID NO: 86 (CD28OXZeta) KRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRSRDQRLPPDAHKPPGG GSFRTPIQEEQADAHSTLAKIRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVL DKRRGRDPEMGGKPRRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGL YQGLSTATKDTYDALHMQALPPR A variant sequence may have at least 80%, 85%, 90%, 95%, 98% or 99% sequence identity to any of SEQ ID NO: 79-86 provided that the sequence provides an effective transmembrane domain/intracellular T cell signaling domain. NUCLEIC ACIDS One or more nucleic acid(s) provided herein encode a BCMA CAR and a CD19 CAR of the disclosure. As used herein, the terms “polynucleotide”, “nucleotide”, and “nucleic acid” are intended to be synonymous with each other. The nucleic acid may be, for example, an RNA, a DNA or a cDNA. Nucleic acids may comprise DNA or RNA. They may be single-stranded or double-stranded. They may also be polynucleotides which include within them synthetic or modified nucleotides. A number of different types of modification to oligonucleotides are known in the art. These include methylphosphonate and phosphorothioate backbones, addition of acridine or polylysine chains at the 3’ and/or 5’ ends of the molecule. For the purposes of the use as described herein, it is to be understood that the polynucleotides may be modified by any method available in the art. Such modifications may be carried out in order to enhance the in vivo activity or life span of polynucleotides of interest. Alternative codons may be used in regions of sequence encoding the same or similar amino acid sequences, in order to avoid homologous recombination when the both CARs are encoded by the same vector. Due to the degeneracy of the genetic code, it is possible to use alternative codons which encode the same amino acid sequence. For example, the codons “ccg” and “cca” both encode the amino acid proline, so using “ccg” may be exchanged for “cca” without affecting the amino acid in this position in the sequence of the translated protein. The alternative RNA codons which may be used to encode each amino acid are summarized in Table 4. Table 4 Alternative codons may be used in the portions of nucleic acid which encode the spacer of the first CAR and the spacer of the second CAR, especially if the same or similar spacers are used in the first and second CARs. Alternative codons may be used in the portions of nucleic acid which encode the transmembrane domain of the first CAR and the transmembrane of the second CAR, especially if the same or similar transmembrane domains are used in the first and second CARs. Alternative codons may be used in one or more nucleic acids which encode co- stimulatory domains, such as the CD28 endodomain. Alternative codons may be used in one or more domains which transmit survival signals, such as OX40 and 41BB endodomains. Alternative codons may be used in the portions of nucleic acid encoding a CD3zeta endodomain and/or the portions of nucleic acid encoding one or more costimulatory domain(s) and/or the portions of nucleic acid encoding one or more domain(s) which transmit survival signals. NUCLEIC ACID CONSTRUCT The present disclosure also provides a nucleic acid construct encoding a chimeric receptor of the disclosure. A nucleic acid construct encoding a FabCAR (Figure 2a) may have the structure: VH-CH-spacer-TM-endo-coexpr-VL-CL or VL-CL-spacer-TM-endo-coexpr-VH-CH in which: VH is a nucleic acid sequence encoding a heavy chain variable region; CH is a nucleic acid sequence encoding a heavy chain constant region spacer is a nucleic acid encoding a spacer; TM is a a nucleic acid sequence encoding a transmembrane domain; endo is a nucleic acid sequence encoding an endodomain; coexpr is a nucleic acid sequence enabling co-expression of the first and second polypeptides; VL is a nucleic acid sequence encoding a light chain variable region; and CL is a nucleic acid sequence encoding a light chain constant region. For both structures mentioned above, nucleic acid sequences encoding the two polypeptides may be in either order in the construct. There is also provided a nucleic acid construct encoding an OR gate, which comprises two of more CARs, one of which may be a FabCAR according to the present disclosure. A nucleic acid construct encoding a double OR gate may have the structure: VH-CH-spacer1-TM1-endo1-coexpr1-VL-CL-coexpr2-AgBD-spacer2-TM2-endo2; or VL-CL-spacer-TM1-endo1-coexpr1-VH-CH-coexpr2-AgBD-spacer2-TM2-endo2 in which: VH is a nucleic acid sequence encoding a heavy chain variable region of the first CAR; CH is a nucleic acid sequence encoding a heavy chain constant region of the first CAR; Spacer 1 is a nucleic acid sequence encoding a spacer of the first CAR; TM1 is a a nucleic acid sequence encoding a transmembrane domain of the first CAR; Endo1 is a nucleic acid sequence encoding an endodomain of the first CAR; Coexpr1 and coexpr2, which my be the same or different, are nucleic acid sequences enabling co-expression of the first and second polypeptides of the first CAR; and the first and second CARs; VL is a nucleic acid sequence encoding a light chain variable region of the first CAR; CL is a nucleic acid sequence encoding a light chain constant region of the first CAR; AgBD is a nucleic acid sequence encoding an antigen binding domain of the second CAR; Spacer2 is a nucleic acid sequence encoding a spacer of the second CAR; TM2 is a a nucleic acid sequence encoding a transmembrane domain of the second CAR; and Endo2 is a nucleic acid sequence encoding an endodomain of the second CAR. The antigen-binding domain of the second CAR (AgBD) may, for example, be an scFv or a domain antibody or single domain antibody dAb. For both structures mentioned above, nucleic acid sequences encoding the two polypeptides of the first CAR; and the nucleic acid sequences encoding the first and second CARs may be in any order in the construct. A nucleic acid construct encoding a double FabCAR OR gate may have the structure: VH1-CH1-spacer1-TM1-endo1-coexpr1-VL1-CL1-coexpr2-VH2-CH2-spacer2-TM2- endo2-coexpr3-VL2-CL2; VH1-CH1-spacer1-TM1-endo1-coexpr1-VL1-CL1-coexpr2-VL2-CL2-spacer2-TM2- endo2-coexpr3-VH2-CH2; VL1-CL1-spacer1-TM1-endo1-coexpr1-VH1-CH1-coexpr2-VL2-CL2-spacer2-TM2- endo2-coexpr3-VH2-CH2; or VL1-CL1-spacer1-TM1-endo1-coexpr1-VH1-CH1-coexpr2-VH2-CH2-spacer2-TM2- endo2-coexpr3-VL2-CL2; in which: VH1 is a nucleic acid sequence encoding a heavy chain variable region of the first CAR; CH1 is a nucleic acid sequence encoding a heavy chain constant region of the first CAR; Spacer 1 is a nucleic acid sequence encoding a spacer of the first CAR; TM1 is a a nucleic acid sequence encoding a transmembrane domain of the first CAR; Endo1 is a nucleic acid sequence encoding an endodomain of the first CAR; Coexpr1, coexpr2, and coexpr 3 which may be the same or different, are nucleic acid sequences enabling co-expression of the first and second polypeptides of the first CAR; and the first and second polypeptides of the second CAR; VL2 is a nucleic acid sequence encoding a light chain variable region of the second CAR; CL2 is a nucleic acid sequence encoding a light chain constant region of the second CAR; VH2 is a nucleic acid sequence encoding a heavy chain variable region of the second CAR; CH2 is a nucleic acid sequence encoding a heavy chain constant region of the second CAR; Spacer 2 is a nucleic acid sequence encoding a spacer of the second CAR; TM2 is a nucleic acid sequence encoding a transmembrane domain of the second CAR; Endo2 is a nucleic acid sequence encoding an endodomain of the second CAR; VL2 is a nucleic acid sequence encoding a light chain variable region of the second CAR; CL2 is a nucleic acid sequence encoding a light chain constant region of the second CAR. As used herein, the terms “polynucleotide”, “nucleotide”, and “nucleic acid” are intended to be synonymous with each other. It will be understood by a skilled person that numerous different polynucleotides and nucleic acids can encode the same polypeptide as a result of the degeneracy of the genetic code. In addition, it is to be understood that skilled persons may, using routine techniques, make nucleotide substitutions that do not affect the polypeptide sequence encoded by the polynucleotides described here to reflect the codon usage of any particular host organism in which the polypeptides are to be expressed. Nucleic acids according to the disclosure may comprise DNA or RNA. They may be single-stranded or double-stranded. They may also be polynucleotides which include within them synthetic or modified nucleotides. A number of different types of modification to oligonucleotides are known in the art. These include methylphosphonate and phosphorothioate backbones, addition of acridine or polylysine chains at the 3’ and/or 5’ ends of the molecule. For the purposes of the use as described herein, it is to be understood that the polynucleotides may be modified by any method available in the art. Such modifications may be carried out in order to enhance the in vivo activity or life span of polynucleotides of interest. The terms “variant”, “homologue” or “derivative” in relation to a nucleotide sequence include any substitution of, variation of, modification of, replacement of, deletion of or addition of one (or more) nucleic acid from or to the sequence. In the structure above, “coexpr” is a nucleic acid sequence enabling co-expression of two polypeptides as separate entities. It may be a sequence encoding a cleavage site, such that the nucleic acid construct produces both polypeptides, joined by a cleavage site(s). The cleavage site may be self-cleaving, such that when the polypeptide is produced, it is immediately cleaved into individual peptides without the need for any external cleavage activity. The cleavage site may be any sequence which enables the two polypeptides to become separated. The term “cleavage” is used herein for convenience, but the cleavage site may cause the peptides to separate into individual entities by a mechanism other than classical cleavage. For example, for the Foot-and-Mouth disease virus (FMDV) 2A self- cleaving peptide (see below), various models have been proposed for to account for the “cleavage” activity: proteolysis by a host-cell proteinase, autoproteolysis or a translational effect (Donnelly et al (2001) J. Gen. Virol. 82:1027-1041). The exact mechanism of such “cleavage” is not important for the purposes of the present disclosure, as long as the cleavage site, when positioned between nucleic acid sequences which encode proteins, causes the proteins to be expressed as separate entities. The cleavage site may, for example be a furin cleavage site, a Tobacco Etch Virus (TEV) cleavage site or encode a self-cleaving peptide. A ‘self-cleaving peptide’ refers to a peptide which functions such that when the polypeptide comprising the proteins and the self-cleaving peptide is produced, it is immediately “cleaved” or separated into distinct and discrete first and second polypeptides without the need for any external cleavage activity. The self-cleaving peptide may be a 2A self-cleaving peptide from an aphtho- or a cardiovirus. The primary 2A/2B cleavage of the aptho- and cardioviruses is mediated by 2A “cleaving” at its own C-terminus. In apthoviruses, such as foot-and-mouth disease viruses (FMDV) and equine rhinitis A virus, the 2A region is a short section of about 18 amino acids, which, together with the N-terminal residue of protein 2B (a conserved proline residue) represents an autonomous element capable of mediating “cleavage” at its own C-terminus (Donelly et al (2001) as above). “2A-like” sequences have been found in picornaviruses other than aptho- or cardioviruses, ‘picornavirus-like’ insect viruses, type C rotaviruses and repeated sequences within Trypanosoma spp and a bacterial sequence (Donnelly et al (2001) as above). The cleavage site may comprise the 2A-like sequence shown as SEQ ID NO: 87 (RAEGRGSLLTCGDVEENPGP) or SEQ ID NO: 88 (ATNFSLLKQAGDVEENPGP). SUICIDE GENE A nucleic acid construct may also comprise a nucleic acid encoding a suicide gene. Since T-cells engraft and are autonomous, a means of selectively deleting CAR T- cells in patients is desirable. Suicide genes are genetically encodable mechanisms which result in selective destruction of infused T-cells in the face of unacceptable toxicity. The earliest clinical experience with suicide genes is with the Herpes Virus Thymidine Kinase (HSV-TK) which renders T-cells susceptible to Ganciclovir. HSV- TK is a highly effective suicide gene. However, pre-formed immune responses may restrict its use to clinical settings of considerable immunosuppression such as haploidentical stem cell transplantation. Inducible Caspase 9 (iCasp9) is a suicide gene constructed by replacing the activating domain of Caspase 9 with a modified FKBP12. iCasp9 is activated by an otherwise inert small molecular chemical inducer of dimerization (CID). iCasp9 has been recently tested in the setting of haploidentical HSCT and can abort GvHD. Both iCasp9 and HSV-TK are intracellular proteins, so when used as the sole transgene, they have been co-expressed with a marker gene to allow selection of transduced cells. WO2016/135470 describes a suicide gene which also comprises Caspase 9 but can be induced to dimerise using rapamycin or a rapamycin analog. This suicide gene, sometimes termed Rapcasp9 or Rapacasp9, has the amino acid sequence shown as SEQ ID No.89. SEQ ID No.89 (FRB-FKBP12-L3-dCasp9) <-----------------------FRB--------------------------------- MASRILWHEMWHEGLEEASRLYFGERNVKGMFEVLEPLHAMMERGPQTLKETSFNQAYGR -----------------FRB-------------------><L1-><--FKBP12------ DLMEAQEWCRKYMKSGNVKDLLQAWDLYYHVFRRISKLEYSGGGSLEGVQVETISPGDGR ------------------FKBP12------------------------------------ TFPKRGQTCVVHYTGMLEDGKKFDSSRDRNKPFKFMLGKQEVIRGWEEGVAQMSVGQRAK ---------------------------------><------L3------><--dCasp9- LTISPDYAYGATGHPGIIPPHATLVFDVELLKLESGGGGSGGGGSGGGGSGVDGFGDVGA ------------------------dCasp9------------------------------ LESLRGNADLAYILSMEPCGHCLIINNVNFCRESGLRTRTGSNIDCEKLRRRFSSLHFMV ------------------------dCasp9------------------------------ EVKGDLTAKKMVLALLELAQQDHGALDCCVVVILSHGCQASHLQFPGAVYGTDGCPVSVE ------------------------dCasp9------------------------------ KIVNIFNGTSCPSLGGKPKLFFIQACGGEQKDHGFEVASTSPEDESPGSNPEPDATPFQE ------------------------dCasp9------------------------------ GLRTFDQLDAISSLPTPSDIFVSYSTFPGFVSWRDPKSGSWYVETLDDIFEQWAHSEDLQ --------------dCasp9----------------> SLLLRVANAVSVKGIYKQMPGCFNFLRKKLFFKTSAS In the above sequence “FKBP12” refers to the sequence of FKBP12; “dCasp9” refers to the catalytic domain of Casp9; “L1” is a one repeat linker; “FMD-2A” is a Foot and mouth disease 2A like peptide ERAV; “FRB” is the FRB domain of mTOR; “L3” is a two repeat linker; and “FRBw” is codon wobbled FRB WO2013/153391 describes a marker/suicide gene known as RQR8 which can be detected with the antibody QBEnd10 and expressing cells lysed with the therapeutic antibody Rituximab. The sort/suicide gene RQR8 has the amino acid sequence shown as SEQ ID No.79. SEQ ID No.79 (RQR8) CPYSNPSLCSGGGGSELPTQGTFSNVSTNVSPAKPTTTACPYSNPSLCSGGGGSP APRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACDIYIWAPLAGTCGVLLLS LVITLYCNHRNRRRVCKCPRPVV Including a suicide gene in one or more of the vectors in the viral vector composition of the invention enables the selective ablation of a proportion of transduced cells within the subject. For example, for two vectors A and B, transduced cells will be a mixture of cells transduced with vector A alone, cells transduced with vector B alone, and cells transduced with both vectors A and B. If vector A expresses or co-expresses a suicide gene, activating the suicide gene will cause the deletion of cells transduced with vector A alone, or with vectors A and B, but cells transduced with vector B alone will be spared. This is particularly useful in the treatment of autoantibody-driven autoimmune diseases as it may desirable avoid a long-lasting complete absence of plasma cells. As explained above, antibody secretion by plasma cells is the corner-stone of long- term immune protection resulting from previous antigen exposure and immunisation. Removal (or dramatic reduction of) of the plasma cell compartment by CAR-T cells expressing an anti-BCMA CAR may therefore be undesirable in the long term. If a suicide gene is included on the cassette for the BCMA-expressing CAT, then once a sufficient number of autoantibody-secreting plasma cells have been killed by the CAR-T cell composition, cells expressing the BCMA-targeting CAR can be selectively deleted by triggering the suicide gene. Cells expressing the anti-CD19 CAR alone would be spared and can continue their therapeutic effect against autoantibody- secreting B cells. Alternatively, both the vector expressing the CD19 CAR and the BCMA CAR may comprise a nucleic acid encoding a suicide gene, which may be the same or different. In this way all CAR-T cells can be ablated by administering the or both agent(s). VECTORS The present disclosure also provides a vector, or kit of vectors which comprises one or more CAR-encoding nucleic acid(s). Such a vector may be used to introduce the nucleic acid(s) into a host cell so that it expresses the first and second CARs. The vector may, for example, be a plasmid or a viral vector, such as a retroviral vector or a lentiviral vector, or a transposon-based vector or synthetic mRNA. The vector may be capable of transfecting or transducing a T cell. There is also provided a viral vector composition which comprises two vectors: a first vector which comprises a nucleic acid sequence encoding an anti-CD19 CAR and a second vector which comprises a nucleic acid sequence encoding an anti-BCMA CAR. Transduction of cells with the viral vector composition will produce a combinatorially transduced cell product which comprises the following cell subpopulations: a) cell which express the anti-CD19 CAR alone; b) cells which express the anti-BCMA CAR alone; and c) cells which co-express the anti-CD19 CAR and anti-BCMA CAR. CELLS Cells are provided herein which co-express a first CAR and a second CAR, wherein one CAR binds BCMA and the other CAR binds CD19, such that the cell recognizes a target cell expressing either of these markers. A combinatorial CAR-expressing cell product is also provided which comprise cells which co-express a BCMA CAR and a CD19 CAR, as well as cells that express the BCMA CAR alone and cells that express the CD19 CAR alone. Dual targeting of two antigens has various advantages: 1. In the treatment of autoimmune diseases, the CAR-expressing cells will target both B cells and plasma cells, leading to more efficient cessation of the production of autoantibodies. 2. Dual targeting enables “piggybacking” of BCMA specificity onto long persisting CD19 CAR T cells. CAT19 CAR T-cell persistence is well demonstrated. Reported BCMA CAR T-cell persistence is typically short-lived which is likely to be due to reduced signaling due to low BCMA target density. Cells which co-express CD19 and BCMA CARS are more likely to survive and persist in vivo than cells which express BCMA-CAR alone due to the prevalence of the CD19 antigen. Using a mixed population of cells which comprises cells which co-express a BCMA CAR and a CD19 CAR, as well as cells that express the BCMA CAR alone and cells that express the CD19 CAR alone is also associated with various advantages: 1. A suicide gene can be used on one vector, or different suicide genes on the two vectors, facilitating selective removal of a sub-population of CAR-expressing cells without killing all CAR-expressing cells 2. Flexibility in CAR expression and/or stoichiometry enables in vivo evolution to occur, meaning that cells with the optimal ratio of expression or co-expression for CAR-T persistence and engraftment will win out. 3. Immune response against the transgene products may be reduced. If two potentially immunogenic binders are encoded in the same expression cassette, the probability of triggering and immune response doubles. With double transduction the probability that at least one population will persist increases. The cell may be any eukaryotic cell capable of expressing a CAR at the cell surface, such as an immunological cell. In particular, the cell may be an immune effector cell such as a T cell or a natural killer (NK) cell. T cells or T lymphocytes are a type of lymphocyte that play a central role in cell- mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells (NK cells), by the presence of a T-cell receptor (TCR) on the cell surface. There are various types of T cell, as summarized below. Helper T helper cells (TH cells) assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages. TH cells express CD4 on their surface. TH cells become activated when they are presented with peptide antigens by MHC class II molecules on the surface of antigen presenting cells (APCs). These cells can differentiate into one of several subtypes, including TH1, TH2, TH3, TH17, Th9, or TFH, which secrete different cytokines to facilitate different types of immune responses. Cytotoxic T cells (TC cells, or CTLs) destroy virally infected cells and tumor cells, and are also implicated in transplant rejection. CTLs express the CD8 at their surface. These cells recognize their targets by binding to antigen associated with MHC class I, which is present on the surface of all nucleated cells. Through IL-10, adenosine and other molecules secreted by regulatory T cells, the CD8+ cells can be inactivated to an anergic state, which prevent autoimmune diseases such as experimental autoimmune encephalomyelitis. Memory T cells are a subset of antigen-specific T cells that persist long-term after an infection has resolved. They quickly expand to large numbers of effector T cells upon re-exposure to their cognate antigen, thus providing the immune system with “memory” against past infections. Memory T cells comprise three subtypes: central memory T cells (TCM cells) and two types of effector memory T cells (TEM cells and TEMRA cells). Memory cells may be either CD4+ or CD8+. Memory T cells typically express the cell surface protein CD45RO. Regulatory T cells (Treg cells), formerly known as suppressor T cells, are crucial for the maintenance of immunological tolerance. Their major role is to shut down T cell- mediated immunity toward the end of an immune reaction and to suppress auto- reactive T cells that escaped the process of negative selection in the thymus. Two major classes of CD4+ Treg cells have been described — naturally occurring Treg cells and adaptive Treg cells. Naturally occurring Treg cells (also known as CD4+CD25+FoxP3+ Treg cells) arise in the thymus and have been linked to interactions between developing T cells with both myeloid (CD11c+) and plasmacytoid (CD123+) dendritic cells that have been activated with TSLP. Naturally occurring Treg cells can be distinguished from other T cells by the presence of an intracellular molecule called FoxP3. Mutations of the FOXP3 gene can prevent regulatory T cell development, causing the fatal autoimmune disease IPEX. Adaptive Treg cells (also known as Tr1 cells or Th3 cells) may originate during a normal immune response. The T cell provided herein may be any of the T cell types mentioned above, in particular a CTL. Natural killer (NK) cells are a type of cytolytic cell which forms part of the innate immune system. NK cells provide rapid responses to innate signals from virally infected cells in an MHC independent manner. NK cells (belonging to the group of innate lymphoid cells) are defined as large granular lymphocytes (LGL) and constitute the third kind of cells differentiated from the common lymphoid progenitor generating B and T lymphocytes. NK cells are known to differentiate and mature in the bone marrow, lymph node, spleen, tonsils and thymus where they then enter into the circulation. The CAR-expressing cells provided herein may be any of the cell types mentioned above. CAR-expressing cells, such as CAR-expressing T or NK cells may either be created ex vivo either from a patient’s own peripheral blood (1st party), or in the setting of a haematopoietic stem cell transplant from donor peripheral blood (2nd party), or peripheral blood from an unconnected donor (3rd party). Alternatively, T or NK cells provided herein may be derived from ex vivo differentiation of inducible progenitor cells or embryonic progenitor cells to T or NK cells. Alternatively, an immortalized T-cell line which retains its lytic function and could act as a therapeutic may be used. The CAR cells are generated by introducing DNA or RNA coding for the CARs by one of many means including, but not limited to, transduction with a viral vector, transfection with DNA or RNA. Cells may be activated and/or expanded prior to being transduced with CAR-encoding nucleic acid, for example by treatment with an anti- CD3 monoclonal antibody. The T or NK cells provided herein may be made by: (i) isolation of a T or NK cell- containing sample from a subject or other sources listed above, and (ii) transduction or transfection of the T or NK cells with one or more a nucleic acid(s) encoding the CD19 and BCMA CARs. The T or NK cells may then by purified, for example, selected on the basis of expression of the antigen-binding domain of the antigen-binding polypeptide. The present disclosure also provides a cell composition comprising CAR-expressing T cells and/or CAR-expressing NK cells, which cells co-express a CAR that binds CD19 and another CAR that binds BCMA, such that the cells can recognize a target cell expressing either of these markers. The cell composition may be made by transducing a blood-sample ex vivo with a nucleic acid according to the present disclosure. The term “CD19/BCMA CAR T-cell composition” refers herein to a cell composition comprising a mixture of untransduced cells, cells expressing a CD19 CAR alone, cells expressing a BCMA CAR alone, and cells expressing both the CD19 and BCMA CARs. PHARMACEUTICAL COMPOSITIONS The present disclosure also relates to a pharmaceutical composition containing a plurality of CAR-expressing cells, such as T cells or NK cells provided herein. Pharmaceutical compositions comprising the BCMA/CD19 CAR T-cell product described in the examples are provided. The pharmaceutical composition may additionally comprise a pharmaceutically acceptable carrier, diluent or excipient. The pharmaceutical composition may optionally comprise one or more further pharmaceutically active polypeptides and/or compounds. Such a formulation may, for example, be in a form suitable for intravenous infusion. METHODS OF TREATMENT The cell compositions of the present disclosure, for example combinatorially transduced BCMA/CD19 CAR T-cell composition, are capable of killing cells recognizable by expression of BCMA or CD19, such as B cells and plasma cells. CAR-expressing cells, such as T cells, may either be created ex vivo either from a patient’s own peripheral blood (1st party), or in the setting of a haematopoietic stem cell transplant from donor peripheral blood (2nd party), or peripheral blood from an unconnected donor (3rd party). Alternatively, CAR T-cells may be derived from ex-vivo differentiation of inducible progenitor cells or embryonic progenitor cells to T-cells. In these instances, CAR T-cells are generated by introducing DNA or RNA coding for the CAR by one of many means including transduction with a viral vector, transfection with DNA or RNA. Examples of autoimmune diseases include, but are not limited to: systemic lupus erythematosus (SLE), rheumatoid arthritis, idiopathic inflammatory myopathy (IIM, myositis), ANCA-associated vasculitis, inflammatory bowel disease (IBD), multiple sclerosis (MS), Type I diabetes, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Graves’ disease, Hashimoto’s thyroiditis or Hashimoto’s disease, myasthenia gravis, neuromyelitis optica, N-methyl-D-aspartate receptor (NMDAR) encephalitis, Lambert-Eaton syndrome, scleroderma, vasculitis, pemphigus vulgaris, pemphigus foliaceus, epidermolysis bullosa acquisita, bullous pemphigoid, lupus nephritis, membranous nephropathy, Goodpasture’s syndrome, immune thrombocytopenic purpura, thrombotic thrombocytopenic purpura, primary antiphospholipid syndrome, autoimmune haemolytic anaemia, and acquired haemophilia. The disease may be an autoantibody-driven autoimmune disease and/or an autoimmune disease associated with particularly high autoantibody titers. In particular, the disease may be systemic lupus erythematosus (SLE), lupus nephritis or membranous nephropathy (MN). Treatment with the T cells provided herein may kill autoantibody producing B-cell, plasma cell, and/or precursor cells. The methods provided herein slow or prevent progression of the autoimmune disease, diminish the extent of the autoimmune disease, result in remission (partial or total) of the autoimmune disease, and/or prolong survival of the patient. The patient may be administered a single dose of between 1 x 106 and 1x107 CAR T- cells, such as BCMA/CD19 CAR T-cell product described in the Examples. For example, the patient may be administered a single dose of about 1 x 106, 5 x 106, 50 x 106, 100 x 106, 150 x 106 or about 4x107 CAR T-cells, such as BCMA/CD19 CAR T- cell product described in the Examples. The administration may be an intravenous injection through a Hickman line or peripherally inserted central catheter (PICC line). The patient may be administered conditioning chemotherapy or lymphodepletion prior to receiving the CAR T-cells. The conditioning chemotherapy or lymphodepletion may include cyclophosphamide and fludarabine, such as 300mg/m2 cyclophosphamide x 3 doses on Day -5 and Day -3 and 30mg/m2 fludarabine for 3 doses over Day -5 to Day -3 prior to BCMA/CD19 CAR T-cell product infusion on Day 0. An alternative lymphodepleting regimen may include 60mg/kg cyclophosphamide on Day -6, and and 30mg/m2 fludarabine for 3 doses over Day -5 to Day -3 prior to BCMA/CD19 CAR T-cell product infusion on Day 0. These doses may be adjusted to renal function and serum Fludarabine levels. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) Systemic lupus erythematosus (SLE) is an autoimmune disease that can involve almost all body organs. Lupus may be classified into several subtypes according to the clinical features including systemic lupus erythematosus, cutaneous lupus erythematosus, drug-induced lupus, and neonatal lupus. The progression of SLE involves the immune system. Almost all of the pathological manifestations of SLE are due to antibody formation and deposition of immune complexes in different organs of the body. When the immune complexes are formed, they deposit in different body tissues and vessels, which may lead to complement activation and more organ damage. Other factors, including genetic factors, hormonal abnormalities, and environmental factors, also play a role in the pathogenesis of SLE. There are no established causes of systemic lupus erythematosus, but the most potent risk factors in the development of SLE are known to be female sex, HLA genetic mutations, African American, Asian, or non-Causcasian race, ultraviolet light exposure, and previous exposure to certain infections. Worldwide, the prevalence of systemic lupus erythematosus is 60 per 100,000 persons. SLE can cause numerous flare ups. SLE usually develops in the second and third decades of life, although it can present at any age. SLE usually begins with mild symptoms such as fatigue, fever, and skin rashes. Without treatment, the patient will develop symptoms of end organ damage, which eventually leads to death in most cases. Common complications of systemic lupus erythematosus include dermatitis, nephritis, and arthritis. Most of these complications occur in chronic cases and lead to significant debilitation. The prognosis of systemic lupus erythematosus can vary. SLE can range from a benign illness to an extremely rapidly progressive disease that can lead to fulminant organ failure and death. Without treatment, systemic lupus erythematosus results in very high mortality rate. During the mid-20th century, the mortality rate of SLE was reported to be higher than 60%. SLE can be diagnosed based on SLICC criteria. The patient may have a positive history of familial lupus, skin rashes (especially photosensitive skin rashes), arthritis, and fatigue, which may be suggestive of systemic lupus erythematosus. The most common symptoms of SLE include constitutional symptoms such as fatigue, fever, myalgia, and weight changes. Other, organ-specific symptoms mostly occur with disease progression. SLE may show a variety of symptoms in different organs depending on the complications of the disease. The therapy for systemic lupus erythematosus (SLE) is targeted towards controlling disease activity and preventing organ damage. The choice of treatment for systemic lupus erythematosus (SLE) varies based on the severity of the disease and symptoms. SLE patients are commonly treated with hydroxychloroquine. Other pharmacologic medical therapies for SLE include glucocorticoids like oral prednisone or intravenous methylprednisolone, NSAIDs like celecoxib, and immunosuppressive therapy with mycophenolate, cyclophosphamide, or, particularly in severe cases, rituximab. Cutaneous lupus erythematosus (CLE), if present without the involvement of any other organ system, can be treated with topical corticosteroids. TREATMENT OF SLE Considering the important role of B cells and plasma cells in SLE disease pathogenesis, it contemplated herein that infusion of a patient with a CD19/BCMA CAR T cell product (for example, AUTO8) will eliminate pathogenic, autoantibody- producing cells. Patients to be treated include, but are not limited to, patients with severe, refractory SLE who are predicted to have a poor outcome if treated with standard of care therapy due to disease severity, one or more areas of SLE-related organ system involvement, and prior exposure to multiple SLE treatment strategies. Patients to be treated: may have a diagnosis of SLE fulfilling the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) Classification Criteria for Systemic Lupus Erythematosus; may be positive for at least one of the following autoantibodies: antinuclear antibodies (ANA) at a titer of ≥1:80, or anti-dsDNA (≥30 IU/mL) or anti-Sm (> ULN), anti-histone or anti-chromatin (> ULN); may have severe SLE defined as a) a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of ≥ 8 points (of which 4 are non-laboratory items and with the exclusion of points associated with neurological findings [SLEDAI 2K items 1-7]) and b) at least one of the following significant SLE-related organ involvements: i) renal (ongoing active, biopsy-proven lupus nephritis), ii) moderate or severe pericarditis/myocarditis, iii) moderate or severe pleuritis or other lung involvement, iv) vasculitis, and v) severe hematologic manifestation (e.g. severe thrombocytopenia or severe autoimmune hemolytic anemia); and/or may have refractory SLE defined as lack of response, insufficient response or lack of sustained response or intolerance to: a) hydroxychloroquine treatment in combination with corticosteroids, and b) ≥2 of the following treatment groups used for at least 3 months each or less if intolerant: i) Immunosuppressive drugs (e.g., methotrexate, azathioprine, mycophenolate mofetil, mycophenolic acid, tacrolimus, leflunomide, cyclosporine, voclosporin or cyclophosphamide), ii) B cell-targeting agents (e.g., belimumab, anti-CD20 mAb), and iii) cytokine inhibitors (e.g., anifrolumab). Patients may be subject to a pre-conditioning chemotherapy such as lymphodepletion chemotherapy prior to CD19/BCMA CAR treatment. The lymphodepletion chemotherapy may comprise treatment with fludarabine and cyclophosphamide. The patients may receive three doses of fludarabine 25 mg/m2/d intravenous administration on Day -5, Day -4, and Day -3 relative to CD19/BCMA CAR treatment and one dose of cyclophosphamide 1000 mg/m2 intravenous administration on Day -3 relative to CD19/BCMA CAR treatment. In the methods of treatment provided herein for an autoimmune disease, such as SLE, the patients may be administered a single dose of 50 x 106 (±20%) transduced cells. Alternative doses contemplated are an escalated (100 x 106 [±20%]) or a de- escalated (30 x 106 [±20%]) CAR-T cell dose. The administration may be, for example, an intravenous injection through a Hickman line or peripherally inserted central catheter (PICC line). Treated patients may exhibit improvement in one or more of the following assessments: Definition of Remission in SLE (Doris), improvements may include SLEDAI = 0 and/or PGA < 0.5 on a visual analog scale from 0-3; Lupus Low Disease Activity State (LLDAS), improvements may include SLEDAI-2K < 4 (no activity in major organ systems (renal, central nervous system, cardiopulmonary, vasculitis, fever and no hemolytic anemia or gastrointestinal activity), no new features of lupus disease activity compared to the previous assessment, PGA < 1 on a visual analog scale from 0-3, current prednisolone (or equivalent) dose ≤ 7.5 mg daily, and/or well-tolerated standard maintenance doses of immunosuppressive drugs and approved biologic agents, excluding investigational drugs; Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K) score; Physician’s global assessment (PGA); Health Assessment Questionnaire – Disability Index (HAQ-DI); Functional Assessment of Chronic Illness Therapy – Fatigue Scale (FACIT-Fatigue) score; Safety of Estrogens in Lupus Erythematosus National Assessment-SLEDAI (SELENA-SLEDAI) Flare Index (SFI) score; Urinary protein creatinine ratio (UPCR); Autoantibody panel (antinuclear antibody [ANA], anti-double stranded DNA [anti- dsDNA], anti-Smith, anti-RNA binding protein [anti-RBP]); Antiphospholipid profile (lupus anticoagulant, anti-cardiolipin antibodies and beta-2 glycoprotein 1); Complement panel (CH50, C3, C4); Duration of B cell aplasia; Determination of T and B cell phenotype over time as assessed by flow cytometry in the peripheral blood; Determination of BlyS/BAFF concentration dynamics in the peripheral blood; and Determination of cytokine concentration dynamics in the peripheral blood. LUPUS NEPHRITIS Lupus nephritis is an inflammation of the kidneys caused by systemic lupus erythematosus (SLE), as discussed above. It is a type of glomerulonephritis in which the glomeruli become inflamed. Since it is a result of SLE, this type of glomerulonephritis is said to be secondary, and has a different pattern and outcome from conditions with a primary cause originating in the kidney. The diagnosis of lupus nephritis depends on blood tests, urinalysis, X-rays, ultrasound scans of the kidneys, and a kidney biopsy. On urinalysis, a nephritic picture is found and red blood cell casts, red blood cells and proteinuria is found. MEMBRANOUS NEPHROPATHY (MN) Membranous nephropathy (MN) or membranous glomerulonephritis (MGN) is a common glomerulonephritis that usually presents with nephrotic-range proteinuria, edema, and hypertension. MN is generally classified as primary (idiopathic) or secondary to other systemic disease, such as infections, malignancies, vasculitides etc. Primary MN has been recently associated with phospholipase A2 receptor (PLA2R) nephrotigenic antigen on the membrane surface of glomerular podocytes and the presence of anti-PLA2R antibodies. Kidney biopsy remains the gold standard for the diagnosis of MN, showing subepithelial deposits with capillary wall thickening and IgG deposition under immunofluorescence. While MN is widely considered a chronic condition with a waxing and waning course, it is usually self-limited in the majority of the cases. Heavy proteinuria, a significant marker of prognosis, indicates the need for intervention. Treatment efficacy may be assessed by measuring anti-PLA2R antibody levels. Standard treatment is with corticosteroids, cyclophosphamide and calcineurin inhibitors. More recently B-cell depleting therapeutic antibodies like Rituximab are used. These induce responses in 60% of patients by 12 months; however, randomized studies have not yet shown clear improvement in long-term outcomes. Furthermore, loss of autoantibodies can take months, increasing risk of chronic kidney disease (CKD), as well as cardiovascular complications due to uncontrolled nephrotic syndrome. MN patients frequently relapse and managing the episodic nature of this disease is burdensome. Ultimately many patients require renal replacement (35% at 10 years and 41% at 15 years). Notably, disease recurrence is common (30-40%) following renal transplant. OTHER TERMINOLOGY AND DISCLOSURE As used herein and in the appended claims, the singular forms “a,” “and,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any element, e.g., any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. When a range of values is provided herein, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials for the purpose for which the publications are cited. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order which is logically possible. This disclosure is intended to provide support for all such combinations. As used herein, “may,” “may comprise,” “may be,” “can,” “can comprise” and “can be” all indicate something envisaged by the inventors that is functional and available as part of the subject matter provided. The invention will now be further described by way of Examples, which are meant to serve to assist one of ordinary skill in the art in carrying out the invention and are not intended in any way to limit the scope of the invention. EXAMPLES Example 1 - Expression and characterization of D8/CAT CAR-T cells CAR T cells were generated by transducing normal donor PBMCs with two lentiviral vectors: One which encodes an anti-BCMA CAR having a Fab-type antigen binding domain (known as “D8”) and a second generation endodomain comprising 4-1BB and CD3z; and one which encodes an anti-CD19 CAR having an scFv antigen binding domain (known as “CAT” or “CAT19” and a second generation endodomain comprising 4-1BB and CD3z (Figure 2). Transduction of cells with a mixture of two vectors produces a combinatorial product, as some cells are untransduced; some cells express the BCMA-CAR alone; some cells express the CD19 CAR alone; and some cell co-express the two CARs (Figure 3). Cells were transduced with a mixture of two vectors at a multiplicity of infection (MOI) of 2.5 for each vector. Figure 4 shows flow cytometry plots from a representative double transduction and a stacked bar graph showing mean percentage of D8-CAT-, D8+CAT-, D8+CAT+ and D8-CAT+ cells within the CD3+ population of the transduced PBMCs (n=9). In vitro function of D8/CAT CAR T cells To demonstrate the cytotoxicity of D8/CAT CAR T cells against BCMA-expressing and CD19-expressing targets, co-cultures with different targets and effectors were performed. Effectors were D8 CAR T cells, CAT CAR T cells and D8/CAT CAR T cells. Targets were SupT1 cells (negative for both BCMA and CD19), SupT.BCMAlow, SupT1.CD19 (SupT1 cells engineered to express CD19) and SupT1 BCMAlow.CD19 (SupT1.BCMAlow additionally engineered to express CD19). After a 96-hour incubation period, killing was determined by flow-cytometry. As shown in Figure 5, SupT1 BCMAlow targets were killed by D8 and D8/CAT CAR T cells but not by CAT CAR T cells. Conversely, SupT1 CD19 targets were killed by CAT and D8/CAT CAR T cells but not by D8 CAR T cells. SupT1.BCMAlow.CD19 targets were killed by D8, CAT and D8/CAT CAR T cells. For assessment of cytokine production, CAR T cells were cultured with antigen-negative SupT1 NT cells, BCMA- expressing SupT1-BCMAlow and MM1.S cells and BCMA/CD19 dual positive Raji and Jeko-1 cells. As expected, CAT CAR T cells only showed cytokine production against CD19-expressing Raji and Jeko-1 cells, D8 CAR T cells demonstrated cytokine production against BCMA-expressing cells lines, whilst D8/CAT dual CAR- expressing T cells demonstrated cytokine secretion against all BCMA-expressing lines regardless of the presence or absence of CD19. Proliferation of D8/CAT CAR T cells in response to target cells was also tested. CAR- transduced T cells were labelled with a proliferation tracker dye CTV before co- culturing with target cell lines expressing either BCMA or CD19 alone or co- expressing both antigens. JeKo-1 cells are CD19+. D8/CAT CAR T cells showed significant proliferation against target cell lines which express BCMA (SupT1 BCMAlow, SupT1 BCMAlow CD19, JeKo-1 and MM.1s) which were comparable to that seen with D8 CAR T cells (Figure 6). Furthermore, D8/CAT CAR T cells were capable of proliferating against SupT1 which are expressing CD19 alone whereas D8 single transduced T cells did not, indicative of the proliferative function of CAT19 CAR against CD19 antigen. Example 2 - In vivo testing of D8/CAT CAR T cells in a xenogeneic murine myeloma model To investigate the in vivo efficacy of D8/CAT CAR T cells, Jeko1 cells were used in an NSG mouse model. Figure 7 shows the summary of the experimental design and the results. Briefly, NSG mice were injected with 1x106 Fluc expressing JeKo-1 cells at D0 and were allowed to engraft in the mice for the following 10 days. T cells were transduced at a total MOI of 5 and in the presence of 2.5uM AKTi VIII and 5x106 CAR expressing T cells were subsequently injected into the mice at D10. Mice were then imaged 3 times a week and then sacrificed at D30. There was clear evidence of tumour regression in CAR- treated groups with a trend to a faster anti-tumour response in the mice receiving dual-transduced D8/CAT CAR T cells. All publications mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described methods and system of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in molecular biology or related fields are intended to be within the scope of the following claims.

Claims

CLAIMS 1. A method of treating an autoimmune disease in a patient comprising administering to the patient a cell composition made by transducing cells with a mixture of vectors, the mixture comprising: (i) a first vector which expresses a first chimeric antigen receptor (CAR) which binds CD19; and (ii) a second vector which expresses a second CAR which binds B cell maturation antigen (BCMA), such that the cell composition administered to the patient comprises a mixture of a) cells which express the CD19 CAR alone; b) cells which express the BCMA CAR alone; and c) cells which co-express CD19 and BCMA CARs.
2. A method according to claim 1, wherein the first CAR comprises a CD19- binding domain which comprises: a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: CDR1 – GYAFSSS (SEQ ID NO: 1), CDR2 – YPGDED (SEQ ID NO: 2) and CDR3 – SLLYGDYLDY (SEQ ID NO: 3), and b) a light chain variable region (VL) having CDRs with the following sequences: CDR1 – SASSSVSYMH (SEQ ID NO: 4), CDR2 – DTSKLAS (SEQ ID NO: 5) and CDR3 – QQWNINPLT (SEQ ID NO: 6).
3. A method according to claim 1 or 2, wherein the second CAR comprises a B cell maturation antigen (BCMA)-binding domain which comprises: a) a VH having CDRs with the following sequences: CDR1 - GFIFSDYN (SEQ ID No.7) CDR2 - IIYDGSST (SEQ ID No.8) CDR3 - ATRPGPFAY (SEQ ID No.9); and b) a VL having CDRs with the following sequences: CDR1 - QSLLHSNGNTY (SEQ ID No.10) CDR2 - LVS (SEQ ID No.11) CDR3 - VHGTHAWT (SEQ ID No.12).
4. A method according to any preceding claim wherein the CD19-binding domain of the first CAR comprises a VH domain having the sequence shown as SEQ ID NO: 13 and a VL domain having the sequence shown as SEQ ID NO: 14.
5. A method according to any preceding claim wherein the first CAR comprises the sequence shown as SEQ ID No.15.
6. A method according to any preceding claim wherein the BCMA-binding domain of the second CAR comprises a VH domain having the sequence shown as SEQ ID No.16; and a VL domain having the sequence shown as SEQ ID No.17.
7. A method according to any preceding claim wherein the second CAR comprises the sequence shown as SEQ ID No.18.
8. A method according to any preceding claim, wherein the autoimmune disease is selected from: systemic lupus erythematosus (SLE), rheumatoid arthritis, idiopathic inflammatory myopathy (IIM, myositis), ANCA-associated vasculitis, inflammatory bowel disease (IBD), multiple sclerosis (MS), Type I diabetes, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Graves’ disease, Hashimoto’s thyroiditis or Hashimoto’s disease, myasthenia gravis, neuromyelitis optica, N-methyl-D-aspartate receptor (NMDAR) encephalitis, Lambert- Eaton syndrome, scleroderma, vasculitis, pemphigus vulgaris, pemphigus foliaceus, epidermolysis bullosa acquisita, bullous pemphigoid, lupus nephritis, membranous nephropathy, Goodpasture’s syndrome, immune thrombocytopenic purpura, thrombotic thrombocytopenic purpura, primary antiphospholipid syndrome, autoimmune haemolytic anaemia, and acquired haemophilia.
9. A method according to any preceding claim, wherein the autoimmune disease is selected from: systemic lupus erythematosus (SLE); lupus nephritis; and membranous nephropathy.
10. A method according to any preceding claim, wherein the autoimmune disease is membranous nephropathy.
11. A method according to any preceding claim, wherein the second vector comprises a nucleic acid expressing a suicide gene.
12. A method according to any of claims 1 to 10, wherein both the first and second vector comprise a nucleic acid expressing a suicide gene, wherein the suicide gene expressed by the first vector is different from the suicide gene expressed by the second vector.
13. A method for selectively deleting anti-BCMA CAR-expressing cells in a patient, which method comprises the step of administering an agent to patient, wherein the patient has previously been administered a cell composition as defined in claim 11 or 12 and wherein the agent activates the suicide gene expressed by the second vector.
14. A method for restoring the plasma cell compartment in a patient which has been treated by a method according to claim 11 or 12, which comprises the step of administering an agent to the patient which activates the suicide gene expressed by the second vector, thereby killing cells in the patient which express the second CAR but sparing cells in the patient which express the first CAR alone.
PCT/GB2025/050497 2024-03-12 2025-03-11 Treatment of autoimmune disease by co-expression of cd19-car and bcma-car Pending WO2025191260A1 (en)

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