Antibodies and antibody constructs against CD20

Abstract

Disclosed herein are polypeptide constructs that engage a complement factor (such as C1q) and CD20. Various configurations of the polypeptide constructs and amino acid modifications for improved efficacy are discussed. The polypeptide constructs can be used in the treatment of a disease, for example, cancer, autoimmune diseases, obesity, neurodegenerative diseases, cardiovascular diseases, and metabolic diseases, among others.

Description

[0001] ANTIBODIES AND ANTIBODY CONSTRUCTS AGAINST CD20 CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 24173646.1, filed 1 May 2024, European Patent Application No.24173650.3, filed 1 May 2024, GB Patent Application No. GB 2417959.0, filed 6 December 2024, and GB Patent Application No. GB 2417958.2, filed 6 December 2024, each of which is entirely incorporated herein by reference for all purposes. SUMMARY The present invention relates to antibodies against CD20 and uses thereof. In particular, the present invention relates to antibodies and antibody constructs that are directed against CD20 and to compositions, and in particular to pharmaceutical compositions, that comprise such antibodies and antibody constructs. The antibodies and antibody constructs against CD20 that are provided by the invention are also referred to herein as “antibodies of the invention”. The invention also relates to uses of such antibodies, antibody constructs and compositions in the prevention and treatment of diseases and disorders in human beings, and in particular in the prevention and treatment of diseases and disorders in human beings that can be prevented or treated by suitably administering, to a subject in need thereof, an antibody, antibody construct or composition as described herein (i.e. in one or more suitable amounts and according to a suitable dose regimen). Such diseases and disorders will be clear to the skilled person based on the disclosures herein and will also be referred to herein as “CD20- related diseases and disorders”. For example and without limitation, such CD20-related diseases and disorders may in particular include: (i) diseases and disorders that can be prevented and / or treated by suitably administering, to a subject in need thereof, one or more suitable amounts (i.e. according to a suitable dose regimen) of one of the known antibodies against CD20 referred to herein; and / or (ii) diseases and disorders that can be prevented or treated by depleting (and / or suitably reducing the levels of and / or suitably controlling the level of) at least one cell or cell type expressing CD20 in the body of a subject in need thereof; and / or (iii) diseases and disorders that can be prevented and / or treated by suitably increasing, in the body of the subject to be treated, the activation of complement towards a cell that expresses CD20 on its surface (and in particular such that this may lead to an increase in the complement- dependent cytotoxicity that is exerted by the body of the subject to be treated towards a CD20 expressing cell. As further mentioned herein, such diseases and disorders may in particular include B-cell malignancies and auto-immune diseases (as further described herein). The invention further relates to nucleic acids encoding the antibodies of the invention, (also referred to herein as “nucleic acids of the invention” or “nucleotide sequences of the invention”); to methods for preparing the antibodies of the invention; and to host cells expressing or capable of expressing the antibodies of the invention. Other aspects, embodiments, advantages and applications of the invention will become clear from the further description herein. The international application WO2019 / 238674 describes single domain antibodies for complement regulation which are capable of specifically binding to an epitope of a human complement factor selected from the group consisting of C1q, C3, C4 and / or the proteolytic derivatives C3b and C4b. WO2019 / 238674 also describes bi- and multispecific constructs comprising such a single domain antibody and at least one other antigen binding region (such as a second single domain antibody), in which said second antigen-binding domain binds to another target (such as a marker that is differentially expressed in cancer cells compared to non-malignant cells, a pathogenic marker a tissue-specific marker, an organ-specific marker, such as a marker specific for lung, eye, brain or kidney). WO2019 / 238674 also describes the use of such constructs in the treatment of diseases and disorders (depending, inter alia, on the target(s) of the antigen-binding regions that are present in said constructs next to the complement-binding single domain antibody or antibodies). The international application WO2019 / 238674 also describes a number of specific Nanobodies against C1q, including the Nanobodies called “IF75” (SEQ ID NO: 13 in WO2019 / 238674) and “IF78” (SEQ ID NO:17 in WO2019 / 238674). [Note: IF75 is also referred to herein as Nb75 and IF78 is also referred to herein as Nb78]. WO2019 / 238674 also describes that the Nanobodies described in this application may be humanized. The international application WO2020 / 167919 describes bispecific antigen-binding molecules comprising an antigen-binding domain that binds to a target antigen and an antigen- binding domain that binds to a complement component (such as C1q, C1r, C1s, C2, C3, C4, C5, C6, C7, C8 or C9). WO2020 / 167919 also describes the use of such bispecific antigen- binding molecules in the treatment of diseases and disorders (again depending, inter alia, on the target to which the target-binding antigen-binding domain in the molecule can bind). The non-prepublished International application entitled “Engineered complement engaging polypeptides” in the name of applicant and filed on the same date as the present application describes improved C1q binders that comprise, compared to a wild-type C1q binder, one or more modifications resulting in reduced binding affinity to a C1q complement factor as compared to a binding affinity of said corresponding wild-type C1q binder. Some preferred C1q binders according to this International application may have a binding affinity to the C1q complement factor of from about 10 nanoMolar (nM) to about 2 microMolar (μM), as determined by biolayer interferometry, and / or may bind to the C1q complement factor with a KD from about 10 nM to about 1.5 μM, from about 50 nM to about 1.4 μM, from about 100 nM to about 1.3 μM, from about 150 nM to about 1.2 μM or from about 200 nM to about 1 μM. This International application also describes constructs comprising such C1q binders and at least one other antigen-binding moiety that binds to a target antigen, as well as uses of such constructs in the treatment of diseases and disorders (depending, inter alia, on the target antigen(s) to which said other antigen-binding moiety / moieties can bind). Said C1q binders may also be humanized. In particular aspects, said International application describes that such C1q binders can be generated by suitably introducing one or more alanine mutations into the CDRs of a naturally occurring single domain antibody (or into the CDRs of a suitable humanized variant of a naturally occurring single domain antibody). In some specific aspects, said International application describes such C1q binders that are variants of Nb75 or Nb78 (or of humanized variants of Nb75 or Nb78). The non-prepublished International application entitled “Engineered proteins that engage complement factor and a protein antigen, methods, and uses thereof” in the name of applicant and filed on the same date as the present application describes polypeptide constructs comprising: (a) a first complement factor-engaging domain that binds to C1q; (b) an antigen- binding moiety that binds to a target protein; and (c) a second complement factor-engaging domain, wherein the first complement factor-engaging domain and the second complement factor-engaging domain are linked to the antigen-binding moiety. In one particular embodiment, said International application describes antibodies or antibody-based constructs that comprise two antibody heavy chains and two antibody light chains, which antibodies comprise a first C1q binder that is linked or fused to one of the antibody heavy or light chains and second C1q binder that is linked or fused to another of the antibody heavy or light chains. As further described in more detail this International application, in such antibodies or antibody-based constructs, either the first C1q binder is linked or fused to one of the antibody heavy chains and the second C1q binder is linked or fused to the other antibody heavy chain or alternatively the first C1q binder is linked or fused to one or the antibody light chains and the second C1q binder is linked or fused to the other antibody light chain. As also described in more detail in said International application, in such antibodies or antibody-based constructs, the C1q binders may be linked to the N-terminus or the C-terminus of the antibody heavy chain, or may be linked to the N-terminus or the C-terminus of the antibody light chain (and, according to a specific but non-limiting aspect, when they are linked to the heavy chain, preferably linked to the N-terminus of the heavy chain; and when they are linked to the light chain, preferably linked to the C-terminus of the light chain). As further described in this International application, according to one particular aspect, such antibodies or antibody-based constructs comprise two antibody heavy chains and two antibody light chains and two C1q binders, in which one of said C1q binders is linked or fused to the C-terminus of one or the antibody light chains and the second C1q binder is linked or fused to the C-terminus of the other antibody light chain. Pedersen et al., J Immunol (2023) 211 (3): 403–413, describe that “Fc-independent recruitment of C1 by modular bispecific single-domain Abs that simultaneously bind C1q and a surface Ag [which the authors of this reference also refer to as “BiCE”] can potently activate the complement system”, resulting in “superior ability of the bispecific Abs to induce complement-dependent cytotoxicity” which provides “effective complement activation and cell killing” and “a modality for potent complement activation”. Terms that are not specifically defined herein have the meaning given in these International applications (which are also referred to herein as the “co-pending International applications”). Provided herein are polypeptide constructs, wherein the polypeptide constructs comprise: at least one heavy chain and at least one light chain, wherein the at least one heavy chain and the at least one light chain bind to a cluster of differentiation 20 (CD20); and at least one complement factor-engaging domain that binds to a C1q complement factor, wherein an affinity of the at least one complement factor-engaging domain for the C1q complement factor is between 10 nanoMolar (nM) to about 2 microMolar (μM) as determined by biolayer interferometry. Further provided herein are polypeptide constructs, wherein the polypeptide construct comprises two complement factor-engaging domains that bind to the C1q complement factor. Further provided herein are polypeptide constructs, wherein the at least one complement factor-engaging domain comprise an affinity for the C1q complement factor that is about 0.1 μM up to about 2 μM as determined by biolayer interferometry. Further provided herein are polypeptide constructs, wherein the polypeptide construct comprises two heavy chains that bind to the CD20. Further provided herein are polypeptide constructs, wherein the polypeptide construct comprises two light chains that bind to the CD20. Further provided herein are polypeptide constructs, wherein the at least one heavy chain comprises an amino acid sequence of SEQ ID NO: 1 or a variant thereof, wherein the variant comprises at least one amino acid substitution relative to SEQ ID NO: 1. Further provided herein are polypeptide constructs, wherein at least one light chain comprises an amino acid sequence of SEQ ID NO: 2 or a variant thereof, wherein the variant comprises at least one amino acid substitution relative to SEQ ID NO: 2. Further provided herein are polypeptide constructs, wherein the at least one heavy chain comprises an amino acid sequence of SEQ ID NO: 1; and the at least one light chain comprises an amino acid sequence of SEQ ID NO: 3. Further provided herein are polypeptide constructs, wherein the two heavy chains each comprise two heavy chain variable regions (VH). Further provided herein are polypeptide constructs, wherein the two light chains each comprise two light chain variable regions (VL). Provided herein are polypeptide constructs, wherein the polypeptide constructs comprise a first heavy chain comprising SEQ ID NO: 1; a second heavy chain comprising SEQ ID NO: 1; a first light chain comprising SEQ ID NO: 3; a second light chain comprising: SEQ ID NO: 3; a first complement factor-engaging domain; and a second complement factor- engaging domain. Provided herein are pharmaceutical compositions, wherein the pharmaceutical composition comprises a polypeptide construct provided herein. Provided herein are methods of using an antibody or antibody construct or of a pharmaceutical composition provided herein in the prevention and / or treatment of a disease or disorder that can be prevented or treated by depleting, and / or suitably reducing the levels of and / or suitably controlling the level of, at least one cell or cell type expressing CD20 in the body of a subject in need of such prevention or treatment. Provided herein are methods of using an antibody or antibody construct or a pharmaceutical composition provided herein in the prevention and / or treatment of a disease and disorder that can be prevented and / or treated by (suitably) increasing the complement- dependent cytotoxicity that is exerted by the body of the subject to be directed towards a CD20 expressing cell. BRIEF DESCRIPTION OF THE DRAWINGS The novel features of the present disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosed constructs are utilized, and the accompanying drawings of which: FIG. 1A-FIG. 1B shows exemplary CD20-targeting polypeptide constructs and CDC against human B cells in 10% C1q depleted human serum, with cyno C1q added. FIG. 1A shows CM1475-1234, CM1684-1686, and CM1684-1686. FIG.1B depicts the activity of the exemplary polypeptide constructs in FIG.1A as described herein in CDC assay in WSU cells. Cytotoxicity (%) is shown on the y-axis, and the x-axis represents concentration (nM) of the exemplary polypeptide constructs. A Genmab 11B8 CD20-targeting antibody served as a control. FIG.2 shows a graph of the cytotoxicity of human primary B cells treated with CD20 mAb, CD20-BiCE, or Rituximab at varying concentrations. The y-axis depicts percent cytotoxicity, and the x-axis depicts concentration (nM). FIG. 3 shows a schematic of an exemplary CD20-BiCE and structural features of the polypeptide construct. FIG. 4 shows a graph of the cytotoxicity of human B cells treated with CD20 mAb, CD20-BiCE, or CD-20 BiCE- LALAPG at varying concentrations. The y-axis depicts percent cytotoxicity, and the x-axis depicts concentration (nM). FIG.5 shows a graph of B cell depletion in human peripheral blood mononuclear cells (PBMCs) treated with CD20 mAb, CD20-BiCE, or CD-20 BiCE- LALAPG at varying concentrations. The y-axis depicts percent B cell killing, and the x-axis depicts concentration (nM). FIG. 6 shows a graph of antibody-dependent cellular cytotoxicity (ADCC) in human peripheral blood mononuclear cells (PBMCs) treated with CD20 mAb, CD20-BiCE, or CD-20 BiCE- LALAPG at varying concentrations. The y-axis depicts percent cell lysis, and the x-axis depicts concentration (nM). FIG.7 shows a graph of a human whole blood assay for B cell killing in human blood treated with CD20 mAb, CD20-BiCE, CD-20 BiCE- LALAPG, alemtuzumab, and cetuximab at varying concentrations. The y-axis depicts percent B cell killing, and the x-axis depicts concentration (ug / ml). FIG.8 shows a schematic of Non-Human Primate (NHP) evaluation, conditions, blood draw schedule, and biopsy schedule FIG.9. shows a graph of CD19+ and CD20+ B cells determined by flow cytometry in NHPs treated with CD20-BiCE (sample #: 1001, 1002, 1003) or CD20-BiCE-LALAPG (sample #: 2001, 2002, 2003). The y-axis depicts the absolute counts (cells / μl) of CD19 positive or CD20 positive B cells as indicated, and the x-axis depicts time in days. FIG. 10 shows a graph of CD19+ cells determined by flow cytometry in NHP lymph nodes following treatment with CD20-BiCE (sample #: 1001, 1002, 1003) or CD20-BiCE- LALAPG (sample #: 2001, 2002, 2003). The y-axis depicts the percentage of CD19 positive cells, and the x-axis depicts time in days. FIG. 11 shows a graph of the cytotoxicity of Human B cells treated with CD20 mAb, CD20-BiCE, or CD-20 BiCE- LALAPG at varying concentrations in vitro using human C1q depleted serum and cyno C1q. The y-axis depicts percent cytotoxicity, and the x-axis depicts concentration (nM). FIG. 12 show graphs of B cell killing in populations of PBMCs using different concentrations of CD-20 mAb, CD20-BiCE, and CD20-BiCE-LALAPG. FIG. 12A shows a graph of B cell killing in a population of non-naïve PBMCs with matched serum. FIG. 12B shows a graph of B cell killing in a population of naiive PBMCs with matched serum. The percentage of B cells killed was quantified for each concentration. The y-axis depicts percent B cell killing, and the x-axis depicts concentration (nM). DETAILED DESCRIPTION CD20 is a transmembrane protein that is expressed on the surface of B lymphocytes. It is a well-known target for antibody-based therapies, in particular in B-cell malignancies and auto-immune diseases. In such therapies, anti-CD20 antibodies are usually used to deplete CD20 expressing cells, achieving their cytotoxic effect by employing effector mechanisms of the body’s innate immune system, for example via complement-dependent cytotoxicity (CDC), complement-dependent cellular cytotoxicity (CDCC), antibody- dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis, and direct apoptosis induction. Reference is for example made to Pavlasova and Mraz, Haematologica, 2020 Jun;105(6):1494–1506; Casan et al., Human vaccines & immunotherapeutics, 2018, Vol. 14, No. 12, 2820–2841; Beurskens et al., J Immunol. 2012 April 1; 188(7): 3532–3541; Engelberts et al., J Immunol (2016) 197 (12): 4829–4837.and the further references cited therein. Some of the known antibodies against CD20 that have been approved or that are in various stages of research or development include rituximab (RITUXAN, MABTHERA) ocrelizumab, obinutuzumab, ofatumumab, ibritumomab, tiuxetan, tositumomab, and ublituximab, ocaratuzumab, veltuzumab and 11B8 (Genmab). As mentioned herein, these known antibodies against CD20, as well as the antibodies, antibody constructs and compositions described herein, can be used in the prevention and / or treatment of CD20-related diseases and disorders (as defined herein). Such CD20-related diseases and disorders may in particular but without limitation be one of the following diseases or disorders: B-cell malignancies such as: Chronic Lymphocytic Leukemia , Diffuse Large B-Cell Lymphoma, Follicular Lymphoma, Mantle Cell Lymphoma, Marginal Zone Lymphoma, Waldenström’s Macroglobulinemia; Non-Hodgkin's Lymphoma (NHL); Diffuse Large B-Cell Lymphoma (DLBCL); Follicular Lymphoma (FL); Marginal Zone Lymphoma (MZL); Mantle Cell Lymphoma (MCL); Chronic Lymphocytic Leukemia / Small Lymphocytic Lymphoma (CLL / SLL); Chronic Lymphocytic Leukemia (CLL) (standalone indication as well as within NHL group); Waldenström's Macroglobulinemia (WM); Burkitt Lymphoma (BL); Hairy Cell Leukemia (HCL); Post-Transplant Lymphoproliferative Disorder (PTLD); Primary CNS Lymphoma (PCNSL); B-cell Acute Lymphoblastic Leukemia (B-ALL) (specifically, CD20- positive subset); Lymphoplasmacytic Lymphoma; Richter's Transformation (CLL transforming to aggressive NHL subtype); Autoimmune Lymphoproliferative Syndromes (ALPS) with malignant transformation. Auto-immune diseases such as: Relapsing Multiple Sclerosis, Rheumatoid Arthritis, Systemic Lupus Erythematosus, ANCA-Associated Vasculitis, Myasthenia Gravis; . Rheumatoid Arthritis (RA); Granulomatosis with Polyangiitis (GPA, formerly Wegener's granulomatosis); Microscopic Polyangiitis (MPA); Pemphigus Vulgaris (PV); Multiple Sclerosis (MS) – particularly Relapsing-Remitting MS (RRMS) and Primary Progressive MS (PPMS, specifically ocrelizumab); Systemic Lupus Erythematosus (SLE); Lupus Nephritis (LN); Immune Thrombocytopenia (ITP); Neuromyelitis Optica Spectrum Disorder (NMOSD); Autoimmune Hemolytic Anemia (AIHA); Myasthenia Gravis (MG); Sjogren’s Syndrome (SS); IgG4-related disease (IgG4-RD); Dermatomyositis and Polymyositis; Idiopathic Inflammatory Myopathies (IIM); Systemic Sclerosis (Scleroderma) – especially subsets with inflammatory involvement; Autoimmune Hepatitis (AIH); Bullous Pemphigoid (BP); Cryoglobulinemic Vasculitis (associated frequently with Hepatitis C); Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Other diseases and disorders that can be prevented or treated by suitably depleting (and / or suitably reducing the level of and / or suitably controlling the level of) at least one CD20 expressing cell in the body of subject to be treated (and / or by increasing the complement- dependent cytotoxicity that is exerted by the body of the subject to be treated) towards a CD20 expressing cell, such as neurological disorders such as NMOSD and transplant related uses such as Graft-Versus-Host Disease (GVHD). As mentioned herein, it is assumed that the antibodies of the invention will generally assert their favorable effect upon the body of a subject to be treated by depleting (and / or suitably reducing the level of and / or suitably controlling the level of) at least one CD20 expressing cell in the body of subject to be treated. However, it should be noted that the invention in its broadest sense is not limited to any particular explanation, hypothesis or mechanism-of-action. In particular, it is not excluded that the antibodies of the invention may exert their beneficial influence upon the body of a subject treated with an antibody of the invention via any suitable mechanism-of-action, including but not limited to any mechanism- of-action known per se for one or more of the known antibodies against CD20 referred to herein. While a number of the known antibodies against CD20 have been successfully applied to the prevention and treatment of diseases and disorders in human subject, clinical practice has shown there is a continuous need for new antibodies and antibody constructs against CD20 (and in particular improved antibodies against CD20) that can be used in the prevention and treatment of diseases and disorders in human subjects. The present invention provides such antibodies and antibody constructs. Generally, the invention provides an antibody or antibody construct comprising two antibody heavy chains and two antibody light chains (which antibody heavy chains and antibody light chains form an antibody that is directed against CD20), which antibody or antibody construct suitably comprises two single domain antibodies that are directed against C1q (in accordance with the co-pending International applications referred to herein, such single domain antibodies against C1q are also referred to herein as “C1q binders”). The invention in particular provides such an antibody or antibody construct in which the antibody heavy chains and antibody light chains form an antibody that is directed against the same epitope on CD20 as 11B8. In a further aspect, the invention provides such an antibody or antibody construct in which the two VHdomains that are present in the heavy chains contain the same CDRs as the VH domain that is present in 11B8 and in which the two VL domains that are present in the light chains contain the same CDRs as the VLdomain that is present in 11B8 (in which said CDRs are the CDRs according to Kabat). In a further aspect, the invention provides such an antibody or antibody construct in which the two VH domains that are present in the heavy chains have the same amino acid sequence as the VH domain that is present in 11B8 and in which the two VL domains that are present in the light chains have the same amino acid sequence as the VLdomain that is present in 11B8. In a preferred aspect, the antibodies of the invention are as described in the co-pending International applications referred to herein. Accordingly, as described in these co-pending International applications, in the antibodies of the invention, most preferably and usually: − the two heavy chains will have the same amino acid sequence and the two light chains will have the same amino acid sequence; − the two C1q binders that are present in the antibodies of the invention will have the same amino acid sequence; − when one of the C1q binders is fused or linked to one of the heavy chains, then the other C1q binder will be fused or linked to the other heavy chain; − when one of the C1q binders is fused or linked to one of the light chains, then the other C1q binder will be fused or linked to the other light chain; − when one of the C1q binders is fused or linked to the N-terminus of a heavy or light chain, respectively, then the other C1q binder will also be fused or linked to N-terminus of the other heavy or light chain, respectively; − when one of the C1q binders is fused or linked to the C-terminus of a heavy or light chain, respectively, then the other C1q binder will also be fused or linked to C-terminus of the other heavy or light chain, respectively; and − the C1q binder can be as generally described in WO2019 / 238674, in WO2020 / 167919 or in the co-pending International applications, but is preferably a C1q binder that is as generally described in the co-pending International applications and that has an affinity for C1q of between 10 nanoMolar (nM) to about 2 microMolar (μM), as determined by biolayer interferometry, in particular of about 0.1 μM to about 2 μM, as determined by biolayer interferometry; − the C1q binder is preferably a variant of Nb75 or Nb78, and in particular a humanized variant of Nb75 or Nb78 (as described in the co-pending International applications); − when two elements of a construct are “fused or linked” (as further defined in the Co- pending International applications), any suitable linker known per se may be used for this purpose (for which reference is again made to the Co-pending International applications). In a particular aspect, the invention relates to an antibody of the invention in which the one of the C1q binders is linked to the C-terminus of one of the light chains, and the other C1q binder is linked to the C-terminus of the other light chain. Also, in the antibodies of the invention according to this aspect, the C1q binder is preferably a humanized variant of Nb78 with an affinity for C1q of between 10 nanoMolar (nM) to about 2 microMolar (μM), as determined by biolayer interferometry, in particular of about 0.1 μM to about 2 μM, as determined by biolayer interferometry. In a particularly preferred aspect, the invention relates to an antibody of the invention in which the two heavy chains both (essentially) comprise the amino acid sequence of SEQ ID NO:1 (not taking into account any C1q binders that maybe fused or linked to said heavy chains). SEQ ID NO:1 is the amino acid sequence of the heavy chain of 11B8. EVQLVQSGGGLVHPGGSLRLSCTGSGFTFSYHAMHWVRQAPGKGLEWVSIIG TGGVTYYADSVKGRFTISRDNVKNSLYLQMNSLRAEDMAVYYCARDYYGA GSFYDGLYGMDVWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLV KDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYI CNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLM ISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVV SVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSR DELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYS KLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 1); and in which the two light chains both (essentially) comprise the amino acid sequence of SEQ ID NO: 2 (not taking into account any C1q binders that maybe fused or linked to said light chains). SEQ ID NO:2 is the amino acid sequence of the light chain of 11B8. EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIK RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNS QESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNR GEC (SEQ ID NO: 2). An antibody of the invention may comprise a naturally occurring Fc portion or a non- naturally occurring Fc portion (such as, for example and without limitation, an Fc portion that has been derived from a naturally occurring Fc portion but that (suitably) carries, within its sequence, one or more of the mutations referred to herein for such non-naturally occurring Fc portions). Some specific but non-limiting examples of mutations that can be present in the Fc portion of (the heavy chains that are present in) an antibody of the invention are described herein and / or listed in Table B; and for illustration purposes only Table C gives examples of such non-naturally occurring Fc regions (using the Fc of antibody 11B8 mentioned herein as a reference sequence, again for illustration purposes only). Such mutations may also be used in a suitable combination, as will be clear to the skilled person. For example and without limitation, such mutations or suitable combination of mutations may (i) alter (i.e. increase or decrease) the half-life of the antibody of the invention; (ii) alter (i.e. increase or decrease) the binding / affinity of the antibody to Fc gamma receptors; and / or (iii) alter (i.e. increase or decrease) the binding / affinity of the Fc region and / or the antibody of the invention for C1q (with but preferably essentially without affecting the affinity for C1q of the C1q binder(s) present in the antibody of the invention). These and other suitable mutations will be clear to the skilled person based on the disclosure herein. In one aspect, the invention relates to an antibody of the invention (as further described herein) that contains a non-naturally occurring Fc region, which non-naturally occurring Fc region contains at least one mutation that alter (i.e. increase or decrease, but in particular decrease or essentially removed) the binding / affinity of the antibody to Fc gamma receptors. In particular, the invention relates to an antibody of the invention (as further described herein) that contains a non-naturally occurring Fc region, which non-naturally occurring Fc region contains at least one mutation that alter (i.e. increase or decrease, but in particular decrease or essentially removed) the binding / affinity of the antibody to Fc gamma receptors, where such mutations essentially do not affect the affinity of the antibody of the invention for C1q. Again, suitable mutations or combinations of mutations will be clear to the skilled person based on the disclosure herein or can easily be determined (optionally after a limited degree of testing) by the skilled person, and for example include K320E, Q386R) deletion of G236 and / or K326W, E333S. Some specific but non-limiting examples of antibodies against CD20 are listed in Table A below. In a specifically preferred aspect, the invention relates to an antibody of the invention in which the two heavy chains both (essentially) comprise the amino acid sequence of SEQ ID NO: 1 (and are not fused or linked to a C1q binder) and in which the two light chains both (essentially) comprise the amino acid sequence of SEQ ID NO: 3 EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIK RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNS QESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNR GECGGGGSQVQLVESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAP GQEREAVAAISWRGGSTYYADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAI YYCAADASARAALYSTGYEYDHWGQGTQVTVSS (SEQ ID NO:3) SEQ ID NO: 3 comprises the light chain of 11B8, which is fused at its C-terminus, via a GGGGS linker (SEQ ID NO: 4), to the C1q binder of SEQ ID NO: 5. SEQ ID NO: 5 is a humanized variant of Nb78 with reduced affinity for C1q, as described in the co-pending International applications. QVQLVESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVA AISWRGGSTYYADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADAS ARAALYSTGYEYDHWGQGTQVTVSS (SEQ ID NO: 5) The antibodies provided by the invention (and in particular those that comprise a C1q binders with affinity for C1q of between 10 nanoMolar (nM) to about 2 microMolar (μM), as determined by biolayer interferometry, in particular of about 0.1 μM to about 2 μM, as determined by biolayer interferometry) have a number of advantages over known antibodies against CD20, such as rituximab and 11B8. These generally include the following (individually and in combination): − improved ability to induce CDC, compared to an antibody that does not comprise aC1q binder as described herein (and in particular, compared to 11B8); − the advantages described in the co-pending International applications associated with the use of an antibody format that comprises two single domain antibodies against C1q (as compared to an antibody that does not contain any C1q binder or only a single C1q binder); − the advantages described in the co-pending International applications associated with the use of an antibody format that comprises a single domain antibody against C1q (and in particular two such C1q binders) having an affinity for C1q within the ranges specified above (as compared to an antibody format that comprises one or two C1q binders with “better” / ”higher” affinity for C1q); − improved ability to “activate complement on” a cell that expresses CD20 to which the antigen binding domain is directed (meaning: to trigger / recruit the complement system to mount an immune response or other reaction against such cell) compared to the same antibody without the C1q binder(s); and / or − no requirement for hexamerization upon antigen binding which is needed for efficient complement activation by IgG as described by Diebolder et al., Science.2014 Mar 14;343(6176):1260–1263. This means that more epitopes can be targeted; and / or − potential to recruit more than one C1q resulting in more potent complement activation as a C1q bispecific construct as described herein can – for example - have 3 C1q binding sites whereas an IgG has 1; The antibodies may in addition have one or more of the following advantages (again, compared to the same antibody without the C1q binder), depending on the Fc portion that is present in the specific antibody and in particular on the Fc mutation(s) that may be present in such Fc portion: − the ability to activate complement on a cell that expresses CD20 (i.e. on its surface), without binding to Fc-gamma receptors on immune cells thereby preventing effector mechanisms ADCC and ADCP (in other words, provide a degree of selectivity towards triggering CDC); or − the ability to activate complement on a cell that expresses CD20 (i.e. on its surface), without preventing binding to Fc-gamma receptors on immune cells thereby allowing for additional secondary effector mechanisms including ADCC and ADCP. In another aspect, the invention relates to a nucleic acid that encodes an antibody of the invention (as mentioned, also referred to herein as a “nucleic acid of the invention”). Such a nucleic acid of the invention may for example be in the form of a genetic construct, as will be clear to the person skilled in the art and as described on pages 131-134 of WO 08 / 020079 (incorporated herein by reference). Such genetic constructs generally comprise at least one nucleic acid of the invention that is optionally linked to one or more elements of genetic constructs known per se, such as for example one or more suitable regulatory elements (such as a suitable promoter(s), enhancer(s), terminator(s), etc.) and the further elements of genetic constructs known per se. For example, such a genetic construct may be in a form known per se for the expression or production of the known antibodies against CD20 referred to herein and / or in a suitable form as described in WO2019 / 238674, in WO2020 / 167919 or in the co- pending International applications. In a further aspect, the invention relates to a host or host cell that expresses and / or produces (or that under suitable circumstances is capable of expressing and / or producing) an antibody of the invention; and / or that contains a nucleic acid of the invention. Suitable host cells and cell lines will be clear to the skilled person and may, for example and without limitation, include the cells and cell lines known per se that are used for the expression or production of the known antibodies against CD20 referred to herein, and in particular be mammalian cells (or a mammalian cell line) that are suitable for expressing / producing the antibodies of the invention and / or suitable host cells or cell lines as described in WO2019 / 238674, in WO2020 / 167919 or in the co-pending International applications. The invention also relates to a method of expressing or producing an antibody of the invention, which method at least comprises the step of maintaining a host or host cell that expresses and / or produces (or that under suitable circumstances is capable of expressing and / or producing) an antibody of the invention (and / or that contains a nucleic acid of the invention) under conditions such that said host cell expresses / produces said antibody of the invention. Suitable conditions will be clear to the skilled person based on the disclosure herein and may depend on the particular host cell or cell line used. Reference is again for example made to WO2019 / 238674, WO2020 / 167919 and the co-pending International applications. The invention further relates to a product or composition containing or comprising at least one antibody of the invention and / or at least one nucleic acid of the invention, and optionally one or more further components of such compositions known per se, i.e. depending on the intended use of the composition. Such a product or composition may for example be a pharmaceutical composition (as described herein), a veterinary composition or a product or composition for diagnostic use (as also described herein). Some preferred but non-limiting examples of such products or compositions will become clear from the further description herein. The antibodies of the invention can also be administered using gene therapy methods of delivery (including suitable vaccination methods such as mRNA or DNA vaccination methods) such that, upon such administration, an antibody of the invention is suitably expressed / formed in the body of the subject to be treated. Suitable gene therapy vectors, mRNA vaccines and DNA vaccines and suitable methods of administering the same will be clear to the skilled person. Reference is for example made to U.S. Patent No. 5,399,346, which is incorporated by reference in its entirety. Using a gene therapy method of delivery, primary cells transfected with the gene encoding an antibody of the invention can additionally be transfected with tissue specific promoters to target specific organs, tissue, grafts, tumors, or cells and can additionally be transfected with signal and stabilization sequences for subcellularly localized expression. Generally, for pharmaceutical use, the antibodies of the invention may be formulated as a pharmaceutical preparation or compositions comprising at least one antibody of the invention and at least one pharmaceutically acceptable carrier, diluent or excipient and / or adjuvant, and optionally one or more further pharmaceutically active polypeptides and / or compounds. By means of non-limiting examples, such a formulation may be in a form suitable for oral administration, for parenteral administration (such as by intravenous, intramuscular or subcutaneous injection or intravenous infusion), for topical administration, for administration by inhalation, by a skin patch, by an implant, by a suppository, etc.. Such suitable administration forms - which may be solid, semi-solid or liquid, depending on the manner of administration - as well as methods and carriers for use in the preparation thereof, will be clear to the skilled person based on the disclosure herein, and may for example and without limitation, include formulations (and components and constituents of formulations) known per se that can be used for formulating the known antibodies against CD20 referred to herein and / or the formulations described in WO2019 / 238674, WO2020 / 167919 or in the co-pending International applications. Thus, in a further aspect, the invention relates to a pharmaceutical composition that contains at least one antibody of the invention and at least one suitable carrier, diluent or excipient (i.e. suitable for pharmaceutical use), and optionally one or more further active substances. Generally, the antibodies of the invention can be formulated and administered in any suitable manner known per se, for which reference is for example made to the general background art cited above (and in particular to WO 04 / 041862, WO 04 / 041863, WO 04 / 041865, WO 04 / 041867 and WO 08 / 020079) as well as to the standard handbooks, such as Remington’s Pharmaceutical Sciences, 18thEd., Mack Publishing Company, USA (1990), Remington, the Science and Practice of Pharmacy, 21th Edition, Lippincott Williams and Wilkins (2005); or the Handbook of Therapeutic Antibodies (S. Dubel, Ed.), Wiley, Weinheim, 2007 (see for example pages 252-255). These may for example and without limitation, include means and methods for administration known per se for the administration of the known antibodies against CD20 referred to herein as well as means and methods for administration as described in WO2019 / 238674, WO2020 / 167919 or in the co-pending International applications. For example, the antibodies in may be formulated and administered in any manner known per se for conventional antibodies (including the known anti-CD20 antibodies mentioned herein). Such formulations and methods for preparing the same will be clear to the skilled person, and for example include preparations suitable for parenteral administration (for example intravenous, intraperitoneal, subcutaneous, intramuscular, intraluminal, intra-arterial or intrathecal administration) or for topical (i.e. transdermal or intradermal) administration. Reference is again also made to WO2019 / 238674, WO2020 / 167919 and the co-pending International applications. Preparations for parenteral administration may for example be sterile solutions, suspensions, dispersions or emulsions that are suitable for infusion or injection. Suitable carriers or diluents for such preparations for example include, without limitation, those mentioned in WO2019 / 238674, WO2020 / 167919 and the co-pending International applications. Usually, aqueous solutions or suspensions will be preferred. As will be clear to the skilled person and / or the treating physician, the amount(s) of the antibodies of the invention required for use in treatment (i.e. the dose(s) and dose regimen applied in such treatment) will vary not only with the particular antibody of the invention used, but also with the route of administration, the nature of the condition being treated and the age and condition of the patient and will be ultimately at the discretion of the attendant physician or clinician, who will be able to choose an appropriate dose regimen taking into account the considerations referred to herein. The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations. An administration regimen could include long-term, daily treatment. By “long-term” (or “chronic”) is meant at least two weeks and preferably, several weeks, months, or years of duration. Necessary modifications in this dosage range may be determined by one of ordinary skill in the art using only routine experimentation given the teachings herein. See Remington’s Pharmaceutical Sciences (Martin, E.W., ed.4), Mack Publishing Co., Easton, PA. The dosage can also be adjusted by the individual physician in the event of any complication. In another aspect, the invention relates to a method for the prevention and / or treatment of at least CD20-related disease or disorder (as defined herein), said method comprising administering, to a subject in need thereof, a pharmaceutically active amount of an antibody of the invention and / or of a pharmaceutical composition comprising the same (i.e. in one or more suitable doses and according to a suitable dosage regimen, as further described herein). In the context of the present invention, the term “prevention and / or treatment” not only comprises preventing and / or treating the disease, but also generally comprises preventing the onset of the disease, slowing or reversing the progress of disease, preventing or slowing the onset of one or more symptoms associated with the disease, reducing and / or alleviating one or more symptoms associated with the disease, reducing the severity and / or the duration of the disease and / or of any symptoms associated therewith and / or preventing a further increase in the severity of the disease and / or of any symptoms associated therewith, preventing, reducing or reversing any physiological damage caused by the disease, and generally any pharmacological action that is beneficial to the patient being treated. The subject to be treated may be any warm-blooded animal, but is in particular a mammal, and more in particular a human being. As will be clear to the skilled person, the subject to be treated will in particular be a person suffering from, or at risk of, the diseases and disorders mentioned herein. In another aspect, the invention relates to a method for immunotherapy, which method comprises administering, to a subject suffering from or at risk of a CD20-related disease or disorder, a pharmaceutically active amount of an antibody of the invention or a pharmaceutical composition comprising the same. In another aspect, the invention relates to a method for depleting, reducing the level of and / or controlling the level of at least one cell expressing CD20 on its cell surface (i.e. in the body of a subject in need thereof), which method comprises administering, to said subject, a pharmaceutically active amount of an antibody of the invention or a pharmaceutical composition comprising the same. In another aspect, the invention relates to a method for increasing the complement- dependent cytotoxicity towards a CD20 expressing cell that is exerted by the body of a subject that is in need thereof, which method comprises administering, to said subject, a pharmaceutically active amount of an antibody of the invention or a pharmaceutical composition comprising the same. As mentioned herein, in the practice of the invention, the antibody or composition of the invention will generally be administered to the subject to be treated according to a regime of treatment that is suitable for preventing and / or treating the disease or disorder to be prevented or treated. The clinician will generally be able to determine a suitable treatment regimen, depending on factors such as the disease or disorder to be prevented or treated, the severity of the disease to be treated and / or the severity of the symptoms thereof, the specific antibody of the invention used, the specific route of administration and pharmaceutical formulation or composition to be used, the age, gender, weight, diet, general condition of the patient, and similar factors well known to the clinician. Generally, the treatment regimen will comprise the administration of one or more antibodies of the invention, or of one or more compositions comprising the same, in one or more pharmaceutically effective amounts or doses. The specific amount(s) or doses to administered can be determined by the clinician, again based on the factors cited herein. Generally, for the prevention and / or treatment of the diseases and disorders mentioned herein and depending on the specific disease or disorder to be treated, the potency of the specific antibody of the invention, the specific route of administration and the specific pharmaceutical formulation or composition used, the antibodies of the invention will generally be administered in an amount between 1 gram and 0.01 microgram per kg body weight per day, preferably between 0.1 gram and 0.1 microgram per kg body weight per day, such as about 1, 10, 100 or 1000 microgram per kg body weight per day, either continuously (e.g. by infusion), as a single daily dose or as multiple divided doses during the day. The clinician will generally be able to determine a suitable daily dose, depending on the factors mentioned herein. It will also be clear that in specific cases, the clinician may choose to deviate from these amounts, for example on the basis of the factors cited above and his expert judgment. Generally, some guidance on the amounts to be administered can be obtained from the amounts usually administered for comparable conventional antibodies or antibody fragments against the same target administered via essentially the same route, taking into account however differences in affinity / avidity, efficacy, biodistribution, half-life and similar factors well known to the skilled person. Usually, in the above method, a single antibody of the invention will be used. It is however within the scope of the invention to use two or more antibodies of the invention in combination. The antibodies of the invention may also be used in combination with one or more further pharmaceutically active compounds or principles, i.e. as a combined treatment regimen, which may or may not lead to a synergistic effect. Again, the clinician will be able to select such further compounds or principles, as well as a suitable combined treatment regimen, based on the factors cited above and his expert judgement. In particular, the antibodies of the invention may be used in combination with other pharmaceutically active compounds or principles that are or can be used for the prevention and / or treatment of the diseases and disorders cited herein, as a result of which a synergistic effect may or may not be obtained. Examples of such compounds and principles, as well as routes, methods and pharmaceutical formulations or compositions for administering them will be clear to the clinician, and for example include the active compounds or principles that are or can be used in combination with one of the known antibodies against CD20 referred to herein (e.g. according to a suitable combined treatment regimen, as will be able to be determined by the treating clinician). When two or more substances or principles are to be used as part of a combined treatment regimen, they can be administered via the same route of administration or via different routes of administration, at essentially the same time or at different times (e.g. essentially simultaneously, consecutively, or according to an alternating regime). When the substances or principles are to be administered simultaneously via the same route of administration, they may be administered as different pharmaceutical formulations or compositions or part of a combined pharmaceutical formulation or composition, as will be clear to the skilled person. Also, when two or more active substances or principles are to be used as part of a combined treatment regimen, each of the substances or principles may be administered in the same amount and according to the same regimen as used when the compound or principle is used on its own, and such combined use may or may not lead to a synergistic effect. However, when the combined use of the two or more active substances or principles leads to a synergistic effect, it may also be possible to reduce the amount of one, more or all of the substances or principles to be administered, while still achieving the desired therapeutic action. This may for example be useful for avoiding, limiting or reducing any unwanted side-effects that are associated with the use of one or more of the substances or principles when they are used in their usual amounts, while still obtaining the desired pharmaceutical or therapeutic effect. The effectiveness of the treatment regimen used according to the invention may be determined and / or followed in any manner known per se for the disease or disorder involved, as will be clear to the clinician. Suitable methods and techniques will be clear to the skilled person and will often generally comprise a step of determining the level(s) of the relevant CD20 expressing cell(s) in the body of the subject to be treated (or in a suitable biological sample obtained from such subject). and / or determining any changes in such levels. Such methods and techniques may for example include the methods and techniques commonly used for determining the effectiveness and / or course of a treatment with one of the known antibodies against CD20 referred to herein. The clinician will also be able, where appropriate and on a case-by-case basis, to change or modify a particular treatment regimen, so as to achieve the desired therapeutic effect, to avoid, limit or reduce unwanted side-effects, and / or to achieve an appropriate balance between achieving the desired therapeutic effect on the one hand and avoiding, limiting or reducing undesired side effects on the other hand. Generally, the treatment regimen will be followed until the desired therapeutic effect is achieved and / or for as long as the desired therapeutic effect is to be maintained. Again, this can be determined by the clinician. In another aspect, the invention relates to the use of an antibody of the invention in the preparation of a pharmaceutical composition for prevention and / or treatment of at least one CD20-related disease or disorder (as defined herein); and / or for use in one or more of the methods of treatment mentioned herein. The invention further relates to an antibody of the invention (or a pharmaceutical composition comprising the same) for the prevention and / or treatment of at least one CD20-related disease or disorder (as defined herein). The invention also relates to a method of preventing and / or treating a CD20-related disease or disorder (as defined herein), which method comprises administering, to a subject in need thereof, of an antibody of the invention or a pharmaceutical composition comprising the same (again, according to a suitable route of administration and a suitable dosage regimen, as further described herein). Further uses of the antibodies and compositions of the invention will be clear to the skilled person based on the disclosure herein. For example and without limitation, the antibodies of the invention can be linked to a suitable detectable label and used as markers to detect or determine (qualitatively or quantitatively) the presence of CD20 or CD20 expressing cells, either in vitro, ex vivo or in vivo; and / or to determine whether the antibodies of the invention are capable of bringing together CD20-expressing cells and C1q expressing cells (i.e. in order to initiate complement-dependent cytotoxicity by the complement system). EXAMPLES EXAMPLE 1. Generation and Evaluation of Polypeptide Constructs Comprising C1q Complement Factor-Engaging Domains. Generation of Polypeptide Constructs A polypeptide construct with a complement factor-engaging domain at the C-terminus of an antibody light chain was designed in silico together with a corresponding heavy chain gene. Several affinity variants of the polypeptide constructs comprising C1q complement factor-engaging domains as disclosed herein were designed and tested in this format. Genes we synthesized and cloned into a pCDNA.3.1 vector which was used for transfection of Expi293 cells. Expi293 cells were transfected by mixing OPTI-MEM, DNA and PEI Max which was added to cells. 18h post transfection, each of the transfections were added Valproic acid, sodium propionate, and glucose to enhance the transfection efficacy. Cells were incubated at 37 °C with 8 % CO2. After 6 days, the supernatant was harvest by centrifugation at 200 g for 10 min at room temperature followed by a centrifugation at 4000 g for 30 min at room temperature. The supernatant was added 1 M Tris pH 8 to final concentration of 50 mM and mixed with protein A beads equilibrated in PBS. Beads were incubated on rotation at 4 °C for 1 h and loaded on a gravity column. Beads were washed with 15 column volumes of PBS with 350 mM NaCl added and eluted with 50 mM glycine pH 2.7 into tubes containing 1M TRIS pH 8. Polypeptide purity was evaluated by SDS-PAGE and concentrated to below 500 l. Samples were centrifuged for 10 minutes at 4000 rpm at 4 °C and loaded on a Superdex 200 Increase 10 / 300 GL column in PBS. Eluted fractions containing polypeptide constructs were analysed by SDS-PAGE and fractions containing the polypeptide constructs were pooled. EXAMPLE 2: CD20 -targeting polypeptide constructs increase CDC relative to rituximab alone. Polypeptide constructs with a C1q complement factor-engaging domain at the C- terminus of the light-chain (LC) of an IgG region of a CD20- targeting antibody 11B8 were generated as described herein. The 11B8 sequence comprises the following heavy and light chain sequences below. 11B8 Heavy chain (CM1684 / 1476): EVQLVQSGGGLVHPGGSLRLSCTGSGFTFSYHAMHWVRQAPGKGLEWVSIIG TGGVTYYADSVKGRFTISRDNVKNSLYLQMNSLRAEDMAVYYCARDYYGAGSFYD GLYGMDVWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVT VSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVD KRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHED PEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWE SNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPGK 11B8 Light chain: EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIKRTVA APSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDS KDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC The sequences for the polypeptide constructs are provided below. The structures of each construct are provided in FIG.1A. The C1q binder is hNb78 [M33A, T102A]. The C1q binder that is present is hNb78 [M33A, S103A] QVQLVESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVA AISWRGGSTYYADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADTAARAA LYSTGYEYDHWGQGTQVTVSS (SEQ ID NO:112) CM1475-1478: 11B8 Heavy chain; and CM1478: modified 11B8 Light chain with mutations M33A,S103A: EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIKRTVA APSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDS KDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGQVQLVE SGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVAAISWRGGSTYY ADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADTAARAALYSTGYEYDH WGQGTQVTVSS CM1684-1686: CM1684: 11B8 heavy chain CM1686: modified 11B8 Light chain - 5GS –with mutations M33A,S103A EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIKRTVA APSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDS KDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSQVQLV ESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVAAISWRGGSTY YADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADTAARAALYSTGYEYDH WGQGTQVTVSS CM1475-1688: CM1475: 11B8 heavy chain CM1688: modified 11B8 Light chain EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIKRTVA APSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDS KDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSQVQLV ESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVAAISWRGGSTY YADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADASARAALYSTGYEYDH WGQGTQVTVSS A CDC assay was performed against human B cells with CD20 targeting antibodies in 10% C1q depleted human serum, with cyno C1q added. Rituximab served as a control as well as Genmab 11B8. The CM1684-1686 polypeptide construct increased complement dependent cytotoxicity relative to traditional CD20 antibodies (FIG.1B). EXAMPLE 3: CYTOTOXICITY OF CD20 TARGETING CONSTRUCTS A CD-20 monoclonal antibody (CD20mAb) and a bispecific construct comprising the CD20mAb and two C1q-engaging domains (CD20-BiCE) as shown in FIG.1 and FIG.3 were produced using the methods provided in EXAMPLE 1. The CD-20-BiCE is a fully human anti- CD20 (11B8 clone) fused to two humanized anti-C1q VHHs. The CD-20 BiCE can comprise an IgG1 or an IgG1 modified with a LALAPG. The CD20-BiCE binds to human CD20 with an EC50 of 2 nM and has micromolar affinity for human C1q. The antibody is designed to deplete CD20 positive cells through CDC, CDCC, and CDCP of immune cells in a subject that is administered the CD20-BiCE. A CD20-BiCE with a LALA-PG mutation was also manufactured to mute all secondary effector functions of the IgG1 backbone. Constructs targeting CD20 were assessed in primary B cells. As shown in FIG. 2, the CD20-BiCE enabled strong complement activation relative to the CD-20 monoclonal antibody or rituximab alone. In vitro activity of CD20-BiCE on human B cells and PBMCs was further evaluated (FIG. 4 and FIG. 5). CDC and B cell depletion was driven by VHH C1q engagement with some contribution from the C1q binding site in Fc portion of the bispecific CD20-BiCE. The CD20-BiCE also maintained intact antibody-dependent cellular cytotoxicity (ADCC) in human PBMCs (FIG. 6) showing that the CD-20 BiCE is also deplete CD-20 expressing cells by ADCC. Human whole blood from 3 different donors was contacted with the CD20 mAb, CD- 20-BiCE, or modified CD20- LALAPG BiCE at varying concentrations of 10 micrograms / milliliter (μg / ml), and 100 μg / ml. Alemtuzumab, a monoclonal antibody that targets CD52, was utilized as a positive control for B cell killing. Cetuximab, a monoclonal antibody that inhibits epidermal growth factor (EGFR) was utilized as a negative control. CD- 20-BiCE increased the percentage of B cell killing by approximately 60% more than the CD20 mAb alone (FIG.7). Thus, the foregoing example demonstrates that bispecific constructs having a low affinity C1q complement factor-engaging domain antibody and a high affinity antigen binding moiety that binds CD20 are more effective at inducing complement-mediated cytotoxicity, relative to CD20 monoclonal antibodies. EXAMPLE 4: EVALUATION OF BISPECIFIC C1Q-CD20 BiCE CONSTRUCTS IN NON-HUMAN PRIMATES IN VIVO. The following CD20-BiCE constructs were generated: 11B8-BiCE for cyno (CM1670-1673) CM1670:11B8 Hc EVQLVQSGGGLVHPGGSLRLSCTGSGFTFSYHAMHWVRQAPGKGLEWVSIIG TGGVTYYADSVKGRFTISRDNVKNSLYLQMNSLRAEDMAVYYCARDYYGAGSFYD GLYGMDVWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVT VSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVD KRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHED PEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWE SNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPGK (SEQ ID NO: 16) CM1673: 11B8 Lc - 5GS - hNb78(M33A, S103A) EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIKRTVA APSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDS KDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSQVQLV ESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVAAISWRGGSTY YADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADTAARAALYSTGYEYDH WGQGTQVTVSS (SEQ ID NO: 17) 11B8-BiCE LALAPG for cyno (CM1671-CM1673) CM1671: 11B8 LALAPG Hc EVQLVQSGGGLVHPGGSLRLSCTGSGFTFSYHAMHWVRQAPGKGLEWVSIIG TGGVTYYADSVKGRFTISRDNVKNSLYLQMNSLRAEDMAVYYCARDYYGAGSFYD GLYGMDVWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVT VSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVD KRVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHED PEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKALGAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWE SNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPGK (SEQ ID NO: 18) CM1673: 11B8 Lc - 5GS - hNb78(M33A, S103A) EIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASN RATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSDWPLTFGGGTKVEIKRTVA APSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDS KDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECGGGGSQVQLV ESGGGSVQPGGSLRLSCTASGWTFRDSAYNLGWFRQAPGQEREAVAAISWRGGSTY YADSVKGRFTISRDNAKNTVTLQMNNLKPEDTAIYYCAADTAARAALYSTGYEYDH WGQGTQVTVSS (SEQ ID NO: 19) Non-human cynomolgus primates were administered IV infusions at a dose of 25 milligrams / kilogram (mg / kg) of the CD20 IgG BiCE and the CD20 LALAPG IgG BiCE. Each group of non-human primates (NHPs) were compared to a control group that did not received IV infusion of a bispecific construct. Blood was sampled periodically as shown in (FIG. 8). Lymph node biopsies were performed on day 15 and day 30. At the end of the evaluation, bone marrow and spleen tissues were removed from animals in each group. Blood samples from NHPs were evaluated by flow cytometry for the presence of CD19 positive and CD20 positive cells over the course of 30 days (FIG. 9). Lymph node cells were also evaluated by flow cytometry for the presence of CD19 positive cells in all groups (FIG. 10). All animals were successfully dosed and a rapid, sustained depletion of B cells was observed. Body weight remained the same for all animals with normal levels of hematological function and coagulation. No adverse effects were observed in NHPs that were treated with the bispecific constructs. Further analysis of NHP cells in vitro showed that CDC was increased in CD20-BiCE and CD-20 BiCE LALAPG treated B cells (FIG. 11). Next, NHP B cells were evaluated following administration of different concentrations of CD-20 mAb, CD20-BiCE, and CD20- BiCE-LALAPG to non-naïve PBMCs with matched serum and Naiive PBMCs with matched serum. The percentage of B cells killed following administration to the cells was quantified for each concentration (FIG. 12A and FIG. 12B). Cells administered CD-20- BiCE and CD20- BiCE-LALAPG had a higher percentage of B cell killing relative to cells treated with CD20mAb. The observed CDC and B cell depletion, was therefore driven by the C1q engagement of the CD-20 BiCE constructs. Thus, the foregoing example demonstrates that bispecific constructs having a low affinity C1q complement factor-engaging domain antibody and a high affinity antigen binding moiety that binds CD20 are more effective at inducing complement-mediated cytotoxicity and B cell depletion in vivo in non-human primates, relative to NHPs that did not receive treatment. Moreover, the bispecific constructs also had a good safety profile in NHPs in vivo as characterized by the lack of adverse effects, change in body weight, or hematological function.

[0002] QLSV KGE QSISN D H GSQLG GTW YTPKE PVH WLAVEATAK YVATN D Y LFVTWDLQK QAQRAEYDTR VFY S VKSQWN G SGVSKIK D SGEA LTGGRTSSVELG GLNSIYQGK RTGTLSST PSYFA niA a RFGYR GF SCLEASR A DGR hc CA NSG K A tShL PGFN Y giT ITR R NF V A)lAGTLTLL SPC DFS T S T6WD D:AO 8RAWVKSKTGA S YANebc1 ER 1 GD VP NS S SDVAYCDRAQPS TTSYIneudeqiSATEefiLdSD QSCGYIQ LYQGT LSGAE CSVGLRTS( Sno T IiMALLYKYLSQEQR QH LWDSTSS EP Sah– PSRC 8QPVE SGIAK VTt7h4 TAAD NVQFS GEGPALV DP SC QVNQg1 LVGEPFQAV ANTiM L CIE PP ILYS EMG KE FA V G R Q Q VK G VLS WVY A SSRSIKTK NSGK H NL TGQK MKSVDSQTMD G R DGLDLTAVQ NDY ASIYSV AVDN K HKLH HT F TS PKTK VC KTVPN YSF Sn FR GK FNP EY LPHAS T LoHS KPVE EDT AiTGGStFKPVPPGKRT EVYA GK HFD GSKHnGeSvn GSYL SD DPNLFVN PYM FTVVYL PL NViTeCAR YAVLS ANSWWhS CTN ESI PGNDYPCStLYCPGfRTYGSNYoTGFQVQ L KFVHQGVsneiLVYK S GVTSWQT LEELPP VENSN)G1:ideahGGASoc GTMAbinc S V GPLA D T REL P EWQ QO yPHGII DE S TVSS PVQ CHENteu vaS SGVWDeVSV PVAT ESPPPVVK VAAIRS Inaqe LR VPeSH GWL TFVTCTD VR YKSDSK Q D Ev8GiniB EGL SNTY GDVHTVTSIT PSYV (taath 11- SGnC 5QK MQKV V GV SSKCNKE FTK GLGesy7Vev4ra1 LG QPLWLDTYICL C VQPKKSPSpeQAY M QLVS S EEAV Y LS DG YKPEPL L SeH CVER N MLALGPE TRRLC F LrPAT F S:Ael 87b4atTc1u-r5t7sne41omaM C N C QLSV K S N H GQ SGTW QSIDPVH YTPKEATD WLAVEVN AK YLQKYA TWDQREL FVTVFAY YDSTR QA VK QWN D G SG TS KIKSLSGGLRSVSGEAVE TGNSIYLQSGK RPLTGYTGAFA SSTSnSR A i A a RFGYSCGR R GFLhS ED GR K A cCAGN N YRF V A)t ShL PIFTL TNT S T8:giTLAGTLL SPC DFSWD D AAO VK K GSYANe 8REA R WVS TAYCDIc BGN DS SDVPTTSYn 1u1 PSRAQSCGYIQeSL AQTEq dTS SLGAESe eiSf SDQGiL YdT IL CSYKVLLSGR E QLRT( S WDSS EP Sni oAaLYQ Q HTGIK VThM-PC 6SRQPVE SGt8AAD NVGE PALV QA VNQh6g1TLQFSDP SC AVN SATiM VI GP EPPFQILYGER MG QQ L CEKE FA V GE LG VKG S WVY A SVSIKKLSGK H NL T SRTK MKNVD QDGGQS S TMLDLAVQ Y ARSDGSVVTN KNDLH HIYF T A KD KH CKVN YTSF S S PFT PVKTLP HF R GKTGASSTN HSPKEPVYE P LGEDTTAF KGPVKPFK D GRKEGVY YALGHLVNSPYH S GS SNF PM TDDP TYLN ARF LVVSWWLNVSCSYAVANPNDTLYCSPG CIGFQYEPC VQSFRTYGSniLVYK NYTGKHQGV QLLV ELPN N)aSGVT WGGAS S TEGP PV TERSG7PEQ:e hGTMAVLA DE LWQOcncPGe yID SS TSPVQENu vq aHIVS EVVPSSCHPS SG VK VW AR DIe eHLVA RTVEPP PVVAI SFV CD RKDK QS8GWL TT TVYSSD EniGES TYVHVT IPa Bh 1GLN GD VS( 1SGMQKVSTKV CS TNK YFTC-4QKLKy8v6 V G QLGVL SL DTYEQIPG G KKSPa1 L PeQAYWC M QLV S DGSCLYSVELKP EA TEP VSLY LRP L L SH CVER N M A GPERACTFFLS68t6c1u-r4t8sne61omCaM N C QLSV K S N H GQ SGTW QSIDPVH YTPKEATD WLAVEVN AK YLQKYA TWDQREL FVTVFAY YDSTR QA VK QWN D G SG TS KIKSLSGGLRSVSGEAQSVE TGNSIYTLSGK RPLTGY GAFA nSTSiCSR A A a RFGYSGR h R GFLS ED GR KAc CtSAGN hL PIFN YRF VS )gTL TNT SA3D:iTlAGTLL SPC DFSWD AAO 8RA VK K GSYANeBER WVS TAYCDIc1GN DS SDVPTTSYn1 PSRAQSCuSGYIQe dSAQTEqe TSLGAES eifSiLdSD oLTYIQGLR RT( L CSV YKLSG E QLSWDSS ESniaM ALYQ Q HGI PKVTh-PC 8SRQPVE S TGt8AAD NVGE PALV QA VNQh6g1TLQFSDP SC AVN SATiM VI GP EPPFQILYGER MG QQ L CEKE FA V GE LG VKG S WVY A SVSIKKLSGK H NL T SRTK MKNVD QDGGQS S TMLDLAVQ Y ARSDGSVVTN KNDLH HIYF T A KD KH CKVN YTSF S S PFT PVKTLP HF R GKTGASSTN HSPKEPVYE P LGEDTTAF KGPVKPFK D GRKEGVY YALGHLVNSPYH S GS SNF PM TDDP TYLN ARF LVVSWWLTNVSCSYAV LYCSANPPG NDYEPC RTYGSCIGFQVQSFL VYK NYTGKHQGV QLLV ELPEN N)niSGVT Wa GGAS S TEGP PVSG1D T RP EQ:eh GTMAnS VLAE LWQOcc PGeyHIDS TSPVSQENuvqaIVS EVVPSSCHPSG VK VW AR DIeeh LVAT E P PVVAI SG R VPFV CD RKDK QS8WLSTT TVYSSD EniBGETYVHVT IPa1GLN GD VS(h1SGMQKVSTKV CS TNK YFTLKC;5QKy7v4 V G QLGVL SL Da1 L PCTYEQIPG G KKSPeQAYWC MVQLV S DGSLYSVELKP ETEAP VSLY LPL L SH CER N M A GPERRACTFFLS88t6c1u-r5t7s e4n1omCaM N C 5

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Claims

CLAIMS 1. A polypeptide construct comprising: at least one heavy chain and at least one light chain, wherein the at least one heavy chain and the at least one light chain bind to a cluster of differentiation 20 (CD20); and at least one complement factor-engaging domain that binds to a C1q complement factor, wherein an affinity of the at least one complement factor-engaging domain for the C1q complement factor is between 10 nanoMolar (nM) to about 2 microMolar (μM) as determined by biolayer interferometry.

2. The polypeptide construct of claim 1, wherein the polypeptide construct comprises two complement factor-engaging domains that bind to the C1q complement factor.

3. The polypeptide construct of claim 1, wherein the at least one complement factor-engaging domain comprise an affinity for the C1q complement factor that is about 0.1 μM up to about 2 μM as determined by biolayer interferometry.

4. The polypeptide construct of claim 1, wherein the polypeptide construct comprises two heavy chains that bind to the CD20.

5. The polypeptide construct of claim 1, wherein the polypeptide construct comprises two light chains that bind to the CD20.

6. The polypeptide construct of claim 1, wherein the at least one heavy chain comprises an amino acid sequence of SEQ ID NO: 1 or a variant thereof, wherein the variant comprises at least one amino acid substitution relative to SEQ ID NO:

1.

7. The polypeptide construct of claim 1, wherein the at least one light chain comprises an amino acid sequence of SEQ ID NO: 2 or a variant thereof, wherein the variant comprises at least one amino acid substitution relative to SEQ ID NO:

2.

8. The polypeptide construct of claim 1, wherein the at least one heavy chain comprises an amino acid sequence of SEQ ID NO: 1; and the at least one light chain comprises an amino acid sequence of SEQ ID NO: 3.

9. The polypeptide construct of claim 4, wherein the two heavy chains each comprise two heavy chain variable regions (VH).

10. The polypeptide construct of claim 5, wherein the two light chains each comprise two light chain variable regions (VL).

11. A polypeptide construct comprising: a first heavy chain comprising SEQ ID NO: 1; a second heavy chain comprising SEQ ID NO: 1; a first light chain comprising SEQ ID NO: 3; a second light chain comprising: SEQ ID NO: 3; a first complement factor-engaging domain; and a second complement factor-engaging domain.

12. A pharmaceutical composition comprising the polypeptide construct of any of claims 1-11.

13. Use of a polypeptide construct of any of claims 1 to 12 or of a pharmaceutical composition of claim 13 in the prevention and / or treatment of a disease or disorder that can be prevented to treated by depleting, and / or suitably reducing the levels of and / or suitably controlling the level of, at least one cell or cell type expressing CD20 in the body of a subject in need of such prevention or treatment.

14. Use of a polypeptide construct of any of claims 1 to 12 or of a pharmaceutical composition of claim 13 in the prevention and / or treatment of a disease and disorder that can be prevented and / or treated by (suitably) increasing activation of complement (in particular, leading to the complement-dependent cytotoxicity) that is exerted by the body of the subject to be treated towards a CD20 expressing cell.

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