Bispecific antigen binding proteins (ABP) targeting immune checkpoint molecules and both leukocyte immunoglobulin-like receptor subfamily b1 (lilrb1) and lilrb2; combinations and uses thereof

Abstract

The invention relates to bispecific antigen binding proteins (ABP), such as bispecific antibodies, that bind with a first antigen binding site to both leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and LILRB2 while not binding to, or binding with significantly less affinity to, leukocyte immunoglobulin-like receptor subfamily A (LILRA). The bispecific ABP of the invention bind with a second antigen binding site to immune checkpoint (molecules) such as PD-1 or PD-L1. The bispecific ABP of the invention can also inhibit the interaction between LILRB1 and / or LILRB2 and a natural ligand of ULRB receptors (e.g. interacting proteins, such as HLA-G) on immune cells and the inhibition of such interaction can reduce immune cell suppression and thereby support anti-infection and anti-tumour immune responses in a subject suffering from such diseases. Bispecific molecules combining LILRB1 / 2 antagonism with inhibition of immune checkpoints, such as the inhibition of the PD-1 / PD-L1 axis, is specifically useful in the treatment of proliferative disorders. Also provided are methods of reducing the immune suppression of cells involved with a cell-mediated immune response, and / or methods for treating infective- and / or proliferative diseases, using an LILRB1 and / or LILRB2 antigen binding protein such as an antibody binding to both LILRB1 and / or LILRB2, as well as certain related aspects including detection, diagnostic and screening methods.

Description

BISPECIFIC ANTIGEN BINDING PROTEINS (ABP) TARGETING IMMUNE CHECKPOINT MOLECULES AND BOTH LEUKOCYTE IMMUNOGLOBULIN-LIKE RECEPTOR SUBFAMILY Bl (LILRB1) AND LILRB2;COMBINATIONS AND USES THEREOFDESCRIPTION[1] The invention relates to bispecific antigen binding proteins (ABP), such as bispecific antibodies, that bind with a first antigen binding site to both leukocyte immunoglobulin-like receptor subfamily Bl (LILRB1) and ULRB2 while not binding to, or binding with significantly less affinity to, leukocyte immunoglobulin-like receptor subfamily A (LILRA). The bispecific ABP of the invention bind with a second antigen binding site to immune checkpoint (molecules) such as PD-1 or PD-L1. The bispecific ABP of the invention can also inhibit the interaction between LILRB1 and / or LILRB2 and a natural ligand of ULRB receptors (e.g. interacting proteins, such as HLA-G) on immune cells and the inhibition of such interaction can reduce immune cell suppression and thereby support anti-infection and anti-tumour immune responses in a subject suffering from such diseases. Bispecific molecules combining ULRB1 / 2 antagonism with inhibition of immune checkpoints, such as the inhibition of the PD-1 / PD-L1 axis, is specifically useful in the treatment of proliferative disorders. Also provided are methods of reducing the immune suppression of cells involved with a cell- mediated immune response, and / or methods for treating infective- and / or proliferative diseases, using an LILRB1 and / or ULRB2 antigen binding protein such as an antibody binding to both ULRB1 and / or LILRB2, as well as certain related aspects including detection, diagnostic and screening methods.[2] In the treatment of cancer there are a number of approaches by which therapies may lead to the elimination of tumour cells, including those that involve or exploit one or more components of the immune system, either directly or indirectly. One of the limitations associated with such therapies is that cancerous cells often exploit immune- checkpoints to evade a patient's immune system, such as by preventing immune-recognition or down-regulating a tumour-specific cytotoxic T cell (CTL) response, thereby generating resistance against an immune response (Rabinovich et al 2007, Annu Rev Immunol 25:267; Zitvogel et al 2006, Nat Rev Immunol 6:715). Under normal conditions, such immune-regulatory checkpoints are crucial for the maintenance of self-tolerance under physiological conditions, but there is an increasing recognition of the important role that they can also play in cancer (Hanahan and Weinberg 2011, Cell; 144:646); cancerous cells can take over these mechanisms to evade and suppress the immune system in order to develop into a tumour (Drake et al 2006, Adv Immunol 90:51).[3] Current state of the art cancer therapies include blockade of those few immune-regulatory checkpoints presently known and for which their mechanism of action is understood. For example, blocking antibodies against surface-expressed immune-regulatory proteins, such as CTLA4 and PD-L1 (Chambers et al 2001, Annu Rev Immunol 19:565; Blank et al 2004, Cancer Res 64: 1140), can boost anti-tumour immunity and have shown clinical success against many cancer types (Page et al 2014, Annu Rev Med 65: 185). However, a large proportion of cancer patients does not respond to such checkpoint blockage therapy (Bu et al 2016, Trends Mol Med 22:448; Hugo et al 2016, Cell 165:35; Topalian et al 2012, New Engl J Med 366:2443), indicating that other immune-checkpoint pathways may be active. Indeed, synergistic cooperation between several immune-regulatory pathways maintains immune tolerance against tumours, which might explain why blocking only one immune-regulatory checkpoint node can still result in tumour escape (Woo et al 2012, Cancer Res 72:917; Berrien-Elliott et al 2013, Cancer Res 73:605). However, little is known about the molecular factors that are central to the mechanism of action of such immune-regulatory pathways. Indeed, successful cancer immunotherapy requires a systematic delineation of the entire immune-regulatory circuit — the 'immune modulatome' — expressed by tumours. Therefore, today, there is still an unmet need for identifying further molecular targets that may serve as immune-regulatory checkpoints and in particular an unmet need for means and methods to modulate, detect and otherwise utilise such possible checkpoint targets, such as in medicine, diagnosisand research.[4] The human leukocyte immunoglobulin-like receptor (LILR), also known as immunoglobulin-like transcript (ILT) family belongs to the superfamily of paired receptors that have the potential to transmit stimulatory or inhibitory signals according to the presence or absence of tyrosine-based signalling motifs in their cytoplasmic tail. Human ULRs consist of six stimulatory receptors (ULRA1-6) and five inhibitory receptors (ULRBI -5). ULRs are predominately expressed on myeloid and lymphoid cells and some non-immune cells, and the expression patterns are different from receptor to receptor. Polymorphism and copy-number variation contribute to diversity within humans. Receptor engagement results in intracellular phosphorylation of the tyrosine-based motifs within the receptors (ULRB) or on associated adaptor molecules (LILRA). Downstream signalling events can be mediated by phosphatases, such as SHP1, SHP2 and SHIP. In general, LILR activity can result in the upregulation or downregulation of both innate and adaptive immune functions with a range of effects on different cell types. Certain ULRs also play regulatory roles in neuronal activity and osteoclast development.[5] ULRBI is broadly expressed on myeloid cells, as well as B cells and subsets of T cells and natural killer (NK) cells. LILRB2-5 are more restricted to myeloid cells and dendritic cells (DCs). Some of the ligands and signaling pathways for ULRBs have been identified. LILRB1 and ULRB2 are the best characterized receptors, and both bind to classical (HLA-A, HLA-B and HLA-C) and non-classical (HLA-E, HLA-F, HLA-G and HLA-H) MHC class I or HLA class I molecules, as well as to members of the angiopoietin-like protein family. Because the immune-suppressive function of ULRBs is similar to that of the classical immune checkpoint proteins, CTLA-4 and PD-1, the interaction between LILRBs and ligands is proposed to serve as immune checkpoints. For example, engagement of LILRB1 and LILRB2 by HLA-G on cancer cells inhibits immune cell activation and generates regulatory T cells (Tregs) and suppressive antigen presenting cells (APCs), which can indirectly support tumour development. Further, the interaction of P2-microglobulin (P2M)-associated MHC class I on cancer cells with LILRB2 on macrophages leads to loss of immune surveillance. Whether the interaction between LILRB2 and ligand also functions as a phagocytosis checkpoint is unknown. ULRBs may also represent targets for induction of transplantation tolerance to prevent allograft rejection. LILRBs (especially ULRB2 and LILRB4) are critical for induction of the tolerogenic phenotype of APCs and initiation of the T cell suppression cascade that results in immune tolerance. LILRB1 and ULRB2 can also mediate graft tolerance by binding to HLA-G. In addition to immune cells, ULRBs are expressed by cancer cells and may support malignant transformation and relapse, as well as the activity of cancer stem cells. Collectively, these findings reveal dual roles for LILRBs as immune checkpoint molecules and as tumour-sustaining factors. Development of agents useful in modulating signaling from ULRBs may be of great benefit in diseases involving dysregulation of the immune system, including cancer, inflammatory diseases and autoimmune diseases, as well as transplantation rejection.[6] Programmed cell death protein 1 (PD-1 or CD279) is an inhibitory member of the CD28 family of receptors, that also includes CD28, CTLA-4, ICOS and BTLA. PD-1 is a cell surface receptor and is expressed on activated B cells, T cells, and myeloid cells (Okazaki et al (2002) Curr. Opin. Immunol. 14: 391779-82; Bennett et al. (2003) J Immunol 170:711-8). The structure of PD-1 is a monomeric type 1 transmembrane protein, consisting of one immunoglobulin variable-like extracellular domain and a cytoplasmic domain containing an immunoreceptor tyrosine-based inhibitory motif (ITIM) and an immunoreceptor tyrosine-based switch motif (ITSM). Activated T cells transiently express PDI, but sustained hyperexpression of PDI and its ligand PDL1 promote immune exhaustion, leading to persistence of viral infections, tumor evasion, increased infections and mortality. PD-1 expression is induced by antigen recognition via the T-cell receptor and its expression is maintained primarily through continuous T-cell receptor signaling. After prolonged antigen exposure, the PD-1 locus fails to be remethylated, which promotes continuous hyperexpression. Blocking the PDI pathway can restore the exhausted T-cell functionality in cancer and chronic viral infections (Sheridan, Nature Biotechnology 30 (2012), 729-730). Monoclonal antibodies to PD-1 have been described, for example, in WO 2003 / 042402, WO 2004 / 004771, WO 2004 / 056875, WO 2004 / 072286, WO 2004 / 087196, WO 2006 / 121168, WO2006 / 133396, WO 2007 / 005874, WO 2008 / 083174, WO 2008 / 156712, WO 2009 / 024531, WO 2009 / 014708, WO2009 / 101611, WO 2009 / 114335, WO 2009 / 154335, WO 2010 / 027828, WO 2010 / 027423, WO 2010 / 029434, WO2010 / 029435, WO 2010 / 036959, WO 2010 / 063011, WO 2010 / 089411, WO 2011 / 066342, WO 2011 / 110604, WO2011 / 110621, WO 2012 / 145493, WO 2013 / 014668, WO 2014 / 179664, and WO 2015 / 112900.[7] Recently, Chen M et al. 2018 reported that ULRB2 antagonism disrupts the activation of certain signalling pathways (SHP1 / 2, AKT, and STAT6) that are typically involved in maintaining the immunosuppressive functions of myeloid cells. This reprogramming leads to reduced infiltration of immunosuppressive cells like granulocytic myeloid- derived suppressor cells (MDSCs) and regulatory T cells (Tregs) in tumour environments. Further, Chen et al demonstrated that there is an enhancement in the effectiveness of T cell immune checkpoint inhibitors, suggesting a potential synergy between ULRB2 blockade and existing immunotherapies.[8] International patent publication WO 2020 / 023268 discloses combination therapies comprising a Programmed Death 1 receptor (PD-1) pathway inhibitor, and a Leukocyte Immunoglobulin Like Receptor B (LILRB) signaling inhibitor, and the use of the combination therapies for the treatment of cancer. Further disclosed is the treatment of cancer patients who are refractory to monotherapy with a PD-1 pathway inhibitor. WO 2020 / 023268 exemplifies that anti-PD- 1 and anti-ULRBl synergistically activated T cells in mixed lymphocyte reaction. Blocking both pathways significantly enhanced T cell activity and IFNy production than blocking each pathway alone.[9] International patent publication WO 2022 / 217019 discloses novel ULRB (also known as ILT4) antibodies, and antigen binding fragments thereof, as well as bispecific and multispecific constructs binding to ULRB1 and PD-L1. Methods of inducing or enhancing an immune response, and methods of treating cancer, by administering the antibodies (or fragments), bispecific constructs, or compositions also are described.

[0010] Therefore, there is a need, from one or more of the above perspectives, for novel approaches to reduce the immune-suppressive functions of the ULRB receptors while avoiding any inhibition of the immune-stimulatory ULRA receptors on immune cells involved in the defense against certain disorders (such as an infection or tumour). The present invention seeks to provide, in particular, novel therapeutic approaches and methods involving novel compounds; for example, bispecific compounds and bispecific ABPs that reduce the immune-suppressive function of ULRB receptors while not inhibiting the immune-stimulatory function of any of the ULRA receptors, and to combine them with inhibitors of immune checkpoints, such as in particular PD-1 / PD-L1. Furthermore, the invention seeks to provide novel strategies to diagnose, prognose and / or monitor immune cells on the basis of LILRB expression. Accordingly, it is an object of the present invention to provide alternative, improved, simpler, cheaper and / or integrated means or methods that address one or more of these or other problems. Such an object underlying the present invention is solved by the subject matter as disclosed or defined anywhere herein, for example by the subject matter of the itemized embodiments and / or attached claims.

[0011] The invention is grounded by the surprising finding that certain antigen binding proteins, such as antibodies, of the invention bind selectively and specifically to both ULRB1 and LILRB2, while not binding, or binding relatively less selective and less specific, to any of the ULRA receptors. Such inventive bispecific molecules are used in the present invention in bispecific and multispecific formats in combination with immune checkpoint inhibitors. In certain preferred aspects of the invention the antibodies of the invention maintain cross-specificity with respect to targets ULRB1 and ULRB2 while binding significantly less to the off-target proteins ULRA1 and LILRA3. Maintaining cross specific binding only with respect to the LILRB on-target proteins without off-target binding to ULRAs is one of multiple surprising features of the antibodies of the present invention.

[0012] Generally, therefore, and by way of brief description, the main aspects of the present invention can be described as follows:

[0013] In a first aspect, the invention relates to a bispecific antigen binding protein (ABP) which with a first antigen binding site specifically binds to LJLRBl and / or LLLRB2 protein (eg to the extra cellular domain (ECD) of LILRB1 and / or LLLRB2 protein) and, optionally, wherein the ABP is able to inhibit the binding of a ligand of LJLRBl and / or LLLRB2 protein or a variant thereof to LILRB1 and / or LLLRB2 protein or a variant thereof, and wherein the bispecific ABP with a second antigen binding site binds to (and preferably inhibits) an immune checkpoint, such as PD-1 / PD-L1. Preferably, the ABP or biABP, with its first antigen binding site, does not specifically binding to, or binds significantly less to, leukocyte immunoglobulin-like receptor subfamily A (LILRA) type proteins.

[0014] In a second aspect, the invention relates to a bispecific ABP comprising a first antigen binding site which competes with the first antigen binding site of a bispecific ABP of a first aspect for a binding to LILRB1 and / or LILRB2 protein (eg to the ECD of LJLRBl and / or LLLRB2 protein), wherein the bispecific ABP of the second aspect comprises a second antigen binding site which binds to (and preferably inhibits) an immune checkpoint, such as PD-1 / PD-L1. In a related aspect, the invention relates to a bispecific ABP which binds to the same epitope as an bispecific ABP of a first aspect, with regard to their first antigen binding site.

[0015] In a third aspect, the invention relates to a nucleic acid encoding for a bispecific ABP of the invention or of components thereof, and in related aspects, the invention relates to a nucleic acid construct (NAC) comprising such a nucleic acid, and relates to a host cell comprising a nucleic acid or NAC of the invention.

[0016] In a fourth aspect, the invention relates to a pharmaceutical composition comprising a bispecific ABP, nucleic acid, NAC or host cell of the invention, or comprising a compound that is a modulator of the expression, function, activity and / or stability of leukocyte immunoglobulin-like receptor subfamily Bl (LJLRBl) and / or LLLRB2 type proteins, and a pharmaceutically acceptable carrier, stabiliser and / or excipient.

[0017] In a fifth aspect, the invention relates to a method for the treatment of certain diseases, disorders or conditions in a subject by administering a product to the subject, wherein the product is selected from the list consisting of a bispecific ABP, nucleic acid, NAC and host cell of the invention, or is a compound that is a modulator of the expression, function, activity and / or stability of LJLRBl and / or LLLRB2. In related aspects, the invention relates to a product for use in medicine, and relates to the use of a product for the manufacture of a medicament, wherein the product is selected from the list consisting of an ABP, nucleic acid, NAC or host cell of the invention, or is a compound that is modulator of the expression, function, activity and / or stability of LJLRBl and / or LLLRB2.

[0018] The invention also relates in other aspects to various methods to produce a recombinant cell line or ABP of the invention, a hybridoma or host cell capable of producing an ABP of the present invention, as well as relating to various determination and / or diagnostic methods or uses, and to kits useful for such determination and / or diagnostic methods, as well as to various methods for identifying and / or charactering compounds, such as those suitable for use in medicine.

[0019] The figures show:

[0020] Figure 1: shows pictorial representation of the domain structure of the Leukocyte Immunoglobulin-Like017 , 16 = A-018 , 17 = A-019 , 18 = A-020 , 19 = A-021 , 20 = A-045 , 21 = A-046 , 22 = A-003 , 23 = A-022 , 24 = A-023 , 25 = A-024 , 26 = A-025 , TJ = A-026 , 28 = A-027, 29 = A-028 , 30 = A-029 , 31 = A-030 , 32 = A-031 , 33 = A-032 , 34 = A-033 , 35 = A-047 , 36 = A-048 , 37 = A-034 , 38 = A-035 , 39 = A-036 , 40 = A-037 , 41 = A-038 , 42 = A-039 , 3 = A-040 , 44 = A-041 , 45 = [Ref047, MK-4830, LILRB2 specific], 46 = [Ref051, BND-22, LILRB1 specific], 47 = [Ref062, NGM707, cross-specific],

[0022] Figure 3: shows inhibition of the interaction of (A) ULRB1 or (B) ULRB2 and their ligand HLA-G using antibody of the invention clone A-001, and maturated variants thereof. Y-axes = Residual Binding (%), x-axes = Antibody concentration (nM); 1 = A-001 , 2 = A-004 , 3 = A-005 , 4 = A-006 , 5 = A-007 , 6 = A-008 , 7 = A-009 , 8 = A-010 , 9 = A-011 , 10 = A-012 , 11 = A-013 , 12 = A-014 , 13 = A-015 , 14 = A-016 , 15 = A-017 , 16 = A-018 , 17 = A-019 , 18 = A-020 , 19 = A-021, 20 = A-045 , 21 = A-046.

[0023] Figure 4: shows inhibition of the interaction of (A) ULRB1 or (B) ULRB2 and their ligand HLA-G using antibody of the invention clone A-003 and maturated variants of thereof. Y-axes = Residual Binding (%), x-axes = Antibody concentration (nM); 22 = A-003 , 23 = A-022 , 24 = A-023 , 25 = A-024 , 26 = A-025 , 27 = A-026 , 28 = A- 027 , 29 = A-028 , 30 = A-029 , 31 = A-030 , 32 = A-031 , 33 = A-032 , 34 = A-033, 35 = A-047 , 36 = A-048.

[0024] Figure 5: shows inhibition of the interaction of ULRB1 or ULRB2 and their ligand HLA-G using reference antibodies. (A) shows inhibition of ULRB1 and HLA-G; (B) shows inhibition of LILRB2 and HLA-G. Y-axes = Residual Binding (%), x-axes = Antibody concentration (nM); open circle = Ref065 [10-108, ULRB2 specific], diamond = Ref062 [NGM707, cross-specific], solid square = Ref051 [BND-22, LILRB1 specific], solid circle = Ref047 [MK-4830, LILRB2 specific], solid star = RefOOl (isotype control).

[0025] Figure 6: shows effects of anti-ULRB2 / l blockade on (A - C) polarization of human M2 macrophages in a functional myeloid assay and (D - H) on polarization of human M2 macrophages and cytotoxic T cells in a myeloid suppression assay. Such effects were assessed by (A and D) surface M2 marker CD163 and (F) early activation marker CD69 (Y axis = median Fl of live cells; B = background), and cytokine secretion of (B) CCL13, (C) CCL23, (E) CCL18, (G) GM-CSF and (H) IFNy (Y axis = cytokine concentration (pg / ml); X axes = antibodies at indicated concentrations; 0 = RefOOl (isotype control); 1 = A-010 ; 2 = A-026 ; 3 = Ref047 [LILRB2 specific MK-4830]; 4 = Ref062 [NGM707, cross-specific]; 5 = A-045; X = isotype control).

[0026] Figure 7: shows target binding of LILRB2 / 1 antibodies (A = A-045, B = Ref047 [LILRB2 specific MK-4830], and C = Ref062 [NGM707, cross-specific]) to transfected Expi293 cells, (D) to primary T cells and (E) to monocytes; Y axis = % positive (of CD8+ cells) [for D only], otherwise Y axes = Median FI (RL1-H) of GFP+cells (pg / ml); X axes = antibodies concentrations (nM); X = isotype control. For A - C: circle = non-transfected, square = ULRB1, triangle = ULRA1, inverted triangle ULRB2, diamond = LILRA2, and hexagon = ULRA3. For D and E: circle = A-045, square = Ref047 [ULRB2 specific MK-4830], and triangle C = Ref062 [NGM707, cross-specific],

[0027] Figure 8: depicts the (A) the Tri-culture Assay principle; AB = addition of antibodies (antibodies will be present throughout the assay), T = addition of T cells, TC = addition of tumour cells, X = differentiation of monocytes with M-CSF, Y = polarization of macrophages by addition of IL-4, IL-10 and TGF-B; Z = activation of autologous T cells by addition of anti-CD3 and anti-CD28; and shows (B) reversal of T cell suppression (Y-axis = IL-2 [pg / ml]) and (C) tumour cell killing (Y-axis = tumour cell signal [RLU]) by optimized A-010; X-axes: 1 = unstimulated T cells only, 2 = stimulated T cells only, 3 = stimulated T cells + M2-polarized macrophages + A-010; 4 = stimulated T cells + M2- polarized macrophages + RefOOl (isotype control); 5 = tumour cells only, 6 = tumour cells + unstimulated T cells only, 7 = tumour cells + stimulated T cells only, 8 = tumour cells + stimulated T cells + M2-polarized macrophages + A- 010, 9 = tumour cells + stimulated T cells + M2-polarized macrophages + RefOOl (isotype control); ac = assay controls.

[0028] Figure 9: depicts BU measurements showing displacement of ULRB2 from HLA-G interaction site and inhibition of new LILRB2 and HLA-G complex formation using antigen binding fragments obtained from antibodies of the invention (A) A-010, (B) A-045, (C) A-047 , (D) A-048, antigen binding fragment obtained from (E) reference molecule Ref062 [NGM707, cross-specific] or (F) assay buffer. Y-axes = wavelength shift (nm), x-axes = time (sec).

[0029] Figure 10: depicts BU measurements showing displacement of ULRB1 from HLA-G interaction site and inhibition of new LILRB1 and HLA-G complex formation using antigen binding fragments obtained from antibodies ofthe invention (A) A-010, (B) A-045, (C) A-047 , (D) A-048, antigen binding fragment obtained from (E) reference molecule Ref062 [NGM707, cross-specific] or (F) assay buffer. Y-axes = wavelength shift (nm), x-axes = time (sec).

[0030] Figure 11: depicts BU measurements showing binding of antibodies to ULRB2 in presence of different concentrations of LILRA1 and ULRA3. The panels show binding to LILRB2 using antibody A-045 of the invention in presence of (A) LILRA1 and (B) LILRA3, as well as reference molecule Ref062 [NGM707, cross-specific] in presence of (C) ULRA1 and (D) ULRA3. Y-axis = normalized binding response, x-axis = time (sec). The start of the dissociation phase is indicated by the vertical dashed line at 600 seconds; X = without addition of LILRA1 or LILRA3, respectively, Y = addition of 20nM LILRA1 or ULRA3, respectively, Z = addition of lOOnM ULRA1 or ULRA3, respectively.

[0031] Figure 12: depicts BU measurements showing binding of antibodies to ULRB1 in presence of different concentrations of LILRA1 and ULRA3. The panels show binding to LILRB1 using antibody A-045 of the invention in presence of (A) ULRA1 and (B) ULRA3, reference molecule Ref062 [NGM707, cross-specific] in presence of (C) ULRA1 and (D) ULRA3, as well as reference molecule Ref051 [Biond / Sanofi BND-22] in presence of (E) ULRA1 and (F) ULRA3. Y-axis = normalized binding response, x-axis = time (sec). The start of the dissociation phase is indicated by the vertical dashed line at 600 seconds; X = without addition of ULRA1 or LILRA3, respectively, Y = addition of 20nM ULRA1 or ULRA3, respectively, Z = addition of lOOnM ULRA1 or ULRA3, respectively.

[0032] Figure 13: shows target binding of antibody A-045, a cross-specific reference antibody (Ref062 [NGM707]) and an appropriate isotype control (RefOOl) on primary T cells (A), neutrophils (B) and monocytes (C) as well as in vitro differentiated Ml (D) - and M2-like (E) macrophages. Binding curves show results of one representative donor. X-axes = antibody concentrations (nM); y-axes = Median-FI (RL-1) of CD8 positive cells for T cells (A), of CD66b positive cells for neutrophils (B) or of live cells (C-E); circle = A-045, square = Ref062 [NGM707, cross-specific] triangle = RefOOl [isotype control],

[0033] Figure 14 depicts activity of antibody A-045 on the repolarization of Ml- like and M2-like macrophages in comparison to a cross-specific reference antibody. Surface expression of different Ml- and M2 markers was assessed by flow cytometry. (A) shows dose- dependent decrease of surface expression of the M2- like marker CD206 on in vitro differentiated Ml-like macrophages. (B) shows the dose- dependent increase in surface expression of the Ml- marker CD86 on in vitro differentiated M 2-like macrophages whereas (C) and (D) show dose- dependent decrease of surface expression of the M2- markers CD163 and CD209 on in vitro differentiated M2-like macrophages. X- axis = concentrations of antibody; y-axis = absolute mean fluorescent intensity values of respective macrophage population gated on live cells; X = isotype control.

[0034] Figure 15: depicts ULRB2 T cell reporter activation upon treatment with antibody A-045, a cross-specific reference antibody (Ref062 [NGM707]) or an isotype control (RefOOl). Figure show (A) the assay principle and (B) the results of one representative donor. X-axis = antibody concentrations (nM); y-axis = absolute luminescence with background subtracted; circle = A-045, square = Ref062 [NGM707, cross-specific], triangle = RefOOl [isotype control],

[0035] Figure 16: shows dose dependent increase in phagocytosis activity of in vitro differentiated M0 macrophages upon treatment with antibody A-045, a cross-specific reference antibody (Ref062 [NGM707]) and an appropriate isotype control (RefOOl). Depicted are the results of one representative donor. X-axis = antibody concentrations (nM); y-axis = the increase in phagocytosis activity as measured by CD45 / CFTR double positive cells by flow cytometry normalized to the isotype control (= 100%); circle = A-045, square = Ref062 [NGM707, cross-specific], triangle = RefOOl [isotype control],

[0036] Figure 17 : depicts sustained strong activity of antibody A-045 in the presence of recombinant ULRA3 on macrophage phenotype and cytokine profile compared to treatment with a cross-specific reference antibody (Ref062 [NGM707]) or an appropriate isotype control (RefOOl). A and B show the effect of LILRB1 / 2 blockade in the presence of recombinant ULRA3 on the phenotype of Ml- like macrophages compared to an appropriate isotype control (RefOOl). CD163 (A) and CD209 (B) expression was assessed by flow cytometry measurement. X- axis = concentrationsof recombinant ULRA3 (nM), 1 = 5nM RefOOl + 150nM rLILRA3, 2 = InM Ref062 + 150nM rLILRA3, 3 = InM Ref062 + 37.5nM rLILRA3, 4 = InM A-045 + 150nM rULRA3, 5 = InM A-045 + 37.5nM rULRA3. Y- axis = % of CD163 or CD209 positive cells as percent of live cells. C - E show cytokine secretion of antibody treated Ml- like macrophages in the presence of recombinant LILRA3 for GM-CSF (C), IFNg (D) and IL-9 (E). X- axis = concentration of recombinant ULRA3 and antibody (nM), 1 = 5nM RefOOl + 150nM rLJLRA3, 2 = InM Ref062 + 150nM rLILRA3, 3 = InM Ref062 + 37.5nM rLILRA3, 4 = InM A-045 + 150nM rLJLRA3, 5 = InM A-045 + 37.5nM rLILRA3. Y- axis = % cytokine release normalized to isotype control (=100%).

[0037] Figure 18: depicts a schematic representation of four different 2+2 format antibodies: (A) IgG(H)-scFv* (200 kDa), (B) scFv-(H)IgG (200 kDa), (C) IgG(L)-scFv (200 kDa) or (D) scFv-(L)IgG (200 kDa).

[0038] Figure 19: depicts an overview of the construct design of the respective antibody formats including (A) stabilizing VH / VL charge pairs (VL: Q38E / K and VH: Q39E / K), (B) stabilizing VH / VL disulphide bridges (VL: G100C and VH: G44C), (C) combination of VH / VL charge pairs and disulfide bridges and (D) CrossMab2 including charge pair in CH1-CL for stabilization.

[0039] Figure 20: depicts an overview of the bispecific antibody of example 13 including (A) a schematic view of the used antibody format indicting the anti-LILRBl / 2 binding site at the bottom, and the anti-PD-1 binding site at the top, (B) the heavy chain sequence (SEQ ID NO: 398) with pembrolizumab sequence double underlined and italic, linker sequences underlined and A-045 sequences in bold, (C) the light chain sequence (SEQ ID NO: 399) with pembrolizumab sequence double underlined and italic.

[0040] Figure 21: depicts SDS-PAGE analysis of the bispecific antibody of example 13under non-reducing conditions (A) and reducing conditions (B) after Protein A purification (a) and after preparative SEC (b), Y-axes = kDa.

[0041] Figure 22: depicts response profiles for the bispecific antibody of example 13 (LILRB1 / 2 - PD-1) in a simultaneous binding assay setup using the Octet RED96e system towards (a) PD-1, (b) LILRB, and (c) PD-1 + ULRB. (A) depicts response profiles obtained using ULRB2 and (B) depicts response profiles obtained using to LILRB1. X- axes = time (sec), Y-axes = nm.

[0042] Figure 23: the figure shows effects of the ULRB1 / 2 - PD1 bispecific molecule on T cell stimulation in an allogenic macrophage-T cell mixed lymphocyte reaction. Such effects were assessed by IL-2 cytokine secretion; Y- axis = fold IL-2 level relative to isotype control, X- axis = antibodies in indicated concentrations; 0 = medium control; 1 = RefOOl 50nM or RefOOl - RefOOl bispecific Isotype control 50nM; 2 = A-045 lOnM; 3 = Ref76 (PD-1 specific) 50nM; 4 = combination of A-045 lOnM + Ref76 50nM; 5 = ULRB1 / 2 - PD1 bispecific lOnM.

[0043] The present invention, and non-limiting aspects and / or embodiments thereof, can be described in more detail as follows:

[0044] The present invention relates to bispecific or multi-specific constructs combining LILRB1 / 2 antigenicity with antigenicity to an immune checkpoint, such as and preferably PD-1 / PD-L1. It should be understood that in the following description a claimed antibody or antigen binding protein is a bispecific or multi-specific binder which comprises at least two separate antigen binding sites. In the following a bispecific antigen binding protein may also be referred to as a biABP, and should be understood to pertain to a molecule that comprises a first binding site binding ULRB1 / LILRB2 and a second binding site binding an immune checkpoint, such as and preferably PD-1 / PD-L1.

[0045] In a first aspect, and as may be further described, defined, claimed or otherwise disclosed herein, the invention relates to an antigen binding protein (ABP or a biABP) which specifically binds to ULRB1 and / or LILRB2 protein (eg to the extra cellular domain (ECD) of LILRB1 and / or LILRB2 protein) and, optionally, wherein the biABP and is able to inhibit (eg, inhibits) the interaction between a natural ligand of LILRB1 and / or ULRB2 (such as HLA-G) protein or a variant thereof and ULRB1 and / or LILRB2 protein or a variant thereof, for example, the ABP or BIABP is optionally able to inhibit (eg, inhibits) the binding of ULRB1 and / or LILRB2 protein or a ligand of LILRB1 and / or ULRB2.The biABP of the invention comprises at least one second antigen binding site which is capable of binding, and preferably inhibiting, an immune checkpoint, such as preferably PD-1 / PD-L1. In context of the present invention in all of its aspects and embodiments, whenever antigen binding proteins of the invention are referred to as binding to ULRB1 and / or ULRB2, in a most preferred variation thereof a binding of such antigen binding protein of the invention, such as an antibody, is preferably one which binds to both LILRB1 and ULRB2. Preferably such antigen-binding protein is one which does not bind to, or binds with less affinity to, LILRA1 and ULRA3.

[0046] The invention in further preferred embodiments relates to antigen binding proteins (ABPs or biABPs) which specifically bind to LILRB1 and ULRB2 protein (eg to the extra cellular domain (ECD) of ULRB1 and LILRB2 protein) and, optionally, wherein the ABP or biABP and is able to inhibit (eg, inhibits) the interaction between a natural ligand of ULRB1 and the natural ligand of ULRB2 protein or (such as HLA-G). Preferably, the ABP or biABP of the invention binds to LILRB1 and LILRB2 with significantly higher affinity compared to the binding of the ABP or biABP to ULRA1 and ULRA2, optionally, wherein the ABP or biABP and is not able to inhibit (eg, does not inhibit) the interaction between a natural ligand of LILRA1 and the natural ligand of ULRA3 protein or (such as HLA-G).

[0047] In certain specific aspects and embodiments of the invention the ABP or biABP of the invention is not an antibody as disclosed as ADA-011 in WO 2023 / 225626, more preferably is specifically not an antibody comprising the heavy chain CDR1 to CDR3 domain sequences of ADA-011 as disclosed in WO 2023 / 225626, and / or is not comprising the light chain CDR1 to CDR3 domain sequences of ADA-011 as disclosed in WO 2023 / 225626. As such, the ABP or biABP of the invention is particularly not an antibody comprising (a) a heavy chain complementarity determining region 1 (H-CDR1) comprising an amino acid sequence set forth in SEQ ID NO: 213 of WO 2023 / 225626; (b) a heavy chain complementarity determining region 2 (H-CDR2) comprising an amino acid sequence set forth in SEQ ID NO: 223 of WO 2023 / 225626; (c) a heavy chain complementarity determining region 3 (H-CDR3) comprising an amino acid sequence set forth in SEQ ID NO: 233 of WO 2023 / 225626; (d) a light chain complementarity determining region 1 (L- CDR1) comprising an amino acid sequence set forth in SEQ ID NO: 243 of WO 2023 / 225626; (e) a light chain complementarity determining region 2 (L-CDR2) comprising an amino acid sequence set forth in SEQ ID NO: 253 of WO 2023 / 225626; and / or (f) a light chain complementarity determining region 3 (L-CDR3) comprising an amino acid sequence set forth in SEQ ID NO: 263 of WO 2023 / 225626.

[0048] Preferably, the bispecific ABP of the invention comprises at least one binding site to an immune checkpoint molecule, such as preferably to PD-1 / PD-L1. The biABP of the invention in preferred embodiments comprises an antibody binding site of a known immune checkpoint inhibitor as second binding site. Many antibodies have been developed and are available to the skilled artisan. Examples of preferred antigen binding sites of known antibodies include binding sites (for example as defined by their heavy and light chain CDR1-CDR3, or VH / VL sequences) include anti PD-1 and PD-L1 antibodies. The term "PD-1 antibody" means an anti-PD-1 antibody that is a folly human, or humanized IgG, optionally optimized, monoclonal antibody or small molecule inhibitor. Anti-PD-1 antibodies are preferably PD-1 inhibitors. PD-1 inhibitors include nivolumab and pembrolizumab. Nivolumab, (OPDIVOTM ) is also known as iMDX- 1106, MDX-1106-04, ONO-4538, or BMS-936558 and has a CAS Registry Number: of 946414-94-4. Nivolumab is a fully human IgG4 monoclonal antibody which specifically blocks PD-1. Nivolumab (clone 5C4) and other human monoclonal antibodies that specifically bind to PD-1 are disclosed in US 8,008,449 and W02006 / 121168. Pembrolizumab, (KEYTRUDATM) (formerly lambrolizumab), also known as Merck 3745, MK-3475 or SCH-900475, is a humanized IgG4 monoclonal antibody that binds to PD-1. Pembrolizumab is disclosed in Hamid, O. et al., New England Journal of Medicine, 2013, 369(2): 134-44; WO2009 / 114335; and US 8,354,509. Additional anti-PD-1 antibodies also include pidilizumab (CT-011) and AMP-224. Other anti- PD-1 antibodies are disclosed in US 8,609,089; US 2010028330; and / or US 20120114649.

[0049] The term "PD-L1 antibody" means an anti-PD-Ll antibody that is a a folly human, or humanized IgG, optionally optimized, monoclonal antibody or small molecule inhibitor. Anti-PD-Ll antibodies are preferred PD-L1 inhibitors. PD-LI inhibitors include YW243.55.S70, MPDL3280A, MEDI-4736, MSB-0010718C, and MDX-1105. YW243.55.S70 is an anti-PD-LI antibody described in W02010 / 077634 and US20100203056. MDPL3280A (also known as RG7446, RO5541267, and atezolizumab) is a fully humanized Fc optimized IgGl monoclonal antibody lacking Fc effctor function that binds to PD-L1. MDPL3280A and other human monoclonal antibodies to PD-L1 are disclosed in US 7,943,743 and US 20120039906. MEDI-4736 (also known as durvalumab) is an Fc optimized antibody to PD-L1. MSB-0010718C (also known as avelumab) is a fully human IgGl monoclonal antibody to PD-L1. MDX-1105, also known as BMS-936559, is an anti-PD-LI antibody described in W02007 / 005874.

[0050] Further anti-PD-1 and anti-PD-LI antibodies are known from for example Mol Cancer. 2022; 21: 28 Published online 2022 Jan 21. doi: 10.1186 / S12943-021-01489-2.

[0051] Formats that are useful for the design of bispecific antibodies of the invention are many and include all kinds of 2x2, lxl and 2x1 formats. Certain preferred examples of formats can be found in figures 18 and 19 and are preferred for the herein disclosed biABP and bispecific antibodies of the invention.

[0052] Bisoecific Antigen binding proteins targeting LILRB1 and / or LILRB2. preferably both LILRB1 and ULRB2. and an immune checkpoint inhibitor

[0053] An "antigen binding protein" ("ABP") as used herein means a protein that specifically binds to a target antigen, such as to one or more epitope(s) displayed by or present on a target antigen. The antigen of the ABPs or biABPs of the invention is ULRB1 and / or ULRB2; and the ABP or biABP can, optionally bind to one or more extracellular domains of said LILRB1 and / or ULRB2 (such as the epitope(s) can be displayed by or present on one or more extracellular domains of said LILRB1 and / or ULRB2). Typically, an antigen binding protein is an antibody (or a fragment thereof), however other forms of antigen binding protein are also envisioned by the invention. For example, the ABP or biABP may be another (non-antibody) receptor protein derived from small and robust non-immunoglobulin "scaffolds", such as those equipped with binding functions for example by using methods of combinatorial protein design (Gebauer 8i Skerra, 2009; Curr Opin Chem Biol, 13:245). Particular examples of such non-antibody ABPs or biABPs include: Affibody molecules based on the Z domain of Protein A (Nygren, 2008; FEBS J 275:2668); Affilins based on gamma-B crystalline and / or ubiquitin (Ebersbach et al, 2007; J Mo Biol, 372: 172); Affimers based on cystatin (Johnson et al, 2012; Anal Chem 84:6553); Affitins based on Sac7d from Sulfolobus acidcaldarius (Krehenbrink et al, 2008; J Mol Biol 383: 1058); Alphabodies based on a triple helix coiled coil (Desmet et al, 2014; Nature Comms 5:5237); Anticalins based on lipocalins (Skerra, 2008; FEBS J 275:2677); Avimers based on A domains of various membrane receptors (Silverman et al, 2005; Nat Biotechnol 23:1556); DARPins based on an ankyrin repeat motif (Strumpp et al, 2008; Drug Discov Today, 13:695); Fynomers based on an SH3 domain of Fyn (Grabulovski et al, 2007; J Biol Chem 282:3196); Kunitz domain peptides based on Kunitz domains of various protease inhibitors (Nixon et al, Curr opin Drug Discov Devel, 9:261) and Centyrins and Monobodies based on a 10th type III domain of fibronectin (Diem et al., 2014; Protein Eng Des Sei 27:419 doi: 10.1093 / protein / gzu016; Koide 8i Koide, 2007; Methods Mol Biol 352:95). In the context of an ABP or biABP of the present invention that specifically binds ULRB1 and / or LILRB2 (and does not bind, or binds with significantly less affinity, ULRA1 and / or ULRA3), such an ABP or biABP is not a protein being a natural ligand of LILRB1 and / or ULRB2 (in particular, a ligand protein having more than 70%, 80% or 90% sequence identify to the amino acid sequence of HLA-G).

[0054] The term "epitope" includes any determinant capable of being bound by an antigen binding protein, such as an antibody. An epitope is a region of an antigen that is bound by an antigen binding protein that targets that antigen, and when the antigen is a protein, includes specific amino acids that bind the antigen binding protein (such as via an antigen binding domain of said protein). Epitope determinants can include chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl or sulfonyl groups, and can have specific three- dimensional structural characteristics, and / or specific charge characteristics. Generally, antigen binding proteins specificfor a particular target antigen will preferentially recognise an epitope on the target antigen in a complex mixture of proteins and / or macromolecules.

[0055] The term "extracellular domain" ("ECD" or "EC" domain) as used herein refers to the region or regions of the protein which are exposed to the extracellular space and which are typically responsible for ligand binding. Immunoglobulin (Ig) superfamily genes typically have an Immunoglobulin-like ECD, such as a Ig-like C2-type domain.

[0056] An antigen binding protein is "specific" when it binds to one antigen (such as ULRBl and / or LILRB2; eg human LILRB1 and / or ULRB2, orthologues and other variants thereof) more preferentially (eg, more strongly or more extensively) than it binds to another antigen, preferably an ULRA protein (such as LILRA1 and LILRA3). The term "specifically binds" (or "binds specifically" and the like) used herein in the context of an ABP or biABP means that said ABP or biABP will preferentially bind to the desired antigen (eg LILRB1 and / or ULRB2, in particular an ECD of LJLRBl and / or LILRB2) than to bind to other proteins (or other molecules), such as preferentially binding to such LILRB1 and / or ULRB2 compared to one or more of a leucocyte immunoglobulin-like subfamily A (ULRBA) proteins. Therefore, preferably, the binding affinity of the ABP or biABP to the LILRB antigen (e.g. LILRB1 and / or LILRB2) is at least 2-fold, 5-fold, at least 10-fold, at least 20-fold, at least 50-fold, at least 100-fold, at least 200-fold, at least 500-fold, at least 1000-fold, at least 2000-fold, at least 5000-fold, at least 10000-fold, at least 105-fold or even at least 105-fold, most preferably at least 2-fold, compared to its affinity to the other targets (e.g. unrelated proteins such as mouse or human Fc domain, or streptavidin).

[0057] Leukocyte Ig-like receptors (HRs) are a family of immunoreceptors expressed predominantly on monocytes and B cells and at lower levels on dendritic cells and natural killer (NK) cells. All members of LIR subfamily B, such as ULRB2, contain a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM) and have an inhibitory function. Upon engagement of members of LIR subfamily B by MHC class I or other ligands and tyrosine phosphorylation of the ITIM, intracellular protein-tyrosine phosphatases, such as SHP1 (PTPN6), are recruited and an inhibitory signal cascade ensues. Most members of UR subfamily A (e.g., ULRA1) have short cytoplasmic regions that lack ITIMs, have transmembrane regions that contain a charged arginine residue, and can initiate stimulatory cascades. One member of subfamily A, ULRA3, lacks a transmembrane region and is presumed to be a soluble receptor (summary by Borges et al., 1997).

[0058] The interaction between ULRBl and / or ULRB2 and a natural ligand thereof (such as HLA-G) has subsequently been independently described (De Louche et al 2022 JCI Insight. 2022;7(2):el51553).

[0059] The human LILRB1 gene is located at chromosomal position 19ql3.42, and has orthologues (eg, is conserved) in many species. The term LILRB1 in some embodiments of the invention may also pertain to variants of the human ULRBl protein having an amino acid sequence that is substantially identical to, or of at least 70%, 75% or 80%, preferably 85%, more preferably at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity (such as at least 90% or 95% sequence identity) to, the amino acid sequence shown in any of SEQ ID NOs. 385-389, as determined using, e.g., the "Blast 2 sequences" algorithm described by Tatusova 8i Madden 1999 (FEMS Microbiol Lett 174: 247- 250), and which (preferably) retain biological activity identical or substantially identical to the respective reference ULRBl (eg to bind to HLA-G) protein and / or to modulate macrophage (or other immune cell) function / activity. The term ULRBl can mean, as applicable to the context (if not more specifically indicated), an ULRBl protein (such as one described above) or an mRNA molecule encoding such an ULRBl protein.

[0060] The human LILRB2 gene is located at chromosomal position 19ql3.42, and has orthologues (eg, is conserved) in many species. The term LILRB2 in some embodiments of the invention may also pertain to variants of the human ULRB2 protein having an amino acid sequence that is substantially identical to, or of at least 70%, 75% or 80%, preferably 85%, more preferably at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity (such as at least 90% or 95% sequence identity) to, the amino acid sequence shown in any of SEQ ID NOs. 390-393, as determined using, e.g., the "Blast 2 sequences" algorithm described by Tatusova 8i Madden 1999 (FEMS Microbiol Lett 174: 247-250), and which (preferably) retain biological activity identical or substantially identical to the respective reference ULRB1 (eg to bind to HLA-G) protein and / or to modulate macrophage (or other immune cell) function / activity. The term ULRB2 can mean, as applicable to the context (if not more specifically indicated), an ULRB2 protein (such as one described above) or an mRNA molecule encoding such an ULRB2 protein.

[0061] In certain of embodiments, an ABP or biABP of the invention that binds to the ECD of human LJLRB1 and / or ULRB2 protein is cross reactive to the ECD of an orthologous protein, such as cross reactive to the ECD of cynomolgus LJLRB1 and / or LILRB2 protein and / or to the ECD of mouse LJLRB1 and / or LILRB2 protein and / or to the ECD of rat LJLRB1 and / or ULRB2 protein.

[0062] The term "orthologue" as used herein means a variant that descends from the same ancestral gene but which is present in another organism due to a speciation event. Orthologues of LJLRB1 and / or LILRB2 are typically expected to retain the same function as (or have a similar function to) human LJLRB1 and / or ULRB2.

[0063] The term "variant" as used herein in the context of a protein means any natural or non-natural version of such protein which comprises one or more amino acid mutations compared to the reference protein, but which shares significant amino acid sequence identity with the reference protein, e.g. at least 70% or 75% amino acid sequence identity, preferably at least 80% amino acid sequence identity, more preferably at least 90% amino acid sequence identity and most preferably at least 95%, 96%, 97%, 98% or 99% amino acid sequence identity. Preferably, the variant of the protein possesses and / or maintains at least one function / activity that is the same, essentially the same or similar as the reference protein. Variants of LILRB1 and / or LILRB2 may include orthologues to and natural variants of human LJLRB1 and / or LILRB2. A "functional variant" of LJLRB1 and / or ULRB2 (such as a functional fragment of an LJLRB1 and / or LILRB2 protein) is a variant of the protein of LJLRB1 and / or LILRB2 that provides, possesses and / or maintains one or more of the herein described functions / activities of the non-variant protein of LJLRB1 and / or LILRB2. For example, such functional variant may bind HLA-G protein and / or to suppress T cell (or other immune cell) function / activity as LILRB1 and / or ULRB2 protein, such as having the same, essentially the same or similar specificity and / or function as a receptor as LILRB1 and / or LILRB2 protein. In other embodiments, such a functional variant may possess other activities than those possessed by the non-variant ULRB1 and / or LILRB2 protein, as long as, preferably, it provides, possesses and / or maintains at least one function / activity that is the same, essentially the same or similar as LILRB1 and / or LILRB2 protein. In more preferred embodiments, a functional variant of ULRB1 and / or ULRB2 may act as an immune checkpoint inhibitor, such as by inhibiting one or more cell-based immune response(s) to a tumour or cancer cell that expresses such functional variant.

[0064] The term "identity" refers to a relationship between the sequences of two or more polypeptide molecules or two or more nucleic acid molecules, as determined by aligning and comparing the sequences. "Percent identity" means the percent of identical residues between the amino acids or nucleotides in the compared molecules and is calculated based on the size of the smallest of the molecules being compared. For these calculations, gaps in alignments (if any) are preferably addressed by a particular mathematical model or computer program (i.e., an "algorithm"). Methods that can be used to calculate the identity of the aligned nucleic acids or polypeptides include those described in Computational Molecular Biology, (Lesk, A. M., ed.), 1988, New York: Oxford University Press; Biocomputing Informatics and Genome Projects, (Smith, D. W., ed.), 1993, New York: Academic Press; Computer Analysis of Sequence Data, Part I, (Griffin, A. M., and Griffin, H. G., eds.), 1994, New Jersey: Humana Press; von Heinje, G., 1987, Sequence Analysis in Molecular Biology, New York: Academic Press; Sequence Analysis Primer, (Gribskov, M. and Devereux, J., eds.), 1991, New York: M. Stockton Press; and Carillo et aL, 1988, SIAM J. Applied Math. 48: 1073.

[0065] In calculating percent identity, the sequences being compared are typically aligned in a way that gives the largest match between the sequences. One example of a computer program that can be used to determine percent identity is the GCG program package, which includes GAP (Devereux et aL, 1984, NucL Acid Res. 12:387; Genetics Computer Group, University of Wisconsin, Madison, WI). The computer algorithm GAP is used to align the twopolypeptides or polynucleotides for which the percent sequence identity is to be determined. The sequences are aligned for optimal matching of their respective amino acid or nucleotide (the "matched span", as determined by the algorithm). A gap opening penalty (which is calculated as 3x the average diagonal, wherein the "average diagonal" is the average of the diagonal of the comparison matrix being used; the "diagonal" is the score or number assigned to each perfect amino acid match by the particular comparison matrix) and a gap extension penalty (which is usually 1 / 10 times the gap opening penalty), as well as a comparison matrix such as PAM 250 or BLOSUM 62 are used in conjunction with the algorithm.

[0066] A standard comparison matrix (see, Dayhoff et al., 1978, Atlas of Protein Sequence and Structure 5:345-352 for the PAM 250 comparison matrix; Henikoff et al., 1992, Proc. Natl. Acad. Sci. U.S.A. 89:10915-10919 for the BLOSUM 62 comparison matrix) may also be used by the algorithm.

[0067] Examples of parameters that can be employed in determining percent identity for polypeptides or nucleotide sequences using the GAP program are the following: (i) Algorithm: Needleman et aL, 1970, J. Mol. Biol. 48:443-453; (ii) Comparison matrix: BLOSUM 62 from Henikoff et al., 1992, supra,- (iii) Gap Penalty: 12 (but with no penalty for end gaps); (iv) Gap Length Penalty: 4; (v) Threshold of Similarity: 0.

[0068] A preferred method of determining similarity between a protein or nucleic acid and (or between) human ULRB1 and / or ULRB2, a paralogue, orthologue or other variant thereof, is that provided by the Blast searches supported at Uniprot supra (e.g., http: / / www.uniprot.org / uniprot / Q8NHL6 for ULRB1 and http: / / www.uniprot.org / uniprot / Q8N423 for LILRB2); in particular for amino acid identity, those using the following parameters: Program: blastp; Matrix: blosum62; Threshold: 10; Filtered: false; Gapped: true; Maximum number of hits reported: 250.

[0069] Certain alignment schemes for aligning two amino acid sequences may result in matching of only a short region of the two sequences, and this small aligned region may have very high sequence identity even though there is no significant relationship between the two full-length sequences. Accordingly, the selected alignment method (GAP program) can be adjusted if so desired to result in an alignment that spans at least about 10, 15, 20, 25, 30, 35, 40, 45, 50 or other number of contiguous amino acids of the target polypeptide or region thereof.

[0070] In particular embodiments of the invention, the ULRB1 is human ULRB1, preferably a protein comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 385, SEQ ID NO: 386, SEQ ID NO: 387, SEQ ID NO: 388, and SEQ ID NO: 389 (in particular, SEQ ID NO. 385), or a protein having no more than two, four, six, eight, or ten, for example no more than one, two or three, such as no more than one, amino acid substitutions, insertions or deletions compared to these sequences.

[0071] In particular embodiments of the invention, the ULRB2 is human ULRB2, preferably a protein comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 390, SEQ ID NO: 391, SEQ ID NO: 392, and SEQ ID NO: 393 (in particular, SEQ ID NO. 390), or a protein having no more than two, four, six, eight, or ten, for example no more than one, two or three, such as no more than one, amino acid substitutions, insertions or deletions compared to these sequences.

[0072] In the context of variants of ULRB1 and / or ULRB2, the invention includes those embodiments where a variant of ULRB1 and / or ULRB2 is a protein comprising an amino acid sequence having at least 80%, 85%, 90%, 92% 95% or 97% sequence identity (in particular, at least 92% or 95% sequence identity) to any one of the sequences of SEQ ID NO: 385-393 (preferably of SEQ ID NO: 353 (ULRB1) or SEQ ID NO 358 (LILRB2)).

[0073] In the context of other variants of ULRB1 and / or LILRB2, the invention also includes those embodiments where a variant of ULRB1 and / or LILRB2 is selected from the group consisting of an ortholog (or paralog) of ULRB1 and / or ULRB2, and a functional fragment of an LILRB1 and / or ULRB2 protein. In certain of such embodiments, such functional fragment of an ULRB1 and / or LILRB2 protein binds to a natural ligand of ULRB1 and / or ULRB2 protein, such as a human leucocyte antigen (HLA) type proteins (such as one described elsewhere herein).

[0074] An ABP or biABP of the invention may, in particular embodiments, be able to inhibit (eg, inhibits) the interaction between a natural ligand of ULRB1 and / or ULRB2 protein and ULRB1 and / or ULRB2 protein (such as for example to HLA-G). For example, the ABP or biABP is optionally able to inhibit (eg, inhibits) the binding of ULRB1 and / or LILRB2 protein to a ligand of ULRB1 and / or LILRB2 (such as for example HLA-G).

[0075] The protein sequences of the canonical isoform, and further isoforms of the off targets ULRA1 and ULRA3 can also be derived from the UniProt database. For LILRA1, protein sequences and additional information is obtainable under the accession number: 075019. The canonical protein sequence is provided herein as SEQ ID NO: 394. For ULRA1, protein sequences and additional information is obtainable under the accession number: 075019. The canonical protein sequence is provided herein as SEQ ID NO: 395.

[0076] As used herein, the term "HLA-G" refers to a protein called human leukocyte antigen G or HLA-G histocompatibility antigen class G, etc. This protein was first discovered in extravillous trophoblasts (EVT) present at the maternal-fetal interface during pregnancy, and is a heterologous material (membrane-bound HLA-G, such as HLA- Gl, G2, G3 and G4 are present) that is expressed only in the cellular membrane by selective conjugation of HLA-G mRNA, and has a single molecular form in a soluble state to be secreted to the outside of the cells (HLA-G5, G6 and G7 are present as soluble HLA-G). Human HLA-G amino acid sequences and further information can be derived from the UniProt database in the version of December 2022 with the accession number P17693.

[0077] An ABP or biABP of the invention may, in particular embodiments, be able to inhibit (eg, inhibits) the interaction between a natural ligand of ULRB1 and LILRB2 protein and ULRB1 and LILRB2 protein (such as for example to HLA- G). For example, the ABP or biABP is optionally able to inhibit (eg, inhibits) the binding of LILRB1 and LILRB2 protein to a ligand of ULRB1 and ULRB2 (such as for example HLA-G). The ABP or biABP of the invention further does not inhibit the interaction of ULRA1 and ULRA3 with a natural ligand of ULRA1 and / or ULRA3.

[0078] Modulators of LILRB1 and / or LILRB2 expression, function, activity and / or stability

[0079] In particular embodiments of such aspect, the ABP or biABP is a modulator of the expression, function, activity and / or stability of LILRB1 and / or LILRB2, or the variant of LILRB1 and / or LILRB2, such as wherein the ABP or biABP inhibits the expression, function, activity and / or stability of ULRB1 and / or LILRB2, or the variant of LILRB1 and / or ULRB2, or in particular where the ABP or biABP is an inhibitor of the function and / or activity of said ULRB1 and / or ULRB2 or the variant of ULRB1 and / or ULRB2. In one of such embodiments, an ABP or biABP of the invention is an inhibitor of the interaction between ULRB1 and / or LILRB2, or the variant of ULRB1 and / or LILRB2, to its endogenous receptor or ligand, such as to a HLA type protein, in particular an ABP or biABP of the invention is capable of inhibiting (eg, inhibits or is an inhibitor of) the binding of a natural ligand of ULRB1 and / or LILRB2 protein to LILRB1 and / or ULRB2 protein. Accordingly, ABPs or biABPs of the invention can be "modulators".

[0080] The term "modulator" as used herein, refers to a molecule that changes, modifies or alters one or more characteristics, properties and / or abilities of another molecule or, for example, that changes, modifies or alters an immune response ("immunomodulators"), such as a cell-mediated immune response. For example, a modulator (eg, an inhibiting or antagonistic modulator) can impair or interfere with, or cause a decrease in the magnitude of, expression, function, activity and / or stability, such as a certain activity or function, of a molecule compared to the magnitude of such characteristic, property or ability observed in the absence of the modulator. In an alternative example, a modulator (eg, an activating or agonistic modulator) can enhance or promote, or cause an increase in the magnitude of, expression, function, activity and / or stability, such as a certain activity or function, of a molecule compared to the magnitude of such characteristic, property or ability observed in the absence of the modulator. Certain exemplary characteristics, properties or abilities of a molecule include, but are not limited to, expression, function, activity and / or stability, such as binding ability or affinity, enzymatic activity, and signal transduction; for example, any of the functions or activities of ULRB1 and / or LILRB2 described herein.

[0081] Modulatory molecules (in particular, modulatory ABPs or biABPs) can act as "inhibitors" ("antagonists") against a receptor such as ULRB1 and / or ULRB2, such as by impairing (e.g. blocking) ligand engagement to such receptor, eg by inhibiting the interaction between LILRB1 and / or ULRB2 and their ligand. Alternatively, modulatory molecules (in particular, modulatory ABPs or biABPs) can act as "activators" ("agonists") for a receptor such as ULRB1 and / or ULRB2, such as by enhancing or promoting function and / or activity of such receptor, for example by triggering the receptor's signalling pathway, such as by mimicking the binding of the endogenous ligand for such receptor.

[0082] A particular embodiment of a modulator of ULRB1 and / or LILRB2 is an "inhibitor of ULRB1 and / or ULRB2" (or"LILRBl and / or LILRB2 inhibitor"), which meaning includes any moiety that inhibits LILRB1 and / or LILRB2, which can mean inhibition of the expression (eg the amount), function, activity and / or stability of LILRB1 and / or ULRB2, especially of protein of ULRB1 and / or ULRB2. In one particular of such embodiments, an inhibitor of LILRB1 and / or ULRB2 can reduce the function (and / or activity) of LILRB1 and / or ULRB2 protein, and in another of such embodiments, an inhibitor of ULRB1 and / or LILRB2 can reduce the expression of ULRB1 and / or ULRB2 mRNA and / or protein.

[0083] General and specific examples of ULRB1 and / or LILRB2 inhibitors (including those that are ABPs or biABPs of the present invention) are described elsewhere herein, including those as may be characterised by the applicable functional and / or structural features set out herein.

[0084] Accordingly, in particular embodiments of the present invention, an ABP or biABP of the invention is one that is capable of specifically binding to (eg which specifically binds to) ULRB1 and / or ULRB2, as well as being capable of inhibiting (eg reducing or blocking) the interaction between ULRB1 and / or LILRB2 protein (or a variant thereof, such as one described above) and its natural ligand (such as a HLA protein, or other ligand). In particular, such an ABP or biABP is able to inhibit (eg inhibits) the binding of HLA-G protein (or a variant thereof, such as one described above) to LILRB1 and / or LILRB2 protein (or a variant thereof, such as one described above).

[0085] Methodologies to determine the interaction (eg binding) between LILRB1 and / or ULRB2 and a HLA protein such as HLA-G protein (or between variants thereof) are known to the person of ordinary skill, and include ELISA assays (such as described in the examples below), and technologies such as inter alia, flow cytometry, surface plasmon resonance, surface acoustic waves and microscale thermophoresis. Such determination methodologies can be used (or adapted) to not only detect the presence of such interaction / binding, but also to measure (eg quantitatively) the degree of binding between the interacting partners ULRB1 and / or ULRB2 and their ligands such as HLA-G proteins (or variants thereof). Such (quantitative) measurement of interaction (binding) may be determined or measured in the presence of a competing (eg inhibiting) ABP or biABP of the invention, and hence the potential of an ABP or biABP of the present invention to inhibit (eg block) such interaction can be measured, and eg reported as an IC50.

[0086] Such IC50 values may be determined, such as using ELISA methodology (eg, using an assay correspond to, or substantially as, the EUSA described in Example 3), in the presence of a suitable concentration of HLA-G protein (or variant thereof) in solution and with surface-bound ULRB1 and / or LILRB2.

[0087] In certain of such embodiments of the invention, the ABP or biABP of the invention (eg one that binds to [one or more epitope(s) displayed by] an extracellular domain(s) of LILRB1 and / or ULRB2, or a paralogue, orthologue or other variant thereof) is capable of inhibiting (eg will inhibit) the binding of a natural ligand of ULRB1 and / or LILRB2 protein or a variant thereof to LILRB1 and / or ULRB2 protein or a variant thereof with an IC50 of lOOnM, 50nM, or preferably 20nM or less, such as 15nM or less, lOnM or less, 5nM or less, 2nM or less, InM or less, 500pM or less, 250pM or less, or lOOpM or less. In particular of such embodiments, an ABP or biABP of the invention is capable of inhibiting (eg will inhibit) the binding of HLA-G protein or a variant thereof to LILRB1 and / or ULRB2 protein or a variant thereof with an IC50 of lOnM or less, such as 5nM or less and preferably 2nM or less.

[0088] In other embodiments, a modulator of the invention (eg, an ABP or biABP that binds to LILRB1 and / or LILRB2) that is an inhibitor or antagonist may instead or also:• inhibit, impair, reduce or reverse ULRB1 and / or LILRB2-mediated inhibition of a cell-mediated immune response (eg in an in-vitro assay or in a subject, such as one in need thereof); and / or• inhibit, impair, reduce or reverse LILRB1 and / or ULRB2-mediated inhibition of humoral immunity (eg in an in- vitro assay or in a subject, such as one in need thereof)• inhibit, impair reduce or reverse ULRB1 and / orULRB2 dependent polarization of a macrophage (such as a tumour associated macrophage (TAM)), such as a polarization of an immune cell into an immune suppressive phenotype, such as an M2 like macrophage or myeloid-derived suppressor cell (MDSC);• increase, support and / or enhance macrophage dependent phagocytosis,• increase, support and / or enhance polarization or repolarization of an immune cell into an immune enhancing phenotype such as an Ml-like macophage.

[0089] The term "cell-mediated immune response", as used herein, may include, but is not limited to, a response in a host organism involving, utilising, and / or promoting any one or combinations of T cell maturation, proliferation, activation, migration, infiltration and / or differentiation, and / or the activation / modulation / migration / infiltration of a macrophage, a natural killer cell, a T lymphocyte (or T cell), a helper T lymphocyte, a memory T lymphocyte, a suppressor T lymphocyte, a regulator T lymphocyte, and / or a cytotoxic T lymphocyte (CTL), and / or the production, release, and / or effect of one or more cell-secretable or cell-secreted factor such as a cytokine or autocoid (in particular a pro-inflammatory cytokine), and / or one or more components of any of such processes (such as a cytokine or autocoid, particular a pro-inflammatory cytokine). The term "cell-mediated immune response," as used herein, may include a cellular response involving a genetically engineered, in-vitrv cultured, autologous, heterologous, modified, and / or transferred T lymphocyte, or it may include a cell-secretable or cell-secreted factor (such as a cytokine or autocoid, in particular a pro-inflammatory cytokine) produced by genetic engineering. A cell-mediated immune response is preferably not a humoral immune response, such as an immune response involving the release of antibodies. In certain embodiments, in particular when the proliferative disorder is a cancer or tumour, the cell-mediated immune response is an anti-tumour cell-mediated immune response. For example, one that leads to a reduction in tumour (cell) growth, such as a cytotoxic cell-mediated immune response (such as a cytotoxic T cell exposure) that kills cells of the cancer or tumour.

[0090] In certain embodiments, the cell mediating the cell-mediated immune response may be mediated by a cell, such as an immune cell, capable of secreting (eg secreting) pro-inflammatory cytokine, such as one selected from the group consisting of: interleukin-1 (IL-1), IL- 2, IL-12, IL-17 and IL- 18, tumour necrosis factor (TNF) [alpha], interferon gamma (IFN-gamma), and granulocyte-macrophage colony stimulating factor.

[0091] In certain embodiments, the cell-mediated immune response can be mediated by a pro-inflammatory cytokine-secreting cell, such as a lymphocyte (eg a T cell), in particular a cytotoxic T lymphocyte (CTL), or a natural killer cell (NK cell).

[0092] In particular embodiments, the cell-mediated immune response may induce killing of cells associated or involved with a disease, disorder or condition, such as a proliferative disorder (eg a cancer).

[0093] The term "humoral immunity" (or "humoral immune response") will also be readily understood by the person of ordinary skill, and includes an aspect of an immune response that is mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides. Humoral immunity is so named because it involves substances found in the humors, or body fluids. Its aspects involving antibodies can be termed antibody-mediated immunity.

[0094] As used herein, a "subject" includes all mammals, including without limitation humans, but also non-human primates such as cynomolgus monkeys. It also includes dogs, cats, horses, sheep, goats, cows, rabbits, pigs and rodents (such as mice and rats). It will be appreciated that a particularly preferred subject according to the invention is a human subject, such as a human suffering from (or at risk of suffering from) a disorder, disease or condition, forexample a human patient.

[0095] In further other embodiments, a modulator of the invention (eg, an ABP or biABP that binds to ULRB1 and / or ULRB2) that is an inhibitor or antagonist, preferably of an interaction of LILRB1 and / or ULRB2 with a natural ligand thereof, such as HLA-G, may instead or also:• Activate and / or reduce suppression of immune signaling pathways, such as AKT and ERK signaling in a cell expressing LILRB1 and / or ULRB2;• Reduce the polarization of, or repolarize, immune-suppressive macrophages, such as M2 macrophages;• Reduce the polarization of, or repolarize, a tolerogenic dendritic cell (DC) phenotype;• Promote adaptive immune responses, such as cellular or humoral immune responses elicited against an antigen or cell or therapeutic antibody (eg in an in-vitro assay or in a subject, such as one in need thereof);• promote humoral immune responses elicited by a therapeutic or prophylactic vaccine (eg in an in-vitro assay or in a subject, such as one in need thereof);• reduce tumour cell immune evasion mediated by HLA-G expression;• mediate any one or combination of at least one of the following effects: (i) increases immune response, (ii) increases T cell activation, (iii) increases cytotoxic T cell activity, (iv) increases NK cell activity, (v) alleviates T-cell suppression, (vi) increases pro-inflammatory cytokine secretion, (vii) increases IL-2 secretion; (viii) increases interferon-gamma production, (ix) increases Thl response, (x) decreases Th2 response, (xi) decreases or eliminates cell number and / or activity of at least one of regulatory T cells (Tregs), myeloid derived suppressor cells (MDSCs), iMCs, mesenchymal stromal cells, TIE2-expressing monocytes, (xii) reduces regulatory cell activity, and / or the activity of one or more of myeloid derived suppressor cells (MDSCs), iMCs, mesenchymal stromal cells, TIE2-expressing monocytes, (xiii) decreases or eliminates M2 macrophages, (xiv) reduces M2 macrophage pro- tumourigenic activity, (xv) decreases or eliminates N2 neutrophils, (xvi) reduces N2 neutrophils pro-tumourigenic activity, (xvii) reduces inhibition of T cell activation, (xviii) reduces inhibition of CTL activation, (xix) reduces inhibition of NK cell activation, (xx) reverses T cell exhaustion, (xxi) increases T cell response, (xxii) increases activity of cytotoxic cells, (xxiii) stimulates antigen-specific memory responses, (xxiv) elicits apoptosis or lysis of cancer cells, (xxv) stimulates cytotoxic or cytostatic effect on cancer cells, (xxvi) induces direct killing of cancer cells, (xxvii) increases Thl7 activity and / or (xxviii) induces complement dependent cytotoxicity and / or antibody dependent cell-mediated cytotoxicity; (eg in an in-vitro assay or in a subject, such as one in need thereof) with the optional proviso that said modulator may elicit an opposite effect to one or more of (i)-(xxviii).

[0096] Bispecific ABP and bispecific Antibodies of the present Invention

[0097] The present invention pertains to bispecific ABP that in their first antigen binding site comprise CDRs as contained in the specific ABP sequences described herein elsewhere (in particular in Table 1). Further, the biABP of the invention comprises at least a second antigen binding site binding to an immune checkpoint. For the biABP of the invention the following applies:

[0098] The term "monospecific" antibody as used herein denotes an antibody or ABP that has one or more binding sites each of which bind to the same epitope of the same antigen.

[0099] The term "bispecific" means that the antibody or ABP is able to specifically bind to at least two distinct antigenic determinants, for example two binding sites (epitopes) each formed by a pair of an antibody heavy chain variable domain (VH) and an antibody light chain variable domain (VL) binding to different antigens or to different epitopes on the same antigen. Such a bispecific antibody or ABP may have an 1+1 format. Other bispecific antibody formats are 2+1 formats (comprising two binding sites for a first antigen or epitope and one binding site for a second antigen or epitope) or 2+2 formats (comprising two binding sites for a first antigen or epitope and two binding sites for a second antigen or epitope). The latter format being preferred.

[0100] The bispecific ABP of the invention can be provided in any bispecific format known to the person of skill. The biABP may be a bi-specific, tri-specific, or tetra-specific antibody, in particular a bi-specific antibody is selected from: a bispecific T-cell engager (BiTE) antibody, a dual-affinity retargeting molecule (DART), a CrossMAb antibody, a DutaMab™ antibody, a DuoBody antibody; a Triomab, a TandAb, a bispecific NanoBody, Tandem scFv, a diabody, a single chain diabody, a HSA body, a (scFv)2 HSA Antibody, an scFv-IgG antibody, a Dock and Lock bispecific antibody, a DVD-IgG antibody, a TBTI DVD-IgG, an IgG-fynomer, a Tetravalent bispecific tandem IgG antibody, a dual-targeting domain antibody, a chemically linked bispecific (Fab')2 molecule, a crosslinked mAb, a Dual-action Fab IgG (DAF-IgG), an orthoFab-IgG, a bispecific CovX-Body, a bispecific hexavalent trimerbody, and an ART-Ig. The biABP of the invention may comprise a further binding functionality as described herein elsewhere. Further formats applicable in context of the invention are described in Spiess C et al Molecular Immunology Volume 67, Issue 2, Part A, October 2015, Pages 95-106.

[0101] The term "valent" as used within the current application denotes the presence of a specified number of binding domains (or paratopes) in an antigen binding molecule. As such, the terms "bivalent", "tetravalent", and "hexavalent" denote the presence of two binding domain, four binding domains, and six binding domains, respectively, in an antigen binding molecule. The bispecific and / or bispecific antibodies or biABPs according to the invention are at least "bivalent" and may be "trivalent" or "multivalent" (e.g. "tetravalent" or "hexavalent"). In a particular aspect, the antibodies or ABPs of the present invention have two or more binding sites and are bispecific. That is, the antibodies or ABPs may be bispecific even in cases where there are more than two binding sites (i.e. that the antibody is trivalent or multivalent).

[0102] As used herein, the term "antigen binding domain" or "antigen-binding site" or "paratope" are used as synonyms and refers to the part of the antigen binding protein (ABP) that specifically binds to an antigenic determinant. More particularly, the term "antigen-binding domain" refers the part of an antibody or ABP that comprises the area which specifically binds to and is complementary to part or all of an antigen. Where an antigen is large, an antigen binding protein may only bind to a particular part of the antigen, which part is termed an epitope. An antigen binding domain may be provided by, for example, one or more variable domains (also called variable regions). Preferably, an antigen binding domain comprises an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH). In one aspect, the antigen binding domain is able to bind to its antigen and block or partly block its function. Antigen binding domains that specifically bind to ULRB1 / LILRB2 are defined herein elsewhere. Therefore, in specific embodiments it is understood that the antigen-binding site is an antibody paratope, preferably wherein the antibody paratope is comprised in an antigen-binding fragment of an antibody, such as comprised in an antibody heavy chain and / or light chain variable domain, preferably wherein the one or more ABP is or comprises a combination of an antibody paratope provided as a full-length antibody, such as an IgG antibody, or provided as an antigen binding fragment of an antibody, such as preferably an F(ab')2-, Fab-, or Fv-fragment, and wherein the fragment is preferably a single-chain (sc) construct, most preferably as a scFab.

[0103] BiABPs of the invention in some embodiments may be composed of antibody fragments including but are not limited to Fv, Fab, Fab', Fab'-SH, F(ab')2; diabodies, triabodies, tetrabodies, cross-Fab fragments; linear antibodies; single-chain antibody molecules (e.g. scFv); multispecific antibodies formed from antibody fragments and single domain antibodies. For a review of certain antibody fragments, see Hudson et al., Nat Med 9, 129-134 (2003). For a review of scFv fragments, see e.g. Pliickthun, in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds., Springer- Verlag, New York, pp. 269-315 (1994); see also WO 93 / 16185; and U.S. Patent Nos. 5,571,894 and 5,587,458. For discussion of Fab and F(ab')2 fragments comprising salvage receptor binding epitope residues and having increased in vivo half-life, see U.S. Patent No. 5,869,046. Diabodies are antibody fragments with two antigen binding domains that may be bivalent or bispecific, see, for example, EP 404,097; WO 1993 / 01161; Hudson et aL, Nat Med 9, 129-134 (2003); and Hollinger et al., Proc Natl Acad Sci USA 90, 6444-6448 (1993). Triabodies and tetrabodiesare also described in Hudson et al., Nat Med 9, 129-134 (2003). Single-domain antibodies are antibody fragments comprising all or a portion of the heavy chain variable domain or all or a portion of the light chain variable domain of an antibody. In certain embodiments, a single-domain antibody is a human single-domain antibody (Domantis, Inc., Waltham, MA; see e.g. U.S. Patent No. 6,248,516 Bl). In addition, antibody fragments comprise single chain polypeptides having the characteristics of a VH domain, namely being able to assemble together with a VL domain, or of a VL domain, namely being able to assemble together with a VH domain to a functional antigen binding site and thereby providing the antigen binding property of fulllength antibodies.

[0104] Antibody fragments can be made by various techniques, including but not limited to proteolytic digestion of an intact antibody as well as production by recombinant host cells (e.g. E. coli or phage), as described herein. Papain digestion of intact antibodies produces two identical antigen-binding fragments, called "Fab" fragments containing each the heavy- and light-chain variable domains and also the constant domain of the light chain and the first constant domain (CHI) of the heavy chain. As used herein, Thus, the term "Fab fragment" refers to an antibody fragment comprising a light chain fragment comprising a VL domain and a constant domain of a light chain (CL), and a VH domain and a first constant domain (CHI) of a heavy chain. Fab' fragments differ from Fab fragments by the addition of a few residues at the carboxy terminus of the heavy chain CHI domain including one or more cysteins from the antibody hinge region. Fab'-SH are Fab' fragments wherein the cysteine residue(s) of the constant domains bear a free thiol group. Pepsin treatment yields an F(ab')2 fragment that has two antigen-combining sites (two Fab fragments) and a part of the Fc region.

[0105] The term "cross-Fab fragment" or "xFab fragment" or "crossover Fab fragment" refers to a Fab fragment, wherein either the variable regions or the constant regions of the heavy and light chain are exchanged. Two different chain compositions of a crossover Fab molecule are possible and comprised in the bispecific antibodies of the invention: On the one hand, the variable regions of the Fab heavy and light chain are exchanged, i.e. the crossover Fab molecule comprises a peptide chain composed of the light chain variable region (VL) and the heavy chain constant region (CHI), and a peptide chain composed of the heavy chain variable region (VH) and the light chain constant region (CL). This crossover Fab molecule is also referred to as CrossFab (VLVH)- On the other hand, when the constant regions of the Fab heavy and light chain are exchanged, the crossover Fab molecule comprises a peptide chain composed of the heavy chain variable region (VH) and the light chain constant region (CL), and a peptide chain composed of the light chain variable region (VL) and the heavy chain constant region (CHI). This crossover Fab molecule is also referred to as CrossFab (CLCHI)-.

[0106] A "single chain Fab fragment" or "scFab" is a polypeptide consisting of an antibody heavy chain variable domain (VH), an antibody constant domain 1 (CHI), an antibody light chain variable domain (VL), an antibody light chain constant domain (CL) and a linker, wherein said antibody domains and said linker have one of the following orders in N-terminal to C-terminal direction: a) VH-CH1 -linker- VL-CL, b) VL-CL-linker-VH-CHI, c) VH-CL-linker-VL-CHI or d) VL-CH1 -linker- VH-CL; and wherein said linker is a polypeptide of at least 30 amino acids, preferably between 32 and 50 amino acids. Said single chain Fab fragments are stabilized via the natural disulfide bond between the CL domain and the CHI domain. In addition, these single chain Fab molecules might be further stabilized by generation of interchain disulfide bonds via insertion of cysteine residues (e.g. position 44 in the variable heavy chain and position 100 in the variable light chain according to Kabat numbering).

[0107] A "crossover single chain Fab fragment" or "x-scFab" is a is a polypeptide consisting of an antibody heavy chain variable domain (VH), an antibody constant domain 1 (CHI), an antibody light chain variable domain (VL), an antibody light chain constant domain (CL) and a linker, wherein said antibody domains and said linker have one of the following orders in N-terminal to C-terminal direction: a) VH-CL-linker-VL-CHI and b) VL-CH1 -linker- VH-CL; wherein VH and VL form together an antigen binding domain which binds specifically to an antigen and wherein said linker is a polypeptide of at least 30 amino acids. In addition, these x-scFab molecules might be further stabilized by generationof interchain disulfide bonds via insertion of cysteine residues (e.g. position 44 in the variable heavy chain and position 100 in the variable light chain according to Kabat numbering).

[0108] A "single-chain variable fragment (scFv)" is a fusion protein of the variable regions of the heavy (VH) and light chains (VL) of an antibody, connected with a short linker peptide of ten to about 25 amino acids. The linker is usually rich in glycine for flexibility, as well as serine or threonine for solubility, and can either connect the N-terminus of the VH with the C-terminus of the VL, or vice versa. This protein retains the specificity of the original antibody, despite removal of the constant regions and the introduction of the linker. scFv antibodies are, e.g. described in Houston, J.S., Methods in Enzymol. 203 (1991) 46-96). In addition, antibody fragments comprise single chain polypeptides having the characteristics of a VH domain, namely being able to assemble together with a VL domain, or of a VL domain, namely being able to assemble together with a VH domain to a functional antigen binding site and thereby providing the antigen binding property of full-length antibodies.

[0109] Bispecific ABPs and bispecific antibodies of the invention may be provided as heterodimeric antibody-like complexes that produced using the so called "knob in the hole" technology which allows a production of the heterodimer without chain mispairing, for example by using a heavy chain constant 3 (CH3) region with an introduced "protuberance" ("knob") in one chain thereof and a corresponding introduced "cavity" ("hole") in the other chain thereof; see US Patent No. 5,821,333, expressly incorporated herein by reference). Such variant CH3 domains were shown be used to promote heterodimerization of two non- identical antibody heavy chains as herein described. Unless otherwise specified herein, numbering of amino acid residues in the Fc region or constant region is according to the EU numbering system, also called the EU index, as described in Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991. This approach is known as the "knob-into-hole” technology which is described e.g. in US 5,731,168; US 7,695,936; Ridgway et al., Prot Eng 9, 617-621 (1996) and Carter, J Immunol Meth 248, 7-15 (2001). Generally, the method involves introducing a protuberance ("knob") at the interface of a first polypeptide and a corresponding cavity ("hole") in the interface of a second polypeptide, such that the protuberance can be positioned in the cavity so as to promote heterodimer formation and hinder homodimer formation. Protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g. tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are created in the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g. alanine or threonine). The protuberance and cavity can be made by altering the nucleic acid encoding the polypeptides, e.g. by site-specific mutagenesis, or by peptide synthesis. In a specific embodiment a knob modification comprises the amino acid substitution T366W in one of the two subunits of the Fc domain, and the hole modification comprises the amino acid substitutions T366S, L368A and Y407V in the other one of the two subunits of the Fc domain. In a further specific embodiment, the subunit of the Fc domain comprising the knob modification additionally comprises the amino acid substitution S354C, and the subunit of the Fc domain comprising the hole modification additionally comprises the amino acid substitution Y349C. Introduction of these two cysteine residues results in the formation of a disulfide bridge between the two subunits of the Fc region, thus further stabilizing the dimer (Carter, J Immunol Methods 248, 7-15 (2001)).

[0110] Combining ABPs of the invention in a bispecific antibody or biABP requires covalent interconnection of one or more amino acid sequences. For the present invention, a biABP of the invention comprises two antibody binding sites (or domains) which are interconnected at least in part covalently. Such covalent connection is realized using peptide linkers and / or covalent bonds such as disulfide bridges. For example, antibody fragments such as Fab or scFab as described herein elsewhere may be connected via a peptide linker. The term "peptide linker" as used in this context refers to a peptide comprising one or more amino acids, typically about 2 to 20 amino acids. Peptide linkers are known in the art or are described herein. Suitable, non-immunogenic linker peptides are, for example, (G4S)n, (SG4)n orG4(SG4)n peptide linkers, wherein "n" is generally a number between 1 and 10, typically between 2 and 8, in particular a G4S)n linker.[HU In particular preferred embodiments of the invention the isolated ABP, or ABP-containing composition, in (B) is a bispecific ABP comprising two first antigen-binding sites and two second antigen binding sites, wherein (X) the two first antigen binding sites are provided as one F(ab')2 fragment or one IgG antibody, wherein the IgG antibody comprises an antibody hinge-, CH2- and / or CH3-domain, and wherein the two second antibody binding sites are provided as two antibody scFv or scFab fragments, each of which is independently covalently connected to one of the two first antigen-binding sites, preferably via a protein linker, or (Y) the two second antigen binding sites are provided as one F(ab')2 fragment or one IgG antibody, wherein the IgG antibody comprises an antibody hinge-, CH2- and / or CH3-domain, and wherein the two first antibody binding sites are provided as two antibody scFv or scFab fragments, each of which is independently covalently connected to the two second antigen-binding sites, preferably via a protein linker.

[0112] Many antibody-like bispecific formats are known to the skilled artisan and shall be included herein as useful for the purposes of the invention. Certain preferred examples of bispecific formats are described herein below.

[0113] One format preferred in context of the present invention is a tetravalent construct (2:2) comprising a homodimer of a single chain construct which combine Fab and / or scFV antibody binding sites of two ABPs (wherein scFv are preferred).

[0114] A preferred embodiment of a bispecific ABP of the invention is composed of at least one, preferably two, first antibody (heavy / light) chain sequences, and at least one, preferably two, second antibody (heavy / light) chain sequences, wherein at least one, preferably both, of the first antibody (heavy / light) chain sequences comprises in N- to C-terminal direction:(1.1) an antibody heavy chain variable domain sequence comprising at least parts of the second antigenbinding site,(1-2) optionally, one or more antibody heavy chain constant domain sequences, such as a CHI, hinge, CH2 and / or CH3 domain,(1-3) a first peptide linker,(1-4) an antibody light chain variable domain sequence comprising at least parts of the first antigen-binding site;(1-5) optionally an antibody light chain constant domain sequence;(1-6) a second peptide linker,(1-7) an antibody heavy chain variable domain sequence comprising at least parts of the first antigenbinding site;(1-8) optionally, an antibody heavy chain constant domain sequence; and wherein at least one, preferably both, of the second antibody (heavy / light) chain sequences comprises in N- to C-terminal direction(2-1) an antibody light chain variable domain sequence comprising at least parts of the second antigenbinding site;(2-2) an antibody light chain constant domain; wherein [(1-4) to (1-5)] and [(1-7) to (1-8)] can be interchanged, and / or wherein (1-4) and (1-5); and (1-7) and (1-8); can be (both) interchanged.

[0115] In this embodiment a part of an antigen binding site shall be understood as either a heavy chain or a light chain half of a complete antibody binding site.

[0116] In this format the first and or second peptide linker preferably has a length of 0 to 100 amino acids, preferably of 0 to 50 amino acids, optionally, wherein the first and / or second peptide linker comprises one or more iterations of 4GS.

[0117] Certain preferred embodiments of the invention pertain to the isolated ABP, which is a bispecific ABP, of a format that is composed of at least one, preferably two, first antibody (heavy / light) chain sequences, and at least one, preferably two, second antibody (heavy / light) chain sequences, wherein at least one, preferably both, of the first antibody (heavy / light) chain sequences comprises in N- to C-terminal direction:(1-1) an antibody heavy chain variable domain sequence comprising at least parts of the first antigenbinding site,(1-2) optionally, one or more antibody heavy chain constant domain sequences, such as a CHI, hinge, CH2 and / or CH3 domain,(1-3) a first peptide linker,(1-4) an antibody light chain variable domain sequence comprising at least parts of the second antigenbinding site;(1-5) optionally an antibody light chain constant domain sequence;(1-6) a second peptide linker,(1-7) an antibody heavy chain variable domain sequence comprising at least parts of the second antigenbinding site;(1-8) optionally, an antibody heavy chain constant domain sequence; and wherein at least one, preferably both, of the second antibody (heavy / light) chain sequences comprises in N- to C-terminal direction(2-1) an antibody light chain variable domain sequence comprising at least parts of the first antigen-binding site;(2-2) an antibody light chain constant domain; wherein [(1-4) to (1-5)] and [(1-7) to (1-8)] can be interchanged, and / or wherein (1-4) and (1-5); and (1-7) and (1- 8); can be (both) interchanged.

[0118] The term "chain pairing domain" in context of the present invention shall refer to an amino acid or amino acid sequence that allows for a specific heterodimeric pairing of the first antibody (heavy / light) chain sequence with the second antibody (heavy / light) chain sequence, which avoids homodimeric mispairing or mispairing with other, unrelated, endogeneous antibody chains. Such chain pairing domains may include domains known as "knobs" or "holes" or positively or negatively charged amino acids. Such chain pairing domains are referred to as donor (knob, or positive) or acceptor (hole, negative) respectively.

[0119] In a specific aspect said chain pairing domain modification is a so-called "knob-into-hole" modification of the ABP of the invention, comprising a "knob" modification in one of the two subunits of the Fc domain and a "hole" modification in the other one of the two subunits of the Fc domain. Thus, the invention relates to a bispecific ABP or bispecific antibody comprising a first antigen binding domain that specifically binds to ULRB1 / LILRB2 (for example with an antigen binding domain contained in any one of an antibody of table 1) and a second antigen-binding site that specifically binds to an immune checkpoint, such as an antigen binding domain of an ant-PDl or anti-PD-Ll antibody, wherein the first subunit of the Fc domain comprises knobs and the second subunit of the Fc domain comprises holes according to the knobs into holes method. In a particular aspect, the first subunit of the Fc domain comprises the amino acid substitutions S354C and T366W (EU numbering) and the second subunit of the Fc domain comprises the amino acid substitutions Y349C, T366S and Y407V (numbering according to Kabat EU index).

[0120] The knob-into-hole technology is described e.g. in US 5,731,168; US 7,695,936; Ridgway et al., Prot Eng 9, 617-621 (1996) and Carter, J Immunol Meth 248, 7-15 (2001). Generally, the method involves introducing aprotuberance ("knob") at the interface of a first polypeptide and a corresponding cavity ("hole") in the interface of a second polypeptide, such that the protuberance can be positioned in the cavity so as to promote heterodimer formation and hinder homodimer formation. Protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g. tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are created in the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g. alanine or threonine).

[0121] Accordingly, in one aspect, in the CH3 domain of the first subunit of the Fc domain of the bispecific antigen binding protein of the invention an amino acid residue is replaced with an amino acid residue having a larger side chain volume, thereby generating a protuberance within the CH3 domain of the first subunit which is positionable in a cavity within the CH3 domain of the second subunit, and in the CH3 domain of the second subunit of the Fc domain an amino acid residue is replaced with an amino acid residue having a smaller side chain volume, thereby generating a cavity within the CH3 domain of the second subunit within which the protuberance within the CH3 domain of the first subunit is positionable. The protuberance and cavity can be made by altering the nucleic acid encoding the polypeptides, e.g. by site-specific mutagenesis, or by peptide synthesis. In a specific aspect, in the CH3 domain of the first subunit of the Fc domain the threonine residue at position 366 is replaced with a tryptophan residue (T366W), and in the CH3 domain of the second subunit of the Fc domain the tyrosine residue at position 407 is replaced with a valine residue (Y407V). In one aspect, in the second subunit of the Fc domain additionally the threonine residue at position 366 is replaced with a serine residue (T366S) and the leucine residue at position 368 is replaced with an alanine residue (L368A).

[0122] In yet a further aspect, in the first subunit of the Fc domain additionally the serine residue at position 354 is replaced with a cysteine residue (S354C), and in the second subunit of the Fc domain additionally the tyrosine residue at position 349 is replaced by a cysteine residue (Y349C). Introduction of these two cysteine residues leads to the formation of a disulfide bridge between the two subunits of the Fc domain, further stabilizing the dimer (Carter (2001), J Immunol Methods 248, 7-15). In a particular aspect, the first subunit of the Fc domain comprises the amino acid substitutions S354C and T366W (EU numbering) and the second subunit of the Fc domain comprises the amino acid substitutions Y349C, T366S and Y407V (numbering according to Kabat EU index).

[0123] But also other knobs-in-holes technologies as described by EP 1 870 459, can be used alternatively or additionally. In one embodiment the bispecific ABP or antibody comprises the mutations R409D and K370E in the CH3 domain of the "knobs chain" and the mutations D399K and E357K in the CH3 domain of the "hole-chain" (numbering according to Kabat EU index). In one aspect, the bispecific ABP or antibody comprises a T366W mutation in the CH3 domain of the "knobs chain" and the mutations T366S, L368A and Y407V in the CH3 domain of the "hole chain" and additionally the mutations R409D and K370E in the CH3 domain of the "knobs chain" and the mutations D399K and E357K in the CH3 domain of the "hole chain" (numbering according to the Kabat EU index).

[0124] In one aspect, the bispecific ABP or antibody comprises the mutations Y349C and T366W in one of the two CH3 domains and the mutations S354C, T366S, L368A and Y407V in the other of the two CH3 domains, or the multispecific antibody comprises the mutations Y349C and T366W in one of the two CH3 domains and the mutations S354C, T366S, L368A and Y407V in the other of the two CH3 domains and additionally the mutations R409D and K370E in the CH3 domain of the "knobs chain" and the mutations D399K and E357K in the CH3 domain of the "hole chain" (numbering according to the Kabat EU index).

[0125] In an alternative aspect, a modification promoting association of the first and the second subunit of the Fc domain comprises a modification mediating electrostatic steering effects, e.g. as described in PCT publication WO 2009 / 089004. Generally, this method involves replacement of one or more amino acid residues at the interface of the two Fc domain subunits by charged amino acid residues so that homodimer formation becomes electrostatically unfavorable but heterodimerization electrostatically favorable.

[0126] Apart from the "knob-into-hole technology" other techniques for modifying the CH3 domains of the heavy chains of a bispecific ABP or antibody to enforce heterodimerization are known in the art. These technologies, especially the ones described in WO 96 / 27011, WO 98 / 050431, EP 1870459, WO 2007 / 110205, WO 2007 / 147901, WO 2009 / 089004, WO 2010 / 129304, WO 2011 / 90754, WO 2011 / 143545, WO 2012 / 058768, WO 2013 / 157954 and WO 2013 / 096291 are contemplated herein as alternatives to the "knob-into-hole technology" in combination with a bispecific ABP or antibody of the invention.

[0127] In one aspect, in the bispecific ABP or antibody the approach described in EP 1870459 is used to support heterodimerization of the first heavy chain and the second heavy chain of the multispecific antibody. This approach is based on the introduction of charged amino acids with opposite charges at specific amino acid positions in the CH3 / CH3-domain-interface between both, the first and the second heavy chain. Accordingly, in this aspect in the tertiary structure of the multispecific antibody the CH3 domain of the first heavy chain and the CH3 domain of the second heavy chain form an interface that is located between the respective antibody CH3 domains, wherein the respective amino acid sequences of the CH3 domain of the first heavy chain and the amino acid sequence of the CH3 domain of the second heavy chain each comprise a set of amino acids that is located within said interface in the tertiary structure of the antibody, wherein from the set of amino acids that is located in the interface in the CH3 domain of one heavy chain a first amino acid is substituted by a positively charged amino acid and from the set of amino acids that is located in the interface in the CH3 domain of the other heavy chain a second amino acid is substituted by a negatively charged amino acid. The bispecific antibody according to this aspect is herein also referred to as "CH3(+ / -)-engineered bispecific antibody" (wherein the abbreviation "+ / -" stands for the oppositely charged amino acids that were introduced in the respective CH3 domains).

[0128] In one aspect, in the CH3(+ / -)-engineered bispecific antibody the positively charged amino acid is selected from K, R and H, and the negatively charged amino acid is selected from E or D.

[0129] In one aspect, in the CH3(+ / -)-engineered bispecific antibody the positively charged amino acid is selected from K and R, and the negatively charged amino acid is selected from E or D.

[0130] In one aspect, in the CH3(+ / -)-engineered bispecific antibody the positively charged amino acid is K, and the negatively charged amino acid is E.

[0131] In one aspect, in the CH3(+ / -)-engineered bispecific antibody in the CH3 domain of one heavy chain the amino acid R at position 409 is substituted by D and the amino acid K at position is substituted by E, and in the CH3 domain of the other heavy chain the amino acid D at position 399 is substituted by K and the amino acid E at position 357 is substituted by K (numbering according to Kabat EU index).

[0132] In one aspect, the approach described in WO 2013 / 157953 is used to support heterodimerization of the first heavy chain and the second heavy chain of the multispecific ABR In one embodiment in the CH3 domain of one heavy chain the amino acid T at position 366 is substituted by K, and in the CH3 domain of the other heavy chain the amino acid L at position 351 is substituted by D (numbering according to Kabat EU index). In another embodiment in the CH3 domain of one heavy chain the amino acid T at position 366 is substituted by K and the amino acid L at position 351 is substituted by K, and in the CH3 domain of the other heavy chain the amino acid L at position 351 is substituted by D (numbering according to Kabat EU index).

[0133] In another aspect, in the CH3 domain of one heavy chain the amino acid T at position 366 is substituted by K and the amino acid L at position 351 is substituted by K, and in the CH3 domain of the other heavy chain the amino acid L at position 351 is substituted by D (numbering according to Kabat EU index). Additionally, at least one of the following substitutions is comprised in the CH3 domain of the other heavy chain: the amino acid Y at position 349 is substituted by E, the amino acid Y at position 349 is substituted by D and the amino acid L at position 368 is substituted by E (numbering according to Kabat EU index). In one embodiment the amino acid L at position 368 is substituted by E (numbering according to Kabat EU index).

[0134] In one aspect, the approach described in WO 2012 / 058768 is used to support heterodimerization of the first heavy chain and the second heavy chain of the multispecific antibody. In one aspect, in the CH3 domain of one heavy chain the amino acid L at position 351 is substituted by Y and the amino acid Y at position 407 is substituted by A, and in the CH3 domain of the other heavy chain the amino acid T at position 366 is substituted by A and the amino acid K at position 409 is substituted by F (numbering according to Kabat EU index). In another embodiment, in addition to the aforementioned substitutions, in the CH3 domain of the other heavy chain at least one of the amino acids at positions 411 (originally T), 399 (originally D), 400 (originally S), 405 (originally F), 390 (originally N) and 392 (originally K) is substituted (numbering according to Kabat EU index). Preferred substitutions are:• substituting the amino acid T at position 411 by an amino acid selected from N, R, Q, K, D, E and W (numbering according to Kabat EU index),• substituting the amino acid D at position 399 by an amino acid selected from R, W, Y, and K (numbering according to Kabat EU index),• substituting the amino acid S at position 400 by an amino acid selected from E, D, R and K (numbering according to Kabat EU index),• substituting the amino acid F at position 405 by an amino acid selected from I, M, T, S, V and W (numbering according to Kabat EU index;• substituting the amino acid N at position 390 by an amino acid selected from R, K and D (numbering according to Kabat EU index; and• substituting the amino acid K at position 392 by an amino acid selected from V, M, R, L, F and E (numbering according to Kabat EU index).

[0135] In another aspect, the bispecific, preferably biparatopoc, ABP or antibody is engineered according to WO 2012 / 058768), i.e. in the CH3 domain of one heavy chain the amino acid L at position 351 is substituted by Y and the amino acid Y at position 407 is substituted by A, and in the CH3 domain of the other heavy chain the amino acid T at position 366 is substituted by V and the amino acid K at position 409 is substituted by F (numbering according to Kabat EU index). In another embodiment of the multispecific antibody, in the CH3 domain of one heavy chain the amino acid Y at position 407 is substituted by A, and in the CH3 domain of the other heavy chain the amino acid T at position 366 is substituted by A and the amino acid K at position 409 is substituted by F (numbering according to Kabat EU index). In the last aforementioned embodiment, in the CH3 domain of the other heavy chain the amino acid K at position 392 is substituted by E, the amino acid T at position 411 is substituted by E, the amino acid D at position 399 is substituted by R and the amino acid S at position 400 is substituted by R (numbering according to Kabat EU index).

[0136] In one aspect, the approach described in WO 2011 / 143545 is used to support heterodimerization of the first heavy chain and the second heavy chain of the multispecific antibody. In one aspect, amino acid modifications in the CH3 domains of both heavy chains are introduced at positions 368 and / or 409 (numbering according to Kabat EU index).

[0137] In one aspect, the approach described in WO 2011 / 090762 is used to support heterodimerization of the first heavy chain and the second heavy chain of the bispecific antibody. WO 2011 / 090762 relates to amino acid modifications according to the "knob-into-hole" (KiH) technology. In one embodiment in the CH3 domain of one heavy chain the amino acid T at position 366 is substituted by W, and in the CH3 domain of the other heavy chain the amino acid Y at position 407 is substituted by A (numbering according to Kabat EU index). In another embodiment in the CH3 domain of one heavy chain the amino acid T at position 366 is substituted by Y, and in the CH3 domain of the other heavy chain the amino acid Y at position 407 is substituted by T (numbering according to Kabat EU index).

[0138] In one aspect, the approach described in WO 2009 / 089004 is used to support heterodimerization of the first heavy chain and the second heavy chain of the bispecific antibody. In one embodiment in the CH3 domain of one heavy chain the amino acid K or N at position 392 is substituted by a negatively charged amino acid (in one embodimentby E or D, in one preferred embodiment by D), and in the CH3 domain of the other heavy chain the amino acid D at position 399 the amino acid E or D at position 356 or the amino acid E at position 357 is substituted by a positively charged amino acid (in one embodiment K or R, in one preferred embodiment by K, in one preferred embodiment the amino acids at positions 399 or 356 are substituted by K) (numbering according to Kabat EU index). In one further embodiment, in addition to the aforementioned substitutions, in the CH3 domain of the one heavy chain the amino acid K or R at position 409 is substituted by a negatively charged amino acid (in one embodiment by E or D, in one preferred embodiment by D) (numbering according to Kabat EU index). In one even further aspect, in addition to or alternatively to the aforementioned substitutions, in the CH3 domain of the one heavy chain the amino acid K at position 439 and / or the amino acid K at position 370 is substituted independently from each other by a negatively charged amino acid (in one embodiment by E or D, in one preferred embodiment by D) (numbering according to Kabat EU index).

[0139] In one aspect, the approach described in WO 2007 / 147901 is used to support heterodimerization of the first heavy chain and the second heavy chain of the multispecific antibody. In one embodiment in the CH3 domain of one heavy chain the amino acid K at position 253 is substituted by E, the amino acid D at position 282 is substituted by K and the amino acid K at position 322 is substituted by D, and in the CH3 domain of the other heavy chain the amino acid D at position 239 is substituted by K, the amino acid E at position 240 is substituted by K and the amino acid K at position 292 is substituted by D (numbering according to Kabat EU index).

[0140] In one aspect of all aspects as reported herein, a bispecific antibody comprising a heavy chain including a C- terminal CH3 domain as specified herein, comprises the C-terminal glycine-lysine dipeptide (G446 and K447, numbering according to Kabat EU index). In one embodiment of all aspects as reported herein, a bispecific antibody comprising a heavy chain including a C-terminal CH3 domain, as specified herein, comprises a C-terminal glycine residue (G446, numbering according to Kabat EU index).

[0141] In one further aspect, the invention relates to a bispecific antibody or biABP comprising a first antigen binding site that specifically binds to LILRB1 / LILRB2 and a second antigen binding site that specifically binds to an immune checkpoint, wherein in one of the antigen binding sites, which may be for example Fab fragments, either the variable domains VH and VL or the constant domains CHI and CL are exchanged. The bispecific antibodies are prepared according to the Crossmab technology. Multispecific antibodies with a domain replacement / exchange in one binding arm (CrossMabVH-VL or CrossMabCH-CL) are described in detail in W02009 / 080252, W02009 / 080253 and Schaefer, W. et al, PNAS, 108 (2011) 11187-1191. They clearly reduce the byproducts caused by the mismatch of a light chain against a first antigen with the wrong heavy chain against the second antigen (compared to approaches without such domain exchange).

[0142] A preferred embodiment therefore pertains to a bipABP in a format of a CrossMabFab, CrossMabVHVLor, preferably, a CrossMabCH1CL, preferably wherein the CrossMabCH1CLbispecific antibody is composed of a first heterodimer, and a second heterodimer, wherein the first heterodimer is composed of:• a first antibody chain sequence comprising in N- to C-terminal orientation an antibody heavy chain variable domain sequence comprising at least parts of the first antigen-binding site (in an alternative embodiment of the second antigen-binding site), and an antibody heavy chain constant region (CHI), and antibody hinge sequence, an antibody CH2 and / or CH3 domain; and• a second antibody chain sequence comprising in N- to C-terminal orientation an antibody light chain variable domain sequence comprising at least parts of the first antigen-binding site (in an alternative embodiment of the second antigen-binding site), and an antibody light chain constant region (CL); and the second heterodimer is composed of: a third antibody chain sequence comprising in N- to C-terminal orientation an antibody heavy chainvariable domain sequence comprising at least parts of the second antigen-binding site (in an alternative embodiment of the first antigen-binding site), and an antibody light chain constant region (CL), an antibody hinge sequence, an antibody CH2 and / or CH3 domain; and• a fourth antibody chain sequence, comprising in N- to C-terminal orientation an antibody light chain variable domain sequence comprising at least parts of the second antigen-binding site (in an alternative embodiment of the first antigen-binding site), and an antibody heavy chain constant region (CHI); wherein at least the first and the third antibody chain sequences comprise each either a donor-, or acceptor- respectively, antibody chain pairing domain which are capable of mediating a specific pairing of the first antibody chain sequence with the third antibody chain sequence.

[0143] An immune checkpoint molecule in context of the invention may be selected from the group consisting of PD- 1, PD-L1 CTLA-4, LAG-3, TIGIT, TIM-3, VISTA, AXL, ILT2, or ILT3. In alternative embodiments, the bispecific ABP of the invention may instead of a binding site binding to an immune checkpoint, comprise a binding site to an immune costimulatory molecule (such as CD27, CD40, 4-1BB, 0X40, or GITR), or a tumour antigen (such as HER2, EGFR, ErB3, or CD24).

[0144] However, exemplary binding agents for use as antigen binding sites directed at immune checkpoints are antibodies or antigen binding fragments thereof which bind to human PD-1 or PD-L1, e.g., a PD-1 or PD-L1 antagonist. An exemplary PD-1 antibody is pembrolizumab (Keytruda®). Other exemplary binding agents include PD-L1 and PD-1 antibodies (or antigen binding fragments thereof) such as durvalumab, nivolumab, cemiplimab (Libtaylo®), avelumab (Bavencio®), durvalumab (Imfinzi®), and atezolizumab (Tecentriq®). An exemplary bispecific antibody on the basis of the antigen binding domain of pembrolizumab is provided herein in Example 13.

[0145] A bispecific antibody according to the invention in preferred embodiments comprises a first antigen binding site which specifically binds to the extra cellular domain (ECD) of leukocyte immunoglobulin-like receptor subfamily Bl (ULRB1) and ULRB2 protein, wherein the first antigen binding site comprises a CDR-containing sequence according to the following disclosure of ABPs or biABPs.

[0146] ABPs or biABPs of the invention comprising one or more complementarity determining regions

[0147] In particular embodiments, an ABP or biABP of the invention can preferentially comprise at least one complementarity determining region (CDR), such as one from an antibody (in particular from a human antibody), and in particular embodiments the ABP or biABP can comprise a CDR having an amino acid sequence with at least 80%, 85%, 90% or 95% sequence identity to (preferably, at least 90% sequence identity to), or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a CDR sequence set forth in Table 1 herein.

[0148] The term "complementarity determining region" (or "CDR" or "hypervariable region"), as used herein, refers broadly to one or more of the hyper-variable or complementarity determining regions (CDRs) found in the variable regions of light or heavy chains of an antibody. See, for example: "IMGT", Lefranc et al, 20003, Dev Comp Immunol 27:55; Honegger 8i Pluckthun, 2001, J Mol Biol 309:657, Abhinandan 8i Martin, 2008, Mol Immunol 45:3832, Kabat, et al. (1987): Sequences of Proteins of Immunological Interest National Institutes of Health, Bethesda, Md. These expressions include the hypervariable regions as defined by Kabat et al (1983) Sequences of Proteins of Immunological Interest, US Dept of Health and Human Services, or the hypervariable loops in 3-dimensional structures of antibodies (Chothia and Lesk, 1987; J Mol Biol 196:901). The CDRs in each chain are held in close proximity by framework regions and, with the CDRs from the other chain, contribute to the formation of the antigen-binding site. Within the CDRs there are select amino acids that have been described as the selectivity determining regions (SDRs) which represent the critical contact residues used by the CDR in the antibody-antigen interaction. (Kashmiri, 2005; Methods 36:25).

[0149] In all of its aspects and embodiments, a framework sequence of an ABP or biABP of the invention may include one or more mutations, for example in order to improve the isoelectric point of the molecules. One preferred mutation of the ABP or biABP of the invention are at position E81, for example is a E81M mutation, in accordance with the Kabat nomenclature.

[0150] As described above, in particular embodiments of the invention, an ABP or biABP can comprise at least one complementarity determining region (CDR). In certain of such embodiments, an ABP or biABP of the invention comprises at least one complementarity determining region 3 (CDR3), such as one having an amino acid sequence with at least 80%, 85%, 90% or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from those heavy and light chain CDR3 sequences shown in Table 1 (eg, a sequence selected from the list consisting of SEQ ID Nos: 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95,99, 103, 107, 111, 115, 119, 123, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187,191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, 255, 259, 263, 267, 271, 275, 279,283, 287, 291, 295, 299, 303, 307, 311, 315, 319, 323, 327, 331, 335, 339, 343, 347, 351, 355, 359, 363, 367, 371,375, 379, and 383).

[0151] An ABP or biABP of the invention may, alternatively or as well as a CDR3 sequence, comprise at least one CDR1, and / or at least one CDR2 (such as one from an antibody, in particular from a human antibody). Preferably, and ABP or biABP of the invention comprises at least one such CDR3, as well as at least one such CDR1 and at least one such CDR2, more preferably where each of such CDRs having an amino acid sequence with at least 80%, 85%, 90% or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from the corresponding (heavy and light chain) CDR1, CD2 and CD3 sequences shown in Table 1.

[0152] In certain preferred embodiments, the antibodies of the invention are derived from three parental antibody sequences denoted as A-001, A-002 and A-003. As such, the invention shows an inventive binding profile for the parental sequences, but also for maturated derivative antibody heavy and / or light chain sequences. The invention therefore in specific embodiments also pertains to antibody chain combination of any light chain sequence with any heavy chain sequence, of an antibody of the invention.

[0153] In particular embodiments, an ABP or biABP of the invention can be an antibody or an antigen binding fragment thereof.

[0154] As used herein, the term "antibody" may be understood in the broadest sense as any immunoglobulin (Ig) that enables binding to its epitope. An antibody as such is a species of an ABP or biABP. Full length "antibodies" or "immunoglobulins" are generally heterotetrameric glycoproteins of about 150 kDa, composed of two identical light and two identical heavy chains. Each light chain is linked to a heavy chain by one covalent disulphide bond, while the number of disulphide linkages varies between the heavy chain of different immunoglobulin isotypes. Each heavy and light chain also has regularly spaced intrachain disulphide bridges. Each heavy chain has an amino terminal variable domain (VH) followed by three carboxy terminal constant domains (CH). Each light chain has a variable N-terminal domain (VL) and a single C-terminal constant domain (CL). The VH and VL regions can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The variable regions of the heavy and light chains contain a binding domain that interacts with an antigen. The constant regions of the antibodies may mediate the binding of the immunoglobulin to cells or factors, including various cells of the immune system (e.g., effector cells) and the first component (Clq) of the classical complement system. Other forms of antibodies include heavy-chain antibodies, being those which consist only of two heavy chains and lack the two lightchains usually found in antibodies. Heavy-chain antibodies include the hdgG (IgG-like) antibodies of camelids such as dromedaries, camels, llamas and alpacas, and the IgNAR antibodies of cartilaginous fishes (for example sharks). And yet other forms of antibodies include single-domain antibodies (sdAb, called Nanobody by Ablynx, the developer) being an antibody fragment consisting of a single monomeric variable antibody domain. Single-domain antibodies are typically produced from heavy-chain antibodies, but may also be derived from conventional antibodies.

[0155] Antibodies (or those from which fragments thereof can be isolated) can include, for instance, chimeric, humanized, (folly) human, or hybrid antibodies with dual or multiple antigen or epitope specificities, antibody fragments and antibody sub-fragments, e.g., Fab, Fab' or F(ab')2 fragments, single chain antibodies (scFv) and the like (described below), including hybrid fragments of any immunoglobulin or any natural, synthetic or genetically engineered protein that acts like an antibody by binding to a specific antigen to form a complex.

[0156] Accordingly, in certain embodiments an ABP or biABP of the invention can comprise an antibody heavy chain, or an antigen binding fragment thereof, and / or an antibody light chain, or an antigen binding fragment thereof.

[0157] In further embodiments, an ABP or biABP of the invention can comprise an antibody heavy chain variable region, or an antigen binding fragment thereof, and / or an antibody light chain variable region, or an antigen binding fragment thereof, and in yet further embodiments, an ABP or biABP of the invention can comprise an antibody heavy chain variable region CDR1, CDR2, and CDR3, and / or an antibody light chain variable region CDR1, CDR2, and CDR3.

[0158] In particular embodiments of the invention, when the ABP or biABP comprises an antibody heavy chain sequence and / or an antibody light chain sequence, or an antigen binding fragment thereof; the antibody heavy chain sequence, or the fragment thereof, can comprise a CDR3 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a CDR3 sequence selected from those heavy chain CDR3 sequences shown in Table 1 (eg, a sequence selected from the list consisting of SEQ ID Nos: 3, 11, 19, l, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227, 235, 243, 251, 259, 267, 275, 283, 291, 299, 307, 315, 323, 331, 339, 347, 345, 363, 371 and 379), and / or wherein antibody light chain sequence, or the fragment thereof, can comprise a CDR3 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a CDR3 sequence selected from those light chain CDR3 sequences shown in Table 1 (eg, a sequence selected from the list consisting of SEQ ID Nos: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239, 247, 255, 263, 271, 279, 287, 295, 303, 311, 319, 327, 335, 343, 351, 359, 367, 375, and 383).

[0159] In particular embodiments of the invention, when the ABP or biABP comprises an antibody heavy chain sequence and / or an antibody light chain sequence, or an antigen binding fragment thereof; the antibody heavy chain sequence, or the fragment thereof, can comprise a CDR3 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a CDR3 sequence selected from those heavy chain CDR3 sequences selected from the list consisting of SEQ ID Nos: 75, 115, and 195, and / or wherein antibody light chain sequence, or the fragment thereof, can comprise a CDR3 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to a CDR3 sequence selected from those light chain CDR3 sequences selected from the list consisting of SEQ ID Nos: 287, 311, and 319. Any combination of these heavy chain CDR3 and light chain CDR3 are included in ABP or biABP of the invention, in particular the combinations selected from SEQ ID NO: 75 and 287, SEQ ID NO: 115 and 287, SEQ ID NO: 195 and 311 and SEQ ID NO: 195 and 319.

[0160] In further embodiments of the invention, when the ABP or biABP comprises an antibody heavy chain, or an antigen binding fragment thereof, the antibody heavy chain sequence, or the fragment thereof, can further comprisea CDR1 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from SEQ ID NOs. 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97, 105, 113, 121, 129, 137, 145, 153, 161, 169, 177, 185, 193, 201, 209, 217, 225, 233, 241, 249, 257, 265, 273, 281, 289, 297, 305, 313, 321, 329, 337, 345, 353, 361, 369, and 377(eg a heavy chain CDR1 sequence disclosed in Table 1); and / or a CDR2 having at 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from SEQ ID NOs. 2, 10, 18, 26, 34, 42, 50, 58, 66, 74, 82, 90, 98, 106, 114, 122, 130, 138, 146, 154, 162, 170, 178, 186, 194, 202, 210, 218, 226, 234, 242, 250, 258, 266, 274, 282, 290, 298, 306, 314, 322, 330, 338, 346, 354, 362, 370, and 378(eg a CDR2 sequence disclosed in Table 1).

[0161] In yet further embodiments of the present invention, an ABP or biABP of the invention comprises an antibody light chain, or an antigen binding fragment thereof, wherein the antibody light chain sequence, or the fragment thereof, further comprises a CDR1 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from SEQ ID NOs. 5, 13, 21, 29, 37, 45, 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, 141, 149, 157, 165, 173, 181, 189, 197, 205, 213, 221, 229, 237, 245, 253, 261, 269, , 285, 293, 301, 309, 317, 325, 333, 341, 349, 357, 365, 373, and 381(eg a light chain CDR1 sequence disclosed in Table 1); and / or a CDR2 having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from SEQ ID NOs. 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 102, 110, 118, 126, 134, 142, 150, 158, 166, 174, 182, 190, 198, 206, 214, 222, 230, 238, 246, 254, 262, 270, 278, 286, 294, 302, 310, 318, 326, 334, 342, 350, 358, 366, 374, and 382(eg a light chain CDR2 sequence disclosed in Table 1).

[0162] In other embodiments of the present invention, an ABP or biABP of the invention can comprise an antibody variable chain sequence having at least 80%, 85%, 90%; or 95% (preferably at least 90%) sequence identity to, or having no more than ten, nine, eight, seven, six, five, four, three, two or one, preferably no more than three, two or one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from SEQ ID NOs. 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120,124, 128, 132, 136, 140, 144, 148, 152, 156, 160, 164, 168, 172, 176, 180, 184, 188, 192, 196, 200, 204, 208, 212,216, 220, 224, 228, 232, 236, 240, 244, 248, 252, 256, 260, 264, 268, 272, 276, 280, 284, 288, 292, 296, 300, 304,308, 312, 316, 320, 324, 328, 332, 336, 340, 344, 348, 352, 356, 360, 364, 368, 372, 376, 380, and 384(eg, a VH orVL sequence disclosed in Table 1).

[0163] In particular embodiments of the invention, an ABP or biABP of the invention comprises an antigen binding fragment of an antibody, wherein the antigen binding fragment comprises CDR1, CDR2 and CDR3. In certain of such embodiments, the CDR1 is selected from those disclosed in Table 1, the CDR2 is selected from those disclosed in Table 1 and the CDR3 is selected from those disclosed in Table 1 (eg, the CDR1, CDR2 and CDR3 are selected from the CDR1, CDR2 and CDR3 sequences having the respective amino acid sequences of SEQ ID Nos. 1, 2, 3; or 9, 10, 11; or 17, 18, 19; or 25, 26, 27; or 33, 34, 35; or 41, 42, 43; or 49, 50, 51; or 57, 58, 59; or 65, 66, 67; or 73, 74, 75; or 81, 82, 83; or 89, 90, 91; or 97, 98, 99; or 105, 106, 107; or 113, 114, 115; or 121, 122, 123; or 129, 130, 131; or 137, 138, 139; or 145, 146, 147; or 153, 154, 155; or 161, 162, 163; or 169, 170, 171; or 177, 178, 179; or 185, 186, 187; or 193, 194, 195; or 201, 202, 203; or 209, 210, 211; or 217, 218, 219; or 225, 226, 227; or 233, 234, 235; or 241, 242, 243; or 249, 250, 251; or 257, 258, 259; or 265, 266, 267; or 273, 274, 275; or 281, 282, 283; or 289, 290, 291; or 297, 298, 299; or 305, 306, 307; or 313, 314, 315; or 321, 322, 323; or 329, 330, 331; or 337, 338, 339; or 345, 346, 347; or 5, 6, 7; or 13, 14, 15; or 21, 22, 23; or 29, 30, 31; or 37, 38, 39; or 45, 46, 47; or 53, 54, 55; or 61, 62, 63; or 69, 70, 71; or 77, 78, 79; or 85, 86, 87; or 93, 94, 95; or 101, 102, 103; or 109, 110, 111; or 117, 118, 119;or 125, 126, 127; or 133, 134, 135; or 141, 142, 143; or 149, 150, 151; or 157, 158, 159; or 165, 166, 167; or 173, 174, 175; or 181, 182, 183; or 189, 190, 191; or 197, 198, 199; or 205, 206, 207; or 213, 214, 215; or 221, 222, 223; or 229, 230, 231; or 237, 238, 239; or 245, 246, 247; or 253, 254, 255; or 261, 262, 263; or 269, 270, 271; or , 278, 279; or 285, 286, 287; or 293, 294, 295; or 301, 302, 303; or 309, 310, 311; or 317, 318, 319; or 325, 326, 327; or 333, 334, 335; or 341, 342, 343; or 349, 350, 351; or 353, 354, 355; or 357, 358, 359; or 361, 362, 363; or 365, 366, 367;or 369, 370, 371; or 373; 374, 375; or 377, 378, 379; or 381, 382, 383); in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0164] In further particular embodiments of the present invention, an ABP or biABP of the invention can comprise an antibody heavy chain variable region CDR1, CDR2, and CDR3, and / or an antibody light chain variable region CDR1, CDR2, and CDR3, wherein the CDR1 has an amino acid sequence of a heavy or light chain CDR1 shown in Table 1 (eg has an amino acid sequence selected from the list consisting of SEQ ID No 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233, 237, 241, 245, 249, 253, 257, 261, 265, 269, 273, 277, 281, 285, 289, 293, 297, 301, 305, 309, 313, 317, 321, 325, 329, 333, 337, 341, 345, 349, 353, 357, 361, 365, 369, 373, 377, and 381), and wherein the CDR2 has an amino acid sequence of a heavy or light chain CDR2 shown in Table 1 (eg has an amino acid sequence selected from the list consisting of SEQ ID No 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 102, 106, 110, 114, 118, 122, 126, 130, 134, 138, 142, 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 214, 218, 222, 226, 230, 234, 238, 242, 246, 250, 254, 258, 262, 266, 270, 274, 278, 282, 286, 290, 294, 298, 302, 306, 310, 314, 318, 322, 326, 330, 334, 338, 342, 346, 350, 354, 358, 362, 366, 370, 374, 378, 382), and wherein the CDR3 has an amino acid sequence of a heavy or light chain CDR3 shown in Table 1 (eg has an amino acid sequence selected from the list consisting of SEQ ID No 3, 7, 11, 15, 19, 23, J, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, 99, 103, 107, 111, 115, 119, 123, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163,167, 171, 175, 179, 183, 187, 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, 255,259, 263, 267, 271, 275, 279, 283, 287, 291, 295, 299, 303, 307, 311, 315, 319, 323, 327, 331, 335, 339, 343, 347,351, 355, 359, 363, 367, 371, 375, 379, and 383); in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0165] In preferred of such embodiments, the ABP or biABP may be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences and at least one, preferably both, of the antibody light chain sequences comprise CDR1 to CDR3 sequences in a combination selected from any of the combinations of heavy chain CDRs shown in Table B and / or selected from any of the combinations of light chain CDRs shown in Table B (in each case, combinations CDRs-A-001 to CDRs-A-044); in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. Preferably, the combination of both the heavy chain CDRs and the light chain CDRs is one selected from a row marked by any one of the combinations CDRs-A-001 to CDRs-A- 044, in each CDR independently optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.Table B: preferred combinations of heavy chain CDRs and preferred combinations of light chain CDRs

[0166] In other preferred embodiments of the invention, the ABP or biABP may be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chain sequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown in Table C (eg, selected from any of the variable chain combinations Chains-A-001 to Chains-A-044); in each case independently, optionally with no more than ten, nine, eight, seven, six, five, four, preferably no more than three, two or one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.Table C: preferred combinations of heavy and light chain variably domains

[0167] The ABP or biABP of the invention are all characterized by an advantageous and surprising on-target and off- target binding affinity profile. Hence, the present invention is some embodiments pertain to ABPs or biABPs binding to ULRB1 and ULRB2, while not binding to LILRA1 and not binding to ULRA3. More specifically, the ABP or biABP of the invention is an ABP or biABP wherein the binding of the ABP or biABP to any of the on target LILRB1 or ULRB2 is at least 2 or 3 times higher than to any of the off targets ULRA1 or ULRA3, preferably wherein the binding affinity is measured by BU in KD (monovalent) under conditions set out in the example section of this disclosure. More preferably the invention provides for the first time, advantageous binding profiles, wherein the binding of the ABP or biABP to anyof the on target LILRB1 or ULRB2 is at least 5, or preferably 10 times higher than to any of the off targets LILRA1 or ULRA3, preferably wherein the binding affinity is measured by BLI in KD (monovalent) under conditions set out in the example section of this disclosure. In addition thereto, in some embodiments, the ABP or biABP has a variable heavy chain sequence that is at least 90%, preferably 95%, 96%, 97%, 98% or 99% identical to the variable heavy chain sequence shown in any one of ABPs A-001 to A-048; and / or wherein, the ABP or biABP has a variable light chain sequence that is at least 90%, preferably 95%, 96%, 97%, 98% or 99% identical to the variable light chain sequence shown in any one of ABPs A-001 to A-048.

[0168] In particularly preferred embodiment, an ABP or biABP of the invention can comprise a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-010, such as shown in Table B by row CDRs-A-010 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 73, 74 and 75, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 77, 78 and 79, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences each comprises heavy chain CDR1 to CDR3 sequences in the combination CDRs- A-010 and at least one, preferably both, of the antibody light chain sequences each comprises light chain CDR1 to CDR3 sequences in the combination shown in the row of Table B marked by CDRs-A-010, in each CDR independently, optionally with no more than one amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In yet another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chain sequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown the row of Table B marked by Chains-A-010. In each of such particularly preferred embodiments of the ABP or biABP, optionally, the ABP or biABP is able to inhibit the binding of HLA-G protein or a variant thereof to LILRB1 and / or ULRB2 protein or a variant thereof with an IC50 of 20nM or less or lOnM or less, such as 5nM or less, or preferably 2nM or less. Such IC50s can be determined using the methods described elsewhere herein.

[0169] In particularly preferred embodiment, an ABP or biABP of the invention can comprise a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-026, such as shown in Table B by row CDRs-A-026 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 201, 202 and 203, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos 205, 206 and 207, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences each comprises heavy chain CDR1 to CDR3 sequences in the combination CDRs- A-026 and at least one, preferably both, of the antibody light chain sequences each comprises light chain CDR1 to CDR3 sequences in the combination shown in the row of Table B marked by CDRs-A-026, in each CDR independently, optionally with no more than one amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In yet another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chainsequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown the row of Table B marked by Chains-A-026. In each of such particularly preferred embodiments of the ABP or biABP, optionally, the ABP or biABP is able to inhibit the binding of HLA-G protein or a variant thereof to LILRB1 and / or ULRB2 protein or a variant thereof with an IC50 of 20nM or less or lOnM or less, such as 5nM or less, or preferably 2nM or less. Such IC50s can be determined using the methods described elsewhere herein.

[0170] In particularly preferred embodiment, an ABP or biABP of the invention can comprise a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-045, such as shown in Table B by row CDRs-A-045 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 353, 354, and 355, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 357, 358, and 359, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences each comprises heavy chain CDR1 to CDR3 sequences in the combination CDRs-A-045 and at least one, preferably both, of the antibody light chain sequences each comprises light chain CDR1 to CDR3 sequences in the combination shown in the row of Table B marked by CDRs-A-045, in each CDR independently, optionally with no more than one amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In yet another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chain sequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown the row of Table B marked by Chains-A-045. In each of such particularly preferred embodiments of the ABP or biABP, optionally, the ABP or biABP is able to inhibit the binding of HLA-G protein or a variant thereof to ULRB1 and / or LILRB2 protein or a variant thereof with an IC50 of 20nM or less or lOnM or less, such as 5nM or less. Such IC50s can be determined using the methods described elsewhere herein (see Example 3). Preferably, the ABP or biABP of this embodiment has a binding affinity to ULRB1 and / or ULRB2 as measured in KD (monovalent) of less than 20nM, more preferably of less than lOnM more preferably of less than 5nM, wherein the binding affinity ranges are provided preferably for both binding to ULRB1 and ULRB2, as measured using BU under conditions as described in the examples. Hence, the ABP or biABP of this embodiment is preferably a ULRB1 and ULRB2 ABP or biABP. In another preferred embodiment of the invention such antibody is further characterized by a significantly lower binding affinity to the counter targets LILRA1 and ULRA3, wherein the binding is with less affinity compared to the binding to ULRB1 and / or ULRB2. Preferably the binding affinity as measured in KD (monovalent) of such ABP or biABP of this embodiment to ULRA1 and ULRA3 is higher than 50 nM, more preferably higher lOOnm, more preferably higher than 200 nM, and most preferably higher than 400 nM, also as measured using BLI under conditions described herein in the example section.

[0171] In particularly preferred embodiment, an ABP or biABP of the invention can comprise a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-046, such as shown in Table B by row CDRs-A-046 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 361, 362, and 363, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 365, 366, and 367, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two,antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences each comprises heavy chain CDR1 to CDR3 sequences in the combination CDRs-A-046 and at least one, preferably both, of the antibody light chain sequences each comprises light chain CDR1 to CDR3 sequences in the combination shown in the row of Table B marked by CDRs-A-046, in each CDR independently, optionally with no more than one amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In yet another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chain sequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown the row of Table B marked by Chains-A-046. In each of such particularly preferred embodiments of the ABP or biABP, optionally, the ABP or biABP is able to inhibit the binding of HLA-G protein or a variant thereof to ULRB1 and / or LILRB2 protein or a variant thereof with an IC50 of 20nM or less or lOnM or less, such as 5nM or less. Such IC50s can be determined using the methods described elsewhere herein (see Example 3). Preferably, the ABP or biABP of this embodiment has a binding affinity to ULRB1 and / or ULRB2 as measured in KD (monovalent) of less than lOOnM, more preferably of less than 50nM more preferably of less than 15nM, wherein the binding affinity ranges are provided preferably for both binding to ULRB1 and ULRB2, as measured using BU under conditions as described in the examples. Hence, the ABP or biABP of this embodiment is preferably a ULRB1 and ULRB2 ABP or biABP. In another preferred embodiment of the invention such antibody is further characterized by a significantly lower binding affinity to the counter targets LILRA1 and ULRA3, wherein the binding is with less affinity compared to the binding to ULRB1 and / or ULRB2. Preferably the binding affinity as measured in KD (monovalent) of such ABP or biABP of this embodiment to ULRA1 and LILRA3 is higher than 100 nM, more preferably higher 500nm, more preferably higher than 1000 nM, and most preferably higher than 2000 nM, also as measured using BU under conditions described herein in the example section.

[0172] In particularly preferred embodiment, an ABP or biABP of the invention can comprise a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-047, such as shown in Table B by row CDRs-A-047 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 369, 370, and 371, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 373, 374, and 375, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences each comprises heavy chain CDR1 to CDR3 sequences in the combination CDRs-A-047 and at least one, preferably both, of the antibody light chain sequences each comprises light chain CDR1 to CDR3 sequences in the combination shown in the row of Table B marked by CDRs-A-047, in each CDR independently, optionally with no more than one amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In yet another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chain sequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown the row of Table B marked by Chains-A-047. In each of such particularly preferred embodiments of the ABP or biABP, optionally, the ABP or biABP is able to inhibit the binding of HLA-G protein or a variant thereof to ULRB1 and / or LILRB2 protein or a variant thereof with an IC50 of 20nM or less or lOnM or less, such as 5nM or less. Such IC50s can be determined using the methods described elsewhere herein (see Example 3).Preferably, the ABP or biABP of this embodiment has a binding affinity to LILRB1 and ULRB2 as measured in KD (monovalent) of less than 20nM, more preferably of less than lOnM more preferably of less than 5nM, wherein the binding affinity ranges are provided preferably for both binding to ULRB1 and ULRB2, as measured using BU under conditions as described in the examples. Hence, the ABP or biABP of this embodiment is preferably a ULRB1 and ULRB2 ABP or biABP. In another preferred embodiment of the invention such antibody is further characterized by a significantly lower binding affinity to the counter targets LILRA1 and ULRA3, wherein the binding is with less affinity compared to the binding to ULRB1 and / or ULRB2. Preferably the binding affinity as measured in KD (monovalent) of such ABP or biABP of this embodiment to ULRA1 and LILRA3 is higher than 20 nM, more preferably higher 50nm, more preferably higher than 100 nM, also as measured using BU under conditions described herein in the example section.

[0173] In particularly preferred embodiment, an ABP or biABP of the invention can comprise a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-048, such as shown in Table B by row CDRs-A-048 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 377, 378, and 379, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 381, 382, and 383, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences each comprises heavy chain CDR1 to CDR3 sequences in the combination CDRs-A-048 and at least one, preferably both, of the antibody light chain sequences each comprises light chain CDR1 to CDR3 sequences in the combination shown in the row of Table B marked by CDRs-A-048, in each CDR independently, optionally with no more than one amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. In yet another particularly preferred embodiment, an ABP or biABP of the invention can be an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequence, and at least one, preferably two, antibody light chain sequence, wherein the antibody heavy chain sequence and the antibody light chain sequence each comprises a variable region sequence in a combination of heavy and light chain variable domain shown the row of Table B marked by Chains-A-048. In each of such particularly preferred embodiments of the ABP or biABP, optionally, the ABP or biABP is able to inhibit the binding of HLA-G protein or a variant thereof to ULRB1 and / or LILRB2 protein or a variant thereof with an IC50 of 20nM or less or lOnM or less, such as 5nM or less. Such IC50s can be determined using the methods described elsewhere herein (see Example 3). Preferably, the ABP or biABP of this embodiment has a binding affinity to LILRB1 and ULRB2 as measured in KD (monovalent) of less than lOOnM, more preferably of less than 50nM more preferably of less than lOnM, wherein the binding affinity ranges are provided preferably for both binding to ULRB1 and ULRB2, as measured using BU under conditions as described in the examples. Hence, the ABP or biABP of this embodiment is preferably a ULRB1 and ULRB2 ABP or biABP. In another preferred embodiment of the invention such antibody is further characterized by a significantly lower binding affinity to the counter targets LILRA1 and ULRA3, wherein the binding is with less affinity compared to the binding to ULRB1 and / or ULRB2. Preferably the binding affinity as measured in KD (monovalent) of such ABP or biABP of this embodiment to ULRA1 and ULRA3 is higher than 50 nM, more preferably higher lOOnm, more preferably higher than 500 nM, and most preferably higher than 1000 nM, also as measured using BU under conditions described herein in the example section.

[0174] Specifically preferred bispecific antibodies are the following:In particularly preferred embodiment, the invention pertains to a bispecific antibody comprising a first antigen binding site specifically binding to ULRB1 / 2 and a second antigen binding site specifically binding to PD-1 or PD-L1, whereinthe first binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-010, such as shown in Table B by row CDRs-A-010 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 73, 74 and 75, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 77, 78 and 79, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. And wherein the second binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences of known PD-1 or PD-L1 antibodies, such as in particular pembrolizumab, and most preferably as contained in SEQ ID NO: 396 (pembrolizumab heavy chain variable sequence) and SEQ ID NO: 397 (pembrolizumab light chain variable sequence). Preferably, such bispecific antibody is a tetravalent antibody, having for each binding specificity two binding sites. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. In particular preferred embodiments, the bispecific antibody comprises the full variable chain sequences of the aforementioned antibody (both LILRB1 / 2 and PD-1 / PD-L1), in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0175] In particularly preferred embodiment, the invention pertains to a bispecific antibody comprising a first antigen binding site specifically binding to LILRB1 / 2 and a second antigen binding site specifically binding to PD-1 or PD-L1, wherein the first binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-026, such as shown in Table B by row CDRs-A-026 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 201, 202 and 203, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos 205, 206 and 207, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. And wherein the second binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences of known PD-1 or PD-L1 antibodies, such as in particular pembrolizumab, and most preferably as contained in SEQ ID NO: 396 (pembrolizumab heavy chain variable sequence) and SEQ ID NO: 397 (pembrolizumab light chain variable sequence). Preferably, such bispecific antibody is a tetravalent antibody, having for each binding specificity two binding sites. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. In particular preferred embodiments, the bispecific antibody comprises the foil variable chain sequences of the aforementioned antibody (both LILRB1 / 2 and PD-1 / PD-L1), in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0176] In particularly preferred embodiment, the invention pertains to a bispecific antibody comprising a first antigen binding site specifically binding to LILRB1 / 2 and a second antigen binding site specifically binding to PD-1 or PD-L1, wherein the first binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-045, such as shown in Table B by row CDRs-A-045 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 353, 354, and 355, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 357, 358, and 359, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. And wherein the second binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences of known PD-1 or PD-L1 antibodies, such as in particular pembrolizumab, and most preferably as contained in SEQ ID NO: 396 (pembrolizumab heavy chain variable sequence)and SEQ ID NO: 397 (pembrolizumab light chain variable sequence). Preferably, such bispecific antibody is a tetravalent antibody, having for each binding specificity two binding sites. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. In particular preferred embodiments, the bispecific antibody comprises the foil variable chain sequences of the aforementioned antibody (both LILRB1 / 2 and PD-1 / PD-L1), in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0177] In particularly preferred embodiment, the invention pertains to a bispecific antibody comprising a first antigen binding site specifically binding to LILRB1 / 2 and a second antigen binding site specifically binding to PD-1 or PD-L1, wherein the first binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-046, such as shown in Table B by row CDRs-A-046 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 361, 362, and 363, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 365, 366, and 367, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. And wherein the second binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences of known PD-1 or PD-L1 antibodies, such as in particular pembrolizumab, and most preferably as contained in SEQ ID NO: 396 (pembrolizumab heavy chain variable sequence) and SEQ ID NO: 397 (pembrolizumab light chain variable sequence). Preferably, such bispecific antibody is a tetravalent antibody, having for each binding specificity two binding sites. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. In particular preferred embodiments, the bispecific antibody comprises the foil variable chain sequences of the aforementioned antibody (both LILRB1 / 2 and PD-1 / PD-L1), in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0178] In particularly preferred embodiment, the invention pertains to a bispecific antibody comprising a first antigen binding site specifically binding to LILRB1 / 2 and a second antigen binding site specifically binding to PD-1 or PD-L1, wherein the first binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-047, such as shown in Table B by row CDRs-A-047 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 369, 370, and 371, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 373, 374, and 375, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. And wherein the second binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences of known PD-1 or PD-L1 antibodies, such as in particular pembrolizumab, and most preferably as contained in SEQ ID NO: 396 (pembrolizumab heavy chain variable sequence) and SEQ ID NO: 397 (pembrolizumab light chain variable sequence). Preferably, such bispecific antibody is a tetravalent antibody, having for each binding specificity two binding sites. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. In particular preferred embodiments, the bispecific antibody comprises the foil variable chain sequences of the aforementioned antibody (both LILRB1 / 2 and PD-1 / PD-L1), in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0179] In particularly preferred embodiment, the invention pertains to a bispecific antibody comprising a first antigen binding site specifically binding to LILRB1 / 2 and a second antigen binding site specifically binding to PD-1 or PD-L1, wherein the first binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences in the combination shown by antibody A-048, such as shown in Table B by row CDRs-A-048 (eg, heavy chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 377, 378, and 379, respectively, and light chain CDR1, CDR2 and CDR3 having a sequence shown by SEQ ID Nos, 381, 382, and 383, respectively), in each CDR independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences. And wherein the second binding site comprises a combination of heavy chain CDR1, CDR2 and CDR3 sequences and a combination of light chain CDR1, CDR2 and CDR3 sequences of known PD-1 or PD-L1 antibodies, such as in particular pembrolizumab, and most preferably as contained in SEQ ID NO: 396 (pembrolizumab heavy chain variable sequence) and SEQ ID NO: 397 (pembrolizumab light chain variable sequence). Preferably, such bispecific antibody is a tetravalent antibody, having for each binding specificity two binding sites. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. Most preferably, the first binding site of the bispecific antibody is an scFv, and the second binding site is an IgG. In particular preferred embodiments, the bispecific antibody comprises the foil variable chain sequences of the aforementioned antibody (both LILRB1 / 2 and PD-1 / PD-L1), in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0180] More particularly, provided is a bispecific antibody comprising a first antigen-binding site that specifically binds to LILRB1 and LILRB2 (as a cross-specific binding site) and a second antigen-binding site that specifically binds to PD- 1, wherein said second antigen-binding site specifically binding to PD-1 comprises a VH domain comprising the amino acid seouence of a known anti-PD-1 antibody, preferably a VH domain comprising the amino acid seouence of SEO ID NO: 396 and a VL domain comprising the amino acid seouence of the known anti-PD-1 antibody, more preferably a VL domain comprising the amino acid seouence of SEO ID NO: 397, and said first antigen-binding site specifically binding to ULRB1 / ULRB2 comprises a VH and a VL each comprising the seouence as indicated for one of the antibodies in Table C (and in the therein shown combination): more preferably wherein said first antigen-binding site specifically binding to LILRB1 / ULRB2 comprises• a VH domain comprising the amino acid seouence of SEO ID NO: 76 and a VL domain comprising the amino acid seouence of SEO ID NO: 80: or• a VH domain comprising the amino acid seouence of SEO ID NO: 204 and a VL domain comprising the amino acid seouence of SEO ID NO: 208: or• a VH domain comprising the amino acid seouence of SEO ID NO: 348 and a VL domain comprising the amino acid seouence of SEO ID NO: 352: or• a VH domain comprising the amino acid seouence of SEO ID NO: 356 and a VL domain comprising the amino acid seouence of SEO ID NO: 360: or• a VH domain comprising the amino acid seouence of SEO ID NO: 364 and a VL domain comprising the amino acid seouence of SEO ID NO: 368: or• a VH domain comprising the amino acid seouence of SEO ID NO: 372 and a VL domain comprising the amino acid seouence of SEO ID NO: 376: or• a VH domain comprising the amino acid seouence of SEO ID NO: 380 and a VL domain comprising the amino acid seouence of SEO ID NO: 384.

[0181] One preferred example of a bispecific antibody of the present invention is composed of a heavy chain antibody sequence as shown in SEQ ID NO: 398, and a light chain antibody sequence shown in SEQ ID NO: 399.

[0182] The ABP or biABP of the invention are preferably ABP or biABP that show the advantageous on target off target profile as shown in the example section. In particular, the invention pertains to an ABP or biABP that is crossspecific for a binding to ULRB1 and ULRB2, but that does not bind to, or binds significantly less to ULRA1 and / or ULRA2. Hence, the ABP or biABP of the invention are characterized by maintaining cross-specificity, while not being able to bind to their off targets in the ULRA receptor family, specifically not to, or significantly less to, ULRA1 and ULRA3.

[0183] Specific embodiments of the ABP or biABP of the invention also pertain to an ABP or biABP, wherein the ABP or biABP binds to the ECD of ULRB1 and LILRB2 with at least 5 times higher, or preferably 10 times higher binding affinity compared the binding of the ABP or biABP to an ECD of LILRA1 and / or ULRA3, preferably wherein the ABP or biABP binding affinity is determined by bio-layer interferometry (BLI).

[0184] Further, in some additional or alternative embodiments, the ABP or biABP of the invention binds to the ECD of LILRB1 and / or ULRB2 with a binding dissociation constant (KD) that is at least 2 times lower, preferably 3 times lower, more preferably 5 times lower, most preferably 10 times lower, compared to the binding KD of the ABP or biABP to an ECD of ULRA1 and / or LILRA3, wherein the KD is determined by bio-layer interferometry (BU), preferably under the conditions set out in example 3 herein below.

[0185] Yet another embodiment of the invention pertains to an ABP or biABP, wherein the ABP or biABP binds to an ECD of ULRB1 and ULRB2 with a dissociation constant (KD) that is at least 2 times lower, preferably 3 times lower, more preferably 5 times lower, most preferably 10 times lower, compared to the KD of the ABP or biABP to an ECD of ULRA1 and ULRA3, wherein the KD is determined by bio-layer interferometry (BU), preferably under the conditions set out in example 3.

[0186] Specific embodiments of the invention pertain to such antibodies with the above characterized binding profile to LILRB1 and ULRB2 as well as LILRA1 and LILRA3 (non-binging thereof, or lower binding), wherein such ABP or biABP of the invention comprises one, preferably two, an antibody heavy chain sequence and one, preferably two, antibody light chain sequence, and wherein the antibody heavy chain sequence and the antibody light chain sequence are derived from one or a combination of the antibody parental clones A-001 to A-003, preferably from A-001 and / or A-003. Further preferably, the ABP or biABP comprises comprises one, preferably two, an antibody heavy chain variable sequence and one, preferably two, antibody light chain variable sequence, wherein the antibody heavy and light chain variable sequence each comprise a sequence that is at least 90%, preferably at least 95%, more preferably at least 96%, 97%, 98%, 99% identical to an antibody heavy or light chain variable sequence shown for any of the parental antibody sequences A-001 to A-003, preferably A-001 and / or A-003 (see Table 1 herein below).

[0187] In further embodiments of the invention, the ABP or biABP of the invention is preferred in embodiments, wherein the ABP or biABP competes for binding to an ECD of LILRB1 and / or ULRB2, or to ECD of the variant of LILRB1 and / or ULRB2, with an endogenous ULRB1 and / or ULRB2 ligand or receptor, preferably wherein said endogenous ULRB1 and / or ULRB2 ligand or receptor is a HLA-G protein (or a variant of HLA-G)

[0188] Specifically, such ABPs or biABPs of the invention are preferred that are characterized in that the lowest affinity selected from the two binding affinities of the group consisting of the binding affinity of the ABP or biABP to the ECD of ULRB1 and the binding affinity of the ABP or biABP to the ECD ofLILRB2,such lowest binding affinity is still at least 2 times higher than, or preferably at least 3 times higher (in some embodiments at least 5 times higher, more preferably at least 10 times higher) than the highest binding affinity out of the binding affinities of the ABP or biABP to an ECD of the off targets such as ULRA1 and LILRA3. In other words, an ABP or biABP is preferred that is characterized in that the highest KD with respect to the KDs of such ABP or biABP to ULRB1 and LILRB2 is still 2 times lower, preferably 3 times lower (in some embodiments at least 5 times lower, more preferably at least 10 times lower) than the lowest KD out of the two KDs of such ABP or biABP to ULRA1 and ULRA3.

[0189] Further aspects and embodiments of ABPs or biABPs of the invention

[0190] In a second aspect, the invention relates to an ABP or biABP which competes with an ABP or biABP of a first aspect for binding to LILRB1 and / or LILRB2 protein (eg to the ECD of LJLRBl and / or LILRB2 protein) or variant thereof, in particular can relate to an ABP or biABP that competes with one of the particularly preferred ABPs or biABPs described above for binding to the LILRB1 and / or LILRB2 protein or variant.

[0191] The term "compete" when used in the context of ABPs or biABPs (e.g., modulator ABPs or biABPs) that compete for binding for the same antigen (or epitope displayed by such antigen) means competition between ABPs or biABPs as may be determined by an assay in which the ABP or biABP (e.g., antibody or binding fragment thereof) being tested prevents or inhibits (e.g., reduces) binding of a reference ABP or biABP (e.g., a ligand, or a reference antibody) to a common antigen (e.g., LJLRBl and / or LILRB2 or a fragment thereof such as an ECD of LJLRBl and / or LILRB2).

[0192] In a related aspect, the invention relates to an ABP or biABP which binds to the same epitope as an ABP or biABP of a first aspect.

[0193] ABPs or biABPs of a second aspect of the invention may include one or more features (or specific combinations thereof) of the ABPs or biABPs described above. In particular, an ABP or biABP of a second aspect of the invention may be capable of inhibiting (eg inhibits) the binding of a natural ligand of LILRB1 and / or LLLRB2 protein, such as described in more details above, and / or an ABP or biABP of a second aspect of the invention may modulate the expression, function, activity and / or stability of LILRB1 and / or LILRB2, or the variant of LJLRBl and / or LLLRB2 (such as in anyway described elsewhere herein).

[0194] In particular embodiments of the invention, as well as (or instead of) an ABP or biABP of the invention's capability to inhibit (eg block) the interaction between LJLRBl and / or LLLRB2 protein or a variant thereof, and binding of a natural ligand of LILRB1 and / or LILRB2 protein; an ABP or biABP of the invention (including those of a first or second aspect as above) may display, exhibit or otherwise possess other functional features, in particular those which are associated with their utility in sensitising cells to a cell-mediated immune response.

[0195] In further of such particular embodiments, an ABP or biABP of the invention is capable of antagonizing immune-suppressive macrophage polarization, such as a polarization into M2 macrophages, and thereby to enhance cell-mediated immune responses. Such enhancement can be assessed, for example, using a suitable assay such as one described in Example 6 hereof.

[0196] The term "immune cell" is art recognised to describe any cell of an organism involved in the immune system of such organism, in particular of a mammal such as a human. Leukocytes (white blood cells) are immune cells that are involved in the innate immune system, and the cells of the adaptive immune system are special types of leukocytes, known as lymphocytes. B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow. B cells are involved in the humoral immune response, whereas T cells are involved in cell-mediated immune response. In preferred embodiments of the invention, the immune cell can be a myeloid cell eg a T cell, and in particular (such as when an increase in cell-mediated immune response is required, such as to treat a cancer) the T cell can be a cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell). A CTL is a T-cell that is involved in the killing of cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways. Other preferred immune cells for such embodiments can include Tumour-Infiltrating Lymphocytes (TILs). TILs are white blood cells that have left the bloodstream and migrated into a tumour. Typically, TILs are a mix of different types of cells (i.e., T cells, B cells, NK cells) in variable proportions, T cells being the most abundant cells. TILs can often be found in the stroma and within the tumour itself, and are implicated in killing tumour cells. The presence of lymphocytes in tumours is often associated with better clinical outcomes.

[0197] Other particular functional characteristics of an ABP or biABP of the invention may be that of: (i) enhancing a cell-mediated immune response, such as that mediated by an activated cytotoxic T-cell (CTL), to a mammalian cellexpressing said LJLRBl and / or LLLRB2 or the variant of LJLRBl and / or LLLRB2; and / or (ii) increasing immune cell, such as T-cell, activity and / or survival (and / or proliferation) in the presence of a mammalian cell expressing said LILRB1 and / or LLLRB2 or the variant of LILRB1 and / or LLLRB2. In some embodiments, the mammalian cell expressing the LJLRBl and / or LLLRB2 may be a cell associated with a disease, disorder or condition such as a cancer cell being (directly) associated with the cancer. In other the mammalian cell expressing the LJLRBl and / or LLLRB2 may be an immune cell, such as a T cell (see below), for example an immune cell that is directly or indirectly associated with the disease, disorder or condition.

[0198] Other particular functional characteristics of an ABP or biABP of the invention that is an inhibitor or antagonist of LILRB1 and / or LLLRB2 expression, function, activity and / or stability can be any one, or a combination or at least one, functional characteristic of the inhibiting or antagonistic modulators described herein, in particular in the section above "Modulators of LILRB1 and / or LILRB2 expression, function, activity and / or stability".

[0199] Those particular functional characteristics of an ABP or biABP of the invention that is an activator or agonist of LILRB1 and / or LLLRB2 expression, function, activity and / or stability can be any one, or a combination or at least one, functional characteristic of the activating or agonistic modulators described herein, in particular in the section above "Modulators of LILRB1 and / or LILRB2 expression, function, activity and / or stability".

[0200] In preferred embodiments of all ABPs or biABPs of the invention, the ABP or biABP is isolated and / or substantially pure.

[0201] The term "isolated" as used herein in the context of a protein, such as an ABP or biABP (an example of which could be an antibody), refers to a protein that is purified from proteins or polypeptides or other contaminants that would interfere with its therapeutic, diagnostic, prophylactic, research or other use. An isolated ABP or biABP according to the invention may be a recombinant, synthetic or modified (non-natural) ABP or biABP. The term "isolated" as used herein in the context of a nucleic acid or cells refers to a nucleic acid or cells that is / are purified from DNA, RNA, proteins or polypeptides or other contaminants (such as other cells) that would interfere with its therapeutic, diagnostic, prophylactic, research or other use, or it refers to a recombinant, synthetic or modified (non-natural) nucleic acid. Preferably an isolated ABP or biABP or nucleic acid or cells is / are substantially pure. In this context, a "recombinant" protein or nucleic acid is one made using recombinant techniques. Methods and techniques for the production of recombinant nucleic acids and proteins are well known in the art.

[0202] The term "isolated" as used herein in the context of a protein, such as an ABP or biABP (an example of which could be an antibody), refers to a protein that is purified from proteins or polypeptides or other contaminants that would interfere with its therapeutic, diagnostic, prophylactic, research or other use. An isolated ABP or biABP according to the invention may be a recombinant, synthetic or modified (non-natural) ABP or biABP. The term "isolated" as used herein in the context of a nucleic acid or cells refers to a nucleic acid or cells that is / are purified from DNA, RNA, proteins or polypeptides or other contaminants (such as other cells) that would interfere with its therapeutic, diagnostic, prophylactic, research or other use, or it refers to a recombinant, synthetic or modified (non-natural) nucleic acid. Preferably an isolated ABP or biABP or nucleic acid or cells is / are substantially pure. In this context, a "recombinant" protein or nucleic acid is one made using recombinant techniques. Methods and techniques for the production of recombinant nucleic acids and proteins are well known in the art.

[0203] In some embodiments, an ABP or biABP of the invention may bind to (e.g., via one or more epitope(s) displayed by one or more EC domain(s) of) LJLRBl and / or LLLRB2 or a paralogue, orthologue or other variant thereof (such as any LILRB1 and / or LILRB2 or variant described herein) with a KD that is less than 20nM, such as less than about lOnM, 5nM or 2nM (in particular, less than about 1 nM). In a preferred embodiment, the ABP or biABP of the invention will bind (e.g. said epitope(s) of) said LJLRBl and / or LILRB2 or variant with a KD that is less than 100 pM. In a more preferred embodiment, the ABP or biABP of the invention will bind said LILRB1 and / or LLLRB2 or variant with a KD that is less than 10 pM. In a most preferred embodiment, the ABP or biABP of the invention will bind saidULRB1 and / or LILRB2 or variant with a KD that is less than 2 pM. Binding of an ABP or biABP of the invention, such as an antibody of the invention, to a human cell line expressing said LILRB1 and / or ULRB2 or variant may, in some embodiments, occur at an EC50 of less than about lOpg / mL, 5pg / mL, 2pg / mL, lpg / mL, 0.5pg / mL or 0.2pg / mL, preferably with an EC50 of less than 2pg / mL. Binding of an ABP or biABP of the invention, such as an antibody of the invention, to a Cynomolgus cell line expressing an orthologue of said ULRB1 and / or LILRB2 or variant may, in some embodiments, occur at an EC50 of less than about lOpg / mL, 5pg / mL, 2pg / mL, lpg / mL, 0.5pg / mL or 0.2pg / mL, preferably with an EC50 of less than 2pg / mL.

[0204] In other embodiments, an ABP or biABP of the invention may: (i) bind to the ULRB1 and / or LILRB2, or to the variant of LILRB1 and / or ULRB2, with a KD that is less than 20nM, such as less than about lOnM, 5nM or 2nM (in particular, less than about 1 nM), is less than 100 pM, or is less than 10 pM; and / or (ii) binds to a human cell line expressing the LILRB1 and / or ULRB2 or the variant of LILRB1 and / or ULRB2 with an EC50 of less than 2ug / mL.

[0205] In some embodiments, an ABP or biABP of the invention may not bind to LILRB counter targets LILRAs, such as specifically not to LILRA1 and ULRA3, or a orthologue or other variant thereof. In alternative embodiments, the ABP or biABP of the invention binds to one or more, or any of, a ULRA protein (preferably an ECD thereof) with a KD that at least 2 fold higher than the KD of its binding to LILRB1 and / or ULRB2, more preferably with a KD that is at least 3 fold, 4 fold 5 or 10 fold higher. In other such embodiments, the ABP or biABP of the invention binds to an ULRA protein with a KD of more than lOOnM, preferably more than 50nm, even more preferably of more than 20nM.

[0206] The term "KD", as used herein, is intended to refer to the dissociation constant, which is obtained from the ratio of Kd to Ka (i. e., Kd / Ka) and is expressed as a molar concentration (M). KD values for antibodies can be determined using methods well established in the art such as plasmon resonance (BIAcore®), ELISA and KINEXA. A preferred method for determining the KD of an antibody is by using surface plasmon resonance, preferably using a biosensor system such as a BIAcore® system or by EUSA. Another preferred method of the present invention to determine KD values for ABPs or biABPs of the invention is by bio-layer interferometry (BU), such as using the Octet Red® system. Conditions for measuring binding affinities of the ABP or biABP of the invention can be derived from the example section herein. "Ka" (or "K-assoc"), as used herein, refers broadly to the association rate of a particular antibody-antigen interaction, whereas the term "Kd" (or "K-diss"), as used herein, refers to the dissociation rate of a particular antibody-antigen interaction.

[0207] In yet other embodiments, an ABP or biABP of the invention may compete for binding to ULRB1 and / or ULRB2, or to the variant of LILRB1 and / or ULRB2, with an endogenous LILRB1 and / or ULRB2 ligand or receptor, preferably wherein said endogenous ULRB1 and / or LILRB2 ligand or receptor is HLA-G (or a variant of HLA-G). For example, in certain of such embodiments, the ABP or biABP of the invention (eg one that binds to [one or more epitope(s) displayed by] an extracellular domain(s) of ULRB1 and / or LILRB2, or a paralogue, orthologue or other variant thereof) is capable of inhibiting (eg will inhibit) the binding of HLA-G protein or a variant thereof to ULRB1 and / or ULRB2 protein or a variant thereof with an IC50 of lOOnM or less, 50nM or less, or preferably 20nM or less, such as 15nM or less, lOnM or less, 5nM or less, 2nM or less, InM or less. In particular of such embodiments, an ABP or biABP of the invention is capable of inhibiting (eg will inhibit) the binding of HLA-G protein or a variant thereof to ULRB1 and / or ULRB2 protein or a variant thereof with an IC50 of lOnM or less, such as 5nM or less and preferably 2nM or less.

[0208] In one embodiment, an ABP or biABP of the invention is a polyclonal antibody (mixture), or the antigen binding fragment is a fragment of a polyclonal antibody (mixture).

[0209] In an alternative, and preferred, embodiment of all ABPs or biABPs of the invention, the ABP or biABP is an antibody or an antigen binding fragment thereof, and the antibody is a monoclonal antibody, or wherein the antigen binding fragment is a fragment of a monoclonal antibody.

[0210] The term "monoclonal antibody" or "mAb" as used herein refers to an antibody obtained from a population of substantially identical antibodies based on their amino acid sequence. Monoclonal antibodies are typically highly specific. Furthermore, in contrast to conventional (polyclonal) antibody preparations which typically include different antibodies directed against different determinants (e.g. epitopes) of an antigen, each mAb is typically directed against a single determinant on the antigen. In addition to their specificity, mAbs are advantageous in that they can be synthesized by cell culture (hybridomas, recombinant cells or the like) uncontaminated by other immunoglobulins. The mAbs herein include for example chimeric, humanized or human antibodies or antibody fragments.

[0211] Monoclonal antibodies in accordance with the present invention may be prepared by methods well known to those skilled in the art. For example, mice, rats or rabbits may be immunized with an antigen of interest together with adjuvant. Splenocytes are harvested as a pool from the animals that are administered several immunisations at certain intervals with test bleeds performed to assess for serum antibody titers. Splenocytes are prepared that are either used immediately in fusion experiments or stored in liquid nitrogen for use in future fusions. Fusion experiments are then performed according to the procedure of Stewart & Fuller, J. Immunol. Methods 1989, 123:45-53. Supernatants from wells with growing hybrids are screened by eg enzyme-linked immunosorbent assay (ELISA) for mAb secretors. ELISA- positive cultures are cloned either by limiting dilutions or fluorescence-activated cell sorting, typically resulting in hybridomas established from single colonies. The ability of an antibody, including an antibody fragment or subfragment, to bind to a specific antigen can be determined by binding assays known in the art, for example, using the antigen of interest as the binding partner.

[0212] In a further preferred embodiment, an ABP or biABP of the invention is an antibody or an antigen binding fragment thereof, wherein the antibody is a human antibody a humanised antibody or a chimeric-human antibody, or wherein the antigen binding fragment is a fragment of a human antibody a humanised antibody or a chimeric-human antibody.

[0213] Human antibodies can also be derived by in vitro methods. Suitable examples include but are not limited to phage display (CAT, Morphosys, Dyax, Biosite / Medarex, Xoma, Yumab, Symphogen, Alexion, Affimed) and the like. In phage display, a polynucleotide encoding a single Fab or Fv antibody fragment is expressed on the surface of a phage particle (see e.g., Hoogenboom et al., J. Mol. BioL, 227: 381 (1991); Marks et aL, J Mol Biol 222: 581 (1991); U.S. Patent No. 5,885,793). Phage are "screened" to identify those antibody fragments having affinity for target. Thus, certain such processes mimic immune selection through the display of antibody fragment repertoires on the surface of filamentous bacteriophage, and subsequent selection of phage by their binding to target. In certain such procedures, high affinity functional neutralizing antibody fragments are isolated. A complete repertoire of human antibody genes may thus be created by cloning naturally rearranged human V genes from peripheral blood lymphocytes (see, e.g., Mullinax et al., Proc Natl Acad Sci (USA), 87: 8095-8099 (1990)) or by generating folly synthetic or semi-synthetic phage display libraries with human antibody sequences (see Knappik et al 2000; J Mol Biol 296:57; de Kruif et al, 1995; J Mol Biol 248): 97).

[0214] The antibodies described herein may alternatively be prepared through the utilization of the XenoMouse® technology. Such mice are capable of producing human immunoglobulin molecules and antibodies and are deficient in the production of murine immunoglobulin molecules and antibodies. In particular, a preferred embodiment of transgenic production of mice and antibodies is disclosed in U.S. Patent Application Serial No. 08 / 759,620, filed December 3, 1996 and International Patent Application Nos. WO 98 / 24893, published June 11, 1998 and WO 00 / 76310, published December 21, 2000. See also Mendez et aL, Nature Genetics, 15:146-156 (1997). Through the use of such technology, fully human monoclonal antibodies to a variety of antigens have been produced. Essentially, XenoMouse® lines of mice are immunized with an antigen of interest, e.g. ULRB1 and / or ULRB2, lymphatic cells (such as B-cells) are recovered from the hyper-immunized mice, and the recovered lymphocytes are fused with a myeloid-type cell line to prepare immortal hybridoma cell lines. These hybridoma cell lines are screened and selected to identify hybridoma cell linesthat produce antibodies specific to the antigen of interest. Other "humanised" mice are also commercially available: eg, Medarex - HuMab mouse, Kymab - Kymouse, Regeneron - Velocimmune mouse, Kirin -TC mouse, Trianni -Trianni mouse, OmniAb - OmniMouse, Harbour Antibodies - H2L2 mouse, Merus - MeMo mouse. Also are available are "humanised" other species: rats: OmniAb - OmniRat, OMT - UniRat. Chicken: OmniAb - OmniChicken.

[0215] The term "humanised antibody" according to the present invention refers to immunoglobulin chains or fragments thereof (such as Fab, Fab', F(ab')2, Fv, or other antigen-binding sub-sequences of antibodies), which contain minimal sequence (but typically, still at least a portion) derived from non-human immunoglobulin. For the most part, humanised antibodies are human immunoglobulins (the recipient antibody) in which CDR residues of the recipient antibody are replaced by CDR residues from a non-human species immunoglobulin (the donor antibody) such as a mouse, rat or rabbit having the desired specificity, affinity and capacity. As such, at least a portion of the framework sequence of said antibody or fragment thereof may be a human consensus framework sequence. In some instances, Fv framework residues of the human immunoglobulin need to be replaced by the corresponding non-human residues to increase specificity or affinity. Furthermore, humanised antibodies can comprise residues which are found neither in the recipient antibody nor in the imported CDR or framework sequences. These modifications are made to further refine and maximise antibody performance. In general, the humanised antibody will comprise substantially all of at least one, and typically at least two, variable domains, in which all or substantially all of the CDR regions correspond to those of a non-human immunoglobulin and all or substantially all of the framework regions are those of a human immunoglobulin consensus sequence. The humanised antibody optimally also will comprise at least a portion of an immunoglobulin constant region, typically that of a human immunoglobulin, which (eg human) immunoglobulin constant region may be modified (eg by mutations or glycoengineering) to optimise one or more properties of such region and / or to improve the function of the (eg therapeutic) antibody, such as to increase or reduce Fc effector functions or to increase serum half-life. Exemplary such Fc modification (for example, Fc engineering or Fc enhancement) are described elsewhere herein.

[0216] The term "chimeric antibody" according to the present invention refers to an antibody whose light and / or heavy chain genes have been constructed, typically by genetic engineering, from immunoglobulin variable and constant regions which are identical to, or homologous to, corresponding sequences of different species, such as mouse and human. Alternatively, variable region genes derive from a particular antibody class or subclass while the remainder of the chain derives from another antibody class or subclass of the same or a different species. It covers also fragments of such antibodies. For example, a typical therapeutic chimeric antibody is a hybrid protein composed of the variable or antigen-binding domain from a mouse antibody and the constant or effector domain from a human antibody, although other mammalian species may be used.

[0217] In particular of such embodiments, an ABP or biABP of the invention comprises an antigen binding domain of an antibody wherein the antigen binding domain is of a human antibody. Preferably, ABP or biABP comprises an antigen binding domain of an antibody or an antigen binding fragment thereof, which is a human antigen binding domain; (ii) the antibody is a monoclonal antibody, or wherein the antigen binding fragment is a fragment of a monoclonal antibody; and (iii) the antibody is a human antibody or a humanised antibody, or wherein the antigen binding fragment is a fragment of a human antibody, a humanised antibody or a chimeric-human antibody.

[0218] Light chains of human antibodies generally are classified as kappa and lambda light chains, and each of these contains one variable region and one constant domain. Heavy chains are typically classified as mu, delta, gamma, alpha, or epsilon chains, and these define the antibody's isotype as IgM, IgD, IgG, IgA, and IgE, respectively. Human IgG has several subtypes, including, but not limited to, IgGl, lgG2, lgG3, and lgG4. Human IgM subtypes include IgM, and lgM2. Human IgA subtypes include IgAl and lgA2. In humans, the IgA and IgD isotypes contain four heavy chains and four light chains; the IgG and IgE isotypes contain two heavy chains and two light chains; and the IgM isotypecontains ten or twelve heavy chains and ten or twelve light chains. Antibodies according to the invention may be IgG, IgE, IgD, IgA, or IgM immunoglobulins.

[0219] In some embodiments, the ABP or biABP of the invention is an IgG antibody or fragment thereof. In some embodiments, the ABP or biABP of the invention is an IgE antibody or fragment thereof. In some embodiments, the ABP or biABP of the invention is an IgD antibody or fragment thereof. In some embodiments, the ABP or biABP of the invention is an IgA antibody or fragment thereof. In some embodiments, the ABP or biABP of the invention is an IgM antibody or fragment thereof. Preferably the ABP or biABP of the invention is, comprises or is derived from an IgG immunoglobulin or fragment thereof; such as a human, human-derived IgG immunoglobulin, or a rabbit- or rat-derived IgG, and / or an IgG2 immunoglobulin, or fragment thereof. When the ABP or biABP of the invention is, comprises or is derived from a rat-derived IgG, then preferably, the ABP or biABP is, comprises or is derived from, a rat IgG2a or IgG2b immunoglobulin. When the ABP or biABP of the invention is, comprises or is derived from a human-derived IgG, then more preferably, the ABP or biABP of the invention is, comprises or is derived from a human IgGl, IgG2 or IgG4, most preferably, the ABP of the invention is, comprises or is derived from a human IgGl, IgG2, or IgG4.

[0220] Accordingly, in particular embodiments of the invention, an ABP is an antibody wherein the antibody is an IgG, IgE, IgD, IgA, or IgM immunoglobulin; preferably an IgG immunoglobulin.

[0221] An ABP of the invention, where comprising at least a portion of an immunoglobulin constant region (typically that of a human immunoglobulin) may have such (eg human) immunoglobulin constant region modified - for example eg by glycoengineering or mutations - to optimise one or more properties of such region and / or to improve the function of the (eg therapeutic) antibody, such as to increase or reduce Fc effector functions or to increase serum half-life.

[0222] ABPs or biABPs of the invention, in particular those useful in the present methods include antibodies that induce antibody-dependent cytotoxicity (ADCC) of ULRB1 and / or LJLRB2-expressing cells. The ADCC of an anti-LILRBl and / or LILRB2 antibody can be improved by using antibodies that have low levels of or lack fucose. Antibodies lacking fucose have been correlated with enhanced ADCC (antibody- dependent cellular cytotoxicity) activity, especially at low doses of antibody (Shields et ah, 2002, J. Biol. Chem. 277:26733-26740; Shinkawa et ah, 2003, J. Biol. Chem. 278:3466).

[0223] Methods of preparing fucose-less antibodies or antibodies with reduced fucose levels include growth in rat myeloma YB2 / 0 cells (ATCC CRL 1662). YB 2 / 0 cells express low levels of FUT8 mRNA, which encodes an enzyme (.alpha. 1,6- fucosyltransferase) necessary for focosylation of polypeptides.

[0224] Alternatively, during the expression of such antibodies, an inhibitor against an enzyme relating to the modification of a sugar chain may be used, including: tunicamycin which selectively inhibits formation of GIcNAc-P-P- Dol which is the first step of the formation of a core oligosaccharide which is a precursor of an N-glycoside-linked sugar chain, castanospermin and W-methyl-l-deoxynojirimycin which are inhibitors of glycosidase I, kifonensine which is an inhibitor of mannosidase I, bromocondulitol which is an inhibitor of glycosidase II, 1 - deoxynojirimycin and 1 ,4-dioxy- 1 ,4-imino-D-mannitol which are inhibitors of mannosidase I, swainsonine which is an inhibitor of mannosidase II and the like. Examples of an inhibitor specific for a glycosyltransferase include deoxy derivatives of substrates against N- acetylglucosamine transferase V (GnTV) and the like. Also, it is known that 1 -deoxynojirimycin inhibits synthesis of a complex type sugar chain and increases the ration of high mannose type and hybrid type sugar chains (Glycobiology series 2 -Destiny of Sugar Chain in Cell, edited by Katsutaka Nagai, Senichiro Hakomori and Akira Kobata, 1993).

[0225] Based on these data, several cell lines have been genetically engineered to produce antibodies containing no or low levels of fucose (Mori et al, 2004; Yamane-Ohnuki et al., 2004) to engineer the glycosylation patterns of IgG in order to select therapeutic monoclonal antibodies exhibiting particular profiles of Fc-gamma-R engagement that could be used in various pathologies.

[0226] Umana et al. and Davis et al. showed that an IgGl antibody engineered to contain increasing amounts of bisected complex oligosaccharides (bisecting A / -acetylglucosamine, GIcNAC) allows triggering a strong ADCC ascompared to its parental counterpart (Umana et aL, 1999; Davies et al., 2001 ). Second, a lack of fucose on human IgGl N-linked oligosaccharides has been shown to improve FCGRIII binding and ADCC.

[0227] GLYCART BIOTECHNOLOGY AG (Zurich, CH) has expressed N-acetyl-glucosaminyltransferase III (GnTIII) which catalyses the addition of the bisecting GIcNac residue to the N-linked oligosaccharide, in a Chinese hamster ovary (CHO) cell line, and showed a greater ADCC of IgGl antibody produced (WO 99 / 54342; WO 03 / 01 1878; WO 2005 / 044859).

[0228] W020070166306 is related to the modification of an antibody anti-CD19 containing 60% N-acetylglucosamine bisecting oligosaccharides and 10% non-fucosylated N-acetylglucosamine bisecting oligosaccharides produced in a mammalian human 293T embryonal kidney cells transfected with (i) the cDNA for the anti-CD19 antibody and (ii) the cDNA for the GnTIII enzyme.

[0229] Recombinant human IgGl produced in YB2 / 0 cells (Shinkawa et aL, 2003; Siberil et aL, 2006) or in CHO-Lecl3 (Shields et aL, 2002) which exhibited a low-focose content or were deficient in fucose as compared to the same IgGl produced in wild-type CHO cells, showed an enhanced ability to trigger cellular cytotoxicity. By contrast, a correlation between galactose and ADCC was not observed and the content of bisecting GIcNAC only marginally affected ADCC (Shinkawa et al., 2003).

[0230] By removing or supplanting fucose from the Fc portion of the antibody, KYOWA HAKKO KOGYO (Tokyo, Japan) has enhanced Fc binding and improved ADCC, and thus the efficacy of the MAb (US 6,946,292). This improved Fc- gamma-RIIIA-dependent effector functions of low-focosylated IgG has been shown to be independent from Fc-gamma- RI 11 allelic form (Niwa et al., 2005). Moreover, it has been recently shown that the antigenic density required to induce an efficient ADCC is lower when the IgG has a low content in fucose as compared to a highly focosylated IgG (Niwa et al., 2005)

[0231] The Laboratoire Francais du Fractionnement et des Biotechnologies (LFB) (France) showed that the ratio Fuc / Gal in MAb oligosaccharide should be equal or lower than 0.6 to get antibodies with a high ADCC (FR 2 861 080).

[0232] Cardarelli et al., 2019 produce an anti-CD19 antibody in MS-704PF CHO cells deficient in the FUT8 gene which encodes alphal-1 ,6-focosyltransferase. Non-focosylation of the antibody in this paper requires the engineering of an enzyme-deficient cell line. This paper does not consider amino acid mutations.

[0233] Herbst et al. generated a humanized IgGl MAb MEDI-551 expressed in a fucosyltransferase-deficient producer CHO cell line This paper does not consider amino acid mutations (Herbst et al., 2010).

[0049] S. Siberil et al used the rat myeloma YB2 / 0 cell line to produce a MAb anti RhD with a low fucose content. Whereas the MAb produced in a wild type CHO exhibited a high fucose content (81 %), the same MAb produced in YB2 / 0 cell exhibiited a lower fucose content (32%). This paper does consider amino acid mutations (Siberil et aL, 2006).

[0234] Accordingly, an ABP or biABP of the invention may be prepared and / or may have one or more of the characteristics of such glycoengineering (eg afocosylated) approaches / antibodies described above.

[0235] Alternative methods for increasing ADDC activity for an ABP or biABP of the invention include mutations in an Fc portion of such ABP or biABP, particularly mutations which increase antibody affinity for an Fc-gamma-R receptor.

[0236] Accordingly, any of the ABPs or biABPs of the invention described above can be produced with different antibody isotypes or mutant isotypes to control the extent of binding to different Fc-gamma receptors. Antibodies lacking an Fc region (e.g., Fab fragments) lack binding to different Fc-gamma receptors. Selection of isotype also affects binding to different Fc-gamma receptors. The respective affinities of various human IgG isotypes for the three different Fc-gamma receptors, Fc-gamma-RI, Fc- gamma-RII, and Fc- gamma-RIII, have been determined. (See Ravetch 8i Kinet, Annu. Rev. Immunol. 9, 457 (1991)). Fc- gamma-RI is a high affinity receptor that binds to IgGs in monomeric form, and the latter two are low affinity receptors that bind IgGs only in multimeric form. In general, both IgGl and IgG3 have significant binding activity to all three receptors, IgG4 to Fc-gamma-RI, and IgG2 to only one type of Fc-gamma-RII called IlaLR (see Parren et al., J. Immunol. 148, 695 (1992). Therefore, human isotype IgGl is usually selected for stronger binding to Fc-gamma receptors, and IgG2 or IgG4 is usually selected for weaker binding.

[0237] A correlation between increased Fc-gamma-R binding with mutated Fc has been demonstrated using targeted cytoxicity cell-based assays (Shields et ah, 2001, J. Biol. Chem. 276:6591-6604; Presta et ah, 2002, Biochem Soc. Trans. 30:487-490). Methods for increasing ADCC activity through specific Fc region mutations include the Fc variants comprising at least one amino acid substitution at a position selected from the group consisting of: 234, 235, 239, 240, 241, 243, 244, 245, 247, 262, 263, 264, 265, 266, 267, 269, 296, 297, 298, 299, 313, 325, 327, 328, 329, 330 and 332, wherein the numbering of the residues in the Fc region is that of the EU index as in Kabat (Kabat et ah, Sequences of Proteins of Immunological Interest (National Institute of Health, Bethesda, Md. 1987).

[0238] In certain specific embodiments, said Fc variants comprise at least one substitution selected from the group consisting of L234D, L234E, L234N, L234Q, L234T, L234H, L234Y, L234I, L234V, L234F, L235D, L235S, L235N, L235Q, L235T, L235H, L235Y, L235I, L235V, L235F, S239D, S239E, S239N, S239Q, S239F, S239T, S239H, S239Y, V240I, V240A, V240T, V240M, F241W, F241L, F241Y, F241E, F241R, F243W, F243L, F243Y, F243R, F243Q, P244H, P245A, P247V, P247G, V262I, V262A, V262T, V262E, V263I, V263A, V263T, V263M, V264L, V264I, V264W, V264T, V264R, V264F, V264M, V264Y, V264E, D265G, D265N, D265Q, D265Y, D265F, D265V, D265I, D265L, D265H, D265T, V266I, V266A, V266T, V266M, S267Q, S267L, E269H, E269Y, E269F, E269R, Y296E, Y296Q, Y296D, Y296N, Y296S, Y296T, Y296L, Y296I, Y296H, N297S, N297D, N297E, A298H, T299I, T299L, T299A, T299S, T299V, T299H, T299F, T299E, W313F, N325Q, N325L, N325I, N325D, N325E, N325A, N325T, N325V, N325H, A327N, A327L, L328M, L328D, L328E, L328N, L328Q, L328F, L328I, L328V, L328T, L328H, L328A, P329F, A330L, A330Y, A330V, A330I, A330F, A330R, A330H, I332D, I332E, I332N, I332Q, I332T, I332H, I332Y and I332A, wherein the numbering of the residues in the Fc region is that of the EU index as in Kabat.

[0239] Fc variants can also be selected from the group consisting of V264L, V264I, F241W, F241L, F243W, F243L,F241L / F243L / V262I / V264I, F241W / F243W, F241W / F243W / V262A / V264A, F241L / V262I, F243L / V264I,F243L / V262I / V264W, F241Y / F243Y / V262T / V264T, F241E / F243R / V262E / V264R, F241E / F243Q / V262T / V264E,F241R / F243Q / V262T / V264R, F241E / F243Y / V262T / V264R, L328M, L328E, L328F, I332E, L3238M / I332E, P244H, P245A, P247V, W313F, P244H / P245A / P247V, P247G, V264I / I332E, F241E / F243R / V262E / V264R / I332E,F241E / F243Q / V262T / 264E / I332E, F241R / F243Q / V262T / V264R / I332E, F241E / F243Y / V262T / V264R / I332E,S298A / I332E, S239E / I332E, S239Q / I332E, S239E, D265G, D265N, S239E / D265G, S239E / D265N, S239E / D265Q, Y296E, Y296Q, T299I, A327N, S267Q / A327S, S267L / A327S, A327L, P329F, A330L, A330Y, I332D, N297S, N297D, N297S / I332E, N297D / I332E, N297E / I332E, D265Y / N297D / I332E, D265Y / N297D / T299L / I332E, D265F / N297E / I332E, L328I / I332E, L328Q / I332E, I332N, I332Q, V264T, V264F, V240I, V263I, V266I, T299A, T299S, T299V, N325Q, N325L, N325I, S239D, S239N, S239F, S239D / I332D, S239D / I332E, S239D / I332N, S239D / I332Q, S239E / I332D, S239E / I332N, S239E / I332Q, S239N / I332D, S239N / I332E, S239N / I332N, S239N / I332Q, S239Q / I332D, S239Q / I332N, S239Q / I332Q, Y296D, Y296N, F241Y / F243Y / V262T / V264T / N297D / I332E, A330Y / I332E, V264I / A330Y / I332E, A330L / I332E, V264I / A330L / I332E, L234D, L234E, L234N, L234Q, L234T, L234H, L234Y, L234I, L234V, L234F, L235D, L235S, L235N, L235Q, L235T, L235H, L235Y, L235I, L235V, L235F, S239T, S239H, S239Y, V240A, V240T, V240M, V263A, V263T, V263M, V264M, V264Y, V266A, V266T, V266M, E269H, E269Y, E269F, E269R, Y296S, Y296T, Y296L, Y296I, A298H, T299H, A330V, A330I, A330F, A330R, A330H, N325D, N325E, N325A, N325T, N325V, N325H, L328D / I332E, L328E / I332E, L328N / I332E, L328Q / I332E, L328V / I332E, L328T / I332E, L328H / I332E, L328I / I332E, L328A, I332T, I332H, I332Y, I332A, S239E / V264I / I332E, S239Q / V264I / I332E, S239E / V264I / A330Y / I332E,S239E / V264I / S298A / A330Y / I332E, S239D / N297D / I332E, S239E / N297D / I332E, S239D / D265V / N297D / I332E,S239D / D265I / N297D / I332E, S239D / D265L / N297D / I332E, S239D / D265F / N297D / I332E, S239D / D265Y / N297D / I332E, S239D / D265H / N297D / I332E, S239D / D265T / N297D / I332E, V264E / N297D / I332E, Y296D / N297D / I332E,Y296E / N297D / I332E, Y296N / N297D / I332E, Y296Q / N297D / I332E, Y296H / N297D / I332E, Y296T / N297D / I332E,N297D / T299V / I332E, N297D / T299I / I332E, N297D / T299L / I332E, N297D / T299F / I332E, N297D / T299H / I332E, N297D / T299E / I332E, N297D / A330Y / I332E, N297D / S298A / A330Y / I332E, S239D / A330Y / I332E, S239N / A330Y / I332E, S239D / A330L / I332E, S239N / A330L / I332E, V264I / S298A / I332E, S239D / S298A / I332E, S239N / S298A / I332E, S239D / V264I / I332E, S239D / V264I / S298A / I332E, and S239D / 264I / A330L / I332E, wherein the numbering of the residues in the Fc region is that of the EU index as in Kabat. See also W02004029207, incorporated by reference herein.

[0240] In particular embodiments, mutations on, adjacent, or close to sites in the hinge link region (e.g., replacing residues 234, 235, 236 and / or 237 with another residue) can be made, in all of the isotypes, to reduce affinity for Fc- gamma receptors, particularly Fc-gamma-RI receptor (see, eg US6624821). Optionally, positions 234, 236 and / or 237 are substituted with alanine and position 235 with glutamate. (See, eg US5624821.) Position 236 is missing in the human IgG2 isotype. Exemplary segments of amino acids for positions 234, 235 and 237 for human IgG2 are Ala Ala Gly, Vai Ala Ala, Ala Ala Ala, Vai Glu Ala, and Ala Glu Ala. A preferred combination of mutants is L234A, L235E and G237A, or is L234A, L235A, and G237A for human isotype IgGl. A particular preferred ABP or biABP of the invention is an antibody having human isotype IgGl and one of these three mutations of the Fc region. Other substitutions that decrease binding to Fc-gamma receptors are an E233P mutation (particularly in mouse IgGl) and D265A (particularly in mouse IgG2a). Other examples of mutations and combinations of mutations reducing Fc and / or Clq binding are E318A / K320A / R322A (particularly in mouse IgGl), L235A / E318A / K320A / K322A (particularly in mouse IgG2a). Similarly, residue 241 (Ser) in human IgG4 can be replaced, eg with proline to disrupt Fc binding.

[0241] Additional mutations can be made to a constant region to modulate effector activity. For example, mutations can be made to the IgGl or IgG2 constant region at A330S, P331S, or both. For IgG4, mutations can be made at E233P, F234V and L235A, with G236 deleted, or any combination thereof. IgG4 can also have one or both of the following mutations S228P and L235E. The use of disrupted constant region sequences to modulate effector function is further described, eg in WO2006118,959 and W02006036291.

[0242] Additional mutations can be made to the constant region of human IgG to modulate effector activity (see, e.g., W0200603291). These include the following substitutions: (i) A327G, A330S, P331S; (ii) E233P, L234V, L235A, G236 deleted; (iii) E233P, L234V, L235A; (iv) E233P, L234V, L235A, G236 deleted, A327G, A330S, P331S; and (v) E233P, L234V, L235A, A327G, A330S, P331S to human IgGl; or in particular, (vi) L234A, L235E, G237A, A330S and P331S (eg, to human IgGl), wherein the numbering of the residues in the Fc region is that of the EU index as in Kabat. See also W02004029207, incorporated by reference herein.

[0243] The affinity of an antibody for the Fc-gamma-R can be altered by mutating certain residues of the heavy chain constant region. For example, disruption of the glycosylation site of human IgGl can reduce Fc-gamma-R binding, and thus effector function, of the antibody (see, eg W02006036291). The tripeptide sequences NXS and NXT, where X is any amino acid other than proline, are the enzymatic recognition sites for glycosylation of the N residue. Disruption of any of the tripeptide amino acids, particularly in the CH2 region of IgG, will prevent glycosylation at that site. For example, mutation of N297 of human IgGl prevents glycosylation and reduces Fc-gamma-R binding to the antibody.

[0244] Although activation of ADCC and CDC is often desirable for therapeutic antibodies, there are circumstances in which an ABP or biABP of the invention unable to activate effector functions is preferential (eg, an ABP or biABP of the invention that is an agnostic modulator). For these purposes IgG4 has commonly been used but this has fallen out of favour in recent years due the unique ability of this sub-class to undergo Fab-arm exchange, where heavy chains can be swapped between IgG4 in vivo as well as residual ADCC activity. Accordingly, Fc engineering approaches can also be used to determine the key interaction sites for the Fc domain with Fc-gamma receptors and Clq and then mutate these positions, such as in an Fc of an ABP or biABP of the invention, to reduce or abolish binding. Through alanine scanning Duncan and Winter (1998; Nature 332:738) first isolated the binding site of Clq to a region covering the hinge and upper CH2 of the Fc domain. Researchers at Genmab identified mutants K322A, L234A and L235A, which incombination are sufficient to almost completely abolish Fc-gamma-R and Clq binding (Hezareh et al, 2001; J Virol 75:12161). In a similar manner Medlmmune later identified a set of three mutations, L234F / L235E / P331S (dubbed TM), which have a very similar effect (Oganesyan et al, 2008; Acta Crystallographica 64:700). An alternative approach is modification of the glycosylation on asparagine 297 of the Fc domain, which is known to be required for optimal FcR interaction. A loss of binding to Fc-gammaRs has been observed in N297 point mutations (Tao et al, 1989; J Immunol 143:2595), enzymatically degylcosylated Fc domains (Mimura et al, 2001; J Biol Chem 276:45539), recombinantly expressed antibodies in the presence of a glycosylation inhibitor (Walker et al, 1989; Biochem J 259:347) and the expression of Fc domains in bacteria (Mazor et al 2007; Nat Biotechnol 25:563). Accordingly, the invention also includes embodiments of the ABPs or biABPs in which such technologies or mutations have been used to reduce effector functions.

[0245] IgG naturally persists for a prolonged period in (eg human) serum due to FcRn-mediated recycling, giving it a typical half-life of approximately 21 days. Despite this there have been a number of efforts to engineer the pH dependant interaction of the Fc domain with FcRn to increase affinity at pH 6.0 while retaining minimal binding at pH 7.4. Researchers at PDL BioPharma identified the mutations T250Q / M428L, which resulted in an approximate 2-fold increase in IgG half-life in rhesus monkeys (Hinto et al, 2004; J Biol Chem 279:6213), and researchers at Medlmmune have identified mutations M252Y / S254T / T256E (dubbed YTE), which resulted in an approximate 4-fold increase in IgG half-life in cynomolgus monkeys (Dall'Acqua, et al 2006; J Biol Chem 281:23514). A combination of the M252Y / S254T / T256E mutations with point mutations H433K / N434F lead to similar effects (Vaccaro et al., 2005, Nat Biotechnol. Oct;23(10):1283-8). ABPs or biABPs of the invention may also be PEGylated. PEGylation, ie chemical coupling with the synthetic polymer poly-ethylene glycol (PEG), has emerged as an accepted technology for the development of biologies that exercise prolonged action, with around 10 clinically approved protein and peptide drugs to date (Jevsevar et al., 2010; Biotechnol J 5:113). ABPs or biABPs of the invention may also be subjected to PASylation, a biological alternative to PEGylation for extending the plasma half-life of pharmaceutically active proteins (Schlapschy et al, 2013; Protein Eng Des Sei 26:489; XL-protein GmbH, Germany). Similarily, the XTEN half-life extension technology from Amunix provides another biological alternative to PEGylation (Schellenberger, 2009, Nat Biotechnol. ;27(12): 1186- 90. doi: 10.1038 / nbt.l588). Accordingly, the invention also includes embodiments of the ABPs or biABPs in which such technologies or mutations have been used to prolong serum half-life, especially in human serum.

[0246] Antibody fragments include "Fab fragments", which are composed of one constant and one variable domain of each of the heavy and the light chains, held together by the adjacent constant region of the light chain and the first constant domain (CHI) of the heavy chain. These may be formed by protease digestion, e.g. with papain, from conventional antibodies, but similar Fab fragments may also be produced by genetic engineering. Fab fragments include Fab', Fab and "Fab-SH" (which are Fab fragments containing at least one free sulfhydryl group).

[0247] Fab' fragments differ from Fab fragments in that they contain additional residues at the carboxy terminus of the first constant domain of the heavy chain including one or more cysteines from the antibody hinge region. Fab' fragments include "Fab'-SH" (which are Fab' fragments containing at least one free sulfhydryl group).

[0248] Further, antibody fragments include F(ab')2 fragments, which contain two light chains and two heavy chains containing a portion of the constant region between the CHI and CH2 domains ("hinge region"), such that an interchain disulphide bond is formed between the two heavy chains. A F(ab')2 fragment thus is composed of two Fab' fragments that are held together by a disulphide bond between the two heavy chains. F(ab')2 fragments may be prepared from conventional antibodies by proteolytic cleavage with an enzyme that cleaves below the hinge region, e.g. with pepsin, or by genetic engineering.

[0249] An "Fv region" comprises the variable regions from both the heavy and light chains, but lacks the constant regions. "Single-chain antibodies" or "scFv" are Fv molecules in which the heavy and light chain variable regions have been connected by a flexible linker to form a single polypeptide chain, which forms an antigen binding region.

[0250] An "Fc region" comprises two heavy chain fragments comprising the CH2 and CH3 domains of an antibody. The two heavy chain fragments are held together by two or more disulphide bonds and by hydrophobic interactions of the CH3 domains.

[0251] Accordingly, in some embodiments, the ABP or biABP of the invention is an antibody fragment selected from the list consisting of: Fab' Fab, Fab'-SH, Fab-SH, Fv, scFv and F(ab')2.

[0252] In those embodiments of ABPs or biABPs that are fragments of immunoglobulins, such as an antibody fragment, preferred are those fragments capable of binding to (eg an epitope displayed by) the extracellular domain(s) of LILRB1 and / or LILRB2, or a paralogue, orthologue or other variant thereof, such as any epitope or other binding characteristic as described herein: and more preferably said fragment is a modulator (such as an inhibitor or antagonist) of the expression, function, activity and / or stability of ULRB1 and / or LILRB2 or a paralogue, orthologue or other variant of ULRB1 and / or ULRB2.

[0253] In a preferred embodiment, an ABP or biABP of the invention is an antibody wherein at least a portion of the framework sequence of said antibody or fragment thereof is a human consensus framework sequence, for example, comprises a human germline-encoded framework sequence.

[0254] In some embodiments, an ABP or biABP of the invention is modified or engineered to increase antibodydependent cellular cytotoxicity (ADCC). As will now be understood by the person of ordinary skill, such ABPs or biABPs of the invention will have particular utility in the therapy of diseases or disorders associated with cellular resistance against immune cells like CTLs (such as an ULRB1 and / or ULRB2-positive cancer); as the ADCC mechanism (a cell- mediated immune defence whereby an effector cell of the immune system actively lyses a target cell, whose membranesurface antigens have been bound by specific antibodies) would be enhanced in respect of the cells having resistance against immune cells like CTLs, hence leading to an increase in attachment by and / or lysis of such cells by effector cells of the immune system.

[0255] As used herein, "therapy" is synonymous with treating a disease, disorder or condition, which includes reducing symptoms of the disease, disorder or condition, inhibiting progression of the disease, disorder or condition, causing regression of the disease, disorder or condition and / or curing the disease, disorder or condition.

[0256] Various techniques to modify or engineer an ABP or biABP of the invention to increase ADCC are known (Satoh et al, 2006; Expert Opin Biol Ther 6: 1161; W02009 / 135181), and hence such embodiments include those wherein an ABP or biABP of the invention may be afocosylated (GlycArt Biotechnology) e.g., in which antibodies are produced in CHO cells in which the endogenous FUT8 gene has been knocked out; or the ABP or biABP may be a "Sugar-Engineered Antibody" (Seattle Genetics), e.g. in which fucose analogues are added to antibody-expressing CHO cells, resulting in a significant reduction in fucosylation. Other afocosylation approaches that may be applied to an ABP or biABP of the invention are described elsewhere herein.

[0257] Other techniques to modify or engineer an ABP or biABP of the invention to increase ADCC include mutations in a Fc portion of the ABP or biABP, (such as described in more detail elsewhere herein), in particular where one or more of residues 234, 235, 236 and / or 237, and / or residues 330, 331 of human Fc are so mutated; wherein such numbering of the residues in the Fc region is that of the EU index as in Kabat (Kabat et ah, Sequences of Proteins of Immunological Interest (National Institute of Health, Bethesda, Md. 1987).

[0258] Accordingly, in certain embodiments, the ABP or biABP of the invention is modified or engineered to increase antibody-dependent cell-mediated cytotoxicity (ADCC), preferably wherein said ABP or biABP is afocosylated and / or an Fc of said ABP or biABP is mutated. In alternative embodiments, the ABP or biABP of the invention is modified or engineered to reduce ADCC (eg where an Fc is mutated using one or more of the following residue changes: L234A, L235E, G237A, A330S and / or P331S).

[0259] In other certain embodiments, the ABP or biABP of the invention is modified to prolong serum half-life, especially in human serum. For example, an ABP or biABP of the invention may be PEGylated and / or PASylated, or has an Fc region with a T250Q / M428L, H433K / N434F / Y436 or M252Y / S254T / T256E / H433K / N434F modification.

[0260] In yet other embodiments, an ABP or biABP of the invention can comprise a chimeric antigen receptor (CAR), and preferably comprises an extracellular antigen binding region, a membrane anchor such as a transmembrane domain, and an intracellular region, for example, an intracellular signalling region.

[0261] In preferred embodiments, an ABP or biABP of the invention can comprise at least one antibody constant domain, in particular wherein at least one antibody constant domain is a CHI, CH2, or CH3 domain, or a combination thereof.

[0262] In further of such embodiments, an ABP or biABP of the invention having antibody constant domain comprises a mutated Fc region, for example for increasing interaction of the Fc region with a Fc receptor (Fc receptor on an immune effector cell (eg Saxena &Wu, 2016; Front Immunol 7:580). Examples and embodiments thereof are described elsewhere herein.

[0263] In other embodiments, an ABP or biABP of the invention may comprises an effector group and / or a labelling group.

[0264] The term "effector group" means any group, in particular one coupled to another molecule such as an antigen binding protein, that acts as a cytotoxic agent. Examples for suitable effector groups are radioisotopes or radionuclides. Other suitable effector groups include toxins, therapeutic groups, or chemotherapeutic groups. Examples of suitable effector groups include calicheamicins, auristatins, geldanamycins, alpha-amanitine, pyrrolobenzodiazepines and maytansines.

[0265] The term "label" or "labelling group" refers to any detectable label. In general, labels fall into a variety of classes, depending on the assay in which they are to be detected: a) isotopic labels, which may be radioactive or heavy isotopes; b) magnetic labels (e.g., magnetic particles); c) redox active moieties; d) optical dyes; enzymatic groups (e.g. horseradish peroxidase, p-galactosidase, luciferase, alkaline phosphatase); e) biotinylated groups; and f) predetermined polypeptide epitopes recognized by a secondary reporter (e.g., leucine zipper pair sequences, binding sites for secondary antibodies, metal binding domains, epitope tags, etc.).

[0266] In some embodiments, an effector group or a labelling group is coupled to another molecule (such as the ABP) via spacer arms of various lengths to reduce potential steric hindrance.

[0267] In another aspect, the invention relates to an antigen binding domain (ABD) of an ABP or biABP of the invention, such as of any ABP or biABP as described above or elsewhere herein. In certain embodiments, an ABD of the invention is capable, when comprised in an applicable scaffold, of binding to the ECD of ULRB1 and / or ULRB2 (or variant thereof). An ABD of the invention may, in certain embodiments, be isolated and / or substantial pure.

[0268] Nucleic acids, nucleic acid constructs and (host) cells

[0269] In a third aspect, the invention relates to a nucleic acid encoding for an ABP or biABP (or ABD) of the invention (such as one described above) or of components thereof. For example, the component encoded by a nucleic acid of the invention may be all or part of one chain of an antibody of the invention; or the component may be a scFV of said ABP or biABP. The component encoded by such a nucleic acid may be all or part of one or other of the chains of an antibody of the invention; for example, the component encoded by such a nucleic acid may be an ABP or biABP of the invention. The nucleic acids of the invention may also encode a fragment, derivative, mutant, or variant of an ABP or biABP of the invention, and / or represent components that are polynucleotides suitable and / or sufficient for use as hybridisation probes, polymerase chain reaction (PCR) primers or sequencing primers for identifying, analyzing, mutating or amplifying a polynucleotide encoding a polypeptide, anti-sense or inhibitory nucleic acids (such asRNAi / siRNA / shRNA or gRNA molecules) for inhibiting expression of a polynucleotide, and complementary sequences of the foregoing.

[0270] In particular embodiments of the invention, a nucleic acid of the invention comprises a nucleic acid having a sequence encoding a heavy or light chain CDR, a combination of heavy and / or light chain CDR1, CDR2 and CDR3 or a heavy or light chain variable domain, in each case as displayed in Table 1, or a functional fragment thereof. In other embodiments, a nucleic acid of the invention comprises a nucleic acid sequence at least 60%, 65%, 70%, 75%, 80%, 85%, 90%; or 95% (preferably at least 75%) sequence identity to (or having no more than fifty, forty, thirty, twenty, fifteen, ten or five, preferably no more than three, two or one, base substitution(s), insertion(s) or deletion(s), preferably at the third base of a codon of) a nucleic acid sequence selected from the list consisting of SEQ IDS Nos. 9, 10, 19, 20, 29, 30, 39, 40, 49, 50, 59, 60, 69, 70, 79, 80, 89, 90, 99, 100, 109, 110, 119, 120, 129, 130, 139, 140,149, 150, 159 160, 169, 170, 179, 180, 189, 190, 199, 200, 209, 210, 219, 220, 229, 230, 239, 240, 249, 250, 259, 260, 269, 270, 279, 280, 289, 290, 299, 300, 309, 310, 319, 320, 329, 330, 339, 340, 349, 350, 359, 360, 369 and 370; preferably wherein such nucleic acid encodes a heavy or light chain variable domain of an ABP or biABP of the invention, such as encodes the corresponding heavy or light chain variable domain having the amino acid sequence set forth in Table 1, and optionally having no more than ten, nine, eight, seven, six, five, four, preferably no more than three, two or one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

[0271] The nucleic acid according to the invention may be a DNA or RNA of genomic, mRNA, cDNA, or synthetic origin or some combination thereof, optionally linked to a polynucleotide to which it is not linked in nature. In some embodiments, such nucleic acid may comprise one or more (such as 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 20, in particular between 1 and about 5, or preferably all instances of a particular nucleotide in the sequence) unnatural (e.g. synthetic) nucleotides; and / or such nucleic acid may comprise (e.g. is conjugated to) another chemical moiety, such as a labelling group or an effector group; for example, a labelling group or an effector group as described elsewhere herein.

[0272] In one embodiment, the nucleic acid of the invention may be isolated or substantially pure. In another embodiment, the nucleic acid of the invention may be recombinant, synthetic and / or modified, or in any other way non-natural. For example, a nucleic acid of the invention may contain at least one nucleic acid substitution (or deletion) modification (such as 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 such modifications, in particular between 1 and about 5 such modifications, preferably 2 or 3 such modifications) relative to a product of nature, such as a human nucleic acid.

[0273] The nucleic acids can be any suitable length, such as about 10, 15, 20, 25, 30, 35, 40, 45, 50, 75, 100, 125,150, 175, 200, 250, 300, 350, 400, 450, 500, 750, 1,000, 1,500, 3,000, 5,000 or more nucleotides in length. For example: siRNA nucleic acids may, preferably, be between about 15 to about 25 base pairs in length (preferably between about 19 and about 21 base pairs in length); shRNA nucleic acids may, preferably, comprise a 20-30 base pair stem, a loop of at least 4 nucleotides, and a dinucleotide overhang at the 3' end; microRNA may, preferably, be about 22 base pairs in length; an mRNA or DNA sequence encoding an ABP or biABP or a component thereof (such as a heavy or light chain or an IgG antibody) of the invention may, preferably, be between about 500 and 1,500 nucleotides. More preferably, a nucleic acid encoding a mammalian light chain of an antibody may be between about 630 and about 650 nucleotides, and one encoding a mammalian heavy chain of an antibody may be between about 1,300 and about 1,650 nucleotides. A nucleic acid can comprise one or more additional sequences, for example, regulatory sequences, and / or be part of a larger nucleic acid. The nucleic acids can be single-stranded or doublestranded and can comprise RNA and / or DNA nucleotides, and artificial variants thereof (e.g., peptide nucleic acids).

[0274] Nucleic acids encoding antibody polypeptides (e.g., heavy or light chain, variable domain only, or foil length) may be isolated from B-cells of mice, rats, llamas, alpacas, chicken or rabbits that have been immunized with an LILRB1 and / or ULRB2 antigen or fragment thereof, such as one or more EC domains (or a polynucleotide encoding and capableof expressing an LILRB1 and / or LILRB2 antigen or fragment thereof). The nucleic acid may be isolated by conventional procedures such as PCR.

[0275] Changes can be introduced by mutation into the sequence of a nucleic acid of the invention. Such changes, depending on their nature and location in a codon, can lead to changes in the amino acid sequence of a polypeptide (e.g., an antigen binding protein) that it encodes. Mutations can be introduced using any technique known in the art.

[0276] In one embodiment, one or more particular amino acid residues may be changed using, for example, a site- directed mutagenesis protocol. In another embodiment, one or more randomly selected residues may be changed using, for example, a random mutagenesis protocol. However, it is made, a mutant polypeptide can be expressed and screened for a desired property. Mutations can be introduced into a nucleic acid without significantly altering the biological activity of a polypeptide that it encodes. For example, one can make nucleotide substitutions leading to amino acid substitutions at non-essential amino acid residues.

[0277] Other changes that may be made (e.g. by mutation) to the sequence of a nucleic acid of the invention may not alter the amino acid sequence of the encoded polypeptide, but may lead to changes to its stability and / or effectiveness of expression of the encoded polypeptide. For example, by codon optimisation, the expression of a given polypeptide sequence may be improved by utilising the more common codons for a given amino acid that are found for the species in which the nucleotide is to be expressed. Methods of codon optimisation, and alternative methods (such as optimisation of CpG and G / C content), are described in, for example, Hass et al, 1996 (Current Biology 6:315); WO1996 / 09378; W02006 / 015789 and WO 2002 / 098443).

[0278] In one related aspect, the invention relates to a nucleic acid construct (NAC) comprising at least one nucleic acid of the invention (such as described above). Such an NAC can comprise one or more additional features permitting the expression of the encoded ABP or biABP or component of said ABP or biABP (eg the ABD) in a cell (such as in a host cell). Examples of NACs of the invention include, but are not limited to, plasmid vectors, viral vectors, mRNA, non-episomal mammalian vectors and expression vectors, for example, recombinant expression vectors. The nucleic acid constructs of the invention can comprise a nucleic acid of the invention in a form suitable for expression of the nucleic acid in a cell, such as a host cell, (see below). The nucleic acid constructs of the invention will be, typically, recombinant nucleic acids, and / or may be isolated and / or substantially pure. Recombinant nucleic acids will, typically, be non-natural; particularly if they comprise portions that are derived from different species and / or synthetic, in-vitro or mutagenic methods.

[0279] In some embodiments, an NAC of the invention comprises one or more constructs either of which includes a nucleic acid encoding either a heavy or a light antibody chain. In some embodiments, the NAC of the invention comprises two constructs, one of which includes a nucleic acid encoding the heavy antibody chain, the other of which includes a nucleic acid encoding the light antibody chain, such that expression from both constructs can generate a complete antibody molecule. In some embodiments, the NAC of the invention comprises a construct which includes nucleic acids encoding both heavy and light antibody chains, such that a complete antibody molecule can be expressed from one construct. In other embodiments, an NAC of the invention can comprise a single construct that encodes a single chain which is sufficient to form an ABP or biABP of the invention; for example, if the encoded ABP or biABP is a scFv or a single-domain antibody (such as a camelid antibody).

[0280] In some embodiments, the NAC of the invention includes sequences encoding all or part of a constant region, enabling an entire, or a part of, a heavy and / or light chain to be expressed.

[0281] An NAC according to the invention may comprise (or consist of) a mRNA molecule which includes an open reading frame encoding an ABP or biABP of the invention, and for example together with upstream and downstream elements (such as 5' and / or 3' UTRs and / or poly-A stretch) that enables expression of the ABP or biABP, and preferably enhancing stability of the mRNA and / or expression of the ABP or biABP. The use of mRNA as NACs to introduce into and express polynucleotides in cells is described, for example, in Zangi et al in Nat. Biotechnol. vol. 31, 898-907 (2013),Sahin et al (2014) Nature Reviews Drug Discovery 13:759 and by Thess et al in Mol. Ther. vol. 23 no.9, 1456-1464 (2015). Particular UTRs that may be comprised in an mRNA NAC of the invention include: 5'UTR of a TOP gene (WO2013 / 143699), and / or a histone stem-loop (WO 2013 / 120629). An mRNA NAC of the invention may further comprise one or more chemical modifications (EP 1 685 844); including a 5'-cap, such as m7G(5')ppp, (5'(A,G(5')ppp(5')A or G(5')ppp(5')G and / or at least one nucleotide that is an analogue of naturally occurring nucleotides, such as phosphorothioates, phosphoroamidates, peptide nucleotides, methylphosphonates, 7-deaza- guanosine, 5-methylcytosine or inosine.

[0282] NACs, such as DNA-, retroviral- and mRNA-based NACs of the invention may be used in genetic therapeutic methods in order to treat or prevent diseases of the immune system (see Methods of Treatment below), whereby an NAC that comprises an expressible sequence encoding an ABP or biABP of the invention is administered to the cell or organism (e.g. by transfection). In particular, the use of mRNA therapeutics for the expression of antibodies is known from W02008 / 083949.

[0283] In another related aspect, the invention relates to a cell (such as a host cell and / or a recombinant host cell) comprising one or more nucleic acid or NAC of the invention. Preferably, such cell is capable of expressing the ABP or biABP (or component thereof) encoded by said NAC(s). For example, if an ABP or biABP of the invention comprises two separate polypeptide chains (e.g. a heavy and light chain of an IgG), then the cell of the invention may comprise a first NAC that encodes (and can express) the heavy chain of such ABP or biABP as well as a second NAC that encodes (and can express) the light chain of such ABP; alternatively, the cell may comprise a single NAC that encodes both chains of such ABP or biABP. In these ways, such a cell of the invention would be capable of expressing a functional (e.g. binding and / or inhibitory) ABP or biABP of the invention. A (host) cell of invention may be one of the mammalian, prokaryotic or eukaryotic host cells as described elsewhere herein, in particularly where the cell is a Chinese hamster ovary (CHO) cell.

[0284] In certain embodiments of such aspect, the (host) cell is a human cell; in particular it may be a human cell that has been sampled from a specific individual (eg an autologous human cell). In such embodiments, such human cell can be propagated and / or manipulated in-vitro so as to introduce a NAC of the present invention. The utility of a manipulated human cell from a specific individual can be to produce an ABP or biABP of the invention, including to reintroduce a population of such manipulated human cells into a human subject, such as for use in therapy. In certain of such uses, the manipulated human cell may be introduced into the same human individual from which it was first sampled; for example, as an autologous human cell.

[0285] The human cell that is subject to such manipulation can be of any germ cell or somatic cell type in the body. For example, the donor cell can be a germ cell or a somatic cell selected from the group consisting of fibroblasts, B cells, T cells, dendritic cells, keratinocytes, adipose cells, epithelial cells, epidermal cells, chondrocytes, cumulus cells, neural cells, glial cells, astrocytes, cardiac cells, oesophageal cells, muscle cells, melanocytes, hematopoietic cells, macrophages, monocytes, and mononuclear cells. The donor cell can be obtained from any organ or tissue in the body; for example, it can be a cell from an organ selected from the group consisting of liver, stomach, intestines, lung, pancreas, cornea, skin, gallbladder, ovary, testes, kidneys, heart, bladder, and urethra.

[0286] Pharmaceutical compositions

[0287] To be used in therapy, the ABPs or biABPs, nucleic acids or NACs (or the cells, such as host cells) of the invention may be formulated into a pharmaceutical composition appropriate to facilitate administration to animals or humans. The term "pharmaceutical composition" means a mixture of substances including a therapeutically active substance (such as an ABP or biABP of the invention) for pharmaceutical use.

[0288] Accordingly, in a fourth aspect, the invention relates to a pharmaceutical composition comprising a compound that is modulator of the expression, function, activity and / or stability of immunoglobulin superfamily member11 (ULRB1 and / or ULRB2), or of a variant of ULRB1 and / or ULRB2 and a pharmaceutically acceptable carrier, stabiliser and / or excipient. For example, the LILRB1 and / or ULRB2 modulator is an ABP or biABP of the invention, and / or at least one NAC of the invention, and / or a (host) cell of the invention. Accordingly, in a related aspect, herein provided is a pharmaceutical composition comprising an ABP or biABP of the invention, and / or at least one NAC of the invention, and / or a (host) cell of the invention, and a pharmaceutically acceptable excipient or carrier.

[0289] In a preferred embodiment, the pharmaceutical composition comprises an ABP or biABP of the invention, for example in such embodiment, the LILRB1 and / or ULRB2 modulator is an ABP or biABP of the invention (eg an LILRB1 and / or LILRB2-inhibitory ABP or biABP of the invention).

[0290] By way of example, the pharmaceutical composition of the invention may comprise between 0.1% and 100% (w / w) active ingredient (for example, an ULRB1 and / or LILRB2 modulator), such as about 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8% 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98% or 99%, preferably between about 1% and about 20%, between about 10% and 50% or between about 40% and 90%.

[0291] As used herein the language "pharmaceutically acceptable" excipient, stabiliser or carrier is intended to include any and all solvents, solubilisers, fillers, stabilisers, binders, absorbents, bases, buffering agents, lubricants, controlled release vehicles, diluents, emulsifying agents, humectants, dispersion media, coatings, antibacterial or antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well-known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the compositions is contemplated. Supplementary agents can also be incorporated into the compositions.

[0292] The pharmaceutical composition of (or for use with) the invention is, typically, formulated to be compatible with its intended route of administration. Examples of routes of administration include oral, parenteral, e.g., intrathecal, intra-arterial, intravenous, intradermal, subcutaneous, oral, transdermal (topical) and transmucosal administration.

[0293] Solutions or suspensions used for parenteral, intradermal, or subcutaneous application, as well as comprising a compound of (or for use with) the invention (eg an ULRB1 and / or LILRB2 modulator), can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine; propylene glycol or other synthetic solvents; anti-bacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulphate; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

[0294] Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Kolliphor® EL (formerly Cremophor EL™; BASF, Parsippany, NJ.) or phosphate buffered saline (PBS). In all cases, the injectable composition should, typically, be sterile and be fluid to the extent that easy syringability exists. It should, typically, be stable under the conditions of manufacture and storage and be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the requited particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, and sodium chloride in the composition. Prolongedabsorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminium monostearate and gelatin.

[0295] Sterile injectable solutions can be prepared by incorporating the compound of (or for use with) the invention (e.g., an ULRB1 and / or LILRB2 modulator) in the required amount in an appropriate solvent with one or a combination of ingredients described herein, as required, followed by filtered sterilisation. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those described herein. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

[0296] Oral compositions, as well as comprising a compound of (or for use with) the invention (eg an ULRB1 and / or ULRB2 inhibitor), generally include an inert diluent or an edible carrier. They can be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules. Oral compositions can also be prepared using a fluid carrier for use as a mouthwash, wherein the compound in the fluid carrier is applied orally and swished and expectorated or swallowed. Pharmaceutically compatible binding agents, and / or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Stertes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavouring agent such as peppermint, methyl salicylate, or orange flavouring.

[0297] Furthermore, the compounds of (or for use with) the invention (eg an ULRB1 and / or LILRB2 modulator) can be administered rectally. A rectal composition can be any rectally acceptable dosage form including, but not limited to, cream, gel, emulsion, enema, suspension, suppository, and tablet. One preferred dosage form is a suppository having a shape and size designed for introduction into the rectal orifice of the human body. A suppository usually softens, melts, or dissolves at body temperature. Suppository excipients include, but are not limited to, theobroma oil (cocoa butter), glycerinated gelatin, hydrogenated vegetable oils, mixtures of polyethylene glycols of various molecular weights, and fatty acid esters of polyethylene glycol.

[0298] For administration by inhalation, the compounds of (or for use with) the invention (eg an LILRB1 and / or ULRB2 modulator) are typically delivered in the form of an aerosol spray from pressured container or dispenser which contains a suitable propellant, e.g., a gas such as carbon dioxide, or a nebuliser.

[0299] Cells, such as immune cells (eg CAR T cells) for use with the invention can be included in pharmaceutical formulations suitable for administration into the bloodstream or for administration directly into tissues or organs. A suitable format is determined by the skilled person (such as a medical practitioner) for each patient, tissue, and organ, according to standard procedures. Suitable pharmaceutically acceptable carriers and their formulation are known in the art (see, e.g. Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed., 1980). Such cells, when formed in a pharmaceutical composition, are preferably formulated in solution at a pH from about 6.5 to about 8.5. Excipients to bring the solution to isotonicity can also be added, for example, 4.5% mannitol or 0.9% sodium chloride, pH buffered with art-known buffer solutions, such as sodium phosphate. Other pharmaceutically acceptable agents can also be used to bring the solution to isotonicity, including, but not limited to, dextrose, boric acid, sodium tartrate, propylene glycol, polyols (such as mannitol and sorbitol) or other inorganic or organic solutes. In one embodiment, a media formulation is tailored to preserve the cells while maintaining cell health and identity. For example, a premixture including an aqueous solution of anticoagulant (ACD-A), an equal amount of dextrose (50%), and phosphate buffered saline (PBS), or the like is pre-mixed and aliquoted in a volume to typically match or approximate the cellular matrix or environment from which the cell was extracted from the tissue or organ.

[0300] Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fosidic acid derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the pharmaceutical compositions can be formulated into ointments, salves, gels, or creams as generally known in the art.

[0301] In certain embodiments, the pharmaceutical composition is formulated for sustained or controlled release of a compound of (or for use with) the invention (eg an ULRB1 and / or ULRB2 modulator). Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art.

[0302] It is especially advantageous to formulate oral, rectal or parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein includes physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and the limitations inherent in the art of compounding such an active compound for the treatment of individuals.

[0303] In some embodiments, the pharmaceutical composition comprising an ULRB1 and / or ULRB2 modulator is in unit dose form of between 10 and lOOOmg LILRB1 and / or LILRB2 modulator. In some embodiments, the pharmaceutical composition comprising an LILRB1 and / or ULRB2 modulator is in unit dose form of between 10 and 200mg LILRB1 and / or LILRB2 modulator. In some embodiments, the pharmaceutical composition comprising an ABP or biABP is in unit dose form of between 200 and 400mg LILRB1 and / or ULRB2 modulator. In some embodiments, the pharmaceutical composition comprising an LILRB1 and / or ULRB2 modulator is in unit dose form of between 400 and 600mg ULRB1 and / or ULRB2 modulator. In some embodiments, the pharmaceutical composition comprising an LILRB1 and / or ULRB2 modulator is in unit dose form of between 600 and 800mg ULRB1 and / or LILRB2 modulator. In some embodiments, the pharmaceutical composition comprising an LILRB1 and / or LILRB2 modulator is in unit dose form of between 800 and 100 mg ULRB1 and / or LILRB2 modulator.

[0304] Exemplary unit dosage forms for pharmaceutical compositions comprising LILRB1 and / or ULRB2 modulators are tablets, capsules (eg as powder, granules, microtablets or micropellets), suspensions or as single-use pre-loaded syringes. In certain embodiments, kits are provided for producing a single-dose administration unit. The kit can contain both a first container having a dried active ingredient and a second container having an aqueous formulation. Alternatively, the kit can contain single and multi-chambered pre-loaded syringes.

[0305] Toxicity and therapeutic efficacy (eg effectiveness) of such active ingredients can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, eg, for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50 / ED50. Active agents which exhibit large therapeutic indices are preferred. While compounds that exhibit toxic side effects may be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue in order to minimise potential damage to uninfected cells and, thereby, reduce side effects.

[0306] The data obtained from the cell culture assays and animal studies can be used in formulating a range of dosage of the active ingredients (eg an ULRB1 and / or ULRB2 modulator), such as for use in humans. The dosage ofsuch active ingredients lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilised. For any active ingredients used in the therapeutic approaches of the invention, the (therapeutically) effective dose can be estimated initially from cell culture assays. A dose may be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 (ie, the concentration of the active ingredients which achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful (eg effective) amounts or doses, such as for administration to humans. The pharmaceutical compositions can be included in a container, pack, or dispenser together with instructions for administration.

[0307] In the context of the invention, an effective amount of the LJLRBl and / or LLLRB2 modulator or the pharmaceutical composition can be one that will elicit the biological, physiological, pharmacological, therapeutic or medical response of a cell, tissue, system, body, animal, individual, patient or human that is being sought by the researcher, scientist, pharmacologist, pharmacist, veterinarian, medical doctor, or other clinician, eg, lessening of the effects / symptoms of a disorder, disease or condition, such as a proliferative disorder, for example, a cancer or tumour, or killing or inhibiting growth of a cell involved with a proliferative disorder, such as a tumour cell. The effective amount can be determined by standard procedures, including those described below.

[0308] In accordance with all aspects and embodiments of the medical uses and methods of treatment provided herein, the effective amount administered at least once to a subject in need of treatment with a LJLRBl and / or LLLRB2 modulator is, typically, between about O.Olmg / kg and about lOOmg / kg per administration, such as between about lmg / kg and about lOmg / kg per administration. In some embodiments, the effective amount administered at least once to said subject of a LJLRBl and / or LLLRB2 modulator is between about O.Olmg / kg and about 0. lmg / kg per administration, between about 0. lmg / kg and about lmg / kg per administration, between about lmg / kg and about 5mg / kg per administration, between about 5mg / kg and about lOmg / kg per administration, between about lOmg / kg and about 50mg / kg per administration, or between about 50mg / kg and about lOOmg / kg per administration.

[0309] For the prevention or treatment of disease, the appropriate dosage of a LJLRBl and / or LLLRB2 modulator (or a pharmaceutical composition comprised thereof) will depend on the type of disease to be treated, the severity and course of the disease, whether the LJLRBl and / or LLLRB2 modulator and / or pharmaceutical composition is administered for preventive or therapeutic purposes, previous therapy, the patient's clinical history, age, size / weight and response to the LILRB1 and / or LLLRB2 modulator and / or pharmaceutical composition, and the discretion of the attending physician. The LJLRBl and / or LILRB2 modulator and / or pharmaceutical composition is suitably administered to the patient at one time or over a series of treatments. If such LILRB1 and / or LILRB2 inhibitor and / or pharmaceutical composition is administered over a series of treatments, the total number of administrations for a given course of treatment may consist of a total of about 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than about 10 treatments. For example, a treatment may be given once every day (or 2, 3 or 4 times a day) for a week, a month or even several months. In certain embodiments, the course of treatment may continue indefinitely.

[0310] The amount of the LILRB1 and / or LLLRB2 modulator and / or pharmaceutical composition administered will depend on variables such as the type and extent of disease or indication to be treated, the overall health, age, size / weight of the patient, the in vivo potency of the LJLRBl and / or LILRB2 modulator and / or pharmaceutical composition, and the route of administration. The initial dosage can be increased beyond the upper level in order to rapidly achieve the desired blood-level or tissue level. Alternatively, the initial dosage can be smaller than the optimum, and the daily dosage may be progressively increased during the course of treatment. Human dosage can be optimised, e.g., in a conventional Phase I dose escalation study designed to run from relatively low initial doses, for example from about O.Olmg / kg to about 20mg / kg of active ingredient. Dosing frequency can vary, depending on factors such as route of administration, dosage amount and the disease being treated. Exemplary dosing frequencies are once per day,once per week and once every two weeks. Formulation of an ULRB1 and / or ULRB2 modulator of (or for use with) the present is within the ordinary skill in the art. In some embodiments of the invention such LILRB1 and / or ULRB2 modulator is lyophilised and reconstituted in buffered saline at the time of administration. The LILRB1 and / or ULRB2 modulator and / or pharmaceutical composition of may further result in a reduced relapsing of the disease to be treated or reduce the incidence of drug resistance or increase the time until drug resistance is developing; and in the case of cancer may result in an increase in the period of progression-free survival and / or overall survival.

[0311] ULRB1 and / or ULRB2 modulating uses, medical uses and methods of treatment

[0312] Modulating compounds of LILRB1 and / or LILRB2, in particular inhibiting the interaction of ULRB1 and / or ULRB2 and a natural ligand thereof (such as HLA-G) or of a variant of LILRB1 and / or ULRB2, and / or the ABPs or biABPs, NAC, (host) cells and the pharmaceutical compositions of the invention can be used in various ways to modulate the expression, function, activity and / or stability of the ULRB1 and / or LILRB2 (or variant thereof), including their use in therapy or for prophylaxis.

[0313] Accordingly, in a further aspect, herein provided is a method of modulating the expression, function, activity and / or stability of of ULRB1 and / or ULRB2, or of a variant of LILRB1 and / or ULRB2 comprising contacting a cell that expresses said LILRB1 and / or ULRB2 or variant with a modulating compound as described above, in particular an ABP or biABP of the invention or an NAC encoding said ABP or biABP. When such ABP or biABP is a modulator of the expression, function, activity and / or stability of said LILRB1 and / or ULRB2 or variant, thereby the expression, function, activity and / or stability of said ULRB1 and / or ULRB2 or variant is modulated. Such method may be practiced on cells that are present ex-vivo, that is where said cells are contained in receptacles or containers, such as those used in research facilities. Accordingly, in such embodiments such method of the invention can be described as an in-vitro method of modulating the expression, function, activity and / or stability of ULRB1 and / or ULRB2, or of a variant of ULRB1 and / or ULRB2. However, in alternative embodiments, the method may be practiced using cells within the body, for example an in-vivo method of modulating the expression, function, activity and / or stability of ULRB1 and / or ULRB2, or of a variant of ULRB1 and / or LILRB2.

[0314] In particular of such embodiments, such an in-vitro (or in-vivo) method comprises the inhibition of the function and / or activity of the ULRB1 and / or ULRB2 or variant, when such modulating compound (eg the ABP) is an inhibitor of and / or antagonist of such function and / or activity. In some embodiments of such method, it further comprises the step of contacting the cell with an immune cell, such as a CTL or TIL. Preferably, the ABP or biABP is an antibody, or an antibody fragment, and is an inhibitor or antagonist of the function and / or activity of the ULRB1 and / or ULRB2 or variant.

[0315] In particular of such embodiments, such an in-vitro (or in-vivo) method comprises the activation of the function and / or activity of the ULRB1 and / or LILRB2 or variant, when such modulating compound (eg the ABP) is an activator of and / or agonistof such function and / or activity. In some embodiments of such method, it further comprises the step of contacting the cell with an immune cell, such as a CTL or TIL. Preferably, the ABP or biABP is an antibody, or an antibody fragment, and is an activator and / or agonistof the function and / or activity of the ULRB1 and / or LILRB2 or variant. In certain embodiments of these aspects, the method of modulating comprises contacting a cell that expresses said ULRB1 and / or LILRB2 or variant with a modulating compound as described above that is an activator and / or agonist of the function and / or activity of the ULRB1 and / or LILRB2 or variant, and the method mediates any one or combination of at least one of the functional characteristic or effects of the activating or agonistic modulators described herein, in particular as set forth in the section above "Modulators of LILRB1 and / or ULRB2 expression, function, activity and / or stability.

[0316] In other certain embodiments of these aspects, the method of modulating comprises contacting a cell that expresses said ULRB1 and / or ULRB2 or variant with a modulating compound as described above that is an inhibitorand / or antagonist of the function and / or activity of the LILRB1 and / or ULRB2 or variant, and the method mediates any one or combination of at least one of the functional characteristic or effects of the inhibitor or antagonist modulators described herein, in particular as set forth in the section above "Modulators of LILRB1 and / or ULRB2 expression, function, activity and / or stability.

[0317] In particular embodiments, the modulating compound (in particular, an ABP) is an inhibitor and / or antagonist of the function and / or activity of the ULRB1 and / or LILRB2 or variant and inhibits the interaction between of a natural ligand of ULRB1 and / or ULRB2 (such as HLA-G) protein or a variant thereof and ULRB1 and / or LILRB2 protein or a variant thereof; that is, such a compound inhibits the binding function and / or activity of the ULRB1 and / or ULRB2 protein or variant thereof.

[0318] In preferred embodiments of the therapeutic aspects, the modulating compound (such as one that is an inhibitor or antagonist of expression, function, activity and / or stability of the ULRB1 and / or LILRB2 or variant) for example an ABP or biABP, or an NAC encoding said ABP or biABP, is capable of: (i) modulating the expression, function, activity and / or stability of the LILRB1 and / or LILRB2 or variant; and / or (ii) enhancing a cell-mediated immune response to a mammalian cell, decreases or reduces the resistance of cells (such as tumour cells that express a natural ligand of ULRB1 and / or ULRB2 (for example HLA-G or variant)), to an immune response. In other certain preferred embodiments of the invention, the ABP or biABP (such as one that is an inhibitor or antagonist of expression, function, activity and / or stability of the ULRB1 and / or LILRB2 or variant, in particular one that inhibits the binding function and / or activity of the ULRB1 and / or ULRB2 protein to a ligand of ULRB1 and / or ULRB2), or an NAC encoding said ABP or biABP, enhances or increases the sensitivity of cells (such as tumour cells that express a natural ligand of ULRB1 and / or LILRB2 (for example HLA-G or variant)), to an immune response.

[0319] The term "resistance" refers to an acquired or natural resistance of a cell involved with (eg of or affected by) a disease (eg a proliferative disorder), such as tumour or cancer cell, to a patient's own immune response (such as a cell-mediated immune response), or to immune responses aided by immune therapy such as adoptive T-cell transfer or treatment with checkpoint blockers. Therefore, a resistant cell (eg a resistant tumour or cancer cell) is more likely to escape and survive humoural and / or cellular immune defence mechanisms in a subject having the disorder (such as the tumour or cancer). A treatment of a resistant proliferative disease, such as tumour / cancer resistance, in context of the invention shall be effective if, compared to a non-treated control, the cell involved with the proliferative disease (such as a cell of the tumour of cancer) becomes more sensitive or susceptible to an immune response (such as a cell- mediated immune response) - in other words will be more likely to be recognised and / or neutralised (for example by cytotoxic processes such as apoptosis) by the subject's immune response.

[0320] Accordingly, in particular embodiments of the invention, cell(s) involved with the disease may be resistant against (to) a cell-mediated immune response; and / or such cell(s) may have or display a resistant phenotype.

[0321] In preferred embodiments of the invention, the terms "cellular resistance", "cell resistance" and the like refers to a resistance of the subject cell(s) (such as a tumour or cancer cell) to a cell-mediated immune response, such as a cytotoxic T lymphocyte (CTL) response (eg, the tumour or tumour cell being nonresponsive to, or having reduced or limited response to a CTL targeting a tumour cell). A tumour cell may show a reduced or limited response when contacted with a CTL specific for an antigen expressed on that tumour cell. A reduced or limited response is a reduction to a 90% cytotoxic T cell response, preferably a reduction to 80%, 70%, 60%, 50% or more preferably a reduction to 40%, 30%, 20% or even less. In this case, 100% would denote the state wherein the CTLs can kill all of the subject cells involved with the proliferative disorder in a sample. Whether or not a subject cell (eg a tumour cell) is resistant to a patient's (cell-mediated) immune response may be tested in-vitro by contacting a sample of the subjects such cells (eg autologous tumour cells) with (eg autologous) T-cells and thereafter quantifying the survival / proliferation rate of the (eg) tumour cells. As an alternative, the reduction in (cell-mediated) immune response is determined by comparing cancer samples of the same cancer before and after the resistance is acquired (for example induced bytherapy), or by comparing with a cancer sample derived from a different cancer which is known to have no resistance to the CTL. On the other hand, the treatments of the present invention include the sensitisation of cells involved with the proliferative disorder against CTL and therefor to decrease resistance of such cells. A decrease of (eg tumour) cell resistance against CTL is preferably a significant increase of CTL toxicity, preferably a 10% increase, more preferably 20%, 30%, 40%, 50%, 60%, 70%, 80% or more, even more preferably 2 fold increase, 3 fold, 4 fold, 5 fold or more.

[0322] In particular embodiments, a resistant phenotype of the cells involved with the proliferative disorder is displayed by such cells when a subject suffering from the proliferative disorder (eg a cancer or tumour) has been previously treated with an (immune)therapy and, for example, such proliferative disorders has progressed despite such prior (immune)therapy. For example, a class of subject suitable for the various therapeutic methods of the invention can be those whose tumour (or cancer) has progressed (such as has relapsed or recurred, or has not responded to) after prior treatment with a cancer immunotherapy. In certain embodiments, such prior treatment may be any immunotherapy as described elsewhere herein, including adoptive immune cell transfer (eg TCR or CART cell therapy), an anti-tumour vaccine, an antibody binding to an immune checkpoint molecule (such as CTLA-4, PD-1 or PD-L1). In other embodiments, the subject may suffer from a tumour or cancer, and such cancer may have progressed (such as has relapsed or recurred, or has not responded to) after prior radiotherapy.

[0323] The immune response, is, in particular of such embodiments, a cell-mediated immune response such as one mediated by T-cells including cytotoxic T-cells and / or TILs; and / or the immune response is the lysis and / or killing of the cells, in particular those that express ULRB1 and / or LILRB2 or a variant thereof) that is mediated by cytotoxic T- cells and / or TILs. In other particular of such embodiments, the immune response is a cytotoxic immune response against cells (such as tumour cells), in particular a cell-mediated cytotoxic immune response such as one mediated by T-cells including cytotoxic T-cells and / or TILs. ULRB1 and / or ULRB2 expressing cells are found in the myeloid compartment and modulate cell-mediated immune responses.

[0324] Specifically, in certain preferred embodiments of such therapeutic aspects the modulating compound as disclosed herein, in particular the ABP or biABP (such as one that is an inhibitor or antagonist of expression, function, activity and / or stability of the LILRB1 and / or ULRB2 or variant thereof), or an NAC encoding said ABP or biABP, enhances or increases killing and / or lysis of cells associated with the proliferative disorder, such as tumour cells. Such effect is brought about via modulation of cells expressing ULRB1 and / or ULRB2 or variant thereof, (such as macrophage cells); which modulate a killing and / or lysis of tumour cells mediated by cytotoxic T-cells and / or TILs, and / or mediated by an enhancement of or increase in the sensitivity of the cells of the immune system, and / or mediated by a decrease in or reduction of the immune inhibitory effects of the cells expressing the ULRB1 and / or ULRB2 or variant thereof on a (cytotoxic) immune response, such an immune response described above. As such LILRB1 and / or ULRB2 expressing cells brought into contact with the agents of the invention are therefore less immune inhibitory and support a subject's immune response against a proliferative disease to be treated.

[0325] The cells that express LILRB1 and / or ULRB2 or variant thereof are, in certain of such preferred embodiments, cells of the myeloid compartment, such as macrophages, or alternatively in some instances may be cancer cells or are cells that originated from a tumour cell. Exemplary cancer or tumour cells can be those as described or exemplified elsewhere herein.

[0326] In other certain preferred embodiments of such therapeutic aspects, the modulating compounds, in particular the ABP or biABP (such as one that is an inhibitor or antagonist of expression, function, activity and / or stability of ULRB1 and / or ULRB2 or variant thereof, in particular that is an inhibitor of the HLA-G-binding function of the ULRB1 and / or LILRB2 or variant), or an NAC encoding said ABP or biABP, increases T-cell activity and / or survival (and / or increases T-cell proliferation), which in certain embodiments, may lead to an enhancement of a (cytotoxic) immune response mediated by such T-cells.

[0327] Accordingly, in a fifth aspect, the invention relates to a method for the treatment of a disease, disorder or condition in a mammalian subject by administering a product to the subject wherein the product is a modulator of the expression, function, activity and / or stability of immunoglobulin superfamily member 11 (LILRB1 and / or LILRB2), or of a variant of ULRB1 and / or ULRB2. In a related aspect, the invention relates to a product for use in medicine, wherein the product is a compound that is modulator of the expression, function, activity and / or stability of immunoglobulin superfamily member 11 (LILRB1 and / or LILRB2), or of a variant of ULRB1 and / or LILRB2. In particular embodiments, of these medical / treatment claims, the modulating compound (such as an ABP) is an inhibitor of the binding HLA-G-binding function of ULRB1 and / or ULRB2 or variant thereof; and / or wherein the product is selected from the list consisting of an ABP or biABP, ABD, nucleic acid, NAC or recombinant host cell of the invention, in particular an ABP or biABP of the invention.

[0328] In a related aspect, the invention also relates to method of treating or preventing a disease, disorder or condition in a mammalian subject in need thereof, comprising administering to said subject at least once an effective amount of modulating compound as desired above, or, and in particular administering to said subject at least once an effective amount of the ABP or biABP, the NAC, the (host) cells, or the pharmaceutical composition as described above.

[0329] In another related aspect, the invention also relates to the use of a product of the invention as describe above, or a modulating compound as described above (in particular an ABP or biABP of the invention) for the manufacture of a medicament, in particular for the treatment of a disease, disorder or condition in a mammalian subject, in particular where the disease, disorder or condition is one as set out herein.

[0330] The term "treatment" in the present invention is meant to include therapy, e.g. therapeutic treatment, as well as prophylactic or suppressive measures for a disease (or disorder or condition). Thus, for example, successful administration of a LILRB1 and / or LILRB2 inhibitor prior to onset of the disease results in treatment of the disease. "Treatment" also encompasses administration of a ULRB1 and / or ULRB2 inhibitor after the appearance of the disease in order to ameliorate or eradicate the disease (or symptoms thereof). Administration of a LILRB1 and / or LILRB2 inhibitor after onset and after clinical symptoms, with possible abatement of clinical symptoms and perhaps amelioration of the disease, also comprises treatment of the disease. Those "in need of treatment" include subjects (such as a human subject) already having the disease, disorder or condition, as well as those prone to or suspected of having the disease, disorder or condition, including those in which the disease, disorder or condition is to be prevented.

[0331] In particular embodiments of these aspects, the modulating compound is one described above, and / or is an ABP or biABP, NAC, a (host) cell, or a pharmaceutical composition of the present invention; in particular is an ABP or biABP of the invention, and / or is an inhibitory nucleic acid of the invention.

[0332] Such a compound can for example in preferred embodiments, be an inhibitor or antagonist of expression, function, activity and / or stability of LILRB1 and / or ULRB2, or of the variant of LILRB1 and / or LILRB2. In particular, the compound inhibits the binding of a natural ligand of ULRB1 and / or ULRB2 protein (such as HLA-G or a variant thereof) to ULRB1 and / or LILRB2 protein (or a variant thereof), in particular inhibits the binding of HLA-G protein (or a variant thereof) to human ULRB1 and / or ULRB2 protein (or a variant thereof), such as inhibits the binding between the ECDs of such proteins; preferably wherein such proteins (or variants) and the inhibitions is described as above.

[0333] Such a compound can, for example, be a compound (such as an ABP or biABP or inhibitors nucleic acid) that has the any one or any combination of the following characteristics• specific binding to human ULRB1 and / or (preferably and) ULRB2 (e.g. comprising the amino acid sequence of SEQ ID NO: 353 (LILRB1) or SEQ ID NO: 358 (ULRB2), e.g., with a KD 50 nM or less, or of 20nM or less; more preferably of lOnM or less or 5nM or less lack of specific binding to a ULRA protein, such as preferably ULRA1 and / or LILRA3;• stimulates T cell activation, e.g., in a mixed lymphocyte reaction (MLR) assay, as measured by increased T cell proliferation or IFN-gamma secretion, e.g.;• stimulates differentiation or activation of monocytes into macrophages, e.g., stimulates differentiation of monocytes into pro-inflammatory macrophages, e.g., as shown in an assay described in the Examples;• inhibits binding of ULRB1 and / or (preferably and) LILRB2 to HLA-A and HLA-B, preferably to HLA-G;• has a binding profile as shown in Table 2;• promotes pro-inflammatory polarization of macrophages towards Ml macrophages; and• does not induce (or trigger) basophil activation;

[0334] In other aspects described elsewhere herein, are provided methods to detect and / or diagnose a disease, disorder or condition in a mammalian subject.

[0335] In one particular embodiment, the disease, disorder or condition that is characterised by a pathological immune response.

[0336] In a further particular embodiment, the disease, disorder or condition is characterised by expression of a natural ligand of ULRB1 and / or ULRB2, in particular by expression of HLA-G, by cells associated with the disease, disorder or condition, such as cancer cells. For example, the disease, disorder or condition can be associated with the undesired presence of a natural ligand of ULRB1 and / or ULRB2, such as a HLA-G positive cells or cells positive for such a ligand, in particular a disease or condition characterized by ULRB1 and / or ULRB2 positive monocytes and / or macrophages (in particular, TAMs).

[0337] In a yet further particular embodiment, a subject suffering from, or suspected of suffering from, a disease, disorder or condition is characterised as: (i) having a cancer positive for a natural ligand of ULRB1 and / or ULRB2, such as HLA-G and / or (ii) having ULRB1 and / or LILRB2 positive immune cells, in particular ULRB1 and / or LILRB2 positive monocytes and / or macrophages; and / or (iii) having ULRB1 and / or ULRB2 positive immune cells, in particular ULRB1 and / or ULRB2 positive monocytes (or macrophages); preferably wherein such ULRB1 and / or LILRB2 positive immune cells are present at or associated with the site of a cancer or tumour (such as being present in the tumour bed or tumour micro environment (TME) of such cancer or tumour, in particular with the presence of TAMs and / or MDSCs).

[0338] A disorder, disorder or condition treatable by the subject matter of the invention is, in certain alterative embodiments, one characterised by expression of a ligand of ULRB1 and / or ULRB2; in particular, one characterised by such expression that is aberrant, for example over- (or under-) expression or representation or activity of a ligand of ULRB1 and / or ULRB2 (in particular of HLA-G) in a given cell or tissue (such as those cells or tissues involved with the proliferative disease of the subject) compared to that in a healthy subject or a normal cell.

[0339] In yet a further particular embodiment, the disease, disorder or condition is characterised by expression and / or activity of ULRB1 and / or LILRB2 in an immune cell, such as a macrophage, in particular such cells express mRNA and / or protein of ULRB1 and / or ULRB2, and / or are positive for such ULRB1 and / or ULRB2 expression and / or activity.

[0340] In another particular embodiment, the disease, disorder or condition is a proliferative disorder (or a condition associated with such disorder or disease), in particular when the product or modulating compound (such as a ABP or biABP, ABD, nucleic acid, NAC or recombinant host cell of the invention, in particular an ABP or biABP of the invention) is an inhibitor and / or antagonist of the expression, function, activity and / or stability of ULRB1 and / or LILRB2 or a variant of LILRB1 and / or LILRB2.

[0341] A "proliferative disorder" refers to a disorder characterised by abnormal proliferation of cells. A proliferative disorder does not imply any limitation with respect to the rate of cell growth, but merely indicates loss of normal controls that affect growth and cell division. Thus, in some embodiments, cells of a proliferative disorder can have the same cell division rates as normal cells but do not respond to signals that limit such growth. Within the ambit of "proliferative disorder" is neoplasm or tumour, which is an abnormal growth of tissue or cells. Cancer is art understood, and includes any of various malignant neoplasms characterised by the proliferation of cells that have the capability to invade surrounding tissue and / or metastasise to new colonisation sites. Proliferative disorders include cancer, atherosclerosis, rheumatoid arthritis, idiopathic pulmonary fibrosis and cirrhosis of the liver. Non-cancerous proliferative disorders also include hyperproliferation of cells in the skin such as psoriasis and its varied clinical forms, Reiter's syndrome, pityriasis rubra pilaris, and hyperproliferative variants of disorders of keratinization (e.g., actinic keratosis, senile keratosis), scleroderma, and the like.

[0342] In more particular embodiments, the proliferative disorder is a cancer or tumour, in particular a solid tumour (or a condition associated with such cancer or tumour). Such proliferative disorders include, but are not limited to, head and neck cancer, squamous cell carcinoma, multiple myeloma, solitary plasmacytoma, renal cell cancer, retinoblastoma, germ cell tumours, hepatoblastoma, hepatocellular carcinoma, melanoma, rhabdoid tumour of the kidney, Ewing Sarcoma, chondrosarcoma, any haemotological malignancy (e.g., chronic lymphoblastic leukemia, chronic myelomonocytic leukemia, acute lymphoblastic leukemia, acute lymphocytic leukemia, acute myelogenous leukemia, acute myeloblasts leukemia, chronic myeloblastic leukemia, Hodgkin's disease, non- Hodgkin's lymphoma, chronic lymphocytic leukemia, chronic myelogenous leukemia, myelodysplastic syndrome, hairy cell leukemia, mast cell leukemia, mast cell neoplasm, follicular lymphoma, diffuse large cell lymphoma, mantle cell lymphoma, marginal zone lymphoma, Burkitt Lymphoma, mycosis fongoides, seary syndrome, cutaneous T-cell lymphoma, peripheral T cell lymphoma, chronic myeloproliferative disorders, myelofibrosis, myeloid metaplasia, systemic mastocytosis), and cental nervous system tumours (e.g., brain cancer, glioblastoma, non- glioblastoma brain cancer, meningioma, pituitary adenoma, vestibular schwannoma, a primitive neuroectodermal tumour, medulloblastoma, astrocytoma, anaplastic astrocytoma, oligodendroglioma, ependymoma and choroid plexus papilloma), myeloproliferative disorders (e.g., polycythemia vera, thrombocythemia, idiopathic myelofibrosis), soft tissue sarcoma, thyroid cancer, endometrial cancer, carcinoid cancer, or liver cancer.

[0343] In one preferred embodiment, the various aspects of the invention relate to, for example the ABPs or biABPs of the invention used to detect / diagnose, prevent and / or treat, such proliferative disorders that include but are not limited to carcinoma (including breast cancer, prostate cancer, gastric cancer, lung cancer, colorectal and / or colon cancer, hepatocellular carcinoma, melanoma), lymphoma (including non-Hodgkin's lymphoma and mycosis fongoides), leukemia, sarcoma, mesothelioma, brain cancer (including glioma), germinoma (including testicular cancer and ovarian cancer), choriocarcinoma, renal cancer, pancreatic cancer, thyroid cancer, head and neck cancer, endometrial cancer, cervical cancer, bladder cancer, or stomach cancer.

[0344] Accordingly, in a preferred embodiment, the proliferative disease is a cancer, for example lung cancer, breast cancer, colorectal cancer, gastric cancer, hepatocellular carcinoma, pancreatic cancer, ovarian cancer, melanoma, myeloma, kidney cancer, head and neck cancer, Hodgkin lymphoma, bladder cancer or prostate cancer, in particular one selected from the list consisting of: melanoma, lung cancer (such as non-small cell lung cancer), bladder cancer (such as urothelial carcinoma), kidney cancer (such as renal cell carcinoma), head and neck cancer (such as squamous cell cancer of the head and neck) and Hodgkin lymphoma. Preferably, the proliferative disease is melanoma, or lung cancer (such as non-small cell lung cancer).

[0345] In a particularly preferred embodiment, the disease, disorder or condition is a cancer positive for the ligand of ULRB1 and / or LILRB2 (such as HLA-G) and / or is a cancer characterised by the presence of LILRB1 and / or ULRB2 positive immune cells, in particular ULRB1 and / or ULRB2 positive monocytes and / or macrophages and / or is a cancer(or other proliferative disorder) characterised by being resistant and / or refractory to blockade of an immune checkpoint molecule (eg resistant and / or refractory to therapy for blockade of an immune checkpoint molecule), such as blockade using a ligand to an immune checkpoint molecule (as further described below, such as blockade of PD1 / CTLA4; analogous to Gao et al, 2017). For example, in one such embodiment, the disease, disorder or condition can be a proliferative disorder (such as cancer) resistant and / or refractory to PD1 / CTLA4 blockade therapy.

[0346] A preferred embodiment pertains to treatment of a disease, disorder or condition, preferably a proliferative disorder, which is characterized by a resistance to a therapy to a PD-1 / PD-L1 inhibitor therapy, such as a therapy with a anti- PD-1 inhibitory antibody.

[0347] In a further particular embodiment, the disease, disorder or condition is an infectious disease (or a condition associated with such disorder or disease), in particular when the product or modulating compound (such as a ABP or biABP, ABD, nucleic acid, NAC or recombinant host cell of the invention, in particular an ABP or biABP of the invention) is an inhibitor and / or antagonist of the expression, function, activity and / or stability of ULRB1 and / or LILRB2 or a variant of LILRB1 and / or LILRB2.

[0348] The term "infectious disease" is art recognized, and as used herein includes those diseases, disorders or conditions associated with (eg resulting from or caused by) by any pathogen or agent that infects mammalian cells, preferable human cells. Examples of such pathogens include bacteria, yeast, fungi, protozoans, mycoplasma, viruses, prions, and parasites. Examples of infectious disease include( a) viral diseases such as, for example, diseases resulting from infection by an adenovirus, a herpesvirus (e.g., HSV-I, HSV-II, CMV, or VZV), a poxvirus (e~g-, an orthopoxvirus such as variola or vaccinia, or molluscum contagiosum), a picornavirus (e.g., rhinovirus or enterovirus), an orthomyxovirus (e.g., influenza virus), a paramyxovirus (e.g., parainfluenza virus, mumps virus, measles virus, and respiratory syncytial virus (RSV)), a cononavirus (e.g., SARS), a papovavirus (e.g., papillomaviruses, such as those that cause genital warts, common warts, or plantar warts), a hepadnavirus (e.g., hepatitis B virus), a flavi virus (e.g., hepatitis C virus or Dengue virus), or a retrovirus (e.g., a lentivirus such as HIV); (b) bacterial diseases such as, for example, diseases resulting from infection by bacteria of, for example, the genus Escherichia, Enterobacter, Salmonella, Staphylococcus, Shigella, Listeria, Aerobacter, Helicobacter, Klebsiella, Proteus, Pseudomonas, Streptococcus, Chlamydia, Mycoplasma, Pneumococcus, Neisseria, Clostridium, Bacillus, Corynebacterium, Mycobacterium, Campylobacter, Vibrio, Serratia, Providencia, Chromobacterium, Brucella, Yersinia, Haemophilus, or Bordetella; (c) other infectious diseases, such chlamydia, fungal diseases including but not limited to candidiasis, aspergillosis, histoplasmosis, cryptococcal meningitis, parasitic diseases including but not limited to malaria, Pneumocystis camii pneumonia, leishmaniasis, cryptosporidiosis, toxoplasmosis, and trypanosome infection and prions that cause human disease such as Creutzfeldt-Jakob Disease (CJD), variant Creutzfeldt-Jakob Disease (vCJD), Gerstmann-Straeussler- Scheinker syndrome, Fatal Familial Insomnia and kuru.

[0349] In yet another particular embodiment, the disease, disorder or condition is one associated with an over-active or immune system or an immune system displaying undesired activity, such as autoimmunity, allergy or inflammatory conditions, in particular for allergy, autoimmunity, transplant rejection, inflammation, graft vs host disease or sepsis (or a condition associated with such diseases, disorders or conditions), in particular when the product or modulating compound (such as a ABP or biABP, ABD, nucleic acid, NAC or recombinant host cell of the invention, in particular an ABP or biABP of the invention) is an activator and / or agonist of the expression, function, activity and / or stability of ULRB1 and / or ULRB2 or a variant of LILRB1 and / or ULRB2.

[0350] According to the medical uses and methods of treatment disclosed herein, the subject is a mammal, and may include mice, rats, rabbits, monkeys and humans. In a preferred embodiment, the mammalian subject is a human patient.

[0351] In one embodiment, cells involved in the proliferative disorder are resistant to a humoral or cell-mediated immune response. For example, cells involved in the proliferative disorder (eg cells of a cancer or tumour) are resistantand / or refractory to blockade of an immune checkpoint molecule such as blockade using a ligand to an immune checkpoint molecule, in exemplary instances blockade of PD1 / CTLA4 (analogous to Gao et al, 2017).

[0352] In particular, the treatment methods may be applied to a proliferative disorder that has been subjected to prior immunotherapy (such as therapy for blockade of an immune checkpoint molecule, eg blockade of PD1 / CTLA4), in particular prior immunotherapy with a ligand to an immune checkpoint molecule. For example, in certain embodiments the ULRB1 and / or ULRB2 (eg antagonist) modulator, such as an ABP or biABP of the present invention, can be for use in the treatment of a proliferative disorder in a subject in need thereof, and the subject has been subjected to to prior immunotherapy, in particular prior administration of a ligand to an immune checkpoint molecule.

[0353] In other methods, the modulating (eg inhibiting) compound (eg an ABP or biABP, such as one of the present invention) may be used is in combination with a different anti-proliferative therapy, in particular a different anti-cancer therapy, in particular where the different anti-proliferative therapy is immunotherapy, in particular immunotherapy with a ligand to an immune checkpoint molecule. Accordingly, the composition can be for use in the treatment of a proliferative disorder in a subject in need thereof, where the subject is subjected to to co-treatment by immunotherapy, in particular co-therapy (eg combination treatment) with a ligand to an immune checkpoint molecule.

[0354] In such embodiments, the ligand is one that binds to an immune (inhibitory) checkpoint molecule. For example, such checkpoint molecule may be one selected from the group consisting of: A2AR, B7-H3, B7-H4, CTLA-4, IDO, KIR, LAG3, PD-1 (or one of its ligands PD-L1 and PD-L2), TIM-3 (or its ligand galectin-9), TIGIT and VISTA. In particular of such embodiments, the ligand binds to a checkpoint molecule selected from: CTLA-4, PD-1 and PD-L1. In other more particular embodiments, the ligand is an antibody selected from the group consisting of: ipilimumab, nivolumab, pembrolizumab, BGB-A317, atezolizumab, avelumab and durvaluma; in particular an antibody selected from the group consisting of: ipilimumab (YERVOY), nivolumab (OPDIVO), pembrolizumab (KEYTRUDA) and atezolizumab (TECENTRIQ).

[0355] When a method or use in therapy of the present invention (eg, one involving an ABP or biABP of the invention) is used in combination treatments together with any of such other procedures (eg, another agent or a cancer immunotherapy, such as a ligand that binds to an immune (inhibitory) checkpoint molecule), then such method or use being a combination treatment regimen may comprise embodiments where such exposures / administrations are concomitant. In alternative embodiments, such administrations may be sequential; in particular those embodiments where the LILRB1 and / or ULRB2 modulator (eg an ABP or biABP of the invention) is administered before such other procedure. For example, such ULRB1 and / or LILRB2 modulator may be sequentially administered within about 14 days of (eg before) the other procedure, such as within about 10 days, 7 days, 5 days, 2 days or 1 day of (eg before) the other procedure; and further including where the ULRB1 and / or ULRB2 modulator may be sequentially administered within about 48 hours, 24 hours, 12 hours, 8 hours, 6 hours, 4 hours, 2 hours, 1 hours, 30 mins, 15 mins or 5 mins of (eg before) the other procedure.

[0356] In certain embodiments, the medical uses or compositions are for use in enhancing an immune response in the subject, preferably for use in aiding a cell-mediated immune response in the subject such as the subject's T cell mediated immune response, for example for treating a proliferative disease such as a cancer disease.

[0357] In particular embodiments, the treatment can comprise a transfer of cells to the subject, preferably a transfer of immune cells to the subject, more preferably an adoptive T-cell transfer. For example, such cells can be autologous cells of the subject, for example autologous immune cells, such as T-cells, dendritic cells or Natural Killer (NK)-cells, of the subject.

[0358] In a preferred embodiment of the medical uses or compositions, the modulating compound (eg ABP or biABP of the invention) is an inhibitor or antagonist of expression, function, activity and / or stability of said ULRB1 and / or ULRB2, or the variant of LILRB1 and / or LILRB2, and wherein the inhibition of the expression, function, activity and / or stability of said LILRB1 and / or ULRB2, or the variant of ULRB1 and / or ULRB2, enhances an immune response,preferably enhances a cell-mediated immune response in the subject such as a T-cell mediated immune response in the subject, for example for treating an infectious disease or a proliferative disease such as a cancer disease, in particular where the composition is an...

Claims

CLAIMS1. An isolated bispecific antigen binding protein (ABP), comprising (i) a first antigen-binding site which specifically binds to the extra cellular domain (ECD) of leukocyte immunoglobulin-like receptor subfamily Bl (LILRB1) and LILRB2 protein and wherein the isolated bispecific ABP comprises at least one, preferably 3 or 6, complementarity determining regions (CDRs) and is capable of inhibiting the binding of LILRB1 and LILRB2 to a natural ligand thereof (a natural ligand of LILRB1 and / or LILRB2, such as HLA-G), wherein the bispec’ific ABP does not bind to, or binds with less affinity to (at least 2 times less), LILRA1 and LILRA3, and (ii) a second antigen-binding site specifically binding to an immune checkpoint inhibitor, preferably PD1 or PDL1.

2. The isolated bispecific ABP of claim 1, wherein the first antigen-binding site of the bispec'ific ABP competes for binding to an ECD of LILRB1 and / or LILRB2, or to an ECD of the variant of LILRB1 and / or LILRB2, with an endogenous LILRB1 and / or LILRB2 ligand or receptor, preferably wherein said endogenous LILRB1 and / or LILRB2 ligand or receptor is an HLA-G protein (or a variant of HLA-G).

3. The isolated bispecific ABP of claim 2, wherein the first antigen-binding site of the bispecific ABP is capable of inhibiting the binding of HLA-G protein or a variant thereof to ULRB1 and / or LILRB2 protein ora variant thereof with an IC50 of less than lOOnM, less than 50nM, or preferably 20nM or less, such as 15nM or less, or less than l OnM, as determined by ELISA.

4. The isolated bispedfic ABP of any one claims Fehler! Verweisquelle konnte nicht gefunden werden. to 3, wherein the first antigen-binding site of the bispecific ABP comprises at least one complementarity determining region 3 (CDR3) having an amino acid sequence with at least 90% sequence identity to, or having no more than three or two, preferably no more than one amino acid substitution(s), deletion(s) or insertion(s) compared to, a sequence selected from SEQ ID Nos. 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, 99, 103, 107, 111, 115, 119, 123, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187, 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, 255, 259, 263, 267, 271, 275, 279, 283, 287, 291, 295, 299, 303, 307, 311, 315, 319, 323, 327, 331, 335, 339, 343, 347, 351, 355, 359, 363, 367, 371, 375, 379, and 383.

5. The isolated bispecific ABP of any one of claims Fehler! Verweisquelle konnte nicht gefunden weiden. to 4, wherein the first antigen-binding site of the bispecific ABP is an antibody, or an antigen binding fragment thereof, composed of at least one, preferably two, antibody heavy chain sequences, and at least one, preferably two, antibody light chain sequences, wherein at least one, preferably both, of the antibody heavy chain sequences and at least one, preferably both, of the antibody light chain sequences comprise CDR1 to CDR3 sequences in a combination selected from any of the following combinations of heavy and / or light chain CDRs, CDRs-A-001 to CDRs-A-048:in each case independently, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to these sequences.

6. The isolated bispecific ABP of any one of claims 1 to 5, wherein the first antigen-binding site of the bispecific ABP comprises a heavy chain variable domain sequence comprising: - a heavy chain CDR1 of SEQ ID NO: 353, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s)or deletion(s) compared to this sequence; anda heavy chain CDR2 of SEQ ID NO: 354, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to this sequence; and a heavy chain CDR3 of SEQ ID NO: 355, optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to this sequence; and comprises a light chain variable domain sequence comprising a light chain CDR1 of SEQ ID NO: 357, optionally with no more than three or two, preferably no more than one, amino add substitution(s), insertion(s) or deletion(s) compared to this sequence; and a light chain CDR2 of SEQ ID NO: 358, optionally with no more than three ortwo, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to this sequence; and a light chain CDR3 of SEQ ID NO: 359; optionally with no more than three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to this sequence.

7. The isolated bispedficABP of any one of claims 1 to 6, wherein the first antigen-binding site of the bispecific ABP comprises an antibody heavy chain variable domain sequence of SEQ ID No: 356, optionally with no more than ten, nine, eight, seven, six, five, four, three ortwo, preferably no more than one, aminoacid substitution(s), insertion(s) or deletion(s) compared to this sequence; and comprises an antibody light chain variable domain sequence of SEQ ID No: 360, optionally with no more than ten, nine, eight, seven, six, five, four, three or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to this sequence.

8. The isolated bispecific ABP of any one of claims 1 to 7, wherein the first antigen-binding site of the bispecific ABP binds to the same epitope of an extracellular domain of LILRB1 and / or ULRB2 as antibody clone A-045.

9. The isolated bispecific ABP of any one of claims 1 to 8, characterized by: a. specifically binding to ULRB1 and LILRB2, wherein the bispecific ABP is characterized by binding the same epitope on LILRB1 and LILRB2 as an antibody of Table 1, preferably A-001, A-003, A-010 or A- 045; b. not binding to, or binding with less affinity to, LILRA1; c. not binding to, or binding with less affinity to, LILRA3; and / or d. when bound to LILRB1 and / or LILRB2 on a human monocyte decrease M2-like polarization of monocyte,10. The isolated bispecific ABP of claim 9, wherein the first antigen-binding site of the bispecific ABP is characterized by not binding to, or binding with less affinity to, LILRA1 and LILRA3 compared to the binding affinity of the ABP to LILRB1 and LILRB2.

11. The isolated bispedficABP of claim 9 or 10, further characterized by e. when bound to LILRB1 on a human macrophage induces phagocytosis of the cell.

12. The isolated bispecific ABP of any one of claims 9 to 11, wherein the bispecific ABP is further characterized by f. when bound to human LILRB1 and / or LILRB2 on a human monocyte or macrophage reduces expression of markers of M2-like macrophages, such as CD163, CD206 or CD209.

13. The isolated bispedficABP of any one of claims ') to 12 wherein the bispedfic ABP is further characterized by g. when bound to human LILRB1 and / orLILRB2 on a human monocyte ormacrophageincreasesexpressionof marteis of Ml-like macrophages, such as CD86.

14. The isolated bispecific ABP of any one of claims 9 to 13, wherein the bispecific ABP is further characterized by h. when bound to human LILRB1 and / or LILRB2 on a human monocyte or macrophage induces secretion of pro- inflammatory cytokines, such as increases secretion GM-CSF, IFNg and IL-9; preferably independent of the presence of LILRA1 and / or LILRA3.

15. The isolated bispedficABPofanyone of claims I to 14, wherein the bispedficABP is an inhibitororantagonist of ULRB1 and LILRB2, preferably of an interaction of LILRB1 and LILRB2 with a natural ligand thereof, such as HLA- G.

16. The isolated bispedfic ABP of any one of claims 1 to 15, wherein the bispecific ABP when bound to LILRB1 or LILRB2 on a macrophage reduces the polarization into an M2 like macrophage or repolarize an M2 like macrophage.

17. The isolated bispedfic ABP of any one of claims 1 to 16, wherein the bispecific ABP when bound to LILRB1 or LILRB2 on a macrophage reduces the polarization into an M2 like macrophage or repolarize an M2 like macrophage into an Ml like macrophage.

18. The isolated bispecific ABP of any one of claims 1 to 17, wherein the bispedficABP comprises at least one, alternatively two, first antigen-binding site(s), and at least one, alternatively two, second antigen -binding site(s).

19. The isolated bispecific ABP of any one of claims I to 18, wherein the bispedfic ABP comprises two first antigenbinding sites and two second antigen binding sites, wherein (X) the two second antigen binding sites are provided as one F(ab')2 fragment or one IgG antibody, wherein the IgG antibody comprises an antibody hinge-, CH2- and / or CH3- domain, and wherein the two first antibody binding sites are provided as two antibody scFv or scFab fragments, each of which is independently covalently connected to one of the two first antigen -binding sites, preferably via a protein linker, or (Y) the two first antigen binding sites are provided as one F(ab')2 fragment or one IgG antibody, wherein the IgG antibody comprises an antibody hinge-, CH2- and / or CH3-domain, and wherein the two first antibody binding sites are provided as two antibody scFv or scFab fragments, each of which is independently covalently connected to the two second antigen-binding sites, preferably via a protein linker.

20. The isolated bispedfic ABP of claim 19, which is composed of at least one, preferably two, first antibody (heavy / light) chain sequences, and at least one, preferably two, second antibody (heavy / light) chain sequences, wherein at least one, preferably both, of the first antibody (heavy / light) chain sequences comprises in N- to C-terminal direction:(1-1) an antibody heavy chain variable domain sequence comprising at least parts of the second antigen -binding site,(1-2) optionally, one or more antibody heavy chain constant domain sequences, such as a CHI, hinge, CH2 and / or CH3 domain,(1-3) a first peptide linker,(1-4) an antibody light chain variable domain sequence comprising at least parts of the first antigen -binding site;(1-5) optionally an antibody light chain constant domain sequence;(1-6) a second peptide linker,(1-7) an antibody heavy chain variable domain sequence comprising at least parts of the first antigen-binding site;(1-8) optionally, an antibody heavy chain constant domain sequence; and wherein at least one, preferably both, of the second antibody (heavy / light) chain sequences comprises in N-to C- terminal direction(2-1) an antibody light chain variabledomain sequence comprising at least parts of the second antigen -binding site;(2-2) an antibody light chain constant domain; wherein [(1-4) to (1-5)] and [(1-7) to (1-8)] can be interchanged, and / or wherein (l-4)and (1-5); and (l-7)and (1- 8); can be (both) interchanged.

21. The isolated bispecific ABP of claim 19, which is a bispecific ABP composed of at least one, preferably two, first antibody (heavy / light) chain sequences, and at least one, preferably two, second antibody (heavy / light) chain sequences, wherein at least one, preferably both, of the first antibody (heavy / light) chain sequences comprises in N- to C-terminal direction:(1-1) an antibody heavy chain variable domain sequence comprising at least parts of the first antigen-binding site,(1-2) optionally, one or more antibody heavy chain constant domain sequences, such as a CHI, hinge, CH2 and / or CH3 domain,(1-3) a first peptide linker,(1-4) an antibody light chain va liable domain sequence comprising at least parts of the second antigen -binding site;(1-5) optionally an antibody light chain constant domain sequence;(1-6) a second peptide linker,(1-7) an antibody heavy chain variable domain sequence comprising at least parts of the second antigen -binding site;(1-8) optionally, an antibody heavy chain constant domain sequence; and wherein at least one, preferably both, of the second antibody (heavy / light) chain sequences comprises in N-to C- terminal direction(2-1) an antibody light chain variable domain sequence comprising at least parts of the first antigen -binding site;(2-2) an antibody light chain constant domain; wherein [(1-4) to (1-5)] and [(1-7) to (1-8)] can be interchanged, and / or wherein (l-4)and (1-5); and (l-7)and (1-8); can be (both) interchanged.

22. The isolated bispecific ABP of claim 18, which is a biparatopic ABP in a format of a CrossMabfeb, CrossMab' or, preferably, a CrossMabCH1CL, preferably wherein the CrossMabCH1CLbiparatopic antibody is composed of a first heterodimer, and a second heterodimer, wherein the first heterodimer is composed of: a first antibody chain sequence comprising in N- to C-terminal orientation an antibody heavy chain variable domain sequence comprising at least parts of the first antigen -binding site (in an alternative embodiment of the second antigen-binding site), and an antibody heavy chain constant region (CHI), an antibody hinge sequence, an antibody CH2 and / or CH3 domain; and a second antibody chain sequence comprising in N- to C-terminal orientation an antibody light chain variable domain sequence comprising at least parts of the first antigen -binding site (in an alternative embodiment of the second antigen-binding site), and an antibody light chain constant region (CL); and the second heterodimer is composed of: a third antibody chain sequence comprising in N- to C-terminal orientation an antibody heavy chain variable domain sequence comprising at least parts of the second antigen -binding site (in an alternative embodiment of the first antigen-binding site), and an antibody light chain constant region (CL), an antibody hinge sequence, an antibody CH2 and / or CH3 domain; and a fourth antibody chain sequence, comprising in N- to C-terminal orientation an antibody light chain variable domain sequence comprising at least parts of the second antigen -binding site (in an alternative embodiment of the first antigen-binding site), and an antibody heavy chain constant region (CHI); wherein at least the first and the third antibody chain sequences comprise each either a donor-, or acceptor- respectively, antibody chain pairing domain which are capable of mediating a specific pairing of the first antibody chain sequence with the third antibody chain sequence.

23. The isolated bispecific ABP of claim 19, wherein the one or two antibody heavy chain sequence comprises the amino acid sequence shown in SEQ ID NO: 398, optionally with no more than 10, 9, 8, 7, 6, 5, 4, 3 or two, preferably no more than one, amino acid substitution(s), insertion(s) or deletion(s) compared to the sequence; and / or wherein the one or two antibody light chain sequence comprises the amino acid sequence shown in SEQ ID NO: 399, optionally with no more than 10, 9, 8, 7, 6, 5, 4, 3 or two, preferably no more than one, amino add substitution(s), insertions) or deletion(s) compared to the sequence.

24. The isolated bispedficABP of any one of claims 1 to 23, wherein the second antigen binding site is an anti- PD-1 / PD-L1 binding site.

25. The isolated bispecific ABP of claim 24, wherein the second antigen binding site comprises CDR1, CDR2 and CDR3 regions from a known inhibitory anti-PD-l / PD-Ll antibody.

26. The isolated bispedfic ABP of claim 25, wherein the anti-PD-l / PD-Ll antibody is selected from nivolumab durvalumab, pembrolizumab, cemiplimab, avelumab, durvalumab, and atezolizumab, and preferably is pembrolizumab.

27. An isolated bispecific ABP which competes with a bispedfic ABP as recited in any one of claims Fehleri Verweisquelle konnte nicht gefunden werden. to 26 for binding to the ECD of the LILRB1 and / or LILRB2 protein and is able to inhibit the binding of the LILRB1 and / or LILRB2 protein or the variant thereof to a natural ligand of LILRB1 and / or LILRB2.

28. The isolated bispecific ABP of any one of claims Fehler! Verweisquelle konnte nicht gefunden weiden. to 27 that (i) inhibits a binding of a natural ligand of LILRB1 and / or LILRB2 to LILRB1 and / or LILRB2, wherein such ligand is preferably HLA-G, and / or (ii) reduces development of immune-suppressive phenotypes, for example in a tumour microenvironment.

29. The isolated bispecific ABP of any one of claims Fehler! Verweisquelle konnte nicht gefunden weiden. to 28 that is an antibody or an antigen binding fragment thereof, wherein the antibody is a monoclonal antibody, or wherein the antigen binding fragment is a fragment of a monoclonal antibody.

30. An isolated nucleic acid encoding for a bispecific ABP, or for an antigen binding fragment or a monomer of a bispecific ABP, wherein the bispecific ABP is one recited in any one of claims Fehler! Verweisquelle konnte nicht gefunden werden. to 29.

31. The isolated nucleic acid of claim 30, comprising a nucleic acid having a sequence encoding a heavy or light chain CDR, a combination of heavy and / or light chain CDR1, CDR2 and CDR3 ora heavy or light chain variable domain, in each case as displayed in Table 1.

32. A nucleic acid construct (NAC), comprising a nucleic acid of claim 30 or 31, optionally with one or more additional features permitting the expression of the encoded bispecific ABP or component of said bispecific ABP in a cell, such as in a host cell.

33. The NAC of claim 32, comprising two constructs, one of which includes a nucleic acid encoding the heavy antibody chain, the other of which includes a nucleic acid encoding the light antibody chain, such that expression from both constructs can generate a complete antibody molecule.

34. A recombinant host cell comprising a nucleic add recited in claim 30 or 31, or a NAC recited in claim 32 or 33.

35. A pharmaceutical composition comprising: (i) a bispecific ABP recited in any one of claims Fehler! Verweisquelle konnte nicht gefunden werden. to 29, or (ii) a nucleic acid redted in claim 30 or 31, or (iii) a NAS recited in claim 32 or 33, or (iv) a recombinant host cell of 34, and a pharmaceutically acceptable carrier, stabiliser and / or excipient.

36. A product for use in medicine, wherein the product is selected from the list consisting of: (i) a bispecrfic ABP recited in any one of claims Fehler! Verweisquelle konnte nicht gefunden werden. to 29, or (ii) a nucleic acid recited in claim 30 or 31, or (iii) a NAC recited in claim 32 or 33, or (iv) a recombinant host cell of 34, and (iv) a pharmaceutical composition of claim 35.

37. The product for use of claim 36, wherein the use in medicine is a treatment of a proliferative disorder and wherein cells involved in the proliferative disorder express a natural ligand of LILRB1 and / or LILRB2, and wherein such cells induce an immune-suppressive phenotype in immune cells, such as macrophages, preferably of the subject.

38. The product for use of claim 36 or 37, wherein the product is for use in enhancing an immune response in a mammalian subject to be treated, preferably for use in promoting immune-activation of a humoral or cell-mediated immune response in the subject, such as promoting pro-inflammatory polarization of macrophages towards an Ml phenotype, for exam le for treating a proliferative disease, such as a cancer disease, of for treating an infectious disease.

39. The product for use of any one of claims 36 to 38, wherein the product has any one or any combination of the following characteristics: a. specific binding to human LILRB1 and / or (preferably and) LILRB2 (e.g. comprising the amino add sequence of SEQ ID NO: 353 (LILRB1) and SEQ ID NO: 358 (LILRB2)), e.g., with a KD 50 nM or less, or of 20nM or less; more preferably of lOnM or less or 5nM or less; b. lack of specific binding to a LILRA protein, such as preferably ULRA1 and / or LILRA3; c. stim ulates Tcell activation, e.g., in a mixed lymphocyte reaction (MLR) assay, as measured by increased T cell proliferation or IFN-gamma secretion; d. stimulates differentiation or activation of monocytes into macrophages, e.g., stimulates differentiation of monocytes into pro-inflammatory macrophages, e.g., as shown in an assay described in the Examples; e. inhibits binding of LILRB1 and / or (preferably and) ULRB2 to HLA-A and HLA-B, preferably to HLA-G; f. has a binding profile as shown in Table 2; g. promotes pro-inflammatory polarization of macrophages towards Ml macrophages; and h. does not induce (or trigger) basophil activation; i. induces secretion of proinflammatory cytokines in macrophages, such as GM-CSF, IFNg and IL-9; and j. induces phagocytosis.

40. The product for use of any one of claims 36 to 39, wherein the bispeaficABP is characterized by binding to an epitope of an extracellular domain of LILRB1 and LILRB2 which is bound by the antibody clone A-045.

41. A method of inducing phagocytosis in a cell, preferably a macrophage, the method comprising a step of contacting the macrophage with a bispecific ABP of any one of claims 1 to 29.

42. A method of modulating macrophage polarization, the method comprising a step of contacting a target cell with a bispecific ABP of any one of claims 1 to 29, and thereby inducing or enhancing Ml like macrophage phenotype in said target cell.

43. The method of claim 42, wherein the target cell is a monocyte or macrophage.

44. The method of claim 42 or 43, wherein macrophage polarization is modulated in the presence of cells expressing LILRA1 and / or LILRA3.

45. The method of any one of claims 42 to 44, wherein the modulation is a repolarization of an M2 like phenotype into an Ml like phenotype.

46. A method of treatment of a disease in a subject, the method comprising a step of administering to the subject a therapeutically effective amount of a bispecific ABP of any one of claims 1 to 29.

47. The method of claim 46, wherein the treatment comprises a use recited in any one of claims 36 to 40.

48. The method of claim 46 or 47, wherein the disease is a proliferative disease, preferably a cancer49. The method of any one of claims 46 to 48, wherein the treatment involves antagonizing immune-suppressive macrophage polarization in the subject, such as a polarization into M2 macrophages, and thereby enhances cell - mediated immune responses against cells involved with the disease.