WO2018014068A9 - Attenuated type i ifn cd47 combination therapy - Google Patents

Abstract

The present invention provides a combination therapy for treating a tumor in a subject. The combination therapy comprises administration of (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 antibody. The present invention also provides a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 antibody.

Description

ATTENUATED TYPE I IFN CD47 COMBINATION THERAPY RELATED APPLICATION

[0001] This application claims priority to US Provisional Patent Application No. 62/363,986 the entire disclosure of which is incorporated herein by cross reference.

FIELD OF INVENTION

[0002] The present invention relates to a polypeptide construct and its use in a combination therapy for the treatment of tumors. The polypeptide comprises an attenuated Type I interferon (IFN) linked to an anti-CD47 antibody. This construct can be used in the treatment of tumors in combination with an antibody which binds to a cell surface-associated antigen expressed on the tumor cell to provide a heightened anti-tumor response.

BACKGROUND OF INVENTION

[0003] Numerous peptide and polypeptide molecules have been described to function by interacting with a receptor on a cell surface, and thereby stimulating, inhibiting, or otherwise modulating a biological response, usually involving signal transduction pathways inside the cell that bears the said receptor. Examples of such molecules include peptide and polypeptide hormones, cytokines, chemokines, growth factors, apoptosis-inducing factors and the like. These molecules can be either soluble or can be attached to the surface of another cell.

[0004] Due to the biological activity of such molecules, some have potential use as therapeutics. Several peptide or polypeptide molecules have been approved by regulatory agencies as therapeutic products, including, for example, human growth hormone, insulin, interferon IFNα2b, IFNα2a, ΙFΝβ, ΙFΝγ, erythropoietin, G-CSF and GM-CSF. Many of these and other peptides have demonstrated potential in therapeutic applications, but have also exhibited toxicity when administered to human patients. One reason for toxicity is that most of these molecules trigger receptors on a variety of cells, including cells other than those that mediate the desired therapeutic effect. For example, when IFNα2b is used to treat multiple myeloma its utility resides, at least in part, in its binding to type I interferon receptors on the myeloma cells, which in turn triggers reduced proliferation and hence limits disease progression. Unfortunately, however, this IFN also binds to numerous other, normal cells within the body, triggering a variety of other cellular responses which are undesirable in the therapeutic setting, some of which are harmful (e.g. flu-like symptoms, neutropenia, depression). A consequence of such "off target" activity of peptides is that many peptides are not suitable as drug candidates. In this context, "off target activity" refers to activity on the peptide's natural receptor, but on the surface of cells other than those that mediate therapeutically beneficial effects.

[0005] Even though some peptides, such as IFNα2b, are approved for the treatment of medical conditions, they are poorly tolerated due to their "off target" biological activity. The off-target activity and associated poor tolerability also mean that some of these peptide based drugs cannot be administered at sufficiently high dosages to produce optimal therapeutic effects on the target cells which mediate the therapeutic effect.

[0006] Similarly, it has been known since the mid- 1980' s that interferons, in particular IFNα, are able to increase apoptosis and decrease proliferation of certain cancer cells. These biological activities are mediated by type I interferon receptors on the surface of the cancer cells which, when stimulated, initiate various signal transduction pathways leading to reduced proliferation and/or the induction of terminal differentiation or apoptosis. IFNα has been approved by the FDA for the treatment of several cancers including melanoma, renal cell carcinoma, B cell lymphoma, multiple myeloma, chronic myelogenous leukemia (CML) and hairy cell leukemia. A "direct" effect of IFNα on the tumor cells is mediated by the IFNα binding directly to the type I IFN receptor on those cells and stimulating apoptosis, terminal differentiation or reduced proliferation. One "indirect" effect of IFNα on non-cancer cells is to stimulate the immune system, which may produce an additional anti-cancer effect by causing the immune system to reject the tumor.

[0007] Unfortunately, the type I interferon receptor is also present on most non-cancerous cells. Activation of this receptor on non-cancerous cells by an IFNα causes the expression of numerous pro-inflammatory cytokines and chemokines, leading to toxicity. Such toxicity prevents the dosing of IFNα to a subject at levels that exert the maximum anti-proliferative and pro-apoptotic activity on the cancer cells.

[0008] Ozzello et al. (Breast Cancer Research and Treatment 25:265-76, 1993) described covalently attaching human IFNα to a tumor-targeting antibody, thereby localizing the direct inhibitory activity of IFNα to the tumor as a way of reducing tumor growth rates, and demonstrated that such conjugates have anti-tumor activity in a xenograft model of a human cancer. The mechanism of the observed anti-cancer activity was attributed to a direct effect of IFNα on the cancer cells, since the human IFNα used in the experiments did not interact appreciably with the murine type I IFN receptor, which could have led to an indirect anti-cancer effect. Because of this lack of binding of the human IFNα to the murine cells, however, the authors could not evaluate the toxicity of the antibody-IFNα conjugate relative to free IFNα. These authors used a chemical method to attach the IFNα to the antibody.

[0009] Alkan et al., (Journal of Interferon Research, volume 4, number 3, p. 355-63, 1984) demonstrated that attaching human IFNα to an antibody that binds to the Epstein-Barr virus (EBV) membrane antigen (MA) increased its antiproliferative activities towards cells that express the EBV-MA antigen. This increased potency was dependent on both antigen expression by the target cells and the binding specificity of the antibody. The cell line tested was the cancer cell line QIMR-WIL, a myeloblastic leukemia. The authors suggested that the attachment of IFNα to an antibody could be used as a treatment for cancer since it would reduce tumor growth. Alkan et al did not address the potential toxicity of these antibody-IFNα conjugates arising from their interactions with normal, antigen-negative cells.

[0010] It is also known that the linkage between an antibody and IFNα may be

accomplished by making a fusion protein construct. For example, IDEC (WOOl/97844) disclose a direct fusion of human IFNα to the C terminus of the heavy chain of an IgG targeting the tumor antigen CD20. Other groups have disclosed the use of various linkers between the C- terminus of an IgG heavy chain and the IFNα. For example, US 7,456,257 discloses that the C- terminus of an antibody heavy chain constant region may be connected to IFNα via an intervening serine-glycine rich (S/G) linker of the sequence (GGGGS)_n, where n may be 1, 2 or 3, and that there are no significant differences in the IFNα activity of the fusion protein construct regardless of linker length.

[0011] Morrison et al. (US8,563,692; and Xuan C, Steward KK, Timmerman JM, Morrison SL. Targeted delivery of interferon-a via fusion to anti-CD20 results in potent antitumor activity against B-cell lymphoma. Blood 2010;115:2864-71) also disclose IFNα linked to the C-terminus of the heavy chain of a cancer-targeting IgG antibody, with an intervening S/G linker, and observed that the fusion of the IgG and linker to the IFNα reduced the activity of IFNα on cells that did not express the corresponding antigen on the cell surface. The decreased IFN activity of these fusion protein constructs was modest when compared to human non-fusion protein IFNα (free IFNα) acting on human cells, but appeared to be more significant for murine IFNα on murine cells. The decrease in the activity of human IFNα that results from fusing it to the C- terminus of an antibody, as observed by Morrison et al, and in US 7,456,257 is modest and is generally considered to be a disadvantage since it reduces potency of the IFN. This disadvantage was pointed out, for example, by Rossi et al (Blood vol. 1 14, No. 18, pp3864-71), who used an alternative strategy of attaching the IFNα to a tumor targeting antibody in such a way that no loss in IFNα activity was observed.

[0012] In general the prior art teaches to use a potent IFN and to target this IFN to cancer cells. While this approach results in an increase in activity of the IFN against cancer cells, it does not address the issue of activity of the IFN on normal "off-target" cells. In prior art examples referred to above, the human IFNα portion of the antibody-IFNα fusion protein maintained a high proportion of native IFNα activity when exposed to human cells that do not express the corresponding antigen on their cell surfaces. This activity may lead to toxicity arising from the activation of non-cancerous, normal ("off target") cells by the IFNα portion of the fusion protein. Accordingly, there exists a need to decrease the "off-target" activity of IFN- based drugs, while retaining the "on-target", therapeutic effect of such drugs. The maintenance of target- specific activity and at the same time a reduction in non-target toxicity of these types of therapeutic agents would create a greater therapeutic concentration window for therapeutically useful peptides. It would for example be desirable to use human IFNα in a form such that its activity can be directed to the cancer cells while minimizing its effects on normal human cells. Ideally the type I interferon receptor on the cancer cells would be maximally stimulated, while the same receptor on non-cancerous cells would experience minimal stimulation. There is a need to target human IFNα to the cancer cells in such a way that it has dramatically more activity on the cancer cells, which display the antigen, than on the normal cells, which do not display the antigen. The same logic applies to other potentially therapeutic molecules, e.g. other cytokines, peptide and polypeptide hormones, chemokines, growth factors, apoptosis-inducing factors and the like.

[0013] The logic of this approach has been demonstrated in WO 2013/059885,

WO 2014/178820 and WO 2016/065409, the disclosure of each of which is incorporated herein by cross reference.

[0014] Macrophages are innate immune cells that reside in all tissues. In cancer, macrophages can promote or inhibit tumor growth depending on cellular signals.

Characterization of subsets of macrophages has revealed at least 2 subsets; one subset, M2 macrophages, produces arginase and promotes tumor growth while another subset, Ml macrophages, produces nitrous oxide synthetase and mediates tumor killing. Macrophages can kill via antibody dependent mechanisms such as antibody-dependent cellular phagocytosis (ADCP) or antibody independent mechanisms.

[0015] Unlike healthy cells, unwanted, aged or dying cells display markers or ligands called "eat-me" signals, i.e. "altered self", which can in turn be recognized by receptors on phagocytes such as neutrophils, monocytes and macrophages. Healthy cells may display "don't eat-me" signals that actively inhibit phagocytosis; these signals are either downregulated in the dying cells, are present in an altered conformation or they are superseded by the upregulation of "eat- me" or pro-phagocytic signals. The cell surface protein CD47 on healthy cells and its engagement of a phagocyte receptor, Signal Regulatory Protein a (SIRPa), constitutes a key "don't eat-me" signal that can turn off engulfment mediated by multiple modalities, including apoptotic cell clearance and FcR mediated phagocytosis. Blocking the CD47 mediated engagement of SIRPoc on a phagocyte, or the loss of CD47 expression in knockout mice, can cause removal of live cells and non-aged erythrocytes. Blocking SIRPoc also allows engulfment of targets that are not normally phagocytosed, for those cells where pre-phagocytic signals are also present.

[0016] CD47 is a broadly expressed transmembrane glycoprotein with a single Ig-like domain and five membrane spanning regions, which functions as a cellular ligand for SIRPoc, with binding mediated through the NH2-terminal V-like domain of SIRPoc. SIRPoc is expressed primarily on myeloid cells, including macrophages, granulocytes, myeloid dendritic cells (DCs), mast cells, and their precursors, including hematopoietic stem cells. Structural determinants on SIRPoc that mediate CD47 binding are discussed by Lee et al. (2007) J. Immunol. 179:7741- 7750; Hatherley et al. (2007) J.B.C. 282: 14567-75; and the role of SIRPoc cis dimerization in CD47 binding is discussed by Lee et al. (2010) J.B.C. 285:37953-63. In keeping with the role of CD47 to inhibit phagocytosis of normal cells, there is evidence that it is transiently upregulated on hematopoietic stem cells (HSCs) and progenitors just prior to and during their migratory phase, and that the level of CD47 on these cells determines the probability that they are engulfed in vivo.

[0017] CD47 is overexpressed in all cancers tested to date. Indeed it has been shown that CD47 is over-expressed on tumor versus normal cells by approximately 3.3 fold (Majeti et al (2009) Cell 138:286-289: Willingham et al (2012) PNAS 109:6662-6667).

[0018] Programmed cell death (PCD) and phagocytic cell removal are amongst the ways that an organism responds in order to remove damaged, precancerous, or infected cells. Thus, the cells that survive this organismal response (e.g., cancerous cells, chronically infected cells, etc.) have devised ways to evade PCD and phagocytic cell removal. CD47, the "don't eat me" signal, is constitutively upregulated on a wide variety of diseased cells, cancer cells, and infected cells, allowing these cells to evade phagocytosis. Anti-CD47 agents that block the interaction between CD47 on one cell (e.g., a cancer cell, an infected cell, etc.) and SIRPoc on another cell (e.g., a phagocytic cell) counteract the increase of CD47 expression and facilitate the phagocytosis of the cancer cell and/or the infected cell. Thus, anti-CD47 agents can be used to treat and/or protect against a wide variety of conditions/disorders.

SUMMARY OF INVENTION

[0019] In a first aspect the present invention provides combination therapy for treating a tumor in a subject, the combination therapy comprising administration of (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti- CD47 ligand.

[0020] In a second aspect the present invention provides a polypeptide construct comprising a first and a second region wherein the first region comprises an anti-CD47 ligand and the second region comprises an attenuated Type I interferon (IFN).

[0021] In both aspects it is preferred that the anti-CD47 ligand is an anti-CD47 antibody which preferably lacks effector function.

[0022] In the combination therapy of the present invention components (i) and (ii) may be administered sequentially or simultaneously.

[0023] In a third aspect the present invention provides a method of treating a tumor in a subject comprising using the combination therapy of the present invention.

[0024] In a fourth aspect the present invention provides a composition comprising (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti- CD47 ligand in admixture.

[0025] In a fifth aspect the present invention provides the use of (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti- CD47 ligand in the preparation of a medicament(s) for use in the treatment of a tumor. [0026] In a sixth aspect the present invention provides the use of the polypeptide construct of the second aspect of the present invention in the preparation of a medicament(s) for use in the treatment of a tumor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1: A graph demonstrating the robust anti-myeloma tumor activity observed in mice treated with anti-hCD47 antibody -attenuated IFNα2b fusion protein plus anti-hCD38 antibody. Treatment with either of the single agents anti-CD38 antibody or anti- CD47 antibody did not lead to tumor free survival (TFS). Similarly the combination of naked anti-hCD47 antibody plus naked anti-hCD38 antibody also did not lead to TFS. Coadministration of the anti-hCD47 antibody- attenuated IFNα2b fusion protein and a naked anti- CD38 antibody led to 100% TFS.

[0028] Figure 2. A graph demonstrating robust anti-tumor activity of an anti-hCD47 antibody-attenuated IFNα2b fusion protein in combination with naked anti-hCD38 antibody in the myeloma xenograft model utilizing a different anti-hCD38 naked antibody (G005). The results indicated strong anti-tumor activity of anti-hCD47 antibody-attenuated interferon α2b fusion protein in combination with naked anti-hCD38 (G005) antibody, with 10 of 10 mice remaining tumor free at the end of the study (day 60).

[0029] Figure 3. Figure 3. A graph demonstrating the combination of an anti-hCD47 antibody-attenuated IFNα2b fusion protein plus anti-hCD38 naked antibody leads to enhanced anti-tumor response in a refractory myeloma model, OPM-2. OPM2 tumors only weakly respond to just anti-hCD47 antibody- attenuated IFNα2b fusion protein treatment or just anti-hCD38 antibody treatment, resulting in slight delay in tumor growth. When these two agents are co- administered, however, this treatment leads to strong tumor control and

significantly delayed tumor growth.

[0030] Figure 4. A graph demonstrating strong anti-myeloma tumor activity with the combination of an anti-hCD38 antibody with different anti-hCD47 antibody-attenuated IFNα2b fusion proteins generated from two different anti-CD47 antibody clones (2A1 and 5F9). The two CD47 antibodies (2A1 and 5F9) used to create additional fusion proteins bind distinct epitopes from that of B6H12 used in Example 1.

[0031] Figure 5. Graph demonstrating robust anti-leukemia tumor activity observed in mice treated with anti-hCD47 antibody-attenuated IFNα2b fusion protein plus anti-hCD52 antibody. The xenograft model of acute T cell leukemia, CCRF-CEM, showed strongly enhanced survival when treated with a combination of anti-hCD47 antibody- attenuated IFNα2b fusion protein plus anti-CD52 antibody.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or integer or group of elements or integers but not the exclusion of any other element or integer or group of elements or integers.

[0033] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0034] All publications mentioned in this specification are herein incorporated by reference in their entirety.

[0035] It must be noted that, as used in the subject specification, the singular forms "a", "an" and "the" include plural aspects unless the context clearly dictates otherwise. Thus, for example, reference to "an agent" includes a single agent, as well as two or more agents; reference to "a molecule" includes a single molecule, as well as two or more molecules; and so forth.

[0036] In a first aspect the present invention provides combination therapy for treating a tumor in a subject, the combination therapy comprising administration of (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand.

[0037] In a second aspect the present invention provides a polypeptide construct comprising a first and a second region wherein the first region comprises an anti-CD47 ligand and the second region comprises an attenuated Type I interferon (IFN).

[0038] In both aspects it is preferred that the anti-CD47 ligand is an anti-CD47 antibody which preferably lacks effector function. In particular it is preferred that the Fc region of the antibody does not bind the Fey receptor. A lack of effector function may be advantageous in that the anti-CD47 antibody, by itself, does not stimulate functions such as antibody dependent cytotoxic phagocytosis (ADCP), but instead depends for ADCP on the binding of another antibody, such as an antibody targeting a cell surface associated antigen on another cell surface, which does contain effector function.

[0039] There are various ways known in the art to remove effector function. One is replacement of the N-linked glycosylation site on residue N297 to another residue, such as alanine (as shown in the examples and designated "non-glycosylated"). Other methods include making an antibody (which includes N297) in a cellular host that does not glycosylate N297 (e.g. in E. coli). Another way is to use an antigen-binding antibody fragment (Fab, Fab' 2, scFv, Fv, etc) in which relevant effector function portions of the Fc are removed. Another way is to remove the glycosylation on residue N297 with a glycosidase such as PNGase F. Other ways of removing effector function are inclusion of one or more of various known Fc mutations that obliterate binding to various Fey receptors. Further information regarding ablating Fc effector function is provided in WO 2011/066501, WO 2012130831, WO 2009/100309, WO

2006/076594, WO 1999/58572, US 2006/0134709, WO 2006/047350, WO 2006/053301, US 6,737,056, US 5,624,821, US 2010/0166740, Dall'Acqua (2006) J Immunol 177: 1129-1138, Chan et al (2010) Nature Reviews Immunology 10:301-316, Lo et al (2017) JBC Ml 16.767749, Leabman et al (2013) MAbs 5:896-903, Arduin et al (2015) Mol Immunol 63:456-463, and Schloter et al (2016) Protein Eng Des Sel 10:457-466. [0040] The invention, however, also includes versions of the polypeptide construct where the anti-CD47 ligand does have effector function, such as those with normal IgGl, IgG2 or IgG4 Fc's (including IgG4 with the hinge-stabilizing mutation). These forms of the CD47 are likely to be less safe than versions lacking effector function, but could nonetheless have a role when delivered at selected dose levels.

[0041] In the combination therapy of the present invention components (i) and (ii) may be administered sequentially or simultaneously.

[0042] In a third aspect the present invention provides a method of treating a tumor in a subject comprising using the combination therapy of the present invention.

[0043] In a fourth aspect the present invention provides a composition comprising (i) an antibody which binds to a cell surface-associated antigen expressed on a tumor cell and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand for use in a method for treating tumors.

[0044] In a fifth aspect the present invention provides the use of (i) an antibody which binds to a cell surface-associated antigen expressed on a tumor cell and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand for use in a method for treating tumors of the combination therapy of the present invention in the preparation of one or more medicament(s) for use in the treatment of a tumor.

[0045] In a sixth aspect the present invention provides a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand for use as a medicament.

[0046] In a seventh aspect the present invention provides the use of a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand in the preparation of a medicament(s) for use in the treatment of a tumor.

[0047] As will be clear it is a feature of the present invention that the Type I interferon is attenuated. As used herein the term "attenuated Type I IFN" means that the sequence of the Type I IFN is altered (mutated) in manner to reduce the potency of the Type I interferon for a cell possessing an IFN receptor. This reduced potency may be due to decreased affinity of the attenuated Type 1 IFN for the IFN receptor.

[0048] In certain embodiments the attenuated Type I IFN is linked to the antibody via a peptide bond. This linkage may be direct or via a linker of 1 to 20 amino acids in length.

Typically the attenuated Type I IFN will be linked to the C-terminus of the light chain or heavy chain constant region of the antibody.

[0049] It is preferred that the attenuated Type I IFN is attenuated IFNα.

[0050] The attenuated Type I IFNα may have any amino acid sequence selected from SEQ ID NOs 1 to 3, 80 to 90, 434 and 435. This sequence will also include at least one amino acid substitution or deletion which attenuates the IFNα activity.

[0051] In certain embodiments the attenuated IFNα is attenuated IFNα2b. An exemplary wild type IFNα2b sequence is shown in SEQ ID NO: 3 and in certain embodiments the attenuated IFNα2b comprises, relative to wild type, at least one amino acid substitution or deletion selected from the group consisting of L15A, R22A, R23A, S25A, L26A, F27A, L30A, L30V, K31A, D32A, R33A, R33K, R33Q, H34A, Q40A, Dl 14R, LI 17A, R120A, R120E, R125A, R125E, K131A, E132A, K133A, K134A, M148A, R149A, S152A, L153A, N156A, (L30A, H57Y, E58N and Q61S), (R33A, H57Y, E58N and Q61S), (M148A, H57Y, E58N and Q61S), (L153A, H57Y, E58N and Q61S), (R144A, H57Y, E58N and Q61S), (N65A, L80A, Y85A and Y89A,) (N65A, L80A, Y85A, Y89A and Dl 14A), (N65A, L80A, Y85A, Y89A and L117A), (N65A, L80A, Y85A, Y89A and R120A), (Y85A, Y89A and D114A), (D114A and R120A), (L117A and R120A), (LI 17A, R120A and K121A), (R120A and K121A), (R120E and K121E), replacement of R at position 144 with A, D, E, G, H, I, K, L, N, Q, S, T, V or Y, replacement of A at position 145 with D, E, G, H, I, K, L, M, N, Q, S, T, V or Y, deletion of residues LI 61 to El 65, and combinations thereof. A preferred mutation, relative to wild type, is A145D and an example of such an attenuated IFNα2b is shown in SEQ ID NO: 44 and SEQ ID NO:536. [0052] As will be recognized by those skilled in the art where a different IFNα2b sequence is used the mutations referred to above will be made in corresponding positions from the wild- type IFNα2b sequence.

[0053] The attenuated IFNα2b may also be aglycosylated attenuated IFNα2b. The residue T 106 of the aglycosylated attenuated IFNα2b may be deleted or substituted with an amino acid other than T in order to remove a site of glycosylation when the IFNα2b is produced in a mammalian cell.

[0054] In another embodiment the cell surface-associated antigen is selected from the group consisting of CD38, CD138, RANK-Ligand, HM1.24, CD56, CS 1 , CD20, CD74, IL-6R, Blys (BAFF), BCMA, Kininogen, beta2 microglobulin, FGFR3, ICAM-1, matriptase, CD52, EGFR, GM2, alpha4-integrin, IFG-1R, KIR, CD3, CD4, CD8, CD24, CD30, CD37, CD44, CD69, CD71 , CD79, CD83, CD86, CD96, HLA, PD- 1 , ICOS, CD33, CD1 15, CDl lc, CD19, CD52, CD14, FSP1 , FAP, PDGFR alpha, PDGFR beta, ASGR1 , ASGR2, FSP1 , LyPD3, RTI140/Ti- alpha, HTI56, VEGF receptor, CD241 the product of the RCHE gene, CD1 17 (c-kit), CD71 (transferrin receptor), CD36 (thrombospondin receptor), CD34, CD45RO, CD45RA, CD1 15, CD 168, CD235, CD236, CD237, CD238, CD239, CD240 TROP2, CD70, CCR2, HER2, EGFR, IGF1R, CEA and CCR3.

[0055] In some embodiments cell surface associated antigens include CD38, CD 138, EpCAM, TROP2, CD 19, CD20, CD79b, CD22 and CD52. Antibodies directed against these antigens include CD138 (Indatuximab ravtansine (BT062), Kevin R. Kelly et al. Blood 2013 122:758, EpCAM (adecatumumab and edrocolomab, Miinz et al. Cancer Cell International 2010, 10:44 DOI: 10.1186/1475-2867-10-44), TROP2 (Sacituzumab govitecan, Cardillo et al,

Bioconjug Chem. 2015 May 20;26(5):919-31. doi: 10.1021/acs.bioconjchem. 5b00223), CD19 (Blinotumumab, Naddafi et al. Int J Mol Cell Med. 2015 Summer; 4(3): 143-151), CD20 (example rituximab, Shane D. Cancer Practice Volume 6, Issue 3. 5/1/1998 Pages 195-197 and ofatumumab, Thomas S. Lin, Pharmacogenomics and personalized Medicine May 10, 2010 and Obinutuzumab (afutuzumab), Evans et al. J Adv Pract Oncol. 2015 Jul-Aug;6(4):370-4), CD79b (polatuzumab, pfeifer er al. Leukemia (2015) 29, 1578-1586), CD22 (example, epratuzumab, Carnahan et al. Clinical Cancer Research Vol. 9, September 1, 2003 and pinatuzumab, pfeifer er al. Leukemia (2015) 29, 1578-1586)) and CD52 (example alemtuzumab, Christian et al. Semin Hematol. 2008 Apr; 45(2): 95-103.)

[0056] In a more particular embodiment the cell surface-associated antigen is CD38. In certain embodiments the VH sequence of the antibody is selected from the group consisting of SEQ ID Nos: 342, 344, 346, 504, 511 and 538, and the V_L sequence of the antibody is selected from the group consisting of SEQ ID Nos: 341, 343, 345, 505, 512, 533and 537; as well as related antibodies of any combination of the foregoing V_H and V_L sequences. An antibody that is a "related antibody" (which encompasses a "related antigen-binding fragment") of a reference antibody encompasses antibodies (and antigen-binding fragments thereof) that: compete with the reference antibody for binding the target antigen (e.g., in some embodiments, competition for the same, overlapping, or adjacent epitopes), have the epitopic specificity of the reference antibody, comprise the complementarity determining regions (CDRs) of the reference antibody (in some embodiments, there may be up to 1, 2, 3, 4, or 5 conservative amino acid substitutions in the whole of the CDRs, or up to 1 or 2 conservative substitutions in each CDR), or comprise the variable heavy and variable light domains of the reference antibody (or may have at least 80, 85, 90, 95, 96, 97, 98, 99%, or more amino acid identity to the variable domains, where any amino acid changes are in the framework region and may be conservative or non-conservative). In some embodiments, conservative substitutions are determined by BLASTp's default parameters, while, in other embodiments, conservative mutations are within class substitutions, where the classes are aliphatic (glycine, alanine, valine, leucine, isoleucine), hydroxyl or sulphur/selenium- containing (serine, cysteine, selenocysteine, threonine, methionine), cyclic (proline), armotaic (phenylalanine, tyrosine, tryptophan), basic (histidine, lysine, arginine), and acidic and amides (aspartate, glutamate, asparagine, glutamine). Those of skill in this art recognize that, in general, single amino acid substitutions in non-essential regions of a polypeptide do not substantially alter biological activity (see, e.g., Watson et al. (1987) Molecular Biology of the Gene, The

Benjamin/Cummings Pub. Co., p. 224 (4th Ed.)). In addition, substitutions of structurally or functionally similar amino acids are less likely to disrupt biological activity. [0057] In a particular embodiment the VH sequence is SEQ ID NO:538 and the VL sequence is SEQ ID NO:537.

[0058] The anti-CD47 ligand binds CD47 and inhibits its interaction with the SIRPα receptor. The anti-CD47 ligand may be an anti-CD47 antibody, preferably a human or humanized monoclonal antibody Examples of anti-CD47 antibodies include those disclosed in WO2017/053423, US 2013/0224188 and antibodies known as 5F9 (Wang et al, 2015, PLoS ONE 10(9): e0137345), ZFl (Zeng et al, Oncotarget, 2016, Vol 7, 83040-8350), INBRX-103 (CC-90002) (Celgene), Hu5f9-G4 (Forty Seven Inc.), NI-1701 (Novimmune), NI-1801

(Novimmune), SRF231 (Surface Oncology).

[0059] In certain embodiments the sequence of the anti-CD47 antibody is provided in SEQ ID NOs:509/510, 513/514, 515/516, 517/518, 519/520, 509/534 and related antibodies.

Examples of anti-CD47 attenuated IFNα2b include SEQ ID NOS:509/539, 513/540, 515/541, 517/542, 519/543, 509/544, 513/545, 515/546, 517/547, 519/548, 509/549 and 509/550.

[0060] In another option the anti-CD47 ligand may be the extracellular domain of SIRPoc. The extracellular domain of SIRPoc may be attached to an Fc. An example of such a fusion protein is TTI-621 (Petrova et al, Clin Cancer Res, 2016; DOI: 10.1158/1078-0432.CCR-16- 1700)

[0061] Further discussion of known antagonists which inhibit the interaction CD47 with the SIRPoc receptor is provided in Weiskopf, European Journal of Cancer, 2017, 76: 100- 109, Sockolosky et al, PNAS, 2016, 10.1073, E2646-E2654, and Sick et al, 2012, 167, 1415- 1430. The disclosure of these references is included herein by cross reference.

[0062] Components (i) and (ii) of the combination therapy may be administered sequentially or simultaneously. If administration is sequential, either component (i) may be administered before component (ii), or component (ii) may be administered before component (i).

[0063] In certain preferred embodiments the constructs of the present invention are antibody-attenuated aglycosylated IFNα2b fusion constructs. WO 2013/059885 and WO 2016/065409 disclose a number of attenuated Type I IFN- antibody constructs (the disclosures of these two applications are incorporated herein by reference). The constructs of these applications typically involves the linkage of an attenuated interferon to the heavy chain of an antibody directed against a cell surface-associated antigen present on tumor cells. These constructs were shown to have potent anti-tumor activity.

[0064] Surprisingly, the present inventors have now found that the use of an anti-CD47 antibody to which is attached an attenuated Type I IFN in combination in combination with a naked antibody (not linked to an attenuated IFN) directed against a cell surface associated antigen present on a tumor cell provides potent anti-tumor activity. It is believed that these findings can be readily extrapolated to other ligands which bind CD47 and in particular to molecules like TTI-621 discussed above.

[0065] As explained in WO 2016/065409 an advantage is obtained using attenuated aglycosylated IFNα2b in the constructs of the present invention. Accordingly in certain embodiments these attenuated cytokines are preferred.

[0066] As will be understood examples of Type I interferons are IFN-α (alpha) which comes in various forms (IFN-α1, IFN-α2, IFN-α4, IFN-α5, IFN-α6, IFN-α7, IFN-α8, IFN-αlO, IFN- al3, IFN-αl4, IFN-αl6, IFN-αl7 and IFN-α21), IFN-β (beta), IFN-κ (kappa), IFN-δ (delta), IFN-ε (epsilon), IFN-τ (tau), IFN-ω (omega), and IFN-ζ (zeta, also known as limitin).

[0067] The invention also contemplates the combination of the constructs of the present invention with other drugs and/or in addition to other treatment regimens or modalities such as radiation therapy or surgery. When the combination therapy of the present invention is used in combination with known therapeutic agents the combination may be administered either in sequence (either continuously or broken up by periods of no treatment) or concurrently or as an admixture. In the case of cancer, there are numerous known anticancer agents that may be used in this context. Treatment in combination is also contemplated to encompass the treatment with either the construct of the invention followed by a known treatment, or treatment with a known agent followed by treatment with the construct of the invention, for example, as maintenance therapy. For example, in the treatment of cancer it is contemplated that the constructs of the present invention may be administered in combination with an alkylating agent (such as mechlorethamine, cyclophosphamide, chlorambucil, ifosfamidecysplatin, or platinum-containing alkylating-like agents such as cysplatin, carboplatin and oxaliplatin), an antimetabolite (such as a purine or pyrimidine analogue or an antifolate agent, such as azathioprine and mercaptopurine), an anthracycline (such as Daunorubicin, Doxorubicin, Epirubicin, Idarubicin, Valrubicin, Mitoxantrone, or anthracycline analog), a plant alkaloid (such as a vinca alkaloid or a taxane, such as Vincristine, Vinblastine, Vinorelbine, Vindesine, paclitaxel or Dosetaxel), a

topoisomerase inhibitor (such as a type I or type II topoisomerase inhibitor), a Podophyllotoxin (such as etoposide or teniposide), or a tyrosine kinase inhibitor (such as imatinib mesylate, Nilotinib, or Dasatinib). In particular anthracyclines are known to initiate an interferon response in breast tumor cells, inducing CXCL5 production and macrophage chemotaxis and activation. Tumor localised administration of IFN in with the form of a construct with CD47 is expected to increase the effectiveness of these agents.

[0068] In the case of the treatment of multiple myeloma, it is contemplated that the combination of the present invention may be administered in combination with current therapies, such as steroids such as dexamethasone, proteasome inhibitors (such as bortezomib or carfilzomib), immunomodulatory drugs (such as thalidomide, lenalidomide or pomalidomide), with or without other chemotherapeutic agents such as Melphalan hydrochloride or the chemotherapeutic agents listed above.

[0069] In the case of the treatment of Hodgkin's lymphoma, it is contemplated that the combination of the present invention may be administered in combination with current therapeutic approaches, such as ABVD (Adriamycin (doxorubicin), bleomycin, vinblastine, and dacarbazine), or Stanford V (doxorubicin, bleomycin, vinblastine, vincristine, mechlorethamine, etoposide, prednisone), or BEACOPP (doxorubicin, bleomycin, vincristine, cyclophosphamide, procarbazine, etoposide, prednisone).

[0070] In the case of non-Hodgkin's lymphoma or other lymphomas, it is contemplated that the combination of the present invention may be administered in combination current therapeutic approaches. Examples of drugs approved for non-Hodgkin lymphoma include Abitrexate (Methotrexate), Adriamycin PFS (Doxorubicin Hydrochloride), Adriamycin RDF (Doxorubicin Hydrochloride), Ambochlorin (Chlorambucil), Amboclorin (Chlorambucil), Arranon

(Nelarabine), Bendamustine Hydrochloride, Bexxar (Tositumomab and Iodine 1 131

Tositumomab), Blenoxane (Bleomycin), Bleomycin, Bortezomib, Chlorambucil, Clafen

(Cyclophosphamide), Cyclophosphamide, Cytoxan (Cyclophosphamide), Denileukin Diftitox, DepoCyt (Liposomal Cytarabine), Doxorubicin Hydrochloride, DTIC-Dome (Dacarbazine), Folex (Methotrexate), Folex PFS (Methotrexate), Folotyn (Pralatrexate), Ibritumomab Tiuxetan, Istodax (Romidepsin), Leukeran (Chlorambucil), Linfolizin (Chlorambucil), Liposomal Cytarabine, Matulane (Procarbazine Hydrochloride), Methotrexate, Methotrexate LPF

(Methotrexate), Mexate (Methotrexate), Mexate-AQ (Methotrexate), Mozobil (Plerixafor), Nelarabine, Neosar (Cyclophosphamide), Ontak (Denileukin Diftitox), Plerixafor, Pralatrexate, Rituxan (Rituximab), Rituximab, Romidepsin, Tositumomab and Iodine 1 131 Tositumomab, Treanda (Bendamustine Hydrochloride), Velban (Vinblastine Sulfate), Velcade (Bortezomib), and Velsar (Vinblastine Sulfate), Vinblastine Sulfate, Vincasar PFS (Vincristine Sulfate), Vincristine Sulfate, Vorinostat, Zevalin (Ibritumomab Tiuxetan), Zolinza (Vorinostat).

Examples of drug combinations used in treating non-Hodgkin lymphoma include CHOP (C = Cyclophosphamide, H = Doxorubicin Hydrochloride (Hydroxydaunomycin), O = Vincristine Sulfate (Oncovin), P = Prednisone); COPP (C = Cyclophosphamide, O = Vincristine Sulfate (Oncovin), P = Procarbazine Hydrochloride, P = Prednisone); CVP (C = Cyclophosphamide, V = Vincristine Sulfate, P = Prednisone); EPOCH (E = Etoposide, P = Prednisone, O = Vincristine Sulfate (Oncovin), C = Cyclophosphamide, H = Doxorubicin Hydrochloride

(Hydroxydaunomycin)); ICE (I = Ifosfamide, C = Carboplatin, E = Etoposide) and R-CHOP (R = Rituximab, C = Cyclophosphamide, H = Doxorubicin Hydrochloride (Hydroxydaunomycin), O = Vincristine Sulfate (Oncovin), P = Prednisone.

[0071] Combination of retinoids with the combination of the present invention is also contemplated. Retinoids are a family of molecules that play a major role in many biological functions including growth, vision, reproduction, epithelial cell differentiation and immune function (Meyskens, F. et al. Crit Rev Oncol Hematol 3:75, 1987, Herold, M. et al. Acta Dermatovener 74:29 1975). Early preclinical studies with the retinol all-trans retinoic acid or ATRA, either alone or in combination with other agents, demonstrated activity against acute promyelocytic leukemia (APL), myelodysplastic syndrome, chronic myelogenous leukemia (CML), mycosis fungoides and multiple myeloma (reviewed in Smith, M. J. Clin. Oncol. 10:839, 1992). These studies led to the approval of ATRA for the treatment of APL. Currently there are over 100 clinical trials evaluating the activity of ATRA in combination with other therapies for the treatment of hematological malignancies, kidney cancers, lung cancers, squamous cell carcinomas and more. Of particular interest and pertaining directly to this invention are the studies demonstrating enhanced efficacy of interferon-α treatment when combined with ATRA. This is described for mantle cell lymphoma (Col, J. et al. Cancer Res. 72: 1825, 2012), renal cell carcinoma (Aass, N. et al. J. Clin. Oncol. 23:4172, 2005; Motzer, R. J. Clin. Oncol. 18:2972, 2000), CML, melanoma, myeloma and renal cell carcinoma (Kast, R. Cancer Biology and Therapy, 7: 1515, 2008) and breast cancer (Recchia, F. et al. J. Interferon Cytokine Res. 15:605, 1995). The present inventors therefor predict enhanced activity of the combination of our targeted attenuated IFNs and CD47 blockade when combined with therapeutic dosing of ATRA in the clinic. In addition, Mehta (Mol Cancer Ther 3(3):345-52, 2004) demonstrated that in vitro treatment of leukemia cells with retinoic acid induced expression of CD38 antigen. Thus, the enhanced efficacy of interferon plus the induced expression of the target CD38 would indicate a combination therapy of ATRA with our anti-CD38 antibody- attenuated IFNα in the treatment of IFN-sensitive cancers that express CD38 or may be induced by ATRA to express CD38.

Examples of such cancers are multiple myeloma, non-Hodgkin's lymphoma, CML and AML.

[0072] Type I IFNs can have anti-cancer activity based on a direct stimulation of the type I IFN receptor on cancer cells. This has been shown for numerous types of cancer including multiple myeloma, melanoma, B cell lymphoma, non-small cell lung cancer, renal cell carcinoma, hairy cell leukemia, chronic myelogenous leukemia, ovarian cancer, fibrosarcoma, cervical cancer, bladder cancer, astrocytoma, pancreatic cancer, etc (Borden, Cancer Research 42:4948-53, 1982; Chawla-Sarkar, Clinical Cancer Research 7: 1821-31, 2001 ; Morgensen, Int J. Cancer 28:575-82, 1981 ; Otsuka, British Journal of Haematology 103:518-529, 1998;

Lindner, J of Interferon and Cytokine Research 17:681-693, 1997; Caraglia, Cell Death and Differentiation 6:773-80, 1999; Ma, World J Gastroenterol 11(10): 1521-8, 2005). One of skill in the art will recognize that the present invention has many aspects resulting from the combination of CD47fused with mutated type I interferons with antibodies to tumor associated antigens , and that the resulting fusion protein constructs may be used to reduce the proliferation of various interferon-sensitive cancers that express the corresponding tumor associated antigens.

[0073] Many other examples of signaling ligands are also known in the art and may, as described in the non-limiting exemplary embodiments above, be attenuated and attached to an antibody (or fragment thereof) that binds to an antigen on specific target cells, thereby allowing the ligand to generate its biological signal on those target cells to a much greater degree than it generates its signal on antigen-negative cells. Examples of ligands that have a tumorigenic macrophage induction or stimulation activity include TNFα, , Fas Ligand, ΙFΝβ, IFNy or ΙFΝλ, which can be targeted to various tumor cell surface antigens as discussed above for IFNα and combined with blockade by an anti-CD47 antibody- attenuated Type I IFN .

[0074] The term "antibody", as used herein, broadly refers to any immunoglobulin (Ig) molecule comprised of four polypeptide chains, two heavy (H) chains and two light (L) chains, or any functional fragment, mutant, variant, or derivation thereof, which retains the essential epitope binding features of an Ig molecule. Such mutant, variant, or derivative antibody formats are known in the art, non-limiting embodiments of which are discussed below.

[0075] In a full-length antibody, each heavy chain is comprised of a heavy chain variable region (abbreviated herein as HCVR or V_H) and a heavy chain constant region. The heavy chain constant region is comprised of three domains, CHI, CH2 and CH3. Each light chain is comprised of a light chain variable region (abbreviated herein as LCVR or V_L) and a light chain constant region. The light chain constant region is comprised of one domain, CL, which in humans may be of either the κ or λ class. The V_H and V_L 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 V_H and V_L is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FRl, CDRl, FR2, CDR2, FR3, CDR3, FR4. Immunoglobulin molecules can be of any type (e.g., IgG, IgE, IgM, IgD, IgA and IgY), class (e.g., IgGl, IgG2, IgG3, IgG4, IgAl and IgA2) or subclass. [0076] The term "antigen binding domain" or "antigen binding portion" of an antibody, as used herein, refers to one or more fragments of an antibody or protein that retain the ability to specifically bind to an antigen (e.g., CD38). It has been shown that the antigen-binding function of an antibody can be performed by fragments of a full-length antibody. Such antibody embodiments may also be bispecific, dual specific, or multi- specific formats, specifically binding to two or more different antigens. Examples of binding fragments encompassed within the term "antigen-binding portion" of an antibody include (i) a Fab fragment, a monovalent fragment consisting of the V_L, V_H, C_L and CHI domains; (ii) a F(ab')2 fragment, a bivalent fragment comprising two Fab fragments in addition to a portion of the hinge region, linked by a disulfide bridge at the hinge region; (iii) an Fd fragment consisting of the V_H and CHI domains; (iv) an Fv fragment consisting of the V_L and V_H domains of a single arm of an antibody , (v) a domain antibody (dAb) (Ward et al. 1989 Nature 341 544-6, Winter et al, PCT publication WO

90/05144 Al herein incorporated by reference), which comprises a single variable domain; and (vi) an isolated complementarity determining region (CDR). Furthermore, although the two domains of the Fv fragment, V_L and V_H, are coded for by separate genes, they can be joined, using recombinant methods, by a synthetic linker that enables them to be made as a single protein chain in which the V_L and V_H regions pair to form monovalent molecules (known as single chain Fv (scFv); see e.g., Bird et al. 1988 Science 242 423-6; Huston et al. 1988 Proc Natl Acad Sci U S A 85 5879-83). Such single chain antibodies are also intended to be encompassed within the term "antigen-binding portion" of an antibody. Other forms of single chain antibodies, such as diabodies, are also encompassed. Diabodies are bivalent, bispecific antibodies in which V_H and V_L domains are expressed on a single polypeptide chain, but using a linker that is too short to allow for pairing between the two domains on the same chain, thereby forcing the domains to pair with complementary domains of another chain and creating two antigen binding sites (see e.g., Holliger, P., et al, 1993, Proc. Natl. Acad. Sci. USA 90:6444-6448; Poljak, R. J., et al, 1994, Structure 2: 1121-1123). Such antibody binding portions are known in the art (Kontermann and Dubel eds., Antibody Engineering 2001 Springer- Verlag. New York. 790 pp., ISBN 3-540-41354-5). In an embodiment the antibody binding portion is a Fab fragment.

[0077] The antibody described herein may be a humanized antibody. The term "humanized antibody" shall be understood to refer to a protein comprising a human-like variable region, which includes CDRs from an antibody from a non-human species (e.g., mouse or rat or non- human primate) grafted onto or inserted into FRs from a human antibody (this type of antibody is also referred to a "CDR-grafted antibody"). Humanized antibodies also include proteins in which one or more residues of the human protein are modified by one or more amino acid substitutions and/or one or more FR residues of the human protein are replaced by corresponding non-human residues. Humanized antibodies may also comprise residues which are found in neither the human antibody or in the non-human antibody. Any additional regions of the protein (e.g., Fc region) are generally human. Humanization can be performed using a method known in the art, e.g., US5,225,539, US6,054,297, US7,566,771 or US5,585,089. The term "humanized antibody" also encompasses a super-humanized antibody, e.g., as described in US7,732,578.

[0078] The antibody described herein may be human. The term "human antibody" as used herein refers to proteins having variable and, optionally, constant antibody regions found in humans, e.g. in the human germline or somatic cells or from libraries produced using such regions. The "human" antibodies can include amino acid residues not encoded by human sequences, e.g. mutations introduced by random or site directed mutations in vitro (in particular mutations which involve conservative substitutions or mutations in a small number of residues of the protein, e.g. in 1, 2, 3, 4 or 5 of the residues of the protein). These "human antibodies" do not necessarily need to be generated as a result of an immune response of a human, rather, they can be generated using recombinant means (e.g., screening a phage display library) and/or by a transgenic animal (e.g., a mouse) comprising nucleic acid encoding human antibody constant and/or variable regions and/or using guided selection (e.g., as described in or US5,565,332). This term also encompasses affinity matured forms of such antibodies. For the purposes of the present disclosure, a human protein will also be considered to include a protein comprising FRs from a human antibody or FRs comprising sequences from a consensus sequence of human FRs and in which one or more of the CDRs are random or semi-random, e.g., as described in

US6,300,064 and/or US6,248,516.

[0079] The antibody portions of polypeptides of the present invention may be full length antibodies of any class, preferably IgGl, IgG2 or IgG4. The constant domains of such antibodies are preferably human. The variable regions of such antibodies may be of non-human origin or, preferably, be of human origin or be humanized. Antibody fragments may also be used in place of the full length antibodies.

[0080] The term "antibody" also includes engineered antibodies. As will be appreciated there are many variations of engineered antibodies (e.g. mouse monoclonal, chimeric, humanized and human monoclonal antibodies, single chain variable antibody fragments (scFv's), minibodies, aptamers, as well as bispecific antibodies and diabodies as described above).

[0081] Single variable region domains (termed dAbs) are, for example, disclosed in (Ward et al., 1989, Nature 341 : 544-546; Hamers-Casterman et al., 1993, Nature 363: 446-448; Davies & Riechmann, 1994, FEBS Lett. 339: 285-290).

[0082] Minibodies are small versions of whole antibodies, which encode in a single chain the essential elements of a whole antibody. Suitably, the minibody is comprised of the VH and VL domains of a native antibody fused to the hinge region and CH3 domain of the

immunoglobulin molecule as, for example, disclosed in U.S. Patent No 5,837,821.

[0083] In an alternate embodiment, the engineered antibody may comprise non- immunoglobulin derived, protein frameworks. For example, reference may be made to (Ku & Schutz, 1995, Proc. Natl. Acad. Sci. USA 92: 6552-6556) which discloses a four-helix bundle protein cytochrome b562 having two loops randomized to create CDRs, which have been selected for antigen binding.

[0084] Using methods well known in the art it is possible to increase antigen binding, by for example, affinity maturation, or to decrease immunogenicity by removing predicted MHC class II-binding motifs. The therapeutic utility of the antibodies described herein which bind to the cell surface-associated antigen can be further enhanced by modulating their functional characteristics, such as antibody-dependent cell-mediated cytotoxicity (ADCC), complement- dependent cytotoxicity (CDC), ADCP, serum half-life, biodistribution and binding to Fc receptors or the combination of any of these. This modulation can be achieved by protein- engineering, glyco-engineering or chemical methods. Depending on the therapeutic application required, it could be advantageous to either increase or decrease any of these activities. As is discussed above it is preferred that these activities are decreased for the anti-CD47 ligand. It is, however, preferred that these activities are increased only for the antibody which binds to the cell surface-associated tumor antigen and not for the anti-CD47 ligand.

[0085] An example of glyco-engineering used the Potelligent® method as described in Shinkawa T. et al., 2003 (J Biol Chem 278: 3466-73).

[0086] Numerous methods for affinity maturation of antibodies are known in the art. Many of these are based on the general strategy of generating panels or libraries of variant proteins by mutagenesis followed by selection and/or screening for improved affinity. Mutagenesis is often performed at the DNA level, for example by error prone PCR (Thie, Voedisch et al. 2009, Methods Mol Biol 525: 309-322), by gene shuffling (Kolkman and Stemmer 2001, Nat

Biotechnol. May; 19(5):423-8), by use of mutagenic chemicals or irradiation, by use of 'mutator' strains with error prone replication machinery (Greener 1996, In Vitro Mutagenesis Protocols. Humana press, NJ) or by somatic hypermutation approaches that harness natural affinity maturation machinery (Peled, Kuang et al. 2008, Annu Rev Immunol. 26:481-511). Mutagenesis can also be performed at the RNA level, for example by use of QP replicase (Kopsidas, Roberts et al. 2006, Immunol Lett. 2006 Nov 15; 107(2): 163-8). Library-based methods allowing screening for improved variant proteins can be based on various display technologies such as phage, yeast, ribosome, bacterial or mammalian cells, and are well known in the art (Benhar 2007, Expert Opin Biol Ther. May; 7(5): 763-79). Affinity maturation can be achieved by more directed/predictive methods for example by site-directed mutagenesis or gene synthesis guided by findings from 3D protein modeling (see for example Queen, Schneider et al. 1989, PNAS, 86(24): 10029-33 or US patent 6,180,370 or US patent 5,225,539).

[0087] Methods of increasing ADCC have been described by Ferrara, Brunker et al. 2006, Biotechnol Bioeng; 93:851-61; Li, Sethuraman et al. 2006, Nat Biotechnol; 24:210-5;

Stavenhagen, Gorlatov et al. 2007, Cancer Res; 67:8882-90; Shields, Namenuk et al. 2001, J Biol Chem; 276:6591-604; Shinkawa, Nakamura et al. 2003, J Biol Chem; 278:3466-73; and WO 2008/006554. [0088] Mutations may also be made in the Fc region of the antibody which binds to the cell surface associated antigen on the tumor cell that enhance binding to FcyRIIa which enhance macrophage phagocytosis of tumor cells. These include S239D, I332E and G236A. (Richards, J. et al. 2008 Mol. Cane. Ther. Vol. 8, pp:2517.)

[0089] Methods of increasing CDC have been described by Idusogie, Wong et al. 2001, J Immunol; 176:346-56; Dall'Acqua, Cook et al. 2006, J Biol Chem; 281 :23514-24; Michaelsen, Aase et al. 1990, Scand J Immunol; 32:517-28; Brekke, Bremnes et al. 1993, Mol Immunol; 30: 1419-25; Tan, Shopes et al. 1990, PNAS; 87: 162-6; and Norderhaug, Brekke et al. 1991 , Eur J Immunol; 21:2379-84.

[0090] Methods of increasing ADCP have been described in Braster, O'Toole et al. 2014, Methods; 65:28-37, Gul & Egmond, 2015, Cancer Res; 75:5008-5013.

[0091] References describing methods of increasing ADCC and CDC include Natsume, In et al. 2008, Cancer Res; 68:3863-72. The disclosure of each of these references is included herein by cross reference.

[0092] A number of methods for modulating antibody serum half-life and biodistribution are based on modifying the interaction between antibody and the neonatal Fc receptor (FcRn), a receptor with a key role in protecting IgG from catabolism, and maintaining high serum antibody concentration. Dall'Acqua et al describe substitutions in the Fc region of IgGl that enhance binding affinity to FcRn, thereby increasing serum half-life (Dall'Acqua, Woods et al. 2002, J Immunol; 169:5171-80) and further demonstrate enhanced bioavailability and modulation of ADCC activity with triple substitution of M252Y/S254T/T256E (with residue numbering according to the EU Index) or M265Y/S267T/T269 (with residue numbering according to the Kabat numbering system) (Dall'Acqua, Kiener et al. 2006, J Biol Chem; 279:6213-6). See also U.S Pat. Nos 6,277,375; 6,821,505; and 7,083,784. Hinton et al have described constant domain amino acid substitutions at positions 250 and 428 that confer increased in vivo half-life (Hinton, Johlfs et al. 2004, J Biol Chem; 279:6213-6; Hinton, Xiong et al. 2006, J Immunol; 176:346-56). See also U.S Pat. No 7,217,797. Petkova et al have described constant domain amino acid substitutions at positions 307, 380 and 434 that confer increased in vivo half-life (Petkova, Akilesh et al. 2006, Int Immunol; 18: 1759-69). See also Shields et al 2001 , J Biol Chem;

276:6591-604 and WO 2000/42072. Other examples of constant domain amino acid

substitutions which modulate binding to Fc receptors and subsequent function mediated by these receptors, including FcRn binding and serum half-life, are described in U.S Pat. Application Nos 20090142340; 20090068175 and 20090092599. The substitution referred to herein as "S228P" which is numbered according to the EU index as in Kabat has also been referred to as "S241P" according to Kabat et al. (1987 Sequences of proteins of immunological interest. United States Department of Health and Human Services, Washington DC). This substitution stabilizes the hinge region of IgG4 molecules, having the effect of making the sequence of the core of the hinge region the same as that of an IgGl or IgG2 isotype antibody. This results in a reduction in the spontaneous dissociation and reassociation of the heavy chains which often leads to the production of heterodimeric IgG4 antibodies.

[0093] The glycans linked to antibody molecules, and in particular the antibody which binds to a cell surface-associated antigen expressed on the tumor cell, are known to influence interactions of antibody with Fc receptors and glycan receptors and thereby influence antibody activity, including serum half-life (Kaneko, Nimmerjahn et al. 2006, Science; 313:670-3; Jones, Papac et al. 2007, Glycobiology; 17:529-40; and Kanda, Yamada et al. 2007, Glycobiology; 17: 104-18). Hence, certain glycoforms that modulate desired antibody activities can confer therapeutic advantage. Methods for generating engineered glycoforms are known in the art and include but are not limited to those described in U.S. Pat. Nos US6,602,684; US7,326,681 ; US7,388,081 and in WO 2008/006554.

[0094] Extension of half-life by addition of polyethylene glycol (PEG) has been widely used to extend the serum half-life of proteins, as reviewed, for example, by Fishburn 2008, J Pharm Sci; 97:4167-83.

[0095] As will be recognised it is possible to make conservative amino acid substitutions within the sequences of the current invention. By "conservative substitution" is meant amino acids having similar properties. As used in this specification the following groups of amino acids are to be seen as conservative substitutions: H, R and K; D, E, N and Q; V, I and L; C and M; S, T, P, A and G; and F, Y and W. It is not intended, however, that substitutions other than those specifically recited are made at the sites of attenuation and/or glycosylation.

[0096] The term "cell surface-associated antigen", as used herein, broadly refers to any antigen expressed on surfaces of cells, including without limitation malignant cells or infectious or foreign cells.

[0097] The combination of the present invention comprises an anti-CD47 ligand. The anti- CD47 ligand represses the binding of CD47 to Sirpa. There are a number of molecules which are known to antagonise the binding of CD47 to Sirpa. A number of these molecules are disclosed in the following references which are included herein by cross reference:

US 7,282,556, US 8,101,719, US 8,562,997, US 8,758,750, US 9,017,675, US 9,045,541, US 9,221,908, US 2012/0189625, US 2012/0282174, US 2014/0140989, US

2014/0161805, US 2014/0199308, US 2015/0274826, US 2015/0329616,

US 2015/0353642, US 2016/0008429, US 2016/0009814, and US 2016/0009815,

[0098] In certain aspects of the present invention, the combination or compositions of the present invention is used to treat patients with cancer. Cancers contemplated herein include: a group of diseases and disorders that are characterized by uncontrolled cellular growth (e.g.

formation of tumor) without any differentiation of those cells into specialized and different cells. The tumors to be treated may be solid tumors or a diffuse collection of cells such as a

hematological malignancy. Such diseases and disorders include ABL1 protooncogene, AIDS related cancers, acoustic neuroma, acute lymphocytic leukaemia, acute myeloid leukaemia, adenocystic carcinoma, adrenocortical cancer, agnogenic myeloid metaplasia, alopecia, alveolar soft-part sarcoma, anal cancer, angiosarcoma, aplastic anaemia, astrocytoma, ataxia- telangiectasia, basal cell carcinoma (skin), bladder cancer, bone cancers, bowel cancer, brain stem glioma, brain and CNS tumors, breast cancer, carcinoid tumors, cervical cancer, childhood brain tumors, childhood cancer, childhood leukaemia, childhood soft tissue sarcoma,

chondrosarcoma, choriocarcinoma, chronic lymphocytic leukaemia, chronic myeloid leukaemia, colorectal cancers, cutaneous T-Cell lymphoma, dermatofibrosarcoma-protuberans,

desmoplastic-small-round-cell-tumor, ductal carcinoma, endocrine cancers, endometrial cancer, ependymoma, esophageal cancer, Ewing's sarcoma, extra-hepatic bile duct cancer, eye cancer, eye: melanoma, retinoblastoma, fallopian tube cancer, fanconi anemia, fibrosarcoma, gall bladder cancer, gastric cancer, gastrointestinal cancers, gastrointestinal-carcinoid-tumor, genitourinary cancers, germ cell tumors, gestational-trophoblastic-disease, glioma,

gynaecological cancers, hematological malignancies, hairy cell leukaemia, head and neck cancer, hepatocellular cancer, hereditary breast cancer, histiocytosis, Hodgkin's disease, human papillomavirus, hydatidiform mole, hypercalcemia, hypopharynx cancer, intraocular melanoma, islet cell cancer, Kaposi's sarcoma, kidney cancer, Langerhan's-cell-histiocytosis, laryngeal cancer, leiomyosarcoma, leukemia, Li-Fraumeni syndrome, lip cancer, liposarcoma, liver cancer, lung cancer, lymphedema, lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, male breast cancer, malignant-rhabdoid-tumor-of-kidney, medulloblastoma, melanoma, merkel cell cancer, mesothelioma, metastatic cancer, mouth cancer, multiple endocrine neoplasia, mycosis fungoides, myelodysplastic syndromes, multiple myeloma, myeloproliferative disorders, nasal cancer, nasopharyngeal cancer, nephroblastoma, neuroblastoma, neurofibromatosis, nijmegen breakage syndrome, non-melanoma skin cancer, non-small-cell-lung-cancer-(NSCLC), ocular cancers, oesophageal cancer, oral cavity cancer, oropharynx cancer, osteosarcoma, ostomy ovarian cancer, pancreas cancer, paranasal cancer, parathyroid cancer, parotid gland cancer, penile cancer, peripheral-neuroectodermal-tumors, pituitary cancer, polycythemia vera, prostate cancer, rare-cancers-and-associated-disorders, renal cell carcinoma, retinoblastoma,

rhabdomyosarcoma, Rothmund-Thomson syndrome, salivary gland cancer, sarcoma,

schwannoma, Sezary syndrome, skin cancer, small cell lung cancer (SCLC), small intestine cancer, soft tissue sarcoma, spinal cord tumors, squamous-cell-carcinoma-(skin), stomach cancer, synovial sarcoma, testicular cancer, thymus cancer, thyroid cancer, transitional-cell- cancer-(bladder), transitional-cell-cancer-(renal-pelvis-/-ureter), trophoblastic cancer, urethral cancer, urinary system cancer, uroplakins, uterine sarcoma, uterus cancer, vaginal cancer, vulva cancer, Waldenstrom' s-macroglobulinemia and Wilms' tumor. In an embodiment the tumor is selected from a group of multiple myeloma or non-hodgkin's lymphoma.

[0099] As contemplated for the treatment of cancer, the antibody portions of the polypeptide constructs of the combination of the present invention may bind to tumor-associated antigens, i.e., cell surface antigens that are selectively expressed by cancer cells or over-expressed in cancer cells relative to most normal cells. There are many tumor-associated antigens (TAAs) known in the art. Non-limiting examples of TAAs include enzyme tyrosinase; melanoma antigen GM2; alphafetoprotein (AFP); carcinoembryonic antigen (CEA); Mucin 1 (MUC1); Human epidermal growth factor receptor (Her2/Neu); T-cell leukemia/lymphoma 1 (TCL1 ) oncoprotein. Exemplary TAAs associated with a number of different cancers are telomerase (hTERT); prostate-specific membrane antigen (PSMA); urokinase plasminogen activator and its receptor (uPA/uPAR); vascular endothelial growth factor and its receptor (VEGF/VEGFR); extracellular matrix metalloproteinase inducer (EMMPRIN/CD147); epidermal growth factor (EGFR); platelet-derived growth factor and its receptor (PDGF/PDGFR) and c-kit (CD117).

[0100] A list of other TAAs is provided in US 2010/0297076, the disclosure of which is included herein by reference. Of particular interest are cell surface antigens associated with multiple myeloma leukemia or lymphoma cells, including but not limited to CD38, CD138, CD79, CSl . and HM1.24.

[0101] CD38 is a 46kDa type II transmembrane glycoprotein. It has a short N-terminal cytoplasmic tail of 20 amino acids, a single transmembrane helix and a long extracellular domain of 256 amino acids (Bergsagel, P., Blood; 85:436, 1995 and Liu, Q., Structure, 13: 1331, 2005). It is expressed on the surface of many immune cells including CD4 and CD8 positive T cells, B cells, NK cells, monocytes, plasma cells and on a significant proportion of normal bone marrow precursor cells (Malavasi, F., Hum. Immunol. 9:9, 1984). In lymphocytes, however, the expression appears to be dependent on the differentiation and activation state of the cell. Resting T and B cells are negative while immature and activated lymphocytes are predominantly positive for CD38 expression (Funaro, A., J. Immunol. 145:2390, 1990). Additional studies indicate mRNA expression in non-hemopoeitic organs such as pancreas, brain, spleen and liver (Koguma, T., Biochim. Biophys. Acta 1223: 160, 1994.)

[0102] CD38 is a multifunctional ectoenzyme that is involved in transmembrane signaling and cell adhesion. It is also known as cyclic ADP ribose hydrolase because it can transform NAD⁺ and NADP⁺ into cADPR, ADPR and NAADP, depending on extracellular pH. These products induce Ca²⁺ -mobilization inside the cell which can lead to tyrosine phosphorylation and activation of the cell. CD38 is also a receptor that can interact with a ligand, CD31.

Activation of receptor via CD31 leads to intracellular events including Ca²⁺ mobilization, cell activation, proliferation, differentiation and migration (reviewed in Deaglio, S., Trends in Mol. Med. 14:210, 2008.)

[0103] CD38 is expressed at high levels on multiple myeloma cells, in most cases of T- and B-lineage acute lymphoblastic leukemias, some acute myelocytic leukemias, follicular center cell lymphomas and T lymphoblastic lymphomas. (Malavasi, F., J. Clin Lab Res. 22:73, 1992).

More recently, CD38 expression has become a reliable prognostic marker in B-lineage chronic lymphoblastic leukemia (B-CLL) (Ibrahim, S., Blood. 98: 181 , 2001 and Durig, J., Leuk. Res. 25:927, 2002). Independent groups have demonstrated that B-CLL patients presenting with a CD38⁺ clone are characterized by an unfavorable clinical course with a more advance stage of disease, poor responsiveness to chemotherapy and shorter survival time (Morabito, F.,

Haematologica. 87:217,2002). The consistent and enhanced expression of CD38 on lymphoid tumors makes this an attractive target for therapeutic antibody technologies.

[0104] Examples of antibodies targeting CD38 are provided in US7829672,

US2009/0123950, US2009/304710, WO 2012/092612 and WO 2014/18820, US2002/0164788. The disclosure of each these references is included herein by cross-reference. Of particular interest is the range of anti-CD38 antibodies disclosed in WO 2014/178820.

[0105] Antigens other than CD38 are well known in the art and non-protein examples of such antigens include, sphingolipids, ganglioside GD2 (Saleh et al, 1993, J. Immunol., 151, 3390-3398), ganglioside GD3 (Shitara et al, 1993, Cancer Immunol. Immunother. 36:373-380), ganglioside GM2 (Livingston et al, 1994, J. Clin. Oncol. 12: 1036-1044), ganglioside GM3 (Hoon et al, 1993, Cancer Res. 53:5244-5250) and Lewis", lewis^y and lewis^xy carbohydrate antigens that can be displayed on proteins or glycolipids. Examples of protein antigens are HER- 2/neu, human papillomavirus-E6 or -E7, MUC-1; KS 1/4 pan-carcinoma antigen (Perez and Walker, 1990, J. Immunol. 142:3662-3667; Bumal, 1988, Hybridoma 7(4):407-415); ovarian carcinoma antigen CA125 (Yu et al, 1991, Cancer Res. 51(2):468-475); prostatic acid phosphate (Tailor et al, 1990, Nucl. Acids Res. 18(16):4928); prostate specific antigen (Henttu and Vihko, 1989, Biochem. Biophys. Res. Comm. 160(2):903-910; Israeli et al, 1993, Cancer Res. 53:227- 230); melanoma-associated antigen p97 (Estin et al, 1989, J. Natl. Cancer Instit. 81(6):445-446); melanoma antigen gp75 (Vijayasardahl et al, 1990, J. Exp. Med. 171 (4): 1375-1380); prostate specific membrane antigen; carcinoembryonic antigen (CEA) (Foon et al, 1994, Proc. Am. Soc. Clin. Oncol. 13:294), MUC16 (antibodies include MJ-170, MJ-171, MJ-172 and MJ-173 [US 7,202,346],3A5 [US 7,723,485]).NMB (US 8,039,593), malignant human lymphocyte antigen- APO-1 (Bernhard et al, 1989, Science 245:301-304); high molecular weight melanoma antigen (HMW-MAA) (Natali et al, 1987, Cancer 59:55-63; Mittelman et al, 1990, J. Clin. Invest. 86:2136-2144); Burkitt's lymphoma antigen-38.13; CD19 (Ghetie et al, 1994, Blood 83: 1329- 1336); human B-lymphoma antigen-CD20 (Reff et al, 1994, Blood 83:435-445); GICA 19-9 (Herlyn et al, 1982, J. Clin. Immunol. 2: 135), CTA-1 and LEA; CD33 (Sgouros et al, 1993, J. Nucl. Med. 34:422-430); oncofetal antigens such as alpha-fetoprotein for liver cancer or bladder tumor oncofetal antigen (Hellstrom et al, 1985, Cancer. Res. 45:2210-2188); differentiation antigens such as human lung carcinoma antigen L6 or L20 (Hellstrom et al, 1986, Cancer Res. 46:3917-3923); antigens of fibrosarcoma; human leukemia T cell antigen-Gp37 (Bhattacharya- Chatterjee et al, 1988, J. Immunol. 141 : 1398-1403); tumor-specific transplantation type of cell- surface antigen (TSTA) such as virally-induced tumor antigens including T-antigen, DNA tumor virus and envelope antigens of RNA tumor viruses; neoglycoproteins, breast cancer antigens such as EGFR (Epidermal growth factor receptor), polymorphic epithelial mucin (PEM) (Hilkens et al, 1992, Trends in Bio. Chem. Sci. 17:359); polymorphic epithelial mucin antigen; human milk fat globule antigen; colorectal tumor- associated antigens such as TAG-72 (Yokata et al, 1992, Cancer Res. 52:3402-3408), CO 17-1A (Ragnhammar et al, 1993, Int. J. Cancer 53:751- 758); differentiation antigens (Feizi, 1985, Nature 314:53-57) such as I(Ma) found in gastric adenocarcinomas, SSEA-1 found in myeloid cells, VEP8, VEP9, Myl, VIM-D5, Ml 8 and M39 found in breast epithelial cancers, D 156-22 found in colorectal cancer, TRA-1-85 (blood group H), C14 found in colonic adenocarcinoma, F3 found in lung adenocarcinoma, AH6 found in gastric cancer, Y hapten found in embryonal carcinoma cells, TL5 (blood group A), El series (blood group B) antigens found in pancreatic cancer, FC10.2 found in embryonal carcinoma cells, gastric adenocarcinoma antigen, CO-514 (blood group Le^a) found in adenocarcinoma, NS-10 found in adenocarcinomas, CO-43 (blood group Le^b), G49 found in A431 cells, 19.9 found in colon cancer; gastric cancer mucins; R₂₄ found in melanoma, MH2 (blood group ALe^b/Le^y) found in colonic adenocarcinoma, 4.2, Dl. l, OFA-1, G_M2, OFA-2 and Ml:22:25:8 found in embryonal carcinoma cells and SSEA-3 and SSEA-4. HMW-MAA (SEQ ID NO:433), also known as melanoma chondroitin sulfate proteoglycan, is a membrane-bound protein of 2322 residues which is overexpressed on over 90% of the surgically removed benign nevi and melanoma lesions (Camploi, et. al, Crit Rev Immunol. ;24:267,2004). Accordingly it may be a potential target cell surface associated antigen.

[0106] Other example cancer antigens for targeting in the present invention include

(exemplary cancers are shown in parentheses): CD5 (T-cell leukemia/lymphoma), CA15-3 (carcinomas), CA19-9 (carcinomas), L6 (carcinomas), CA 242 (colorectal), placental alkaline phosphatase (carcinomas), prostatic acid phosphatase (prostate), MAGE-1 (carcinomas), MAGE- 2 (carcinomas), MAGE-3 (carcinomas), MAGE -4 (carcinomas), transferrin receptor

(carcinomas), p97 (melanoma), MUC1 (breast cancer), MARTI (melanoma), CD20 (non Hodgkin's lymphoma), CD52 (leukemia), CD33 (leukemia), human chorionic gonadotropin (carcinoma), CD38 (multiple myeloma), CD21 (B-cell lymphoma), CD22 (lymphoma), CD25 (B-cell Lymphoma), CD37 (B-cell lymphoma), CD45 (acute myeloblastic leukemia), HLA-DR (B-cell lymphoma), IL-2 receptor (T-cell leukemia and lymphomas), CD40 (lymphoma), CD79 (B cell leukemia or lymphoma, Hodgkin lymphoma), various mucins (carcinomas), P21

(carcinomas), MPG (melanoma), Ep-CAM (Epithelial Tumors), Folate-receptor alpha (Ovarian), A33 (Colorectal), G250 (renal), Ferritin (Hodgkin lymphoma), de2-7 EGFR (glioblastoma, breast, and lung), Fibroblast activation protein (epithelial) and tenascin metalloproteinases (glioblastoma). Some specific, useful antibodies include, but are not limited to, BR64 (Trail et al, 1997, Cancer Research 57: 100 105), BR96 mAb (Trail et al, 1993, Science 261:212-215), mAbs against the CD40 antigen, such as S2C6 mAb (Francisco et al, 2000, Cancer Res.

60:3225-3231) or other anti-CD40 antibodies, such as those disclosed in U.S Patent Publication Nos. 2003-0211100 and 2002-0142358; mAbs against the CD30 antigen, such as ACIO (Bowen et al, 1993, J. Immunol. 151:5896-5906; Wahl et al, 2002 Cancer Res. 62(13):3736-42) or MDX-0060 (U.S. Patent Publication No. 2004-0006215) and mAbs against the CD70 antigen, such as 1F6 mAb and 2F2 mAb (see, e.g., U.S. Patent Publication No. 2006-0083736) or antibodies 2H5, 10B4, 8B5, 18E7, 69A7 (US 8,124,738). Other antibodies have been reviewed elsewhere (Franke et al., 2000, Cancer Biother. Radiopharm. 15:459 76; Murray, 2000, Semin. Oncol. 27:64 70; Breitling, F., and Dubel, S., Recombinant Antibodies, John Wiley, and Sons, New York, 1998).

[0107] In certain embodiments, useful antibodies can bind to a receptor or a complex of receptors expressed on a target cell. The receptor or receptor complex can comprise an immunoglobulin gene superfamily member, a major histocompatibility protein, a cytokine receptor, a TNF receptor superfamily member, a chemokine receptor, an integrin, a lectin, a complement control protein, a growth factor receptor, a hormone receptor or a neuro-transmitter receptor. Non-limiting examples of appropriate immunoglobulin superfamily members are CD2, CD3, CD4, CD8, CD19, CD22, CD79, CD90, CD152/CTLA-4, PD-1 , B7-H4, B7-H3, and ICOS. Non-limiting examples of suitable TNF receptor superfamily members are TACI, BCMA, CD27, CD40, CD95/Fas, CD 134/0X40, CD 137/4- IBB, TNFR1 , TNFR2, RANK,

osteoprotegerin, APO 3, Apo2/TRAIL Rl , TRAIL R2, TRAIL R3, and TRAIL R4. Non-limiting examples of suitable integrins are CDl la, CDl lb, CDl lc, CD18, CD29, CD41, CD49a, CD49b, CD49c, CD49d, CD49e, CD49f, CD 103 and CD 104. Non-limiting examples of suitable lectins are S type, C type, and I type lectin. Examples of antibodies to CEA are shown in Table 1.

[0108] Antibodies that bind the CD22 antigen expressed on human B cells include, for example, HD6, RFB4, UV22-2, Tol5, 4KB 128 and a humanized anti-CD22 antibody (hLL2) (see, e.g., Li et al. (1989) Cell. Immunol. I l l : 85-99; Mason et al. (1987) Blood 69: 836-40; Behr et al. (1999) Clin. Cancer Res. 5: 3304s-3314s; Bonardi et al. (1993) Cancer Res. 53: 3015- 3021).

[0109] Antibodies to CD33 include, for example, HuM195 (see, e.g., Kossman et al. (1999) Clin. Cancer Res. 5: 2748-2755; US5693761) and CMA-676 (see, e.g., Sievers et al, (1999) Blood 93: 3678-3684).

[0110] Illustrative anti-MUC-1 antibodies include, but are not limited to Mc5 (see, e.g., Peterson et al. (1997) Cancer Res. 57: 1103-1108; Ozzello et al. (1993) Breast Cancer Res. Treat. 25: 265-276), and hCTMOl (see, e.g., Van Hof et al. (1996) Cancer Res. 56: 5179-5185).

[0111] Illustrative anti-TAG-72 antibodies include, but are not limited to CC49 (see, e.g., Pavlinkova et al. (1999) Clin. Cancer Res. 5: 2613-2619), B72.3 (see, e.g., Divgi et al. (1994) Nucl. Med. Biol. 21 : 9-15), and those disclosed in U.S. Pat. No. 5,976,531.

[0112] Illustrative anti-HM1.24 antibodies include, but are not limited to a mouse monoclonal anti-HM1.24 and a humanized anti-HM1.24 IgGlkappa antibody (see, e.g., Ono et al. (1999) Mol. Immuno. 36: 387-395).

[0113] In certain embodiments the targeting moiety comprises an anti-Her2 antibody. The erBB 2 gene, more commonly known as (Her-2/neu), is an oncogene encoding a transmembrane receptor. Several antibodies have been developed against Her-2/neu, and some of these are in clinical use. These include trastuzumab (e.g., HERCEPTIN™; Fornir et al. (1999) Oncology (Huntingt) 13: 647-58), TAB-250 (Rosenblum et al. (1999) Clin. Cancer Res. 5: 865-874), BACH-250 (Id.), TAl (Maier et al. (1991) Cancer Res. 51: 5361-5369), and the mAbs described in U.S. Pat. Nos. 5,772,997; 5,770,195 (mAb 4D5; ATCC CRL 10463); and U.S. Pat. No.

5,677,171.

[0114] Other fully human anti-Her2/neu antibodies are well known to those of skill in the art. Such antibodies include, but are not limited to the C6 antibodies such as C6.5, DPL5, G98A, C6MH3-B 1, B 1D2, C6VLB, C6VLD, C6VLE, C6VLF, C6MH3-D7, C6MH3-D6, C6MH3-D5, C6MH3-D3, C6MH3-D2, C6MH3-D1, C6MH3-C4, C6MH3-C3, C6MH3-B9, C6MH3-B5, C6MH3-B48, C6MH3-B47, C6MH3-B46, C6MH3-B43, C6MH3-B41 , C6MH3-B39, C6MH3- B34, C6MH3-B33, C6MH3-B31 , C6MH3-B27, C6MH3-B25, C6MH3-B21 , C6MH3-B20, C6MH3-B2, C6MH3-B 16, C6MH3-B 15, C6MH3-B 11, C6MH3-B1, C6MH3-A3, C6MH3-A2, and C6ML3-9. These and other anti-HER2/neu antibodies are described in U.S. Pat. Nos.

6,512,097 and 5,977,322, in PCT Publication WO 97/00271, in Schier et al. (1996) J Mol Biol 255: 28-43, Schier et al. (1996) J Mol Biol 263: 551-567, and the like.

[0115] More generally, antibodies directed to various members of the epidermal growth factor receptor family are well suited for use. Such antibodies include, but are not limited to anti- EGFR antibodies as described in U.S. Pat. Nos. 5,844,093 and 5,558,864, and in European Patent No. 706J99A. Other illustrative anti-EGFR family antibodies include, but are not limited to antibodies such as C6.5, C6ML3-9, C6MH3-B 1 , C6-B 1D2, F5, HER3.A5, HER3.F4, HER3.H1, HER3.H3, HER3.E12, HER3.B12, EGFR.E12, EGFR.C10, EGFR.B11, EGFR.E8, HER4.B4, HER4.G4, HER4.F4, HER4.A8, HER4.B6, HER4.D4, HER4.D7, HER4.D1 1 , HER4.D12, HER4.E3, HER4.E7, HER4.F8 and HER4.C7 and the like (see, e.g., U.S. Patent publications US 2006/0099205 Al and US 2004/0071696 Al which are incorporated herein by reference).

[0116] CD38 is of particular interest as an antibody target in the present invention.

Antibodies to CD38 include for example, AT13/5 (see, e.g., Ellis et al. (1995) J. Immunol. 155: 925-937), HB7, antibodies disclosed in WO 2014/178820 (the disclosure of which is included herein by reference) and the like.

[0117] The present invention also provides compositions comprising the combination of the present invention. These compositions can further comprise at least one of any suitable auxiliary, such as, but not limited to, diluent, binder, stabiliser, buffers, salts, lipophilic solvents, preservative, adjuvant or the like. Pharmaceutically acceptable auxiliaries are preferred. Non- limiting examples of, and methods of preparing such sterile solutions are well known in the art, such as, but not limited to, Gennaro, Ed., Remington's Pharmaceutical Sciences, 18th Edition, Mack Publishing Co. (Easton, Pa.) 1990. Pharmaceutically acceptable carriers can be routinely selected that are suitable for the mode of administration, solubility and/or stability of the antibody composition as well known in the art or as described herein.

[0118] Pharmaceutical excipients and additives useful in the present composition include but are not limited to proteins, peptides, amino acids, lipids, and carbohydrates (e.g., sugars, including monosaccharides, di-, tri-, terra-, and oligosaccharides; derivatised sugars such as alditols, aldonic acids, esterified sugars and the like; and polysaccharides or sugar polymers), which can be present singly or in combination, comprising alone or in combination 1-99.99% by weight or volume. Exemplary protein excipients include serum albumin, such as human serum albumin (HSA), recombinant human albumin (rHA), gelatin, casein, and the like. Representative amino acids which can also function in a buffering capacity include alanine, glycine, arginine, betaine, histidine, glutamic acid, aspartic acid, cysteine, lysine, leucine, isoleucine, valine, methionine, phenylalanine, aspartame, combinations thereof such as arginine-histidine buffers and the like. One preferred amino acid is histidine. A second preferred amino acid is arginine.

[0119] Carbohydrate excipients suitable for use in the invention include, for example, monosaccharides, such as fructose, maltose, galactose, glucose, D-mannose, sorbose, and the like; disaccharides, such as lactose, sucrose, trehalose, cellobiose, and the like; polysaccharides, such as raffinose, melezitose, maltodextrins, dextrans, starches, and the like; and alditols, such as mannitol, xylitol, maltitol, lactitol, xylitol sorbitol (glucitol), myoinositol and the like. Preferred carbohydrate excipients for use in the present invention are mannitol, trehalose, and raffinose.

[0120] Antibody compositions can also include a buffer or a pH adjusting agent; typically, the buffer is a salt prepared from an organic acid or base. Representative buffers include organic acid salts, such as salts of citric acid, ascorbic acid, gluconic acid, carbonic acid, tartaric acid, succinic acid, acetic acid, or phthalic acid; Tris, tromethamine hydrochloride, phosphate buffers or amino acid buffers. Preferred buffers for use in the present compositions are organic acid salts, such as citrate or amino acids.

[0121] Additionally, the compositions of the invention can include polymeric

excipients/additives, such as polyvinylpyrrolidones, ficolls (a polymeric sugar), dextrates (e.g., cyclodextrins, such as 2-hydroxypropyl-P-cyclodextrin), polyethylene glycols, flavoring agents, antimicrobial agents, sweeteners, antioxidants, antistatic agents, surfactants (e.g., polysorbates such as "TWEEN® 20" and 'TWEEN® 80"), lipids (e.g., phospholipids, fatty acids), steroids (e.g., cholesterol), and chelating agents (e.g., EDTA).

[0122] These and additional known pharmaceutical excipients and/or additives suitable for use in the antibody compositions according to the invention are known in the art, e.g., as listed in "Remington: The Science & Practice of Pharmacy", 19 th ed., Williams & Williams, (1995), and in the "Physician's Desk Reference", 52 nd ed., Medical Economics, Montvale, NJ. (1998), the disclosures of which are entirely incorporated herein by reference. Preferred carrier or excipient materials are carbohydrates (e.g., saccharides and alditols) and buffers (e.g., citrate) or polymeric agents.

[0123] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within the spirit and scope. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

[0124] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any materials and methods similar or equivalent to those described herein can be used to practice or test the present invention, the preferred materials and methods are now described.

EXAMPLE 1

Robust anti-tumor activity of anti-hCD47-attenuated IFNα2b fusion protein in

combination with naked anti-hCD38 antibody in myeloma xenograft model

[0125] NCI-H929 plasma cell myeloma cells were maintained as exponentially growing suspension cultures in standard growth media and conditions. The tumor cells used for implantation were harvested during log phase growth and resuspended at a concentration of 1 x

10 8 cells/mL in 50% Matrigel (BD Biosciences). 1 x 107 tumor cells (0.1 mL cell suspension) were implanted subcutaneously (s.c.) into left flank of 8-9 week old female severe combined immunodeficient (SCID) mice. In this model, the CD38⁺ myeloma tumor cells grow as a vascularized subcutaneous mass. Tumors were allowed to grow to an average volume of 150mm before treatment began. Tumors were measured with callipers in two dimensions to monitor size. Mice (10/cohort) were treated intraperitoneally (i.p.) twice per week for 4 weeks with vehicle (PBS), or with 200μL of each of the following test agents: 60 μg/dose naked anti- human CD38 (hlOA2-hIgG4) antibody (SEQ ID NOS: 506 and 507) alone, 100 μg/dose naked non-glycosylated anti-hCD47 antibody (hlgGl , given every other day for 14 days) (SEQ ID NOS: 509/534) alone or together with 60 μg/dose naked anti-hCD38 (hlOA2-hIgG4) antibody , 125 μg/dose anti-h CD47-attenuated interferon α2b fusion protein (non-glycosylated to remove effector function) (SEQ ID NOS:509 and 550) together with naked anti-hCD38 (hlOA2-hIgG4) antibody. Mean (+/- SEM) tumor volumes are presented in Figure 1. The results indicated the robust anti-tumor activity of anti-hCD47-attenuated interferon α2b fusion protein in combination with naked anti-hCD38 antibody with 10 of 10 mice tumor free at the end of the study. The combination of the unarmed naked anti-hCD47 antibody plus anti-hCD38 antibodies did not produce tumor free survival in any mice.

EXAMPLE 2:

Another example of robust anti-tumor activity of anti-hCD47-attenuated IFNα2b fusion protein in combination with naked anti-hCD38 antibody in the myeloma xenograft model utilizing a second anti-hCD38 naked antibody (G005).

[0126] NCI-H929 myeloma xenograft model was performed as described in Example 1. In this study, mice (10/cohort) were treated intraperitoneally (i.p.) twice per week for 4 weeks with vehicle (PBS), or with 200μL (100μg) each of the following test agents: naked anti-hCD38 (G005-hIgG4) antibody (SEQ ID NOS: 506/507) alone, or anti-hCD47-attenuated interferon α2b fusion protein (non-glycosylated to remove effector function) (SEQ ID NOS: 509 and 550) either alone or together with naked anti-hCD38 (G005) antibody. Tumor volumes were monitored and measured by calipers. Mean (+/- SEM) tumor volumes are presented in Figure 2. The results indicated the robust anti-tumor activity of anti-hCD47-attenuated interferon α2b fusion protein in combination with naked anti-hCD38 (G005) antibody with 10 of 10 mice remaining tumor free at the end of the study (day 60), while in this model these agents alone were not capable of resolving the tumors.

EXAMPLE 3

Combination of anti-hCD47-attenuated IFNα2b fusion protein plus anti-hCD38 naked antibody leads to enhanced anti-tumor response in a refractory myeloma model, OPM-2.

[0127] OPM-2 plasma cell myeloma cells were maintained as exponentially growing suspension cultures in standard growth media and conditions. The tumor cells were harvested during log phase growth and resuspended at a concentration of 1 x 10 cells/mL in 50% Matrigel (BD Biosciences). 1 x 10⁷ tumor cells (0.1 mL cell suspension) were implanted subcutaneously (s.c.) into flank of 8-9 week old female CB.17 SCID (severe combined immunodeficient) mice. The OPM-2 myeloma tumor cells grow as a vascularized subcutaneous mass. Tumors were allowed to grow to an average volume of 150mm^' before treatment began. Mice (10/cohort) were treated intraperitoneally (i.p.) twice per week for 4 weeks with vehicle (PBS), or with 200μL, of each of the following test agents: 60 μg/dose naked anti-hCD38 (hl0A2-hIgG4) antibody (SEQ ID NOS: 506/507) alone, 66 Mg/dose anti-hCD47-attenuated interferon α2b fusion protein (non-glycosylated to remove effector function) (SEQ ID NOS:509/550) either alone or together with naked anti-hCD38 (hlOA2-hIgG4) antibody, or naked anti-hCD38 (hlOA2-IgG4) antibody plus 100 μg/dose naked non-glycoslyated anti-hCD47 antibody (hIgG4, given every other day for 14 days) (SEQ NOS: 509/534). Tumor volumes were monitored and measured by callipers. Mean (+/- SEM) tumor volumes are presented in Figure 3. The results indicated that anti-CD47-attenuated interferon α2b fusion protein in combination with naked anti-hCD38 antibody provided the strongest anti-tumor response compared to the other test agents, although in this refractory myeloma model tumors began to show regrowth about day 40, 12 days after treatment stopped (day 28). EXAMPLE 4

Combination of anti-hCD38 antibody plus one of two different anti-hCD47-attenuated IFNα2b fusion proteins derived from two independent anti-hCD47 antibodies (clone 2A1 and clone 5F9) leads to enhanced anti-tumor responses in the refractory myeloma model OPM-2.

[0128] The OPM-2 refractory myeloma xenograft model was performed as described in Example 3. Mice (10/cohort) were treated intraperitoneally (i.p.) twice per week for 4 weeks with vehicle (PBS), or with 200μL (lOCμg) of each of the following test agents: anti-hCD47- attenuated interferon α2b (clone 2A1) fusion protein (non-glycosylated to remove effector function) (SEQ ID NOS: 517/542) alone or in combination with naked anti-hCD38 (M0A2- hIgG4) (SEQ ID NOS: 506/507), or anti-hCD47-attenuated interferon α2b (clone 5F9) fusion protein (non-glycosylated to remove effector function) (SEQ ID NOS: 519/543) alone or in combination with naked anti-hCD38 (hlOA2-hIgG4) antibody. The results indicated that each of two additional different anti-hCD47-attenuated IFNα2b fusion proteins from anti-CD47 (clone 5F9 and clone 2A1) demonstrated strong anti-tumor activity in combination with anti-hCD38 antibody in this refractory myeloma tumor model.

EXAMPLE 5

Robust anti-leukemia tumor activity observed in mice treated with anti-hCD47-attenuated IFNα2b fusion protein plus anti-hCD52 naked antibody.

[0129] Acute T cell leukemia cells, CCRF-CEM, were maintained as exponentially growing suspension cultures in standard growth media and conditions. The tumor cells were harvested during log phase growth and resuspended in saline at a concentration of 2.5 x 10⁷ cells/mL. 5 x 10⁷ tumor cells (0.2 mL cell suspension) were inoculated intravenously (i.v.) into 8-9 week old female CB.17 SCID (severe combined immunodeficient) mice. Treatment was started 7 days post inoculation and tumor free survival (TFS) was monitored. Mice (10/cohort) were treated intraperitoneally (i.p.) twice per week for 4 weeks with vehicle (PBS), or with 200μL (100μg) of each of the following test agents: anti-h CD47-attenuated interferon α2b fusion protein (non- glycosylated to remove effector function) (SEQ ID NOS:509 and 550) either alone or together with naked anti-hCD52 (anti-CD52-hIgGl) antibody (SEQ ID NOS: 523/551), or naked anti- hCD52 (anti-CD52-hIgGl ) antibody plus naked non-glycosylated anti-hCD47 (hIgG4, given every other day for 14 days) antibody (SEQ ID NOS:509/534). The results in this T cell leukemia model indicate strong enhanced survival in mice treated with a combination of anti- hCD47-attenuated IFNα2b fusion protein plus anti-hCD52 naked antibody.

Claims

1. A combination therapy for treating a tumor in a subject, the combination therapy

comprising administration of (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand.

2. The combination therapy as claimed in claim 1 in which the anti-CD47 ligand is an antibody.

3. The combination therapy as claimed in claim 1 in which the anti-CD47 ligand

comprises the extracellular domain of SIRPoc linked to an Fc.

4. The combination therapy as claimed in any one of claims 1 to 3 in which the anti-CD47 ligand lacks effector function.

5. The combination therapy as claimed in any one of claims 1 to 4 in which the attenuated Type I IFN is linked to the anti-CD47 ligand via a peptide bond.

6. The combination therapy as claimed in any one of claims 1 to 5 in which the attenuated Type I IFN is linked to the anti-CD47 ligand directly or via a linker of 1 to 20 amino acids in length.

7. The combination therapy as claimed in any one of claims 1 to 6 in which the attenuated Type I IFN is attenuated IFNα.

8. The combination therapy as claimed in claim 7, in which the amino acid sequence of the IFNα is selected from SEQ ID NOs 1 to 3, 80 to 90, 391, and 392 and wherein the IFNα comprises at least one amino acid substitution or deletion which attenuates the IFNα activity.

9. The combination therapy as claimed in 7 or claim 8 in which the attenuated IFNα is attenuated IFNα2b.

10. The combination therapy as claimed in claim 9 in which the attenuated IFNα2b has a sequence which comprises relative to SEQ ID NO: 3 at least one amino acid substitution or deletion selected from the group consisting of L15A, R22A, R23A, S25A, L26A, F27A, L30A, L30V, K31A, D32A, R33A, R33K, R33Q, H34A, Q40A, D114R, L117A, R120A, R120E, R125A, R125E, K131A, E132A, K133A, K134A, M148A, R149A, S152A, L153A, N156A, (L30A, H57Y, E58N and Q61S), (R33A, H57Y, E58N and Q61 S), (M148A, H57Y, E58N and Q61 S), (L153A, H57Y, E58N and Q61 S), (R144A, H57Y, E58N and Q61 S), (N65A, L80A, Y85A and Y89A,) (N65A, L80A, Y85A, Y89A and Dl 14A), (N65A, L80A, Y85A, Y89A and LI 17A), (N65A, L80A, Y85A, Y89A and R120A), (Y85A, Y89A and Dl 14A), (Dl 14A and R120A), (LI 17A and R120A), (LI 17A, R120A and K121A), (R120A and K121A), (R120E and K121E), replacement of R at position 144 with A, D, E, G, H, I, K, L, N, Q, S, T, V or Y, replacement of A at position 145 with D, E, G, H, I, K, L, M, N, Q, S, T, V or Y, deletion of residues L161 to E165, and combinations thereof.

1 1. The combination therapy as claimed in any one of claims 7 to 9 wherein the attenuated IFNα is aglycosylated attenuated IFNα2b.

12. The combination therapy as claimed in claim 11 wherein T106, relative to wild type sequence, of the aglycosylated attenuated IFNα2b is deleted or substituted with an amino acid other than T.

13. The combination therapy as claimed in claim 11 or claim 12 wherein T106, relative to wild type sequence, of the aglycosylated attenuated IFNα2b is substituted with A.

14. The combination therapy as claimed in claim 11 or claim 12 wherein T106, relative to wild type sequence, of the aglycosylated attenuated IFNα2b is deleted.

15. The combination therapy as claimed in any one of claims 7 to 14 wherein the sequence of the attenuated IFNα2b is SEQ ID NO: 44 or SEQ ID NO:536.

16. The combination therapy as claimed in any one of claims claim 1 to 15 in which the cell surface-associated antigen is selected from the group consisting of CD38, CD 138, RANK-Ligand, HM1.24, CD56, CS1 , CD20, CD74, IL-6R, Blys (BAFF), BCMA, Kininogen, beta2 microglobulin, FGFR3, ICAM-1 , matriptase, CD52, EGFR, GM2, alpha4-integrin, IFG-1R, KIR, CD3, CD4, CD8, CD24, CD30, CD37, CD44, CD69, CD71 , CD79, CD83, CD86, CD96, HLA, PD-1 , ICOS, CD33, CDl 15, CDl lc, CD19, CD52, CD14, FSP1, FAP, PDGFR alpha, PDGFR beta, ASGR1, ASGR2, FSP1, LyPD3, RTI140/Ti-alpha, HTI56, VEGF receptor, CD241 the product of the RCHE gene, CDl 17 (c-kit), CD71 (transferrin receptor), CD36 (thrombospondin receptor), CD34, CD45RO, CD45RA, CDl 15, CD 168, CD235, CD236, CD237, CD238, CD239, CD240, TROP2, CD70, CCR2, HER2, EGFR and CCR3.

17. The combination therapy as claimed in any one of claims 1 to 16 in which the cell surface-associated antigen is selected from the group consisting of CD38, CDl 38, EpCAM, TROP2, CD 19, CD20, CD79b, CD22 and CD52.

18. The combination therapy as claimed in claim 17 in which the cell surface-associated antigen is CD38.

19. The combination therapy as claimed in claim 18 in which the V_H sequence of the

antibody which binds to the cell surface-associated antigen is selected from the group consisting of SEQ ID Nos: 342, 344, 346, 504, 511 and 540.

20. The combination therapy as claimed in claim 18 or claim 19 in which the V_L sequence of the antibody which binds to the cell surface- associated antigen is selected from the group consisting of SEQ ID Nos: 341, 343, 345, 505, 512, 538 and 539.

21. The combination therapy as claimed in claim 19 or claim 20 in which the V_H is SEQ ID NO:540 and the V_L sequence is SEQ ID NO:539.

22. The combination therapy as claimed in any one of claims 1 to 21 wherein the sequence of the polypeptide construct is selected from the group consisting of SEQ ID NOs: 509/541, 513/542, 515/543, 517/544, 519/545, 509/546, 513/547, 515/548, 517/549 and 519/550.

23. The combination therapy as claimed in any one of claims 1 to 22 in which (i) an

antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand are administered sequentially or simultaneously.

24. A method of treating a tumor in a subject comprising the combination therapy as

claimed in any one of claims 1 to 23.

25. A method of treating a tumor in a subject according to claim 24 wherein the tumor is selected from multiple myeloma or non-Hodgkin's lymphoma

26. A composition comprising (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand of any one of claims 1 to 22 in admixture.

27. The use of (i) an antibody which binds to a cell surface-associated antigen expressed on the tumor cell, and (ii) a polypeptide construct comprising an attenuated Type I interferon (IFN) linked to an anti-CD47 ligand of any one of claims 1 to 22 in the preparation of a medicament(s) for the treatment of a tumor.

28. A polypeptide construct comprising a first and a second region wherein the first region comprises an anti-CD47 ligand and the second region comprises an attenuated Type I interferon (IFN).

29. The polypeptide construct as claimed in claim 28 in which the anti-CD47 ligand is an antibody.

30. The polypeptide construct as claimed in claim 28 in which the anti-CD47 ligand

comprises the extracellular domain of SIRPoc linked to an Fc.

31. The polypeptide construct as claimed in any one of claims 28 to 30 in which the anti- CD47 ligand lacks effector function.

32. The polypeptide construct as claimed in any one of claims 28 to 31 in which the

attenuated Type I IFN is linked to the anti-CD47 ligand via a peptide bond.

33. The polypeptide construct as claimed in any one of claims 28 to 32 in which the

attenuated Type I IFN is linked to the anti-CD47 ligand directly or via a linker of 1 to 20 amino acids in length.

34. The polypeptide construct as claimed in claim 28 to 33 in which the attenuated Type I IFN is attenuated IFNα.

35. The polypeptide construct as claimed in claim 34, in which the amino acid sequence of the IFNα is selected from SEQ ID NOs 1 to 3, 80 to 90, 391 and 392 and wherein the IFNα comprises at least one amino acid substitution or deletion which attenuates the IFNα activity.

36. The polypeptide construct as claimed in 34 or claim 35 in which the attenuated IFNα is attenuated IFNα2b.

37. The polypeptide construct as claimed in claim 36 in which the attenuated IFNα2b has a sequence which comprises relative to SEQ ID NO: 3 at least one amino acid substitution or deletion selected from the group consisting of L15A, R22A, R23A, S25A, L26A, F27A, L30A, L30V, K31A, D32A, R33A, R33K, R33Q, H34A, Q40A, D114R, L117A, R120A, R120E, R125A, R125E, K131A, E132A, K133A, K134A, M148A, R149A, S152A, L153A, N156A, (L30A, H57Y, E58N and Q61S), (R33A, H57Y, E58N and Q61S), (M148A, H57Y, E58N and Q61S), (L153A, H57Y, E58N and Q61S), (R144A, H57Y, E58N and Q61S), (N65A, L80A, Y85A and Y89A,) (N65A, L80A, Y85A, Y89A and Dl 14A), (N65A, L80A, Y85A, Y89A and LI 17A), (N65A, L80A, Y85A, Y89A and R120A), (Y85A, Y89A and Dl 14A), (Dl 14A and R120A), (LI 17A and R120A), (LI 17 A, R120A and K121A), (R120A and K121A), (R120E and K121E), replacement of R at position 144 with A, D, E, G, H, I, K, L, N, Q, S, T, V or Y, replacement of A at position 145 with D, E, G, H, I, K, L, M, N, Q, S, T, V or Y, deletion of residues L161 to E165, and combinations thereof.

38. The combination therapy as claimed in any one of claims 45 to 47 wherein the

attenuated IFNα2b is aglycosylated attenuated IFNα2b.

39. The combination therapy as claimed in claim 38 wherein T106, relative to wild type sequence, of the aglycosylated attenuated IFNα2b is deleted or substituted with an amino acid other than T.

40. The combination therapy as claimed in claim 38 wherein T106, relative to wild type sequence, of the aglycosylated attenuated IFNα2b is substituted with A.

41. The combination therapy as claimed in claim 38 wherein T106, relative to wild type sequence, of the aglycosylated attenuated IFNα2b is deleted.

42. The polypeptide construct as claimed in claim 36 or claim 37 wherein the sequence of the attenuated IFNα2b is SEQ ID NO: 44 or SEQ ID NO:536.

43. The polypeptide construct as claimed in any one of claims 28 to 42 in which the

sequence of the construct is SEQ ID NO:535 and either SEQ ID NO:549 or SEQ ID NO:550.