Use of Engineered Fc Fragments in Immunotherapy

Abstract

The present invention relates to an isolated recombinant Fc fragment having an altered affinity for at least one Fc receptor (FcR), particularly an increased affinity for FcRn, for use in the treatment of autoimmune and / or inflammatory diseases.

Description

[Technical field]

[0001] The present invention relates to the immunotherapy of autoimmune and / or inflammatory diseases. [Background technology]

[0002] Immunotherapy, which consists of the administration of exogenous antibodies to a patient, is widely used today to treat a variety of medical conditions, particularly autoimmune and inflammatory diseases.

[0003] Two types of immunoglobulin-based therapies are typically proposed to treat these diseases: i) intravenous immunoglobulin (IVIg)-based therapies, consisting of the intravenous administration to the patient of immunoglobulins (most often IgG) derived from a pool of human plasma, and ii) therapies based on the use of recombinant antibodies (i.e. antibodies obtained by genetic engineering). The latter are certainly an improvement in the management of patients with autoimmune and inflammatory diseases, especially since they offer the possibility of avoiding the drawbacks related to the use of plasma-derived immunoglobulins, in particular the risk of supply shortages and possibly the risk of transmission of pathogens present in the plasma.

[0004] The presence of Fab fragments in immunoglobulins can be the cause of serious adverse reactions in treated patients. To avoid these side effects, patent application WO2004 / 099374 discloses the use of isolated recombinant Fc fragments to treat patients, particularly those with autoimmune diseases.

[0005] However, there is still a need to optimize these Fc fragments, in particular to increase their half-life and / or therapeutic efficacy. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent application WO2004 / 099374 [Patent Document 2] Patent application WO2010 / 106180 [Patent Document 3] Patent application WO01 / 77181 [Patent Document 4] Application WO02 / 038756 [Patent Document 5] Document WO200748077 [Patent Document 6] Document US7700321 [Patent Document 7] Document US2010291628 [Patent Document 8] US20090228994 [Patent Document 9] EP1500698 [Patent Document 10] EP1792987 [Patent Document 11] US7846725 [Patent Document 12] Document US7393683 [Patent Document 13] Document WO2006133148 [Patent Document 14] Document WO0200879 [Patent Document 15] Document EP1176195 [Patent Document 16] US7214775 [Patent Document 17] US6994292 [Patent Document 18] US7425449 [Patent Document 19] US2010223686 [Patent Document 20] WO2007099988 [Patent Document 21] EP1705251 [Non-patent literature]

[0007] [Non-Patent Document 1] Kabat et al., Sequences of proteins of immunological interest, 5thEd. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) [Non-Patent Document 2] Basic and Clinical Immunology, 8th Edition, Daniel P. Stites, Abba I. Terr and Tristram G. Parslow (eds.), Appleton and Lange, Norwalk, Conn., 1994, pp. 71 and Chapter 6 [Non-Patent Document 3] Ravetch and Kinet, Annual Review of Immunology, Vol. 9: 457-492 (1991) [Non-Patent Document 4] Uananue and Benacerraf, Textbook of Immunology, 2nd Edition, Williams and Wilkins, p. 218 (1984) [Non-Patent Document 5] Muta T et al., Nature, 1994, 368:70-73 [Non-Patent Document 6] Ayala M, Gavilondo J, Rodriguez M, Fuentes A, Enriquez G, Perez L, Cremata J, Pujol M.Production of plantibodies in Nicotiana plants.Methods Mol Biol.2009;483:103~34 [Non-Patent Document 7] Pollock, DP, JPKutzko, E. Birck-Wilson, JL Williams, Y. Echelard and HMMeade. (1999). Transgenic milk as a method for the production of recombinant antibodies. Journal of Immunological Methods. 231: 147-157. [Non-Patent Document 8] Popov et al., Mol. Immunol. 33:521-530 (1996) Summary of the Invention [Means for solving the problem]

[0008] The inventors now propose the use of Fc fragments that have an altered affinity for at least one Fc receptor (FcR) compared to the parent Fc fragment. According to the invention, the Fc fragments are isolated, i.e. they are not associated with Fab fragments or conjugated or fused to any other protein, polypeptide or peptide. In particular, they are not complete immunoglobulins.

[0009] The present invention relates to a composition comprising an antibody Fc fragment for use in the treatment of an autoimmune and / or inflammatory disease, wherein said Fc fragment is an isolated Fc fragment having improved affinity for Fc-gamma receptor III (FcγRIII) compared to the parent Fc fragment.

[0010] In a preferred embodiment, the Fc fragment is: - an Fc fragment which has the combination of mutations 315D / 330V / 361D / 378V / 434Y compared to the parent Fc fragment of wild type IgG1 and preferably consists of the sequence SEQ ID NO: 11. - an Fc fragment which has the combination of mutations T260A and 315D / 330V / 361D / 378V / 434Y compared to the parent Fc fragment of wild type IgG1, and which preferably consists of the sequence SEQ ID NO: 12. - an Fc fragment which has the combination of mutations E258I and 315D / 330V / 361D / 378V / 434Y compared to the parent Fc fragment of wild type IgG1, and which preferably consists of the sequence SEQ ID NO: 13. - an Fc fragment which has the combination of mutations K290Y and 315D / 330V / 361D / 378V / 434Y compared to the parent Fc fragment of wild type IgG1 and which consists of the sequence SEQ ID NO: 14. - an Fc fragment which has the combination of mutations E294A and 315D / 330V / 361D / 378V / 434Y compared to the parent Fc fragment of wild type IgG1, and which preferably consists of the sequence SEQ ID NO: 15. - an Fc fragment which has the combination of mutations Y296W and 315D / 330V / 361D / 378V / 434Y compared to the parent Fc fragment of wild type IgG1, and which preferably consists of the sequence SEQ ID NO: 16. - an Fc fragment which has the combination of mutations K334N / P352S / A378V / V397M compared to the parent Fc fragment of wild type IgG1 and preferably consists of the sequence SEQ ID NO: 19. - an Fc fragment which has the combination of mutations G316D / K326E / A378V compared to the parent Fc fragment of wild type IgG1 and preferably consists of the sequence SEQ ID NO: 20. - an Fc fragment which has the combination of mutations A378V / P396L / N421T compared to the parent Fc fragment of wild type IgG1 and preferably consists of the sequence SEQ ID NO: 21. - an Fc fragment which has the mutation T260A compared to the parent Fc fragment of wild type IgG1 and which preferably consists of the sequence SEQ ID NO: 17. - an Fc fragment which has the mutation K290Y compared to the parent Fc fragment of wild type IgG1 and which preferably consists of the sequence SEQ ID NO: 18.

[0011] The invention also more generally provides compositions comprising an antibody Fc fragment for use in the treatment of autoimmune and / or inflammatory diseases, wherein the Fc fragment is an isolated Fc fragment having an altered affinity for at least one Fc receptor (FcR) compared to the parent Fc fragment.

[0012] In a particular embodiment, the composition comprises an antibody Fc fragment having at least one mutation of one or more amino acids and / or having an N-glycan on its glycosylation site (Asn297), wherein said N-glycan of the Fc fragment has a degree of fucosylation lower than 65%. [Brief description of the drawings]

[0013] [Figure 1] Figure 1 shows a sequence alignment of native human IgG1 and the corresponding sequences of human IgG2 (SEQ ID NO: 7), human IgG3 (SEQ ID NO: 8) and human IgG4 (SEQ ID NO: 9) for positions 216-447 (according to the EU index). The IgG1 sequence refers to the G1m1,17 allotype (SEQ ID NO: 6), and the G1m3 allotype (SEQ ID NO: 10). The "CH2-CH3 lower hinge" domain of IgG1 starts at position 226 (see arrow). The CH2 domain is highlighted in grey and the CH3 domain is in italics. [Diagram 2] Schematic diagram of IgG1Fc (A) and scFc (B). CH2 is represented in grey and CH3 in white. Disulfide bridges are represented by light grey dotted lines. In scFc, the two CH2-CH3 polypeptides are joined by a peptide linker represented by a bold dotted line. [Diagram 3] FIG. 1 shows glycan structures of types G0, G0F, G1 and G1F which may be present in the Fc fragment of the present invention. [Figure 4] FIG. 1 is a graph showing the rate of effector cell-mediated lysis of rhesus D+ red blood cells in the presence of monoclonal anti-rhesus D (RhD) antibodies observed after addition of various amounts of polyvalent immunoglobulin (IVIg) or non-mutated or mutated recombinant Fc fragments (Fc fragments containing the mutations 315D / 330V / 361D / 378V / 434Y). [Diagram 5]Graph showing the effector cell-mediated lysis rate of rhesus D+ red blood cells in the presence of monoclonal anti-rhesus D (RhD) antibodies observed after addition of various amounts of polyvalent immunoglobulin (IVIg) or non-mutated or mutated recombinant Fc fragments (Fc fragments containing mutations according to Table 1). "rFcWT" indicates wild type recombinant Fc fragment. Positive controls are represented by IVIG (i.e. a mixture of plasma antibodies extracted from human plasma, IVIG is the reference treatment for idiopathic thrombocytopenic purpura (ITP)) and "IgG Mabs starting" corresponding to Herceptin Fc fragments (antibodies transgenically produced in mammals and then subjected to papain enzyme digestion to generate Fc fragments). [Figure 6] FIG. 1 depicts an in vitro binding assay measuring the affinity (Kd) of WT (wild type) and human FcRn (A) and CD16aV (V polymorphism at position 158 of CD16) (B) mutant Fc fragments assessed by surface plasmon resonance (SPR) using a Biacore. [Figure 7] FIG. 2 shows a map of the pCEP4 vector used for expression of variant T5A-74 as defined below, and a map of the OptiCHO vector used for expression of variant T5A-74. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] definition Throughout the specification, the numbering of residues in the Fc fragment is according to the EU index or as described in Kabat et al., Sequences of proteins of immunological interest, 5, which is expressly incorporated herein by reference. thThe numbering of immunoglobulin heavy chains is as described in Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991). "EU index" or "EU index or Kabat equivalent" refers herein to the numbering of the residues of a human IgG1 antibody.

[0015] The term "immunoglobulin" refers to a structure that consists of a biological antibody in its native state, containing constant regions (also called fragments) and variable regions. Immunoglobulin molecules are molecules whose basic unit is a heterotetramer consisting of two heavy chains (H) of about 50-70 kDa each and two light chains (L) of about 25 kDa each, bound together by intra- and inter-bridge disulfide bridges.

[0016] Each chain is composed of a variable domain or region at the N-terminal position, called VL for light chains and VH for heavy chains, and a constant region consisting of a single domain at the C-terminal position, called CL for light chains, and three or four domains, called CH1, CH2, CH3 and CH4 for heavy chains.

[0017] Only IgM and IgE contain the CH4 domain.

[0018] Each domain contains about 110 amino acids and follows a similar type of structure. The two heavy chains are linked by disulfide bridges in the CH2 domain, and each heavy chain is linked to a light chain by a disulfide bridge between CH1 and CL. The regions that determine the specificity of the antibody to the antigen are carried by the variable portion, while the constant portion can interact with Fc receptors (FcR) of molecules such as effector cells or complement proteins to induce various functionalities. The collection of chains that make up an antibody can define a characteristic Y-shaped three-dimensional structure, in which - the base of Y corresponds to the constant Fc region (or Fc fragment) which is recognized by complement and Fc receptors and mediates the effector functions of the molecule, - the ends of the Y arms correspond to the respective assemblies of the light and heavy chain variable regions, which constitute the Fab fragment and determine the specificity of the antibody for the antigen.

[0019] More precisely, there are five heavy chain isotypes (gamma, alpha, mu, delta and epsilon) and two light chain isotypes (kappa and lambda, the lambda chain itself being divided into two types, lambda 1 and lambda 2). It is the heavy chain that determines the class of immunoglobulin. Thus, there are five classes of Ig, IgG (gamma isotype), IgA (alpha isotype), IgM (mu isotype), IgD (delta isotype) and IgE (epsilon isotype).

[0020] Kappa and lambda light chains are shared by all classes and subclasses. In humans, kappa and lambda are produced in a ratio of 2:1.

[0021] IgG are the most abundant immunoglobulins in serum (75%-80% of circulating antibodies). Existing in a monomeric form, they have the longest serum half-life of all immunoglobulins (approximately 21 days).

[0022] There are four types of gamma heavy chains that determine four IgG subclasses (IgG1 for gamma 1, IgG2 for gamma 2, IgG3 for gamma 3, and IgG4 for gamma 4). These four subclasses differ in the number of variable regions and the location of disulfide bridges (Basic and Clinical Immunology, 8 th Edition, Daniel P. Stites, Abba I. Terr and Tristram G. Parslow (eds.), Appleton and Lange, Norwalk, Conn., 1994, pp. 71 and Chapter 6).

[0023] The four human IgG subclasses, despite their highly homologous structure (greater than 95% sequence homology for the Fc region), are further differentiated according to their biological activities.

[0024] The term "biological activity" refers to the ability of complement proteins, in particular (e.g., protein C1q [Basic and Clinical Immunology, 8 th It particularly refers to the ability of the IgG constant region to bind to the FcγRs (FcγRI, FcγRII, FcγRIII; Ravetch and Kinet, Annual Review of Immunology, Vol. 9:457-492 (1991))] and / or the IgG receptors: FcγRs (FcγRI, FcγRII, FcγRIII; Ravetch and Kinet, Annual Review of Immunology, Vol. 9:457-492 (1991)).

[0025] Depending on the type of binding, different mechanisms of action can be activated, such as opsonization, phagocytosis, antibody-dependent cell-mediated cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC). For further details, see Uananue and Benacerraf, Textbook of Immunology, 2006, 144:1311-1325. nd Edition, Williams and Wilkins, p. 218 (1984).

[0026] The term "Fc fragment" refers to the constant region of a full-length immunoglobulin, excluding the first immunoglobulin constant region domain. Thus, "Fc fragment" refers to the last two constant domains (CH2-CH3) of IgA, IgD, and IgG, the last three constant domains (CH2-CH3-CH4) of IgE and IgM, and the N-terminal flexible hinge of these domains. For IgA and IgM, the Fc fragment may include the J chain. For IgG, the Fc fragment includes the CH2, CH3 domains, and the lower hinge region between CH1 and CH2. In other words, the Fc region of IgG1 consists of the CH2-CH3 lower hinge, i.e., the portion from amino acid C226 to the carboxy terminus, the numbering of which is indicated according to the EU index or Kabat equivalent. Analogous domains for other IgG subclasses can be determined from the alignment of the amino acid sequences of the heavy chain or heavy chain fragments of the IgG subclasses and the amino acid sequence of human IgG1 (see FIG. 1). The Fc fragment used according to the invention may further comprise a portion of the upper hinge region upstream of position 226 (according to the EU index). In this case, preferably an Fc fragment of human IgG1 is used, which comprises a portion of the region located between positions 216 and 226. In this case, "Fc fragment of human IgG1" refers to the portion from amino acid 216, 217, 218, 219, 220, 221, 222, 223, 224 or 225 to the carboxy terminus. The term "Fc fragment" also refers to a single chain Fc (scFc) fragment. The term "scFc fragment" refers to a single chain Fc fragment obtained by genetic fusion of two Fc monomers linked by a polypeptide linker. scFc naturally folds into a functional dimeric Fc region.

[0027] The term "parent Fc fragment" or "parent polypeptide" as used herein refers to a reference polypeptide among wild-type Fc regions or variants optionally containing mutations other than those considered. The term "wild-type" or "WT" as used herein refers to an amino acid sequence or a nucleotide sequence found in nature, i.e., of natural origin, including allelic variations, and that has not been intentionally modified by molecular biological techniques such as mutagenesis. For example, a "wild-type" Fc region specifically refers to an IgG1 Fc region having the sequence of SEQ ID NO: 1 (G1m1,17 allotype), an IgG2 Fc region having the sequence of SEQ ID NO: 2, an IgG3 Fc region having the sequence of SEQ ID NO: 3, an IgG4 Fc region having the sequence of SEQ ID NO: 4, and an IgG1 Fc region having the sequence of SEQ ID NO: 5 (G1m3 allotype).

[0028] The Fc fragments used in the present invention are present in monomeric form, i.e., they are not fused or conjugated to each other.

[0029] The term "altered affinity" refers to a decreased or increased affinity compared to the parent Fc fragment.

[0030] As used herein, the term "neonatal Fc receptor" or "FcRn" refers to a protein that binds to the IgG Fc region and is at least partially encoded by the FcRn gene. FcRn may be from any organism, including but not limited to human, mouse, rat, rabbit, and monkey. As is known in the art, a functional FcRn protein comprises two polypeptides, often designated by the names heavy and light chains. The light chain is β2-microglobulin, and the heavy chain is encoded by the FcRn gene. Unless otherwise specified herein, the term "FcRn" or "FcRn protein" refers to the complex of α chain and β2-microglobulin. In humans, the gene encoding FcRn is called FCGRT.

[0031] The term "increased FcRn binding" as used herein refers to an increase in the binding affinity of the variant Fc fragment of the present invention for FcRn in vivo or in vitro compared to the parent polypeptide. The ability of the variant Fc fragment of the present invention to bind to FcRn can be assessed in vitro by ELISA, for example as described in patent application WO2010 / 106180.

[0032] In the present invention, the term "half-life" refers to the amount of time that an Fc fragment is half-cleared from the circulation or other tissues after it is present in the serum of a patient to whom it is administered.

[0033] The term "Fcγ receptor" or "FcγR" refers to the IgG-type immunoglobulin receptors called CD64 (FcγRI), CD32 (FcγRII), and CD16 (FcγRIII), specifically the five expressed receptors (FcγRIa, FcγRIIa, FcγRIIb, FcγRIIIa, FcγRIIIb). All are effector cell activating receptors, except for human FcγRIIb, which is a receptor that inhibits immune cell activation (Muta T et al., Nature, 1994, 368:70-73).

[0034] The term "effector cell" refers to any cell that has an Fc receptor, such as lymphocytes, monocytes, neutrophils, natural killer (NK) cells, eosinophils, basophils, mast cells, dendritic cells, Langerhans cells, and platelets.

[0035] In the context of the present invention, the term "glycosylation" refers to the addition of one or more carbohydrates to the sequence of the recombinant Fc fragment by an enzymatic reaction.

[0036] In the context of the present invention, the term "hypersialylation" refers to the addition of one or more sialic acid groups to the sequence of the Fc fragment. The addition of one or more sialic acid groups can be performed by an enzymatic reaction, by a cellular reaction, or by directed mutagenesis of the Fc targeting one or more amino acids involved in Fc sialylation.

[0037] The term "patient" refers to any human or animal subject, preferably a mammal. In a preferred embodiment, the patient is a human being, regardless of age or sex.

[0038] The term "treatment" or "treating" refers to the amelioration or prevention or reversal of a disease or disorder, or at least one symptom distinguishable therefrom, or the amelioration or prevention or reversal of at least one measurable physical parameter associated with the disease or disorder being treated that is not necessarily distinguishable by the subject being treated. The term "treatment" or "treating" further includes inhibiting or slowing the progression of a disease or disorder physically, e.g., stabilizing a physiologically distinguishable symptom, e.g., stabilizing a physical parameter, or both.

[0039] Compositions of Fc fragments according to the present invention The antibody Fc fragment used in the present invention is preferably an Fc fragment of an IgG1, IgG2, IgG3 or IgG4 immunoglobulin that has an altered affinity for at least one Fc receptor (FcR) compared to the parent Fc fragment.

[0040] An Fc fragment according to the invention has reduced affinity for at least one Fc receptor and / or increased affinity for at least one Fc receptor compared to the parent Fc fragment.

[0041] The affinity is preferentially increased by a ratio at least equal to 2, preferably greater than 5, preferably greater than 10, preferably greater than 15, preferably greater than 20, preferably greater than 25, and preferably greater than 30, as compared to the affinity of the parent Fc. In other words, the affinity of the variant Fc region for an FcR is higher than that of the parent polypeptide. Alternatively, said variant Fc region has a reduced affinity for at least one FcR. The affinity is preferentially reduced by a ratio at least equal to 2, preferably greater than 5, preferably greater than 10, preferably greater than 15, preferably greater than 20, preferably greater than 25, and preferably greater than 30, as compared to the affinity of the parent Fc. In other words, the affinity of the variant Fc region for an FcR is lower than that of the parent polypeptide.

[0042] The affinity of a polypeptide comprising an Fc region for an FcR can be evaluated by methods well known in the art. For example, one skilled in the art can determine the affinity (Kd) by using surface plasmon resonance (SPR), which can be measured by a Biacore system. Alternatively, one skilled in the art can perform a suitable ELISA. A suitable ELISA can be used to compare the binding strength of the parental Fc and the variant Fc. The specific signal detected from the variant Fc is compared to the specific signal detected from the parental Fc. The binding affinity can be determined similarly by evaluating the entire polypeptide or by evaluating the Fc region isolated therefrom.

[0043] In particular, the Fc fragments used according to the invention have reduced affinity for at least one Fc receptor selected from FcRn, Fcγ receptors, and complement C1q, and / or increased affinity for at least one Fc receptor selected from FcRn, Fcγ receptors, and complement C1q, compared to the parent Fc fragment.

[0044] According to a particular embodiment, the Fc fragments used according to the invention have an altered, advantageously increased, affinity for FcRn, which increases the FcRn binding leading to improved serum retention in vivo and consequently increased half-life.

[0045] The Fc fragments can be used alone or in mixtures, for example several Fc fragments with different mutations can be administered in a mixture or simultaneously.

[0046] The Fc fragments of the present invention can also be used in a composition comprising one type of variant Fc fragment, in other words, the composition comprises molecules of Fc fragments of the same sequence.

[0047] According to one embodiment of the invention, the Fc fragment having an altered affinity for at least one Fc receptor contains at least one amino acid mutation compared to the parent Fc fragment, the relevant mutation being an artificial mutation rather than the naturally occurring mutations that define immunoglobulin isotypes, and the method of its production results in an Fc fragment containing the desired mutation.

[0048] Preferably, the mutation is a substitution, deletion or insertion of one or more amino acids. A mutant Fc fragment may have several mutations affecting several, preferably 2 to 10, amino acids.

[0049] In a preferred embodiment, the Fc fragment comprises the amino acids 226, 227, 228, 230, 231, 233, 234, 239, 241, 243, 246, 250, 252, 256, 259, 264, 265, 267, 269, 270, 276, 284, 285, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 339, 341, 343, 346, 350, 352, 356, 359, 364, 365, 367, 369, 370, 376, 377, 378, 379, 380, 381, 382, ​​383, 384, 385, 386, 387, 388, 389, 390, 391, 39 94, 297, 298, 299, 301, 302, 303, 305, 307, 308, 309, 311, 315, 317, 320, 322, 325, 327, 330, 332, 334, 335, 338, 340, 342, 343, 345, 347, 350, 352, 354, 355, 356, 359, 360, 361, 362, 369, 370, 371, 375, 378, 380, 382, ​​383, 384, 385, 386, 387, 389, 390, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 403, 404, 408, 411, 412, 414, 415, 416, 418, 419, 420, 421, 422, 424, 426, 428, 433, 434, 438, 439, 440, 443, 444, 445, 446 or 447, wherein the numbering of the Fc fragment amino acids refers to the EU index or Kabat equivalent numbering.

[0050] Particular amino acid positions from the above list are preferred, namely 226, 230, 241, 256, 259, 264, 307, 315, 330, 342, 361, 362, 378, 382, ​​383, 389, 396, 397, 421, 428 and 434. In particular, variant Fc fragments with high binding affinity to FcRn may contain at least one amino acid change at said amino acid positions. Among these, positions 230, 264, 307, 315, 330, 378 and 434 are preferred, and positions 264, 315, 378 and 434 are more preferred.

[0051] In particular embodiments, at least two, and indeed three, four or five amino acid mutations may result in significantly improved binding affinity to FcRn compared to the parent Fc.

[0052] In particular embodiments, the mutation is the following mutation: (i) one or two mutations selected from the group consisting of positions 226, 230, 241, 264, 307, 315, 330, 342, 362, 378, 382, ​​389, 396, 397, 421 and 434, preferably 230, 264, 307, 315, 330, 378 and 434, more preferably 264, 315, 378 and 434, and (ii) positions 226, 227, 228, 230, 231, 233, 234, 239, 241, 243, 246, 250, 252, 256; 259, 264, 265, 267, 269, 270, 276, 284, 285, 288, 289, 290, 291, 292, 293, 29 4, 297, 298, 299, 301, 302, 303, 305, 307, 308, 309, 311, 315, 317, 320, 322, 325, 327, 330, 332, 334, 335, 338, 340, 342, 343, 345, 347, 350, 352, 354, 355 356, 359, 360, 361, 362, 369, 370, 371, 375, 378, 380, 382, ​​383, 384, 385, 386, 387, 389, 390, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 403, 404, 408, 411, 412, 414, 415, 416, 418, 419, 420, 421, 422, 424, 426, 428, 433, 434, 438, 439, 440, 443, 444, 445, 446 and 447, preferably 226, 230, 241, 264, 307, 315, 330, 342, 362, 378, 382, ​​389, 396, 397, 421 and 434.

[0053] In a preferred embodiment, at least one of positions 378 and 434, and optionally also at least one other position selected from the group consisting of 226, 230, 241, 264, 307, 315, 330, 342, 362, 378, 382, ​​389, 396, 397, 421 and 434, are mutated.

[0054] The mutations are 226G, 226Y, 227S, 227L, 228R, 228L, 230S, 230T, 230L, 230A, 230Q, 231T, 231V, 233D, 234R, 239A, 241L, 241Y, 241R, 243L, 246R, 250A, 252L, 256N, 259I, 264A, 264E, 264M, 265G, 265N, 267N, 267R, 269D, 269G, 270N, 270E, 276S, 284L, 285Y, 288R, 289I, 290R, 290E, 291S, and 291Q. 292W, 293del, 294del, 297D, 298G, 298N, 299M, 299A, 299K, 301C, 302A, 303A, 303I, 305A, 307P, 307A, 307N , 3081, 309P, 311R, 315D, 317R, 320T, 320E, 322R, 325S, 327V, 327T, 330V, 330T, 332V, 334E, 334R, 335A, 338 R, 340E, 342R, 342E, 342K, 343S, 345Q, 345G, 347R, 350A, 352S, 354P, 355Q, 355G, 356N, 359A, 360N, 360R, 3 61D, 361S, 362R, 362E, 369A, 370R, 371D, 375A, 375G, 378V, 378T, 378S, 380Q, 382V, 382G, 383R, 383N, 384I, 384T, 385R, 386R, 386K, 387S, 387T, 389T, 389K, 389R, 390S, 392E, 392R, 393N, 394A, 395A, 395S, 396S, 396 L, 397A, 397M, 398P, 399N, 400P, 401A, 401G, 403T, 404L, 408T, 411A, 412A, 414R, 415D, 415N, 416K, 416G, 41 8R, 418K, 418E, 419H, 420R, 421T, 421S, 421D, 422A, 424L, 426T, 428L, 433R, 433P, 434Y, 434S, 434H, 438R, 439R, 440R, 440N, 443R, 444F, 444P, 445S, 446A, 447N and 447E are preferred and are also described in patent application WO2010 / 106180.

[0055] In another embodiment, the Fc fragment is 226G, 227L, 230S, 230T, 230L, 231T, 241L, 243L, 250A, 256N, 259I, 264E, 265G, 267R, 290E, 293del, 294del, 303A, 305A, 307P, 307A, 308I, 315D, 322R, 325S, 327V, 330V, 342R, 347R, 352S, 361D, 362R, 362E, 370R, 378V, 378T, 382V, 383N, 386R, 386K, 387T, 38 9T, 389K, 392R, 395A, 396L, 397M, 403T, 404L, 415N, 416K, 421T, 426T, 428L, 433R, 434Y, 434S and 439R, preferably 226G, 230S, 230T, 230L, 241L, 264E, 307P, 315D, 330V, 342R, 362R, 362E, 378V, 378T, 382V, 389T, 389K, 396L, 397M, 421T, 434Y and 434S.

[0056] Detailed examples of combinations of mutations are given below: 226G / 330V, 230L / 264E, 230L / 378V, 230S / 315D, 230S / 434Y, 230T / 378V, 241L / 434S, 250A / 434Y, 264E / 378T, 305A / 315D, 305A / 330 V, 305A / 434Y, 307P / 434Y, 315D / 389T, 330V / 382V, 330V / 389T, 378V / 421T, 389K / 434Y, 389T / 434Y, 396L / 434S, 230T / 264E, 230T / 3 15D, 230T / 434S, 230T / 434Y, 241L / 307P, 264E / 307P, 264E / 396L, 315D / 362R, 315D / 382V, 362R / 434Y, 378V / 434Y, 382V / 434Y, 226G / 315D, 226G / 434Y, 241L / 378V, 307P / 378V, 241L / 264E, 378V / 434S, 264E / 378V, 264E / 434S, 315D / 330V, 330V / 434Y, and 315D / 434Y; or 226G / 315D / 330V, 226G / 315D / 434Y, 226G / 330V / 434Y, 230L / 264E / 378V, 230T / 26 4E / 378V, 230T / 264E / 434S, 230S / 315D / 434Y, 230T / 315D / 434Y, 230T / 389T / 434S, 241L / 264E / 434S, 241L / 264E / 378V, 241L / 264E / 307P, 241L / 307P / 378V, 250A / 389 K / 434Y, 256N / 378V / 434Y, 259I / 315D / 434Y, 264E / 378T / 396L, 264E / 378V / 416K, 2 94del / 307P / 434Y, 264E / 307P / 378V, 264E / 396L / 434S, 264E / 378V / 434S, 305A / 3 15D / 330V, 305A / 315D / 434Y, 305A / 330V / 434Y, 307P / 378V / 434Y, 315D / 330V / 382V , 315D / 330V / 389T, 315D / 378V / 434Y, 315D / 389T / 434Y, 315D / 362R / 434Y, 315D / 382V / 434Y, 315D / 330V / 434Y, 330V / 382V / 434Y, 330V / 389T / 434Y & 378V / 383N / 434Y

[0057] In a particularly advantageous embodiment, the Fc fragment has a combination of mutations selected from 315D / 330V / 361D / 378V / 434Y (a combination of mutations also referred to as "T5A-74"; an Fc fragment having this combination of mutations is therefore also referred to as "rFcT5A-74"), 230S / 315D / 428L / 434Y, 307A / 315D / 330V / 382V / 389T / 434Y, 259I / 315D / 434Y, 256N / 378V / 383N / 434Y, E294del / T307P / N434Y (a combination of mutations also referred to as "C6A_66"; an Fc fragment having this combination of mutations is therefore also referred to as "rFcC6A_66").

[0058] In another embodiment, the Fc fragment comprises one or more of the following amino acids: V240H, V240I, V240M, V240N, V240S, F241H, F241Y, L242A, L242F, L242G, L242H, L242I, L242K, L242P, L242S, L242T, L242V, F243L, F243S, E258G, E258I, E258R, E258M, E258Q, E258Y, V259, V260, V261, V262, V263, V264, V265, V266, V267, V268, V269, V270, V271, V272, V273, V274, V275, V276, V277, V278, V279, V280, V281, V282, V283, V284, V285, V286, V287, V288, V289, V290, V291, V292, V293, V294, V295, V296, V297, V298, V299, V299, V298, V299, V299, V298, V299, V299, V290, V291, V292, V293, V294, V295, V296, V297, V298, V299, V299, V298, V299, V299, V299, V298, V299, V299, V290, V299, V29 C, V259I, V259L, T260A, T260H, T260I, T260M, T260N, T260R, T260S, T260W, V262A, V262S, V263T, V264L, V2 64S, V264T, V266L, V266M, S267A, S267Q, S267V, K290D, K290E, K290G, K290H, K290L, K290N, K290Q, K290R, K 290S, K290Y, P291G, P291Q, P291R, R292I, R292L, E293A, E293D, E293G, E293M, E293Q, E293S, E293T, E294A , E294G, E294P, E294Q, E294R, E294T, E294V, Q295I, Q295M, Y296H, Y296W, S298A, S298R, Y300I, Y300V, Y30 0W, R301A, R301M, R301P, R301S, V302A, V302F, V302L, V302M, V302R, V302S, V303S, V303Y, S304T, V305A, V305F, V305I, V305L, V305R and V305S, the numbering of which is that of the EU index or Kabat equivalent.

[0059] In one embodiment the variant according to the invention has an increased affinity for FcγRIIIa (CD16a). In this particular embodiment said variant comprises at least one mutation i) of said Fc fragment selected from S298A, S298R, F243S, F243L, L242A, L242F, L242G, L242I, L242K, L242S, L242V, V240I, V240M, V240N, V240S, E258I, T260A, K290D, K290E, K290G, K290H, K290Q, K290S, K290Y, Y296H, Y296W, the numbering of which is according to the EU index or the equivalent numbering of Kabat.

[0060] The particular Fc fragment has the sequence of SEQ ID NO: 17: DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVACVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK Fragment of ZAC2-85(T260A), or the sequence of SEQ ID NO: 18: DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTYPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK The fragment ZAC3-172(K290Y) is

[0061] In another embodiment, the variant according to the invention has an increased affinity for FcγRIIa (CD32a). In this particular embodiment, said variant is selected from the group consisting of F241H, F241Y, F243L, L242A, L242F, L242G, L242H, L242I, L242K, L242P, L242S, L242T, L242V, V240H, V240I, V240M, V240S, E258G, E258I, E258R, E258M, E258Q, E258Y, S267 A, S267Q, S267V, T260A, T260H, T260I, T260M, T260N, T260R, T260S, T260W, V259C, V259I, V259L, V 262A, V262S, V263T, V264L, V264S, V264T, V266L, V266M, E293A, E293D, E293G, E293M, E293Q, E293S , E293T, E294A, E294G, E294P, E294Q, E294R, E294T, E294V, K290D, K290E, K290G, K290H, K290L, K2 90N, K290Q, K290R, K290S, K290Y, P291G, P291Q, P291R, Q295I, Q295M, R292I, R292L, R301A, R301P, at least one mutation i) selected from R301S, S304T, V302A, V302F, V302L, V302M, V302R, V302S, V303Y, V305A, V305F, V305L, V305R, V305S, Y300I, Y300V or Y300W, the numbering of which is that of the EU index or the Kabat equivalent.

[0062] In another embodiment the variant according to the invention has an increased affinity for FcγRIIb (CD32b). In this particular embodiment said variant comprises at least one mutation i) in said Fc fragment selected from E258R, E258Y, V262A, S267A, S267Q, S267V, V264S, V266L, V266M, K290R, R301A, R301M, S304T, V302A, V302L, V302R, V303S, V305A, V305F, V305I, V305R, Y300V, the numbering of which is according to the EU index or the equivalent numbering of Kabat.

[0063] Preferably, the variant according to the invention is characterized in that the Fc fragment of the parent polypeptide comprises at least: (i) the Fc fragments V240H, V240I, V240M, V240N, V240S, F241H, F241Y, L242A, L242F, L242G, L242H, L242I, L242K, L242P, L242S, L242T, L242V, F243L, F243S, E258G, E258I, E258R, E258M, E258Q, E258Y, V259C, V260C, V260D, V260E, V260F, V260H, V260I, V260M, V260N, V260S, F241H, F241Y, L242A, L242F, L242G, L242H, L242I, L242K, L242P, L242S, L242T, L242V, F243L, F243S, E258G, E258I, E258R, E258M, E258Q, E258Y, V259C, V260F ... 59I, V259L, T260A, T260H, T260I, T260M, T260N, T260R, T260S, T260W, V262A, V262S, V263T, V264L, V2 64S, V264T, V266L, V266M, S267A, S267Q, S267V, K290D, K290E, K290G, K290H, K290L, K290N, K290Q, K29 0R, K290S, K290Y, P291G, P291Q, P291R, R292I, R292L, E293A, E293D, E293G, E293M, E293Q, E293S, E29 3T, E294A, E294G, E294P, E294Q, E294R, E294T, E294V, Q295I, Q295M, Y296H, Y296W, S298A, S298R, Y30 0I, Y300V, Y300W, R301A, R301M, R301P, R301S, V302A, V302F, V302L, V302M, V302R, V302S, V303S, V303Y, S304T, V305A, V305F, V305I, V305L, V305R and V305S, the numbering of which is the EU index or the Kabat equivalent numbering. (ii) at least one mutation selected from 226G, P228L, P228R, 230S, 230T, 230L, 241L, 264E, 307P, 315D, 330V, 361D, 362R, 378V, 378T, 389T, 389K, 434Y and 434S, the numbering of which is according to the EU index or an equivalent numbering of Kabat, with the proviso that mutations (ii) and (iii) are not at the same amino acid.

[0064] In a particularly advantageous embodiment, the Fc fragment has a combination of mutations selected from the following: (i) T260A and 315D / 330V / 361D / 378V / 434Y (a combination of mutations also referred to as "T5A-74"). The fragment designated "T5A-74I" is an Fc fragment that is distinguished from fragment T5A-74 only by the addition of the mutation T260A. or (ii) E258I and 315D / 330V / 361D / 378V / 434Y (a combination of mutations also referred to as "T5A-74"). The fragment designated "T5A-74J" is an Fc fragment that is distinguished from fragment T5A-74 only by the addition of the mutation E258I. or (iii) K290Y and 315D / 330V / 361D / 378V / 434Y (a combination of mutations also referred to as "T5A-74"). The fragment designated "T5A-74K" is an Fc fragment that is distinguished from the fragment T5A-74 only by the addition of the mutation K290Y. or (iv) E294A and 315D / 330V / 361D / 378V / 434Y (a combination of mutations also referred to as "T5A-74"). The fragment designated "T5A-74L" is an Fc fragment that is distinguished from fragment T5A-74 only by the addition of the mutation E294A. or (v) Y296W and 315D / 330V / 361D / 378V / 434Y (a combination of mutations also referred to as "T5A-74"). The fragment designated "T5A-74M" is an Fc fragment that is distinguished from fragment T5A-74 only by the addition of the mutation Y296W.

[0065] The sequences of Fc fragments T5A-74, T5A-74I, T5A-74J, T5A-74K, T5A-74L and T5A-74M are shown in the attached sequence listing. T5A-74 (N315D / A330V / N361D / A378V / N434Y): SEQ ID NO: 11 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLDGKEYKCKVSNKALPVPIEKTISKAKGQPREPQVYTLPPSRDELTKDQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHYHYTQKSLSLSPGK T5A-74I (T260A / N315D / A330V / N361D / A378V / N434Y) SEQ ID NO: 12 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVACVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLDGKEYKCKVSNKALPVPIEKTISKAKGQPREPQVYTLPPSRDELTKDQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHYHYTQKSLSLSPGK T5A-74J (E258I / N315D / A330V / N361D / A378V / N434Y) SEQ ID NO: 13 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPIVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLDGKEYKCKVSNKALPVPIEKTISKAKGQPREPQVYTLPPSRDELTKDQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHYHYTQKSLSLSPGK T5A-74K (K290Y / N315D / A330V / N361D / A378V / N434Y) SEQ ID NO: 14 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTYPREEQYNSTYRVVSVLTVLHQDWLDGKEYKCKVSNKALPVPIEKTISKAKGQPREPQVYTLPPSRDELTKDQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHYHYTQKSLSLSPGK T5A-74L (E294A / N315D / A330V / N361D / A378V / N434Y) SEQ ID NO: 15 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREAQYNSTYRVVSVLTVLHQDWLDGKEYKCKVSNKALPVPIEKTISKAKGQPREPQVYTLPPSRDELTKDQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHYHYTQKSLSLSPGK T5A-74M (Y296W / N315D / A330V / N361D / A378V / N434Y) SEQ ID NO:16 DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQWNSTYRVVSVLTVLHQDWLDGKEYKCKVSNKALPVPIE KTISKAKGQPREPQVYTLPPSRDELTKDQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHYHYTQKSLSLSPGK

[0066] Preferably, the variant according to the invention is characterized in that the Fc fragment of the parent polypeptide comprises at least: (i) the Fc fragments V240H, V240I, V240M, V240N, V240S, F241H, F241Y, L242A, L242F, L242G, L242H, L242I, L242K, L242P, L242S, L242T, L242V, F243L, F243S, E258G, E258I, E258R, E258M, E258Q, E258Y, V259C, V260C, V260D, V260E, V260F, V260H, V260I, V260M, V260N, V260S, F241H, F241Y, L242A, L242F, L242G, L242H, L242I, L242K, L242P, L242S, L242T, L242V, F243L, F243S, E258G, E258I, E258R, E258M, E258Q, E258Y, V259C, V260F ... 59I, V259L, T260A, T260H, T260I, T260M, T260N, T260R, T260S, T260W, V262A, V262S, V263T, V264L, V2 64S, V264T, V266L, V266M, S267A, S267Q, S267V, K290D, K290E, K290G, K290H, K290L, K290N, K290Q, K29 0R, K290S, K290Y, P291G, P291Q, P291R, R292I, R292L, E293A, E293D, E293G, E293M, E293Q, E293S, E29 3T, E294A, E294G, E294P, E294Q, E294R, E294T, E294V, Q295I, Q295M, Y296H, Y296W, S298A, S298R, Y30 0I, Y300V, Y300W, R301A, R301M, R301P, R301S, V302A, V302F, V302L, V302M, V302R, V302S, V303S, V303Y, S304T, V305A, V305F, V305I, V305L, V305R and V305S, the numbering of which is the EU index or the Kabat equivalent numbering. (ii) a mutation selected from 378V, 378T, 434Y, and 434S.

[0067] In another embodiment, the Fc fragment comprises: G316D, K326E, N315D, N361H, P396L, T350A, V284L, V323I, P352S, A378V, Y436H, V266M, N421T, G385R, K326T, H435 R, K447N, N434K, K334N, V397M, E283G, A378T, F423L, A431V, F423S, N325S, P343S, K290E, S375R, F405V, K322E, K34 0E, N389S, F243I, T307P, N389T, S442F, K248E, Y349H, N286I, T359A, S383R, K334R, T394P, V259A, T393A, P352L, Q 418P, V302A, L398P, F423P, S442P, V363I, S383N, S254F, K320E, G402D, I253F, V284A, A431T, N315H, Y319H, C226Y, F405L, T393I, N434S, R255W, A287T, N286Y, A231V, K274R, V308G, K414R, M428T, E345G, F243L, P247T, Q362R, S440 N, Y278H, D312G, V262A, V305A, K246R, V308I, E380G, N276S, K439Q, S267G, F423Y, A231T, K320R, L410R, K320M, V41 2M, T307N, T366A, P230S, Y349S, A339T, K246E, K274E, A231P, I336T, S298N, L234P, S267N, V263A, E333G, V308A, K 439R, K392R, S440G, V397I, I336V, Y373D, K288E, L309P, P227S, V379A, K288R, K320T, V282A, I377T, N421S and C261R wherein the numbering is that of the EU index or Kabat equivalent.

[0068] In a particular embodiment, the Fc fragment comprises a combination of at least two mutations, said combination being selected from: (i) 307N, 326E, 326T, 334N, 334R, 352L, 378V, 378T, 349P, 396L, 397M and 421T, and (ii) 226Y, 227S, 230S, 231V, 234P, 243I, 243L, 246R, 246E, 247T, 248E, 253F, 254F, 255W, 259A, 261R, 262A, 263A, 266M, 267N, 267G, 274E, 274R, 276S, 278H, 282A, 283G, 284L, 286I, 286Y, 287T, 288E, 288R, 290E, 298N, 302A, 305A, 307P, 308A, 308I, 308G, 309P, 312G, 315D, 316D, 319H, 320T , 320R, 320M, 322E, 323I, 325S, 333G, 334N, 334R, 336T, 339T, 340E, 343S, 345G, 349S, 349H, 350A 352S, 359A, 361H, 362R, 363I, 366A, 373D, 375R, 377T, 378V, 378T, 379A, 380G, 383R, 385R, 389S, 389T, 392R, 393A, 393I, 394P, 396L, 397I, 397M, 398P, 405V, 4 at least one mutation selected from 05L, 410R, 412M, 414R, 421T, 421S, 423L, 423Y, 423S, 423P, 428T, 431V, 431T, 434K, 434S, 435R, 436H, 439R, 440G, 440N, 442F, 442P, and 447N; The numbering is that of the EU index or Kabat equivalent, with the proviso that mutation (i) is not at the same amino acid as mutation (ii).

[0069] Preferably, the variant Fc fragment has an increased affinity for complement C1q and comprises a combination of at least two mutations, said combination comprising: i) a mutation selected from 378V, 378T, 396L, 421T, 334R, and 326E, and ii) at least one mutation selected from 361H, 290E, 316D, 248E, 410R, 421T, 334R, 394P, 307P, 447N, 378V, 284L, 421T, 396L, 286I, 315D, and 397M; The numbering is that of the EU index or Kabat equivalent, with the proviso that mutation (i) is not at the same amino acid as mutation (ii).

[0070] Preferably, the variant Fc fragment has increased affinity for FcγRIIIa (CD16a) and comprises a combination of at least two mutations, said combination comprising: i) a mutation selected from 378V, 326E, 397M, 334N and 396L, and ii) at least one mutation selected from 316D, 397M, 334N, 248E, 231V, 246R, 336T, 421T, 361H, 366A, 439R, 290E, 394P, 307P, 378V, 378T, 286I, 286Y, and 298N; The numbering is that of the EU index or Kabat equivalent, with the proviso that mutation (i) is not at the same amino acid as mutation (ii).

[0071] Preferably, the variant Fc fragment has increased affinity for FcγRIIa (CD32a) and comprises a combination of at least two mutations, said combination comprising: i) a mutation selected from 378V, 326E, 397M, 307N, 394P, 326T, 396L, and 334N, and ii) at least one mutation selected from 316D, 334R, 334N, 323I, 231V, 246R, 336T, 378T, 286Y, 286I, 352S, 383R, 359A, 421T, 361H, 315D, 366A, 290E, 307P, and 439R; The numbering is that of the EU index or Kabat equivalent, with the proviso that mutation (i) is not at the same amino acid as mutation (ii).

[0072] Preferably, the variant Fc fragment has increased affinity for FcγRIIb (CD32b) and comprises a combination of at least two mutations, said combination comprising: i) a mutation selected from 326E, 326T, 378V, 397M, 352L, 394P, 396L, and 421T, and ii) at least one mutation selected from 316D, 334R, 248E, 334N, 418P, 231V, 320E, 402D, 359A, 383R, 421T, and 361H; The numbering is that of the EU index or Kabat equivalent, with the proviso that mutation (i) is not at the same amino acid as mutation (ii).

[0073] Preferably, the variant Fc fragment comprises a combination of at least three mutations, said combination comprising: (i) a mutation selected from 326E, 326T, 352L, 378V, 378T, 396L, 397M, 421T, 334N, 334R, 307N, and 394P, and (ii) 226Y, 227S, 230S, 231V, 234P, 243I, 243L, 246R, 246E, 247T, 248E, 253F, 254F, 255W, 259A, 261R, 262A, 263A, 266M, 267N, 267G, 274E, 274R, 276S, 278H, 282A, 283G, 284L, 286I, 286Y, 287T, 288E, 288R, 290E, 298N, 302A, 305A, 307P, 308A, 308I, 308G, 309P, 312G, 315D, 316D, 319H, 320T , 320R, 320M, 322E, 323I, 325S, 333G, 334N, 334R, 336T, 339T, 340E, 343S, 345G, 349S, 349H, 350A 352S, 359A, 361H, 362R, 363I, 366A, 373D, 375R, 377T, 378V, 378T, 379A, 380G, 383R, 385R, 389S, 389T, 392R, 393A, 393I, 394P, 396L, 397I, 397M, 398P, 405V, 4 at least two mutations selected from 05L, 410R, 412M, 414R, 421T, 421S, 423L, 423Y, 423S, 423P, 428T, 431V, 431T, 434K, 434S, 435R, 436H, 439R, 440G, 440N, 442F, 442P, and 447N; The numbering is that of the EU index or Kabat equivalent, with the proviso that mutation (i) is not at the same amino acid as mutation (ii).

[0074] In a particularly advantageous embodiment, the Fc fragment has a combination of mutations selected from K334N / P352S / V397M / A378V (a combination of mutations also referred to as "A3A-184A" and therefore an Fc fragment having this combination of mutations is also referred to as "A3A-184A"), G316D / K326E / A378V (a combination of mutations also referred to as "A3A-105D" and therefore an Fc fragment having this combination of mutations is also referred to as "A3A-105D"), P396L / N421T / A378V (a combination of mutations also referred to as "J3B-118A" and therefore an Fc fragment having this combination of mutations is also referred to as "J3B-118A").

[0075] The sequence of fragment A3A-184A (K334N / P352S / A378V / V397M) is represented in the sequence listing as SEQ ID NO: 19: DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE NTISKAKGQPREPQVYTLSPSRDELTKNQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK

[0076] The sequence of fragment A3A-105D (G316D / K326E / A378V) is represented in the sequence listing as SEQ ID NO: 20: DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNDKEYKCKVSNEALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK

[0077] The sequence of fragment J3B-118A (A378V / P396L / N421T) is represented in the sequence listing as SEQ ID NO: 21: DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIVVEWESNGQPENNYKTTPLVLDSDGSFFLYSKLTVDKSRWQQGTVFSCSVMHEALHNHYTQKSLSLSPGK

[0078] According to another particular embodiment, the variant Fc fragment used in the present invention has a deletion of an amino acid at position 293 or 294 (del293 or del294), the numbering of the Fc fragment amino acids referring to the EU index or the equivalent numbering of Kabat. This deletion may be the only mutation of the Fc fragment or may be accompanied by other mutations, especially among those mentioned above.

[0079] This single mutation results in specific glycosylation of the fragment, ie hypersialylation, which is highly advantageous with regard to glycoprotein half-life and inflammatory processes.

[0080] According to another more specific embodiment, the variant Fc fragment used in the present invention has a deletion of an amino acid at position 293 or 294 and further has one or more mutations at a position selected from the following list: 226, 230, 241, 256, 259, 264, 307, 315, 330, 342, 361, 362, 378, 382, ​​383, 389, 396, 397, 421, 428 and 434.

[0081] For example, a preferred Fc fragment has the combination of the mutations 307P, 434Y in combination with the deletion del294 or del293.

[0082] Another aspect of the invention uses a composition comprising multiple Fc fragments, all having substantially the same sequence and an overall specific glycosylation profile.

[0083] According to a particular embodiment, the composition for use in the context of the present invention comprises an Fc fragment having an N-glycan on its glycosylation site (Asn297), said N-glycan of the Fc fragment being characterized in that it has a degree of fucosylation lower than 65%, preferably lower than 60%, preferably lower than 55%, preferably lower than 50%, more preferably lower than 45%, preferably lower than 40%, preferably lower than 35%, preferably lower than 30%, preferably lower than 25%, preferably lower than 20%.

[0084] According to yet another embodiment, the composition for use in the context of the present invention comprises an Fc fragment, said Fc fragment having an N-glycan on its glycosylation site (Asn297), said N-glycan of the Fc fragment being characterized in that it has a short chain, low sialylation and a biantennary glycan structure with terminal mannose and / or non-intercalated terminal N-acetylglucosamine.

[0085] According to a more detailed embodiment, the composition for use in the context of the present invention comprises an Fc fragment, said Fc fragment having an N-glycan on its glycosylation site (Asn297), characterized in that more than 60% of said N-glycans of the Fc fragment are of the type G0+G1+G0F+G1F and less than 50% of the type G0F+G1F.

[0086] According to another more detailed embodiment, the composition for use in the context of the present invention comprises an Fc fragment, said Fc fragment having an N-glycan on its glycosylation site (Asn297), characterized in that more than 60% of said N-glycans of the Fc fragment are of the type G0+G1+G0F+G1F and with a fucose content lower than 65%.

[0087] According to another even more detailed embodiment, the composition for use in the context of the present invention comprises an Fc fragment, said Fc fragment having an N-glycan on its glycosylation site (Asn297), characterized in that less than 40% of said N-glycans of the Fc fragment are of the G1F+G0F type.

[0088] According to a more detailed embodiment, the composition used in the context of the present invention comprises an Fc fragment having an N-glycan on its glycosylation site (Asn297), said N-glycan of the Fc fragment having a degree of fucosylation equal to 0%.The present invention therefore provides a composition comprising an Fc fragment having an N-glycan on its glycosylation site Asn297, characterized in that said N-glycan of the Fc fragment does not contain fucose.

[0089] Furthermore, according to a particular embodiment, the composition for use in the context of the present invention is characterized in that it comprises an Fc fragment having an N-glycan on its glycosylation site Asn297, said N-glycan of the Fc fragment having a degree of fucosylation ranging between 20% and 55%. In particular, the present invention provides a composition comprising an Fc fragment having an N-glycan on its glycosylation site Asn297, said N-glycan of the Fc fragment having a degree of fucosylation ranging between 20% and 50%, between 25% and 55%, between 25% and 50%, between 20% and 45%, or between 25% and 45%.

[0090] According to a more detailed embodiment, a useful composition according to the invention comprises an Fc fragment having an N-glycan on its glycosylation site Asn297, characterized in that more than 60%, preferably more than 80%, of said N-glycans of the Fc fragment are of the type G0+G1+G0F+G1F and less than 50%, preferably 40% or less than 30% of the type G0F+G1F.

[0091] In another more detailed embodiment, more than 60% of the N-glycans of the Fc fragment in the composition are of the type G0+G1+G0F+G1F and have a fucose content of less than 65%.

[0092] In yet another more detailed embodiment, less than 50%, preferably less than 40% or less than 30% of the N-glycans of the Fc fragments in the composition are of the G1F+G0F type.

[0093] The G0, G0F, G1 and G1F types are selected from the types shown in FIG.

[0094] Advantageously, the N-glycans of the Fc fragment within the composition have an average sialic acid percentage of less than 25%, 20%, 15% or 10%, preferably less than 5%, 4%, 3% or 2%.

[0095] A composition that can be used in the context of the present invention comprises an Fc fragment having an N-glycan on its glycosylation site (Asn297), said N-glycan of the Fc fragment having a short chain, low sialylation, a biantennary glycan structure with terminal mannose and / or non-intercalated terminal N-acetylglucosamine, e.g., more than 60% of the N-glycans are of the G0+G1+G0F+G1F type, and low fucosylation, wherein less than 50% of the N-glycans are of the G0F+G1F type.

[0096] In a particular embodiment, the Fc fragment according to the invention has a glycan structure as described in patent application WO01 / 77181.

[0097] According to an advantageous embodiment, the Fc fragment used in the present invention comprises at least one amino acid mutation compared to the parent Fc fragment and has an N-glycan on its glycosylation site (Asn297), said N-glycan of the Fc fragment having a degree of fucosylation lower than 65%, preferably lower than 60%, preferably lower than 55%, preferably lower than 50%, more preferably lower than 45%, preferably lower than 40%, preferably lower than 35%, preferably lower than 30%, preferably lower than 25%, preferably lower than 20%. Preferably, the Fc fragment has one or more mutations at a position selected from the aforementioned positions, in particular at a position selected from the following list: 226, 230, 241, 256, 259, 264, 307, 315, 330, 342, 361, 362, 378, 382, ​​383, 389, 396, 397, 421, 428 and 434, and further has an N-glycan on its glycosylation site (Asn297) with a degree of fucosylation lower than 55%, preferably lower than 50%, more preferably lower than 45%, preferably lower than 40%, preferably lower than 35%, preferably lower than 30%, preferably lower than 25%, preferably lower than 20%.

[0098] More preferably, the Fc fragment of the composition according to the invention has a combination of mutations selected from 315D / 330V / 361D / 378V / 434Y, 230S / 315D / 428L / 434Y, 307A / 315D / 330V / 382V / 389T / 434Y, 259I / 315D / 434Y, 256N / 378V / 383N / 434Y and del294 / 307P / 434Y, and further has an N-glycan on its glycosylation site (Asn297) with a degree of fucosylation lower than 55%, preferably lower than 50%, more preferably lower than 45%, preferably lower than 40%, preferably lower than 35%, preferably lower than 30%, preferably lower than 25%, preferably lower than 20%.

[0099] Fc fragments with altered glycosylation, particularly hypofucosylation, at the glycosylation site at position 297 advantageously have high binding to Fc-gamma receptors (FcγR), particularly FcγRIIIa (CD16a).

[0100] Preferably, the Fc fragment has a molecular weight of at least 2×10 as measured by Scatchard analysis or BIAcore technology (a label-free surface plasmon resonance based technology). 6 M -1 is at least 2 x 10 7 M -1 , 2×10 8 M -1 Or 2 x 10 9 M -1 The antibody has an affinity for CD16a equal to

[0101] Very advantageously, the variant Fc fragments of the present invention can be used in combination with different variant Fc fragments with different mutations, for example a mixture of variant FcFc-del294, variant FcT5A-74 (to also target FcRn), variant Fc improved for binding to FcγR (type A3A-184A) can be advantageously used.

[0102] Generation of Fc fragments according to the present invention The Fc fragments used in the present invention may be produced by any method known to those of skill in the art, for example by chemical synthesis or recombinantly.

[0103] In a preferred embodiment, the Fc fragments used in the present invention are called "recombinant", ie they are recombinantly obtained.

[0104] When the Fc fragment according to the invention has one or more amino acid mutations, the mutations can optionally be introduced by well-known techniques such as gene synthesis, directed mutagenesis, in particular by PCR using specific primers that introduce the desired mutations, or by random mutagenesis. Preferably, random mutagenesis, i.e. the MutaGen technique, as described in application WO02 / 038756, is used. This technique uses a human DNA mutases, in particular a polymerase selected from DNA polymerases β, η and τ. Conventional recombinant techniques include recombination in a host cell, transformed with one or more vectors that allow the expression, with or without secretion, of the Fc fragment sequence into the extracellular medium. The vector generally comprises a promoter, signals for the initiation and termination of translation, and a region suitable for the control of transcription. The vector can be stably maintained in the host cell and can optionally have specific signals that specify the secretion of the translated protein. These various elements are selected and optimized by the skilled person depending on the host cell used.

[0105] Such vectors can be prepared by methods commonly used by those skilled in the art, and the resulting clones can be introduced into a suitable host by standard methods such as lipofection, electroporation, the use of polycationic substances, heat shock, or chemical methods.

[0106] The host cells can be selected from prokaryotic or eukaryotic systems, such as bacterial cells, but also yeast cells or animal cells, in particular mammalian cells, Insect cells or plant cells can also be used.

[0107] The Fc fragment used in the present invention can be produced by culturing a host cell expressing the Fc fragment in an appropriate medium and culture conditions, and recovering the fragment thus produced from the culture medium or from the cultured cells.

[0108] Preferred mammals for expressing the Fc fragment are the rat cell line YB2 / 0, the cell line Vero, the hamster cell line CHO, in particular the cell lines CHOdhfr- and CHOLec13, CHO-lec10, CHO-lec1, CHOK1SV Potelligent® (Lonza, Switzerland), CHOGnTIII (Glycart, Switzerland), PER.C6™ (Crucell), HEK293, T1080, EB66, K562, NS0, SP2 / 0, BHK or COS.

[0109] Another production format is the expression of the Fc fragment in transgenic organisms, for example in plants (Ayala M, Gavilondo J, Rodriguez M, Fuentes A, Enriquez G, Perez L, Cremata J, Pujol M. Production of plantibodies in Nicotiana plants. Methods Mol Biol. 2009; 483: 103-34) or in the milk of transgenic animals such as rabbits, goats, rats or pigs (Pollock, DP, JP Kutzko, E. Birck-Wilson, JL Williams, Y. Echelard and HM Meade. (1999). Transgenic milk as a method for the production of recombinant antibodies. Journal of Immunological Methods. 231: 147-157). In this regard, see also document WO200748077.

[0110] In an alternative embodiment, the Fc fragment is obtained by proteolytic processing of an immunoglobulin which is itself mutated.

[0111] The glycosylation of the Fc fragment can be modified by known techniques. The Fc fragment with glycosylation according to the invention can in particular be produced by cleavage of an antibody produced according to the technique described in WO01 / 77181, in particular by the enzyme papain. Slightly fucosylated Fc fragments can also be obtained by production in cells cultured in the presence of kifunensine, for example as described in document US7700321, or in cells in which the GDP-fucose synthesis pathway is inhibited, for example by inhibition of at least one enzyme of the fucose synthesis cycle (see in particular documents US2010291628 or US20090228994, EP1500698, EP1792987 or US7846725). Interfering RNA (RNAi) that inhibits 1,6-fucosyltransferase can also be used, as described in document US7393683 or document WO2006133148. The preparation in yeast may also be an option, as described, for example, in document WO0200879.

[0112] When the Fc fragment has 100% non-fucosylated oligosaccharides, i.e. when the Fc fragment does not contain any fucose, preparation methods known to the skilled person can be used, such as, for example, but not limited to, the preparation methods disclosed in documents EP1176195, US7214775, US6994292, US7425449, US2010223686, WO2007099988, EP1705251. A method can also be used that uses a host cell expressing at least one nucleic acid encoding an Fc fragment and modifying the glycosylation by deletion of a gene encoding an α1,6-fucosyltransferase or by adding a mutation in said gene for removing the α1,6-fucosyltransferase activity and consequently for the expression of a fucose-free antibody fragment.

[0113] therapeutic use Due to their many advantages, both in terms of efficacy and optimized effector function or reduced side effects, the Fc fragments described herein are useful in the treatment of autoimmune and / or inflammatory diseases.

[0114] Described herein is a method for treating an autoimmune and / or inflammatory disease in a patient, the method comprising administering to the patient a therapeutically effective amount of an Fc fragment having an altered affinity for at least one Fc receptor as described herein.

[0115] In the present invention, the expression "autoimmune and / or inflammatory disease" refers to organ-specific or systemic, primary or secondary autoimmune and / or inflammatory diseases, optionally associated with pathogenic autoantibodies.

[0116] For example, diseases include thrombocytopenic thrombotic purpura (TTP), idiopathic thrombotic purpura (ITP), organ or transplant rejection, graft-versus-host disease, rheumatoid arthritis, systemic lupus erythematosus, different types of sclerosis, primary Sjogren's syndrome (or Goujerow-Sjogren's syndrome), autoimmune polyneuropathy such as multiple sclerosis, type 1 diabetes, autoimmune hepatitis, ankylosing spondylitis, Reiter's syndrome, gouty arthritis, celiac disease, Crohn's disease, Hashimoto's thyroiditis (hypothyroidism), Addison's disease, autoimmune hepatitis, Graves' disease (hyperthyroidism), ulcerative colitis, vasculitis such as antineutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis, autoimmune cytopenias and other vascular complications in adults and children, such as acute or chronic autoimmune thrombocytopenia, autoimmune hemolytic anemia, hemolytic disease of the newborn (HDN), cold agglutinin disease, thrombocytopenic thrombotic purpura and acquired autoimmune hemophilia, Goodpasture's syndrome, extramembranous nephropathy, autoimmune bullous skin disorders, refractory myasthenia, mixed cryoglobulinemia, psoriasis, juvenile chronic arthritis , inflammatory myositis, dermatomyositis in children including antiphospholipid syndrome and systemic autoimmune diseases, connective tissue diseases, different types of sclerosis, autoimmune pneumonia, Guillain-Barre syndrome, Kawasaki disease, multifocal motor neuropathy (MMN), chronic demyelinating inflammatory polyradiculoneuropathy (CDIP), autoimmune thyroiditis, diabetes mellitus, myasthenia gravis, autoimmune inflammatory diseases of the eye, neuromyelitis optica (Dewig's disease), scleroderma, pemphigus, diabetes mellitus due to insulin resistance, polymyositis, Bielmer's anemia, glomerulonephritis, The disease may be selected from Wegener's disease, giant cell arteritis, periarteritis nodosa and Churg-Strauss syndrome, Still's disease, atrophic polychondritis, Behcet's disease, monoclonal gammopathy, Wegener's granulomatosis, lupus, ulcerative colitis, psoriatic rheumatism, sarcoidosis, collagenous colitis, dermatitis herpetica, familial Mediterranean fever, glomerulonephritis with IgA deposition, Lambert-Eaton myasthenic syndrome, sympathetic ophthalmia, Fissinger-Leroy-Reiter syndrome and uveomeningoencephalitis syndrome.

[0117] Also included are other inflammatory diseases such as acute respiratory distress syndrome (ARDS), acute septic arthritis, adjuvant-induced arthritis, allergic encephalomyelitis, allergic rhinitis, allergic vasculitis, allergies, asthma, atherosclerosis, chronic inflammation due to chronic bacterial or viral infection, chronic obstructive pulmonary disease (COPD), coronary heart disease, encephalitis, inflammatory bowel disease, inflammatory osteolysis, inflammation associated with acute and delayed hypersensitivity reactions, inflammation associated with tumors, inflammation associated with peripheral nerve injury or demyelinating disease, inflammation associated with tissue trauma and ischemia such as burns, inflammation due to meningitis, multiple organ dysfunction syndrome (MODS), pulmonary fibrosis, sepsis or septic shock, Stevens-Johnson syndrome, undifferentiated arthritis, and undifferentiated spondyloarthritis.

[0118] In particular embodiments of the invention, the autoimmune diseases are idiopathic thrombotic purpura (ITP) and chronic demyelinating inflammatory polyneuropathy (CDIP).

[0119] One of the effects observed is the limiting or reducing of platelet destruction observed especially in ITP pathologies, and the limiting or reducing of peripheral nerve demyelination in CDIP.

[0120] In another particular embodiment, the disease is in particular an inflammatory disease, such as graft-versus-host disease, in which case Fc fragments carrying mutations that induce hypersialylation, such as a deletion of an amino acid at position 294 (del294) or at position 293 (del293), are particularly advantageous.

[0121] Any route of administration is envisaged, in particular parenteral routes, such as intravenous, intramuscular, subcutaneous, intradermal or topical routes, or via mucosal routes, such as via inhalation. Enteral (oral, rectal) and intrathecal routes are also envisaged. Preferably, the intravenous route is used.

[0122] The Fc fragments according to the invention are generally formulated in a pharmaceutical composition comprising a pharma- ceutically acceptable excipient.

[0123] The pharmaceutical composition may be in any dosage form suitable for the chosen route of administration.

[0124] The pharmaceutical compositions useful according to the invention advantageously comprise one or more pharma- ceutically acceptable excipients or carriers. For example, saline, physiological, isotonic or buffer solutions, etc., known to those skilled in the art, suitable for pharmaceutical use, may be mentioned. The compositions may contain one or more agents or carriers selected from dispersants, solubilizers, stabilizers, preservatives, etc. Agents or carriers (liquid and / or injectable and / or solid) useful in the formulation are in particular methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, polysorbate 80, mannitol, gelatin, lactose, vegetable oils, acacia, etc. The compositions may optionally be formulated with dosage forms or devices that provide extended and / or delayed release. For this type of formulation, it is advantageous to use agents such as cellulose, carbonates or starch.

[0125] The dose to be administered may vary, inter alia, according to the weight and age of the patient and the severity of the disease as assessed by a person skilled in the art.

[0126] In a preferred embodiment, the dose of the Fc fragment according to the present invention is within the range of about 0.05 mg to about 1 g per kg of body weight, i.e., about 20 mg to about 100 g per day for an adult. Preferably, the dose is about 330 mg / kg to 660 mg / kg per day.

[0127] The following examples illustrate the invention without limiting its scope.

[0128] Construction of expression vectors for recombinant Fc (wild type and mutant types): The sequence of the recombinant Fc (amino acids 221-447) was cloned using standard PCR protocols into a pCEP4-derived general eukaryotic expression vector (Invitrogen) for expression in HEK cells, and into the OptiCHO vector for expression in YB2 / 0 cells.

[0129] All the desired mutations in the Fc fragment were inserted into the expression vector by overlap PCR using two primers containing the mutations. The fragments thus obtained by PCR were then combined and the resulting fragments were amplified by PCR using standard protocols. The PCR products were purified in a 1% (w / v) agarose gel, digested with the appropriate restriction enzymes and cloned into the expression vector for recombinant Fc.

[0130] FIG. 7 shows a map of the pCEP4 vector used for expression of variant T5A-74 in HEK cells and a map of the OptiCHO vector used for expression of variant T5A-74 in YB2 / 0 cells.

[0131] Production of recombinant Fc in HEK cells HEK293 cells were transfected with pCEP4 expression vector for recombinant Fc (wild type or mutant type) according to standard protocols (Invitrogen). These cells were cultured to transiently produce antibodies. The produced antibodies could be isolated and purified according to standard techniques in the art, taking into account their characteristics. The obtained production rate is about 150-500 μg / mL. The purity and quality of the products were verified by SDS-PAGE and SEC.

[0132] Production of recombinant Fc in YB2 / 0 cells YB2 / 0 cells were stably transfected by electroporation with OptiCHO expression vectors for recombinant Fc (wild type or mutant) according to standard protocols. Production was performed in stable pools or after cloning of YB2 / 0 cells.

[0133] The steps of producing the antibodies by cell culture and purifying them were carried out according to standard techniques in the art, taking into account their characteristics. The obtained production rate is about 3-30 μg / mL. The purity and quality of the products were verified by SDS-PAGE and SEC. EXAMPLES

[0134] Efficacy Test (Inhibition of Red Blood Cell Lysis): To mimic the situation of red blood cell lysis observed in idiopathic thrombocytopenic purpura (ITP), which is associated with autoantibodies in ITP patients, effector cell-mediated red blood cell lysis was performed in the presence of monoclonal anti-Rhesus D (RhD) antibodies and the ability of various amounts of polyvalent immunoglobulin (IVIg), or mutated (recombinant Fc fragments containing mutations according to Table 1 below) and non-mutated recombinant Fc fragments to inhibit said lysis, e.g. by competing with anti-RhD for Fc receptor binding to the effector cell surface, was assessed.

[0135] Table 1: Construction of preferred mutant Fc variants of the invention The table below represents the different variants of mutant Fc fragments that were tested in the experiments for efficacy testing (inhibition of red blood cell lysis) and binding testing to human FcRn and CD16aV by surface plasmon resonance (SPR).

[0136] [Table 1]

[0137] For that purpose, peripheral blood mononuclear cells (PBMCs) were purified from peripheral blood by Ficoll gradient as effector cells. Rh-D+ red blood cells obtained from healthy Rh-D+ blood donors were mixed with anti-RhD monoclonal antibodies. PBMCs were incubated with opsonized Rh-D+ red blood cells (effector / target ratio of 2:1).

[0138] To evaluate the ability of the candidate substances (IVIg, and recombinant Fc fragments mutated as defined according to Table 1, and non-mutated) to inhibit the cytotoxicity induced by anti-RhD antibodies by competition and / or saturation of the Fc receptor, various concentrations of the candidate substances (0-9.75 μM) were added to each well. After 16 h, the percentage of lysed red blood cells was estimated by measuring the amount of hemoglobin released in the supernatant (measurement of the optical density (OD)) by chromosomes. The specific lysis rate was calculated as a percentage according to the following formula:

[0139] OD sample - OD control 0% / OD control 100% - OD control 0% x 100 = % lysis In the above formula: "OD control 100%" corresponds to complete lysis of red blood cells (e.g., NH 4 Cl) "OD control 0%" corresponds to the lysis observed in reaction mixtures without antibody

[0140] The results are expressed as % specific lysis (see Figures 4 and 5). EXAMPLES

[0141] Binding assay to human FcRn and CD16aV by surface plasmon resonance (SPR) on BiacoreX100: Proteins used: Recombinant human FcRn (FcRnα and β2-microglobulin) was produced in baculovirus cells by GTP Technology (Labege, France) as previously described (Popov et al., Mol. Immunol. 33:521-530 (1996)). Recombinant human CD16aV is commercially available (R and D Systems).

[0142] Testing for FcRn: FC1 and FC2 cells on a CM5 chip (Biacore, GE Healthcare) were activated with a 1:1 mixture of 0.1 M N-hydroxysuccinimide and 0.1 M 3-(N,N-dimethylamino)propyl-N-ethylcarbodiimide at 30 μL / min for 3 min. Recombinant FcRn was then immobilized on FC2 cells at 32.6 μg / mL in 10 mM sodium acetate buffer (pH 5) (100 s immobilization, final immobilization level of 350 RU). FC1 cells, prepared in the same format as FC2 but in the absence of recombinant FcRn, were used as a negative control. The recombinant Fc to be tested was injected at 6 different concentrations (300 nM, 150 nM, 75 nM, 30 nM, 15 nM and 0) in 50 mM sodium phosphate, 150 mM NaCl, 0.05% Tween 20 buffer (pH 6) at 10 μL / min over the FC1 and FC2 cells. The FC1 and FC2 cells were regenerated between each sample concentration by injecting 50 mM sodium phosphate, 150 mM NaCl, 0.05% Tween 20 buffer (pH 7.8) for 1 min. The generated data was analyzed with BIAevaluation version 3.1 software (Biacore) by subtracting the control signal obtained on FC1 from the test signal obtained on FC2.

[0143] Testing for CD16aV: FC1 and FC2 cells of a CM5 chip (Biacore, GE Healthcare) were prepared with His capture kit (GE Healthcare, item 28-9950-56) and immobilized with anti-histidine antibody at 50 μg / mL (5 μL / min flow rate on FC1 and FC2, 7 min EDC / NHS activation, 7 min immobilization, 12,000 RU final immobilization level). Recombinant human CD16aV was immobilized on the FC2 cells for 60 s at 5 μL / min (1 μg / mL in HBS-EP+, Biacore, GE Healthcare). The recombinant Fc to be tested was injected in 5 different concentrations (1000 nM, 500 nM, 250 nM, 125 nM and 25 nM) in HBS-EP+ buffer in single cycle kinetic (SCK) conditions with a contact time of 60 s, dissociation of 300 s and a flow rate of 30 μL / min without regeneration between each concentration. A final regeneration between each recombinant Fc was performed in 10 mM glycine buffer (pH 1.5) at 30 μL / min in the FC1 and FC2 cells for 60 s. The generated data was analyzed with BIAevaluation version 3.1 software (Biacore) by subtracting the control signal obtained in FC1 from the test signal obtained in FC2.

Claims

1. 1. A composition comprising an antibody Fc fragment for use in the treatment of an autoimmune and / or inflammatory disease, wherein said Fc fragment is an isolated Fc fragment having improved affinity for the FcγRIII receptor compared to a parent Fc fragment of human wild-type IgG1, said Fc fragment having a combination of mutations compared to said parent Fc fragment, said combination of mutations comprising: Y296W / 315D / 330V / 361D / 378V / 434Y, and wherein the numbering of the Fc fragment amino acids refers to the EU index or Kabat equivalent numbering.

2. The composition of claim 1, wherein the Fc fragment is recombinantly obtained.

3. The composition according to claim 1 or 2, wherein the Fc fragment has an N-glycan at its glycosylation site (Asn297), and the N-glycan of the Fc fragment has a degree of fucosylation of less than 65%.

4. 4. The composition of claim 1, wherein the Fc fragment has an N-glycan at its glycosylation site (Asn297), the N-glycan of the Fc fragment having a short chain, low sialylation, and a biantennary glycan structure with terminal mannose and / or non-intercalated terminal N-acetylglucosamine.

5. The composition according to any one of claims 1 to 4, wherein the Fc fragment has an N-glycan at its glycosylation site (Asn297), and more than 60% of the N-glycans of the Fc fragment are of the G0+G1+G0F+G1F type, and less than 50% are of the G0F+G1F type.

6. The composition of any one of claims 1 to 4, wherein the Fc fragment has an N-glycan at its glycosylation site (Asn297), and more than 60% of the N-glycans of the Fc fragment are of the G0+G1+G0F+G1F type, and the fucose content is less than 65%.

7. The composition according to claim 5 or 6, wherein the Fc fragment has an N-glycan at its glycosylation site (Asn297), and less than 40% of the N-glycans of the Fc fragment are of the G1F+G0F type.

8. The disease is selected from the group consisting of idiopathic thrombotic purpura, chronic demyelinating inflammatory polyneuropathy (CDIP), organ or graft rejection, graft-versus-host disease, rheumatoid arthritis, systemic lupus erythematosus, primary Sjogren's syndrome (or Goujerow-Sjogren's syndrome), autoimmune polyneuropathy, type 1 diabetes, autoimmune hepatitis, ankylosing spondylitis, Reiter's syndrome, gouty arthritis, celiac disease, Crohn's disease, Hashimoto's thyroiditis (hypothyroidism), inflammatory myositis, Addison's disease, autoimmune hepatitis, Graves' disease (hyperthyroidism), ulcerative colitis, vasculitis, autoimmune cytopenias and other vascular complications in adults and children, Goodpasture's syndrome, epimembranous nephropathy, autoimmune bullous skin disorders, refractory myasthenia, mixed cryoglobulinemia, psoriasis, juvenile chronic arthritis, inflammatory myositis, dermatomyositis in children and systemic autoimmune diseases including antiphospholipid syndrome, connective tissue diseases, autoimmune pneumonia, Guillain-Barre syndrome, Kawasaki disease, multifocal motor neuropathy (MMN), autoimmune thyroiditis, diabetes mellitus, myasthenia gravis, autoimmune inflammatory diseases of the eye, pemphigus, diabetes mellitus due to insulin resistance, polymyositis, Bielmer's anemia, glomerulonephritis, Wegener's disease, giant cell arteritis, periarteritis nodosa and Churg-Strauss syndrome, Still's disease, atrophic polychondritis, Behçet's disease, monoclonal gamma 8. The composition of claim 1, wherein the disease is selected from the group consisting of pulmonary globulinemia, Wegener's granulomatosis, lupus, ulcerative colitis, psoriatic rheumatoid arthritis, sarcoidosis, collagenous colitis, herpetic dermatitis, familial Mediterranean fever, glomerulonephritis with IgA deposition, Lambert-Eaton myasthenic syndrome, sympathetic ophthalmia, Fissinger-Leroy-Reiter syndrome and uveomeningoencephalitis syndrome, neuromyelitis optica (Devic's disease) and scleroderma.

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