Anti-FcRn antibody or antigen-binding fragment thereof with improved stability

Abstract

The present disclosure relates to an anti-FcRn antibody or an antigen-binding fragment thereof with improved stability and its use. The anti-FcRn antibody or the antigen-binding fragment thereof binds to FcRn non-competitively with IgG or the like with respect to the parent antibody HL161AN, thereby having improved stability. For example, the production rate of aggregates is decreased, and at the same time, the biological activity of significantly reducing the amount of pathogenic autoantibodies in the blood is maintained. Therefore, it can be more efficiently used for the treatment of autoimmune diseases.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefits of Korean Patent Application No. 10 - 2022 - 0066176, filed on May 30, 2022; U.S. Provisional Patent Application No. 63 / 352,948, filed on Jun. 16, 2022; No. 63 / 370,772, filed on Aug. 8, 2022; No. 63 / 377,283, filed on Sep. 27, 2022; and No. 63 / 499,116, filed on Apr. 28, 2023, each of which is incorporated herein by reference in its entirety.

[0002] Incorporation by Reference of Sequence Listing The content of the text file created on May 25, 2023 and named MUNO - 008_001WO_SeqList.xml with a size of 61,442 bytes is incorporated herein by reference in its entirety.

[0003] The present invention relates to an anti - FcRn antibody or an antigen - binding fragment thereof with improved stability and its use.

Background Art

[0004] The causes of autoimmune diseases have been studied for a long time from genetic, environmental, and immunological perspectives, but the exact cause of this disease is still unclear. Many recent studies have revealed that some autoimmune diseases are caused by IgG - type autoantibodies. In fact, in research for the diagnosis and treatment of autoimmune diseases, the relationship between the presence, absence, or decrease of disease - specific autoantibodies and their therapeutic effects has been widely investigated.

[0005] As a therapeutic agent for such autoimmune diseases, the first-choice drug is a systemic high-dose steroid injection. When the symptoms are severe or difficult to control with steroids, high-dose IVIG (intravenous immunoglobulin) administration or plasmapheresis is applied. Repeated use of high-dose steroids may result in weakening of the effect or severe side effects. In the case of IVIG and plasmapheresis, since the treatment cost is high and there are various side effects and risks of infectious diseases, the development of therapeutic agents in this treatment field is urgently needed.

[0006] On the other hand, in recent years, therapeutic agents for autoimmune diseases using FcRn antibodies have been studied (Korean Registered Patent No. 10-1815265). This is a drug with a new mechanism, in which the antibody blocks FcRn (neonatal Fc receptor) involved in the recycling of IgG and improves the catabolism of IgG in the body, thereby reducing the autoantibody level to treat the disease. This anti-FcRn antibody is expected as a product that can solve the problems of existing therapeutic agents.

[0007] However, in order to apply this antibody to severe autoimmune diseases caused by the production of autoantibodies against self-antigens in the body, such as pemphigus or neuromyelitis optica, it is necessary to develop an antibody that has stability and at the same time maintains the affinity and biological activity of existing antibodies.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] Accordingly, the inventors of the present invention have generated a mutant of an anti-FcRn antibody with improved stability by significantly reducing the production rate of aggregates while maintaining the affinity and biological activity of the anti-FcRn antibody HL161AN developed so far, thereby completing the present invention.

Means for Solving the Problems

[0010] In an aspect of the present invention, there is provided an anti-FcRn antibody or an antigen-binding fragment thereof, comprising a light chain variable region containing LCDR1 having the amino acid sequence of SEQ ID NO: 1, LCDR2 having the amino acid sequence of SEQ ID NO: 2, and LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region containing HCDR1 having the amino acid sequence of SEQ ID NO: 5, HCDR2 having the amino acid sequence of SEQ ID NO: 6, and HCDR3 having the amino acid sequence of SEQ ID NO: 7, wherein the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 is substituted with another amino acid, or the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 is substituted with another amino acid. In some embodiments, the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 is substituted with Ser (S) or Gln (Q). In some embodiments, the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 is substituted with Ser (S) or Tyr (Y).

[0011] In another aspect of the present invention, there is provided an anti-FcRn antibody or an antigen-binding fragment thereof comprising a light chain variable region comprising the amino acid sequence of SEQ ID NO: 4 and a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 8, wherein the amino acid at N25 within the amino acid sequence of SEQ ID NO: 4 is substituted with another amino acid, and the amino acid at C32 or Q82 within the amino acid sequence of SEQ ID NO: 8 is substituted with another amino acid. In some embodiments, the amino acid at N25 within the amino acid sequence of SEQ ID NO: 4 is substituted with Ser (S) or Gln (Q). In some embodiments, the amino acid at C32 within the amino acid sequence of SEQ ID NO: 8 is substituted with Ser (S) or Tyr (Y). In some embodiments, the amino acid at Q82 within the amino acid sequence of SEQ ID NO: 8 can be substituted with Glu (E), but is not limited thereto.

[0012] In some embodiments, the anti-FcRn antibody or antigen-binding fragment thereof provided herein comprises a heavy chain variable region comprising a framework consisting of framework region 1 (FR1) of the amino acid sequence of SEQ ID NO: 15, FR2 of the amino acid sequence of SEQ ID NO: 16, FR3 of the amino acid sequence of SEQ ID NO: 17, and FR4 of the amino acid sequence of SEQ ID NO: 18. In some embodiments, the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 is substituted with another amino acid. In some embodiments, the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 is substituted with Glu (E).

[0013] In some embodiments, there is provided an anti-FcRn antibody or an antigen-binding fragment thereof comprising a light chain variable region comprising LCDR1 comprising the amino acid sequence of SEQ ID NO: 9, LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 comprising the amino acid sequence of SEQ ID NO: 11, HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and HCDR3 comprising the amino acid sequence of SEQ ID NO: 7.

[0014] In some embodiments, the anti-FcRn antibody comprises an Fc region, and this Fc region is an IgG1 Fc region or an IgG4 Fc region. In some embodiments, the Fc region is an IgG1 Fc region comprising the amino acid substitutions of Leu234Ala and Leu235Ala. In some embodiments, the Fc region is an IgG4 Fc region comprising the S228P mutation.

[0015] In another aspect of the invention, there is provided a polynucleotide encoding an anti-FcRn antibody or an antigen-binding fragment thereof.

[0016] In another aspect of the invention, there is provided a recombinant expression vector comprising this polynucleotide.

[0017] In another aspect of the invention, there is provided a host cell transformed with this recombinant expression vector.

[0018] In another aspect of the invention, there is provided a method for producing an anti-FcRn antibody or an antigen-binding fragment thereof, comprising culturing a host cell to produce an antibody and isolating and purifying this produced antibody to recover an antibody that specifically binds to FcRn.

[0019] In another aspect of the invention, there is provided a pharmaceutical composition for treating an autoimmune disease, comprising an anti-FcRn antibody or an antigen-binding fragment thereof. In some embodiments, the autoimmune disease is an autoimmune neutropenia, Guillain - Barré syndrome, epilepsy, autoimmune encephalitis, Isaac's syndrome, vitiligo, pemphigus vulgaris, deciduous pemphigus, bullous pemphigoid, epidermolysis bullosa acquisita, pemphigoid gestationis, mucous membrane pemphigoid, antiphospholipid syndrome, autoimmune anemia, autoimmune Graves' disease, thyroid eye disease (TED), Goodpasture's syndrome, myasthenia gravis, multiple sclerosis, rheumatoid arthritis, lupus, idiopathic thrombocytopenic purpura (ITP), warm autoimmune hemolytic anemia (WAIHA), chronic inflammatory demyelinating polyneuropathy (CIDP), lupus nephritis, IgA nephropathy (Berger's disease), dermatomyositis, necrotizing autoimmune myopathy, and membranous nephropathy, which is an autoimmune disease selected from the group consisting of.

[0020] In another aspect of the present invention, there is provided a method of treating an autoimmune disease in a subject in need thereof, comprising administering an anti-FcRn antibody or an antigen-binding fragment thereof or a pharmaceutical composition thereto. In some embodiments, the subject is human. In some embodiments, the autoimmune disease is selected from the group consisting of autoimmune neutropenia, Guillain-Barré syndrome, epilepsy, autoimmune encephalitis, Isaac's syndrome, vitiligo syndrome, pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, epidermolysis bullosa acquisita, pemphigoid gestationis, mucous membrane pemphigoid, antiphospholipid syndrome, autoimmune anemia, autoimmune Graves' disease, Goodpasture's syndrome, myasthenia gravis, multiple sclerosis, rheumatoid arthritis, lupus, idiopathic thrombocytopenic purpura (ITP), lupus nephritis, and membranous nephropathy.

[0021] In some embodiments, the administration is parenteral administration. In some embodiments, the administration is subcutaneous or intravenous administration. In some embodiments, the administration is administration at a dose of 300 mg to 2400 mg. In some embodiments, the administration is once a week, once every two weeks, once every three weeks or once a month. In some embodiments, the administration is once-weekly subcutaneous administration at a dose of 300 mg to 900 mg. In some embodiments, the administration is once-every-two-weeks subcutaneous administration at a dose of 300 mg to 1800 mg. In some embodiments, administration does not result in a decrease in the blood albumin level in the subject that exceeds 5% or 10% compared to the blood albumin level before administration of the anti-FcRn antibody or antigen-binding fragment. In some embodiments, administration does not result in an increase in the total blood cholesterol or low density lipoprotein (LDL) level in the subject that exceeds 5% or 10% compared to the total blood cholesterol or LDL level before administration of the anti-FcRn antibody or antigen-binding fragment.

Advantages of the Invention

[0022] The FcRn-specific antibody according to the present invention has improved stability compared to the parental antibody HL161AN. For example, the production rate of aggregates is decreased, and at the same time, it has excellent productivity and biological activity. The antibody of the present invention not only has a high affinity for FcRn, but also has or is predicted to have high specificity and non-immunogenicity or low immunogenicity, binds to FcRn, and significantly reduces the amount of pathogenic autoantibodies in the blood. Therefore, it can be used for the treatment of autoimmune diseases.

Brief Description of the Drawings

[0023]

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Modes for Carrying Out the Invention

[0024] An anti-FcRn antibody variant or an antigen-binding fragment thereof In an embodiment of the present invention, provided is a stabilized anti-FcRn antibody or an antigen-binding fragment thereof, which comprises a light chain variable region containing an LCDR1 having the amino acid sequence of SEQ ID NO: 1, an LCDR2 having the amino acid sequence of SEQ ID NO: 2, and an LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region containing an HCDR1 having the amino acid sequence of SEQ ID NO: 5, an HCDR2 having the amino acid sequence of SEQ ID NO: 6, and an HCDR3 having the amino acid sequence of SEQ ID NO: 7.

[0025] Next, the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 can be substituted with another amino acid, or the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 can be substituted with another amino acid. The "amino acid at N3 within the amino acid sequence of SEQ ID NO: 1" refers to the 3rd amino acid (asparagine) of SEQ ID NO: 1, and the "amino acid at C2 within the amino acid sequence of SEQ ID NO: 5" refers to the 2nd amino acid (cysteine) of SEQ ID NO: 5.

[0026] As used herein, the terms "FcRn" or "neonatal Fc receptor" refer to an MHC class I-related protein that is expressed in vascular endothelial cells and binds to IgG and albumin. The characteristic is that when the pH is weakly acidic, the binding between IgG and FcRn is strong, and at neutral pH, there is no binding force. Thus, IgG that has entered the cell by pinocytosis or endocytosis can avoid the degradative lysosomal pathway by strongly binding to FcRn, a type I of the Fc gamma receptor (FcγR), within the endosome under the condition of pH 6.0. During reverse recycling to the cell membrane, IgG rapidly dissociates from FcRn in the bloodstream at pH 7.4. It has been found that this receptor-mediated recycling mechanism extends the half-life of IgG by efficiently blocking the degradation of IgG within the lysosome by FcRn. That is, FcRn plays an important role in maintaining the antibody level in the serum by binding to antibodies of the IgG isotype and acting as a receptor for recovering the antibodies.

[0027] On the other hand, it has been suggested that autoimmune diseases caused by autoantibodies can be treated by shortening the serum half-life of IgG by inhibiting the binding between IgG and FcRn (Li et al., J. Clin. Invest., 115:3440, 2005).

[0028] As used herein, the term "anti-FcRn antibody" is used interchangeably with the term "anti-FcRn antibody variant" and refers to an antibody specific for FcRn. This antibody includes not only the intact antibody form but also the antigen-binding fragment of the antibody.

[0029] Generally, antibody molecules obtained from humans are associated with one of the immunoglobulin classes (IgG, IgM, IgA, IgE, and IgD) that differ from each other by the nature of the heavy chains present in the molecule. A particular class also has subclasses such as IgG1, IgG2, IgG3, or IgG4. Moreover, in humans, the light chain can be a kappa chain or a lambda chain. Thus, in one embodiment, the antibodies disclosed herein are human IgG antibodies. In some embodiments, the antibody is an IgG1 antibody. In some embodiments, the antibody is an IgG4 antibody. In some embodiments, the anti-FcRn antibodies described herein are protein scaffold-based synthetic antibodies that have the ability to bind to FcRn.

[0030] In some embodiments, the anti-FcRn antibody is a monoclonal antibody. As used herein, the term "monoclonal antibody" (MAb or mAb) or "monoclonal antibody composition" refers to a population of antibody molecules that includes only a single molecular species of an antibody molecule consisting of a unique light chain gene product and a unique heavy chain gene product.

[0031] As used herein, the term "antigen-binding fragment" refers to one or more fragments of an intact antibody that retain the ability to specifically bind to a given antigen, i.e., FcRn. Fragments of the antibodies according to the invention include, but are not limited to, single-chain antibodies, bispecific antibodies, trispecific antibodies, multispecific antibodies such as diabodies, triabodies, and tetra-bodies, Fab fragments, F(ab’)2 fragments, Fd, scFv, domain antibodies, dual-specific antibodies, minibodies, scap (sterol regulatory element-binding protein cleavage-activating protein), chelated recombinant antibodies, tribodies, biobodies, intrabodies, nanobodies, SMIPs (small modular immunopharmaceuticals), binding domain immunoglobulin fusion proteins, camelized antibodies, VHH-containing antibodies, antibody constant region derivatives.

[0032] The anti-FcRn antibodies or antigen-binding fragments thereof provided herein can be humanized antibodies, human antibodies, chimeric antibodies or mouse antibodies.

[0033] It will be apparent to those skilled in the art that any type of fragment of the antibody according to the present disclosure will exhibit the same characteristics as the antibody according to the present disclosure as long as the binding function to FcRn is maintained.

[0034] Examples of CDR sequences of the anti-FcRn antibodies disclosed herein are set forth in Table 1. These CDRs are defined according to the Kabat method.

[0035] [Table 1]

[0036] In one embodiment, the anti-FcRn antibody or antigen-binding fragment thereof comprises a light chain variable region comprising LCDR1 comprising the amino acid sequence of SEQ ID NO: 1, LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 comprising the amino acid sequence of SEQ ID NO: 5, HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and HCDR3 comprising the amino acid sequence of SEQ ID NO: 7, wherein the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 can be substituted with another amino acid, or the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 can be substituted with another amino acid.

[0037] As used herein, the term "heavy chain (HC)" refers to both a variable region domain VH comprising an amino acid sequence having a variable region sequence sufficient to confer specificity for an antigen, and a full-length heavy chain comprising three constant region domains CH1, CH2, and CH3, and fragments thereof. In addition, as used herein, the term "light chain (LC)" refers to both a variable region domain VL comprising an amino acid sequence having a variable region sequence sufficient to confer specificity for an antigen, and a full-length light chain comprising a constant region domain CL, and fragments thereof.

[0038] As used herein, the term "variable" indicates that the sequences of particular portions of the variable regions vary significantly between antibodies. The V regions mediate antigen binding and define the specificity of a particular antibody for a particular antigen. The variability is concentrated in three segments called hypervariable regions (HVRs) within both the light and heavy chain variable regions, i.e., the CDRs. The more highly conserved portions of the variable regions are called framework (FR) regions. The heavy chain variable region and the light chain variable region have FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4 structures from the N-terminus to the C-terminus.

[0039] As used herein, the term "CDR (complementary determining region)" refers to the amino acid sequences of the hypervariable regions of immunoglobulin heavy and light chains. The heavy chain (HCDR1, HCDR2, and HCDR3) and the light chain (LCDR1, LCDR2, and LCDR3) each contain three CDRs. The CDRs provide the contact residues that are key to the binding of the antibody to the antigen or epitope.

[0040] As used herein, the term "substitution with another amino acid" refers to substitution with another amino acid residue having properties similar to the original amino acid sequence. This is not particularly limited as long as the properties of the antibody according to the present disclosure are maintained even if an amino acid substitution occurs. The "amino acid" introduced by the above substitution can be any one selected from the group consisting of lysine (K), alanine (A), arginine (R), asparagine (N), aspartic acid (D), cysteine (C), glutamine (Q), glutamic acid (E), glycine (G), histidine (H), isoleucine (I), leucine (L), methionine (M), phenylalanine (F), proline (P), serine (S), threonine (T), tryptophan (W), tyrosine (Y), and valine (V). The substitution may be described, for example, as "the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1", which refers to the 3rd N of SEQ ID NO: 1.

[0041] In one embodiment, the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 can be substituted with, but is not limited to, Ser (S) or Gln (Q).

[0042] In one embodiment, the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 can be substituted with, but is not limited to, Ser (S) or Tyr (Y).

[0043] In one embodiment, Variant No. 1 may include a light chain variable region comprising an LCDR1 containing the amino acid sequence of SEQ ID NO: 9, an LCDR2 containing the amino acid sequence of SEQ ID NO: 2, and an LCDR3 containing the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising an HCDR1 containing the amino acid sequence of SEQ ID NO: 11, an HCDR2 containing the amino acid sequence of SEQ ID NO: 6, and an HCDR3 containing the amino acid sequence of SEQ ID NO: 7. In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant No. 1 can be represented as HL161ANS, HL161ANS (IgG1null), or HL161ANS (IgG4).

[0044] In one embodiment, Variant No. 12 may include a light chain variable region comprising an LCDR1 containing the amino acid sequence of SEQ ID NO: 13, an LCDR2 containing the amino acid sequence of SEQ ID NO: 2, and an LCDR3 containing the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising an HCDR1 containing the amino acid sequence of SEQ ID NO: 11, an HCDR2 containing the amino acid sequence of SEQ ID NO: 6, and an HCDR3 containing the amino acid sequence of SEQ ID NO: 7. In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant No. 12 can be represented as HL161ANQ, HL161ANQ (IgG1null), or HL161ANQ (IgG4).

[0045] In one embodiment, Variant No. 2 may include a light chain variable region comprising LCDR1 having an amino acid sequence in which the amino acid at N3 in the amino acid sequence of SEQ ID NO: 1 is substituted with Ser (S), LCDR2 having the amino acid sequence of SEQ ID NO: 2, and LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having an amino acid sequence in which the amino acid at C2 in the amino acid sequence of SEQ ID NO: 5 is substituted with Tyr (Y), HCDR2 having the amino acid sequence of SEQ ID NO: 6, and HCDR3 having the amino acid sequence of SEQ ID NO: 7. In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant No. 2 may be represented as HL161ANSY, HL161ANSY (IgG1null) or HL161ANSY (IgG4).

[0046] In one embodiment, Variant No. 13 may include a light chain variable region comprising LCDR1 having an amino acid sequence in which the amino acid at N3 in the amino acid sequence of SEQ ID NO: 1 is substituted with Gln (Q), LCDR2 having the amino acid sequence of SEQ ID NO: 2, and LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having an amino acid sequence in which the amino acid at C2 in the amino acid sequence of SEQ ID NO: 5 is substituted with Tyr (Y), HCDR2 having the amino acid sequence of SEQ ID NO: 6, and HCDR3 having the amino acid sequence of SEQ ID NO: 7. In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant No. 13 may be represented as HL161ANQY, HL161ANQY (IgG1null) or HL161ANQY (IgG4).

[0047] In one embodiment, variant number 23 may include a light chain variable region comprising LCDR1 having an amino acid sequence in which the amino acid at N3 in the amino acid sequence of SEQ ID NO: 1 is substituted with Ser (S), LCDR2 having the amino acid sequence of SEQ ID NO: 2, and LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having an amino acid sequence in which the amino acid at C2 in the amino acid sequence of SEQ ID NO: 5 is substituted with Tyr (Y), HCDR2 having the amino acid sequence of SEQ ID NO: 6, and HCDR3 having the amino acid sequence of SEQ ID NO: 7. In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant number 23 may be represented as HL161ANSY, HL161ANSY (IgG1null) or HL161ANSY (IgG4).

[0048] In some embodiments, the anti-FcRn antibody or antigen-binding fragment thereof may include a VL CDR1 comprising the sequence of GGX1NIGSTSV (SEQ ID NO: 38), where X1 is N, S or Q. In some embodiments, the anti-FcRn antibody or antigen-binding fragment thereof may include a VH CDR1 comprising the sequence of SX2VMT (SEQ ID NO: 39), where X2 is C, S or Y.

[0049] In one embodiment, the heavy chain variable region of the anti-FcRn antibody or antigen-binding fragment thereof may include a framework composed of FR1 of the amino acid sequence of SEQ ID NO: 15, FR2 of the amino acid sequence of SEQ ID NO: 16, FR3 of the amino acid sequence of SEQ ID NO: 17, and FR4 of the amino acid sequence of SEQ ID NO: 18.

[0050] In FR3 within the framework on the heavy chain variable region, certain amino acids may be substituted with other amino acids, but are not limited thereto. Specifically, the amino acid at Q16 in the amino acid sequence of SEQ ID NO: 17 may be substituted with another amino acid.

[0051] As described above, the above-mentioned "substitution with another amino acid" is not particularly limited as long as the properties of the antibody according to the present disclosure are maintained even if amino acid substitution occurs.

[0052] In one embodiment, the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 can be replaced with, but is not limited to, Glu (E).

[0053] In one embodiment, Variant No. 8 includes a light chain variable region comprising LCDR1 having the amino acid sequence of SEQ ID NO: 9, LCDR2 having the amino acid sequence of SEQ ID NO: 2, and LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having the amino acid sequence of SEQ ID NO: 11, HCDR2 having the amino acid sequence of SEQ ID NO: 6, and HCDR3 having the amino acid sequence of SEQ ID NO: 7, and includes a FR3 of an amino acid sequence in which the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 is replaced with Glu (E). In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant No. 8 can be represented as HL161ANSE, HL161ANSE (IgG1null), or HL161ANSE (IgG4).

[0054] In one embodiment, Variant No. 19 includes a light chain variable region comprising LCDR1 having the amino acid sequence of SEQ ID NO: 13, LCDR2 having the amino acid sequence of SEQ ID NO: 2, and LCDR3 having the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having the amino acid sequence of SEQ ID NO: 11, HCDR2 having the amino acid sequence of SEQ ID NO: 6, and HCDR3 having the amino acid sequence of SEQ ID NO: 7, and includes a FR3 of an amino acid sequence in which the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 is replaced with Glu (E). In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant No. 19 can be represented as HL161ANQE, HL161ANQE (IgG1null), or HL161ANQE (IgG4).

[0055] In one embodiment, variant number 11 comprises a light chain variable region comprising LCDR1 having an amino acid sequence in which the amino acid at N3 in the amino acid sequence of SEQ ID NO: 1 is replaced with Ser (S), LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having an amino acid sequence in which the amino acid at C2 in the amino acid sequence of SEQ ID NO: 5 is replaced with Tyr (Y), HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and HCDR3 comprising the amino acid sequence of SEQ ID NO: 7, the heavy chain variable region optionally comprising FR3 having an amino acid sequence in which the amino acid at Q16 in the amino acid sequence of SEQ ID NO: 17 is replaced with Glu (E). In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant number 11 can be designated as HL161ANSYE, HL161ANSYE (IgG1null), or HL161ANSYE (IgG4).

[0056] In one embodiment, variant number 22 comprises a light chain variable region comprising LCDR1 having an amino acid sequence in which the amino acid at N3 in the amino acid sequence of SEQ ID NO: 1 is replaced with Gln (Q), LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising HCDR1 having an amino acid sequence in which the amino acid at C2 in the amino acid sequence of SEQ ID NO: 5 is replaced with Tyr (Y), HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and HCDR3 comprising the amino acid sequence of SEQ ID NO: 7, the heavy chain variable region optionally comprising FR3 having an amino acid sequence in which the amino acid at Q16 in the amino acid sequence of SEQ ID NO: 17 is replaced with Glu (E). In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof. Variant number 22 can be designated as HL161ANQYE, HL161ANQYE (IgG1null), or HL161ANQYE (IgG4).

[0057] In another aspect of the present disclosure, there is provided an anti-FcRn antibody or an antigen-binding fragment thereof comprising a light chain variable region comprising the amino acid sequence of SEQ ID NO: 4 and a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 8.

[0058] In this regard, in the anti-FcRn antibody or antigen-binding fragment thereof, the amino acid at N25 within the amino acid sequence of SEQ ID NO: 4 may be substituted with another amino acid, and the amino acids at C32 or Q82 within the amino acid sequence of SEQ ID NO: 8 may be substituted with another amino acid.

[0059] "Anti-FcRn antibody", "antigen-binding fragment", and "substitution with another amino acid" are as described above.

[0060] In one embodiment, the amino acid at N25 within the amino acid sequence of SEQ ID NO: 4 may be substituted with Ser (S) or Gln (Q), but is not limited thereto.

[0061] In one embodiment, the amino acid at C32 within the amino acid sequence of SEQ ID NO: 8 may be substituted with Ser (S) or Tyr (Y), but is not limited thereto.

[0062] In one embodiment, the amino acid at Q82 within the amino acid sequence of SEQ ID NO: 8 may be substituted with Glu (E), but is not limited thereto.

[0063] In one embodiment, Variant No. 1 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 10 and a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 12. In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0064] In one embodiment, Variant No. 12 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14 and a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 12. In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0065] In one embodiment, variant number 2 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 10, and a heavy chain variable region comprising an amino acid sequence in which the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Tyr (Y). In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0066] In one embodiment, variant number 13 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14, and a heavy chain variable region comprising an amino acid sequence in which the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Tyr (Y). In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0067] In one embodiment, variant number 8 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 10, and a heavy chain variable region comprising an amino acid sequence in which the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Ser (S), and the amino acid at Q82 is substituted with Glu (E). In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0068] In one embodiment, variant number 19 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14, and a heavy chain variable region comprising an amino acid sequence in which the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Ser (S), and the amino acid at Q82 is substituted with Glu (E). In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0069] In one embodiment, variant number 11 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 10, and a heavy chain variable region comprising an amino acid sequence in which the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Tyr (Y), and the amino acid at Q82 is substituted with Glu (E). In this regard, the Fc region of the antibody may be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0070] In one embodiment, Variant No. 22 may include a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14, and a heavy chain variable region comprising an amino acid sequence in which the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Tyr (Y), and the amino acid at Q82 is substituted with Glu (E). In this regard, the Fc region of the antibody can be IgG1 or a variant thereof, IgG4 or a variant thereof.

[0071] In some embodiments, the anti-FcRn antibody comprises a light chain variable region having a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to the sequence set forth in SEQ ID NO: 4. In some such embodiments, the sequences of the CDRs of the light chain variable region are 100% identical to SEQ ID NO: 4. In some embodiments, the anti-FcRn antibody comprises a light chain variable region having a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to the sequence set forth in SEQ ID NO: 10. In some such embodiments, the sequences of the CDRs of the light chain variable region are 100% identical to SEQ ID NO: 10. In some embodiments, the anti-FcRn antibody comprises a light chain variable region having a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to the sequence set forth in SEQ ID NO: 14. In some such embodiments, the sequences of the CDRs of the light chain variable region are 100% identical to SEQ ID NO: 14.

[0072] In some embodiments, the anti-FcRn antibody comprises a heavy chain variable region comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to the sequence set forth in SEQ ID NO: 8. In some such embodiments, the sequences of the CDRs of the heavy chain variable region are 100% identical to SEQ ID NO: 8. In some embodiments, the anti-FcRn antibody comprises a heavy chain variable region comprising a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identical to the sequence set forth in SEQ ID NO: 12. In some such embodiments, the sequences of the CDRs of the heavy chain variable region are 100% identical to SEQ ID NO: 12.

[0073] In some embodiments, the anti-FcRn antibody comprises any one of the CDRs, light chain variable regions, and / or heavy chain variable regions described herein, and further comprises an IgG1 Fc region. In some embodiments, the anti-FcRn antibody comprises any one of the CDRs, light chain variable regions, and / or heavy chain variable regions described herein, and further comprises an IgG1 Fc region comprising the Leu234Ala / Leu235Ala (「LALA」) amino acid substitution (「IgG1-LALA」).

[0074] In some embodiments, the anti-FcRn antibody comprises any one of the CDRs, light chain variable regions, and / or heavy chain variable regions described herein, and further comprises an IgG4 Fc region. In some embodiments, the anti-FcRn antibody comprises any one of the CDRs, light chain variable regions, and / or heavy chain variable regions described herein, and further comprises an IgG4 Fc region comprising the S228P amino acid substitution (「IgG4 S228P」).

[0075] In some embodiments, the anti-FcRn antibody is an IgG1 antibody and includes a light chain variable region comprising an LCDR1 comprising the amino acid sequence of SEQ ID NO: 9, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising an HCDR1 comprising the amino acid sequence of SEQ ID NO: 11, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 7. In some embodiments, the anti-FcRn antibody is an IgG4 antibody and includes a light chain variable region comprising an LCDR1 comprising the amino acid sequence of SEQ ID NO: 9, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising an HCDR1 comprising the amino acid sequence of SEQ ID NO: 11, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 7.

[0076] In some embodiments, the anti-FcRn antibody is an IgG1-LALA antibody and includes a light chain variable region comprising an LCDR1 comprising the amino acid sequence of SEQ ID NO: 9, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising an HCDR1 comprising the amino acid sequence of SEQ ID NO: 11, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 7. In some embodiments, the anti-FcRn antibody is an IgG4 S228P antibody and includes a light chain variable region comprising an LCDR1 comprising the amino acid sequence of SEQ ID NO: 9, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 2, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 3, and a heavy chain variable region comprising an HCDR1 comprising the amino acid sequence of SEQ ID NO: 11, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 7.

[0077] In one embodiment, HL161ANS (IgG1null) can include a light chain region comprising the amino acid sequence of SEQ ID NO: 21 and a heavy chain region comprising the amino acid sequence of SEQ ID NO: 22.

[0078] In one embodiment, HL161ANS (IgG4) may include a light chain region containing the amino acid sequence of SEQ ID NO: 21 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 23.

[0079] In one embodiment, HL161ANQ (IgG1null) may include a light chain region containing the amino acid sequence of SEQ ID NO: 24 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 22.

[0080] In one embodiment, HL161ANQ (IgG4) may include a light chain region containing the amino acid sequence of SEQ ID NO: 24 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 23.

[0081] In one embodiment, HL161ANSY (IgG1null) may include a light chain region containing the amino acid sequence of SEQ ID NO: 21 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 25.

[0082] In one embodiment, HL161ANSE (IgG1null) may include a light chain region containing the amino acid sequence of SEQ ID NO: 21 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 26.

[0083] In one embodiment, HL161ANSYE (IgG1null) may include a light chain region containing the amino acid sequence of SEQ ID NO: 21 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 27.

[0084] In one embodiment, HL161ANQY (IgG1null) may include a light chain region containing the amino acid sequence of SEQ ID NO: 24 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 25.

[0085] In one embodiment, HL161ANQE (IgG1null) may include a light chain region containing the amino acid sequence of SEQ ID NO: 24 and a heavy chain region containing the amino acid sequence of SEQ ID NO: 26.

[0086] In one embodiment, HL161ANQYE (IgG1null) may include a light chain region including the amino acid sequence of SEQ ID NO: 24 and a heavy chain region including the amino acid sequence of SEQ ID NO: 27.

[0087] In one embodiment, the anti-FcRn antibody is an anti-FcRn antibody variant prepared by substituting amino acid residues at specific sites of the parent antibody HL161AN. It has been confirmed that while the production rate of aggregates is decreased, it maintains a high affinity and specificity for FcRn similar to the parent antibody. In one embodiment, the anti-FcRn antibody is an anti-FcRn antibody variant prepared by substituting amino acid residues at specific sites of the parent antibody HL161AN. It has been confirmed that while the production rate of aggregates is decreased, it maintains a high affinity for FcRn similar to the parent antibody. Specifically, the anti-FcRn antibody variant according to the present disclosure has improved stability. For example, while the production rate of aggregates is decreased to at most 1 / 2 or less, it has excellent biological activities similar to the previously developed parent antibody HL161AN (Korean Patent No. 10-1954906). For example, it has been confirmed to have productivity, an action as an inhibitor against the binding of IgG and FcRn, and an IgG catabolic effect, that is, promotion of IgG clearance.

[0088] Therefore, the anti-FcRn antibody variant according to the present disclosure, which has significantly improved stability and excellent biological activities similar to the previously developed parent antibody HL161AN, can be usefully used for the treatment of autoimmune diseases.

[0089] In some embodiments, when the anti-FcRn antibody described herein is administered to a subject, the blood immunoglobulin level (e.g., IgG level) in the subject decreases by 30%, 40%, 50%, 60%, 65% or 80% or more compared to the blood immunoglobulin level (e.g., IgG level) in the subject before administration of the anti-FcRn antibody.

[0090] In some embodiments, when administered to a subject, the anti-FcRn antibodies described herein cause the blood immunoglobulin level (e.g., IgG level) of the subject to decrease more than that of another anti-FcRn antibody. In some embodiments, the anti-FcRn antibodies described herein cause the blood immunoglobulin level (e.g., IgG level) of the subject to decrease more than that of batoclimab. In some embodiments, when the anti-FcRn antibodies described herein are administered to a subject, the blood immunoglobulin level (e.g., IgG level) of the subject decreases to approximately the same level as when an equivalent dose of batoclimab is administered. Batoclimab is known in the art and is also described, for example, in International Patent Application Publication No. WO2015 / 167293, which is hereby incorporated by reference in its entirety, and batoclimab is referred to as "HL161BKN" in WO2015 / 167293.

[0091] In some embodiments, when an effective amount of the anti-FcRn antibodies described herein is administered to a subject (e.g., a human), the blood albumin level decreases by less than 5%, less than 10%, less than 20% or less than 30% compared to the blood albumin level before administration. In some embodiments, when an effective amount of the anti-FcRn antibodies described herein is administered to a subject (e.g., a human), the blood cholesterol level increases by less than 5%, less than 10%, less than 20% or less than 30% compared to the blood cholesterol level before administration.

[0092] In some embodiments, when an effective amount of the anti-FcRn antibodies described herein is administered to a subject (e.g., a human), the total blood cholesterol level increases by less than 5%, less than 10%, less than 20% or less than 30% compared to the total blood cholesterol level before administration.

[0093] In some embodiments, when an effective amount of the anti-FcRn antibodies described herein is administered to a subject (e.g., a human), the blood LDL level increases by less than 5%, less than 10%, less than 20% or less than 30% compared to the blood LDL level before administration.

[0094] In some embodiments, administration of an effective amount of an anti-FcRn antibody described herein to a subject (e.g., a human) results in a reduction in blood immunoglobulin levels of at least about 40%, 50%, 65% or 80% compared to pre-administration levels, but (i) has no or minimal effect on blood albumin levels (e.g., less than 20%, 10%, less than 5%, less than 2% or less than 1% reduction in blood albumin), and / or (ii) has no or minimal effect on blood total cholesterol levels and / or blood LDL levels (e.g., less than 20%, 10%, less than 5%, less than 2% or less than 1% increase in cholesterol).

[0095] In some embodiments, administration of an effective amount of an anti-FcRn antibody described herein to a subject (e.g., a human) results in a reduction in blood immunoglobulin levels of at least about 40%, 50%, 65% or 80% compared to pre-administration levels, but has no or minimal effect on blood albumin levels (e.g., less than 10%, less than 5%, less than 2% or less than 1% reduction in blood albumin), and has no or minimal effect on blood cholesterol levels (e.g., less than 10%, less than 5%, less than 2% or less than 1% increase in cholesterol).

[0096] In some embodiments, subcutaneous administration of an effective amount of an anti-FcRn antibody described herein to a human subject (e.g., long-term subcutaneous administration to a human) results in a reduction in blood immunoglobulin levels of at least about 40%, 50%, 65% or 80% compared to pre-administration levels, but has no or minimal effect on blood albumin levels (e.g., less than 10%, less than 5%, less than 2% or less than 1% reduction in blood albumin), and has no or minimal effect on blood cholesterol levels (e.g., less than 10%, less than 5%, less than 2% or less than 1% increase in cholesterol).

[0097] In some embodiments, administering an effective amount of the anti-FcRn antibody described herein to a subject (e.g., a human) results in a decrease in blood immunoglobulin levels of at least about 40%, 50%, 65% or 80% compared to pre-administration levels, but has no or minimal effect on blood albumin levels (e.g., less than 10%, 5%, 2% or 1% decrease in blood albumin) and has no or minimal effect on blood LDL levels (e.g., less than 10%, 5%, 2% or 1% increase in LDL).

[0098] In some embodiments, subcutaneous administration of an effective amount of the anti-FcRn antibody described herein to a human subject (e.g., long-term subcutaneous administration to a human) results in a decrease in blood immunoglobulin levels of at least about 40%, 50%, 65% or 80% compared to pre-administration levels, but has no or minimal effect on blood albumin levels (e.g., less than 10%, 5%, 2% or 1% decrease in blood albumin) and has no or minimal effect on blood LDL levels (e.g., less than 10%, 5%, 2% or 1% increase in LDL).

[0099] In some embodiments, long-term subcutaneous administration of an effective amount of the anti-FcRn antibody described herein to a human for 12 weeks or more results in a decrease in blood immunoglobulin levels of at least about 40%, 50%, 65% or 80% compared to pre-administration levels, but has no or minimal effect on blood albumin levels (e.g., less than 10%, 5%, 2% or 1% decrease in blood albumin) and has no or minimal effect on blood LDL levels and / or blood cholesterol levels (e.g., less than 10%, 5%, 2% or 1% increase in LDL and / or cholesterol).

[0100] Also included by the present disclosure are antibodies or functional variants of antigen-binding fragments thereof described herein. As used herein, the term "functional variant" includes modifications or chemical equivalents of the amino acid and nucleic acid sequences disclosed herein that perform substantially the same function as the polypeptides or nucleic acid molecules disclosed herein. For example, functional variants of the polypeptides disclosed herein include, but are not limited to, conservative amino acid substitutions. "Conservative amino acid substitutions" as used herein are substitutions in which one amino acid residue is replaced with another amino acid residue, and the substitution changes the amino acid to a different amino acid having similar biochemical properties (e.g., charge, hydrophobicity, and size). For example, lysine, arginine, and histidine have similar properties in that they have basic side chains, and aspartic acid and glutamic acid have similar properties in that they have acidic side chains. In addition, glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, and tryptophan have similar properties in that they have uncharged polar side chains, and alanine, valine, leucine, threonine, isoleucine, proline, phenylalanine, and methionine have similar properties in that they have nonpolar side chains. Also, tyrosine, phenylalanine, tryptophan, and histidine have similar properties in that they have aromatic side chains. Thus, it will be apparent to those skilled in the art that substitutions of amino acid residues at groups showing similar properties as described above do not show specific changes in properties. Also, variants of polypeptides include additions and deletions to the polypeptide sequences disclosed herein. In addition, the nucleotide sequences of variants include such analogs and derivatives. Variants of the binding proteins disclosed herein include proteins that bind to the same antigen or epitope as the binding protein.

[0101] As will be apparent to those skilled in the art, the C-terminal lysine of the immunoglobulin heavy chain can be cleaved during production. Thus, in some embodiments, the antibodies described herein contain two C-terminal lysine residues (i.e., one C-terminal lysine on each heavy chain). In some embodiments, the antibodies described herein contain one C-terminal lysine residue (i.e., one heavy chain contains a C-terminal lysine and the other heavy chain does not contain a C-terminal lysine). In some embodiments, the antibodies described herein do not contain a C-terminal lysine residue on either heavy chain.

[0102] The effector functions of the antibodies described herein may, for example, desirably be modified to enhance the effectiveness of the antibodies in the treatment of related diseases and disorders. For example, by introducing cysteine residue(s) into the Fc region, inter-chain disulfide bonds can be formed within this region. The homodimeric antibodies produced in this way may have improved internalization ability and / or enhanced complement-mediated cytotoxicity and antibody-dependent cell cytotoxicity (ADCC) (see Caron et al., J Exp Med., 176:1191-1195 (1992) and Shopes, J. Immunol., 148:2918-2922 (1992)). Alternatively, the antibody can be modified to have enhanced complement lysis ability and ADCC ability by having a dual Fc region (see Stevenson et al., Anti-Cancer Drug Design, 3:219-230 (1989)). Mutations that affect the effector functions of antibodies are known in the art, and for examples of Fc modifications that can be introduced into the antibodies described herein, see, for example, Saunders et al., 2019; Front. Immunol. 10:1296 and Wang et al., 2018, Protein Cell 9(1): 63-73. Each of these is incorporated herein by reference in its entirety. Unless otherwise indicated, Fc mutations in this section are described according to the Kabat numbering convention for immunoglobulins.Exemplary mutations and combinations of mutations that can be introduced into the Fc of the anti-FcRn antibodies provided herein include Lys326Trp / Glu333Ser, Ser267Glu / His268Phe / Ser324Thr, Lys326Trp / Glu333Ser, Lys326Ala / Glu333Ala, Lys326Met / Glu333Ser, Cys221Asp / Asp222Cys, Ser267Glu, His268Phe, Ser324Thr, Glu345Arg, S239D / I332E, S239D / I332E / A330L, Arg435His, Met252Tyr / Ser254Thr / Thr256Glu ("YTE"), Met428Leu / Asn434Ser, Thr252Leu / Thr253Ser / Thr254Phe, Leu235Glu, Leu234Ala / Leu235Ala ("LALA"), Ser228Pro / Leu235Glu, Leu234Ala / Leu235Ala / Pro329Gly, Pro331Ser / Leu234Glu / Leu235Phe, Asp265Ala, and Ala330Leu, but are not limited thereto.

[0103] In some embodiments, the anti-FcRn antibody is an IgG1 antibody comprising the Leu234Ala / Leu235Ala ("LALA") mutation (i.e., an "IgG1-LALA" antibody). In some embodiments, the anti-FcRn antibody is an IgG4 antibody comprising the S228P mutation (i.e., an "IgG4 S228P" antibody).

[0104] Polynucleotides encoding anti-FcRn antibody variants In another aspect of the disclosure, polynucleotides encoding anti-FcRn antibodies or antigen-binding fragments thereof are provided.

[0105] Specifically, the polynucleotide encoding the heavy chain may comprise the sequence of SEQ ID NO: 31, 33, 35 or 37. Additionally, the polynucleotide encoding the light chain may comprise the sequence of SEQ ID NO: 30, 32, 34 or 36.

[0106] This polynucleotide may comprise a nucleic acid sequence having at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99% or at least about 100% identity to SEQ ID NO: 30, 31, 32, 33, 34, 35, 36 or 37.

[0107] In some embodiments, the polynucleotide comprises the sequence of SEQ ID NO: 30. In some embodiments, the polynucleotide comprises the sequence of SEQ ID NO: 31. In some embodiments, the polynucleotide comprises the sequences of SEQ ID NO: 30 and SEQ ID NO: 31. In some embodiments, the polynucleotide comprises the sequence of SEQ ID NO: 32. In some embodiments, the polynucleotide comprises the sequence of SEQ ID NO: 33. In some embodiments, the polynucleotide comprises the sequences of SEQ ID NO: 32 and SEQ ID NO: 33.

[0108] The polynucleotide can be mutated by substitution, deletion, insertion of one or more bases, or combinations thereof. When preparing the nucleotide sequence by chemical synthesis, synthetic methods well known in the art may be used, such as the methods described in the literature (Engels and Uhlmann, Angew Chem IntEd Engl., 37:73-127, 1988), including methods using triester, phosphite, phosphoramidite, and H-phosphate, methods using PCR and other primers, methods for synthesizing oligonucleotides on solid supports, etc.

[0109] A vector filled with a polynucleotide encoding an anti-FcRn antibody variant In another aspect of the present disclosure, there is provided a recombinant expression vector comprising this polynucleotide.

[0110] In addition, the polynucleotide can be packed into one vector with the heavy and light chains, or into two vectors respectively.

[0111] Specifically, when packed into one vector, the polynucleotide can include the polynucleotide of SEQ ID NO: 30 and the polynucleotide of SEQ ID NO: 31, the polynucleotide of SEQ ID NO: 32 and the polynucleotide of SEQ ID NO: 33, the polynucleotide of SEQ ID NO: 34 and the polynucleotide of SEQ ID NO: 35, or the polynucleotide of SEQ ID NO: 36 and the polynucleotide of SEQ ID NO: 37.

[0112] The vectors provided herein can include a polynucleotide encoding the light chain of an anti-FcRn antibody or an antigen-binding fragment thereof and / or the heavy chain of an anti-FcRn antibody or an antigen-binding fragment thereof.

[0113] In some embodiments, the vector includes a polynucleotide containing the sequence of SEQ ID NO: 30. In some embodiments, the vector includes a polynucleotide containing the sequence of SEQ ID NO: 31. In some embodiments, the vector includes a polynucleotide containing the sequence of SEQ ID NO: 30 (encoding the light chain) and the sequence of SEQ ID NO: 31 (encoding the heavy chain).

[0114] In some embodiments, the vector includes a polynucleotide containing the sequence of SEQ ID NO: 32. In some embodiments, the vector includes a polynucleotide containing the sequence of SEQ ID NO: 33. In some embodiments, the vector includes a polynucleotide containing the sequence of SEQ ID NO: 32 (encoding the light chain) and the sequence of SEQ ID NO: 33 (encoding the heavy chain).

[0115] A vector can be introduced into a host cell, recombined, and inserted into the host cell genome. Alternatively, a vector is understood to be a means by which a polynucleotide sequence that can replicate spontaneously as an episome is included in a nucleic acid. Vectors include linear nucleic acids, plasmids, phagemids, cosmids, RNA vectors, viral vectors, and analogs thereof. Examples of viral vectors include, but are not limited to, retroviruses, adenoviruses, and adeno-associated viruses.

[0116] Specifically, a vector can be plasmid DNA, phage DNA, etc. In addition, commercially developed plasmids (such as pUC18, pBAD, pIDTSAMRT-AMP, etc.), plasmids derived from Escherichia coli (such as pYG601BR322, pBR325, pUC118, pUC119, etc.), plasmids derived from Bacillus subtilis (such as pUB110, pTP5, etc.), plasmids derived from yeast (such as YEp13, YEp24, YCp50, etc.), phage DNA (such as Charon4A, Charon21A, EMBL3, EMBL4, λgt10, λgt11, λZAP, etc.), animal viral vectors (such as retroviruses, adenoviruses, vaccinia viruses, etc.), insect viral vectors (such as baculoviruses, etc.). Since vectors exhibit various protein expression levels and modifications depending on the host cell, it is preferable to select and use the host cell most suitable for the purpose.

[0117] The vector of the present disclosure can be fused with other sequences to facilitate the purification of the antibody to be expressed therefrom. Examples of the sequences to be fused include, for example, glutathione S-transferase (Pharmacia, USA), maltose-binding protein (NEB, USA), FLAG (IBI, USA), 6×His (hexahistidine; Quiagen, USA), etc.

[0118] In addition, since the protein expressed by the vector of the present disclosure is an antibody, the expressed antibody can be easily purified by a protein A column or the like without adding an additional sequence for purification.

[0119] Transformed cells expressing anti-FcRn antibody variants In another aspect of the present disclosure, there is provided a host cell transformed with a recombinant expression vector.

[0120] The host cell of the transformed cell can include, but is not limited to, prokaryotic cells, eukaryotic cells, mammals, plants, insects, fungi, or cells of cellular origin. Escherichia coli can be used as an example of prokaryotic cells. In addition, yeast can be used as an example of eukaryotic cells. In addition, as mammalian cells, CHO cells, F2N cells, CSO cells, BHK cells, Bowes melanoma cells, HeLa cells, 911 cells, AT1080 cells, A549 cells, HEK293 cells, HEK293T cells, etc. can be used, but are not limited thereto, and any cells known to those skilled in the art that can be used as mammalian host cells are available.

[0121] In the present disclosure, "transformation" or "transfection" of a host cell includes any method of introducing nucleic acid into an organism, cell, tissue, or organ, and as is known in the art, standard techniques suitable according to the host cell can be selected and implemented. For example, the calcium chloride precipitation method, the Hanahan method in which DMSO (dimethyl sulfoxide) is used as a reducing agent in the calcium chloride precipitation method to improve efficiency, electroporation, the calcium phosphate precipitation method, the protoplast fusion method, the stirring method using silicon carbide fibers, the Agrobacterium-mediated transformation method, the transformation method using PEG, dextran sulfate, lipofectamine, and the drying / inhibition-mediated transformation method, etc. can be used.

[0122] Method for producing an anti-FcRn antibody variant or an antigen-binding fragment thereof In another aspect of the present disclosure, there is provided a method for producing an anti-FcRn antibody or an antigen-binding fragment thereof, including culturing a host cell to produce an antibody and isolating and purifying the produced antibody to recover an antibody specifically binding to FcRn.

[0123] The FcRn-specific antibody according to the present disclosure may be produced in large quantities by culturing a transformant expressing a recombinant vector in a nutrient medium, and a medium and culture conditions showing tolerance according to the host cell can be appropriately selected and used. In the culture, conditions such as temperature, pH of the medium, and culture period can be appropriately adjusted to be suitable for cell growth and large-scale protein production. The antibody or antibody fragment produced recombinantly as described above may be recovered from the medium or cell lysate and isolated and purified by conventional biochemical separation techniques (Sambrook et al., Molecular Cloning: A laboratory Manual, 2nd Ed., Cold Spring Harbor Laboratory Press (1989); Deuscher, M., Guide to Protein Purification Methods Enzymology, Vol. 182. Academic Press. Inc., San Diego, CA (1990)). Examples include, but are not limited to, electrophoresis, centrifugation, gel filtration, precipitation, dialysis, chromatography (ion exchange chromatography, affinity chromatography, immunoaffinity chromatography, size exclusion chromatography, etc.), isoelectric focusing electrophoresis, and various modified methods and combinations thereof. In particular, isolation and purification using Protein A are preferred.

[0124] In particular, the anti-FcRn antibody or its antigen-binding fragment is preferably prepared by expression and purification using a genetic recombination method. Specifically, it is preferable to prepare the variable region encoding the antibody according to the present disclosure that specifically binds to FcRn by co-expression in one host cell.

[0125] Use of anti-FcRn antibody variant or its antigen-binding fragment In another aspect of the present disclosure, there is provided a pharmaceutical composition for treating an autoimmune disease, comprising an anti-FcRn antibody or an antigen-binding fragment thereof. Also provided herein is a method of treating an autoimmune disorder, comprising administering to a subject in need thereof an effective amount of the anti-FcRn antibody or antigen-binding fragment thereof or pharmaceutical composition described herein.

[0126] "Anti-FcRn antibody" and "antigen-binding fragment" are as described above.

[0127] As used herein, the term "autoimmune disease" is a general term for diseases that occur when the immune system attacks normal tissues, organs, or other body components due to an immune system abnormality of unknown cause. This is a systemic disease that can occur in almost all parts of the body, including the nervous system, gastrointestinal tract, endocrine system, skin, skeletal system, vascular tissue, and the like.

[0128] The pharmaceutical composition can be applied to all autoimmune diseases mediated by IgG and FcRn. Representative autoimmune diseases include autoimmune neutropenia, Guillain-Barré syndrome, epilepsy, autoimmune encephalitis, Isaac's syndrome, phakomatosis, pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, epidermolysis bullosa acquisita, pemphigoid gestationis, mucous membrane pemphigoid, antiphospholipid syndrome, autoimmune anemia, autoimmune Graves' disease, Goodpasture syndrome, myasthenia gravis, multiple sclerosis, rheumatoid arthritis, lupus, idiopathic thrombocytopenic purpura (ITP), lupus nephritis, membranous nephropathy, islet allograft rejection, alopecia areata, ankylosing spondylitis, autoimmune Addison's disease, Alzheimer's disease, antineutrophil cytoplasmic autoantibody (ANCA), autoimmune adrenal disorder, warm autoimmune hemolytic anemia (WAIHA), autoimmune hepatitis, autoimmune myocarditis, autoimmune oophoritis and autoimmune orchitis, autoimmune thrombocytopenia, autoimmune urticaria, Behçet's disease, cardiomyopathy, Castleman's syndrome, celiac sprue dermatitis, chronic fatigue immune dysfunction syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), Churg-Strauss syndrome, cicatricial pemphigoid, CREST syndrome, cold agglutinin disease, Crohn's disease, dermatomyositis, dilated cardiomyopathy, discoid lupus, essential mixed cryoglobulinemia, factor VIII deficiency, fibromyalgia / fibromyositis, glomerulonephritis, thyroid eye disease (TED, also known as Graves' ophthalmopathy);It can be an autoimmune disease selected from the group consisting of graft-versus-host disease (GVHD), Hashimoto's thyroiditis, hemophilia A, idiopathic membranous nephropathy, idiopathic pulmonary fibrosis, IgA nephropathy, IgM polyneuropathy, immune thrombocytopenia, juvenile arthritis, Kawasaki disease, lichen planus, lichen sclerosus, lupus erythematosus, Meniere's disease, mixed connective tissue disease, type 1 diabetes, multifocal motor neuropathy (MMN), paraneoplastic pemphigoid, pemphigus foliaceus, pernicious anemia, polyarteritis nodosa, polychondritis, polyglandular syndrome, polymyalgia rheumatica, polymyositis and dermatomyositis, primary agammaglobulinemia, primary biliary cirrhosis, psoriasis, psoriatic arthritis, relapsing polychondritis, Raynaud's phenomenon, Reiter's syndrome, sarcoidosis, scleroderma, Sjogren's syndrome, solid organ transplant rejection, stiff-man syndrome, systemic lupus erythematosus, Takayasu arteritis, toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), temporal arteritis, giant cell arteritis, thrombotic thrombocytopenic purpura, ulcerative colitis, uveitis, dermatitis herpetiformis, vasculitis, antineutrophil cytoplasmic antibody-related vasculitis, vitiligo, and Wegener's granulomatosis. In some embodiments, the autoimmune disorder is an autoimmune channelopathy, which is autoimmune limbic encephalitis, neuromyelitis optica, Lambert-Eaton myasthenic syndrome, myasthenia gravis, anti-N-methyl-D-aspartic acid (NMDA) receptor encephalitis, anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor encephalitis, Morvan's syndrome, neuromyotonia, streptococcal infection-related pediatric autoimmune neuropsychiatric disorders (PANDAS), glycine receptor antibody-related disorders, myositis, myelin oligodendrocyte glycoprotein antibody disorders (MOG antibody disorders), fetal hemolytic disease and neonatal hemolytic disease, cutaneous lupus erythematosus, refractory rheumatoid arthritis, immune thrombocytopenia, anti-GBM disease, idiopathic membranous nephropathy, necrotizing autoimmune myopathy, anti-synthetase syndrome, ANCA vasculitis, hidradenitis suppurativa, pulmonary alveolar proteinosis (PAP), and systemic lupus erythematosus (SLE), etc., which are appropriately selected from the group consisting of, but not limited to, these.;

[0129] In some embodiments, the disease to be treated according to the methods described herein is a disease characterized by or indicative of an elevated total blood IgG level in the subject to be treated. In some embodiments, the disease to be treated according to the methods described herein is any one of the autoimmune diseases referred to herein. In some embodiments, the disease is autoimmune Graves' disease. In some embodiments, the disease is thyroid eye disease (TED, also known as Graves' ophthalmopathy). In some embodiments, the disease is warm autoimmune hemolytic anemia (WAIHA). In some embodiments, the disease is myasthenia gravis. In some embodiments, the disease is chronic inflammatory demyelinating polyneuropathy (CIDP). In some embodiments, the disease is pemphigus vulgaris, pemphigus foliaceus, pemphigus desquamativus, bullous pemphigoid, pemphigoid gestationis or mucous membrane pemphigoid.

[0130] In some embodiments, the disease to be treated according to the methods described herein is a disease responsive to plasmapheresis. The subject to be treated according to the methods described herein may have had experience with plasmapheresis previously. In some embodiments, the disease to be treated according to the methods described herein is a disease responsive to treatment that reduces total IgG levels. The subject to be treated according to the methods described herein may have had experience with treatment that reduces total IgG levels previously. In some embodiments, the disease to be treated according to the methods described herein is a disease responsive to rituximab. The subject to be treated according to the methods described herein may have had experience with treatment with rituximab previously.

[0131] In some embodiments, the anti-FcRn antibodies or antigen-specific fragments thereof described herein reduce the levels of antigen-specific immunoglobulins, or autoantibodies, e.g., any of the autoantibodies described herein or known in the art. In some embodiments, the anti-FcRn antibodies or antigen-specific fragments thereof described herein reduce the levels of autoantibody specific for an autoimmune disease, or an autoantibody associated with or known to be associated with an autoimmune disease, e.g., any of the autoantibodies described herein or known in the art. In some embodiments, the autoimmune disease is any of the autoimmune diseases disclosed herein.

[0132] In some embodiments, administration (e.g., subcutaneous) of an effective amount of the anti-FcRn antibodies described herein to a subject (e.g., a human) results in a reduction in the levels of antigen-specific immunoglobulins or autoantibodies in the blood (e.g., the levels of any one or more of the autoantibodies described herein) of at least about 40%, 50%, 65% or 80%. In some embodiments, such administration has no or minimal effect on blood albumin levels (e.g., less than 10%, 5%, 2% or 1% decrease in blood albumin) and / or no or minimal effect on blood LDL levels (e.g., less than 10%, 5%, 2% or 1% increase in LDL) compared to pre-administration levels. In some embodiments, the antigen-specific immunoglobulins or autoantibodies are associated with diseases such as autoimmune diseases.

[0133] In some embodiments, long-term subcutaneous administration of an effective amount of the anti-FcRn antibodies described herein to humans for 12 weeks or more results in a reduction of at least about 40%, 50%, 65% or 80% in the level of antigen-specific immunoglobulins or autoantibodies (e.g., the level of any one or more of the autoantibodies described herein) in the blood compared to the pre-administration level, but has no or minimal effect on the blood albumin level (e.g., less than 10%, 5%, 2% or 1% decrease in blood albumin) and has no or minimal effect on the blood LDL level and / or cholesterol level (e.g., less than 10%, 5%, 2% or 1% increase in LDL and / or cholesterol). In some embodiments, the antigen-specific immunoglobulins or autoantibodies are associated with diseases such as autoimmune diseases.

[0134] Exemplary examples of autoantibodies associated with specific autoimmune diseases include the following: - Anti-desmoglein 3 (anti-Dsg3) antibodies (associated with pemphigus vulgaris), - Anti-desmoglein 1 (anti-Dsg1) antibodies (associated with pemphigus vulgaris and pemphigus foliaceus), - Anti-bullous pemphigoid 180 (anti-BP180 or anti-collagen XVII) antibodies and anti-bullous pemphigoid 230 (anti-BP230) antibodies (both associated with bullous pemphigoid), - Antibodies against the non-collagenous domain 1 of the triple helix of type IV collagen (anti-α3NC1 antibodies) and antibodies against the non-collagenous domain 1 of the pentamer of type IV collagen (anti-α5NC1 antibodies) (both associated with anti-GBM disease), - Anti-phospholipase A2 receptor (anti-PLA2R) antibodies (associated with idiopathic membranous nephropathy), - Anti-proteinase 3 (anti-PR3) antibodies and anti-myeloperoxidase (anti-MPO) antibodies (both associated with ANCA-associated vasculitis), - Anti-double-stranded (ds) DNA antibodies, antibodies against Sjogren's syndrome-related antigen A (anti-SSA / Ro antibodies) and antibodies against Sjogren's syndrome-related antigen B (anti-SSB / La antibodies), anti-Smith antibodies, anti-ribonucleoprotein (anti-RNP) antibodies, anti-complement C1q antibodies, anti-proliferating cell nuclear antigen (PCNA) antibodies, anti-cardiolipin antibodies, anti-beta2 glycoprotein antibodies, anti-granzyme B antibodies, and anti-nucleosome antibodies (all associated with systemic lupus erythematosus), - Anti-nuclear antibodies (associated with systemic lupus erythematosus, systemic sclerosis, and autoimmune hepatitis), - Rheumatoid factor, anti-citrullinated peptide antibodies (ACPA), anti-CarP antibodies, and anti-acetylated peptide antibodies (AAPA) (all associated with rheumatoid arthritis), - Anti-centromere antibodies (ACA), anti-Scl-70 antibodies, anti-endothelial cell antibodies (AECA), angiotensin II type 1 receptor (anti-AT1R) antibodies, and anti-endothelin 1 type A receptor (anti-ETAR) antibodies (all associated with systemic sclerosis), - Anti-signal recognition particle (anti-SRP) antibodies (associated with immune-mediated necrotizing myopathy and polymyositis), - Anti-HMG-CoA reductase (anti-HMGCR) antibodies (associated with immune-mediated necrotizing myopathy), - Anti-Jo-1 antibodies, anti-PL-7 antibodies, anti-PL-12 antibodies, anti-EJ antibodies, anti-OJ antibodies, anti-Mi-2 antibodies, anti-U3 ribonucleoprotein (anti-U3 RNP or anti-fibrillarin) antibodies, and anti-U2 ribonucleoprotein (anti-U2 RNP) antibodies (all associated with polymyositis), - Anti-Ku antibodies (associated with systemic lupus erythematosus and polymyositis), - Anti-nuclear matrix protein 2 (anti-NXP-2) antibodies, anti-Mi2 antibodies, anti-melanoma differentiation-associated protein 5 (anti-MDA5) antibodies, and anti-transcription intermediary factor 1-gamma (anti-TIF1γ) antibodies (all associated with dermatomyositis), - Anti-acetylcholine receptor (anti-AChR) antibodies, anti-muscle-specific kinase (anti-MuSK) antibodies, and anti-lipoprotein-related protein 4 (anti-LRP4) antibodies (all associated with myasthenia gravis), - Anti-neurofascin-155 (anti-Nfasc155) antibody, anti-neurofascin-140 / 186 (anti-Nfasc140 / 186) antibody, anti-contactin 1 (anti-CNTN1) antibody, and anti-contactin-associated protein-like 1 (anti-Caspr1) antibody (all associated with chronic inflammatory demyelinating polyneuropathy (CIDP)), - Anti-ganglioside GM1 (anti-GM1) antibody, anti-ganglioside GT1a (anti-GT1a) antibody, and anti-ganglioside GD1a (anti-GD1a) antibody (all associated with Guillain-Barré syndrome), - Anti-ganglioside GQ1b (anti-GQ1b) antibody (associated with Guillain-Barré syndrome and Miller Fisher syndrome), - Anti-aquaporin 4 (anti-AQP4) antibody (associated with neuromyelitis spectrum disorder), - Anti-NMDAR antibody (associated with systemic lupus erythematosus and antibody-positive autoimmune encephalitis), - Anti-contactin-associated protein-like 2 (anti-Caspr2) antibody, anti-gamma-aminobutyric acid receptor type B (anti-GABAbR) antibody, anti-leucine-rich glioma-inactivated 1 (anti-LGI1) antibody, and anti-Kelch-like protein 11 (anti-Klh11) antibody (all associated with antibody-positive autoimmune encephalitis), - Anti-β2 glycoprotein I (anti-β2GPI) antibody and anti-phospholipid antibody (both associated with primary antiphospholipid syndrome), - Anti-FcγRIIIb antibody and anti-CD177 antibody (both associated with primary autoimmune neutropenia), - Anti-smooth muscle actin (anti-SMA) antibody and anti-liver kidney microsome (anti-LKM) antibody (both associated with autoimmune hepatitis), - Anti-ADAMTS13 antibody (associated with thrombotic thrombocytopenic purpura), - Anti-platelet GP IIb / IIIa antibody and anti-platelet GP Ib / IX antibody (both associated with idiopathic immune thrombocytopenic purpura), - Thyroid Stimulating Hormone (TSH) Binding Inhibitor Immunoglobulin (TBII), Thyroid Stimulating Immunoglobulin (TSI), Thyrotropin Binding Inhibitor (TBI) antibody, and anti-Insulin-like Growth Factor 1 Receptor (anti-IFG1R) antibody (all associated with Graves' disease and thyroid ophthalmopathy), - Anti-Thyroid Peroxidase (anti-TPO) antibody (associated with autoimmune thyroiditis / Hashimoto's thyroiditis), - Anti-Thyroglobulin antibody (associated with Graves' disease), - Islet Cytoplasmic Autoantibody (ICA), Glutamic Acid Decarboxylase Autoantibody (GADA), Insulinoma-Associated 2 Autoantibody (IA-2A), and Insulin Autoantibody (IAA) (all associated with type 1 diabetes), - Anti-Adenovirus Neutralizing Antibody, Anti-Lentivirus Neutralizing Antibody, Anti-AAV1 Neutralizing Antibody, Anti-AAV2 Neutralizing Antibody, Anti-AAV3 Neutralizing Antibody, Anti-AAV4 Neutralizing Antibody, Anti-AAV5 Neutralizing Antibody, Anti-AAV6 Neutralizing Antibody, Anti-AAV7 Neutralizing Antibody, Anti-AAV8 Neutralizing Antibody, and / or Anti-AAV9 Neutralizing Antibody (associated with previous gene therapies), and - Anti-Granulocyte Macrophage Colony-Stimulating Factor (anti-GM-CSF) antibody (associated with pulmonary alveolar proteinosis (PAP)).

[0135] In some embodiments, when an effective amount of the anti-FcRn antibody described herein is administered to a human subject (e.g., subcutaneous or long-term subcutaneous administration to a human), proteinuria in a subject with lupus nephritis decreases by at least about 40%, 50%, 65% or 80% as measured by the subject's urinary protein level.

[0136] The preferred dosage of the pharmaceutical composition may vary depending on the patient's symptoms and weight, the severity of the disease, the form of the drug, the route of administration, and the duration of administration, but can be appropriately selected by those skilled in the art. In the pharmaceutical composition of the present disclosure for the treatment or prevention of autoimmune diseases, the active ingredient may be contained in any amount (effective amount) according to the use, formulation, combined use purpose, etc., as long as it can exhibit a therapeutic activity against autoimmune diseases or particularly a therapeutic effect against autoimmune diseases. A typical effective amount is determined within the range of 0.001% to 20.0% by weight based on the total weight of the composition. As used herein, the term "effective amount" refers to the amount of the active ingredient having an effect of treating or improving the state of an autoimmune disease, particularly the amount of the active ingredient capable of inducing an effect of treating or improving the state of an autoimmune disease. Such an effective amount can be determined empirically within the ability of those skilled in the art.

[0137] In one embodiment, the term "treatment" includes any form of administration or application for treating a disease in mammals including humans. In addition, the above term includes inhibition or delay of the disease or its progression, recovery or repair of impaired or lost function, partial or complete remission of the disease thereby, stimulation of an inefficient process, or alleviation of a severe disease.

[0138] In another aspect, the present disclosure provides a method for preventing an autoimmune disorder, which includes administering an effective amount of the anti-FcRn antibody or its antigen-binding fragment or pharmaceutical composition described herein to a subject in need thereof.

[0139] Any embodiment of the present specification referring to a method for treating an autoimmune disorder that includes administering an anti-FcRn antibody, its antigen-binding fragment or pharmaceutical composition also includes the use of an anti-FcRn antibody, its antigen-binding fragment or pharmaceutical composition for the preparation of a medicament for treating an autoimmune disorder. Similarly, any embodiment of the present specification referring to a method for preventing an autoimmune disorder that includes administering an anti-FcRn antibody, its antigen-binding fragment or pharmaceutical composition also includes the use of an anti-FcRn antibody, its antigen-binding fragment or pharmaceutical composition for the preparation of a medicament for preventing an autoimmune disorder.

[0140] Pharmacokinetic parameters, such as bioavailability, and underlying parameters, such as clearance rate, can also affect efficacy. Thus, "improved efficacy" (e.g., improvement in efficacy) may be due to improvement in pharmacokinetic parameters and improvement in efficacy, and parameters such as clearance rate and treatment or amelioration of autoimmune diseases can be measured by comparing in experimental animals or human subjects.

[0141] As used herein, the terms "therapeutically effective amount" or "pharmaceutically effective amount" refer to the amount of a compound or composition effective for the prevention or treatment of a target disease, which is an amount sufficient to treat the disease and has a reasonable benefit / risk ratio applicable to medical treatment and does not cause side effects. The level of the effective amount can be determined according to factors including the patient's health status, the type and severity of the disease, the activity of the drug, the sensitivity to the drug, the administration method, the administration time, the administration route, and the excretion rate, the treatment period, factors including concomitant or co-administered drugs, as well as other factors well-known in the medical field. In one embodiment, the therapeutically effective amount refers to the amount of a drug effective for treating an autoimmune disease.

[0142] In this regard, the pharmaceutical composition may further comprise a pharmaceutically acceptable carrier. The pharmaceutically acceptable carrier can be any non-toxic substance suitable for delivery to the patient. Distilled water, alcohol, fats, waxes, and inert solids can be included as carriers. In addition, pharmaceutically acceptable adjuvants (buffers, dispersants) can be included in the pharmaceutical composition.

[0143] Specifically, the pharmaceutical composition may, in addition to the active ingredient, comprise a pharmaceutically acceptable carrier and can be prepared by conventional methods known in the art as a parenteral formulation according to the administration route. Here, "pharmaceutically acceptable" means not inhibiting the activity of the active ingredient and not exceeding the toxicity tolerable by the subject to which it is applied (formulated).

[0144] When preparing the pharmaceutical composition as a parenteral preparation, it can be formulated according to a method known in the art with a suitable carrier in the form of an injection, a transdermal preparation, a nasal inhalant, and a suppository. The formulation of the pharmaceutical composition is known in the art, and specifically, reference can be made to literature such as [Remington's Pharmaceutical Sciences (19th ed., 1995)]. This literature is considered to be a part of this specification.

[0145] The preferred dosage of the pharmaceutical composition may vary depending on the patient's symptoms, weight, gender, and age, the severity of the disease, the administration route, etc., but can be appropriately selected by those skilled in the art.

[0146] The subjects to whom the pharmaceutical composition can be applied (prescribed) are mammals and humans, particularly preferably humans.

[0147] In another aspect of the present disclosure, there is provided a method for treating an autoimmune disease, which includes administering an effective amount of an antibody that specifically binds to FcRn or an antigen-binding fragment thereof to a patient in need of treatment for an autoimmune disease.

[0148] In another aspect of the present disclosure, there is provided a method for alleviating autoimmune or alloimmune symptoms, which includes administering an anti-FcRn antibody or an antigen-binding fragment thereof to a subject in need thereof. In addition, an anti-FcRn specific therapy is provided simultaneously.

[0149] The method according to the present disclosure or the anti-FcRn therapy for alleviating autoimmune or alloimmune symptoms can be achieved by administering the pharmaceutical composition according to the present disclosure to a subject. The pharmaceutical composition according to the present disclosure can be administered orally or parenterally. For example, it can be administered via administration routes such as intravenous injection, subcutaneous injection, intramuscular injection, intraperitoneal injection, topical administration, intranasal administration, pulmonary administration, and rectal administration. In some embodiments, the pharmaceutical composition disclosed herein can be administered subcutaneously.

[0150] The preferred dosage of the pharmaceutical composition may vary depending on the patient's symptoms and weight, the severity of the disease, the form of the drug, the route of administration and the duration of administration, but may be appropriately selected by those skilled in the art and may be administered once or repeatedly.

[0151] In various embodiments of the treatment methods and uses disclosed herein, the antibody or antigen-binding fragment is administered to the patient as a fixed dose. In various embodiments of the treatment methods and uses disclosed herein, the antibody or antigen-binding fragment is administered to the patient as a dosage based on body weight. That is, the dosage depends on the patient's body weight. In various embodiments of the treatment methods and uses disclosed herein, the antibody or antigen-binding fragment is administered to the patient as a dosage based on body surface area. That is, the dosage depends on the patient's body surface area (BSA). In various embodiments, the dosage administered to the patient comprises a therapeutically effective amount of the antibody or antigen-binding fragment.

[0152] In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 300 mg to about 500 mg. In some embodiments, the antibody or antigen-binding fragment is administered subcutaneously to a patient at a dose of about 300 mg to about 500 mg, for example, once a week, once a month, once every two weeks, or once every three weeks. In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient at a dose of about 300 mg, about 310 mg, about 320 mg, about 330 mg, about 340 mg, about 350 mg, about 360 mg, about 370 mg, about 380 mg, about 390 mg, about 400 mg, about 410 mg, about 420 mg, about 430 mg, about 440 mg, about 450 mg, about 460 mg, about 470 mg, about 480 mg, about 490 mg, or about 500 mg (e.g., once a week, once a month, once every two weeks, or once every three weeks). In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient at a dose of about 300 mg or more (e.g., once a week, once a month, or once every two weeks). In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 340 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week, once a month, or once every two weeks at a dose of about 340 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week at a dose of about 340 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient as a single subcutaneous injection once a week at a dose of about 340 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 340 mg once a week for at least two weeks (e.g., two weeks, three weeks, four weeks, five weeks, six weeks, seven weeks, eight weeks, ten weeks, twelve weeks, or more). In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 340 mg once a week for at least four weeks. In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 340 mg once a week for at least seven weeks. In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 340 mg once a week for at least twelve weeks. In some embodiments, the administration is subcutaneous administration.

[0153] In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 500 mg to about 700 mg. In some embodiments, the antibody or antigen-binding fragment is administered subcutaneously to a patient at a dose of about 500 mg to about 700 mg, for example, once a week, once a month, once every two weeks or once every three weeks. In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient at a dose of about 500 mg, about 510 mg, about 520 mg, about 530 mg, about 540 mg, about 550 mg, about 560 mg, about 570 mg, about 580 mg, about 590 mg, about 600 mg, about 610 mg, about 620 mg, about 630 mg, about 640 mg, about 650 mg, about 660 mg, about 670 mg, about 680 mg, about 690 mg or about 700 mg (e.g., once a week, once a month, once every two weeks or once every three weeks). In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient at a dose of about 750 mg or less than 700 mg (e.g., once a week, once a month or once every two weeks). In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 680 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week, once a month or once every two weeks at a dose of about 680 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week at a dose of about 680 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient as consecutive subcutaneous injections once a week at a dose of about 680 mg for two or more times (e.g., twice). In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week at a dose of about 680 mg for at least two weeks (e.g., two weeks, three weeks, four weeks, five weeks, six weeks, seven weeks, eight weeks, ten weeks, twelve weeks or more). In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week at a dose of about 680 mg for at least four weeks. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week at a dose of about 680 mg for at least seven weeks. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week at a dose of about 680 mg for at least twelve weeks. In some embodiments, the administration is subcutaneous administration.

[0154] In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dosage of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg. In some embodiments, the antibody or antigen-binding fragment is administered intravenously to a patient at a dosage of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg. In some embodiments, the antibody or antigen-binding fragment is administered subcutaneously to a patient at a dosage of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg.

[0155] In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dosage within a dosage range between any of the dosage values mentioned herein. In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dosage less than any of the dosage values mentioned herein.

[0156] In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient once a week at a dose of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg.

[0157] In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient once every two weeks at a dose of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg.

[0158] In some embodiments, the antibody or antigen-binding fragment is administered (e.g., subcutaneously) to a patient once every three weeks at a dose of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg.

[0159] In some embodiments, the antibody or antigen-binding fragment is administered to the patient once a month (e.g., subcutaneously) at a dose of about 100 mg, about 150 mg, about 200 mg, about 300 mg, about 400 mg, about 450 mg, about 500 mg, about 600 mg, about 700 mg, about 800 mg, about 900 mg, about 1000 mg, about 1100 mg, about 1,200 mg, about 1300 mg, about 1400 mg, about 1500 mg, about 1600 mg, about 1700 mg, about 1800 mg, about 1900 mg, about 2000 mg, about 2100 mg, about 2200 mg, about 2300 mg, about 2400 mg or about 2500 mg.

[0160] In some embodiments, the antibody or antigen-binding fragment is administered to a patient at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg. In some embodiments, the antibody or antigen-binding fragment is administered intravenously to a patient at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg. In some embodiments, the antibody or antigen-binding fragment is administered subcutaneously to a patient at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a week (e.g., subcutaneously) at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg or about 2100 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once every two weeks (e.g., subcutaneously) at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once every three weeks (e.g., subcutaneously) at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg. In some embodiments, the antibody or antigen-binding fragment is administered to a patient once a month (e.g., subcutaneously) at a dose of about 300 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg.

[0161] In some embodiments, the antibody is administered to a patient at a dose of about 150 mg, about 300 mg, about 450 mg, about 600 mg, about 900 mg, about 1200 mg, about 1500 mg, about 1800 mg, about 2100 mg or about 2400 mg, or at any dose between any two of such doses (e.g., subcutaneously) (e.g., subcutaneously once a week, once every two weeks, once every three weeks, or once a month at this dose). In some embodiments, the doses presented herein are doses suitable for administration to humans.

[0162] In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week or once a month. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least one week, at least two weeks, at least three weeks, at least four weeks, at least five weeks, at least six weeks, at least seven weeks, at least eight weeks, at least nine weeks, at least ten weeks, at least twelve weeks, at least twenty weeks, at least twenty-four weeks, at least thirty weeks, at least forty weeks, at least fifty weeks, at least sixty weeks, at least seventy weeks, at least seventy-six weeks, at least eighty weeks or more.

[0163] In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once every about two or three weeks. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once every other week (i.e., once every two weeks) for at least two weeks, at least four weeks, at least six weeks, at least eight weeks, at least ten weeks, at least twelve weeks, at least twenty weeks, at least twenty-four weeks, at least thirty weeks, at least forty weeks, at least fifty weeks, at least sixty weeks, at least seventy weeks, at least seventy-six weeks, at least eighty weeks or more.

[0164] In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient at least once every three weeks for at least three weeks, at least six weeks, at least nine weeks, at least twelve weeks, at least eighteen weeks, at least twenty-one weeks, at least twenty-four weeks, at least thirty weeks, at least forty-two weeks, at least forty-eight weeks, at least sixty weeks, at least seventy-two weeks, at least seventy-eight weeks, at least eighty-one weeks or longer.

[0165] In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient at least once a month for at least one month, at least two months, at least three months, at least four months, at least five months, at least six months, at least seven months, at least eight months, at least nine months, at least ten months, at least twelve months, at least twenty months, at least twenty-four months, at least thirty months, at least forty months, at least fifty months, at least sixty months, at least seventy months, at least seventy-six months, at least eighty months or longer.

[0166] In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for 6 to 76 weeks or any period therebetween. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least two weeks, at least three weeks, at least four weeks or at least six weeks. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least four weeks. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least seven weeks. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least twelve weeks. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least twenty-four weeks. In some embodiments, the antibody, antigen-binding fragment or pharmaceutical composition is administered to a patient once a week for at least fifty-two weeks.

[0167] In some embodiments, the antibody or antigen-binding fragment is administered to the patient in one or more doses (e.g., two or more different doses). For example, in some embodiments, the antibody or antigen-binding fragment is administered to the patient in two different doses, e.g., at least one high dose followed by at least one low dose. The high dose (e.g., the high dose of the two different doses) may be referred to herein as the "induction" dose, i.e., a dose capable of reducing the level of at least one autoantibody and / or pathogenic antibody (e.g., at least one IgG) in the patient and / or a patient-derived sample. The low dose (e.g., the low dose of the two different doses) may be referred to herein as the "maintenance" dose, i.e., a dose capable of maintaining a reduction [e.g., about 20% to 80% of the value before administration (pre-induction dose)] in the level of at least one autoantibody and / or pathogenic antibody (e.g., at least one IgG) in the patient and / or a patient-derived sample after at least one induction dose of the antibody or antigen-binding fragment. In some embodiments, the maintenance dose maintains the level of at least one autoantibody and / or pathogenic antibody (e.g., at least one IgG) in the patient and / or a patient-derived sample at about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75% or about 80% or less of the value before administration (pre-induction dose).

[0168] In some embodiments, the induction dose and the maintenance dose may be changed, e.g., the induction dose may be administered to the patient for a first period, then the maintenance dose for a first period, then the induction dose for a second period, and then the maintenance dose for the second period, as appropriate. In some embodiments, the cycle of the induction dose and the maintenance dose (one cycle is the administration of a period with the induction dose followed by a period with the maintenance dose) repeats 1, 2, 3, 4, 5, 6, 7 or 10 times. In some embodiments, the cycle of the induction dose and the maintenance dose repeats for about 3 months, about 6 months, about 12 months, about 15 months, about 18 months, about 24 months or longer.

[0169] In some embodiments, the at least one high dose and / or induction dose is about 680 mg or more per single dose (e.g., about 680 mg, about 700 mg per single dose, about 720 mg per single dose, about 750 mg per single dose or more). In some embodiments, the at least one high dose and / or induction dose is about 1, about 2, about 3, about 4, or about 5 single doses of about 680 mg or more per single dose (e.g., about 680 mg, about 700 mg per single dose, about 720 mg per single dose, about 750 mg per single dose or more). In some embodiments, the at least one high dose and / or induction dose is about 3 single doses of about 680 mg or more per single dose (e.g., about 680 mg, about 700 mg per single dose, about 720 mg per single dose, about 750 mg per single dose or more).

[0170] In some embodiments, the at least one high dose and / or induction dose is administered to the patient once, once a week, once every two weeks, or once a month. In some embodiments, the at least one high dose and / or induction dose is administered intravenously to the patient. In some embodiments, the at least one high dose and / or induction dose is administered subcutaneously to the patient. In some embodiments, each high dose is administered to the patient as one or more subcutaneous injections. In some embodiments, each high dose is administered to the patient as two consecutive subcutaneous injections.

[0171] In some embodiments, at least one low dose and / or maintenance dose is about 340 mg or more per single dose (e.g., about 340 mg, about 360 mg, about 380 mg, about 400 mg or more per single dose). In some embodiments, at least one low dose and / or maintenance dose is about 1, about 2, about 3, about 4, or about 5 single doses of about 340 mg or more per single dose (e.g., about 340 mg, about 360 mg, about 380 mg, about 400 mg or more per single dose). In some embodiments, at least one low dose and / or maintenance dose is about 3 single doses of about 340 mg or more per single dose (e.g., about 340 mg, about 360 mg, about 380 mg, about 400 mg or more per single dose). In some embodiments, at least one low dose and / or maintenance dose is administered to the patient once, once a week, once every two weeks, or once a month. In some embodiments, at least one low dose and / or maintenance dose is administered subcutaneously to the patient. In some embodiments, each low dose is administered to the patient as one or more subcutaneous injections. In some embodiments, each low dose is administered to the patient as a single subcutaneous injection.

Example

[0172] Hereinafter, the present disclosure will be described in more detail by the following examples. However, the following examples are merely for illustrative purposes of the present disclosure, and the scope of the present disclosure is not limited thereto.

[0173] I. Design of Mutants to Improve the Physical Properties of the HL161AN Antibody For the purpose of improving the stability of HL161AN by molecular engineering, amino acid sites that may affect stability were identified using Lonza's in silico tools and LC-MS / MS analysis, and mutants were designed. A schematic diagram of the in silico design of the HL161AN mutant is shown in FIG. 1.

[0174] Therapeutic proteins containing antibodies exist in heterogeneous forms due to post-translational modifications (PTMs) and chemical modifications. Modifications include glycosylation, deamidation, oxidation, etc., and are known to occur depending on the host cell line, production process, storage conditions, etc. This modification is considered a major issue in the production process of therapeutic proteins because side effects such as a decrease in efficacy, limitation of shelf life, and immune response due to aggregation occur (De Groot 2006).

[0175] HL161AN is an anti-hFcRn antibody in the form of a modified human IgG1 and has a high affinity for human FcRn (2×10 -10 M) and has a high PD effect in in vivo tests on cynomolgus monkeys. However, it has a low thermal stability (about 58.4 °C), aggregation occurs at a concentration of 30 mg / mL or higher, and there is a disadvantage that many charged variants are identified in the analysis by CEX-HPLC and cIEF. Therefore, using in silico tools, based on the analysis results of the amino acid sequence and X-ray crystal structure, the PTM sites and the main sites of aggregation were found, and the modified sites were identified by LC-MS / MS analysis of the HL161AN sample. Subsequently, by integrating the two results, an attempt was made to design variants that reduce the risks of PTM and aggregation. [Example 1]

[0176] In silico evaluation of aggregation risk and PTM risk The risks of aggregation and post-translational modification were predicted by in silico analysis.

[0177] Protein aggregation is affected by environmental factors such as pH, concentration, buffer, excipients, shear force, etc. and intrinsic properties. To predict the risk of aggregation based on the amino acid sequence, the Lonza Sentinel APART™ database was used. This is a program validated based on experimental results for the aggregation of more than 500 antibodies. When the sequence of the tested antibody is input, the risk of aggregation is predicted. In the Sentinel APART algorithm, it was predicted that the aggregation risk of HL161AN is increased.

[0178] In addition, an in-silico tool developed by Lonza was used to predict post-translational modifications (PTMs) as described below (Figures 2 and 3). Specifically, the prediction of the risk of post-translational modifications was performed considering i) asparagine deamidation, ii) aspartic acid isomerization and fragmentation, iii) C-terminal lysine clipping, iv) Fc ADCC / CDC response, half-life, and protein A purification, v) free cysteine thiol groups, vi) N-glycosylation, O-glycosylation, vii) oxidation, and viii) pyroglutamic acid formation, etc.

[0179] As a result of the analysis of the HL161AN amino acid sequence, the possibility of asparagine deamidation was predicted at 4 sites in the light chain (L) and 12 sites in the heavy chain (H). Most of these were conserved asparagines and predicted to be of low risk, and 4 sites had the possibility of deamidation but did not correspond to the CDR region, and it was confirmed that no protein modification was required. Therefore, it was analyzed that only L:Asn25 in the light chain CDR region requires protein modification.

[0180] In addition, free cysteine thiol groups can cause protein misfolding, aggregation, non-specific tissue binding, immunogenicity, and potentially low productivity. As a result of confirming whether HL161AN has free cysteine thiol groups, a free thiol group was found at H:Cys32, and it was determined that protein modification of this amino acid is necessary. [Example 2]

[0181] Analysis of PTM Sites by LC-MS / MS Modifications due to deamidation and oxidation of two lots of HL161AN were analyzed by LC-MS / MS. As a result of peptide mapping using two enzymes, namely, a trypsin + LysC mixed enzyme and chymotrypsin, 100% sequence coverage was confirmed (Figure 4).

[0182] As a result of the modification analysis, deamidation and oxidation were confirmed at 7 sites and 6 sites, respectively, in the in-house standard sample of HL161AN, and at 10 sites and 8 sites, respectively, in the HL161AN B012 sample.

[0183] The deamidation sites and oxidation sites of the HL161AN sample by LC-MS / MS are summarized and shown in Tables 2 and 3 below, respectively.

[0184] [Table 2]

[0185] [Table 3] [Example 3]

[0186] Selection of Sites to be Modified Based on the in-silico analysis results and LC-MS / MS results, substitution amino acids for three amino acid sites (L: Asn25, H: Cys32, H: Gln82) determined to require modification were selected. From the X-ray crystallographic analysis data, it was determined that such three amino acid sites are far from the CDR region that binds to the target antigen, so substitution would not affect the affinity (Figure 5). In the selection of amino acid substitutions, it was determined that the risk of PTM could be reduced by substituting Serine (Ser) or Glutamine (Gln) for L: Asn25, Serine (Ser) or Tyrosine (Tyr) for H: Cys32, and Serine (Ser), Threonine (Tyr) or Glutamic acid (Glu) for H: Gln82. In each amino acid selection method, a chemically similar side-chain substitution method was used. For example, asparagine was replaced with glutamine (Table 4). Based on such results, 2 light chains and 11 heavy chains were designed (Table 5).

[0187] The substitutions for the proposed selected PTM sites are summarized and shown in Table 4 below. Also, the designed HL161AN variants are summarized and shown in Table 5 below.

[0188]

Table 4

[0189]

Table 5

[0190] Integrating the above series of results gives the following.

[0191] For the purpose of improving stability by molecular engineering of HL161AN, Lonza's in-silico tools and LC-MS / MS analysis were used to identify amino acid sites that could affect stability, and mutants were designed by mutation.

[0192] As a result, it was determined that three amino acid sites of the HL161AN antibody (L: Asn25, H: Cys32, H: Gln82) required modification. It was determined that substitution with serine or glutamine for L: Asn25, substitution with serine or tyrosine for H: Cys32, and substitution with serine, threonine or glutamic acid for H: Gln82 could reduce the risk of PTM. A total of 22 HL161AN variants (2 light chains and 11 heavy chains of the HL161AN variant) were designed by amino acid substitution.

[0193] Subsequently, 22 variants were prepared by site-directed mutagenesis and then screened for antibodies with improved stability by in vitro and in vivo evaluations.

[0194] II. In Vitro Screening of HL161AN Antibody Variants HL161AN has excellent pharmacological efficacy in vitro / in vivo, but has insufficient physicochemical properties, resulting in insufficient stability during storage and the disadvantage of difficulty in preparing high-concentration SC (subcutaneous) formulations. To improve this, sites that can affect the stability of the antibody were determined by amino acid sequence analysis and molecular structure analysis of HL161AN as described above, and a total of 22 HL161AN variants were prepared by modifying the derived amino acid sites (Table 6). Subsequently, in vitro evaluation was performed by generating the 22 obtained HL161AN variants. Preparation Example 1. Preparation of Test Substances Preparation Example 1.1. HL161AN Reference Standard Sample (Reference Standard, RS): Control 1 - Lot number: HL161AN / 16E11 / ST01 - Concentration: 13 mg / mL - Formulation buffer: 100 mM histidine, 100 mM arginine-HCl, pH 6.0 - Storage condition: ≤ -60°C Preparation Example 1.2. HL161AN Variant Plasmid - Light chain variant 2 and heavy chain variant 11 - Storage condition: ≤ -60°C

[0195] In the amino acid sequence of HL161AN, two or more amino acids were substituted as shown in Table 6 below.

[0196] [Table 6] [Example 4]

[0197] In vitro evaluation of 22 HL161AN mutants Twenty-two HL161AN mutants were evaluated in comparison with the control antibody HL161AN. [Example 4.1]

[0198] Sample generation One day before transfection, Expi293F cells were seeded at 1×10 6 cells / mL (in a 100 mL volume) into a 500 mL Erlenmeyer flask and then incubated with shaking for 24 hours in an incubator at 8% CO2, 125 rpm, and 37°C. On the day of transfection, the cell concentration was adjusted to 2×10 6 cells / mL, and then the cells were transfected with the plasmid DNA of each mutant. The antibody plasmid was diluted to 1 μg / μL in LAL water (Lonza Bioscience). 0.12 mL of the heavy chain plasmid and 0.12 mL of the light chain plasmid were each added to 5 mL of Opti-MEM SFM and suspended. 0.24 mL of FectoPro was added to 5 mL of Opti-MEM SFM and suspended.

[0199] Plasmid DNA and FectoPro were mixed at a 1:1 ratio and incubated at room temperature for 10 minutes, then added to the flask containing cells. This was incubated with shaking in an incubator at 8% CO2, 37 °C, and 125 rpm for 3 hours, then 100 μL of Booster was added to continue the culture. On the 6th day from the start of the culture, the culture medium was allowed to stand in a 250 mL centrifuge tube and centrifuged at 3,000 rpm for 15 minutes. Then, only the supernatant was collected and filtered through a 0.2 μm bottle-top filter. The antibody expression level of the collected culture medium was quantified using a Cedex bioanalyzer.

[0200] As a result, a total of 22 HL161AN antibody mutants were transiently expressed using Expi293F cells. Transfection was performed at a 100 mL culture scale to obtain an expression medium in an amount of 0.5 mg or more for each antibody, and the culture medium was collected on the 6th day. The expression levels of the obtained media were 65 - 181 mg / L (Table 7). The production results of the 22 HL161AN mutants are summarized and shown in Table 7 below.

[0201]

Table 7

[0202] Purification of Antibody The sample was purified by packing 1.5 mL of MabSelect SuRe™ LX resin into a Poly-prep® chromatography column. 1×PBS (pH 7.4) was used as the binding buffer and washing buffer, and elution was performed with 1.5 mL fractions using 0.1 M glycine (pH 3.0) buffer. All fraction tubes were neutralized to pH 7.0 by adding 1 M Tris-HCl (pH 9.0), and then pooled. The pooled eluate was purified by buffer exchange with citrate phosphate buffer (pH 8.0) and concentration to 1.0 mg / mL using a Millipore centricon (cutoff 30 kDa). Also, using HL161AN RS, in vitro evaluation was performed by buffer exchange with citrate phosphate buffer (pH 8.0) in the same manner as the HL161AN variant. For each sample, the A280 value was measured using a Nanodrop, and the concentration was calculated. Based on the quantification values, for each antibody, the sample status was confirmed by SDS-PAGE analysis.

[0203] As a result, the culture solution obtained by transiently expressing a total of 22 kinds of HL161AN antibody variants using Expi293F cells was purified by a protein A column and concentrated to a concentration of 1.0 mg / mL. It was confirmed by SDS-PAGE analysis and SEC-HPLC analysis that the generated sample had a purity of 97% or more (Figure 6 and Table 7). [Example 4.3]

[0204] SPR analysis SPR (surface plasmon resonance) analysis was performed using a Proteon XPR36 instrument under two conditions of pH 6.0 and pH 7.4. shFcRn (soluble human FcRn) was immobilized on a GLC chip, and the antibody sample was reacted at five concentrations, and then sensorgram results were obtained. Kinetic analysis was performed using a 1:1 Langmuir binding model, and the average KD value was obtained by repeating the analysis six times under each condition of pH 6.0 and pH 7.4.

[0205] Chip activation was performed under the conditions of EDAC / NHS 0.5×, 30 μL / min, and 300 sec. Subsequently, 250 μL of 2 μg / mL shFcRn was prepared using acetate buffer (pH 5.5), and immobilization was performed while flowing at 30 μL / min. When the immobilization level corresponded to 200 RU - 300 RU, the reaction was stopped. Subsequently, non-activation was performed using ethanolamine at 30 μL / min for 300 sec. Antibody samples were prepared by serial dilution with 1 / 2 - 5 nM, 2.5 nM, 1.25 nM, 0.625 nM, and 0.312 nM based on a concentration of 10 nM. Sample dilution was performed using 1×PBST (pH 7.4) or 1×PBST (pH 6.0) buffer according to the analysis pH. Under the sample analysis conditions, association was performed by a reaction of 50 μL / min for 200 sec, and dissociation was performed by a reaction of 50 μL / min for 600 sec. Subsequently, regeneration was performed by a reaction of 100 μL / min for 18 sec using glycine buffer (pH 2.0). In the kinetic analysis, samples were prepared and reacted once in three cells with immobilized shFcRn. Then, three kinetic values were obtained, and then the average KD value was measured. When analyzing the reaction signal, double-referencing was performed using interspot-referencing and the signal analyzed with buffer only.

[0206] As described above, SPR analysis was performed on 22 HL161AN antibody mutants at pH 6.0 and pH 7.4. As a result, the HL161AN mutants showed similar binding affinities compared to the binding affinity of HL161AN for shFcRn [1.16E-10 M (pH 6.0) and 2.94E-10 M (pH 7.4)] (Figure 7 and Table 8).

[0207] The kinetic results of the HL161AN mutants are summarized and shown in Table 8 below.

[0208]

Table 8

[0209] Analysis of hFcRn Binding of Antibody Variants Using FACS Analysis of hFcRn binding using FACS was performed under two conditions of pH 6.0 and pH 7.4. HEK293 (hFcRn HEK293) cells expressing hFcRn were diluted with reaction buffer (0.05% BSA in PBS, pH 6.0 or pH 7.4), and 1×10 5 Cells were prepared in duplicate in 96-well plates. In addition, each antibody sample was diluted to 10 nM with reaction buffer, then placed in a 96-well plate and incubated at 4°C for 90 minutes. Thereafter, the plate was centrifuged to remove the supernatant, then Alexa488 goat anti-hIgG Ab (1:200) was added thereto and incubated again at 4°C for 90 minutes. After the reaction was completed, it was centrifuged to remove the supernatant, 200 μL of reaction buffer was added to resuspend the cell pellet, and then the MFI value was measured by a FACS instrument.

[0210] As described above, binding evaluation using FACS was performed for 22 HL161AN antibody variants at pH 6.0 and pH 7.4. As a result, the 22 HL161AN variants showed MFI values similar to those of HL161AN (Figure 8). [Example 4.5]

[0211] Analysis of hFcRn Blocking Ability of Antibodies Using FACS 1×10 hFcRn HEK293 cells 7 The cells were seeded in a T75 flask and cultured for 24 hours. After culturing, the cells were removed, and 1×10 for each sample 5 The cells were allowed to stand in duplicate in 96-well plates. Thereafter, each antibody sample (0.2 nM, 2 nM, 20 nM, and 200 nM) and 100 nM Alexa488-hIgG1 were added in a 1:1 ratio and incubated at 4°C for 90 minutes. After the reaction was completed, it was centrifuged to remove the supernatant, 200 μL of reaction buffer was added to resuspend the cell pellet, and then the MFI value was measured by a FACS instrument. Each MFI value was converted to % blocking and fitted with a 4-PL to obtain EC 50The value was obtained.

[0212] As a result, blocking evaluations using FACS were performed at 0.1 nM, 1 nM, 10 nM, and 100 nM. Each antibody blocked in a concentration-dependent manner, and the EC 50 values were confirmed to be similar. Similar to the results of the hFcRn binding analysis using FACS, the EC 50 values of the 22 HL161AN mutants were confirmed to be similar to those of the control antibody HL161AN. Therefore, it was determined that the amino acid substitutions did not affect the function of the HL161AN mutants (Figure 9). [Example 4.6]

[0213] Evaluation of stability 200 μL of each purified sample was aliquoted into 1.5 mL tubes, and then the samples were stored at 40 °C under accelerated conditions for up to 4 weeks. Samples at Week0, Week1, Week2, and Week4 were analyzed by SEC-HPLC. The analysis of each sample was performed under the SEC-HPLC analysis conditions shown in Table 9 below to analyze the degree of stability under accelerated conditions.

[0214] [Table 9]

[0215] The samples were stored at 40 °C under accelerated conditions for up to 4 weeks, and the stability of the samples was analyzed by SEC-HPLC. As a result, in the case of HL161AN, compared with the sample at Week0, the aggregates in the sample increased by 47.5% and the fragments increased by 4.8% at Week4. On the other hand, the production rates of aggregates of the 22 mutants were 5.6% to 39.6%, which were lower than those of HL161AN. Also, the production rates of fragments were 3.2% to 12.3%, which were increased or similar to the production rate of HL161AN (Figure 10, Figure 11, and Table 10).

[0216] [Table 10] [Example 4.7]

[0217] DSC analysis Differential scanning calorimetry (DSC) analysis was performed using a NANO DSC instrument (TA Instrument, PN: 602000, SN: K10126), and the Tm value was analyzed using NanoAnalyze software according to the two-state scale model. The DSC analysis was performed by K Bio Health (Osong Medical Innovation Foundation, New Drug Development Support Center).

[0218] The thermal stability of the HL161AN variant was analyzed. As a result, as shown in Table 11 below, the Tm value of HL161AN was 58.4 °C, and the Tm values of the HL161AN variants were 60 °C to 61.5 °C. Therefore, it was confirmed that the Tm value of the HL161AN variant increased by up to 2 °C compared to HL161AN.

[0219] The thermal stability of the HL161AN variant is summarized and shown in Table 11 below.

[0220]

Table 11

[0221] The results of the first in vitro evaluation of the 22 HL161AN variants described above are summarized and shown in Table 12 below.

[0222] The FcRn binding affinity / blocking and stability were evaluated for a total of 22 HL161AN variants. As a result, it was confirmed that the binding affinity and blocking actions were similar to those of HL161AN, and the stability of all HL161AN variants was improved compared to HL161AN with respect to the production of aggregates. Therefore, when stored at 40 °C for 4 weeks, the top 8 variants with an aggregate production rate of less than 10% were selected, and after preparing high-concentration samples and performing the second in vitro screening, it was decided to finally select the top molecule.

[0223]

Table 12

[0224] Second in vitro evaluation of high-concentration samples of 8 HL161AN variants Eight high-concentration HL161AN variants and the control antibody HL161AN were evaluated. [Example 5.1]

[0225] Sample generation The culture method for generating high-concentration samples is the same as the method in Example 4.1. To obtain 120 mg or more of the antibody, more than 1 L was cultured for each antibody variant. [Example 5.2]

[0226] Antibody purification The purification method of the sample is the same as that in Example 4.2. The eluate was buffer-exchanged with 50 mM histidine buffer (pH 5.0) and concentrated to a concentration of about 150 mg / mL to complete the purification. In the case of HL161AN RS, similar to the case of the HL161AN variant, the eluate was buffer-exchanged with 50 mM histidine (pH 5.0) and concentrated to a concentration of about 150 mg / mL to obtain the sample. For each antibody sample, the concentration was calculated using Nanodrop, and based on this, SDS-PAGE analysis was performed to confirm the state of the sample. [Example 5.3]

[0227] Generation of high-concentration samples of HL161AN variants Eight HL161AN mutants selected in the first in vitro evaluation were transiently expressed in Expi293F cells in the same manner as in Examples 5.1 and 5.2 above, purified, and prepared at a concentration of 150 mg / mL or higher. HL161AN was used by concentrating the standard product to a high concentration. All samples were analyzed by A280 and SEC-HPLC after production (Table 13), and it was confirmed that all samples except mutant No. 2 and mutant No. 13 had a high purity of 98% or higher. In the case of mutant No. 2 and mutant No. 13, precipitates were observed during the concentration process, and it was confirmed that the SEC-HPLC purity decreased to about 93% (Table 13).

[0228]

Table 13

[0229] Analysis of hFcRn Binding of Antibodies Using FACS Performed in the same manner as in Example 4.4. For eight high-concentration HL161AN mutants and HL161AN, the evaluation of hFcRn binding was performed using FACS at pH 6.0 and pH 7.4. As a result, the eight HL161AN mutants showed MFI values similar to those of HL161AN (pH 6.0: 2952, pH 7.4: 7155) (Figure 12). [Example 5.5]

[0230] Analysis of hFcRn Blocking of Antibodies Using FACS Performed in the same manner as in Example 4.5. The evaluation of hFcRn blocking was performed using FACS at 0.1 nM, 1 nM, 10 nM, and 100 nM. Each antibody blocked in a concentration-dependent manner, and the EC 50 values were similar to those of the control antibody HL161AN (Figure 13). [Example 5.6]

[0231] Evaluation of Stability It was carried out in the same manner as in Example 4.6. In order to evaluate the stability of eight high-concentration HL161AN mutants, the change in the purity of the samples stored at 40 °C for 4 weeks was confirmed by SDS-PAGE and SEC-HPLC. In the case of HL161AN, the production rate of aggregates was 50% or more after storage for 4 weeks, which was also confirmed by SDS-PAGE (Figure 14). In the case of the eight HL161AN mutants, the production rate of aggregates was 8.4% to 25.7%, which was increased compared to HL161AN, and the production rate of fragments was 3.5% to 4.4%, which was confirmed to be similar to the production rate of HL161AN (4.1%) (Figure 15). [Example 5.7]

[0232] Analysis of viscosity The VROC chip was placed on the main body of a viscometer (m-VROC system), and then each of about 300 μL of a high-concentration HL161AN RS control sample and an HL161AN mutant sample was filled into a syringe. The VROC chip was connected to the syringe, and after stabilizing at a set temperature of 25 °C, the viscosity was measured by repeating three times.

[0233] The viscosities of the control substance HL161AN and four high-concentration HL161AN mutants with sufficient sample volumes were analyzed. The viscosity of the buffer (50 mM histidine) was measured to be 0.93 cP. The average viscosities of the four HL161AN mutants were measured to be 5.57 cP to 7.65 cP, which were less than the viscosity that can be administered subcutaneously (sc) (<20 cP) (Table 14). The viscosities of the four high-concentration HL161AN mutants are summarized and shown in Table 14 below.

[0234]

Table 14

[0235] The results of the second in vitro evaluation of the high-concentration (150 - 170 mg / mL) samples of the eight HL161AN mutants described above are summarized and shown in Table 15 below.

[0236] In the first in vitro evaluation, for the eight HL161AN variants selected, high-concentration samples of 150 mg / mL to 163 mg / mL were prepared, and FcRn binding / blocking and stability were measured to select the lead molecule. As a result, HL161AN variant number 1 and variant number 12, which had FcRn binding / blocking similar to that of HL161AN and improved stability, were selected as the lead molecules (Table 15).

[0237]

Table 15

[0238] Conclusion of in vitro screening of HL161AN antibody variants In the in vitro evaluation of 22 HL161AN variants designed to improve the physical properties of HL161AN, a total of 22 HL161AN variants were generated, and FcRn binding affinity / blocking and stability were measured. As a result, all 22 variants showed biological activities similar to those of HL161AN, and the top eight variants with improved stability were selected first. High-concentration samples (150 mg / mL to 163 mg / mL) of the eight selected variants were prepared and stability evaluation was carried out. As a result, all eight HL161AN variants showed biological activities similar to those of HL161AN and had improved stability compared to HL161AN.

[0239] The light chain N25S mutation was added to HL161AN mutant number 1, mutant number 2, mutant number 8, and mutant number 11, and the N25Q mutation was added to mutant number 12, mutant number 13, mutant number 19, and mutant number 22. However, there was no difference in stability between the two groups. In the case of the heavy chain, C32 was further mutated to S or Y, and Q82 was further mutated to S, T, or E. However, in all mutants, the production rate of aggregates decreased by at least half compared to the control group HL161AN. In particular, when C32 was mutated to S, the production rate of aggregates (10% or less) decreased by more than one-fifth compared to HL161AN, and the stability was most improved compared to other mutants (Figure 16). Therefore, HL161AN mutant number 1 (LC: N25S, HC: C32S; HL161ANS) and mutant number 12 (LC: N25Q, HC: C32S; HL161ANQ) having an aggregate production rate of 10% or less were finally selected as the lead molecules.

[0240] III. Evaluation of hIgG catabolism of HL161AN antibody mutants using hFcRn transgenic mice The in vivo hIgG catabolic efficacy of three HL161AN mutants modified to improve stability was evaluated using hFcRn transgenic (Tg) 32 mice.

[0241] The test substances for the hIgG catabolism test of anti-FcRn antibody (HL161AN) mutants using hFcRn transgenic mice were prepared as follows. The test substance information is shown in Table 16. Three HL161AN mutants, HL161ANS-IgG1LALA, HL161ANQ-IgG1LALA, and HL161ANQ-IgG4 S228P, were diluted with the buffer shown in Table 16 below to prepare a concentration of 2 mg / mL. 10 mL for administration to 5 animals was prepared, divided into 4 doses of 2.5 mL / day, and stored at -60°C or lower until administration.

[0242]

Table 16

[0243] In addition, the comparative substance HL161AN was prepared as shown in Table 17. HL161AN was diluted with 50 mM histidine (pH 5.9) dilution buffer to a concentration of 2 mg / mL. 10 mL for administration to 5 animals was prepared, divided into 4 doses of 2.5 mL / day, and stored at -60°C or lower until administration.

[0244] [Table 17]

[0245] As a control substance, IV-Globulin SN Inj. (IVIG), a commercially available product from GC Biopharma, was used. The product information is shown in Table 18. Specifically, 0.4 mL of 50 mg / mL IV-Globulin Inj. was diluted to a concentration of 2 mg / mL by adding 9.6 mL of PBS (pH 7.4), divided into 4 doses of 2.5 mL / day, and stored at 4°C for up to 4 days until administration.

[0246] [Table 18]

[0247] In addition, a tracer was prepared by mixing 495 mg / kg of total hIgG and 5 mg / kg of biotin-hIgG. Specifically, total hIgG was prepared at a concentration of 49.5 mg / mL, and 495 mg / kg of IV-Globulin Inj. was administered by adding 0.2 mL of PBS (pH 7.4) to 19.8 mL of 50 mg / mL IV-Globulin Inj. In addition, biotin-hIgG was prepared by adding 267 μL of 10 mM biotin to 20 mg of IV-Globulin Inj., followed by incubation at room temperature for 30 minutes. Then, in order to remove free biotin, the sample was transferred to a dialysis bag and dialysis was performed with 1×PBS (pH 7.4). Biotin-labeled hIgG was quantified by measuring the absorbance at UV 280nm (IgG E1% = 14.0 at 280 nm). [Example 7]

[0248] Animal experiment method The mFcRn that had been bred - / - hFcRn gene - transfected (Tg) 32 mice (Jackson Laboratory, USA) (male, 5 - 10 weeks old) were identified by tagging their tails and placing 5 mice in each cage. After registration, they were acclimatized to the climate for 1 - 2 weeks. In addition, the sample substances were administered by dividing them into the groups shown in Table 19 below.

[0249] [Table 19]

[0250] Specifically, as a tracer, 495 mg / kg of total hIgG and 5 mg / kg of biotin - hIgG were intraperitoneally administered (i.p.) at a dose of 10 mL / kg, and the administration time was set at 0 hour. In addition, the test substances HL161ANS (IgG1 - LALA), HL161ANQ (IgG1 - LALA), and HL161ANQ (IgG4 S228P), the comparative substance HL161AN, and the control substances, namely the vehicle and IVIG, were intraperitoneally administered 4 times at a dose of 20 mg / kg at 24 hours, 48 hours, 72 hours, and 96 hours after the tracer administration.

[0251] Thereafter, the administration time of the tracer was set at 0 hour, and then blood was collected at 24 hours, 48 hours, 72 hours, 96 hours, 120 hours, and 168 hours. The test substances, comparative substances, and control substances were administered at 24 hours, 48 hours, 72 hours, and 96 hours. In this case, blood was collected first, and then the administration was carried out. The mice were anesthetized using a respiratory anesthesia device and then blood was collected from the orbital venous plexus using a microhematocrit capillary tube.

[0252] Approximately 0.2 mL of whole blood was centrifuged at 3000 rpm for 15 minutes. Thereafter, the obtained serum was transferred to a 1.5 - mL microcentrifuge tube and stored at - 60°C or lower until analysis. [Example 8]

[0253] Confirmation of the degree of catabolism of biotin-hIgG tracer by ELISA analysis The degree of catabolism of the biotin-hIgG tracer in the body was confirmed using the serum obtained by the above method.

[0254] Specifically, the diluent / blocking buffer (assay diluent (AD), 1% BSA in 1×PBS, pH 7.4): 10 g of Probumin® was dissolved in 900 mL of 1×PBS (pH 7.4), adjusted to a final volume of 1 L, filtered through a 0.2 μm filter, and then stored at 4°C. In addition, the standard stock solution (500 ng / mL of biotin-hIgG) was prepared by mixing 10 μL of biotin-hIgG (4 mg / mL) with 990 μL of PBS to obtain 40 μg / mL. Then, 750 μL of the diluent was mixed with 250 μL of 40 μg / mL of biotin-hIgG to prepare 10 μg / mL. The 500 ng / mL standard stock solution was prepared by mixing 50 μL of 10 μg / mL of biotin-hIgG with 950 μL of the diluent, and then aliquoted into 50 μL portions. The aliquoted standard stock solution was stored at -80°C. In addition, neutral avidin was used by diluting 10 μL of 2 mg / mL of neutral avidin to 2 μg / mL with 10 mL of 1×PBS.

[0255] Thereafter, the samples in the vehicle group and the IVIG group were all diluted 1:10,000 using the diluent to prepare analysis samples. Except for the HL161ANS (IgG1-LALA) group, the samples at 24 hr, 48 hr, and 72 hr were diluted 1:10,000, and the samples at 96 hr, 120 hr, and 168 hr were diluted 1:1,000. In the case of the HL161ANS (IgG1-LALA) group, only the sample at 168 hr was diluted 1:1,000, and all samples at other time points were diluted 1:10,000. The diluted samples were filled in duplicates of 100 μL per well and incubated at room temperature for 2 hours.

[0256] The blood concentration of biotin-hIgG administered at 0 hours was measured by ELISA at 24 hours, 48 hours, 72 hours, 96 hours, 120 hours, and 168 hours after administration of 20 mg / kg of HL161ANS (IgG1-LALA), HL161ANQ (IgG1-LALA), HL161ANQ (IgG4 S228P), HL161AN, and IVIG. As a result, the other test groups showed a significant decrease in biotin-hIgG over time compared to the vehicle and IVIG administration groups. On the other hand, there was no significant difference among the three HL161AN variants and HL161AN. Among the three variants, HL161ANQ (LC:N25Q, HC:C32S)-IgG1-LALA showed a relatively high effect on biotin-hIgG catabolism. However, since there was no statistical significance, this was determined to be a similar effect (Tables 20, 21, and Figure 17).

[0257] The concentration of biotin-hIgG after administration of 20 mg / kg of the HL161AN variant is summarized and shown in Table 20 below.

[0258] [Table 20]

[0259] The results of biotin-hIgG catabolism of the HL161AN variant in Tg32 mice (% at 24 hours after tracer administration) are summarized and shown in Table 21 below.

[0260] [Table 21] [Example 9]

[0261] Calculation of the half-life of the biotin-IgG tracer by pharmacokinetic (PK) analysis Using the quantitative analysis results of biotin-hIgG by ELISA, the half-life of the tracer was calculated by BA calc (2007, Korea) after administration of each test substance. Specifically, using the ELISA analysis results, the half-life from 24 hours to 120 hours after tracer administration was calculated for three HL161AN variants (Table 16), the comparator substance, and the control substance.

[0262] As a result, as shown in Table 22, the half-life was 22.7 ± 9.0 hours for HL161ANS (IgG1-LALA), 15.9 ± 0.9 hours for HL161ANQ (IgG1-LALA), and 17.8 ± 2.6 hours for HL161ANQ (IgG4 S228P). The half-life of the comparator substance HL161AN was 20.6 ± 3.6 hours, and it was confirmed to be equivalent to the half-lives of the three HL161AN variants. In addition, the half-lives of the vehicle and IVIG were 108.2 ± 29.0 hours and 98.0 ± 16.8 hours, respectively, and it was confirmed that they were similar. The results of the half-life analysis of biotin-hIgG after administration of HL161AN variants in Tg mice are summarized and shown in Table 22 below.

[0263]

Table 22

[0264] hIgG catabolism of HL161AN antibody variants in hFcRn transgenic mice The effect of hIgG catabolism was confirmed after administration of 20 mg / kg of three HL161AN variants modified to improve the stability of HL161AN to Tg32 mice. As a result, it was confirmed that HL161ANS (IgG1-LALA), HL161ANQ (IgG1-LALA), and HL161ANQ (IgG4 S228P) had an hIgG catabolic effect equivalent to that of the comparator substance HL161AN.

[0265] As a conclusion, it was confirmed that HL161ANS (light chain: N32S, heavy chain: C32S) and HL161ANQ (light chain: N32Q, heavy chain: C32S), substances in which two amino acids in the variable domain of HL161AN were substituted to improve stability, have an in vivo IgG catabolic effect similar to that of the original molecule HL161AN. That is, it was confirmed that the three HL161AN mutants modified to improve stability did not affect the in vivo efficacy compared to the existing HL161AN. [Example 11]

[0266] Conclusion on hIgG catabolism by administration of anti-FcRn antibody (HL161AN) mutants to hFcRn gene-transferred mice To evaluate the effects of HL161AN and HL161AN mutants (HL161ANS and HL161ANQ) on the in vivo catabolism of biotin-hIgG, blood was collected up to the time point after administration to Tg32 mice at 20 mg / kg, and the blood concentration of biotin-hIgG was confirmed.

[0267] As a result, in the case of biotin-hIgG, a similar biotin-hIgG catabolic effect was confirmed for all three administered substances. All test substances (HL161AN, HL161ANS, and HL161ANQ) reduced the concentration of biotin-hIgG by more than 90% within 120 hours after administration compared to the IVIG control group.

[0268] As a conclusion, it was confirmed by hIgG catabolism test that there is no significant difference between the hIgG catabolic effects of HL161ANS and HL161ANQ and that of HL161AN. [Example 12]

[0269] Comparison of HL161ANS antibody and batoclimab In this one-to-one study in monkeys, the HL161ANS mutant (also called IMVT-1402) was compared with another anti-FcRn antibody, batoclimab (HL161BKN, see, for example, International Patent Application Publication No. WO2015 / 167293).

[0270] Twenty monkeys in four groups were administered batoclimab at 50 mg / kg, HL161ANS at 5 mg / kg, HL161ANS at 50 mg / kg, or placebo intravenously. IgG, albumin, and low-density lipoprotein (LDL) and cholesterol were measured at the indicated time points. Cynomolgus monkeys are known to be a reliable pharmacodynamic surrogate for the effect of anti-FcRn on IgG (see, for example, Lledo-Garcia, et al., UCB Pharma, 2022).

[0271] At the comparative doses, the IgG reduction was almost the same between batoclimab and HL161ANS (Figure 18). The IgG-reducing effect was dose-dependent. Similar effects on albumin, LDL, and cholesterol were demonstrated with HL161ANS and placebo (Figures 19A - 19C, respectively). Thus, there was no substantial effect of HL161ANS on albumin, LDL, or cholesterol levels. [Example 13]

[0272] Four-week intravenous exploratory pharmacology study in cynomolgus monkeys and subsequent four-week recovery period The purpose of the study was to determine the pharmacology, toxicity, and toxicokinetics (TK) profiles of the test article HL161ANS after intravenous injection administration once a week for four weeks (Day 1, Day 8, Day 15, and Day 22) to cynomolgus monkeys, and to evaluate the persistence, delayed onset, or reversibility of any changes after a four-week recovery period.

[0273] The test article, positive control article, and control / vehicle article were administered to groups of monkeys once a week by intravenous injection (over approximately 60 seconds) on Day 1, Day 8, Day 15, and Day 22 as described in Table 23 below.

[0274]

Table 23

[0275] After completion of the final weekly dosing cycle, all animals were observed for 4 weeks and then animals in Groups 1, 3, and 4 were euthanized and subjected to necropsy on Day 57.

[0276] Parameters monitored during this study included mortality, clinical findings, and body weight. In addition, clinical pathology parameters (hematology, coagulation, clinical chemistry, and urinalysis) were evaluated. Blood samples were taken for the evaluation of pharmacokinetics, apo B, IgG, and ADA. Necropsies were performed and tissues were collected for possible histopathological examination.

[0277] Neither mortality nor clinical signs related to HL161ANS were observed.

[0278] No effects on the test items were observed with respect to body weight, hematology, coagulation, clinical chemistry, and urinalysis.

[0279] Increased incidences of splenic plaque formation in HL161ANS at 5 mg / kg and 50 mg / kg and small thymus at 50 mg / kg were observed. Since microscopic examinations were not performed, it was not possible to determine the toxicological significance of such findings.

[0280] In conclusion, once-weekly intravenous administration of HL161ANS at 5 mg / kg and 50 mg / kg to cynomolgus monkeys for 4 weeks (Day 1, Day 8, Day 15, and Day 22) was well tolerated. [Example 14]

[0281] Toxicity study and pharmacokinetic study of HL161ANS by subcutaneous injection and / or intravenous injection for 6 weeks and 9-week recovery period in cynomolgus monkeys The purpose of this study was to evaluate the toxicity of HL161ANS when administered to cynomolgus monkeys by subcutaneous injection and / or intravenous (continuous bolus) injection twice a week for at least 6 weeks (a total of 13 dosing intervals), to determine the pharmacokinetics, and to evaluate the reversibility or persistence of any effects after a 9-week recovery period.

[0282] Male and female cynomolgus monkeys were assigned to 6 groups and administered as shown in Table 24. The animals were administered at a volume of 1.3 mL / kg / time on Day 1, Day 4, Day 8, Day 11, Day 15, Day 18, Day 22, Day 25, Day 29, Day 32, Day 36, Day 39, and Day 43 of the administration period by subcutaneous (SC) injection (Groups 1-4) and / or intravenous (IV)-(continuous bolus) injection (Groups 1, 5, and 6). The vehicle control article / diluent was the HL161ANS formulation buffer. In addition, KLH was administered to each animal once on Day 14 of the administration period and once on Day 28 of the recovery period by subcutaneous injection at a volume of 1 mL / time.

[0283]

Table 24

[0284] Toxicity was evaluated based on mortality, clinical findings, body weight, quantitative food intake, ophthalmic findings, electrocardiogram (ECG) measurements, skin findings, neurobehavioral findings, respiratory rate assessment, and clinical and anatomical pathology. Blood samples were collected for evaluation by toxicokinetics, ADA, and immunotoxicology.

[0285] Toxicokinetic parameters were generally similar (within 2-fold) in male and female monkeys. For SC administration, the systemic exposure of HL161ANS increased with the dose level as indicated by the C max value and AUC 0-72 value. Since sacrifice occurred at the end stage on Day 44, the AUC 0-72The evaluation is limited to any animals other than the animals in the recovery period of the 198.4 mg / kg / time group. This increase was generally larger than the proportional value between the doses of 50.0 mg / kg / time and 198.4 mg / kg / time. After repeated SC administration twice a week, based on the gender-mixed AR average value, no serum accumulation was observed in the 50.0 mg / kg / time group from Day 1 to Day 22, and a quite low value of less than 1.0 was shown in two individual female animals of the group. Accumulation did not occur at high doses, and the degree of accumulation increased with the dose. C max Values and AUC 0-72 The accumulation ratio to the value was 1.65 - 1.86 in the 100.0 mg / kg / time group (Day 1 - Day 22) and 1.83 - 2.88 in the 198.4 mg / kg / time group (Day 1 - Day 22 and Day 43). In IV administration, the C max Values and AUC 0-72 Values increased with the dose level. AUC 0-72 The increase in the value was larger than the proportional value between the doses of 50.0 mg / kg / time and 198.4 mg / kg / time. After IV bolus administration, the C max showed an increase approximately proportional to the dose on Day 1 by the dose proportionality evaluation for, but due to the contribution of the accumulation effect, the interpretation of this evaluation became difficult on Days 22 and Day 43. After repeated IV administration twice a week, the serum accumulation based on C max was slight (50.0 mg / kg / time) to moderate (198.4 mg / kg / time), and the ARs were 1.11 - 1.23 and 1.40 - 1.63 respectively. For AUC 0-72 in the 50.0 mg / kg / time group, the gender-mixed exposure average value decreased to half from Day 1 to Day 22 and remained the same until Day 43, and the AR was approximately 0.460. As a result, a very low AR was shown in 5 out of 6 animals in this group. In the IV group of 198.4 mg / kg / time, for AUC 0-72A moderate increase was observed, with the AR being approximately 1.5. Positive anti-drug antibody (ADA) titers were observed in 35 out of 38 (92.1%) of the HL161ANS-treated animals (1 animal receiving 100 mg / kg / dose SC and 2 animals receiving 198.4 mg / kg / dose IV were negative for ADA titers). Since there was a tendency for the AR to decrease with an increase in the ADA titer, there was a possibility that HL161ANS-induced ADA affected the accumulation ratio on Day 22 and Day 43. The 50 mg / kg / dose group was more affected than the other groups.

[0286] On Day 30 of the dosing period, 1 female receiving 100 mg / kg / dose SC was sacrificed due to emaciation (0.3 kg weight loss), low body condition score, sunken eyes, decreased skin elasticity, loose stools, and hypothermia (36.4°C). The animal had been examined previously and treated for swelling and laceration of the left foot on Day 23 of the dosing period, but the condition of this animal deteriorated. The clinical pathological changes associated with HL161ANS consisted of a mild to moderate decrease in total protein concentration and total albumin concentration. Such changes were similar to those observed in animals that survived until planned sacrifice and had the potential to be exacerbated by the clinical findings of inflammatory response and loose stools.

[0287] Findings by the naked eye included cerebral shape abnormalities and compression, which were microscopically correlated with slight swelling of the brainstem and were judged to be incidental. A minimal increase in the cellularity of myeloid progenitor cells in the sternal marrow had the potential to be correlated with the inflammatory response associated with a finger laceration. The cause of the moribund state was undetermined by microscopic findings, but a finger wound leading to continuous liquid feces and decreased motility and food intake was considered to have contributed to the moribund state of this animal. Based on the available clinical findings and clinical and anatomical pathological results, this mortality was not associated with HL161ANS. Clinical findings associated with HL161ANS; ophthalmoscopic findings; changes in body weight and food intake; effects on respiratory rate; skin findings; effects on ECG; effects on coagulation, urine tests, and IgM and IgA titers; effects on CH50 levels; effects on immunity and lymphocyte subsets; organ weight differences; and macroscopic findings were also not observed.

[0288] Prior to dosing on Day 22 of the dosing period, an increase in IgM titer compared to that before dosing on Day 1 of the dosing period was observed in most controls and in both male and female animals administered HL161ANS at 50 mg / kg / occasion or more. Subsequently, a decrease in IgM titer was observed in female animals administered HL161ANS at 50 mg / kg / occasion or more before dosing on Day 43 of the dosing period and 1344 hours after dosing, and the values maintained equivalence with the control. In male animals administered HL161ANS, the IgM titer before dosing on Day 43 of the dosing period maintained equivalence with that before dosing on Day 22 of the dosing period, and subsequently, a decrease was observed 1344 hours after dosing on Day 43 of the dosing period. Before dosing on Day 4 of the dosing period, a decrease in IgG concentration compared to that before dosing on Day 1 of the dosing period was observed in all animals administered HL161ANS at 50 mg / kg / occasion or more. The percent change in the average value of IgG concentration for the group administered 50 mg / kg / occasion or more decreased by approximately 48 - 76% from the baseline value on Day 43 of the dosing period, consistent with pharmacological predictions. The average value of IgG concentration for each group increased from Day 15 of the recovery period and returned to the baseline level by the end of the recovery period. An increase in IgG concentration compared to that before dosing on Day 1 of the dosing period was observed in two female animals administered 198.4 mg / kg / occasion by SC injection starting from Day 15 of the dosing period after a decrease was observed on Day 4 of the dosing period. The IgG concentration maintained a high level in both animals until Day 43 of the dosing period and then decreased on Day 1 of the recovery period. An increase in IgG concentration compared to that before dosing on Day 1 of the dosing period was observed in one male animal administered 198.4 mg / kg / occasion by SC injection starting from Day 15 of the dosing period after a decrease was observed on Day 4 of the dosing period. The IgG concentration maintained a high level until Day 32 of the dosing period and then decreased on Day 36 of the dosing period. The IgG concentration decreased below the baseline by Day 50 of the recovery period. The increase in IgG concentration in one animal may be related to vascular inflammation observed in various tissues in microscopic examination. Such variations by group mean that the relationship between IgG concentration and the HL161ANS and / or ADA titer is unknown.

[0289] A slight increase in C3a levels compared to control and baseline values was observed in animals administered 198.4 mg / kg / once SC or IV on Day 43 of the dosing period. This was consistent across genders and was considered potentially related to HL161ANS due to the small scale of the change. C3a is an effector in the complement system and has various stimulatory functions on the immune system. The effects related to HL161ANS in clinical chemistry test results consisted of a minimal to mild decrease in total protein concentration in animals administered up to 198.4 mg / kg / once SC or IV on Day 43 of the dosing period. A minimal to moderate decrease in albumin concentration was observed in animals administered more than 50 mg / kg / once SC on Day 16 and / or Day 43 of the dosing period, male animals administered more than 50 mg / kg / once IV, and female animals administered 198.4 mg / kg / once IV. A minimal decrease in globulin concentration was observed in male animals administered 50 or 100 mg / kg / once SC or more than 50 mg / kg / once IV on Day 43 of the dosing period, and female animals administered 50 mg / kg / once SC or IV. Male animals administered 50 mg / kg / once IV showed evidence of reversibility of albumin effects by Day 43 of the dosing period, and evidence of reversibility was shown by Day 22 or 50 of the recovery period for all other effects in clinical chemistry test results for animals administered 198.4 mg / kg / once SC or IV.

[0290] The effects associated with HL161ANS in the hematological test results were minor and consisted of a minimal decrease in the absolute neutrophil count in animals administered 198.4 mg / kg / occasion IV on Day 43 of the dosing period. Such effects showed evidence of reversibility by Day 22 or 50 of the recovery period, except for one male administered 198.4 mg / kg / occasion IV. One female administered 198.4 mg / kg / occasion SC showed a minimal increase in the absolute monocyte count on Day 43 of the dosing period, which correlated with microscopic findings of vascular inflammation and mononuclear cell infiltration. At necropsy at the end stage, microscopic findings associated with HL161ANS of vascular inflammation, which may be related to immune complex-mediated disorders, were observed in the lungs, liver, gallbladder, kidneys, stomach, small and large intestines, tongue, heart, uterus, and subcutaneous injection site E of one female administered 198.4 mg / kg / occasion SC. Further findings in this animal included minor extramedullary hematopoiesis and mild hypertrophy of hepatic Kupffer cells and mild hypertrophy of the pulmonary vascular media. Findings associated with HL161ANS were not observed at necropsy during the recovery period.

[0291] In conclusion, male and female cynomolgus monkeys were administered vehicle control article / diluent or HL161ANS at 50, 100, 198.4 mg / kg / occasion twice a week for 6 weeks by SC and / or IV injection. An increase in C3A level was observed in animals administered 198.4 mg / kg / occasion SC or IV on Day 43 of the dosing period. This finding was reversible during the recovery period. Clinical pathological changes included a slight decrease in total protein concentration in both sexes administered up to 198.4 mg / kg / occasion SC or IV, a minimal to moderate decrease in albumin concentration in both sexes administered 198.4 mg / kg / occasion SC, males administered 50 mg / kg / occasion or more IV, and females administered 198.4 mg / kg / occasion IV, a minimal decrease in globulin concentration in males administered 50 or 100 mg / kg / occasion SC or 50 mg / kg / occasion or more IV and females administered 50 mg / kg / occasion SC or IV, and a minimal decrease in the absolute neutrophil count in both sexes administered 198.4 mg / kg / occasion IV. Such findings were reversible during the recovery period.

[0292] Microscopic findings related to HL161ANS included vascular inflammation in the lungs, liver, gallbladder, kidneys, stomach, small and large intestines, tongue, heart, uterus, and subcutaneous injection site E in one female administered SC at 198.4 mg / kg / time. Findings related to HL161ANS were not observed at necropsy during the recovery period. Due to the systemic nature of the microscopic findings in animals administered SC at 198.4 mg / kg / time, the effects for this dose were determined to be harmful. Since the severity of the findings was mild and there was no impact on the health and well-being of animals administered SC at 100 mg / kg / time or IV at 198.4 mg / kg / time, the effects for such doses were determined to be non-harmful. Therefore, the no-observed-adverse-effect level (NOAEL) was 100 mg / kg / time by SC injection and 198.4 mg / kg / time by IV injection. The SC dose level corresponded to a mean maximum plasma concentration (Cmax) of 964 mg / L observed on Day 43 of the dosing period and an area under the plasma concentration-time curve (AUCtau or AUC0-72) value of 2290 mg / L over the dosing interval on Day 22 of the dosing period (note that the AUC0-72 on Day 43 could not be calculated because necropsy at the end stage was 1 day after the dosing on Day 43). The IV dose level corresponded to a mean maximum plasma concentration (Cmax) of 7100 mg / L observed on Day 43 of the dosing period and an area under the plasma concentration-time curve (AUC tau or AUC 0-72 ) value of 10800 mg×day / L. [Example 15]

[0293] Subcutaneous and / or intravenous injection dose ranges, toxicokinetics, and pharmacodynamics studies to find the toxicity of HL161ANS in cynomolgus monkeys The purpose of this study was to evaluate the toxicity of HL161ANS when administered to cynomolgus monkeys at least 6 weeks by subcutaneous (SC) injection twice a week or intravenous (IV, continuous bolus) injection once a week, and to determine toxicokinetics (TK) and pharmacodynamics (PD).

[0294] Male and female cynomolgus monkeys were assigned to 6 groups and dosed as shown in the following table. The animals were dosed at a volume of 1 mL / kg / time, once or twice a week, by intravenous injection and / or subcutaneous injection. The vehicle control article / diluent was the HL161ANS formulation buffer.

[0295]

Table 25

[0296] Toxicity evaluation was based on mortality, clinical findings, body weight, food intake, skin findings, immunotoxicology, and clinical and anatomical pathology. Blood samples were collected for pharmacokinetic evaluation and anti-drug antibody analysis.

[0297] There were no deaths associated with HL161ANS, and no clinical findings, skin findings, changes in body weight, weight gain, and food intake, organ weight differences, gross findings, or microscopic findings associated with HL161ANS were observed.

[0298] The clinical chemical effects associated with HL161ANS observed in animals dosed at 100 mg / kg / time by IV or SC were limited to a minimal to mild decrease in albumin concentration observed for individual animals. The decrease in albumin was more consistently observed in animals dosed at 100 mg / kg / time by SC from Day 15 or 22 to 50, but this was mainly observed in animals dosed at 100 mg / kg / time by IV on Day 36 and Day 43 of the dosing period. The mechanism of the albumin decrease was unknown.

[0299] As a result, male and female cynomolgus monkeys were administered HL161ANS formulation buffer (vehicle control) subcutaneously twice a week and intravenously once a week, or 3, 10 or 100 mg / kg / time of HL161ANS intravenously once a week, or 100 mg / kg / time of HL161ANS subcutaneously twice a week. The tolerance of HL161ANS was good at all dose levels and all routes of administration. There were no deaths associated with HL161ANS, and no changes in clinical findings, body weight, weight gain, and food intake, organ weight differences, gross findings, and microscopic findings associated with HL161ANS were observed. No clinically pathological effects associated with HL161ANS were observed in animals administered up to 100 mg / kg / time IV. The clinically pathological effects associated with HL161ANS observed in animals administered 100 mg / kg / time SC were limited to a minimal to mild decrease in albumin concentration from Day 15 or 22 to Day 50. Based on such findings, 100 mg / kg / time of HL161ANS, the highest dose level administered intravenously or subcutaneously, was determined to be the maximum tolerated dose (MTD). [Example 16]

[0300] Phase 1 study to evaluate the safety, tolerance, pharmacokinetics, and pharmacodynamics of HL161ANS in healthy participants In this example, a Phase 1 randomized placebo-controlled double-blind sequential parallel group study is described to investigate the safety, tolerance, pharmacokinetics (PK), and pharmacodynamics (PD) of single and multiple escalating doses of HL161ANS in healthy adult male participants and non-childbearing potential (NCBP) adult female participants. Participants participate in one dosing cohort.

[0301] There are six single ascending dose (SAD) cohorts [intravenous (IV) administration of 100 mg, 300 mg, 600 mg, and 1,200 mg; and subcutaneous (SC) administration of 300 mg and 600 mg]. There are two multiple ascending dose (MAD) cohorts [300 mg and 600 mg of SC once weekly (QW)] and optionally two MAD cohorts (150 mg and 450 mg of SC QW). Each MAD cohort receives 4 weeks of administration of HL161ANS or placebo. In each cohort, two sentinel subjects are administered (one active drug and one placebo).

[0302] Each SAD cohort consists of 6 participants by HL161ANS and 2 participants by placebo, and each of the four MAD cohorts consists of 10 participants by HL161ANS and 2 participants by placebo. Thus, this trial has a total of up to 96 participants (76 by HL161ANS and 20 by placebo).

[0303] The selected doses should not exceed a fixed dose of 1,530 mg IV for SAD and 800 mg SC for MAD.

[0304] Participants are screened, eligibility is evaluated, and randomization to the trial is performed. In the SAD cohorts, participants are randomized into six sequential dosing cohorts of 8 participants per cohort. In each SAD cohort, 2 participants are randomized 1:1 and administered HL161ANS or placebo for sentinel dosing, and then, if the tolerability of HL161ANS in each sentinel participant is good, the remaining 6 participants are randomized 5:1 and administered HL161ANS or placebo.

[0305] In the MAD cohort, participants are randomized into up to four sequential cohorts (two planned and two additional as appropriate), with 12 participants per cohort. In each MAD cohort, two participants are randomized 1:1 and administered HL161ANS or placebo as a sentinel dose, and then, if the tolerability of HL161ANS is good in each sentinel participant, the remaining 10 participants are randomized 9:1 and administered HL161ANS or placebo.

[0306] The objectives and evaluation items are shown in Table 25.

[0307]

Table 26

Claims

1. A light chain variable region comprising LCDR1 containing the amino acid sequence of SEQ ID NO: 1, LCDR2 containing the amino acid sequence of SEQ ID NO: 2, and LCDR3 containing the amino acid sequence of SEQ ID NO: 3, and A heavy chain variable region comprising HCDR1 containing the amino acid sequence of SEQ ID NO: 5, HCDR2 containing the amino acid sequence of SEQ ID NO: 6, and HCDR3 containing the amino acid sequence of SEQ ID NO: 7 An anti-FcRn antibody or an antigen-binding fragment thereof, comprising An anti-FcRn antibody or an antigen-binding fragment thereof, wherein the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 is substituted with another amino acid and / or the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 is substituted with another amino acid.

2. The anti-FcRn antibody or an antigen-binding fragment thereof according to claim 1, wherein the amino acid at N3 within the amino acid sequence of SEQ ID NO: 1 is substituted with Ser (S) or Gln (Q).

3. The anti-FcRn antibody or an antigen-binding fragment thereof according to claim 1 or 2, wherein the amino acid at C2 within the amino acid sequence of SEQ ID NO: 5 is substituted with Ser (S) or Tyr (Y).

4. The anti-FcRn antibody or an antigen-binding fragment thereof according to any one of claims 1 to 3, wherein the heavy chain variable region comprises a framework composed of FR1 of the amino acid sequence of SEQ ID NO: 15, FR2 of the amino acid sequence of SEQ ID NO: 16, FR3 of the amino acid sequence of SEQ ID NO: 17, and FR4 of the amino acid sequence of SEQ ID NO:

18.

5. The anti-FcRn antibody or an antigen-binding fragment thereof according to claim 4, wherein the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 is substituted with another amino acid.

6. The anti-FcRn antibody or an antigen-binding fragment thereof according to claim 5, wherein the amino acid at Q16 within the amino acid sequence of SEQ ID NO: 17 is substituted with Glu (E).

7. An anti-FcRn antibody or an antigen-binding fragment thereof, comprising a light chain variable region containing the amino acid sequence of SEQ ID NO: 4 and a heavy chain variable region containing the amino acid sequence of SEQ ID NO: 8, An anti-FcRn antibody or an antigen-binding fragment thereof, wherein the amino acid at N25 within the amino acid sequence of SEQ ID NO: 4 is substituted with another amino acid, and the amino acid at C32 or Q82 within the amino acid sequence of SEQ ID NO: 8 is substituted with another amino acid.

8. The anti-FcRn antibody or antigen-binding fragment thereof according to claim 7, wherein the amino acid at N25 in the amino acid sequence of SEQ ID NO: 4 is substituted with Ser (S) or Gln (Q). **Claim 9** The anti-FcRn antibody or antigen-binding fragment thereof according to claim 7 or 8, wherein the amino acid at C32 in the amino acid sequence of SEQ ID NO: 8 is substituted with Ser (S) or Tyr (Y). **Claim 10** The anti-FcRn antibody or antigen-binding fragment thereof according to any one of claims 7 to 9, wherein the amino acid at Q82 in the amino acid sequence of SEQ ID NO: 8 is substituted with Glu (E). **Claim 11** A light chain variable region comprising LCDR1 containing the amino acid sequence of SEQ ID NO: 9, LCDR2 containing the amino acid sequence of SEQ ID NO: 2, and LCDR3 containing the amino acid sequence of SEQ ID NO: 3, and A heavy chain variable region comprising HCDR1 containing the amino acid sequence of SEQ ID NO: 11, HCDR2 containing the amino acid sequence of SEQ ID NO: 6, and HCDR3 containing the amino acid sequence of SEQ ID NO: 7 The anti-FcRn antibody or antigen-binding fragment thereof comprising the same. **Claim 12** The anti-FcRn antibody according to any one of claims 1 to 11, wherein the anti-FcRn antibody comprises an Fc region, and the Fc region is an IgG1 Fc region or an IgG4 Fc region. **Claim 13** The anti-FcRn antibody according to claim 12, wherein the Fc region is an IgG1 Fc region containing amino acid substitutions of Leu234Ala and Leu235Ala. **Claim 14** A polynucleotide encoding the anti-FcRn antibody or antigen-binding fragment thereof according to any one of claims 1 to 13. **Claim 15** A recombinant expression vector comprising the polynucleotide according to claim 14. **Claim 16** A host cell transformed with the recombinant expression vector according to claim 15. **Claim 17** Culturing the host cell according to claim 16 to produce an antibody, and Isolating and purifying the produced antibody to recover an antibody specifically binding to FcRn A method for producing an anti-FcRn antibody or antigen-binding fragment thereof comprising the same. **Claim 18** A pharmaceutical composition comprising the anti-FcRn antibody or antigen-binding fragment thereof according to any one of claims 1 to 13 and a pharmaceutically acceptable carrier. **Claim 19** A pharmaceutical composition for treating an autoimmune disease, comprising the anti-FcRn antibody or antigen-binding fragment thereof according to any one of claims 1 to 13. **Claim 20** The pharmaceutical composition according to claim 19, wherein the autoimmune disease is selected from the group consisting of autoimmune neutropenia, Guillain-Barré syndrome, epilepsy, autoimmune encephalitis, Isaac's syndrome, phakomatosis, pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, acquired epidermolysis bullosa, pemphigoid gestationis, mucous membrane pemphigoid, antiphospholipid syndrome, autoimmune anemia, autoimmune Graves' disease, thyroid eye disease (TED), Goodpasture's syndrome, myasthenia gravis, multiple sclerosis, rheumatoid arthritis, lupus, idiopathic thrombocytopenic purpura (ITP), warm autoimmune hemolytic anemia (WAHA), chronic inflammatory demyelinating polyneuropathy (CIDP), lupus nephritis, and membranous nephropathy.

21. A method for treating an autoimmune disease in a subject in need thereof, comprising administering to the subject an anti-FcRn antibody or an antigen-binding fragment thereof according to any one of claims 1 to 13 or a pharmaceutical composition according to any one of claims 18 to 20, wherein the subject may be human.

22. The method according to claim 21, wherein the autoimmune disease is selected from the group consisting of autoimmune neutropenia, Guillain-Barré syndrome, epilepsy, autoimmune encephalitis, Isaac's syndrome, phakomatosis, pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, acquired epidermolysis bullosa, pemphigoid gestationis, mucous membrane pemphigoid, antiphospholipid syndrome, autoimmune anemia, myasthenia gravis, autoimmune Graves' disease, thyroid eye disease (TED), Goodpasture's syndrome, multiple sclerosis, rheumatoid arthritis, lupus, idiopathic thrombocytopenic purpura (ITP), warm autoimmune hemolytic anemia (WAHA), chronic inflammatory demyelinating polyneuropathy (CIDP), lupus nephritis, and membranous nephropathy.

23. The method according to claim 21 or 22, wherein the administration is parenteral administration.

24. The method according to claim 23, wherein the administration is subcutaneous or intravenous administration.

25. The method according to any one of claims 21 to 24, wherein the administration is at a dose of 300 mg to 2400 mg.

26. The method according to any one of claims 21 to 24, wherein the administration is once a week, once every two weeks, once every three weeks, or once a month.

27. The method according to any one of claims 21 to 26, wherein the administration is once-weekly subcutaneous administration at a dose of 300 mg to 900 mg.

28. The method according to any one of claims 21 to 26, wherein the administration is subcutaneous administration once every two weeks at a dose of 300 mg to 1800 mg.

29. The method according to any one of claims 21 to 28, wherein administration does not result in a decrease in the blood albumin level in the subject that exceeds 5% or exceeds 10% compared to the blood albumin level before administration of the anti-FcRn antibody or antigen-binding fragment.

30. The method according to any one of claims 21 to 29, wherein administration does not result in an increase in the total blood cholesterol or LDL level in the subject that exceeds 5% or exceeds 10% compared to the total blood cholesterol or LDL level before administration of the anti-FcRn antibody or antigen-binding fragment.

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