Fcrn antagonist molecules and methods of use thereof

Abstract

The present application relates to FCRN antagonist molecules and methods of use thereof. The present disclosure provides populations of FcRn antagonist molecules, mixtures of these populations, and methods of using these populations to reduce serum IgG autoantibody levels in a subject.

Description

[0001] This application is a divisional application of Chinese patent application No. 202380082826.4 entitled "FCRN antagonist molecule and method of use thereof". The original application was PCT international application PCT / IB2023 / 000696 filed on November 14, 2023, which entered the Chinese national phase on May 30, 2025.

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 383,599, filed November 14, 2022, the entire contents of each of which are hereby incorporated herein by reference.

[0004] References to sequence lists

[0005] This application contains a sequence list which has been electronically submitted in ST.26 format and is hereby incorporated in its entirety by reference (the ST.26 version created on 7 November 2023 is named "404373_T2213WO.xml" and is 39,782 bytes in size). Technical Field

[0006] This disclosure relates to FcRn antagonist molecules, compositions comprising such FcRn antagonist molecules, and methods for using these FcRn antagonist molecules and compositions to reduce serum IgG antibody (e.g., autoantibody) levels in subjects. Background Technology

[0007] It is estimated that more than 2.5% of the population is affected by autoantibody-driven autoimmune diseases in which autoreactive antibodies are directly pathogenic. The serum half-life of IgG is prolonged relative to that of other plasma proteins (Roopenian et al., J. Immunology 170:3528 (2003); Junghans and Anderson, Proc. Natl. Acad. Sci. USA 93:5512 (1996)). This long half-life is partly attributed to the binding of the Fc region of IgG to the Fc receptor FcRn. Although FcRn was initially characterized as a neonatal transport receptor for maternal IgG, it also plays a protective role against IgG degradation in adults. FcRn binds to pinocytocytotic IgG and protects IgG from transport to degrading lysosomes by recycling IgG back to the extracellular compartment. The pH-dependent binding of IgG to FcRn promotes this recycling, with the IgG / FcRn interaction being stronger at acidic endosome pH than at extracellular physiological pH.

[0008] When serum IgG concentrations exceed the levels of available FcRn molecules, unbound IgG is not protected against degradation mechanisms and therefore has a reduced serum half-life. Therefore, inhibiting IgG binding to FcRn reduces the serum half-life of IgG by preventing IgG endosome recycling. Consequently, agents that antagonize IgG binding to FcRn can be used to regulate, treat, or prevent antibody-mediated disorders such as autoimmune diseases and inflammatory diseases.

[0009] There is a need in the field for agents that antagonize the binding of FcRn to IgG for use in the treatment of antibody-mediated diseases. Summary of the Invention

[0010] This disclosure relates to novel FcRn antagonist molecules, compositions comprising these FcRn antagonist molecules, and methods for reducing serum IgG antibody (e.g., autoantibodies) levels in subjects using these FcRn antagonist molecules and compositions. This document also provides nucleic acids encoding FcRn antagonist molecules, as well as vectors, host cells, methods of manufacture, and methods for using them to treat IgG antibody-mediated disorders. The FcRn antagonist molecules provided herein are particularly advantageous because they all rapidly reduce serum IgG antibody levels in subjects and exhibit long-term stability in aqueous formulations.

[0011] This disclosure provides a composition comprising a population of FcRn antagonist molecules, wherein at least a portion of the FcRn antagonist molecules in the population comprises a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are as defined in SEQ ID NO: 1, provided that the population is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 2, 3, 20, or 21. In some embodiments, each FcRn antagonist molecule in the population comprises a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are as defined in SEQ ID NO: 1.

[0012] In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:3 and SEQ ID NO:12, respectively. In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:3 and SEQ ID NO:9, respectively. In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:2 and SEQ ID NO:3, respectively. In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:3 and SEQ ID NO:6, respectively.

[0013] In some embodiments, the amino acid sequence of the first Fc domain consists of any one of SEQ ID NO: 2-22, and the amino acid sequence of the second Fc domain consists of any one of SEQ ID NO: 2-22. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 5. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 6. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 7. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 8. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 9. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 10. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 11. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 12. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 13. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 14. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 15. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 16. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 17. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 18. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 19. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 22.

[0014] In some embodiments, the group comprises: a first subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the first subgroup are composed of SEQ ID NO: 3; and at least one of the following: a second subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the second subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 12, respectively; a third subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the third subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively; and a fourth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the fourth subgroup are composed of SEQ ID NO: 3; The FcRn antagonist molecules are composed of three groups, wherein two asparagine residues in each FcRn antagonist molecule in the fourth subgroup are deaminoked; the FcRn antagonist molecules are composed of a fifth subgroup, wherein the amino acid sequences of the first and second Fc domains of the FcRn antagonist molecules in the fifth subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively, and one asparagine residue in each FcRn antagonist molecule in the fifth subgroup is deaminoked; the FcRn antagonist molecules are composed of a sixth subgroup, wherein the amino acid sequences of the first and second Fc domains of the FcRn antagonist molecules in the sixth subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively; the FcRn antagonist molecules are composed of a seventh subgroup, wherein the amino acid sequences of the first and second Fc domains of the FcRn antagonist molecules in the seventh subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 9, respectively. The FcRn antagonist molecules are composed of three groups, wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the seventh subgroup is oxidized; the FcRn antagonist molecules are composed of an eighth subgroup, wherein the amino acid sequences of both the first and second Fc domains of the FcRn antagonist molecules in the eighth subgroup are composed of SEQ ID NO: 2; the FcRn antagonist molecules are composed of a ninth subgroup, wherein the amino acid sequences of the first and second Fc domains of the FcRn antagonist molecules in the ninth subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 6, respectively; and the FcRn antagonist molecules are composed of a tenth subgroup, wherein the amino acid sequences of the first and second Fc domains of the FcRn antagonist molecules in the tenth subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the tenth subgroup is oxidized;And the eleventh subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first and second Fc domains of the FcRn antagonist molecules in the eleventh subgroup consist of SEQ ID NO: 3, and wherein two amino acid residues independently selected from methionine and tryptophan are oxidized in each FcRn antagonist molecule in the eleventh subgroup.

[0015] In some embodiments, the group includes 2, 3, 4, 5, 6, 7, 8, 9, 10, or all of the aforementioned subgroups. In some embodiments, the group includes the seventh subgroup, the ninth subgroup, or the eleventh subgroup. In some embodiments, the group includes the seventh subgroup, the ninth subgroup, and the eleventh subgroup.

[0016] In some embodiments, the first subgroup constitutes at least 55% of the population, optionally 60% to 70% of the population. In some embodiments, the second subgroup constitutes no more than 2.5% of the population, optionally 1% to 2.5% of the population. In some embodiments, the third subgroup constitutes no more than 2.5% of the population, optionally 1% to 2.5% of the population. In some embodiments, the fourth subgroup constitutes no more than 5% of the population, optionally 2% to 5% of the population. In some embodiments, the fifth subgroup constitutes no more than 10% of the population, optionally 7% to 10% of the population. In some embodiments, the sixth subgroup constitutes no more than 20% of the population, optionally 7% to 14% of the population. In some embodiments, the seventh subgroup constitutes no more than 6% of the population, optionally 1.5% to 2.5% of the population. In some embodiments, the eighth subgroup constitutes no more than 8% of the population, optionally 3.5% to 7.5% of the population. In some embodiments, the ninth subgroup constitutes no more than 3.5% of the population, optionally 0.5% to 3.5% of the population. In some embodiments, the tenth subgroup does not exceed 1% of the population. In some embodiments, the eleventh subgroup does not exceed 1% of the population.

[0017] In some embodiments, at least 97%, optionally 97% to 99%, of the Fc domains in the population contain N-glycans at EU position 297. In some embodiments, at least 50%, optionally 50% to 70%, of the Fc domains in the population contain G0F N-glycans at EU position 297. In some embodiments, at least 20%, optionally 20% to 30%, of the Fc domains in the population contain G1F N-glycans at EU position 297. In some embodiments, at least 5%, optionally 8% to 10%, of the Fc domains in the population contain G2F N-glycans at EU position 297. In some embodiments, at least 2%, optionally 2% to 5%, of the Fc domains in the population contain G0 N-glycans at EU position 297.

[0018] In some embodiments, at least 40%, optionally 40% to 55% of the population includes a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G0F N-glycan at EU position 297. In some embodiments, at least 20%, optionally 20% to 25% of the population includes a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G1F N-glycan at EU position 297. In some embodiments, at least 10%, optionally 10% to 15% of the population includes a first Fc domain containing G1F N-glycan at EU position 297 and a second Fc domain containing G1F N-glycan at EU position 297, or a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297. In some embodiments, at least 5%, optionally 5% to 10%, of the population includes a first Fc domain containing G1F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297. In some embodiments, at least 2%, optionally 2% to 4%, of the population includes a first Fc domain containing G2F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297. In some embodiments, at least 4%, optionally 4% to 6%, of the population includes a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G0 N-glycan at EU position 297.

[0019] This disclosure also provides a composition comprising an FcRn antagonist molecule, the FcRn antagonist molecule being composed of a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 1, and wherein at least one Fc domain comprises G0F N-glycan at EU position 297, G1F N-glycan at EU position 297, G2F N-glycan at EU position 297, or G0 N-glycan at EU position 297.

[0020] In some embodiments, the first Fc domain contains a GOF N-glycan at EU position 297, and the second Fc domain contains a GOF N-glycan at EU position 297. In some embodiments, the first Fc domain contains a GOF N-glycan at EU position 297, and the second Fc domain contains a G1F N-glycan at EU position 297. In some embodiments, the first Fc domain contains a GOF N-glycan at EU position 297, and the second Fc domain contains a G2F N-glycan at EU position 297. In some embodiments, the first Fc domain contains a G1F N-glycan at EU position 297, and the second Fc domain contains a G1F N-glycan at EU position 297. In some embodiments, the first Fc domain contains a G2F N-glycan at EU position 297, and the second Fc domain contains a G2F N-glycan at EU position 297. In some embodiments, the first Fc domain contains a GOF N-glycan at EU position 297, and the second Fc domain contains a GO N-glycan at EU position 297. In some embodiments, the first Fc domain contains a GO N-glycan at EU position 297, and the second Fc domain contains a GON-glycan at EU position 297. In some embodiments, the first Fc domain contains a G1F N-glycan at EU position 297, and the second Fc domain contains a G2F + NANA N-glycan at EU position 297. In some embodiments, the first Fc domain contains a G2F N-glycan at EU position 297, and the second Fc domain contains a G2F + 2 x NANA N-glycan at EU position 297.

[0021] In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:3 and SEQ ID NO:12, respectively. In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:3 and SEQ ID NO:9, respectively. In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:2 and SEQ ID NO:3, respectively. In some embodiments, the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:3 and SEQ ID NO:6, respectively.

[0022] In some embodiments, the amino acid sequence of the first Fc domain consists of any one of SEQ ID NO: 2-22, and the amino acid sequence of the second Fc domain consists of any one of SEQ ID NO: 2-22. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 2. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 3. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 4. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 5. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 6. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 7. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain consist of SEQ ID NO: 8. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 9. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 10. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 11. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 12. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 13. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 14. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 15. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 16. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 17. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 18. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 19. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 20.In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 21. In some embodiments, the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 22.

[0023] In some embodiments, at least 85%, optionally 85% to 95%, of the Fc domains in the population are deficient in an amino acid at EU position 441. In some embodiments, no more than 15%, optionally 5% to 15%, of the Fc domains in the population have glycine and lysine at EU positions 440 and 441, respectively. In some embodiments, no more than 1% of the Fc domains in the population are deficient in an amino acid at EU positions 440 and 441, and contain amidated proline at EU position 439.

[0024] In some embodiments, at least 95%, optionally 95% to 99%, of the Fc domains in the population contain aspartic acid, lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 221, 222, 223, 224, 225, and 226, respectively. In some embodiments, no more than 1% of the Fc domains in the population are deficient in amino acids at EU position 221 and contain lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 222, 223, 224, 225, and 226, respectively. In some embodiments, no more than 1% of the Fc domains in the population are deficient in amino acids at EU positions 221 and 222 and contain threonine, histidine, threonine, and cysteine ​​at EU positions 223, 224, 225, and 226, respectively. In some embodiments, no more than 2% of the Fc domains in the population are deficient in amino acids at EU positions 221 to 224 and contain threonine and cysteine ​​at EU positions 225 and 226, respectively. In some embodiments, no more than 1% of the Fc domains in the population are deficient in amino acids at EU positions 221, 222, 223, 224, 225 and 226.

[0025] In some embodiments, no more than 1% of the Fc domains in the population are isomerized with aspartic acid at EU position 280 or 401. In some embodiments, no more than 10% of the Fc domains in the population are deamidated with asparagine at EU position 384, 389, or 390. In some embodiments, no more than 3% of the Fc domains in the population are deamidated with asparagine at EU position 315. In some embodiments, no more than 3% of the Fc domains in the population are deamidated with asparagine at EU position 361. In some embodiments, no more than 1% of the Fc domains in the population are deamidated with asparagine at EU position 276 or 286. In some embodiments, no more than 5% of the Fc domains are oxidized with methionine at EU position 428. In some embodiments, no more than 1% of the Fc domains are amidated with proline at EU position 445. In some embodiments, no more than 1% of the Fc domains are oxidized with tryptophan at EU position 277.

[0026] In some embodiments, no more than 0.5% of the FcRn antagonist molecules in the population are aggregated. In some embodiments, at least 95%, optionally at least 99%, of the dimers in the population are linked by at least one disulfide bond. In some embodiments, the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is 54 to 56 kDa, optionally 54.4 to 54.7 kDa. In some embodiments, the percentage of free thiol groups in the population is no more than 1%.

[0027] In some embodiments, at least 35%, optionally 35% to 55%, of the Fc domains in the population comprises galactose. In some embodiments, at least 90%, optionally 90% to 98%, of the Fc domains in the population comprises fucose. In some embodiments, at most 1.5%, optionally 0.5% to 1.5%, of the Fc domains in the population comprises sialic acid.

[0028] In some embodiments, the composition described above or herein comprises an aqueous solution containing about 25 mM sodium phosphate, about 100 mM sodium chloride, about 150 mM L-arginine, and about 0.02% (w / v) polysorbate 80, wherein the composition has a pH of about 6.7. In some embodiments, the composition comprises a population of 20 mg / ml of FcRn antagonist molecules.

[0029] In some embodiments, the composition described above or herein comprises an aqueous solution containing about 4 mM sodium phosphate, about 146 mM sodium chloride, about 24 mM L-arginine, and about 0.0032% (w / v) polysorbate 80, wherein the composition has a pH of about 6.7. In some embodiments, the composition comprises a population of about 3.2 mg / ml of FcRn antagonist molecules.

[0030] In some embodiments, the composition described above or herein comprises an aqueous solution containing about 20 mM L-histidine, about 100 mM sodium chloride, about 60 mM sucrose, about 10 mM L-methionine, and about 0.04% (w / v) polysorbate 20, wherein the composition has a pH of about 6.0. In some embodiments, the composition comprises a population of about 180 mg / ml of FcRn antagonist molecules.

[0031] In some embodiments, the composition described above or herein comprises an aqueous solution containing about 20 mM L-histidine, about 50 mM M-arginine, about 100 mM sodium chloride, about 60 mM sucrose, about 10 mM L-methionine, and about 0.04% (w / v) polysorbate 80, wherein the composition has a pH of about 6.0. In some embodiments, the composition comprises a population of about 200 mg / ml of FcRn antagonist molecules.

[0032] This disclosure also provides an FcRn antagonist molecule comprising a variant Fc region containing a homodimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first and second Fc domains are composed of either SEQ ID NO: 5-20 and 22. This disclosure also provides a polynucleotide encoding an FcRn antagonist molecule. This disclosure also provides a vector comprising the polynucleotide. This disclosure also provides a cell comprising the polynucleotide. This disclosure also provides a method for preparing an FcRn antagonist molecule, the method comprising culturing the cells described above and herein under conditions that express the polynucleotide described above and herein and produce the FcRn antagonist molecule. In some embodiments, the method further includes isolating the FcRn antagonist molecule from the cells.

[0033] This disclosure also provides a method comprising mixing the compositions, FcRn antagonists, polynucleotides, carriers, or cells provided above and herein with one or more pharmaceutically acceptable excipients.

[0034] This disclosure also provides a method for reducing serum IgG autoantibody levels in a subject, the method comprising administering to the subject any one or more of the compositions provided above and herein, any one or more of the FcRn antagonists provided above and herein, any one or more of the polynucleotides provided above and herein, any one or more of the vectors provided above and herein, or any one or more of the cells provided above and herein.

[0035] This disclosure also provides a method for treating an autoimmune disease in a subject, the method comprising administering to the subject any one or more of the compositions provided above and herein, any one or more of the FcRn antagonists provided above and herein, any one or more of the polynucleotides provided above and herein, any one or more of the carriers provided above and herein, or any one or more of the cells provided above and herein.

[0036] This disclosure also provides any one or more of the compositions described above and herein, any one or more of the FcRn antagonists described above and herein, any one or more of the polynucleotides described above and herein, any one or more of the vectors described above and herein, or any one or more of the cells described above and herein, for use in the treatment of autoimmune diseases.

[0037] This disclosure also provides for use in treating autoimmune diseases by any one or more of the compositions described above and herein, any one or more of the FcRn antagonists described above and herein, any one or more of the polynucleotides described above and herein, any one or more of the vectors described above and herein, or any one or more of the cells described above and herein.

[0038] This disclosure also provides any one or more of the compositions described above and herein, any one or more of the FcRn antagonists described above and herein, any one or more of the polynucleotides described above and herein, any one or more of the carriers described above and herein, or any one or more of the cells described above and herein, for use in the manufacture of medicaments for treating autoimmune diseases.

[0039] This disclosure also provides any one or more of the compositions described above and herein, any one or more of the FcRn antagonists described above and herein, any one or more of the polynucleotides described above and herein, any one or more of the carriers described above and herein, or any one or more of the cells described above and herein, for use in medicine. Attached Figure Description

[0040] Figure 1 Chromatograms of cation exchange high-performance liquid chromatography (CEXHPLC) fractionation of FcRn antagonist reference standards batches 2 and 3 were plotted. In each case, absorbance (AU) at 220 nm was plotted against relative column retention time.

[0041] Figure 2Chromatograms of FcRn antagonist fractions produced from the ARFCB11 cell line, depicting a population of FcRn antagonist molecules, were plotted using CEXHPLC. In each case, absorbance at 220 nm (AU) was plotted against relative column retention time.

[0042] Figure 3 Chromatograms depicting the imaging capillary isoelectric focusing (icIEF) results of reference standard batches 2 and 3 are presented.

[0043] Figure 4 A line graph depicting the area under the curve (AUC) of charged variant 4 at -70°C, +5°C, and +25°C as a function of storage time (in months) is presented.

[0044] Figure 5 Line graphs depicting the area under the curve (AUC) of charged variant 5 at -70°C, +5°C, and +25°C as a function of storage time (in months) are presented.

[0045] Figure 6 A line graph depicting the area under the curve (AUC) of charged variant 9 at -70°C, +5°C, and +25°C as a function of storage time (in months) is presented.

[0046] Figure 7 Line graphs depicting the area under the curve (AUC) of charged variant 11 at -70°C, +5°C, and +25°C as a function of storage time (in months) are presented.

[0047] Figure 8 A line graph depicting the area under the curve (AUC) of charged isomer 1 at -70°C, +5°C, and +25°C as a function of storage time (in months) is presented.

[0048] Figure 9 A line graph depicting the area under the curve (AUC) of charged isomer 2 at -70°C, +5°C, and +25°C as a function of storage time (in months) is presented.

[0049] Figure 10 A hydrophilic interaction liquid chromatography (HILIC) chromatogram of a reference sample labeled with 2-aminobenzamide (2-AB) is depicted.

[0050] Figure 11 Depicting Figure 10 An enlarged version of a portion of it.

[0051] Figure 12 A bar graph depicting the relative percentage intensity of 2-AB labeled glycans in the reference sample was plotted.

[0052] Figure 13 A bar chart depicting the relative percentage intensity of galactosylation, fucosylation, and sialylation in the reference sample was created.

[0053] Figure 14 A set of absorbance plots depicting the 214 nm spectra of reversed-phase liquid chromatography (RPLC-UV) with UV detection are presented, showing the electrospray ionization mass spectrometry (ESI-MS) results of reference standards batches 1, 2, and 3.

[0054] Figure 15 The deconvolution spectrum of the main peak observed in the RPLC-UV 214 nm spectrum of the reference sample is depicted, with the sugar forms of sample batches 1, 2 and 3 marked.

[0055] Figure 16 A bar graph depicting the N-glycosylation of sample batches 1, 2, and 3 is presented.

[0056] Figure 17 Gel permeation high performance liquid chromatography (GP-HPLC) spectra of reference standard batches 2 and 3 were depicted.

[0057] Figure 18 Non-reducing capillary electrophoresis spectra of sodium dodecyl sulfate (CE-SDS) for reference standards batches 2 and 3 were depicted. Detailed Implementation Plan

[0058] This disclosure provides FcRn antagonist molecules and compositions comprising these FcRn antagonist molecules. The FcRn antagonist molecules and compositions provided herein are capable of reducing serum levels of IgG antibodies (e.g., IgG autoantibodies) in a subject. This disclosure also provides nucleic acids encoding FcRn antagonist molecules, as well as vectors, host cells, methods of manufacture, and methods for using them to treat IgG antibody-mediated disorders.

[0059] definition

[0060] As used herein, the term "FcRn" refers to the neonatal Fc receptor. Exemplary FcRn molecules include human FcRn encoded by the FCGRT gene, as shown in RefSeqNM 004107. The amino acid sequence of the corresponding protein is shown in RefSeq NP_004098.

[0061] As used herein, the term "FcRn antagonist molecule" refers to any agent that specifically binds to an FcRn and inhibits the binding of immunoglobulins to the FcRn (e.g., human FcRn). In one embodiment, an FcRn antagonist comprises an Fc region (e.g., a variant Fc region disclosed herein) that specifically binds to an FcRn and inhibits the binding of IgG to the FcRn. In one embodiment, an FcRn antagonist is not a full-length IgG antibody. In one embodiment, an FcRn antagonist comprises an antigen-binding domain that binds to a target antigen and a variant Fc region. In one embodiment, the term "FcRn antagonist molecule" refers to an antibody or an antigen-binding fragment thereof that specifically binds to an FcRn via its antigen-binding domain and / or via its Fc region and inhibits the binding of immunoglobulins (e.g., IgG autoantibodies) to the FcRn.

[0062] As used in this article, the term “affinity” or “binding affinity” refers to the strength of the binding interaction between two molecules.

[0063] As used herein, the term "specific binding" refers to the ability of any molecule to preferentially bind to a given target. For example, a molecule that specifically binds to a given target can bind to other molecules, typically with lower affinity, as demonstrated by, for example, immunoassays or BIAcore. TM The determination is made by a KinExA 3000 instrument (Sapidyne Instruments, Boise, Id.) or other assays known in the art. In one specific embodiment, the KD of a molecule that specifically binds to a given target bound to an antigen is at least 2, 2.5, 3, 4, or less lower than the KD of the molecule when it nonspecifically binds to another target.

[0064] As used herein, the term "operably linked" refers to the connection of polynucleotide sequence elements in a functional relationship. For example, a polynucleotide sequence is operably linked when it is placed in a functional relationship with another polynucleotide sequence. In some embodiments, a transcriptionally regulatory polynucleotide sequence (e.g., a promoter, enhancer, or other expression control element) that influences the transcription of a protein-coding polynucleotide sequence is operably linked to that protein-coding polynucleotide sequence. Operablely linked elements can be contiguous or discontinuous.

[0065] As used herein, the term "link" refers to a physical connection (e.g., direct or indirect) between amino acid sequences (e.g., different segments, regions, or domains). The linked regions, domains, and segments of the FcRn antagonist molecules of this disclosure can be continuous or discontinuous (e.g., connected to each other via linkers). In some embodiments, the link is covalent. In some embodiments, the link is non-covalent.

[0066] As used herein, the term "covalent link" refers to the connection of two molecules or chemical parts by a covalent bond. In some embodiments, the covalent bond is a peptide bond or a disulfide bond. As used herein, the term "fusion" refers to the connection of two peptides by a peptide bond or peptide linker. In some embodiments, two proteins are fused together directly and sequentially by a peptide bond. In some embodiments, two proteins are fused indirectly and discontinuously by a peptide linker. In some embodiments, one protein is fused to a peptide linker by a peptide bond at a first position, and a second protein is fused to a peptide linker by a peptide bond at a second position. As used herein, the term "non-covalent link" refers to the connection of two molecules or chemical parts by a non-covalent interaction or bond. In some embodiments, non-covalent interactions or bonds include hydrogen bonds, electrostatic bonds or interactions, halogen bonds, π stacking, and van der Waals interactions.

[0067] As used herein, the terms “antibody” and “antibodies” include full-length antibodies, antigen-binding fragments of full-length antibodies, and molecules containing antibody CDRs, VH regions, or VL regions. Examples of antibodies include monoclonal antibodies, recombinant antibodies, monospecific antibodies, multispecific antibodies (including bispecific antibodies), human antibodies, humanized antibodies, chimeric antibodies, immunoglobulins, synthetic antibodies, tetrameric antibodies comprising two heavy chain and two light chain molecules, antibody light chain monomers, antibody heavy chain monomers, antibody light chain dimers, antibody heavy chain dimers, antibody light chain-antibody heavy chain pairs, intracellular antibodies, heteroconjugated antibodies, antibody-drug conjugates, single-domain antibodies (sdAbs), monovalent antibodies, single-chain antibodies or single-chain Fvs (scFvs), camel antibodies, single-domain antibodies (sdAbs), humanized antibodies, affinity molecules, VHH fragments, Fab fragments, F(ab')2 fragments, disulfide-linked Fvs (sdFvs), anti-individual genotype (anti-Id) antibodies (including, for example, anti-anti-Id antibodies), and antigen-binding fragments of any of the above. Antibodies can be any isotype (e.g., IgG, IgE, IgM, IgD, IgA, or IgY), any subclass (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, or IgA2), or species (e.g., mouse IgG2a or IgG2b) of immunoglobulin molecules.

[0068] As used herein, the term "Fc region" refers to the portion of an immunoglobulin formed by the Fc domains of its two heavy chains. The Fc region can be a wild-type Fc region (natural Fc region) or a variant Fc region. Natural Fc regions are homodimers. Fc regions can be derived from any natural immunoglobulin. In some embodiments, the Fc region is formed by the constant region of the IgA, IgD, IgE, or IgG heavy chain. In some embodiments, the Fc region is formed by the constant region of the IgG heavy chain. In some embodiments, the IgG heavy chain is the constant region of the IgG1, IgG2, IgG3, or IgG4 heavy chain. In some embodiments, the Fc region is formed by the constant region of the IgG1 heavy chain. In some embodiments, the IgG1 heavy chain constant region comprises allotypes of G1m1(a), G1m2(x), G1m3(f), or G1m17(z). See, for example, Jefferis and Lefranc, (2009) mAbs 1(4): 332-338, and de Taeye et al., (2020) Front Immunol.11:740, which are incorporated herein by reference in their entirety.

[0069] As used herein, the term "variant Fc region" refers to a variant of an Fc region that has one or more alterations relative to a native Fc region. Alterations may include amino acid substitutions, additions and / or deletions, the linking of additional moieties, and / or changes to the native glycan. The term encompasses heterodimeric Fc regions where each of the constitutive Fc domains is distinct. The term also encompasses single-chain Fc regions where the constitutive Fc domains are linked together by linker sites.

[0070] As used herein, the term "Fc domain" refers to a portion of a single immunoglobulin heavy chain that includes both the CH2 and CH3 domains of an antibody. In some embodiments, the Fc domain includes at least a portion of a hinge region (e.g., upper, middle, and / or lower hinge regions), a CH2 domain, and a CH3 domain. In some embodiments, the Fc domain does not include a hinge region.

[0071] As used herein, the term "hinge region" refers to the portion of a heavy chain molecule that joins the CH1 and CH2 domains. In some embodiments, the hinge region is up to 70 amino acid residues long. In some embodiments, the hinge region contains approximately 11 to 17 amino acid residues and is flexible, thus allowing the two N-terminal antigen-binding regions to move independently. In some embodiments, the hinge region is 12 amino acids long. In some embodiments, the hinge region is 15 amino acids long. In some embodiments, the hinge region is 62 amino acids long. The hinge region can be subdivided into three distinct domains: upper, middle, and lower hinge domains. The FcRn antagonist molecules of this disclosure may include all or any portion of the hinge region. In some embodiments, the hinge region is derived from an IgG1 antibody. In some embodiments, the hinge region comprises the amino acid sequence of EPKSCDKTHTCPPCP (SEQ ID NO: 23).

[0072] As used herein, the term “EU position” refers to the amino acid position of the Fc region in the EU numbering convention as described in Edelman, GM et al., Proc. Natl. Acad. USA, 63, 78-85 (1969) and Kabat et al., “Sequences of Proteins of Immunological Interest,” US Dept. Health and Human Services, 5th edition, 1991.

[0073] As used herein, the term "antibody-mediated disorder" refers to any disorder in which the symptoms of the disorder are caused by abnormal levels of one or more antibodies in the subject's body. As used herein, the term "autoantibody-mediated disorder" refers to any disease or disorder in which the underlying pathology is at least in part caused by pathogenic IgG autoantibodies.

[0074] As used herein, the terms “treat,” “treating,” and “treatment” refer to the therapeutic or preventative measures described herein. A method of “treatment” involves administering a peptide to a subject who has a disease or disorder or is susceptible to such a disease or disorder, in order to prevent, cure, delay, or relapse the disease or disorder, reduce its severity, or improve one or more of its symptoms, or to extend the subject’s survival beyond what would be expected in the absence of such treatment.

[0075] As used in this article, the term "effective amount" in the context of administering a therapy to a subject refers to the amount of therapy required to achieve the desired preventive or therapeutic effect.

[0076] As used herein, the term “dosage” or “administration” refers to the amount of a drug administered to a subject in a single administration.

[0077] As used herein, the terms “subject” or “patient” or “participant” include any human or non-human animal. In one embodiment, the subject or patient or participant is a human or non-human mammal. In another embodiment, the subject or patient or participant is a human.

[0078] As used herein, the terms “about” or “approximately” when referring to measurable values ​​(such as doses) cover a variation of ±5% of a given value or range.

[0079] As used herein, the term "molecular weight" can refer to either "predicted molecular weight" or "observed molecular weight." The "predicted molecular weight" of a protein is the sum of the molecular weights of all the amino acids in the protein. In some cases, the "predicted molecular weight" may differ from the "observed molecular weight" of the molecule. In some embodiments, these differences can occur in the protein due to changes in glycosylation, glycation, ubiquitination, phosphorylation, or protein cleavage of the protein or a complex of another protein with a given protein.

[0080] FcRn antagonist molecules

[0081] The FcRn antagonist molecules disclosed herein contain or consist of at least one Fc domain, which contains or consists of the amino acid sequence of SEQ ID NO:1 provided below.

[0082] Table 1

[0083]

[0084] In some embodiments, the FcRn antagonist molecule disclosed herein comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 1.

[0085] This disclosure also provides a population of FcRn antagonist molecules, wherein the FcRn antagonist molecules in the population comprise or consist of a variant Fc region comprising or consist of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or consist of the amino acid sequence of SEQ ID NO: 1, provided that the population is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first Fc domain and the second Fc domain comprise or consist of the amino acid sequences of SEQ ID NO: 2, 3, 20 or 21 as listed in Table 2.

[0086] Table 2

[0087]

[0088] In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identical to or constitutes the amino acid sequence of the variant Fc region, the variant Fc region comprising or being composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2-22, provided that the population is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2, 3, 20, or 21. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2-22, provided that the population is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2, 3, 20, or 21. The amino acid sequences of SEQ ID NO: 4-19 and 22 are listed in Table 3.

[0089] Table 3

[0090]

[0091]

[0092]

[0093] Examples of various FcRn antagonist molecules are shown in Table 4 below. The amino acid sequence of each member of the dimer of the first Fc domain (I) and the second Fc domain (II) is shown by SEQ ID NO. Thus, for example, I = 2 and II = 3 shown in the second cell of Table 4 represent FcRn antagonist molecules in the population that contain or are composed of a variant Fc region containing or composed of a dimer of the first Fc domain (I) and the second Fc domain (II), wherein the amino acid sequences of the first Fc domain and the second Fc domain contain or are composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively.

[0094] Table 4

[0095]

[0096] In some embodiments, the population of FcRn antagonist molecules described herein is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first and second Fc domains consist of the amino acid sequences of SEQ ID NO: 2, 3, 20, or 21. In some embodiments, the population of FcRn antagonist molecules described herein includes homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first and second Fc domains consist of the amino acid sequences of SEQ ID NO: 2, 3, 20, or 21; however, these populations further include other FcRn antagonist molecules. In some embodiments, these other FcRn antagonist molecules are presented in Table 4 above, i.e., excluding the following: I = 2 and II = 2; I = 3 and II = 3; I = 20 and II = 20; and I = 21 and II = 21.

[0097] In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of amino acid sequences that are at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequences of SEQ ID NO: 3 and 12, respectively. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 12, respectively. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequences of SEQ ID NO: 3 and 9, respectively. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 9, respectively. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequences of SEQ ID NO: 2 and 3, respectively. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively.In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequences of SEQ ID NO: 3 and 6, respectively. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 6, respectively.

[0098] In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 4. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 5. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 6. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 7. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 8.In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 9. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 10. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 11. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 12. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 13.In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 14. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 15. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 16. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 17. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 18.In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 19. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of SEQ ID NO: 22.

[0099] In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 4. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 5. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 6. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 7. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 8. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 9. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 10. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 11.In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 12. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 13. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 14. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 15. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 16. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 17. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 18. In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 19.In some embodiments, each FcRn antagonist molecule in the population comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 22.

[0100] In some embodiments, the FcRn antagonist molecule in the population includes glycanization on one or both of its Fc domains. In some embodiments, the FcRn antagonist molecule in the population includes glycanization at EU position 297 on one or both of its Fc domains. In some embodiments, the glycanization comprises N-glycans. In some embodiments, the N-glycans include G0F N-glycans, G1F N-glycans, G2F N-glycans, or G0 N-glycans.

[0101] In some embodiments, the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein one of the Fc domains is glycanized. In some embodiments, glycanization comprises N-glycans. In some embodiments, N-glycans include G0F N-glycans, G1F N-glycans, G2F N-glycans, or G0 N-glycans.

[0102] In some embodiments, the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or composed of a dimer of a first Fc domain and a second Fc domain, wherein both of the Fc domains are glycanized. In some embodiments, glycanization comprises N-glycans. In some embodiments, the N-glycans include G0F N-glycans, G1F N-glycans, G2F N-glycans, or G0 N-glycans. In some embodiments, the Fc domain comprises a G0F N-glycan. In some embodiments, the Fc domain comprises a G1F N-glycan. In some embodiments, the Fc domain comprises a G2F N-glycan. In some embodiments, the Fc domain comprises a G0 N-glycan.

[0103] In some embodiments, the first Fc domain and the second Fc domain have different N-glycanizations at EU position 297. In some embodiments, the first Fc domain contains G0F N-glycan, and the second Fc domain contains G1F N-glycan. In some embodiments, the first Fc domain contains G0F N-glycan, and the second Fc domain contains G2F N-glycan. In some embodiments, the first Fc domain contains G0F N-glycan, and the second Fc domain contains G0 N-glycan. In some embodiments, the first Fc domain contains G1F N-glycan, and the second Fc domain contains G2F N-glycan. In some embodiments, the first Fc domain contains G1F N-glycan, and the second Fc domain contains G2F + NANA N-glycan. In some embodiments, the first Fc domain contains G2F N-glycan, and the second Fc domain contains G2F + 2 x NANA N-glycan. In some embodiments, the first Fc domain comprises a G1F N-glycan, and the second Fc domain comprises a GO N-glycan. In some embodiments, the first Fc domain comprises a G2F N-glycan, and the second Fc domain comprises a GO N-glycan. In some embodiments, one or more of the amino acids in the FcRn antagonist molecule are modified. In some embodiments, an asparagine residue is deaminoked. In some embodiments, a methionine residue is oxidized. In some embodiments, a tryptophan residue is oxidized. In some embodiments, both methionine and tryptophan residues are oxidized.

[0104] In some embodiments, the FcRn antagonist molecule population comprises or is composed of multiple subgroups of FcRn antagonist molecules. In some embodiments, the FcRn antagonist molecule population comprises or is composed of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 subgroups. In some embodiments, the FcRn antagonist molecule population comprises or is composed of 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 subgroups.

[0105] In some embodiments, a first subgroup of FcRn antagonist molecules comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% the amino acid sequence of SEQ ID NO: 3.

[0106] In some embodiments, the second subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of the amino acid sequences of SEQ ID NO: 3 and 12, respectively.

[0107] In some embodiments, a third subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of the amino acid sequences of SEQ ID NO: 3 and 9, respectively.

[0108] In some embodiments, a fourth subgroup of FcRn antagonist molecules comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% the same amino acid sequence as the amino acid sequence of SEQ ID NO: 3, and wherein two asparagine residues in each FcRn antagonist molecule in the fourth subgroup are deaminoked.

[0109] In some embodiments, the fifth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical amino acid sequences to or composed of the amino acid sequences of SEQ ID NO: 3 and 9, respectively, and wherein one asparagine residue in each FcRn antagonist molecule in the fifth subgroup is deaminoked.

[0110] In some embodiments, the sixth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of the amino acid sequences of SEQ ID NO: 2 and 3, respectively.

[0111] In some embodiments, the seventh subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical amino acid sequences to or composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the seventh subgroup is oxidized.

[0112] In some embodiments, the eighth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% the amino acid sequence of SEQ ID NO: 2.

[0113] In some embodiments, the ninth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of the amino acid sequences of SEQ ID NO: 3 and 6, respectively.

[0114] In some embodiments, the tenth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical amino acid sequences to or composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the tenth subgroup is oxidized.

[0115] In some embodiments, the eleventh subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% the same amino acid sequence as the amino acid sequence of SEQ ID NO: 3, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the eleventh subgroup is oxidized.

[0116] In some embodiments, a first subgroup of FcRn antagonist molecules comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 3.

[0117] In some embodiments, the second subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 12, respectively.

[0118] In some embodiments, the third subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 9, respectively.

[0119] In some embodiments, the fourth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 3, and wherein two asparagine residues in each FcRn antagonist molecule in the fourth subgroup are deaminoked.

[0120] In some embodiments, the fifth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 9, respectively, and wherein one asparagine residue in each FcRn antagonist molecule in the fifth subgroup is deaminoked.

[0121] In some embodiments, the sixth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively.

[0122] In some embodiments, the seventh subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the seventh subgroup is oxidized.

[0123] In some embodiments, the eighth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 2.

[0124] In some embodiments, the ninth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 3 and 6, respectively.

[0125] In some embodiments, the tenth subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequences of SEQ ID NO: 2 and 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the tenth subgroup is oxidized.

[0126] In some embodiments, the eleventh subgroup of the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain comprise or are composed of the amino acid sequence of SEQ ID NO: 3, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the eleventh subgroup is oxidized.

[0127] In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and one of the second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroups. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and two of the second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroups. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and three of the second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroups. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and four of the following subgroups: a second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroup. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and five of the following subgroups: a second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroup. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and six of the following subgroups: a second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroup. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and seven of the following subgroups: second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and eight of the following subgroups: second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh. In some embodiments, the FcRn antagonist molecular population comprises, or is composed of, a first subgroup and nine of the following subgroups: second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh. In some embodiments, the FcRn antagonist molecular population comprises or consists of all of the first subgroup and the second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh subgroups.

[0128] In some embodiments, a group comprises or consists of a first subgroup and a second subgroup. In some embodiments, a group comprises or consists of a first subgroup and a third subgroup. In some embodiments, a group comprises or consists of a first subgroup and a fourth subgroup. In some embodiments, a group comprises or consists of a first subgroup and a fifth subgroup. In some embodiments, a group comprises or consists of a first subgroup and a sixth subgroup. In some embodiments, a group comprises or consists of a first subgroup and a seventh subgroup. In some embodiments, a group comprises or consists of a first subgroup and an eighth subgroup. In some embodiments, a group comprises or consists of a first subgroup and a ninth subgroup. In some embodiments, a group comprises or consists of a first subgroup and a tenth subgroup. In some embodiments, a group comprises or consists of a first subgroup and an eleventh subgroup. In some embodiments, the groups listed above further comprise or consist of 1, 2, 3, 4, 5, 6, 7, 8, or 9 additional subgroups. In some embodiments, these additional subgroups are one or more of the subgroups described above.

[0129] In some embodiments, the group includes or consists of the first subgroup and the seventh subgroup, the ninth subgroup, or the eleventh subgroup.

[0130] In some embodiments, the first subgroup comprises at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90% of the FcRn antagonist molecular population. In some embodiments, the first subgroup comprises about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or about 90% of the FcRn antagonist molecular population. In some embodiments, the first subgroup comprises 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% of the FcRn antagonist molecular population. In some embodiments, the first subgroup comprises 40%-90%, 50%-80%, or 55%-70% of the FcRn antagonist molecular population. In some embodiments, the first subgroup accounts for 56.9%-68.3% or 59.5%-67.9% of the FcRn antagonist molecular population.

[0131] In some embodiments, the second subgroup constitutes less than 3.0%, less than 2.5%, less than 2.0%, less than 1.5%, less than 1%, or less than 0.5% of the FcRn antagonist molecular population. In some embodiments, the second subgroup constitutes about 3.0%, about 2.5%, about 2.0%, about 1.5%, about 1%, or about 0.5% of the FcRn antagonist molecular population. In some embodiments, the second subgroup constitutes 3.0%, 2.5%, 2.0%, 1.5%, 1%, or 0.5% of the FcRn antagonist molecular population. In some embodiments, the second subgroup constitutes 0.5%-3.0%, 1.0%-2.5%, or 1.0%-2.0% of the FcRn antagonist molecular population. In some embodiments, the second subgroup constitutes 0.8%-2.0% or 0.8%-2.1% of the FcRn antagonist molecular population.

[0132] In some embodiments, the third subgroup constitutes less than 3.0%, less than 2.5%, less than 2.0%, less than 1.5%, less than 1%, or less than 0.5% of the FcRn antagonist molecular population. In some embodiments, the third subgroup constitutes about 3.0%, about 2.5%, about 2.0%, about 1.5%, about 1%, or about 0.5% of the FcRn antagonist molecular population. In some embodiments, the third subgroup constitutes 3.0%, 2.5%, 2.0%, 1.5%, 1%, or 0.5% of the FcRn antagonist molecular population. In some embodiments, the third subgroup constitutes 0.5%-3.0%, 1.0%-2.5%, or 1.0%-2.0% of the FcRn antagonist molecular population. In some embodiments, the third subgroup constitutes 1.1%-2.1% or 1.0%-1.9% of the FcRn antagonist molecular population.

[0133] In some embodiments, the fourth subgroup comprises less than 5%, less than 4%, less than 3%, less than 2%, or less than 1% of the FcRn antagonist molecular population. In some embodiments, the fourth subgroup comprises about 5%, about 4%, about 3%, about 2%, or about 1% of the FcRn antagonist molecular population. In some embodiments, the fourth subgroup comprises 5%, 4%, 3%, 2%, or 1% of the FcRn antagonist molecular population. In some embodiments, the fourth subgroup comprises 1%-5%, 2%-4%, or 2%-3% of the FcRn antagonist molecular population. In some embodiments, the fourth subgroup comprises 2.1%-3.2% or 2.0%-3.1% of the FcRn antagonist molecular population.

[0134] In some embodiments, the fifth subgroup comprises less than 12%, less than 11%, less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, or less than 5% of the FcRn antagonist molecular population. In some embodiments, the fifth subgroup comprises about 12%, about 11%, about 10%, about 9%, about 8%, about 7%, about 6%, or about 5% of the FcRn antagonist molecular population. In some embodiments, the fifth subgroup comprises 12%, 11%, 10%, 9%, 8%, 7%, 6%, or 5% of the FcRn antagonist molecular population. In some embodiments, the fifth subgroup comprises 5%-12%, 6%-10%, or 7%-8% of the FcRn antagonist molecular population. In some embodiments, the fifth subgroup comprises 6.8%-9.4% or 6.9%-8.7% of the FcRn antagonist molecular population.

[0135] In some embodiments, the sixth subgroup comprises less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, less than 11%, less than 10%, less than 9%, less than 8%, less than 7%, or less than 6% of the FcRn antagonist molecular population. In some embodiments, the sixth subgroup comprises about 17%, about 16%, about 15%, about 14%, about 13%, about 12%, about 11%, about 10%, about 9%, about 8%, about 7%, or about 6% of the FcRn antagonist molecular population. In some embodiments, the sixth subgroup comprises 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, or 6% of the FcRn antagonist molecular population. In some embodiments, the sixth subgroup comprises 7%-17%, 10%-15%, or 11%-12% of the FcRn antagonist molecular population. In some embodiments, the sixth subgroup accounts for 7.0%-14.0% or 10.0%-14.4% of the FcRn antagonist molecular population.

[0136] In some embodiments, the seventh subgroup constitutes less than 6.0%, less than 5.5%, less than 5.0%, less than 4.5%, less than 4.0%, less than 3.5%, less than 3.0%, less than 2.5%, less than 2.0%, less than 1.5%, less than 1%, or less than 0.5% of the FcRn antagonist molecular population. In some embodiments, the seventh subgroup constitutes approximately 6.0%, approximately 5.5%, approximately 5.0%, approximately 4.5%, approximately 4.0%, approximately 3.5%, approximately 3.0%, approximately 2.5%, approximately 2.0%, approximately 1.5%, approximately 1%, or approximately 0.5% of the FcRn antagonist molecular population. In some embodiments, the seventh subgroup constitutes 6.0%, 5.5%, 5.0%, 4.5%, 4.0%, 3.5%, 3.0%, 2.5%, 2.0%, 1.5%, 1%, or 0.5% of the FcRn antagonist molecular population. In some embodiments, the seventh subgroup comprises 0.5%-5.5%, 1.0%-3.0%, or 1.5%-2.5% of the FcRn antagonist molecular population. In some embodiments, the seventh subgroup comprises 1.5%-5.5% or 1.4%-4.9% of the FcRn antagonist molecular population.

[0137] In some embodiments, the eighth subgroup constitutes less than 7.5%, less than 7.0%, less than 6.5%, less than 6.0%, less than 5.5%, less than 5.0%, less than 4.5%, less than 4.0%, less than 3.5%, less than 3.0%, or less than 2.5% of the FcRn antagonist molecular population. In some embodiments, the eighth subgroup constitutes approximately 7.5%, approximately 7.0%, approximately 6.5%, approximately 6.0%, approximately 5.5%, approximately 5.0%, approximately 4.5%, approximately 4.0%, approximately 3.5%, approximately 3.0%, or approximately 2.5% of the FcRn antagonist molecular population. In some embodiments, the eighth subgroup constitutes 7.5%, 7.0%, 6.5%, 6.0%, 5.5%, 5.0%, 4.5%, 4.0%, 3.5%, 3.0%, or 2.5% of the FcRn antagonist molecular population. In some embodiments, the eighth subgroup comprises 2.5%-7.5%, 3.0%-5.0%, or 3.5%-4.5% of the FcRn antagonist molecular population. In some embodiments, the eighth subgroup comprises 2.9%-7.4% or 3.0%-6.3% of the FcRn antagonist molecular population.

[0138] In some embodiments, the ninth subgroup constitutes less than 3.5%, less than 3.0%, less than 2.5%, less than 2.0%, less than 1.5%, less than 1%, or less than 0.5% of the FcRn antagonist molecular population. In some embodiments, the ninth subgroup constitutes about 3.5%, about 3.0%, about 2.5%, about 2.0%, about 1.5%, about 1%, or about 0.5% of the FcRn antagonist molecular population. In some embodiments, the ninth subgroup constitutes 3.5%, 3.0%, 2.5%, 2.0%, 1.5%, 1%, or 0.5% of the FcRn antagonist molecular population. In some embodiments, the ninth subgroup constitutes 0.5%-3.5%, 1.5%-2.0%, or 1.0%-1.5% of the FcRn antagonist molecular population. In some embodiments, the ninth subgroup constitutes 0.4%-3.2% or 0.5%-2.6% of the FcRn antagonist molecular population.

[0139] In some embodiments, the tenth subgroup comprises less than 2.0%, less than 1.5%, less than 1%, or less than 0.5% of the FcRn antagonist molecular population. In some embodiments, the tenth subgroup comprises about 2.0%, about 1.5%, about 1%, or about 0.5% of the FcRn antagonist molecular population. In some embodiments, the tenth subgroup comprises 2.0%, 1.5%, 1%, or 0.5% of the FcRn antagonist molecular population. In some embodiments, the tenth subgroup comprises 0.5%-2.0%, 0.5%-1.5%, or 1.0%-1.5% of the FcRn antagonist molecular population.

[0140] In some embodiments, the eleventh subgroup constitutes less than 2.0%, less than 1.5%, less than 1%, or less than 0.5% of the FcRn antagonist molecular population. In some embodiments, the eleventh subgroup constitutes about 2.0%, about 1.5%, about 1%, or about 0.5% of the FcRn antagonist molecular population. In some embodiments, the eleventh subgroup constitutes 2.0%, 1.5%, 1%, or 0.5% of the FcRn antagonist molecular population. In some embodiments, the eleventh subgroup constitutes 0.5%-2.0%, 0.5%-1.5%, or 1.0%-1.5% of the FcRn antagonist molecular population.

[0141] In some embodiments, the FcRn antagonist molecule in the population includes glycanization on one or both of its Fc domains. In some embodiments, the FcRn antagonist molecule in the population includes glycanization at EU position 297 on one or both of its Fc domains. In some embodiments, the glycanization comprises N-glycans. In some embodiments, the N-glycans include G0F N-glycans, G1F N-glycans, G2F N-glycans, or G0 N-glycans.

[0142] In some embodiments, the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or is composed of a dimer of a first Fc domain and a second Fc domain, wherein one of the Fc domains is glycanized. In some embodiments, glycanization comprises N-glycans. In some embodiments, N-glycans include G0F N-glycans, G1F N-glycans, G2F N-glycans, or G0 N-glycans.

[0143] In some embodiments, the FcRn antagonist molecule comprises or is composed of a variant Fc region comprising or composed of a dimer of a first Fc domain and a second Fc domain, wherein both of the Fc domains are glycanized. In some embodiments, glycanization comprises N-glycans. In some embodiments, the N-glycans include G0F N-glycans, G1F N-glycans, G2F N-glycans, or G0 N-glycans. In some embodiments, the Fc domain comprises a G0F N-glycan. In some embodiments, the Fc domain comprises a G1F N-glycan. In some embodiments, the Fc domain comprises a G2F N-glycan. In some embodiments, the Fc domain comprises a G0 N-glycan.

[0144] In some embodiments, the first Fc domain and the second Fc domain have different N-glycanizations at EU position 297. In some embodiments, the first Fc domain contains G0F N-glycan, and the second Fc domain contains G1F N-glycan. In some embodiments, the first Fc domain contains G0F N-glycan, and the second Fc domain contains G2F N-glycan. In some embodiments, the first Fc domain contains G0F N-glycan, and the second Fc domain contains G0 N-glycan. In some embodiments, the first Fc domain contains G1F N-glycan, and the second Fc domain contains G2F N-glycan. In some embodiments, the first Fc domain contains G1F N-glycan, and the second Fc domain contains G2F + NANA N-glycan. In some embodiments, the first Fc domain contains G2F N-glycan, and the second Fc domain contains G2F + 2 x NANA N-glycan. In some embodiments, the first Fc domain comprises G1F N-glycan, and the second Fc domain comprises G0 N-glycan. In some embodiments, the first Fc domain comprises G2F N-glycan, and the second Fc domain comprises G0 N-glycan.

[0145] In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the Fc domain population of the FcRn antagonist molecules contains N-glycans at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein about 95%, about 96%, about 97%, about 98%, or about 99% of the Fc domain population of the FcRn antagonist molecules contains N-glycans at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 95%, 96%, 97%, 98%, or 99% of the Fc domain population of the FcRn antagonist molecules contains N-glycans at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 95% to 99%, 96% to 99%, or 97% to 99% of the Fc domain population of the FcRn antagonist molecule contains an N-glycan at EU position 297.

[0146] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein at least 48%, at least 49%, at least 50%, at least 51%, at least 52%, at least 53%, at least 54%, at least 55%, at least 56%, at least 57%, at least 58%, at least 59%, at least 60%, at least 61%, at least 62%, at least 63%, at least 64%, at least 65%, at least 66%, or at least 67% of the Fc domain population of the FcRn antagonist molecule contains G0F N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein approximately 48%, approximately 49%, approximately 50%, approximately 51%, approximately 52%, approximately 53%, approximately 54%, approximately 55%, approximately 56%, approximately 57%, approximately 58%, approximately 59%, approximately 60%, approximately 61%, approximately 62%, approximately 63%, approximately 64%, approximately 65%, approximately 66%, or approximately 67% of the Fc domain population of the FcRn antagonist molecule contains a G0F N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein approximately 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, or 67% of the Fc domain population of the FcRn antagonist molecule contains a G0F N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 48% to 67%, 51% to 66%, or 50% to 65% of the Fc domain population of the FcRn antagonist molecule contains a GOF N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 53.8% to 64.1% or 53.8% to 63.1% of the Fc domain population of the FcRn antagonist molecule contains a GOF N-glycan at EU position 297.

[0147] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein at least 21%, at least 22%, at least 23%, at least 24%, at least 25%, at least 26%, at least 27%, at least 28%, at least 29%, at least 30%, at least 31%, or at least 32% of the Fc domain population of the FcRn antagonist molecule contains G1F N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, or about 30%, about 31%, or about 32% of the Fc domain population of the FcRn antagonist molecule contains G1F N-glycan at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, or 32% of the Fc domain population of the FcRn antagonist molecules contains G1F N-glycans at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 21% to 32%, 24% to 31%, or 25% to 30% of the Fc domain population of the FcRn antagonist molecules contains G1F N-glycans at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 22.6% to 28.3% or 23.5% to 28.0% of the Fc domain population of the FcRn antagonist molecules contains G1F N-glycans at EU position 297.

[0148] In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, or at least 12% of the Fc domain population of the FcRn antagonist molecules contains G2F N-glycan at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, or about 12% of the Fc domain population of the FcRn antagonist molecules contains G2F N-glycan at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, or 12% of the Fc domain population of the FcRn antagonist molecules contains G2F N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 3% to 12%, 5% to 11%, or 7% to 10% of the Fc domain population of the FcRn antagonist molecule contains G2F N-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 5.6% to 9.2% or 6.2% to 9.2% of the Fc domain population of the FcRn antagonist molecule contains G2F N-glycan at EU position 297.

[0149] In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6% of the Fc domain population of the FcRn antagonist molecules contains GON-glycans at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein about 1%, about 2%, about 3%, about 4%, about 5%, or about 6% of the Fc domain population of the FcRn antagonist molecules contains GON-glycans at EU position 297. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 1%, 2%, 3%, 4%, 5%, or 6% of the Fc domain population of the FcRn antagonist molecules contains GON-glycans at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 1% to 6%, 2% to 5%, or 2% to 4% of the Fc domain population of the FcRn antagonist molecule contains a GON-glycan at EU position 297. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 2.5% to 4.5% or 2.5% to 3.2% of the Fc domain population of the FcRn antagonist molecule contains a GON-glycan at EU position 297.

[0150] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein at least 33%, at least 34%, at least 35%, at least 36%, at least 37%, at least 38%, at least 39%, at least 40%, at least 41%, at least 42%, at least 43%, at least 44%, at least 45%, at least 46%, at least 47%, at least 48%, at least 49%, at least 50%, at least 51%, at least 52%, at least 53%, at least 54%, at least 55%, at least 56%, or at least 57% of the Fc domain population of the FcRn antagonist molecule contains galactose. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, or about 57% of the Fc domain population of the FcRn antagonist molecule contains galactose. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, or 57% of the Fc domain population of the FcRn antagonist molecules comprises galactose. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 33% to 57%, 34% to 56%, or 35% to 55% of the Fc domain population of the FcRn antagonist molecules comprises galactose.

[0151] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein at least 88%, at least 89%, 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% of the Fc domain population of the FcRn antagonist molecule comprises fucose. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% of the Fc domain population of the FcRn antagonist molecule comprises fucose. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the Fc domain population of the FcRn antagonist molecules comprises fucose. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 33% to 57%, 34% to 56%, or 35% to 55% of the Fc domain population of the FcRn antagonist molecules comprises fucose.

[0152] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein up to 0.3%, up to 0.4%, up to 0.5%, up to 0.6%, up to 0.7%, up to 0.8%, up to 0.9%, up to 1.0%, up to 1.1%, up to 1.2%, up to 1.3%, up to 1.4%, up to 1.5%, up to 1.6%, or up to 1.7% of the Fc domain population of the FcRn antagonist molecule contains sialic acid. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 0.3%, about 0.4%, about 0.5%, about 0.6%, about 0.7%, about 0.8%, about 0.9%, about 1.0%, about 1.1%, about 1.2%, about 1.3%, about 1.4%, about 1.5%, about 1.6%, or about 1.7% of the Fc domain population of the FcRn antagonist molecule contains sialic acid. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, or 1.7% of the Fc domain population of the FcRn antagonist molecule comprises sialic acid. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.3% to 1.7%, 0.4% to 1.6%, or 0.5% to 1.5% of the Fc domain population of the FcRn antagonist molecule comprises sialic acid.

[0153] In some embodiments, the group comprises or consists of an FcRn antagonist molecule, wherein at least 38%, at least 39%, at least 40%, at least 41%, at least 42%, at least 43%, at least 44%, at least 45%, at least 46%, at least 47%, at least 48%, at least 49%, at least 50%, at least 51%, at least 52%, at least 53%, at least 54%, at least 55%, at least 56%, or at least 57% of the FcRn antagonist molecule comprises a first Fc domain containing a G0F N-glycan at EU position 297 and a second Fc domain containing a G0F N-glycan at EU position 297. In some embodiments, the group comprises or consists of an FcRn antagonist molecule, wherein about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, or about 57% of the FcRn antagonist molecule comprises a first Fc domain containing a G0F N-glycan at EU position 297 and a second Fc domain containing a G0F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, or 57% of the FcRn antagonist molecules comprise a first Fc domain containing a GOF N-glycan at EU position 297 and a second Fc domain containing a GOF N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 38% to 57%, 39% to 56%, or 40% to 55% of the FcRn antagonist molecules comprise a first Fc domain containing a GOF N-glycan at EU position 297 and a second Fc domain containing a GOF N-glycan at EU position 297.

[0154] In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein at least 18%, at least 19%, at least 20%, at least 21%, at least 22%, at least 23%, at least 24%, at least 25%, at least 26%, or at least 27% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G1F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein about 18%, about 19%, about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, or about 27% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G1F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, or 27% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G1F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 18% to 27%, 19% to 28%, or 20% to 25% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G1F N-glycan at EU position 297.

[0155] In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, at least 16%, or at least 17% of the FcRn antagonist molecules comprise a first Fc domain comprising G1F N-glycan at EU position 297 and a second Fc domain comprising G1F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, or about 17% of the FcRn antagonist molecules comprise a first Fc domain comprising G1F N-glycan at EU position 297 and a second Fc domain comprising G1F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, or 17% of the FcRn antagonist molecules comprise a first Fc domain containing a G1F N-glycan at EU position 297 and a second Fc domain containing a G1F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 8% to 17%, 9% to 28%, or 10% to 15% of the FcRn antagonist molecules comprise a first Fc domain containing a G1F N-glycan at EU position 297 and a second Fc domain containing a G1F N-glycan at EU position 297.

[0156] In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, at least 16%, or at least 17% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, or about 17% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, or 17% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 8% to 17%, 9% to 28%, or 10% to 15% of the FcRn antagonist molecules comprise a first Fc domain comprising a G0F N-glycan at EU position 297 and a second Fc domain comprising a G2F N-glycan at EU position 297.

[0157] In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, or at least 12% of the FcRn antagonist molecules comprise a first Fc domain comprising a G1F N-glycan at EU position 297 and a second Fc domain comprising a G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, or about 12% of the FcRn antagonist molecules comprise a first Fc domain comprising a G1F N-glycan at EU position 297 and a second Fc domain comprising a G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, or 12% of the FcRn antagonist molecules comprise a first Fc domain containing a G1F N-glycan at EU position 297 and a second Fc domain containing a G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 3% to 12%, 4% to 11%, or 5% to 10% of the FcRn antagonist molecules comprise a first Fc domain containing a G1F N-glycan at EU position 297 and a second Fc domain containing a G2F N-glycan at EU position 297.

[0158] In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6% of the FcRn antagonist molecules comprise a first Fc domain containing G2F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein about 1%, about 2%, about 3%, about 4%, about 5%, or about 6% of the FcRn antagonist molecules comprise a first Fc domain containing G2F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 1%, 2%, 3%, 4%, 5%, or 6% of the FcRn antagonist molecules comprise a first Fc domain containing G2F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 1% to 6%, 1% to 4%, or 2% to 4% of the FcRn antagonist molecules comprise a first Fc domain containing G2F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297.

[0159] In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, or at least 8% of the FcRn antagonist molecules comprise a first Fc domain comprising a GOF N-glycan at EU position 297 and a second Fc domain comprising a GO N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, or about 8% of the FcRn antagonist molecules comprise a first Fc domain comprising a GOF N-glycan at EU position 297 and a second Fc domain comprising a GO N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 2%, 3%, 4%, 5%, 6%, 7%, or 8% of the FcRn antagonist molecules comprise a first Fc domain containing a GOF N-glycan at EU position 297 and a second Fc domain containing a GO N-glycan at EU position 297. In some embodiments, the population comprises or is composed of FcRn antagonist molecules, wherein 2% to 8%, 3% to 7%, or 4% to 6% of the FcRn antagonist molecules comprise a first Fc domain containing a GOF N-glycan at EU position 297 and a second Fc domain containing a GO N-glycan at EU position 297.

[0160] In some embodiments, the FcRn antagonist molecule lacks an amino acid at EU position 441 of one or both Fc domains. In some embodiments, the FcRn antagonist molecule contains glycine and lysine at EU positions 440 and 441, respectively. In some embodiments, the FcRn antagonist molecule lacks an amino acid at EU positions 440 and 441. In some embodiments, the FcRn antagonist molecule contains amidated proline at EU position 439. In some embodiments, the FcRn antagonist molecule contains amidated proline at EU position 439. In some embodiments, the FcRn antagonist molecule lacks an amino acid at EU positions 440 and 441, and contains amidated proline at EU position 439.

[0161] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, or at least 97% of the Fc domains in the population are deficient in an amino acid at EU position 441. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein approximately 83%, approximately 84%, approximately 85%, approximately 86%, approximately 87%, approximately 88%, approximately 89%, approximately 90%, approximately 91%, approximately 92%, approximately 93%, approximately 94%, approximately 95%, approximately 96%, or approximately 97% of the Fc domains in the population are deficient in an amino acid at EU position 441. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, or 97% of the Fc domains in the population lack an amino acid at EU position 441. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 83% to 97%, 84% to 94%, or 85% to 95% of the Fc domains in the population lack an amino acid at EU position 441.

[0162] In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein less than 3%, less than 4%, less than 5%, less than 6%, less than 7%, less than 8%, less than 9%, less than 10%, less than 11%, less than 12%, less than 13%, less than 14%, less than 15%, less than 16%, or less than 17% of the Fc domains in the population have glycine and lysine at EU positions 440 and 441, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, or about 17% of the Fc domains in the population have glycine and lysine at EU positions 440 and 441, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, or 17% of the Fc domains in the population have glycine and lysine at EU positions 440 and 441, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 3% to 17%, 4% to 14%, or 5% to 15% of the Fc domains in the population have glycine and lysine at EU positions 440 and 441, respectively.

[0163] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, less than 1.5%, or less than 2% of the Fc domains in the population lack amino acids at EU positions 440 and 441, and contains an amidated proline at EU position 439. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, about 1.5%, or about 2% of the Fc domains in the population lack amino acids at EU positions 440 and 441, and contains an amidated proline at EU position 439. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5%, 1.0%, 1.5%, or 2% of the Fc domains in the population lack amino acids at EU positions 440 and 441, and contains an amidated proline at EU position 439. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5% to 2%, 0.5% to 1.5%, or 0.5% to 1.0% of the Fc domains in the population are deficient in amino acids at EU positions 440 and 441, and contain an amidated proline at EU position 439.

[0164] In some embodiments, the FcRn antagonist molecule contains aspartic acid, lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 221, 222, 223, 224, 225, and 226, respectively. In some embodiments, the FcRn antagonist molecule lacks an amino acid at EU position 221 and contains lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 222, 223, 224, 225, and 226, respectively. In some embodiments, the FcRn antagonist molecule lacks amino acids at EU positions 221 and 222 and contains threonine, histidine, threonine, and cysteine ​​at EU positions 223, 224, 225, and 226, respectively. In some embodiments, the FcRn antagonist molecule lacks amino acids at EU positions 221 to 224 and contains threonine and cysteine ​​at EU positions 225 and 226, respectively. In some embodiments, the FcRn antagonist molecule lacks amino acids at EU positions 221, 222, 223, 224, 225, and 226.

[0165] In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the Fc domains in the population have aspartic acid, lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 221, 222, 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% of the Fc domains in the population have aspartic acid, lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 221, 222, 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the Fc domains in the population have aspartic acid, lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 221, 222, 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 93% to 99%, 94% to 99%, or 95% to 99% of the Fc domains in the population have aspartic acid, lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 221, 222, 223, 224, 225, and 226, respectively.

[0166] In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population lack an amino acid at EU position 221, and have lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 222, 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population lack an amino acid at EU position 221, and have lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 222, 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population are deficient in an amino acid at EU position 221, and contain lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 222, 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population are deficient in an amino acid at EU position 221, and contain lysine, threonine, histidine, threonine, and cysteine ​​at EU positions 222, 223, 224, 225, and 226, respectively.

[0167] In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population lack amino acids at EU positions 221 and 222, and have threonine, histidine, threonine, and cysteine ​​at EU positions 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population lack amino acids at EU positions 221 and 222, and have threonine, histidine, threonine, and cysteine ​​at EU positions 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population are deficient in amino acids at EU positions 221 and 222, and contain threonine, histidine, threonine, and cysteine ​​at EU positions 223, 224, 225, and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population are deficient in amino acids at EU positions 221 and 222, and contain threonine, histidine, threonine, and cysteine ​​at EU positions 223, 224, 225, and 226, respectively.

[0168] In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, less than 1.5%, less than 2.5%, or less than 3.0% of the Fc domains in the population are deficient in amino acids at EU positions 221 to 224, and contain threonine and cysteine ​​at EU positions 225 and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, about 1.5%, about 2.5%, or about 3.0% of the Fc domains in the population are deficient in amino acids at EU positions 221 to 224, and contain threonine and cysteine ​​at EU positions 225 and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 0.5%, 1.0%, 1.5%, 2.5%, or 3.0% of the Fc domains in the population are deficient in amino acids at EU positions 221 to 224, and contain threonine and cysteine ​​at EU positions 225 and 226, respectively. In some embodiments, the population comprises or is composed of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population are deficient in amino acids at EU positions 221 to 224, and contain threonine and cysteine ​​at EU positions 225 and 226, respectively.

[0169] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population lack amino acids at EU positions 221, 222, 223, 224, 225, and 226. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population lack amino acids at EU positions 221, 222, 223, 224, 225, and 226. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population lack amino acids at EU positions 221, 222, 223, 224, 225, and 226. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population are deficient in amino acids at EU positions 221, 222, 223, 224, 225, and 226.

[0170] In some embodiments, the FcRn antagonist molecule contains an isomerization of aspartic acid at EU position 280 or 401. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population contain an isomerization of aspartic acid at EU position 280 or 401. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population contain an isomerization of aspartic acid at EU position 280 or 401. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population contain an isomerization of aspartic acid at EU position 280 or 401. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population contain an isomerization of aspartic acid at EU position 280 or 401.

[0171] In some embodiments, the FcRn antagonist molecule contains asparagine deamidation at EU positions 384, 389, or 390. In some embodiments, the FcRn antagonist molecule contains asparagine deamidation at EU position 315. In some embodiments, the FcRn antagonist molecule contains asparagine deamidation at EU position 361. In some embodiments, the FcRn antagonist molecule contains asparagine deamidation at EU positions 276 or 286.

[0172] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 8%, less than 9%, less than 10%, less than 11%, or less than 12% of the Fc domains in the population contain asparagine deamidation at EU positions 384, 389, or 390. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 8%, about 9%, about 10%, about 11%, or about 12% of the Fc domains in the population contain asparagine deamidation at EU positions 384, 389, or 390. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 8%, 9%, 10%, 11%, or 12% of the Fc domains in the population contain asparagine deamidation at EU positions 384, 389, or 390. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 8% to 12%, 7% to 11%, or 8% to 10% of the Fc domains in the population contain asparagine deamidation at EU positions 384, 389, or 390.

[0173] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 1%, less than 2%, less than 3%, less than 4%, or less than 5% of the Fc domains in the population are deamidated with asparagine at EU position 315. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 1%, about 2%, about 3%, about 4%, or about 5% of the Fc domains in the population are deamidated with asparagine at EU position 315. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 1%, 2%, 3%, 4%, or 5% of the Fc domains in the population are deamidated with asparagine at EU position 315. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 1% to 5%, 2% to 4%, or 2% to 3% of the Fc domains in the population are deamidated with asparagine at EU position 315.

[0174] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 1%, less than 2%, less than 3%, less than 4%, or less than 5% of the Fc domains in the population are deamidated with asparagine at EU position 361. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 1%, about 2%, about 3%, about 4%, or about 5% of the Fc domains in the population are deamidated with asparagine at EU position 361. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 1%, 2%, 3%, 4%, or 5% of the Fc domains in the population are deamidated with asparagine at EU position 361. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 1% to 5%, 2% to 4%, or 2% to 3% of the Fc domains in the population are deamidated with asparagine at EU position 361.

[0175] In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population are deamidated with asparagine at EU position 276 or 286. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population are deamidated with asparagine at EU position 276 or 286. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population are deamidated with asparagine at EU position 276 or 286. In some embodiments, the population comprises or consists of FcRn antagonist molecules, wherein 0.5% to 1.0% of the Fc domains in the population are deamidated with asparagine at EU position 276 or 286.

[0176] In some embodiments, the FcRn antagonist molecule contains the oxidation of methionine at EU position 428. In some embodiments, the FcRn antagonist molecule contains the oxidation of tryptophan at EU position 277.

[0177] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 3%, less than 4%, less than 5%, less than 6%, or less than 7% of the Fc domains in the population contain methionine oxidation at EU position 428. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 3%, about 4%, about 5%, about 6%, or about 7% of the Fc domains in the population contain methionine oxidation at EU position 428. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 3%, 4%, 5%, 6%, or 7% of the Fc domains in the population contain methionine oxidation at EU position 428. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 3% to 7%, 4% to 6%, or 4% to 5% of the Fc domains in the population contain methionine oxidation at EU position 428.

[0178] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population contain tryptophan oxidation at EU position 277. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population contain tryptophan oxidation at EU position 277. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population contain tryptophan oxidation at EU position 277. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population contain tryptophan oxidation at EU position 277.

[0179] In some embodiments, the FcRn antagonist molecule contains an amidation of proline at EU position 445.

[0180] In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein less than 0.5%, less than 1.0%, or less than 1.5% of the Fc domains in the population contain proline amidation at EU position 445. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein about 0.5%, about 1.0%, or about 1.5% of the Fc domains in the population contain proline amidation at EU position 445. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5%, 1.0%, or 1.5% of the Fc domains in the population contain proline amidation at EU position 445. In some embodiments, the population comprises or consists of an FcRn antagonist molecule, wherein 0.5% to 1.0% of the Fc domains in the population contain proline amidation at EU position 445.

[0181] Polynucleotides, vectors and production methods

[0182] This disclosure also provides polynucleotides encoding the FcRn antagonist molecules or fragments thereof disclosed herein. In some embodiments, the polynucleotides described herein are isolated or purified. As used herein, an “isolated” polynucleotide is a polynucleotide isolated from other nucleic acid molecules, such as polynucleotides present in natural sources of polynucleotides (e.g., mice or humans), or polynucleotides that are substantially free of other cellular material or culture medium when produced by recombinant technology, or polynucleotides that are substantially free of chemical precursors or other chemicals when chemically synthesized. The language “substantially free” includes, but is not limited to, formulations of polynucleotides having less than about 15%, 10%, 5%, 2%, 1%, 0.5%, or 0.1% (particularly less than about 10%) of other substances (e.g., cellular material, culture medium, other nucleic acid molecules, chemical precursors, and / or other chemicals).

[0183] In one aspect, this document provides a polynucleotide comprising a nucleotide sequence encoding the FcRn antagonist molecule described herein. In some embodiments, the polynucleotide comprises a nucleotide sequence encoding an Fc domain comprising at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of any of SEQ ID NO: 1 to 22. In some embodiments, the polynucleotide consists of a nucleotide sequence encoding an Fc domain comprising at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of any of SEQ ID NO: 1 to 22.

[0184] In some embodiments, the polynucleotide comprises a nucleotide sequence encoding an Fc domain comprising the amino acid sequence of any one of SEQ ID NO: 1 to 22. In some embodiments, the polynucleotide comprises a nucleotide sequence encoding an Fc domain consisting of the amino acid sequence of any one of SEQ ID NO: 1 to 22.

[0185] In some embodiments, the polynucleotide comprises a nucleotide sequence encoding two or more Fc domains. In some embodiments, the polynucleotide comprises a nucleotide sequence encoding two Fc domains. In some embodiments, the polynucleotide comprises a first nucleotide sequence encoding a first Fc domain and a second nucleotide sequence encoding a second Fc domain. In some embodiments, the first nucleotide sequence and the second nucleotide sequence are contained in different nucleic acid molecules. In some embodiments, the first nucleotide sequence and the second nucleotide sequence are contained in the same nucleic acid molecule.

[0186] In some embodiments, the first nucleotide sequence and the second nucleotide sequence encode the same Fc domain. In some embodiments, both the first nucleotide sequence and the second nucleotide sequence encode an Fc domain comprising at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence identical to any of SEQ ID NOs: 5 to 20 and 22. In some embodiments, both the first nucleotide sequence and the second nucleotide sequence encode an Fc domain consisting of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence identical to any of SEQ ID NOs: 5 to 20 and 22. In some embodiments, both the first nucleotide sequence and the second nucleotide sequence encode an Fc domain comprising the amino acid sequence of any of SEQ ID NOs: 5 to 20 and 22. In some embodiments, both the first nucleotide sequence and the second nucleotide sequence encode an Fc domain consisting of the amino acid sequence of any of SEQ ID NOs: 5 to 20 and 22.

[0187] In some embodiments, the first nucleotide sequence and the second nucleotide sequence encode different Fc domains. In some embodiments, the first nucleotide sequence encodes an Fc domain comprising at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of any of SEQ ID NO: 1 to 22, and the second nucleotide sequence encodes a different Fc domain comprising at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of any of SEQ ID NO: 1 to 22. In some embodiments, a first nucleotide sequence encodes an Fc domain consisting of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of any of SEQ ID NO: 1 to 22, and a second nucleotide sequence encodes a different Fc domain consisting of at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of any of SEQ ID NO: 1 to 22. In some embodiments, a first nucleotide sequence encodes an Fc domain comprising an amino acid sequence of any of SEQ ID NO: 1 to 22, and a second nucleotide sequence encodes a different Fc domain comprising an amino acid sequence of any of SEQ ID NO: 1 to 22. In some embodiments, a first nucleotide sequence encodes an Fc domain consisting of an amino acid sequence of any of SEQ ID NO: 1 to 22, and a second nucleotide sequence encodes a different Fc domain consisting of an amino acid sequence of any of SEQ ID NO: 1 to 22.

[0188] This document also provides polynucleotides encoding polypeptides as described above, which are optimized, for example, through codon / RNA optimization, replacement with heterologous signal sequences, and elimination of mRNA instability elements. Methods for generating optimized nucleic acids for recombinant expression by introducing codon changes and / or eliminating repressive regions in mRNA can be performed by adapting optimization methods described, for example, in U.S. Patent Nos. 5,965,726; 6,174,666; 6,291,664; 6,414,132; and 6,794,498, all of which are incorporated herein by reference in their entirety. For example, potential splicing sites and instability elements (e.g., A / T- or A / U-rich elements) within RNA can be mutated without altering the amino acids encoded by the nucleic acid sequence to increase the stability of the RNA for recombinant expression. These alterations exploit the degeneracy of the genetic code, for example, by using alternative codons for the same amino acids. In one embodiment, it may be desirable to alter one or more codons to encode conserved mutations, such as similar amino acids having similar chemical structures and properties and / or functions to the original amino acids.

[0189] Polynucleotides can be obtained and their nucleotide sequences determined by any method known in the art. The nucleotide sequences encoding the proteins described herein and the modified forms of these antibodies can be determined using methods well known in the art, i.e., assembling in a manner that uses known nucleotide codons encoding specific amino acids to produce nucleic acids encoding proteins. Such protein-encoding polynucleotides can be assembled from chemically synthesized oligonucleotides (e.g., as described in Kutmeier G et al., (1994) BioTechniques 17: 242-6, which is incorporated herein by reference in its entirety), which simply involves synthesizing overlapping oligonucleotides containing portions of the sequence encoding the antibody, annealing and linking those oligonucleotides, and then amplifying the linked oligonucleotides by PCR.

[0190] Alternatively, polynucleotides encoding the proteins described herein can be generated from nucleic acids from a suitable source (e.g., hybridoma) using methods well-known in the art (e.g., PCR and other molecular cloning methods). For example, PCR amplification using synthetic primers capable of hybridizing to the 3' and 5' ends of a known sequence can be performed using genomic DNA obtained from hybridoma cells that produce the polypeptide of interest. Such PCR amplification methods can be used to obtain nucleic acids containing sequences encoding polypeptides. The amplified nucleic acids can be cloned into vectors for expression in host cells and for further cloning.

[0191] If a clone of a nucleic acid encoding a specific polypeptide is unavailable, but the sequence of that polypeptide is known, the nucleic acid encoding the polypeptide can be chemically synthesized or obtained from a suitable source (e.g., a cDNA library generated from any tissue or cell expressing the polypeptide described herein, or nucleic acid isolated from any tissue or cell expressing the polypeptide described herein, preferably polyA+RNA) by PCR amplification using synthetic primers capable of hybridizing to the 3' and 5' ends of the sequence, or by cloning using oligonucleotide probes specific to a particular gene sequence, to identify, for example, a cDNA clone encoding the polypeptide from a cDNA library. The amplified nucleic acid produced by PCR can then be cloned into a reproducible cloning vector using any method well known in the art.

[0192] The DNA encoding the proteins described herein can be readily isolated and sequenced using standard procedures. Hybridoma cells can be used as a source of such DNA. Once isolated, the DNA can be placed in an expression vector and then transfected into host cells, such as E. coli cells, simian COS cells, Chinese hamster ovary (CHO) cells (e.g., CHO cells from the CHO GS System™ (Lonza)), or myeloma cells that do not otherwise produce the proteins described herein.

[0193] It also provides polynucleotides that hybridize with polynucleotides encoding the proteins described herein under high-strictness, medium-strictness, or low-strictness hybridization conditions.

[0194] Hybridization conditions have been described in the art and are known to those skilled in the art. For example, hybridization under stringent conditions may include hybridization of DNA bound to a filter membrane in 6x sodium chloride / sodium citrate (SSC) at about 45°C, followed by one or more washes in 0.2x SSC / 0.1% SDS at about 50°C to 65°C; hybridization under highly stringent conditions may include hybridization of nucleic acids bound to a filter membrane in 6x SSC at about 45°C, followed by one or more washes in 0.1x SSC / 0.2% SDS at about 68°C. Hybridization under other stringent conditions is known to those skilled in the art and has been described, see, for example, Ausubel FM et al., ed., (1989) Current Protocols in Molecular Biology, Vol. I, Green Publishing Associates, Inc. and John Wiley & Sons, Inc., New York, pp. 6.3.1 to 6.3.6 and 2.10.3, which are incorporated herein by reference in their entirety.

[0195] In one aspect, this document provides (e.g., recombinantly) cells (e.g., host cells) for expressing the proteins described herein, as well as associated polynucleotides and expression vectors. This document provides vectors (e.g., expression vectors) comprising polynucleotides containing a nucleotide sequence encoding the protein described herein for recombinant expression in host cells, preferably mammalian cells (e.g., CHO cells). This document also provides host cells containing such vectors for recombinant expression of the proteins described herein. In another aspect, this document provides methods for producing the proteins described herein, the methods comprising expressing polypeptides from host cells.

[0196] Recombinant expression of proteins described herein typically involves constructing expression vectors containing polynucleotides encoding polypeptides. Once a polynucleotide encoding the polypeptide described herein is obtained, a vector for producing the polypeptide can be generated using recombinant DNA techniques well known in the art. Therefore, methods for preparing proteins by expressing polynucleotides containing nucleotide sequences encoding polypeptides are described herein. Methods well known to those skilled in the art can be used to construct expression vectors containing polypeptide-coding sequences and appropriate transcription and translation control signals. These methods include, for example, in vitro recombinant DNA techniques, synthetic techniques, and in vivo gene recombination. Replicable vectors containing nucleotide sequences encoding the polypeptide described herein, operably linked to a promoter, are also provided. Expression vectors can be transferred into cells (e.g., host cells) using conventional techniques, and the resulting cells can then be cultured using conventional techniques to produce the polypeptide described herein or fragments thereof. Therefore, host cells containing polynucleotides encoding the polypeptide described herein or fragments thereof, or its heavy or light chain, or fragments thereof, or the single-chain antibody described herein, operably linked to a promoter, are provided herein for expressing such sequences in host cells.

[0197] In one embodiment, the host cell comprises a polynucleotide comprising one of the first nucleotide sequences and one of the second nucleotide sequences described above. In another embodiment, the host cell comprises a first polynucleotide and a second polynucleotide, wherein the first polynucleotide comprises one of the first nucleotide sequences described above, and the second polynucleotide comprises one of the first nucleotide sequences described above. In another embodiment, the host cell comprises a first vector, wherein the first vector comprises one of the first nucleotide sequences described above, and the second polynucleotide comprises one of the first nucleotide sequences described above. In yet another embodiment, the host cell comprises a first vector and a second vector, wherein the first vector comprises one of the first nucleotide sequences described above, and the second vector comprises a second polynucleotide, wherein the second polynucleotide comprises one of the first nucleotide sequences described above.

[0198] In some embodiments, an Fc domain expressed by a first host cell associates with an Fc domain expressed by a second host cell to form an FcRn antagonist molecule. In some embodiments, this document provides a host cell population comprising such first and second host cells.

[0199] In some embodiments, this document provides a vector family comprising a first vector and a second vector, wherein the first vector comprises a polynucleotide encoding an Fc domain and the second vector comprises a polynucleotide encoding an Fc domain. In some embodiments, this document provides a vector family comprising a first vector and a second vector, wherein the first vector comprises a polynucleotide encoding an Fc domain and the second vector comprises a polynucleotide encoding an Fc domain. In some embodiments, this document provides a vector family comprising a first vector, wherein the first vector comprises a polynucleotide encoding both an Fc domain and a polynucleotide encoding an Fc domain. In some embodiments, this document provides a vector family comprising a first vector, wherein the first vector comprises a polynucleotide encoding two Fc domains.

[0200] A variety of host-expression vector systems can be used to express the peptides described herein (see, for example, U.S. Patent No. 5,807,715, which is incorporated herein by reference in its entirety). Such host-expression systems represent media that can generate and subsequently purify the coding sequence of interest, but also represent cells that can express the peptides described herein in situ when transformed or transfected with a suitable nucleotide coding sequence. These include, but are not limited to: microorganisms, such as bacteria transformed with recombinant phage DNA, plasmid DNA, or copious DNA expression vectors containing, for example, antibody-encoding sequences (e.g., *Escherichia coli* and *Bacillus subtilis*); yeast transformed with, for example, recombinant yeast expression vectors containing, for example, antibody-encoding sequences (e.g., *Saccharomyces* and *Pichia*); insect cell systems infected with, for example, recombinant viral expression vectors containing, for example, antibody-encoding sequences (e.g., baculoviruses); plant cell systems infected with, for example, recombinant viral expression vectors containing, for example, antibody-encoding sequences (e.g., cauliflower mosaic virus CaMV; tobacco mosaic virus TMV) or transformed with, for example, recombinant plasmid expression vectors (e.g., Ti plasmids) (e.g., green algae such as *Chlamydomonas reinhardtii*); or mammalian cell systems (e.g., COS (e.g., COS1 or COS), CHO, BHK, MDCK, HEK). Cells such as 293, NS0, PER.C6, VERO, CRL7O3O, HsS78Bst, HeLa, NIH 3T3, HEK-293T, HepG2, SP210, R1.1, BW, LM, BSC1, BSC40, YB / 20, and BMT10 contain, for example, recombinant expression constructs containing promoters derived from mammalian cell genomes (e.g., metallothionein promoters) or promoters derived from mammalian viruses (e.g., adenovirus late promoters; vaccinia virus 7.5K promoters). In one embodiment, the cells used to express the antibodies described herein are Chinese hamster ovary (CHO) cells, such as CHO cells from the CHO GS System™ (Lonza). In one embodiment, the heavy and / or light chains of the antibodies produced by CHO cells may have N-terminal glutamine or glutamate residues replaced by pyroglutamic acid. In one embodiment, the cells used to express the polypeptides described herein are human cells, such as human cell lines. In one embodiment, the mammalian expression vector is pOptiVEC™ or pcDNA3.3. In another embodiment, bacterial cells such as Escherichia coli, or eukaryotic cells (e.g., mammalian cells) are used to express the recombinant peptide.For example, mammalian cells such as CHO cells, bound to vectors such as major intermediate early gene promoter elements from human cytomegalovirus, are efficient antibody expression systems (Foecking MK and Hofstetter H, (1986) Gene 45: 101-5; and Cockett MI et al., (1990) Biotechnology 8(7): 662-7, each incorporated herein by reference in its entirety). In one embodiment, the polypeptide described herein is produced by CHO cells or NSO cells. In one embodiment, the expression of the nucleotide sequence encoding the polypeptide described herein, containing one, two, or three binding sites of human FcRn, is regulated by a constitutive promoter, an inducible promoter, or a tissue-specific promoter.

[0201] In bacterial systems, a number of expression vectors can be advantageously selected based on the intended use of the expressed antibody molecule. For example, when producing large quantities of such peptides, a vector that directs the high-level expression of an easily purified fusion protein product may be desirable in order to generate a pharmaceutical composition of the antibody molecule. Such vectors include, but are not limited to: the E. coli expression vector pUR278 (Ruether U and Mueller-Hill B, (1983) EMBO J 2: 1791-1794), in which the coding sequence can be individually ligated into the vector along with the lac Z coding region to produce a fusion protein; the pIN vector (Inouye S and Inouye M, (1985) Nuc Acids Res 13: 3101-3109; Van Heeke G and Schuster SM, (1989) J Biol Chem 24: 5503-5509); and so on, all of which are incorporated herein by reference in their entirety. For example, the pGEX vector can also be used to express exogenous peptides as fusion proteins with glutathione 5-transferase (GST). Typically, such fusion proteins are soluble and can be readily purified from lysed cells by adsorption and binding to matrix glutathione agarose beads, followed by elution in the presence of free glutathione. The pGEX vector is designed to include thrombin or factor Xa protease cleavage sites, allowing the cloned target gene product to be released from the GST moiety.

[0202] In insect systems, for example, the alfalfa silver-striped armyworm (Autographa californica) nucleopolyhedrovirus (AcNPV) can be used as a vector for expressing exogenous genes. This virus grows in cells of the fall armyworm (Spodoptera frugiperda). The coding sequence can be cloned separately into non-essential regions of the virus (e.g., polyhedromic protein genes) and placed under the control of AcNPV promoters (e.g., polyhedromic protein promoters).

[0203] In mammalian host cells, numerous virus-based expression systems can be utilized. When adenovirus is used as the expression vector, the coding sequence of interest can be linked to the adenoviral transcription / translation control complex, such as the late promoter and triple leader sequence. This chimeric gene can then be inserted into the adenoviral genome via in vitro or in vivo recombination. Insertion into non-essential regions of the viral genome (e.g., E1 or E3 regions) will produce a viable recombinant virus capable of expressing the molecule in an infected host (see, e.g., Logan J and Shenk T, (1984) PNAS 81(12):3655-9, which is incorporated herein by reference in its entirety). Effective translation of the inserted coding sequence may also require specific start signals. These signals include the ATG start codon and adjacent sequences. Furthermore, the start codon must be in phase with the reading frame of the desired coding sequence to ensure translation of the entire inserted fragment. These exogenous translation control signals and start codons can have a variety of sources, including both natural and synthetic ones. The efficiency of expression can be enhanced by including appropriate transcriptional enhancer elements, transcription terminators, etc. (see, for example, Bitter G et al., (1987) Methods Enzymol. 153: 516-544, which is incorporated herein by reference in its entirety).

[0204] Furthermore, host cell lines can be selected to regulate the expression of inserted sequences or to modify and process gene products in a desired specific manner. Such modifications (e.g., glycosylation) and processing (e.g., cleavage) of protein products can be important for protein function. Different host cells possess characteristic and specific mechanisms for post-translational processing and modification of proteins and gene products. Suitable cell lines or host systems can be selected to ensure proper modification and processing of expressed exogenous proteins. For this purpose, eukaryotic host cells can be used, which possess cellular mechanisms for the appropriate processing of primary transcripts, glycosylation, and phosphorylation of gene products. Such mammalian host cells include, but are not limited to, CHO, VERO, BHK, HeLa, MDCK, HEK 293, NIH 3T3, W138, BT483, Hs578T, HTB2, BT2O, T47D, NSO (a mouse myeloma cell line that does not endogenously produce any immunoglobulin chains), CRL7O3O, COS (e.g., COS1 or COS), PER.C6, VERO, HsS78Bst, HEK-293T, HepG2, SP210, R1.1, BW, LM, BSC1, BSC40, YB / 20, BMT10, and HsS78Bst cells. In one embodiment, the proteins described herein are produced in mammalian cells such as CHO cells.

[0205] In one embodiment, the polypeptide described herein comprises a portion of an antibody having reduced or no fucose content. Such proteins can be produced using techniques known to those skilled in the art. For example, the protein can be expressed in cells deficient in or lacking fucosylation capacity. In one example, a cell line with two alleles knocked out of α1,6-fucosyltransferase can be used to produce an antibody with reduced fucose content. The Potelligent® system (Lonza) is an example of such a system that can be used to produce an antibody with reduced fucose content.

[0206] For long-term, high-yield production of recombinant proteins, stable expression cells can be generated. For example, cell lines that stably express the proteins described herein can be engineered. In one embodiment, the cells provided herein stably express the FcRn antagonist molecule.

[0207] In some respects, instead of using expression vectors containing viral origins of replication, host cells can be transformed with DNA and selectable markers controlled by appropriate expression control elements (e.g., promoters, enhancers, sequences, transcription terminators, polyadenylation sites, etc.). Following the introduction of exogenous DNA / polynucleotides, engineered cells can be allowed to grow in enrichment media for one to two days and then transferred to selectable media. The selectable markers in the recombinant plasmid confer resistance to selection and allow cells to stably integrate the plasmid into their chromosomes and grow to form colonies, which can then be cloned and amplified into cell lines. This method can be advantageously used to engineer cell lines expressing peptides or fragments thereof containing one, two, or three binding sites of the human FcRn described herein. Such engineered cell lines can be particularly useful for screening and evaluating compositions that interact directly or indirectly with the peptide.

[0208] Many selection systems can be used, including but not limited to the herpes simplex virus thymidine kinase (Wigler M et al., (1977) Cell 11(1): 223-32) in tk-, hgprt-, or aprt- cells, respectively; hypoxanthine-guanine phosphoribosyltransferase (Szybalska EH and Szybalski W, (1962) PNAS 48(12): 2026-2034); and adenine phosphoribosyltransferase (Lowy I et al., (1980) Cell 22(3): 817-23) genes, all of which are incorporated herein by reference in their entirety. In addition, antimetabolite resistance can be used as a basis for selecting the following genes: dhfr, which confers resistance to methotrexate (Wigler M et al., (1980) PNAS 77(6): 3567-70; O'Hare K et al., (1981) PNAS 78: 1527-31); gpt, which confers resistance to mycophenolic acid (Mulligan RC and Berg P, (1981) PNAS78(4): 2072-6); neo, which confers resistance to the aminoglycoside G-418 (Wu GY and Wu CH, (1991) Biotherapy 3: 87-95; Tolstoshev P, (1993) Ann Rev Pharmacol Toxicol 32: 573-596; Mulligan RC, (1993) Science 260: 926-932; and Morgan RA and Anderson WF, (1993) Ann Rev Biochem 62: 191-217; Nabel GJ and Felgner PL, (1993) Trends Biotechnol 11(5): 211-5; and hygro, which confers resistance to hygromycin (Santerre RF et al., (1984) Gene 30(1-3): 147-56), all of which are incorporated herein by reference in their entirety.Commonly known methods in the field of recombinant DNA technology can be routinely applied to select desired recombinant clones, and such methods are described, for example, Ausubel FM et al. (eds.), Current Protocols in Molecular Biology, John Wiley & Sons, NY (1993); Kriegler M, Gene Transfer and Expression, A Laboratory Manual, Stockton Press, NY (1990); and in Chapters 12 and 13, Dracopoli NC et al. (eds.), Current Protocols in Human Genetics, John Wiley & Sons, NY (1994); Colbère-Garapin F et al., (1981) J Mol Biol 150: 1-14, all of which are incorporated herein by reference in their entirety.

[0209] Peptide expression levels can be increased by vector amplification (for a review, see Bebbington CR and Henschel CCG, The use of vectors based on gene amplification for the expression of cloned genes in mammalian cells in DNA cloning, pp. 163–188. In DNA Cloning, Vol. III, A Practical Approach. DM Glover (ed.) (Academic Press, New York, 1987), which is incorporated herein by reference in its entirety). When the marker in the vector system is amplifiable, an increase in the level of inhibitor present in the host cell culture will increase the copy number of the marker gene. Since the amplified region is associated with the gene of interest, peptide yield will also increase (Crouse GF et al., (1983) MolCell Biol 3: 257–66, which is incorporated herein by reference in its entirety).

[0210] Host cells can be co-transfected with two or more expression vectors as described herein. These two vectors can contain the same selective markers that enable equal expression of heavy and light chain polypeptides. Host cells can be co-transfected with different amounts of two or more expression vectors. For example, host cells can be transfected with a first expression vector and a second expression vector in any of the following ratios: approximately 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:12, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, or 1:50.

[0211] Alternatively, a single vector encoding and capable of expressing two polypeptides can be used. The coding sequence may contain cDNA or genomic DNA. The expression vector may be monocistronic or polycistronic. Polycistronic nucleic acid constructs may encode 2, 3, 4, 5, 6, 7, 8, 9, 10 or more gene / nucleotide sequences, or in the range of 2 to 5, 5 to 10, or 10 to 20 gene / nucleotide sequences. For example, bicistronic nucleic acid constructs may contain a promoter, a first gene, and a second gene in the following order. In such expression vectors, transcription of both genes may be driven by the promoter, while translation of mRNA from the first gene may be driven by a cap-dependent scanning mechanism, and translation of mRNA from the second gene may be driven by a cap-independent mechanism (e.g., by IRES).

[0212] Once the polypeptide described herein is generated through recombinant expression, it can be purified using any method known in the art for protein purification, such as chromatography (e.g., ion exchange, affinity, particularly affinity for the specific antigen following protein A, and size column chromatography), centrifugation, differential dissolution, or any other standard technique for protein purification. Furthermore, the polypeptide described herein can be fused with heterologous polypeptide sequences described herein or known in the art to facilitate purification.

[0213] In one embodiment, the polypeptide described herein is isolated or purified. In one embodiment, the isolated polypeptide is a polypeptide substantially free of other polypeptides having an antigen specificity different from that of the isolated polypeptide. For example, in some embodiments, the protein formulations described herein are substantially free of cellular material and / or chemical precursors. The language “substantially free of cellular material” includes formulations of polypeptides in which the polypeptide is isolated from the cellular components of the cells from which the polypeptide was isolated or recombined to produce the polypeptide. Thus, polypeptides substantially free of cellular material include polypeptide formulations having less than about 30%, 20%, 10%, 5%, 2%, 1%, 0.5%, or 0.1% (by dry weight) of heterologous proteins (also referred to herein as “contaminating proteins”) and / or polypeptide variants (e.g., different post-translational modifications of the polypeptide or other different versions of the polypeptide (e.g., polypeptide fragments)). When the polypeptide is recombined to produce the polypeptide, it is generally also substantially free of culture medium, i.e., the culture medium constitutes less than about 20%, 10%, 2%, 1%, 0.5%, or 0.1% of the volume of the protein formulation. When the polypeptide is produced by chemical synthesis, it is generally substantially free of chemical precursors or other chemicals, i.e., it is isolated from chemical precursors or other chemicals involved in protein synthesis. Therefore, such protein formulations contain less than about 30%, 20%, 10%, or 5% (on a dry weight) of a chemical precursor or compound other than the protein of interest. In one embodiment, the polypeptide described herein is isolated or purified.

[0214] The peptides described herein can be produced by any method known in the art for protein synthesis, such as chemical synthesis or recombinant expression techniques. Unless otherwise stated, the methods described herein employ conventional techniques from molecular biology, microbiology, genetic analysis, recombinant DNA, organic chemistry, biochemistry, PCR, oligonucleotide synthesis and modification, nucleic acid hybridization, and related fields within the scope of this art. These techniques are described, for example, in the references cited herein and are fully explained therein. See, for example, Maniatis T et al., (1982) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press; Sambrook J et al., (1989) Molecular Cloning: A Laboratory Manual, 2nd Edition, Cold Spring Harbor Laboratory Press; Sambrook J et al., (2001) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY; Ausubel FM et al., Current Protocols in Molecular Biology, John Wiley & Sons (1987 and annual updates); Current Protocols in Immunology, John Wiley & Sons (1987 and annual updates); Gait (ed.) (1984) Oligonucleotide Synthesis: A Practical Approach, IRL Press; Eckstein (ed.) (1991) Oligonucleotides and Analogues: A Practical Approach, IRL Press; Birren B et al. (ed.) (1999) Genome Analysis: A Laboratory Manual, ColdSpring Harbor Laboratory Press, and all these references are incorporated into this article in their entirety by reference.

[0215] In one embodiment, the polypeptide described herein is prepared, expressed, generated, or isolated by any means involving generation, such as via the synthesis of a DNA sequence or genetic engineering. In one embodiment, such polypeptides contain sequences (e.g., DNA sequences or amino acid sequences) that are not naturally present in an antibody phylogenetic library of an in vivo animal or mammal (e.g., a human).

[0216] Pharmaceutical Composition

[0217] In one aspect, this disclosure provides pharmaceutical compositions comprising FcRn antagonist molecules as disclosed herein, used in methods of treating antibody-mediated disorders (e.g., autoantibody-mediated disorders). Typically, these FcRn antagonist molecules inhibit the binding of Fc-containing agents (e.g., antibodies and immunoadhesins) to FcRn in vivo, resulting in an increased degradation rate of the Fc-containing agents and a decrease in serum levels of these agents.

[0218] In some embodiments, the FcRn antagonist molecules of this disclosure have a predicted molecular weight ranging from about 50 kDa to about 57 kDa. In some embodiments, the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is 50 kDa to 57 kDa, 51 kDa to 56 kDa, 52 kDa to 55 kDa, 54 kDa to 55 kDa, or 54.4 kDa to 54.7 kDa. In some embodiments, the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is about 50 kDa, about 51 kDa, about 52 kDa, about 53 kDa, about 54 kDa, about 55 kDa, about 56 kDa, or about 57 kDa. In some embodiments, the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is 50 kDa, 51 kDa, 52 kDa, 53 kDa, 54 kDa, 55 kDa, 56 kDa, or 57 kDa. In some embodiments, the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is about 54.0 kDa, about 54.1 kDa, about 54.2 kDa, about 54.3 kDa, about 54.4 kDa, about 54.5 kDa, about 54.6 kDa, about 54.7 kDa, about 54.8 kDa, or about 54.9 kDa. In some embodiments, the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is 54.0 kDa, 54.1 kDa, 54.2 kDa, 54.3 kDa, 54.4 kDa, 54.5 kDa, 54.6 kDa, 54.7 kDa, 54.8 kDa, or 54.9 kDa.

[0219] In some embodiments, no more than 0.1%, no more than 0.2%, no more than 0.3%, no more than 0.4%, no more than 0.5%, no more than 0.6%, no more than 0.7%, no more than 0.8%, no more than 0.9%, or no more than 1.0% of the FcRn antagonist molecules in the population are aggregated. In some embodiments, about 0.1%, about 0.2%, about 0.3%, about 0.4%, about 0.5%, about 0.6%, about 0.7%, about 0.8%, about 0.9%, or about 1.0% of the FcRn antagonist molecules in the population are aggregated. In some embodiments, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0% of the FcRn antagonist molecules in the population are aggregated. In some embodiments, 0.1% to 1.0%, 0.3% to 0.8%, 0.4% to 0.6%, or 0.3% to 0.5% of the FcRn antagonist molecules in the population are aggregated.

[0220] In some embodiments, 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% of the dimers in a population of FcRn antagonist molecules are linked by at least one disulfide bond. In some embodiments, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% of the dimers in a population of FcRn antagonist molecules are linked by at least one disulfide bond. In some embodiments, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the dimers in a population of FcRn antagonist molecules are linked by at least one disulfide bond. In some embodiments, 90% to 99%, 92% to 97%, 94% to 96%, or 93% to 95% of the dimers in a population of FcRn antagonist molecules are linked by at least one disulfide bond.

[0221] In some embodiments, no more than 0.2%, no more than 0.4%, no more than 0.6%, no more than 0.8%, no more than 1.0%, no more than 1.2%, no more than 1.4%, no more than 1.6%, no more than 1.8%, or no more than 2.0% of the FcRn antagonist molecules in the population have free thiol groups. In some embodiments, about 0.2%, about 0.4%, about 0.6%, about 0.8%, about 1.0%, about 1.2%, about 1.4%, about 1.6%, about 1.8%, or about 2.0% of the FcRn antagonist molecules in the population have free thiol groups. In some embodiments, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, or 2.0% of the FcRn antagonist molecules in the population have free thiol groups. In some embodiments, 0.2% to 2.0%, 0.6% to 1.6%, 0.8% to 1.2%, or 0.7% to 1.0% of the FcRn antagonist molecules in the population have free thiol groups.

[0222] In some embodiments, the FcRn antagonist molecule is administered intravenously (IV) or subcutaneously (SC).

[0223] For IV administration, in some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising sodium phosphate, sodium chloride, L-arginine hydrochloride, and polysorbate 80. In some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising about 25 mM sodium phosphate, about 100 mM sodium chloride, about 150 mM L-arginine hydrochloride (pH 6.7), and about 0.02% (w / v) polysorbate 80. In some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising 25 mM sodium phosphate, 100 mM sodium chloride, 150 mM L-arginine hydrochloride (pH 6.7), and 0.02% (w / v) polysorbate 80. In some embodiments, the FcRn antagonist molecule can be administered intravenously in a total volume of about 250 mL over a period of about 2 hours, in a formulation comprising about 25 mM sodium phosphate, about 100 mM sodium chloride, and about 150 mM L-arginine hydrochloride (pH 6.7) and about 0.02% (w / v) polysorbate 80. See, for example, WO2019110823A1, which is incorporated herein by reference in its entirety.

[0224] In some embodiments, the FcRn antagonist molecule can be administered as a formulation comprising an aqueous solution containing about 25 mM sodium phosphate, about 100 mM sodium chloride, and about 150 mM L-arginine hydrochloride, at a pH of about 6.7, and containing about 0.02% (w / v) polysorbate 80, diluted for intravenous infusion over a period of about 1 hour to a total volume of about 125 mL. In some embodiments, the FcRn antagonist molecule can be administered as a formulation comprising an aqueous solution containing 25 mM sodium phosphate, 100 mM sodium chloride, and 150 mM L-arginine hydrochloride, at a pH of 6.7, and containing 0.02% (w / v) polysorbate 80, diluted for intravenous infusion over a period of 1 hour to a total volume of 125 mL.

[0225] In some embodiments, the FcRn antagonist molecule can be administered as a formulation comprising an aqueous solution containing about 4 mM sodium phosphate, about 146 mM sodium chloride, about 24 mM L-arginine, and about 0.0032% (w / v) polysorbate 80, at a pH of about 6.7. This formulation is administered via intravenous infusion, with a total intravenous infusion volume of about 125 mL over a period of about 1 hour. In some embodiments, the FcRn antagonist molecule can be administered as a formulation comprising an aqueous solution containing 4 mM sodium phosphate, 146 mM sodium chloride, 24 mM L-arginine, and 0.0032% (w / v) polysorbate 80, at a pH of 6.7. This formulation is administered via intravenous infusion, with a total intravenous infusion volume of 125 mL over a period of 1 hour.

[0226] In some embodiments, the FcRn antagonist molecule may be administered via intravenous infusion and provided as a sterile, colorless, clear concentrated solution at a concentration of about 20 mg / mL.

[0227] In some embodiments, the FcRn antagonist molecule may be administered via IV infusion and provided in a vial (e.g., a single-dose vial). In some embodiments, the vial of the FcRn antagonist molecule contains about 400 mg of the FcRn antagonist molecule at a concentration of about 20 mg / mL. In some embodiments, each mL of solution in the vial of the FcRn antagonist molecule contains about 31.6 mg of L-arginine hydrochloride, about 0.2 mg of polysorbate 80, about 5.8 mg of sodium chloride, about 2.4 mg of anhydrous disodium hydrogen phosphate, about 1.1 mg of sodium dihydrogen phosphate monohydrate, and water for injection, USP, pH about 6.7. In some embodiments, each mL of the FcRn antagonist molecule vial contains 31.6 mg L-arginine hydrochloride, 0.2 mg polysorbate 80, 5.8 mg sodium chloride, 2.4 mg anhydrous disodium hydrogen phosphate, 1.1 mg sodium dihydrogen phosphate monohydrate, and water for injection, USP, pH 6.7.

[0228] In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered via intravenous infusion at a dose of approximately 10 mg / kg. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered via intravenous infusion at a dose of approximately 10 mg / kg over approximately one hour. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered via intravenous infusion at a dose of approximately 10 mg / kg once weekly over approximately one hour. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered via intravenous infusion at a dose of approximately 10 mg / kg once weekly over approximately one hour for approximately 4 weeks. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered via intravenous infusion at a dose of 10 mg / kg. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered via intravenous infusion at a dose of 10 mg / kg over one hour. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered once weekly via one-hour intravenous infusion at a dose of 10 mg / kg. In some embodiments, for patients weighing less than 120 kg, the FcRn antagonist molecule may be administered once weekly via one-hour intravenous infusion for 4 weeks. In some embodiments, for patients weighing 120 kg or more, the FcRn antagonist molecule may be administered at a dose of approximately 1200 mg per intravenous infusion. In some embodiments, for patients weighing 120 kg or more, the FcRn antagonist molecule may be administered at a dose of 1200 mg per intravenous infusion.

[0229] For SC administration, in some embodiments, the FcRn antagonist molecule may be administered alone. Alternatively, for SC administration, in some embodiments, the FcRn antagonist molecule may be co-formulated with hyaluronidase (e.g., particularly rHuPH20). Co-formulated materials will allow for a larger volume of SC administration.

[0230] In some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising an aqueous solution containing about 20 mM L-histidine, about 100 mM sodium chloride, about 60 mM sucrose, about 10 mM L-methionine, and about 0.04% (w / v) polysorbate 20, wherein the composition has a pH of about 6.0. In some embodiments, the formulation comprises about 180 mg / mL of the FcRn antagonist molecule. In some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising an aqueous solution containing 20 mM L-histidine, 100 mM sodium chloride, 60 mM sucrose, 10 mM L-methionine, and 0.04% (w / v) polysorbate 20, wherein the composition has a pH of 6.0. In some embodiments, the formulation comprises 180 mg / mL of the FcRn antagonist molecule.

[0231] In some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising an aqueous solution containing about 20 mM L-histidine, about 50 mM L-arginine, about 100 mM sodium chloride, about 60 mM sucrose, about 10 mM L-methionine, and about 0.04% (w / v) polysorbate 80, wherein the composition has a pH of about 6.0. In some embodiments, the formulation comprises about 200 mg / mL of the FcRn antagonist molecule. In some embodiments, the FcRn antagonist molecule may be administered as a formulation comprising an aqueous solution containing 20 mM L-histidine, 50 mM L-arginine, 100 mM sodium chloride, 60 mM sucrose, 10 mM L-methionine, and 0.04% (w / v) polysorbate 80, wherein the composition has a pH of 6.0. In some embodiments, the formulation comprises 200 mg / mL of the FcRn antagonist molecule.

[0232] The formulations disclosed herein include bulk pharmaceutical compositions that can be used to manufacture pharmaceutical compositions (e.g., compositions suitable for administration to subjects or patients) and that can be used to prepare unit dosage forms. In one embodiment, the compositions of the present invention are pharmaceutical compositions. Such compositions comprise a preventive or therapeutically effective amount of one or more of the preventive or therapeutic agents of the present invention (e.g., FcRn antagonist molecules) (or other preventive or therapeutic agents) and a pharmaceutically acceptable carrier.

[0233] In some embodiments, the pharmaceutical compositions are formulated for administration to a subject via any suitable route of administration, including but not limited to intramuscular, intravenous, intradermal, intraperitoneal, subcutaneous, epidural, intranasal, oral, rectal, local, inhalation, oral (e.g., sublingual), and transdermal administration. In one embodiment, the pharmaceutical compositions are formulated for intravenous administration to a subject. In one embodiment, the pharmaceutical compositions are formulated for subcutaneous administration to a subject.

[0234] Treatment

[0235] In one embodiment, the FcRn antagonist molecule antagonizes the binding of FcRn to the Fc region of an antibody. This disclosure provides a method for reducing serum IgG in a subject, comprising administering to the subject a therapeutically effective amount of an FcRn antagonist molecule according to this disclosure or a pharmaceutical composition comprising thereto. In one embodiment, the level of serum IgG in the subject decreases after administration of the FcRn antagonist molecule compared to baseline serum IgG levels. In one embodiment, a reduction of approximately 60% in total serum IgG compared to baseline serum IgG levels is achieved. In one embodiment, a reduction of approximately 65%, approximately 70%, approximately 75%, or approximately 80% in total serum IgG compared to baseline serum IgG levels is achieved. In one embodiment, a reduction of approximately 65% ​​in total serum IgG compared to baseline serum IgG levels is achieved. In one embodiment, a reduction of approximately 70% in total serum IgG compared to baseline serum IgG levels is achieved. In one embodiment, a reduction of approximately 75% in total serum IgG compared to baseline serum IgG levels is achieved. In one embodiment, a reduction of approximately 80% in total serum IgG compared to baseline serum IgG levels is achieved.

[0236] In one embodiment, the level of FcRn in the subject did not decrease after administration of the FcRn antagonist molecule compared to baseline FcRn levels. In one embodiment, a decrease in FcRn of less than about 1%, 2%, 3%, 4%, or 5% compared to baseline FcRn levels was observed. In one embodiment, a decrease in FcRn of less than about 10% compared to baseline FcRn levels was observed.

[0237] This disclosure also provides a method for treating antibody-mediated disorders (e.g., autoantibody-mediated disorders), comprising administering to a subject a therapeutically effective amount of an FcRn antagonist molecule according to this disclosure or a pharmaceutical composition comprising thereunder.

[0238] In some embodiments, antibody-mediated disorders are autoimmune diseases.In some embodiments, autoimmune diseases are selected from the group consisting of: allogeneic islet transplant rejection, alopecia areata, ankylosing spondylitis, antiphospholipid syndrome, autoimmune Addison's disease, Alzheimer's disease, antineutrophil cytoplasmic autoantibodies (ANCA), adrenal autoimmune diseases, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune myocarditis, autoimmune neutropenia, autoimmune oophoritis and orchitis, immune thrombocytopenic purpura (ITP or idiopathic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, immune-mediated thrombocytopenia or primary immune thrombocytopenia), autoimmune urticaria, Behcet's disease, bullous pemphigoid (BP), cardiomyopathy, giant lymphadenopathy, celiac disease and herpetic dermatitis, chronic fatigue immune dysfunction syndrome, chronic inflammatory diseases, etc. Demyelinating polyneuropathy (CIDP), Chalcger-Strauss syndrome, cicatricial pemphigoid, CREST syndrome, cold agglutinin disease, Crohn's disease, dilated cardiomyopathy, discoid lupus, acquired epidermolysis bullosa, mixed cryoglobulinemia, factor VIII deficiency, fibromyalgia-fibromyositis, glomerulonephritis, Graves' disease, Guillain-Barré syndrome, pulmonary hemorrhage nephritis syndrome, graft-versus-host disease (GVHD), Hashimoto's thyroiditis, hemophilia A, idiopathic inflammatory myopathy (IIM), idiopathic membranous neuropathy, idiopathic pulmonary fibrosis, IgA neuropathy, IgM polyneuropathy, immune-mediated necrotizing myopathy (IMNM), juvenile arthritis, Kawasaki disease, lichen planus, lichen sclerosus, lupus erythematosus, lupus nephritis, Ménière's disease Diseases, mixed connective tissue disease, mucosal pemphigoid, multiple sclerosis, type 1 diabetes, multifocal motor neuropathy (MMN), myasthenia gravis (MG), generalized myasthenia gravis (gMG), myositis, paraneoplastic bullous pemphigoid, gestational pemphigoid, pemphigus vulgaris (PV), pemphigus foliaceus (PF), pernicious anemia, polyarteritis nodosa, relapsing polychondritis, polygonatum syndrome, polymyalgia rheumatica, polymyositis, dermatomyositis (DM), necrotizing autoimmune myopathy (NAM), antisynthetic enzyme syndrome (ASyS), primary agammaglobulinemia, primary biliary cirrhosis, psoriasis, psoriatic arthritis, relapsing chondritis, Raynaud's phenomenon, Reiter's syndrome, rheumatoid arthritis, sarcoidosis, scleroderma, Sjögren's syndrome (Syndrome), solid organ transplant rejection, stiff-person syndrome, systemic lupus erythematosus, aortitis, toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), temporal arteritis / giant cell arteritis, thrombotic thrombocytopenic purpura, ulcerative colitis, uveitis, herpetic dermatitis vasculitis, antineutrophil cytoplasmic antibody-associated vasculitis, vitiligo, and Wegener's granulomatosis.

[0239] In one embodiment, after administration of the FcRn antagonist molecule, at least one IgG subtype is reduced in the subject's body. In one embodiment, after administration of the FcRn antagonist molecule, at least one IgG subtype is reduced in the subject's serum. In one embodiment, IgG1 is reduced. In one embodiment, IgG2 is reduced. In one embodiment, IgG3 is reduced. In one embodiment, IgG4 is reduced. In some embodiments, after a single administration of the FcRn antagonist molecule, the total serum IgG in the subject is reduced by at least 10%, at least 20%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70%.

[0240] In some embodiments, the clearance rate of total serum IgG in the subject increases after administration of the FcRn antagonist molecule. In some embodiments, the clearance rate of total serum IgG in the subject after a single therapeutic administration of the FcRn antagonist molecule is comparable to the clearance rate of total serum IgG in the subject after a single therapeutic administration of efgartigimod. In some embodiments, the clearance rate of total serum IgG in the subject after a single therapeutic administration of the FcRn antagonist molecule is similar to or the same as the clearance rate of total serum IgG in the subject after a single therapeutic administration of efgartigimod.

[0241] In some embodiments, the clearance rate of total serum IgG in a subject after a single administration of an FcRn antagonist molecule is comparable to the clearance rate of total serum IgG in a subject after a single administration of an equivalent amount of icamod. In some embodiments, the clearance rate of total serum IgG in a subject after a single administration of an FcRn antagonist molecule is similar to or the same as the clearance rate of total serum IgG in a subject after a single administration of an equivalent amount of icamod.

[0242] In one embodiment, the FcRn antagonist molecule is administered to the subject simultaneously or sequentially with another therapeutic agent. In one embodiment, the other therapeutic agent is an anti-inflammatory agent. In one embodiment, the other therapeutic agent is a corticosteroid. In one embodiment, the other therapeutic agent is rituximab, daclizumab, basiliximab, muromonab-CD3, infliximab, adalimumab, omalizumab, efalizumab, natalizumab, tocilizumab, eculizumab, golimumab, canakinumab, ustekinumab, or belimumab. In one embodiment, the additional therapeutic agent is a leukocyte-depleting agent.

[0243] In one embodiment, the additional therapeutic agent is a B-cell depleting agent. In one embodiment, the B-cell depleting agent is an antibody. In one embodiment, the B-cell depleting antibody is an antibody that specifically binds to CD10, CD19, CD20, CD21, CD22, CD23, CD24, CD37, CD53, CD70, CD72, CD74, CD75, CD77, CD79a, CD79b, CD80, CD81, CD82, CD83, CD84, CD85, or CD86.

[0244] In some embodiments, the FcRn antagonist molecule is administered intravenously. In some embodiments, the FcRn antagonist molecule is administered intravenously once a week, once every two weeks, once every three weeks, once every four weeks, once a month, or once every six weeks.

[0245] In some embodiments, FcRn antagonist molecules are administered subcutaneously. In some embodiments, FcRn antagonist molecules are administered subcutaneously once a week, once every two weeks, once every three weeks, once every four weeks, once a month, or once every six weeks.

[0246] Example

[0247] The following examples are provided in an illustrative rather than restrictive manner.

[0248] Example 1: Identification of molecular variants of FcRn antagonists

[0249] Compositions containing a population of Fc antagonist molecules were characterized and their components identified. Sample batch 1 was used as an analytical reference standard. All analyses were performed against batch 1 and working reference standards (batch 2 sample, both derived from the same drug substance batch) and reference standards used throughout clinical development (batch 3 sample). Batches were prepared using vectors designed to express SEQ ID NO:2 using the CHOK1SV GS-KO cell line (Lonza Group Ltd.).

[0250] The charge heterogeneity of the reference sample was assessed using strong cation exchange high-performance liquid chromatography (CEX HPLC). This assay was used to determine the charge heterogeneity characteristics of the sample to assess purity. Proteins present in the sample were separated and quantified based on the interaction between the charge on the protein surface and the charged groups on the column surface, according to their surface charge distribution. Proteins carry a positive charge in buffer solutions with pH values ​​lower than their p1. Proteins were eluted from the column using a sodium chloride gradient (mobile phase B), first eluting acidic species and then eluting more basic species. The separated fractions were passed through a UV detector unit, and absorbance was measured at a wavelength of 220 nm. The results are shown in Table 5 and... Figure 1 middle.

[0251] Based on the elution time of the eluted species relative to the main peak in the CEX spectrum, the peaks of the eluted species were classified as acidic or basic. Peaks eluted earlier than the main peak (peak 8) were identified as acidic species (peaks 1 to 7), while peaks eluted later (peaks 9 to 12) were identified as basic species. A total of twelve (12) charged species were identified by CEX for all three reference standards. The main isomer was present with approximately 65% ​​of the relative percentage area. The total basic and acidic isomers accounted for approximately 18% and 17% of the relative percentage area, respectively.

[0252] Table 5: CEX Results of FcRn Antagonist Reference Standards

[0253]

[0254] The identities of different CEX isomer peaks were determined by reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) analysis of the complete and trypsin-digested separated CEX fractions. The identities of the various peaks are presented in... Figure 2 And in Table 6.

[0255] Analysis of the samples after treatment with carboxypeptidase B (CPB) (resulting in complete lysine truncation) also confirmed the identities of peak 9 (i.e., the single lysine cleavage variant) and peak 11 (i.e., the uncleaved lysine variant).

[0256] Table 6: Identity of Charge Variants in CEX

[0257]

[0258] - =Identity could not be determined because the abundance of the peak was too low for the graded collection.

[0259] 1 Trace amounts of the sialylated variant (Fc / 0K+NANA) were co-eluted at peaks 4, 6, and 7.

[0260] 2 Fc fragments, double C-terminal lysine cleavage, and double C-terminal extension variants (Fc / 0k / +2ext) also eluted at peak 6 (if present).

[0261] 3 Fc fragments, double C-terminal lysine cleavage, and single C-terminal extension variants (Fc / 0k / +1ext) also eluted at peak 7 (if present).

[0262] 4 Since carboxypeptidase treatment did not result in a complete reduction of peaks 9 and 11, the unknown variant may have been co-eluted at this retention time.

[0263] The charge heterogeneity of the reference sample was also assessed using imaging capillary isoelectric focusing (icIEF). The results are shown in Table 7 and... Figure 3 middle.

[0264] Peaks were numbered based on their measured isoelectric point (pI) relative to the main peak. Peaks showing a pI at pH values ​​below the main peak were identified as acidic species, while peaks showing a pI at higher pH values ​​were identified as basic species.

[0265] Six isomers were detected in the pI range of 6.7 to 7.6. The main isomer was detected with a pI of approximately 7.2 and a relative percentage area of ​​67%. The total basic isomer accounted for 15% of the relative percentage area, and the total acidic isomer accounted for 18% of the relative percentage area.

[0266] Table 7: icIEF test results of the reference standard

[0267]

[0268] Since classifying the separated charge variants is more challenging for icIEF compared to CEX, a different approach was used to characterize the charge variants resolved by icIEF. The separated and identified CEX fractions were subjected to icIEF, and isomers were identified based on electrophoresis maps. The identities of the different isomers are presented in Table 8.

[0269] By performing icIEF on the CEX fraction of peak 6, it can be concluded that both the double deamidated and double-extended variants elute as isomer 5 on icIEF. Earlier icIEF spiking studies using the double C-terminal extended variant generated from pure recombination also showed that the double-extended variant eluted as isomer 5 on icIEF.

[0270] The CEX fraction of peak 7 was eluted as isomer 4 on icIEF, thus isomer 4 was identified as a co-elutant of a single deamidated and a single extended variant.

[0271] The major variant on CEX, peak 8, was identified as the Fc of the bis-lysine cleavage and eluted as the main isomer 3 on icIEF.

[0272] Isomer 2 on icIEF was identified as a monolysine cleavage variant. This was confirmed by icIEF of CEX peak 9.

[0273] Isomer 1 was identified as a non-lysine cleavage variant by icIEF of CEX peak 11. The identities of the monolysine and non-lysine cleavage variants were also confirmed by analysis of samples after treatment with carboxypeptidase (CPB) (resulting in complete lysine truncation). After CPB treatment, reductions in isomers 1 and 2 were observed, and the unknown variant was observed to elute at the same retention time, similar to the observations at CEX.

[0274] Compared to CEX spectra, the oxidized members of the Fc antagonist molecule population were not separated by icIEF. This was confirmed by analyzing the CEX fractions of peak 10 (single oxidation on a dilysine cleavage variant) and peak 11b (double oxidation on a dilysine cleavage variant) (both eluted as isomer 3 (previously confirmed as a dilysine cleavage variant) on icIEF), and by analyzing the CEX fraction of peak 11a (a monolysine cleavage and single oxidation variant) (eluted as isomer 2 (previously confirmed as a monolysine cleavage variant) on icIEF). This is related to the mechanism of separation. On icIEF, charge variants are separated based on apparent pI. On CEX, charge variants are separated by surface charge. For Fc antagonist molecules, oxidation affects the surface charge, resulting in the resolvable peaks on CEX.

[0275] Table 8: Analysis based on CEX classification, identifying charge variants of icIEF

[0276]

[0277] - =Identification could not be determined because the abundance of the peak was too low for fractional collection and icIEF analysis.

[0278] 1Fc fragments, double C-terminal lysine cleavage, and double C-terminal extension variants (Fc / 0k / +2ext) were also eluted at CEX peak 6 (if present).

[0279] 2 Fc fragments, double C-terminal lysine cleavage, and single C-terminal extension variants (Fc / 0k / +1ext) were also eluted at CEX peak 7 (if present).

[0280] Example 2: Identification of the universality of FcRn antagonist molecular variants

[0281] The prevalence of N-terminal truncation was detected by RPLC-MS of complete and N-deglycosylated and reduced proteins, as well as by reduced peptide mapping (trypsin and chymotrypsin digestion), and quantified by CEX HPLC. Table 9 shows the relative peak areas of peak 4 (N-terminal deletion of DKTH), peak 5 (N-terminal deletion of DK), and peak 12 (N-terminal deletion of D).

[0282] A fairly low level of N-terminal truncation was observed during CEX release, such as Figure 1 As shown, the data comes from reference standard samples and process validation batches.

[0283] Table 9: Relative percentage of N-terminal truncation determined by CEX

[0284]

[0285] Furthermore, in the long-term stability study, no changes were observed in peaks 4 and 5 at -70℃, +5℃, and +25℃, as shown below. Figure 4 and Figure 5 As shown.

[0286] N-terminal truncated variants are considered a quality attribute that contributes to product heterogeneity.

[0287] C-terminal lysine cleavage can be detected by RPLC-MS of intact, N-deglycosylated, and reduced proteins, as well as by mapping the reduced peptides, and can be quantified by CEX HPLC and icIEF. In the CEX spectrum, the main peak 8 and the basic peaks 9 and 11 correspond to the dilysine cleavage, monolysine cleavage, and lysine uncleavage variants, respectively (see Table 6). In the icIEF spectrum, the same isomers appear as the main isomer (dilysine cleavage), basic isomer 2 (monolysine cleavage), and basic isomer 1 (lysine uncleavage) (see Table 8).

[0288] The levels of C-terminal lysine cleavage variants identified by CEX and icIEF were consistent between the reference standard samples and process validation batches using both methods, as shown in Tables 10 and 11.

[0289] Table 10: Relative percentage of C-terminal lysine cleavage variants determined by CEX

[0290]

[0291] Table 11: Relative percentage of C-terminal lysine cleavage variants determined by icIEF

[0292]

[0293] Furthermore, in long-term stability studies, no changes were observed in CEX peaks 9 and 11 or in icIEF isomers 1 or 2 at -70℃, +5℃, and +25℃. Figures 6 to 9 As shown. Therefore, C-terminal lysine variants are considered a quality attribute that contributes to product heterogeneity and has no effect on efficacy.

[0294] During reduced trypsin peptide mapping and subsequent RP-LC / MS assays, three deamidation sites were identified in members of the Fc antagonist molecule population (see Table 15). These three identified deamidation sites were GFYPSDIAVEWESNGQPENNYK (SEQ ID NO: 24) (T19; amino acid positions 151-172), VVSVLTVLHQDWLNGK (SEQ ID NO: 25) (T08, amino acid positions 082-097), and NQVSLTCLVK (SEQ ID NO: 26) (T18, amino acid positions 141-150), and none of them are involved in FcRn binding.

[0295] Example 3: The prevalence of post-translation modification in the Fc structural domain

[0296] The prevalence of post-translational modifications in the Fc domain of the Fc antagonist reference sample was estimated by comparing the ionic strength of the modified peptide with that of the unmodified peptide.

[0297] For trypsin digestion, the test sample was denatured in urea before reduction with dithiothreitol (DTT). The resulting free thiol groups were alkylated using sodium iodoacetate. The sample was then digested with trypsin, and the resulting peptides were analyzed using RPLC combined with UV and MS detection (ESI Q-TOF).

[0298] The measured signals were matched to the sequences using the BioConfirm algorithm integrated in MassHunter software. The quality tolerance for experimental data matching to sequence was set at 20 ppm. For peptide mapping under reducing conditions, methionine and tryptophan oxidation, asparagine and glutamine deamidation, and complex N-glycans (G0, G0F, G1F, G2F, Man5) were considered variable modifications, while cysteine ​​aminomethylation (sample preparation relevant) was considered a fixed modification. The specified enzyme was trypsin (cleaving at the C-terminus of lysine or arginine), with 0 to 2 missed cuts allowed. Peak areas of the extracted ion chromatograms obtained at a quality accuracy of 20 ppm were used to quantify the modifications. Peptides containing aspartic acid and isoaspartic acid had the same m / z but could be distinguished based on chromatographic retention time, with isoaspartic acid eluting before the aspartic acid-containing peptide.

[0299] For chymotrypsin digestion, the test sample was denatured in RapiGest before reduction with dithiothreitol (DTT). The resulting free thiol groups were alkylated using iodoacetamide. The sample was then digested with chymotrypsin, and the resulting peptides were analyzed using RPLC combined with UV and MS detection (ESI Q-TOF).

[0300] The measured signals were matched to the sequences using the BioConfirm algorithm integrated in MassHunter software. The quality tolerance for experimental data to sequence matching was set at 20 ppm. For mapping of the reduced chymotrypsin peptide, N-terminal truncation was considered a variable modification, while cysteine ​​carbamoyl methylation (sample preparation relevant) was considered a fixed modification. The specified enzyme was chymotrypsin (C-terminated at tyrosine, tryptophan, and phenylalanine), with 0 to 2 missed cuts allowed. Peak areas from the extracted ion chromatograms obtained at a quality tolerance of 20 ppm were used to quantify the modifications.

[0301] N-terminal modification

[0302] The assessment of potential processing (e.g., truncation) occurring at the N-terminus using the current sample preparation is hampered by the fact that trypsin cleaves at both K and R. Therefore, additional digestion is performed using chymotrypsin with different preferred cleavage sites.

[0303] Three N-terminal variants, -D, -DK, and -DKTH, were identified at low abundance (<1%) using chymotrypsin.

[0304] The truncated DKTH peptide (TCPPCPAPELLGGPSVFLFPPKPK (SEQ ID NO: 27), 005-028) was also identified using trypsin digestion. The levels of this peptide are shown in Table 12. Similar low levels (<1.6%) of this peptide were found in all samples tested.

[0305] Table 12: Relative quantification of N-terminal modifications. Quantification based on extracted ion MS chromatograms.

[0306]

[0307] C-terminal modification

[0308] Table 13 lists the C-terminal peptide species present in the population of Fc antagonist molecules. The dominant C-terminal peptide is a cleaved lysine (K). The K truncation level ranges from 88.0% to 89.0%. The lysine truncation is similar in all reference standards. Another C-terminal variant, SLSLSP (caused by C-terminal -GK truncation and P-amidation), was identified at a level of approximately 0.5%.

[0309] Table 13: Relative quantification of C-terminal modification based on extracted ion MS chromatograms

[0310]

[0311] Deamidation and isomerization

[0312] The identified aspartic acid (D) isomerization and asparagine (Q) deamidation sites are presented in Tables 14 and 15.

[0313] Two peptide isomerizations were found, peptides 055-068 and 173-189. The percentage of isomerization was relatively low (<1%) and comparable to the reference standard.

[0314] Three peptides were found to be deamidated: peptides 082-097, 141-150, and 151-172. The levels of deamidation were comparable among the reference standards, with peptide 151-172 showing the highest level.

[0315] Table 14: Relative quantification of aspartic acid isomerization based on extracted ion MS chromatograms

[0316]

[0317] Table 15: Relative quantification of deamidation based on extracted ion MS chromatograms

[0318]

[0319] Oxidation

[0320] The identified oxidation sites are presented in Table 16. For the reference samples analyzed, the methionine oxidation levels in peptides 197-213 ranged from 0.7% to 1.0%. No tryptophan oxidation was observed.

[0321] Table 16: Relative quantification of methionine oxidation based on extracted ion MS chromatograms

[0322]

[0323] N-glycosylation

[0324] Table 17 presents the occupancy rates of N-glycosylation sites (Asn77 in peptides 073-081). The total occupancy rates for the three reference standards ranged from 97.8% to 97.9%. The dominant glycoform was G0F (59.2% to 64.3%). The observed glycoforms aligned well with those observed in RPLC-MS and N-linked oligosaccharide analyses.

[0325] Table 17: Relative quantification of N-glycosylation based on extracted ion MS chromatograms

[0326]

[0327] Figure 10 and Figure 11 Hydrophilic interaction liquid chromatography (HILIC) fluorescence chromatograms of 2-aminobenzamide (2-AB)-labeled N-glycans derived from reference samples are shown. Peak identification is a result of mass spectrometry data interpretation and chromatographic elution, as well as the rules governing glycan biosynthesis. Quantification is based on fluorescence peak area. N-glycan identity and relative intensities are shown in Table 18. Figure 12 The same data are shown graphically. The degrees of galactosylation and fucosylation are shown in Table 19. Figure 13 middle.

[0328]

[0329] Table 19: Galactosylation and Fucosylation Degrees of Reference Samples at Glycan Levels

[0330]

[0331] All samples exhibited similar spectra, with G0F being the dominant glycoform, followed by G1F and G2F. Low levels of unfucosylated N-glycans, Man5, sialic acid addition, and GlcNac loss were detected at comparable levels in all samples. Reference sample batch 3 showed a slightly lower degree of galactosylation compared to other samples. Fucosylation levels ranged between 94.7% and 94.9% for all tested samples.

[0332] The complete RPLC-UV 214 nm spectrum of the reference standard is shown in... Figure 14 The identity and quality accuracy of the annotated peaks obtained from the deconvolution MS spectra of each peak are presented in Table 20.

[0333] Table 20: Complete ESI-MS Results of Main Reference Standard Batch 1

[0334]

[0335] Da = Dalton; Fc / 0K = dilysine cleavage; Fc / 1K = monolysine cleavage; Fc / 2K = non-lysine cleavage.

[0336] 1. Possible methods to induce variants.

[0337] The detected major mass was comparable to the theoretical major intact mass of the population of 53,915 Da Fc antagonist molecules calculated based on the amino acid sequence of the double C-terminal lysine cleavage, with each of the two G0F glycans accounting for 100%. Other peaks were identified as C-terminal lysine cleavage variants (single or double cleavage), N-terminal DK deletion, addition of +18 Da or +36 Da (possibly induced by water addition), reductoids (deficient interchain disulfide bonds), column-on-column reoxidation of reductoids, partially non-glycosylated Fc, and Fc lacking disulfide bonds.

[0338] Figure 15 The deconvolution spectra of the main peak in the RPLC spectrum (i.e., the double C-terminal lysine cleavage variant) are shown (labeled N-glycoforms). The measured molecular weight and mass precision for each glycoform are shown in Table 21. The relative intensities for each glycoform are shown in Table 22. Figure 16 The figure provides a graphical representation of the relative amounts of various N-glycans for all samples.

[0339] Table 21: Measured molecular weight and corresponding mass precision of sugar forms for complete reference samples

[0340]

[0341]

[0342] Table 22: Relative strength of sugar types in the complete reference samples

[0343]

[0344] The figure shows that the main glycoform is G0F / G0F, and small differences in N-glycosylation were observed between samples.

[0345] Example 4: Properties of Drug Compounds

[0346] Gathering

[0347] GP HPLC was performed to determine the levels of monomeric and aggregate species present in the FcRn antagonist reference sample and to assess the protein conformation under non-denaturing conditions. The results are shown in Table 23 and... Figure 17 In all three reference standards, the percentage of monomers was 99.6%, and the percentage of aggregates was 0.4%.

[0348] Table 23: GP HPLC detection results of reference standards

[0349]

[0350] LOQ = 0.1%, LOD = 0.04%

[0351] disulfide bonds

[0352] Under non-reducing conditions, such as Figure 18 As shown in Table 24, the main peak corresponding to the molecular weight of the intact Fc region is visible in the electrophoresis pattern. The purity (intact Fc %) under non-reducing conditions is 98.2%. In magnified views of the electrophoresis patterns of primary reference standard batch 1 and working reference standard batch 2, several secondary peaks migrating before the IgG peak can be seen, which likely correspond to the reduced (single Fc domain) fragment.

[0353] Table 24: Non-reducing CE SDS test results of reference standards

[0354]

[0355] Quality and quality heterogeneity

[0356] SEC-MALS was performed to further confirm the molecular weight distribution and relative amounts of monomeric and aggregate species observed by GP HPLC combined with UV detection. The ability of the separated components to scatter light, measured using a light scattering detector, was used to estimate molecular weight.

[0357] The monomer molecular weight of the reference standard determined by size exclusion chromatography with multi-angle light scattering (SEC-MALS) is comparable to the theoretical molecular weight of 53,915 Da and is consistent with the results obtained by GP HPLC (see Table 25 and...). Figure 18 ).

[0358] Table 25: Results of Monomer Mass Heterogeneity Analysis of Reference Standards

[0359]

[0360] ND: Not detected

[0361] Free thiols

[0362] The free thiol content of the reference standard was determined using Ellman's reagent. To determine the presence of any free cysteine ​​residues within the protein's internal structure, the assay was also performed after antibody denaturation.

[0363] Under natural conditions, the free thiol levels were below the calculated limit of quantitation (LOQ) of this method (Table 26). Under denaturing conditions, slightly higher free thiol levels were detected for primary reference standard batch 1 / working reference standard batch 2 compared to reference standard batch 3. However, these free thiol levels were considered low and close to the LOQ of this method.

[0364] Table 26: Results of Free Thiol Determination for Reference Samples

[0365]

[0366] Example 5: Batch variability of compositions containing FcRn antagonist molecular variants

[0367] Compositions that characterize a group containing Fc antagonist molecules, and whose composition is determined similarly to that in Example 1.

[0368] The charge heterogeneity of the samples was assessed using strong cation exchange high-performance liquid chromatography (CEX HPLC). Proteins present in the samples were separated and quantified based on the interaction between the charge on the protein surface and the charged groups on the column surface, according to their surface charge distribution. Proteins carry a positive charge in buffer solutions with a pH lower than their pI. Proteins were eluted from the column using a sodium chloride gradient (mobile phase B), first eluting acidic species and then more basic species. The separated fractions were passed through a UV detector unit, and absorbance was measured at a wavelength of 220 nm. The results are shown in Tables 26 and 27.

[0369] Based on the elution time of the eluted species relative to the main peak in the CEX spectrum, the peaks of the eluted species were classified as acidic or basic. Peaks eluted earlier than the main peak (peak 8) were identified as acidic species (peaks 1 to 7), while peaks eluted later (peaks 9 to 12) were identified as basic species. For all tested samples, a total of twelve (12) charged species were identified by CEX. Consistent with the results in Example 1, the main isomer was present with approximately 64% of the relative percentage area. The total basic and acidic isomers accounted for approximately 16% and 19% of the relative percentage area, respectively. The identities of the different CEX isomer peaks are presented in Figure 2 And in Table 6.

[0370] The charge heterogeneity of the samples was also assessed by imaging capillary isoelectric focusing (icIEF), and the results are shown in Tables 27 and 28.

[0371] In Example 1, peaks were numbered based on their measured isoelectric point (pI) relative to the main peak. Peaks showing a pI at pH values ​​below the main peak were identified as acidic species, while peaks showing a pI at higher pH values ​​were identified as basic species.

[0372] Six isomers were detected in the pI range of 6.7 to 7.6. The main isomer was detected with a pI of approximately 7.2 and a relative percentage area of ​​approximately 65%. The total basic isomer accounted for approximately 16% of the relative percentage area, and the total acidic isomer accounted for approximately 18% of the relative percentage area. The identities of the different isomers are presented in Table 8.

[0373]

[0374]

[0375] Batch variations in the N-glycan form of the FcRn antagonist compositions were also analyzed. As described in Example 3, hydrophilic interaction liquid chromatography (HILIC) fluorescence chromatograms of 2-aminobenzamide (2-AB)-labeled N-glycans derived from the samples were analyzed. Peak identification was the result of mass spectrometry data interpretation and chromatographic elution, as well as the rules governing glycan biosynthesis. Quantification was based on fluorescence peak area. The N-glycan identity and relative intensities of the samples are shown in Tables 29 to 35.

[0376]

[0377]

[0378]

[0379]

[0380]

[0381] * * *

[0382] The scope of this invention is not limited to the specific embodiments described herein. In fact, various modifications to the invention, other than those described, will become apparent to those skilled in the art from the foregoing description and drawings. Such modifications are intended to fall within the scope of the appended claims.

[0383] The technical solutions corresponding to the original claims of the parent application are hereby incorporated in this specification:

[0384] 1. A composition comprising a population of FcRn antagonist molecules, wherein at least a portion of the FcRn antagonist molecules in the population comprises a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 1, provided that the population is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 2, 3, 20 or 21.

[0385] 2. The composition according to item 1, wherein each FcRn antagonist molecule in the population comprises a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 1.

[0386] 3. The composition according to item 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 3 and SEQ ID NO: 12, respectively.

[0387] 4. The composition according to item 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively.

[0388] 5. The composition according to item 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 2 and SEQ ID NO: 3.

[0389] 6. The composition according to item 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO: 6.

[0390] 7. The composition according to item 1, wherein the amino acid sequence of the first Fc domain consists of any one of SEQ ID NO: 2 to 22, and the amino acid sequence of the second Fc domain consists of any one of SEQ ID NO: 2 to 22.

[0391] 8. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 5.

[0392] 9. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 6.

[0393] 10. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 7.

[0394] 11. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 8.

[0395] 12. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 9.

[0396] 13. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 10.

[0397] 14. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 11.

[0398] 15. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 12.

[0399] 16. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 13.

[0400] 17. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 14.

[0401] 18. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 15.

[0402] 19. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 16.

[0403] 20. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 17.

[0404] 21. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 18.

[0405] 22. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 19.

[0406] 23. The composition according to item 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 22.

[0407] 24. The composition according to item 1, wherein the group comprises:

[0408] (a) A first subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the first subgroup are composed of SEQ ID NO: 3; and

[0409] (b) at least one of the following:

[0410] (i) A second subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the second subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 12, respectively;

[0411] (ii) A third subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the third subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively;

[0412] (iii) A fourth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the fourth subgroup are composed of SEQ ID NO: 3, and wherein two asparagine residues in each FcRn antagonist molecule in the fourth subgroup are deaminoked.

[0413] (iv) A fifth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the fifth subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively, and wherein one asparagine residue in each FcRn antagonist molecule in the fifth subgroup is deaminoked;

[0414] (v) A sixth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the sixth subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively;

[0415] (vi) A seventh subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the seventh subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the seventh subgroup is oxidized.

[0416] (vii) The eighth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecule in the eighth subgroup are composed of SEQ ID NO: 2;

[0417] (viii) A ninth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the ninth subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 6, respectively;

[0418] (ix) A tenth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the tenth subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the tenth subgroup is oxidized; and

[0419] (x) An eleventh subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the eleventh subgroup are composed of SEQ ID NO: 3, and wherein two amino acid residues independently selected from methionine residues and tryptophan are oxidized in each FcRn antagonist molecule in the eleventh subgroup.

[0420] 25. The composition according to item 24, wherein the group comprises 2, 3, 4, 5, 6, 7, 8, 9, 10 or all of the subgroups listed in (b).

[0421] 26. The composition according to item 24, wherein the group comprises the seventh subgroup, the ninth subgroup, or the eleventh subgroup.

[0422] 27. The composition according to item 24, wherein the population comprises the seventh subgroup, the ninth subgroup, and the eleventh subgroup.

[0423] 28. The composition according to any one of items 24 to 27, wherein the first subgroup is at least 55% of the population, and optionally the first subgroup is 60% to 70% of the population.

[0424] 29. The composition according to any one of items 24 to 28, wherein the second subgroup comprises no more than 2.5% of the population, and optionally the second subgroup comprises 1% to 2.5% of the population.

[0425] 30. The composition according to any one of items 24 to 29, wherein the third subgroup comprises no more than 2.5% of the population, and optionally the third subgroup comprises 1% to 2.5% of the population.

[0426] 31. The composition according to any one of items 24 to 30, wherein the fourth subgroup does not exceed 4% of the population, and optionally the fourth subgroup is 2% to 5% of the population.

[0427] 32. The composition according to any one of items 24 to 31, wherein the fifth subgroup does not exceed 10% of the population, and optionally the fifth subgroup is 7% to 10% of the population.

[0428] 33. The composition according to any one of items 24 to 32, wherein the sixth subgroup does not exceed 20% of the population, and optionally the sixth subgroup is 7% to 14% of the population.

[0429] 34. The composition according to any one of items 24 to 33, wherein the seventh subgroup comprises no more than 6% of the population, and optionally the seventh subgroup comprises 1.5% to 2.5% of the population.

[0430] 35. The composition according to any one of items 24 to 34, wherein the eighth subgroup does not exceed 8% of the population, and optionally the eighth subgroup is 3.5% to 7.5% of the population.

[0431] 36. The composition according to any one of items 24 to 35, wherein the ninth subgroup does not exceed 3.5% of the population, and optionally the ninth subgroup is 0.5% to 3.5% of the population.

[0432] 37. The composition according to any one of items 24 to 36, wherein the tenth subgroup does not exceed 1% of the group.

[0433] 38. The composition according to any one of items 24 to 37, wherein the eleventh subgroup does not exceed 1% of the population.

[0434] 39. The composition according to any one of the preceding items, wherein at least 97%, optionally 97% to 99%, of the Fc domains in said group comprises N-glycans at EU position 297.

[0435] 40. The composition according to any one of the preceding items, wherein at least 50%, optionally 50% to 70% of the Fc domains in the group contain G0F N-glycan at EU position 297.

[0436] 41. The composition according to any one of the preceding items, wherein at least 20%, optionally 20% to 30% of the Fc domains in the group contain G1F N-glycan at EU position 297.

[0437] 42. The composition according to any one of the preceding items, wherein at least 5%, optionally 8% to 10%, of the Fc domain in said group comprises G2F N-glycan at EU position 297.

[0438] 43. The composition according to any one of the preceding items, wherein at least 2%, optionally 2% to 5% of the Fc domain in the group comprises G0 N-glycan at EU position 297.

[0439] 44. The composition according to any one of the preceding items, wherein at least 40%, optionally 40% to 55% of the group comprises a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G0F N-glycan at EU position 297.

[0440] 45. The composition according to any one of the preceding items, wherein at least 20%, optionally 20% to 25% of the group comprises a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G1F N-glycan at EU position 297.

[0441] 46. ​​The composition according to any one of the preceding items, wherein at least 10%, optionally 10% to 15% of the group comprises a first Fc domain containing G1F N-glycan at EU position 297 and a second Fc domain containing G1F N-glycan at EU position 297, or a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297.

[0442] 47. The composition according to any one of the preceding items, wherein at least 5%, optionally 5% to 10% of the group comprises a first Fc domain containing G1F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297.

[0443] 48. The composition according to any one of the preceding items, wherein at least 2%, optionally 2% to 4% of the group comprises a first Fc domain containing G2F N-glycan at EU position 297 and a second Fc domain containing G2F N-glycan at EU position 297.

[0444] 49. The composition according to any one of the preceding items, wherein at least 4%, optionally 4% to 6% of the group comprises a first Fc domain containing G0F N-glycan at EU position 297 and a second Fc domain containing G0 N-glycan at EU position 297.

[0445] 50. A composition comprising an FcRn antagonist molecule, the FcRn antagonist molecule comprising a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 1, and wherein at least one Fc domain comprises G0F N-glycan at EU position 297, G1F N-glycan at EU position 297, G2F N-glycan at EU position 297, or G0 N-glycan at EU position 297.

[0446] 51. The composition according to item 50, wherein the first Fc domain comprises G0F N-glycan at EU position 297, and the second Fc domain comprises G0F N-glycan at EU position 297.

[0447] 52. The composition according to item 50, wherein the first Fc domain comprises G0F N-glycan at EU position 297, and the second Fc domain comprises G1F N-glycan at EU position 297.

[0448] 53. The composition according to item 50, wherein the first Fc domain comprises G0F N-glycan at EU position 297, and the second Fc domain comprises G2F N-glycan at EU position 297.

[0449] 54. The composition according to item 50, wherein the first Fc domain comprises G1F N-glycan at EU position 297, and the second Fc domain comprises G1F N-glycan at EU position 297.

[0450] 55. The composition according to item 50, wherein the first Fc domain comprises G2F N-glycan at EU position 297, and the second Fc domain comprises G2F N-glycan at EU position 297.

[0451] 56. The composition according to item 50, wherein the first Fc domain comprises G0N-glycan at EU position 297, and the second Fc domain comprises G0N-glycan at EU position 297.

[0452] 57. The composition according to item 50, wherein the first Fc domain comprises a GO N-glycan at EU position 297, and the second Fc domain comprises a GO N-glycan at EU position 297.

[0453] 58. The composition according to item 50, wherein the first Fc domain comprises G1F N-glycan at EU position 297, and the second Fc domain comprises G2F +NANA N-glycan at EU position 297.

[0454] 59. The composition according to item 50, wherein the first Fc domain comprises G2F N-glycan at EU position 297, and the second Fc domain comprises G2F + 2 x NANA N-glycan at EU position 297.

[0455] 60. The composition according to any one of items 50 to 59, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO: 12.

[0456] 61. The composition according to any one of items 50 to 59, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO: 9.

[0457] 62. The composition according to any one of items 50 to 59, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 2 and SEQ ID NO: 3.

[0458] 63. The composition according to any one of items 50 to 59, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO: 6.

[0459] 64. The composition according to any one of items 50 to 59, wherein the amino acid sequence of the first Fc domain consists of any one of SEQ ID NO: 2 to 22, and the amino acid sequence of the second Fc domain consists of any one of SEQ ID NO: 2 to 22.

[0460] 65. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 2.

[0461] 66. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 3.

[0462] 67. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 4.

[0463] 68. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 5.

[0464] 69. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 6.

[0465] 70. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 7.

[0466] 71. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 8.

[0467] 72. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 9.

[0468] 73. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 10.

[0469] 74. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 11.

[0470] 75. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 12.

[0471] 76. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 13.

[0472] 77. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 14.

[0473] 78. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 15.

[0474] 79. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 16.

[0475] 80. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 17.

[0476] 81. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 18.

[0477] 82. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 19.

[0478] 83. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 20.

[0479] 84. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 21.

[0480] 85. The composition according to any one of items 50 to 59, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 22.

[0481] 86. The composition according to any one of the preceding items, wherein at least 85%, optionally 85% to 95%, of the Fc domains in said population are deficient in an amino acid at EU position 441.

[0482] 87. The composition according to any one of the preceding items, wherein no more than 15%, optionally 5% to 15%, of the Fc domains in the group have glycine and lysine at EU positions 440 and 441, respectively.

[0483] 88. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domain in the population is deficient in amino acids at EU positions 440 and 441, and contains amidated proline at EU position 439.

[0484] 89. The composition according to any one of the preceding items, wherein at least 95%, optionally 95% to 99% of the Fc domains in the group have aspartic acid, lysine, threonine, histidine, threonine and cysteine ​​at EU positions 221, 222, 223, 224, 225 and 226, respectively.

[0485] 90. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domain in the population is deficient in an amino acid at EU position 221, and has lysine, threonine, histidine, threonine and cysteine ​​at EU positions 222, 223, 224, 225 and 226, respectively.

[0486] 91. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domains in the population are deficient in amino acids at EU positions 221 and 222, and have threonine, histidine, threonine and cysteine ​​at EU positions 223, 224, 225 and 226, respectively.

[0487] 92. The composition according to any one of the preceding items, wherein no more than 2% of the Fc domains in the population are deficient in amino acids at EU positions 221 to 224, and have threonine and cysteine ​​at EU positions 225 and 226, respectively.

[0488] 93. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domains in the population are deficient in amino acids at EU positions 221, 222, 223, 224, 225 and 226.

[0489] 94. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domain in the population has aspartic acid isomerization at EU position 280 or 401.

[0490] 95. The composition according to any one of the preceding items, wherein no more than 10% of the Fc domains in the group have asparagine deamidation at EU positions 384, 389 or 390.

[0491] 96. The composition according to any one of the preceding items, wherein no more than 3% of the Fc domain in the population has asparagine deamidation at EU position 315.

[0492] 97. The composition according to any one of the preceding items, wherein no more than 3% of the Fc domain in the population has asparagine deamidation at EU position 361.

[0493] 98. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domains in the population have asparagine deamidation at EU position 276 or 286.

[0494] 99. The composition according to any one of the preceding items, wherein no more than 5% of the Fc domain has methionine oxidation at EU position 428.

[0495] 100. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domain is amidated with proline at EU position 445.

[0496] 101. The composition according to any one of the preceding items, wherein no more than 1% of the Fc domain has tryptophan oxidation at EU position 277.

[0497] 102. The composition according to any one of the preceding items, wherein no more than 0.5% of the FcRn antagonist molecules in the said group are aggregated.

[0498] 103. The composition according to any one of the preceding items, wherein at least 95%, optionally at least 99%, of the dimers in the group are linked by at least one disulfide bond.

[0499] 104. The composition according to any one of the preceding items, wherein the average molecular weight of the non-aggregated FcRn antagonist molecules in the population is 54 to 56 kDa, optionally 54.4 to 54.7 kDa.

[0500] 105. The composition according to any one of the preceding items, wherein the percentage of free thiol groups in said group does not exceed 1%.

[0501] 106. The composition according to any one of the preceding items, wherein at least 35%, optionally 35% to 55% of the Fc domains in the group comprise galactose.

[0502] 107. The composition according to any one of the preceding items, wherein at least 90%, optionally 90% to 98%, of the Fc domains in the group comprises fucose.

[0503] 108. The composition according to any one of the preceding items, wherein at most 1.5%, optionally from 0.5% to 1.5% of the Fc domain in said group comprises sialic acid.

[0504] 109. The composition according to any one of the preceding items is an aqueous solution comprising about 25 mM sodium phosphate, about 100 mM sodium chloride, about 150 mM L-arginine, and about 0.02% (w / v) polysorbate 80, wherein the composition has a pH of about 6.7.

[0505] 110. The composition according to item 109, comprising the population of 20 mg / ml FcRn antagonist molecules.

[0506] 111. The composition according to any one of the preceding items is an aqueous solution comprising about 4 mM sodium phosphate, about 146 mM sodium chloride, about 24 mM L-arginine, and about 0.0032% (w / v) polysorbate 80, wherein the composition has a pH of about 6.7.

[0507] 112. The composition according to item 111, comprising the population of about 3.2 mg / ml of FcRn antagonist molecules.

[0508] 113. The composition according to any one of the preceding items is an aqueous solution comprising about 20 mM L-histidine, about 100 mM sodium chloride, about 60 mM sucrose, about 10 mM L-methionine and about 0.04% (w / v) polysorbate 20, wherein the composition has a pH of about 6.0.

[0509] 114. The composition according to item 113, comprising the population of about 180 mg / ml of FcRn antagonist molecules.

[0510] 115. The composition according to any one of the preceding items is an aqueous solution comprising about 20 mM L-histidine, about 50 mM M-arginine, about 100 mM sodium chloride, about 60 mM sucrose, about 10 mM L-methionine and about 0.04% (w / v) polysorbate 80, wherein the composition has a pH of about 6.0.

[0511] 116. The composition according to item 115, comprising the population of about 200 mg / ml of FcRn antagonist molecules.

[0512] 117. An FcRn antagonist molecule comprising a variant Fc region comprising a homodimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of any one of SEQ ID NO: 5 to 20 and 22.

[0513] 118. A polynucleotide encoding an FcRn antagonist molecule as described in item 117.

[0514] 119. A vector comprising the polynucleotide as described in item 118.

[0515] 120. A cell comprising the polynucleotides described in item 118.

[0516] 121. A method for preparing an FcRn antagonist molecule, the method comprising culturing cells according to item 118 under conditions that cause the expression of a polynucleotide and the production of the FcRn antagonist molecule.

[0517] 122. The method according to item 121, further comprising isolating the FcRn antagonist molecule from the cell.

[0518] 123. A method comprising mixing a composition according to any one of items 1 to 116, an FcRn antagonist according to item 117, a polynucleotide according to item 118, a carrier according to item 119, or a cell according to item 120 with one or more pharmaceutically acceptable excipients.

[0519] 124. A method for reducing serum IgG autoantibody levels in a subject, the method comprising administering to the subject a composition according to any one of items 1 to 116, an FcRn antagonist according to item 117, a polynucleotide according to item 118, a carrier according to item 119, or a cell according to item 120.

[0520] 125. A method of treating an autoimmune disease in a subject, the method comprising administering to the subject a composition according to any one of items 1 to 116, an FcRn antagonist according to item 117, a polynucleotide according to item 118, a carrier according to item 119, or a cell according to item 120.

[0521] 126. The composition according to any one of items 1 to 116, the FcRn antagonist according to item 117, the polynucleotide according to item 118, the carrier according to item 119, or the cell according to item 120, for use in the treatment of autoimmune diseases.

[0522] 127. Use of a composition according to any one of items 1 to 116, an FcRn antagonist according to item 117, a polynucleotide according to item 118, a carrier according to item 119, or a cell according to item 120 for the treatment of autoimmune diseases.

[0523] 128. The composition according to any one of items 1 to 116, the FcRn antagonist according to item 117, the polynucleotide according to item 118, the carrier according to item 119, or the cell according to item 120, used in the manufacture of a medicament for treating autoimmune diseases.

[0524] 129. The composition according to any one of items 1 to 116, the FcRn antagonist according to item 117, the polynucleotide according to item 118, the carrier according to item 119, or the cell according to item 120, for use in medicine.

Claims

1. A composition comprising a population of FcRn antagonist molecules, wherein at least a portion of the FcRn antagonist molecules in the population comprises a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO: 1, provided that the population is not a homogeneous population of homodimeric FcRn antagonist molecules in which the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO: 2, 3, 20 or 21.

2. The composition of claim 1, wherein each FcRn antagonist molecule in the population comprises a variant Fc region comprising a dimer of a first Fc domain and a second Fc domain, wherein the amino acid sequences of the first Fc domain and the second Fc domain are composed of SEQ ID NO:

1.

3. The composition according to claim 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO:

12.

4. The composition according to claim 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO:

9.

5. The composition according to claim 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 2 and SEQ ID NO:

3.

6. The composition according to claim 1, wherein the amino acid sequences of the first Fc domain and the second Fc domain are respectively composed of SEQ ID NO: 3 and SEQ ID NO:

6.

7. The composition according to claim 1, wherein the amino acid sequence of the first Fc domain consists of any one of SEQ ID NO: 2 to 22, and the amino acid sequence of the second Fc domain consists of any one of SEQ ID NO: 2 to 22.

8. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

5.

9. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

6.

10. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

7.

11. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

8.

12. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

9.

13. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

10.

14. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

11.

15. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

12.

16. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

13.

17. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

14.

18. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

15.

19. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

16.

20. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

17.

21. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

18.

22. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

19.

23. The composition according to claim 1, wherein the amino acid sequences of both the first Fc domain and the second Fc domain are composed of SEQ ID NO:

22.

24. The composition of claim 1, wherein the group comprises: (a) A first subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the first subgroup are composed of SEQ ID NO: 3; and (b) at least one of the following: (i) A second subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the second subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 12, respectively; (ii) A third subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the third subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively; (iii) A fourth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the fourth subgroup are composed of SEQ ID NO: 3, and wherein two asparagine residues in each FcRn antagonist molecule in the fourth subgroup are deaminoked. (iv) A fifth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the fifth subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 9, respectively, and wherein one asparagine residue in each FcRn antagonist molecule in the fifth subgroup is deaminoked; (v) A sixth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the sixth subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively; (vi) A seventh subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the seventh subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the seventh subgroup is oxidized; (vii) The eighth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecule in the eighth subgroup are composed of SEQ ID NO: 2; (viii) A ninth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the ninth subgroup are composed of SEQ ID NO: 3 and SEQ ID NO: 6, respectively; (ix) A tenth subgroup of FcRn antagonist molecules, wherein the amino acid sequences of the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the tenth subgroup are composed of SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and wherein one methionine residue or one tryptophan residue in each FcRn antagonist molecule in the tenth subgroup is oxidized; and (x) An eleventh subgroup of FcRn antagonist molecules, wherein the amino acid sequences of both the first Fc domain and the second Fc domain of the FcRn antagonist molecules in the eleventh subgroup are composed of SEQ ID NO: 3, and wherein two amino acid residues independently selected from methionine residues and tryptophan are oxidized in each FcRn antagonist molecule in the eleventh subgroup.

Images