Formulations of TACI-FC fusion immunomodulatory protein and uses thereof

Abstract

Provided herein are formulations of immunomodulatory TACI-Fc fusion proteins, and methods and uses of the provided formulations for treating a variety of immunological diseases, disorders or conditions, such as B cell-mediated diseases, disorder or conditions. The formulations provided herein provide improved stability of the TACI-Fc fusion protein for long-term storage.

Description

Attorney Docket No. 01245-0082-00PCT FORMULATIONS OF TACI-FC FUSION IMMUNOMODULATORY PROTEIN AND USES THEREOFCross-Reference to Related Applications

[0001] This application claims the benefit of priority to United States Provisional Application No. 63 / 779,927 entitled “FORMULATIONS OF TACI-FC FUSION IMMUNOMODULATORY PROTEIN AND USES THEREOF,” filed March 28, 2025, the contents of which are incorporated herein by reference in their entirety for all purposes.Incorporation by Reference of Sequence Listing

[0002] The application contains a Sequence Listing which has been submitted electronically in .XML format and is hereby incorporated by reference in its entirety. Said .XML copy, created on March 26, 2026, is named “01245-0082-00PCT_xml” and is 254,107 bytes in size. The sequence listing contained in this .XML file is part of the specification and is hereby incorporated by reference herein in its entirety.Field

[0003] The present disclosure provides formulations of immunomodulatory TACI-Fc fusion proteins. The formulations containing an immunomodulatory TACI-Fc fusion protein are for use in methods and uses to provide therapeutic utility for a variety of immunological diseases, disorders or conditions, such as B cell-mediated diseases, disorder or conditions. The formulations provided herein provide improved stability of the TACI-Fc fusion protein for longterm storage.Background

[0004] Modulation of the immune response by intervening in processes involving interactions between soluble ligands and their receptors is of increasing medical interest. B cell activating factor (BAFF) and a proliferation inducing ligand (APRIL) are TNF superfamily members that bind TACI (transmembrane activator and CAML interactor), BCMA (B cell maturation antigen), and / or BAFF-R on B cells and together support B cell development, differentiation, and survival. The neutralization of BAFF, APRIL and / or BAFF-R by TACI-Fc fusion proteins reduces B cell survival and function including antibody production, and thereby can be used to modulate the immune response and particularly B cell responses, such as for treatment for various autoimmune and inflammatory conditions. Improved strategies areAttorney Docket No. 01245-0082-00PCT needed to improve the therapeutic effectiveness of TACI-Fc fusion proteins. Provided are embodiments that meet such needs.Summary

[0005] Embodiments herein include but are not limited to the following enumerated embodiments. Additional embodiments herein are also described throughout the application.

[0006] 1. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 50 mM to about 200 mM of a tonicifying agent, wherein the tonicifying agent comprises arginine;b. an acetate buffer; andc. at or about 0.002% to about 1.0% (w / v) of a non-ionic surfactant;wherein the formulation comprises:a TACI-Fc fusion protein concentration of at or about 140 mg / mL to about 200 mg / mL; and a formulation pH of at or about 4.4 to about 5.1.

[0007] 2. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 1% to about 4% (w / v) proline;b. an acetate buffer; andc. at or about 0.002% to about 1.0% (w / v) of a non-ionic surfactant;a TACI-Fc fusion protein concentration of at or about 140 mg / mL to about 200 mg / mL; and a formulation pH of at or about 4.7 to about 5.7.

[0008] 3 A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 1% to about 4% (w / v) proline;b. an acetate buffer;c. at or about 0.002% to about 1.0% (w / v) of a non-ionic surfactant; andd. a salt; whereina TACI-Fc fusion protein concentration of at or about 140 mg / mL to about 200 mg / mL; and a formulation pH of at or about 4.4 to about 5.1.

[0009] 4. A formulation comprising a TACI-Fc fusion protein, comprising:a. water and a buffering agent that provides a formulation pH of at or about 4.3 to about 5.5;b. a tonicifying agent having a positive charge at the formulation pH;c. a non-ionic surfactant; andd. a TACI-Fc fusion protein at a concentration of at or about 100 mg / mL to about 200 mg / mL.Attorney Docket No. 01245-0082-00PCT

[0010] 5. The formulation of embodiments 1 or 4, wherein the tonicifying agent is present in the formulation at a concentration of at or about 50 mM to about 200 mM, 70 mM to about 190 mM; at or about 135 mM to about 165 mM; at or about 145 M to about 150 mM; at or about 140 mM, at or about 145 mM, at or about 150 mM, or at or about 155 mM.

[0011] 6. The formulation of any one of embodiments 1-5 having a tonicity of an isotonic tonicity, of at or about 250 to about 350 mOsm / Kg, or of at or about 250 mOsm / Kg to about 600 mOsm / Kg.

[0012] 7. The formulation of any one of embodiments 1-6, comprising at or about 40 mM to about 150 mM sodium chloride.

[0013] 8. The formulation of any one of embodiments 1 and 3-7, wherein the formulation pH is at or about 4.5 to about 5.0; at or about 4.5 to about 4.8; at or about 4.6 at or about 4.7, or at or about 4.8.

[0014] 9. The formulation of any one of embodiments 1-8, wherein TACI-Fc fusion protein concentration is at or about 150 mg / mL, at or about 160 mg / mL, at or about 170 mg / mL, at or about 175 mg / mL, at or about 180 mg / mL, at or about 190 mg / mL, or at or about 200 mg / mL.

[0015] 10. The formulation of any one of embodiments 1-9, comprising from at or about 1 mM to about 30 mM, from about 3mM to about 15 mM, from at or about 4 mM to about 20 mM, from at or about 5 mM to about 10 mM, from at or about 8 mM to about 25 mM, from at or about 10 mM to about 20 mM, from at or about 10 mM to about 30 mM, from at or about 7 mM to about 25 mM acetate, or from at or about 15 mM to about 25 mM acetate as a component of the acetate buffer.

[0016] 11. The formulation of any one of embodiments 1-10, wherein the non-ionic surfactant is a polysorbate (polysorbate 80), or is a pol oxamer poly ether (pol oxamer 188).

[0017] 12. The formulation of any one of embodiments 1-11, comprising at or about 0.002% to about 0.2% (w / v); at or about 0.01% to about 0.04% (w / v); or at or about 0.02% (w / v) of the non-ionic surfactant, wherein the non-ionic surfactant is polysorbate 80.

[0018] 13. The formulation of any one of embodiments 1-11, comprising 0.01% to about 1.0% (w / v); at or about 0.05% to about 0.2% (w / v); or at or about 0.1% (w / v) of the non-ionic surfactant, wherein the non-ionic surfactant is poloxamer 188.

[0019] 14. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 135 mM to about 165 mM arginine;b. an acetate buffer; andc. at or about 0.05% to about 0.2% (w / v) poloxamer 188 (P188); whereinthe TACI-Fc fusion protein is at a concentration of at or about 160 mg / mL to about 190 mg / mL; and the formulation has a formulation pH of at or about 4.6 to about 4.8.Attorney Docket No. 01245-0082-00PCT

[0020] 15. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 140 mM to about 150 mM arginine;b. an acetate buffer; andc. at or about 0.1% (w / v) poloxamer 188 (P188); whereinthe TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 4.7.

[0021] 16. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 140 mM to about 150 mM arginine;b. an acetate buffer; andc. at or about 0.01% to about 0.04% (w / v) polysorbate 80 (PS80); whereinthe TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 4.7.

[0022] 17. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 3.0% (w / v) proline;b. an acetate buffer;c. at or about 0.05% (w / v) to about 0.2% (w / v) poloxamer 188; andd. at or about 50 mM sodium chloride; whereinthe TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 4.7.

[0023] 18. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 3.0% (w / v) proline;b. an acetate buffer; andc. at or about 0.01% to about 0.04% (w / v) polysorbate 80 (PS80); whereinthe TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 5.2.

[0024] 19. The formulation of any one of embodiments 1, 2, 4-11, 13-15 and 17, wherein the formulation does not comprise a polysorbate surfactant.

[0025] 20. The formulation of any one of embodiments 1-19, wherein the TACI-Fc fusion protein comprises (i) a TACI polypeptide sequence comprising the amino acid sequence of SEQ ID NO: 26; and (ii) an immunoglobulin Fc region.

[0026] 21. The formulation of embodiment 20, wherein the immunoglobulin Fc region comprises the amino acid sequence of any one of SEQ ID NOS: 73, 75, 83, 136, 175, 176, or 221.

[0027] 22. The formulation of any one of embodiments 1-19, wherein the TACI-Fc fusion protein comprises the amino acid sequence of SEQ ID NO: 168.Attorney Docket No. 01245-0082-00PCT

[0028] 23. The formulation of any one of embodiments 1-19, wherein the TACI-Fc fusion protein comprises the amino acid sequence of SEQ ID NO: 167.

[0029] 24. The formulation of any one of embodiments 1-23, wherein the TACI-Fc fusion protein is a homodimer comprising two identical copies of the TACI-Fc fusion protein.

[0030] 25. The formulation of any one of embodiments 1-19 wherein the TACI-Fc fusion protein is a homodimer comprising two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0031] 26. The formulation of any one of embodiments 1-19 wherein the TACI-Fc fusion protein is a homodimer comprising two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

[0032] 27. The formulation of any one of embodiments 1-26, wherein the TACI-Fc fusion protein comprises a variant TACI polypeptide, and / or the TACI-Fc fusion protein has an isoelectric point (pl) of at or about 7.0 to about 7.8, at or about 7.0 to about 7.7, at or about 7.0 to about 7.6, at or about 7.0 to about 7.5, at or about 7.0 to about 7.3, at or about 7.1 to about 7.5, at or about 7.1 to about 7.3, or about 7.2.

[0033] 28. The formulation of any one of embodiments 1-27, that is a liquid formulation that has not been lyophilized and is not lyophilized prior to administration to a subject.

[0034] 29. The formulation of any one of embodiments 1-28, wherein, after storage for 12 months in liquid form at a storage temperature of at or about 2°C to about 8°C, optionally at or about 5°C, and as measured by size exclusion chromatography (SEC) and as expressed in terms of area% under a curve that includes the TACI-Fc fusion protein in a form of a homodimer comprising two identical copies of the TACI-Fc fusion protein linked by a covalent disulfide bond as a main species, wherein:- the main species is at least 95%, at least 98%, or at least 99% of all observed species under the curve;- less than 5%, less than 2%, or less than 1% of species under the curve have a size greater than a size of the main species;- less than 5%, less than 2%, or less than 1% of species under the curve have a size less than a size of the main species;- the loss of the main species is less than 1%;- the increase in species under the curve having a size greater than a size of the main species is less than 1%; and / or- the increase in species under the curve having a size less than a size of the main species is less than 1%.Attorney Docket No. 01245-0082-00PCT

[0035] 30. The formulation of any one of embodiments 1-29, wherein the formulation is a liquid formulation having a viscosity of at or about 3 cP to about 15 cP at about 25°C as assessed using a rheometer or a cone and plate viscometer.

[0036] 31. The formulation of any one of embodiments 1-30, wherein the formulation is a liquid formulation comprising less than about 6,000 particles / mL having a particle size diameter of > 10 pm; and / or comprising less than about 600 parti cles / mL having a particle size diameter of > 25 pm, after storage for 12 months in liquid form at a storage temperature of at or about 2°C to about 8°C, optionally at or about 5°C.

[0037] 32. An article of manufacture comprising the formulation of any one of embodiments 1-31 in a container, for example in a vial or a syringe barrel.

[0038] 33. A kit comprising the formulation of any one of embodiments 1-31 or the article of manufacture of embodiment 32, and instructions for use.

[0039] 34. A method of manufacturing the formulation of any one of embodiments 1-31, the method comprising combining the TACI-Fc fusion protein and the components (a), (b), and (c).

[0040] 35. A method for reducing degradation and / or aggregation of a TACI-Fc fusion protein homodimer in a liquid pharmaceutical formulation comprising a TACI-Fc fusion protein at a concentration of at least 160 mg / mL, comprising combining the TACI-Fc fusion protein and the components (a), (b), and (c) of any one of the formulations of embodiments 1-31.

[0041] 36. A method of reducing an immune response in a subject, comprising administering the formulation of any one of embodiments 1-31 to a subject in need thereof.

[0042] 37. The formulation of any one of embodiments 1-31 for use in reducing an immune response in a subject.

[0043] 38. Use of formulation of any one of embodiments 1-31 in the manufacture of a medicament for reducing an immune response in a subject.

[0044] 39. The method of embodiment 36, the formulation for use of embodiment 37, or the use of embodiment 38, wherein the immune response is a B cell immune response, wherein reducing the immune response reduces or inhibits B cell maturation, differentiation and / or proliferation; and / or wherein reducing the immune response reduces circulating levels of APRIL, BAFF or an APRIL / BAFF heterotrimer in the subject.

[0045] 40. The method of embodiment 36 or 39, the formulation for use of embodiment 37 or 39, or the use of embodiment 38 or 39, wherein reducing the immune response treats a disease, disorder or condition in the subject.

[0046] 41. A method of treating a disease, disorder or condition in a subject, comprising administering a formulation of any one of embodiments 1-31 to a subject in need thereof.Attorney Docket No. 01245-0082-00PCT

[0047] 42. The formulation of any one of embodiments 1-31 for use in treating a disease, disorder or condition in a subject.

[0048] 43. Use of the formulation of any one of embodiments 1-31 in the manufacture of a medicament for treating a disease, disorder or condition in a subject.

[0049] 44. The method of embodiment 40 or 41, the formulation for use of embodiment 40 or 42, or the use of embodiment 40 or 43, wherein the disease, disorder or condition is an autoimmune disease or an inflammatory condition.

[0050] 45. The method of embodiment 40 or 41, the formulation for use of embodiment 40 or 42, or the use of embodiment 40 or 43, wherein the disease, disorder or condition is a B cell cancer, an antibody-mediated pathology, a renal disease, a graft rejection, graft versus host disease, or a viral infection.

[0051] 46. The method of embodiment 40 or 41, the formulation for use of embodiment 40 or 42, or the use of embodiment 40 or 43, wherein the disease, disorder or condition is selected from the group consisting of systemic lupus erythematosus (SLE), lupus nephritis, cutaneous lupus erythematosus, Sjogren’s syndrome, scleroderma (systemic sclerosis), multiple sclerosis, diabetes (e.g. Type I diabetes), polymyositis, primary biliary cirrhosis, IgG4-related disease, IgA nephropathy, IgA vasculitis, ANCA vasculitis (microscopic polyangiitis, granulomatosis with polyangiitis [Wegener’s granulomatosis], eosinophilic granulomatosis with polyangiitis [Churg-Strauss]) cryoglobulinemia, cold agglutinin or warm agglutinin disease, immune thrombocytopenic purpura, optic neuritis, amyloidosis, antiphospholipid antibody syndrome (APS), autoimmune polyglandular syndrome type II (APS II), autoimmune thyroid disease (AITD), Graves’ disease, autoimmune adrenalitis, pemphigus vulgaris, bullous pemphigoid, myasthenia gravis, graft versus host disease (GVHD), transplantation, rheumatoid arthritis, acute lupus nephritis, amyotrophic lateral sclerosis, neuromyelitis optica, transverse myelitis, Rasmussen’s encephalitis, CNS autoimmunity, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, neurocystercercosis, sarcoidosis, antiphospholipid antibody syndrome, IgG4-related disease, Hashimoto’s thyroiditis, immune thrombocytopenia, Addison’s Disease, and dermatomyositis.

[0052] 47. The method of embodiment 40 or 41, the formulation for use of embodiment 40 or 42, or the use of embodiment 40 or 43, wherein the disease or disorder is autoantibody-associated glomerular disease.

[0053] 48. The method, the formulation for use, or the use of embodiment 46 or 47, wherein the disease, disorder, or condition is immunoglobulin (Ig) A nephropathy (IgAN), lupus nephritis (LN), primary membranous nephropathy (pMN), myasthenia gravis, or renal anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).Attorney Docket No. 01245-0082-00PCT

[0054] 49. The method of embodiment 40 or 41, the formulation for use of embodiment 40 or 42, or the use of embodiment 40 or 43, wherein the disease, disorder or condition is immune thrombocytopenia, autoimmune hemolytic anemia, or cold agglutinin disease.

[0055] 50. The method of embodiment 40 or 41, the formulation for use of embodiment 40 or 42, or the use of embodiment 40 or 43, wherein the disease, disorder or condition is a B cell cancer, optionally wherein the cancer is myeloma.

[0056] Provided herein are also, among other embodiments, a formulation containing a TACI-Fc fusion protein, about 50 mM to about 200 mM of a tonicifying agent comprising arginine, or about 1.5% to about 4% (w / v) arginine hydrochloride (Arg-HCl); about 5 mM to about 30 mM of an acetate; and about 0.01% to about 0.2% (w / v) of a surfactant, optionally a non-ionic surfactant; wherein the concentration of the TACI-Fc fusion protein in the formulation is between about 150 mg / mL and about 200 mg / mL; and the formulation pH is at or about 4.4 to about 5.1.

[0057] In some of any embodiments, the formulation contains at or about 2.7% to 3.5% (w / v) arginine hydrochloride; or wherein the formulation contains arginine hydrochloride at a concentration of at or about 3.1% (w / v); or wherein the formulation contains about 135 mM to about 165 mM of a tonicifying agent comprising arginine.

[0058] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains about 1.5% to about 4% (w / v) proline; about 5 mM to about 30 mM of an acetate; about 0.01% to about 0.2% (w / v) of surfactant, optionally a non-ionic surfactant; and a salt; wherein the concentration of the TACI-Fc fusion protein in the composition is between about 150 mg / mL and about 200 mg / mL; and the formulation pH is at or about 4.4 to about 5.1.

[0059] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains about 1.5% to about 4% (w / v) proline; about 5 mM to about 30 mM of an acetate; and a salt; wherein the concentration of the TACI-Fc fusion protein in the composition is between about 150 mg / mL and about 200 mg / mL; and the formulation pH is at or about 4.4 to about 5.1. In some of any embodiments, the proline in the formulation is L-proline. In some of any embodiments, the proline is at a concentration of at or about 2% or at or about 3% (w / v). In some of any embodiments, the formulation contains a salt, wherein the salt is sodium chloride (NaCl). In some of any embodiments, the formulation contains between about 40 mM and 100 mM NaCl. In some of any embodiments, the NaCl is at a concentration of 50 mM.

[0060] In some of any embodiments, the formulation pH is at or about 4.5 to about 5.0. In some of any embodiments, the formulation pH is at or about 4.5 to about 4.8. In some of any embodiments, the formulation pH is at or about 4.7. In some of any embodiments, the formulation pH is at or about 4.6.Attorney Docket No. 01245-0082-00PCT

[0061] In some of any embodiments, the formulation contains at or about lOmM acetate. In some of any embodiments, the formulation contains at or about 20 mM acetate. In some of any embodiments, the acetate is sodium acetate.

[0062] In some of any embodiments, the concentration of the TACI-Fc fusion protein in the formulation is at or about 140 mg / mL, at or about 160 mg / mL, at or about 165 mg / mL, at or about 170 mg / mL, at or about 175 mg / mL, at or about 180 mg / mL, or at or about 190 mg / mL, at or about 200 mg / mL, at or about 210 mg / mL, at or about 220 mg / mL, or at or about 230 mg / mL. In some of any embodiments, the concentration of the TACI-Fc fusion protein in the formulation is at or about 160 mg / mL. In some of any embodiments, the concentration of the TACI-Fc fusion protein in the formulation is at or about 175 mg / mL.

[0063] In some of any embodiments, the formulation contains at or about 0.015% of surfactant. In some of any embodiments, the formulation contains at or about 0.02% of surfactant. In some of any embodiments, the formulation contains at or about 0.04% to 0.16% of surfactant. In some of any embodiments, the formulation contains at or about 0.1% of surfactant. In some of any embodiments, the formulation contains a surfactant that is a non-ionic surfactant. In some of any embodiments, the formulation contains a surfactant that is a poloxamer. In some of any embodiments, the formulation contains a surfactant that is a poloxamer 188. In some of any embodiments, the formulation contains a surfactant that is a polysorbate 80. In some of any embodiments, the surfactant is not a polysorbate. In some of any embodiments, the formulation does not comprise a polysorbate surfactant.

[0064] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains about at or about 3.1% (w / v) arginine hydrochloride (Arg-HCl) or contains about 135 mM to about 165 mM or about 140 mM to about 150 mM of a tonicifying agent comprising arginine; at or about 10 mM sodium acetate; and at or about 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; and the formulation pH is at or about 4.7.

[0065] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains about at or about 3.1% (w / v) arginine hydrochloride (Arg-HCl) or contains about 135 mM to about 165 mM or about 140 mM to about 150 mM of a tonicifying agent comprising arginine; at or about 10 mM sodium acetate; and at or about 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; and the formulation pH is at or about 4.7.

[0066] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains at or about 3.1% (w / v) arginine hydrochloride (Arg-HCl) or contains about 135 mM to about 165 mM or about 140 mM to about 150 mM of a tonicifying agent comprising arginine; atAttorney Docket No. 01245-0082-00PCT or about 10 mM sodium acetate; and at or about 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; and the formulation pH is at or about 4.7.

[0067] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains at or about 3.1% (w / v) arginine hydrochloride (Arg-HCl) or contains about 135 mM to about 165 mM or about 140 mM to about 150 mM of a tonicifying agent comprising arginine; at or about 10 mM sodium acetate; and at or about 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; and the formulation pH is at or about 4.7.

[0068] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains at or about 2.0% or at or about 3.0% (w / v) proline; at or about 10 mM sodium acetate; at or about 0.1% (w / v) poloxamer 188; and at or about 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; and the formulation pH is at or about 4.7.

[0069] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains at or about 2.0% or at or about 3.0% (w / v) proline; at or about 10 mM sodium acetate; at or about 0.1% (w / v) poloxamer 188; and at or about 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; and the formulation pH is at or about 4.7.

[0070] In some of any embodiments, the formulation containing a TACI-Fc fusion protein, contains at least 90% of the TACI-Fc fusion protein in the main (homodimeric) species. In some of any embodiments, at least 95% of the TACI-Fc fusion protein is in the main species. In some of any embodiments, at least 98% of the TACI-Fc fusion protein is in the main species. In some of any embodiments, at least 99% of the TACI-Fc fusion protein is in the main species.

[0071] In some of any embodiments, at least 90% of the TACI-Fc protein in the formulation is the main TACI-Fc protein species containing two polypeptide chains of SEQ ID NO. 167 linked by a covalent bond. In some of any embodiments, at least 95% of the TACI-Fc in protein the formulation is the main TACI-Fc protein species containing two polypeptide chains of SEQ ID NO. 167 linked by a covalent bond. In some of any embodiments, at least 98% of the TACI-Fc protein in the formulation is the main TACI-Fc protein species containing two polypeptide chains of SEQ ID NO. 167 linked by a covalent bond.

[0072] In some of any embodiments, the molecular weight of the main species of a TACI-Fc fusion protein is at or about 62.6 kDa to at or about 116.4 kDa. In some of any embodiments, the molecular weight of the main species of a TACI-Fc fusion protein is at or about 62.6 kDa.Attorney Docket No. 01245-0082-00PCT

[0073] In some of any embodiments, less than 5% of the TACI-Fc fusion protein in the formulation is a high molecular weight (HMW) species. In some of any embodiments, the molecular weight of the HMW species of a TACI-Fc fusion protein is greater than the molecular weight of the corresponding main species of the TACI-Fc fusion protein. In some of any embodiments, the molecular weight of the HMW species of a TACI-Fc fusion protein is at least 93.9 kDa.

[0074] In some of any embodiments, less than 5% of the TACI-Fc fusion protein in the formulation is a low molecular weight (LMW) species. In some of any embodiments, the molecular weight of the LMW species of a TACI-Fc fusion protein is less than 62.6 kDa.

[0075] In some of any embodiments, the combination of the low molecular weight species and high molecular weight species is less than 5% of the TACI-Fc fusion protein in the formulation.

[0076] In some of any embodiments, the TACI-Fc protein species is assessed at about 2°C to about 8°C, optionally at or about 5°C. In some of any embodiments, the TACI-Fc protein species is assessed at about 12°C to about 18°C, optionally at or about 15°C. In some of any embodiments, the TACI-Fc species is assessed at about 18°C to about 22°C, optionally at or about 20°C. In some of any embodiments, the TACI-Fc species is assessed about 22°C to about 28°C, optionally at or about 25°C. In some of any embodiments, the TACI-Fc species is assessed at about 28°C to about 32°C, such as at or about 30°C.

[0077] In some of any embodiments, the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein are assessed by size exclusion chromatography (SEC), Reduced Capillary electrophoresis sodium dodecyl sulfate (rCE-SDS), or Imaged capillary isoelectric focusing (icIEF). In some of any embodiments, the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein are assessed by size exclusion chromatography (SEC).

[0078] In some of any embodiments, upon storage the loss of the main species of the TACI-Fc fusion protein in the formulation is less than 1% per week; and / or the increase in the amount of low molecular weight (LMW) species of the TACI-Fc fusion protein in the formulation is less than about 0.03% per week; and / or the increase in the amount of high molecular weight (HMW) species of the TACI-Fc fusion protein in the formulation is less than 0.9% per week.

[0079] In some of any embodiments, the loss of the main species of the TACI-Fc fusion protein in the formulation is less than 0.1% per week. In some of any embodiments, the increase in the amount of low molecular weight (LMW) species of the TACI-Fc fusion protein in the formulation is less than 0.1% per week. In some of any embodiments, the increase in the amountAttorney Docket No. 01245-0082-00PCT of high molecular weight (BMW) species of the TACI-Fc fusion protein in the formulation is less than 0.1% per week.

[0080] In some of any embodiments, one or more of the viscosity of the formulation is less than about 15 cP; the concentration of particles with average particle size of less than about 2 pm is less than about 10,000 particles / mL; and the concentration of particles with average particle size of less than about 10 pm is less than about 500 parti cles / mL.

[0081] In some of any embodiments, the formulation containing the TACI-Fc fusion protein is a low viscosity liquid that can flow.

[0082] In some of any embodiments, the viscosity of the TACI-Fc formulation is assessed at about 2°C to about 8°C, optionally at or about 5°C. In some of any embodiments, the viscosity of the TACI-Fc formulation is assessed at about 12°C to about 18°C, optionally at or about 15°C. In some of any embodiments, viscosity of the TACI-Fc formulation is assessed at about 18°C to about 22°C, optionally at or about 20°C. In some of any embodiments, the viscosity of the TACI-Fc formulation is assessed at about 22°C to about 28°C, optionally at or about 25°C.

[0083] In some of any embodiments, the viscosity of the TACI-Fc formulation is assessed at about 28°C to about 32°C, such as at or about 30°C. In some of any embodiments, the TACI-Fc formulation has a viscosity of at or from about 3 cP to about 15 cP. In some of any embodiments, the TACI-Fc formulation has a viscosity of at or about 15 cP at 5°C. In some of any embodiments, the TACI-Fc formulation has a viscosity of at about 5 cP to about 10 cP, optionally about 6 cP to about 8 cP. In some of any embodiments, the TACI-Fc formulation has a viscosity of a viscosity of at or about 10 cP at 15°C. In some of any embodiments, the TACI-Fc formulation has a viscosity of at or about 7 cP at 25°C. In some of any embodiments, the viscosity of the TACI-Fc formulation is assessed using a rheometer or a cone and plate viscometer.

[0084] In some of any embodiments, the formulation containing a TACI-Fc fusion protein contains less than 6,000 > 10 pm particles / mL. In some of any embodiments, the formulation containing a TACI-Fc fusion protein contains less than about 600 > 25 pm particles / mL. In some of any embodiments, subvisible particles in the TACI-Fc formulation are assessed by Background Membrane Imaging (BMI) or a Liquid Particle Counter.

[0085] In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 2°C to about 8°C. In some of any embodiments, the amount of the main species, high molecular weight species,Attorney Docket No. 01245-0082-00PCT and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at about 5°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 12°C to about 18°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 15°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 18°C to about 22°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 20°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 22°C to about 28°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at a storage temperature of about 25°C. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at for at least at or about 2 weeks. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at for at least at or about 1 year. In some of any embodiments, the amount of the main species, high molecular weight species, and / or low molecular weight species of the TACI-Fc fusion protein in the formulation is assessed after storage at for at least at or about 2 years.In some of any embodiments, after storage for 12 months in liquid form at a storage temperature of at or about 2°C to about 8°C, optionally at or about 5°C, and as measured by size exclusion chromatography (SEC) and as expressed in terms of area% under a curve that includes the TACI-Fc fusion protein in a form of a homodimer comprising two identical copies of the TACI-Fc fusion protein linked by a covalent disulfide bond as a main species, wherein:- the main species is at least 95%, at least 98%, or at least 99% of all observed species under the curve;- less than 5%, less than 2%, or less than 1% of species under the curve have a size greater than a size of the main species;Attorney Docket No. 01245-0082-00PCT - less than 5%, less than 2%, or less than 1% of species under the curve have a size less than a size of the main species;- the loss of the main species is less than 1%;- the increase in species under the curve having a size greater than a size of the main species is less than 1%; and / or- the increase in species under the curve having a size less than a size of the main species is less than 1%.

[0086] In some of any embodiments, the TACI-Fc fusion protein comprises a variant TACI polypeptide, and / or the TACI-Fc fusion protein has an isoelectric point (pl) of at or about 7.0 to about 7.8, at or about 7.0 to about 7.7, at or about 7.0 to about 7.6, at or about 7.0 to about 7.5, at or about 7.0 to about 7.3, at or about 7.1 to about 7.5, at or about 7.1 to about 7.3, or about 7.2.

[0087] In some of any embodiments, the formulation has a tonicity of an isotonic tonicity, of at or about 250 to about 350 mOsm / Kg, or of at or about 250 mOsm / Kg to about 600 mOsm / Kg.

[0088] In some of any embodiments, the formulation containing the TACI-Fc fusion protein is formulated for direct administration without dilution. In some of any embodiments, the formulation containing the TACI-Fc fusion protein is formulated for intravenous administration. In some of any embodiments, the formulation containing the TACI-Fc fusion protein is formulated for subcutaneous administration. In some of any embodiments, the formulation is a liquid formulation that has not been lyophilized and is not lyophilized prior to administration to a subject. In some of any embodiments, the formulation is a liquid formulation having a viscosity of at or about 3 cP to about 15 cP at 25°C as assessed using a rheometer or a cone and plate viscometer. In some of any embodiments, the formulation is a liquid formulation comprising less than about 6,000 parti cles / mL having a particle size diameter of > 10 pm; and / or comprising less than about 600 parti cles / mL having a particle size diameter of > 25 pm, after storage for 12 months in liquid form at a storage temperature of at or about 2°C to about 8°C, optionally at or about 5°C.

[0089] In some of any embodiments, the TACI-Fc fusion protein in the formulation contains (i) a TACI polypeptide sequence that is an extracellular domain (ECD) or portion of the ECD of a TACI polypeptide or is a variant TACI polypeptide thereof; and (ii) an Fc region.

[0090] In some of any embodiments, the TACI-Fc fusion protein in the formulation contains a variant TACI polypeptide containing one or more amino acid substitutions in the extracellular domain (ECD) of a reference TACI polypeptide, wherein the one or more amino acid substitutions comprise substitution(s) at positions selected from among 40, 59, 60, 61, 74, 75, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 92, 95, 97, 98, 99, 101, 102 and 103, corresponding to numbering of positions set forth in SEQ ID NO: 122.Attorney Docket No. 01245-0082-00PCT

[0091] In some of any embodiments, the reference TACI polypeptide is a truncated polypeptide consisting of the extracellular domain of TACI or a specific binding portion thereof that binds to APRIL, B AFF, or a B AFF / APRIL heterotrimer.

[0092] In some of any embodiments, the reference TACI polypeptide comprises the sequence of amino acids set forth in SEQ ID NO: 122, or a portion thereof containing one or both of a CRD1 domain and a CRD2 domain that binds to APRIL, BAFF, or a B AFF / APRIL heterotrimer.

[0093] In some of any embodiments, the reference TACI polypeptide lacks an N-terminal methionine.

[0094] In some of any embodiments, the reference TACI polypeptide comprises the CRD1 domain and the CRD2 domain.

[0095] In some of any embodiments, the reference TACI polypeptide the sequence set forth in SEQ ID NO: 1.

[0096] In some of any embodiments, the reference TACI polypeptide consists of the sequence set forth in SEQ ID NO: 1.

[0097] In some of any embodiments, the reference TACI polypeptide is a truncated wildtype TACI extracellular domain that contains the cysteine rich domain 2 (CRD2) but lacks the entirety of the cysteine rich domain 1 (CRD1), wherein the variant TACI polypeptide comprises one or more amino acid substitutions in the truncated wild-type TACI extracellular domain.

[0098] In some of any embodiments, the reference TACI polypeptide is a truncated wildtype TACI extracellular domain that consists of a contiguous sequence contained within amino acid residues 67-118 that includes amino acid residues 71-104, with reference to positions set forth in SEQ ID NO: 122, wherein the variant TACI polypeptide comprises one or more amino acid substitutions in the truncated wild-type TACI extracellular domain.

[0099] In some of any embodiments, the reference TACI polypeptide is a truncated wildtype TACI extracellular domain that is 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 59, 50 or 51 amino acids in length.

[0100] In some of any embodiments, the reference TACI polypeptide consists essentially of the CRD2 domain.

[0101] In some of any embodiments, the reference TACI polypeptide is a truncated wildtype TACI extracellular domain that consists of amino acid residues 68-110 set forth in SEQ ID NO: 122.

[0102] In some of any embodiments, the reference TACI polypeptide comprises the sequence set forth in SEQ ID NO: 13.Attorney Docket No. 01245-0082-00PCT

[0103] In some of any embodiments, the reference TACI polypeptide consists of the sequence set forth in SEQ ID NO: 13.

[0104] In some of any embodiments, the reference TACI polypeptide the variant TACI polypeptide comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid substitutions.

[0105] In some of any embodiments, the TACI-Fc fusion protein in the formulation contains a variant TACI polypeptide that comprises two or more amino acid substitutions.

[0106] In some of any embodiments, the TACI-Fc fusion protein in the formulation contains a variant TACI polypeptide that comprises one or more amino acid substitutions are selected from W40R, Q59R, R60G, T61P E74V, Q75E, Q75R, G76S, K77E, F78Y, Y79F, L82H, L82P, L83S, R84G, R84L, R84Q, D85E, D85V, C86Y, I87L, I87M, S88N, 192 V, Q95R, P97S, K98T, Q99E, A101D, Y102D, F103S, Fl 03V, and Fl 03 Y, or a conservative amino acid substitution thereof. In some of any embodiments, the one or more amino acid substitutions comprises at least one of E74V, K77E, Y79F, L82H, L82P, R84G, R84L, R84Q, D85V, or C86Y.

[0107] In some of any embodiments, the one or more amino acid substitutions comprise an amino acid substitution selected from the group consisting of Q75E, K77E, F78Y, R84G, R84Q, A101D, and Y102D, or any combination thereof.

[0108] In some of any embodiments, the one or more amino acid substitutions comprise Q75E / R84Q, Q75E / K77E, Q75E / F78Y, Q75E / A101D, Q75E / Y102D, F77E / F78Y, K77E / R84Q, K77E / A101D, K77E / Y102D, F78Y / R84Q, F78Y / A101D, F78Y / Y102D, R84Q / A101D, R84Q / Y102D, or A101D / Y102D.

[0109] In some of any embodiments, the one or more amino acid substitutions are K77E / F78Y.

[0110] In some of any embodiments, the one or more amino acid substitutions are K77E / F78Y / Y102D.[OHl] In some of any embodiments, the variant TACI polypeptide has increased binding affinity to one or both of APRIL and BAFF compared to the reference TACI polypeptide.

[0112] In some of any embodiments, the variant TACI polypeptide has increased binding affinity to APRIL.

[0113] In some of any embodiments, the variant TACI polypeptide has increased binding affinity to BAFF.

[0114] In some of any embodiments, the variant TACI polypeptide has increased binding affinity to APRIL and BAFF. In some of any embodiments, the increased binding affinity for BAFF or APRIL is independently increased more than 1.2-fold, 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold or 60-fold.Attorney Docket No. 01245-0082-00PCT

[0115] In some of any embodiments, the variant TACI polypeptide has up to 10 amino acid modifications compared to the reference TACI polypeptide.

[0116] In some of any embodiments, the variant TACI polypeptide has up to 5 amino acid modifications compared to the reference TACI polypeptide.

[0117] In some of any embodiments, the variant TACI polypeptide has the at least 90% sequence identity to the amino acid sequence set forth in SEQ ID NO: 122 or a specific binding fragment thereof containing the CRD1 domain and / or CRD2 domain. In some of any embodiments, the variant TACI polypeptide has at least 95% sequence identity to the amino acid sequence set forth in SEQ ID NO: 122 or a specific binding fragment thereof containing the CRD1 domain and / or CRD2 domain.

[0118] In some of any embodiments, the specific binding fragment of the TACI polypeptide is set forth in SEQ ID NO: 1, SEQ ID NO: 13, SEQ ID NO: 130, or SEQ ID NO: 131.

[0119] In some of any embodiments, the variant TACI polypeptide has at least 90% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13. In some of any embodiments, the variant TACI polypeptide has at least 95% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13.

[0120] In some of any embodiments, the variant TACI polypeptide comprises the sequence of amino acids set forth in any one of SEQ ID NOS: 2-12, 21, 22 and 101-120; or the variant TACI polypeptide comprises the sequence of amino acids set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100 and 177-192.

[0121] In some of any embodiments, the variant TACI polypeptide consists or consists essentially of the sequence of amino acids set forth in any one of SEQ ID NOS: 2-12, 21, 22 and 101-120; or the variant TACI polypeptide consists or consists essentially of the sequence of amino acids set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100 and 177-192.

[0122] In some of any embodiments, the variant TACI polypeptide comprises the sequence of amino acids set forth in SEQ ID NO: 26.

[0123] In some of any embodiments, the sequence of the variant TACI polypeptide is set forth in SEQ ID NO: 26.

[0124] In some of any embodiments, the TACI is a TACI polypeptide that is a truncated wild-type TACI extracellular domain, wherein the truncated wild-type TACI extracellular domain contains the cysteine rich domain 2 (CRD2) but lacks the entirety of the cysteine rich domain 1 (CRD1).

[0125] In some of any embodiments, the TACI in the TACI-Fc fusion protein is a TACI polypeptide that is a truncated wild-type TACI extracellular domain, wherein the truncated wildtype TACI extracellular domain consists of a contiguous sequence contained within amino acidAttorney Docket No. 01245-0082-00PCT residues 67-118 that consists of amino acid residues 71-104, with reference to positions set forth in SEQ ID NO: 122.

[0126] In some of any embodiments, the TACI in the TACI-Fc fusion protein is a TACI polypeptide that is a truncated wild-type TACI extracellular domain that is 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 59, 50 or 51 amino acids in length.

[0127] In some of any embodiments, the TACI in the TACI-Fc fusion protein is a TACI polypeptide that is a truncated wild-type TACI extracellular domain that consists of amino acid residues 68-110 set forth in SEQ ID NO: 122.

[0128] In some of any embodiments, the TACI in the TACI-Fc fusion protein is a TACI polypeptide that is a truncated wild-type TACI extracellular domain that consists of the sequence of amino acid set forth in SEQ ID NO: 13.

[0129] In some of any embodiments, the TACI polypeptide in the TACI-Fc fusion protein is linked to an Fc region of an immunoglobulin via a linker, wherein the TACI-Fc fusion protein comprises the structure: TACI polypeptide (TACI)-Linker-Fc region.

[0130] In some of any embodiments, the TACI polypeptide in the TACI-Fc fusion protein is linked to an Fc region of an immunoglobulin via a linker that comprises a peptide linker and the peptide linker is selected from GSGGS (SEQ ID NO: 76), GGGGS (G4S; SEQ ID NO: 77), GSGGGGS (SEQ ID NO: 74), GGGGSGGGGS (2xGGGGS; SEQ ID NO: 78), GGGGSGGGGSGGGGS (3xGGGGS; SEQ ID NO: 79), GGGGSGGGGSGGGGSGGGGS (4xGGGGS, SEQ ID NO: 84), GGGGSGGGGSGGGGSGGGGSGGGGS (5XGGGGS, SEQ ID NO: 91), GGGGSSA (SEQ ID NO: 80), or GSGGGGSGGGGS (SEQ ID NO: 194), or combinations thereof.

[0131] In some of any embodiments, the Fc is an immunoglobulin Fc that is an IgGl Fc domain, or is a variant Fc that exhibits reduced binding affinity to an Fc receptor and / or reduced effector function, optionally as compared to a wild-type IgGl Fc domain.

[0132] In some of any embodiments, the Fc is an immunoglobulin Fc that is an IgGl Fc domain and the Fc comprises the amino acid sequence set forth in SEQ ID NO:81.

[0133] In some of any embodiments, the Fc is an immunoglobulin Fc that is a variant IgGl Fc domain containing one or more amino acid substitutions selected from L234A, L234V, L235A, L235E, G237A, S267K, R292C, N297G, and V302C, by EU numbering. In some of any embodiments, the immunoglobulin Fc region comprises the amino acid substitutions L234A, L235E and G237A by EU numbering. In some of any embodiments, the immunoglobulin Fc region is set forth in any of SEQ ID NOS: 73, 75, 83, 136, or 221. In some of any embodiments, the immunoglobulin Fc region further comprises the amino acid substitutions A330S and P331S.Attorney Docket No. 01245-0082-00PCT In some of any embodiments, the immunoglobulin Fc region is set forth in SEQ ID NO: 175 or SEQ ID NO: 176.

[0134] In some of any embodiments, the Fc is a variant Fc containing the amino acid sequence set forth in SEQ ID NO: 73.

[0135] In some of any embodiments, the TACI-Fc fusion protein is set forth in SEQ ID NO: 168.

[0136] In some of any embodiments, the TACI-Fc fusion protein is set forth in SEQ ID NO: 170.

[0137] In some of any embodiments, the TACI-Fc fusion protein is set forth in SEQ ID NO: 167.

[0138] In some of any embodiments, the TACI-Fc fusion protein is set forth in SEQ ID NO: 169.

[0139] In some of any embodiments, the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein.

[0140] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing: 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

[0141] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

[0142] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.Attorney Docket No. 01245-0082-00PCT

[0143] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

[0144] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

[0145] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

[0146] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0147] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; andO.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0148] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165Attorney Docket No. 01245-0082-00PCT mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0149] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0150] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0151] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.

[0152] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 169 linked by a covalent disulfide bond.

[0153] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein inAttorney Docket No. 01245-0082-00PCT the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 169 linked by a covalent disulfide bond.

[0154] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 169 linked by a covalent disulfide bond.

[0155] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl); 10 mM sodium acetate; and0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 169 linked by a covalent disulfide bond.

[0156] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 169 linked by a covalent disulfide bond.

[0157] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 169 linked by a covalent disulfide bond.

[0158] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 170 linked by a covalent disulfide bond.Attorney Docket No. 01245-0082-00PCT

[0159] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.1% (w / v) poloxamer 188 (P188); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 170 linked by a covalent disulfide bond.

[0160] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and 0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 170 linked by a covalent disulfide bond.

[0161] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 3.1% (w / v) arginine hydrochloride (Arg-HCl) or at or about 135 mM to about 165 mM arginine or at or about 140 mM to about 150 mM arginine; 10 mM sodium acetate; and0.02% (w / v) polysorbate 80 (PS80); wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 170 linked by a covalent disulfide bond.

[0162] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline; 10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 160 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 170 linked by a covalent disulfide bond.

[0163] Also provided herein is a formulation containing a TACI-Fc fusion protein, containing 2.0% or 3.0% (w / v) proline;10 mM sodium acetate; 0.1% (w / v) poloxamer 188; and 50 mM sodium chloride; wherein the concentration of the TACI-Fc fusion protein in the composition is about 175 mg / mL; the formulation pH is at or about 4.7; and the TACI-Fc fusion protein is a homodimer containing two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 170 linked by a covalent disulfide bond.

[0164] In some of any embodiments, the TACI-Fc fusion protein neutralizes APRIL and BAFF. In some of any embodiments, the TACI-Fc fusion protein neutralizes APRIL and BAFFAttorney Docket No. 01245-0082-00PCT where the IC50 of the TACI-Fc fusion protein for neutralizing APRIL is less than 100 pM, less than 50 pM, less than 40 pM, less than 30 pM, less than 20 pM, less than 10 pM, less than 5 pM or less than 1 pM, or is any value between any of the foregoing; and / or the IC50 of the TACI-Fc for neutralizing BAFF is less than 400 pM, less than 300 pM, less than 200 pM, less than 100 pM, less than 75 pM, less than 50 pM, less than 25 pm, or less than 10 pM, or is any value between any of the foregoing.

[0165] In some of any embodiments, the TACI-Fc fusion protein blocks binding of APRIL, BAFF, or an APRIL / BAFF heterotrimer to BCMA or TACI; and / or the TACI-Fc fusion protein reduces the levels of circulating APRIL, BAFF, or an APRIL / BAFF in the blood following administration to a subject.

[0166] In some of any embodiments, the TACI-Fc fusion protein reduces or inhibits B cell maturation, differentiation and / or proliferation.

[0167] In some of any embodiments, the formulation containing the TACI-Fc fusion protein further contains an additional pharmaceutically acceptable excipient.

[0168] Also provided herein is an article of manufacture containing a TACI-Fc formulation provided herein in a vial or container. In some of any embodiments, the container is a syringe. In some of any embodiments, the container is an autoinjector.

[0169] Also provided herein is an article of manufacture containing the TACI-Fc formulation provided herein in a prefilled syringe.

[0170] Also provided herein is a kit containing a TACI-Fc formulation provided herein or an article of manufacture containing a TACI-Fc formulation provided herein, and instructions for use.

[0171] Also provided herein is a method of manufacturing or producing a TACI-Fc formulation provided herein.

[0172] Provided herein are methods of reducing an immune response in a subject, containing administering the formulation of any of the embodiments described herein to a subject in need thereof. In some of any embodiments, a B cell immune response is reduced in the subject, whereby B cell maturation, differentiation and / or proliferation is reduced or inhibited. In some of any embodiments, circulating levels of APRIL, BAFF or an APRIL / BAFF heterotrimer are reduced in the subject.

[0173] Also provided herein is a method of reducing circulating levels of APRIL, BAFF or an APRIL / BAFF heterotrimer in a subject containing administering the formulation of any of the embodiments described herein.

[0174] In some of any embodiments, reducing the immune response treats a disease, disorder or condition in the subject.Attorney Docket No. 01245-0082-00PCT

[0175] Also provided herein is a method of treating a disease, disorder or condition in a subject, containing administering a formulation the formulation of any of the embodiments described herein to a subject in need thereof.

[0176] In some of any embodiments, the disease, disorder or condition is an autoimmune disease or an inflammatory condition.

[0177] In some of any embodiments, the disease, disorder or condition is a B cell cancer, an antibody- mediated pathology, a renal disease, a graft rejection, graft versus host disease, or a viral infection.

[0178] In some of any embodiments, the disease, disorder or condition is selected from the group consisting of systemic lupus erythematosus (SLE), lupus nephritis, cutaneous lupus erythematosus, Sjogren’s syndrome, scleroderma (systemic sclerosis), multiple sclerosis, diabetes (e.g. Type I diabetes), polymyositis, primary biliary cirrhosis, IgG4-related disease, IgA nephropathy, IgA vasculitis, ANCA vasculitis (microscopic polyangiitis, granulomatosis with polyangiitis [Wegener’s granulomatosis], eosinophilic granulomatosis with polyangiitis [Churg-Strauss]) cryoglobulinemia, cold agglutinin or warm agglutinin disease, immune thrombocytopenic purpura, optic neuritis, amyloidosis, antiphospholipid antibody syndrome (APS), autoimmune polyglandular syndrome type II (APS II), autoimmune thyroid disease (AITD), Graves’ disease, autoimmune adrenalitis, pemphigus vulgaris, bullous pemphigoid, myasthenia gravis, graft versus host disease (GVHD), transplantation, rheumatoid arthritis, acute lupus nephritis, amyotrophic lateral sclerosis, neuromyelitis optica, transverse myelitis, Rasmussen’s encephalitis, CNS autoimmunity, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, neurocystercercosis, sarcoidosis, antiphospholipid antibody syndrome, IgG4-related disease, Hashimoto’s thyroiditis, immune thrombocytopenia, Addison’s Disease, dermatomyositis.

[0179] In some of any embodiments, the disease or disorder is autoantibody-associated glomerular disease.

[0180] In some of any embodiments, wherein the autoantibody-associated glomerular disease is immunoglobulin (Ig) A nephropathy (IgAN), lupus nephritis (LN), primary membranous nephropathy (pMN), myasthenia gravis, or renal anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

[0181] In some of any embodiments, the disease, disorder or condition is immune thrombocytopenia, autoimmune hemolytic anemia, or cold agglutinin disease.

[0182] In some of any embodiments, the disease, disorder or condition immunoglobulin A (IgA) nephropathy.Attorney Docket No. 01245-0082-00PCT

[0183] In some of any embodiments, the disease, disorder or condition is a B cell cancer and the cancer is myeloma.

[0184] Also provided herein is a formulation of any of the embodiments described herein for use in reducing an immune response in a subject.

[0185] Also provided herein is use of formulation of any of the embodiments described herein in the manufacture of a medicament for reducing an immune response in a subject.

[0186] In some of any embodiments of the formulation for use or the uses provided herein, the immune response is a B cell immune response, wherein reducing the immune response reduces or inhibits B cell maturation, differentiation and / or proliferation. In some of any embodiments of the formulation for use or the uses provided herein, reducing the immune response reduces circulating levels of APRIL, BAFF or an APRIL / BAFF heterotrimer in the subject. In some of any embodiments of the formulation for use or the uses provided herein, reducing the immune response treats a disease, disorder or condition in the subject.

[0187] Also provided herein is a formulation of any of the embodiments described herein for use in treating a disease, disorder or condition in a subject.

[0188] Also provided herein is use of formulation of any of the embodiments described herein in the manufacture of a medicament for treating a disease, disorder or condition in a subject.

[0189] In some of any embodiments of the formulation for use or the uses provided herein, the disease, disorder or condition is an autoimmune disease or an inflammatory condition.

[0190] In some of any embodiments of the formulation for use or the uses provided herein, disease, disorder or condition is a B cell cancer, an antibody- mediated pathology, a renal disease, a graft rejection, graft versus host disease, or a viral infection.

[0191] In some of any embodiments of the formulation for use or the uses provided herein, disease, disorder or condition is selected from the group consisting of systemic lupus erythematosus (SLE), lupus nephritis, cutaneous lupus erythematosus, Sjogren’s syndrome, scleroderma (systemic sclerosis), multiple sclerosis, diabetes (e.g. Type I diabetes), polymyositis, primary biliary cirrhosis, IgG4-related disease, IgA nephropathy, IgA vasculitis, ANC A vasculitis (microscopic polyangiitis, granulomatosis with polyangiitis [Wegener’s granulomatosis], eosinophilic granulomatosis with polyangiitis [Churg-Strauss]) cryoglobulinemia, cold agglutinin or warm agglutinin disease, immune thrombocytopenic purpura, optic neuritis, amyloidosis, antiphospholipid antibody syndrome (APS), autoimmune polyglandular syndrome type II (APS II), autoimmune thyroid disease (AITD), Graves’ disease, autoimmune adrenalitis, pemphigus vulgaris, bullous pemphigoid, myasthenia gravis, graft versus host disease (GVHD), transplantation, rheumatoid arthritis, acute lupus nephritis,Attorney Docket No. 01245-0082-00PCT amyotrophic lateral sclerosis, neuromyelitis optica, transverse myelitis, Rasmussen’s encephalitis, CNS autoimmunity, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, neurocystercercosis, sarcoidosis, antiphospholipid antibody syndrome, IgG4-related disease, Hashimoto’s thyroiditis, immune thrombocytopenia, Addison’s Disease, dermatomyositis.

[0192] In some of any embodiments of the formulation for use or the uses provided herein, disease or disorder is autoantibody-associated glomerular disease.

[0193] In some of any embodiments of the formulation for use or the uses provided herein, autoantibody-associated glomerular disease is immunoglobulin (Ig) A nephropathy (IgAN), lupus nephritis (LN), primary membranous nephropathy (pMN), myasthenia gravis, or renal antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

[0194] In some of any embodiments of the formulation for use or the uses provided herein, disease, disorder or condition is immune thrombocytopenia, autoimmune hemolytic anemia, or cold agglutinin disease.

[0195] In some of any embodiments of the formulation for use or the uses provided herein, disease, disorder or condition is a B cell cancer, optionally wherein the cancer is myeloma.

[0196] Also provided herein is a method for reducing the loss of a TACI-Fc fusion protein homodimer in a liquid pharmaceutical formulation containing a TACI-Fc fusion protein at a concentration of at least 160 mg / mL, containing the step of combining the TACI-Fc fusion protein with a viscosity-reducing concentration of a tonicifying agent comprising arginine.Brief Description of the Drawings

[0197] FIG. 1 depicts the viscosity measurements for formulations 1-20 at 160 mg / ml time = 0.

[0198] FIG. 2 depicts the viscosity measurements for formulations #1-4 at time = 0, 8 weeks at 4°C, and 8 weeks at 30°C.

[0199] FIGs. 3A-3C depict the results of a long-term stability study for formulations 1-20 at 2-8°C as measured by HP-SEC. FIG. 3A depicts the rate of change per week of %high molecular weight (HMW) species. FIG. 3B depicts the rate of change per week of the % main species. FIG. 3C depicts the rate of change per week of the %low molecular weight (LMW) species.

[0200] FIGs. 4A-4E depict the results of a long-term stability study for formulations 1-20 at 30°C as measured by HP-SEC. FIG. 4A depicts the rate of change per week of % high molecular weight (HMW) species. FIG. 4B depicts the rate of change per week of % main species. FIG.4C depicts the rate of change per week of the % low molecular weight (LMW) species. FIG. 4DAttorney Docket No. 01245-0082-00PCT depicts a subset of the conditions from FIGs. 4A, while FIG. 4E depicts a subset of the conditions from FIG. 4B.

[0201] FIGs. 5A-5C depict particle counts by background membrane imaging (BMI) measured at the final timepoint of 8 weeks of storage for formulations 1-20 at 2-8°C. FIG. 5A depicts particles greater than or equal to 2pm. FIG. 5B depicts particles greater than or equal to 10pm. FIG. 5C depicts particles greater than or equal to 25 pm.

[0202] FIGs. 6A-6C depict particle counts by background membrane imaging (BMI) measured at the final timepoint of 8 weeks of storage for formulations 1-20 at 30°C. FIG. 6A depicts particles greater than or equal to 2pm. FIG. 6B depicts particles greater than or equal to 10pm. FIG. 6C depicts particles greater than or equal to 25 pm.

[0203] FIG. 7 depicts the viscosity measurements of formulations 21-40 with ranges from approximately 7.3-5.2 cP at time = 0.

[0204] FIGs. 8A-8C depict the results of a long-term stability study for formulations 21-40 at 2-8°C as measured by HP-SEC. FIG. 8A depicts the rate of change per week of % total high molecular weight (HMW) species. FIG. 8B depicts the rate of change per week of % main species. FIG. 8C depicts the rate of change per week of % low molecular weight (LMW) species.

[0205] FIGs. 9A-9E depict the results of a long-term stability study for formulations 21-40 at 30°C as measured by HP-SEC. FIG. 9A depicts the rate of change per week of %high molecular weight (HMW) species. FIG. 9B depicts the rate of change per week of % main species. FIG. 9C depicts the rate of change per week of % low molecular weight (LMW) species. FIG. 9D depicts a subset of the conditions from FIGs. 9A, while FIG. 9E depicts a subset of the conditions from FIG. 9B.

[0206] FIGs. 10A-10C depict particle counts by background membrane imaging (BMI) measured at the final timepoint after 8 weeks of storage for formulations 21-40 at 2-8°C. FIG.10A depicts the number of particles greater than or equal to 2pm. FIG. 10B depicts number of particles greater than or equal to 10pm. FIG. 10C depicts number of particles greater than or equal to 25 pm.

[0207] FIGs. 11A-11C depict particle counts by background membrane imaging (BMI) measured at 2, 4, and 8 weeks of storage for formulations 21-40 at 30°C. FIG. HA depicts particles greater than or equal to 2pm. FIG. 11B depicts particles greater than or equal to 10pm.FIG. 11C depicts particles greater than or equal to 25 pm.

[0208] FIGs. 12A-12C depict particle counts by background membrane imaging (BMI) measured at the final timepoint of 8 weeks of storage for formulations 21-40 at 30°C. FIG. 12AAttorney Docket No. 01245-0082-00PCT depicts particles greater than or equal to 2pm. FIG. 12B depicts particles greater than or equal to 10pm. FIG. 12C depicts particles greater than or equal to 25 pm.

[0209] FIG. 13 depicts the comparison of viscosity curves for formulations 41-46.

[0210] FIGs. 14A-14I: FIGs. 14A-14F depict the results from size exclusion chromatography (SEC) and reduced capillary electrophoresis sodium dodecyl sulfate (rCE-SDS) assays to assess stability. FIG. 14A depicts the rate of change in % main species by SEC at -70°C, -20°C, and 5°C. FIG. 14B depicts the rate of change in % main species by SEC at 25°C and 40°C. FIG. 14C depicts the % main species by SEC during storage at 5°C for 24 months.FIG. 14D depicts % main rate by rCE-SDS at -70°C, -20°C, and 5°C. FIG. 14E depicts % main rate by rCE-SDS at 25°C and 40°C. 14F depicts % main rate by rCE-SDS after storage at 5°C for 24 months. FIGs. 14G-14I depict the result from an imaged capillary isoelectric focusing (icIEF) assay. FIG. 14G depicts the % main species by icIEF during storage at 5°C for 24 months. FIG. 14H depicts the % acidic species by icIEF during storage at 5°C for 24 months.FIG. 141 depicts % basic species by icIEF during storage at 5°C for 24 months.

[0211] FIGs. 15A-D depict particle counts by light obscuration. FIG. 15A and FIG. 15B depict counts for particles greater than or equal to 2pm at 5°C and 25°C respectively. FIG. 15C and FIG. 15D depict counts for particles greater than or equal to 10pm at 5°C and 25°C respectively.

[0212] FIGs. 16A-F depict the potency by ELISA of TACI-Fc protein in different formulation buffers over a 104-week period. FIG. 16A and FIG. 16C depict potency in a 0.015% PS80 w / v formulation for BAFF and APRIL respectively. FIG. 16B and FIG. 16D depict potency in a 0.1% P188 w / v formulation for BAFF and APRIL respectively. FIG. 16E and FIG. 16F depict potency for formulations in PS80 and Pl 88 after storage at 5°C for APRIL and BAFF, respectively.

[0213] FIG. 17 depicts recorded temperatures in Celsius (°C) during transport of formulation buffers 48-62.

[0214] FIGs. 18A-18C depicts results from a size exclusion chromatography (SEC) assay after a simulated transport study at varying pol oxamer 188 concentrations for formulations 48-62. In addition to the two replicates transported, there is a control condition where samples were stored quiescent at 2-8°C and not subjected to transport. FIG. 18A depicts 175 mg / mL TACI-Fc protein in 10 mM sodium acetate, 3.1% arginine HC1 (w / v) at pH 4.6. FIG. 18B depicts 175 mg / mL TACI-Fc protein in 10 mM sodium acetate, 2% proline (w / v), 50 mM NaCl at pH 4.6.FIG. 18C depicts 160 mg / mL TACI-Fc protein in 10 mM sodium acetate, 2% proline (w / v), 50 mMNaCl at pH 4.6.Attorney Docket No. 01245-0082-00PCT

[0215] FIGs. 19A-19F depict particle counts by light obscuration after simulated transport compared to controls that were not subject to simulated transport at varying pol oxamer 188 concentrations. FIG. 19A and FIG. 19B depict particle counts in formulation buffer 175 mg / mL TACI-Fc protein in 10 mM sodium acetate, 3.1% arginine HC1 (w / v) at pH 4.6 for particles greater than or equal to 2pm and 10pm, respectively. FIG. 19C and FIG. 19D depict particle counts in formulation buffer 175 mg / mL TACI-Fc protein in 10 mM sodium acetate, 2% proline (w / v), 50 mM NaCl at pH 4.6 for particles greater than or equal to 2pm and 10pm, respectively.FIG. 19E and FIG. 19F depict particle counts in formulation buffer 160 mg / mL TACI-Fc protein in 10 mM sodium acetate, 2% proline (w / v), 50 mM NaCl at pH 4.6 for particles greater than or equal to 2pm and 10pm, respectively.

[0216] FIGs. 20A-20F depict potency by ELISA of BAFF and APRIL in various formulation buffers for a simulated transport condition at varying pol oxamer 188 concentrations compared to a control. FIG. 20A and FIG. 20B depict potency of 175 mg / mL TACI-Fc protein in 10 mM sodium acetate, 3.1% arginine HC1 (w / v) at pH 4.6 for BAFF and APRIL, respectively. FIG. 20C and FIG. 20D depict potency of 175 mg / mL TACI-Fc protein in 10 mM sodium acetate, 2% proline (w / v), 50 mM NaCl at pH 4.6 for BAFF and APRIL, respectively. FIG. 20E and FIG. 20F depict potency of 160 mg / mL TACI-Fc protein in 10 mM sodium acetate, 2% proline (w / v), 50 mM NaCl at pH 4.6 for BAFF and APRIL respectively.

[0217] FIGs. 21A-21D depict results from a size exclusion chromatography (SEC) assay on formulations 51, 56, and 61. FIG. 21A depicts change in percent main per week at -70°C, -20°C, and 5°C. FIG. 21B depicts change in percent main per week at 25°C and 40°C. FIG. 21C depicts change in percent total high molecular weight (HMW) per week at -70°C, -20°C, and 5°C. FIG. 21D depicts change in percent total HMW per week at 25°C and 40°C.

[0218] FIGs. 22A-22C depict assessments of percent main (FIG. 22A), high molecular weight (HMW) (FIG. 22B), and low molecular weight (LMW) (FIG. 22C) for formulations 51, 56, and 61 over time at 5°C.

[0219] FIGs. 23A and 23B depict results from a reduced capillary electrophoresis sodium dodecyl sulfate (rCE-SDS) on formulations 51, 56, and 61 to assess rate of change by percent total purity per week. FIG. 23A depicts results from incubation temperatures of -70°C, -20°C, and 5°C. FIG. 23B depicts results from incubation temperatures of 25°C and 40°C.

[0220] FIGs. 24A and 24B depict results from a reduced capillary electrophoresis sodium dodecyl sulfate (rCE-SDS) on formulations 51, 56, and 61 to assess percent total purity during storage. FIG. 24A depicts results at 5°C incubation and FIG. 24B depicts results after 25°C incubation.Attorney Docket No. 01245-0082-00PCT

[0221] FIGs. 25A and 25B depict results from an imaged capillary isoelectric focusing (icIEF) assay to assess rate of change as percent main per week for formulation 51, 56, and 61.FIG. 25A depicts results from incubation temperatures of -70°C, -20°C, and 5°C. FIG. 25B depicts results from incubation temperatures of 25°C and 40°C.

[0222] FIGs. 26A-C depict results from an imaged capillary isoelectric focusing (icIEF) assay to assess percent main, percent acidic, and percent basic for formulation 51, 56, and 61 after 5°C incubation. FIG. 26A depicts results for percent main species, FIG. 26B depicts results for percent acidic species, and FIG. 26C depicts results for percent basic species.

[0223] FIGs. 27A-D depict results from an assessment of subvisible particles by light obscuration formulated in formulations 51, 56, and 61 during long term storage. FIG. 27A and 27C depict particle counts out to 52 weeks at 5 °C for particles greater than or equal to 2pm or 10pm, respectively . FIG. 27B and 27D depict particle counts out to 26 weeks at 25°C for particles greater than or equal to 2pm and 10pm, respectively.

[0224] FIGs. 28A-28C depict results from a bioactivity assessment by ELISA (percent relative potency of BAFF) conducted on formulation buffers 51, 56, and 61 at -70°C, -20°C, 2-8°C, 25°C, and 40°C over time. FIG. 28A depicts formulation 51, FIG. 28B depicts formulation 56, and FIG. 28C depicts formulations 61.

[0225] FIGs. 29A-29C depict results from a bioactivity assessment by ELISA (percent relative potency of APRIL) conducted on formulation buffers 51, 56, and 61 at -70°C, -20°C, 2-8°C, 25°C, and 40°C over time. FIG. 29A depicts formulation 51, FIG. 29B depicts formulation 56, and FIG. 29C depicts formulations 61.

[0226] FIGs. 30A-C depict assessments of change in percent main per week of various formulation buffers at one of four pHs (pH 4.3, 4.4, 4.6, and 5.0) by size exclusion chromatography (SEC). FIG. 30A depicts results for formulations after 12 weeks at 5°C, FIG.30B depicts results for formulations after 12 weeks at 25°C, and FIG. 30C depicts results from formulations after 12 weeks at 40°C.

[0227] FIGs. 31A-C depicts results from a reduced capillary electrophoresis sodium dodecyl sulfate (rCE-SDS) to assess change in percent main / week for various buffers. FIG. 31A depicts results after 12 weeks at 5°C, FIG. 31B depicts results after 12 weeks at 25°C, and FIG. 31C depicts results after 12 weeks at 40°C.

[0228] FIGs. 32A-C depicts results from an imaged capillary isoelectric focusing (icIEF) assay to assess change in percent main / week for various buffers. FIG. 32A depicts results after 12 weeks at 5°C, FIG. 32B depicts results after 12 weeks at 25°C, and FIG. 32C depicts results after 12 weeks at 40°C.Attorney Docket No. 01245-0082-00PCT

[0229] FIGs. 33A-F depicts results from an imaged capillary isoelectric focusing (icIEF) assay to assess the change in basic and acidic species of the TACI-Fc by change in percent species per week. FIGs. 33A-C depict the percent basic per week after 12 weeks at 5°C, 25°C, and 40°C, respectively. FIGs. 33D-F depict the percent acid per week after 12 weeks at 5°C, 25°C, and 40°C, respectively.

[0230] FIGs. 34A-I depict particle counts by flow imaging for formulation 65 and 66 at 0, 0.5, 1, 2, and 3 months of storage. FIG. 34A, 34B, and 34C depict counts for particles greater than or equal to 2pm at 5°C, 25°C, and 40°C, respectively. FIG. 34D, 34E, and 34F depict counts for particles greater than or equal to 10pm at 5°C, 25°C, and 40°C, respectively. FIG. 34G, 34H, and 341 depict counts for particles greater than or equal to 25pm at 5°C, 25°C, and 40°C, respectively.

[0231] FIGs. 35A-H depict the potency by ELISA and cell-based assay (CBA) of TACI-Fc for BAFF and APRIL in different formulations. FIG. 35A and 35B depict percent relative potency for Formulation 66 at -70°C, 4°C, 25°C, and 40°C for ELISA APRIL and ELISA BAFF, respectively. FIG. 35C and 35D depict percent relative potency for Formulation 67 at 4°C, 25°C, and 40°C for ELISA APRIL and ELISA BAFF, respectively. FIG. 35E and 35G depict percent relative potency for Formulation 66 at -70°C, 4°C, 25°C, and 40°C for CBA APRIL and CBA BAFF, respectively. FIG. 35F and 35H depict percent relative potency for Formulation 67 at 4°C, 25°C, and 40°C for CBA APRIL and CBA BAFF, respectively.Detailed Description

[0232] Provided herein are formulations comprising a TACI-Fc fusion protein that are stable. The TACI-Fc formulations provided herein contain components that permit formulation at high concentrations of TACI-Fc protein in the formulation where the TACI-Fc maintains stability after storage. The TACI-Fc formulation provided herein can be dispensed precisely and is stable with respect to TACI-Fc decomposition products and aggregates over the duration of storage, including storage at refrigerated and increased temperatures, and after transport. As described herein, formulations provided herein are highly stable upon storage, such as prolonged storage at altered temperature, maintaining substantially the same viscosity, and / or showing little or no protein aggregation upon storage. In some embodiments, at least about 95% of the TACI-Fc protein in the formulation is in the homodimer form (or “main species” or “main” form) as measured by size exclusion chromatography (SEC) before and / or after storage. In some embodiments, the formulation comprises no more than about 5% of formation of low and high molecular weight species as measured by size exclusion chromatography before and / or afterAttorney Docket No. 01245-0082-00PCT storage. Moreover, the low viscosity of the presently described formulations in spite of high protein concentrations permits convenient processing, including but not limited to ultrafiltration and sterile filtration, and injection of the drug product solution at relatively low total volumes through a syringe needle, for example. These properties make the TACI-Fc formulation particularly suitable as a pharmaceutical product that can be administered to human patients, for example by subcutaneous administration.

[0233] The provided formulations comprise a TACI-Fc fusion protein, such as variant TACI-fusion proteins, that bind to BAFF or APRIL ligands to neutralize their activity and block or antagonize the activity of B cell stimulatory receptors. Among the provided formulations are those comprising variant TACI polypeptides, such as those described herein and in International Patent Publication Nos. WO2021226551 and WO 2022236335. In embodiments herein, the provided formulations comprise immunomodulatory proteins that are fusion proteins of a TACI extracellular domain or binding portion thereof (hereinafter TACI ECD) and a multimerization domain that is immunoglobulin Fc (e.g., a TACI-Fc fusion protein). In embodiments, the formulations provided herein comprise a TACI-Fc fusion protein comprising a variant TACI polypeptide, such as those described herein and in International Patent Publication Nos.WO2021226551 and WO 2022236335.

[0234] In embodiments herein, the provided formulations contain a TACI-Fc fusion protein that has significantly improved ligand affinity; is superior to WT TACLIg, BAFF and / or APRIL-only inhibitors; and is well -tolerated in healthy adults via IV or SC administration with dosedependent PK / PD. In embodiments, herein the provided formulations contain TACI-Fc fusion proteins and immunomodulatory proteins comprising the TACI-Fc fusion protins that are suitable for multiple autoantibody-related inflammatory diseases.

[0235] In embodiments herein, formulations containing variant TACI polypeptides (e.g., variant TACI-Fc fusion proteins) such as those described herein and set forth in International Patent Publication Nos. WO2021226551 and WO 202223633, can be administered at a reduced dosing frequency compared to wild-type TACI. This reduced dose frequency may provide a treated subject with better symptom control, improve adherence to the dosing regimen, increase patient quality of life or patient satisfaction and / or overall reduce the costs of receiving the treatment. Moreover, reducing the dose, even at a more regular frequency such as once weekly, may also mitigate against certain adverse effects, such as those associated with administration.

[0236] In some embodiments, the formulations containing the TACI-Fc fusion proteins provided herein can be used for the treatment of diseases, disorders or conditions that are associated with a dysregulated immune response, such as associated with inflammatory or autoimmune symptoms including an inflammatory disease or an autoimmune disease.Attorney Docket No. 01245-0082-00PCT

[0237] The formulations provided herein contain a TACI-Fc fusion protein at high concentrations of greater than 100 mg / mL. High concentrations of protein therapeutics can lead to protein instability that can lead to protein aggregation or degradation, which can decrease or eliminate the functionality of the protein (e.g., TACI-Fc fusion protein). Protein aggregation and / or degradation also can lead to undesirable side effects upon administration, such as immune reactions at the injection site. Aggregation of the protein in a pharmaceutical formulation also can decrease the amount of the protein in the active state. For example, aggregation of a TACI-Fc fusion protein into high molecular weight (HMW) species (i.e., greater than two TACI-Fc polypeptide chains e.g., greater than about 62.6 kDa) can titrate away the TACI-Fc polypeptide(s) from the active homodimer form (i.e., the “main species”). Protein aggregation and / or degradation in a pharmaceutical formulation containing a highly concentrated protein therapeutic also can result in viscous formulations that are difficult to administer. Highly viscous pharmaceutical formulations can have decreased syringeability and / or injectability. Provided herein are TACI-Fc formulations that contain a high concentration of TACI-Fc fusion protein and other excipients as described herein and maintain the majority of the TACI-Fc fusion protein in the main, homodimer state, and are more easily administered.

[0238] In embodiments herein the provided formulations contain TACI-Fc fusion proteins at a concentration of greater than 100 mg / mL, such as at or about 140 mg / mL to about 230 mg / mL, at or about 140 mg / mL to about 200 mg / mL, at or about 160 mg / mL, or at or about 175 mg / mL. Even at these high concentrations, the majority of the TACI-Fc is the main species (homodimeric form). Also, as shown herein, even at these high concentrations the majority of the TACI-Fc protein is in the main species (homodimeric form) after prolonged storage, such as prolonged storage at low (e.g., 2-8°C, or 5°C) storage temperatures for up to about 1, 2, or 3 years or high (e.g., 30°C) for up to about 6 months.

[0239] In embodiments herein the provided formulations contain TACI-Fc fusion proteins that are well tolerated for administration at low doses (e.g., 80 mg) to high doses (e.g., 960 mg) without adverse effects. In embodiments herein, the provided formulations contain TACI-Fc fusion proteins that are also well tolerated when administered once every four weeks (Q4W). Furthermore, in embodiments herein the provided formulations contain TACI-Fc fusion proteins that are effective whether injected SC or IV at low doses (e.g., 80 mg).

[0240] All publications, including patent documents, scientific articles and databases, referred to in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication were individually incorporated by reference. If a definition set forth herein is contrary to or otherwise inconsistent with a definition set forth in the patents, applications, published applications and other publications that are herein incorporatedAttorney Docket No. 01245-0082-00PCT by reference, the definition set forth herein prevails over the definition that is incorporated herein by reference.

[0241] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.I. DEFINITIONS

[0242] Unless defined otherwise, all terms of art, notations and other technical and scientific terms or terminology used herein are intended to have the same meaning as is commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and / or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art.

[0243] As used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise.

[0244] The term “about” as used herein refers to the usual error range for the respective value readily known to the skilled person in this technical field. Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. For example, description referring to “about” X or “at or about” X includes description of “X”. In some embodiments, a numerical range or numerical value such as a concentration or pH range may be presented as: “at or about” value X to “about” value Y, for example (or similar language “at or about X to Y” or “at or about X to at or about Y”), or “between about” value X to “between about” value Y (or similar language “between about X to Y”), for example, or “at or about” value X. Such ranges herein in each case include each of the endpoint X and Y values, as well as the exact range from X to Y or the exact value X, as well as a range from “about X” to “about Y.”

[0245] The term “affinity-modified” as used in the context of a domain of a protein means a mammalian protein having an altered amino acid sequence in an extracellular domain or a specific binding portion thereof (relative to the corresponding wild-type parental or unmodified domain) such that it has an increased or decreased binding activity, such as binding affinity, to at least one of its binding partners (alternatively counter-structures) compared to the parental wildtype or unmodified (i.e., non-affinity modified domain) protein. In some embodiments, the affinity-modified domain can contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more amino acid differences, such as amino acid substitutions, in a wild-type or unmodified domain. An increase or decrease in binding activity, e.g. binding affinity, can be determined using well known binding assays, including flowAttorney Docket No. 01245-0082-00PCT cytometry. Larsen et al., American Journal of Transplantation, Vol 5: 443-453 (2005). See also, Linsley et al., Immunity, 1: 7930801 (1994). An increase in a protein’s binding activity, e.g. affinity, to its binding partner(s) is to a value at least 10% greater than that of the wild-type control and in some embodiments, at least 20%, 30%, 40%, 50%, 100%, 200%, 300%, 500%, 1000%, 5000%, or 10000% greater than that of the wild-type control value. A decrease in a protein’s binding activity, e.g. affinity, to at least one of its binding partners is to a value no greater than 90% of the control but no less than 10% of the wild-type control value, and in some embodiments no greater than 80%, 70% 60%, 50%, 40%, 30%, or 20% but no less than 10% of the wild-type control value. An affinity-modified protein is altered in primary amino acid sequence of the extracellular domain or a specific binding portion thereof by substitution, addition, or deletion of amino acid residues. The term affinity-modified is not to be construed as imposing any condition for any particular starting composition or method by which the affinity-modified protein was created. Thus, an affinity-modified protein is not limited to wild-type protein domains that are then transformed to an affinity -modified domain by any particular process of affinity modification. An affinity-modified domain polypeptide can, for example, be generated starting from wild-type mammalian domain sequence information, then modeled in silico for binding to its binding partner, and finally recombinantly or chemically synthesized to yield the affinity-modified domain composition of matter. In but one alternative example, an affinity-modified domain can be created by site-directed mutagenesis of a wild-type domain. Thus, “affinity modified TD domain” denotes a product and not necessarily a product produced by any given process. A variety of techniques including recombinant methods, chemical synthesis, or combinations thereof, may be employed.

[0246] The term “affinity-modified TD domain” refers to an affinity-modified domain of a member of the tumor necrosis factor receptor superfamily (TNFRSF) protein or a TNF ligand thereof having an altered amino acid sequence of a TNFR domain or of a TNF domain therein, respectively. For example, an affinity-modified TD domain of a TNFRSF protein has an altered amino acid sequence of a TNFR domain composed of at least one cysteine rich domain (CRD) within the extracellular domain of the TNFRSF protein or a specific binding portion thereof (relative to the corresponding wild-type parental or unmodified domain) such that it has an increased or decreased binding activity, such as binding affinity, to at least one of its binding partners (alternatively counter-structures) compared to the parental wild-type or unmodified protein containing the non-affinity modified or unmodified TD domain.

[0247] An “affinity-modified TACI” (also referred to as a variant TACI) refers to a TACI protein molecule that antagonizes or blocks the activity of a B cell stimulatory receptor. For example, TACI binds to APRIL and / or BAFF, which are ligands of the B cell stimulatoryAttorney Docket No. 01245-0082-00PCT receptors B cell maturation antigen (BCMA), B cell activation factor receptor (BAFF-R), and transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI). In particular embodiments, a BIM includes the extracellular domain of TACI, or a portion of the extracellular domain of TACI containing a TNF receptor family domain (e.g. TD, e.g. CRD) that binds to cognate ligands APRIL and / or BAFF, and heterotrimers of APRIL and BAFF. An affinity-modified variant of the extracellular domain or portion thereof of TACI can include one more amino acid modifications (e.g. amino acid substitutions) in the TD that increase binding affinity for the cognate ligand (e.g. APRIL and / or BAFF, and heterotrimers of APRIL and BAFF).

[0248] As used herein, a “main species” of TACI-Fc protein is used interchangeably with “main” and refers to a disulfide-linked homodimer consisting of two identical TACI-Fc fusion polypeptide chains, each with a TACI domain-Fc fusion polypeptide, where the identical chains in the pair are linked by covalent disulfide bonds. In a formulation of purified TACI-Fc protein, the majority of TACI-Fc in the formulation is a homodimer of the two TACI-Fc fusion polypeptide chains. The molecular weight of the main TACI-Fc fusion protein is less than the molecular weight of a high molecular weight species of a TACI-Fc fusion protein. The molecular weight of the main TACI-Fc fusion protein is more than the molecular weight of a low molecular weight species of a TACI-Fc fusion protein. The main species of a TACI-Fc fusion protein, comprising two chains, each comprising the CRD2 of TACI (e.g., set forth in SEQ ID NO. 13 or containing amino acid modifications in the sequence of amino acids set forth in SEQ ID NO. 13) fused to an Fc domain, has a molecular weight of approximately 62.6 kDa. The molecular weight of the main species of a TACI-Fc fusion protein of SEQ ID NO. 167 is approximately 62.6 kDa. The molecular weight of the main species of the TACI-Fc fusion protein can depend on the length of the TACI polypeptide in the fusion protein. In embodiments herein, the molecular weight of the main species of a TACI-Fc fusion protein comprising the full ECD of TACI can be at or about 116.4 kDa. In embodiments herein, the molecular weight of the main species of a TACI-Fc protein is at or about 62.6 kDa to at or about 116.4 kDa. In some embodiments the TACI polypeptide in the TACI-Fc fusion protein in the main species does not contain the entire CRD2 and the molecular weight of the TACI-Fc main is less than about 62.6 kDa. In embodiments herein, the approximate molecular weight of the main TACI-Fc species is calculated by taking the molecular weight of the TACI-Fc fusion protein and multiplying by two.

[0249] As used herein, a “high molecular weight” (HMW) species of TACI-Fc protein refers a species of TACI-Fc protein that comprises more TACI-Fc polypeptide chains than a dimer of two identical TACI- Fc fusion polypeptide chains. The HMW species of a TACI-Fc fusion protein contains more TACI domain-Fc fusion polypeptide chains than the main species of aAttorney Docket No. 01245-0082-00PCT TACI-Fc fusion protein. In some examples, a HMW species of a TACI-Fc protein contains 3, 4, 5, 6, or more TACI- Fc fusion polypeptide chains. The molecular weight of the HMW species of a TACI-Fc fusion protein is higher than the molecular weight of the main species of a corresponding TACI-Fc fusion protein. In embodiments herein, the molecular weight of the HMW species of a TACI-Fc fusion protein comprising the full ECD of TACI is greater than about 116.4 kDa. The molecular weight of a HMW species of a TACI-Fc fusion protein of SEQ ID NO. 167 is greater than approximately 62.6 kDa. In embodiments herein, the molecular weight of the HMW species of a TACI-Fc protein is greater than 62.6 kDa. In embodiments herein, the molecular weight of the HMW species of a TACI-Fc protein is at least 93.9 kDa. In embodiments herein, the approximate molecular weight of the high molecular weight species of the TACI-Fc protein can be calculated by taking the molecular weight of the TACI-Fc fusion protein and multiplying by the number of TACI-Fc fusion proteins in the HMW species (e.g., > 2).

[0250] As used herein, a “low molecular weight” (LMW) species of TACI-Fc protein refers a species of TACI-Fc protein that comprises fewer TACI-Fc polypeptide chains than a dimer of two identical TACI- Fc fusion polypeptide chains. The LMW species of a TACI-Fc fusion protein contains fewer TACI domain-Fc fusion polypeptide chains than the main species of a TACI-Fc fusion protein. In some examples, a LMW species of a TACI-Fc protein contains 1 or fewer TACI-Fc fusion polypeptide chains. The molecular weight of the LMW species of a TACI-Fc fusion protein is less than the molecular weight of the main species of a corresponding TACI-Fc fusion protein. The molecular weight of a LMW species of a TACI-Fc fusion protein of SEQ ID NO. 167 is less than approximately 62.6 kDa, such as at or about 31.3 kDa. In embodiments herein, the molecular weight of the LMW species of a TACI-Fc fusion protein comprising the full ECD of TACI is less than about 116.4 kDa, such as at or about 58.3 kDa. In embodiments herein, the molecular weight of the low molecular weight species of the TACI-Fc protein is calculated by taking the molecular weight of a single TACI-Fc fusion polypeptide chain and multiplying by the number of TACI-Fc fusion polypeptide chains in the LMW species (eg., 1).

[0251] As used herein, a “B cell stimulatory receptor” refers to one or more of B cell maturation antigen (BCMA), B cell activation factor receptor (BAFF-R), and transmembrane activator and calcium modulatory and cyclophilin ligand interactor (TACI), which are related tumor necrosis factor (TNF) superfamily receptors expressed on B cells. Engagement or ligation of these related receptors by their cognate ligands, BAFF and / or APRIL, or heterotrimers of APRIL and BAFF, regulate B cell homeostasis, including B cell survival, B cell maturation and differentiation and immunoglobulin class switching. A B cell stimulatory receptor generallyAttorney Docket No. 01245-0082-00PCT contains an extracellular portion, a transmembrane domain and cytoplasmic region, in which the cytoplasmic region contains one or more TNF receptor associated factor (TRAF) binding sites. Recruitment of various TRAF molecules to the cytoplasmic domain can activate various transcription factors, such as NF-KB (e.g. NF-KB1 or NF-KB2), to mediate B cell signaling pathways regulating B cell homeostasis.

[0252] As used herein, “bind,” “bound,” or grammatical variations thereof refers to the participation of a molecule in any attractive interaction with another molecule, resulting in a stable association in which the two molecules are in close proximity to one another. Binding includes, but is not limited to, non-covalent bonds, covalent bonds (such as reversible and irreversible covalent bonds), and includes interactions between molecules such as, but not limited to, proteins, nucleic acids, carbohydrates, lipids, and small molecules, such as chemical compounds including drugs.

[0253] As used herein, “binding activity” refers to characteristics of a molecule, e.g. a polypeptide, relating to whether or not, and how, it binds one or more binding partners. A binding activity can include any measure of binding of one molecule for a binding partner. Binding activities include the ability to bind the binding partner(s), the affinity with which it binds to the binding partner (e.g. high affinity), the avidity with which it binds to the binding partner, the strength of the bond with the binding partner and / or specificity or selectivity for binding with the binding partner.

[0254] The term “binding affinity” as used herein means the specific binding affinity of a protein for its binding partner (i.e., its counter- structure) under specific binding conditions. The binding affinity refers to the strength of the interaction between two or more molecules, such as binding partners, typically the strength of the noncovalent interactions between two binding partners. An increase or attenuation in binding affinity of an affinity-modified domain, or an immunomodulatory protein containing an affinity-modified domain, to a binding partner is determined relative to the binding affinity of the unmodified domain (e.g., the native or wildtype TD domain). Methods for determining binding affinity, or relative binding affinity, are known in art, and include solid-phase ELISA immunoassays, ForteBio® Octet™, Biacore® measurements or flow cytometry. See, for example, Larsen et al., American Journal of Transplantation, vol. 5: 443-453 (2005); Linsley et al., Immunity, Vol 1 (9): 793-801 (1994). In some embodiments, binding affinity can be measured by flow cytometry, such as based on a Mean Fluorescence Intensity (MFI) in a flow binding assay.

[0255] The term “binding avidity” as used herein means the specific binding avidity of a protein for its binding partner (i.e., its counter- structure) under specific binding conditions. In biochemical kinetics, “avidity” refers to the accumulated strength of multiple affinities ofAttorney Docket No. 01245-0082-00PCT individual non-covalent binding interactions, such as between a protein for its binding partner (i.e., its counter-structure). As such, avidity is distinct from affinity, which describes the strength of a single interaction.

[0256] The term “biological half-life” refers to the amount of time it takes for a substance, such as an immunomodulatory protein, to lose half of its pharmacologic or physiologic activity or concentration. Biological half-life can be affected by elimination, excretion, degradation (e.g., enzymatic degradation / digestion) of the substance, or absorption and concentration in certain organs or tissues of the body. In some embodiments, biological half-life can be assessed by determining the time it takes for the blood plasma concentration of the substance to reach half its steady state level (plasma half-life). Conjugates that can be used to derivatize and increase the biological half-life of a protein are known in the art and include, but are not limited to, multimerization domains (e.g. Fc immunoglobulin domain), polyethylene glycol (PEG), hydroxyethyl starch (HES), XTEN (extended recombinant peptides; see, WO2013130683), human serum albumin (HSA), bovine serum albumin (BSA), lipids (acylation), and poly-Pro-Ala-Ser (PAS), polyglutamic acid (glutamyl ati on).

[0257] The term “cell surface counter- structure” (alternatively “cell surface binding partner”) as used herein is a counter- structure (alternatively is a binding partner) expressed on a mammalian cell. Typically, the cell surface binding partner is a transmembrane protein. In some embodiments, the cell surface binding partner is a receptor.

[0258] The terms “binding partner” or “counter- structure” in reference to a protein, such as a receptor, soluble ligand, or to an extracellular domain or portion thereof or affinity-modified variant thereof, refers to at least one molecule (typically a native mammalian protein) to which the referenced protein specifically binds under specific binding conditions. In some aspects, an affinity-modified domain, or an immunomodulatory protein containing an affinity-modified domain, specifically binds to the binding partner of the corresponding domain of the native or wild-type protein but with increased or attenuated affinity. A cell surface binding partner is a binding partner expressed on a mammalian cell. Typically, the cell surface binding partner is a transmembrane protein. In some embodiments, the cell surface binding partner is a receptor, or a ligand of a receptor expressed on and by cells, such as mammalian cells, forming the immunological synapse, for example immune cells.

[0259] The term “cis” with reference to binding to cell surface molecules refers to binding to two or more different cell surface molecules, each of which is present on the surface of the same cell. In some embodiments, cis means that the two or more cell surface molecules are exclusively on one or exclusively the other (but not both) of the two mammalian cells forming the IS.Attorney Docket No. 01245-0082-00PCT

[0260] The term “conservative amino acid substitution” as used herein means an amino acid substitution in which an amino acid residue is substituted by another amino acid residue having a side chain R group with similar chemical properties (e.g., charge or hydrophobicity). Examples of groups of amino acids that have side chains with similar chemical properties include 1) aliphatic side chains: glycine, alanine, valine, leucine, and isoleucine; 2) aliphatic-hydroxyl side chains: serine and threonine; 3) amide-containing side chains: asparagine and glutamine; 4) aromatic side chains: phenylalanine, tyrosine, and tryptophan; 5) basic side chains: lysine, arginine, and histidine; 6) acidic side chains: aspartic acid and glutamic acid; and 7) sulfur-containing side chains: cysteine and methionine. Conservative amino acid substitution groups are: valine-leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, glutamateaspartate, and asparagine-glutamine.

[0261] The term “corresponding to” with reference to positions of a protein, such as recitation that nucleotides or amino acid positions “correspond to” nucleotides or amino acid positions in a disclosed sequence, such as set forth in the Sequence Listing, refers to nucleotides or amino acid positions identified upon alignment with the disclosed sequence based on structural sequence alignment or using a standard alignment algorithm, such as the GAP algorithm. By aligning the sequences, one skilled in the art can identify corresponding residues, for example, using conserved and identical amino acid residues as guides.

[0262] As used herein, “domain” (typically a sequence of three or more, generally 5 or 7 or more amino acids, such as 10 to 200 amino acid residues) refers to a portion of a molecule, such as a protein or encoding nucleic acid, that is structurally and / or functionally distinct from other portions of the molecule and is identifiable. For example, domains include those portions of a polypeptide chain that can form an independently folded structure within a protein made up of one or more structural motifs and / or that is recognized by virtue of a functional activity, such as binding activity. A protein can have one, or more than one, distinct domains. For example, a domain can be identified, defined or distinguished by homology of the primary sequence or structure to related family members, such as homology to motifs. In another example, a domain can be distinguished by its function, such as an ability to interact with a biomolecule, such as a cognate binding partner. A domain independently can exhibit a biological function or activity such that the domain independently or fused to another molecule can perform an activity, such as, for example binding. A domain can be a linear sequence of amino acids or a non-linear sequence of amino acids. Many polypeptides contain a plurality of domains. Such domains are known, and can be identified by those of skill in the art. For exemplification herein, definitions are provided, but it is understood that it is well within the skill in the art to recognize particular domains by name. If needed, appropriate software can be employed to identify domains. It isAttorney Docket No. 01245-0082-00PCT understood that reference to amino acids, including to a specific sequence set forth as a SEQ ID NO used to describe domain organization (e.g. of a TD domain) are for illustrative purposes and are not meant to limit the scope of the embodiments provided. It is understood that polypeptides and the description of domains thereof are theoretically derived based on homology analysis and alignments with similar molecules. Also, in some cases, adjacent N- and / or C-terminal amino acids of a given domain (e.g. TD) also can be included in a sequence, such as to ensure proper folding of the domain when expressed. Thus, the exact locus can vary, and is not necessarily the same for each protein. For example, a specific TD domain, such as specific CRD domain, can be several amino acids (1-10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) longer or shorter.

[0263] The terms “ectodomain,” “extracellular domain,” or “ECD,” which are used interchangeably herein, refer to a region of a membrane protein, such as a transmembrane protein, which lies outside the vesicular membrane (e.g., the space outside of a cell), when a full-length form of the membrane protein is expressed from a cell. For purposes herein, it is understood that reference to the ECD refers to sequences and domains that make up this region and do not require that a protein that contains an ECD is a membrane protein or that the domain is present outside a cell. For example, a soluble immunomodulatory protein can contain ECD sequences of a membrane protein fused to another moiety, such as a multimerization domain, for example an Fc region. Ectodomains often interact with specific ligands or specific cell surface receptors, such as via a binding domain that specifically binds to the ligand or cell surface receptor. Examples of binding domains include cysteine rich domains (CRDs). Ectodomains of members of the TNFR superfamily contain a TD domain (e.g. a CRD domain). Thus, reference to an ECD herein includes a full-length sequence of an ECD of a membrane protein as well as specific-binding fragments thereof containing a CRD that bind to a ligand or cognate binding partner.

[0264] The terms “effective amount” or “therapeutically effective amount” refer to a quantity and / or concentration of a therapeutic pharmaceutical formulation or pharmaceutical composition, such as containing an immunomodulatory protein or Fc fusion protein, that when administered ex vivo (by contact with a cell from a patient) or in vivo (by administration into a patient) either alone (i.e., as a monotherapy) or in combination with additional therapeutic agents, yields a statistically significant inhibition of disease progression as, for example, by ameliorating or eliminating symptoms and / or the cause of the disease. An effective amount for treating a disease, condition or disorder, such as an immune system disease, condition or disorder, may be an amount that relieves, lessens, or alleviates at least one symptom or biological response or effect associated with the disease, condition or disorder, prevents progression of the disease, condition or disorder, or improves physical functioning of the patient. In the case of cell therapy,Attorney Docket No. 01245-0082-00PCT the effective amount is an effective dose or number of cells administered to a patient. In some embodiments the patient is a human patient.

[0265] As used herein, “fusion protein” refers to a polypeptide encoded by a nucleic acid sequence containing a coding sequence for two or more proteins, in some cases 2, 3, 4, 5 or more proteins, in which the coding sequences are in the same reading frame such that when the fusion construct is transcribed and translated in a host cell, the protein is produced containing the two or more proteins. Each of the two or more proteins can be adjacent to another protein in the construct or separated by a linker polypeptide that contains, 1, 2, 3, or more, but typically fewer than 20, 15, 10, 9, 8, 7, or 6 amino acids. The protein product encoded by a fusion construct is referred to as a fusion polypeptide. An example of a fusion protein in accord with the provided embodiments is an Fc fusion protein containing an affinity-modified domain (e.g. a variant of a TACI extracellular domain or portion thereof containing a CRD) that is linked to an immunoglobulin Fc domain.

[0266] The term “half-life extending moiety” refers to a moiety of a polypeptide fusion or chemical conjugate that extends the half-life of a protein circulating in mammalian blood serum compared to the half-life of the protein that is not so conjugated to the moiety. In some embodiments, half-life is extended by greater than or about 1.2-fold, about 1.5-fold, about 2.0-fold, about 3.0-fold, about 4.0-fold, about 5.0-fold, or about 6.0-fold. In some embodiments, half-life is extended by more than 6 hours, more than 12 hours, more than 24 hours, more than 48 hours, more than 72 hours, more than 96 hours or more than 1 week after in vivo administration compared to the protein without the half-life extending moiety. The half-life refers to the amount of time it takes for the protein to lose half of its concentration, amount, or activity. Half-life can be determined for example, by using an ELISA assay or an activity assay. Exemplary half-life extending moi eties include an Fc domain, a multimerization domain, polyethylene glycol (PEG), hydroxyethyl starch (HES), XTEN (extended recombinant peptides; see, WO2013130683), human serum albumin (HSA), bovine serum albumin (BSA), lipids (acylation), and poly-Pro- Ala-Ser (PAS), and polyglutamic acid (glutamyl ati on).

[0267] An Fc (fragment crystallizable) region or domain of an immunoglobulin molecule (also termed an Fc polypeptide) corresponds largely to the constant region of the immunoglobulin heavy chain, and which, in some cases, is responsible for various functions, including the antibody’s effector function(s). The Fc domain contains part or all of a hinge domain of an immunoglobulin molecule plus a CH2 and a CH3 domain. In some cases, for inclusion in a provided fusion protein, all or a portion of the Fc hinge sequence may be deleted. The Fc domain can form a dimer of two polypeptide chains joined by one or more disulfide bonds. In some embodiments, the Fc is a variant Fc that exhibits reduced (e.g. reduced greaterAttorney Docket No. 01245-0082-00PCT than about 30%, 40%, 50%, 60%, 70%, 80%, 90% or more) activity to facilitate an effector function. In some embodiments, reference to amino acid substitutions in an Fc region is by EU numbering system unless described with reference to a specific SEQ ID NO. EU numbering is known and is according to the most recently updated IMGT Scientific Chart (IMGT®, the international ImMunoGeneTics® information system. http: / / www.imgt.org / IMGTScientificChart / Numbering / Hu_IGHGnber.html (created: 17 May 2001, last updated: 10 Jan 2013) and the EU index as reported in Kabat, E.A. et al. Sequences of Proteins of Immunological interest. 5th ed. US Department of Health and Human Services, NIH publication No. 91-3242 (1991).

[0268] An immunoglobulin Fc fusion (Fc-fusion), such as an immunomodulatory Fc fusion protein, is a molecule comprising one or more polypeptides operably linked to an Fc region of an immunoglobulin. An Fc-fusion may comprise, for example, an Fc region operably linked to a TACI extracellular domain or portion thereof containing a CRD, including any of the provided affinity-modified variants thereof. An immunoglobulin Fc region may be linked indirectly or directly to the one or more polypeptides. Various linkers are known in the art and can optionally be used to link an Fc to a fusion partner to generate an Fc-fusion. Fc-fusions of identical species can be dimerized to form Fc-fusion homodimers. Fc fusion of non-identical species (e.g. knob into hole engineering) may be used to form Fc-fusion heterodimers. In some embodiments, the Fc is a mammalian Fc such as a murine or human Fc.

[0269] The term “host cell” refers to any cell that can be used to express a protein encoded by a recombinant expression vector. A host cell can be a prokaryote, for example, E. coli, or it can be a eukaryote, for example, a single-celled eukaryote (e.g., a yeast or other fungus), a plant cell (e.g., a tobacco or tomato plant cell), an animal cell (e.g., a human cell, a monkey cell, a hamster cell, a rat cell, a mouse cell, or an insect cell) or a hybridoma. Examples of host cells include Chinese hamster ovary (CHO) cells or their derivatives such as Veggie CHO and related cell lines which grow in serum-free media or CHO strain DX-B11, which is deficient in DHFR.

[0270] The term “immunological synapse” or “immune synapse” (abbreviated IS) as used herein means the interface between a mammalian cell that expresses MHC I (major histocompatibility complex) or MHC II, such as an antigen-presenting cell or tumor cell, and a mammalian lymphocyte such as an effector T cell or Natural Killer (NK) cell.

[0271] The term “immunoglobulin” (abbreviated Ig) as used herein is synonymous with the term “antibody” (abbreviated Ab) and refers to a mammalian immunoglobulin protein including any of the five human classes: IgA (which includes subclasses IgAl and IgA2), IgD, IgE, IgG (which includes subclasses IgGl, IgG2, IgG3, and IgG4), and IgM. The term is also inclusive of immunoglobulins that are less than full-length, whether wholly or partially synthetic (e.g.,Attorney Docket No. 01245-0082-00PCT recombinant or chemical synthesis) or naturally produced, including any fragment thereof containing at least a portion of the variable heavy (VH) chain and / or variable light (VL) chain region of the immunoglobulin molecule that is sufficient to form an antigen binding site and, when assembled, to specifically bind antigen. The antibody also can include all or a portion of the constant region. Such fragments include antigen binding fragment (Fab), variable fragment (Fv) containing VH and VL, the single chain variable fragment (scFv) containing VH and VL linked together in one chain, as well as other antibody V region fragments, such as Fab', F(ab)2, F(ab')2, dsFv diabody, Fc, and Fd polypeptide fragments. Hence, it is understood that reference to an antibody herein includes full-length antibody and antigen-binding fragments. The term “antibody” also includes antibody compositions with polyepitopic specificity, multispecific antibodies (e.g., bispecific antibodies), diabodies, and single-chain molecules. Bispecific antibodies, homobispecific and heterobi specific, are included within the meaning of the term. Antibodies include polyclonal antibodies or monoclonal antibodies. “Antibody” also includes synthetic antibodies or recombinantly produced antibodies. For the structure and properties of the different classes of antibodies, see e.g., Basic and Clinical Immunology, 8th Edition, Daniel P. Sties, Abba I. Terr and Tristram G. Parsolw (eds), Appleton & Lange, Norwalk, CT, 1994, page 71 and Chapter 6.

[0272] The terms “full-length antibody,” “intact antibody” or “whole antibody” are used interchangeably to refer to an antibody in its substantially intact form, as opposed to an antibody fragment. A full-length antibody is an antibody typically having two full-length heavy chains (e.g., VH-CH1-CH2-CH3 or VH-CH1-CH2-CH3-CH4) and two full-length light chains (VL-CL) and hinge regions, such as antibodies produced from mammalian species (e.g. human, mouse, rat, rabbit, non-human primate, etc.) by antibody secreting B cells and antibodies with the same domains that are produced synthetically. Specifically, whole antibodies include those with heavy and light chains including an Fc region. The constant domains may be native sequence constant domains (e.g, human native sequence constant domains) or amino acid sequence variants thereof. In some cases, the intact antibody may have one or more effector functions.

[0273] An antibody fragment comprises a portion of an intact antibody, the antigen binding and / or the variable region of the intact antibody. Antibody fragments, include, but are not limited to, Fab fragments, Fab1fragments, F(ab')2 fragments, Fv fragments, disulfide-linked Fvs (dsFv), Fd fragments, Fd' fragments; diabodies; linear antibodies (see U.S. Pat. No. 5,641,870, Example 2; Zapata etal., Protein Eng. 8(10): 1057-1062

[1995] ); single-chain antibody molecules, including single-chain Fvs (scFv) or single-chain Fabs (scFab); antigen-binding fragments of any of the above and multispecific antibodies from antibody fragments.Attorney Docket No. 01245-0082-00PCT

[0274] Fv is composed of one heavy- and one light-chain variable region domain linked by non-covalent association. From the folding of these two domains emanate six complementarity determining regions (CDR) (3 in each from the heavy and light chain) that contribute the amino acid residues for antigen binding and confer antigen binding specificity to the antibody.However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen, although, in some cases, at a lower affinity than the entire binding site.

[0275] dsFv refers to an Fv with an engineered intermolecular disulfide bond, which stabilizes the VH-VL pair.

[0276] An Fd fragment is a fragment of an antibody containing a variable domain (VH) and one constant region domain (CHI) of an antibody heavy chain.

[0277] A Fab fragment is an antibody fragment that results from digestion of a full-length immunoglobulin with papain, or a fragment having the same structure that is produced synthetically, e.g., by recombinant methods. A Fab fragment contains a light chain (containing a VL and CL) and another chain containing a variable domain of a heavy chain (VH) and one constant region domain of the heavy chain (CHI).

[0278] A F(ab')2 fragment is an antibody fragment that results from digestion of an immunoglobulin with pepsin at pH 4.0-4.5, or a fragment having the same structure that is produced synthetically, e.g., by recombinant methods. The F(ab')2 fragment essentially contains two Fab fragments where each heavy chain portion contains an additional few amino acids including cysteine residues that form disulfide linkages joining the two fragments.

[0279] A Fab' fragment is a fragment containing one half (one heavy chain and one light chain) of the F(ab')2 fragment.

[0280] An Fd’ fragment is a fragment of an antibody containing one heavy chain portion of a F(ab')2 fragment.

[0281] An Fv’ fragment is a fragment containing only the VH and VL domains of an antibody molecule.

[0282] An scFv fragment refers to an antibody fragment that contains a variable light chain (VL) and variable heavy chain (VH), covalently connected by a polypeptide linker in any order. The linker is of a length such that the two variable domains are bridged without substantial interference. Exemplary linkers are (Gly-Ser)nresidues with some Glu or Lys residues dispersed throughout to increase solubility.

[0283] Diabodies are dimeric scFv; diabodies typically have shorter peptide linkers than scFvs, and preferentially dimerize.Attorney Docket No. 01245-0082-00PCT

[0284] The term immunological activity as used herein refers to one or more activities of immune cells, such as T cells or B cells, including, for example, activation, cell survival, cell proliferation, cytokine production (e.g. interferon-gamma), cytotoxicity activity, or ability to activate NF-KB pathway or other signaling cascade leading to activation of a transcription factor in the immune cell. Assays to assess immunological activity of immunomodulatory proteins can be compared to control proteins with a known activity.

[0285] An immunomodulatory protein or immunomodulatory polypeptide is a protein that modulates immunological activity. By modulation or modulating an immune response is meant that immunological activity is either enhanced or suppressed. Such modulation includes any induction, or alteration in degree or extent, or suppression of immunological activity of an immune cell, such as a B cell or a T cell. For example, soluble Fc fusion proteins herein may suppress immunological activity of B cells. An immunomodulatory protein can be a single polypeptide chain or a multimer (dimers or higher order multimers) of at least two polypeptide chains covalently bonded to each other by, for example, interchain disulfide bonds. Thus, monomeric, dimeric, and higher order multimeric proteins are within the scope of the defined term. Multimeric proteins can be homomultimeric (of identical polypeptide chains) or heteromultimeric (of different polypeptide chains).

[0286] As used herein, modification is in reference to modification of a sequence of amino acids of a polypeptide or a sequence of nucleotides in a nucleic acid molecule and includes a change in amino acids or nucleotides, respectively, of the sequence. The amino acid modification or change may be a deletion, insertion, or replacement (substitution) of amino acids or nucleotides, respectively. Methods of modifying a polypeptide are routine to those of skill in the art, such as by using recombinant DNA methodologies.

[0287] The term, a multimerization domain refers to a sequence of amino acids that promotes the formation of a multimer of two or more polypeptides. A multimerization domain includes sequences that promote stable interaction of a polypeptide molecule with one or more additional polypeptide molecules, each containing a complementary multimerization domain (e.g. a first multimerization domain and a second multimerization domain), which can be the same or a different multimerization domain. The interactions between complementary multimerization domains, e.g. interaction between a first multimerization domain and a second multimerization domain, form a stable protein-protein interaction to produce a multimer of the polypeptide molecule with the additional polypeptide molecule. In some cases, the multimerization domain is the same and interacts with itself to form a stable protein-protein interaction between two polypeptide chains. Generally, a polypeptide is joined directly or indirectly to the multimerization domain. Exemplary multimerization domains include theAttorney Docket No. 01245-0082-00PCT immunoglobulin sequences or portions thereof, leucine zippers, hydrophobic regions, hydrophilic regions, and compatible protein-protein interaction domains. The multimerization domain, for example, can be an immunoglobulin constant region or domain, such as, for example, the Fc domain or portions thereof from IgG, including IgGl, IgG2, IgG3 or IgG4 subtypes, IgA, IgE, IgD and IgM and modified forms thereof.

[0288] The terms nucleic acid and polynucleotide are used interchangeably to refer to a polymer of nucleic acid residues (e.g., deoxyribonucleotides or ribonucleotides) in either single-or double-stranded form. Unless specifically limited, the terms encompass nucleic acids containing known analogues of natural nucleotides and that have similar binding properties to it and are metabolized in a manner similar to naturally occurring nucleotides. Unless otherwise indicated, a particular nucleic acid sequence also implicitly encompasses conservatively modified variants thereof (e.g., degenerate codon substitutions) and complementary nucleotide sequences as well as the sequence explicitly indicated. Specifically, degenerate codon substitutions may be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed-base and / or deoxyinosine residues. The term nucleic acid or polynucleotide encompasses cDNA or mRNA encoded by a gene.

[0289] The terms in operable combination, in operable order and operably linked as used herein refer to the linkage of nucleic acid sequences in such a manner or orientation that the segments are arranged so that they function in concert for their intended purposes. In some embodiments, the term refers to linkage of nucleic acids to produce a nucleic acid molecule capable of directing the transcription of a given gene and / or to produce a desired protein molecule that is functional. For example, segments of a DNA sequence, e.g. a coding sequence and a regulatory sequence(s), are linked in such a way as to permit gene expression when the appropriate molecules (e.g. transcriptional activator proteins) are bound to the regulatory sequence.

[0290] The term pharmaceutical composition or pharmaceutical formulation or formulation or TACI-Fc formulation are used interchangeably and refers to a composition or formulation suitable for pharmaceutical use in a mammalian subject, often a human. A pharmaceutical composition or pharmaceutical formulation herein comprises an effective amount of an active agent (e.g., a TACI-Fc fusion protein) and other components as provided herein.

[0291] As used herein, the term salt refers to inorganic salts, which include but are not limited to sodium chloride (NaCl), sodium sulfate (Na2SC>4), sodium thiocyanate (NaSCN), magnesium chloride (MgCl), magnesium sulfate (MgSC ), ammonium thiocyanate (NEESCN), ammonium sulfate ((NFUkSC ), ammonium chloride (NFUCl), calcium chloride (CaCh), calcium sulfate (CaSC ), zinc chloride (ZnCh) and the like, or combinations thereof. UnlessAttorney Docket No. 01245-0082-00PCT otherwise indicated, the protein formulations provided herein are characterized by a substantial absence of added salt. It will be understood by those of skill in the art that the presence of inorganic salts within the presently disclosed formulations that are introduced by pH adjustment are not considered to be added salts and such inorganic salts, if present in a formulation according to the present embodiments. In some embodiments herein, a salt can be added to the pharmaceutical formulations provided herein. In embodiments, a salt or salts is added to pharmaceutical formulations provided herein in the presence of an amino acid in the formulation, such as, for example, proline.

[0292] As used herein, the term “surfactant” refers to a pharmaceutically acceptable surfaceactive agent. Surfactants herein include “non-ionic surfactants” including, without limitation, polysorbates and poloxamers. In some embodiments the poloxamer is poloxamer 188. In some embodiments the polysorbate is polysorbate 20 and / or 80. The use of non-ionic surfactants permits the formulations to be exposed to shear and surface stresses without causing denaturation of the protein in the formulation (e.g., TACI-Fc), and also can reduce protein adsorption on the surfaces during processing and storage. The formulations provided herein include, without limitation, formulations having one or more non-ionic surfactant(s) including, for example, one or more polysorbate(s), such as polysorbate 80 or 20; one or more poloxamers, such as poloxamer 188. Exemplified herein are formulations having a poloxamer, such as a poloxamer 188 (e.g., Kolliphor® P 188 Bio, BASF). Also exemplified herein are formulations containing a polysorbate, such as polysorbate 80 (e.g., Tween® 80). Amounts of surfactants effective to provide stable high concentration protein formulations herein generally are in the range of 0.005% to 0.3% (w / v) of the formulation.

[0293] The surfactant in the formulations may be or comprise a poloxamer. “Poloxamer” refers to ABA-type copolymers of poly (ethylene oxide (EO)) (PEO=A) and poly (propylene oxide (PO)) (PPO=B). One exemplary poloxamer is “poloxamer 188,” which is also known as Pl 88 or as polyethylene glycol)-Z> / ocA poly(propylene glycol)-Z> / ocA poly(ethylene glycol), or as CAS-9003-11-6. The approximate relative amount of PEO and the average molecular weight of the PPO may be indicated in the name of the poloxamer. The generic term “poloxamer” is commonly followed by a numerical value of 3 digits: the first 2 digits, multiplied x 100, indicates the MW of the hydrophobic core of propylene glycol, and the last digit, multiplied x 10, gives the percentage of the hydrophilic PEG content. Poloxamer 188 contains about 80% ethylene oxide repeats by weight, with two about 75-repeat polyethylene chains (about 6600 g / mol out of an average 8400 g / mol), or in other words it contains about 80% m / m PEO (P 188; 8x10= 80%) and an approximate average molecular weight of PPO of 1800 (P 188; 18x100= 1800). The poloxamer may have an average molecular weight of PPO of about 1800,Attorney Docket No. 01245-0082-00PCT or from about 1750 to about 1850, or from about 1700 to about 1900, or from about 1500 to about 2000, as examples. The poloxamer may contain about 80% m / m PEO, or from about 78% to about 82% m / m PEO, or from about 80% to about 85% m / m PEO, as examples. The poloxamer is soluble in water and may be characterized by its hydrophilic lipophilic balance (HLB), which may range, for example, from about 14 to about 18, or from about 15 to about 17, or may be about 16 as in the case of poloxamer 188. The poloxamer may be in admixture with byproduct present in a minor amount, where one such byproduct is A-B diblock copolymer. The poloxamer may be of various grades suitable for pharmaceutical uses, e.g., BASF offers poloxamer 188 as Kolliphor® P 188 Bio and Kolliphor® P 188 Cell Culture, which differ slightly, e.g., by peak molecular weight.

[0294] The poloxamer may be characterized in terms of the number of repeating EO and PO units in the copolymer, where a poloxamer of formula (PEO)a-(PPO)b-(PEO)a may have “a” equal to about 65-95 EO units in each PEO and “b” equal to about 20-35 PO units in PPO. The poloxamer may be poloxamer 188, wherein “a” is equal to 75-85 and “b” is equal to 25-30.

[0295] A “tonicifying agent” or “tonicity agent” as used herein, refers to a substance that is capable of modifying the osmotic pressure of a formulation or solution. In some embodiments, a tonicifying agent may be added to a formulation to make it “isotonic” with a reference solution or fluid such as a bodily fluid, or alternatively, to make it hypertonic or hypotonic with respect to such a reference solution or fluid.

[0296] As used herein, the term “viscosity” refers to the resistance of a liquid formulation to flow, such as when injected through a syringe needle during administration to a patient.Viscosity measurements can be assessed by techniques know in the art. For example, viscosity can be assessed by a cone and plate technique with a Peltier element set at a defined temperature, such as 5°C to 25°C as described herein. Typically, a well-defined shear stress gradient is applied to the liquid formulation and the resulting shear rate is measured. The viscosity is the ratio of the shear stress to the shear rate. As used herein, viscosity is expressed in units of cP.

[0297] As used herein, a “stable” formulation, such as a stable liquid pharmaceutical formulation is a liquid TACI-Fc formulation with no significant changes observed after storage at a refrigerated temperature (2-8°C) for at least 12 weeks, such as at least 26 weeks, at least about 26 weeks, at least 36 weeks, at least 52 weeks (1 year), at least 18 months, or at least 24 months, or is one with no significant changes observed after storage at room temperature (25°C) for at least or about 8 weeks or 12 weeks. In some embodiments a stable TACI-Fc formulation is one where at least about 95% of the TACI-Fc protein in the formulation is in the main species as measured by size exclusion chromatography (SEC) after storage, and / or wherein the formulation comprises no more than about 5% of low and high molecular weight species as measured by sizeAttorney Docket No. 01245-0082-00PCT exclusion chromatography after storage at a refrigerated temperature (2-8°C) for at least 12 weeks, such as at least 26 weeks, at least about 26 weeks, at least 36 weeks, at least 52 weeks (1 year), at least 18 months, or at least 24 months, or is one with no significant changes observed after storage at room temperature (25°C) for at least or about 8 weeks or 12 weeks, no more than 5% of TACI-Fc homodimer is degraded as measured by size exclusion chromatography (SEC-HPLC) after storage for 52 weeks at refrigerated temperature (2-8°C) or after storage for eight-weeks at room temperature (25°C). A stable TACI-Fc formulation, in some embodiments, is one where the protein concentration of the formulation changes by no more than + / - 10% after such storage, as measured by methods known in the art such as size exclusion chromatography (SEC-HPLC), imaged capillary isoelectric focusing (icIEF), non-reduced and reduced capillary electrophoresis, subvisible particle assessment, visual inspection, and / or anti-APRIL and anti-BAFF activity.

[0298] The terms “polypeptide” and “protein” are used interchangeably herein and refer to a molecular chain of two or more amino acids linked through peptide bonds. The terms do not refer to a specific length of the product. Thus, peptides and oligopeptides, are included within the definition of polypeptide. The terms include post-translational modifications of the polypeptide, for example, glycosylations, acetylations, phosphorylations, and the like. The terms also include molecules in which one or more amino acid analogs or non-canonical or unnatural amino acids are included as can be synthesized or expressed recombinantly using known protein engineering techniques. In addition, proteins can be derivatized as described herein by well-known organic chemistry techniques.

[0299] The term “purified” as applied to polypeptides generally denotes a polypeptide that is substantially free from other components as determined by analytical techniques well known in the art (e.g., a purified polypeptide or polynucleotide forms a discrete band in an electrophoretic gel, chromatographic eluate, and / or a media subjected to density gradient centrifugation). For example, a nucleic acid or polypeptide that gives rise to essentially one band in an electrophoretic gel is purified. A purified nucleic acid or protein is at least about 35% pure, such as usually at least about 50%, 75%, 80%, 85%, 90%, 95%, 96%, 99% or more pure (e.g., percent by weight or on a molar basis).

[0300] The term “recombinant” indicates that the material (e.g., a nucleic acid or a polypeptide) has been artificially (i.e., non-naturally) altered by human intervention. The alteration can be performed on the material within, or removed from, its natural environment or state. For example, a recombinant nucleic acid is one that is made by recombining nucleic acids, e.g., during cloning, affinity modification, DNA shuffling or other well-known molecular biological procedures. A recombinant DNA molecule, is comprised of segments of DNA joinedAttorney Docket No. 01245-0082-00PCT together by means of such molecular biological techniques. The term recombinant protein or recombinant polypeptide as used herein refers to a protein molecule (e.g., an immunomodulatory protein) which is expressed using a recombinant DNA molecule. A recombinant host cell is a cell that contains and / or expresses a recombinant nucleic acid or that is otherwise altered by genetic engineering, such as by introducing into the cell a nucleic acid molecule encoding a recombinant protein, such as an immunomodulatory protein provided herein. Transcriptional control signals in eukaryotes comprise promoter and enhancer elements. Promoters and enhancers consist of short arrays of DNA sequences that interact specifically with cellular proteins involved in transcription. Promoter and enhancer elements have been isolated from a variety of eukaryotic sources including genes in yeast, insect and mammalian cells and viruses (analogous control elements, i.e., promoters, are also found in prokaryotes). The selection of a particular promoter and enhancer depends on what cell type is to be used to express the protein of interest.

[0301] The term “recombinant expression vector” as used herein refers to a DNA molecule containing a desired coding sequence (e.g., encoding an immunomodulatory protein) and appropriate nucleic acid sequences necessary for the expression of an operably linked coding sequence in a particular cell. Nucleic acid sequences necessary for expression in prokaryotes include a promoter, optionally an operator sequence, a ribosome binding site and possibly other sequences. Eukaryotic cells are known to utilize promoters, enhancers, and termination and polyadenylation signals. A secretory signal peptide sequence can also, optionally, be encoded by the recombinant expression vector, operably linked to the coding sequence so that the expressed protein can be secreted by the recombinant host cell, such as for its expression as a secretable protein or for more facile isolation or purification of the immunomodulatory protein from the cell, if desired. The term includes the vector as a self-replicating nucleic acid structure as well as the vector incorporated into the genome of a host cell into which it has been introduced. Among the vectors are viral vectors, such as lentiviral vectors.

[0302] The term “sequence identity” as used herein refers to the sequence identity between genes or proteins at the nucleotide or amino acid level, respectively. Sequence identity is a measure of identity between proteins at the amino acid level and a measure of identity between nucleic acids at nucleotide level. The protein sequence identity may be determined by comparing the amino acid sequence in a given position in each sequence when the sequences are aligned. Similarly, the nucleic acid sequence identity may be determined by comparing the nucleotide sequence in a given position in each sequence when the sequences are aligned.Methods for the alignment of sequences for comparison are well known in the art, such methods include GAP, BESTFIT, BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software,Attorney Docket No. 01245-0082-00PCT FASTA and TFASTA. The BLAST algorithm calculates percent sequence identity and performs a statistical analysis of the similarity between the two sequences. The software for performing BLAST analysis is publicly available through the National Center for Biotechnology Information (NCBI) website. In some cases, a percent sequence identity can be determined as the percentage of amino acid residues (or nucleotide residues) in a candidate sequence that are identical with the amino acid residues (or nucleotide residues) in a reference sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity.Reference to sequence identity includes sequence identity across the full length of each of the sequences being compared. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared.

[0303] The term “soluble” as used herein in reference to proteins means that the protein is not a membrane protein or is not anchored in a cell membrane. A protein can be constructed as a soluble protein by inclusion of only an extracellular domain or a portion thereof and without a transmembrane domain. In some cases, solubility of a protein can be improved by linkage or attachment, directly or indirectly via a linker, to an Fc domain or other half-life extending molecule, which, in some cases, also can improve the stability and / or half-life of the protein. In some aspects, a soluble protein is an Fc fusion protein.

[0304] The term “specifically binds” as used herein means the ability of a protein, under specific binding conditions, to bind to a target protein such that its affinity or avidity is at least 10 times as great, but optionally 50, 100, 250 or 500 times as great, or even at least 1000 times as great as the average affinity or avidity of the same protein to a collection of random peptides or polypeptides of sufficient statistical size. A specifically binding protein need not bind exclusively to a single target molecule but may specifically bind to more than one target molecule. In some cases, a specifically binding protein may bind to a protein that has similarity in structural conformation with the target protein (e.g., paralogs or orthologs). Those of skill will recognize that specific binding to a molecule having the same function in a different species of animal (i.e., ortholog) or to a molecule having a substantially similar epitope as the target molecule (e.g., paralog) is possible and does not detract from the specificity of binding which is determined relative to a statistically valid collection of unique non-targets (e.g., random polypeptides). Thus, an immunomodulatory protein of the invention may specifically bind to more than one distinct species of target molecule due to cross-reactivity. Solid-phase ELISA immunoassays, ForteBio Octet or Biacore measurements can be used to determine specific binding between two proteins. Generally, interactions between two binding proteins have dissociation constants (Kd) less than about IxlO'5M, and often as low as about 1 x 10'12M. InAttorney Docket No. 01245-0082-00PCT certain aspects of the present disclosure, interactions between two binding proteins have dissociation constants of less than about IxlO'6M, IxlO'7M, 1X10'8M, IxlO'9M, IxlO'10M, or IxlO'11M or less.

[0305] The term “specific binding fragment” or “fragment” as used herein in reference to a protein means a polypeptide that is shorter than a full-length protein or a specific domain or region thereof and that specifically binds in vitro and / or in vivo to a binding partner of the full-length protein or of the specific domain or region. A specific finding fragment is in reference to a fragment of a full-length extracellular domain of a polypeptide or a binding domain of a polypeptide, but that still binds to a binding partner of the binding domain. For example, a specific binding fragment is in reference to a fragment of an extracellular domain of a full-length TNFR family member or a full-length TNFR domain (TD) thereof (e.g. CRD), but that still binds to a binding partner of the TNFR family member or of a CRD of an TNFR family member. In some embodiments, the specific binding fragment is at least about 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% the sequence length of the full-length sequence of the extracellular domain or of a domain or region of the extracellular domain. In some embodiments, the specific binding fragment can have an amino acid length of at least 50 amino acids, such as at least 60, 70, 80, 90, 100, or 110 amino acids. In some embodiments, the specific binding fragment includes the CRD1 and / or CRD2 domain. In some embodiments, the specific binding fragment includes the CRD2 domain.

[0306] As used herein, an “injection device” is an apparatus for administration of a formulation herein. In embodiments herein, an injection device contains a needle for administration. In other embodiments here, an injection device is a needle free injection device, such as, for example, a needle free autoinjector. An injection device can be used for administration of a formulation to a subject, such as, for example, for subcutaneous or intravenous administration. Examples of an injection device are a syringe or a syringe / autoinjector combination. In some embodiments herein, an autoinjector contains a syringe loaded into the autoinjector.

[0307] As used herein, a “subject” is a mammal, such as a human or other animal, and typically is human. The subject can be male or female and can be any suitable age, including infant, juvenile, adolescent, adult, and geriatric subjects.

[0308] As used herein, “synthetic,” with reference to, for example, a synthetic nucleic acid molecule or a synthetic gene or a synthetic peptide refers to a nucleic acid molecule or polypeptide molecule that is produced by recombinant methods and / or by chemical synthesis methods.Attorney Docket No. 01245-0082-00PCT

[0309] The term “TNF receptor” superfamily or TNFRSF as used herein means the group of cell surface cytokine receptors that are all type I (N-terminus extracellular) transmembrane glycoproteins that contain one to six cysteine rich domains (CRD) in their extracellular domain. Molecules are categorized as members of this superfamily based on the shared structural features that include the one or more cysteine rich domain (CRD) present in their N-terminal extracellular region, which often play a role in protein binding of their cognate binding partner or ligand. A TNFRSF protein may have only one or several CRDs (e.g. CRD1, CRD2, etc.). Typically, ECD or ectodomain of TNFRSF members contain between 1 and 6 pseudorepeats of CRDs. For example, BAFF-receptor and BCMA each contain one CRD while TACI contains two CRDs (CRD1 and CRD2). TNFRSF members are usually trimeric or multimeric complexes that are stabilized by their intracysteine disulfide bonds. Binding of TNFRSF proteins to their ligands facilitates various biological activities in cells, such as the induction of apoptotic cell death or cell survival and proliferation.

[0310] The term “TD” refers to a structural domain or domains of TNFRSF proteins or of TNF family ligands. For example, a TD of a TNFRSF protein is a cysteine-rich domain (CRD) module of about 40 amino acids containing six (6) conserved cysteines. Hence, reference to CRD also can be used interchangeably with the term TD in reference to a TD of a TNFRSF protein. The six cysteines are involved in formation of intrachain disulphide bonds. The extracellular domain (ECD) of TNFRSF members contains one or more CRD domains; hence, the term TD is also used with reference to the ECD of such protein molecules. Reference to a variant TD (vTD) refers to a variant or modified sequence of a TD.

[0311] The term “trans” with reference to binding to cell surface molecules refers to binding to two different cell surface molecules, each of which is present on the surface of a different cell. In some embodiments, trans means that with respect to two different cell surface molecules, the first is exclusively present on one of the two mammalian cells forming the IS and the second is present exclusively on the second of the two mammalian cells forming the IS.

[0312] The term “transmembrane protein” as used herein means a membrane protein that substantially or completely spans a lipid bilayer such as those lipid bilayers found in a biological membrane such as a mammalian cell, or in an artificial construct such as a liposome. The transmembrane protein comprises a transmembrane domain (transmembrane domain) by which it is integrated into the lipid bilayer and by which the integration is thermodynamically stable under physiological conditions. Transmembrane domains are generally predictable from their amino acid sequence via any number of commercially available bioinformatics software applications on the basis of their elevated hydrophobicity relative to regions of the protein that interact with aqueous environments (e.g., cytosol, extracellular fluid). A transmembrane domainAttorney Docket No. 01245-0082-00PCT is often a hydrophobic alpha helix that spans the membrane. A transmembrane protein can pass through both layers of the lipid bilayer once or multiple times.

[0313] The terms “treating,” “treatment,” or “therapy” of a disease, condition or disorder as used herein mean slowing, stopping or reversing the disease or disorders progression, as evidenced by decreasing, cessation or elimination of either clinical or diagnostic symptoms, by administration of a formulation or protein or engineered cells of the present invention either alone or in combination with another compound as described herein. Treating, treatment, or therapy also means a decrease in the severity of symptoms in an acute or chronic disease, condition or disorder or a decrease in the relapse rate as for example in the case of a relapsing or remitting autoimmune disease course or inflammatory condition or a decrease in inflammation in the case of an inflammatory aspect of an autoimmune disease or inflammatory condition. The terms “preventing,” “prophylaxis,” or “prevention” of a disease, condition or disorder as used in the context of this invention refers to the administration of a formulation or protein or engineered cells of the present invention, either alone or in combination with another compound, to prevent the occurrence or onset of a disease, condition or disorder or of some or all of the symptoms of a disease, condition or disorder or to lessen the likelihood of the onset of a disease, condition or disorder.

[0314] The term “variant” (also modified or mutant, which can be used interchangeably) as used in reference to a variant protein or polypeptide means a protein, such as a mammalian (e.g., human or murine) protein created by human intervention. The variant is a polypeptide having an altered or modified amino acid sequence, such as by one or more amino acid substitutions, deletions, additions or combinations thereof, relative to an unmodified or wild-type protein or to a domain thereof. A variant polypeptide can contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more amino acid differences, such as amino acid substitutions. A variant polypeptide generally exhibits at least about 50%, 60%, 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to a corresponding form of a wild-type or unmodified protein, such as a mature sequence thereof (lacking the signal sequence) or a portion thereof containing the extracellular domain or an binding domain thereof. Non-naturally occurring amino acids as well as naturally occurring amino acids are included within the scope of permissible substitutions or additions. A variant protein is not limited to any particular method of making and includes, for example, chemical synthesis, recombinant DNA techniques, or combinations thereof. A variant protein of the invention specifically binds to at least one or more binding partners. In some embodiments, the altered amino acid sequence results in an altered (i.e., increased or decreased)Attorney Docket No. 01245-0082-00PCT binding activity, such as binding affinity or avidity, to the one or more binding partners. A variant protein may thus be an affinity-modified protein as described herein.

[0315] The term “wild-type” or “natural” or “native,” which are used interchangeably, as used herein is used in connection with biological materials such as nucleic acid molecules, proteins, host cells, and the like, which are found in nature and not modified by human intervention.II. PHARMACEUTICAL FORMULATIONS

[0316] Provided herein are formulations containing a fusion protein comprising a TACI polypeptide and an Fc region (TACI-Fc fusion protein), such as any TACI-Fc fusion protein described herein. In provided embodiments, the TACI polypeptide is an extracellular domain or portion containing a TNF receptor domain (TD, e.g, CRD2) of TACI or is a variant TACI polypeptide thereof containing one or more amino acid substitutions. Provided embodiments include methods and uses of a formulation comprising a variant TACI-Fc fusion protein that is an Fc fusion protein of a variant TACI extracellular domain or portion containing a TD (e.g., CRD2) that simultaneously inhibits the BAFF and APRIL cytokines. Provided embodiments also include methods and uses of a formulation comprising a wild-type TACI-Fc fusion protein that is an Fc fusion protein of a wild-type TACI extracellular domain or portion that contains a TD (e.g. CRD2) that inhibits BAFF or APRIL or simultaneously inhibits the BAFF and APRIL cytokines. The formulations contain a TACI-Fc fusion biologic for the treatment of serious autoimmune and / or inflammatory diseases, including B cell-related diseases such as any described in Section V.

[0317] In some embodiments, pharmaceutical formulations comprise a therapeutically effective amount of a TACI-Fc fusion protein, such as any amount described herein. Also provided are any of the provided pharmaceutical formulations for use in treating an autoimmune or inflammatory disease in a patient in need thereof, such as any uses for treating such diseases or conditions as described in Section V. Also provided are methods of treating an autoimmune or inflammatory disease in a patient in need thereof by administering any of such pharmaceutical formulations, such as for treating any disease or conditions as described in Section V.

[0318] As described herein, among the provided formulations are TACI-Fc formulations that contain a high concentration of TACI-Fc protein. The formulations contain a combination of excipients such that the TACI-Fc in the formulation is stable after prolonged storage.A. TACI-Fc protein

[0319] The provided formulations are prepared with any TACI-Fc fusion protein. The TACI-Fc fusion protein may contain an extracellular domain (ECD) or portion of the ECD of the TACIAttorney Docket No. 01245-0082-00PCT receptor, or a variant thereof, that bind to at least one TACI cognate binding partner. Also provided herein are formulations containing variant TACI polypeptides that exhibit altered (e.g. increased) binding activity or affinity for one or more of a TACI cognate binding partner. In some embodiments, the TACI cognate binding partner is one or more of BAFF or APRIL or is a BAFF / APRIL heterotrimer. The provided TACLFc fusion proteins are soluble fusion proteins in which the TACI extracellular domain or portion thereof, or variant thereof, is linked to an immunoglobulin Fc. In some embodiments, provided is a formulation containing a TACLFc fusion protein containing (1) a TACI polypeptide composed of the extracellular domain of the TACI receptor or a portion thereof, or a variant TACI polypeptide thereof, that binds to at least one TACI cognate binding partner, and (2) an Fc domain. The TACI polypeptide or variant TACI polypeptide can be linked directly or indirectly (e.g. via a peptide linker) to the Fc domain.

[0320] TACI is a tumor necrosis factor receptor family member characterized by having an extracellular domain (ECD) containing cysteine-rich pseudo-repeat domains (CRDs). TACI is a membrane bound receptor, which has an extracellular domain containing two cysteine-rich pseudo-repeats (CRD1 and CRD2), a transmembrane domain and a cytoplasmic domain that interacts with CAML (calcium-modulator and cyclophilin ligand), an integral membrane protein located at intracellular vesicles which is a co-inducer of NF-AT activation when overexpressed in Jurkat cells. TACI is associated with B cells and a subset of T cells. The TACI receptor binds two members of the tumor necrosis factor (TNF) ligand family. One ligand is designated BAFF (B cell Activating Factor of the TNF Family), and also is variously designated as ZTNF4, “neutrokine-a,” “BLyS,” “TALL-1,” and “THANK” (Yu et al., international publication No. WO98 / 18921 (1998), Moore et al., Science 285:269 (1999); Mukhopadhyay et al., J. Biol.Chem. 274:15978 (1999); Schneider et al., J. Exp. Med. 189:1747 (1999); Shu et al., J. Leukoc. Biol. 65:680 (1999)). The other ligand has been designated as APRIL, and also is variously designated as “ZTNF2” and “TNRF death ligand-1” (Hahne et al., J. Exp. Med. 188:1185 (1998); Kelly et al., Cancer Res. 60: 1021 (2000)). Both ligands are also bound by the B-cell maturation receptor (BCMA) (Gross et al., Nature 404:995 (2000)). Binding of TACI receptor to its ligands BAFF or APRIL stimulates B cell responses, including T cell-independent B cell antibody responses, isotype switching, and B cell homeostasis.

[0321] The amino acid sequence of full-length TACI is set forth in SEQ ID NO:88. The protein is a type III membrane protein and lacks a signal peptide; following expression in eukaryotic cells the N-terminal methionine is removed. In some embodiments, a mature TACI protein does not contain the N-terminal methionine as set forth in SEQ ID NO:88. The extracellular domain of TACI (amino acid residues 1-166 of SEQ ID NO:88; ECD set forth in SEQ ID NO: 122) contains two cysteine rich domain (CRDs, hereinafter also called a tumorAttorney Docket No. 01245-0082-00PCT necrosis family receptor domain or TD), each of which exhibit affinity for binding to BAFF and APRIL. The first cysteine rich domain (CRD1) contains amino acid residues 34-66 of the sequence set forth in SEQ ID NO: 122. The second cysteine rich domain (CRD2) corresponds to amino acids 71-104 of the sequence set forth in SEQ ID NO: 122. TACI also contains a stalk region of about 60 amino acids following the second cysteine repeat in the extracellular domain, corresponding to amino acid residues 105 -165 of the sequence set forth in SEQ ID NO: 122.

[0322] The provided formulations contain a TACI-Fc fusion protein containing a wild-type or variant TACI polypeptide. In some embodiments, for production of the TACI-Fc fusion protein, a nucleic acid molecule encoding a single polypeptide chain of the TACI-Fc fusion protein is inserted into an appropriate expression vector. The resulting TACI-Fc fusion protein can be expressed in host cells transformed with the expression vector, where assembly between Fc domains occurs by interchain disulfide bonds formed between the Fc moieties to yield dimeric, such as divalent, TACI-Fc fusion proteins. The resulting Fc fusion proteins can be easily purified by affinity chromatography over Protein A or Protein G columns. In embodiments, when produced and expressed from a cell, the provided TACI-Fc fusion proteins (e.g. variant TACI-Fc fusion protein) is a homodimer containing two identical polypeptide chains.

[0323] Among the provided formulations are those that provide a TACI-Fc fusion protein for neutralizing activity and suppression or reduction of B cell responses. In some embodiments, the TACI-Fc fusion protein provides improved neutralizing activity and suppression or reduction of B cell responses. In some embodiments, the improved activity is mediated by increased or improved binding or interaction of the provided TACI-Fc fusion protein with BAFF and / or APRIL. The provided TACI-Fc fusion proteins block or antagonize interactions of BAFF or APRIL, such as homotrimers of BAFF or APRIL, heterotrimers of BAFF / APRIL or BAFF 60mers, with a cognate B cell stimulatory receptor, and thereby neutralize activity of BAFF and / or APRIL ligands. In some embodiments, the provided TACI-Fc fusion proteins reduce one or more B cell response or activity, including the ability of B cells to produce immunoglobulins. In some embodiments, the provided TACI-Fc fusion proteins (e.g. TACI-Fc fusion protein), when administered to a subject, reduce circulating serum immunoglobulins. In some embodiments, the provided TACI-Fc fusion proteins reduce one or more of B cell maturation, differentiation and proliferation.

[0324] In some embodiments, provided TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, exhibit an ICso for neutralizing BAFF of less than 400 pM. In some embodiments, the IC50 for neutralizing BAFF is between 1 pM and 400 pM, such as between 10 pM and 300 pM, between 10 pM and 200 pM, between 10 pM and 100 pM, between 10 pM andAttorney Docket No. 01245-0082-00PCT 50 pM, between 10 pM and 20 pM, between 20 pM and 400 pM, between 20 pM and 300 pM, between 20 pM and 200 pM, between 20 pM and 100 pM, between 20 pM and 50 pM, between 50 pM and 400 pM, between 50 pM and 300 pM, between 50 pM and 200 pM, between 50 pM and 100 pM, between 100 pM and 400 pM, between 100 pM and 300 pM, between 100 pM and 200 pM, between 200 pM and 400 pM, between 200 pM and 300 pM, or between 300 pM and 400 pM. In some embodiments, the ICso for neutralizing BAFF is at or about 10 pM, 15 pM, 20 pM, 25 pM, 30 pM, 35 pM, 40 pM, 45 pM, 50 pM, 55 pM, 60 pM, 65 pM, 70 pM, 75 pM, 80 pM, 85 pM, 90 pM, 95 pM or 100 pM or any value between any of the foregoing.

[0325] In some embodiments, provided TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, exhibits an ICso for neutralizing APRIL of less than 400 pM. In some embodiments, the IC50 for neutralizing APRIL is between 0.5 pM and 100 pM, such as between 0.5 pM and 50 pM, between 0.5 pM and 25 pM, between 0.5 pM and 10 pM, between 0.5 pM and 5 pM, between 0.5 pM and 1 pM, between 1 pM and 100 pM, between 1 pM and 50 pM, between 1 pM and 25 pM, between 1 pM and 10 pM, between 1 pM and 5 pM, between 5 pM and 100 pM, between 5 pM and 50 pM, between 5 pM and 25 pM, between 5 pM and 10 pM, between 10 pM and 100 pM, between 10 pM and 50 pM, between 10 pM and 25 pM, or between 25 pM and 100 pM, between 25 pM and 50 pM, or between 50 pM and 100 pM. In some embodiments, the ICso for neutralizing APRIL is at or about 0.5 pM, 0.75 pM, 1 pM, 2 pM, 3 pM, 4 pM, 5 pM, 6 pM, 7 pM, 8 pM, 9 pM, 10 pM, 11 pM, 12 pM, 13 pM, 14 pM, 15 pM, 20 pM or 25 pM or any value between any of the foregoing.

[0326] In some embodiments herein, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage. In embodiments, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage of up to 36 months, such as up to 24 months at refrigerated temperatures (e.g, 2-8°C) and / or up to 6 months, such as up to 3 months or up to 6 months, at elevated temperatures (e.g., 30°C). In embodiments herein, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage of up to 36 months, such as up to 24 months at refrigerated temperatures (e.g, 2-8°C) and / or up to 6 months, such as up to 3 months or up to 6 months, at elevated temperatures (e.g., 30°C) that is at least or at least about 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more compared to the activity prior to storage. In embodiments herein, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFFAttorney Docket No. 01245-0082-00PCT and APRIL after storage for up to 52 weeks at 2-8°C, such as, for example, 5°C, that is at least or at least about 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more compared to the activity prior to storage. In embodiments herein, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage for up to 104 weeks at 2-8°C, such as, for example, 5°C, that is at least or at least about 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more compared to the activity prior to storage. In embodiments herein, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage for up to 3 years at 2-8°C, such as, for example, 5°C, that is at least or at least about 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more compared to the activity prior to storage. In embodiments herein, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage for up to 12 weeks at about 25°C that is at least or at least about 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more compared to the activity prior to storage. In some embodiments, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage for up to 52 weeks at 2-8°C, such as, for example, 5°C that is at least 95% compared to the activity prior to storage. In some embodiments, the TACI-Fc (e.g. variant TACI-Fc) fusion proteins, such as homodimers thereof, provided in the formulations herein exhibit neutralizing activity of BAFF and APRIL after storage for up to 3 years at 2-8°C, such as, for example, 5°C that is at least 95% compared to the activity prior to storage.1. TA CI Polypeptides

[0327] In some embodiments, the provided formulations comprise a TACI-Fc fusion protein comprising a variant TACI polypeptide. In some embodiments, the provided formulations comprise a TACI-Fc fusion protein comprising a wild-type TACI polypeptide. Exemplary TACI polypeptides in the TACI-Fc fusion proteins are described below.

[0328] In some embodiments, the variant TACI polypeptide is a wild-type TACI sequence or is a portion thereof that contains one or both CRDs. In some embodiments, the TACI polypeptide is or comprises the extracellular domain (ECD) of TACI or a portion thereofAttorney Docket No. 01245-0082-00PCT containing one or both CRD domains. In some embodiments, the extracellular domain of a reference (e.g., unmodified) TACI polypeptide comprises a CRD1 and CRD2. In some embodiments, the TACI polypeptide is a soluble polypeptide and lacks a transmembrane domain.

[0329] In some embodiments, the TACI polypeptide sequence is a mammalian TACI sequence. In some embodiments, the TACI polypeptide sequence can be a mammalian TACI that includes, but is not limited to, human, mouse, cynomolgus monkey, or rat. In some embodiments, the TACI polypeptide sequence is human. The extracellular domain of an exemplary human TACI sequence is set forth in SEQ ID NO: 122.

[0330] In some embodiments, the TACI polypeptide sequence has (i) the sequence of amino acids set forth in SEQ ID NO: 122 or a sequence thereof that lacks the N-terminal methionine, (ii) a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 122 and that binds to APRIL, BAFF or an APRIL / BAFF heterotrimer, or (iii) is a fragment or portion of (i) or (ii) containing a CRD1 and / or CRD2, in which the portion binds to APRIL, BAFF or an APRIL / BAFF heterotrimer. In some embodiments, the TACI polypeptide sequence lacks the N-terminal methionine as set forth in SEQ ID NO: 122.TACI Extracellular Domain (ECD): SEQ ID NO: 122 MSGLGRSRRGGRSRVDQEERFPQGLWTGVAMRSCPEEQYWDPLLGTCMSCKTIC NHQSQRTCAAFCRSLSCRKEQGKFYDHLLRDCISCASICGQHPKQCAYFCENKLRS PVNLPPELRRQRSGEVENNSDNSGRYQGLEHRGSEASPALPGLKLSADQVALVYST

[0331] In some embodiments, the TACI polypeptide sequence is an extracellular domain sequence of TACI that is a portion of the ECD that contains an N-terminal deletion relative to the sequence of amino acids set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-28 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-29 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-30 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-31 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-32 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-33 corresponding to residues set forth in SEQ ID NO: 122.Attorney Docket No. 01245-0082-00PCT

[0332] Provided herein is an immunomodulatory protein (e.g. TACI-Fc fusion protein) containing a TACI polypeptide that is a portion of the TACI extracellular domain (ECD) region that contains the CRD2, with a deletion of the N-terminal region and CRD1 and deletion of one or more residues of the stalk portion of the TACI extracellular domain, e.g. relative to the sequence of amino acids set forth in SEQ ID NO: 122. In some embodiments, the portion of the TACI extracellular domain that contains the CRD2 includes amino acid residues 71-104 corresponding to residues set forth in SEQ ID NO: 122. In provided embodiments, the TACI polypeptide of the immunomodulatory protein contains deletion of N-terminal amino acid residues 1-66 corresponding to residues set forth in SEQ ID NO: 122. In provided embodiments, the TACI polypeptide of the immunomodulatory protein contains deletion of N-terminal amino acid residues 1-67 corresponding to residues set forth in SEQ ID NO: 122. In provided embodiments, the TACI polypeptide of the immunomodulatory protein contains deletion of N-terminal amino acid residues 1-68 corresponding to residues set forth in SEQ ID NO: 122. In provided embodiments, the TACI polypeptide of the immunomodulatory protein contains deletion of N-terminal amino acid residues 1-69 corresponding to residues set forth in SEQ ID NO: 122. In provided embodiments, the TACI polypeptide of the immunomodulatory protein contains deletion of N-terminal amino acid residues 1-70 corresponding to residues set forth in SEQ ID NO: 122. In embodiments of any such embodiments, the TACI polypeptide of the immunomodulatory protein lacks one or more contiguous C-terminal amino acid residues beginning at residue 105 and up to or including amino acid residue 166 corresponding to residues of the ECD sequence set forth in SEQ ID NO: 122. In some embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61 or 62 residues of the ECD sequence are deleted.

[0333] In some embodiments, the TACI polypeptide sequence contains an ECD portion having a contiguous sequence of amino acids that includes the CRD1 and / or CRD2 (e.g. CRD1 and CRD2 or CRD2 only) and only a segment or portion of the stalk sequence. Suitable stalk segments include one or more amino acids of amino acid residues 105 to 154 of SEQ ID NO: 122. For example, the stalk segment can consist of the following with reference to SEQ ID NO: 122: amino acid residue 105, amino acid residues 105 to 106, amino acid residues 105 to 107, amino acid residues 105 to 108, amino acid residues 105 to 109, amino acid residues 105 to 110, amino acid residues 105 to 111, amino acid residues 105 to 112, amino acid residues 105 to 113, amino acid residues 105 to 114, amino acid residues 105 to 115, amino acid residues 105 to 116, amino acid residues 105 to 117, amino acid residues 105 to 118, amino acid residues 105 to 119, amino acid residues 105 to 120, amino acid residues 105 to 121, amino acid residues 105 toAttorney Docket No. 01245-0082-00PCT 122, amino acid residues 105 to 123, amino acid residues 105 to 124, amino acid residues 105 to 125, amino acid residues 105 to 126, amino acid residues 105 to 127, amino acid residues 105 to 128, amino acid residues 105 to 129, amino acid residues 105 to 130, amino acid residues 105 to 131, amino acid residues 105 to 132, amino acid residues 105 to 133, amino acid residues 105 to 134, amino acid residues 105 to 135, amino acid residues 105 to 136, amino acid residues 105 to 137, amino acid residues 105 to 138, amino acid residues 105 to 139, amino acid residues 105 to 140, amino acid residues 105 to 141, amino acid residues 105 to 142, amino acid residues 105 to 143, amino acid residues 105 to 144, amino acid residues 105 to 145, amino acid residues 105 to 146, amino acid residues 105 to 147, amino acid residues 105 to 148, amino acid residues 105 to 149, amino acid residues 105 to 150, amino acid residues 105 to 151, amino acid residues 105 to 152, amino acid residues 105 to 153, and amino acid residues 105 to 154.

[0334] In some embodiments, the TACI polypeptide sequence lacks or is mutated in one or more potential furin cleavage sites. In some cases, the TACI polypeptide sequence is an ECD or portion that in which the arginine residue at position 119 is mutated, e.g. R119G. In some cases, the reference (e.g. unmodified) TACI sequence is an ECD or portion that in which the glutamine residue at position 121 is mutated, e.g. Q121P. In some cases, the reference (e.g. unmodified) TACI sequence is an ECD or portion that in which the arginine residue at position 122 is mutated, e.g. R122Q.

[0335] In some embodiments, the reference TACI sequence is a TACI ECD sequence as set forth in international PCT publication No. W02000 / 067034, W02002 / 094852 or WO2008 / 154814.

[0336] In some embodiments, the TACI polypeptide sequence is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 131.TACI ECD (CRD1 / CRD2): SEQ ID NO: 131SRVDQEER FPQGLWTGVA MRSCPEEQYW DPLLGTCMSCKTICNHQSQR TCAAFCRSLS CRKEQGKFYD HLLRDCISCA SICGQHPKQCAYFCENKLRS PVNLPPEL

[0337] In some embodiments, the TACI polypeptide sequence is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 130.TACI ECD (CRD1 / CRD2): SEQ ID NO: 130 AMRSCPEEQYWDPLLGTCMSCKTICNHQSQRTCAAFCRSLSCRKEQGKFYDHLLR DCISCASICGQHPKQCAYFCENKLRS

[0338] In some embodiments, the TACI polypeptide sequence is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 1 (encoded by the sequence of nucleotides set forth in SEQ ID NO:36).Attorney Docket No. 01245-0082-00PCT TACI ECD (CRD1 / CRD2): SEQ ID NO:1 VAMRSCPEEQYWDPLLGTCMSCKTICNHQSQRTCAAFCRSLSCRKEQGKFYDHLLR DCISCASICGQHPKQCAYFCENKLRS

[0339] In some embodiments, an immunomodulatory protein (e.g. TACI-Fc fusion protein) provided herein has a TACI polypeptide with a sequence that contains an ECD portion having a contiguous sequence of amino acids of a TACI ECD that includes the CRD2 (e.g. residues 71-104 with reference to SEQ ID NO: 122), but with a deletion of the N-terminal region and CRD1 and deletion of one or more residues of the stalk portion of the TACI extracellular domain, e.g. relative to the sequence of amino acids set forth in SEQ ID NO: 122. For example, the TACI ECD portion can consist of the following with reference to amino acid residues set forth in SEQ ID NO: 122: amino acid residues 67 to 118, amino acid residues 67 to 117, amino acid residues 67 to 116, amino acid residues 67 to 115, amino acid residues 67 to 114, amino acid residues 67 to 113, amino acid residues 67 to 112, amino acid residues 67 to 111, amino acid residues 67 to 110, amino acid residues 67 to 109, amino acid residues 67 to 108, amino acid residues 67 to 107, amino acid residues 67 to 106, amino acid residues 67 to 105, or amino acid residues 67 to 104, In some examples, the TACI ECD portion can consist of the following with reference to residues set forth in SEQ ID NO: 122: amino acid residues 68 to 118, amino acid residues 68 to 117, amino acid residues 68 to 116, amino acid residues 68 to 115, amino acid residues 68 to 114, amino acid residues 68 to 113, amino acid residues 68 to 112, amino acid residues 68 to 111, amino acid residues 68 to 110, amino acid residues 68 to 109, amino acid residues 68 to 108, amino acid residues 68 to 107, amino acid residues 68 to 106, amino acid residues 68 to 105, or amino acid residues 68 to 104. In some examples, the TACI ECD portion can consist of the following with reference to residues set forth in SEQ ID NO: 122: amino acid residues 69 to 118, amino acid residues 69 to 117, amino acid residues 69 to 116, amino acid residues 69 to 115, amino acid residues 69 to 114, amino acid residues 69 to 113, amino acid residues 69 to 112, amino acid residues 69 to 111, amino acid residues 69 to 110, amino acid residues 69 to 109, amino acid residues 69 to 108, amino acid residues 69 to 107, amino acid residues 69 to 106, amino acid residues 69 to 105, or amino acid residues 69 to 104. In some examples, the TACI ECD portion can consist of the following with reference to residues set forth in SEQ ID NO: 122: amino acid residues 70 to 118, amino acid residues 70 to 117, amino acid residues 70 to 116, amino acid residues 70 to 115, amino acid residues 70 to 114, amino acid residues 70 to 113, amino acid residues 70 to 112, amino acid residues 70 to 111, amino acid residues 70 to 110, amino acid residues 70 to 109, amino acid residues 70 to 108, amino acid residues 70 to 107, amino acid residues 70 to 106, amino acid residues 70 to 105, or amino acid residues 70 to 104. In some examples, the TACI ECD portion can consist of the following with reference toAttorney Docket No. 01245-0082-00PCT residues set forth in SEQ ID NO: 122: amino acid residues 71 to 118, amino acid residues 71 to 117, amino acid residues 71 to 116, amino acid residues 71 to 115, amino acid residues 71 to 114, amino acid residues 71 to 113, amino acid residues 71 to 112, amino acid residues 71 to 111, amino acid residues 71 to 110, amino acid residues 71 to 109, amino acid residues 71 to 108, amino acid residues 71 to 107, amino acid residues 71 to 106, amino acid residues 71 to 105, or amino acid residues 71 to 104. Any of the above TACI ECD sequences also can be a TACI reference sequence in accord with the immunomodulatory proteins provided herein, in which such immunomodulatory proteins contain a variant TACI polypeptide that is modified by one or more amino acid modification (e.g. substitution) as described herein compared to such TACI reference sequence.

[0340] In some embodiments, the TACI polypeptide sequence is an extracellular domain region of TACI that consists essentially of only the CRD2 sequence and that is deleted in or lacks the entirety of the sequence of the CRD1 and substantially all of the stalk region. In embodiments, a TACI-Fc fusion protein with a TACI extracellular region that consists essentially only of the CRD2 with a small portion of the stalk region exhibits substantially improved cognate binding activity compared to a longer TACI molecule containing both the CRD1 and CRD2.

[0341] In particular, among TACI polypeptides provided herein is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 13 (encoded by the sequence of nucleotides set forth in SEQ ID NO:48).TACI ECD sequence (CRD2): SEQ ID NO: 13 SLSCRKEQGKFYDHLLRDCISCASICGQHPKQCAYFCENKLRS

[0342] In some embodiments, the TACI polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO:204. In some embodiments, the TACI polypeptide sequence consists of the amino acid sequence set forth in SEQ ID NO:204. In some embodiments, the TACI polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO:206. In some embodiments, the TACI polypeptide sequence consists of the amino acid sequence set forth in SEQ ID NO:206. In some embodiments, the TACI polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO:215. In some embodiments, the TACI polypeptide sequence consists of the amino acid sequence set forth in SEQ ID NO:215. In some embodiments, the TACI polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO:217. In some embodiments, the TACI polypeptide sequence consists of the amino acid sequence set forth in SEQ ID NO:217. In some embodiments, the TACI polypeptideAttorney Docket No. 01245-0082-00PCT sequence comprises the amino acid sequence set forth in SEQ ID NO:240. In some embodiments, the TACI polypeptide sequence consists of the amino acid sequence set forth in SEQ ID NO:240. In some embodiments, the TACI polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO:241. In some embodiments, the TACI polypeptide sequence consists of the amino acid sequence set forth in SEQ ID NO: 241.

[0343] In some embodiments, the TACI polypeptide of the TACI-Fc fusion protein is a variant of any of the above TACI polypeptides in which is contained one or more amino acid substitutions (mutations) compared to such TACI polypeptide. Exemplary variant TACI polypeptides are described in Patent Publication Nos. WO2021226551 and WO 2022236335. Non-limiting examples of variant TACI polypeptides are described in the following subsection.a. Variant TACI Polypeptide

[0344] Provided embodiments include formulations comprising variant TACI polypeptides engineered to have improved affinity towards APRIL and / or BAFF. Among the formulations provided herein are formulations containing variant TACI polypeptides that confer improved binding affinity of the protein for BAFF and / or APRIL. In particular embodiments the provided formulations contain variant TACI polypeptides that provide for improved, combined BAFF and APRIL inhibition. In some embodiments, the improved affinity is by introduction of one or more amino acid substitutions following random mutagenesis and directed evolution of TACI extracellular domain, such as mutagenesis of residues of the second cysteine rich domain (CRD2) of TACI (e.g., spanning residues 68-110). The variant TACI polypeptides may include any TACI polypeptides described in International Patent Publication Nos. WO2021226551 and WO 2022236335, each of which are incorporated by reference in their entirety.

[0345] In some embodiments, the variant TACI polypeptides provided herein contain one or more amino acid modifications, such as one or more substitutions (alternatively, referred to herein as mutations or replacements), deletions or additions in the extracellular domain of a reference TACI polypeptide, such as a wild-type or unmodified TACI polypeptide containing a CRD(s) (hereinafter also called TDs). Thus, a provided variant TACI polypeptide is or comprises a variant TD (vTD) in which the one or more amino acid modifications (e.g. substitutions) is in a CRD. In some embodiments, the one or more amino acid modifications, such as one or more substitutions (referred to herein as mutations or replacements), deletions or additions, is in the CRD1 region. In some embodiments, the one or more amino acid modifications, such as one or more substitutions (alternatively, mutations or replacements), deletions or additions, is in the CRD2 region. In some embodiments, the one or more amino acidAttorney Docket No. 01245-0082-00PCT modifications, such as one or more substitutions (alternatively, mutations or replacements), deletions or additions, is in amino acids within both the CRD1 and CRD2 regions.

[0346] In some embodiments, the reference (e.g. unmodified) TACI sequence is a wild-type TACI sequence or is a portion thereof that contains one or both CRDs. In some embodiments, the reference (e.g., unmodified) TACI is or comprises the extracellular domain (ECD) of TACI or a portion thereof containing one or both CRD domains. In some embodiments, the extracellular domain of a reference (e.g., unmodified) TACI polypeptide comprises a CRD1 and CRD2. However, the variant TACI polypeptide need not comprise both the CRD1 and the CRD2. In some embodiments, the variant TACI polypeptide comprises or consists essentially of the CRD1 or a specific binding fragment thereof. In some embodiments, the variant TACI polypeptide comprises or consists essentially of the CRD2 or specific binding fragments thereof. In some embodiments, the variant TACI is a soluble polypeptide and lacks a transmembrane domain.

[0347] In some embodiments, the reference (e.g., unmodified) TACI sequence is a mammalian TACI sequence. In some embodiments, the reference (e.g., unmodified) TACI sequence can be a mammalian TACI that includes, but is not limited to, human, mouse, cynomolgus monkey, or rat. In some embodiments, the reference (e.g., unmodified) TACI sequence is human. The extracellular domain of an exemplary human TACI sequence is set forth in SEQ ID NO: 122.

[0348] In some embodiments, the reference (e.g., unmodified) TACI sequence has (i) the sequence of amino acids set forth in SEQ ID NO: 122 or a sequence thereof that lacks the N-terminal methionine, (ii) a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 122 and that binds to APRIL, BAFF or an APRIL / BAFF heterotrimer, or (iii) is a fragment or portion of (i) or (ii) containing a CRD1 and / or CRD2, in which the portion binds to APRIL, BAFF or an APRIL / BAFF heterotrimer. In some embodiments, the reference (e.g., unmodified) TACI sequence lacks the N-terminal methionine as set forth in SEQ ID NO: 122.

[0349] In some embodiments, the reference (e.g. unmodified) TACI sequence is an extracellular domain sequence of TACI that is a portion of the ECD that contains an N-terminal deletion relative to the sequence of amino acids set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-28 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-29 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-30 corresponding to residues set forth in SEQ ID NO: 122. In someAttorney Docket No. 01245-0082-00PCT embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-31 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-32 corresponding to residues set forth in SEQ ID NO: 122. In some embodiments, the N-terminal deletion is deletion of N-terminal amino acid residues 1-33 corresponding to residues set forth in SEQ ID NO: 122.

[0350] In embodiments of any of the provided embodiments, the reference (e.g. unmodified) TACI sequence is an ECD portion that contains deletion of one or more residues of the stalk portion of the TACI extracellular domain. In some embodiments, the reference (e.g. unmodified) TACI sequence is an ECD portion that lacks one or more contiguous C-terminal amino acid residues beginning at residue 105 and up to or including amino acid residue 166 corresponding to residues of the ECD sequence set forth in SEQ ID NO: 122. In some embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61 or 62 residues of the ECD sequence are deleted.

[0351] In some embodiments, the reference (e.g. unmodified) TACI sequence contains an ECD portion having a contiguous sequence of amino acids that includes the CRD1 and / or CRD2 (e.g. CRD1 and CRD2 or CRD2 only) and only a segment or portion of the stalk sequence. Suitable stalk segments include one or more amino acids of amino acid residues 105 to 154 of SEQ ID NO: 122. For example, the stalk segment can consist of the following with reference to SEQ ID NO: 122: amino acid residue 105, amino acid residues 105 to 106, amino acid residues 105 to 107, amino acid residues 105 to 108, amino acid residues 105 to 109, amino acid residues 105 to 110, amino acid residues 105 to 111, amino acid residues 105 to 112, amino acid residues 105 to 113, amino acid residues 105 to 114, amino acid residues 105 to 115, amino acid residues 105 to 116, amino acid residues 105 to 117, amino acid residues 105 to 118, amino acid residues 105 to 119, amino acid residues 105 to 120, amino acid residues 105 to 121, amino acid residues 105 to 122, amino acid residues 105 to 123, amino acid residues 105 to 124, amino acid residues 105 to 125, amino acid residues 105 to 126, amino acid residues 105 to 127, amino acid residues 105 to 128, amino acid residues 105 to 129, amino acid residues 105 to 130, amino acid residues 105 to 131, amino acid residues 105 to 132, amino acid residues 105 to 133, amino acid residues 105 to 134, amino acid residues 105 to 135, amino acid residues 105 to 136, amino acid residues 105 to 137, amino acid residues 105 to 138, amino acid residues 105 to 139, amino acid residues 105 to 140, amino acid residues 105 to 141, amino acid residues 105 to 142, amino acid residues 105 to 143, amino acid residues 105 to 144, amino acid residues 105 to 145, amino acid residues 105 to 146, amino acid residues 105 to 147, amino acid residues 105 to 148, amino acid residuesAttorney Docket No. 01245-0082-00PCT 105 to 149, amino acid residues 105 to 150, amino acid residues 105 to 151, amino acid residues 105 to 152, amino acid residues 105 to 153, and amino acid residues 105 to 154.

[0352] In some embodiments, the reference (e.g. unmodified) TACI sequence lacks or is mutated in one or more potential furin cleavage sites. In some cases, the reference (e.g. unmodified) TACI sequence is an ECD or portion that in which the arginine residue at position 119 is mutated, e.g. R119G. In some cases, the reference (e.g. unmodified) TACI sequence is an ECD or portion that in which the glutamine residue at position 121 is mutated, e.g. Q121P. In some cases, the reference (e.g. unmodified) TACI sequence is an ECD or portion that in which the arginine residue at position 122 is mutated, e.g. R122Q.

[0353] In some embodiments, the reference TACI sequence is a TACI ECD sequence as set forth in international PCT publication No. W02000 / 067034, W02002 / 094852 or WO2008 / 154814.

[0354] In some embodiments, the reference TACI sequence is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 131.

[0355] In some embodiments, the reference TACI sequence is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 130.

[0356] In some embodiments, the reference TACI sequence is a TACI ECD sequence that has or consists of the sequence set forth in SEQ ID NO: 1 (encoded by the sequence of nucleotides set forth in SEQ ID NO:36).

[0357] In some embodiments, the reference TACI sequence is an extracellular domain region of TACI that consists essentially of only the CRD2 sequence and that is deleted in or lacks the entirety of the sequence of the CRD1 and substantially all of the stalk region. In some embodiments, the reference TACI sequence has or consists of the sequence set forth in SEQ ID NO: 13, in which a provided variant TACI polypeptide is modified by one or more amino acid modification (e.g. substitution) as described herein compared to such reference TACI sequence.

[0358] In some embodiments, the reference TACI sequence comprises the amino acid sequence set forth in SEQ ID NO:204. In some embodiments, the reference TACI sequence consists of the amino acid sequence set forth in SEQ ID NO:204. In some embodiments, the reference TACI sequence comprises the amino acid sequence set forth in SEQ ID NO:206. In some embodiments, the reference TACI sequence consists of the amino acid sequence set forth in SEQ ID NO:206. In some embodiments, the reference TACI sequence comprises the amino acid sequence encoded by the nucleic acid sequence set forth in SEQ ID NO:215. In some embodiments, the reference TACI sequence consists of the amino acid sequence encoded by the nucleic acid sequence set forth in SEQ ID NO:215. In some embodiments, the reference TACI sequence comprises the amino acid sequence encoded by the nucleic acid sequence set forth inAttorney Docket No. 01245-0082-00PCT SEQ ID NO:217. In some embodiments, the reference TACI sequence consists of the amino acid sequence encoded by the nucleic acid sequence set forth in SEQ ID NO:217. In some embodiments, the reference TACI sequence comprises the amino acid sequence set forth in SEQ ID NO:240. In some embodiments, the reference TACI sequence consists of the amino acid sequence set forth in SEQ ID NO:240. In some embodiments, the reference TACI sequence comprises the amino acid sequence set forth in SEQ ID NO:241. In some embodiments, the reference TACI sequence consists of the amino acid sequence set forth in SEQ ID NO: 241.

[0359] In any of the provided embodiments, the variant TACI sequence has the sequence of the reference (e.g. unmodified) TACI sequence, such as any described above, but additionally contains one more amino acid modifications, such as one or more amino acid substitutions. In particular, provided herein are variant TACI polypeptides containing at least one affinity-modified TD domain (e.g., CRD1 and / or CRD2) or a specific binding fragment thereof that contains one or more amino acid substitutions in a TD domain of a reference (e.g., unmodified or wild-type) TACI polypeptide, such that the variant TACI polypeptide exhibits altered (e.g. increased) binding activity or affinity for one or both of APRIL or BAFF compared to the reference (e.g., unmodified or wild-type) TACI polypeptide. In some embodiments, a variant TACI polypeptide has a binding affinity for APRIL and / or BAFF that differs from that of a reference (e.g., unmodified or wild-type) TACI polypeptide control sequence as determined by, for example, solid-phase ELISA immunoassays, flow cytometry or Biacore assays. Binding affinities for each of the cognate binding partners are independent; that is, in some embodiments, a variant TACI polypeptide has an increased binding affinity for one or both APRIL and BAFF, and a decreased or unchanged binding affinity for the other of APRIL or BAFF, relative to a reference (e.g., unmodified or wild-type) TACI polypeptide.

[0360] In some embodiments, the variant TACI polypeptide has an increased binding affinity for BAFF, relative to the reference (unmodified or wild-type) TACI polypeptide. In some embodiments, the variant TACI polypeptide has an increased binding affinity for APRIL relative to the reference (unmodified or wild-type) TACI polypeptide. In some embodiments, the variant TACI polypeptide has an increased binding affinity for APRIL and BAFF relative to the reference (unmodified or wild-type) TACI polypeptide. The cognate ligands BAFF and / or APRIL can be a mammalian protein, such as a human protein or a murine protein. In particular embodiments, the cognate ligands BAFF and / or APRIL are human. In some embodiments, a variant TACI polypeptide with increased or greater binding affinity to APRIL and / or BAFF will have an increase in binding affinity relative to the reference (e.g., unmodified or wild-type) TACI polypeptide control of at least about 5%, such as at least about 10%, 15%, 20%, 25%, 35%, or 50%. In some embodiments, the increase in binding affinity relative to the referenceAttorney Docket No. 01245-0082-00PCT (e.g., unmodified or wild-type) TACI polypeptide is more than about 1.2-fold, about 1.5-fold, about 2-fold, about 3-fold, about 4-fold, about 5-fold, about 6-fold, about 7-fold, about 8-fold, about 9-fold, about 10-fold, about 20-fold, about 30-fold, about 40-fold or about 50-fold. In any of the examples, the reference (e.g., unmodified or wild-type) TACI polypeptide has the same sequence as the variant TACI polypeptide except that it does not contain the one or more amino acid modifications (e.g., substitutions).

[0361] In some embodiments, the equilibrium dissociation constant (Kd) of any of the foregoing embodiments to BAFF can be less than 1X10'5M, IxlO'6M, IxlO'7M, IxlO'8M, IxlO'9M, IxlO'10M or lxlO'nM, or IxlO'12M. In some embodiments, the Kd of any of the foregoing embodiments to BAFF is less than at or about IxlO'9M, IxlO'10M or lxlO'nM, or IxlO'12M. In some embodiments, the Kd of any of the foregoing embodiments to BAFF is between IxlO'9M and at or about 1X10'12M. In some embodiments, the Kd of any of the foregoing embodiments to BAFF is at or about IxlO'9M, at or about 2xl0'9M, at or about 4x10'9M, at or about 6xl0'9M, at or about 8xl0'9M, at or about IxlO'10M, at or about 2xlO'10M, at or about 4xlO'10M, at or about 6xlO'10M, at or about 8xlO'10M, at or about IxlO'11M, at or about 2xl0'nM, at or about 4xl0'nM, at or about 6xl0'nM, at or about 8xl0'nM, or at or about 1X10'12M, or any value between any of the foregoing. In some embodiments, a provided embodiment includes a variant TACI polypeptide as described above and the Kd to BAFF is decreased (higher binding affinity) by greater than or greater than about 1.5-fold, such as greater than or about 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold or more.

[0362] In some embodiments, the equilibrium dissociation constant (Kd) of any of the foregoing embodiments to APRIL can be less than 1X10'5M, IxlO'6M, IxlO'7M, IxlO'8M, IxlO'9M, IxlO'10M or lxlO'nM, or IxlO'12M. In some embodiments, the Kd of any of the foregoing embodiments to APRIL is less than at or about IxlO'9M, IxlO'10M or lxlO'nM, or IxlO'12M. In some embodiments, the Kd of any of the foregoing embodiments to APRIL is between IxlO'9M and at or about 1X10'12M. In some embodiments, the Kd of any of the foregoing embodiments to APRIL is at or about IxlO'9M, at or about 2xl0'9M, at or about 4xl0'9M, at or about 6xl0'9M, at or about 8xl0'9M, at or about IxlO'10M, at or about 2xlO'10M, at or about 4xlO'10M, at or about 6xlO'10M, at or about 8xlO'10M, at or about IxlO'11M, at or about 2xl0'nM, at or about 4xl0'nM, at or about 6xl0'nM, at or about 8xl0'nM, or at or about 1X10'12M, or any value between any of the foregoing. In some embodiments, a provided embodiment includes a variant TACI polypeptide as described above and the Kd to APRIL is decreased (higher binding affinity) by greater than or greater than about 1.5-fold, such as greater than or about 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold or more.Attorney Docket No. 01245-0082-00PCT

[0363] The reference (e.g., unmodified or wild-type) TACI sequence does not necessarily have to be used as a starting composition to generate variant TACI polypeptides described herein. Therefore, use of the term “modification”, such as “substitution” does not imply that the present embodiments are limited to a particular method of making variant TACI polypeptides or immunomodulatory proteins containing the same. Variant TACI polypeptides can be made, for example, by de novo peptide synthesis and thus does not necessarily require a modification, such as a “substitution”, in the sense of altering a codon to encode for the modification, e.g. substitution. This principle also extends to the terms “addition” and “deletion” of an amino acid residue which likewise do not imply a particular method of making. The means by which the variant TACI polypeptides are designed or created is not limited to any particular method. In some embodiments, however, a reference (e.g., unmodified or wild-type) TACI encoding nucleic acid is mutagenized from reference (e.g., unmodified or wild-type) TACI genetic material and screened for desired specific binding affinity or other functional activity. In some embodiments, a variant TACI polypeptide is synthesized de novo utilizing protein or nucleic acid sequences available at any number of publicly available databases and then subsequently screened. The National Center for Biotechnology Information provides such information, and its website is publicly accessible via the internet as is the UniProtKB database as discussed previously.

[0364] Unless stated otherwise, as indicated throughout the present disclosure, the amino acid modification(s) in a variant TACI polypeptide are designated by amino acid position number corresponding to the numbering of positions of the reference ECD sequence set forth in SEQ ID NO: 122. It is within the level of a skilled artisan to identify the corresponding position of a modification, e.g. amino acid substitution, in a TACI polypeptide, including portion thereof containing TD (e.g. CRD1 and / or CRD2) thereof, such as by alignment of a reference sequence (e.g. SEQ ID NO: 1 or 13) with SEQ ID NO: 122. An alignment identifying corresponding residues is exemplified in FIG. 9. In the listing of modifications throughout this disclosure, the amino acid position is indicated in the middle, with the corresponding reference (e.g. unmodified or wild-type) amino acid listed before the number and the identified variant amino acid substitution listed after the number. If the modification is a deletion of the position a “del” is indicated and if the modification is an insertion at the position an “ins” is indicated. In some cases, an insertion is listed with the amino acid position indicated in the middle, with the corresponding reference amino acid listed before and after the number and the identified variant amino acid insertion listed after the unmodified (e.g. wild-type) amino acid.

[0365] In some embodiments, the variant TACI polypeptide has one or more amino acid modification, e.g. substitution relative to a reference (e.g., unmodified or wild-type) TACI sequence, such as any as described. The one or more amino acid modification, e.g. substitution,Attorney Docket No. 01245-0082-00PCT can be in the ectodomain (extracellular domain) of the reference (e.g., unmodified or wild-type) TACI sequence. In some embodiments, the one or more amino acid modification, e.g. substitution is in the CRD1 domain or specific binding fragment thereof. In some embodiments, the one or more amino acid modification, e.g. substitution is in the CRD2 domain or specific binding fragment thereof. In some embodiments of the variant TACI polypeptide, some of the one or more amino acid modification, e.g. substitution is in the CRD1 domain or a specific binding fragment thereof, and some of the one or more amino acid modification, e.g. substitution is in the CRD2 domain or a specific binding fragment thereof.

[0366] In some embodiments, the variant TACI polypeptide has up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid modification(s), e.g. substitution, in the reference TACI sequence. The modification, e.g. substitution can be in the CRD1 domain or the CRD2 domain. In some embodiments, the variant TACI polypeptide has up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions in the CRD1 domain or specific binding fragment thereof of the reference TACI sequence. In some embodiments, the variant TACI polypeptide has up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid substitutions in the CRD2 domain or specific binding fragment thereof of the reference TACI sequence.

[0367] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substations) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the reference (e.g., unmodified or wild-type) TACI polypeptide set forth in SEQ ID NO: 122 or specific binding fragment thereof containing the CRD1 and / or CRD2 domain. In some embodiments, the specific binding fragment contains the CRD1 domain, e.g. the specific binding fragment contains the sequence set forth as amino acids 34-66 of SEQ ID NO: 122. In some cases, the CRD1 domain is the only full CRD domain in the specific binding fragment. In some embodiments, the specific binding fragment is or contains the CRD2 domain, e.g. the specific binding fragment contains the sequence set forth as amino acids 71-104 of SEQ ID NO: 122. In some cases, the CRD2 domain is the only full CRD domain in the specific binding fragment. In some embodiments, the specific binding fragment is or contains the CRD1 domain and the CRD2 domain, e.g. the specific binding fragment contains amino acids 34-104 of SEQ ID NO: 122. In some embodiments, the specific binding fragment contains a contiguous portion of the stalk domain, e.g. the specific binding fragment contains a contiguous portion of amino acids 105-165 of SEQ ID NO: 122. In embodiments of any embodiments, the specific binding fragment of SEQ ID NO: 122 is less than the full-length ECD set forth in SEQ ID NO: 122. In some embodiments, the specific binding fragment is set forth in SEQ ID NO: 1. In someAttorney Docket No. 01245-0082-00PCT embodiments, the specific binding fragment is set forth in SEQ ID NO: 13. In some embodiments, the specific binding fragment is set forth in SEQ ID NO: 130. In some embodiments, the specific binding fragment is set forth in SEQ ID NO: 131.

[0368] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substitutions) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the reference (e.g., unmodified or wild-type) TACI polypeptide or specific binding fragment thereof, such as with the amino acid sequence of SEQ ID NO: 1, 13 or 122.

[0369] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substitutions) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the amino acid sequence of SEQ ID NO: 122.

[0370] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substitutions) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the amino acid sequence of SEQ ID NO: 1.

[0371] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substitutions) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the amino acid sequence of SEQ ID NO: 13.

[0372] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substitutions) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the amino acid sequence of SEQ ID NO: 130.

[0373] In some embodiments, the variant TACI polypeptide containing the one or more amino acid modifications (e.g. amino acid substitutions) as described has at least about 85%, 86%, 86%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the amino acid sequence of SEQ ID NO: 131.

[0374] In some embodiments, the variant TACI polypeptide has one or more amino acid modification, e.g. substitution relative to a reference TACI polypeptide or specific binding fragment there of corresponding to position(s) 40, 59, 60, 61, 74, 75, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 92, 95, 97, 98, 99, 101, 102 and 103 with reference to numbering of SEQ ID NO: 122. In some embodiments, the variant TACI polypeptide has one or more amino acid modification, e.g. substitution selected from W40R, Q59R, R60G, T61P, E74V, Q75E, Q75R, G76S, K77E, F78Y, Y79F, L82H, L82P, L83S, R84G, R84L, R84Q, D85E, D85V, C86Y, I87L,Attorney Docket No. 01245-0082-00PCT I87M, S88N, 192 V, Q95R, P97S, K98T, Q99E, A101D, Y102D, F1O3S, Fl O3V, F103Y, or a conservative amino acid substitution thereof. In some embodiments, the reference TACI polypeptide includes the CRD1 domain or CRD2 domain, for example the reference TACI polypeptide is set forth in SEQ ID NO: 1 or SEQ ID NO: 122.

[0375] In some embodiments, the amino acid substitutions are in the CRD2 domain only. In some embodiments, the variant TACI polypeptide has one or more amino acid modification, e.g. substitution relative to a reference TACI polypeptide or specific binding fragment thereof corresponding to position(s) 74, 75, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 92, 95, 97, 98, 99, 101, 102 and 103 with reference to numbering of SEQ ID NO: 122. In some embodiments, the variant TACI polypeptide has one or more amino acid modification, e.g. substitution selected from E74V, Q75E, Q75R, G76S, K77E, F78Y, Y79F, L82H, L82P, L83S, R84G, R84L, R84Q, D85E, D85V, C86Y, I87L, I87M, S88N, I92V, Q95R, P97S, K98T, Q99E, A101D, Y102D, F103S, Fl 03V, F103Y, or a conservative amino acid substitution thereof. In some embodiments, among the CRD domains, the reference TACI polypeptide includes only the CRD2 domain but lacks the CRD1 domain, for example the reference TACI polypeptide is set forth in SEQ ID NO: 13. Accordingly, in some embodiments, the variant TACI polypeptide includes a portion of the ECD sequence of a TACI polypeptide that includes the CRD2 domain but lacks the CRD1 domain.

[0376] A conservative amino acid modification, e.g. substitution is any amino acid that falls in the same class of amino acids as the substituted amino acids, other than the reference (e.g., unmodified) or wild-type amino acid. The classes of amino acids are aliphatic (glycine, alanine, valine, leucine, and isoleucine), hydroxyl or sulfur-containing (serine, cysteine, threonine, and methionine), cyclic (proline), aromatic (phenylalanine, tyrosine, tryptophan), basic (histidine, lysine, and arginine), and acidic / amide (aspartate, glutamate, asparagine, and glutamine).

[0377] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution at position 75 with reference to numbering of SEQ ID NO: 122. In some embodiments, the amino acid substitution at position 75 confers increased binding to BAFF or APRIL compared to the reference (e.g. wildtype or unmodified) TACI polypeptide not containing the amino acid substitution. In some embodiments, the substituted amino acid is an acidic amino acid or amide, such as to a different acidic amino acid or amide compared to the reference (e.g. wildtype or unmodified) TACI polypeptide. In some embodiments, the substituted amino acid at position 75 is a glutamic acid (Glu, E). In some embodiments, the substituted amino acid at position 75 is an aspartic acid (Asp, D). In some embodiments, the substituted amino acid at position 75 is an asparagine (Asn, N). In some embodiments, the substituted amino acid at position 75 is a glutamine (Gin, Q).Attorney Docket No. 01245-0082-00PCT

[0378] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution at position 77 with reference to numbering of SEQ ID NO: 122. In some embodiments, the amino acid substitution at position 77 confers increased binding to BAFF or APRIL compared to the reference (e.g. wildtype or unmodified) TACI polypeptide not containing the amino acid substitution. In some embodiments, the substituted amino acid at position 77 is an acidic amino acid or amide. In some embodiments, the substituted amino acid at position 77 is a glutamic acid (Glu, E). In some embodiments, the substituted amino acid at position 77 is an aspartic acid (Asp, D). In some embodiments, the substituted amino acid at position 77 is an asparagine (Asn, N). In some embodiments, the substituted amino acid at position 77 is a glutamine (Gin, Q).

[0379] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution at position 78 with reference to numbering of SEQ ID NO: 122. In some embodiments, the amino acid substitution at position 78 confers increased binding to BAFF or APRIL compared to the reference (e.g. wildtype or unmodified) TACI polypeptide not containing the amino acid substitution. In some embodiments, the substituted amino acid at position 78 is an aromatic amino acid, such as to a different aromatic amino acid compared to the reference (e.g. wildtype or unmodified) TACI polypeptide. In some embodiments, the substituted amino acid at position 78 is a phenylalanine (Phe, F). In some embodiments, the substituted amino acid at position 78 is a tyrosine (Tyr, Y). In some embodiments, the substituted amino acid at position 78is a tryptophan (Trp, W).

[0380] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution at position 84 with reference to numbering of SEQ ID NO: 122. In some embodiments, the amino acid substitution at position 84 confers increased binding to BAFF or APRIL compared to the reference (e.g. wildtype or unmodified) TACI polypeptide not containing the amino acid substitution. In some embodiments, the substituted amino acid at position 84 is an acidic amino acid or amide. In some embodiments, the substituted amino acid at position 84 is a glutamic acid (Glu, E). In some embodiments, the substituted amino acid at position 84 is an aspartic acid (Asp, D). In some embodiments, the substituted amino acid at position 84 is an asparagine (Asn, N). In some embodiments, the substituted amino acid at position 84 is a glutamine (Gin, Q).

[0381] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution at position 101 with reference to numbering of SEQ ID NO: 122. In some embodiments, the amino acid substitution at position 101 confers increased binding to BAFF or APRIL compared to the reference (e.g. wildtype or unmodified) TACI polypeptide not containing the amino acid substitution. In some embodiments, the substituted amino acid atAttorney Docket No. 01245-0082-00PCT position 101 is an acidic amino acid or amide. In some embodiments, the substituted amino acid at position 101 is a glutamic acid (Glu, E). In some embodiments, the substituted amino acid at position 101 is an aspartic acid (Asp, D). In some embodiments, the substituted amino acid at position 101 is an asparagine (Asn, N). In some embodiments, the substituted amino acid at position 101 is a glutamine (Gin, Q).

[0382] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution at position 102 with reference to numbering of SEQ ID NO: 122. In some embodiments, the amino acid substitution at position 102 confers increased binding to BAFF or APRIL compared to the reference (e.g. wildtype or unmodified) TACI polypeptide not containing the amino acid substitution. In some embodiments, the substituted amino acid at position 102 is an acidic amino acid or amide. In some embodiments, the substituted amino acid at position 102 is a glutamic acid (Glu, E). In some embodiments, the substituted amino acid at position 102 is an aspartic acid (Asp, D). In some embodiments, the substituted amino acid at position 102 is an asparagine (Asn, N). In some embodiments, the substituted amino acid at position 102 is a glutamine (Gin, Q).

[0383] In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution E74V. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution Q75E. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution K77E. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution F78Y. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution Y79F. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution L82H. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution L82P. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution R84G. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution R84L. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution R84Q. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution D85V. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution C86Y. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution A101D. In some embodiments, the variant TACI polypeptide includes at least one amino acid substitution Y102D. In some embodiments, the variant TACI polypeptide contains two or more amino acid substitutions of any two or more of the foregoing. In some embodiments, the variant TACI polypeptide includes one or more amino acid substitution that is a conservative amino acid substitution of any of the foregoing. In provided embodiments, the variant TACI polypeptideAttorney Docket No. 01245-0082-00PCT includes the at least one amino acid substitution in any reference TACI polypeptide sequence as described. In some embodiments, the at least one amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the at least one amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the at least one amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the at least one amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0384] In some embodiments, the variant TACI polypeptide includes the amino acid substitution E74V. In some embodiments, the variant TACI polypeptide includes the amino acid substitution Q75E.In some embodiments, the variant TACI polypeptide includes the amino acid substitution K77E. In some embodiments, the variant TACI polypeptide includes the amino acid substitution F78Y. In some embodiments, the variant TACI polypeptide includes the amino acid substitution Y79F. In some embodiments, the variant TACI polypeptide includes the amino acid substitution L82H. In some embodiments, the variant TACI polypeptide includes the amino acid substitution L82P. In some embodiments, the variant TACI polypeptide includes the amino acid substitution R84G. In some embodiments, the variant TACI polypeptide includes the amino acid substitution R84L. In some embodiments, the variant TACI polypeptide includes the amino acid substitution R84Q. In some embodiments, the variant TACI polypeptide includes the amino acid substitution D85V. In some embodiments, the variant TACI polypeptide includes the amino acid substitution C86Y. In some embodiments, the variant TACI polypeptide includes the amino acid substitution A102D. In some embodiments, the variant TACI polypeptide includes the amino acid substitution Y102D. In some embodiments, the variant TACI polypeptide contains two or more amino acid substitutions of any two or more of the foregoing. In some embodiments, the variant TACI polypeptide includes one or more of amino acid substitution that is a conservative amino acid substitution of any of the foregoing. In provided embodiments, the variant TACI polypeptide includes the amino acid substitution in any reference TACI polypeptide sequence as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0385] In some embodiments, the amino acid substitutions are D85E / K98T. In some embodiments, the amino acid substitutions are I87L / K98T. In some embodiments, the amino acid substitutions are R60G / Q75E / L82P. In some embodiments, the amino acid substitutions are R60G / C86Y. In some embodiments, the amino acid substitutions are W40R / L82P / F103Y. InAttorney Docket No. 01245-0082-00PCT some embodiments, the amino acid substitutions are W40R / Q59R / T61P / K98T. In some embodiments, the amino acid substitutions are L82P / I87L. In some embodiments, the amino acid substitutions are G76S / P97S. In some embodiments, the amino acid substitutions are K77E / R84L / F103Y. In some embodiments, the amino acid substitutions are Y79F / Q99E. In some embodiments, the amino acid substitutions are L83S / F103S. In some embodiments, the amino acid substitutions are K77E / R84Q. In some embodiments, the amino acid substitutions are K77E / A101D. In some embodiments, the amino acid substitutions are K77E / F78Y / Y102D. In some embodiments, the amino acid substitutions are Q75E / R84Q. In some embodiments, the amino acid substitutions are Q75R / R84G / I92V. In some embodiments, the amino acid substitutions are K77E / A101D / Y102D. In some embodiments, the amino acid substitutions are R84Q / S88N / A101D. In some embodiments, the amino acid substitutions are R84Q / F103V. In some embodiments, the amino acid substitutions are K77E / Q95R / A101D. In some embodiments, the amino acid substitutions are I87M / A101D. In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0386] In embodiments of any embodiments, the variant TACI polypeptide includes one or more amino acid substitutions from Q75E, K77E, F78Y, R84G, R84Q, A101D or Y102D, or any combination thereof. In some embodiments, the variant TACI polypeptide includes any 1, 2, 3, 4, 5 or 6 of the above amino acid substitutions. In some embodiments, the variant TACI polypeptide contains one of the above amino acid substitutions. In some embodiments, the variant TACI polypeptide contains two of the above amino acid substitutions. In some embodiments, the variant TACI polypeptide contains three of the above amino acid substitutions. In some embodiments, the variant TACI polypeptide contains four of the above amino acid substitutions. In some embodiments, the variant TACI polypeptide contains five of the above amino acid substitutions. In some embodiments, the variant TACI polypeptide contains six of the above amino acid substitutions.

[0387] In embodiments of any embodiments, the one or more amino acid substitutions comprise Q75E / R84Q. In embodiments of any embodiments, the one or more amino acid substitutions comprise Q75E / K77E. In embodiments of any embodiments, the one or more amino acid substitutions comprise Q75E / F78Y. In embodiments of any embodiments, the one orAttorney Docket No. 01245-0082-00PCT more amino acid substitutions comprise Q75E / A101D. In embodiments of any embodiments, the one or more amino acid substitutions comprise Q75E / Y102D. In embodiments of any embodiments, the one or more amino acid substitutions comprise K77E / F78Y. In embodiments of any embodiments, the one or more amino acid substitutions comprise K77E / R84Q. In embodiments of any embodiments, the one or more amino acid substitutions comprise K77E / A101D. In embodiments of any embodiments, the one more amino acid substitutions comprise K77E / Y102D. In embodiments of any embodiments, the one or more amino acid substitutions comprise F78Y / R84Q. In embodiments of any embodiments, the one or more amino acid substitutions comprise F78Y / A101D. In embodiments of any embodiments, the one or more amino acid substitutions comprise F78Y / Y102D. In embodiments of any embodiments, the one or more amino acid substitutions comprise R84Q / A101D. In embodiments of any embodiments, the one or more amino acid substitutions comprise R84Q / Y102D. In embodiments of any embodiments, the one or more amino acid substitutions comprise A101D / Y102D. In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described, such as in the sequence set forth in SEQ ID NO:1, SEQ IDNO:13, SEQ ID NO: 130 or SEQ IDNO: 131.

[0388] In some embodiments, the variant TACI polypeptides include the amino acid substitution(s) R84G, A101D, K77E / R84Q, K77E / A101D, K77E / F78Y, K77E / F78Y / Y102D, Q75E / R84Q, K77E / A101D / Y102D, R84Q, K77E, A101D, Q75E, K77E / F78Y / R84Q, F78Y, F78Y / R84Q, F78Y / A101D, F78Y / Y102D, or K77E / Y102D. In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described, such as in the sequence set forth in SEQ ID NO:1, SEQ ID NO: 13, SEQ ID NO: 130 or SEQ ID NO: 131.

[0389] In some embodiments, the variant TACI polypeptide includes the amino acid substitutions K77E and F78Y (K77E / F78Y). In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0390] In some embodiments, the variant TACI polypeptide includes the amino acid substitutions K77E and Y102D (K77E / Y102D). In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequenceAttorney Docket No. 01245-0082-00PCT as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0391] In some embodiments, the variant TACI polypeptide contains the amino acid substitutions F78Y and Y102D (F78Y / Y012D). In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0392] In some embodiments the variant TACI polypeptide contains the amino acid substitutions K77E, F78Y and Y102D (K77E / F78Y / Y102D). In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0393] In some embodiments, the variant TACI polypeptide contains the amino acid substitutions Q75E / R84Q. In provided embodiments, the variant TACI polypeptide includes the amino acid substitutions in any reference TACI polypeptide sequence as described. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 1. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 13. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 130. In some embodiments, the amino acid substitution is in the reference TACI sequence set forth in SEQ ID NO: 131.

[0394] In some embodiments, the variant TACI polypeptide comprises any of the mutations listed in Table 1. Table 1 also provides exemplary sequences by reference to the SEQ ID NO of the reference (e.g., unmodified) TACI polypeptide, and exemplary variant TACI polypeptides.Attorney Docket No. 01245-0082-00PCT As indicated, the exact locus or residues corresponding to a given domain can vary, such as depending on the methods used to identify or classify the domain. Also, in some cases, adjacent N- and / or C-terminal amino acids of a given domain (e.g. CRD) also can be included in a sequence of a variant TACI polypeptide, such as to ensure proper folding of the domain when expressed. Thus, it is understood that the exemplification of the SEQ ID NOs in Table 1 is not to be construed as limiting. For example, the particular domain, such as the ECD domain or a portion thereof containing the CRD1 / CRD2 or CRD2 only, of a variant TACI polypeptide can be several amino acids longer or shorter, such as 1-10, e.g., 1, 2, 3, 4, 5, 6 or 7 amino acids longer or shorter, than the sequence of amino acids set forth in the respective SEQ ID NO.

[0395] In some embodiments, the variant TACI polypeptide comprises any of the mutations (amino acid substitutions) listed in Table 1. In some examples, the mutations (amino acid substitutions) are made in a reference TACI containing the sequence of amino acids set forth in SEQ ID NO: 122. In some examples, the mutations (amino acid substitutions) are made a reference TACI that contains the CRD1 and CRD2 domain of TACI, for example as set forth in SEQ ID NO: 1. In some examples, the mutations (amino acid substitutions) are made in a reference TACI that is further truncated by deletion of N-terminal and C-terminal amino acid residues to retain the CRD2, for example as set forth in SEQ ID NO: 13.

[0396] The use of the term “modification”, such as “substitution” or “mutation,” does not imply that the present embodiments are limited to a particular method of making the immunomodulatory proteins. A variant TACI polypeptide can be made, for example, by de novo peptide synthesis and thus does not necessarily require a modification, such as a “substitution” in the sense of altering a codon to encode for the modification, e.g. substitution. This principle also extends to the terms “addition” and “deletion” of an amino acid residue which likewise do not imply a particular method of making. The means by which the vTDs are designed or created is not limited to any particular method. In some embodiments, however, a wild-type or unmodified TD encoding nucleic acid is mutagenized from wild-type or unmodified TD genetic material and screened for desired specific binding activity, e.g. binding affinity, and / or alteration of NF-KB modulation or other functional activity. In some embodiments, a vTD is synthesized de novo utilizing protein or nucleic acid sequences available at any number of publicly available databases and then subsequently screened. The National Center for Biotechnology Information provides such information and its website is publicly accessible via the internet as is the UniProtKB database.

[0397] In some embodiments, the variant TACI polypeptide comprises an extracellular domain (ECD) sequence containing a CRD1 and CRD2, such as a variant TACI polypeptide set forth in any one of SEQ ID NOS: 2-12, 21, 22, 101-120. In some embodiments, the variantAttorney Docket No. 01245-0082-00PCT TACI polypeptide comprises a polypeptide sequence that exhibits at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, at least about 94% identity, at least about 95% identity, such as at least about 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 2-12, 21, 22, 101-120, and retains the amino acid modification(s), e.g. substitution(s) therein not present in the reference (e.g., unmodified or wild-type) TACI. In some embodiments, the variant TACI polypeptide comprises a specific binding fragment of any one of SEQ ID NOS: 2-12, 21, 22, 101-120, in which the specific binding fragment binds B AFF, APRIL or a BAFF / APRIL heterotrimer, and contains a contiguous sequence therein that contains the amino acid modification(s), e.g. substitution (s) therein not present in the reference (e.g., unmodified or wild-type) TACI.

[0398] In some embodiments, the variant TACI polypeptide consists or consists essentially of a variant TACI extracellular domain (ECD) sequence set forth in any one of SEQ ID NOS: 2-12, 21, 22, 101-120. In some embodiments, the variant TACI polypeptide consists or consists essentially of a polypeptide sequence that exhibits at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, at least about 94% identity, at least about 95% identity, such as at least about 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 2-12, 21, 22, 101-120, and retains the amino acid modification(s), e.g. substitution(s) therein not present in the reference (e.g., unmodified or wildtype) TACI. In some embodiments, the variant TACI polypeptide consists or consists essentially of a specific binding fragment of any one of SEQ ID NOS: 2-12, 21, 22, 101-120, in which the specific binding fragment binds BAFF, APRIL or an APRIL / BAFF heterotrimer and contains a contiguous sequence therein that contains the amino acid modification(s), e.g. substitution (s) therein not present in the reference (e.g., unmodified or wild-type) TACI.

[0399] In some embodiments, the variant TACI polypeptide comprises an extracellular domain (ECD) sequence containing a CRD2 but lacking the CRD1 of a reference TACI polypeptide, such as a variant TACI polypeptide set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192. In some embodiments, the variant TACI polypeptide comprises a polypeptide sequence that exhibits at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, at least about 94% identity, at least about 95% identity, such as at least about 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192, and retains the amino acid modification(s), e.g. substitution(s) therein not present in the reference (e.g., unmodified or wildtype) TACI. In some embodiments, the variant TACI polypeptide comprises a specific binding fragment of any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192 in which the specific binding fragment binds BAFF, APRIL or a BAFF / APRIL heterotrimer, and contains aAttorney Docket No. 01245-0082-00PCT contiguous sequence therein that contains the amino acid modification(s), e.g. substitution (s) therein not present in the reference (e.g., unmodified or wild-type) TACI.

[0400] In some embodiments, the variant TACI polypeptide consists or consists essentially of the sequence set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192. In some embodiments, the variant TACI polypeptide consists or consists essentially of a polypeptide sequence that exhibits at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, at least about 94% identity, at least about 95% identity, such as at least about 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192, and retains the amino acid modification(s), e.g. substitution(s) therein not present in the reference (e.g., unmodified or wild-type) TACI. In some embodiments, the variant TACI polypeptide consists or consists essentially of a specific binding fragment of any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192, in which the specific binding fragment binds B AFF, APRIL or a BAFF / APRIL heterotrimer, and contains a contiguous sequence therein that contains the amino acid modification(s), e.g. substitution (s) therein not present in the reference (e.g., unmodified or wild-type) TACI.

[0401] In some embodiments, the variant TACI polypeptide comprises the sequence set forth in SEQ ID NO:20. In some embodiments, the variant TACI polypeptide consists essentially of the sequence set forth in SEQ ID NO:20. In some embodiments, the variant TACI polypeptide consists of the sequence set forth in SEQ ID NO: 20.

[0402] In some embodiments, the variant TACI polypeptide comprises the sequence set forth in SEQ ID NO:26. In some embodiments, the variant TACI polypeptide consists essentially of the sequence set forth in SEQ ID NO:26. In some embodiments, the variant TACI polypeptide consists of the sequence set forth in SEQ ID NO: 26.

[0403] In some embodiments, the variant TACI polypeptide comprises the sequence set forth in SEQ ID NO:27. In some embodiments, the variant TACI polypeptide consists essentially of the sequence set forth in SEQ ID NO:27. In some embodiments, the variant TACI polypeptide consists of the sequence set forth in SEQ ID NO: 27.

[0404] In some embodiments, the variant TACI polypeptide comprises the sequence set forth in SEQ ID NO: 107. In some embodiments, the variant TACI polypeptide consists essentially of the sequence set forth in SEQ ID NO: 107. In some embodiments, the variant TACI polypeptide consists of the sequence set forth in SEQ ID NO: 107.

[0405] In some embodiments, the variant TACI polypeptide is encoded by a sequence of nucleotides set forth in any of SEQ ID NOS: 37-47, 56 or 57. In some embodiments, the variant TACI polypeptide is encoded by a sequence of nucleotides that exhibits at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, atAttorney Docket No. 01245-0082-00PCT least about 94% identity, at least about 95% identity, such as at least about 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 37-47, 56 or 57, and retains the amino acid modification(s), e.g. substitution s) therein not present in the reference (e.g., unmodified or wild-type) TACI. Also provided herein is a nucleic acid containing the sequence set forth in any of SEQ ID NOS: 37-47, 56 or 57 or a sequence that exhibits at least 90% identity, at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, such as at least 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 37-47, 56 or 57.

[0406] In some embodiments, the variant TACI polypeptide is encoded by a sequence of nucleotides set forth in any of SEQ ID NOS: 49-55 or 58-70. In some embodiments, the variant TACI polypeptide is encoded by a sequence of nucleotides that exhibits at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, at least about 94% identity, at least about 95% identity, such as at least about 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 49-55 or 58-70, and retains the amino acid modification(s), e.g. substitution s) therein not present in the reference(e.g., unmodified or wild-type) TACI. Also provided herein is a nucleic acid containing the sequence set forth in any of SEQ ID NOS: 49-55 or 58-70 or a sequence that exhibits at least 90% identity, at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, such as at least 96% identity, 97% identity, 98% identity, or 99% identity to any one of SEQ ID NOS: 49-55 or 58-70.TABLE 1: Exemplary variant TACIECD(CRD1 / CRD2) ECD (CRD2) Name Mutation(s) NT NT AA SEQ AA SEQ SEQ SEQ ID NO ID ID NO ID NO NO1 (WT) TACI CRD1 / CRD213 (WT) TACI CRD2 Wild-type 1 36 13 48 2 TACI CRD1 / CRD292 TACI CRD2 L82P 2 37 92 3 TACI CRD1 / CRD2D85E, K98T 3 38 93 93 TACI CRD24 TACI CRD1 / CRD2I87L, K98T 4 39 94 94 TACI CRD25 TACI CRD1 / CRD2 R60G, Q75E, L82P 5 406 TACI CRD1 / CRD2 R60G, C86Y 6 417 TACI CRD1 / CRD295 TACI CRD2 A101D 7 42 95Attorney Docket No. 01245-0082-00PCT TABLE 1: Exemplary variant TACIECD(CRD1 / CRD2) ECD (CRD2) Name Mutation(s) N AA NT AA T SEQ SEQ SEQ SEQ ID NO ID ID NO ID NO NO8 TACI CRD1 / CRD2C86Y 8 43 96 96 TACI CRD29 TACI CRD1 / CRD2 W40R, L82P, F103Y 9 4410 TACI CRD1 / CRD2 W40R, Q59R, T61P, K98T 10 4511 TACI CRD 1 / CRD2L82P, I87L 11 46 97 97 TACI CRD212 TACI CRD1 / CRD212 47 98 98 TACI CRD2 G76S, P97S101 TACI CRD 1 / CRD2101 14 49 14 TACI CRD2 D85V102 TACI CRD1 / CRD2102 15 50 15 TACI CRD2 E74V103 TACI CRD1 / CRD2R84L 103 16 51 16 TACI CRD2104 TACI CRD1 / CRD2 K77E, R84L, F103Y 104 17 52 17 TACI CRD2105 TACI CRD1 / CRD2Y79F, Q99E 105 18 53 18 TACI CRD2106 TACI CRD1 / CRD2Y79F 106 19 54 19TACI CRD2107 TACI CRD1 / CRD2107 20 55 20 TACI CRD2 R84G21 TACI CRD1 / CRD221 56 99 99 TACI CRD2 L83S, F103S22 TACI CRD1 / CRD2L82H 22 57 100 100 TACI CRD2108 TACI CRD1 / CRD2A101D 108 23 58 23 TACI CRD2109 TACI CRD1 / CRD2 K77E, R84Q 109 24 59 24 TACI CRD2110 TACI CRD 1 / CRD2K77E, A101D 110 25 60 25 TACI CRD2111 TACI CRD 1 / CRD2K77E, F78Y, Y102D 111 26 61 26 TACI CRD2112 TACI CRD 1 / CRD2Q75E, R84Q 112 27 62 27 TACI CRD2113 TACI CRD 1 / CRD2113 28 63 28 TACI CRD2 Q75R, R84G, I92V114 TACI CRD 1 / CRD2K77E, A101D, Y102D 114 29 64 29 TACI CRD2115 TACI CRD 1 / CRD2R84Q 115 30 65 30 TACI CRD2116 TACI CRD 1 / CRD2R84Q, S88N, A101D 116 31 6631 TACI CRD2Attorney Docket No. 01245-0082-00PCT TABLE 1: Exemplary variant TACIECD(CRD1 / CRD2) ECD (CRD2) Name Mutation(s) AA SEQ NT AA NT SEQ SEQ SEQ ID NO ID ID NO ID NO NO117 TACI CRD 1 / CRD2K77E 117 32 67 32 TACI CRD2118 TACI CRD 1 / CRD2R84Q, F103V 118 33 68 33 TACI CRD2119 TACI CRD 1 / CRD2K77E, Q95R, A101D 119 34 69 34 TACI CRD2120 TACI CRD1 / CRD2I87M, A101D 120 35 70 35 TACI CRD2177 TACI CRD2 Q75E 177 178 TACI CRD2 Q75E, K77E 178 179 TACI CRD2 Q75E, F78Y 179 180 TACI CRD2 Q75E, A101D 180 181 TACI CRD2 Q75E, Y102D 181 182 TACI CRD2 K77E, F78Y, R84Q 182 183 TACI CRD2 F78Y 183 184 TACI CRD2 F78Y, R84Q 184 185 TACI CRD2 F78Y, A101D 185 186 TACI CRD2 F78Y, Y102D 186 187 TACI CRD2 R84Q, A101D 187 188 TACI CRD2 R84Q, Y102D 188 189 TACI CRD2 A101D, Y102D 189 190 TACI CRD2 Y102D 190 191 TACI CRD2 K77E, F78Y 191 192 TACI CRD2 K77E, Y102D 192

[0407] Among the provided formulation herein are those comprising a variant TACI-Fc polypeptide with improved binding affinity of the protein for BAFF and / or APRIL, such as any described herein and set forth in International Patent Publication Nos. WO2021226551 and WOAttorney Docket No. 01245-0082-00PCT 202223633. Such variant TACI polypeptides contain a variant TNFR domain (vTD, e.g., CRD2 domain) generated by directed evolution by affinity modification of the ectodomain of TACI to and have improved affinity for APRIL and / or BAFF. TACLFc fusion proteins of such variant TACI polypeptides linked with an immunoglobulin Fc provide for immunomodulatory proteins that suppress B cell activity and response. For instance, reformatted as a soluble Fc fusion protein, the affinity-matured TACI variant outputs exhibited inhibition of APRIL and BAFF, including with lower IC50 values than wild-type TACI-Fc and other therapeutic comparators (e.g., belimumab). Further, among such tested variant TACI-Fc fusion proteins are those that provide for rapid and significantly reduced key lymphocyte subsets including plasma cells, germinal center B cells, and follicular T helper cells. Further, tested variant molecules exhibited improved activities in mouse models, including significantly reduced autoantibodies and sialadenitis in the spontaneous SjS model, inhibited glomerular IgG deposition in the bml2-induced model of lupus, and potently suppressed anti-dsDNA autoantibodies, blood urea nitrogen levels, proteinuria, sialadenitis, kidney lesions and renal immune complex deposition in the NZB / W lupus model. Further, as compared to wild-type TACI-Fc, tested variant TACI-Fc fusions exhibited significantly and persistently decreased titers of serum IgM, IgG, and IgA antibodies in mice.2. Fc Region

[0408] In some embodiments, a TACI polypeptide, such as any described above, is linked or fused to an immunoglobulin Fc region, such as any described herein. In some embodiments, the individual TACI-Fc fusion polypeptides of the TACI-Fc fusion protein form a multimer, e.g., a dimer. In some embodiments, the dimer is a homodimer in which the two polypeptides of the TACI-Fc fusion protein are the same. In some embodiments, the dimer is a heterodimer in which the two TACI-Fc fusion polypeptides of the TACI-Fc fusion protein are different.Exemplary Fc regions are described below.

[0409] The TACI polypeptide sequence (e.g. variant TACI polypeptide sequence) can be joined anywhere, but typically via its N- or C-terminus, to the N- or C-terminus of a Fc region to form a fusion polypeptide. The linkage can be direct or indirect via a linker. For example, when preparing a chimeric polypeptide containing an Fc region, nucleic acid encoding all or part of a TACI polypeptide sequence such as any described TACI ECD, including a variant TACI polypeptide sequence, can be operably linked to nucleic acid encoding the Fc region sequence, directly or indirectly or optionally via a linker domain. In some cases, the construct encodes a fusion polypeptide where the C-terminus of the TACI polypeptide sequence is joined to the N-terminus of the Fc region. In some instances, a construct can encode a fusion polypeptide whereAttorney Docket No. 01245-0082-00PCT the N-terminus of the TACI polypeptide sequence is joined to the N- or C-terminus of the Fc region.

[0410] A polypeptide multimer contains two fusion polypeptides created by linking, directly or indirectly, two of the same or different TACI polypeptide sequences (e.g. two of the same or different variant TACI polypeptide sequences) directly or indirectly to an Fc region. In some examples, a gene fusion encoding the TACI polypeptide sequence (e.g. variant TACI polypeptide sequence) and Fc region is inserted into an appropriate expression vector. The resulting fusion protein can be expressed in host cells transformed with the recombinant expression vector, and allowed to assemble into multimers, where the Fc region domains interact to form multivalent polypeptides.

[0411] The resulting fusion proteins, such as dimers formed therefrom from individual polypeptide chains, can be purified by any suitable method such as, for example, by affinity chromatography over Protein A or Protein G columns. Where two nucleic acid molecules encoding different polypeptides are transformed into cells, formation of homo- and heterodimers will occur. Conditions for expression can be adjusted so that heterodimer formation is favored over homodimer formation. For the generation of heterodimers, additional steps for purification can be necessary. For example, where two nucleic acids encoding different immunomodulatory proteins are transformed into cells, the formation of heterodimers must be biochemically achieved since immunomodulatory protein carrying the Fc-domain will be expressed as disulfide-linked homodimers as well. Thus, homodimers can be reduced under conditions that favor the disruption of interchain disulfides but do not affect intra-chain disulfides. In some cases, different TACI-Fc fusion protein monomers are mixed in equimolar amounts and oxidized to form a mixture of homo- and heterodimers. The components of this mixture are separated by chromatographic techniques. Alternatively, the formation of this type of heterodimer can be biased by genetically engineering and expressing immunomodulatory proteins containing Fc fusion molecules that contain one or more TACI variants using knob-into-hole methods as described.

[0412] In provided embodiments of a TACI-Fc, the immunoglobulin Fc region can be a wild-type Fc of an immunoglobulin, such as an IgGl Fc. In some cases, the Fc region can be a variant Fc that lacks effector function (also called effectorless Fc). Exemplary Fc regions and variants thereof in provided TACI-Fc fusion proteins are described below.

[0413] In some embodiments, the Fc is murine or human Fc. In some embodiments, the Fc is a mammalian or human IgGl, lgG2, lgG3, or lgG4 Fc regions.

[0414] In some embodiments, the Fc region is or comprises the sequence set forth in any one of SEQ ID NOs: 71, 73, 75, 81, 82, 83, 134, 135, 136, 137, 138, 139, 140, 173, 174, 175,Attorney Docket No. 01245-0082-00PCT 176, 193, 218, 219, 220, or 221. In some embodiments, the Fc region is or is derived from an IgGl, such as set forth in any one of SEQ ID NOS: 71, 73, 75, 81, 82, 83, 134, 135, 136, 137, 139, 140, 173, 174, 175, 176, 193, 218, 220, or 221. In some embodiments, the Fc region is or is derived from an IgG2, such as any set forth in SEQ ID NO: 138 or 219. In some embodiments, the Fc region is or is derived from an IgG4, such as any set forth in SEQ ID NO: 139, 140 or 220. In some embodiments, an Fc region in Fc fusion proteins provided herein also can include an Fc region that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% to any of the above Fc regions.

[0415] In some embodiments, the Fc is derived from IgGl, such as human IgGl. In some embodiments, the Fc is an IgGl Fc set forth in SEQ ID NO: 71 having an allotype containing residues Glu (E) and Met (M) at positions 356 and 358 by EU numbering. In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 71 or a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 71. In other embodiments, the Fc is an IgGl Fc that contains amino acids of the human Glml allotype, such as residues containing Asp (D) and Leu (L) at positions 356 and 358, e.g. as set forth in SEQ ID NO:81. Thus, in some cases, an Fc provided herein can contain amino acid substitutions E356D and M358L to reconstitute residues of allotype G1 ml. In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 81 or a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 81.

[0416] In some embodiments, the Fc region has the amino acid sequence set forth in SEQ IDNO:81.EPKSSDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK FNWYVDGVEVHNAI<TI<PREEQYNSTYRVVSVLTVLHQDWLNGI<EYI<CI<VSNI<ALP APIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPE NNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO:81)

[0417] In some embodiments, the Fc region comprises the amino acid sequence set forth in SEQ ID NO:81. In some embodiments, the Fc region consists of the amino acid sequence set forth in SEQ IDNO:81.

[0418] In some embodiments, the variant Fc comprises the sequence set forth in SEQ ID NO: 173. In some embodiments, the variant Fc comprises the sequence set forth in SEQ ID NO: 174. In some embodiments, an Fc region used in a construct provided herein can further lack a C-terminal lysine residue.Attorney Docket No. 01245-0082-00PCT

[0419] In some embodiments, the Fc is derived from IgG2, such as human IgG2. In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 138 or a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 138. In some embodiments, the Fc region is an IgG2 Fc region that has the sequence set forth in SEQ ID NO: 138. In some embodiments, the Fc region is an IgG2 Fc region that has the sequence set forth in SEQ ID NO: 219.

[0420] In some embodiments, the Fc is derived from IgG4, such as human IgG4. In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 139 or a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 139. In some embodiments, the IgG4 Fc is a stabilized Fc in which the CH3 domain of human IgG4 is substituted with the CH3 domain of human IgGl and which exhibits inhibited aggregate formation, an antibody in which the CH3 and CH2 domains of human IgG4 are substituted with the CH3 and CH2 domains of human IgGl, respectively, or an antibody in which arginine at position 409 indicated in the EU index proposed by Kabat et al. of human IgG4 is substituted with lysine and which exhibits inhibited aggregate formation (see e.g. U.S. Patent No. 8,911,726. In some embodiments, the Fc is an IgG4 containing the S228P mutation, which has been shown to prevent recombination between a therapeutic antibody and an endogenous IgG4 by Fab-arm exchange (see e.g. Labrijin et al. (2009) Nat. Biotechnol., 27(8): 767-71.) In some embodiments, the Fc comprises the amino acid sequence set forth in SEQ ID NO: 140 or a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 140. In some embodiments, the Fc region is an IgG4 Fc region set forth in SEQ ID NO: 140. In some embodiments, the Fc region is an IgG4 Fc region set forth in SEQ ID NO:220.

[0421] In some embodiments, the Fc region is a variant Fc region in which a wild-type Fc is modified by one or more amino acid substitutions to reduce effector activity or to render the Fc inert for Fc effector function. Exemplary effectorless or inert mutations include those described herein.

[0422] In some embodiments, the Fc region contains one more modifications that alter (e.g. reduce) one or more of its normal functions. In general, the Fc region is responsible for effector functions, such as complement-dependent cytotoxicity (CDC) and antibody-dependent cell cytotoxicity (ADCC), in addition to the antigen-binding capacity, which is the main function of immunoglobulins. Additionally, the FcRn sequence present in the Fc region plays the role of regulating the IgG level in serum by increasing the in vivo half-life by conjugation to an in vivoAttorney Docket No. 01245-0082-00PCT FcRn receptor. In some embodiments, such functions can be reduced or altered in an Fc for use with the provided Fc fusion proteins.

[0423] In some embodiments, one or more amino acid modifications may be introduced into the Fc region, thereby generating an Fc region variant. In some embodiments, the Fc region variant has decreased effector function. There are many examples of changes or mutations to Fc sequences that can alter effector function. For example, WO 00 / 42072, W02006019447, WO2012125850, WO2015 / 107026, US2016 / 0017041 and Shields etal. J Biol. Chem. 9(2): 6591-6604 (2001) describe exemplary Fc variants with improved or diminished binding to FcRs. The contents of those publications are specifically incorporated herein by reference.

[0424] In some embodiments, the provided immunomodulatory proteins comprise an Fc region that exhibits reduced effector functions, which makes it a desirable candidate for applications in which the half-life of the immunomodulatory protein in vivo is important yet certain effector functions (such as CDC and ADCC) are unnecessary or deleterious. In vitro and / or in vivo cytotoxicity assays can be conducted to confirm the reduction / depletion of CDC and / or ADCC activities. For example, Fc receptor (FcR) binding assays can be conducted to ensure that the immunomodulatory protein lacks FcyR binding (hence likely lacking ADCC activity), but retains FcRn binding ability. The primary cells for mediating ADCC, NK cells, express FcyRIII only, whereas monocytes express FcyRI, FcyRII and FcyRIII. FcR expression on hematopoietic cells is summarized in Table 2 on page 464 of Ravetch and Kinet, Annu. Rev. Immunol. 9:457-492 (1991). Non-limiting examples of in vitro assays to assess ADCC activity of a molecule of interest is described in U.S. Pat. No. 5,500,362 (see, e.g. Hellstrom, I. etal. Proc. Nat'l Acad. Sci. USA 83:7059-7063 (1986)) and Hellstrom, I etal.., Proc. Nat'l Acad. Sci. USA 82:1499-1502 (1985); U.S. Pat. No. 5,821,337 (see Bruggemann, M. et al., J. Exp. Med.166:1351-1361 (1987)). Alternatively, non-radioactive assay methods may be employed (see, for example, ACTI™ non-radioactive cytotoxicity assay for flow cytometry (CellTechnology, Inc. Mountain View, Calif.; and CytoTox 96™ non -radioactive cytotoxicity assay (Promega, Madison, Wis.). Useful effector cells for such assays include peripheral blood mononuclear cells (PBMC) and Natural Killer (NK) cells. Alternatively, or additionally, ADCC activity of the molecule of interest may be assessed in vivo, e.g., in an animal model such as that disclosed in Clynes etal. Proc. Nat'l Acad. Sci. USA 95:652-656 (1998). Clq binding assays may also be carried out to confirm that the immunomodulatory protein is unable to bind Clq and hence lacks CDC activity. See, e.g., Clq and C3c binding ELISA in WO 2006 / 029879 and WO 2005 / 100402. To assess complement activation, a CDC assay may be performed (see, for example, Gazzano- Santoro et al., J. Immunol. Methods 202:163 (1996); Cragg, M. S. et al., Blood 101:1045-1052 (2003); and Cragg, M. S. and M. J. Glennie, Blood 103:2738-2743Attorney Docket No. 01245-0082-00PCT (2004)). FcRn binding and in vivo clearance / half life determinations can also be performed using methods known in the art (see, e.g., Petkova, S. B. etal., Int'l. Immunol. 18(12): 1759-1769 (2006)).

[0425] Immunomodulatory proteins with reduced effector function include those with substitution of one or more of Fc region residues 238, 265, 269, 270, 297, 327 and 329 by EU numbering (U.S. Pat. No. 6,737,056). Such Fc mutants include Fc mutants with substitutions at two or more of amino acid positions 265, 269, 270, 297 and 327 by EU numbering, including the so-called “DANA” Fc mutant with substitution of residues 265 and 297 to alanine (U.S. Pat. No.7,332,581).

[0426] In some embodiments, the Fc region of immunomodulatory proteins has an Fc region in which any one or more of amino acids at positions 234, 235, 236, 237, 238, 239, 270, 297, 298, 325, and 329 (indicated by EU numbering) are substituted with different amino acids compared to the native Fc region. Such alterations of Fc region include, for example, alterations such as deglycosylated chains (N297A and N297Q), IgGl-N297G, IgGl-L234A / L235A, IgGl-L234A / L235E / G237A, IgGl-A325A / A330S / P331S, IgGl-C226S / C229S, IgGl-C226S / C229S / E233P / L234V / L235A, IgGl- E233P / L234V / L235A / G236del / S267K, IgGl-L234F / L235E / P331S, IgGl-S267E / L328F, IgG2-V234A / G237A, IgG2-H268Q / V309L / A330S / A331S, IgG4-L235A / G237A / E318A, and IgG4-L236E described in Current Opinion in Biotechnology (2009) 20 (6), 685-691; alterations such as G236R / L328R, L235G / G236R, N325A / L328R, and N325LL328R described in WO 2008 / 092117; amino acid insertions at positions 233, 234, 235, and 237 (indicated by EU numbering); and alterations at the sites described in WO 2000 / 042072.

[0427] Certain Fc variants with improved or diminished binding to FcRs are described. (See, e.g., U.S. Pat. No. 6,737,056; WO 2004 / 056312, W02006019447 and Shields etal., J. Biol. Chem. 9(2): 6591-6604 (2001).)

[0428] In some embodiments, there is provided an immunomodulatory protein comprising a variant Fc region comprising one or more amino acid substitutions which increase half-life and / or improve binding to the neonatal Fc receptor (FcRn). Antibodies with increased half-lives and improved binding to FcRn are described in US2005 / 0014934A1 (Hinton et all) or W02015107026. Those antibodies comprise an Fc region with one or more substitutions therein which improve binding of the Fc region to FcRn. Such Fc variants include those with substitutions at one or more of Fc region residues: 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434 by EU numbering, e.g., substitution of Fc region residue 434 (U.S. Pat. No. 7,371,826).Attorney Docket No. 01245-0082-00PCT

[0429] In some embodiments, the Fc region of the immunomodulatory protein comprises one or more amino acid substitutions C220S, C226S and / or C229S by EU numbering. In some embodiments, the Fc region of the immunomodulatory protein comprises one or more amino acid substitutions R292C and V302C. See also Duncan & Winter, Nature 322:738-40 (1988); U.S. Pat. No. 5,648,260; U.S. Pat. No. 5,624,821; and WO 94 / 29351 concerning other examples of Fc region variants.

[0430] In some embodiments, alterations are made in the Fc region that result in diminished Clq binding and / or Complement Dependent Cytotoxicity (CDC), e.g., as described in U.S. Pat. No. 6,194,551, WO 99 / 51642, and Idusogie etal., J. Immunol. 164: 4178-4184 (2000).

[0431] In some embodiments, the variant Fc region comprising the one or more amino acid modifications (e.g. amino acid substitutions) is derived from a wild-type IgGl, such as a wildtype human IgGl. In some embodiments, the wild-type IgGl Fc can be the Fc set forth in SEQ ID NO: 71 having an allotype containing residues Glu (E) and Met (M) at positions 356 and 358 by EU numbering. In some embodiments, the variant Fc region is derived from the amino acid sequence set forth in SEQ ID NO: 71. In other embodiments, the wild-type IgGl Fc contains amino acids of the human Glml allotype, such as residues containing Asp (D) and Leu (L) at positions 356 and 358, e.g. as set forth in SEQ ID NO:81. Thus, in some cases, the variant Fc is derived from the amino acid sequence set forth in SEQ ID NO:81.

[0432] In some embodiments, the Fc region lacks the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 71 or 81 (corresponding to K447del by EU numbering).

[0433] In some embodiments, the variant Fc region comprises a C5S amino acid modification of the wild-type or unmodified Fc region by numbering of SEQ ID NO: 71 (corresponding to C220S by EU numbering).

[0434] In some embodiments, the Fc region is a variant Fc that contains at least one amino acid substitution that is N82G by numbering of SEQ ID NO: 71 (corresponding to N297G by EU numbering). In some embodiments, the Fc further contains at least one amino acid substitution that is R77C or V87C by numbering of SEQ ID NO: 71 (corresponding to R292C or V302C by EU numbering). In some embodiments, the variant Fc region further comprises a C5S amino acid modification by numbering of SEQ ID NO: 71 (corresponding to C220S by EU numbering). For example, in some embodiments, the variant Fc region comprises the following amino acid modifications: N297G and one or more of the following amino acid modifications C220S, R292C or V302C by EU numbering (corresponding to N82G and one or more of the following amino acid modifications C5S, R77C or V87C with reference to SEQ ID NO:71), e.g., the Fc region comprises the sequence set forth in SEQ ID NO:82.Attorney Docket No. 01245-0082-00PCT

[0435] In some embodiments, the variant Fc contains the amino acid substitutions L234A / L235E / G237A, by EU numbering. In some embodiments, the variant Fc contains the amino acid substitutions A330S / P331S, by EU numbering. In some embodiments, the variant Fc contains the amino acid substitutions L234A / L235E / G237A / A330S / P331S (Gross et al. (2001) Immunity 15:289). In some embodiments, the variant Fc comprises the sequence set forth in SEQ ID NO: 175. In some embodiments, the variant Fc comprises the sequence set forth in SEQ ID NO: 176. In some embodiments, an Fc region used in a construct provided herein can further lack a C-terminal lysine residue.

[0436] In some embodiments, the Fc region is a variant Fc that includes mutations L234A, L235E and G237A by EU numbering. In some embodiments, a wild-type Fc is further modified by the removal of one or more cysteine residue, such as by replacement of the cysteine residues to a serine residue at position 220 (C220S) by EU numbering. Exemplary inert Fc regions having reduced effector function are set forth in SEQ ID NO: 83 and SEQ ID NO:75, which are based on allotypes set forth in SEQ ID NO:71 or SEQ ID NO: 81, respectively. In some embodiments, an Fc region can further lack a C-terminal lysine residue. In some embodiments, the variant Fc region comprises one or more of the amino acid modifications C220S, L234A, L235E or G237A, e.g. the Fc region comprises the sequence set forth in SEQ ID NO:73, 75, 83 or 136. In some embodiments, the variant Fc comprises has the sequence set forth in SEQ ID NO: 73. In some embodiments, the variant Fc comprises has the sequence set forth in SEQ ID NO: 75. In some embodiments, the variant Fc comprises has the sequence set forth in SEQ ID NO: 83. In some embodiments, the variant Fc comprises has the sequence set forth in SEQ ID NO: 136.

[0437] In some embodiments, the Fc region is a variant Fc that has the sequence set forth in SEQ ID NO: 73.EPKSSDKTHTCPPCPAPEAEGAPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK FNWYVDGVEVHNAI<TI<PREEQYNSTYRVVSVLTVLHQDWLNGI<EYI<CI<VSNI<ALP APIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPE NNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 73)

[0438] In some embodiments, the Fc region is an IgGl Fc but does not contain a hinge sequence. In some embodiments, the IgGl Fc region does not contain the hinge sequence EPKSC (SEQ ID NO:239). In some embodiments, the IgGl Fc region does not contain a hinge sequence EPKSS (SEQ ID NO: 238).

[0439] In some embodiments, the Fc region is a variant Fc that has the sequence set forth in SEQ ID NO: 221.Attorney Docket No. 01245-0082-00PCT DKTHTCPPCPAPEAEGAPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWY VDGVEVHNAI<TI<PREEQYNSTYRVVSVLTVLHQDWLNGI<EYI<CI<VSNI<ALPAPIEI< TISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYK TTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG(SEQ ID NO:221)

[0440] In some embodiments, the Fc region is a variant Fc region that comprises one or more of the amino acid modifications C220S, E233P, L234V, L235A, G236del or S267K, e.g. the Fc region comprises the sequence set forth in SEQ ID NO: 134. In some embodiments, the Fc region lacks the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 71 (corresponding to K447del by EU numbering). In some embodiments, the Fc region comprises the sequence set forth in SEQ ID NO: 137.

[0441] In some embodiments, the Fc region is a variant Fc region that comprises one or more of the amino acid modifications C220S, R292C, N297G, V302C. In some embodiments, the Fc region lacks the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 71 (corresponding to K447del by EU numbering). An exemplary variant Fc region is set forth in SEQ ID NO: 135.

[0442] In some embodiments, the variant Fc region comprises one or more of the amino acid modifications C220S / E233P / L234V / L235A / G236del / S267K. In some embodiments, the Fc region lacks the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 71 (corresponding to K447del by EU numbering). An exemplary variant Fc region is set forth in SEQ ID NO: 137.

[0443] Examples of such Fc regions for inclusion in an immunomodulatory polypeptide are set forth in Table 2.Table 2: Exemplary IgGl Fc Regions, wild-type or variant (effectorless)Fc mutations (EU numbering) 356E / 358M 356D / 358L allotype allotype SEQ ID NO SEQ ID NO(wild-type) 71 81 (with C220S, K447del) C220S, R292C, N297G, V302C 82C220S, R292C, N297G, V302C, K447del 135C220S, L234A, L235E, G237A 83 75C220S, L234A, L235E, G237A, K447del 136 73Attorney Docket No. 01245-0082-00PCT L234A, L235E, G237A, K447del, with deletion of 221hingeC220S, E233P, L234V, L235A, G236del,S267K 134 C220S / E233P / L234V / L235A / G236del / S267K / K447del 137L234A, L235E, G237A, A330S, P331S 176 L234A, L235E, G237A, A330S, P331S, with deletion 175of hinge

[0444] In some embodiments, the Fc region is a variant Fc region containing any combination of the Fc mutations in Table 2. In some embodiments, the Fc region is a variant Fc region having the sequence set forth in any one of the SEQ ID NOs in Table 2.

[0445] For example, a variant Fc region may be an effectorless Fc that exhibits reduced effector activity compared to a wild-type IgGl set forth in SEQ ID NO:71 or SEQ ID NO:81. In some embodiments, the variant Fc comprises the sequence of amino acids set forth in any of SEQ ID NOS:75, 82, 83, 134, 73, 135, 136, or 137 or a sequence of amino acids that exhibits at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to any of SEQ ID NOS: 75, 82, 83, 134, 73, 135, 136, or 137. In some embodiments, the variant Fc has the sequence set forth in SEQ ID NO: 73. In embodiments, when produced and expressed from cells, the provided immunomodulatory protein (e.g. TACI-Fc fusion) is a homodimer containing two identical polypeptide chains.

[0446] In some embodiments, the immunomodulatory protein contains a first immunomodulatory Fc fusion polypeptide and a second immunomodulatory Fc fusion polypeptide in which the first and second polypeptide are different. In some embodiments, a first Fc polypeptide fusion contains an Fc region and one or more variant TACI polypeptide sequence and a second polypeptide fusion contains an Fc region and one or more TACI polypeptide sequence. In such embodiments, the Fc region can be a region that promotes or facilitates formation of heterodimers.

[0447] In some embodiments, the Fc domain of one or both of the first and second immunomodulatory Fc fusion polypeptides comprise a modification (e.g. substitution) such that the interface of the Fc molecule is modified to facilitate and / or promote heterodimerization. Methods to promote heterodimerization of Fc chains include mutagenesis of the Fc region, such as by including a set of knob-into-hole mutations or including mutations to effect electrostatic steering of the Fc to favor attractive interactions among different polypeptide chains. In some embodiments, the Fc region of the heterodimeric molecule additionally can contain one or more other Fc mutation, such as any described above. In some embodiments, the heterodimerAttorney Docket No. 01245-0082-00PCT molecule contains an Fc region with a mutation that reduces effector function. In some embodiments, such Fc regions contain mutations C220S, L234A, L235E and / or G237A by EU numbering. In some embodiments, any of the above mutations in an Fc backbone can be made in an allotype containing residues Glu (E) and Met (M) at positions 356 and 358 by EU numbering. In other embodiments, any of the above mutations in an Fc backbone can be made in an allotype containing residue Asp (D) and Leu (L) at positions 356 and 358 by EU numbering.

[0448] In addition, an Fc region can include an amino acid sequence comprising a protuberance complementary to an amino acid sequence comprising a hole, such as is described, for example, in U.S. Pat. No. 5,731,168; International Patent Pub. Nos. WO 98 / 50431 and WO 2005 / 063816; Ridgway et al. (1996) Protein Engineering, 9:617-621. Such a multimerization region can be engineered such that steric interactions not only promote stable interaction, but further promote the formation of heterodimers over homodimers from a mixture of chimeric monomers. Generally, protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g., tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are optionally created on the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine).

[0449] In some embodiments, modifications include introduction of a protuberance (knob) into a first Fc polypeptide and a cavity (hole) into a second Fc polypeptide such that the protuberance is positionable in the cavity to promote complexing of the first and second Fc-containing polypeptides. Amino acids targeted for replacement and / or modification to create protuberances or cavities in a polypeptide are typically interface amino acids that interact or contact with one or more amino acids in the interface of a second polypeptide.

[0450] In some embodiments, a first polypeptide that is modified to contain protuberance (knob) amino acids include replacement of a native or original amino acid with an amino acid that has at least one side chain which projects from the interface of the first polypeptide and is therefore positionable in a compensatory cavity (hole) in an adjacent interface of a second polypeptide. Most often, the replacement amino acid is one which has a larger side chain volume than the original amino acid residue. One of skill in the art knows how to determine and / or assess the properties of amino acid residues to identify those that are ideal replacement amino acids to create a protuberance. In some embodiments, the replacement residues for the formation of a protuberance are naturally occurring amino acid residues and include, for example, arginine (R), phenylalanine (F), tyrosine (Y), or tryptophan (W). In some examples, the original residueAttorney Docket No. 01245-0082-00PCT identified for replacement is an amino acid residue that has a small side chain such as, for example, alanine, asparagine, aspartic acid, glycine, serine, threonine, or valine.

[0451] In some embodiments, a second polypeptide that is modified to contain a cavity (hole) is one that includes replacement of a native or original amino acid with an amino acid that has at least one side chain that is recessed from the interface of the second polypeptide and thus is able to accommodate a corresponding protuberance from the interface of a first polypeptide. Most often, the replacement amino acid is one which has a smaller side chain volume than the original amino acid residue. One of skill in the art knows how to determine and / or assess the properties of amino acid residues to identify those that are ideal replacement residues for the formation of a cavity. Generally, the replacement residues for the formation of a cavity are naturally occurring amino acids and include, for example, alanine (A), serine (S), threonine (T) and valine (V). In some examples, the original amino acid identified for replacement is an amino acid that has a large side chain such as, for example, tyrosine, arginine, phenylalanine, or tryptophan.

[0452] The CH3 interface of human IgGl, for example, involves sixteen residues on each domain located on four anti -parallel P-strands which buries 1090 A2 from each surface (see e.g., Deisenhofer et al. (1981) Biochemistry, 20:2361-2370; Miller et al., (1990) J Mol. Biol., 216, 965-973; Ridgway et al., (1996) Prot. Engin., 9: 617-621; U.S. Pat. No. 5,731,168).Modifications of a CH3 domain to create protuberances or cavities are described, for example, in U.S. Pat. No. 5,731,168; International Patent Applications WO98 / 50431 and WO 2005 / 063816; and Ridgway et al., (1996) Prot. Engin., 9: 617-621. In some examples, modifications of a CH3 domain to create protuberances or cavities are typically targeted to residues located on the two central anti-parallel P-strands. The aim is to minimize the risk that the protuberances which are created can be accommodated by protruding into the surrounding solvent rather than being accommodated by a compensatory cavity in the partner CH3 domain.

[0453] In some embodiments, the heterodimeric molecule contains a T366W mutation in the CH3 domain of the “knobs chain” and T366S, L368A, Y407V mutations in the CH3 domain of the “hole chain.” In some cases, an additional interchain disulfide bridge between the CH3 domains can also be used (Merchant, A. M., et al., Nature Biotech. 16 (1998) 677-681) e.g. by introducing a Y349C mutation into the CH3 domain of the “knobs” or “hole” chain and a E356C mutation or a S354C mutation into the CH3 domain of the other chain. In some embodiments, the heterodimeric molecule contains S354C, T366W mutations in one of the two CH3 domains and Y349C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. For example, the knob Fc may contain the sequence set forth in SEQ ID NO: 89, containing S354C and T366W, and a hole Fc set forth in SEQ ID NO: 90, containing mutations Y349C, T366S,Attorney Docket No. 01245-0082-00PCT L368A and Y407V). In some embodiments, the heterodimeric molecule comprises E356C, T366W mutations in one of the two CH3 domains and Y349C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. In some embodiments, the heterodimeric molecule comprises Y349C, T366W mutations in one of the two CH3 domains and E356C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. In some embodiments, the heterodimeric molecule comprises Y349C, T366W mutations in one of the two CH3 domains and S354C, T366S, L368A, Y407V mutations in the other of the two CH3 domains. Examples of other knobs-in-holes technologies are known in the art, e.g. as described by EP 1 870459 Al.

[0454] In some embodiments, an Fc variant containing CH3 protuberance (knob) or cavity(hole) modifications can be joined to a multi-domain immunomodulatory polypeptide anywhere, but typically via its N- or C-terminus, to the N- or C-terminus of the one or more TACI polypeptide sequence (e.g. variant TACI polypeptide sequence), such as to form a fusion polypeptide. The linkage can be direct or indirect via a linker. Typically, a knob and hole molecule is generated by co-expression of a first immunomodulatory polypeptide linked to an Fc variant containing CH3 protuberance modification(s) with a second immunomodulatory polypeptide linked to an Fc variant containing CH3 cavity modification(s).

[0455] Exemplary sequences for knob and hole Fc polypeptides are set forth in SEQ ID NOs: 128, and 129, respectively. In some embodiments, the knob or hold Fc region lacks the C-terminal lysine corresponding to position 232 of the wild-type or unmodified Fc set forth in SEQ ID NO: 71 (corresponding to K447del by EU numbering). Exemplary sequences for knob and hole Fc polypeptides are set forth in SEQ ID NOs: 89 and 90, respectively.

[0456] In some embodiment, individual polypeptide of a multi-domain polypeptide or individual polypeptides of a single-domain polypeptide are linked to a multimerization domain that forms an immunomodulatory protein is a trimer, tetramer or pentamer. In some embodiments, the individual polypeptides of such a molecule are the same. In some embodiments, such a multimerization domain is a cartilage oligomeric matrix protein (COMP) assembly domain, a vasodilator-stimulated phosphoprotein (VASP) tetramerization domain or a ZymoZipper (ZZ) 12.6 domain.

[0457] In some embodiments, the multimerization domain is a portion of the cartilage oligomeric matrix protein (COMP) assembly domain (Voulgaraki et al., Immunology (2005) 115(3):337-346. In some examples, the COMP is or contains an amino acid sequence as set forth in SEQ ID NO: 146 (e.g. amino acids 29-72 of the full length COMP, Uniprot accession number P49747) or a sequence that has about 85%, 85%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 146.Attorney Docket No. 01245-0082-00PCT

[0458] In some embodiments, the multimerization domain is a vasodilator-stimulated phosphoprotein (VASP) tetramerization domain (Bachmann et al., J Biol Chem (1999) 274(33):23549-23557). In some embodiments, the VASP is or contains an amino acid sequence as set forth in SEQ ID NO: 147 (e.g. amino acids 343-375 of the full length VASP; Uniprot accession number P50552) or a sequence that has about 85%, 85%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to SEQ ID NO: 147.

[0459] In some embodiments, a TACI polypeptide sequence (e.g. variant TACI polypeptide sequence) is joined to the multimerization domain (e.g. Fc region) via a linker, such as a peptide linker. In some embodiments, a peptide linker can be a single amino acid residue or greater in length. In some embodiments, the peptide linker has at least one amino acid residue but is no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residues in length.

[0460] In some embodiments, the linker is (in one-letter amino acid code): GGGGS (“4GS”; SEQ ID NO: 77) or multimers of the 4GS linker, such as repeats of 2, 3, 4, or 54GS linkers. In some embodiments, the peptide linker is the peptide linker is (GGGGS)2 (SEQ ID NO: 78), (GGGGS)3(SEQ ID NO: 79), (GGGGS)4(SEQ ID NO: 84) or (GGGGS)s (SEQ ID NO: 91). In some embodiments, the linker also can include a series of alanine residues alone or in addition to another peptide linker (such as a 4GS linker or multimer thereof). In some embodiments, the linker (in one-letter amino acid code) is GSGGGGS (SEQ ID NO: 74) or GGGGSSA (SEQ ID NO: 80). In some examples, the linker is a 2xGGGGS followed by three alanines (GGGGSGGGGSAAA; SEQ ID NO: 133). In some examples, the linker is set forth in SEQ ID NO: 194 or 195.

[0461] In some embodiments, the TACI polypeptide, such as the variant TACI polypeptide, is directly linked to the Fc sequence. In some embodiments, the TACI polypeptide, such as the variant TACI polypeptide, is indirectly linked to the Fc sequence, such as via a linker. In some embodiments, one or more “peptide linkers” link the TACI polypeptide (e.g. variant TACI polypeptide) and the Fc region. In some embodiments, a peptide linker can be a single amino acid residue or greater in length. In some embodiments, the peptide linker has at least one amino acid residue but is no more than 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residues in length. Exemplary linkers include any linker as described herein.3. Exemplary TACI-Fc fusion proteins

[0462] In some embodiments, the TACI-Fc fusion protein has the structure TACI polypeptide (TACI)-Linker-Fc region. In some embodiments, the immunomodulatory protein is a homodimer of two identical copies of the TACI-Fc fusion protein. For instance, interactionsAttorney Docket No. 01245-0082-00PCT between Fc regions of the two identical polypeptide fusions form covalent disulfide bonds to result in a dimeric molecule containing two TACI polypeptides (e.g. two variant TACI polypeptides).

[0463] In some embodiments, there is provided a TACI-Fc fusion protein containing in order a TACI polypeptide, e.g. any as described above, a linker and an Fc region. In some embodiments, each TACI polypeptide of the TACI Fc fusion is a truncated wild-type TACI polypeptide, such as any as described. In some embodiments, the TACI polypeptide of the TACI Fc fusion is set forth in SEQ ID NO: 13. In some embodiments, provided herein is a TACI-Fc fusion sequence that contains (1) a TACI ECD sequence that comprises the sequence set forth in SEQ ID NO: 13, and (2) an immunoglobulin Fc region. In some embodiments, provided herein is a TACI-Fc fusion sequence that contains (1) a TACI ECD sequence that consists or consists essentially of the sequence set forth in SEQ ID NO: 13, and (2) an immunoglobulin Fc region. The linker may be any as described. In some embodiments, the linker is GSGGGGS (SEQ ID NO: 74). In some embodiments, the linker is GS(G4S)2 (SEQ ID NO: 194). The Fc region may be any Fc region as described. In some embodiments, the Fc region is a wild-type IgGl Fc set forth in SEQ ID NO:81. In some embodiments, the Fc region is a variant Fc set forth in SEQ ID NO: 73.

[0464] In some embodiments, the TACI-Fc fusion protein has the sequence set forth in SEQ ID NO: 171. In some embodiments, the TACI-Fc fusion protein has the sequence set forth in SEQ ID NO: 197. In some embodiments, the TACI-Fc fusion is encoded by the sequence set forth in SEQ IDNO:208.SLSCRKEQGKFYDHLLRDCISCASICGQHPKQCAYFCENKLRSGSGGGGSEPKSSDKT HTCPPCPAPEAEGAPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAI<TI<PREEQYNSTYRVVSVLTVLHQDWLNGI<EYI<CI<VSNI<ALPAPIEI<TIS KAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 171)

[0465] In some embodiments, the TACI-Fc fusion protein has the sequence set forth in SEQ ID NO: 172.SLSCRKEQGKFYDHLLRDCISCASICGQHPKQCAYFCENKLRSGSGGGGSEPKSSDKT HTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAI<TI<PREEQYNSTYRVVSVLTVLHQDWLNGI<EYI<CI<VSNI<ALPAPIEI<TIS KAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTT PPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 172)Attorney Docket No. 01245-0082-00PCT

[0466] In some embodiments, the TACI-Fc fusion protein has the sequence set forth in SEQ ID NO: 196, and encoded the sequence set forth in SEQ ID NO:207.

[0467] In other embodiments, the formulations provided herein can contain TACI-Fc immunomodulators that contain a wild-type TACI polypeptide portion of the ECD such as, for example, atacicept or telitacicept. In some embodiments, the formulations provided herein can contain a TACI-Fc set forth in SEQ ID NO: 131; corresponding to the TACI ECD portion in telitacicept, or a TACI-Fc set forth in SEQ ID NO: 130; corresponding to the TACI ECD portion in atacicept, SEQ ID NO: 132.

[0468] In some embodiments, the TACI-Fc fusion is a variant TACI-Fc fusion containing or consisting of any of the above-described variant TACI polypeptides and an immunoglobulin Fc region.

[0469] In some embodiments, provided herein is a variant TACI-Fc fusion sequence that contains (1) a TACI ECD sequence containing a CRD1 and a CRD2, for example a TACI sequence that contains the sequence set forth in any one of SEQ ID NOS: 2-12, 21, 22, 101-120, and (2) an immunoglobulin Fc region. In some embodiments, provided herein is a variant TACI-Fc fusion sequence that contains (1) a TACI ECD sequence containing a CRD1 and a CRD2, for example a TACI sequence that consist or consists essentially of the sequence set forth in any one of SEQ ID NOS: 2-12, 21, 22, 101-120, and (2) an immunoglobulin Fc region.

[0470] In some embodiments, provided herein is a variant TACI-Fc fusion sequence that contains (1) a TACI ECD sequence containing the CRD2 but lacking the CRD1 domain, for example a TACI sequence that contains the sequence set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192 and (2) an immunoglobulin Fc region. In some embodiments, provided herein is a variant TACI-Fc fusion sequence that contains (1) a TACI ECD sequence containing the CRD2 domain but lacking the CRD1 domain, for example a TACI sequence that consists or consists essentially of the sequence set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100, 177-192 and (2) an immunoglobulin Fc region.

[0471] In some embodiments, the TACI polypeptide is a variant TACI polypeptide. In some embodiments, there is provided a variant TACI-Fc fusion protein containing in order a variant TACI polypeptide, e.g. any as described above, a linker and an Fc region. In some embodiments, the TACI polypeptide of the TACI Fc fusion is a variant TACI polypeptide, such as any as described. In some embodiments, the variant TACI of the variant TACI Fc fusion is set forth in any one of SEQ ID NOS: 2-12, 21, 22, or 101-120. In some embodiments, the variant TACI of the variant TACI Fc fusion is set forth in any one of SEQ ID NOS: 14-20, 23-35, 92-100 or 177-192. In some embodiments, the linker is GSGGGGS (SEQ ID NO: 74). In some embodiments, the linker is GS(G4S)2 (SEQ ID NO: 194). In some embodiments, the Fc regionAttorney Docket No. 01245-0082-00PCT is a wild-type IgGl Fc set forth in SEQ ID N0:81. In some embodiments, the Fc region is a variant Fc set forth in SEQ ID NO: 73.

[0472] In some embodiments, the TACI-Fc fusion protein has the sequence of amino acids set forth in any one of SEQ ID NOS: 167-170, 200, or 222-237.

[0473] In some embodiments, the TACI-Fc fusion protein has the sequence set forth in SEQ ID NO: 167.SLSCRKEQGEYYDHLLRDCISCASICGQHPKQCADFCENKLRSGSGGGGSEPKSSD KTHTCPPCPAPEAEGAPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNW YVDGVEVHNAI<TI<PREEQYNSTYRVVSVLTVLHQDWLNGI<EYI<CI<VSNI<ALPA PIEKTISKAKGQPREPQVYTLPPSRD...

Claims

1. Attorney Docket No. 01245-0082-00PCT WHAT IS CLAIMED:

1. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 50 mM to about 200 mM of a tonicifying agent, wherein the tonicifying agent comprises arginine;b. an acetate buffer; andc. at or about 0.002% to about 1.0% (w / v) of a non-ionic surfactant; wherein the formulation comprises:a TACI-Fc fusion protein concentration of at or about 140 mg / mL to about 200 mg / mL; anda formulation pH of at or about 4.4 to about 5.1.

2. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 1% to about 4% (w / v) proline;b. an acetate buffer; andc. at or about 0.002% to about 1.0% (w / v) of a non-ionic surfactant;a TACI-Fc fusion protein concentration of at or about 140 mg / mL to about 200 mg / mL; anda formulation pH of at or about 4.7 to about 5.7.3 A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 1% to about 4% (w / v) proline;b. an acetate buffer;c. at or about 0.002% to about 1.0% (w / v) of a non-ionic surfactant; and d. a salt; whereina TACI-Fc fusion protein concentration of at or about 140 mg / mL to about 200 mg / mL; anda formulation pH of at or about 4.4 to about 5.1.

4. A formulation comprising a TACI-Fc fusion protein, comprising:a. water and a buffering agent that provides a formulation pH of at or about 4.3 to about 5.5;b. a tonicifying agent having a positive charge at the formulation pH; c. a non-ionic surfactant; andAttorney Docket No. 01245-0082-00PCT d. a TACI-Fc fusion protein at a concentration of at or about 100 mg / mL to about 200 mg / mL.

5. The formulation of claims 1 or 4, wherein the tonicifying agent is present in the formulation at a concentration of at or about 50 mM to about 200 mM, 70 mM to about 190 mM; at or about 135 mM to about 165 mM; at or about 145 M to about 150 mM; at or about 140 mM, at or about 145 mM, at or about 150 mM, or at or about 155 mM.

6. The formulation of any one of claims 1-5 having a tonicity of an isotonic tonicity, of at or about 250 to about 350 mOsm / Kg, or of at or about 250 mOsm / Kg to about 600 mOsm / Kg.

7. The formulation of any one of claims 1-6, comprising at or about 40 mM to about 150 mM sodium chloride.

8. The formulation of any one of claims 1 and 3-7, wherein the formulation pH is at or about 4.5 to about 5.0; at or about 4.5 to about 4.8; at or about 4.6 at or about 4.7, or at or about 4.8.

9. The formulation of any one of claims 1-8, wherein TACI-Fc fusion protein concentration is at or about 150 mg / mL, at or about 160 mg / mL, at or about 170 mg / mL, at or about 175 mg / mL, at or about 180 mg / mL, at or about 190 mg / mL, or at or about 200 mg / mL.

10. The formulation of any one of claims 1-9, comprising from at or about 1 mM to about 30 mM, from about 3mM to about 15 mM, from at or about 4 mM to about 20 mM, from at or about 5 mM to about 10 mM, from at or about 8 mM to about 25 mM, from at or about 10 mM to about 20 mM, from at or about 10 mM to about 30 mM, from at or about 7 mM to about 25 mM acetate, or from at or about 15 mM to about 25 mM acetate as a component of the acetate buffer.

11. The formulation of any one of claims 1-10, wherein the non-ionic surfactant is a polysorbate (polysorbate 80), or is a pol oxamer poly ether (pol oxamer 188).Attorney Docket No. 01245-0082-00PCT 12. The formulation of any one of claims 1-11, comprising at or about 0.002% to about 0.2% (w / v); at or about 0.01% to about 0.04% (w / v); or at or about 0.02% (w / v) of the non-ionic surfactant, wherein the non-ionic surfactant is polysorbate 80.

13. The formulation of any one of claims 1-11, comprising 0.01% to about 1.0% (w / v); at or about 0.05% to about 0.2% (w / v); or at or about 0.1% (w / v) of the non-ionic surfactant, wherein the non-ionic surfactant is poloxamer 188.

14. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 135 mM to about 165 mM arginine;b. an acetate buffer; andc. at or about 0.05% to about 0.2% (w / v) poloxamer 188 (P188); wherein the TACI-Fc fusion protein is at a concentration of at or about 160 mg / mL to about 190 mg / mL; andthe formulation has a formulation pH of at or about 4.6 to about 4.8.

15. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 140 mM to about 150 mM arginine;b. an acetate buffer; andc. at or about 0.1% (w / v) poloxamer 188 (P188); whereinthe TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 4.7.

16. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 140 mM to about 150 mM arginine;b. an acetate buffer; andc. at or about 0.01% to about 0.04% (w / v) polysorbate 80 (PS80); wherein the TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 4.7.

17. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 3.0% (w / v) proline;b. an acetate buffer;c. at or about 0.05% (w / v) to about 0.2% (w / v) poloxamer 188; and d. at or about 50 mM sodium chloride; whereinAttorney Docket No. 01245-0082-00PCT the TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 4.7.

18. A formulation comprising a TACI-Fc fusion protein, comprising:a. at or about 3.0% (w / v) proline;b. an acetate buffer; andc. at or about 0.01% to about 0.04% (w / v) polysorbate 80 (PS80); wherein the TACI-Fc fusion protein is at a concentration of at or about 175 mg / mL; and the formulation has a formulation pH of at or about 5.2.

19. The formulation of any one of claims 1, 2, 4-11, 13-15 and 17, wherein the formulation does not comprise a polysorbate surfactant.

20. The formulation of any one of claims 1-19, wherein the TACI-Fc fusion protein comprises (i) a TACI polypeptide sequence comprising the amino acid sequence of SEQ ID NO: 26; and (ii) an immunoglobulin Fc region.

21. The formulation of claim 20, wherein the immunoglobulin Fc region comprises the amino acid sequence of any one of SEQ ID NOS: 73, 75, 83, 136, 175, 176, or 221.

22. The formulation of any one of claims 1-19, wherein the TACI-Fc fusion protein comprises the amino acid sequence of SEQ ID NO: 168.

23. The formulation of any one of claims 1-19, wherein the TACI-Fc fusion protein comprises the amino acid sequence of SEQ ID NO: 167.

24. The formulation of any one of claims 1-23, wherein the TACI-Fc fusion protein is a homodimer comprising two identical copies of the TACI-Fc fusion protein.

25. The formulation of any one of claims 1-19 wherein the TACI-Fc fusion protein is a homodimer comprising two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 168 linked by a covalent disulfide bond.Attorney Docket No. 01245-0082-00PCT 26. The formulation of any one of claims 1-19 wherein the TACI-Fc fusion protein is a homodimer comprising two identical copies of the TACI-Fc fusion protein set forth in SEQ ID NO: 167 linked by a covalent disulfide bond.

27. The formulation of any one of claims 1-26, wherein the TACI-Fc fusion protein comprises a variant TACI polypeptide, and / or the TACI-Fc fusion protein has an isoelectric point (pl) of at or about 7.0 to about 7.8, at or about 7.0 to about 7.7, at or about 7.0 to about 7.6, at or about 7.0 to about 7.5, at or about 7.0 to about 7.3, at or about 7.1 to about 7.5, at or about 7.1 to about 7.3, or about 7.2.

28. The formulation of any one of claims 1-27, that is a liquid formulation that has not been lyophilized and is not lyophilized prior to administration to a subject.

29. The formulation of any one of claims 1-28, wherein, after storage for 12 months in liquid form at a storage temperature of at or about 2°C to about 8°C, optionally at or about 5°C, and as measured by size exclusion chromatography (SEC) and as expressed in terms of area% under a curve that includes the TACI-Fc fusion protein in a form of a homodimer comprising two identical copies of the TACI-Fc fusion protein linked by a covalent disulfide bond as a main species, wherein:- the main species is at least 95%, at least 98%, or at least 99% of all observed species under the curve;- less than 5%, less than 2%, or less than 1% of species under the curve have a size greater than a size of the main species;- less than 5%, less than 2%, or less than 1% of species under the curve have a size less than a size of the main species;- the loss of the main species is less than 1%;- the increase in species under the curve having a size greater than a size of the main species is less than 1%; and / or- the increase in species under the curve having a size less than a size of the main species is less than 1%.

30. The formulation of any one of claims 1-29, wherein the formulation is a liquid formulation having a viscosity of at or about 3 cP to about 15 cP at about 25°C as assessed using a rheometer or a cone and plate viscometer.Attorney Docket No. 01245-0082-00PCT 31. The formulation of any one of claims 1-30, wherein the formulation is a liquid formulation comprising less than about 6,000 parti cles / mL having a particle size diameter of > 10 pm; and / or comprising less than about 600 parti cles / mL having a particle size diameter of > 25 pm, after storage for 12 months in liquid form at a storage temperature of at or about 2°C to about 8°C, optionally at or about 5°C.

32. An article of manufacture comprising the formulation of any one of claims 1-31 in a container, for example in a vial or a syringe barrel.

33. A kit comprising the formulation of any one of claims 1-31 or the article of manufacture of claim 32, and instructions for use.

34. A method of manufacturing the formulation of any one of claims 1-31, the method comprising combining the TACI-Fc fusion protein and the components (a), (b), and (c).

35. A method for reducing degradation and / or aggregation of a TACI-Fc fusion protein homodimer in a liquid pharmaceutical formulation comprising a TACI-Fc fusion protein at a concentration of at least 160 mg / mL, comprising combining the TACI-Fc fusion protein and the components (a), (b), and (c) of any one of the formulations of claims 1-31.

36. A method of reducing an immune response in a subject, comprising administering the formulation of any one of claims 1-31 to a subject in need thereof.

37. The formulation of any one of claims 1-31 for use in reducing an immune response in a subject.

38. Use of formulation of any one of claims 1-31 in the manufacture of a medicament for reducing an immune response in a subject.

39. The method of claim 36, the formulation for use of claim 37, or the use of claim 38, wherein the immune response is a B cell immune response, wherein reducing the immune response reduces or inhibits B cell maturation, differentiation and / or proliferation; and / or wherein reducing the immune response reduces circulating levels of APRIL, BAFF or an APRIL / BAFF heterotrimer in the subject.Attorney Docket No. 01245-0082-00PCT 40. The method of claim 36 or 39, the formulation for use of claim 37 or 39, or the use of claim 38 or 39, wherein reducing the immune response treats a disease, disorder or condition in the subject.

41. A method of treating a disease, disorder or condition in a subject, comprising administering a formulation of any one of claims 1-31 to a subject in need thereof.

42. The formulation of any one of claims 1-31 for use in treating a disease, disorder or condition in a subject.

43. Use of the formulation of any one of claims 1-31 in the manufacture of a medicament for treating a disease, disorder or condition in a subject.

44. The method of claim 40 or 41, the formulation for use of claim 40 or 42, or the use of claim 40 or 43, wherein the disease, disorder or condition is an autoimmune disease or an inflammatory condition.

45. The method of claim 40 or 41, the formulation for use of claim 40 or 42, or the use of claim 40 or 43, wherein the disease, disorder or condition is a B cell cancer, an antibody-mediated pathology, a renal disease, a graft rejection, graft versus host disease, or a viral infection.

46. The method of claim 40 or 41, the formulation for use of claim 40 or 42, or the use of claim 40 or 43, wherein the disease, disorder or condition is selected from the group consisting of systemic lupus erythematosus (SLE), lupus nephritis, cutaneous lupus erythematosus, Sjogren’s syndrome, scleroderma (systemic sclerosis), multiple sclerosis, diabetes (e.g. Type I diabetes), polymyositis, primary biliary cirrhosis, IgG4-related disease, IgA nephropathy, IgA vasculitis, ANCA vasculitis (microscopic polyangiitis, granulomatosis with polyangiitis [Wegener’s granulomatosis], eosinophilic granulomatosis with polyangiitis [Churg-Strauss]) cryoglobulinemia, cold agglutinin or warm agglutinin disease, immune thrombocytopenic purpura, optic neuritis, amyloidosis, antiphospholipid antibody syndrome (APS), autoimmune polyglandular syndrome type II (APS II), autoimmune thyroid disease (AITD), Graves’ disease, autoimmune adrenalitis, pemphigus vulgaris, bullous pemphigoid, myasthenia gravis, graft versus host disease (GVHD), transplantation, rheumatoid arthritis, acute lupus nephritis, amyotrophic lateral sclerosis, neuromyelitis optica, transverse myelitis,Attorney Docket No. 01245-0082-00PCT Rasmussen’s encephalitis, CNS autoimmunity, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, neurocystercercosis, sarcoidosis, antiphospholipid antibody syndrome, IgG4-related disease, Hashimoto’s thyroiditis, immune thrombocytopenia, Addison’s Disease, and dermatomyositis.

47. The method of claim 40 or 41, the formulation for use of claim 40 or 42, or the use of claim 40 or 43, wherein the disease or disorder is autoantibody-associated glomerular disease.

48. The method, the formulation for use, or the use of claim 47, wherein the autoantibody-associated glomerular disease is immunoglobulin (Ig) A nephropathy (IgAN), lupus nephritis (LN), primary membranous nephropathy (pMN), or renal anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

49. The method of claim 40 or 41, the formulation for use of claim 40 or 42, or the use of claim 40 or 43, wherein the disease, disorder or condition is immune thrombocytopenia, autoimmune hemolytic anemia, or cold agglutinin disease.

50. The method of claim 40 or 41, the formulation for use of claim 40 or 42, or the use of claim 40 or 43, wherein the disease, disorder or condition is a B cell cancer, wherein the cancer is myeloma.

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