Methods of treating membranous nephropathy with TACI-Fc fusion proteins

Abstract

The invention relates to a medicine for treating membranous nephropathy by using TACI-Fc fusion protein, a dosage scheme, an administration interval and an administration mode. A result shows that the TACI-Fc fusion protein provided by the invention shows a relatively good clinical curative effect and good safety in a process of treating a patient with membranous nephropathy.

Description

Method for treating membranous nephropathy using TACI-Fc fusion protein Technical Field

[0001] The present invention relates to a TACI-Fc fusion protein drug for treating membranous nephropathy, a dosage regimen, a dosing interval and an administration method. Background Art

[0002] Membranous nephropathy (MN) is an antibody-mediated glomerular disease characterized by the formation of immunoprecipitates containing antigens, IgG, and complement components beneath the epithelial cells in the glomerular vascular loops. Sublethal damage to the epithelial cells leads to cellular simplification and destruction of the glomerular filtration barrier, resulting in proteinuria and other manifestations of nephrotic syndrome.

[0003] Clinically, membranous nephropathy can be divided into primary membranous nephropathy and secondary membranous nephropathy according to the cause. Most membranous nephropathy is primary membranous nephropathy, also called idiopathic membranous nephropathy, which is an organ-specific autoimmune disease that occurs without any definite cause or initiating event. About 20-30% of membranous nephropathy is secondary membranous nephropathy, and common causes are autoimmune diseases (such as lupus), viruses (hepatitis B, hepatitis C, syphilis), tumors, certain drugs (such as painkillers), toxins (such as exposure to heavy metals such as lead and mercury), etc. Membranous nephropathy is one of the most common causes of nephrotic syndrome in non-diabetic adults, accounting for up to 1 / 3 of the nephrotic syndrome biopsy results. Its main clinical symptoms are edema, proteinuria, hypoalbuminemia and hyperlipidemia, etc., which mainly affect the function of the glomerular basement membrane and increase the risk of thrombosis, infection, cardiovascular disease, etc.

[0004] Currently, the global incidence of MN is approximately 1 case per 100,000 people per year. Whether the incidence varies by region or ethnicity is unclear, but it is known that MN affects patients of all ages and races. In the United States, the incidence of MN is approximately 12 cases per million people per year, with an average age of onset between 50 and 60 years. In China, the incidence of MN has been steadily increasing over the past 20 years, and other studies suggest that the high incidence may be related to increasing levels of air pollution. According to statistics, among patients with MN who remain untreated for a long time, nearly 60% experience renal impairment, and 30-40% will eventually progress to end-stage renal disease within 10 years. Even with immunosuppressant therapy, 20-40% of patients will experience persistent heavy proteinuria and progress to end-stage renal disease within 10 years, requiring renal replacement therapy or transplantation.

[0005] The treatment of membranous nephropathy depends on its type and cause. Currently, the treatment of membranous nephropathy mainly includes the following treatment methods: ① Conventional treatment: If the 24-hour urine protein quantity of membranous nephropathy is less than 3.5g; or between 3.5g-8g, and the renal function is normal and there is no high-risk phenomenon, pril drugs and sartans are usually used to reduce urine protein, and supportive treatment such as diuresis, antihypertensive, and anticoagulant treatment is given; ② Hormone combined with immunosuppressant: If the 24-hour urine protein quantity of membranous nephropathy exceeds 3.5g and is accompanied by renal impairment, or the urine protein exceeds 8g, a combination of hormones + immunosuppressants is used for treatment; ③ Monoclonal antibodies: such as rituximab.

[0006] Table 1 Recommendations for treatment of membranous nephropathy in the 2021 KDIGO guidelines

[0007] The 2021 KDIGO guidelines recommend five treatment options for membranous nephropathy (see Table 1), namely, cyclical or continuous use of cyclophosphamide, rituximab, tacrolimus, and cyclosporine. Among them: ① The cyclical or continuous use of cyclophosphamide must be combined with hormone drugs (such as prednisone), and hormones have large side effects, and cyclophosphamide also has adverse reactions such as reproductive toxicity, bone marrow suppression, infection, and hemorrhagic cystitis. In addition, from the application situation, nearly half of the patients still cannot get relief after treatment with hormone + cyclophosphamide regimen, and once the patients who get relief stop taking the drug, they are likely to cause recurrence of the disease. ② Tacrolimus and cyclosporine are calcineurin inhibitors (CNIs), which belong to a large class of immunosuppressive drugs. For patients who are unwilling to accept glucocorticoids + cyclophosphamide or have treatment contraindications, CNIs can be used for treatment. Among them, the advantages of cyclosporine treatment are rapid onset of action, superior efficacy to cyclophosphamide, and fewer and milder adverse reactions than cyclophosphamide. However, the disadvantages are that the overall remission rate is not higher than that of the cyclophosphamide regimen and the short-term relapse rate is significantly higher than that of cyclophosphamide. Tacrolimus has a 10- to 100-fold higher immunosuppressive potency than cyclosporine, but its disadvantages are similar to those of cyclosporine, with a high relapse rate. In addition, tacrolimus has more prominent adverse reactions, including impaired glucose tolerance and new-onset diabetes. Currently, rituximab alone or in combination with a calcineurin inhibitor is recommended for the initial treatment of primary MN at intermediate, high, or very high risk. It has a remission rate of 67% for MN and is suitable for patients with MN who are either positive or negative for anti-PLA2R antibodies. However, rituximab is expensive, not widely available to patients, and has severe infusion reactions. Various studies have reported that the incidence of rituximab-related infusion reactions is 26% to 85%. In patients with hematological malignancies, rituximab has also been reported to cause rare adverse events such as hepatitis B virus reactivation and severe skin reactions (such as toxic epidermal necrolysis and Stevens-Johnson syndrome) (Reference 1: Alsharhan L, Beck LH Jr. Membranous Nephropathy: Core Curriculum 2021. Am J Kidney Dis. 2021 Mar; 77(3): 440-453.). In general, the clinical course of membranous nephropathy is often indolent and existing treatments are toxic. Existing treatment options have certain limitations and risks, and the treatment effects are not satisfactory. However, from a clinical application perspective, if hormone combined with immunosuppressant treatment is ineffective, monoclonal antibodies (such as rituximab) are usually used for treatment. Therefore, the development of new biological drugs (such as monoclonal antibodies) has become an urgent need for the current treatment of membranous nephropathy.

[0008] Table 2 Biologic drugs approved / in phase III clinical trials for the treatment of membranous nephropathy

[0009] As of September 22, 2022, only two biological drugs for membranous nephropathy have been approved for marketing worldwide: rituximab and obinutuzumab. Two other drugs are in Phase III clinical trials (see Table 2). Among these drugs, although rituximab was included in the recommended treatment options for membranous nephropathy in the KDIGO guidelines in 2021, it still faces problems such as low remission rate, high infusion reactions, more serious adverse reactions, and high prices. As for obinutuzumab, which also targets CD20, although it can achieve certain therapeutic effects in patients with membranous nephropathy who have failed treatment, the relevant treatment effect is only partial relief, not complete relief, because it cannot completely eliminate antibodies and immune complexes, the basement membrane of the kidney is still damaged, and some urine protein will still leak out. In addition, since obinutuzumab has stronger cytotoxicity and a stronger ability to consume B cells than rituximab, its adverse reactions may face greater challenges (Reference 2: Hudson, R., Rawlings, C., Mon, SY et al. Treatment resistant M-type phospholipase A2 receptor associated membranous nephropathy responds to obinutuzumab: a report of two cases. BMC Nephrol 23, 134 (2022).). Therefore, there is a huge unmet clinical need in the treatment of membranous nephropathy both in China and globally.

[0010] Summary of the Invention

[0011] The present invention surprisingly discovered that the TACI-Fc fusion protein produced a significant therapeutic effect in treating patients with membranous nephropathy.

[0012] Specifically, the present invention provides a method for treating membranous nephropathy, comprising administering a therapeutically effective amount of TACI-Fc fusion protein to a patient with the membranous nephropathy.

[0013] Specifically, the present invention also provides a method for treating a patient with membranous nephropathy who has received a membranous nephropathy treatment regimen, the method comprising (1) determining whether the patient has received a membranous nephropathy treatment regimen, and (2) if the patient has previously received membranous nephropathy treatment, administering an effective amount of TACI-Fc fusion protein to the patient with the membranous nephropathy.

[0014] Specifically, the present invention also provides a use of a TACI-Fc fusion protein in preparing a drug for treating membranous nephropathy.

[0015] Furthermore, the TACI-Fc fusion protein described in any one of the above items comprises: (i) the extracellular region of TACI or a fragment thereof that binds to Blys and / or APRIL; and (ii) a human immunoglobulin constant region fragment.

[0016] Preferably, the TACI extracellular region or a fragment thereof comprises the amino acid sequence shown in SEQ ID NO: 1.

[0017] Preferably, the human immunoglobulin is IgG1.

[0018] Furthermore, the human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 2 or comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 2.

[0019] Furthermore, the human immunoglobulin constant region fragment comprises amino acid modifications at one or more positions corresponding to positions 3, 8, 14, 15, 17, 110, 111 or 173 of SEQ ID NO: 2.

[0020] Furthermore, the modification is amino acid substitution, deletion or insertion.

[0021] Furthermore, the substitution is selected from the following group: P3T, L8P, L14A, L15E, G17A, A110S, P111S and A173T.

[0022] Preferably, the human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 3.

[0023] Preferably, the TACI-Fc fusion protein has the amino acid sequence shown in SEQ ID NO:4.

[0024] Preferably, the TACI-Fc fusion protein is Telitacicept.

[0025] Furthermore, the single dose of the TACI-Fc fusion protein is about 0.1 to 10 mg / kg, further including 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2 .8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.6, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.7, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8. 4, 8.8, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.9, 9.6, 9.7, 9.8, 9.9, 10mg / kg.

[0026] Furthermore, the single administration dose of the TACI-Fc fusion protein is 160-240 mg, more preferably 160 mg, 170 mg, 180 mg, 190 mg, 200 mg, 210 mg, 220 mg, 230 mg, or 240 mg.

[0027] Furthermore, the fusion protein content was determined by UV-visible spectrophotometry, where the absorbance of the tetasip sample at 280 nm was measured, based on the maximum UV absorption of the protein at that wavelength. After correcting the absorbance at 320 nm, the absorbance at 280 nm was proportional to the protein concentration. The protein concentration was calculated according to the Lambert-Beer law to determine the protein content. The protein content calculation formula is as follows:

[0028] Where, ε is the extinction coefficient of tadalafil, unit is (mg / ml) -1 cm -1 ;

[0029] A 280 is the average absorbance of the sample solution at 280 nm;

[0030] A 280 (Correction) is the average value of the corrected absorbance of the sample solution at 280 nm.

[0031] Furthermore, the TACI-Fc fusion protein is used 2-4 times at intervals of one month, that is, the administration frequency of the TACI-Fc fusion protein is 2 times per month, 3 times per month, or 4 times per month.

[0032] Furthermore, the TACI-Fc fusion protein is administered once a week.

[0033] Further preferably, the treatment lasts for about 2-50 weeks. Further preferably, the treatment lasts for 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 ​​weeks, 49 weeks, 50 weeks.

[0034] More preferably, the TACI-Fc fusion protein is administered subcutaneously, intramuscularly, or intravenously, preferably into the thigh, abdomen, or upper arm. In some specific embodiments, the TACI-Fc fusion protein is administered subcutaneously, intramuscularly, or intravenously.

[0035] Further preferably, the injection site of the TACI-Fc fusion protein is the same or different each time. In some specific embodiments, the injection site of the TACI-Fc fusion protein is the same each time; in other specific embodiments, the injection site of the TACI-Fc fusion protein is different each time.

[0036] Furthermore, the membranous nephropathy is idiopathic membranous nephropathy or secondary membranous nephropathy.

[0037] Furthermore, the membranous nephropathy is manifested as PLA2R positive or PLA2R negative.

[0038] Furthermore, the patient is an adult patient or a pediatric patient.

[0039] Furthermore, the patient has previously received a treatment regimen for membranous nephropathy.

[0040] Furthermore, the membranous nephropathy treatment regimen includes: conventional membranous nephropathy treatment, hormone combined with immunosuppressant treatment regimen, and monoclonal antibody drug treatment regimen.

[0041] Furthermore, the membranous nephropathy treatment regimen comprises: periodic administration of cyclophosphamide combined with hormone drugs to the patient, or continuous administration of cyclophosphamide combined with hormone drugs to the patient, or administration of tacrolimus to the patient, or administration of cyclosporine to the patient, or administration of rituximab to the patient, or administration of obinutuzumab to the patient, or administration of MIL62 to the patient, or administration of fezinomab to the patient.

[0042] The TACI-Fc fusion protein provided by the present invention shows unexpected clinical efficacy and good safety in the treatment of membranous nephropathy patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 shows the albumin changes during the treatment of the subjects in Example 1;

[0044] FIG2 is a diachronic analysis of the rate of change of immunoglobulin IgG levels compared to baseline during treatment in the subjects of Example 1;

[0045] FIG3 is a diachronic analysis of the rate of change of immunoglobulin IgM levels compared to baseline during treatment of the subjects in Example 1;

[0046] FIG4 is a diachronic analysis of the rate of change of immunoglobulin IgA levels compared to the baseline during treatment of the subjects in Example 1. DETAILED DESCRIPTION

[0047] Unless otherwise defined, all technical terms used herein have the same meanings as understood by those of ordinary skill in the art. For definitions and terms in this field, professionals can refer to Current Protocols in Molecular Biology (Ausubel).

[0048] The three-letter and one-letter codes for amino acids used in the present invention are as described in J. biol. chem, 243, p3558 (1968).

[0049] The term "TACI" as used herein stands for transmembrane activator and CAML interactor, a member of the tumor necrosis factor receptor superfamily. The term "BLys" as used herein refers to B lymphocyte stimulator, a member of the TNF ligand superfamily that exists in both membrane-bound and soluble forms. It is specifically expressed on the surface of bone marrow cells and selectively stimulates B lymphocyte proliferation and immunoglobulin production. The term "APRIL" (a proliferation-inducing ligand) as used herein refers to a tumor necrosis factor (TNF) analog that stimulates the proliferation of naive B and T cells in the body, promoting B cell accumulation and increasing splenic levels. APRIL specifically binds to TACI and BCMA, preventing APRIL from binding to B cells and inhibiting APRIL-stimulated naive B cell proliferation. Furthermore, APRIL competes with BLys for binding to receptors (BCMA and TACI).

[0050] The term "TACI-Fc fusion protein" involved in the present invention refers to a transmembrane activator, calcium regulator and cyclophilin ligand interactor (TACI)-immunoglobulin fusion protein (i.e., TACI-Fc fusion protein). The TACI-immunoglobulin fusion protein provided by the present invention includes: (i) the TACI extracellular region or a fragment thereof that binds to Blys and / or APRIL; and (ii) a human immunoglobulin constant region fragment.

[0051] The term "TACI extracellular region or a fragment thereof that binds to Blys and / or APRIL" can be specifically referred to the extracellular domain of TACI disclosed in U.S. Patent Nos. 5,969,102, 6,316,222 and 6,500,428 and U.S. patent applications 09 / 569,245 and 09 / 627,206 (the contents of which are incorporated herein by reference), as well as specific fragments of the TACI extracellular domain that can interact with the TACI ligand, or the amino acid fragment of position 13-118 of the TACI extracellular domain disclosed in Chinese Patent Publication No. CN101323643A.

[0052] In the term "human immunoglobulin constant region fragment", the immunoglobulin portion is preferably IgG1, which may include a heavy chain constant region, such as a human heavy chain constant region. The preferred "human immunoglobulin constant region fragment" of the present invention is an amino acid fragment containing part of the hinge region domain, the CH2 domain, and the CH3 domain. In some more preferred embodiments, the amino acid sequence of the "human immunoglobulin constant region fragment" of the present invention is as shown in SEQ ID NO: 2, or comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 2. In some more preferred embodiments, the amino acid sequence of the "human immunoglobulin constant region fragment" is as shown in SEQ ID NO: 3.

[0053] The term "treatment" as used herein is related to a given disease or condition, including but not limited to: inhibiting the disease or condition, such as preventing the development of the disease or condition; alleviating the disease or condition, such as causing the disease or condition to disappear; or alleviating the symptoms caused by the disease or condition, such as alleviating, preventing or treating the symptoms of the disease or condition.

[0054] The term "amino acid" as used in the present invention is understood in the broadest sense and is a general term for a class of organic compounds containing amino and carboxyl groups. Preferably, the amino acids involved in the present invention are the main units that make up proteins in living organisms, including but not limited to: glycine, alanine, valine, leucine, isoleucine, methionine (methionine), proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine and histidine.

[0055] The amino acid three-letter code and single-letter code used in the present invention are as described in J. biol. chem, 243, p3558 (1968). There are many ways to number amino acid sites, such as the Kabat numbering system, the EU numbering system, the sequential numbering system, etc. In the present invention, the numbering of amino acid sites adopts the "sequential numbering" method. For example, "position 3, 8, 14, 15, 17, 110, 111 or 173 of SEQ ID NO: 2" in the present invention refers to the 3rd amino acid, the 8th amino acid of SEQ ID NO: 2, and so on; for example, "P3T" in the present invention refers to the mutation of the 3rd amino acid sequence of SEQ ID NO: 2 from the previous "P" to "T", and for example, "L8P" refers to the mutation of the 8th amino acid sequence of SEQ ID NO: 2 from the previous "L" to "P", and so on.

[0056] As an alternative embodiment, the constant region of the immunoglobulin provided by the present invention can introduce one or more amino acid changes, such as substitution (ie, mutation), addition (ie, insertion) or deletion (ie, deletion).

[0057] The term "Telitacicept" (or "Telitacicept", which can be used interchangeably in the present invention) in the present invention is a TACI-Fc fusion protein, whose INN name is Telitacicept, and its amino acid sequence is shown in SEQ ID NO: 4, or as shown in https: / / extranet.who.int / soinn / mod / page / view.php?id=137&inn_n=10932.

[0058] The TACI-Fc fusion protein of the present invention can be administered by any of a variety of routes, including but not limited to oral, intravenous, intramuscular, intraarterial, intramedullary, intraperitoneal, intrathecal, intracardiac, transdermal, transdermal, topical, subcutaneous, intranasal, enteral, sublingual, vaginal or rectal routes.

[0059] The term "membranous nephropathy" in the present invention represents a spectrum of diseases that share a common histopathological pattern, namely the presence of immunoglobulins and complement-containing immunoprecipitates in a subepithelial location.

[0060] The term "idiopathic membranous nephropathy" in the present invention refers to an organ-specific autoimmune disease that occurs without any identifiable cause or initiating event, including but not limited to PLA2R-related idiopathic membranous nephropathy, THS7A-related idiopathic membranous nephropathy, NELL-1-related idiopathic membranous nephropathy, Sema3B-related idiopathic membranous nephropathy and other related idiopathic membranous nephropathy.

[0061] The term "secondary membranous nephropathy" in the present invention refers to a glomerular disease with clear systemic diseases involving kidney disease and pathological changes into membranous nephropathy. The causes of secondary membranous nephropathy include immune diseases (such as systemic lupus erythematosus, type 1 diabetes, rheumatoid arthritis, Hashimoto's thyroiditis, Graves' disease, mixed connective tissue disease, Henoch-Schonlein purpura, primary biliary cirrhosis, enteropathic syndrome, anti-glomerular basement membrane nephritis, ANCA-associated crescentic nephritis, graft-versus-host disease, bone marrow and stem cell transplantation, etc.), infections and parasitic diseases (such as HBV, HCV, syphilis, filariasis, cysticercosis, schistosomiasis, malaria parasites, leprosy, etc.), drugs and toxins (such as gold preparations, penicillamine, non-steroidal anti-inflammatory drugs, mercury, captopril, formaldehyde, hydrocarbons) and others (such as tumors, kidney transplantation).

[0062] The term "PLA2R positive" in the present invention means that PLA2R is detected in the patient's blood, that is, PLA2R is serologically positive.

[0063] The term "PLA2R negative" in the present invention means that PLA2R cannot be detected in the patient's blood.

[0064] The term "conventional treatment of membranous nephropathy" in the present invention exemplarily refers to if the 24-hour urine protein quantity of membranous nephropathy is below 3.5g; or between 3.5g-8g, and the renal function is normal and there are no high-risk phenomena, usually pril drugs and sartans are used to reduce urine protein, and supportive treatment such as diuretics, antihypertensives, and anticoagulation are given.

[0065] The term "hormone combined with immunosuppressant treatment regimen" in the present invention exemplarily refers to the use of a combined hormone + immunosuppressant method for treatment if the 24-hour urine protein quantity of membranous nephropathy exceeds 3.5g and is accompanied by renal impairment, or the urine protein exceeds 8g, wherein the immunosuppressant includes but is not limited to tacrolimus and cyclosporine.

[0066] The term "monoclonal antibody drug treatment regimen" in the present invention refers to, for example, the treatment recommended in the 2021 KDIGO guidelines, using but not limited to rituximab, 1000 mg of rituximab intravenously twice within two weeks; rituximab 375 mg per square meter of body surface area, once a week for a total of 1 to 4 times.

[0067] The term "cyclical administration of cyclophosphamide combined with hormone drugs" in the present invention refers to the recommendation in the 2021 KDIGO guidelines: intravenous injection of 1 gram of methylprednisolone for three consecutive days in the first few days of the 1st, 3rd and 5th months; oral administration of 0.5 mg / kg of prednisone per day; and oral administration of cyclophosphamide 2.5 mg per kilogram of body weight per day in the 2nd, 4th and 6th months.

[0068] The term "continuous administration of cyclophosphamide combined with hormone drugs" in the present invention refers to the recommendation in the 2021 KDIGO guidelines: intravenous injection of 1 gram of methylprednisolone for three consecutive days on the first day of the 1st, 3rd, and 5th months; oral administration of 0.5 mg / kg of prednisone every other day for 1-6 months and then gradually reducing the dose; oral administration of cyclophosphamide, 1.5 mg per kilogram of body weight per day, for 16 months.

[0069] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.

[0070] Example 1 Clinical trial of Tetasip in the treatment of membranous nephropathy

[0071] 1. Research Methods

[0072] This prospective, single-center, open-label, single-arm clinical trial aims to evaluate the efficacy and safety of tetasip in the treatment of MN and to explore the side effects of tetasip in refractory MN. Thirty patients with MN are enrolled (12 patients have been enrolled, and an interim analysis is underway). They will receive tetasip, 160 mg, subcutaneously once weekly for 48 weeks.

[0073] 2. Patient selection

[0074] Subject inclusion criteria:

[0075] Patients diagnosed with primary membranous nephropathy by renal biopsy and also positive for PLA2R antibodies;

[0076] Age 18-70 years old;

[0077] ● Prior to enrollment, patients must have maintained a 24-hour urine protein (UTP) ≥ 3.5 g on adequate ACEI / ARB therapy for at least three months;

[0078] Stable blood pressure ≤140 / 90 mmHg

[0079] Estimated glomerular filtration rate (eGFR) ≥45 mL / min / 1.73 m 2 ;

[0080] ●Agree to maintain a stable diet and sodium intake during the study;

[0081] ●Agree and sign the informed consent form.

[0082] Subjects were excluded from the study if:

[0083] ● Unstable urine protein in the past two months, with fluctuations of >2 g / day in 24-hour urine protein;

[0084] ●Combined with chronic liver disease, or liver enzymes exceeding 3 times the upper limit of normal;

[0085] New cardiovascular or cerebrovascular disease (acute coronary syndrome, heart failure, cerebral infarction, stroke) within 3 months;

[0086] Uncontrolled severe hypertension;

[0087] Malignant tumors

[0088] ●Patients with severe infection;

[0089] ●Patients who have used tetanuscept in the past, or who are allergic to tetanuscept or have other contraindications;

[0090] ●Pregnancy or breastfeeding;

[0091] Life expectancy is less than 6 months;

[0092] ●Currently participating in other clinical studies;

[0093] ●Other circumstances that the researcher deems unsuitable for participation in this study.

[0094] 3. Endpoint indicators

[0095] (1) Primary endpoint

[0096] (2) Secondary endpoints

[0097] 5. Main results of the interim analysis

[0098] 5.1 Primary Efficacy Endpoint

[0099] The primary endpoint of this study was 24-hour urinary protein excretion at week 48. A complete response was defined as a 24-hour urinary protein level less than 0.3 g / 24 hours. A partial response was defined as a 24-hour urinary protein level between 0.3 and 3.5 g / 24 hours or a 50% reduction from baseline. At week 48 or the end of treatment, 10 subjects (83.3% of the enrolled population) achieved a decrease in urinary protein from baseline. Five subjects achieved a 24-hour urinary protein level between 0.3 and 3.5 g / 24 hours, and three subjects achieved a decrease of greater than 50% from baseline (reduction percentages from baseline of 70.86%, 77.42%, and 94.17%, respectively). Therefore, five subjects achieved a partial response in this trial, representing 42% of the total enrolled population. Table 2 details the 24-hour urinary protein levels and the percentage of decrease from baseline at baseline and at week 48 or the end of treatment.

[0100] Table 2. 24-hour urine protein content and the percentage of decrease compared with baseline

[0101] 5.2 Secondary Efficacy Endpoints

[0102] 5.2.1. Analysis of Changes in Urine Protein / Creatinine Ratio and Urine Albumin / Creatinine Ratio

[0103] In this study, the subjects' average urine protein / creatinine ratio (UPCR) and urine albumin-to-creatinine ratio (UCAR) decreased compared to baseline, and the decrease was statistically significant.

[0104] 5.2.2. Analysis of changes in estimated glomerular filtration rate (eGFR)

[0105] In this study, after the end of medication, the estimated glomerular filtration rate (eGFR) of 4 subjects increased, among which the subject with the highest increase had an eGFR of 47.9 mL / min / 1.73 m 2 Increased to 62.46 mL / min / 1.73 m 2 , an increase of 30.4%.

[0106] 5.2.3. Chronic Analysis of Serum Albumin

[0107] In this study, the average albumin level decreased during the treatment process. After the end of medication, the average serum albumin level of the enrolled subjects decreased by 0.59 g / L compared with the baseline. The temporal changes in albumin are shown in Figure 1.

[0108] 5.2.4. Immunological indicators (IgG, IgM, IgA)

[0109] 5.2.4.1. Chronic Analysis of Immunoglobulin (IgG)

[0110] Compared with the baseline, after 48 weeks of administration, the average IgG level of the enrolled subjects showed an overall downward trend, with the average IgG level decreasing by approximately 2.60 g / L (a decrease of 38.8%). The temporal change rate of the average IgG level of the enrolled subjects is shown in Figure 2.

[0111] 5.2.4.2. Chronological Analysis of Immunoglobulin (IgM)

[0112] Compared with the baseline, the average IgM level of the enrolled subjects also showed an overall downward trend. After 48 weeks of administration, the average IgM level decreased by approximately 0.708 g / L (a decrease of 70.1%). The temporal change rate of the average IgM level of the enrolled subjects is shown in Figure 3.

[0113] 5.2.4.3. Chronological Analysis of Immunoglobulin (IgA)

[0114] Compared with the baseline, the change rate of the average IgA level of the enrolled subjects also showed an overall downward trend. After 48 weeks of administration, the average IgA level decreased by approximately 0.717 g / L (a decrease of 39.7%). The temporal change rate of the average IgA level of the enrolled subjects is shown in Figure 4.

[0115] 5.3 Effectiveness Results

[0116] In this study, available data demonstrate that tetasip demonstrates sustained clinical improvement in patients with primary MN, with statistically significant decreases in mean urine protein-to-creatinine ratio (UPCR) and urine albumin-to-creatinine ratio (UCAR) compared to baseline. Tetasip also significantly reduced mean IgG, IgA, and IgM levels compared to baseline.

[0117] 5.4 Safety Results

[0118] In this study, the current results demonstrate that once-weekly administration of 160 mg of tetasip is safe in patients with primary MN. Adverse events and reactions were mild in severity (CTCAE Grade 1), with no CTCAE Grade 2, 3, 4, or 5 adverse events or reactions occurring. No adverse events or reactions led to study withdrawal or death, and no serious adverse reactions occurred. Two subjects experienced adverse events during the study, one of which experienced abdominal pain and vomiting, but this adverse event or reaction was not considered related to tetasip. The other experienced pruritus, which resolved after 2-3 days without medication.

[0119] 5.5 Conclusion

[0120] Based on the above results and analysis, in this study, current experimental data showed that the use of tetanusip in the treatment of patients with membranous nephropathy showed good clinical efficacy and safety.

[0121] The above description is merely a preferred embodiment, which is intended to be illustrative and non-limiting of the combinations of features necessary to implement the present invention. The titles provided are not intended to limit the various embodiments of the present invention. Terms such as "comprising," "including," and "including" are not intended to be limiting. In addition, unless otherwise indicated, the absence of a numeral modifier includes the plural form, and "or" and "or" mean "and / or." Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art.

[0122] All disclosures and patents mentioned in this application are incorporated herein by reference. Without departing from the scope and spirit of the present invention, multiple modifications and variants of the described method and composition of the present invention will be apparent to those skilled in the art. Although the present invention has been described by specific preferred embodiments, it should be understood that the claimed invention should not be unduly limited to these specific embodiments. In fact, those multiple variants of the described pattern that are apparent to those skilled in the relevant art are intended to be included in the scope of the appended claims.

Claims

1. A method for treating membranous nephropathy, comprising administering a therapeutically effective amount of TACI-Fc fusion protein to a patient with membranous nephropathy, wherein: The TACI-Fc fusion protein comprises: (i) the extracellular domain of TACI or a fragment thereof that binds to Blys and / or APRIL; and (ii) Human immunoglobulin constant region fragments.

2. The method according to claim 1, characterized in that The TACI extracellular region or the fragment thereof that binds to Blys and / or APRIL comprises the amino acid sequence shown in SEQ ID NO:

1.

3. The method according to claim 2, characterized in that The human immunoglobulin is IgG1 or the human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 2 or comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:

2.

4. The method according to claim 3, characterized in that The human immunoglobulin constant region fragment comprises amino acid modifications at one or more positions corresponding to positions 3, 8, 14, 15, 17, 110, 111 or 173 of SEQ ID NO:

2.

5. The method according to claim 4, characterized in that The modification is amino acid substitution, deletion or insertion.

6. The method according to claim 5, characterized in that The substitution is selected from the group consisting of P3T, L8P, L14A, L15E, G17A, A110S, P111S and A173T.

7. The method according to claim 7, characterized in that The human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO:

3.

8. The method according to claim 1, characterized in that The TACI-Fc fusion protein has the amino acid sequence shown in SEQ ID NO:

4.

9. The method according to claim 8, characterized in that The TACI-Fc fusion protein is Telitacicept.

10. The method according to claim 8 or 9, characterized in that The membranous nephropathy includes primary membranous nephropathy or secondary membranous nephropathy.

11. The method according to claim 10, characterized in that The membranous nephropathy is manifested as PLA2R positive or PLA2R negative.

12. The method according to claim 11, characterized in that The patient is an adult patient or a pediatric patient.

13. The method according to claim 12, characterized in that The patient described had previously received treatment regimens for membranous nephropathy.

14. The method according to claim 12 or 13, characterized in that The single administration dose of the TACI-Fc fusion protein is about 0.1 to 10 mg / kg.

15. The method according to claim 12 or 13, characterized in that in, The single dosage of the TACI-Fc fusion protein is 160-240 mg, more preferably 160 mg or 240 mg.

16. The method according to claim 12 or 13, characterized in that The TACI-Fc fusion protein is administered subcutaneously, intramuscularly or intravenously, or the administration site is the thigh, abdomen or upper arm.

17. The method according to claim 12 or 13, characterized in that The TACI-Fc fusion protein is administered 2-4 times at one-month intervals and / or the treatment lasts for about 2-50 weeks.

18. The method according to claim 17, characterized in that The TACI-Fc fusion protein is administered once a week.

Images