Method of treating antiphospholipid syndrome with tacifc fusion protein

Abstract

This study relates to medications, dosage regimens, dosing intervals, and administration methods that utilize effective amounts of drugs targeting Blys and / or APRIL to treat or alleviate antiphospholipid syndrome. Results showed that the provided effective amounts of drugs targeting Blys and / or APRIL demonstrated good safety and optimal therapeutic efficacy in treating or alleviating patients with antiphospholipid syndrome.

Description

Methods of treating anti-phospholipid syndrome with tacifc fusion proteins TECHNICAL FIELD

[0001] The present invention relates to a TACI-Fc fusion protein drug, dosage regimen, dosing interval and administration method for treating anti-phospholipid syndrome. BACKGROUND

[0002] Anti-phospholipid syndrome (APS) is a systemic autoimmune disease mediated by anti-phospholipid antibodies, with clinical manifestations of thrombosis and / or obstetric complications, accompanied by persistent moderate or high positivity of anti-phospholipid antibodies (aPLs) (literature 1: Knight J S, Branch D W, Ortel T L. Antiphospholipid syndrome: advances in diagnosis, pathogenesis, and management BMJ 2023; 380: e069717 doi: 10.1136 / bmj-2021-069717). Anti-phospholipid antibodies are a group of antibodies that refer to a general term for autoantibodies targeting phospholipids and / or phospholipid binding proteins. The most common anti-phospholipid antibodies in clinical practice include anti-cardiolipin antibodies (aCL), lupus anticoagulants (LAC) and anti-β2 glycoprotein I antibodies (aβ2GPI), which are three currently widely detected and referred to as diagnostic standard antibodies. In addition, there are non-diagnostic standard antibodies: anti-phosphatidylserine / thrombin complex antibodies, anti-thrombin antibodies, anti-β2-glycoprotein I domain 1 antibodies, anti-phosphatidyl ethanolamine antibodies, anti-protein S and protein C antibodies, anti-phosphatidyl inositol antibodies, anti-vimentin / heart phospholipid complex antibodies, anti-annexin A2 and A5 antibodies, and anti-phosphatidic acid antibodies, which are beneficial supplements to diagnostic standard antibodies and can assist in the diagnosis of anti-phospholipid syndrome.

[0003] APS is clinically divided into primary APS (PAPS) and secondary APS (SAPS) according to whether it is accompanied by other autoimmune diseases. Primary APS refers to systemic autoimmune diseases that occur without related autoimmune diseases. When APS is associated with another disease, APS is called secondary APS, including systemic lupus erythematosus (SLE) and other autoimmune diseases, lymphoproliferative diseases, tumors, infections (bacteria, viruses, and protozoa), inflammation, etc. In antiphospholipid syndrome, thrombosis can occur in almost any blood vessel in the body, but it most commonly occurs in blood vessels in the lower limbs. If a blood clot forms in a blood vessel in the brain, blood flow is impaired and can cause a stroke. The clinical manifestations of APS are mostly caused by organ dysfunction caused by thrombosis, embolism, and post-embolism ischemia.

[0004] APS is more common in women, with a male to female ratio of 1:9. The median age of women with the disease is 30 years old, and it is more common in young and middle-aged people. It is estimated that there is one person with antiphospholipid syndrome per 2,000 people. APS is usually diagnosed in relatively young individuals, and in a study of 1,000 patients, only 12.7% of patients were diagnosed with APS after the age of 50. It is estimated that 20% of stroke patients under the age of 50 have antiphospholipid syndrome, and 10% to 15% of patients with systemic lupus erythematosus have antiphospholipid syndrome. The epidemiology of antiphospholipid syndrome is still insufficient, and studies on patients of different ages and ethnic backgrounds are needed. The prevalence of people with persistent positive antiphospholipid antibodies in healthy individuals has not been accurately determined, and pediatric antiphospholipid syndrome is relatively rare, but may be underdiagnosed for various reasons. A study of 121 children reported that the average age of onset of antiphospholipid syndrome was 10.7 years. Non-thrombotic manifestations of antiphospholipid syndrome, such as thrombocytopenia and autoimmune hemolytic anemia, may be more common in children (Literature 2: Knight J S, Branch D W, Ortel T L. Antiphospholipid syndrome: advances in diagnosis, pathogenesis, and management BMJ 2023; 380: e069717 doi: 10.1136 / bmj-2021-069717; National Library of Medicine https: / / medlineplus.gov / genetics / condition / antiphospholipid-syndrome / #resources).

[0005] Women with antiphospholipid syndrome are at increased risk of complications during pregnancy. These complications include high blood pressure during pregnancy (pre-eclampsia), poor placental development (placental insufficiency), premature birth or miscarriage. In addition, women with antiphospholipid syndrome are at higher risk of blood clots during pregnancy than at other times in their lives. At birth, babies of mothers with antiphospholipid syndrome can be small for their gestational age and underweight. Blood clots or pregnancy complications are usually the first signs of antiphospholipid syndrome. This usually occurs in early to mid-adulthood, but can start at any age. Other signs and symptoms of antiphospholipid syndrome that affect blood cells and blood vessels include a decrease in the number of cells involved in blood clotting, called thrombocytopenia (thrombocytopenia), a lack of red blood cells due to their premature breakdown (hemolysis), and a purple skin discoloration caused by abnormalities in the tiny blood vessels of the skin. In addition, affected people can have open sores on the skin, migraines, heart disease, or intellectual disability. Many people with antiphospholipid syndrome also have other autoimmune diseases, such as systemic lupus erythematosus. Rarely, people with antiphospholipid syndrome will have blood clots in multiple blood vessels throughout the body. These clots block blood flow to affected organs, impairing their function and eventually leading to organ failure. These people are said to have catastrophic antiphospholipid syndrome (CAPS). CAPS usually affects the kidneys, lungs, brain, heart, and liver, and is fatal in more than half of those infected. Less than 1% of people with antiphospholipid syndrome develop CAPS.

[0006] The main goal of treatment for APS is to prevent blood clots and avoid pregnancy failure, and treatment methods include anticoagulation, glucocorticoids and immunosuppressive agents, and symptomatic supportive treatment. The "EULAR Treatment Guidelines for Adult Antiphospholipid Syndrome" published in 2019 clearly defines the high-risk and low-risk antiphospholipid antibody spectrum (Table 1), and publishes the management recommendations for adult antiphospholipid syndrome (Table 2), which proposes 3 general principles and 12 management opinions (Literature 3: Tektonidou M G, Andreoli L, Limper M, et al. EULAR recommendations for the management of antiphospholipid syndrome in adults [J]. Annals of the rheumatic diseases, 2019, 78(10): 1296-1304.). Table 1 Definition of high-titer antiphospholipid antibodies (aPL), low-risk and high-risk antiphospholipid antibody spectrum Table 2 Management recommendations for adult antiphospholipid syndrome published by the European League Against Rheumatism (EULAR) Note: INR: international normalized ratio, is the ratio of ISI (ISI: international sensitivity index, is the factory calibration of reagent by the manufacturer) of the patient's prothrombin time and the normal control prothrombin time, is a method that can correct the difference of thromboplastin reagent on the prothrombin time value and standardize the report. The normal value range of INR is 0.8-1.2. The World Health Organization stipulates that when oral anticoagulants are used for the treatment of deep vein thrombosis, the allowable range of INR is 2.0-3.0.

[0007] As of May 22, 2024, there are five drugs targeting antiphospholipid syndrome that have advanced to the clinical stage globally (see Table 3). Among these drugs, although rituximab is included in the EULAR published management recommendations for adult antiphospholipid syndrome, anti-CD20+ B cell depletion therapy increases the body's sensitivity to infection and may cause long-term reduction in serum antibody titers in some patients, further increasing the risk of infection. Belimumab has been shown to significantly improve thrombocytopenia in APS patients who do not respond to glucocorticoids and rituximab, and some APS patients may benefit from Blys-targeted therapy. Daratumumab can exert immune-mediated activity by modulating the immune microenvironment and may be suitable for APS patients who do not respond to anticoagulant therapy and standard immunosuppression. There is currently a clinical trial of certolizumab for pregnant APS patients (ClinicalTrials.NCT03152058), and no research results have been announced. Another study using the complement C5 inhibitor olendalizumab to treat APS non-standard manifestations in an open-label phase II trial was terminated due to low patient enrollment (clinicaltrials.NCT02128269).(Literature 4: Yun Z, Duan L, Liu X, Cai Q, Li C. An update on the biologics for the treatment of antiphospholipid syndrome. Front Immunol. 2023 May 19;14:1145145. doi: 10.3389 / fimmu.2023.1145145. PMID: 37275894; PMCID: PMC10237350.) For patients with refractory APS symptoms after standard treatment, immunosuppressants may be the best choice. However, immunosuppressive therapy also exposes a number of adverse reactions and problems in the length of treatment, which also prompts us to make more research and exploration on new immunosuppressants and new application methods. Therefore, there is a huge unmet clinical need in the field of antiphospholipid syndrome treatment both in China and globally.

[0008] Telitacicept is the first of its kind recombinant TACI-Fc fusion protein targeting B cell-related autoimmune diseases, which can target and neutralize two key cell signaling molecules BLyS and APRIL in the B cell pathway. It is an antibody-like structure fusion protein composed of truncated TACI and sequence-optimized immunoglobulin Fc with reduced ADCC and CDC effects, with excellent biological activity and safety, and has been approved for marketing in China for the treatment of systemic lupus erythematosus, rheumatoid arthritis and myasthenia gravis.

[0009] Atacicept is a recombinant fusion protein comprising the extracellular ligand-binding portion of the TACI receptor and the Fc portion of human IgG, which can bind to BLyS and APRIL. The drug is exploring indications such as IgA nephropathy (Phase III), lupus nephritis (Phase III), systemic lupus erythematosus (Phase III), rheumatoid arthritis (Phase II), etc., and is in different clinical stages.

[0010] Povetacicept is an engineered TACI domain Fc fusion protein, which is a Blys / APRIL dual antagonist, and is exploring indications such as IgA nephropathy (Phase III), immune thrombocytopenia (Phase II), cold agglutinin disease (Phase II), lupus nephritis (Phase II), autoimmune cytopenia (Phase II), systemic lupus erythematosus (Phase I), etc., and is in different research stages. SUMMARY

[0011] The present application surprisingly found that the TACI-Fc fusion protein produced a significant therapeutic effect in treating patients with antiphospholipid syndrome.

[0012] Specifically, the present application provides a method for treating antiphospholipid syndrome, which comprises administering to a patient with said antiphospholipid syndrome a therapeutically effective amount of a drug targeting Blys and / or APRIL.

[0013] Specifically, the present application also provides the use of a drug targeting Blys and / or APRIL in the preparation of a drug for treating or alleviating patients with antiphospholipid syndrome.

[0014] Specifically, the present application also provides the use of a TACI-Fc fusion protein in the preparation of a drug for treating or alleviating patients with antiphospholipid syndrome.

[0015] Specifically, the present application also provides the use of atacicept in the preparation of a drug for treating or alleviating patients with antiphospholipid syndrome.

[0016] Further, the antiphospholipid syndrome is selected from primary antiphospholipid syndrome or secondary antiphospholipid syndrome; and more further, the antiphospholipid syndrome is primary antiphospholipid syndrome.

[0017] Further, the drug targeting Blys and / or APRIL is a TACI-Fc fusion protein.

[0018] Further, the TACI-Fc fusion protein of any one of the above comprises: (i) a TACI extracellular region or a fragment thereof that binds to Blys and / or APRIL; and (ii) a fragment of a human immunoglobulin constant region. Further, the TACI-Fc fusion protein of any one of the above comprises: (i) a TACI extracellular region or a fragment thereof that binds to Blys and / or APRIL; and (ii) a fragment of a human immunoglobulin constant region.

[0019] Further, the TACI extracellular region or the fragment thereof that binds Blys and / or APRIL comprises the amino acid sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2 or SEQ ID NO: 3. SEQ ID NO: 1 SEQ ID NO: 2 SEQ ID NO: 3

[0020] Further, the TACI extracellular region or the fragment thereof that binds Blys and / or APRIL comprises the amino acid sequence set forth in SEQ ID NO: 1.

[0021] Further, the human immunoglobulin is IgGl.

[0022] Further, the human immunoglobulin constant region fragment comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 4. SEQ ID NO: 4

[0023] Further, the human immunoglobulin constant region fragment comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 4. SEQ ID NO: 4

[0024] Further, the human immunoglobulin constant region fragment comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 4. SEQ ID NO: 4

[0025] Further, the modification is a substitution, deletion, or insertion of an amino acid.

[0026] Further, the substitution comprises one or more of P3T, L8P, L14A, L15E, G17A, A110S, P111S, and / or A173T.

[0027] Further, the insertion is an insertion of 1, 2, 3, 4, 5, 6, 7, 8, or more amino acids at the N-terminus of the human immunoglobulin constant region fragment.

[0028] Still further, the insertion is an insertion of 5 amino acids at the N-terminus of the human immunoglobulin constant region fragment.

[0029] Still further, the insertion is an insertion of the 5 amino acids EPKSS at the N-terminus of the human immunoglobulin constant region fragment.

[0030] Further, the human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 5. SEQ ID NO: 5

[0031] Further, the human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 6. SEQ ID NO: 6

[0032] Further, the TACI-Fc fusion protein has an amino acid sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 7. SEQ ID NO: 7

[0033] Further, the TACI-Fc fusion protein has an amino acid sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 7. SEQ ID NO: 7

[0034] Further, the TACI-Fc fusion protein has an amino acid sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 7. SEQ ID NO: 7

[0035] Further, the TACI-Fc fusion protein has an amino acid sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 7. SEQ ID NO: 7

[0036] Further, the TACI-Fc fusion protein is telitacicept, atacicept, or povetacicept.

[0037] Further, 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, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10 mg / kg.

[0038] Further, the single dose of the TACI-Fc fusion protein is 40-300 mg, preferably 80-240 mg, more preferably 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg, 200 mg, 210 mg, 220 mg, 230 mg, or 240 mg.

[0039] Further, the detection method of the content of the above-mentioned drug protein is ultraviolet-visible spectrophotometry. According to the maximum ultraviolet absorption of the protein at 280 nm, the absorbance value of the TACI-Fc fusion protein sample at this wavelength is determined. After the absorbance at 320 nm is corrected, the absorbance value at 280 nm is proportional to the protein concentration. According to the Lambert-Beer law, the protein concentration is calculated to determine the protein content. The calculation formula of the protein content is as follows: wherein ε is the extinction coefficient value of the TACI-Fc fusion protein, the unit is (mg / ml) -1 ·cm -1 ; A 280 is the average value of the absorbance of the sample solution at 280 nm; A 280 (corrected) is the average value of the corrected absorbance of the sample solution at 280 nm.

[0040] Further, the TACI-Fc fusion protein is used 1-4 times during a one-month interval, further comprising 1 time, 2 times, 3 times, 4 times, i.e., the administration frequency of the TACI-Fc fusion protein is once a month or twice a month or three times a month or four times a month.

[0041] Further, the administration frequency of the TACI-Fc fusion protein is once a week or once every two weeks or once every three weeks or once every four weeks.

[0042] 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.

[0043] Further preferably, the administration mode of the TACI-Fc fusion protein is subcutaneous, intramuscular or intravenous administration, and the administration site is preferably the thigh, abdomen or upper arm. In some specific embodiments, the administration mode of the TACI-Fc fusion protein is subcutaneous injection, intramuscular injection or intravenous injection.

[0044] 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.

[0045] Further, the primary antiphospholipid syndrome is manifested as persistent moderate or high positivity of antiphospholipid antibodies.

[0046] Further, the antiphospholipid antibodies include but are not limited to anticardiolipin antibodies, anti-β2-glycoprotein I antibodies, lupus anticoagulants, anti-phosphatidylserine / thrombin complex antibodies, anti-thromboplastin antibodies, anti-β2-glycoprotein I domain 1 antibodies, anti-phosphatidylethanolamine antibodies, anti-protein S and protein C antibodies, anti-phosphatidylinositol antibodies, anti-vimentin / cardiolipin complex antibodies, anti-annexin A2 and A5 antibodies, anti-phosphatidic acid antibodies.

[0047] Further, the patient is an adult patient or a pediatric patient.

[0048] Further, the patient has previously received a treatment regimen for primary antiphospholipid syndrome or has not previously received a treatment regimen for primary antiphospholipid syndrome.

[0049] Further, the patient has one or more other diseases.

[0050] The present application also provides a method for treating primary antiphospholipid syndrome, which comprises administering to a patient with the primary antiphospholipid syndrome a therapeutically effective amount of a TACI-Fc fusion protein and other therapeutic drugs in combination, wherein the TACI-Fc fusion protein comprises: (i) a TACI extracellular region or a fragment thereof that binds Blys and / or APRIL; and (ii) a human immunoglobulin constant region fragment.

[0051] Further, the other therapeutic drugs include, but are not limited to, anticoagulant drugs, belimumab, rituximab, and eculizumab.

[0052] Further, the anticoagulant drugs include, but are not limited to, antiplatelet drugs, vitamin K antagonists, heparin or low molecular weight heparin, hydroxychloroquine, and statins.

[0053] Further, the antiplatelet drugs include, but are not limited to, aspirin, dipyridamole, ticlopidine, and clopidogrel.

[0054] The TACI-Fc fusion protein provided by the present application exhibits unexpected clinical efficacy and good safety in the treatment of patients with antiphospholipid syndrome. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 is a graph showing the changes in anti-cardiolipin antibody titers during the treatment with SOC (standard of care) + etanercept in Example 2.

[0056] Figure 2 is a graph showing the changes in anti-cardiolipin antibody titers during the treatment with SOC in Example 2.

[0057] Figure 3 is a graph showing the changes in anti-β2-glycoprotein I antibody titers during the treatment with SOC + etanercept in Example 2.

[0058] Figure 4 is a graph showing the changes in anti-β2-glycoprotein I antibody titers during the treatment with SOC in Example 2.

[0059] Figure 5 is a graph showing the changes in lupus anticoagulant titers during the treatment with SOC + etanercept in Example 2.

[0060] Figure 6 is a graph showing the changes in lupus anticoagulant titers during the treatment with SOC in Example 2. DETAILED DESCRIPTION

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. For reference on definitions and terms of the art, see Current Protocols in Molecular Biology (Ausubel).

[0062] The three letter and one letter codes for amino acid residues used herein are in accordance with the IUPAC-IUBMB standards as described in J. Biol. Chem., 243, p. 3558 (1968).

[0063] The term "TACI" as used herein refers to a member of the tumor necrosis factor receptor superfamily. The term "BLys" as used herein refers to B lymphocyte stimulator, which is a member of the TNF ligand superfamily that exists in two forms, membrane bound and soluble, and is expressed specifically on the surface of bone marrow cells and selectively stimulates B lymphocyte proliferation and immunoglobulin production. The term "APRIL" as used herein refers to a tumor necrosis factor (TNF) like molecule that stimulates the proliferation of both naive B cells and T cells in vivo, promotes B cell accumulation and increases spleen size. APRIL can specifically bind to TACI and BCMA, and after binding, prevents APRIL from binding to B cells and inhibits the proliferation of naive B cells stimulated by APRIL. Moreover, APRIL can competitively bind to the receptor (BCMA, TACI) with BLys.

[0064] The term "TACI-Fc fusion protein" as used herein refers to a transmembrane activator and CAML interactor (TACI)-immunoglobulin fusion protein (i.e., TACI-Fc fusion protein). The TACI- immunoglobulin fusion protein provided herein comprises: (i) a TACI extracellular region or a fragment thereof that binds to Blys and / or APRIL; and (ii) a human immunoglobulin constant region fragment.

[0065] The term "TACI extracellular region or a fragment thereof that binds to Blys and / or APRIL" can refer to the extracellular domain of TACI and specific fragments of the extracellular domain of TACI that can interact with TACI ligands as disclosed in U.S. Patent Nos. 5,969,102, 6,316,222 and 6,500,428 and U.S. Patent Application Nos. 09 / 569,245 and 09 / 627,206 (the contents of which are incorporated herein by reference), or the fragment of amino acids 13-118 of the extracellular domain of TACI as disclosed in Chinese Patent Publication No. CN101323643A.

[0066] Examples of the term "TACI-Fc fusion protein" as used herein include Atacicept (amino acid sequence: SEQ ID NO: 7), Elacept (amino acid sequence: SEQ ID NO: 8), and Lym-1 (amino acid sequence: SEQ ID NO: 9).

[0067] The term "human immunoglobulin constant region fragment" as used herein refers to an amino acid fragment that comprises a portion of a hinge region domain, a CH2 domain, and a CH3 domain. In some more preferred embodiments, the amino acid sequence of the "human immunoglobulin constant region fragment" as used herein is set forth in SEQ ID NO: 4, or comprises an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 4. In some more preferred embodiments, the amino acid sequence of the "human immunoglobulin constant region fragment" as used herein is set forth in SEQ ID NO: 5.

[0068] The term "treatment" as used herein refers to clinical intervention designed to alter the natural course of the individual or cell being treated, and includes both therapeutic treatment and prophylactic or preventative measures. Desirable effects of treatment include decreasing the rate of disease progression, ameliorating or palliating a disease state, and remission or improved prognosis. For example, a decrease or elimination of one or more symptoms associated with the disease or condition being treated, such as cancer, inflammation, or an autoimmune disease. In some embodiments, the term "treatment" refers to effective reduction in the rate of disease progression, amelioration or palliation of a disease state, and remission or improved prognosis, to a statistically significant or to a degree detectable by one of skill in the art.

[0069] The term "remission" as used herein refers to the absence of clinical symptoms or signs associated with anti-phospholipid syndrome at the beginning or end of treatment.

[0070] The term "amino acid" as used herein is understood in its broadest sense as a general term for a class of organic compounds that contain both an amino and a carboxyl group. Preferably, the amino acids referred to herein are the primary units of proteins that make up living organisms, which include, but are not limited to, glycine, alanine, valine, leucine, isoleucine, methionine (met), proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartate, glutamate, lysine, arginine, and histidine.

[0071] The three-letter code and one-letter code of amino acids used in the present application are as described in J. Biol. Chem, 243, p3558 (1968). There are various ways of numbering the amino acid sites, such as the Kabat numbering system, the EU numbering system, sequential numbering, etc. In the present application, the numbering of the amino acid sites is performed in the manner of "sequential numbering", as described in the present application, "site 3, 8, 14, 15, 17, 110, 111 or 173 of SEQ ID NO: 4" refers to the 3rd amino acid, the 8th amino acid of SEQ ID NO: 4, and so on; as described in the present application, "P3T" refers to mutating the 3rd amino acid sequence of SEQ ID NO: 4 from the previous "P" to "T", and so on.

[0072] As an alternative embodiment, the constant region of the immunoglobulin provided by the present application can introduce one or more amino acid changes, such as substitution (i.e. mutation), addition (i.e. insertion) or deletion (i.e. deletion).

[0073] The term "telitacicept" (or "talizumab", which can be used interchangeably in the present application) in the present application is a TACI-Fc fusion protein, the INN name of which is telitacicept, the amino acid sequence of which is shown in SEQ ID NO: 7, or see https: / / extranet.who.int / somin / mod / page / view.php?id=137&inn_n=10932.

[0074] The term "atacicept" in the present application is a TACI-Fc fusion protein, the INN name of which is atacicept, the amino acid sequence of which is shown in SEQ ID NO: 8, or see https: / / extranet.who.int / somin / mod / page / view.php?id=137&inn_n=8669.

[0075] The term "povetacicept" in the present application is a TACI-Fc fusion protein, the INN name of which is povetacicept, the amino acid sequence of which is shown in SEQ ID NO: 9, or see https: / / extranet.who.int / somin / mod / page / view.php?id=137&inn_n=12264.

[0076] The TACI-Fc fusion protein of the present application can be administered by any of a variety of routes, including but not limited to oral, intravenous, intramuscular, intraarterial, intramedullary, intraperitoneal, intrathecal, intracerebral, transdermal, transcutaneous, topical, subcutaneous, intranasal, enteral, sublingual, intravaginal or rectal routes, etc.

[0077] The term "antiphospholipid syndrome" in the present application refers to a non-inflammatory autoimmune disease, which is clinically manifested by arterial and venous thrombosis, pathologic pregnancy (early miscarriage and late fetal death), thrombocytopenia, kidney damage, etc. One or more of the following anti-phospholipid antibodies exist in serum: anti-cardiolipin antibody, lupus anticoagulant, anti-β2 glycoprotein I antibody, anti-phosphatidylserine / thrombin complex antibody, anti-thrombin antibody, anti-β2 glycoprotein I domain 1 antibody, anti-phosphatidylethanolamine antibody, anti-protein S and protein C antibody, anti-phosphatidylinositol antibody, anti-vimentin / cardiolipin complex antibody, anti-annexin A2 and A5 antibody, and anti-phosphatidic acid antibody.

[0078] The term "primary antiphospholipid syndrome" in the present application refers to antiphospholipid syndrome that occurs alone without other autoimmune diseases.

[0079] The term "secondary antiphospholipid syndrome" in the present application refers to antiphospholipid syndrome secondary to other autoimmune diseases, including but not limited to lupus erythematosus (such as systemic lupus erythematosus), rheumatoid arthritis, Sjogren's syndrome, etc.

[0080] The term "aPL profile" in the present application refers to the levels of anti-cardiolipin antibody (IgG or IgM) and anti-β2 glycoprotein I antibody (IgG or IgM) and lupus anticoagulant.

[0081] The term "aPL" in the present application refers to anti-phospholipid antibodies present in the body of a patient.

[0082] The term "standard treatment regimen" in the present application includes aspirin and / or vitamin K antagonists (VKA) and / or low molecular weight heparin.

[0083] The term "heparin" in the present application, also known as ordinary heparin, is a kind of sulfated amino glucan extracted and refined from pig intestinal mucosa or bovine lung, which can bind to antithrombin III, inhibit the activity of thrombin, thereby prolonging the blood clotting time, and is mainly used for anticoagulation and antithrombosis in clinic.

[0084] The term "low molecular weight heparin" in the present application includes low molecular weight heparin sodium / calcium, enoxaparin, nadroparin, dalteparin, etc., which is a kind of glucamine with lower molecular weight obtained by chemical method or enzymatic hydrolysis from ordinary heparin.

[0085] The term "vitamin K antagonists" in the present invention refers to drugs that inhibit the synthesis of vitamin K-dependent clotting factors, including warfarin, dicoumarol, phenprocoumon, acenocoumarol, etc.

[0086] The term "about" in the present invention is used to indicate that a numerical value includes the inherent error variations of the equipment or method used to determine the numerical value, or the variations that exist between the samples being measured. Unless otherwise stated or apparent from context, the term "about" means within 10% above or below the reported numerical value (unless that number would exceed 100% of the possible value or be less than 0%). When used in connection with a range or series of numbers, the term "about" applies to each of the numbers in the range or series, unless otherwise stated.

[0087] Embodiments of the present invention will now be described in detail in connection with the following examples, but the skilled person will understand that the following examples are for illustration only and should not be taken as limiting the scope of the present invention.

[0088] Example 1 Affinity study

[0089] Comparing the affinity of itacitinib, pexiditinib and APRIL, Blys.

[0090] The affinity of itacitinib, pexiditinib, APRIL homotrimer and Blys homotrimer were tested by enzyme-linked immunosorbent assay (ELISA) method, respectively, in which null-IgG1 was used as a blank control. The experimental results are shown in Table 4. Table 4. APRIL or Blys homotrimer ELISA binding assay

[0091] Note: "N.B" means no binding.

[0092] Conclusion

[0093] In the APRIL or Blys homotrimer ELISA binding assay, itacitinib and pexiditinib can achieve good binding with APRIL and Blys.

[0094] Example 2 Clinical trial of itacitinib in the treatment of primary antiphospholipid syndrome

[0095] 1. Study method

[0096] This study is a single-center, randomized controlled, open clinical study. The main purpose is to evaluate the effect of eteplirsen on anti-phospholipid antibody (aPL) spectrum in patients with primary APS carrying high-risk anti-phospholipid antibody spectrum. The secondary purpose is to evaluate the effect of eteplirsen on thrombosis recurrence in patients with primary APS, and to reveal the heterogeneity changes of cell gene characteristics and functions before and after treatment with eteplirsen by single-cell RNA sequencing (scRNAseq) of B cells.

[0097] 2. Subjects

[0098] 2.1 Patient inclusion criteria ●≥18 years old. ● Clinically diagnosed with primary antiphospholipid syndrome according to the Sydney criteria. ● Inclusion of persistent anti-phospholipid antibody positivity within 12 months (at least 12 weeks apart), risk stratification according to antibody level as high-risk anti-phospholipid antibody spectrum, at least one of the following conditions: 1, lupus anticoagulant (LAC) positive (detection according to ISTH guidelines); 2, two or three aPL positive (any two or all three of lupus anticoagulant, anticardiolipin antibody and anti-beta2 glycoprotein I antibody); 3, or persistent high titer aPL; ● No concurrent occurrence of other autoimmune diseases. ● Stable APS treatment regimen according to EULAR recommendations on antiphospholipid syndrome. ● Female patients who are not pregnant, not breastfeeding, have no reproductive potential or are not using contraception.

[0099] 2.2 Healthy volunteer inclusion criteria ● Age 18-75 years, healthy, no history of chronic diseases such as hypertension, diabetes, no history of infectious diseases such as tuberculosis, hepatitis B, no history of trauma, surgery, blood transfusion, no family history of genetic diseases. ● Normal vital signs: including body temperature, respiration, blood pressure and heart rate; ● Normal physical examination: including height (only screening period), weight, head, eye, ear, nose, throat, neck, heart, chest (including lungs), abdomen, limbs, skin, lymph nodes, nervous system; ● Normal laboratory tests: including three routine tests, biochemistry, liver and kidney function, coagulation function, etc.; ● Normal ECG, echocardiography and other tests.

[0100] 3. Treatment and administration method

[0101] Patients were randomly divided into SOC (Standard of Care) group and SOC+eteplirsen group after enrollment. Each of the SOC group and the SOC+eteplirsen group included 10 patients. The use of eteplirsen in this study: subcutaneous injection of 160 mg each time, once a week, for a total of 48 weeks of treatment.

[0102] Patients enrolled will be concurrently receiving SOC treatment for 48 weeks. Patients will be assessed at Day 0 and then re-assessed every 12 weeks for 48 weeks. SOC treatment for this study is based on patient clinical presentation and anti-phospholipid antibody profile using aspirin, vitamin K antagonists (VKA) and low molecular weight heparin (SOC treatment see EULAR recommendations for the management of antiphospholipid syndrome in adults. Tektonidou, M.G., et al., Ann Rheum Dis, 2019, vol. 78, no. 10, pp. 1296-1304).

[0103] Primary checks including safety assessments will be performed at Day 0 and then every 12 weeks for 48 weeks. A total of 5 visit checks.

[0104] 4. Efficacy outcomes

[0105] 4.1 Primary endpoint

[0106] The primary efficacy endpoint of this study is the proportion of patients with a reduction in anti-phospholipid antibody titers at Week 48 of treatment.

[0107] The changes in anti-cardiolipin antibody titers in patients enrolled in SOC+etanercept group after 48 weeks of etanercept administration are shown in Figure 1, the changes in anti-β2-glycoprotein I antibody titers are shown in Figure 3, and the changes in lupus anticoagulant titers are shown in Figure 5. Since one patient (TA-9) in this group did not complete the medication, the results are not included in the analysis, and “TA-1” to “TA-8” and “TA-10” in the figure represent other patients receiving SOC+etanercept treatment. The changes in anti-cardiolipin antibody titers in patients enrolled in SOC group are shown in Figure 2, the changes in anti-β2-glycoprotein I antibody titers are shown in Figure 4, and the changes in lupus anticoagulant titers are shown in Figure 6. “CON-1” to “CON-10” in the figure represent patients receiving SOC treatment.

[0108] The experimental results show that:

[0109] 1) The titers of aCL IgG, aCL IgM and aCL IgA in patients administered etanercept all decreased to varying degrees, and overall, the proportion of patients with a reduction in anti-cardiolipin antibody titers accounted for 88.9% of all patients in the group who completed the medication, and only one patient (TA-10) had a slight increase in aCL IgG titer compared to the baseline level, but the titers of aCL IgM and aCL IgA were both decreased compared to the baseline level (as shown in Figure 1), and in the SOC group, only 50% of patients had a simultaneous decrease in the titers of aCL IgG, aCL IgM and aCL IgA (as shown in Figure 2).

[0110] 2) 66.7% (6) of patients administered with etarnecept had a simultaneous decrease in the titers of anti-β2 glycoprotein I antibodies (aβ2GPI IgG, aβ2GPI IgM and aβ2GPI IgA) (as shown in Figure 3), with 3 patients having a significant decrease in the titers of aβ2GPI IgM and aβ2GPI IgA and a slight increase in the titer of aβ2GPI IgG (TA-2, TA-4, TA-10), while only 2 patients (20% of the patients enrolled) in the SOC group had a decrease in the titers of aβ2GPI IgG, aβ2GPI IgM and aβ2GPI IgA (Con-2, Con-5) (as shown in Figure 4).

[0111] 3) During the administration of etarnecept, some patients had a greater fluctuation in the titers of lupus anticoagulants, but still showed a decreasing trend in the overall level of change (as shown in Figure 5), about 55.6% (5), higher than the 20% of the SOC group (as shown in Figure 6).

[0112] In summary, the use of etarnecept significantly reduces the levels of anti-phospholipid antibodies and effectively treats or alleviates primary antiphospholipid syndrome.

[0113] The foregoing description is of a preferred embodiment only and is not intended to limit the scope of the application as encompassed by the appended claims. The title provided is not meant to limit the various embodiments of the application. The terms "comprising," "including," and "having" are intended to be open-ended terms that do not preclude additional elements not specifically recited. Also, the term "or" is intended to mean "and / or" unless otherwise indicated. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0114] All publications and patents mentioned in this application are herein incorporated by reference. Various modifications and variations to the described methods and compositions of the application will be apparent to those skilled in the art from the foregoing description. While the application has been described in connection with specific preferred embodiments, it will be understood that it is not intended to limit the application to these embodiments. On the contrary, it is intended to cover all modifications, alternatives, and equivalents falling within the spirit and scope of the application. Although the application has been described by reference to specific preferred embodiments, it should be understood that the application is not intended to be limited to these specific embodiments. Indeed, various modifications and variations that will be apparent to those skilled in the art are intended to be within the scope of the application.

Claims

1. A method of treating or alleviating antiphospholipid syndrome, the method comprising administering to a patient having the antiphospholipid syndrome a therapeutically effective amount of a drug targeting Blys and / or APRIL; preferably, the antiphospholipid syndrome is selected from primary antiphospholipid syndrome or secondary antiphospholipid syndrome; more preferably, the antiphospholipid syndrome is primary antiphospholipid syndrome.

2. The method of claim 1, wherein the drug targeting Blys and / or APRIL is a TACI-Fc fusion protein.

3. The method of claim 2, wherein, The TACI-Fc fusion protein comprises: (i) a TACI extracellular region or a fragment thereof that binds Blys and / or APRIL; and (ii) a human immunoglobulin constant region fragment.

4. The method of claim 3, wherein, The TACI extracellular region or a fragment thereof that binds Blys and / or APRIL comprises the amino acid sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2 or SEQ ID NO:

3.

5. The method of claim 3, wherein, The human immunoglobulin is IgGl or the human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 4 or an amino acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO:

4.

6. The method of claim 3, wherein, The human immunoglobulin constant region fragment comprises a modification of an amino acid at one or more positions corresponding to positions 3, 8, 14, 15, 17, 110, 111, or 173 of SEQ ID NO: 4; preferably, the human immunoglobulin constant region fragment comprises 1, 2, 3, 4, 5, 6, 7, 8 or more amino acid modifications at positions compared to SEQ ID NO:

4.

7. The method of claim 6, wherein, The modification is a substitution, deletion, or insertion of an amino acid; preferably, the substitution comprises 1 or more of P3T, L8P, L14A, L15E, G17A, A110S, P111S, and / or A173T; preferably, the insertion is an insertion of 1, 2, 3, 4, 5, 6, 7, 8 or more amino acids at the N-terminus of the human immunoglobulin constant region fragment.

8. The method of claim 6, wherein, The human immunoglobulin constant region fragment comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO:

6.

9. The method of claim 8, wherein, The TACI-Fc fusion protein has an amino acid sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 7, preferably the TACI-Fc fusion protein has the amino acid sequence set forth in SEQ ID NO: 7 or SEQ ID NO: 8 or SEQ ID NO: 9, preferably the TACI-Fc fusion protein is telitacicept, atacicept, or povetacicept.

10. The method according to any one of claims 1-9, characterized in that, The method further comprises administering to the patient a standard treatment regimen.

11. The method of claim 10, wherein, The standard treatment regimen comprises aspirin and / or vitamin K antagonists (VKA) and / or low molecular weight heparin.

12. The method of claim 11, wherein, The standard treatment regimen comprises aspirin and / or vitamin K antagonists (VKA) and / or low molecular weight heparin according to the clinical manifestations and the spectrum of anti-phospholipid antibodies of the patient.

13. The method according to any one of claims 1 to 12, characterized in that, The primary antiphospholipid syndrome is characterized by persistent moderate or high positivity of antiphospholipid antibodies (aPLs), which include but are not limited to anti-cardiolipin antibodies, anti-β2-glycoprotein I antibodies, lupus anticoagulants, anti-phosphatidylserine / prothrombin complex antibodies, anti-prothrombin antibodies, anti-β2-glycoprotein I domain 1 antibodies, anti-phosphatidyl ethanolamine antibodies, anti-protein S and protein C antibodies, anti-phosphatidylinositol antibodies, anti-vimentin / cardiolipin complex antibodies, anti-annexin A2 and A5 antibodies, and anti-phosphatidic acid antibodies.

14. The method according to any one of claims 1 to 13, characterized in that, The patient is an adult patient or a child patient.

15. The method according to any one of claims 1 to 14, characterized in that, The patient has previously received a treatment regimen for primary antiphospholipid syndrome or has not previously received a treatment regimen for primary antiphospholipid syndrome.

16. The method according to any one of claims 1 to 15, characterized in that, The patient is also suffering from one or more other diseases.

17. The method according to any one of claims 1 to 16, characterized in that, The single dose of the TACI-Fc fusion protein is about 0.1 to 10 mg / kg; preferably 40-300 mg; preferably 80-240 mg, further preferably 80 mg or 160 mg or 240 mg.

18. The method according to any one of claims 1 to 17, characterized in that, The TACI-Fc fusion protein is administered subcutaneously, intramuscularly or intravenously or at the thigh, abdomen or upper arm.

19. The method according to any one of claims 1 to 18, characterized in that, The TACI-Fc fusion protein is used 1-4 times at an interval of one month and / or the treatment lasts for about 2-50 weeks; preferably, the TACI-Fc fusion protein is administered once a week or once every two weeks or once every three weeks or once every four weeks.

20. The method of any one of claims 1-19, wherein, The TACI-Fc fusion protein is administered at a dose of 40-300 mg / week; preferably 80-240 mg / week, further preferably 80 mg / week or 160 mg / week or 240 mg / week, further preferably 160 mg / week.

21. A method of treating primary antiphospholipid syndrome, the method comprising administering to a patient having the primary antiphospholipid syndrome a therapeutically effective amount of a TACI-Fc fusion protein in combination with another therapeutic agent, wherein, The TACI-Fc fusion protein comprises: (i) a TACI extracellular region or a fragment thereof that binds Blys and / or APRIL; and (ii) a human immunoglobulin-constant region fragment.

22. The method of claim 21, wherein, The other therapeutic drugs include but are not limited to anticoagulants, belimumab, rituximab, eculizumab, wherein the anticoagulants include but are not limited to anti-platelet drugs, vitamin K antagonists, heparin or low molecular weight heparin, hydroxychloroquine, statins, wherein the anti-platelet drugs include but are not limited to aspirin, dipyridamole, ticlopidine, clopidogrel.

23. The method of any one of claims 1-22, wherein, The treatment causes the titer of anti-phospholipid antibodies (aPL) in the patient to decrease.

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