Use of SE-DR affinity peptides for the preparation of drugs to treat rheumatic diseases

Abstract

The present invention provides the use of SE-DR (HLA-DR molecule containing a shared epitope) affinity peptide for the preparation of a medicament for treating rheumatic diseases in rheumatic patients who are tuberculosis positive and / or have hepatitis B. The present invention solves the problem that patients with rheumatic diseases have limited drug options. The present invention also provides a pharmaceutical composition comprising an SE-DR affinity peptide and a non-antigen specific antirheumatic drug, and its use for the preparation of a medicament for the treatment of various types of rheumatic diseases. The pharmaceutical composition can rapidly inhibit the progression of rheumatic diseases for complete control of rheumatic diseases, and can achieve sustained remission even after tapering or discontinuation of the drug.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims the rights of Chinese Patent Application No. 202110873116.6, filed on 30 July 2021. Chinese Patent Application No. 202110873116.6 is incorporated by reference throughout this specification.

[0002] (Technical field) The present invention belongs to the field of biopharmaceuticals and, in particular, relates to the use of SE-DR affinity peptides in the preparation of agents for treating rheumatic diseases in rheumatoid arthritis patients who are tuberculosis-positive and / or have hepatitis B. Furthermore, the present invention also relates to pharmaceutical compositions comprising SE-DR affinity peptides and non-antigen-specific antirheumatic drugs, and their use in the preparation of agents for treating various types of rheumatic diseases. [Background technology]

[0003] Rheumatic diseases are a very common group of clinical syndromes characterized by joint pain and fear of wind and cold. Rheumatism is an abbreviation for rheumatic disease and generally refers to a large group of diseases that affect bones, joints, muscles, and surrounding soft tissues such as bursae, tendons, fascia, blood vessels, and nerves. Rheumatoid arthritis (RA) is one of the most common rheumatic diseases. Rheumatoid arthritis is a chronic, systemic autoimmune disease characterized by erosive synovitis, causing destruction of articular cartilage and bone, leading to joint deformities and ultimately disability. The 3-year disability rate for patients without standard treatment is high at 75%, and it is one of the major causes of loss of workforce among young and middle-aged people. The average life expectancy of patients is 3 to 10 years shorter than that of healthy people, and it is therefore called "immortal cancer." This disease causes serious social and economic problems. In the early stages of the disease, patients can still work, but after 10 years, 50% of patients lose their ability to work, and after 15 years, this reaches 67%. Rheumatoid arthritis is known internationally as the "5Ds," meaning it can cause illness, depression, disability, death, and debt. The global prevalence of rheumatoid arthritis is 0.5-1%, while in China it is approximately 0.3%, affecting about 5 million people. In China, the peak age of onset for female patients is 35-44 years old, and for male patients it is 55-64 years old, with the incidence increasing with age. It is more common in women, with a female-to-male ratio of 2:1-3:1.

[0004] The pathogenesis of rheumatic diseases is highly complex. Under the influence of environmental or genetic factors, pathogenic antigens from a susceptible population activate the innate immune system. These antigens are presented by antigen-presenting cells (APCs), which then activate T cells. T cell activation requires co-stimulation by two independent signals. The first signal is the formation of a tripolecular complex of "human leukocyte antigen (HLA)-antigen peptide-T cell receptor (TCR)," where HLA and the antigen peptide first form a molecular complex, and then associate with the TCR to form a tripolecular complex. The second signal is the binding of CD28 on the surface of T cells to CD80 / 86 on the surface of APC cells. Activated T cells can further activate B cells, and these activated T cells and B cells enter the peripheral circulation and reach lesion sites containing autoantigens with structures similar to pathogenic antigens. Autoantigens function as pathogenic antigens, continuously activating T cells and B cells, leading to the massive secretion of inflammatory cytokines, chemokines, and collagenases. This promotes synovial hyperplasia, pannus formation, and persistent inflammation, ultimately causing bone destruction. T lymphocytes play a crucial role in the onset, persistence, and relapse of rheumatoid arthritis. In particular, the differentiation of activated T cells into helper T cells is becoming increasingly important in the study of the pathogenesis and therapeutics of rheumatoid arthritis. In this field, changes in the levels of Th17 cells and Treg cells are a focus of research.

[0005] Currently, drugs for treating rheumatic diseases (especially RA) can be divided into four generations based on their development period and mechanism of action. The first generation consists of nonsteroidal anti-inflammatory drugs (NSAIDs), the second generation consists of glucocorticoids (GCs), the third generation consists of disease-modifying antirheumatic drugs (DMARDs), and the fourth generation consists of biological agents, typified by TNF-α inhibitors. Fourth-generation rheumatic disease drugs include TNF-α inhibitors, IL-1 antagonists, IL-6 antagonists, JAK3 inhibitors, T-cell inhibitors, and B-cell inhibitors, and currently account for up to 97% of the market in Japan, the US, and Europe. However, drugs commonly used clinically for treating rheumatic diseases (especially RA) have significant drawbacks in terms of safety and efficacy.

[0006] Currently, common NSAIDs, GCs, DMARDs, and biological agents have safety concerns and are somewhat limited in their clinical application. The median lethal dose (MLD) of methotrexate, the recommended first-line drug in clinical practice, is 43 mg / kg in rats, with its main toxicities being myelosuppression and gastrointestinal toxicity. Etanercept, one of the second-line drugs in clinical practice, primarily manifests as latent tuberculosis infection in its preclinical toxicity, while its clinical toxicity mainly induces immune disorders and serious infections, and increases the incidence of cancer. In a preclinical safety study regarding abatacept carcinogenicity, approximately 50% of mice in the treatment group died from lymphoma, and the incidence of breast cancer also increased. Clinical trials have also shown that abatacept exacerbates infections and increases the risk of cancer. Most biological agents (such as TNF inhibitors) have black-box warnings from the FDA indicating the risk of tumors and infections, requiring patients to undergo tuberculin skin tests and hepatitis B-related tests before administration. In tuberculin-positive patients, biological agents should be administered after tuberculosis treatment, and even if the tuberculin test is negative, active tuberculosis should be monitored during administration of biological agents. For patients with hepatitis B, prophylactic antiviral therapy should be administered when HBcAg-positive patients initiate rituximab therapy or targeted synthetic DMARD therapy. HBcAb-positive / HBcAg-negative patients should be carefully monitored when initiating non-rituximab biological agents or targeted synthetic DMARD therapy. Therefore, for tuberculosis-positive patients or patients with hepatitis B, there is a problem of limited drug options and increased drug risks.

[0007] Furthermore, current follow-up studies after two years of treatment using different regimens and criteria for common clinical medications show that remission rates worldwide are only around 40%, meaning nearly half of patients remain in an effective state of control. In China, the clinical remission rate for RA patients, when followed up using different clinical criteria after treatment, ranges from only 8.6% to 25.2%. A significant number of patients are unable to achieve clinical remission and disease control with current treatments.

[0008] A common reason for the safety issues with existing clinical drugs that can alleviate rheumatic diseases (especially RA) can be attributed to "insufficient specificity to the target." NSAIDs, GCs, and DMARDs have broad immunosuppressive effects but cannot specifically inhibit disease-related lymphocytes. Biologics and novel small molecule drugs are targeted therapies for RA, but most target cytokines and kinases downstream of the pathogenesis of RA. While inhibiting the above factors, they can lead to side effects such as increased incidence of tuberculosis infection and tumors after inhibiting TNF-α. Abatacept is effective in activating T cells, which are at the very upstream of RA development. Its safety is superior to that of TNF-α inhibitors and DMARDs, but because its target is broad T cell activation rather than disease-specific T cells, it can cause immunodeficiency and may further increase the incidence of serious infections and cancer during treatment. Therefore, the development of RA treatments that target disease-specific targets is a major way to resolve the safety issues of existing drugs.

[0009] SE-DR affinity peptides (FNS007, etc.) are innovative drugs uniquely developed in China that act directly on T lymphocytes and can be considered fifth-generation drugs for the treatment of rheumatic diseases (especially RA). SE-DR affinity peptides play a role by competitively inhibiting the binding of rheumatic disease-associated antigen peptides to major histocompatibility complex molecules, thereby inhibiting the formation of the three-molecule complex "HLA-antigen peptide-T lymphocyte receptor (TCR)," which is the initial signaling pathway for specific T cell activation mediated by rheumatic disease-associated antigens. This antigen-specific therapeutic agent can inhibit the activation and proliferation of disease-specific autoreactive T cells, altering T cell differentiation and downstream cytokine secretion, thereby achieving therapeutic objectives for rheumatic diseases (especially RA). "Antigen-specific therapy" is a key characteristic of the mechanism of SE-DR affinity peptides. SE-DR affinity peptides are peptide ligands that modify major Ran autoantigen epitopes. They act on specific stages of RA development and onset, inhibiting the binding of various RA-related antigen peptides to HLA molecules and controlling the patient's disrupted immune microenvironment. By reducing inflammatory cells and increasing anti-inflammatory cells, they are expected to restore immune tolerance and completely prevent disease progression through long-term improvement. The mechanism of action of SE-DR affinity peptides (e.g., FNS007) in the treatment of rheumatic diseases indicates the future direction of development for anti-rheumatic drugs.

[0010] FNS007 is a novel Class 1.1 drug developed by Hebei Fitness Biotechnology Co., Ltd., which has entered the clinical research phase and is currently in Phase 1 clinical research. This invention is the result of the company's diligent research into novel applications of SE-DR affinity peptides (particularly FNS007), targeting the shortcomings in safety and efficacy of existing rheumatic disease treatments. Accordingly, an object of this invention is to provide the use of SE-DR affinity peptides in the preparation of therapeutic drugs for rheumatic diseases in rheumatoid arthritis patients who are tuberculosis-positive and / or have hepatitis B. Another object of this invention is to provide a pharmaceutical composition comprising SE-DR affinity peptides and non-antigenic antirheumatic drugs, and its use in the preparation of therapeutic drugs for various rheumatic diseases. [Overview of the project]

[0011] For existing rheumatic disease treatments, balancing clinical safety and efficacy is crucial. Increasing the dosage within a certain range can enhance drug efficacy and improve remission rates, but it can also increase the incidence of side effects. Identifying more disease-specific drugs for the treatment of rheumatic diseases, and the associated risks of drug use, is a major avenue and a new approach to address the problem of insufficient remission rates with existing drugs and to meet the treatment acceptance needs of rheumatic disease patients in China.

[0012] Antigen-specific therapy is a novel idea to address the clinical shortcomings of the aforementioned drugs for rheumatic diseases. While existing non-antigen-specific therapies (such as TNF-α inhibitors) currently show some efficacy, restoring tolerance to autoantigens is key to treating autoimmune diseases, and using more specific targets can also reduce the toxicity of drugs, such as those causing infections. Therefore, the combination of antigen-specific or non-antigen-specific therapy is becoming a new trend in the treatment of rheumatic diseases.

[0013] To achieve the objectives of the present invention, the following technical proposals are provided.

[0014] In a first aspect, the present invention provides for the use of an SE-DR affinity peptide, which means a peptide segment that binds to HLA DR molecules sharing an epitope, and is used in the preparation of a medicament for the treatment of rheumatic diseases in rheumatic patients who are tuberculous positive and / or have concurrent hepatitis B. Preferably, the shared epitope is a 5-amino acid motif having QK / RRAA at positions 70-74 of the HLA-DRβ chain. The SE-DR affinity peptide plays a role in competitively inhibiting the binding between antigen peptides associated with rheumatic diseases and HLA-DR molecules, but has no extensive immunosuppressive effect and no risk of inducing infectious diseases or tumors.

[0015] Alternatively, in the above use, the core sequence of the SE-DR affinity peptide bound to SE-DR contains core amino acids corresponding to P1-P9. The P1 site is an amino acid having a hydrophobic side chain and a rare or unnatural amino acid having similar properties. The P4 site is a non-polar, polar and uncharged, polar and negatively charged amino acid and a rare or unnatural amino acid having similar properties.

[0016] Preferably, the corresponding P1 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is selected from Tyr (Y), Phe (F), Trp (W), Leu (L), Ile (I), Met (M), Val (V) or Ala (A), and the P4 site is selected from Met (M), Ala (A), Val (V), Ile (I), Leu (L), Asp (D), Glu (E), Gln (Q), Ser (S) or Cit.

[0017] More preferably, the corresponding P1 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is selected from Tyr (Y), Phe (F) or Trp (W), and the P4 site is selected from Met (M), Leu (L), Asp (D), Glu (E) or Cit.

[0018] Alternatively, in the above use, the corresponding P6 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is an amino acid with a short side chain, a rare or non-natural amino acid with similar properties, and the P9 site is an amino acid with a medium to short side chain, a rare or non-natural amino acid with similar properties.

[0019] Preferably, the corresponding P6 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is selected from Ala (A), Gly (G), Ser (S), Thr (T) or Asn (N), and the P9 site is selected from Ala (A), Gly (G), Leu (L) or Met (M).

[0020] Alternatively, in the above use, the SE-DR affinity peptide comprises the following amino acid sequence: FXGEQGXXGE, or FXGEXAXXGE, where X is selected from P, K, Q, A or G.

[0021] Preferably, X is selected from A or G. More preferably, the SE-DR affinity peptide is FNS007 (FKGEQAGAGE).

[0022] Alternatively, in the above use, the SE-DR affinity peptide comprises the following amino acid sequence: YXKQXTXXLA, where X is selected from V, A, G, N, L or K.

[0023] Preferably, X is selected from A or G. More preferably, the amino acid sequence of the SE-DR affinity peptide is selected from the group consisting of PKYVKQNTLKLAT, PGYVKQGTLGLAT, YVKQNTLKLA, YVAQNTLKLA, YAKQATLKLA, or YAKQATLALA.

[0024] Alternatively, in the above use, the SE-DR affinity peptide comprises the following amino acid sequence: IWYIXCFXCEXHXXL, where X is selected from A, G, M, T, V, N, Q or S.

[0025] Preferably, X is selected from A or G. More preferably, the amino acid sequence of the SE-DR affinity peptide is selected from IWYINCFGCETHAML, IWYIQCFGCETHAML, IWYISCFGCETHAML, IWYITCFGCETHAML, IWYINCFACETHAML, or IWYINCFVCETHAML.

[0026] Alternatively, in the above use, the SE-DR affinity peptide comprises the following amino acid sequence: RSFXLAXSXXGVG, where X is selected from A, G, T, S, or E.

[0027] Preferably, X is selected from A or G. More preferably, the amino acid sequence of the SE-DR affinity peptide is selected from RSFTLASSETGVG, RSFALASSETGVG, RSFTAASSETGVG, RSFTLDSSETGVG, RSFTLAASETGVG, RSFTLASSATGVG, RSFTLASSEAGVG, or RSFTLDSSETGVG.

[0028] Alternatively, in the above use, the SE-DR affinity peptide comprises the following amino acid sequence: SAVXLCitXSXXGVR, where X is selected from A, G, R, S, V, or P.

[0029] Preferably, the amino acid sequence of the SE-DR affinity peptide is SAVRLCitSSVPGVR, SAVELCitSSVPGVR, SAVDLCitSSVPGVR, SAVGLCitSSVPGVR, SAVRLCitFSVPGVR, SAVRLCitSSVEGVR, SAVRLCitSSVKGVR, SAVRLCitSSVWGVR, SAVRLCitWSVPGVR, SAVRLCitSSVRGVR, SAVRLCitKSVPGVR, SAVALCitSSVPGVR, or SAVRLCitRSVPGVR.

[0030] Alternatively, the SE-DR affinity peptide comprises the following amino acid sequence: GVYXTCitXSXXCitLCit, where X is selected from A, G, or V. Preferably, X is selected from A or G. More preferably, the amino acid sequence of the SE-DR affinity peptide is GVYATCitSSAVCitLCit.

[0031] Alternatively, the SE-DR affinity peptide may have the following amino acid sequence: QDXNCitXNXXKNS, where X is selected from A, G, F, I, K, or L. Preferably, X is selected from A or G. More preferably, the amino acid sequence of the SE-DR affinity peptide is QDFTNCitANKLKNS.

[0032] Alternatively, the SE-DR affinity peptide may have the following amino acid sequence: VVLLVATXGCitXRXXSAYQDK, where X is selected from A, G, E, V, or N. Preferably, X is selected from A or G. More preferably, the amino acid sequence of the SE-DR affinity peptide is VVLLVATEGCitVRVNSAYQDK.

[0033] Alternatively, in the above use, the amino acid sequence of the SE-DR affinity peptide is selected from MGPKGRTVIIEQSWGSPKVTK, MGPKGRTVIIEQSLGSPKVTK, SIDLKDKKYKNIGAKLVQDVANNTNEEA, SIDLKDKKYKNIGAKLVQLVANNTNEEA, QYMCitADQAAGGLR, LTQCitGSVLR, WYNCitCHAAN, VETCitDGQVI, or VCitLCitSSVESTCitGRSCitPAPPPACitGLT.

[0034] Alternatively, in the above use, the rheumatic disease is selected from rheumatoid arthritis, psoriasis, psoriatic arthritis, ankylosing spondylitis, undifferentiated spondyloarthropathy, systemic lupus erythematosus, systemic sclerosis, or collagen disease.

[0035] In a second embodiment, the present invention provides a pharmaceutical composition for the treatment of rheumatic diseases comprising an SE-DR affinity peptide, a non-antigen-specific antirheumatic drug, and a pharmaceutically acceptable carrier. Preferably, the weight ratio of the SE-DR affinity peptide to the non-antigen-specific antirheumatic drug is in the range of 50:1 to 1:50, more preferably the weight ratio can be selected from 20:1 to 1:20, 15:1 to 1:15, 10:1 to 1:10, 5:1 to 1:5, 4:1 to 1:4, 3:1 to 1:3, or 2:1 to 1:2, and the specific dosage ratio can be determined by a clinician in relation to the type of non-antigen-specific antirheumatic drug selected. The SE-DR affinity peptide refers to a peptide segment that binds to an HLA-DR molecule sharing an epitope, preferably the shared epitope refers to a peptide segment located at amino acid sequence positions 70 to 74 of HLA-DR, all expressing a QK / RRAA sequence. SE-DR affinity peptides competitively inhibit the binding of antigen peptides associated with rheumatic diseases to HLA-DR molecules, thereby regulating the disrupted immune microenvironment in the body and restoring immune balance. This pharmaceutical composition rapidly slows the progression of rheumatic diseases and achieves sustained remission even after gradual reduction or discontinuation of the drug.

[0036] Alternatively, in the above pharmaceutical composition, the core sequence of the SE-DR affinity peptide bound to SE-DR includes core amino acids corresponding to P1 to P9, where the P1 site is an amino acid having a hydrophobic side chain, and is a rare amino acid or unnatural amino acid having similar properties.

[0037] Preferably, the corresponding P1 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is selected from Tyr(Y), Phe(F), Trp(W), Leu(L), Ile(I), Met(M), Val(V), or Ala(A), and the P4 site is a nonpolar, polar and uncharged, polar and negatively charged amino acid, and a rare or unnatural amino acid having similar properties. Preferably, the corresponding P4 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is selected from Met(M), Ala(A), Val(V), Ile(I), Leu(L), Asp(D), Glu(E), Gln(Q), or Ser(S). The corresponding P6 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is an amino acid containing a short side chain and a rare or non-natural amino acid having similar properties, and the P9 site is an amino acid containing a moderate to short side chain and a rare or non-natural amino acid having similar properties. Preferably, the corresponding P6 site in the core sequence of the SE-DR affinity peptide bound to SE-DR is selected from Ala(A), Gly(G), Ser(S), Thr(T), or Asn(N), and the P9 site is selected from Ala(A), Gly(G), Leu(L), or Met(M).

[0038] Non-antigen-specific antirheumatic drugs are selected from one or more of the following: cytokine-targeting drugs, B-cell-targeting drugs, T-cell-targeting drugs, JAK kinase-targeting drugs, conventional disease-modifying antirheumatic drugs (DMARDs), nonsteroidal anti-inflammatory drugs (NSAIDs), or glucocorticoid drugs.

[0039] Preferably, the non-antigen-specific antirheumatic drug is selected from one or more of the following: tumor necrosis factor (TNF) inhibitors, IL-6 inhibitors, IL-1 inhibitors, IL-17 inhibitors, RANKL inhibitors, T cell costimulatory signaling inhibitors, CD20 inhibitors, CD22 inhibitors, BLyS and APRIL inhibitors, BAFF inhibitors, JAK inhibitors, BTK inhibitors, Syk inhibitors, IRAK4 inhibitors, p38 inhibitors, or small molecule immunosuppressants.

[0040] More preferably, the non-antigen-specific anti-rheumatic disease treatment agent is selected from one or more of the following: adalimumab, tocilizumab, anakinra, tofacitinib, abatacept, rituximab, or their biosimilars or generic drugs, methotrexate, or leflunomide.

[0041] Alternatively, in the above drug composition, the SE-DR affinity peptide comprises the following amino acid sequence: FXGEQGXXGE or FXGEXAXXGE, where X is selected from K, Q, A, or G. Preferably, X is selected from A or G. More preferably, the SE-DR affinity peptide is FNS007(FKGEQAGAGE).

[0042] Alternatively, the amino acid sequence of the SE-DR affinity peptide may be selected from MGPKGRTVIIEQSWGSPKVTK, MGPKGRTVIIEQSLGSPKVTK, SIDLKDKKYKNIGAKLVQDVANNTNEEA, SIDLKDKKYKNIGAKLVQLVANNTNEEA, QYMCitADQAAGGLR, LTQCitGSVLR, WYNCitCHAAN, VETCitDGQVI, or VCitLCitSSVESTCitGRSCitPAPPPACitGLT.

[0043] Alternatively, in the above pharmaceutical composition, a pharmaceutically acceptable carrier may include a binder, a surfactant, a solubilizer, a stabilizer, a lubricant, a wetting agent, and / or a diluent. The dosage forms of the pharmaceutical composition are capsules, tablets, pills, liquids, powders, granules, fine granules, film-coated tablets, precipitants, lozenges, sublingual preparations, chewable preparations, buccal preparations, pastes, syrups, suspensions, elixirs, emulsions, topical preparations, ointments, patches, compresses, transdermal preparations, lotions, inhalants, aerosols, injections, or suppositories.

[0044] Alternatively, the above-mentioned pharmaceutical composition is suitable for administration via various routes, such as oral administration, intravenous administration, subcutaneous administration, intramuscular administration, intracerebral administration, intranasal administration, intrapulmonary administration, intra-arterial administration, intra-articular administration, intradermal administration, intravitreous administration, intramedullary injection, intraperitoneal administration, intrathecal administration, or transdermal administration.

[0045] Alternatively, in the above pharmaceutical composition, the rheumatic disease is selected from rheumatoid arthritis, juvenile idiopathic arthritis, psoriasis, psoriatic arthritis, ankylosing spondylitis, undifferentiated spondyloarthritis, systemic lupus erythematosus, systemic sclerosis, collagen disease, Crohn's disease, and ulcerative colitis.

[0046] Preferably, patients with rheumatic diseases are tuberculosis-positive or tuberculosis-negative, and patients with rheumatic diseases may or may not have hepatitis B.

[0047] Compared to prior art, the present invention has the following beneficial effects: (1) We were the first to discover that the antigen-specific drug SE-DR affinity peptide (particularly FNS007) does not have a significant effect on the immune systems of healthy humans, healthy cynomolgus monkeys, and healthy rats. (2) We were the first to discover that SE-DR affinity peptides (especially FNS007) significantly suppressed the development of tuberculosis in a rat model of latent Mycobacterium tuberculosis infection with type II collagen-induced arthritis (CIA), compared to adalimumab. (3) We were the first to discover that in type II collagen-induced arthritis model mice (CIA) infected with chronic hepatitis B, SE-DR affinity peptides (especially FNS007) significantly reduced the hepatitis B activation rate compared to abatacept. (4) In CIA rats, we discovered for the first time that combining antigen-specific drugs (especially FNS007 and APL20) with non-antigen-specific drugs (adalimumab, abatacept, or methotrexate, etc.) can rapidly slow disease progression, is safer than using adalimumab, abatacept, or methotrexate alone, and, in particular, maintains remission even after drug tapering or discontinuation. (5) Rheumatoid arthritis can be completely controlled by using antigen-specific drugs (FNS007, APL20, etc.) in combination with other non-antigen-specific drugs. [Brief explanation of the drawing]

[0048] [Figure 1] This graph shows the inflammation score at each time point during administration in the CIA rat model of the experiment shown in Example 9. [Figure 2] This is a graph of inflammation scores at each time point during drug discontinuation in the CIA rat model of the experiment shown in Example 9. [Modes for carrying out the invention]

[0049] The present invention will be further described below with reference to specific examples. It should be understood that the specific examples described herein are merely illustrative of the present invention and are not intended to limit the scope of the invention.

[0050] If specific techniques or conditions are not specified in the examples, the techniques or conditions described in the relevant literature or product specifications shall be followed. If the manufacturers of the reagents or equipment used are not specified, these reagents or equipment are all conventional products that can be purchased through normal channels.

[0051] Unless otherwise specified, the experimental methods in the following examples are all conventional methods. Unless otherwise specified, the test materials used in the following examples are all commercially available.

[0052] In this invention, the polypeptide used was synthesized by Hebei Fitness Biotechnology Co., Ltd. using a solid-phase synthesis method and purified using high-performance liquid chromatography. Mass spectrometry analysis of this polypeptide revealed that the polypeptide sequence was correct and the purity was 95% or higher.

[0053] Part I: In vitro test results of SE-DR affinity peptides SE-DR molecules are directly related to the pathogenesis of rheumatoid arthritis (RA). SE-DR molecules present RA-related autoantigens such as type II collagen (CII), heat shock protein 60 (Hsp60), and cartilage glycoprotein (HCgp-39) in vivo, further activating autoreactive T cells and causing the development of rheumatoid arthritis. A key therapeutic strategy for rheumatoid arthritis is to inhibit the activation of autoreactive T cells by autoantigen peptides through competitive inhibition. Currently, the main approach is to modify autoantigen peptides to not only inhibit autoantigen binding but also prevent the activation of autoreactive T cells. To achieve this, the modified peptide ligand must not only have a predetermined affinity for SE-DR but also exhibit suppression of T cell activation. Based on these principles, we designed and synthesized a series of modified peptide ligands and screened their affinity for SE-DR and their activating ability in peripheral blood T cells from RA patients. Specific steps and results are shown in Examples 1 and 2.

[0054] Example 1: Determination of polypeptide affinity Reaction system setup: A 200 μL reaction system was prepared in a 96-well plate. Each well contained 500 nM HLA-DR1, 25 nM fluorescently labeled polypeptide, and the test polypeptide, which had been sequentially diluted five times at a 5-fold rate starting from 200 μM. The last well was left empty as a quality control well. In the quality control well, a fluorescently labeled polypeptide without MHCII molecules was used to measure the free polypeptide signal. The reaction system pH was 7.4. A protease inhibitor cocktail was added before use, and the system was incubated at 37°C for 30 minutes. The degree of fluorescence change was read. The average value of the free labeled polypeptide was defined as FP_free, and the value in the well without the competing peptide was defined as FP_no_comp. The relative binding rates of the other wells were calculated according to the formula = (FP_sample - FP_free) / (FP_no_comp - FP_free). Curves were plotted using the relative binding rates and the concentrations of the test polypeptide, and the IC50 value was calculated by curve fitting.

[0055] Considering the amino acid properties of SE-DR-bound and unbound polypeptides comprehensively, it can be identified that P1, P4, P6, and P9 are important amino acids that influence the affinity between the polypeptide and SE-DR. In particular, P1 is an amino acid with a hydrophobic side chain and is a rare or unnatural amino acid with similar properties; the P4 site is an amino acid with nonpolar, polar and uncharged, polar and negatively charged properties and is a rare or unnatural amino acid with similar properties; the P6 site is an amino acid with a short side chain and is a rare or unnatural amino acid with similar properties; and the P9 site is an amino acid with a moderate to short side chain and is a rare or unnatural amino acid with similar properties.

[0056] [Table 1] (Note that P1-P9 in the table indicate the binding sites of polypeptides to HLA-DR. Polypeptides APL36 and APL37 are special and therefore their binding sites are not shown.)

[0057] [Table 2] (Note that P1-P9 in the table indicate the binding sites of polypeptides to HLA-DR.)

[0058] Example 2: PBMC stimulation test Add 3 mL of Ficoll to a 15 mL centrifuge tube, and dropwise add 4 mL of blood sample to the surface of the Ficoll. Centrifuge the tube at 18-20°C and 400 g for 30-40 minutes. Aspirate the upper layer of plasma with a Pasteur pipette, aspirate the PBMC layer (approximately 2 mL), and add it to a 14 mL centrifuge tube pre-filled with at least 3 volumes (6 mL) of PBS. Gently resuspend the mixture. Centrifuge the tube at 18-20°C and 60-100 g for 10 minutes. After centrifugation, remove the supernatant with a Pasteur pipette, suspend the resulting cell aggregate in 6-8 mL of PBS, centrifuge at 18-20°C and 60-100°C for 10 minutes, and remove the supernatant. Resuspend the cells in an appropriate volume of 1640 complete medium, count the cells, and then 1 × 10⁶ cells. 6The cell suspension was diluted to cells / ml. The diluted cell suspension was added to a 96-well plate. 100 μl of allosteric peptide, a positive control, was added to cell culture medium to a final concentration of 10 μg / ml. This mixture was supplemented with 200 μl of 1640 complete medium. After 5 days of culture, the supernatant was aspirated, centrifuged at 3000 rpm for 5 minutes, and the IL-6 level in the supernatant was detected by ELISA.

[0059] [Table 3]

[0060] Through Examples 1 and 2, several SE-DR affinity peptides were subjected to pharmacodynamic testing at the animal level.

[0061] Part II: Pharmacodynamic Results of SE-DR Affinity Peptides 1. SE-DR affinity peptides significantly suppressed disease progression in CIA rats and promoted the differentiation of peripheral blood T cells into Th2 and Treg cells in CIA rats (Example 3). A collagen-induced arthritis (CIA) model was established by intradermal injection of an emulsion prepared with type II bovine collagen (CII) and incomplete Freund's adjuvant (IFA) into the tail and head of female Lewis rats. After model establishment, morphological changes in the rats' limbs were examined daily. When the inflammation score was 1, affected rats were randomly divided into a model group, an SE-DR affinity peptide group (administered with FNS007 (APL2), APL7, APL9, APL20, ALP21, and ALP37, respectively), an autoantigen peptide group (i.e., type II collagen CII263-272), and an unrelated peptide group. Except for the model group, the polypeptide dose was 0.2 mmol in all cases. A control group was also established and administered via tail vein injection once every other day for 15 consecutive days. For efficacy analysis, the area under the curve (AUC) of the inflammation score was used once every other day from the day of rat registration until the end of administration. Furthermore, 144 hours after the end of administration, blood was collected from the orbital angular vein, and the proportion of helper T cells (Th1, Th2, Th17) and T regulatory cells (Treg) in peripheral blood mononuclear cells was measured by flow cytometry.

[0062] The results are shown in Table 4, which examines the effects of repeated administration of SE-DR affinity peptides (FNS007(APL2), APL7, APL9, APL20, ALP21, ALP37) for 144 hours on changes in the proportion of T cell subtypes in the peripheral blood of rats. Compared to the control group, the model group showed a significant increase in the proportion of Th1 and Th17 cells and the Th1 / Th2 cell ratio (p<0.05, p<0.01), while the proportion of Th2 and Treg cells showed a significant decrease (p<0.05, p<0.01). Compared to the model group, the SE-DR affinity peptide administration group showed a significant decrease in the proportion of Th1 and Th17 cells (p<0.05, p<0.01), while the proportion of Th2 and Treg cells showed a significant increase (p<0.05, p<0.01). The results are shown in Table 4. In conclusion, SE-DR affinity peptides promoted the differentiation of peripheral blood T cells from inflammatory Th1 and Th2 cells to anti-inflammatory Th2 and Treg cells in CIA rats.

[0063] [Table 4] Note: When compared to the control group. # P<0.05, ## P<0.01; compared to the model group * P<0.05, ** P<0.01.

[0064] 2. Test results of SE-DR affinity peptides in tuberculosis-positive RA patients 2.1: SE-DR affinity peptides do not inhibit normal immune function. SE-DR affinity peptides inhibit only the activation of T cells involved in self-antigen recognition and do not affect the normal immune system that protects the body from external infections. Therefore, they do not pose a risk of infection or tumors and can be used in tuberculosis-positive rheumatoid arthritis patients. Accordingly, the present invention can provide a novel therapeutic agent for tuberculosis-positive RA patients and solve the problem that anti-rheumatic biological agents cannot be used in this type of RA patient.

[0065] Studies have shown that SE-DR affinity peptides do not significantly alter the immune systems of healthy humans, healthy monkeys, and healthy rats, suggesting that SE-DR affinity peptides do not interfere with the body's normal immune function, do not reduce the body's defense capabilities, and pose no risk of infection or tumors. Please refer in particular to Examples 4 to 6 below.

[0066] Example 4 The effects of continuous administration of SE-DR affinity peptides for one month on immune indicators in SD rats were investigated. The SE-DR affinity peptides were divided into six administration groups (FNS007(APL2), APL7, APL9, APL20, ALP21, ALP37), and a control group was also established. Each group consisted of 10 males and 10 females, administered once daily for 4 weeks. After administration, serum anti-FNS007 antibodies, various serum immunoglobulins, serum complement, peripheral blood T lymphocytes, and serum cytokines were analyzed.

[0067] As a result, no significant changes were observed in any immune indicators after administration of SE-DR affinity peptides compared to the control group, suggesting that SE-DR affinity peptides do not affect the immune system of healthy rats. Table 5 shows the results of the effects of SE-DR affinity peptides on immune cells in healthy rats.

[0068] [Table 5]

[0069] Example 5 The effects of SE-DR affinity peptides on immune indicators in cynomolgus monkeys after continuous administration for one month were investigated. The SE-DR affinity peptide administration scheme involved dividing the monkeys into six administration groups (FNS007(APL2), APL7, APL9, APL20, ALP21, ALP37) and setting up a control group. Each group consisted of 3 males and 3 females, and the peptides were administered once daily for 4 weeks. After the completion of administration, immune indicators such as anti-FNS007 antibodies in serum, immunoglobulins of other serotypes, serum complement, peripheral blood T lymphocytes, and serum cytokines were observed.

[0070] As a result, no significant changes were observed in any immune indicators compared to the control group after administration, indicating that the SE-DR affinity peptide does not affect the immune system of healthy monkeys. Table 6 shows the effects of the SE-DR affinity peptide on immune cells in healthy monkeys.

[0071] [Table 6]

[0072] Example 6 The effects of a single dose of SE-DR affinity peptide on human immune indicators were investigated in healthy volunteers. The SE-DR affinity peptide used was FNS007, administered in three dose groups (5, 10, and 20 mg / case), with a placebo control group also established. After administration, different serotypes of immunoglobulins, peripheral blood T lymphocytes, and serum cytokines were observed. The results showed no significant changes in any immune indicators after administration compared to the placebo group and baseline values ​​before administration, indicating that SE-DR affinity peptides do not affect the immune system of healthy individuals. Table 7 shows the effects of SE-DR affinity peptides on immune cells in healthy individuals.

[0073] [Table 7]

[0074] 2.2: SE-DR affinity peptides do not pose a risk of inducing tuberculosis infection. Furthermore, to compare the differences in infection induction between SE-DR affinity peptides and biological agents, we used CIA model rats with latent tuberculosis infection in this study and compared the incidence of tuberculosis during arthritis treatment with adalimumab and SE-DR affinity peptides. As a result, both adalimumab and SE-DR affinity peptides showed good therapeutic effects in CIA rats, but adalimumab tended to induce tuberculosis recurrence during treatment, with a high incidence of tuberculosis at 60%. On the other hand, no tuberculosis recurrence was observed in the model group or the SE-DR affinity peptide group. As described above, SE-DR affinity peptides are expected to have good therapeutic effects on rheumatoid arthritis, do not increase the tuberculosis infection rate, and be safe even in tuberculosis-positive RA patients. See Example 7 for details.

[0075] Example 7 Establishment of a latent infection model: 5 × 10⁶ female Lewis rats 3 The rats were intravenously infected with the Erdman strain of CFU (colony-forming units). The amount of Mycobacterium tuberculosis (MTB) in the lung and spleen tissue of the rats was 1 × 10⁶ weeks after infection. 4The above results were reached. At this point, isoniazid (0.1 g / L) and rifampicin (15 g / L), both anti-tuberculosis drugs, were added to the drinking water for 4 weeks. Tuberculosis bacteria cultures from the lungs and spleen of rats became negative 2 weeks after discontinuation of the drugs, suggesting that a latent tuberculosis infection model had been successfully established.

[0076] A latent tuberculosis (CIA) model was established using the female Lewis rats infected with latent tuberculosis described above. Methods: Latent tuberculosis-infected rats were immunized by intradermal injection of an emulsion containing bovine CII and IFA (containing 100 μg of collagen) into the head and tail. After 7 days, the rats were boosted once using the same method. Morphological changes in the rats' limbs were examined daily. With an inflammation score of 1, the rats were randomly divided into a model group, a SE-DR affinity peptide group (FNS007 (APL2), APL7, APL9, APL20, ALP21, ALP37, 0.2 mmol), and an adalimumab 1 mg / kg group, with 10 rats in each group. The other 8 latent-infected rats were not included in the model establishment and were used as a control group. PBS was administered to the model and control groups. The drug corresponding to each group of rats was administered by tail vein injection at a volume of 5 ml / kg, once every other day for 21 consecutive days. Rats were sacrificed 22 days after administration. During administration, the inflammation score of the limbs of rats in each group was evaluated, and MTB cultures of the rat lungs and spleen were detected at the time of sacrifice.

[0077] After model establishment, compared with the control group, the inflammatory score of the model rats increased significantly. To reflect the effect of the drug on the indicators throughout the disease process and evaluate the comprehensive effect of the drug, the area under the curve (AUC) of the inflammatory score was statistically analyzed. As a result, compared with the model group, the SE-DR affinity peptide group and the adalimumab group could significantly reduce the inflammatory score of the diseased rats (P<0.01). At the time of sacrifice, the mycobacterium tuberculosis cultures from the lungs and spleens of the rats in the control group, the model group and the SE-DR affinity peptide group were all negative, while in the adalimumab group, the mycobacterium tuberculosis cultures from the lungs and spleens were positive in 6 / 10 rats. In addition, in the adalimumab group, obvious toxic symptoms such as piloerection and decreased activity were observed during administration, while the condition of the rats after SE-DR affinity peptide administration was good. From the above results, it was suggested that the SE-DR affinity peptide did not increase the recurrence risk of tuberculosis in rats and its safety was better than that of adalimumab. The results are shown in Table 8.

[0078]

Table 8

[0079] 2.3: The SE-DR affinity peptide has no risk of inducing hepatitis B (HBV) infection Furthermore, to compare the differences in infection induction between the SE-DR affinity peptide and biological agents, in this study, CIA mice, a model of chronic hepatitis B infection, were used to compare the activation of hepatitis B in mice during arthritis treatment with abatacept and the SE-DR affinity peptide.

[0080] As a result, both abatacept and SE-DR affinity peptide showed good therapeutic effects in CIA mice. However, abatacept tended to activate hepatitis B during the administration period, and ALT levels rose to 100 IU / ml in 50% of the mice. On the other hand, no significant differences in ALT levels were observed in the SE-DR affinity peptide group, the model group, and the control group. From this, it can be expected that SE-DR affinity peptide can be safely used in RA patients infected with hepatitis B without increasing the rate of hepatitis B activation during rheumatoid arthritis treatment. For details, please refer to Example 8.

[0081] Example 8 Establishment of a mouse model of chronic hepatitis B: Raav8-1.3HBV (1×10) in DBA / 1 mice. 12 A chronic hepatitis B (HBV) model was established by injecting (vg / mL) into the tail vein.

[0082] A chronic hepatitis B infection CIA model was established using DBA / 1 mice infected with chronic hepatitis B. Methods: Raav8-1.3HBV (1 × 10⁻¹⁶) was administered to mice. 12Two days after injecting (vg / mL) into the tail vein, mice were immunized by intradermal injection of an emulsion of bovine CII and CFA (containing 100 μg of collagen) into the tail and head. 21 days later, mice were boosted by a single intraperitoneal injection of an emulsion prepared with bovine CII and IFA (containing 100 μg of collagen). Subsequently, morphological changes in the limbs of the mice were examined daily, and those with an inflammation score of 1 were randomly assigned to the treatment group. Affected mice were randomly divided into a model group, an SE-DR affinity peptide group (50 μmol each of FNS007 (APL2), APL7, APL9, APL20, ALP21, and ALP37), and an abatacept group (100 μg), with 12 mice in each group. Ten mice with latent hepatitis B infection were not used for model establishment and were designated as a control group. Both the model and control groups were administered PBS. Each group of mice was administered the appropriate drug to their tail vein at a dose of 10 ml / kg, once every other day for 27 consecutive days. The mice were sacrificed on day 28 after administration. During administration, the inflammation score of the limbs of each group of mice was evaluated. Serological indicators related to viral injection and liver function in the mice were detected on the booster immunization day (22 days after tail vein injection) and at the time of sacrifice.

[0083] After establishing the mouse model, the inflammation score in the model mice was significantly higher compared to the control group. To reflect the impact of the drug on the indicator throughout the entire course and to evaluate the overall effect of the drug, the area under the curve (AUC) of the inflammation score was statistically analyzed. As a result, the SE-DR affinity peptide group and the abatacept group were able to significantly reduce the inflammation score in affected mice compared to the model group (P<0.01).

[0084] In the evaluation of hepatitis B virus, HBsAg, HBe antigen, and HBV DNA were detected in all mice 22 days after booster immunization, i.e., tail vein injection, and the mean ALT and AST levels were 45 and 65 U / L, respectively. This suggested the successful establishment of a chronic hepatitis B infection model. At the time of sacrifice, serological indicators of liver function in the control, model, and SE-DR affinity peptide groups were similar to those during booster immunization. However, serological indicators of liver function in the abatacept-administered mice were significantly elevated, with ALT levels exceeding 100 IU / ml in 50% of mice, suggesting a significantly increased risk of hepatitis B activation in mice. Furthermore, obvious toxic symptoms such as piloerection and decreased activity were observed during abatacept administration, but the condition of the mice after SE-DR affinity peptide administration was good. These results suggest that SE-DR affinity peptide does not increase the risk of hepatitis B activation in mice and that its safety is superior to that of abatacept. Please refer to Table 9 for the results of each indicator at the time of the final sampling.

[0085] [Table 9] Note: When compared to the control group. # P<0.05, ## P<0.01; compared to the model group * P<0.05, ** P<0.01.

[0086] 3. Results of the study on combination therapy in RA patients The combined use of antigen-specific and non-antigen-specific therapies represents a future direction in rheumatoid arthritis treatment. On the one hand, non-antigen-specific therapies can accelerate antigen-specific therapy and control clinical symptoms (such as inflammation) early, while on the other hand, the immunomodulatory effects of antigen-specific drugs can rebuild immune tolerance and completely control the disease.

[0087] To test this theory, this study used a CIA model to investigate combination therapy with SE-DR affinity peptides (antigen-specific therapeutic agents) and adalimumab / abatacept / methotrexate (non-antigen-specific therapeutic agents), and compared the differences with SE-DR affinity peptides, adalimumab, abatacept, or methotrexate alone. The results showed that combination therapy with SE-DR affinity peptides and adalimumab, SE-DR affinity peptides and abatacept, and SE-DR affinity peptides and methotrexate rapidly suppressed the inflammatory response in rats compared to SE-DR affinity peptide monotherapy.

[0088] The combination therapy group was more effective and safer than adalimumab, abatacept, or methotrexate monotherapy. The therapeutic effect was maintained after discontinuation of treatment in both the SE-DR affinity peptide group and the combination therapy group, but inflammation scores increased after discontinuation in the adalimumab, abatacept, or methotrexate groups. This suggests that combining SE-DR affinity peptides with non-antigen-specific therapeutic agents (adalimumab / abatacept / methotrexate, etc.) can significantly improve clinical remission rates and maintain remission after drug discontinuation, thus enabling drug tapering or discontinuation. See Examples 9, 10, and 11 for further details.

[0089] Example 9 Female Lewis rats were used to establish a CIA model. Methods: Rats were immunized by intradermal injection of an emulsion prepared with bovine CII and IFA into the tail and head. After 7 days, a boost was administered in the same manner. Morphological changes in the rats' limbs were then examined daily. Rats were randomly divided into three groups of 10: a model group, a SE-DR affinity peptide group (FNS007, 0.2 mmol), an adalimumab group (1 mg / kg), and a combination therapy group (FNS007 0.2 mmol + adalimumab 1 mg / kg). Eight other female Lewis rats were excluded from the model establishment and served as the control group. Both the model and control groups were administered PBS. The appropriate drug for each group of rats was administered by intra-tail vein injection at a dose of 5 mL / kg, once every other day for 21 consecutive days. During administration (once every other day), the inflammation score of the limbs of the rats in each group was evaluated, and the area under the curve (AUC) of the inflammation score during administration was calculated. During discontinuation of administration, inflammation scores in the limbs of rats in each group were intermittently evaluated (once every other day), and rats were sacrificed 22 days after discontinuation of administration. HE staining of the ankle joint was performed to assess tissue damage. The specific scoring criteria were as follows: 0 = normal synovial tissue; 1 = synovial hyperplasia and inflammatory cell infiltration; 2 = pannus formation and cartilage erosion; 3 = extensive cartilage destruction with subchondral bone erosion; 4 = loss of joint integrity, ankylosis.

[0090] The results showed that in the CIA rat model, the combination of FNS007 and adalimumab rapidly suppressed the inflammatory response in rats compared to the FNS007 monotherapy group. This was demonstrated by a decrease in the inflammation score in the combination group during the first week of administration compared to the FNS007 monotherapy group, with the AUC of the inflammation score decreasing from 14.26 to 11.93. There was a statistically significant difference between these two groups (P<0.05). The inflammation score AUC in the combination therapy group decreased significantly throughout the entire administration period, with the inflammation score decreasing from 46.17 to 35.88. There was a statistically significant difference between these two groups (P<0.05). Furthermore, the efficacy of the combination therapy group was more pronounced compared to adalimumab (inflammation score decreased from 54.51 to 35.88, statistically significant difference, p<0.05), the incidence of infections in rats decreased, and symptoms of piloerection and epistaxis in rats significantly improved. Simultaneously, administration was discontinued on day 21, followed by a 21-day observation period. During the discontinuation period, the FNS007 group and the combination therapy group maintained their therapeutic effect, but the adalimumab group did not. This was evident from the significant increase in inflammation scores compared to the time of discontinuation (P<0.01). The results are shown in Table 10, Figures 1 and 2.

[0091] [Table 10] Note: When compared to the control group. # P<0.05, ## P<0.01; compared to the model group * P<0.05, ** P<0.01.

[0092] Example 10 Male DBA mice were used to establish a CIA model. Methods: Mice were immunized by intradermal injection of bovine CII and CFA (containing 100 μg of collagen) emulsion into the head and tail. After 21 days, the mice were boosted once by intraperitoneal injection of bovine CII and IFA (containing 100 μg of collagen) emulsion. Morphological changes in the mice's limbs were observed daily, and they were randomly assigned to the treatment group when the inflammation score reached 1. Affected mice were randomly divided into three groups: a model group, an SE-DR affinity peptide group (FNS007, 0.2 mmol), an abatacept group (5 mg / kg), and a combination therapy group (FNS007, 0.2 mmol + abatacept, 5 mg / kg), with 12 mice in each group. Ten other female DBA / 1 mice were not included in the model establishment and were used as the control group. Both the model and control groups were administered PBS. Each group of mice was administered the corresponding drug to the tail vein at a dose of 10 mL / kg, once every other day for 28 consecutive days, followed by a 28-day recovery period. During administration (once every other day), the inflammation score of the limbs of each group of mice was evaluated, and the area under the curve (AUC) of the inflammation score during administration was calculated. Even after discontinuation of administration, the inflammation score of the limbs of each group of rats was continuously evaluated (once every other day), and the rats were sacrificed 28 days after discontinuation. HE staining of the ankle joint was performed to assess tissue damage. The specific scoring criteria were as follows: 0 = normal synovial tissue; 1 = synovial hyperplasia and inflammatory cell infiltration; 2 = pannus formation and cartilage erosion; 3 = extensive cartilage destruction with subchondral bone erosion; 4 = loss of joint integrity, ankylosis.

[0093] The results showed that in the CIA mouse model, the combination therapy of FNS007 and abatacept rapidly suppressed the inflammatory response in mice compared to the FNS007 monotherapy group. This was demonstrated by a decrease in the inflammation score in the combination therapy group during the first 10 days of administration, with the AUC of the inflammation score decreasing from 25.64 to 18.11 compared to the FNS007 monotherapy group. A statistically significant difference was observed between the two groups (p<0.05). The inflammation score AUC in the combination therapy group decreased significantly from 90.23 to 75.87 over the entire administration period, with a statistically significant difference observed between the two groups (P<0.05). Furthermore, the efficacy of the combination therapy group was more pronounced compared to the abatacept group (inflammation score AUC decreased from 89.16 to 75.87, statistically significant difference, p<0.05), the incidence of infection in mice decreased, and symptoms of piloerection and epistaxis significantly improved. Simultaneously, administration was discontinued on day 28, followed by a 28-day observation period. During the discontinuation period, the FNS007 group and the combination therapy group maintained their therapeutic effect, but the abatacept group did not. This was evident from the significant increase in inflammation scores compared to the time of discontinuation (P<0.01). The results are shown in Table 11.

[0094] [Table 11] Note: When compared to the control group. # P<0.05, ## P<0.01; compared to the model group * P<0.05, ** P<0.01.

[0095] Example 11 Female Lewis rats were used to establish a CIA model. Methods: Emulsions prepared with bovine CII and IFA were administered intradermally to the head and tail for immunization. After 7 days, the rats received a single boost using the same method. Subsequently, morphological changes in the rats' limbs were observed daily, and rats with an inflammation score of 1 were randomly assigned to the treatment group. Affected rats were randomly divided into three groups: a model group, a SE-DR affinity peptide group (APL20, 0.2 mmol), a methotrexate group (0.5 mg / kg), and a combination therapy group (APL20, 0.2 mmol + methotrexate, 0.5 mg / kg), with 10 rats in each group. Another 8 female Lewis rats were not included in the model establishment and were used as a control group. PBS was administered to both the model and control groups. Each group of rats was administered the appropriate drug at a dose of 5 mL / kg via intracranial injection. Methotrexate was administered twice a week, and the other drugs were administered every other day for 21 consecutive days, followed by a 21-day recovery period. Inflammation scores of the limbs of each group of rats were assessed during administration (every other day), and the area under the curve (AUC) of the inflammation score during administration was calculated. Inflammation scores of the limbs of each group of rats were continuously assessed (every other day) during discontinuation of administration, and the rats were sacrificed on the 22nd day after discontinuation. HE staining of the ankle joint was performed to assess tissue damage. The specific scoring criteria were as follows: 0 = normal synovial tissue; 1 = synovial hyperplasia and inflammatory cell infiltration; 2 = pannus formation and cartilage erosion; 3 = extensive cartilage destruction with subchondral bone erosion; 4 = loss of joint integrity, ankylosis.

[0096] The results showed that in the CIA rat model, the combination therapy of APL20 and methotrexate rapidly suppressed the inflammatory response in rats compared to the APL20 monotherapy group. This was demonstrated in the first week of administration, when the inflammation score decreased in the combination therapy group compared to the FNS007 monotherapy group, with the inflammation score AUC decreasing from 14.93 to 12.06. There was a statistically significant difference between the two groups (P<0.05). The inflammation score AUC in the combination therapy group decreased significantly from 48.69 to 37.59 throughout the entire administration period, with a statistically significant difference observed between the two groups (P<0.05). Furthermore, the efficacy of the combination therapy group was more pronounced compared to methotrexate alone (inflammation score AUC decreased from 67.69 to 37.59, statistically significant difference, p<0.05), and symptoms of piloerection and epistaxis in rats were significantly improved, and animal mortality was reduced. Simultaneously, administration was discontinued on day 21, followed by a 21-day observation period. During the discontinuation period, the APL20 group and the combination therapy group maintained their therapeutic effect, but the methotrexate group did not. This was evident from the significant increase in inflammation scores compared to the time of discontinuation (P<0.01). The results are shown in Table 12.

[0097] [Table 12] Note: When compared to the control group. # P<0.05, ## P<0.01; compared to the model group * P<0.05, ** P<0.01.

[0098] As described above, by combining SE-DR affinity peptides with non-antigen-specific therapeutic agents (adalimumab / abatacept / methotrexate, etc.), the clinical remission rate can be significantly improved, remission can be sustained even after discontinuation of the drug, and gradual reduction or discontinuation of the drug can be achieved. Therefore, the present invention can provide a novel pharmaceutical composition that can significantly improve the clinical remission rate and is expected to enable gradual reduction or discontinuation of the drug.

[0099] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, the present invention is intended to include such modifications and variations, as long as they are within the scope of the appended claims and their equivalents.

Claims

1. The use of SE-DR affinity peptides for the preparation of drugs for treating rheumatic diseases in rheumatoid arthritis patients who are tuberculosis-positive or rheumatoid arthritis patients who have concomitant hepatitis B, The aforementioned SE-DR affinity peptide is a peptide that binds to an HLA-DR molecule sharing an epitope, the shared epitope being a five-amino acid motif containing QK / RRAA located at positions 70-74 on the β-chain of HLA-DR. The aforementioned SE-DR affinity peptide competitively inhibits the binding of autoantigens associated with rheumatic diseases to the HLA-DR molecule, but does not have broad immunosuppressive effects and does not pose a risk of inducing infections or tumors. The core sequence of the SE-DR affinity peptide that binds to SE-DR includes core amino acids corresponding to P1 to P9. The P1 site is an amino acid with a hydrophobic side chain and rare or unnatural amino acids with similar properties; the P4 site is a nonpolar, polar and uncharged, polar and charged amino acid and rare or unnatural amino acids with similar properties; the P6 site is an amino acid with a short side chain and rare or unnatural amino acids with similar properties; the P9 site is an amino acid with a moderate to short side chain and rare or unnatural amino acids with similar properties. The aforementioned SE-DR affinity peptides are FKGEQGGAGE (APL1), FNS007 (FKGEQAGAGE) (APL2), YVAQNTLKLA (APL5), YAKQATLKLA (APL6), YAKQATLALA (APL7), IWYISCFGCETHAML (APL9), IWYITCFGCETHAML (APL10), RSFTLDSSETGVG (APL15), RSFTLAASETGVG (APL16), RSFTLASSATGVG (APL17), RSFTLDGSETGVG (APL19), and SIDLKDKYKNIGAKLVQL Having an amino acid sequence selected from VANTNEEA (APL20), MGPKGRTVIIEQSLGSPKVTK (APL21), SAVELCitSSVPPGVR (APL22), SAVALCitSSVPPGVR (APL24), SAVRLCitRSVPPGVR (APL26), GVYATCitSSAACitLCit (APL34), QDFTNCitANKLKNS (APL35), VVLLVATEGCitVRVASAYQDK (APL36), or VCitLCitSSSVESTCitGRSCitPAPPPACitGLT (APL37), The use is characterized in that the rheumatic disease is selected from one or more of the following: rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, or undifferentiated spondyloarthropathy.

2. The use according to claim 1, characterized in that the rheumatic disease is rheumatoid arthritis.

3. The use according to Claim 2, characterized in that the SE-DR affinity peptide has an amino acid sequence selected from FKGEQGGAGE (APL1), FNS007 (FKGEQAGAGE) (APL2), YAKQATLALA (APL7), IWYISCFGCETHAML (APL9), SIDLKDKYKNIGAKLVQLVANTNEEA (APL20), MGPKGRTVIIEQSLGSPKVTK (APL21), or VCitLCitSSSVESTCitGRSCitPAPPPACitGLT (APL37).

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