A recombinant IgG-like bispecific antibody acting as interleukin-1β and interleukin-17A inhibitor exhibits a promising efficacy for rheumatoid arthritis

Investigational bispecific antibodies for the treatment of rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disorder with a characteristic chronic inflammation of the synovium that may lead to the destruction of the joints in untreated patients. Interestingly, despite the availability of several effective treatments, many patients do not achieve remission or low disease activity or may experience disease relapse.Following the above unmet needs, bispecific antibodies (BsAbs) have emerged as a new approach to improve the disease's treatment. BsAbs are designed to simultaneously target two different proteins involved in RA pathogenesis, leading to enhanced efficacy and reduced side effects compared to traditional monoclonal antibodies (mAbs).

AREAS COVERED

In this review, we discuss the development of BsAbs for RA treatment, including their mechanism of action, efficacy, and safety profile. We also deal with the challenges and future directions in this field.

EXPERT OPINION

BsAbs show promise in preclinical and clinical evaluations for treating RA. Further research is needed to optimize design and dosage and identify ideal patient groups. BsAbs can benefit disease management and improve outcomes of RA patients.

Two Main Cellular Components in Rheumatoid Arthritis: Communication Between T Cells and Fibroblast-Like Synoviocytes in the Joint Synovium

Rheumatoid arthritis (RA) is a chronic autoimmune disease that endangers the health of approximately 1% of the global population. Current RA medications on the market mainly include non-steroidal anti-inflammatory drugs, biological agents, and disease-modifying drugs. These drugs aim to inhibit the overactivated immune response or inflammation of RA, but they cannot cure RA. A better understanding of the pathogenesis of RA will provide a new understanding to search for RA targets and for drug development. The infiltration of T cells and hyper-proliferation of fibroblast-like synoviocytes (FLS) in the synovium of patients with RA are significantly upregulated. Furthermore, the abnormal activation of these two types of cells has been confirmed to promote development of the course of A by many studies. This article systematically summarizes the interactions between T cells and FLS in RA synovial tissues, including one-way/mutual regulation and direct/indirect regulation between the two. It further aims to investigate the pathogenesis of RA from the perspective of mutual regulation between T cells and FLS and to provide new insights into RA research.

Rheumatoid arthritis: Development after the emergence of a chemokine for neutrophils in the synovium

Rheumatoid arthritis (RA) may not be a multifactorial disease; it can be hypothesized that RA is developed through a series of events following a triggering event, which is the emergence of a chemokine for neutrophils in the synovium. IL-17A, secreted by infiltrated neutrophils, stimulates synoviocytes to produce CCL20, which attracts various CCR6-expressing cells, including Th17 cells. Monocytes (macrophages) appear after neutrophil infiltration according to the natural course of inflammation and secrete IL-1β and TNFα. Then, IL-17A, IL-1β, and TNFα stimulate synoviocytes to produce CCL20, amplifying the inflammation. Varieties of chemokines secreted by infiltrating cells accumulate in the synovium and induce synoviocyte proliferation by binding to the corresponding G protein-coupled receptors, thus expanding the synovial tissue. CCL20 in this tissue attracts circulating monocytes that express both CCR6 and receptor activator of NF-κB (RANK), which differentiate into osteoclasts in the presence of RANKL. In this way, pannus is formed, and bone destruction begins.

An immuno-blocking agent targeting IL-1β and IL-17A reduces the lesion of DSS-induced ulcerative colitis in mice

In recent decades when biological agents have flourished, a part of patients suffering from inflammatory bowel disease (IBD) have received the treatment of tumor necrosis factor inhibitors or IL-1 antibodies. This study aims to investigate the anti-colitis effects of bispecific antibody (FL-BsAb1/17) targeting IL-1β and IL-17A comparing with TNF-α soluble receptor medicine etanercept. IBD model in mice was established by drinking 3% DSS (dextran sulfate sodium salt). On the first day of drinking DSS, treatments with etanercept (5 mg/kg) or different doses of FL-BsAb1/17 (1 mg/kg, 5 mg/kg, and 10 mg/kg) were started by intraperitoneal injection every other day. The results demonstrated that FL-BsAb1/17 treatment was more effective than etanercept at the same dose (5 mg/kg) in relieving the typical symptom of ulcerative colitis induced by DSS (such as the severity score and intestinal shortening), and down-regulating the expression of inflammatory factors (IL-17A, IL-6, IL-12, IL-22, IL-1β, IL-23, TNF-α) in the serum and colon. FL-BsAb1/17 could also reduce the degree of intestinal fibrosis. The same dose of FL-BsAb1/17 (5 mg/kg) performed better than etanercept in down-regulating MDA and up-regulating SOD (superoxide dismutase), CAT (catalase), and T-AOC (total antioxidant capacity) in serum. Both FL-BsAb1/17 and etanercept could reduce the transcription of Bax and increase the transcription of Bcl-2 and slow down apoptosis in colitis colon tissue. We conclude that the blocking of IL-1β and IL-17A can inhibit DSS-induced ulcerative colitis and FL-BsAb1/17 may have potential to become a new dual-target candidate for colitis treatment.

Biologic therapies for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. If left untreated, persistent synovial inflammation can lead to cartilage and bone destruction, ultimately causing significant longterm disability and mortality. However, since the late 1990s, the combined use of methotrexate, a synthetic diseasemodifying antirheumatic drug (DMARD), and a biological DMARD has revolutionized the treatment of RA. As of 2021, the Korea Food and Drug Administration has approved seven biological DMARDs for RA treatment: four tumor necrosis factor-alpha inhibitors (infliximab, etanercept, adalimumab, and golimumab) and three non-tumor necrosis factor biological products (abatacept, rituximab, and tocilizumab). Although the use of biological products has allowed significant advances in the treatment of RA, there are certain drawbacks, such as high cost, increased infection risk, and the necessity for parenteral route product administration. Therefore, discontinuation of biological DMARD use without a resulting disease flare is the next treatment goal and a desirable result from the standpoint of risk reduction and cost-effectiveness, especially for patients with clinical remission. It is still unclear which biological product is the best. Clinicians must, therefore, personalize the sequence and strategy of treatment by considering patient characteristics, disease activity, comorbidity, and economic condition

Pain Mechanism in Rheumatoid Arthritis: From Cytokines to Central Sensitization

Pain is the most common symptom in patients with rheumatoid arthritis (RA). Although in recent years, through the implementation of targeted treatment and the introduction of disease-modifying antirheumatic drugs (DMARDs), the treatment of RA patients has made a significant progress, a large proportion of patients still feel pain. Finding appropriate treatment to alleviate the pain is very important for RA patients. Current research showed that, in addition to inflammation, RA pain involves peripheral sensitization and abnormalities in the central nervous system (CNS) pain regulatory mechanisms. This review summarized the literature on pain mechanisms of RA published in recent years. A better understanding of pain mechanisms will help to develop new analgesic targets and deploy new and existing therapies.

Regeneration and repair in the healing lung

The lung achieves an efficient gas exchange between a complex non‐sterile atmosphere and the body via a delicate and extensive epithelial surface, with high efficiency because of elastic deformation allowing for an increase and decrease in volume during the process of breathing and because of an extensive vasculature which aids rapid gas diffusion. The lungs’ large surface area exposes the organ to a continual risk of damage from pathogens, toxins or irritants; however, lung damage can be rapidly healed via regenerative processes that restore its structure and function. In response to sustained and extensive damage, the lung is healed via a non‐regenerative process resulting in scar tissue which locally stiffens its structure, which over time leads to a serious loss of lung function and to increasing morbidities. This review discusses what is known about the factors which influence whether a lung is healed by regeneration or repair and what potential new therapeutic approaches may positively influence lung healing.

A novel bispecific antibody alleviates bleomycin-induced systemic sclerosis injury

Systemic sclerosis (SSc) is induced by variety of factors and eventually causes multiple organ damage. In recent years, biological agents targeting cytokines and cell surface molecules have gradually come to market. Here, the anti-inflammatory and antifibrotic effects of a novel bispecific antibody (FL-BsAb1/17) targeting interleukin-17A (IL-17A) and interleukin-1β (IL-1β) were detected. Bleomycin (BLM) was subcutaneously injected for 21 consecutive days to establish the SSc mouse model, and mice were subsequently treated with etanercept or different doses (1, 5, 10 mg/kg) of FL-BsAb1/17. The results showed that FL-BsAb1/17 treatment (10 mg/kg, 5 mg/kg) significantly attenuated BLM-induced SSc-like inflammation by inhibiting the expression of inflammatory factors (IL-17A, IL-1β, IL-8, IL-22, IL-23, IL-6) and fibrosis, with specific outcomes of dermis thickening and lung fibrosis, by inhibiting the expression of fibrotic factors (TGF-β, α-sma, Col-1, Col-3) in the serum, skin and lungs. In addition, FL-BsAb1/17 (10 mg/kg, 5 mg/kg) downregulated protein levels of TGF-β and phosphorylated Smad2/3 in the skin and lungs and reduced collagen 1 protein levels. This indicated that FL-BsAb1/17 can inhibit the development of fibrosis by inhibiting the TGF-β/Smad2/3 signaling pathway. FL-BsAb1/17 (10 mg/kg, 5 mg/kg) could also effectively reduce the content of MDA, increase the activity of SOD and CAT, and improve the total antioxidant capacity (T-AOC). In conclusion, FL-BsAb1/17 alleviated BLM-induced SSc by downregulating inflammatory cascades, relieving oxidative stress and inhibiting TGF-β/Smad2/3 signaling. These data suggest that FL-BsAb1/17 has potential as a novel therapeutic candidate for SSc.

Role of biological agents in treatment of rheumatoid arthritis

Advances in understanding of the pathophysiology of rheumatoid arthritis with concurrent advances in protein engineering led to the development of biological disease-modifying antirheumatic drugs which have dramatically revolutionized the treatment of this condition. This review article focuses on the role of biological agents currently employed in the treatment of rheumatoid arthritis, as well as novel biological agents in development.

Interleukin-17: Functional and Structural Features, Application as a Therapeutic Target

Cytokines of the IL-17 family play a key role in the host organism defense against bacterial and fungal infections. At the same time, upregulated synthesis of IL-17 cytokines is associated with immunoinflammatory and autoimmune diseases such as psoriasis, rheumatoid arthritis, systemic lupus erythematosus, and others. The members of this family are important therapeutic targets in the treatment of various human chronic inflammatory disorders. Elucidation of signaling pathways involving IL-17 family proteins and analysis of the structure of cytokine complexes with specific antibodies, inhibitors, and receptors are essential for the development of new drugs for the therapy of immunoinflammatory rheumatic diseases.

Anti-inflammatory Mechanism of Geniposide: Inhibiting the Hyperpermeability of Fibroblast-Like Synoviocytes via the RhoA/p38MAPK/NF-κB/F-Actin Signal Pathway

Geniposide (GE) is the extraction and purification of iridoid glycosides from the Gardenia jasminoides Ellis, which is a promising anti-inflammatory drug, but its mechanism of actions on rheumatoid arthritis (RA) has not been clarified. This study investigated the molecular mechanism behind GE reduced the high permeability of fibroblast-like synoviocytes (FLSs) derived from SD rats with adjuvant arthritis (AA), with the aims of observing the action of GE in AA rats and exploring new therapeutic strategies for RA treatment. The CCK-8 method was used to detect FLSs proliferation. The pro-inflammatory cytokines levels and anti-inflammatory cytokines levels in FLSs were determined by ELISA kits. FLSs permeability assay was performed on Transwell. Immunofluorescence was used to assay the arrangement and morphology of F-actin. The expression of the key molecules related to FLSs permeability (RhoA, p-p38MAPK, NF-κB p-p65 and F-actin) was detected by western blotting. After treatment with lipopolysaccharide (LPS), the proliferation and the permeability of the cells increased significantly (all P < 0.05). The expression of RhoA, p-p38MAPK, NF-κB p-p65 and F-actin in FLSs was higher compared with the control group, and F-actin was redistributed, with the formation of additional stress fibers. But, these conditions were moderated after treatment with GE. We demonstrated that the treatment of different concentrations of GE (25, 50, and 100 μg/mL) had a significant inhibitory effect on the proliferation and permeability of FLSs in vitro. Furthermore, the levels of interleukin (IL)-1β and IL-17 secreted by FLSs were decreased in different doses of GE groups, and the levels of anti-inflammatory cytokines (IL-4, TGF-β1) were increased. Under treatment with GE, low expression of RhoA downregulated expression of p-p38MAPK, NF-κB p-p65, and F-actin while compared with control group, and restored the hyperpermeability of FLSs due to LPS treatment. Taken together, GE might play its anti-inflammatory and immunoregulatory effects via regulating the relative equilibrium of pro-inflammatory cytokines and anti-inflammatory cytokines. GE attenuated the hyperpermeability of FLSs. The down-regulation of the conduction of RhoA/p38MAPK/NF-κB/F-actin signal may play a critical role in the mechanisms of GE on RA. GE could be an effective therapeutic agent for the treatment of RA.