Etanercept: long-term clinical experience in rheumatoid arthritis and other arthritis

Safety and Effectiveness of Etanercept Biosimilar SB4 for Rheumatic Diseases in South Korea: Real-World Post-marketing Surveillance Data

INTRODUCTION

SB4 is the first approved biosimilar of etanercept, a biologic tumor necrosis factor inhibitor, to treat various autoimmune diseases including axial spondylarthritis (axSpA), rheumatoid arthritis (RA), psoriatic arthritis (PsA), and plaque psoriasis (PsO). This post-marketing surveillance (PMS) study of SB4 investigated safety and effectiveness in routine clinical practice and is part of the drug approval process in Korea.

METHODS

This prospective, multi-center, open-label, observational, phase IV PMS study was designed to enroll patients with axSpA, RA, PsA, and PsO in Korea from September 2015 to September 2019. Both etanercept-naïve patients or patients switched from reference etanercept were included. SB4 was administered weekly via subcutaneous injections using pre-filled syringes. Safety was assessed by the incidence of adverse events (AEs), adverse drug reactions (ADRs) and serious adverse events (SAE). Effectiveness was assessed by the change from baseline of investigator-rated Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in patients with ankylosing spondylitis (AS) and disease activity score-28 (DAS28) in patients with RA.

RESULTS

Among 316 enrolled patients, 314 were included in the safety analysis (176 with AS and 138 with RA). The overall incidence of AEs, ADRs and serious AEs were 17.8, 9.9, and 1.3%, respectively. Most AEs were mild (66.7%) or moderate (31.1%) and not related to SB4 (58.9%). Most common AEs were injection site pruritus (1.9%) and injection site rash (1.3%). At week 24, mean disease activity scores significantly decreased compared to baseline in naïve patients with AS and RA (BASDAI 2.7 vs. 6.2, p < 0.0001; DAS28 3.8 vs. 5.7, p < 0.0001) and in switched patients with AS and RA (BASDAI 1.0 vs. 1.3, p = 0.0018; DAS28 2.4 vs. 2.9, p = 0.0893).

CONCLUSION

This first real-world evidence of SB4 from a phase IV PMS study in Korea shows comparable effectiveness to historical SB4 real-world evidence without any new significant safety signals.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

Recombinant proteins in rheumatology - recent advances

New targeted anti-inflammatory drugs have revolutionized the therapeutic strategies in rheumatology. Recombinant DNA selection technologies have enabled the isolation and humanization of specific antibody fragments of any specificity that can be 'armed' to deliver effective anti-inflammatory 'payloads'. Antibodies and other targeted provide the opportunity to block key soluble mediators of inflammation in their milieu, or alternatively to block intracellular inflammation-triggering pathways by binding to an upstream cell-surface receptor. Designed proteins can be improved with respect to desired pharmacokinetic and pharmacodynamic effects. They facilitate the delivery of the required immunosuppressive effect. However, the individual extent of desired and undesired effects of a particular biologic therapy can be broader than initially predicted and requires careful evaluation during clinical trials. This review highlights advances in the application of recombinant antibody technology for novel biologic therapies in rheumatology.

Impact of innate immunity in a subset of children with autism spectrum disorders: a case control study

Background

Among patients with autism spectrum disorders (ASD) evaluated in our clinic, there appears to be a subset that can be clinically distinguished from other ASD children because of frequent infections (usually viral) accompanied by worsening behavioural symptoms and/or loss/decrease in acquired skills. This study assessed whether these clinical features of this ASD subset are associated with atopy, asthma, food allergy (FA), primary immunodeficiency (PID), or innate immune responses important in viral infections.

Methods

This study included the ASD children described above (ASD test, N = 26) and the following controls: ASD controls (N = 107), non-ASD controls with FA (N = 24), non-ASD controls with chronic rhinosinusitis/recurrent otitis media (CRS/ROM; N = 38), and normal controls (N = 43). We assessed prevalence of atopy, asthma, FA, CRS/ROM, and PID. Innate immune responses were assessed by measuring production of proinflammatory and counter-regulatory cytokines by peripheral blood mononuclear cells (PBMCs) in response to agonists of Toll-like receptors (TLRs), with or without pre-treatment of lipopolysaccharide (LPS), a TLR4 agonist.

Results

Non-IgE mediated FA was equally prevalent in both ASD test and ASD control groups, occurring at higher frequency than in the non-ASD controls. Allergic rhinitis, atopic/non-atopic asthma, and atopic dermatitis were equally prevalent among the study groups except for the CRS/ROM group in which non-atopic asthma was more prevalent (52.6%). CRS/ROM and specific polysaccharide antibody deficiency (SPAD) were more prevalent in the ASD test group than in the ASD control, FA, and normal control groups: 23.1% vs. < 5% for CRS/ROS and 19.2% vs. < 1% for SPAD. However, CRS/ROM patients had the highest prevalence of SPAD (34.2%). When compared to ASD and normal case controls, PBMCs from 19 non-SPAD, ASD test group children produced: 1) less IL-1β with a TLR7/8 agonist, less IL-10 with a TLR2/6 agonist, and more IL-23 with a TLR4 agonist without LPS pre-treatment, and 2) less IL-1β with TLR4/7/8 agonists with LPS pre-treatment. These are cytokines associated with the neuro-immune network.

Conclusion

Clinical features of the ASD test group were not associated with atopy, asthma, FA, or PID in our study but may be associated with altered TLR responses mediating neuro-immune interactions.

Therapeutic advances in rheumatology with the use of recombinant proteins

Antibody engineering and protein design have led to the creation of a new era of targeted anti-inflammatory therapies in rheumatology. Recombinant DNA technologies have enabled the selection and humanization of specific antibody fragments in order to develop therapeutic reagents of any specificity that can be 'armed' to deliver effective anti-inflammatory 'payloads'. Antibodies and antibody-like proteins provide the opportunity to block key soluble mediators of inflammation in their milieu, or alternatively to block intracellular inflammation-triggering pathways by binding to an upstream cell-surface receptor. These designer proteins can be tuned for desired pharmacokinetic and pharmacodynamic effects, and represent tools for specific therapeutic intervention by delivering precisely the required immunosuppressive effect. The extent of desired and undesired effects of a particular biologic therapy, however, can be broader than initially predicted and require careful evaluation during clinical trials. This Review highlights advances in recombinant technologies for the development of novel biologic therapies in rheumatology.

Engineered antibodies of IgG1/IgG3 mixed isotype with enhanced cytotoxic activities

Enhancement of multiple effector functions of an antibody may be a promising approach for antibody therapy. We have previously reported that fucose removal from Fc-linked oligosaccharides greatly enhances antibody-dependent cellular cytotoxicity (ADCC) of therapeutic antibodies. Here, we report a unique approach to enhance complement-dependent cytotoxicity (CDC), another important effector function of antitumor antibodies, by using engineered constant region of human IgG1/IgG3 chimeric isotypes. We systematically shuffled constant domains of IgG1 and IgG3 to generate a comprehensive set of mixed chimeric isotypes of anti-CD20 antibodies. Among these, the variant 1133, consisting of the CH1 and the hinge each from IgG1 and the Fc from IgG3, was unexpectedly found to exhibit markedly enhanced CDC that exceeded wild-type levels. However, it lacked protein A-binding capacity, an important feature for the industrial production. To eliminate this deficiency, a portion in COOH-terminal CH3 domain of 1133 was substituted with IgG1, resulting in full recovery of protein A binding without compromising the enhanced CDC and ADCC activities. The CDC-enhancing effect using a chimeric isotype was also shown in CD52 antigen/antibody system. The ADCC activity of the variants was also maximized by the absence of fucose from its carbohydrate structure, a phenomenon that has previously been observed for wild-type antibodies. Enhanced cytotoxicity of a variant was confirmed in a cynomolgus monkey model. These findings suggest that the variant antibodies with IgG1/IgG3 chimeric constant regions and nonfucosylated oligosaccharides that possess dual-enhanced cytotoxic functions may be an improvement for the next generation of therapeutic antitumor antibodies.

[Toward a non-empirical treatment for rheumatoid arthritis based on its molecular pathology]

Rheumatoid arthritis (RA) is a chronic, disabbling disease that affects individuals during the productive years of their lives. Modern treatment for RA includes the so called "biologic" therapy, which is based on recombinant proteins that modify the biologic processes. These agents have potent therapeutic effects and different mechanisms of action. Nevertheless, therapeutic failure still prevails. Treatment that prevents disability in RA must be started in an early manner, before the development of complications and, ideally, with a minimum possibility of therapeutic failure. As yet, there are no clinical or laboratory criteria to identify those patients with a higher probability of responding to particular types of therapy, delaying control of RA ad affecting the prevention of incapacity. Research into gene diversity through single-nucleotide polymorphisms (SNPs) by means of microarray systems, allows the detailed analysis of gene factors associated to a given disease. SNPs have been recently applied to the study of RA, where the major polymorphisms associated to RA occur primarily in genes that code for proteins related to the initiation of an immune response and/or the control of cellular activity in the immune system, in addition to genes related to tissue repair. The specific meaning of these findings is in its initial stages of research. On the other hand, proteomics relate to the analysis of protein expression profiles at multiple levels. Both types of studies will contribute to the knowledge of patterns of gene expression in RA compared to the general population, and will allow an understanding of the pathogenesis of RA. Moreover, proteomic and genomic profiles can be employed to designs probes that identify individuals with the risk of developing RA, individually predict the response to different therapeutic modalities (pharmacogenomics) and for the follow-up of the biologic response to therapy.