Not all TNF inhibitors in rheumatoid arthritis are created equal: important clinical differences

Small molecule and big function: MicroRNA-mediated apoptosis in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune condition and chronic inflammatory disease, mostly affecting synovial joints. The complex pathogenesis of RA is supportive of high morbidity, disability, and mortality rates. Pathological changes a common characteristic in RA synovial tissue is attributed to the inadequacy of apoptotic pathways. In that regard, apoptotic pathways have been the center of attention in RA therapeutic approaches. As the regulators in the complex network of apoptosis, microRNAs (miRNAs) are found to be vital modulators in both intrinsic and extrinsic pathways through altering their regulatory genes. Indeed, miRNA, a member of the family of non-coding RNAs, are found to be an important player in not even apoptosis, but proliferation, gene expression, signaling pathways, and angiogenesis. Aberrant expression of miRNAs is implicated in attenuation and/or intensification of various apoptosis routes, resulting in culmination of human diseases including RA. Considering the need for more studies focused on the underlying mechanisms of RA in order to elevate the unsatisfactory clinical treatments, this study is aimed to delineate the importance of apoptosis in the pathophysiology of this disease. As well, this review is focused on the critical role of miRNAs in inducing or inhibiting apoptosis of RA-synovial fibroblasts and fibroblast-like synoviocytes and how this mechanism can be exerted for therapeutic purposes for RA.

Facts and Hopes on Neutralization of Protumor Inflammatory Mediators in Cancer Immunotherapy

In cancer pathogenesis, soluble mediators are responsible for a type of inflammation that favors the progression of tumors. The mechanisms chiefly involve changes in the cellular composition of the tumor tissue stroma and in the functional modulation of myeloid and lymphoid leukocytes. Active immunosuppression, proangiogenesis, changes in leukocyte traffic, extracellular matrix remodeling, and alterations in tumor-antigen presentation are the main mechanisms linked to the inflammation that fosters tumor growth and metastasis. Soluble inflammatory mediators and their receptors are amenable to various types of inhibitors that can be combined with other immunotherapy approaches. The main proinflammatory targets which can be interfered with at present and which are under preclinical and clinical development are IL1β, IL6, the CXCR1/2 chemokine axis, TNFα, VEGF, leukemia inhibitory factor, CCL2, IL35, and prostaglandins. In many instances, the corresponding neutralizing agents are already clinically available and can be repurposed as a result of their use in other areas of medicine such as autoimmune diseases and chronic inflammatory conditions.

A Therapeutically Actionable Protumoral Axis of Cytokines Involving IL-8, TNFα, and IL-1β

Interleukin-8 (CXCL8) produced in the tumor microenvironment correlates with poor response to checkpoint inhibitors and is known to chemoattract and activate immunosuppressive myeloid leukocytes. In human cancer, IL8 mRNA levels correlate with IL1B and TNF transcripts. Both cytokines induced IL-8 functional expression from a broad variety of human cancer cell lines, primary colon carcinoma organoids, and fresh human tumor explants. Although IL8 is absent from the mouse genome, a similar murine axis in which TNFα and IL-1β upregulate CXCL1 and CXCL2 in tumor cells was revealed. Furthermore, intratumoral injection of TNFα and IL-1β induced IL-8 release from human malignant cells xenografted in immunodeficient mice. In all these cases, the clinically used TNFα blockers infliximab and etanercept or the IL-1β inhibitor anakinra was able to interfere with this pathogenic cytokine loop. Finally, in paired plasma samples of patients with cancer undergoing TNFα blockade with infliximab in a clinical trial, reductions of circulating IL-8 were substantiated.

SIGNIFICANCE

IL-8 attracts immunosuppressive protumor myeloid cells to the tumor microenvironment, and IL-8 levels correlate with poor response to checkpoint inhibitors. TNFα and IL-1β are identified as major inducers of IL-8 expression on malignant cells across cancer types and models in a manner that is druggable with clinically available neutralizing agents. This article is highlighted in the In This Issue feature, p. 2007.

Mechanisms underlying DMARD inefficacy in difficult-to-treat rheumatoid arthritis: a narrative review with systematic literature search

Management of RA patients has significantly improved over the past decades. However, a substantial proportion of patients is difficult-to-treat (D2T), remaining symptomatic after failing biological and/or targeted synthetic DMARDs. Multiple factors can contribute to D2T RA, including treatment non-adherence, comorbidities and co-existing mimicking diseases (e.g. fibromyalgia). Additionally, currently available biological and/or targeted synthetic DMARDs may be truly ineffective ('true' refractory RA) and/or lead to unacceptable side effects. In this narrative review based on a systematic literature search, an overview of underlying (immune) mechanisms is presented. Potential scenarios are discussed including the influence of different levels of gene expression and clinical characteristics. Although the exact underlying mechanisms remain largely unknown, the heterogeneity between individual patients supports the assumption that D2T RA is a syndrome involving different pathogenic mechanisms.

Integrated Analysis Reveals the Targets and Mechanisms in Immunosuppressive Effect of Mesalazine on Ulcerative Colitis

Background

Ulcerative colitis (UC) is an inflammatory bowel disease that causes inflammation and ulcers in the digestive tract. Approximately 3 million US adults suffer from this disease. Mesalazine, an anti-inflammatory agent, is commonly used for the treatment of UC. However, some studies have demonstrated side effects of mesalazine, such as acute pancreatitis and hypereosinophilia. Therefore, a better understanding of the anti-inflammatory mechanism of mesalazine in UC could help improve the effectiveness of the drug and reduce its side effects. In this study, we used a dextran sodium sulfate-induced UC mouse model, and applied network pharmacology and omics bioinformatics approaches to uncover the potential pharmaceutical targets and the anti-inflammatory mechanism of mesalazine.

Results

Network pharmacology analysis identified the core targets of mesalazine, biological processes, and cell signaling related to immunity and inflammatory responses mediated by mesalazine. Molecular docking analysis then indicated possible binding motifs on the core targets (including TNF-α, PTGS2, IL-1β, and EGFR). Metabolomics and 16S metagenomic analyses highlighted the correlation between gut microbiota and metabolite changes caused by mesalazine in the UC model.

Conclusions

Collectively, the omics and bioinformatics approaches and the experimental data unveiled the detailed molecular mechanisms of mesalazine in UC treatment, functional regulation of the gut immune system, and reduction of intestinal inflammation. More importantly, the identified core targets could be targeted for the treatment of UC.

TNF-α-elicited miR-29b potentiates resistance to apoptosis in peripheral blood monocytes from patients with rheumatoid arthritis

CD14-positive monocytes from patients with rheumatoid arthritis (RA) are more resistant to apoptosis, which promotes their persistence at the inflammatory site and thereby contributes crucially to immunopathology. We sought to elucidate one mechanism underlying this unique pathogenesis: resistance to apoptosis and the potential involvement of miR-29b in this process. CD14-positive peripheral blood monocytes (PBMs) from RA patients were observed to be resistant to spontaneous apoptosis compared to PBMs from healthy volunteers. Intriguingly, expression of miR-29b was significantly upregulated in PBMs from RA patients than those from healthy volunteers, and this upregulation was correlated with RA disease activity. Functionally, forced expression of the exogenous miR-29b in CD14-positive Ctrl PBMs conferred resistance to spontaneous apoptosis and Fas-induced death, thereafter enhancing the production of major proinflammatory cytokines in there cells. Following identification of the potential miR-29b target transcripts using bioinformatic algorithms, we showed that miR-29b could directly bind to the 3'-UTR of the high-mobility group box-containing protein 1 (HBP1) and inhibited its transcription in PBMs. Importantly, stable expression of the exogenous HBP1 in differentiated THP-1 monocytes effectively abolished miR-29b-elicited resistance to Fas-induced apoptosis. Finally, among patients with RA and good clinical responses to immunotherapy, expression levels of miR-29b were significantly compromised in those treated with infliximab (a TNF-α inhibitor) but not in those treated with tocilizumab (a humanized mAb against the IL-6 receptor), pointing to a potential association between miR-29b activation and TNF-α induction. The available data collectively suggest that TNF-α-elicited miR-29b potentiates resistance to apoptosis in PBMs from RA patients via inhibition of HBP1 signaling, and testing patients for miR-29b/HBP1 expression ratios may provide more accurate prognostic information and could influence the recommended course of immunotherapy.

Cost-Effectiveness of Sarilumab Added to Methotrexate in the Treatment of Adult Patients with Moderately to Severely Active Rheumatoid Arthritis Who Have Inadequate Response or Intolerance to Tumor Necrosis Factor Inhibitors

BACKGROUND

Despite a substantial number of treatment options in rheumatoid arthritis (RA) following tumor necrosis factor inhibitor (TNFi) inadequate response or intolerance (TNF-IR), a lack of clarity on the optimal approach remains. Sarilumab, a human monoclonal anti-interleukin-6 receptor alpha antibody, can be used as monotherapy or in combination with methotrexate or other conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) in TNF-IR patients.

OBJECTIVE

To conduct a cost-utility analysis from a U.S. health care system perspective for sarilumab subcutaneous 200 mg + methotrexate versus abatacept + methotrexate or a bundle of TNFi + methotrexate for treatment of adult patients with moderately to severely active RA and TNF-IR.

METHODS

Analysis was conducted via individual patient simulation based on patient profiles from the TARGET trial (NCT01709578); a 6-month decision tree was followed by lifetime semi-Markov model with 6-month cycles. Treatment response at 6 months, informed by network meta-analysis, was based on American College of Rheumatology (ACR) 20/50/70 criteria; patients achieving ≥ ACR20 continued with current therapy, and other patients moved to the next line of biologic DMARD therapy or conventional synthetic DMARD palliative treatment. Direct costs included wholesale acquisition drug costs and administration and routine care costs. Routine care costs and quality-adjusted life-years (QALYs) were estimated by predicting the Health Assessment Questionnaire Disability Index score based on treatment response and were imputed from published equations.

RESULTS

Sarilumab + methotrexate dominated the TNFi bundle + methotrexate, achieving lower costs ($319,324 vs. $356,096) and greater effectiveness (4.27 vs. 4.15 QALYs), and was on the cost-efficiency frontier with abatacept + methotrexate ($360,211 and 4.29 QALYs). Abatacept + methotrexate was not cost-effective versus sarilumab + methotrexate. Scenario analyses indicated the results were robust; sarilumab + methotrexate became dominant against abatacept + methotrexate after reduced model horizon, minimum response based on ACR50 or ACR70, or time to discontinuation per treatment class. Sarilumab + methotrexate was also dominant versus the TNFi bundle; when class-specific time to treatment discontinuation was specified, sarilumab remained cost-effective with an incremental cost-effectiveness ratio of $36,894.

CONCLUSIONS

Sarilumab + methotrexate can be considered an economically dominant (more effective, less costly) option versus a second TNFi + methotrexate; compared with abatacept + methotrexate, it is a less costly but less effective option for patients with moderately to severely active RA who have previously failed TNFi.

DISCLOSURES

This study was funded by Sanofi and Regeneron Pharmaceuticals. Kiss and Gal are employees of Evidera, which received consulting fees from Sanofi/Regeneron for conducting this study. Muszbek was employed by Evidera at the time of this study. Kuznik and Chen are current employees of and stockholders in Regeneron Pharmaceuticals. Fournier is an employee of and stockholder in Sanofi. Proudfoot is a former employee of and current stockholder in Sanofi and current employee and stockholder in ViiV Healthcare/GlaxoSmithKline. Michaud has received grant funding from Pfizer and the Rheumatology Research Foundation. The sponsors were involved in the study design, collection, analysis, and interpretation of data as well as data checking of information provided in the manuscript. The authors had unrestricted access to study data, were responsible for all content and editorial decisions, and received no honoraria related to the development of this publication.

An integrative transcriptome analysis framework for drug efficacy and similarity reveals drug-specific signatures of anti-TNF treatment in a mouse model of inflammatory polyarthritis

Anti-TNF agents have been in the first line of treatment of various inflammatory diseases such as Rheumatoid Arthritis and Crohn’s Disease, with a number of different biologics being currently in use. A detailed analysis of their effect at transcriptome level has nevertheless been lacking. We herein present a concise analysis of an extended transcriptomics profiling of four different anti-TNF biologics upon treatment of the established hTNFTg (Tg197) mouse model of spontaneous inflammatory polyarthritis. We implement a series of computational analyses that include clustering of differentially expressed genes, functional analysis and random forest classification. Taking advantage of our detailed sample structure, we devise metrics of treatment efficiency that take into account changes in gene expression compared to both the healthy and the diseased state. Our results suggest considerable variability in the capacity of different biologics to modulate gene expression that can be attributed to treatment-specific functional pathways and differential preferences to restore over- or under-expressed genes. Early intervention appears to manage inflammation in a more efficient way but is accompanied by increased effects on a number of genes that are seemingly unrelated to the disease. Administration at an early stage is also lacking in capacity to restore healthy expression levels of under-expressed genes. We record quantifiable differences among anti-TNF biologics in their efficiency to modulate over-expressed genes related to immune and inflammatory pathways. More importantly, we find a subset of the tested substances to have quantitative advantages in addressing deregulation of under-expressed genes involved in pathways related to known RA comorbidities. Our study shows the potential of transcriptomic analyses to identify comprehensive and distinct treatment-specific gene signatures combining disease-related and unrelated genes and proposes a generalized framework for the assessment of drug efficacy, the search of biosimilars and the evaluation of the efficacy of TNF small molecule inhibitors.

A number of anti-TNF drugs are being used in the treatment of inflammatory autoimmune diseases, such as Rheumatoid Arthritis and Crohn’s Disease. Despite their wide use there has been, to date, no detailed analysis of their effect on the affected tissues at a transcriptome level. In this work we applied four different anti-TNF drugs on an established mouse model of inflammatory polyarthritis and collected a large number of independent biological replicates from the synovial tissue of healthy, diseased and treated animals. We then applied a series of bioinformatics analyses in order to define the sets of genes, biological pathways and functions that are affected in the diseased animals and modulated by each of the different treatments. Our dataset allowed us to focus on previously overlooked aspects of gene regulation. We found that the majority of differentially expressed genes in disease are under-expressed and that they are also associated with functions related to Rheumatoid Arthritis comorbidities such as cardiovascular disease. We were also able to define gene and pathway subsets that are not changed in the disease but are, nonetheless, altered under various treatments and to use these subsets in drug classification and assessment. Through the application of machine learning approaches we created quantitative efficiency profiles for the tested drugs, which showed some to be more efficiently addressing changes in the inflammatory pathways, while others being quantitatively superior in restoring gene expression changes associated to disease comorbidities. We thus, propose a concise computational pipeline that may be used in the assessment of drug efficacy and biosimilarity and which may form the basis of evaluation protocols for small molecule TNF inhibitors.

Clinical, Ultrasound, and Predictability Outcomes Following Certolizumab Pegol Treatment (with Methotrexate) in Patients with Moderate-to-Severe Rheumatoid Arthritis: 52-Week Results from the CZP-SPEED Study

INTRODUCTION

To assess the impact of certolizumab pegol (CZP) treatment on clinical, patient-reported, and musculoskeletal ultrasound outcomes and to determine the treatment response time point most predictive of long-term outcomes in Italian patients with rheumatoid arthritis (RA).

METHODS

CZP-SPEED (NCT01443364) was a 52-week, open-label, prospective, interventional, multicenter study. Biologic-naïve patients with moderate-to-severe active RA, who had failed at least one DMARD treatment, received CZP (400 mg at weeks 0, 2, and 4, then 200 mg every 2 weeks) concomitantly with methotrexate. The primary objective was to identify the time point of clinical response {decrease in 28-joint Disease Activity Score [DAS28(ESR)] ≥ 1.2} most predictive of a clinical response at week 52. Additional clinical and patient-reported outcomes were measured. Power Doppler (PD) ultrasound was used to assess synovial effusion, synovial proliferation, PD signal, cartilage damage, and bone erosion according to international guidelines.

RESULTS

A total of 132 patients were enrolled and received CZP; 91/132 (69%) completed to week 52. Predicted 52-week responses for early responders (week 2 onwards) were between 65% and 70%. Rapid improvements in joint cavity widening and PD signal were observed to week 8 and maintained to week 52. Cartilage damage and bone erosion were stable over 52 weeks. No new safety signals were identified.

CONCLUSION

In Italian CZP-treated patients with moderate-to-severe RA, week 12 clinical responses may be predictive of long-term response at week 52. Rapid improvements in clinical, patient-reported, and musculoskeletal ultrasound outcomes were maintained to week 52. These data may aid rheumatologists to make earlier treatment decisions.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01443364.

FUNDING

UCB Pharma.