The future of treatment in systemic sclerosis: can we design better trials?

Prevalence of anti-Ro52-kDa/SSA (TRIM21) antibodies and associated clinical phenotype in systemic sclerosis: Data from a French cohort, a systematic review and meta-analysis

OBJECTIVES

Estimate the global prevalence of anti-Ro52-kDa/SSA (TRIM21) autoantibodies in systemic sclerosis (SSc), and describe the associated clinical phenotype, through a systematic review and meta-analysis of published reports and new data from our French cohort.

METHODS

Anti-TRIM21 seropositivity and associated SSc characteristics were assessed in a cross-sectional study including 300 patients of Lille University Hospital. A systematic review of the literature was performed in Pubmed and Embase, followed by a meta-analysis, using data on prevalence, clinical/demographical/biological characteristics of SSc patients and the type of assay used for anti-TRIM21 antibodies detection (PROSPERO n° CRD42021223719).

FINDINGS

In the cross-sectional study, anti-TRIM21 antibodies prevalence was 26% [95%CI: 21; 31]. Anti-centromere antibodies were the most frequent SSc specific autoantibodies coexisting with anti-TRIM21. Patients with anti-TRIM21 antibodies were more frequently women (91% vs 77%, p = 0.006), more likely to present an associated Sjögren's syndrome (19% vs 7%, p < 0.001), had a higher rate of pulmonary arterial hypertension (PAH) (15% vs 6%, p = 0.017) and a greater frequency of digestive complications such as dysphagia (12% vs 5%, p = 0.038) or nausea/vomiting (10% vs 3%, p = 0.009) than anti-TRIM21 negative patients. Thirty-five articles corresponding to a total of 11,751 SSc patients were included in the meta-analysis. In this population, the overall seroprevalence of anti-TRIM21 antibodies was 23% [95%CI: 21; 27] with a high degree of heterogeneity (I2: 93% Phet: <0.0001), partly explained by the methods of detection. Anti-TRIM21 seropositivity was positively associated with female sex (OR: 1.60 [95%CI: 1.25, 2.06]), limited cutaneous subset (OR: 1.29 [1.04, 1.61]), joint manifestations (OR: 1.33 [1.05, 1.68]), pulmonary hypertension (PH) (OR: 1.82 [1.42, 2.33]), and interstitial lung disease (ILD) (OR: 1.31 [1.07, 1.60]).

INTERPRETATION

Anti-TRIM21 antibodies frequently co-exist with usual SSc antibodies, but are independently associated to a higher risk of cardio-pulmonary complications. The presence of these autoantibodies should therefore be considered when assessing the risk of developing PH and ILD, and deserves further studies on appropriate screening and follow-up of patients.

Fibrosis-on-Chip: A Guide to Recapitulate the Essential Features of Fibrotic Disease

Fibrosis, which is primarily marked by excessive extracellular matrix (ECM) deposition, is a pathophysiological process associated with many disorders, which ultimately leads to organ dysfunction and poor patient outcomes. Despite the high prevalence of fibrosis, currently there exist few therapeutic options, and importantly, there is a paucity of in vitro models to accurately study fibrosis. This review discusses the multifaceted nature of fibrosis from the viewpoint of developing organ-on-chip (OoC) disease models, focusing on five key features: the ECM component, inflammation, mechanical cues, hypoxia, and vascularization. The potential of OoC technology is explored for better modeling these features in the context of studying fibrotic diseases and the interplay between various key features is emphasized. This paper reviews how organ-specific fibrotic diseases are modeled in OoC platforms, which elements are included in these existing models, and the avenues for novel research directions are highlighted. Finally, this review concludes with a perspective on how to address the current gap with respect to the inclusion of multiple features to yield more sophisticated and relevant models of fibrotic diseases in an OoC format.

Therapeutic Approaches to Systemic Sclerosis: Recent Approvals and Future Candidate Therapies

Systemic sclerosis is the rheumatic disease with the highest individual mortality. The severity of the disease is determined by the extent of fibrotic changes to cutaneous and internal organ tissues, the most life-threatening visceral manifestations being interstitial lung disease, SSc-associated-pulmonary arterial hypertension and myocardial involvement. The heterogeneity of the disease has initially hindered the design of successful clinical trials, but considerations on classification criteria have improved patient selection in trials, allowing the identification of more homogeneous groups of patients based on progressive visceral manifestations or the extent of skin involvement with a focus of patients with early disease. Two major subsets of systemic sclerosis are classically described: limited cutaneous systemic sclerosis characterized by distal skin fibrosis and the diffuse subset with distal and proximal skin thickening. Beyond this dichotomic subgrouping of systemic sclerosis, new phenotypic considerations based on antibody subtypes have provided a better understanding of the heterogeneity of the disease, anti-Scl70 antibodies being associated with progressive interstitial lung disease regardless of cutaneous involvement. Two targeted therapies, tocilizumab (a monoclonal antibody targeting interleukin-6 receptors (IL-6R)) and nintedanib (a tyrosine kinase inhibitor), have recently been approved by the American Food & Drug Administration to limit the decline of lung function in patients with SSc-associated interstitial lung disease, demonstrating that such better understanding of the disease pathogenesis with the identification of key targets can lead to therapeutic advances in the management of some visceral manifestations of the disease. This review will provide a brief overview of the pathogenesis of SSc and will present a selection of therapies recently approved or evaluated in this context. Therapies evaluated and approved in SSc-ILD will be emphasized and a review of recent phase II trials in diffuse cutaneous systemic sclerosis will be proposed. We will also discuss selected therapeutic pathways currently under investigation in systemic sclerosis that still lack clinical data in this context but that may show promising results in the future based on preclinical data.

Autologous Haematopoietic Stem Cell Transplantation and Systemic Sclerosis: Focus on Interstitial Lung Disease

Autologous hematopoietic stem cells transplantation (AHSCT) has been employed as treatment for severe systemic sclerosis (SSc) with high risk of organ failure. In the last 25 years overall survival and treatment-related mortality have improved, in accordance with a better patient selection and mobilization and conditioning protocols. This review analyzes the evidence from the last 5 years for AHSCT-treated SSc patients, considering in particular the outcomes related to interstitial lung disease. There are increasing data supporting the use of AHSCT in selected patients with rapidly progressive SSc. However, some unmet needs remain, such as an accurate patient selection, pre-transplantation analysis to identify subclinical conditions precluding the transplantation, and the alternatives for post-transplant ILD recurrence.

Emerging Evidence and Treatment Perspectives from Randomized Clinical Trials in Systemic Sclerosis: Focus on Interstitial Lung Disease

Systemic sclerosis (SSc) is a complex rare autoimmune disease with heterogeneous clinical manifestations. Currently, interstitial lung disease (ILD) and cardiac involvement (including pulmonary arterial hypertension) are recognized as the leading causes of SSc-associated mortality. New molecular targets have been discovered and phase II and phase III clinical trials published in the last 5 years on SSc-ILD will be discussed in this review. Details on the study design; the drug tested and its dose; the inclusion and exclusion criteria of the study; the concomitant immunosuppression; the outcomes and the duration of the study were reviewed. The two most common drugs used for the treatment of SSc-ILD are cyclophosphamide and mycophenolate mofetil, both supported by randomized controlled trials. Additional drugs, such as nintedanib and tocilizumab, have been approved to slow pulmonary function decline in SSc-ILD. In this review, we discuss the therapeutic alternatives for SSc management, offering the option to customize the design of future studies to stratify SSc patients and provide a patient-specific treatment according to the new emerging pathogenic features of SSc-ILD.

Symptom experience of limited cutaneous systemic sclerosis from the Patients' perspective: A qualitative study✰,✰✰,★,★★

OBJECTIVES

Limited cutaneous systemic sclerosis (lcSSc) is the largest subgroup of people with SSc, but little is known about symptom experience from the patients' perspective. This study aimed to comprehensively identify domains and symptoms reported as bothersome by patients with lcSSc and to analyze themes and sub-themes capturing symptom experience in this population.

METHODS

Focus groups of patients with lcSSc were conducted using a structured guide. Patients were recruited based on an a priori purposive framework to include men and women with SSc. Focus groups were recorded, transcribed, anonymized, and analyzed using the RADaR technique (rigorous and accelerated data reduction) combined with iterative, deductive and inductive approaches.

RESULTS

Four 2-hour Focus groups comprising participants with lcSSc were conducted (N = 26). Ninety-four symptoms were identified with 22 domains. Symptoms from the following domains were mentioned in all Focus groups: skin, musculoskeletal (MSK), cardiac, pulmonary, gastro-intestinal (GI) manifestations, fatigue, sleep, Raynaud's phenomenon (RP), pain, and digital ulcers. The three most cited domains in a pre-meeting survey were GI, RP and MSK. Seven themes defining symptom experience were identified: difficulty attributing symptoms to this complex systemic disease, influence of symptom temporality, impairment of emotional well-being, limitations in functioning (including several sub-themes of functioning), survival, symptoms management and uncertainty.

CONCLUSION

This study comprehensively identified domains and symptoms considered bothersome from the perspective of patients with lcSSc and summarized patient experience of lcSSc-related symptoms. This study is the first step in the design of a future combined response index dedicated to lcSSc that could foster specific research on this subpopulation of patients.

Novel classifications for systemic sclerosis: challenging historical subsets to unlock new doors

PURPOSE OF REVIEW

Systemic sclerosis (SSc) is a severe rheumatic disease characterized by a considerable heterogeneity in clinical presentations and pathophysiological mechanisms. This variability has a substantial impact on morbidity and mortality and limits the generalizability of clinical trial results. This review aims to highlight recent studies that have proposed new innovative approaches to decipher this heterogeneity, in particular, by attempting to optimize disease classification.

RECENT FINDINGS

The historical dichotomy limited/diffuse subsets based on cutaneous involvement has been challenged by studies highlighting an underestimated heterogeneity between these two subtypes and showing that presence of organ damage and autoantibody profiles markedly influenced survival beyond skin extension. Advanced computational methods using unsupervised machine learning analyses of clinical variables and/or high-throughput omics technologies, clinical variables trajectories modelling overtime or radiomics have provided significant insights on key pathogenic processes that could help defining new subgroups beyond the diffuse/limited subsets.

SUMMARY

We can anticipate that a future classification of SSc patients will integrate innovative approaches encompassing clinical phenotypes, variables trajectories, serological features and innovative omics molecular signatures. It nevertheless seems crucial to also pursue the implementation and standardization of readily available and easy to use tools that can be used in clinical practice.

Considerations for a combined index for limited cutaneous systemic sclerosis to support drug development and improve outcomes

Systemic sclerosis (SSc; systemic scleroderma) is characterized by a heterogeneous range of clinical manifestations. SSc is classified into limited cutaneous SSc (lcSSc) and diffuse cutaneous subgroups (dcSSc) based on the extent of skin involvement. Randomized controlled trials in scleroderma have mainly focused on dcSSc partly because the measurement of skin involvement, critical for evaluating a therapeutic intervention is more dynamic in this subset. Nonetheless, lcSSc, the most common cutaneous subset (about 2/3), is also associated with significant morbidity and detrimental impact on health-related quality of life. The lack of interventional studies in lcSSc is partly due to a lack of relevant outcome measures to evaluate this subgroup. Combining several clinically meaningful outcomes selected specifically for lcSSc may improve representativeness in clinical trials and responsiveness of outcomes measured in randomized controlled trials. A composite index dedicated to lcSSc combining such relevant outcomes could advance clinical trial development for lcSSc by providing the opportunity to test and select among candidate drugs that could act as disease-modifying treatments for this neglected subgroup of SSc. This proposed index would include items selected by expert physicians and patients with lcSSc across domains grounded in the lived experience of lcSSc. This article reviews the reasons behind the relative neglect of lcSSc, discusses the current state of outcome measures for lcSSc, identifies challenges, and proposes a roadmap for a combined lcSSc-specific treatment response index.

Emerging drugs for the treatment of scleroderma: a review of recent phase 2 and 3 trials

INTRODUCTION

Systemic sclerosis (SSc) has the highest case-specific mortality of all connective tissue diseases. Its underlying disease mechanism affects several organs and remains incompletely understood. Ongoing work clarifying its etiopathogenesis is helping to develop targeted therapy.

AREAS COVERED

Several clinical trials have evaluated the safety and efficacy of agents targeting different mechanisms of this disease. This review article reviews those mechanisms and surveys four key recent phase II or III clinical trials that are contributing to the landscape of SSc therapy. The reported trials primarily focus on patients with systemic sclerosis in the early phase of disease.

EXPERT OPINION

Traditional therapies for SSc center on immunosuppressive and cytotoxic agents. A new cadre of therapies is borne from improved understandings of SSc pathobiology and target the inflammatory-fibrotic pathways. Scleroderma trials have entered the initial phase of personalized medicine, recognizing molecular subsets that will improve upon cohort enrichment and maximize the measurable benefit of future therapies.

Randomised controlled trials in systemic sclerosis: patient selection and endpoints for next generation trials

The heterogeneity in the natural history of systemic sclerosis is a major issue in both clinical management and trial design and is dictated by the complex and multifactorial pathogenesis of the disease. Systemic sclerosis is an autoimmune disease and therefore many trials for the disease have targeted immune activation pathways; however, the phase 3 trials that have been positive have targeted pathways directly linked to tissue damage rather than systemic immune activation. On one hand, these results represent enormous progress that has led to the first approved drugs for this extremely challenging condition. On the other hand, they have revealed a possible selection bias in our current approach to trial design. In this Series paper, we describe randomised controlled trials from the past 4 years we believe to be most relevant to future strategies in systemic sclerosis. Based on advances in our understanding of the pathogenesis and natural history of disease, we will also identify important points to consider in the design of the next generation of systemic sclerosis trials.