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

The long-term course of the Health Assessment Questionnaire in patients with systemic sclerosis

Objective

The Health Assessment Questionnaire-Disability Index is an important outcome measure reflecting functional disability, but knowledge on its course over time in patients with systemic sclerosis is scarce. Therefore, we investigated the long-term course of the Health Assessment Questionnaire-Disability Index and its association with baseline characteristics in systemic sclerosis patients.

Methods

Systemic sclerosis patients, fulfilling the European League Against Rheumatism and the American College of Rheumatology 2013 criteria, were included from the Leiden Combined Care in Systemic Sclerosis cohort with annual assessments including the Scleroderma Health Assessment Questionnaire-Disability Index (range = 0-3). The course of the Health Assessment Questionnaire-Disability Index was evaluated over the total follow-up (baseline to last available Health Assessment Questionnaire-Disability Index) and between yearly visits. Based on a minimal clinical important difference of 0.22, courses were categorized into worsening, stable or improvement. The course of the Health Assessment Questionnaire-Disability Index over time was evaluated with linear mixed models. Baseline characteristics were compared between patients with a worsening or improvement of the Health Assessment Questionnaire-Disability Index over the total follow-up period with logistic regression analyses.

Results

A total of 517 systemic sclerosis patients were included, with a median follow-up of 7 years (interquartile range = 4-9; 2649 visits) and a baseline Health Assessment Questionnaire-Disability Index of 0.625 (interquartile range = 0.125-1.25). On group level, the Health Assessment Questionnaire-Disability Index is stable with an annual increase of 0.019 (95% confidence interval = 0.011 to 0.027). Looking at subgroups, patients >65 years or who died/were physically unable to come during follow-up had a worse mean Health Assessment Questionnaire-Disability Index. In individual courses from baseline to the last follow-up, the proportions of patients with a clinically meaningful worsening, stable or improved Health Assessment Questionnaire-Disability Index were 35%, 42% and 23%, respectively. Patients with immunosuppressants (odds ratio = 0.5, 95% confidence interval = 0.3 to 0.9) or gastrointestinal involvement (odds ratio = 0.6, 95% confidence interval = 0.4 to 0.9) at baseline showed a reduced chance of worsening of the Health Assessment Questionnaire-Disability Index over the total follow-up period.

Conclusion

Over time, the average course of the Health Assessment Questionnaire-Disability Index was stable in systemic sclerosis patients. However, individual courses vary, with worsening occurring in one-third. Worsening occurred less often in individuals using immunosuppressants or with gastrointestinal involvement at baseline.

Cutaneous Manifestations, Clinical Characteristics, and Prognosis of Patients With Systemic Sclerosis Sine Scleroderma: Data From the International EUSTAR Database

Importance

Systemic sclerosis (SSc) sine scleroderma (ssSSc) is a subset of SSc defined by the absence of skin fibrosis. Little is known about the natural history and skin manifestations among patients with ssSSc.

Objective

To characterize the clinical phenotype of patients with ssSSc compared with patients with limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) within the EUSTAR database.

Design, Setting, and Participants

This longitudinal observational cohort study based on the international EUSTAR database included all patients fulfilling the classification criteria for SSc assessed by the modified Rodnan Skin score (mRSS) at inclusion and with at least 1 follow-up visit; ssSSc was defined by the absence of skin fibrosis (mRSS = 0 and no sclerodactyly) at all available visits. Data extraction was performed in November 2020, and data analysis was performed from April 2021 to April 2023.

Main Outcomes and Measures

Main outcomes were survival and skin manifestations (onset of skin fibrosis, digital ulcers, telangiectasias, puffy fingers).

Results

Among the 4263 patients fulfilling the inclusion criteria, 376 (8.8%) were classified as having ssSSc (mean [SD] age, 55.3 [13.9] years; 345 [91.8%] were female). At last available visit, in comparison with 708 patients with lcSSc and 708 patients with dcSSc with the same disease duration, patients with ssSSc had a lower prevalence of previous or current digital ulcers (28.2% vs 53.1% in lcSSc; P < .001; and 68.3% in dcSSc; P < .001) and puffy fingers (63.8% vs 82.4% in lcSSc; P < .001; and 87.6% in dcSSc; P < .001). By contrast, the prevalence of interstitial lung disease was similar in ssSSc and lcSSc (49.8% and 57.1%; P = .03) but significantly higher in dcSSc (75.0%; P < .001). Skin telangiectasias were associated with diastolic dysfunction in patients with ssSSc (odds ratio, 4.778; 95% CI, 2.060-11.081; P < .001). The only independent factor for the onset of skin fibrosis in ssSSc was the positivity for anti-Scl-70 antibodies (odds ratio, 3.078; 95% CI, 1.227-7.725; P = .02). Survival rate was higher in patients with ssSSc (92.4%) compared with lcSSc (69.4%; P = .06) and dcSSc (55.5%; P < .001) after up to 15 years of follow-up.

Conclusions and Relevance

Systemic sclerosis sine scleroderma should not be neglected considering the high prevalence of interstitial lung disease (>40%) and SSc renal crisis (almost 3%). Patients with ssSSc had a higher survival than other subsets. Dermatologists should be aware that cutaneous findings in this subgroup may be associated with internal organ dysfunction. In particular, skin telangiectasias in ssSSc were associated with diastolic heart dysfunction.

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.

Sicca syndrome in systemic sclerosis: a narrative review on a neglected issue

SSc is an auto-immune disease characterized by life-threatening manifestations such as lung fibrosis or pulmonary arterial hypertension. Symptoms with a detrimental impact on quality of life are also reported and sicca syndrome (xerostomia, xeropthalmia) is present in up to 80% of patients with SSc. Sicca syndrome can occur in the absence of overlap with Sjögren's disease and recent studies highlight that fibrosis of minor and major salivary glands, directly linked to the pathogenesis of SSc, could be a major contributor of xerostomia in SSc. This narrative review provides an overview of the clinical presentation, diagnostic strategies, management and future perspectives on sicca syndrome in patients with SSc.

Open questions on the management of targeted therapies for the treatment of systemic sclerosis-interstitial lung disease: results of a EUSTAR survey based on a systemic literature review

Background

The results of randomized controlled (RCT) and retrospective studies have expanded the armamentarium of drugs for systemic sclerosis (SSc) - interstitial lung disease (ILD) treatment. The correct positioning of these drugs is not yet clarified.

Objectives

Systemic literature review (SLR) on rituximab (RTX), tocilizumab (TCZ), nintedanib and abatacept (ABT) for the treatment of SSc-ILD. The results of the SLR were used to create a dedicated survey.

Design

The study was performed as a systematic review.

Data sources and methods

the SLR was performed using the following terms: "(systemic sclerosis OR scleroderma) AND (interstitial lung disease OR lung fibrosis OR pulmonary fibrosis) AND (rituximab OR tocilizumab OR abatacept OR nintedanib)". The results of the SLR were integrated in a survey including 8 domains. These were sent to all EUSTAR members and to the participants of the 2020 Scleroderma World Congress.

Results

41 studies (34 on RTX, 5 on TCZ, 2 on ABT, and 1 on nintedanib) were identified. RCTs supported the use of TCZ and nintedanib, while retrospective studies supported the use of RTX for SSc-ILD. No clear data were obtained about ABT. The survey showed that RTX is the most available option (96%) whereas the most frequent reason for targeted therapy introduction is lung progression while on csDMARDs (86% RTX, 59% TCZ and 63% nintedanib). Combination therapy was the most frequently mentioned therapeutic scheme for nintedanib (75%) and RTX (63%). Physicians' perception of safety was similar for all drugs, while drug efficacy was the same for RTX and nintedanib, followed by TCZ (4.8 ± 2). The most frequently raised concerns pertained to efficacy, safety and combination regimens.

Conclusion

Our SLR supports the use of RTX, TCZ and nintedanib for SSc-ILD patients and underlines the need for more data about upfront combination versus monotherapy. It also highlighted the need to identify predictors supporting drug choice according to both pulmonary and extra-pulmonary manifestations.

Domains and outcome measures for the assessment of limited cutaneous systemic sclerosis: an international collaborative scoping review

OBJECTIVES

The aim of this study was to comprehensively identify instruments within relevant domains employed to assess lcSSc since the endorsement of its consensus definition in 1988. The overall objective is to inform the creation of a Combined Response Index for Scleroderma Trials Assessing lcSSc (CRISTAL).

METHODS

MEDLINE and Embase were searched using terms selected to comprehensively retrieve titles and abstracts mentioning both lcSSc and dcSSc, along with those only mentioning lcSSc, SSc sine scleroderma, limited SSc and/or CREST/CRST. Because our initial assessment of the literature revealed that very few studies included only lcSSc subjects, we also assessed literature that included both cutaneous subsets. A total of 3964 titles and abstracts were screened by two reviewers, and 270 articles were selected for data extraction.

RESULTS

We identified 27 domains encompassing 459 instruments. Instruments from 'Skin involvement', 'Pulmonary involvement' and 'Health-related quality of life and general functioning' were the most frequently retrieved. Among the 15 most represented instruments announced as primary end points in efficacy or effectiveness studies, 7 were clinician-reported outcomes (ROs), 7 were patient ROs, and one was a performance outcome (6 min-walk test). The mean proportion of lcSSc patients in studies of lcSSc, including studies that mention both lcSSc and dcSSc, was 56.4%, demonstrating that this subset is underrepresented in the literature, given that the prevalence of lcSSc ranges from 60% to 80% in national registries and international cohorts.

CONCLUSION

This scoping literature review provides a comprehensive identification of domains and outcomes used to assess lcSSc. Our results also highlight that lcSSc is underrepresented in the literature.

Assessment of disease outcome measures in systemic sclerosis

The assessment of disease activity in systemic sclerosis (SSc) is challenging owing to its heterogeneous manifestations across multiple organ systems, the variable rate of disease progression and regression, and the relative paucity of patients in early-phase therapeutic trials. Despite some recent successes, most clinical trials have failed to show efficacy, underscoring the need for improved outcome measures linked directly to disease pathogenesis, particularly applicable for biomarker studies focused on skin disease. Current outcome measures in SSc-associated interstitial lung disease and SSc skin disease are largely adequate, although advancing imaging technology and the incorporation of skin mRNA biomarkers might provide opportunities for earlier detection of the therapeutic effect. Biomarkers can further inform pathogenesis, enabling early phase trials to act as reverse translational studies through the incorporation of routine high-throughput sequencing.

Representativeness of Systemic Sclerosis Patients in Interventional Randomized Trials: an analysis of the EUSTAR database

OBJECTIVE

To estimate the extent of and the reasons for ineligibility in randomized controlled trials (RCTs) of systemic sclerosis (SSc) patients included in the EUSTAR database, and to determine the association between patient's features and generalizability of study results.

METHODS

We searched Clinicaltrials.gov for all records on interventional SSc-RCTs registered from January 2013 to January 2018. Two reviewers selected studies, and information on the main trial features were retrieved. Data from 8046 patients having a visit in the EUSTAR database since 2013 were used to check patient's eligibility. The proportion of potentially eligible patients per trial, and the risk factors for ineligibility were analyzed. Complete-, worst- and best-case analyses were performed.

RESULTS

Of the 37 RCTs included, 43% were conducted in Europe, 35% were industry-funded, and 87% investigated pharmacological treatments. Ninety-one percent of 8046 patients included could have participated in at least one RCT. In complete-case analysis, the median [range] proportion of eligible patients having the main organ complication targeted by each study was 60% [10-100] in the overall sample of trials, ranging from 50% [32-79] for trials on skin fibrosis to 90% [34-77] for those targeting Raynaud's phenomenon. Among the criteria checked, treatment- and safety-related but not demographic were the main barriers to patient's recruitment. Older age, absence of Raynaud's phenomenon, and lower mRSS were independently associated with the failure to fulfill criteria for any of the included studies.

CONCLUSIONS

Patient's representativeness in SSc-RCTs is highly variable and is driven more by treatment- and safety-related rather than demographic criteria.

Domains and outcome measures for the assessment of limited cutaneous systemic sclerosis: a scoping review protocol

INTRODUCTION

Limited cutaneous systemic sclerosis (lcSSc) is the most frequent subset of systemic sclerosis. Despite this, lcSSc is not the major focus of clinical studies. The lack of interventional studies in lcSSc is due, in part, to a paucity of relevant outcome measures to effectively evaluate this subset. A combined response index dedicated to lcSSc would facilitate development of well-designed trials and approval of new drugs. The objective of this scoping review is to perform a broad and comprehensive identification of the outcome measures (core set items) within relevant domains, which have been used so far to assess lcSSc.

METHODS AND ANALYSIS

The planned scoping review will be based on the approach proposed by Arksey et al and further developed by Levac et al. Development and reporting will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Extension for Scoping Reviews checklist and guidelines. The development of the search strategy was guided by the concepts of domains and outcomes based on the Outcome Measures in Rheumatology approach and by the different names and definitions of SSc, with a specific emphasis on their occurrence in clinical trial studies. Two databases will be searched: MEDLINE and Embase. Studies in English, published from the year 1988 onwards, will be included, since 1988 corresponds to the publication of LeRoy's first consensus definition of lcSSc. Data will be extracted and analysed using a standardised charting tool.

ETHICS AND DISSEMINATION

No ethical approval is required for this study. The results will be submitted to an international peer-reviewed journal and scientific conferences, informing the discussion on which items should be included in a combined response index dedicated to lcSSc (the CRISTAL project: Combined Response Index for Scleroderma Trial Assessing lcSSc).