Twenty-two points to consider for clinical trials in systemic sclerosis, based on EULAR standards

A Narrative Review of Pathogenetic and Histopathologic Aspects, Epidemiology, Classification Systems, and Disease Outcome Measures in Systemic Sclerosis

Systemic sclerosis (SSc) is a rare systemic autoimmune disease, characterized by the presence of three main actors: vasculopathy, immune activation, and fibrosis. This pathologic process is then translated in a clinical picture with great variability among different patients in terms of type of organ involvement, disease severity and prognosis. This heterogeneity is a main feature of SSc, which, in addition to the presence of early phases of the disease characterized by mild symptoms, can explain the high difficulty in establishing classification criteria, and in defining patients' subsets and disease outcomes. The definition of disease outcomes is particularly relevant in the setting of clinical trials, where the aim is to provide reliable endpoints, able to measure the magnitude of the efficacy of a certain drug or intervention. For this reason, in the last years, increasing efforts have been done to design measures of disease activity, damage, severity, and response to treatment, often in the context of composite indexes. When considering disease outcomes, the experience of the patient represents a relevant and complementary aspect. The tools able to capture this experience, the patient-reported outcomes, have been increasingly used in the last years in clinical practice and in clinical trials, both as primary and secondary endpoints. This comprehensive narrative review on SSc will therefore cover pathogenetic and histopathologic aspects, epidemiology, classification systems, and disease outcome measures, in order to focus on issues that are relevant for clinical research and design of clinical trials.

PELVIC FLOOR MUSCLE EXERCISE AND PHYSICAL THERAPY MAY IMPROVE SYSTEMIC SCLEROSIS-ASSOCIATED FECAL INCONTINENCE

Gastrointestinal involvement in systemic sclerosis (SSc) is observed in up to 90% of patients. Resolution of some of these gastrointestinal complications is challenging without the support of physical therapy and rehabilitation. One of these complications, SSc-associated fecal incontinence, which can be devastating for those affected, is seen in up to 39%. Studies focusing on fecal incontinence and its treatment are scarce. The hypothesis presented herein suggests that pelvic floor muscle exercise, biofeedback therapy, and neuromodulation methods might be effective and safe treatment strategies for patients affected by this debilitating complication.

Re-evaluating inclusion criteria for autologous hematopoietic stem cell transplantation in advanced systemic sclerosis: Three successful cases and review of the literature

Systemic sclerosis is a chronic autoimmune disease with a poor prognosis, particularly when a patient has rapidly progressive skin or pulmonary involvement. Autologous hematopoietic stem cell transplant is an emerging treatment for this condition, that has been demonstrated to be more effective than immunosuppressants. Careful selection of patients has reduced the transplant-related mortality and maximized the likelihood of benefit. In this report, we present three cases of successful autologous hematopoietic stem cell transplant in patients who would not have met inclusion criteria for entrance into the completed hematopoietic stem cell transplant. After >18 months of follow-up, three patients had clinically significant benefit in terms of skin tightening and pulmonary function tests. Future studies of hematopoietic stem cell transplant in systemic sclerosis may aim to carefully liberalize inclusion criteria to include patients who may not have otherwise been treated while still maintaining an acceptable safety profile.

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.

Enrichment Strategy for Systemic Sclerosis Clinical Trials Targeting Skin Fibrosis: A Prospective, Multiethnic Cohort Study

Objective

The modified Rodnan skin score (mRSS) is often used as a primary outcome measure in systemic sclerosis (SSc) randomized clinical trials (RCTs). Previous cohort studies with predominantly European Caucasian patients showed that setting an upper limit of mRSS as a selection criterion for RCTs leads effectively to enrichment with progressive patients. This study aimed to demonstrate this effect in an ethnically diverse cohort, rich in patients positive for anti‐RNA polymerase III antibodies (Pol3).

Methods

We selected from the Genetics versus Environment in Scleroderma Outcomes Study (GENISOS) cohort patients with diffuse cutaneous SSc (dcSSc), who had mRSS of 7 or more at inclusion and a documented mRSS after 12 ± 2 months. Progression of skin fibrosis was defined as an increase in mRSS greater than 5 points and 25% or more from baseline. To identify the optimal cutoff for the baseline mRSS yielding the highest sensitivity for progressive skin fibrosis, we developed ROC curves and logistic regression models with “progression” as the outcome variable and a binary variable of baseline mRSS cutoff point as predictor.

Results

We included 152 patients (age and disease duration [mean ± SD, years]: 48.7 ± 13.0 and 2.4 ± 1.5 respectively, 22.4% males, 34.2% Pol3‐positive). Seventeen patients (11.2%) had skin fibrosis progression after 12 ± 2 months. An mRSS cutoff of 27 or less had the highest probability of progression (odds ratio, 9.12; 95% confidence interval: 1.173‐70.851; P = 0.035; area under the curve, 0.652; sensitivity, 94%).

Conclusion

We demonstrated in an ethnically diverse cohort of patients with early dcSSc and with a high proportion of patients who are Pol3‐positive that setting an upper limit of the mRSS as a selection criterion leads effectively to cohort enrichment with progressors.

Initial predictors of skin thickness progression in patients with diffuse cutaneous systemic sclerosis: Results from a multicentre prospective cohort in Japan

OBJECTIVE

To identify initial parameters that predict worsening of skin thickening in patients with diffuse cutaneous systemic sclerosis (dcSSc) using a multicentre, prospective, observational cohort in Japan.

METHODS

A total of 171 patients with dcSSc were selected from a prospective cohort database based on the following criteria: dcSSc, modified Rodnan total skin thickness score (mRSS) ≥7, disease duration <60 months, and valid mRSS data at one year. Worsening of skin thickness was defined as an increase in mRSS ≥3 points and an increase ≥25% from baseline to one year. Initial demographic and clinical parameters useful for predicting the progression of skin thickness were identified using univariate and multivariable analysis, and prediction models of skin thickening progression were built based on combinations of independent predictive parameters.

RESULTS

Only 23 patients (13.5%) experienced worsening mRSSs at one year. Short disease duration, low mRSS, absence of nailfold bleeding, arthritis, and a high erythrocyte sedimentation rate at diagnosis were identified as predictors of subsequent worsening of the mRSS even after adjusting for the treatment. Assessment of the best predictive model revealed that patients with a disease duration ≤12 months and mRSS ≤19 had a risk of mRSS worsening within one year, with a sensitivity of 73.9% and specificity of 81.1%.

CONCLUSION

Identification of predictors of subsequent worsening of skin thickness in dcSSc patients is useful for identifying patients who require intensive treatment with potential disease-modifying agents and for improving clinical trial design by characterizing eligible progressors in the Japanese population.

PGE2 in fibrosis and cancer: Insights into fibroblast activation

Fibroblasts are the essential cellular architects of connective tissue and as such are crucial cells in contributing to organ homeostasis. While fulfilling important repair functions during tissue regeneration upon wounding, chronic fibroblast activation provokes pathological organ fibrosis and promotes neoplastic disease progression. Identifying targets that may serve to therapeutically terminate fibroblast activation is therefore desirable. Among the mediators that may be relevant in this context is the prostanoid prostaglandin E₂ (PGE₂) that is produced during inflammatory settings, where pathological fibrosis occurs. Here, we summarize current, in part controversial, concepts on the impact of PGE₂ on fibroblast activation in fibrotic diseases including cancer, and discuss these findings in the context of the evolving concept of fibroblast heterogeneity.

Systemic sclerosis: state of the art on clinical practice guidelines

Systemic sclerosis (SSc) is an orphan disease characterised by autoimmunity, fibrosis of the skin and internal organs, and vasculopathy. SSc may be associated with high morbidity and mortality. In this narrative review we summarise the results of a systematic literature research, which was performed as part of the European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases project, aimed at evaluating existing clinical practice guidelines or recommendations. Only in the domains ‘Vascular & Ulcers’ (ie, non-pharmacological approach to digital ulcer), ‘PAH’ (ie, screening and treatment), ‘Treatment’ and ‘Juveniles’ (ie, evaluation of juveniles with Raynaud’s phenomenon) evidence-based and consensus-based guidelines could be included. Hence there is a preponderance of unmet needs in SSc referring to the diagnosis and (non-)pharmacological treatment of several SSc-specific complications. Patients with SSc experience significant uncertainty concerning SSc-related taxonomy, management (both pharmacological and non-pharmacological) and education. Day-to-day impact of the disease (loss of self-esteem, fatigue, sexual dysfunction, and occupational, nutritional and relational problems) is underestimated and needs evaluation.

A randomised placebo-controlled double-blind trial to assess the safety of intramuscular administration of allogeneic mesenchymal stromal cells for digital ulcers in systemic sclerosis: the MANUS Trial protocol

INTRODUCTION

Systemic sclerosis (SSc) is an autoimmune disease characterised by inflammation, fibrosis and vasculopathy. Digital ulcers (DUs) are a frequent manifestation of vasculopathy in patients with SSc. Despite recent advances in pharmacological treatments, DU still have major health and economic implications. As there is currently no proven therapeutic strategy to promote DU healing, new treatments are urgently needed. Mesenchymal stem or stromal cells (MSCs) may provide a novel therapy for DU in SSc, because of their immunomodulatory and vasculoregenerative properties. Allogeneic MSC therapy involves functionally competent MSCs from healthy donors and may be used as 'off-the-shelf' available treatment. This study will evaluate whether allogeneic MSC therapy is a safe and potentially efficacious treatment for DU of SSc.

METHODS AND ANALYSIS

The MANUS (Mesenchymal stromal cells for Angiogenesis and Neovascularization in digital Ulcers of Systemic Sclerosis) Trial is a double-blind randomised placebo-controlled trial. 20 patients with SSc with refractory DU will be randomised to receive eight intramuscular injections with either placebo or 50*10⁶ MSCs. The primary outcome is the toxicity of the treatment at 12 weeks after administration. Secondary outcomes include (serious) adverse events, number and time to healing of DU, pain, reported hand function, quality of life and SSc disease activity. We will also evaluate changes in nailfold capillaroscopy pattern, as well as biochemical parameters and biomarkers in peripheral blood and skin biopsies. Follow-up visits will be scheduled at 48 hours and 2, 4, 8, 12, 24 and 52 weeks post-treatment. If the results confirm safety, feasibility and potential efficacy, a large multicentre randomised controlled trial with longer follow-up will be initiated focusing on efficacy.

ETHICS AND DISSEMINATION

The study has been approved by the Dutch Central Committee on Research Concerning Human Subjects (protocol no: NL51705.000.15). The results will be disseminated through patient associations and conventional scientific channels.

TRIAL REGISTRATION NUMBER

NCT03211793; Pre-results.

Points to consider for clinical trials of the gastrointestinal tract in systemic sclerosis

The pathogenesis of gastrointestinal tract involvement in SSc is not fully understood. However, gastrointestinal signs and symptoms are very common. Trials to test therapies, with rare exceptions, should be double-blind, randomized trials with either active therapy or placebo as comparators. Trial duration will vary dependent on the anticipated therapy and should usually be 6-24 weeks long, although some motility trials may need to be 52 weeks. As in any well-controlled trial, inclusion and exclusion criteria should encourage relatively uniform patients with sufficiently active disease to discern response, importantly considering disease duration. Previous therapy, co-morbid conditions, potentially confounding and/or concomitant therapy should be considered. Outcome measures should include both objective/semi-objective and subjective measures, although validated measures are not frequent and design needs to consider using only validated measures. Unvalidated measures can be included to validate them for future use. A full analysis plan should be completed before study commencement, including the method to account for missing data.

Functional disability and other health-related quality-of-life domains: points to consider for clinical trials in systemic sclerosis

Patients with SSc have the highest mortality among the rheumatic diseases. In addition, SSc is associated with disfigurement, hand contractures, fatigue, poor sleep, severe RP with numbness and tingling of the fingers can lead to decrements in quality of life. This Points to Consider article provides practical considerations for design of trials for functional disability and other health-related quality-of-life issues.

Interstitial lung disease points to consider for clinical trials in systemic sclerosis

Interstitial lung disease causes major morbidity and mortality in patients with systemic sclerosis (SSc-ILD). Large randomized clinical trials in SSc-ILD have provided important information regarding the feasibility, reliability and validity of outcome measures. Forced vital capacity percentage predicted should be considered as a primary outcome measure, with inclusion of appropriate radiological and patient-reported measures. We provide practical recommendations for trial design in SSc-ILD.

Points to consider for skin ulcers in systemic sclerosis

This article discusses points to consider when undertaking a clinical trial to test therapy for skin ulcers in SSc. A validated definition of skin ulcers should be used if available. Defining a uniform SSc patient population, including consideration of disease duration, history of digital ulcers and capillaroscopic patterns, is important. Excluding confounding factors such as infection, calcinosis and trauma should be strongly considered, or at least accounted for, in defining patients. Outcome measures such as time to healing, prevention of new ulcers, function, pain and objective measures such as US, laser Doppler and thermography can be considered as outcome measures, although their validation has not yet been achieved and efforts may be needed to validate them before use. Likewise, biomarkers should be considered or consideration should be given to storing serum, plasma or cells for possible future analysis. A pre-planned analysis is important and should include consideration of missing data.

Systemic sclerosis

Systemic sclerosis, also called scleroderma, is an immune-mediated rheumatic disease that is characterised by fibrosis of the skin and internal organs and vasculopathy. Although systemic sclerosis is uncommon, it has a high morbidity and mortality. Improved understanding of systemic sclerosis has allowed better management of the disease, including improved classification and more systematic assessment and follow-up. Additionally, treatments for specific complications have emerged and a growing evidence base supports the use of immune suppression for the treatment of skin and lung fibrosis. Some manifestations of the disease, such as scleroderma renal crisis, pulmonary arterial hypertension, digital ulceration, and gastro-oesophageal reflux, are now treatable. However, the burden of non-lethal complications associated with systemic sclerosis is substantial and is likely to become more of a challenge. Here, we review the clinical features of systemic sclerosis and describe the best practice approaches for its management. Furthermore, we identify future areas for development.

Assessment of skin involvement in systemic sclerosis

Skin involvement in SSc is an important marker of disease activity, severity and prognosis, making the assessment of skin a key issue in SSc clinical research. We reviewed the published data assessing skin involvement in clinical trials and summarized the major conclusions important in SSc clinical research. A systematic literature review identified randomized controlled trials using skin outcomes in SSc. Analysis examined the validity of the different skin measures based on literature findings. Twenty-two randomized controlled trials were found. The average study duration was 10.2 (s.d. 4.5) months, mean (s.d.) sample size 32.4 (32.6) and 26.7 (27.8) in intervention and control arms, respectively. The 17-site modified Rodnan skin score is a fully validated primary outcome measure in diffuse cutaneous SSc. Skin histology seems to be an appropriate method for evaluation of skin thickness. These findings have important implications for clinical trial design targeting skin involvement in SSc.

Multiplex serum protein analysis reveals potential mechanisms and markers of response to hyperimmune caprine serum in systemic sclerosis

Background

Hyperimmune caprine serum (HICS) is a novel biological therapy with potential benefit for skin in established diffuse cutaneous systemic sclerosis. Here we report multiplex protein analysis of blood samples from a placebo-controlled phase II clinical trial and explore mechanisms of action and markers of response.

Methods

Patients were treated with HICS (n = 10) or placebo (n = 10) over 26 weeks, with follow-up open-label treatment to 52 weeks in 14 patients. Serum or plasma samples at baseline, 26 and 52 weeks were analysed using multiplex or individual immunoassays for 41 proteins. Patterns of change were analysed by clustering using Netwalker 1.0, Pearson coefficient and significance analysis of microarrays (SAM) correction.

Results

Cluster analysis, SAM multiplex testing and paired comparison of individual analytes identified proteins that were upregulated or downregulated during treatment with HICS. There was upregulation of the hypothalamo-pituitary-adrenal axis after HICS treatment evidenced by increases in α-MSH and ACTH in cases treated with HICS. Interestingly, significant increase in PIIINP was associated with HICS treatment and improved MRSS suggesting that this may be a marker of extracellular matrix turnover. Other relevant factors reduced in HICS-treated patients compared with controls, although not reaching statistical significance included COMP, CCL2, IL6, TIMP2, Fractalkine and TGFβ1 levels.

Conclusions

Our results suggest mechanisms of action for HICS, including upregulation of α-MSH, that has been shown to be anti-fibrotic in preclinical models, and possible markers to be included in future trials targeting skin in diffuse cutaneous systemic sclerosis.

Trial registration

Eudract, No. 2007-003122-24. ClinTrials.gov, No. NCT00769028. Registered 7 October 2008.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1252-x) contains supplementary material, which is available to authorized users.

A Point-Scoring System for the Clinical Diagnosis of Sjögren's Syndrome Based on Quantified SPECT Imaging of Salivary Gland

Objective

To establish a point-scoring diagnostic system for Sjögren's syndrome (SS) based on quantified SPECT imaging of salivary gland, and evaluate its feasibility and performance compared with 2002 AECG criteria and 2012 ACR criteria.

Methods

213 patients with suspected SS enrolled in this study. The related clinical data of all patients were collected. All patients were evaluated and grouped on a clinical basis and posttreatment follow-up by rheumatology specialists as the unified standard (SS group with 149 cases and nSS group with 64 cases). From SPECT imaging of salivary gland, T_max, UI_max, T_s and EF_s were derived for bilateral parotid and submandibular glands, and compared between the groups. A point-scoring diagnostic system for SS was established based on the quantified SPECT imaging of salivary gland. We estimated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for the new diagnostic system, compared with 2002 AECG criteria and 2012 ACR criteria.

Results

When 7.0 was used as the cut-off point, the sensitivity, specificity, PPV, NPV and accuracy for the new point-scoring system in diagnosing SS were 89.93% (134/149), 93.75% (60/64), 97.10% (134/138), 80.00% (60/75) and 91.08% (194/213), respectively. The new point-scoring diagnostic system based on quantified SPECT imaging of salivary gland keeps the specificity comparatively to 2002 AECG criteria and 2012 ACR criteria, but improves the sensitivity significantly (P<0.01).

Conclusion

The new point-scoring diagnostic system for SS based on quantified SPECT imaging of salivary gland may be superior to 2002 AECG criteria and 2012 ACR criteria, with higher sensitivity and similar specificity in the diagnosis of SS. Additionally, it also has good feasibility in the clinical settings.

Systemic sclerosis: The need for structured care

Autoimmune connective tissue diseases (CTDs) have a propensity to affect multiple organ systems as well as physical function, quality of life, and survival. Their clinical heterogeneity, multisystem involvement, and low worldwide prevalence present challenges for researchers to establish a study design to help better understand the course and outcomes of CTDs. Systemic sclerosis (SSc) is a notable example of a CTD, wherein longitudinal cohort studies (LCS) have enabled us to elucidate disease manifestations, disease course, and risk and prognostic factors for clinically important outcomes, by embedding research in clinical practice. Nevertheless, further efforts are needed to better understand SSc especially with regard to recognizing organ involvement early, developing new therapies, optimizing the use of existing therapies, and defining treatment targets. The heterogeneous multi-organ nature of SSc would lend itself well to a structured model of care, wherein step-up treatment algorithms are used with the goal of attaining a prespecified treatment target. In this chapter, we discuss the rationale for a structured treatment approach in SSc and propose possible treatment algorithms for three of the more common disease manifestations, namely skin involvement, digital ulcers and gastrointestinal tract involvement. We discuss possible strategies for evaluating and implementing these algorithms in the setting of LCS. We conclude by presenting a research agenda for the development of structured models of care in SSc.

Scleroderma: Not an orphan disease any more

Scleroderma (or systemic sclerosis) is a rare disease associated with significant morbidity and mortality. Although previously thought to have a uniformly poor prognosis, the outlook has changed in recent years. We review recent insights into the pathogenesis, clinical features, assessment and management of scleroderma.

Systemic sclerosis

Systemic sclerosis is a complex autoimmune disease characterized by a chronic and frequently progressive course and by extensive patient-to-patient variability. Like other autoimmune diseases, systemic sclerosis occurs more frequently in women, with a peak of onset in the fifth decade of life. The exact cause of systemic sclerosis remains elusive but is likely to involve environmental factors in a genetically primed individual. Pathogenesis is dominated by vascular changes; evidence of autoimmunity with distinct autoantibodies and activation of both innate and adaptive immunity; and fibrosis of the skin and visceral organs that results in irreversible scarring and organ failure. Intractable progression of vascular and fibrotic organ damage accounts for the chronic morbidity and high mortality. Early and accurate diagnosis and classification might improve patient outcomes. Screening strategies facilitate timely recognition of life-threatening complications and initiation of targeted therapies to halt their progression. Effective treatments of organ-based complications are now within reach. Discovery of biomarkers - including autoantibodies that identify patient subsets at high risk for particular disease complications or rapid progression - is a research priority. Understanding the key pathogenetic pathways, cell types and mediators underlying disease manifestations opens the door for the development of targeted therapies with true disease-modifying potential. For an illustrated summary of this Primer, visit: http://go.nature.com/lchkcA.