Pharmacotherapy of systemic sclerosis

Thickness of anterior sclera and corneal layers in systemic sclerosis

PURPOSE

To evaluate the thickness of anterior sclera and corneal layers in patients with systemic sclerosis.

METHODS

The present cross-sectional study included 41 patients with systemic sclerosis and 41 age- and gender-matched healthy controls. The study and control groups were compared in terms of the thickness of anterior sclera, corneal epithelium, Bowman's layer, corneal stroma, and Descemet's membrane-endothelium complex. The thickness measurements were obtained using the anterior segment module of spectral-domain optical coherence tomography.

RESULTS

The thickness of anterior sclera, corneal epithelium, Bowman's layer, and Descemet's membrane-endothelium complex were similar in the patients with systemic sclerosis and healthy controls (P > 0.05). Total corneal thickness at the apex was 511.1 ± 33.5 µm in the systemic sclerosis group and 528.4 ± 29.5 µm in the control group (P = 0.015). The corneal stroma was thinner in the systemic sclerosis patients compared to the healthy controls (P = 0.02).

CONCLUSIONS

The corneal stroma was thinner in the patients with systemic sclerosis compared to that of healthy controls, while the thickness of the anterior sclera was similar in both groups.

The Oral Bioavailability and Effect of Various Gastric Conditions on the Pharmacokinetics of Dersimelagon in Healthy Adult Volunteers

Dersimelagon is a novel orally administered selective agonist for melanocortin receptor 1 being investigated for the treatment of erythropoietic protoporphyria, X-linked protoporphyria, and diffuse cutaneous systemic sclerosis. In this open-label, multicenter, randomized, two-cohort, sequential crossover study, the relative oral bioavailability of two tablet formulations of dersimelagon was evaluated, and the effect of various gastric conditions (from a high-fat meal, a proton-pump inhibitor, and an acidic carbonated beverage) on the pharmacokinetics of dersimelagon were assessed in healthy participants (N = 50). Both tablet formulations demonstrated rapid absorption, and the 100-mg tablets showed a 97% relative oral bioavailability versus 50-mg tablets. No effect was observed on overall exposure (area under the plasma concentration versus time curve [AUC]) following consumption of a high-fat meal, and C_max was higher (22%, 90% confidence interval [CI] 1.05-1.42) in a fed state compared with fasted conditions. Similarly, overall exposure AUC of dersimelagon was comparable following administration alone or in combination with esomeprazole; however, coadministration of esomeprazole led to a slight decrease in C_max (fasted: 9%, 90%CI 0.77-1.07; fed: 24%, 90%CI 0.66-0.88) compared with administration of dersimelagon alone. In general, the consumption of an acidic beverage increased time to C_max regardless of fed or fasted status and decreased overall exposure AUC and C_max of dersimelagon.

Effect of vasodilator and immunosuppressive therapy on the endothelial dysfunction in patients with systemic sclerosis

A comparative analysis of flow-mediated vasodilation (FMD), vasoactive angiogenic, and fibrogenic mediators between treatment-naive and treated systemic sclerosis (SSc) patients is an unmet need. (1)To assess the FMD and different pathogenic mediators in SSc patients about endothelial dysfunction. (2) To assess the proportion of circulating endothelial cells (CECs) in treatment-naïve patients. SSc patients were grouped into treatment-naïve (Group-I, n = 24) on vasodilator (Group-II, n = 10), on vasodilator + immunosuppressive (Group-III, n = 22)]. Age-sex matched healthy controls (n = 20) were included. Endothelial dysfunction (ED) was measured radiologically using FMD. Serum levels of NO, ET1, NO/ET1, sVCAM, sICAM, TGF, IL-6, and VEGF, as well as gene expressions of eNOS, iNOS, ET-1, and TGF, were measured to assess the status of ED in various study groups. CEC was measured in Group-I and HC. CEC was used as a marker to identify a key regulator of ED in SSc. FMD was significantly decreased in all SSc patients through receiving treatment. Upregulation of serum NO and ET concentrations was noted post-treatment with an unaltered NO/ET1 ratio. NO was positively correlated with FMD (r = 0.6) and negatively with TGFβ (r =  - 0.5). ET-1 showed a negative correlation with TGFβ (r =  - 0.5) but no significant correlation with FMD. Circulating endothelial cell (CEC) was significantly higher in Group-I (3.2%) than HC (0.8%) (p = 0.002), and it showed a good correlation with NO (r =  - 0.7, p = 0.0001) and NO/ET1 (r =  - 0.6, p = 0.007). Persistent ED was observed in all SSc patients irrespective of treatment. Dysbalance in NO/ET1 ratio might be the considering factor for the underlying progression of ED. Based on our findings, it may be hypothesized that reduced NO may be a contributing factor in the pathogenesis of endothelial dysfunction in SSc.

Cannabinoid derivatives acting as dual PPARγ/CB2 agonists as therapeutic agents for systemic sclerosis

The endocannabinoid system (ECS) may play a role in the pathophysiology of systemic sclerosis (SSc). Cannabinoids acting as dual PPARγ/CB₂ agonists, such as VCE-004.8 and Ajulemic acid (AjA), have been shown to alleviate skin fibrosis and inflammation in SSc models. Since both compounds are being tested in humans, we compared their activities in the bleomycin (BLM) SSc model. Specifically, the pharmacotranscriptomic signature of the compounds was determined by RNA-Seq changes in the skin of BLM mice treated orally with AjA or EHP-101, a lipidic formulation of VCE-004.8. While both compounds down-regulated the expression of genes involved in the inflammatory and fibrotic components of the disease and the pharmacotranscriptomic signatures were similar for both compounds in some pathways, we found key differences between the compounds in vasculogenesis. Additionally, we found 28 specific genes with translation potential by comparing with a list of human scleroderma genes. Immunohistochemical analysis revealed that both compounds prevented fibrosis, collagen accumulation and Tenascin C (TNC) expression. The endothelial CD31⁺/CD34⁺ cells and telocytes were reduced in BLM mice and restored only by EHP-101 treatment. Finally, differences were found in plasmatic biomarker analysis; EHP-101, but not AjA, enhanced the expression of some factors related to angiogenesis and vasculogenesis. Altogether the results indicate that dual PPARγ/CB2 agonists qualify as a novel therapeutic approach for the treatment of SSc and other fibrotic diseases. EHP-101 demonstrated unique mechanisms of action related to the pathophysiology of SSc that could be beneficial in the treatment of this complex disease without current therapeutic options.

Systemic Sclerosis Pathogenesis and Emerging Therapies, beyond the Fibroblast

Systemic sclerosis (SSc) is a complex rheumatologic autoimmune disease in which inflammation, fibrosis, and vasculopathy share several pathogenic pathways that lead to skin and internal organ damage. Recent findings regarding the participation and interaction of the innate and acquired immune system have led to a better understanding of the pathogenesis of the disease and to the identification of new therapeutic targets, many of which have been tested in preclinical and clinical trials with varying results. In this manuscript, we review the state of the art of the pathogenesis of this disease and discuss the main therapeutic targets related to each pathogenic mechanism that have been discovered so far.

Humanistic and cost burden of systemic sclerosis: A review of the literature

BACKGROUND

Systemic sclerosis (SSc), or systemic scleroderma, is a chronic multisystem autoimmune disease characterised by widespread vascular injury and progressive fibrosis of the skin and internal organs. Patients with SSc have decreased survival, with pulmonary involvement as the main cause of death. Current treatments for SSc manage a range of symptoms but not the cause of the disease. Our review describes the humanistic and cost burden of SSc.

METHODS

A structured review of the literature was conducted, using predefined search strategies to search PubMed, Embase, and the Cochrane Library. Grey literature searches also were conducted.

RESULTS

In total, 2226 articles were identified in the databases and 52 were included; an additional 10 sources were included from the grey literature. The review identified six studies reporting relevant cost estimates conducted in five different countries and four studies that assessed the humanistic burden of SSc. Total direct annual medical costs per patient for Europe varied from €3544 to €8452. For Canada, these costs were reported to be from Can$5038 to Can$10,673. In the United States, the total direct health care costs were reported to be US$17,365 to US$18,396. Different key drivers of direct costs were reported, including hospitalisations, outpatients, and medication. The total annual costs per patient were reported at Can$18,453 in Canada and varied from €11,074 to €22,459 in Europe. Indirect costs represented the largest component of the total costs. EQ-5D utility scores were lower for patients with SSc than those observed in the general population, with reported mean values of 0.49 and 0.68, respectively. The average value of the Health Assessment Questionnaire for patients with SSc was significantly higher than the control population (0.94), and the average value of the SF-36 was significantly lower than the control population: 49.99 for the physical dimension and 58.42 for the mental dimension.

CONCLUSIONS

Overall, there is a paucity of information on the burden of SSc. Nonetheless, our review indicates that the quality of life of patients with SSc is considerably lower than that of the general population. In addition, SSc places a considerable economic burden on health care systems and society as a whole.

Cellular Therapies in Systemic Sclerosis: Recent Progress

Systemic sclerosis (SSc) is a rare autoimmune connective tissue disease with a high mortality and morbidity. While progress has been made in terms of identifying high-risk patients and implementing new treatment strategies, therapeutic options remain limited. In the past few decades, various cellular therapies have emerged, which have been studied in SSc and other conditions. Here, we provide a comprehensive review of currently available cellular therapies and critically assess their merit as disease-modifying treatment for SSc. Currently, hematopoietic stem cell transplantation is the only cellular therapy that has demonstrated clinical effects on the immune system, neoangiogenesis, and fibrosis. Robust mechanistic studies as well as clinical trials are essential to move the field forward.

High reactive oxygen species in fibrotic and nonfibrotic skin of patients with diffuse cutaneous systemic sclerosis

Systemic sclerosis (SSc) is a chronic multisystemic connective tissue disease characterized by progressive fibrosis affecting skin and internal organs. Despite serious efforts to unveil the pathogenic mechanisms of SSc, they are still unclear. High levels of reactive oxygen species (ROS) in affected patients have been shown, and ROS are suggested to play a role in fibrosis pathogenesis. In this study we evaluate ROS levels in nonfibrotic and fibrotic skin of patients with SSc and we compare them with those obtained from healthy controls. We enrolled nine SSc patients fulfilling the EULAR/ACR classification criteria and seven healthy controls. Patients included four men and five women with mean age of 46 ± 10 years. Controls were matched by sex and age. All patients were affected by the diffuse cutaneous form of SSc and the ANA pattern anti-Scl70. Mean disease duration was 7.5 ± 5 years. Skin involvement was evaluated by modified Rodnan skin score. Skin samples (4-mm punch biopsy) were taken from fibrotic skin and nonfibrotic skin of patients and from healthy controls as well. To detect ROS, specimens were analyzed immediately after sampling by electron paramagnetic resonance spectroscopy. Blood samples were drawn from all patients and controls to assess oxidative stress biomarkers. ROS levels (expressed as median and range, in nmol/L/min/mg of dry weight) were 24.7 (10.9-47.0) in fibrotic skin, 18.7 (7.3-34.0) in nonfibrotic skin, and 7.7 (3.5-13.6) in healthy control skin. ROS levels in fibrotic and nonfibrotic skin of SSc patients were significantly higher than in healthy controls (p = 0.002 and p = 0.009, respectively). ROS levels in fibrotic skin were raised in comparison to nonfibrotic skin, when samples related to each patient were compared (p = 0.01). ROS levels in fibrotic skin were correlated with forced vital capacity (r = -0.75, p = 0.02) and erythrocyte sedimentation rate (r = 0.70, p = 0.04). All other clinical and lab parameters showed no significant correlation. Compared to controls, blood from SSc patients showed lower ascorbate (vitamin C) levels (8 (3.8-9.8) vs 10.5 (9-19.1) mg/L, p = 0.004) and higher lipid peroxides (873.5 (342-1973) vs 422 (105-576) μmol/L, p = 0.004). Our results indicate the presence of high oxidative stress in both nonfibrotic skin and fibrotic skin of SSc patients, but with higher tendency in the latter. Raised ROS levels in nonfibrotic skin of SSc patients might be a hint of early involvement in skin fibrogenesis. However, a longitudinal prospective study is necessary for such proof.

Pathogenesis of Systemic Sclerosis

Systemic scleroderma (SSc) is one of the most complex systemic autoimmune diseases. It targets the vasculature, connective tissue-producing cells (namely fibroblasts/myofibroblasts), and components of the innate and adaptive immune systems. Clinical and pathologic manifestations of SSc are the result of: (1) innate/adaptive immune system abnormalities leading to production of autoantibodies and cell-mediated autoimmunity, (2) microvascular endothelial cell/small vessel fibroproliferative vasculopathy, and (3) fibroblast dysfunction generating excessive accumulation of collagen and other matrix components in skin and internal organs. All three of these processes interact and affect each other. The disease is heterogeneous in its clinical presentation that likely reflects different genetic or triggering factor (i.e., infection or environmental toxin) influences on the immune system, vasculature, and connective tissue cells. The roles played by other ubiquitous molecular entities (such as lysophospholipids, endocannabinoids, and their diverse receptors and vitamin D) in influencing the immune system, vasculature, and connective tissue cells are just beginning to be realized and studied and may provide insights into new therapeutic approaches to treat SSc.

Effect of menopause on the modified Rodnan skin score in systemic sclerosis

Introduction

We aimed to evaluate the effect of menopause on skin thickening, as measured by the modified Rodnan skin score (mRSS), in women with systemic sclerosis (SSc).

Methods

We identified women with either limited or diffuse SSc, aged ≥ 18 years, enrolled within the Canadian Scleroderma Research Group (CSRG) cohort, between 2004 and 2011. As part of the CSRG cohort, subjects undergo annual assessments with standardized questionnaires and physical examinations. We performed multivariate regression analyses using generalized estimating equation (GEE) to determine the effect of menopause on the mRSS, adjusting for relevant covariates including notably age, follow-up time, and disease duration.

Results

We identified 1070 women with SSc, contributing a total of 3546 observations over the study period. Of these women, at baseline, 65% had limited disease and 35% diffuse disease. In multivariate analyses, we observed a substantial effect of postmenopausal status on the mean mRSS in women with diffuse disease subtype [−2.62 units, 95% confidence interval (CI) -4.44, −0.80] and significant interaction between menopausal status and disease subtype (2.04 units, 95% CI 0.20, 3.88). The effect of postmenopausal status on the mean mRSS was smaller in women with limited SSc (−0.58, 95% CI −1.50, 0.34).

Conclusions

Our results suggest that menopause has a substantial effect on skin thickening in diffuse SSc, with postmenopausal status being associated with a lower mean mRSS compared to premenopausal status.

Dose-escalation of human anti-interferon-α receptor monoclonal antibody MEDI-546 in subjects with systemic sclerosis: a phase 1, multicenter, open label study

Introduction

Type I interferons (IFNs) are implicated in the pathogenesis of systemic sclerosis (SSc). MEDI-546 is an investigational human monoclonal antibody directed against the type I IFN receptor. This Phase 1 study evaluated the safety/tolerability, pharmacokinetics (PK), immunogenicity, and pharmacodynamics (PD) of single and multiple intravenous doses of MEDI-546 in adults with SSc.

Methods

Subjects (≥18 years) with SSc were enrolled in an open-label, dose-escalation study to receive single (0.1, 0.3, 1.0, 3.0, 10.0, or 20.0 mg/kg), or 4 weekly intravenous doses (0.3, 1.0, or 5.0 mg/kg/week) of MEDI-546. Subjects were followed for 12 weeks. Safety assessments included adverse events (AEs), laboratory results, and viral monitoring. Blood samples were collected from all subjects for determination of PK, presence of anti-drug antibodies (ADAs), and expression of type I IFN-inducible genes.

Results

Of 34 subjects (mean age 47.4 years), 32 completed treatment and 33 completed the study. Overall, 148 treatment-emergent AEs (TEAEs) were reported (68.9% mild, 27.7% moderate). TEAEs included one grade 1 infusion reaction (5.0 mg/kg/week multiple dose). Of 4 treatment-emergent serious AEs (skin ulcer, osteomyelitis, vertigo, and chronic myelogenous leukemia (CML)), only CML (1.0 mg/kg/week multiple dose) was considered possibly treatment-related. MEDI-546 exhibited non-linear PK at lower doses. ADAs were detected in 5 subjects; no apparent impact on PK was observed. Peak inhibition of the type I IFN signature in whole blood was achieved within 1 day and in skin after 7 days.

Conclusion

The safety/tolerability, PK, and PD profiles observed in this study support further clinical development of MEDI-546.

Trial Registration

ClinicalTrials.gov NCT00930683

Autoimmune connective tissue diseases

Connective tissue diseases are a rare and diverse group of disorders that result in pathology of the connective tissues of the body. This article focuses on the systemic autoimmune connective tissue diseases, and aims to provide a practical overview of these conditions for use in primary care.

Annual Medical Costs and Healthcare Resource Use in Patients with Systemic Sclerosis in an Insured Population

Objective.

Systemic sclerosis (SSc) is a chronic autoimmune disease. The objective of our study was to estimate the medical costs and healthcare resource use of subjects with SSc in a large US managed care plan.

Methods.

Subjects at least 18 years of age and with claims-based evidence of SSc (ICD-9-CM code 710.1x) were identified from a health plan database from 2003 through 2008. Subjects were matched to unaffected controls, based on index date, age, sex, geographic region, time on insurance, and comorbidity score. Costs and resource use were identified during the 12-month postindex period. A generalized linear model (GLM) was used to estimate costs, controlling for demographic and clinical characteristics.

Results.

In this study, 1648 subjects with SSc were matched to 4944 controls. Mean overall annual medical costs were higher among SSc subjects than controls ($17,365 vs $5,508; p < 0.001). A GLM model supported these results. Evidence of lung disease, gastrointestinal bleeding, or renal disease increased costs (all p < 0.001). Compared to controls, significantly higher proportions of SSc subjects had postindex ambulatory visits, emergency department visits, and inpatient hospital stays (all p < 0.001).

Conclusion.

Our findings suggest that the medical costs and resource use associated with treating SSc are high (compared to matched controls), and as expected, subjects with serious disease complications experience the highest costs.

CD109, a TGF-β co-receptor, attenuates extracellular matrix production in scleroderma skin fibroblasts

Introduction

Scleroderma or systemic sclerosis (SSc) is a complex connective tissue disease characterized by fibrosis of skin and internal organs. Transforming growth factor beta (TGF-β) plays a key role in the pathogenesis of SSc fibrosis. We have previously identified CD109 as a novel TGF-β co-receptor that inhibits TGF-β signaling. The aim of the present study was to determine the role of CD109 in regulating extracellular matrix (ECM) production in human SSc skin fibroblasts.

Methods

CD109 expression was determined in skin tissue and cultured skin fibroblasts of SSc patients and normal healthy subjects, using immunofluorescence, western blot and RT-PCR. The effect of CD109 on ECM synthesis was determined by blocking CD109 expression using CD109-specific siRNA or addition of recombinant CD109 protein, and analyzing the expression of ECM components by western blot.

Results

The expression of CD109 proteinis markedly increased in SSc skin tissue in vivo and in SSc skin fibroblasts in vitro as compared to their normal counterparts. Importantly, both SSc and normal skin fibroblasts transfected with CD109-specific siRNA display increased fibronectin, collagen type I and CCN2 protein levels and enhanced Smad2/3 phosphorylation compared with control siRNA transfectants. Furthermore, addition of recombinant CD109 protein decreases TGF-β₁-induced fibronectin, collagen type I and CCN2 levels in SSc and normal fibroblasts.

Conclusion

The upregulation of CD109 protein in SSc may represent an adaptation or consequence of aberrant TGF-β signaling in SSc. Our finding that CD109 is able to decrease excessive ECM production in SSc fibroblasts suggest that this molecule has potential therapeutic value for the treatment of SSc.

Canonical Wnt signaling induces skin fibrosis and subcutaneous lipoatrophy: a novel mouse model for scleroderma?

OBJECTIVE

Because aberrant Wnt signaling has been linked with systemic sclerosis (SSc) and pulmonary fibrosis, we sought to investigate the effect of Wnt-10b on skin homeostasis and differentiation in transgenic mice and in explanted mesenchymal cells.

METHODS

The expression of Wnt-10b in patients with SSc and in a mouse model of fibrosis was investigated. The skin phenotype and biochemical characteristics of Wnt-10b-transgenic mice were evaluated. The in vitro effects of ectopic Wnt-10b were examined in explanted skin fibroblasts and preadipocytes.

RESULTS

The expression of Wnt-10b was increased in lesional skin biopsy specimens from patients with SSc and in those obtained from mice with bleomycin-induced fibrosis. Transgenic mice expressing Wnt-10b showed progressive loss of subcutaneous adipose tissue accompanied by dermal fibrosis, increased collagen deposition, fibroblast activation, and myofibroblast accumulation. Wnt activity correlated with collagen gene expression in these biopsy specimens. Explanted skin fibroblasts from transgenic mice demonstrated persistent Wnt/β-catenin signaling and elevated collagen and α-smooth muscle actin gene expression. Wnt-10b infection of normal fibroblasts and preadipocytes resulted in blockade of adipogenesis and transforming growth factor β (TGFβ)-independent up-regulation of fibrotic gene expression.

CONCLUSION

SSc is associated with increased Wnt-10b expression in the skin. Ectopic Wnt-10b causes loss of subcutaneous adipose tissue and TGFβ-independent dermal fibrosis in transgenic mice. These findings suggest that Wnt-10b switches differentiation of mesenchymal cells toward myofibroblasts by inducing a fibrogenic transcriptional program while suppressing adipogenesis. Wnt-10b-transgenic mice represent a novel animal model for investigating Wnt signaling in the setting of fibrosis.

Vascular involvement in systemic sclerosis (scleroderma)

Systemic sclerosis (SSc) is an acquired multiorgan connective tissue disease with variable mortality and morbidity dictated by clinical subset type. The etiology of the basic disease and pathogenesis of the systemic autoimmunity, fibrosis, and fibroproliferative vasculopathy are unknown and debated. In this review, the spectrum of vascular abnormalities and the options currently available to treat the vascular manifestations of SSc are discussed. Also discussed is how the hallmark pathologies (ie, how autoimmunity, vasculopathy, and fibrosis of the disease) might be effected and interconnected with modulatory input from lysophospholipids, sphingosine 1-phosphate, and lysophosphatidic acid.