Sjögren Syndrome: Why Do Clinical Trials Fail?

CD40 ligand antagonist dazodalibep in Sjögren's disease: a randomized, double-blinded, placebo-controlled, phase 2 trial

Sjögren's disease (SjD) is a chronic, systemic autoimmune disease with no approved disease-modifying therapies. Dazodalibep (DAZ), a novel nonantibody fusion protein, is a CD40 ligand antagonist that blocks costimulatory signals between T and B cells and antigen-presenting cells, and therefore may suppress the wide spectrum of cellular and humoral responses that drive autoimmunity in SjD. This study was a phase 2, randomized, double-blinded, placebo (PBO)-controlled trial of DAZ with a crossover stage in two distinct populations of participants with SjD. Population 1 had moderate-to-severe systemic disease activity and population 2 had an unacceptable symptom burden and limited systemic organ involvement. All participants had a diagnosis of SjD, with 21.6% and 10.1% having an associated connective tissue disease (rheumatoid arthritis or systemic lupus erythematosus) in populations 1 and 2, respectively. The remaining participants would be considered as having primary Sjögren's syndrome. The primary endpoint for population 1 (n = 74) was the change from baseline in the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index at day 169. The primary endpoint for population 2 (n = 109) was the change from baseline in the European League Against Rheumatism Sjögren's Syndrome Patient Reported Index at day 169. The primary endpoints (least squares mean ± standard error) were achieved with statistical significance for both population 1 (DAZ, -6.3 ± 0.6; PBO, -4.1 ± 0.6; P = 0.0167) and population 2 (DAZ, -1.8 ± 0.2; PBO, -0.5 ± 0.2; P = 0.0002). DAZ was generally safe and well tolerated. Among the most frequently reported adverse events were COVID-19, diarrhea, headache, nasopharyngitis, upper respiratory tract infection, arthralgia, constipation and urinary tract infection. In summary, DAZ appears to be a potential new therapy for SjD and its efficacy implies an important role for the CD40/CD40 ligand pathway in its pathogenesis. ClinicalTrials.gov identifier: NCT04129164 .

Elevated unphosphorylated STAT1 and IRF9 in T and B cells of primary sjögren's syndrome: Novel biomarkers for disease activity and subsets

OBJECTIVES

Autoreactive B cells and interferon (IFN) signature are hallmarks of primary sjögren's syndrome (pSS), but how IFN signaling pathways influence autoantibody production and clinical manifestations remain unclear. More detailed studies hold promise for improved diagnostic methodologies and personalized treatment.

METHODS

We analyzed peripheral blood T and B cell subsets from 34 pSS patients and 38 healthy donors (HDs) at baseline and upon stimulation regarding their expression levels of type I and II IFN signaling molecules (STAT1/2, IRF1, IRF9). Additionally, we investigated how the levels of these molecules correlated with serological and clinical characteristics and performed ROC analysis.

RESULTS

Patients showed elevated IFN pathway molecules, including STAT1, STAT2 and IRF9 among most T and B cell subsets. We found a reduced ratio of phosphorylated STAT1 and STAT2 in patients in comparison to HDs, although B cells from patients were highly responsive by increased phosphorylation upon IFN stimulation. Correlation matrices showed further interrelations between STAT1, IRF1 and IRF9 in pSS. Levels of STAT1 and IRF9 in T and B cells correlated with the IFN type I marker Siglec-1 (CD169) on monocytes. High levels of STAT1 and IRF9 within pSS B cells were significantly associated with hypergammaglobulinemia as well as anti-SSA/anti-SSB autoantibodies. Elevated STAT1 levels were found in patients with extraglandular disease and could serve as a biomarker for this subgroup (p < 0.01). Notably, IRF9 levels in T and B cells correlated with EULAR Sjögren's syndrome disease activity index (ESSDAI).

CONCLUSION

Here, we provide evidence that in active pSS patients, enhanced IFN signaling incl. unphosphorylated STAT1 and STAT2 with IRFs entertain chronic T and B cell activation. Furthermore, increased STAT1 levels candidate as biomarker of extraglandular disease, while IRF9 levels can serve as biomarker for disease activity.

Single-cell clonal tracing of glandular and circulating T cells identifies a population of CD9+ CD8+ T cells in primary Sjogren's syndrome

Primary Sjogren's syndrome (pSS) is a complex chronic autoimmune disease in which local tissue damage in exocrine glands is combined with broader systemic involvement across the body in tissues including the skin. These combined manifestations negatively impact patient health and quality of life. While studies have previously reported differences in immune cell composition in the peripheral blood of pSS patients relative to healthy control subjects, a detailed immune cell landscape of the damaged exocrine glands of these patients remains lacking. Through single-cell transcriptomics and repertoire sequencing of immune cells in paired peripheral blood samples and salivary gland biopsies, we present here a preliminary picture of adaptive immune response in pSS. We characterize a number of points of divergence between circulating and glandular immune responses that have been hitherto underappreciated, and identify a novel population of CD8+ CD9+ cells with tissue-residential properties that are highly enriched in the salivary glands of pSS patients. Through comparative analyses with other sequencing data, we also observe a potential connection between these cells and the tissue-resident memory cells found in cutaneous vasculitis lesions. Together, these results indicate a potential role for CD8+ CD9+ cells in mediating glandular and systemic effects associated with pSS and other autoimmune disorders.

Research hotspots and emerging trends in the treatment of Sjogren's syndrome: A bibliometric analysis from 1900 to 2022

Objective

Sjogren's syndrome (SS) is an autoimmune disease that mainly affects the salivary and lacrimal glands and further leads to dry mouth and eyes. In recent years, knowledge about the treatment of SS is developing rapidly. This study aims to assess research progress on SS treatment using a bibliometric approach and to identify research hotspots and emerging trends in this area.

Methods

The publications related to the treatment of SS were retrieved from the Science Citation Index Expanded (SCI-E) database. The following search terms were used to extract document data: TS=(Sjogren* OR Sicca*) AND TS= (Treat* OR Therap* OR Disease Management). Articles and review articles published in English from 1900 to 2022 were selected. After the manual screening, the publication data were exported to a plain text file and applied for cooperative network analysis, keyword analysis, and reference co-citation analysis by using CiteSpace.

Results

A total of 2038 publications were included in the analysis from 571 journals by 9063 authors. The annual number of published studies and times cited showed an overall upward trend since 1992. There was a degree of national/regional collaboration in this area, but direct collaboration between institutions and authors was still lacking. The country with the highest number of publications was in the United States, followed by China and Japan. Five SS-related treatments as the research hotspots were summarized by analyzing keywords and references, including immunosuppressive and anti-inflammatory therapy, regenerative therapy, gene therapy, surgical treatment, and symptomatic treatment. Among them, B cells, T cells, mucosal-associated invariant T (MAIT) cells, mesenchymal stem cells (MSCs), rituximab, belimumab, cell-target therapy, and immunosuppressive and anti-inflammatory therapy were emerging trends in this field.

Conclusions

This study conducted a data-based and objective introduction to the treatment of SS from a fresh perspective. An analysis of the intellectual bases, research hotspots, and emerging trends in the field will contribute to future research and treatment decisions, which will ultimately benefit SS patients.

Unpublished clinical trials of common rheumatic diseases

OBJECTIVES

Randomized controlled trials (RCTs) provide high-quality evidence for treatment efficacy, but many RCTs remain unpublished. The objective of this study was to describe the proportion of unpublished RCTs in five rheumatic diseases and to identify factors associated with publication.

METHODS

Registered RCTs for five rheumatic diseases (SLE, vasculitis, spondyloarthritis, SS and PsA) with over 30 months since study completion were identified using ClinicalTrials.gov. Index publications were identified by NCT ID numbers and structured text searches of publication databases. The results of unpublished studies were identified in abstracts and press releases; reasons for non-publication were assessed by surveying corresponding authors.

RESULTS

Out of 203 studies that met eligibility criteria, 17.2% remained unpublished, representing data from 4281 trial participants. Higher proportions of published trials were phase 3 RCTs (57.1% vs 28.6% unpublished, P < 0.05) or had a positive primary outcome measure (64.9% vs 25.7% unpublished, P < 0.001). In a multivariable Cox proportional hazards model, a positive outcome was independently associated with publication (hazard ratio 1.55; 95% CI: 1.09, 2.22). Corresponding authors of 10 unpublished trials cited ongoing preparation of the manuscript (50.0%), sponsor/funder issues (40.0%) and unimportant/negative result (20.0%) as reasons for lack of publication.

CONCLUSIONS

Nearly one in five RCTs in rheumatology remain unpublished 2 years after trial completion, and publication is associated with positive primary outcome measures. Efforts to encourage universal publication of rheumatology RCTs and reanalysis of previously unpublished trials should be undertaken.

Emerging treatment for Sjögren's disease: a review of recent phase II and III trials

INTRODUCTION

Sjögren's Disease, SjD, is a systemic autoimmune disorder characterized by reduced function of the salivary and lacrimal glands. Patients suffer from dryness, fatigue, and pain and may present with or without extra-glandular organ involvement. Symptoms limit SjD patients' quality of life and are the most difficult to improve with therapy. SjD patients are heterogeneous and clustering them into biologically similar subgroups might improve the efficacy of therapies. The need for therapies that address both the symptoms and extra glandular organ involvement of SjD presents an unmet opportunity that has recently attracted a growing interest in the pharmaceutical industry.

AREAS COVERED

The goal of this report is to review recent phase II/III studies in SjD. To accomplish our goal, we performed a literature search for phase II/III studies and abstracts recently presented at conferences.

EXPERT OPINION

This review allows updates the reader on the multitude of recent phase II/III clinical trials. We speculate on how subtypes of SjD will drive future therapeutic targeting and inform pathogenesis.

Symptom-Based Cluster Analysis Categorizes Sjögren's Disease Subtypes: An International Cohort Study Highlighting Disease Severity and Treatment Discordance

OBJECTIVE

Although symptom relief is a critical aspect for successful drug development in Sjögren's disease, patient experiences with Sjögren's-related symptoms are understudied. Our objective was to determine how pain, dryness, and fatigue, the cardinal symptoms of Sjögren's disease, drive cluster phenotypes.

METHODS

We used data from the Sjögren's International Collaborative Clinical Alliance (SICCA) Registry and a Sjögren's Foundation survey. We performed hierarchical clustering of symptoms by levels of dryness, fatigue, and pain. Using international and US cohorts, we performed multiple logistic regression analysis to compare the clusters, which included comparisons of differences in symptoms, quality of life (QoL), medication use, and systemic manifestations.

RESULTS

Four similar clusters were identified among 1,454 SICCA registrants and 2,920 Sjögren's Foundation survey participants: 1) low symptom burden in all categories (LSB); 2) dry with low pain and low fatigue (DLP); 3) dry with high pain and low to moderate fatigue (DHP); and 4) high symptom burden in all categories (HSB). Distribution of SICCA registrants matching the symptom profile for each cluster was 10% in the LSB cluster, 30% in the DLP cluster, 23% in the DHP cluster, and 37% in the HSB cluster. Distribution of survey participants matching the symptom profile for each cluster was 23% in the LSB cluster, 14% in the DLP cluster, 21% in the DHP cluster, and 42% in the HSB cluster. Individuals in the HSB cluster had more total symptoms and lower QoL but lower disease severity than those in the other clusters. Despite having milder disease as measured by laboratory tests and organ involvement, individuals in the HSB cluster received immunomodulatory treatment most often.

CONCLUSION

We identified 4 symptom-based Sjögren's clusters and showed that symptom burden and immunomodulatory medication use do not correlate with Sjögren's end-organ or laboratory abnormalities. Findings highlight a discordance between objective measures and treatments and offer updates to proposed symptom-based clustering approaches.

Clinical influences of anticentromere antibody on primary Sjögren's syndrome in a prospective Korean cohort

BACKGROUND/AIMS

This study was performed to clarify influences of anticentromere antibody (ACA) on clinical phenotypes of primary Sjögren's syndrome (pSS) patients in Korea.

METHODS

We assessed 318 patients who met the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for pSS. All patients were selected from the Korean Initiative of primary Sjögren's Syndrome (KISS), a prospective cohort. Among them, 53 patients were positive for ACA, while another 265 patients were not. We compared various clinical data including demographic features, extra-glandular manifestations (EGMs), clinical indices, and laboratory values available from the KISS database between the two groups.

RESULTS

Patients in the ACA-positive pSS group were older (p = 0.042), and had higher xerostomia inventory scores (p = 0.040), whereas glandular dysfunction represented with Schirmer I test was more severe in the ACA-negative group. More frequent Raynaud's phenomenon and liver involvement (both p < 0.001) and less articular involvement (p = 0.037) were observed among the EGMs in the ACA-positive group. Less frequency of leukopenia (p = 0.021), rheumatoid factor (p < 0.001), anti-Ro/SSA antibody positivity (p < 0.001), and hypergammaglobulinemia (p = 0.006), as well as higher positivity rates of anti-nuclear antibody and anti-topoisomerase antibody (p < 0.001 and p = 0.006, respectively) were found in the laboratory data in the ACA-positive pSS group.

CONCLUSION

Considering distinct phenotypes in hematological and serological features and EGMs, we should monitor the occurrence of these clinical features among pSS patients with ACA in caution.

Treatment of Sjögren's syndrome: current therapy and future directions

SS is usually described as having severe fatigue, dryness, diffuse pain, glandular swelling, and various extraglandular (systemic) manifestations. Clinical trials have generally failed because the vast majority of enrolled patients had no extraglandular manifestations at the time of enrolment but suffered from fatigue, dryness and pain that did not significantly respond to the study medication. A number of hypotheses on the pathogenesis of pSS have been put forward, including disturbances of innate and adaptive immunity as well as abnormalities of the interface between immune disorders and the neuro-endocrine system related to lacrimal and secretory gland dysfunction. Thus, future therapies must be designed for improvement of the symptoms of dry eyes and dry mouth, extraglandular disease, and fatigue and cognitive deficits. Given the inadequacies and limitations of current treatment options, we suggest that innovative directions involving interactions with neuroscientists and neuropsychiatrists together or combined with new immune targeting may be hold promise for better treating pSS.

EULAR recommendations for the management of Sjögren’s syndrome with topical and systemic therapies

The therapeutic management of Sjögren syndrome (SjS) has not changed substantially in recent decades: treatment decisions remain challenging in clinical practice, without a specific therapeutic target beyond the relief of symptoms as the most important goal. In view of this scenario, the European League Against Rheumatism (EULAR) promoted and supported an international collaborative study (EULAR SS Task Force) aimed at developing the first EULAR evidence and consensus-based recommendations for the management of patients with SjS with topical and systemic medications. The aim was to develop a rational therapeutic approach to SjS patients useful for healthcare professionals, physicians undergoing specialist training, medical students, the pharmaceutical industry and drug regulatory organisations following the 2014 EULAR standardised operating procedures. The Task Force (TF) included specialists in rheumatology, internal medicine, oral health, ophthalmology, gynaecology, dermatology and epidemiology, statisticians, general practitioners, nurses and patient representatives from 30 countries of the 5 continents. Evidence was collected from studies including primary SjS patients fulfilling the 2002/2016 criteria; when no evidence was available, evidence from studies including associated SjS or patients fulfilling previous sets of criteria was considered and extrapolated. The TF endorsed the presentation of general principles for the management of patients with SjS as three overarching, general consensus-based recommendations and 12 specific recommendations that form a logical sequence, starting with the management of the central triplet of symptoms (dryness, fatigue and pain) followed by the management of systemic disease. The recommendations address the use of topical oral (saliva substitutes) and ocular (artificial tear drops, topical non-steroidal anti-inflammatory drugs, topical corticosteroids, topical CyA, serum tear drops) therapies, oral muscarinic agonists (pilocarpine, cevimeline), hydroxychloroquine, oral glucocorticoids, synthetic immunosuppressive agents (cyclophosphamide, azathioprine, methotrexate, leflunomide and mycophenolate), and biological therapies (rituximab, abatacept and belimumab). For each recommendation, levels of evidence (mostly modest) and TF agreement (mostly very high) are provided. The 2019 EULAR recommendations are based on the evidence collected in the last 16 years in the management of primary 2002 SjS patients and on discussions between a large and broadly international TF. The recommendations synthesise current thinking on SjS treatment in a set of overarching principles and recommendations. We hope that the current recommendations will be broadly applied in clinical practice and/or serve as a template for national societies to develop local recommendations.

Current perspective on rituximab in rheumatic diseases

The steadily increasing knowledge regarding pathogenetic mechanisms in autoimmune rheumatic diseases has paved the way to different therapeutic approaches. In particular, the market entry of biologics has dramatically modified the natural history of rheumatic chronic inflammatory diseases with a meaningful impact on patients’ quality of life. Among the wide spectrum of available biological treatments, rituximab (RTX), first used in the treatment of non-Hodgkin’s lymphoma, was later approved for rheumatoid arthritis and anti-neutrophil cytoplasmic antibodies-associated vasculitis. Nowadays, in rheumatology, RTX is also used with off-label indications in patients with systemic sclerosis, Sjögren’s syndrome and systemic lupus erythematosus. RTX is a monoclonal antibody directed to CD20 molecules expressed on the surfaces of pre-B and mature B lymphocytes. It acts by causing apoptosis of these cells with antibody- and complement-dependent cytotoxicity. As inflammatory responses to cell-associated immune complexes are key elements in the pathogenesis of several autoimmune rheumatic diseases, such an approach might be effective in these patients. In fact, RTX, by promoting the rapid and long-term depletion of circulating and lymphoid tissue-associated B cells, leads to a lower recruitment of these effector cells at sites of immune complex deposition, thus reducing inflammation and tissue damage. RTX is of the most interest to rheumatologists as it represents an important additional therapeutic approach. Thus, the advent in clinical practice of approved RTX biosimilars, such as CT-P10, may be of help in improving treatment access as well as in reducing costs.

Autonomic dysfunction in primary Sjogren's syndrome: a prospective cohort analysis of 154 Korean patients

BACKGROUND/AIMS

To determine the prevalence of autonomic dysfunction among Korean patients with primary Sjogren's syndrome (pSS) and its associations with the clinical features of pSS.

METHODS

We analyzed 154 participants from the Korean Initiative of primary Sjogren's Syndrome (KISS) as a prospective pSS cohort and 154 age- and sex-matched healthy controls. A standardized 5-minute, supine, resting heart rate variability (HRV) test was performed, and autonomic dysfunction was defined as standard deviation of normal-to-normal RR intervals (SDNN) < 30 ms in patients < 50 years old and SDNN < 20 ms in patients ≥ 50 years old. The associations between autonomic dysfunction and various clinical features of pSS were analyzed.

RESULTS

The overall autonomic activity in patients with pSS was significantly lower than that in controls. Autonomic dysfunction with the HRV test was observed in 35.7% of the KISS participants and was associated with a higher European League Against Rheumatism Sjogren's Syndrome Patient Reported Index fatigue score (p = 0.024). Raynaud's phenomenon was a more frequent clinical presentation in pSS patients with autonomic dysfunction than in those without autonomic dysfunction (29.4% and 14.4%, respectively; p = 0.048). Decreased parasympathetic activity was observed in 41.6% of pSS patients. No differences were found in the oral and ocular signs of pSS according to the decreased parasympathetic activity.

CONCLUSIONS

In Korean patients with pSS, decreased and imbalanced autonomic activity is prevalent and is associated with fatigue. However, an association between autonomic dysfunction and glandular manifestations was not detected.