Lessons learned from the failure of several recent trials with biologic treatment in systemic lupus erythematosus

Pathogenic cellular and molecular mediators in lupus nephritis

Kidney involvement in patients with systemic lupus erythematosus - lupus nephritis (LN) - is one of the most important and common clinical manifestations of this disease and occurs in 40-60% of patients. Current treatment regimens achieve a complete kidney response in only a minority of affected individuals, and 10-15% of patients with LN develop kidney failure, with its attendant morbidity and considerable prognostic implications. Moreover, the medications most often used to treat LN - corticosteroids in combination with immunosuppressive or cytotoxic drugs - are associated with substantial side effects. Advances in proteomics, flow cytometry and RNA sequencing have led to important new insights into immune cells, molecules and mechanistic pathways that are instrumental in the pathogenesis of LN. These insights, together with a renewed focus on the study of human LN kidney tissue, suggest new therapeutic targets that are already being tested in lupus animal models and early-phase clinical trials and, as such, are hoped to eventually lead to meaningful improvements in the care of patients with systemic lupus erythematosus-associated kidney disease.

Gut microbiota in SLE: from animal models to clinical evidence and pharmacological perspectives

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease driven by complex interactions between genetics and environmental factors. SLE is characterised by breaking self-immune tolerance and autoantibody production that triggers inflammation and damage of multiple organs. Given the highly heterogeneous nature of SLE, the treatments currently used are still not satisfactory with considerable side effects, and the development of new therapies is a major health issue for better patient management. In this context, mouse models significantly contribute to our knowledge of the pathogenesis of SLE and are an invaluable tool for testing novel therapeutic targets. Here, we discuss the role of the most used SLE mouse models and their contribution to therapeutic improvement. Considering the complexity of developing targeted therapies for SLE, adjuvant therapies are also increasingly proposed. Indeed, murine and human studies have recently revealed that gut microbiota is a potential target and holds great promises for successful new SLE therapies. However, the mechanisms of gut microbiota dysbiosis in SLE remain unclear to date. In this review, we propose an inventory of existing studies investigating the relationship between gut microbiota dysbiosis and SLE to establish microbiome signature that may serve as a potential biomarker of the disease and its severity as well as a new potential therapy target. This approach may open new possibilities for early diagnosis, prevention and therapeutic perspectives of SLE based on gut microbiome.

10 Years of belimumab experience: What have we learnt?

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease affecting both adults and children. Belimumab is the only biologic approved for SLE, and the first in a class of drugs known as B-lymphocyte stimulator-specific inhibitors. The introduction of intravenous belimumab in 2011 was a major advance, being the first new therapy approved for SLE in over 50 years. As of April 2021, more than 7200 people with SLE have received belimumab in clinical studies, and it is approved in over 75 countries for the treatment of adults with SLE. A subcutaneous, self-injectable belimumab formulation was licensed in 2017 by both the US Food and Drug Administration (FDA) and European Medicines Agency (EMA). Belimumab was then approved for use in children in Europe, the USA and Japan in 2019, and China and Brazil in 2020. Recently, belimumab became the first FDA-approved drug for the treatment of adults with active lupus nephritis (LN), the most-common severe manifestation of SLE.Over the past 10 years, belimumab has established its position as a disease modifier in the SLE treatment paradigms. Robust evidence from randomised clinical studies and observational, real-world studies has demonstrated the tolerability and efficacy of belimumab for reducing disease activity and the risk of new, severe SLE flares. This enables patients to taper their glucocorticoid use, which limits damage accumulation. Significantly more patients with active LN met the criteria for renal responses and were at less risk of a renal-related event or death after receiving belimumab plus standard therapy, compared with standard therapy on top of mandatory steroid reduction. Ongoing clinical studies are evaluating belimumab's effectiveness in various indications beyond SLE. Post-marketing and registry studies are gathering additional data on key areas such as pregnancy outcomes after belimumab exposure and belimumab co-administration with other biologics.

Camptothecin and Topotecan, Inhibitors of Transcription Factor Fli-1 and Topoisomerase, Markedly Ameliorate Lupus Nephritis in (NZB × NZW)F1 Mice and Reduce the Production of Inflammatory Mediators in Human Renal Cells

OBJECTIVE

To examine the therapeutic effects of camptothecin (CPT) and topotecan (TPT), inhibitors of transcription factor Fli-1 and topoisomerase, on lupus nephritis in (NZB × NZW)F1 (NZBWF1) mice, and to examine the effects of CPT and TPT on inflammatory mediators in human renal cells.

METHODS

Female NZBWF1 mice were treated with vehicle, cyclophosphamide (CYC), CPT (1 mg/kg or 2 mg/kg), or TPT (0.03 mg/kg, 0.1 mg/kg, or 0. 3 mg/kg) by intraperitoneal injection twice a week, beginning at the age of 25 weeks (n = 8-10 mice per group). Blood and urine were collected for monitoring autoantibodies and proteinuria. Mice were euthanized at 40 weeks, and renal pathology scores were assessed. Human renal endothelial and mesangial cells were treated with CPT or TPT, and cytokine expression was measured.

RESULTS

None of the NZBWF1 mice treated with 1 mg/kg or 2 mg/kg of CPT or 0.3 mg/kg of TPT had proteinuria >100 mg/dl at the age of 40 weeks. One of 8 mice treated with 0.1 mg/kg of TPT and 1 of 10 mice treated with CYC had proteinuria >300 mg/dl, whereas 90% of the mice treated with vehicle had proteinuria >300 mg/dl. Compared to vehicle control, mice treated with 1 mg/kg or 2 mg/kg of CPT, 0.1 mg/kg or 0.3 mg/kg of TPT, or CYC had significantly prolonged survival, attenuated renal injury, diminished splenomegaly, reduced anti-double-stranded DNA autoantibody levels, and reduced IgG and C3 deposits in the glomeruli (all P < 0.05). Human renal cells treated with CPT or TPT had reduced expression of Fli-1 and decreased monocyte chemotactic protein 1 production following stimulation with interferon-α (IFNα) or IFNγ.

CONCLUSION

Our findings indicate that low-dose CPT and TPT could be repurposed to treat lupus nephritis.

Chinese Herbal Medicine for Systemic Lupus Erythematosus: A Systematic Review and Meta-analysis of Randomized, Placebo-Controlled Trials

OBJECTIVE

To provide evidence on the efficacy and safety of Chinese herbal medicine (CHM) as interventions for systemic lupus erythematosus (SLE).

METHODS

Seven electronic databases, including the Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), Chinese Biomedical Literature Service System (SinoMed), Wanfang, Embase, and PubMed, were comprehensively searched, from their inception to August 16, 2020, for all randomized controlled trials (RCTs) that focused on CHM used alone or in combination with conventional medicine for SLE. Outcomes were SLE activity index (SLEDAI), traditional Chinese medicine symptom/syndrome score (TCMSS), dosage of glucocorticoids, main serological testing, and incidence of adverse events. Data were extracted and pooled using Review Manager 5.3 software.

RESULTS

A total of 13 RCTs enrolling 856 participants met our inclusion criteria. Meta-analyses showed that, compared to placebo, CHM had statistically significant effect on reducing SLEDAI score (MD=-1.74, 95% CI: -2.29 to -1.18), diminishing TCMSS (SMD=-0.89, 95% CI: -1.16 to -0.62), decreasing dosage of glucocorticoids (MD=-2.41 mg/d, 95% CI: -3.34 to -1.48), lowering erythrocyte sedimentation rate (MD=-4.78 mm/h, 95% CI: -8.86 to -0.71), and increasing serum complement C4 level (MD=0.03 mg/dL, 95% CI: 0.00 to 0.06). No significant difference was found between CHM and placebo on adverse events.

CONCLUSIONS

CHM provided significant beneficial effect on controlling disease activity and reducing dose of glucocorticoids used among SLE patients. Future advanced designed RCTs for CHM treating moderate to severe SLE with multicenter and longer follow-up are urgently needed.

What are the topics you care about making trials in lupus more effective? Results of an Open Space meeting of international lupus experts

Despite promising candidates for new therapeutic options in the treatment of systemic lupus erythematosus (SLE), many clinical trials have failed in the past few years. The disappointing results have been at least partly be attributed to trial designs. With the aim of stimulating new developments in SLE trial design, an international open space meeting was held on occasion of the European Lupus Meeting 2018 in Duesseldorf, Germany about ‘What are the topics you care about for making trials in lupus more effective?’. The Open Space is a participant-driven technology, where the discussion topics and schedule are selected during the meeting by all participants and discussion rounds are led by the people attending encouraging active contributions. Eleven topics were selected for further discussion, of which 6 were voted to be more intensively discussed in two consecutive rounds. Major topics were the optimal handling of glucocorticoids in clinical trials, the improvement of outcome measures, reducing or controlling the placebo response and the identification of biomarkers and stratification parameters. Further, the importance of local and international networks was emphasised. By networking, collaborations are facilitated, patient recruitment is more efficient and treatment can be harmonised thus lead to more successful SLE trials. Further discussions are needed to substantiate the results and develop new trial designs.

Repository Corticotropin Injection for Persistently Active Systemic Lupus Erythematosus: Results from a Phase 4, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

INTRODUCTION

We assessed the efficacy and safety of repository corticotropin injection (RCI; Acthar® Gel) for persistently active systemic lupus erythematosus (SLE) despite use of moderate-dose glucocorticoids.

METHODS

This multicenter, double-blind, randomized, placebo-controlled study enrolled patients ≥ 18 years with active SLE and moderate to severe rash and/or arthritis despite stable glucocorticoid doses (7.5-30 mg/day prednisone equivalent) and antimalarials for ≥ 4 weeks and/or immunosuppressants for ≥ 8 weeks before screening. Stable glucocorticoid doses were required through week 16 with optional taper from weeks 16 to 24. Patients were randomized (1:1) to 80 U RCI subcutaneously or placebo every other day to week 4, then twice weekly to week 24. Endpoints included the proportion of SLE Responder Index (SRI)-4 responders at week 16; changes from baseline to week 16 in 28 Swollen Joint Count/Tender Joint Count (28 SJC/TJC) and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI)-Activity score; and changes from baseline to week 24 in inflammatory cytokines. Safety was assessed by adverse events.

RESULTS

In the modified intention-to-treat population (RCI, n = 84; placebo, n = 85), the proportion of SRI-4 responders at week 16 was not significantly different between groups (RCI, 47.6%; placebo, 43.5%; OR [95% CI] 1.2 [0.6 to 2.2]; p = 0.5762). RCI treatment resulted in a reduction from baseline to week 16 in 28 SJC/TJC and CLASI-Activity score and from baseline to week 8 in a proliferation-inducing ligand cytokine. Post hoc analyses demonstrated a greater proportion of BILAG-based Combined Lupus Assessment responders for RCI than placebo at weeks 4, 12, and 20 and greater SRI-4 response in RCI-treated patients with baseline SLE Disease Activity Index-2000 ≥ 10 and CLASI-Activity ≥ 11. No new safety signals were identified.

CONCLUSIONS

Despite failure to achieve the primary endpoint, these results support the utility of RCI for treating persistently active SLE.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02953821.

Update on Lupus Nephritis: Looking for a New Vision

Lupus nephritis (LN) is one of the most common manifestations of systemic lupus erythematosus (SLE), affecting approximately 40% of patients with lupus. It represents a major risk factor for morbidity and mortality, and 10% of patients with LN will develop end-stage kidney disease (ESKD). Therefore, there are a number of areas for improvement in the field of LN such as the search for new clinical biomarkers with a more accurate correlation with lupus activity and the redefinition of the histological classification into different subgroups in order to guide a personalized treatment. Although the role of protocol repeat kidney biopsies in LN is controversial, recent publications suggest that repeat histological assessment can be useful in guiding therapeutic decisions that may yield toward precision medicine. In the last decade, LN therapy has remained largely unchanged, with a probability of achieving complete or partial remission not exceeding 60-70%. Thus, optimization of old treatment strategies and search for new agents are urgently needed in order to improve outcomes such as mortality or development of ESKD. Future trials should focus in addressing unanswered issues such as the appropriate dose and duration of immunosuppressive treatment, timing of steroid withdrawal, and drug toxicity. In addition, data are still lacking regarding pregnancy and kidney transplantation in LN and knowledge about these important areas is essential for the management of a subset of patients with SLE. In summary, several major gaps are still present in the therapeutic approach and follow-up of patients with LN. The development of new clinical trial designs will be crucial in the search to improve long-term outcomes.

Association of explanatory histological findings and urinary protein and serum creatinine levels at renal biopsy in lupus nephritis: a cross-sectional study

Background

The aim of the present study was to evaluate the association between the histology of active and chronic lesions and urinary protein and serum creatinine (SCr) levels, as common clinical endpoints in clinical trials for lupus nephritis (LN).

Methods

In total, 119 patients diagnosed with LN class III, IV, and V, as defined by the International Society of Nephrology/Renal Pathology Society, between 1990 and 2015, were enrolled in the present study. Multiple regression analysis was performed to explore semi-quantitative histological variables associated with urinary protein and SCr levels.

Results

The mean age of the enrolled patients was 45 years, and 79% were female. The mean SCr and mean urinary protein levels at the time of renal biopsy were 0.87 mg/dl and 3.00 g/gCr, respectively. Class IV (71%) was the most common type of LN followed by class III (17%), and class V (13%). Multicollinearity was confirmed between monocellular infiltration (variance inflation factor [VIF] = 10.22) and interstitial fibrosis (VIF = 10.29), and between karyorrhexis (VIF = 4.14) and fibrinoid necrosis (VIF = 4.29). Fibrinoid necrosis and monocellular infiltration were subsequently excluded, and multiple regression analysis revealed that only the urinary protein level was correlated with wire loop lesions (β-coefficient [β]: 1.09 and confidence interval [CI]: 0.35 to 1.83), and that the SCr level was correlated with glomerular sclerosis (β: 1.08 and CI: 0.43 to 1.74).

Conclusion

As urinary protein and SCr levels were not quantitatively associated with active lesions, they may not accurately reflect the response to remission induction therapy in patients with LN.

Unmet need in rheumatology: reports from the Targeted Therapies meeting 2019

OBJECTIVES

To detail the greatest areas of unmet scientific and clinical needs in rheumatology.

METHODS

The 21st annual international Advances in Targeted Therapies meeting brought together more than 100 leading basic scientists and clinical researchers in rheumatology, immunology, epidemiology, molecular biology and other specialties. During the meeting, breakout sessions were convened, consisting of 5 disease-specific groups with 20-30 experts assigned to each group based on expertise. Specific groups included: rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, systemic lupus erythematosus and other systemic autoimmune rheumatic diseases. In each group, experts were asked to identify unmet clinical and translational research needs in general and then to prioritise and detail the most important specific needs within each disease area.

RESULTS

Overarching themes across all disease states included the need to innovate clinical trial design with emphasis on studying patients with refractory disease, the development of trials that take into account disease endotypes and patients with overlapping inflammatory diseases, the need to better understand the prevalence and incidence of inflammatory diseases in developing regions of the world and ultimately to develop therapies that can cure inflammatory autoimmune diseases.

CONCLUSIONS

Unmet needs for new therapies and trial designs, particularly for those with treatment refractory disease, remain a top priority in rheumatology.

Drug repurposing to improve treatment of rheumatic autoimmune inflammatory diseases

The past century has been characterized by intensive efforts, within both academia and the pharmaceutical industry, to introduce new treatments to individuals with rheumatic autoimmune inflammatory diseases (RAIDs), often by 'borrowing' treatments already employed in one RAID or previously used in an entirely different disease, a concept known as drug repurposing. However, despite sharing some clinical manifestations and immune dysregulation, disease pathogenesis and phenotype vary greatly among RAIDs, and limited understanding of their aetiology has made repurposing drugs for RAIDs challenging. Nevertheless, the past century has been characterized by different 'waves' of repurposing. Early drug repurposing occurred in academia and was based on serendipitous observations or perceived disease similarity, often driven by the availability and popularity of drug classes. Since the 1990s, most biologic therapies have been developed for one or several RAIDs and then tested among the others, with varying levels of success. The past two decades have seen data-driven repurposing characterized by signature-based approaches that rely on molecular biology and genomics. Additionally, many data-driven strategies employ computational modelling and machine learning to integrate multiple sources of data. Together, these repurposing periods have led to advances in the treatment for many RAIDs.