Autoimmune diseases arise when self-antigen-specific T and B cells escape central and peripheral mechanisms of tolerance. One such mechanism is control of autoreactivity by regulatory T cells (Tregs), which have an essential role in suppressing autoimmunity. Consequently, there is significant interest in developing ways to boost or restore the function of Tregs in order to prevent or treat autoimmunity, induce tolerance, and thus reduce the reliance on broadly immunosuppressive agents. Strategies include enhancing the numbers and/or function of Tregs directly in vivo or via adoptive cell therapy. Here, we review recent advances in our understanding of how pharmacologic approaches can be applied to enhance Treg function in vivo through repurposing of established drug therapies or application of new therapies. Specifically, we discuss the potential of Treg-promoting drugs, including interleukin-2 and its derivatives, and tumor necrosis factor receptor 2 agonists, as well as Treg-preserving tyrosine kinase 2 inhibitors. We discuss how co-stimulatory blockade with CTLA-4 immunoglobulin affects tolerogenic environments and consider whether lymphodepleting therapies, such as antithymocyte globulin and teplizumab, might be needed to condition the environment for better Treg-promoting effects. We focus on the potential application of Treg-promoting drugs in type 1 diabetes and draw on evidence from transplantation. With multiple pharmacotherapeutic strategies to optimize Tregs in vivo, there is significant promise for new approaches to effectively and durably induce autoimmune disease remission.

As more lupus nephritis (LN) medications become available, identifying treatments that are disease-modifying is critical in making treatment decisions. Based on our 2022 published working definition of LN disease modification as 'minimizing disease activity with the fewest treatment-associated toxicities and slowing progression to end-stage kidney disease' (ESKD), the objective of this review was to classify current LN treatments according to the proposed kidney disease modification criteria, excluding toxicities. Based upon a selection of LN clinical trial (n = 27) and observational study (n = 20) publications, as well as the authors' clinical experiences, we evaluated the disease modification potential for 16 LN treatments (inclusive of antimalarials, glucocorticoids, immunosuppressants, calcineurin inhibitors and biologics) according to the proposed kidney disease activity and organ damage criteria at year 1, years 2-5, and > 5-year time points. Fulfilling criteria at year 1 and years 2-5 was considered evidence for disease modification potential. Satisfying criteria at > 5 years (slowing or preventing progression in SLICC/ACR Damage Index [SDI] and ESKD, and/or doubling of serum creatinine) was used to confirm disease modification. Each treatment was designated as one of the following at each time point: (a) criterion met; (b) inconclusive; (c) no available supportive data. This review excluded an assessment of potential toxicities. All LN treatments met at least one of the potential kidney disease-modification criteria at any time point, but limited relevant data in the literature meant disease modification > 5 years could only be confirmed for cyclophosphamide. Belimumab met more criteria across the three time points than any other biologic treatment but lacked > 5-year data to confirm disease modification. Further research is needed to support the classification of LN treatments as disease modifiers, particularly for > 5 years. We discuss considerations for future studies, challenges to the classification, and possible updates to published criteria.

Systemic lupus erythematosus (SLE) is a chronic inflammatory illness with heterogeneous clinical manifestations covering multiple organs. Diversified types of medications have been shown effective for alleviating SLE syndromes, ranging from cytokines, antibodies, hormones, molecular inhibitors or antagonists, to cell transfusion. Drugs developed for treating other diseases may benefit SLE patients, and agents established as SLE therapeutics may be SLE-inductive. Complexities regarding SLE therapeutics render it essential and urgent to identify the mechanisms-of-action and pivotal signaling axis driving SLE pathogenesis, and to establish innovative SLE-targeting approaches with desirable therapeutic outcome and safety. After introducing the research history of SLE and its epidemiology, we categorized primary determinants driving SLE pathogenesis by their mechanisms; combed through current knowledge on SLE diagnosis and grouped them by disease onset, activity and comorbidity; introduced the genetic, epigenetic, hormonal and environmental factors predisposing SLE; and comprehensively categorized preventive strategies and available SLE therapeutics according to their functioning mechanisms. In summary, we proposed three mechanisms with determinant roles on SLE initiation and progression, i.e., attenuating the immune system, restoring the cytokine microenvironment homeostasis, and rescuing the impaired debris clearance machinery; and provided updated insights on current understandings of SLE regarding its pathogenesis, diagnosis, prevention and therapeutics, which may open an innovative avenue in the fields of SLE management.

Lupus nephritis (LN) can occur as an isolated component of disease activity or be accompanied by diverse extrarenal manifestations. Whether isolated renal disease is sufficient to decrease health-related quality of life (HRQOL) remains unknown. This study compared Patient-Reported Outcomes Measurement Information System 29-Item (PROMIS-29) scores in LN patients with isolated renal disease to those with extrarenal symptoms to evaluate the burden of LN on HRQOL and inform future LN clinical trials incorporating HRQOL outcomes.

A total of 181 LN patients consecutively enrolled in the multicentre multi-ethnic/racial Accelerating Medicines Partnership completed PROMIS-29 questionnaires at the time of a clinically indicated renal biopsy. Raw PROMIS-29 scores were converted to standardized T scores.

Seventy-five (41%) patients had extrarenal disease (mean age 34, 85% female) and 106 (59%) had isolated renal (mean age 36, 82% female). Rash (45%), arthritis (40%) and alopecia (40%) were the most common extrarenal manifestations. Compared with isolated renal, patients with extrarenal disease reported significantly worse pain interference, ability to participate in social roles, physical function, and fatigue. Patients with extrarenal disease had PROMIS-29 scores that significantly differed from the general population by >0.5 SD of the reference mean in pain interference, physical function, and fatigue. Arthritis was most strongly associated with worse scores in these three domains.

Most patients had isolated renal disease and extrarenal manifestations associated with worse HRQOL. These data highlight the importance of comprehensive disease management strategies that address both renal and extrarenal manifestations to improve overall patient outcomes.

Traditional initial treatment regimens for lupus nephritis (LN) used oral glucocorticoids (GC) in starting doses up to 1.0 mg/kg/day prednisone equivalent with or without a preceding intravenous methylprednisolone pulse. More recent management guidelines recommend lower starting oral GC doses following intravenous pulse therapy. As there have been no large studies directly comparing patients receiving low versus high initial oral GC doses, this pooled analysis of high-quality randomised controlled trials (RCTs) aims to evaluate differences in efficacy and safety.

Published data were analysed from RCTs that assessed variable GC doses in the standard of care (SOC) treatment arms. Patients receiving starting prednisone doses up to 0.5 mg/kg/day (low dose) were compared with 1.0 mg/kg/day (high dose). Complete renal response requiring urine protein-creatinine ratio <0.5 mg/mg (CRR 0.5), CRR or partial renal response (PRR), serious adverse events (SAE) and SAE due to infections at 12 months of treatment were compared between groups.

417 patients from SOC arms of five studies were exposed to low-dose initial GC after intravenous pulse, while 521 patients from four studies were treated with high-dose oral GC. In patients with low-dose oral GC, 25.2% achieved CRR 0.5 at 12 months compared with 27.2% in high-dose groups, p=0.54. CRR or PRR was attained in 48.7% low-dose vs 43.6% high-dose patients, p=0.14. SAEs and infection SAEs were less common in the low-dose GC group (19.4% vs 31.6%, p<0.001 and 9.8% vs 16.5%, p=0.012, respectively).

Based on pooled RCT data, there was no significant difference in 12-month renal responses between patients receiving low-dose prednisone following intravenous GC compared with those receiving initial high doses. SAEs were less frequent in patients receiving low-dose initial GC. These findings support the use of lower oral GC doses in LN treatment.

We performed a scoping review of randomised clinical trials (RCTs) assessing pharmacological therapies for the initial management of lupus nephritis (LN), focusing on study design, included populations and outcome definitions, to assess the generalisability of their results and identify gaps in the evidence.

RCTs evaluating pharmacological interventions for the initial therapy of LN published between 2000 and 2024 were evaluated. Extracted variables included study design, selection criteria, outcome definitions, populations recruited and clinical characteristics of participants. Each study arm was included as intervention and segregated into guideline-recommended regimens (cyclophosphamide (CYC), mycophenolic acid analogues (MPAAs), calcineurin inhibitors and belimumab) or other regimens. Data were analysed by descriptive statistics, and Fragility Index (FI) was estimated to assess robustness of studies.

We included 124 intervention arms within 61 RCT, involving 7058 participants. Seventy-nine arms (63.7%) corresponded to guideline-recommended therapies: 33 (26.6%) MPAA, 28 (22.6%) NIH-CYC and 7 (5.6%) triple-drug therapies. While 100% of triple-drug therapies RCT were multinational, only 7.1% of NIH-CYC and 0% of tacrolimus RCTs were conducted in more than one country. Only 9 (14.8%) had follow-up ≥24 months. Ten (16.4%) RCTs exclusively included participants with severe or refractory LN. Only 29 (47.5%) reported serious adverse events, and few described patient-reported outcomes. Black and other race participants were under-represented, as well as participants from Middle East, North Africa, and the sub-Saharan African region. Response was variably defined and assessed at different intervals. Robustness of RCTs evaluating double-drug guideline-recommended therapies were mostly low, with FI ranging from 1 to 3.

Considering new recommendations for the management of LN, we call for broader inclusion of under-represented populations and homogenisation of study design. This study provides the rationale for evaluating unexplored treatment comparisons and conducting research on newer interventions in clinical settings where evidence is currently lacking.

Our objective was to evaluate the effect of glucocorticoid regimens on renal response, infections, and mortality among patients with lupus nephritis (LN).

We performed a systematic review and meta-analysis of the control arms of randomized clinical trials (RCTs). We included RCTs of biopsy-proven LN that used a protocolized regimen of glucocorticoids in combination with mycophenolic acid analogs or cyclophosphamide and reported the outcomes of complete response (CR), serious infections, and death. The starting dosage of glucocorticoids, tapering method, and administration of glucocorticoid pulses were abstracted. Meta-analysis of proportions, meta-regression, and subgroup meta-analysis were performed at 6 and 12 months for all outcomes.

Fifty RCT arms (3,231 patients with LN) were included. The predicted rates of CR, serious infections, and death when starting on oral prednisone at 25 mg/day without pulses were 19.5% (95% confidence interval [CI] 7.3-31.5), 3.2% (95% CI 2.4-4.0), and 0.2% (95% CI 0.0-0.4), respectively. Starting on prednisone at 60 mg/day (without pulses) increased the rates to 34.6% (95% CI 16.9-52.3), 12.1% (95% CI 9.3-14.9), and 2.7% (95% CI 0.0-5.3), respectively. Adding glucocorticoid pulses increased the rates of CR and death but not serious infections. We observed a dose-response gradient between the initial glucocorticoid dosage and all the outcomes at six months after accounting for the administration of glucocorticoid pulses, underlying immunosuppressant, and baseline proteinuria.

A higher exposure to glucocorticoids during the initial therapy of LN was associated with better renal outcomes at the cost of increased infections and death.

Lupus nephritis (LN) is the most common major organ manifestation of the autoimmune disease SLE (lupus), with 10% of those afflicted progressing to ESKD. The kidney in LN is characterized by a significant immune infiltrate and proinflammatory cytokine milieu that affects intrinsic renal cells and is, in part, responsible for the tissue damage observed in LN. It is now increasingly appreciated that LN is not due to unidirectional immune cell activation with subsequent kidney damage. Rather, the kidney microenvironment influences the recruitment, survival, differentiation, and activation of immune cells, which, in turn, modify kidney cell function. This review covers how the biochemical environment of the kidney ( i.e ., low oxygen tension and hypertonicity) and unique kidney cell types affect the intrarenal immune cells in LN. The pathways used by intrinsic renal cells to interact with immune cells, such as antigen presentation and cytokine production, are discussed in detail. An understanding of these mechanisms can lead to the design of more kidney-targeted treatments and the avoidance of systemic immunosuppressive effects and may represent the next frontier of LN therapies.

Lupus nephritis (LN), a severe manifestation of systemic lupus erythematosus, has greater severity in children versus adults. Belimumab is approved for systemic lupus erythematosus treatment in patients aged ≥ 5 years, and for active LN in adults in the European Union, China, Japan and Latin America, and patients aged ≥ 5 years in the USA. Low prevalence of paediatric active LN makes conducting a clinical study within a reasonable period unfeasible. We describe a model-based extrapolation of belimumab efficacy and pharmacokinetics from adults to children with LN to support US Food and Drug Administration approval of intravenous belimumab 10 mg/kg (administered every 4 weeks after the loading dose) in children (aged 5-17 years) with active LN.

This concept assumed that disease progression, response to belimumab, exposure-response, and the target belimumab exposure for efficacy are similar across adult and paediatric systemic lupus erythematosus and LN, evaluated against the published literature for paediatric LN and belimumab systemic lupus erythematosus and LN clinical trial data in adults and children. A two-compartmental population pharmacokinetic model, previously developed for adults with LN, was used to extrapolate belimumab pharmacokinetics to children with LN.

The model captured the dependence of time-varying proteinuria on belimumab clearance, and therefore exposure. Sufficient target exposures for efficacy were achieved in children with active LN. A small proportion of children aged 5-11 years are predicted to have exposures below adult levels but no impact to efficacy is expected.

Our model demonstrated that intravenous belimumab 10 mg/kg every 4 weeks is appropriate for children aged 5-17 years with active LN.

Previous studies comparing the efficacy and safety of different treatment regimens for lupus nephritis are scarce. Moreover, confounding factors such as the duration of follow-up were hardly adjusted in those studies, potentially compromising the results and their extents to clinical settings.

To rigorously investigate the efficacy and safety of biologics in patients with lupus nephritis using Bayesian network meta-regression analyses that adjust for the follow-up period, in order to provide more robust evidence for clinicians.

Databases comprising PubMed, Embase, MedlinePlus, Cochrane Library, Google Scholars, and Scopus were retrieved for eligible articles from inception to February 29, 2024. The primary endpoint was the complete response rate, the secondary endpoint was the partial response rate, the tertiary endpoints were the adverse events, and infection-related adverse events. Napierian Logarithm of hazard ratio (lnHR) and the standard error of lnHR (selnHR) were generated for dichotomous variants by STATA 18.0 MP and then put into Rstudio 4.3.2 to conduct Bayesian network meta-analysis as well as network meta-regression analysis to yield hazard ratio (HR) as pairwise effect size.

Ten studies involving 2138 patients and 11 treatment regimens were ultimately included. In the original analysis, for the primary endpoint, compared to the control group, obinutuzumab (22.6 months), abatacept-30mg (20.5 months), abatacept-10mg (17.8 months), and belimumab (23.3 months) demonstrated significant superiority (HR ranged from 1.6 to 2.5), more ever, their significance regarding relative efficacy was correlated with follow up period, namely "time window" (shown in parentheses above). For the secondary endpoint, compared to the control group, obinutuzumab and abatacept-30mg showed conspicuous preponderance (HR ranged from 1.6 to 2.4), "time window" was also detected in abatacept-30mg (20.5 months), whereas obinutuzumab remained consistently obviously effective regardless of the follow-up period (shown in parentheses above). For the tertiary endpoint, there were no differences among active regimens and control.

Considering the efficacy and safety and "time window" phenomenon, we recommend obinutuzumab as the preferred treatment for LN. Certainly, more rigorous head-to-head clinical trials are warranted to validate those findings.

B- and T-lymphocyte attenuator (BTLA; CD272) is an immunoglobulin superfamily member and part of a family of checkpoint inhibitory receptors that negatively regulate immune cell activation. The natural ligand for BTLA is herpes virus entry mediator (HVEM; TNFRSF14), and binding of HVEM to BTLA leads to attenuation of lymphocyte activation. In this study, we evaluated the role of BTLA and HVEM expression in the pathogenesis of systemic lupus erythematosus (SLE), a multisystem autoimmune disease. Peripheral blood mononuclear cells from healthy volunteers (N = 7) were evaluated by mass cytometry by time-of-flight to establish baseline expression of BTLA and HVEM on human lymphocytes compared with patients with SLE during a self-reported flare (N = 5). High levels of BTLA protein were observed on B cells, CD4+, and CD8+ T cells, and plasmacytoid dendritic cells in healthy participants. HVEM protein levels were lower in patients with SLE compared with healthy participants, while BTLA levels were similar between SLE and healthy groups. Correlations of BTLA-HVEM hub genes' expression with patient and disease characteristics were also analyzed using whole blood gene expression data from patients with SLE (N = 1,760) and compared with healthy participants (N = 60). HVEM, being one of the SLE-associated genes, showed an exceptionally strong negative association with disease activity. Several other genes in the BTLA-HVEM signaling network were strongly (negative or positive) correlated, while BTLA had a low association with disease activity. Collectively, these data provide a clinical rationale for targeting BTLA with an agonist in SLE patients with low HVEM expression.

Systemic Lupus Erythematosus (SLE) and lupus nephritis treatment is still based on non-specific immune suppression despite the first biological therapy for the disease having been approved more than a decade ago. Intense basic and translational research has uncovered a multitude of pathways that are actively being evaluated as treatment targets in SLE and lupus nephritis, with two new medications receiving FDA approval in the last 3 years. Herein we provide an overview of targeted therapies for SLE including medications targeting the B lymphocyte compartment, intracellular signaling, co-stimulation, and finally the interferons and other cytokines.

Decreased sialylation of IgG-Fc glycans has been reported in autoimmune diseases, but its role in systemic lupus erythematosus (SLE) is not fully understood. In this study, we examined the pathogenicity of IgG desialylation and its association with Th17 in SLE using an animal model.

B6SKG mice, which develop lupus-like systemic autoimmunity due to the ZAP70 mutation, were used to investigate the pathogenicity of IgG desialylation. The proportion of sialylated IgG was compared between B6SKG and wild-type mice with or without β-glucan treatment-induced Th17 expansion. Anti-interleukin (IL)-23 and anti-IL-17 antibodies were used to examine the role of Th17 cells in IgG glycosylation. Activation-induced cytidine deaminase-specific St6gal1 conditionally knockout (cKO) mice were generated to examine the direct effect of IgG desialylation.

The proportions of sialylated IgG were similar between B6SKG and wild-type mice in the steady state. However, IgG desialylation was observed after β-glucan-induced Th17 expansion, and nephropathy also worsened in B6SKG mice. Anti-IL-23/17 treatment suppressed IgG desialylation and nephropathy. Glomerular atrophy was observed in the cKO mice, suggesting that IgG desialylation is directly involved in disease exacerbation.

IgG desialylation contributes to the progression of nephropathy, which is ameliorated by blocking IL-17A or IL-23 in an SLE mouse model.

Lupus nephritis is an important manifestation of systemic lupus erythematosus, which leads to chronic kidney disease, kidney failure, and can result in mortality. About 35%-60% of children with systemic lupus erythematosus develop kidney involvement. Over the past few decades, the outcome of patients with lupus nephritis has improved significantly with advances in immunosuppressive therapies and clinical management. Nonetheless, there is a paucity of high-level evidence to guide the management of childhood-onset lupus nephritis, because of the relatively small number of patients at each centre and also because children and adolescents are often excluded from clinical trials. Children and adults differ in more ways than just size, and there are remarkable differences between childhood- and adult-onset lupus nephritis in terms of disease severity, treatment efficacy, tolerance to medications and most importantly, psychosocial perspective. In this article, we review the 'art and science' of managing childhood-onset lupus nephritis, which has evolved in recent years, and highlight special considerations in this specific patient population.

Outcomes of therapy for LN are often suboptimal. Guidelines offer varied options for treatment of LN and treatment strategies may differ between clinicians and regions. We aimed to assess variations in the usual practice of UK physicians who treat LN.

We conducted an online survey of simulated LN cases for UK rheumatologists and nephrologists to identify treatment preferences for class IV and class V LN.

Of 77 respondents, 48 (62.3%) were rheumatologists and 29 (37.7%) were nephrologists. A total of 37 (48.0%) reported having a joint clinic between nephrologists and rheumatologists, 54 (70.0%) reported having a multidisciplinary team meeting for LN and 26 (33.7%) reported having a specialized lupus nurse. Of the respondents, 58 (75%) reported arranging a renal biopsy before starting the treatment. A total of 20 (69%) of the nephrologists, but only 13 (27%) rheumatologists, reported having a formal departmental protocol for treating patients with LN (P < 0.001). The first-choice treatment of class IV LN in pre-menopausal patients was MMF [41 (53.2%)], followed by CYC [15 (19.6%)], rituximab [RTX; 12 (12.5%)] or a combination of immunosuppressive drugs [9 (11.7%)] with differences between nephrologists' and rheumatologists' choices (P = 0.026). For class V LN, MMF was the preferred initial treatment, irrespective of whether proteinuria was in the nephrotic range or not. RTX was the preferred second-line therapy for non-responders.

There was variation in the use of protocols, specialist clinic service provision, biopsies and primary and secondary treatment choices for LN reported by nephrologists and rheumatologists in the UK.

The CD28 family receptors include the CD28, ICOS (inducible co-stimulator), CTLA-4 (cytotoxic T-lymphocyte antigen-4), PD-1 (programmed cell death protein 1), and BTLA (B- and T-lymphocyte attenuator) molecules. They characterize a group of molecules similar to immunoglobulins that control the immune response through modulating T-cell activity. Among the family members, CD28 and ICOS act as enhancers of T-cell activity, while three others-BTLA, CTLA-4, and PD-1-function as suppressors. The receptors of the CD28 family interact with the B7 family of ligands. The cooperation between these molecules is essential for controlling the course of the adaptive response, but it also significantly impacts the development of immune-related diseases. This review introduces the reader to the molecular basis of the functioning of CD28 family receptors and their impact on T-cell activity.

We aimed to evaluate the robustness of phase III randomised controlled trials (RCTs) for SLE and lupus nephritis (LN) using the fragility index (FI), the reverse FI (RFI) and the fragility quotient (FQ).

We searched for phase III RCTs that included patients with active SLE or LN. Data on primary endpoints, total participants and the number of events for each arm were obtained. We calculated the FI score for RCTs with statistically significant results (number of patients required to change from event to non-event to make the study lose statistical significance), the RFI for RCTs without statistically significant results (number of patients required to change from non-event to event to make study gain statistical significance) and the FQ score for both (FI or RFI score divided by the sample size).

We evaluated 20 RCTs (16 SLE, four LN). The mean FI/RFI score was 13.6 (SD 6.6). There were nine RCTs with statistically significant results (seven SLE, two LN), and the mean FI score was 10.2 (SD 6.2). The lowest FI was for the ILLUMINATE-2 trial (FI=2), and the highest FI was for the BLISS-52 trial (FI=17).Twelve studies had non-statistically significant results (10 SLE, two LN) with a mean RFI score of 15.6 (SD 6.1). The lowest RFI was for the ILLUMINATE-1 trial (RFI=4), and the highest RFI was for the TULIP-1 trial (RFI=27). The lowest FQ scores were found in the ILLUMINATE trials and the highest in the Rituximab trials (EXPLORER and LUNAR), meaning that the last ones were the most robust results after accounting for sample size.

The evidence of therapies for patients with SLE and LN is derived mostly from fragile RCTs. Clinicians and trialists must be aware of the fragility of these RCTs for clinical decision-making and designing trials for novel therapeutics.

Lupus nephritis (LN), a severe manifestation of systemic lupus erythematosus, poses a substantial risk of progression to end-stage renal disease, with increased mortality. Conventional therapy for LN relies on broad-spectrum immunosuppressants such as glucocorticoids, mycophenolate mofetil, and calcineurin inhibitors. Although therapeutic regimens have evolved over the years, they have inherent limitations, including non-specific targeting, substantial adverse effects, high relapse rates, and prolonged maintenance and remission courses. These drawbacks underscore the need for targeted therapeutic strategies for LN. Recent advancements in our understanding of LN pathogenesis have led to the identification of novel therapeutic targets and the emergence of biological agents and small-molecule inhibitors with improved specificity and reduced toxicity. This review provides an overview of the current evidence on targeted therapies for LN, elucidates the biological mechanisms of responses and failure, highlights the challenges ahead, and outlines strategies for subsequent clinical trials and integrated immunomodulatory approaches.

Podocyte injury can disrupt the glomerular filtration barrier (GFB), leading to podocytopathies that emphasize podocytes as the glomerulus's key organizer. The coordinated cytoskeleton is essential for supporting the elegant structure and complete functions of podocytes. Therefore, cytoskeleton rearrangement is closely related to the pathogenesis of podocytopathies. In podocytopathies, the rearrangement of the cytoskeleton refers to significant alterations in a string of slit diaphragm (SD) and focal adhesion proteins such as the signaling node nephrin, calcium influx via transient receptor potential channel 6 (TRPC6), and regulation of the Rho family, eventually leading to the disorganization of the original cytoskeletal architecture. Thus, it is imperative to focus on these proteins and signaling pathways to probe the cytoskeleton rearrangement in podocytopathies. In this review, we describe podocytopathies and the podocyte cytoskeleton, then discuss the molecular mechanisms involved in cytoskeleton rearrangement in podocytopathies and summarize the effects of currently existing drugs on regulating the podocyte cytoskeleton.

Obexelimab is an investigational, bifunctional, noncytolytic monoclonal antibody that binds CD19 and FcyRIIb to inhibit B cells, plasmablasts, and plasma cells. This trial evaluated the efficacy and safety of obexelimab in the treatment of patients with systemic lupus erythematosus (SLE).

During screening, patients with active, non-organ-threatening SLE received corticosteroid injections to ameliorate symptoms while immunosuppressants were withdrawn (≤10 mg/day prednisone equivalent and ≤400 mg/day hydroxychloroquine allowed). Patients with improved disease activity were randomized 1:1 to obexelimab 5 mg/kg intravenously or placebo once every 2 weeks until week 32 or loss of improvement (LOI).

In this study, 104 patients were randomized. Analysis of the primary endpoint, proportion of patients reaching week 32 without LOI, used an efficacy-evaluable (EE) population defined as patients who completed the study or withdrew for flare or treatment-related toxicity. This endpoint did not reach statistical significance: 21 of 50 obexelimab-treated patients (42.0%) versus 12 of 42 patients (28.6%) treated with a placebo (P = 0.183). Time to LOI was increased in obexelimab-treated patients versus patients treated with a placebo in the EE (hazard ratio [HR] 0.53, P = 0.025) and intention-to-treat (HR 0.59, P = 0.062) populations. In obexelimab-treated patients, B cells decreased approximately 50%, and trough concentration and inclusion in baseline gene expression clusters with high B cell pathway modules were associated with increased time to LOI. Obexelimab was associated with infusion reactions but was generally safe and well-tolerated.

Although the primary endpoint was not reached, secondary analysis showed time to LOI was significantly increased in obexelimab-treated patients, and analysis of patient subsets defined by gene expression patterns at baseline suggests a responding subpopulation.

Due to the suboptimal therapeutic efficacy and potential adverse effects associated with traditional immunosuppressive medications, there has been an increasing emphasis on the development and utilization of immunotherapies. This paper aims to provide clinicians with valuable insights for selecting appropriate therapeutic approaches and contribute to the development of novel immunotherapeutic drugs.

This paper categorizes the immunotherapeutic drugs that are used for the treatment of immune-mediated glomerular diseases into three groups: immunotherapies targeting antigen-presenting cells (anti-CD80), immunotherapies targeting T/B cells (anti-CD20, anti-CD22, BAFF and APRIL inhibitors, CD40-CD40L inhibitors, proteasome inhibitors, Syk inhibitors, and Btk inhibitors), and immunotherapies targeting the complement system (C5 inhibitors, C5a/C5aR inhibitors, C3 inhibitors, MASP2 inhibitors, factor B inhibitors, and factor D inhibitors). The article then provides a comprehensive overview of advances related to these immunotherapeutic drugs in clinical research.

Certain immunotherapeutic drugs, such as rituximab, belimumab, and eculizumab, have exhibited notable efficacy in treating specific immune-mediated glomerular diseases, thereby providing novel therapeutic approaches for patients. Nonetheless, the efficacy of numerous immunotherapeutic drugs remains to be substantiated.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the loss of immune tolerance. Lupus nephritis (LN) is one of the most common manifestations of severe organ damage in SLE, and also an important cause of disability and death. Its pathogenesis is associated with immune abnormalities such as immune cells, cytokines, and immune complex deposition. Traditional immunosuppressive therapy has been unable to meet the treatment needs of patients while bringing them toxic effects. In recent years, targeted therapies have emerged, and several novel biologics have gradually entered people's sight. This review will briefly introduce the pathogenesis of LN and the mechanism of biological targets, and summarize and analyze the clinical trials of new biologics for treating LN. Although not all biologics show positive results in clinical trials, the experience learned from these trials can help researchers adjust and plan future trial programs to seek better treatment methods.

Lupus nephritis is a major cause of morbidity in patients with systemic lupus erythematosus. Responsiveness to treatment is crucial to avoid chronic kidney disease. New molecules have been developed in recent years to improve renal survival rates. Biological therapies as coadjutant to conventional induction treatment have been tested in randomized clinical trials with heterogeneous results. Like many others biologic therapies, Abatacept has not shown a clear benefit in the context of clinical trials. We present two cases of lupus nephritis patients in whom addition of abatacept resulted in complete remission of the renal disease. The first case described a 49-year-old male with class IV lupus nephritis with nephrotic range proteinuria and high immunological activity refractory to conventional treatment with cyclophosphamide and corticosteroids and multitarget therapy with tacrolimus, mycophenolate mofetil and prednisone. Several biological therapies (rituximab, belimumab and tocilizumab) were unsuccessfully tried, so that abatacept was added to his background multitarget therapy showing complete clinical response. The second case described a 52-year-old female with class IV lupus nephritis treated initially with conventional treatment with partial response. In successive renal flares with nephrotic proteinuria, she showed intolerance to rituximab and refractoriness to voclosporin. Finally, abatacept was added to her background therapy with MMF and PDN showing complete and maintained remission of the disease. In no case the use of abatacept was associated with serious adverse events. Based on our experience, abatacept should be considered as a safe rescue therapy in patients with refractory lupus nephritis and proteinuria with nephrotic range. In addition to this case, we reviewed the use of abatacept in lupus nephritis in the literature.

Focal segmental glomerulosclerosis (FSGS) is an important cause of refractory nephrotic syndrome (NS) in children and adults. Urinary CD80 is elevated in some patients with primary FSGS, however, its clinical value is not fully clarified. This study aims to evaluate the clinical and pathological significance of urinary CD80 in patients with primary FSGS.

Sixty-one adult patients with biopsy-proven primary FSGS, with standard treatment and long-term follow up, were enrolled retrospectively. Urinary CD80, on the day of kidney biopsy, was measured using commercial ELISA kits and adjusted by urinary creatinine excretion. Their associations with clinical and pathological parameters were investigated.

Urinary CD80 was detectable in 30/61 (49.2%) patients, who presented with a higher level of proteinuria (10.7 vs. 5.8 g/24h; p = 0.01), a lower level of serum albumin (19.3 ± 3.9 vs. 24.2 ± 8.2 g/L; p = 0.005), a higher prevalence of hematuria (70.0 vs. 38.7%; p = 0.01), and showed a lower percentage of segmental glomerulosclerosis lesion [4.8 (3.7-14.0) vs. 9.1 (5.6-21.1) %; p = 0.06]. The cumulative relapse rate was remarkably high in these patients (log-rank, p = 0.001). Multivariate analysis identified that the elevated urinary CD80 was an independent risk factor for steroid-dependent NS (OR 8.81, 95% CI 1.41-54.89; p = 0.02) and relapse (HR, 2.87; 95% CI 1.29-6.38; p = 0.01).

The elevated urinary CD80 is associated with mild pathological change and steroid-dependent cases of primary FSGS adults, which indicates these patients are more similar to minimal change disease (MCD) in clinicopathological features.

To compare the clinical effectiveness and safety of novel biologics for the treatment of lupus nephritis based on a reticulated meta-analysis approach. Registered clinical trials in 4 major databases (PubMed, Embase, Web of Science, The Cochrane Register of Clinical Trials) and ClinicalTrials.gov were systematically searched with a search time frame of build to June 2022. And we screened registered randomized controlled clinical trials of biologics for the treatment of lupus nephritis according to the protocol's nadir criteria. Trials were evaluated for quality using the Cochrane Risk of Bias Assessment Tool, and data were statistically analyzed using Stata 16.0 and Review Manager 5.3 software to compare and rank differences in effectiveness and safety between the biologics. A total of 10 registered randomized controlled clinical trials involving 2148 subjects were included in this study. The interventions were ranked from best to worst in terms of the primary outcome indicator of effectiveness, renal complete remission: belimumab > anifrolumab (900 + 300) mg > obinutuzumab > ocrelizumab 400 mg > abatacept 30/10 mg/kg > belimumab + rituximab > abatacept 10/10 mg/kg > abatacept (30/10 + 10/10) mg/kg > placeo > ocrelizumab 1000 mg > rituximab > anifrolumab 300 mg, belimumab was superior to placebo [OR = 1.75, 95% CI (1.13, 2.70)] and anifrolumab 300 mg [OR = 3.27, 95% CI (1.05, 10.14)], anifrolumab (900 + 300) mg was superior to anifrolumab 300 mg [OR = 3.56, 95% CI (1.30, 9.76)], and all were statistically significant. The ranking of each intervention in terms of overall renal remission for secondary outcome indicators from best to worst was: obinutuzumab > belimumab + rituximab > anifrolumab (900 + 300) mg > ocrelizumab 1000 mg > ocrelizumab 400 mg > belimumab > rituximab 1000 mg > abatacept 30/10 mg/kg > abatacept (30/10 + 10/10) mg/kg > placeo > abatacept 10/10 mg/kg > anifrolumab 300 mg, obinutuzumab was superior to placebo [OR = 2.27, 95% CI (1.11, 4.67)] and belimumab was also superior to placebo [OR = 1.56, 95% CI (1.07, 2.27)], and all were statistically significant. In terms of safety, with a focus on serious adverse events and serious infections, the results were: Serious adverse events at 1 year of monitoring occurred better with ocrelizumab 1000 mg than ocrelizumab 400 mg [OR = 0.51, 95% CI (0.29, 0.89)] and were statistically different; serious adverse events at 2 years of monitoring infection adverse events occurred better with obinutuzumab than with abatacept (30/10 + 10/10) mg/kg [OR = 0.24, 95% CI (0.07, 0.81)] and were statistically different. The safety of the new biologics in combination with conventional standard therapies is generally good, but it is belimumab and obinutuzumab that are most effective in achieving complete and overall remission in the kidney. This study protocol has been registered with PROSPERO, with a registration number of CRD42021262498.

Most childhood-onset SLE patients (cSLE) develop lupus nephritis (cLN), but only a small proportion achieve complete response to current therapies. The prognosis of children with LN and end-stage renal disease is particularly dire. Mortality rates within the first five years of renal replacement therapy may reach 22%. Thus, there is urgent need to decipher and target immune mechanisms that drive cLN. Despite the clear role of autoantibody production in SLE, targeted B cell therapies such as rituximab (anti-CD20) and belimumab (anti-BAFF) have shown only modest efficacy in cLN. While many studies have linked dysregulation of germinal center formation to SLE pathogenesis, other work supports a role for extrafollicular B cell activation in generation of pathogenic antibody secreting cells. However, whether extrafollicular B cell subsets and their T cell collaborators play a role in specific organ involvement in cLN and/or track with disease activity remains unknown.

We analyzed high-dimensional mass cytometry and gene expression data from 24 treatment naïve cSLE patients at the time of diagnosis and longitudinally, applying novel computational tools to identify abnormalities associated with clinical manifestations (cLN) and disease activity (SLEDAI).

cSLE patients have an extrafollicular B cell expansion signature, with increased frequency of i) DN2, ii) Bnd2, iii) plasmablasts, and iv) peripheral T helper cells. Most importantly, we discovered that this extrafollicular signature correlates with disease activity in cLN, supporting extrafollicular T/B interactions as a mechanism underlying pediatric renal pathogenesis.

This study integrates established and emerging themes of extrafollicular B cell involvement in SLE by providing evidence for extrafollicular B and peripheral T helper cell expansion, along with elevated type 1 IFN activation, in a homogeneous cohort of treatment-naïve cSLE patients, a point at which they should display the most extreme state of their immune dysregulation.

Systemic lupus erythematosus (SLE) is a severe multisystem autoimmune disease that can cause injury in almost every body system. While considered a classic example of autoimmunity, it is still relatively poorly understood. Treatment with immunosuppressive agents is challenging, as many agents are relatively non-specific, and the underlying disease is characterized by unpredictable flares and remissions. This State of The Art Review provides a comprehensive current summary of systemic lupus erythematosus based on recent literature. In basic and translational science, this summary includes the current state of genetics, epigenetics, differences by ancestry, and updates about the molecular and immunological pathogenesis of systemic lupus erythematosus. In clinical science, the summary includes updates in diagnosis and classification, clinical features and subphenotypes, and current guidelines and strategies for treatment. The paper also provides a comprehensive review of the large number of recent clinical trials in systemic lupus erythematosus. Current knowns and unknowns are presented, and potential directions for the future are suggested. Improved knowledge of immunological pathogenesis and the molecular differences that exist between patients should help to personalize treatment, minimize side effects, and achieve better outcomes in this difficult disease.

Childhood-onset systemic lupus erythematosus is an inflammatory and autoimmune condition characterized by heterogeneous multisystem involvement and a chronic course with unpredictable flares. Kidney involvement, commonly called lupus nephritis, mainly presents with immune complex-mediated glomerulonephritis and is more frequent and severe in adults. Despite a considerable improvement in long-term renal prognosis, children and adolescents with lupus nephritis still experience significant morbidity and mortality. Moreover, current literature often lacks pediatric-specific data, leading clinicians to rely exclusively on adult therapeutic approaches. This review aims to describe pediatric lupus nephritis and provide an overview of the novel perspectives on the pathogenetic mechanisms, histopathological classification, therapeutic approach, novel biomarkers, and follow-up targets in children and adolescents with lupus nephritis.

To determine the safety and efficacy of biological agents used in the treatment of systemic lupus erythematosus (SLE) in adults.

Systematic review and meta-analysis following PRISMA guidelines.

MEDLINE (through Pubmed), EMBASE, Cochrane library, Clinicaltrials.gov, Australianclinicaltrials.gov.au, ANZCTR.org.au and WHO International Clinical Trials Registry Platform for studies published from 20 May 2021 and 15 years prior. A grey literature search was performed and completed on 31 May 2021.

Phase II, III or quasi randomised controlled trials, studies with only cerebral or cutaneous lupus were excluded.

Two authors independently screened studies for eligibility, extracted, reviewed data for accuracy, and used the Cochrane tool to assess risk of bias.

Forty-four studies were identified, consisting of 15 groups of drugs and 25 different biological agents, totalling 16,889 patients. The main outcomes assessed included Systemic Lupus Erythematosus Responder Index (SRI), BILAG-Based Composite Lupus Assessment (BICLA) and combined combined/partial renal remission (CRR/PRR). Four groups of biologics were found to improve outcomes. Anti-interferons: Anifrolumab increased BICLA response and SRI 5 to 8, decreased prednisone dosages, with increased herpes zoster infections, but fewer serious adverse events. Sifalimumab improved SRI but also increased herpes zoster infections. Anti BAFF/BLyS and/or APRIL: Belimumab consistently improved SRI 4, decreased prednisone dosages, increased combined CRR/PRR, and had no adverse safety outcomes. Tabalumab increased SRI 5 at 52 weeks with no steroid sparing effect but was associated with increased infusion related adverse events. Telitacicept improved SRI 4 at 52 weeks, with no increased adverse events, though data was rather sparse. Anti CD-20 monoclonal antibody, Obinutuzumab increased combined CRR/PRR at 1 and 2 years. Anti IL12/23 monoclonal antibody, Ustekinumab, increased SRI 4 to 6, but not BICLA at 24 weeks, with no concerning safety outcomes.

Multiple biologic agents are shown in high quality studies to have a significant therapeutic impact on outcomes in SLE.

Systemic lupus erythematosus is a chronic autoimmune disease characterized by loss of tolerance against nuclear and cytoplasmic self-antigens, induction of immunity and tissue inflammation. Lupus nephritis (LN), the most important predictor of morbidity in SLE, develops in almost 30% of SLE patients at disease onset and in up to 50-60% within the first 10 years. Firstly, in this review, we put the pathogenic mechanisms of the disease into a conceptual frame, giving emphasis to the role of the innate immune system in this loss of self-tolerance and the induction of the adaptive immune response. In this aspect, many mechanisms have been described such as dysregulation and acceleration of cell-death pathways, an aberrant clearance and overload of immunogenic acid-nucleic-containing debris and IC, and the involvement of antigen-presenting cells and other innate immune cells in the induction of this adaptive immune response. This result in a clonal expansion of autoreactive lymphocytes with generation of effector T-cells, memory B-cells and plasma cells that produce autoantibodies that will cause kidney damage. Secondly, we review the immunological pathways of damage in the kidney parenchyma, initiated by autoantibody binding and immune complex deposition, and followed by complement-mediated microvascular injury, activation of kidney stromal cells and the recruitment of leukocytes. Finally, we summarize the rationale for the treatment of LN, from conventional to new targeted therapies, focusing on their systemic immunologic effects and the minimization of podocytary damage.

Lupus nephritis is a severe, organ-threatening manifestation of systemic lupus erythematosus. The current standard of care in the treatment of lupus nephritis is limited to broad-spectrum immunosuppressants, which have significant concerns of short- and long-term toxicity. With traditional approaches, kidney survival and patient outcomes have remained suboptimal. Robust research in the therapeutics of lupus nephritis has resulted in development of many novel drugs targeting specific inflammatory response pathways. Some newer agents have shown a definitive signal of benefit when added to standard of care. With the advent of precision medicine in nephrology, lupus nephritis treatment may undergo a shift toward incorporating approaches using these newer drugs and individualizing care of our patients. This review highlights major advances in management of lupus nephritis over the last 25 years and explores the ongoing trials of emerging therapies in lupus nephritis.

Lupus nephritis (LN) is a frequent and serious complication of systemic lupus erythematosus (SLE), impairing patients' quality of life and significantly increasing mortality. Despite optimizing the use of conventional immunosuppressants and other biological drugs, its management remains unsatisfactory. This is mainly due to the heterogeneity of SLE, but also to insufficiently effective treatment regimens and clinical trial limitations (strict criteria, low number of patients included, and side effects). Most clinical trials of new biological therapies have failed to meet their primary endpoints in both general SLE and LN, with only two biological drugs (belimumab and anifrolumab) being approved by the Food and Drug Administration (FDA) for the treatment of SLE. Recently, several Phase II randomized controlled trials have evaluated the efficacy and safety of new biologics in LN, and some of them have demonstrated an improvement in clinical and laboratory measures. Multi-target therapies are also being successfully developed and encourage a belief that there will be an improvement in LN outcomes.

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune systemic disease with a wide range of clinical symptoms, complex development processes, and uncertain prognosis. The clinical treatment of SLE is mainly based on hormones and immunosuppressants. Research on novel therapy strategies for SLE has flourished in recent years, especially the emergence of new targeted drugs and natural products that can modulate related symptoms. This review discusses the current experience including B-cell targeted drugs (belimumab, tabalumab, blisibimod, atacicept, rituximab, ofatumumab, ocrelizumab, obexelimab, and epratuzumab), T-cell targeted drugs (abatacept, dapirolizumab, and inhibitor of syk and CaMKIV), cytokines targeted drugs (anifrolumab and sifalimumab), and natural products (curcumin, oleuropein, punicalagin, sulforaphane, icariin, apigenin, and resveratrol). The aim of this paper is to combine the existing in vitro and in vivo models and clinical research results to summarize the efficacy and mechanism of natural drugs and targeted drugs in SLE for the reference and consideration of researchers.

Systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), and Sjögren's syndrome (SS) are heterogeneous autoimmune diseases. Severe manifestations and refractory/intolerance to conventional immunosuppressants demand other options, namely biological drugs, and small molecules. We aimed to define evidence and practice-based guidance for the off-label use of biologics in SLE, APS, and SS. Recommendations were made by an independent expert panel, following a comprehensive literature review and two consensus rounds. The panel included 17 internal medicine experts with recognized practice in autoimmune disease management. The literature review was systematic from 2014 until 2019 and later updated by cross-reference checking and experts' input until 2021. Preliminary recommendations were drafted by working groups for each disease. A revision meeting with all experts anticipated the consensus meeting held in June 2021. All experts voted (agree, disagree, neither agree nor disagree) during two rounds, and recommendations with at least 75% agreement were approved. A total of 32 final recommendations (20 for SLE treatment, 5 for APS, and 7 for SS) were approved by the experts. These recommendations consider organ involvement, manifestations, severity, and response to previous treatments. In these three autoimmune diseases, most recommendations refer to rituximab, which aligns with the higher number of studies and clinical experience with this biological agent. Belimumab sequential treatment after rituximab may also be used in severe cases of SLE and SS. Second-line therapy with baricitinib, bortezomib, eculizumab, secukinumab, or tocilizumab can be considered in SLE-specific manifestations. These evidence and practice-based recommendations may support treatment decision and, ultimately, improve the outcome of patients living with SLE, APS, or SS.

Childhood-onset systemic lupus erythematosus (SLE) is characterized by increased rates of kidney involvement, termed lupus nephritis. Despite the significant morbidity and mortality associated with this disease, lupus nephritis trials have been plagued by repeated failures to meet clinical endpoints. However, improvements in trial design and the development of targeted approaches have begun to yield promising results, including two new FDA-approved lupus nephritis treatments since 2020. These include belimumab, a monoclonal antibody targeting the B cell survival cytokine BAFF (B cell activating factor), and voclosporin, a cyclosporin analog with improved pharmacokinetic characteristics. In this review, we will summarize the data supporting regulatory approval for these agents in lupus nephritis and highlight ongoing clinical trials targeting the diverse immunologic drivers of renal inflammation in SLE. While pediatric patients remain underrepresented in lupus clinical trials, given the increased severity of childhood-onset SLE and need for long-term protection from kidney damage, we anticipate the need for off-label use of these targeted therapies in the pediatric population. Future studies are needed to define optimal patient selection, drug combinations, and treatment duration in pediatric lupus nephritis.

The stimulator of interferon genes (STING) is a critical protein in the activation of the immune system in response to DNA. It can participate the inflammatory response process by modulating the inflammation-preferred translation program through the STING-PKR-like endoplasmic reticulum kinase (PERK)-eIF2α pathway or by inducing the secretion of type I interferons (IFNs) and a variety of proinflammatory factors through the recruitment of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) or the regulation of the nuclear factor kappa-B (NF-κB) pathway. Based on the structure, location, function, genotype, and regulatory mechanism of STING, this review summarizes the potential value of STING inhibitors in the prevention and treatment of infectious diseases, psoriasis, systemic lupus erythematosus, non-alcoholic fatty liver disease, and other inflammatory and autoimmune diseases.

The aim of this study was to examine the effect and safety of biological agents for lupus nephritis (LN).

PubMed, EMBASE, and the Cochrane Library databases were searched from their inception up to November 2021. The outcomes were overall response, complete remission, proteinuria, renal activity index, and adverse events (AEs). Only randomized controlled trials (RCTs) were included.

Nine RCTs (1645 patients) were included. The RCTs evaluated abatacept (n = 2), belimumab (n = 1), obinutuzumab (n = 1), atacicept (n = 1), IL-2 (n = 1), ocrelizumab (n = 1), and rituximab (n = 2). The use of biological agents was associated with higher likelihoods of achieving an overall response (relative risk [RR], 1.26; 95% confidence interval [CI], 1.15-1.39; p < 0.001; I2 = 14.3%; pQ = 0.301) and a complete response (RR, 1.33; 95% CI, 1.16-1.54; p < 0.001; I2 = 41.8%; pQ = 0.056). The use of biological agents was not associated with improvements in the urinary protein-to-creatinine ratio (weighted mean difference, 3.83; 95% CI, -3.71 to 11.38; p = 0.319; I2 = 99.4%; pQ < 0.001). The use of biological agents in patients with LN was also not associated with an increased risk of any AEs (RR, 1.01; 95% CI, 0.98-1.04; p = 0.519; I2 = 0.0%; pQ = 0.533), serious AEs (RR, 0.95; 95% CI, 0.82-1.09; p = 0.457; I2 = 0.0%; pQ = 0.667), grade >3 AEs (RR, 0.91; 95% CI, 0.67-1.22; p = 0.522; I2 = 0.0%; pQ = 0.977), infections (RR, 1.09; 95% CI, 0.99-1.20; p = 0.084; I2 = 0.0%; pQ = 0.430), and deaths (RR, 0.67; 95% CI, 0.36-1.24; p = 0.200; I2 = 0.0%; pQ = 0.439). The meta-regression analysis showed that follow-up duration and the sample size did not influence the complete response rate, whereas publications in 2012 to 2014 influence the rate compared with 2015 to 2020.

Biological agents seem to be effective and safe for managing patients with LN.

Despite available therapies, persistently active and corticosteroid-dependent Systemic Lupus Erythematosus (SLE) represent a significant therapeutic challenge. The purpose of this systematic review was to provide an updated view of targeted therapies currently in clinical development in SLE, with a special focus on the most promising ones.

We performed a systematic review of targeted therapies in clinical development in SLE in clinicaltrials.gov (search date: 28th of August 2022). Targeted therapies (defined as drugs specifically designed to block certain molecules, receptors, or pathways involved in the development of SLE) were extracted. For each investigational drug, we considered only the study at the most advanced stage of clinical development.

The systematic review yielded a total of 92 targeted therapies (58 biological DMARDs [bDMARDs] and 34 targeted synthetic [ts]DMARDs) assessed in a total of 203 clinical trials. The candidate drugs reached phase I (n=20), Ia/IIb (n=6), phase II (n=51), phase II/III (n=1), phase III (n=13) and phase IV (n=1). These trials were reported as recruiting (n=31), active but not recruiting (n=8), not yet recruiting (n=4), enrolling by invitation (n=2), completed (n=31), prematurely terminated (n=12) and withdrawn in 1 (status unknown in 3). The main investigational drugs for SLE target inflammatory cytokines, chemokines or their receptors (n=19), intracellular signaling pathways (n=18), B cells (n=14) or plasma cells (n=7),T/B cells co-stimulation molecules (n=10), complement molecules (n=5),T lymphocytes (n=2), plasmacytoid dendritic cells (n=2), as well as various other immune targets (n=15).

The pipeline of investigational drugs in SLE is highly diversified and will hopefully enable more optimal Treat-To-Target with the goal of disease modification. Companion biomarkers will be needed to better characterized SLE heterogeneity and optimize treatment selection at the individual-patient level.