Effectiveness of Belimumab After Rituximab in Systemic Lupus Erythematosus : A Randomized Controlled Trial

Monoclonal antibodies targeting interleukins for systemic lupus erythematosus: updates in early clinical drug development

INTRODUCTION

The advent of biological therapies has already revolutionized treatment strategies and disease course of several rheumatologic conditions, and monoclonal antibodies (mAbs) targeting cytokines and interleukins represent a considerable portion of this family of drugs. In systemic lupus erythematosus (SLE) dysregulation of different cytokine and interleukin-related pathways have been linked to disease development and perpetration, offering palatable therapeutic targets addressable via such mAbs.

AREAS COVERED

In this review, we provide an overview of the different biological therapies under development targeting cytokines and interleukins, with a focus on mAbs, while providing the rationale behind their choice as therapeutic targets and analyzing the scientific evidence linking them to SLE pathogenesis.

EXPERT OPINION

An unprecedented number of clinical trials on biological drugs targeting different immunological pathways are ongoing in SLE. Their success might allow us to tackle present challenges of SLE management, including the overuse of glucocorticoids in daily clinical practice, as well as SLE heterogenicity in treatment response among different individuals, hopefully paving the way toward precision medicine.

Combined rituximab and belimumab to treat recalcitrant epidermolysis bullosa aquisita associated with systemic lupus erythematosus

We report two cases of recalcitrant epidermolysis bullosa aquisita with associated systemic lupus erythematosus treated with combination rituximab and belimumab therapy. This resulted in the complete resolution of cutaneous lesions and a partial response of the mucosal lesions. These cases support the use of combined rituximab and belimumab for the treatment of recalcitrant immunobullous disease.

Sustained depression of B cell counts in lupus nephritis after treatment with rituximab and/or belimumab is associated with fewer disease flares

OBJECTIVE

To study the risk of lupus nephritis flare (LNF) or severe lupus flare (SLF) as a function of B cell count kinetics in lupus nephritis (LN) patients after they achieve at least a partial renal response (PRR) with induction treatment that includes rituximab (RTX) and/or belimumab (BLM).

METHODS

We performed a retrospective analysis of a cohort of 19 patients with severe LN that received a B cell agent (BCA), RTX and/or BLM, as part of an initial treatment regimen for an LN flare and had subsequent CD19+ B cell measurements in peripheral blood. We then characterized the follow-up periods, after B cell depressions occurred and PRR were achieved, by the corresponding trajectories of B cell counts (BCC). Time periods with sustained low BCC were type 1 (T1) episodes, while those with repletion of BCC>100 cells/μL were called type 2 (T2) episodes. Time periods with rapid BCC repletion, defined as >50 cells/μL in ≤6 months, were called T2b episodes. Corresponding C3, C4, and anti-dsDNA levels were recorded for each episode. The time from PRR until an event, either a LNF or SLF, or to censoring, either at the end of the study period or the end of available patient follow-up, was assessed for each episode type. Kaplan-Meier survival analysis was used to compare time to flare between T1 and T2 episodes.

RESULTS

There were 26 episodes of B cell depression. Seventeen (65%) were T1 and 9 (35%) were T2. Compared to T1 episodes, T2 episodes were 9.0 times more likely to result in flare over the follow-up period (hazard ratio (HR) = 9.0, 95% CI for HR = 2.2-36.7); this risk was even larger for T2b vs T1 episodes. Median BCC was 14 cells/μL in T1 and 160 cells/μL in T2 episodes. Both C3 and C4 levels significantly increased over the duration of the episode in T1 episodes only.

CONCLUSION

Sustained low BCC was associated with prolonged serologic and clinical response, whereas repletion, and particularly rapid repletion, of B cells after treatment with BCA was associated with subsequent disease flare.

New and emerging therapies for systemic lupus erythematosus

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.

Systemic lupus erythematosus therapeutic strategy: From immunotherapy to gut microbiota modulation

Systemic lupus erythematosus (SLE) is characterized by a systemic dysfunction of the innate and adaptive immune systems, leading to an attack on healthy tissues of the body. During the development of SLE, pathogenic features, such as the formation of autoantibodies to self-nuclear antigens, caused tissue damage including necrosis and fibrosis, with an increased expression of type Ⅰ interferon (IFN) regulated genes. Treatment of lupus with immunosuppressants and glucocorticoids, which are used as the standard therapy, is not effective enough and causes side effects. As an alternative, more effective immunotherapies have been developed, including monoclonal and bispecific antibodies that target B cells, T cells, co-stimulatory molecules, cytokines or their receptors, and signaling molecules. Encouraging results have been observed in clinical trials with some of these therapies. Furthermore, a chimeric antigen receptor T cells (CAR-T) therapy has emerged as the most effective, safe, and promising treatment option for SLE, as demonstrated by successful pilot studies. Additionally, emerging evidence suggests that gut microbiota dysbiosis may play a significant role in the severity of SLE, and the use of methods to normalize the gut microbiota, particularly fecal microbiota transplantation (FMT), opens up new opportunities for effective treatment of SLE.

Emerging biologic therapies for systemic lupus erythematosus

PURPOSE OF REVIEW

The approval of belimumab and anifrolumab has expanded the scope of treatment for systemic lupus erythematosus (SLE) patients. However, many patients remain refractory to currently available therapies and suffer from drug toxicities. This review will discuss approved and target-specific therapeutics in development that bring hope for better SLE treatments.

RECENT FINDINGS

Since the last review on this subject in the journal, the FDA has approved anifrolumab and belimumab for SLE and lupus nephritis (LN), respectively. A fully humanized anti-CD20, obinutuzumab, met the primary end point in a phase II trial in LN. A Tyk2 inhibitor, deucravacitinib, and an antibody targeting plasmacytoid dendritic cells, litifilimab, met the primary end point in phase II trials in SLE and cutaneous lupus erythematosus (CLE). Ustekinumab and baricitinib met the primary end point in phase II but not in phase III trials.

SUMMARY

While many drug candidates which met the end points in phase II trials have failed phase III trials, the number of target-specific therapies for SLE has continued to expand.

Novel and potential future therapeutic options in systemic autoimmune diseases

Autoimmune inflammation is caused by the loss of tolerance to specific self-antigens and can result in organ-specific or systemic disorders. Systemic autoimmune diseases affect a significant portion of the population with an increasing rate of incidence, which means that is essential to have effective therapies to control these chronic disorders. Unfortunately, several patients with systemic autoimmune diseases do not respond at all or just partially respond to available conventional synthetic disease-modifying antirheumatic drugs and targeted therapies. However, during the past few years, some new medications have been approved and can be used in real-life clinical settings. Meanwhile, several new candidates appeared and can offer promising novel treatment options in the future. Here, we summarize the newly available medications and the most encouraging drug candidates in the treatment of systemic lupus erythematosus, rheumatoid arthritis, Sjögren's disease, systemic sclerosis, systemic vasculitis, and autoimmune myositis.

Determinants of neuropsychiatric flares in patients with systemic lupus erythematosus: results from five phase III trials of belimumab

OBJECTIVE

To identify determinants of neuropsychiatric (NP) flares in patients with SLE treated for active SLE yet no ongoing severe NPSLE with non-biologic standard therapy plus belimumab or placebo.

METHODS

We analysed data from five phase III trials (BLISS-52, BLISS-76, BLISS-NEA, BLISS-SC, EMBRACE; n = 3638) after exclusion of patients with baseline NP BILAG A. Factors associated with NPSLE flare, defined as a new NP BILAG A or B, were investigated using Cox regression. In a subgroup analysis, we studied patients with baseline NP BILAG E for determinants of de novo NPSLE flare. Organ damage was assessed using the SLICC/ACR Damage Index (SDI).

RESULTS

We documented 105 (2.9%) NPSLE flares. In multivariable analysis, male sex (HR = 2.37; 95% CI: 1.31, 4.28; P = 0.004), baseline NP BILAG B-D (HR = 5.91; 95% CI: 3.86, 9.06; P < 0.001), and increasing SDI scores (HR = 1.35; 95% CI: 1.21, 1.50; P < 0.001) were strongly associated with NPSLE flare. Belimumab use yielded no association at any dose or administration form. In analysis of SDI domains, NP damage was the strongest determinant of NPSLE flare (HR = 3.25; 95% CI: 2.72, 3.88; P < 0.001), holding true for cognitive impairment (HR = 14.29; 95% CI: 9.22, 22.14; P < 0.001), transverse myelitis (HR = 21.89; 95% CI: 5.40, 88.72; P < 0.001), and neuropathy (HR = 8.87; 95% CI: 5.59, 14.09; P < 0.001). Male sex was the strongest determinant of de novo NPSLE flare (HR = 3.26; 95% CI: 1.51, 7.04; P = 0.003).

CONCLUSION

Male sex, NPSLE history, and NP damage were strong determinants of impending NPSLE flare. No clear protection or predisposition was conferred from add-on belimumab.

Usefulness of Belimumab in Adult Patients With Systemic Lupus Erythematosus Evaluated Using Single Indexes: A Meta-Analysis and Systematic Review

Background

Belimumab is the first antibody drug approved for systemic lupus erythematosus (SLE), and is a fully human monoclonal antibody that inhibits soluble B lymphocyte stimulator protein. In clinical trials, a composite index was used to assess efficacy of belimumab. However, clinical guidelines on SLE treatment currently use single efficacy indexes.

Objective

The main objective of this study was to perform a meta-analysis to evaluate the efficacy of belimumab utilizing single indexes used in routine clinical practice, rather than the composite efficacy index used in clinical trials during the development phase. As a secondary endpoint, safety was also evaluated.

Methods

Several databases were searched to identify reports published up to December 1, 2021 on randomized controlled trials examining the efficacy of belimumab in adult patients with SLE. From the clinical trial data, efficacy was evaluated using single indexes including the SLE Disease Activity Index (SLEDAI), British Isles Lupus Assessment Group Index, and Physician Global Assessment. Safety was also assessed. Data were synthesized and analyzed using Review Manager 5.4. This study protocol was registered in the UMIN Clinical Trials Registry (Registration number: UMIN000052846).

Results

The search identified 12 reports that met the inclusion criteria. Five reports were included in efficacy evaluation and 9 in safety evaluation. The primary endpoint was SLEDAI. Significantly more belimumab-treated patients achieved a ≥4-point reduction in SLEDAI (relative risk 1.28; 95% confidence interval, 1.16-1.40; P < 0.00001) compared with placebo. Other efficacy endpoints were also improved significantly in the belimumab group. No difference in safety was found between belimumab and placebo.

Conclusions

The present meta-analysis evaluating clinical trial data using various single indexes recommended by clinical guidelines for SLE verifies that addition of belimumab to standard of care is efficacious for moderate-to-severe SLE.

Anticoagulant and non-anticoagulant therapy in thrombotic antiphospholipid syndrome: old drugs and new treatment targets

In this review, we discuss the current evidence on classic and newer oral anticoagulant therapy, older drugs such as HCQ and statins, and new potential treatment targets in APS. Vitamin K antagonists (VKAs) remain the cornerstone treatment for thrombotic events in APS. In patients fulfilling criteria for definite APS presenting with a first venous thrombosis, treatment with VKAs with a target international normalized ratio (INR) 2.0-3.0 is recommended. In patients with arterial thrombosis, treatment with VKA with target INR 2.0-3.0 or 3.0-4.0 is recommended by recent guidelines, considering the individual's bleeding and thrombosis recurrence risk. A combination of VKAs and low-dose aspirin (75-100 mg/daily) may also be considered. According to available evidence direct oral anticoagulants should be avoided in patients with arterial thrombosis and/or those with triple aPL positivity. Adjunctive treatment with HCQ and/or statins can be considered, especially in anticoagulation treatment-refractory APS. Potential targeted treatments in APS include B-cell targeting, complement inhibition, mammalian target of rapamycin inhibition, IFN targeting, adenosine receptors agonists, CD38 targeting or chimeric antigen receptor T-cell therapy. The safety and efficacy of these treatment targets needs to be examined in well-designed randomized controlled trials.

Immunotherapy Strategy for Systemic Autoimmune Diseases: Betting on CAR-T Cells and Antibodies

Systemic autoimmune diseases (SAIDs), such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and rheumatoid arthritis (RA), are fully related to the unregulated innate and adaptive immune systems involved in their pathogenesis. They have similar pathogenic characteristics, including the interferon signature, loss of tolerance to self-nuclear antigens, and enhanced tissue damage like necrosis and fibrosis. Glucocorticoids and immunosuppressants, which have limited specificity and are prone to tolerance, are used as the first-line therapy. A plethora of novel immunotherapies have been developed, including monoclonal and bispecific antibodies, and other biological agents to target cellular and soluble factors involved in disease pathogenesis, such as B cells, co-stimulatory molecules, cytokines or their receptors, and signaling molecules. Many of these have shown encouraging results in clinical trials. CAR-T cell therapy is considered the most promising technique for curing autoimmune diseases, with recent successes in the treatment of SLE and SSc. Here, we overview novel therapeutic approaches based on CAR-T cells and antibodies for targeting systemic autoimmune diseases.

Distinct fibroblast functions associated with fibrotic and immune-mediated inflammatory diseases and their implications for therapeutic development

Fibroblasts are ubiquitous cells that can adopt many functional states. As tissue-resident sentinels, they respond to acute damage signals and shape the earliest events in fibrotic and immune-mediated inflammatory diseases. Upon sensing an insult, fibroblasts produce chemokines and growth factors to organize and support the response. Depending on the size and composition of the resulting infiltrate, these activated fibroblasts may also begin to contract or relax thus changing local stiffness within the tissue. These early events likely contribute to the divergent clinical manifestations of fibrotic and immune-mediated inflammatory diseases. Further, distinct changes to the cellular composition and signaling dialogue in these diseases drive progressive fibroblasts specialization. In fibrotic diseases, fibroblasts support the survival, activation and differentiation of myeloid cells, granulocytes and innate lymphocytes, and produce most of the pathogenic extracellular matrix proteins. Whereas, in immune-mediated inflammatory diseases, sequential accumulation of dendritic cells, T cells and B cells programs fibroblasts to support local, destructive adaptive immune responses. Fibroblast specialization has clear implications for the development of effective induction and maintenance therapies for patients with these clinically distinct diseases.

Targeted therapies for lupus nephritis: Current perspectives and future directions

ABSTRACT

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.

The efficacy of rituximab plus belimumab or telitacicept in refractory lupus nephritis

OBJECTIVE

Lupus nephritis is a severe and common complication of systemic lupus erythematosus (SLE). The pathogenesis of lupus nephritis is characterized by B-cell activation and autoantibody formation. Rituximab and belimumab, as well as telitacicept, target B cells through different mechanisms, potentially exerting a synergistic effect in the treatment of lupus nephritis. This study aims to investigate the efficacy and safety of treatment with rituximab followed by belimumab or telitacicept in the management of refractory lupus nephritis.

METHODS

We conducted a single-center, open-label, retrospective study, including 25 patients with refractory lupus nephritis. All patients received combination therapy with rituximab in individualized dosages to achieve peripheral B-cell depletion, and then followed by belimumab or telitacicept. The follow-up period was at least 12 months, and the primary end point was renal remission rate at the last follow-up.

RESULTS

During a median follow-up of 19 (13, 29) months, 20 of 25 (80%) patients achieved objective remission (OR), including 19 (76%) patients achieved complete renal response (CRR). After rituximab (712 ± 416mg in average), 18 patients received belimumab and seven patients received telitacicept. In the rituximab plus telitacicept group, all patients achieved CRR; while in the rituximab plus belimumab group, 12 (66.7%) patients achieved CRR and 13 (72.2%) patients achieved OR. The mean SLEDAI-2K score decreased from 15 ± 6 to 6 ± 6, representing an average reduction of 60%. At the last follow-up, 18/25 (72%) had prednisone ≤ 5 mg/d or even discontinued prednisone use. Adverse effects were mainly immunoglobulin deficiency, respiratory tract infection, urinary tract infections, and rash. No death occurred.

CONCLUSIONS

Rituximab followed by belimumab or telitacicept may be effective in inducing remission in refractory lupus nephritis, with tolerable adverse effects.

Management of systemic lupus erythematosus: A new scenario

The introduction of targeted biological agents in systemic lupus erythematosus (SLE) has created a momentum for improving overall disease management and patients' prognosis. To achieve this, a comprehensive strategy is required spanning the entire patient journey from diagnosis to prevention and management of late complications and comorbidities. In this review, we focus on four aspects that are closely linked to SLE prognosis, namely early disease recognition and treatment initiation, reduction of the cumulative glucocorticoid exposure, attainment of well-defined targets of remission and low disease activity, prevention of flares and, kidney-protective strategies with non-immune-directed agents. We review the recent literature related to these topics in conjunction with the existing treatment recommendations, highlighting areas of uncertainty and providing guidance towards facilitating the care of SLE patients.

Immunotherapeutic approaches for systemic lupus erythematosus: early overview and future potential

Systemic lupus erythematosus (SLE) is a complex autoimmune disease. Current SLE therapies include immunosuppressants, antimalarial drugs, non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids, but these treatments can cause substantial toxicities to organs and may not be effective for all patients. In recent years, significant progress has been made in the treatment of SLE using immunotherapy, including Benlysta and Saphnelo. These advances in immunotherapy hold promise for SLE patients, providing new therapeutic options that may offer better clinical benefit and effectiveness. Simultaneously, several new biological therapies focusing on cytokines, peptides, targeted antibodies, and cell-based approaches are under clinical evaluation and have shown immense potential for the treatment of SLE. However, the complexity of SLE immunopathogenesis and disease heterogeneity present significant challenges in the development of effective immunological therapies. This review aims to discuss past experiences and understanding of diverse immunological targeting therapies for SLE and highlight future perspectives for the development of novel immunological therapies.

Translational implications of newly characterized pathogenic pathways in systemic lupus erythematosus

Improved characterization of relevant pathogenic pathways in systemic lupus erythematosus (SLE) has been further delineated over the last decades. This led to the development of targeted treatments including belimumab and anifrolumab, which recently became available in clinics. Therapeutic targets in SLE encompass interferon (IFN) signaling, B-T costimulation including immune checkpoints, and increasing modalities of B lineage targeting, such as chimeric antigen receptor (CAR) T cells directed against CD19 or sequential anti-B cell targeting. Patient profiling based on characterization of underlying molecular abnormalities, often performed through comprehensive omics analyses, has recently been shown to better predict patients' treatment responses and also holds promise to unravel key molecular mechanisms driving SLE. SLE carries two key signatures, namely the IFN and B lineage/plasma cell signatures. Recent advances in SLE treatments clearly indicate that targeting innate and adaptive immunity is successful in such a complex autoimmune disease. Although those signatures may interact at the molecular level and provide the basis for the first selective treatments in SLE, it remains to be clarified whether these distinct treatments show different treatment responses among certain patient subsets. In fact, notwithstanding the remarkable amount of novel clues for innovative SLE treatment, harmonization of big data within tailored treatment strategies will be instrumental to better understand and treat this challenging autoimmune disorder. This review will provide an overview of recent improvements in SLE pathogenesis, related insights by analyses of big data and machine learning as well as technical improvements in conducting clinical trials with the ultimate goal that translational research results in improved patient outcomes.

Treatment of systemic lupus erythematosus: new therapeutic options

Systemic lupus erythematosus (SLE) is a systemic autoimmune inflammatory disease of unknown cause, with heterogeneity in its clinical presentation, as well as variability in its clinical course and prognosis. The current goal of treatment is to achieve disease remission or a state of low activity, and thereby improve the patient's quality of life. Biological therapy in lupus, unlike other entities, although it has not been fully established, in recent years it has burst onto the scene with important therapeutic novelties. This review aims to update the therapeutic tools for the treatment of SLE focusing on the new molecules that have achieved the objectives of their clinical trials.

New and future therapies: Changes in the therapeutic armamentarium for SLE

Following better understanding of molecular pathways involved in the pathogenesis of Systemic lupus erythematosus (SLE), pharmaceutical companies have been investigating new targeted drugs for SLE. The purpose of this scoping review is to provide an updated view of the most promising targeted therapies currently in clinical development or recently approved for SLE treatment as well as of the most promising potential future therapeutic strategies in SLE. In the past several years, two new drugs have been developed for lupus treatment along with an extended indication for belimumab. Anifrolumab, the anti-interferon medication, to treat non-renal lupus; voclosporin, a calcineurin inhibitor, for the treatment of lupus nephritis; and belimumab for lupus nephritis. More than 90 investigational drugs are currently in clinical development for SLE treatment, with various targets including inflammatory cytokines and their receptors, intracellular signaling, B cells or plasma cells, co-stimulation molecules, complement fractions, T cells, plasmacytoid dendritic cells as well as various other immunological targets of interest. Researchers are also actively engaged in the development of new therapeutic strategies, including the use of monoclonal antibodies in combination with bispecific monoclonal antibodies, nanobodies and nanoparticles, therapeutic vaccines, utilizing siRNA interference techniques, autologous hematopoietic stem-cell transplantation and Chimeric Antigens Receptor (CAR)-T cells. The therapeutic management and prognosis of SLE have profoundly evolved with changes in the therapeutic armamentarium. With the broad pipeline of targeted treatments in clinical development and new treatment strategies in the future, current challenges are transitioning from the availability of new drugs to the selection of the most appropriate strategy at the patient level.

Disease-modifying effect and long-term safety of belimumab in patients with systemic lupus erythematosus: A single-center retrospective study

BACKGROUND

Disease modification in systemic lupus erythematosus (SLE) is important for minimizing disease activity while limiting treatment-associated toxicities. Belimumab can be used as a remission-induction/maintenance systemic lupus erythematosus therapy; however, its disease-modifying effects are unclear. We aimed to determine these effects in patients with systemic lupus erythematosus.

METHODS

This single-center retrospective cohort study included 92 patients with systemic lupus erythematosus treated with belimumab. We analyzed the changes in flare free rate/lupus low disease activity state (LLDAS) attainment rate/glucocorticoid dosage/Systemic Lupus International Collaborating Clinics and American College of Rheumatology damage index (SDI) score/drug retention rate after treatment initiation.

RESULTS

Fifty-two weeks after initiating belimumab, the flare rate decreased from 82.6% to 14.1% (p < .01). Until week 52 and 1000 days after initiating belimumab treatment, > 70% and ∼90% of the patients attained lupus low disease activity state, respectively. Belimumab treatment significantly reduced glucocorticoid demand (initiation day, 8.88 (6.00-15.00) mg/d; week 52, 5.00 (2.00-7.00) mg/d; final day of the study period, 3.00 (0.46-6.06) mg/d, initiation day vs. week 52: p < .01, initiation day vs. final day: p < .01); at the end of the study period, 68.5% of patients required ≤5 mg/d prednisolone, and 22.8% discontinued glucocorticoids. Most patients were SDI progression-free (week 52, ∼95%; day 1000, ∼90%), and belimumab showed a high drug retention rate (week 52, 90%; day 1000 > 80%).

CONCLUSION

Most patients experienced lupus low disease activity state, reduced flare rate and glucocorticoid demand, and a stable SDI trend after belimumab treatment initiation. Given its efficacy and retention rate, belimumab treatment may serve as a fundamental strategy in disease modification.

Advances in the management of systemic lupus erythematosus

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.

Revisiting treatment-related cardiotoxicity in patients with malignant lymphoma-a review and prospects for the future

Treatment of malignant lymphoma has for years been represented by many cardiotoxic agents especially anthracyclines, cyclophosphamide, and thoracic irradiation. Although they are in clinical practice for decades, the precise mechanism of cardiotoxicity and effective prevention is still part of the research. At this article we discuss most routinely used anti-cancer drugs in chemotherapeutic regiments for malignant lymphoma with the focus on novel insight on molecular mechanisms of cardiotoxicity. Understanding toxicity at molecular levels may unveil possible targets of cardioprotective supportive therapy or optimization of current therapeutic protocols. Additionally, we review novel specific targeted therapy and its challenges in cardio-oncology.

KDOQI US Commentary on the 2021 KDIGO Clinical Practice Guideline for the Management of Glomerular Diseases

The KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases represents the first update to this set of recommendations since the initial set of KDIGO guideline recommendations was published in 2012. The pace of growth in our molecular understanding of glomerular disease has quickened and a number of newer immunosuppressive and targeted therapies have been introduced since the original set of guideline recommendations, making such an update necessary. Despite these updates, many areas of controversy remain. In addition, further updates since the publication of KDIGO 2021 have occurred which this guideline does not encompass. With this commentary, the KDOQI work group has generated a chapter-by-chapter companion opinion article that provides commentary specific to the implementation of the KDIGO 2021 guideline in the United States.

Promising Experimental Treatments for Lupus Nephritis: Key Talking Points and Potential Opportunities

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.

Advances in natural products and antibody drugs for SLE: new therapeutic ideas

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.

Drug development and novel therapeutics to ensure a personalized approach in the treatment of systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is a systemic disease encompassing autoimmunity, vasculopathy, and fibrosis. SSc is still burdened by high mortality and morbidity rates. Recent advances in understanding the pathogenesis of SSc have identified novel potential therapeutic targets. Several clinical trials have been subsequently designed to evaluate the efficacy of a number of new drugs. The aim of this review is to provide clinicians with useful information about these novel molecules.

AREA COVERED

In this narrative review, we summarize the available evidence regarding the most promising targeted therapies currently under investigation for the treatment of SSc. These medications include kinase inhibitors, B-cell depleting agents, and interleukin inhibitors.

EXPERT OPINION

Over the next five years, several new, targeted drugs will be introduced in clinical practice for the treatment of SSc. Such pharmacological agents will expand the existing pharmacopoeia and enable a more personalized and effective approach to patients with SSc. Thus, it will not only possible to target a specific disease domain, but also different stages of the disease.

Current Treatment Approach, Emerging Therapies and New Horizons in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE), the prototype of systemic autoimmune diseases is characterized by extreme heterogeneity with a variable clinical course. Renal involvement may be observed and affects the outcome. Hydroxychloroquine should be administered to every lupus patient irrespective of organ involvement. Conventional immunosuppressive therapy includes corticosteroids, methotrexate, cyclophosphamide, mycophenolate mofetil, azathioprine, cyclosporine and tacrolimus. However, despite conventional immunosuppressive treatment, flares occur and broad immunosuppression is accompanied by multiple side effects. Flare occurrence, target organ involvement, side effects of broad immunosuppression and increased knowledge of the pathogenetic mechanisms involved in SLE pathogenesis as well as the availability of biologic agents has led to the application of biologic agents in SLE management. Biologic agents targeting various pathogenetic paths have been applied. B cell targeting agents have been used successfully. Belimumab, a B cell targeting agent, has been approved for the treatment of SLE. Rituximab, an anti-CD20 targeting agent is also used in SLE. Anifrolumab, an interferon I receptor-targeting agent has beneficial effects on SLE. In conclusion, biologic treatment is applied in SLE and should be further evaluated with the aim of a good treatment response and a significant improvement in quality of life.

SLE is not a one-size-fits-all disease

In this Viewpoint we discuss how experimental medicine applied in the setting of clinical trials can address unmet need in the prototypic autoimmune disease systemic lupus erythematosus (SLE) to improve outcomes for patients.

Off-label use of rituximab in patients with systemic lupus erythematosus with extrarenal disease activity: a retrospective study and literature review

Introduction

Off-label rituximab is commonly used for patients with systemic lupus erythematosus (SLE) with extrarenal disease activity.

Methods

The outcomes and tolerability of rituximab in adult patients with non-renal SLE treated at our hospital from 2013 to 2020 were described. Patients were followed-up until December 2021. Data were retrieved from electronic medical records. Response was classified into complete, partial or no response according to the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI 2 K)-based definitions.

Results

A total of 44 cycles were administered to 33 patients. Median age was 45 years and 97% were female. Median follow-up was 5.9 years (IQR 3.7-7.2). The most frequent symptoms that motivated rituximab use were thrombocytopenia (30.3%), arthritis (30.3%), neurological manifestations (24.2%) and cutaneous lupus (15.2%). After most treatment cycles a partial remission was achieved. The median SLEDAI-2 K score declined from 9 (IQR 5-13) to 1.5 (IQR 0-4) (p < 0.00001). The median number of flares significantly declined after receiving rituximab. Platelet counts significantly improved in patients with thrombocytopenia and patients with skin disorders or neurological manifestations also had a partial or complete response. Only 50% of patients with a predominant joint involvement had either a complete or a partial response. The median time to relapse after the first cycle was 1.6 years (95% CI, 0.6-3.1). Anti-dsDNA levels decreased significantly after rituximab from a median of 64.3 (IQR 12-373.9) to 32.7 (IQR 10-173), p = 0.00338. The most frequent adverse events were infusion-related reactions (18.2%) and infections (57.6%). All patients needed further treatment to maintain remission or to treat new flares.

Conclusion

A partial or complete response was documented after most rituximab cycles in patients with non-renal SLE. Patients with thrombocytopenia, neurolupus, and cutaneous lupus had better response than those with a predominant joint involvement.

Current treatment of systemic lupus erythematosus: a clinician's perspective

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. Its variable course makes it difficult to standardize patient treatment. This article aims at a literature review on available drugs for treating SLE and on drugs that have shown therapeutic effects in this disease. The PubMed/MEDLINE electronic search engine was used to identify relevant studies. This review presents the current therapeutic options, new biological therapies, and combination therapies of biologics with standard immunosuppressive and immunomodulating drugs. We have also underlined the importance to implement the treat-to-target strategy aimed at reducing or discontinuing therapy with glucocorticosteroids (GCs). The awareness of the benefits and risks of using GCs helps in refining their dosage and thereby obtaining a better safety profile. The advent of biological targeted therapies, and more recently, low-molecular-weight compounds such as kinase inhibitors, initiated numerous clinical trials in SLE patients and led to the approval of two biological drugs, belimumab, and anifrolumab, for SLE treatment. Progress in the treatment of SLE was reflected in the 2019 and 2021 recommendations of the European Alliance of Associations for Rheumatology (EULAR). However, a mass of recent clinical research data requires continuous consolidation to optimize patient outcomes.

Targeted Therapy for SLE-What Works, What Doesn't, What's Next

For many years, the failure of randomized controlled trials (RCTs) has prevented patients with systemic lupus erythematosus (SLE) from benefiting from biological drugs that have proved to be effective in other rheumatological diseases. Only two biologics are approved for SLE, however they can only be administered to a restricted proportion of patients. Recently, several phase II RCTs have evaluated the efficacy and safety of new biologics in extra-renal SLE and lupus nephritis. Six drug trials have reported encouraging results, with an improvement in multiple clinical and serological outcome measures. The possibility of combining B-cell depletion and anti-BLyS treatment has also been successfully explored.

Treatment of lupus nephritis: consensus, evidence and perspectives

Despite the continuing development of immunomodulatory agents and supportive care, the prognosis associated with lupus nephritis (LN) has not improved substantially in the past decade, with end-stage kidney disease still developing in 5-30% of patients within 10 years of LN diagnosis. Moreover, inter-ethnic variation in the tolerance of, clinical response to and level of evidence regarding various therapeutic regimens for LN has led to variation in treatment prioritization in different international recommendations. Modalities that better preserve kidney function and reduce the toxicities of concomitant glucocorticoids are unmet needs in the development of therapeutics for LN. In addition to the conventional recommended therapies for LN, there are newly approved treatments as well as investigational drugs in the pipeline, including the newer generation calcineurin inhibitors and biologic agents. In view of the heterogeneity of LN in terms of clinical presentation and prognosis, the choice of therapies depends on a number of clinical considerations. Molecular profiling, gene-signature fingerprints and urine proteomic panels might enhance the accuracy of patient stratification for treatment personalization in the future.

Inhibiting B cell activating factor attenuates preeclamptic symptoms in placental ischemic rats

PROBLEM

Preeclampsia (PE), new-onset hypertension during pregnancy, is associated with a pro-inflammatory state with activated T cells, cytolytic natural killer (NK) cells, dysregulated complement proteins, and B cells secreting agonistic autoantibodies to the angiotensin II type-1 receptor (AT1-AA). The reduced uterine perfusion pressure (RUPP) model of placental ischemia recapitulates these features of PE. Blocking CD40L-CD40 communication between T and B cells or B cell depletion with Rituximab prevents hypertension and AT1-AA production in RUPP rats. This suggests that T cell-dependent B cell activation contributes to the hypertension and AT1-AA associated with PE. B2 cells maturing into antibody producing plasma cells are the product of T cell-dependent B cell-interactions and B cell Activating Factor (BAFF) is an integral cytokine in the development of B2 cells specifically. Thus, we hypothesize that BAFF blockade will selectively deplete B2 cells, therefore reducing blood pressure, AT1-AA, activated NK Cells, and complement in the RUPP rat model of PE.

METHOD OF STUDY

Gestational Day (GD) 14 pregnant rats underwent the RUPP procedure, and a subset were treated with 1 mg/kg Anti-BAFF antibodies via jugular catheters. On GD19, blood pressure was measured, B cells and NK cells were measured by flow cytometry, AT1-AA was measured by cardiomyocyte bioassay, and complement activation was measured by ELISA.

RESULTS

Anti-BAFF therapy attenuated hypertension, AT1-AA, NK cell activation, and APRIL levels in RUPP rats without negatively impacting fetal outcomes.

CONCLUSIONS

This study demonstrates that B2 cells contribute to hypertension, AT1-AA, and NK cell activation in response to placental ischemia during pregnancy.

Combination strategies for lupus nephritis: facts and controversies

INTRODUCTION

There is an unmet need to improve the efficacy of therapeutic regimens in lupus nephritis (LN). Cocktail immunosuppressive therapy for the synergistic effect of individual drugs may enhance efficacy and enable dosage reduction. However, the potential increase in the risk of serious and opportunistic infections is a concern. Moreover, the timing of combination therapy, adoption of a step-up or step-down approach, and the choice of drugs is still controversial, partly related to the cost-effectiveness issue.

AREAS COVERED

Evidence of a combination of conventional, newer immunosuppressive, and biologic/targeted agents in LN.

EXPERT OPINION

Early combination of conventional regimens with anti-B cell activation factor (anti-BAFF) or calcineurin inhibitors (CNIs) enhances the therapeutic effect without increasing serious adverse events in LN. However, combining anti-CD20 and anti-BAFF biologics appears to be less promising from the results of clinical trials. Initial combination strategy may be more cost-effective for patients at risk of treatment failure and renal function deterioration. With the availability of more options, the treat-to-target approach in LN is increasingly feasible and further studies are needed to compare the step-up and step-down approaches in the treatment of LN.

Belimumab for the treatment of pediatric patients with lupus nephritis

INTRODUCTION

The FDA approved the anti-BAFF monoclonal antibody, belimumab, in 2011 for adult systemic lupus erythematosus (SLE), in 2019 for pediatric SLE, in 2020 for adult lupus nephritis (LN), and in 2022 for pediatric LN.

AREAS COVERED

We performed a PUBMED database search through November 2022, using 'belimumab and lupus nephritis,' 'belimumab and childhood systemic lupus erythematosus,' 'belimumab and pediatric systemic lupus erythematosus,' and 'belimumab and juvenile systemic lupus erythematosus' as the search phrases. We also vetted pertinent references cited in the papers gleaned from the above search, and we drew from our personal literature collections.

EXPERT OPINION

Based on clinical-trials and real-world experience, belimumab is useful and safe in adult SLE and LN. In contrast and despite FDA approval, evidence of effectiveness in pediatric SLE and pediatric LN is very limited. Whereas there was a trend favoring belimumab in the only randomized, controlled trial to date in pediatric SLE, the difference between the belimumab and placebo groups failed to achieve statistical significance. Moreover, there have been no randomized, controlled trials for belimumab in pediatric LN. Based largely on information gleaned from experience in adults, the clinician can cautiously prescribe belimumab to his/her pediatric LN patient and hope for benefit.

The cellular biology of plasma cells: Unmet challenges and opportunities

Plasma cells and the antibodies they secrete are paramount for protection against infection but can also be implicated in diseases including autoantibody-mediated disease and multiple myeloma. Plasma cell terminal differentiation relies on a transcriptional switch and on important morphological changes. The cellular and molecular mechanisms underlying these processes are partly understood and how plasma cells manage to survive for long periods of time while secreting large quantities of antibodies remains unclear. In this review we aim to put in perspective what is known about plasma cell cellular biology to highlight the challenges faced by this field of research but also to illustrate how new opportunities may arise from the study of the fundamental mechanisms sustaining plasma cell survival and function.

Sequential treatment of rituximab and belimumab in thrombotic thrombocytopenia purpura associated with systemic lupus erythematous: A respective case series and literature review

INTRODUCTION

Thrombotic thrombocytopenia purpura (TTP) associated with systemic lupus erythematous (SLE), features the appearance of inhibitory autoantibodies against ADAMTS13. Rituximab and belimumab (BEL), as both targeting B cells, seem to be an optimal therapy to induce clinical remission, prevent relapse of disease and contribute to glucocorticoid induction. However, the clinical outcome of SLE-TTP treated with sequential therapy between rituximab and BEL remain elusive.

CASE SERIES

We reported the clinical outcomes of 4 patients diagnosed with SLE-TTP who were administrated a combination of corticosteroids, plasma exchange, and rituximab at stage of induction. BEL was utilized to rapidly reduce the reliance on these agents and prevent relapse of TTP at maintenance stage. Ultimately, 4 patients fully recovered with a SLE Disease Activity Index score of 0 and reached the goal at dose of prednisolone <7.5 mg/d without relapse.

CONCLUSION

Sequential treatment of rituximab and BEL could be an encouraging approach in treatment of SLE-TTP and rapid glucocorticoid reduction.

Targeting B cells and plasma cells in autoimmune diseases: From established treatments to novel therapeutic approaches

Autoimmune diseases are characterized by the recognition of self-antigens by the immune system, which leads to inflammation and tissue damage. B cells are directly and indirectly involved in the pathophysiology of autoimmunity, both via antigen-presentation to T cells and production of proinflammatory cytokines and/or autoantibodies. Consequently, B lineage cells have been identified as therapeutic targets in autoimmune diseases. B cell depleting strategies have proven beneficial in the treatment of rheumatoid arthritis (RA), systemic lupus erythematous (SLE), ANCA-associated vasculitis (AAV), multiple sclerosis (MS), and a wide range of other immune-mediated inflammatory diseases (IMIDs). However, not all patients respond to treatment or may not reach (drug-free) remission. Moreover, B cell depleting therapies do not always target all B cell subsets, such as short-lived and long-lived plasma cells. These cells play an active role in autoimmunity and in certain diseases their depletion would be beneficial to achieve disease remission. In the current review article, we provide an overview of novel strategies to target B lineage cells in autoimmune diseases, with the focus on rheumatic diseases. Both advanced therapies that have recently become available and more experimental treatments that may reach the clinic in the near future are discussed.

B cell depletion and inhibition in systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is characterized by autoantibody expression and aberrant autoreactive B cells contribute to disease progression; therefore, B cell inhibition has been an attractive target for novel therapies. However, after more than two decades of research and over 40 randomized clinical trials, only one such therapy, belimumab, has been approved for use in SLE.

AREAS COVERED

In this review, we discuss the evidence for B cell-targeted therapies in SLE and lupus nephritis. Belimumab has been successful in several large clinical trials and is approved in several countries for use in SLE and lupus nephritis. Despite a lack of supporting phase III evidence, rituximab is used off-label in SLE. Several other B cell-targeted therapies have failed to meet their end points in late-stage clinical trials. Successful phase II trials have recently been reported for obinutuzumab and telitacicept with larger confirmatory trials currently underway.

EXPERT OPINION

Refinements in pharmaceutical mechanisms of action, trial design, and patient selection have resulted in recent preliminary successes, offering renewed optimism for B-cell targeted therapeutics in SLE management.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

Identification of biomarkers to stratify response to B-cell-targeted therapies in systemic lupus erythematosus: an exploratory analysis of a randomised controlled trial

Background

Systemic lupus erythematosus (SLE) is a complex autoimmune disease associated with widespread immune dysregulation and diverse clinical features. Immune abnormalities might be differentially associated with specific organ involvement or response to targeted therapies. We aimed to identify biomarkers of response to belimumab after rituximab to facilitate a personalised approach to therapy.

Methods

In this exploratory analysis of a randomised controlled trial (BEAT-LUPUS), we investigated immune profiles of patients with SLE recruited to the 52-week clinical trial, which tested the combination of rituximab plus belimumab versus rituximab plus placebo. We used machine learning and conventional statistics to investigate relevant laboratory and clinical biomarkers associated with major clinical response. BEAT LUPUS is registered at ISRCTN, 47873003, and is now complete.

Findings

Between Feb 2, 2017, and March 28, 2019, 52 patients were recruited to BEAT-LUPUS, of whom 44 provided clinical data at week 52 and were included in this analysis. 21 (48%) of 44 participants were in the belimumab group (mean age 39·5 years [SD 12·1]; 17 [81%] were female, four [19%] were male, 13 [62%] were White) and 23 (52%) were in the placebo group (mean age 42·1 years [SD 10·5]; 21 [91%] were female, two [9%] were male, 16 [70%] were White). Ten (48%) of 21 participants who received belimumab after rituximab and eight (35%) of 23 who received placebo after rituximab had a major clinical response at 52 weeks (between-group difference of 13% [95% CI -15 to 38]). We found a predictive association between baseline serum IgA2 anti-double stranded DNA (dsDNA) antibody concentrations and clinical response to belimumab after rituximab, with a between-group difference in major clinical response of 48% (95% CI 10 to 70) in patients with elevated baseline serum IgA2 anti-dsDNA antibody concentrations. Moreover, among those who had a major clinical response, serum IgA2 anti-dsDNA antibody concentrations significantly decreased from baseline only in the belimumab group. Increased circulating IgA2 (but not total) plasmablast numbers, and T follicular helper cell numbers predicted clinical response and were both reduced only in patients who responded to belimumab after rituximab. Serum IgA2 anti-dsDNA antibody concentrations were also associated with active renal disease, whereas serum IgA1 anti-dsDNA antibody and IFN-α concentrations were associated with mucocutaneous disease activity but did not predict response to B-cell targeted therapy. Patients with a high baseline serum interleukin-6 concentration were less likely to have a major clinical response, irrespective of therapy.

Interpretation

This exploratory study revealed the presence of distinct molecular networks associated with renal and mucocutaneous involvement, and response to B-cell-targeted therapies, which, if confirmed, could guide precision targeting of advanced therapies for this heterogenous disease.

Funding

Versus Arthritis, UCLH Biomedical Research Centre, LUPUS UK, and GSK.

Efficacy of belimumab combined with rituximab in severe systemic lupus erythematosus: study protocol for the phase 3, multicenter, randomized, open-label Synbiose 2 trial

Background

Belimumab, an anti-B-cell activating factor antibody, is approved for the treatment of auto-antibody positive systemic lupus erythematosus with a high degree of disease activity. Anti-CD20 B cell depletion with rituximab is used in refractory SLE as well, although with variable responses. We hypothesized that incomplete B cell depletion, related to a surge in BAFF levels following rituximab treatment, can cause ongoing disease activity and flares. The Synbiose 1 study primarily focused on immunological effects and shows the preliminary clinical benefit of combined rituximab and belimumab in SLE. The Synbiose 2 study will evaluate the clinical efficacy of combining belimumab with rituximab in patients with severe SLE, allowing the tapering of prednisolone and mycophenolate.

Methods

Synbiose 2 is a phase 3, multicenter, randomized, controlled, open-label 2-year clinical trial. Seventy adults with severe SLE including lupus nephritis will be randomized 1:1 to receive either standard of care consisting of prednisolone and mycophenolate as induction and maintenance treatment, or belimumab and rituximab combined with standard of care as induction treatment, followed by prednisolone and belimumab as maintenance treatment. The primary objective is to assess whether combined B cell therapy will lead to a reduction of treatment failure. Secondary endpoints are complete and partial clinical and renal response and the improvement of SLE-specific autoimmune phenomena. Safety endpoints include the incidence of adverse events, with a special interest in infections.

Discussion

The Synbiose 2 trial is the first multicenter phase 3 clinical trial investigating combined B cell targeted therapy in SLE, including lupus nephritis. The outcome of this study will provide further evidence for the clinical efficacy of this new treatment strategy in severe SLE.

Trial registration

ClinicalTrials.gov NCT03747159. Registered on 20 November 2018.

B cells in systemic lupus erythematosus: Targets of new therapies and surveillance tools

B cell hyperactivity is a hallmark of the complex autoimmune disease systemic lupus erythematosus (SLE), which has justified drug development focusing on B cell altering agents during the last decades, as well as the off-label use of B cell targeting biologics. About a decade ago, the anti-B cell activating factor (BAFF) belimumab was the first biological agent to be licensed for the treatment of adult patients with active yet non-renal and non-neuropsychiatric SLE, to later be expanded to include treatment of pediatric SLE and, recently, lupus nephritis. B cell depletion is recommended as an off-label option in refractory cases, with the anti-CD20 rituximab having been the most used B cell depleting agent to date while agents with a slightly different binding specificity to CD20 such as obinutuzumab have also shown promise, forming a part of the current pipeline. In addition, terminally differentiated B cells have also been the targets of experimental therapies, with the proteasome inhibitor bortezomib being one example. Apart from being promising drug targets, B and plasma cells have also shown promise in the surveillance of patients with SLE, especially for monitoring B cell depleting or B cell altering therapies. Inadequate B cell depletion may signify poor expected clinical response to rituximab, for example, while prominent reductions in certain B cell subsets may signify a protection against flare development in patients treated with belimumab. Toward an era with a richer therapeutic armamentarium in SLE, including to a large extent B cell altering treatments, the challenge that emerges is to determine diagnostic means for evidence-based therapeutic decision-making, that uses clinical information, serological markers, and gene expression patterns to guide individualized precision strategies.