B-cell depletion in SLE: clinical and trial experience with rituximab and ocrelizumab and implications for study design

State of the art: the treatment of systemic lupus erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with dysregulated cells in the immune system. The disease affects organs like kidneys, nervous system, joints, and skin. To manage SLE effectively, novel treatments targeting immune system components have been developed. This review investigates the therapeutic potential of existing targeted therapies and explores future innovative approaches for well tolerated, personalized treatment.

RECENT FINDINGS

SLE treatment involves cytokine targets and specific immunologic pathways, with even small molecules involved.

SUMMARY

The advanced therapeutic options in SLE management give clinicians more tools to control disease activity according to personalized medicine.

Disrupting B and T-cell collaboration in autoimmune disease: T-cell engagers versus CAR T-cell therapy?

B and T cells collaborate to drive autoimmune disease (AID). Historically, B- and T-cell (B-T cell) co-interaction was targeted through different pathways such as alemtuzumab, abatacept, and dapirolizumab with variable impact on B-cell depletion (BCD), whereas the majority of patients with AID including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and organ transplantation benefit from targeted BCD with anti-CD20 monoclonal antibodies such as rituximab, ocrelizumab, or ofatumumab. Refractory AID is a significant problem for patients with incomplete BCD with a greater frequency of IgD-CD27+ switched memory B cells, CD19+CD20- B cells, and plasma cells that are not directly targeted by anti-CD20 antibodies, whereas most lymphoid tissue plasma cells express CD19. Furthermore, B-T-cell collaboration is predominant in lymphoid tissues and at sites of inflammation such as the joint and kidney, where BCD may be inefficient, due to limited access to key effector cells. In the treatment of cancer, chimeric antigen receptor (CAR) T-cell therapy and T-cell engagers (TCE) that recruit T cells to induce B-cell cytotoxicity have delivered promising results for anti-CD19 CAR T-cell therapies, the CD19 TCE blinatumomab and CD20 TCE such as mosunetuzumab, glofitamab, or epcoritamab. Limited evidence suggests that anti-CD19 CAR T-cell therapy may be effective in managing refractory AID whereas we await evaluation of TCE for use in non-oncological indications. Therefore, here, we discuss the potential mechanistic advantages of novel therapies that rely on T cells as effector cells to disrupt B-T-cell collaboration toward overcoming rituximab-resistant AID.

Efficacy and Safety of New B Cell-Targeted Biologic Agent for the Treatment of Systemic Lupus Erythematosus: A Systematic Review and Meta-Analysis

BACKGROUND

B cells are central to the pathogenesis of systemic lupus erythematosus (SLE). We aimed to analyze the efficacy and safety of new B cell-targeted drug therapies for SLE.

METHODS

A systematic review of randomized controlled trials (RCTs) and reference lists of relevant articles published from inception to 2022 were selected from PubMed, Scopus and Web of Science databases. Random effects meta-analyses were performed to estimate an overall effect size for the risk of adverse events (AEs) and serious adverse events (SAEs) with belimumab and tabalumab treatment. Heterogeneity was assessed using the I² statistic and meta-regression. Funnel asymmetry was evaluated using Egger's test.

RESULTS

This study included 13 RCTs, of which three showed high risk of bias. Egger's test showed no asymmetry. The risk of SAEs and AEs was lower in the treatment group with belimumab treatment. The risk of AEs for tabalumab treatment was lower in the treatment group and lower for SAEs.

CONCLUSION

Belimumab and tabalumab therapies are effective and safe in the treatment of SLE, although tabalumab does not show sufficient statistical power. Advances in understanding the underlying mechanisms of SLE will be directed towards correlating clinical manifestations with specific pathogenic pathways and the development of precision medicine.

Nanomaterials for antigen-specific immune tolerance therapy

Impairment of immune tolerance might cause autologous tissue damage or overactive immune response against non-pathogenic molecules. Although autoimmune disease and allergy have complicated pathologies, the current strategies have mainly focused on symptom amelioration or systemic immunosuppression which can lead to fatal adverse events. The induction of antigen-specific immune tolerance may provide therapeutic benefits to autoimmune disease and allergic response, while reducing nonspecific immune adverse responses. Diverse nanomaterials have been studied to induce antigen-specific immune tolerance therapy. This review will cover the immunological background of antigen-specific tolerance, clinical importance of antigen-specific immune tolerance, and nanomaterials designed for autoimmune and allergic diseases. As nanomaterials for modulating immune tolerances, lipid-based nanoparticles, polymeric nanoparticles, and biological carriers have been covered. Strategies to provide antigen-specific immune tolerance have been addressed. Finally, current challenges and perspectives of nanomaterials for antigen-specific immune tolerance therapy will be discussed.

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.

Early and Late Response and Glucocorticoid-Sparing Effect of Belimumab in Patients with Systemic Lupus Erythematosus with Joint and Skin Manifestations: Results from the Belimumab in Real Life Setting Study-Joint and Skin (BeRLiSS-JS)

AIM

To assess the efficacy of belimumab in joint and skin manifestations in a nationwide cohort of patients with SLE.

METHODS

All patients with skin and joint involvement enrolled in the BeRLiSS cohort were considered. Belimumab (intravenous, 10 mg/kg) effectiveness in joint and skin manifestations was assessed by DAS28 and CLASI, respectively. Attainment and predictors of DAS28 remission (<2.6) and LDA (≥2.6, ≤3.2), CLASI = 0, 1, and improvement in DAS28 and CLASI indices ≥20%, ≥50%, and ≥70% were evaluated at 6, 12, 24, and 36 months.

RESULTS

DAS28 < 2.6 was achieved by 46%, 57%, and 71% of patients at 6, 12, and 24 months, respectively. CLASI = 0 was achieved by 36%, 48%, and 62% of patients at 6, 12, and 24 months, respectively. Belimumab showed a glucocorticoid-sparing effect, being glucocorticoid-free at 8.5%, 15.4%, 25.6%, and 31.6% of patients at 6, 12, 24, and 36 months, respectively. Patients achieving DAS-LDA and CLASI-50 at 6 months had a higher probability of remission at 12 months compared with those who did not (p = 0.034 and p = 0.028, respectively).

CONCLUSIONS

Belimumab led to clinical improvement in a significant proportion of patients with joint or skin involvement in a real-life setting and was associated with a glucocorticoid-sparing effect. A significant proportion of patients with a partial response at 6 months achieved remission later on during follow-up.

Implications of rituximab pharmacokinetic and pharmacodynamic alterations in various immune-mediated glomerulopathies and potential anti-CD20 therapy alternatives

The specific B-cell depleting anti-CD20 monoclonal antibody rituximab (RTX) is effective in terms of the treatment of various immune-mediated glomerulopathies. The administration of RTX has been shown to be reliable and highly effective particularly in patients with ANCA-associated vasculitis, which is manifested predominantly with non-nephrotic proteinuria. Stable long-term B-cell depletion is usually readily attained in such patients using standard dosing regimens. However, in patients with nephrotic syndrome and non-selective proteinuria, the RTX pharmacokinetics is altered profoundly and RTX does not maintain high enough levels for a sufficiently long period, which may render RTX treatment ineffective. Since complement-derived cytotoxicity is one of the important modes of action of RTX, hypocomplementemia, frequently associated with systemic lupus erythematodes, may act to hamper the efficacy of RTX in the treatment of patients with lupus nephritis. This review provides a description of RTX pharmacokinetics and pharmacodynamics in several selected glomerulopathies, as well as the impact of proteinuria, anti-drug antibodies and other clinical variables on the clearance and volume of distribution of RTX. The impact of plasmapheresis and peritoneal dialysis on the clearance of RTX is also discussed in the paper. A review is provided of the potential association between pharmacokinetic and pharmacodynamic alterations in various kidney-affecting glomerular diseases, the sustainability of B-cell depletion and the clinical efficacy of RTX, with proposals for potential dosing implications. The role of therapeutic drug monitoring in treatment tailoring is also discussed, and various previously tested RTX dosing schedules are compared in terms of their clinical and laboratory treatment responses. Since alternative anti-CD20 molecules may prove effective in RTX unresponsive patients, their pharmacokinetics, pharmacodynamics and current role in the treatment of glomerulopathies are also mentioned.

Frequency of symptomatic adverse events in rheumatoid arthritis: an exploratory online survey

Objective

To generate initial data on the frequency and impact of symptomatic adverse events (AEs) associated with rheumatoid arthritis (RA) drug therapy from the patients' perspective.

Methods

We conducted an exploratory online survey asking patients with RA to indicate whether they currently or had ever experienced the 80 different symptomatic AEs included in the Patient-Reported Outcomes version of The Common Terminology Criteria For Adverse Events (PRO-CTCAE™). Results were summarized to report their frequency and regression models were used to estimate their associations with RA medication use and overall bother.

Results

The 560 patients who completed the survey and reported taking at least one RA medication (DMARD, steroids, NSAIDs), had a mean disease duration of 8 years, and were on a wide range of DMARDs. The number of symptomatic AEs experienced in the past 7 days was none (6%), 1-10 (28%), 11-20 (28%), and >20 (38%). Overall, most participants reported that side effects bothered them somewhat (28%), quite a bit (24%) or very much (15%). In multivariable regression analyses, current prednisone and NSAID use were associated with the greatest number of current side effects (26 and 22 respectively). Many of the strongest associations between current symptomatic AEs and medication use aligned with known side effect profiles.

Conclusion

In this exploratory online survey, patients with RA reported frequent symptomatic AEs with their medications that are bothersome. Further work is needed to develop and validate a measure for use in patients with rheumatic disease.

Prospects for CAR T cell immunotherapy in autoimmune diseases: clues from Lupus

INTRODUCTION

Medicine stands at the threshold of a new era heralded by the vast potential of cell engineering. Like advances made possible by genetic engineering, current prospects for purposeful control of cell functions through cell engineering may bring breakthroughs in the treatment of previously intractable diseases.

AREAS COVERED

Engineering of cytotoxic T cells for expression of chimeric antigen receptors (CARs) instructs them to attack and destroy malignant cells and thus provides an exciting new approach in oncology. A decade of practical experience and first-in-human trials encourage the search for new and broader uses of CAR technology, including in autoimmune diseases.

EXPERT OPINION

Systemic lupus erythematosus is an example of a broader category of autoimmune diseases, for which cell engineering will provide a powerful new therapeutic approach. This article describes different types of CAR T cell strategies that will provide new treatment options for patients with autoimmune diseases and replace conventional therapies.

Engineering Cell Therapies for Autoimmune Diseases: From Preclinical to Clinical Proof of Concept

Autoimmune diseases are caused by a dysfunction of the acquired immune system. In a subset of autoimmune diseases, B cells escaping immune tolerance present autoantigen and produce cytokines and/or autoantibodies, resulting in systemic or organ-specific autoimmunity. Therefore, B cell depletion with monoclonal Abs targeting B cell lineage markers is standard care therapy for several B cell-mediated autoimmune disorders. In the last 5 years, genetically-engineered cellular immunotherapies targeting B cells have shown superior efficacy and long-term remission of B cell malignancies compared to historical clinical outcomes using B cell depletion with monoclonal Ab therapies. This has raised interest in understanding whether similar durable remission could be achieved with use of genetically-engineered cell therapies for autoimmunity. This review will focus on current human clinical trials using engineered cell therapies for B cell-associated autoimmune diseases.

Interferon α Enhances B Cell Activation Associated With FOXM1 Induction: Potential Novel Therapeutic Strategy for Targeting the Plasmablasts of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease. It is characterized by the production of various pathogenic autoantibodies and is suggested to be triggered by increased type I interferon (IFN) signature. Previous studies have identified increased plasmablasts in the peripheral blood of SLE patients. The biological characteristics of SLE plasmablasts remain unknown, and few treatments that target SLE plasmablasts have been applied despite the unique cellular properties of plasmablasts compared with other B cell subsets and plasma cells. We conducted microarray analysis of naïve and memory B cells and plasmablasts (CD38+CD43+ B cells) that were freshly isolated from healthy controls and active SLE (n = 4, each) to clarify the unique biological properties of SLE plasmablasts. The results revealed that all B cell subsets of SLE expressed more type I IFN-stimulated genes. In addition, SLE plasmablasts upregulated the expression of cell cycle-related genes associated with higher FOXM1 and FOXM1-regulated gene expression levels than that in healthy controls. This suggests that a causative relationship exists between type I IFN priming and enhanced proliferative capacity through FOXM1. The effects of pretreatment of IFNα on B cell activation and FOXM1 inhibitor FDI-6 on B cell proliferation and survival were investigated. Pretreatment with IFNα promoted B cell activation after stimulation with anti-IgG/IgM antibody. Flow cytometry revealed that pretreatment with IFNα preferentially enhanced the Atk and p38 pathways after triggering B cell receptors. FDI-6 inhibited cell division and induced apoptosis in activated B cells. These effects were pronounced in activated B cells pretreated with interferon α. This study can provide better understanding of the pathogenic mechanism of interferon-stimulated genes on SLE B cells and an insight into the development of novel therapeutic strategies.

The Dawn of a New Era of Therapies in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complicated multisystem autoimmune disease that is associated with significant mortality and morbidity in the younger population. The development of novel therapies of SLE lag behinds other autoimmune inflammatory rheumatic diseases because of its clinical and immunological heterogeneities, the complexity of outcome assessments in multiple systems, and difficulty in optimizing the design of clinical trials. Despite the futility of quite a number of clinical trials, we are seeing the dawn of novel therapeutics in SLE, given the promising results of the newer-generation anti-CD20, anti-CD40L biologics, and calcineurin inhibitors (CNIs), as well as anti-cytokine biologics, Jakinibs, and the mammalian target of rapamycin (mTOR) inhibitors. The initial success of the Jakinibs and combination regimens in SLE illustrates the importance of targeting multiple pathogenetic mechanisms. The results of the ongoing phase III clinical trials in SLE are eagerly awaited.

The ISCCA flow protocol for the monitoring of anti-CD20 therapies in autoimmune disorders

BACKGROUND

Anti-CD20 monoclonals (MoAbs) are used in a variety of autoimmune disorders. The aim is to eliminate memory B cells sustaining the tissue damage and the production of pathogenic autoantibodies, while preserving naïve cells. The disappearance of memory B cells and the repopulation by naïve cells correlate with good clinical response, while the reappearance of memory B cells and plasmablasts correlates with relapse or resistance to therapy. Anti-CD20 induce extremely low B cell levels, requiring high-resolution techniques. The immune monitoring protocol developed by ISCCA is described and validated, to provide a standardized method for the clinical decision-making process during anti-CD20 therapies in autoimmune diseases.

METHODS

A 10-marker, 8-color staining panel (CD20-V450, CD45-V500c, CD4-FITC + sIgM-FITC, CD38-PE, CD3-PerCP Cy5.5, CD19-PE-Cy7, CD27-APC, CD8-APC H7 + sIgG-APC-H7) is used to identify B cells, plasma cells/blasts, naïve and memory B cells, sIgM+ and sIgG-switched memory B cells, T and NK cells, with high-sensitivity analysis (>10⁶ CD45+ cells).

RESULTS

After an anti-CD20 dose, the B cell level is about zero in most patients. If B cells remain virtually absent (<0.1/μl), subsetting is not reliable nor meaningful. If B cells raise >0.3-0.5/μl, subsetting is possible and informative, acquiring >1.0-1.5 × 10⁶ CD45+ events. Further testings can follow the quality of B cell repopulation. If B cells become detectable (>1/μl), the prevalence of memory B cells indicates non-responsiveness or a possible relapse.

CONCLUSIONS

The ISCCA Protocol is proposed for a standardized prospective monitoring of patients with autoimmune disorders, to assist the safe and rational usage of anti-CD20 therapies.

Efficacy and safety of rituximab for systemic lupus erythematosus treatment: a meta-analysis

Background:

Given the inconsistency of previous studies and the newly emerging evidence, we decided to conduct a meta-analysis.

Methods:

The meta-analysis included 2 randomized controlled trials and 13 observational studies 742 patients in total. Qualified studies were properly searched from databases . Data were analyzed by the RevMan 5.3 software. Results were demonstrated as WMD , SMD and RR with 95% CIs, I² and P value.

Results:

we observed that a remarkable increase of complement C3 in the rituximab group than placebo group (WMDfixed= 7.67mg/dL, 95%CIs=−0.16~15.50, I²=0%, P=0.05). A significant increase of complement C4 was observed in the rituximab group than placebo group (WMDfixed=3.14mg/dL, 95%CIs=1.06~5.22, I²=0%, P=0.003). Notably decreased peripheral CD19+B cells in rituximab group than placebo group (WMDfixed=−117.93n/µl, 95%CIs=−172.94~−62.91, I²=0%, P<0.0001) in RCTs. Patients with severe or refractory SLE got more satisfactory efficacy results after receiving rituximab in observational studies, such as British Isles Lupus Assessment Group index score, SLE Disease Activity Index score, complement C3/C4, anti-dsDNA antibodies, peripheral CD19⁺B cells and so on. Safety profiles were no difference between rituximab and placebo groups.

Conclusion:

although the efficacy of rituximab is highly controversial for SLE, our study shows that rituximab presents a satisfying efficacy and safety for SLE.

ALW peptide ameliorates lupus nephritis in MRL/lpr mice

Background

Lupus nephritis (LN) is a common and serious complication of systemic lupus erythematosus. Anti-double-stranded (ds) DNA immunoglobulin G (IgG) plays a pivotal role in the pathogenesis of LN. Currently, there are various therapies for patients with LN; however, most of them are associated with considerable side effects. We confirmed previously that ALW (ALWPPNLHAWVP), a 12-amino acid peptide, inhibited the binding of polyclonal anti-dsDNA antibodies to mesangial cells and isolated glomeruli in vitro. In this study, we further investigate whether the administration of ALW peptide decreases renal IgG deposition and relevant damage in MRL/lpr lupus-prone mice.

Methods

Forty female MRL/lpr mice were randomly divided into four groups. The mice were intravenously injected with D-form ALW peptide (ALW group), scrambled peptide (PLP group), and normal saline (NaCl group) or were not treated (blank group). The IgG deposition, the histopathologic changes, and the expressions of profibrotic factors were analyzed in the kidney of MRL/lpr mice.

Results

Compared with the other groups, glomerular deposition of IgG, IgG2a, IgG2b, and IgG3 was decreased in the ALW group. Moreover, ALW administration attenuated renal histopathologic changes in MRL/lpr mice, including mesangial proliferation and infiltration of inflammatory cells. Furthermore, the expressions of profibrotic cytokines, such as transforming growth factor-beta1 (TGF-β1) and platelet-derived growth factor B (PDGF-B), decreased in the serum and kidney tissue of ALW-treated mice.

Conclusions

Our study demonstrated that ALW peptide ameliorates the murine model of LN, possibly through inhibiting renal IgG deposition and relevant tissue inflammation and fibrosis.

Adverse infusion reactions to rituximab in systemic lupus erythematosus: a retrospective analysis

Background

To undertake a retrospective review of patients with SLE who had received Rituximab in order to determine the rates and associated patient characteristics of clinically significant adverse infusion reactions.

Methods

A descriptive analysis was undertaken of each infusion reaction, which was then assessed using the clinical information available to hypothesise on the possible underlying mechanism(s).

Results

Records of 136 SLE patients previously treated with 481 individual infusions of Rituximab were reviewed. A total of 22 patients (17.6%) had 28 (5.8% of total infusions) documented clinically significant adverse infusion reactions. Average age at first Rituximab infusion in patients without a reaction was 37 years (range 16–73) compared with 30 years (range 18–56) in those with a reaction. A high proportion of men (18.2%) experienced an infusion reaction. Severity and type of reaction varied. 6.4% of those who had a reaction were not retreated.

Conclusions

While Rituximab remains an important tool in the treatment of SLE it is important to be aware that rates of infusion reactions may be more significant in SLE than in other diseases. A prospective study is required to better characterise the reactions.

Biologics in the Treatment of Lupus Erythematosus: A Critical Literature Review

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease affecting multiple organ systems that runs an unpredictable course and may present with a wide variety of clinical manifestations. Advances in treatment over the last decades, such as use of corticosteroids and conventional immunosuppressive drugs, have improved life expectancy of SLE sufferers. Unfortunately, in many cases effective management of SLE is still related to severe drug-induced toxicity and contributes to organ function deterioration and infective complications, particularly among patients with refractory disease and/or lupus nephritis. Consequently, there is an unmet need for drugs with a better efficacy and safety profile. A range of different biologic agents have been proposed and subjected to clinical trials, particularly dedicated to this subset of patients whose disease is inadequately controlled by conventional treatment regimes. Unfortunately, most of these trials have given unsatisfactory results, with belimumab being the only targeted therapy approved for the treatment of SLE so far. Despite these pitfalls, several novel biologic agents targeting B cells, T cells, or cytokines are constantly being evaluated in clinical trials. It seems that they may enhance the therapeutic efficacy when combined with standard therapies. These efforts raise the hope that novel drugs for patients with refractory SLE may be available in the near future. This article reviews the current biological therapies being tested in the treatment of SLE.

Corticosteroids combined with doublet or single-agent immunosuppressive therapy for active proliferative lupus nephritis

OBJECTIVES

We performed a meta-analysis to assess whether corticosteroids (C) plus (+) doublet immunosuppressive therapy (IT) is superior to the classical combination of C with single-agent IT in active proliferative lupus nephritis (LN).

METHOD

Randomized trials evaluating the benefits and risks of C+doublet versus single-agent IT in active proliferative LN were obtained by searching PubMed, EMBASE, and Cochrane Central Register. The primary outcome was overall response rate (ORR). The secondary outcomes were the change from baseline in Systemic Lupus Erythematosus Disease Activity Index (SLE-DAI) score, negative conversion ratio of anti-double-stranded DNA (anti-dsDNA), and adverse events. The PROSPERO registry number is CRD42017068491.

RESULTS

Eleven trials with 1855 patients were included. Compared with C+single-agent IT, C+doublet IT had a significantly higher ORR (relative risk [RR], 1.22; 95% confidence interval [CI], 1.09 to 1.35; P < 0.01). In a subgroup analysis, C+doublet IT without biologics had a significantly higher ORR than C+single-agent IT (RR, 1.30; 95% CI, 1.13 to 1.50; P < 0.01), while C+doublet IT including biologics improved ORR only for refractory severe LN (RR, 1.46; 95% CI, 1.09 to 1.96; P = 0.012). A larger change from baseline in SLE-DAI scores (standardized mean difference, - 0.49; 95% CI, - 0.68 to - 0.30; P < 0.01) and a higher negative conversion ratio of anti-dsDNA (RR, 1.34; 95% CI, 1.06 to 1.69; P = 0.014) were observed with C+doublet IT than with C+single-agent IT. The rates of adverse events were similar between the two regimens.

CONCLUSIONS

Compared with single-agent IT, the combination of C and doublet IT without biologics improved clinical outcomes in active proliferative LN. Key Points • Compared with corticosteroids + single-agent immunosuppressive therapy, corticosteroids + doublet immunosuppressive therapy without biologics had a significantly higher overall response rate in active proliferative lupus nephritis. • Compared with corticosteroids + single-agent immunosuppressive therapy, corticosteroids + doublet immunosuppressive therapy including biologics improved overall response rate only for refractory severe lupus nephritis. • A larger change from baseline in SLE-DAI scores and a higher negative conversion ratio of anti-dsDNA were observed with corticosteroids + doublet immunosuppressive therapy than with corticosteroids + single-agent immunosuppressive therapy.

Emerging targets for the treatment of lupus erythematosus: There is no royal road to treating lupus

Systemic lupus erythematosus (SLE) is a highly heterogeneous autoimmune disease that preferentially affects women of child-bearing age. Most current treatments for SLE with the exception of belimumab are not target-specific. Nontargeted therapy such as corticosteroids, cyclophosphamide, and other immunosuppressive drugs results in unwanted adverse effects. Although progress in treatment, including supportive therapy, has dramatically improved the prognosis of patients with SLE, better treatment drugs and protocols with fewer adverse effects and higher efficacy for the most severe form of SLE are needed. Advancements in genomics, immunology, and pathophysiology in the field of systemic autoimmunity have provided physicians with increasing knowledge, but the most appropriate treatment for each patient with SLE remains to be established. Therefore, the search for novel treatment targets in patients with SLE is ongoing. This review focuses on recent findings in the genetics of lupus and the abnormalities in cellular interactions, cytokine profiles, and intracellular signaling in patients with SLE. Novel molecular targets for lupus, mostly introduced through clinical trials, are then discussed based on these findings.

B Cells as a Therapeutic Target in Paediatric Rheumatic Disease

B cells carry out a central role in the pathogenesis of autoimmune disease. In addition to the production of autoantibodies, B cells can contribute to disease development by presenting autoantigens to autoreactive T cells and by secreting pro-inflammatory cytokines and chemokines which leads to the amplification of the inflammatory response. Targeting both the antibody-dependent and antibody-independent function of B cells in adult rheumatic disease has led to the advent of B cell targeted therapies in clinical practice. To date, whether B cell depletion could also be utilized for the treatment of pediatric disease is relatively under explored. In this review, we will discuss the role of B cells in the pathogenesis of the pediatric rheumatic diseases Juvenile Idiopathic Arthritis (JIA), Juvenile Systemic Lupus Erythematosus (JSLE) and Juvenile Dermatomyositis (JDM). We will also explore the rationale behind the use of B cell-targeted therapies in pediatric rheumatic disease by highlighting new case studies that points to their efficacy in JIA, JSLE, and JDM.

The Immunomodulatory Role of G2013 (α-L-Guluronic Acid) on the Expression of TLR2 and TLR4 in HT29 cell line

BACKGROUND

The non-steroidal anti-inflammatory drugs (NSAIDs) play crucial role in the controlling of inflammatory diseases. Due to the vast side effects of NSAIDs, its use is limited. G2013 or α-L-Guluronic Acid is a new NSAID with immunomodulatory features.

OBJECTIVES

Considering the leading role of TLRs in inflammatory responses, in this study, we aimed to evaluate G2013 cytotoxicity and its effect on the expression of TLR2 and TLR4 molecules.

METHODS

HEK293-TLR2 and HEK293-TLR4 cells were cultured and seeded on 96-well cell plate, and MTT assay was performed for detecting the viability of the cells after treatment with different concentrations of G2013. HT29 cells were grown and treated with low and high doses of G2013. After total RNA extraction and cDNA synthesis, quantitative real-time PCR were performed to assess the TLR2 and TLR4 mRNA synthesis.

RESULTS

We found that concentrations of ≤125 µg/ml of G2013 had no apparent cytotoxicity effect on the HEK293-TLR2 and -TLR4 cells. Our results indicated that after G2013 treatment (5 µg/ml) in HT29 cells, TLR2 and TLR4 mRNA expression decreased significantly compared with the untreated control group (p=0.02 and p=0.001 respectively).

CONCLUSION

The results of this study revealed that G2013 can down regulate the TLR2 and TLR4 gene expression and exerts its inhibitory effect. Our findings are parallel to our previous finding which showed G2013 ability to down regulate the signaling pathway of TLRs. However, further studies are needed to identify the molecular mechanism of G2013.

Efficacy and safety of anti-CD20 antibody rituximab for patients with refractory systemic lupus erythematosus

Objective

We examined the efficacy and safety of rituximab in patients with refractory systemic lupus erythematosus (SLE).

Methods

The study enrolled 63 SLE patients who were treated with rituximab between 2002 and 2015. The participants underwent a battery of tests before treatment and at one year. Treatment ranged from two to four times at 500 or 1000 mg.

Results

Baseline characteristics were males:females = 6:57, age 33.9 years, and disease duration 87.2 months. The primary endpoint: The rate of major clinical response (MCR) was 60% while the partial clinical response (PCR) was 25%. Thirty of 36 (83%) patients with lupus nephritis (WHO II: 2, III: 5, IV: 22, V: 4, IV+V: 2, not assessed: 1) and 22 of 24 patients (92%) with neuropsychiatric SLE, who could be followed at one year, showed changes from BILAG A or B score to C or D score at one year. Multivariate analysis identified high anti-dsDNA antibody and shorter disease duration as significant determinants of MCR at one year. Repeat examination was conducted at five years. Primary failure was recorded in 8.8% and secondary failure in 32.4% (time to relapse: 24.4 months). Rituximab was well tolerated although 65 adverse events, mostly infections, were recorded within one year.

Conclusion

Rituximab is potentially efficacious for the treatment of patients with refractory SLE.

Current status of lupus nephritis

Systemic lupus erythematosus (SLE) is a systemic disease of unknown aetiology with variable course and prognosis. Lupus nephritis (LN) is one of the important disease manifestations of SLE with considerable influence on patient outcomes. Immunosuppression therapy has made it possible to control the disease with improved life expectancy and quality of life. In the last few decades, various studies across the globe have clarified the role, dose and duration of immunosuppression currently in use and also provided evidence for new agents such as mycophenolate mofetil, calcineurin inhibitors and rituximab. However, there is still a need to develop new and specific therapy with less adverse effects. In this review, the current evidence of the treatment of LN and its evolution, and new classification criteria for SLE have been discussed. Also, rationale for low-dose intravenous cyclophosphamide as induction agent followed by azathioprine as maintenance agent has been provided with emphasis on individualized and holistic approach.

Implications of designing a bromelain loaded enteric nanoformulation on its stability and anti-inflammatory potential upon oral administration

The objective of the present investigation was to develop an enteric nano-formulation of bromelain to improve its stability and anti-inflammatory potential. Bromelain loaded nanoparticles (Br-NPs) were developed using a Eudragit L 100 polymer by a double emulsion solvent evaporation method to obtain gastro-resistant properties. Br-NPs were characterized for particle size (248.89 ± 22.76 nm), zeta potential (-27.34 ± 2.17 mV), entrapment efficiency (85.42 ± 5.34%), surface morphology (spherical) and in vitro release profile. Infrared spectroscopy confirmed the entrapment of bromelain while thermal and pXRD analysis concomitantly corroborated the reduced crystallinity of bromelain in nanoparticles. Formulations showed gastro-resistant behavior at gastric pH and sustained bromelain release up to 10 h in phosphate buffer at pH 6.8 and followed Higuchi square root release kinetics. The optimized lyophilized formulation ensured 2 year shelf-life at room temperature. In vivo studies revealed significantly improved performance of entrapped bromelain in inhibiting carrageenan induced paw edema by mitigating leucocyte migration and release of nitric oxide, TNFα and IL-1β in paw compared to bromelain solution. In conclusion, enteric Br-NPs could be a viable drug delivery system for effective oral bromelain delivery in inflammatory conditions.

Efficient synthesis and characterization of novel indolizines: exploration of in vitro COX-2 inhibitory activity and molecular modelling studies

Novel indolizine scaffolds as COX-2 inhibiting agents.

Next-generation anti-CD20 monoclonal antibodies in autoimmune disease treatment

The clinical success of anti-CD20 monoclonal antibody (mAb)-mediated B cell depletion therapy has contributed to the understanding of B cells as major players in several autoimmune diseases. The first therapeutic anti-CD20 mAb, rituximab, is a murine-human chimera to which many patients develop antibodies and/or experience infusion-related reactions. A second generation of anti-CD20 mAbs has been designed to be more effective, better tolerated, and of lower immunogenicity. These include the humanized versions: ocrelizumab, obinutuzumab, and veltuzumab, and the fully human, ofatumumab. We conducted a literature search of relevant randomized clinical trials in the PubMed database and ongoing trials in Clinicaltrials.gov. Most of these trials have evaluated intravenous ocrelizumab or subcutaneous ofatumumab in rheumatoid arthritis, multiple sclerosis, or systemic lupus erythematosus. Understanding how newer anti-CD20 mAbs compare with rituximab in terms of efficacy, safety, convenience, and cost is important for guiding future management of anti-CD20 mAb therapy in autoimmune diseases.

HM71224, a selective Bruton's tyrosine kinase inhibitor, attenuates the development of murine lupus

Background

Systemic lupus erythematosus (SLE) is associated with B cell hyperactivity, and lupus nephritis (LN), in particular, is promoted by the production of autoantibodies and immune complex deposition. Bruton’s tyrosine kinase (BTK) plays critical roles in B cell receptor-related and Fc receptor-related signaling. We aimed to investigate the impact of therapeutic intervention with HM71224 (LY3337641), a selective BTK inhibitor, on the development of murine SLE-like disease features.

Methods

We examined the therapeutic effects of HM71224 on SLE-like disease features in MRL/lpr and NZB/W F1 mice. The disease-related skin lesion was macroscopically observed in MRL/lpr mice, and the impact on splenomegaly and lymphadenopathy was determined by the weight of the spleen and cervical lymph node. The renal function was evaluated by measuring blood urea nitrogen, serum creatinine, and urine protein, and the renal damage was assessed by histopathological grading. Survival rate was observed during the administration period. The impact of B cell inhibition was investigated in splenocytes from both mice using flow cytometry. Autoantibody was measured in serum by ELISA.

Results

HM71224 effectively suppressed splenic B220⁺GL7⁺, B220⁺CD138⁺, and B220⁺CD69⁺ B cell counts, and anti-dsDNA IgG and reduced splenomegaly and lymph node enlargement. The compound also prevented skin lesions caused by lupus development, ameliorated renal inflammation and damage with increased blood urea nitrogen and creatinine, and decreased proteinuria. Furthermore, HM71224 also decreased mortality from lupus development in both mouse models.

Conclusion

Our results indicate that inhibition of BTK by HM71224 effectively reduced B cell hyperactivity and significantly attenuated the development of SLE and LN in rodent SLE models.

The unmet need in rheumatology: Reports from the targeted therapies meeting 2017

The 19th annual international Targeted Therapies meeting brought together over 100 leading basic scientists and clinical researchers from around the world in the field of immunology, molecular biology and rheumatology and other specialties. During the meeting, breakout sessions were held consisting of 5 disease-specific groups with 20-40 experts assigned to each group based on clinical or scientific expertise. Specific groups included: rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, systemic lupus erythematous, connective tissue diseases (e.g. Sjogren's syndrome, Systemic sclerosis, vasculitis including Bechet's and IgG4 related disease), and a basic science immunology group spanning all of the above clinical domains. In each group, experts were asked to consider and update previously identified unmet needs in 3 categorical areas: basic/translational science, clinical science and therapeutic development, and clinical care. Overall, similar primary unmet needs were identified within each disease foci, and several additional needs were identified since the time of last year's congress. Within translational/basic science, the need for better understanding the heterogeneity within each disease was highlighted so that predictive tools for therapeutic responses can be developed. Within clinical science and therapeutic trials, a strong focus was placed upon the need to identify pre-clinical states of disease allowing prevention in those at risk. The ability to cure remains perhaps the ultimate unmet need. Further, the need to develop new and affordable therapeutics, as well as to conduct strategic trials of currently approved therapies was again highlighted. Within the clinical care realm, improved co-morbidity management and patient-centered care were identified as unmet needs. Lastly, it was strongly felt there was a need to develop a scientific infrastructure for well-characterized, longitudinal cohorts paired with biobanks and mechanisms to support data-sharing. This infrastructure could facilitate many of the unmet needs identified within each disease area.

Redefining lupus nephritis: clinical implications of pathophysiologic subtypes

Systemic lupus erythematosus (SLE) is associated with a broad spectrum of clinical and immunologic manifestations, of which lupus nephritis is the most common cause of morbidity and mortality. The development of nephritis in patients with SLE involves multiple pathogenic pathways including aberrant apoptosis, autoantibody production, immune complex deposition and complement activation. The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification system for lupus nephritis was widely accepted with high intraobserver and interobserver concordance to guide therapeutic strategy and provide prognostic information. However, this classification system is not based on the underlying disease pathophysiology. Some additional lesions that contribute to disease presentation, including glomerular crescents, podocyte injury, tubulointerstitial lesions and vascular injury, should be recognized. Although outcomes for patients with lupus nephritis have improved over the past 30 years, treatment of this disease remains challenging and is best approached on the basis of the underlying pathogenesis, which is only partially represented by the various pathological phenotypes defined by the ISN/RPS classification. Here, we discuss the heterogeneous mechanisms involved in the pathogenesis of lupus nephritis and how improved understanding of underlying disease mechanisms might help guide therapeutic strategies.

Systemic lupus erythematosus diagnosis and management

SLE presents many challenges for clinicians. The onset of disease may be insidious, with many different symptoms and signs, making early and accurate diagnosis challenging. Tests for SLE in the early stages lack specificity; those that are useful later often appear only after organ damage is manifest. Disease patterns are highly variable; flares are not predictable and not always associated with biomarkers. Children with SLE may have severe disease and present special management issues. Older SLE patients have complicating co-morbid conditions. Therapeutic interventions have improved over recent decades, but available drugs do not adequately control disease in many patients, and successful outcomes are limited by off-target effects; some of these become manifest with longer duration of treatment, now in part revealed by improved rates of survival. Despite all of these challenges, advances in understanding the biological basis of SLE have translated into more effective approaches to patient care. This review considers the current state of SLE diagnosis and management, with a focus on new approaches and anticipated advances.

Modeling Combined Immunosuppressive and Anti-inflammatory Effects of Dexamethasone and Naproxen in Rats Predicts the Steroid-Sparing Potential of Naproxen

Dexamethasone (DEX), a widely prescribed corticosteroid, has long been the cornerstone of the treatment of inflammation and immunologic dysfunctions in rheumatoid arthritis. Corticosteroids are frequently used in combination with other antirheumatic agents such as nonsteroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs to mitigate disease symptoms and minimize unwanted effects. We explored the steroid dose-sparing potential of the NSAID naproxen (NPX) with in vitro and in vivo studies. The single and joint suppressive effects of DEX and NPX on the in vitro mitogen-induced proliferation of T lymphocytes in blood and their anti-inflammatory actions on paw edema were investigated in female and male Lewis rats with collagen-induced arthritis (CIA). As expected, DEX was far more potent than NPX in these systems. Mathematical models incorporating an interaction term ψ were applied to quantitatively assess the nature and intensity of pharmacodynamic interactions between DEX and NPX. Modest synergistic effects of the two drugs were found in suppressing the mitogenic response of T lymphocytes. A pharmacokinetic/pharmacodynamic/disease progression model integrating dual drug inhibition quantitatively described the pharmacokinetics, time-course of single and joint anti-inflammatory effects (paw edema), and sex differences in CIA rats, and indicated additive effects of DEX and NPX. Further model simulations demonstrated the promising steroid-sparing potential of NPX in CIA rats, with the beneficial effects of the combination therapy more likely in males than females.

The AP-1 Transcription Factor c-Jun Promotes Arthritis by Regulating Cyclooxygenase-2 and Arginase-1 Expression in Macrophages

Activation of proinflammatory macrophages is associated with the inflammatory state of rheumatoid arthritis. Their polarization and activation are controlled by transcription factors such as NF-κB and the AP-1 transcription factor member c-Fos. Surprisingly, little is known about the role of the AP-1 transcription factor c-Jun in macrophage activation. In this study, we show that mRNA and protein levels of c-Jun are increased in macrophages following pro- or anti-inflammatory stimulations. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment cluster analyses of microarray data using wild-type and c-Jun-deleted macrophages highlight the central function of c-Jun in macrophages, in particular for immune responses, IL production, and hypoxia pathways. Mice deficient for c-Jun in macrophages show an amelioration of inflammation and bone destruction in the serum-induced arthritis model. In vivo and in vitro gene profiling, together with chromatin immunoprecipitation analysis of macrophages, revealed direct activation of the proinflammatory factor cyclooxygenase-2 and indirect inhibition of the anti-inflammatory factor arginase-1 by c-Jun. Thus, c-Jun regulates the activation state of macrophages and promotes arthritis via differentially regulating cyclooxygenase-2 and arginase-1 levels.

Spotlight on blisibimod and its potential in the treatment of systemic lupus erythematosus: evidence to date

B cells in general and BAFF (B cell activating factor of the tumor necrosis factor [TNF] family) in particular have been primary targets of recent clinical trials in systemic lupus erythematosus (SLE). In 2011, belimumab, a monoclonal antibody against BAFF, became the first biologic agent approved for the treatment of SLE. Follow-up studies have shown excellent long-term safety and tolerability of belimumab. In this review, we critically analyze blisibimod, a novel BAFF-neutralizing agent. In contrast to belimumab that only blocks soluble BAFF trimer but not soluble 60-mer or membrane BAFF, blisibimod blocks with high affinity all three forms of BAFF. Furthermore, blisibimod has a unique structure built on four high-affinity BAFF-binding peptides fused to the IgG1-Fc carrier. It was tested in phase I and II trials in SLE where it showed safety and tolerability. While it failed to reach the primary endpoint in a recent phase II trial, post hoc analysis demonstrated its efficacy in SLE patients with higher disease activity. Based on these results, blisibimod is currently undergoing phase III trials targeting this responder subpopulation of SLE patients. The advantage of blisibimod, compared to its competitors, lies in its higher avidity for BAFF, but a possible drawback may come from its immunogenic potential and the anticipated loss of efficacy over time.

Effect of Disease-Related Changes in Plasma Albumin on the Pharmacokinetics of Naproxen in Male and Female Arthritic Rats

Naproxen (NPX) is used in the treatment of rheumatoid arthritis (RA) for alleviation of pain and inflammation. In view of the extensive albumin binding of NPX, this study investigates whether chronic inflammation and sex influence the physiologic albumin concentrations, plasma protein binding, and pharmacokinetics (PK) of NPX. The PK of NPX was evaluated in a rat model of RA [collagen-induced arthritis (CIA) in Lewis rats] and in healthy controls. These PK studies included 1) NPX in female and male CIA rats that received 10, 25, or 50 mg/kg NPX i.p.; and 2) NPX in healthy female and male rats after i.p. dosing of NPX at 50 mg/kg. Plasma albumin concentrations were quantified by enzyme-linked immunosorbent assay, and protein binding was assessed using ultrafiltration. The NPX concentrations in plasma and filtrates were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma concentration-time data of NPX were first assessed by noncompartmental analysis (NCA). Nonlinear PK as indicated by dose-dependent NCA clearances and distribution volumes was observed. A two-compartment model with a first-order absorption process incorporating nonlinear protein binding in plasma and tissues jointly described the PK data of all groups. Saturable albumin binding accounts for the nonlinearity of NPX PK in all rats as well as part of the PK differences in arthritic rats. The CIA rats exhibited reduced albumin concentrations, reduced overall protein binding, and reduced clearances of unbound NPX, consistent with expectations during inflammation. The net effect of chronic inflammation was an elevation of the C_max and area under the plasma concentration-time curve (AUC) of unbound drug.

Modeling Sex Differences in Pharmacokinetics, Pharmacodynamics, and Disease Progression Effects of Naproxen in Rats with Collagen-Induced Arthritis

Naproxen (NPX) is a frequently used nonsteroidal anti-inflammatory drug for rheumatoid arthritis (RA). Lack of quantitative information about the drug exposure-response relationship has resulted in empirical dosage regimens for use of NPX in RA. Few studies to date have included sex as a factor, although RA predominates in women. A pharmacokinetic, pharmacodynamic, and disease progression model described the anti-inflammatory effects of NPX in collagen-induced arthritic (CIA) male and female rats. Three groups of rats were included for each sex: healthy animals, CIA controls, and CIA rats given a single 50-mg/kg dose of NPX intraperitoneally. Paw volumes of healthy rats indicated natural growth, and disease status was measured by paw edema. An innovative minimal physiologically based pharmacokinetic (mPBPK) model incorporating nonlinear albumin binding of NPX in both plasma and interstitial fluid (ISF) was applied. Arthritic rats exhibited lower plasma and ISF albumin concentrations and reduced clearances of unbound drug to explain pharmacokinetic profiles. The unbound ISF NPX concentrations predicted by the mPBPK model were used as the driving force for pharmacological effects of NPX. A logistic growth function accounting for natural paw growth and an indirect response model for paw edema and drug effects (inhibition of k_in) was applied. Female rats showed a higher incidence of CIA, earlier disease onset, and more severe symptoms. NPX had stronger effects in males, owing to higher unbound ISF NPX concentrations and lower IC₅₀ values. The model described the pharmacokinetics, unbound NPX in ISF, time course of anti-inflammatory effects, and sex differences in CIA rats.

Improving B-cell depletion in systemic lupus erythematosus and rheumatoid arthritis

INTRODUCTION

Rituximab-based B-cell depletion (BCD) therapy is effective in refractory rheumatoid arthritis (RA) and although used to treat patients with refractory systemic lupus erythematosus (SLE) in routine clinical practice, rituximab failed to meet the primary endpoints in two large randomised controlled trials (RCTs) of non-renal (EXPLORER) and renal (LUNAR) SLE. Areas covered: We review how BCD could be improved to achieve better clinical responses in RA and SLE. Insights into the variability in clinical response to BCD in RA and SLE may help develop new therapeutic strategies. To this end, a literature search was performed using the following terms: rheumatoid arthritis, systemic erythematosus lupus, rituximab and B-cell depletion. Expert commentary: Poor trial design may have, at least partly, contributed to the apparent lack of response to BCD in the two RCTs of patients with SLE. Enhanced B-cell depletion and/or sequential therapy with belimumab may improve clinical response at least in some patients with SLE.

Beyond pan-B-cell-directed therapy - new avenues and insights into the pathogenesis of SLE

New insights into the mechanisms of autoimmune diseases have been obtained not only from preclinical studies, but also from clinical trials of pan-B-cell-directed therapy. Overall, the results of these clinical trials suggest that more-specific approaches focusing on pathogenic B-cell functions, and perhaps sparing or even enhancing regulatory B-cell activity, might be attractive alternatives. Importantly, pathogenic B-cell subpopulations function within a network of cellular interactions, many of which might require additional interventions to restore immunologic balance and suppress autoimmune disease. Thus, approaches that simultaneously target innate immune cells as well as multiple nodes of T-cell and B-cell interactions might hold the promise of improved therapeutic efficacy. Interfering with B-cell intracellular signalling pathways, altering their intracellular metabolic pathways and perturbing transcription factors are additional options. This Review critically analyses these approaches, examines the role of cytokines and other functions of B-lineage cells separate from antibody secretion, and provides insights into the potential next generation of therapies targeting B-lineage cells.

Efficacy and safety of rituximab in Japanese patients with relapsed chronic immune thrombocytopenia refractory to conventional therapy

Primary immune thrombocytopenia (ITP) is an autoimmune disease mediated by the production of autoantibody against platelets. Rituximab, an anti-CD20 antibody, is reported to be useful for treatment of ITP. In Japan, however, robust evidence on this treatment has not been accumulated. Hence, we conducted this open-label phase III clinical trial to confirm the efficacy and safety of rituximab, administered at 375 mg/m² once per week at weekly intervals for 4 consecutive weeks in Japanese patients with chronic ITP, who had relapsed and were refractory to conventional therapy. The primary endpoint was defined as the percentage of patients with a platelet count above 50 × 10⁹/L at week 24 after the first dose of rituximab, which was 30.8% of 26 patients (95% confidence interval 14.3-51.8%). Although the lower confidence limit of primary endpoint failed to meet the pre-specified threshold of 20%, the clinical efficacy of rituximab is substantial in consideration of the 2% response rate in the placebo arm in other clinical studies in patients with chronic ITP. We conclude that rituximab is clinically useful and safe in the treatment of Japanese patients with chronic ITP, achieving the goal of maintaining platelet count and reducing risk of bleeding while minimizing treatment-related toxicity.

Success and failure of biological treatment in systemic lupus erythematosus: A critical analysis

Patients affected with systemic lupus erythematosus (SLE) still display increased mortality and decreased quality of life in respect to general population. The major determinant of poor long term prognosis is organ damage, which is predictive of more damage and death. Damage is in turn triggered by uncontrolled disease activity and especially by the long-standing corticosteroid use which often accompanies SLE patients over their disease course, owing both to the need of reaching disease remission and to the habit of keeping patients on a small steroid dose for an indefinite period of time. Hence, the need for new drugs and therapeutic strategies aiming at minimizing damage accrual through a better control of disease activity and a steroid-sparing potential is paramount. So far, however, the therapeutic strategy in SLE requires a multitarget approach which is not devoid of widespread immunesuppression. In fact, several studies have been carried out in recent years targeting both the adaptive and the innate immune system, the majority of which did not achieve their primary endpoint, being often divergent from successful clinical experience and thereby committing physician to off-label use of targeted therapies in face of refractory SLE manifestations. The study designs and the chosen endpoints were often blamed for inadequacy, being at least in part responsible for study failures. In this review, we go over major clinical trials conducted in SLE by analyzing any critical aspects related to study design, predefined endpoints and biological activity of novel compounds that may have hampered study outcome, despite the great effort of providing less toxic drugs within a targeted, pathogenic-based approach.

Optimising B-cell depletion in autoimmune disease: is obinutuzumab the answer?

In Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE), B-cell depletion therapy using rituximab results in variable clinical responses between individuals, which likely relates to variable B-cell depletion in the presence of immune defects. Outcomes in clinical trials with other type I anti-CD20 mAbs, ocrelizumab and ofatumumab, are comparable to rituximab. A mechanistically different type II mAb, obinutuzumab (OBZ), with greater capacity for B-cell depletion, has recently entered clinical trials in SLE. Here we consider whether type II anti-CD20 mAbs will provide mechanistic advantages to overcome the disease-related immune defects in autoimmune diseases such as SLE.

The immunological barriers to xenotransplantation

The availability of cells, tissues and organs from a non-human species such as the pig could, at least in theory, meet the demand of organs necessary for clinical transplantation. At this stage, the important goal of getting over the first year of survival has been reported for both cellular and solid organ xenotransplantation in relevant preclinical primate models. In addition, xenotransplantation is already in the clinic as shown by the broad use of animal-derived medical devices, such as bioprosthetic heart valves and biological materials used for surgical tissue repair. At this stage, however, prior to starting a wide-scale clinical application of xenotransplantation of viable cells and organs, the important obstacle represented by the humoral immune response will need to be overcome. Likewise, the barriers posed by the activation of the innate immune system and coagulative pathway will have to be controlled. As far as xenogeneic nonviable xenografts, increasing evidence suggests that considerable immune reactions, mediated by both innate and adaptive immunity, take place and influence the long-term outcome of xenogeneic materials in patients, possibly precluding the use of bioprosthetic heart valves in young individuals. In this context, the present article provides an overview of current knowledge on the immune processes following xenotransplantation and on the possible therapeutic interventions to overcome the immunological drawbacks involved in xenotransplantation.