The efficacy and safety of abatacept in patients with non-life-threatening manifestations of systemic lupus erythematosus: results of a twelve-month, multicenter, exploratory, phase IIb, randomized, double-blind, placebo-controlled trial

The evolution of drug discovery in systemic lupus erythematosus

Drug discovery in systemic lupus erythematosus (SLE) has lagged behind other rheumatic diseases, in large part because of difficulty in measuring change or improvement in a disorder that involves multiple organ systems to varying degrees at different times. The metrics currently used as primary endpoints are composite indices that rely mainly on disease assessment measures derived before the era of clinical trials of targeted therapies. Only one agent has been approved for the treatment of SLE since 1957. This monograph reviews the evolution of drug development for SLE, problems and pitfalls that have been encountered, and outlines the domains used to evaluate SLE in the clinic. Finally, several initiatives underway to improve clinical trial design are outlined.

The Role of Dendritic Cell Subsets and Innate Immunity in the Pathogenesis of Type 1 Diabetes and Other Autoimmune Diseases

Dendritic cells (DCs) are key antigen-presenting cells that have an important role in autoimmune pathogenesis. DCs control both steady-state T cell tolerance and activation of pathogenic responses. The balance between these two outcomes depends on several factors, including genetic susceptibility, environmental signals that stimulate varied innate responses, and which DC subset is presenting antigen. Although the specific DC phenotype can diverge depending on the tissue location and context, there are four main subsets identified in both mouse and human: conventional cDC1 and cDC2, plasmacytoid DCs, and monocyte-derived DCs. In this review, we will discuss the role of these subsets in autoimmune pathogenesis and regulation, as well as the genetic and environmental signals that influence their function. Specific topics to be addressed include impact of susceptibility loci on DC subsets, alterations in DC subset development, the role of infection- and host-derived innate inflammatory signals, and the role of the intestinal microbiota on DC phenotype. The effects of these various signals on disease progression and the relative effects of DC subset composition and maturation level of DCs will be examined. These areas will be explored using examples from several autoimmune diseases but will focus mainly on type 1 diabetes.

Approaches for estimating minimal clinically important differences in systemic lupus erythematosus

A minimal clinically important difference (MCID) is an important concept used to determine whether a medical intervention improves perceived outcomes in patients. Prior to the introduction of the concept in 1989, studies focused primarily on statistical significance. As most recent clinical trials in systemic lupus erythematosus (SLE) have failed to show significant effects, determining a clinically relevant threshold for outcome scores (that is, the MCID) of existing instruments may be critical for conducting and interpreting meaningful clinical trials as well as for facilitating the establishment of treatment recommendations for patients. To that effect, methods to determine the MCID can be divided into two well-defined categories: distribution-based and anchor-based approaches. Distribution-based approaches are based on statistical characteristics of the obtained samples. There are various methods within the distribution-based approach, including the standard error of measurement, the standard deviation, the effect size, the minimal detectable change, the reliable change index, and the standardized response mean. Anchor-based approaches compare the change in a patient-reported outcome to a second, external measure of change (that is, one that is more clearly understood, such as a global assessment), which serves as the anchor. Finally, the Delphi technique can be applied as an adjunct to defining a clinically important difference. Despite an abundance of methods reported in the literature, little work in MCID estimation has been done in the context of SLE. As the MCID can help determine the effect of a given therapy on a patient and add meaning to statistical inferences made in clinical research, we believe there ought to be renewed focus on this area. Here, we provide an update on the use of MCIDs in clinical research, review some of the work done in this area in SLE, and propose an agenda for future research.

Fc-fusion proteins and FcRn: structural insights for longer-lasting and more effective therapeutics

Nearly 350 IgG-based therapeutics are approved for clinical use or are under development for many diseases lacking adequate treatment options. These include molecularly engineered biologicals comprising the IgG Fc-domain fused to various effector molecules (so-called Fc-fusion proteins) that confer the advantages of IgG, including binding to the neonatal Fc receptor (FcRn) to facilitate in vivo stability, and the therapeutic benefit of the specific effector functions. Advances in IgG structure-function relationships and an understanding of FcRn biology have provided therapeutic opportunities for previously unapproachable diseases. This article discusses approved Fc-fusion therapeutics, novel Fc-fusion proteins and FcRn-dependent delivery approaches in development, and how engineering of the FcRn-Fc interaction can generate longer-lasting and more effective therapeutics.

Republished: new age of biological therapies in paediatric rheumatology

Many paediatric rheumatic diseases result from the abnormal activation or control of the immune system. Biologic drugs, which are synthesised within a biological system, have been designed to target specific molecules involved in cytokine signalling or cell-cell interactions. The past 15 years have seen a revolution in the range of effective treatments for rheumatic diseases, particularly juvenile idiopathic arthritis (JIA). As a result, the target of inactive disease and minimal long-term disease-associated damage is increasingly becoming achievable. In this article we review evidence from recent trials of the use of biologic drugs in the treatment of systemic JIA, juvenile dermatomyositis and juvenile systemic lupus erythematosus. We also highlight novel agents currently undergoing investigation which may broaden our therapeutic armamentarium over the coming decade. Key to these developments are well-designed multicentre controlled clinical trials and long-term safety monitoring as part of international drug registries.

Advances in the assessment of lupus disease activity and damage

PURPOSE OF REVIEW

To provide an update on the advances in the assessment of disease activity and damage in systemic lupus erythematosus.

RECENT FINDINGS

Over the last couple of years, the development of composite responder indices has led to better description of the changes in disease activity, especially for clinical trials. It has been recognized that newer composite responder indices such as Systemic Lupus Erythematosus Responder Index (SRI) and BILAG-based Combined Lupus Assessment (BICLA) capture more comprehensive clinical response as they integrate global lupus assessment, system-based assessment, physician's global assessment and treatment failure defined as an increase in the dose of steroid and/or immunosuppressant. The Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) Responder Index 50 (SRI-50) may be more practical for capturing response in clinical practice. British Isles Lupus Assessment Group 2004 (BILAG 2004) Index may capture flare slightly better than the other available flare indices whilst also capturing response.

SUMMARY

This review will provide an insight into the various tools available to assess disease activity and damage in lupus, with a particular focus on the new responder indices currently in use.

Cytokines: Names and Numbers You Should Care About

Cytokines play an important role in host defense against microorganisms. They orchestrate innate immunity by inducing protective local inflammation and systemic acute phase responses. Cytokines are important in initiating, amplifying, directing, mediating, and regulating adaptive immunity. Unfortunately, they may also direct tissue damage if excessive responses occur or if they are involved in directing and mediating autoimmunity. Under these circumstances, cytokines are potential therapeutic targets. Over the last 20 years, we have seen the successful development and clinical implementation of biologic strategies that target key cytokines in specific inflammatory diseases with efficacy, specificity, and toxicity profiles challenging conventional drug therapies. These therapies are finding new applications and many new agents show promise. Unfortunately, these new cytokine-based therapies have had little effect on renal disease. This review provides evidence that common renal diseases, including those causing AKI and the autoimmune proliferative and crescentic forms of GN, have cytokine mediation profiles that suggest they would be susceptible to cytokine-targeting therapeutic strategies.

Decrease of Functional Activated T and B Cells and Treatment of Glomerulonephitis in Lupus-Prone Mice Using a Natural Flavonoid Astilbin

Treatment of systemic lupus erythematosus (SLE), a chronic inflammatory disease, involves the long-term use of immunosuppressive agents with significant side effects. New therapeutic approaches are being explored to find better treatment possibilities. In this study, age-matched female MRL/lpr mice were treated orally with a natural flavonoid astilbin. Astilbin administration started either at week 8 or week 12 of age though week 20. In the early treatment regimen, the treatment with astilbin reduced splenomegaly / lymphomegaly, autoantibody production and ameliorated lupus nephitis. Several serum cytokines were significantly decreased upon treatment including IFN-g, IL-17A, IL-1b, TNF-a and IL-6. Both spleen CD44^hiCD62L^lo activated T cells and CD138⁺B220^- plasma cells greatly declined. Furthermore, astilbin treatment resulted in decreased mitochondrial membrane potential in activated T cells and downregulated expression of the co-stimulatory molecules CD80 and CD86 on LPS stimulated B cells. Similar but less profound effectiveness was observed in the mice with established disease in the late treatment regimen. These results indicate that the natural product astilbin can mitigate disease development in lupus-prone mice by decreasing functional activated T and B cells.

Functional characterization of human T cell hyporesponsiveness induced by CTLA4-Ig

During activation, T cells integrate multiple signals from APCs and cytokine milieu. The blockade of these signals can have clinical benefits as exemplified by CTLA4-Ig, which blocks interaction of B7 co-stimulatory molecules on APCs with CD28 on T cells. Variants of CTLA4-Ig, abatacept and belatacept are FDA approved as immunosuppressive agents in arthritis and transplantation, yet murine studies suggested that CTLA4-Ig could be beneficial in a number of other diseases. However, detailed analysis of human CD4 cell hyporesponsivness induced by CTLA4-Ig has not been performed. Herein, we established a model to study the effect of CTLA4-Ig on the activation of human naïve T cells in a human mixed lymphocytes system. Comparison of human CD4 cells activated in the presence or absence of CTLA4-Ig showed that co-stimulation blockade during TCR activation does not affect NFAT signaling but results in decreased activation of NF-κB and AP-1 transcription factors followed by a profound decrease in proliferation and cytokine production. The resulting T cells become hyporesponsive to secondary activation and, although capable of receiving TCR signals, fail to proliferate or produce cytokines, demonstrating properties of anergic cells. However, unlike some models of T cell anergy, these cells did not possess increased levels of the TCR signaling inhibitor CBLB. Rather, the CTLA4-Ig-induced hyporesponsiveness was associated with an elevated level of p27kip1 cyclin-dependent kinase inhibitor.

Systemic lupus erythematosus

Systemic lupus erythematosus is a remarkable and challenging disorder. Its diversity of clinical features is matched by the complexity of the factors (genetic, hormonal, and environmental) that cause it, and the array of autoantibodies with which it is associated. In this Seminar we reflect on changes in its classification criteria; consider aspects of its more serious clinical expression; and provide a brief review of its aetiopathogenesis, major complications, coping strategies, and conventional treatment. Increased understanding of the cells and molecules involved in the development of the diseases has encouraged the identification of new, better targeted biological approaches to its treatment. The precise role of these newer therapies remains to be established.

[Biologics in SLE]

Biologics have become indispensable in the last decade in the treatment of the more common rheumatic diseases. For treating systemic lupus erythematodes (SLE), B-cell depletion, albeit off-label, has been a well-accepted strategy in severe and refractory disease. Unexpectedly, however, the results of the first randomized controlled rituximab trials in SLE were negative. New trials with improved study protocols are ongoing, which should resolve this issue. In 2012, with the approval of belimumab, SLE finally entered the era of approved biological therapies. The anti-Blys/BAFF antibody belimumab showed prevention of SLE flares, glucocorticoid sparing, and significant improvement in the quality of life of SLE patients, in part by drastically reducing immune complex mediated fatigue. Positive reports on further targeting approaches give hope that additional biological agents will be available for SLE therapy soon.

B cell epitope spreading: mechanisms and contribution to autoimmune diseases

While a variety of factors act to trigger or initiate autoimmune diseases, the process of epitope spreading is an important contributor in their development. Epitope spreading is a diversification of the epitopes recognized by the immune system. This process happens to both T and B cells, with this review focusing on B cells. Such spreading can progress among multiple epitopes on a single antigen, or from one antigenic molecule to another. Systemic lupus erythematosus, multiple sclerosis, pemphigus, bullous pemphigoid and other autoimmune diseases, are all influenced by intermolecular and intramolecular B cell epitope spreading. Endocytic processing, antigen presentation, and somatic hypermutation act as molecular mechanisms that assist in driving epitope spreading and broadening the immune response in autoimmune diseases. The purpose of this review is to summarize our current understanding of B cell epitope spreading with regard to autoimmunity, how it contributes during the progression of various autoimmune diseases, and treatment options available.

Blockade of co-stimulation in chronic inflammatory diseases

Costimulatory molecules are key elements in T cell activation. Therapeutic inhibition of costimulatory pathways have been recognized as valid therapeutic strategies in the treatment of various inflammatory diseases. This article will describe their mechanisms of action and will summarize the results from clinical trials in the field of rheumatologic diseases.

Pathogenesis and potential therapeutic targets in systemic lupus erythematosus: from bench to bedside

Systemic lupus erythematosus (SLE) is considered an autoimmune disease with multiorgan involvement. Many advances have been made during the last decade regarding inflammatory pathways, genetic and epigenetic alterations, adaptive and innate immune system mechanisms specifically involved in SLE pathogenesis. Apoptosis has been proposed as an important player in SLE pathogenesis more than a decade ago. However, only recently new key apoptotic pathways have been investigated and the link between apoptotic debris containing autoantigens, innate immunity and ongoing inflammation has been further elucidated. Better understanding of cellular mechanisms and involved cytokines contributed to the development of new biological drugs specifically addressed for SLE therapy.

Commensal microbes drive intestinal inflammation by IL-17-producing CD4+ T cells through ICOSL and OX40L costimulation in the absence of B7-1 and B7-2

The costimulatory B7-1 (CD80)/B7-2 (CD86) molecules, along with T-cell receptor stimulation, together facilitate T-cell activation. This explains why in vivo B7 costimulation neutralization efficiently silences a variety of human autoimmune disorders. Paradoxically, however, B7 blockade also potently moderates accumulation of immune-suppressive regulatory T cells (Tregs) essential for protection against multiorgan systemic autoimmunity. Here we show that B7 deprivation in mice overrides the necessity for Tregs in averting systemic autoimmunity and inflammation in extraintestinal tissues, whereas peripherally induced Tregs retained in the absence of B7 selectively mitigate intestinal inflammation caused by Th17 effector CD4(+) T cells. The need for additional immune suppression in the intestine reflects commensal microbe-driven T-cell activation through the accessory costimulation molecules ICOSL and OX40L. Eradication of commensal enteric bacteria mitigates intestinal inflammation and IL-17 production triggered by Treg depletion in B7-deficient mice, whereas re-establishing intestinal colonization with Candida albicans primes expansion of Th17 cells with commensal specificity. Thus, neutralizing B7 costimulation uncovers an essential role for Tregs in selectively averting intestinal inflammation by Th17 CD4(+) T cells with commensal microbe specificity.

New age of biological therapies in paediatric rheumatology

Many paediatric rheumatic diseases result from the abnormal activation or control of the immune system. Biologic drugs, which are synthesised within a biological system, have been designed to target specific molecules involved in cytokine signalling or cell-cell interactions. The past 15 years have seen a revolution in the range of effective treatments for rheumatic diseases, particularly juvenile idiopathic arthritis (JIA). As a result, the target of inactive disease and minimal long-term disease-associated damage is increasingly becoming achievable. In this article we review evidence from recent trials of the use of biologic drugs in the treatment of systemic JIA, juvenile dermatomyositis and juvenile systemic lupus erythematosus. We also highlight novel agents currently undergoing investigation which may broaden our therapeutic armamentarium over the coming decade. Key to these developments are well-designed multicentre controlled clinical trials and long-term safety monitoring as part of international drug registries.

Efficacy and safety of nonbiologic immunosuppressants in the treatment of nonrenal systemic lupus erythematosus: a systematic review

OBJECTIVE

To analyze the efficacy and safety of nonbiologic immunosuppressants in the treatment of nonrenal systemic lupus erythematosus (SLE).

METHODS

We conducted a sensitive literature search in Medline, Embase, and the Cochrane Central Register of Controlled Trials up to October 2011. The selection criteria were studies including adult patients with SLE, a treatment intervention with nonbiologic immunosuppressants, a placebo or active comparator group, and outcome measures assessing efficacy and/or safety. Meta-analyses, systematic reviews, clinical trials, and cohort studies were included. The quality of each study was evaluated using Jadad’s scale and the Oxford Levels of Evidence.

RESULTS

In total, 158 of the 2,827 initially found articles were selected for detailed review; 65 studies fulfilled the predetermined criteria. Overall, the studies were low quality, with only 11 randomized controlled trials (RCTs). Cyclophosphamide demonstrated efficacy for neuropsychiatric SLE, preventing relapses with an additional steroid sparing effect, although its use was associated with cumulative damage, development of cervical intraepithelial neoplasia,and ovarian failure. Other immunosuppressants (azathioprine, methotrexate, leflunomide, mycophenolate mofetil,and cyclosporin A) demonstrated efficacy in reducing nonrenal activity and flares with a steroid-sparing effect, although only on occasion in non–placebo-controlled RCTs of small numbers of patients.

CONCLUSION

Several immunosuppressants demonstrated their safety and efficacy in nonrenal SLE. A specific drug for each particular manifestation cannot be recommended, although cyclophosphamide may be used in more severe cases, and methotrexate may be the first option in most cases of moderately active SLE. High-quality RCTs of larger numbers of patients are needed.

When biologics should be used in systemic lupus erythematosus?

Recently, the use and evaluation of biologics increased in systemic lupus erythematosus (SLE). However, no international recommendation is available concerning the use of biologics with regards to the subset of patients who should be treated, the optimal time to treat, the objective of treatment and the manner to discontinue it. To address these complex questions, we focused on biologics already evaluated in at least two published randomized controlled trials. We summarized the results of these trials and available observational data in registries. Taking into account the clinical evidence, we proposed some guidance on the way biologics could be used in SLE. Many areas of uncertainty persist and require intensifying efforts from the academic world to set up new trials, and develop international recommendations.

Which dose of steroids and which cytotoxics for severe lupus?

There have been a number of major advances in the treatment of systemic lupus erythematosus and we are now in the era of biologic therapies for this multisystem autoimmune disorder. There has been a greater awareness of the toxicities of the traditional therapies including the recognition that the doses of corticosteroids used in the past have been excessive, resulting in unacceptable toxicities. Other advances have included the development of lower cumulative doses of cyclophosphamide and the widespread acceptance of mycophenolate mofetil for the treatment of lupus nephritis. This review addresses the current management of severe lupus with corticosteroids and cytotoxic agents.

Efficacy and safety of abatacept in lupus nephritis: a twelve-month, randomized, double-blind study

OBJECTIVE

To compare the efficacy and safety of intravenous (IV) abatacept, a selective T cell costimulation modulator, versus placebo for the treatment of active class III or IV lupus nephritis, when used on a background of mycophenolate mofetil and glucocorticoids.

METHODS

This was a 12-month, randomized, phase II/III, multicenter, international, double-blind study. A total of 298 patients were treated in 1 of 3 IV treatment arms: placebo, abatacept at the standard weight-tiered dose (approximating 10 mg/kg), or abatacept at 30 mg/kg for 3 months, followed by the standard weight-tiered dose (abatacept 30/10). The primary end point, time to confirmed complete response, was a composite measure that required maintenance of glomerular filtration rate, minimal proteinuria, and inactive urinary sediment over the 52-week treatment period.

RESULTS

There were no differences among treatment arms in the time to confirmed complete response or in the proportion of subjects with confirmed complete response following 52 weeks of treatment. Treatment with abatacept was associated with greater improvements from baseline in anti-double-stranded DNA antibody, C3, and C4 levels. Among 122 patients with nephrotic-range proteinuria, treatment with abatacept resulted in an ∼20-30% greater reduction in mean urinary protein-to-creatinine ratio compared with placebo. Abatacept was well tolerated; rates of deaths, serious adverse events, and serious infections were similar across treatment arms. Gastroenteritis and herpes zoster occurred more frequently with abatacept treatment.

CONCLUSION

Although the primary end point was not met, abatacept showed evidence of biologic activity and was well tolerated in patients with active class III or IV lupus nephritis.

Pediatric lupus nephritis: Management update

Childhood-onset systemic lupus erythematosus (cSLE) is a severe multisystem autoimmune disease. Renal involvement occurs in the majority of cSLE patients and is often fatal. Renal biopsy is an important investigation in the management of lupus nephritis. Treatment of renal lupus consists of an induction phase and maintenance phase. Treatment of childhood lupus nephritis using steroids is associated with poor outcome and excess side-effects. The addition of cyclophosphamide to the treatment schedule has improved disease control. In view of treatment failure using these drugs and a tendency for non-adherence, many newer agents such as immune-modulators and monoclonal antibodies are being tried in patients with cSLE. Trials of these novel agents in the pediatric population are still lacking making a consensus in the management protocol of pediatric lupus nephritis difficult.

How should lupus flares be measured? Deconstruction of the safety of estrogen in lupus erythematosus national assessment-systemic lupus erythematosus disease activity index flare index

OBJECTIVE

Accurate assessment of lupus flares is critical but problematic in clinical trials. This study examined the impact of modifications to the classic Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA)-SLEDAI flare index (cSFI).

METHODS

Ninety-one SLE patient records were evaluated at two visits at which the SLEDAI and BILAG had been scored prospectively. The cSFI was compared with an experimental version (eSFI) that eliminated medication criteria and separated the mild/moderate flare category into its components by clinical judgement based on records. The revised SFI (SFI-R) and some physician's global assessments (PGAs) were also scored using chart notes.

RESULTS

eSFI-rated moderate flares had higher PGA and BILAG scores than those rated as mild. When medication criteria were excluded, 42 of 55 cSFI severe flares and 15 of 49 mild/moderate flares were downgraded in severity. Comparing flares that remained severe with those that were downgraded, disease activity was higher by PGA (P < 0.001), SLEDAI (P < 0.001), BILAG (P < 0.001), number of active BILAG organs (P < 0.04) and flaring SFI-R organs (P < 0.01). PGA (P < 0.001) and the number of SFI-R domains flaring (P < 0.001) were higher in mild/moderate eSFI flares than in those that were downgraded. Twenty-one of 83 (25%) medication changes occurred with no flare. Forty-six of 52 (88%) medication changes defining severe flare by cSFI involved patients rated by physicians with no, mild or moderate flares.

CONCLUSION

A deconstructed flare index improves the discrimination of mild from moderate flares and selects more ill patients with true clinical worsening for each category of flare.

B-cell-targeted therapies in systemic lupus erythematosus and ANCA-associated vasculitis: current progress

B cells play a central role in the pathogenesis of systemic lupus erythematosus and anti-neutrophil cytoplasmic antibody-associated vasculitis. There are various strategies for targeting B cells including depletion, inhibition of survival factors, activation and inhibition of co-stimulatory molecules. Controlled trials in systemic lupus erythematosus have shown positive results for belimumab, promising results for epratuzumab and negative results for rituximab. The failure of rituximab in controlled trials has been attributed to trial design, sample size and outcome measures rather than true inefficacy. In anti-neutrophil cytoplasmic antibody-associated vasculitis, rituximab is effective for remission induction and in relapsing disease. However, the optimal long-term re-treatment strategy remains to be determined. Over the next 5 years, evidence will be available regarding the clinical efficacy of these novel therapies, biomarkers and their long-term safety.

Emerging biological therapies for systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with unpredictable disease course, intermingled with periods of remission and exacerbation. Current therapies for SLE are not ideal in terms of efficacy and toxicity. Although the prognosis of the disease has improved in the past decades, further improvement is hindered by the occurrence of organ damage as a result of persistent disease activity and treatment-related complications. Novel biological therapies targeting at higher treatment efficacy and fewer adverse effects are being developed.

AREAS COVERED

This review summarizes recent data on novel biological therapies for SLE. The pitfalls of clinical trial design and future directions of the development of SLE therapeutics are discussed.

EXPERT OPINION

The variable therapeutic response observed in SLE reflects the clinical and immunological heterogeneity of the disease. The treatment plan of SLE patients should be individualized, with the target of quenching out disease activity, minimizing disease flares, and treatment related morbidities. Despite the disappointment of recent clinical trials, avenues are being opened for novel agents that intervene at different levels of the pathophysiological cascade of SLE. With the availability of a new treatment armamentarium, it is hoped that the survival rate and quality of life of SLE patients can continue to improve.

High CTLA-4 expression on Th17 cells results in increased sensitivity to CTLA-4 coinhibition and resistance to belatacept

The CD28/cytotoxic T-lymphocyte antigen 4 (CTLA-4)blocker belatacept selectively inhibits alloreactive T cell responses but is associated with a high incidence of acute rejection following renal transplantation,which led us to investigate the etiology of belatacept–resistant graft rejection. T cells can differentiate into functionally distinct subsets of memory T cellsthat collectively enable protection against diverse classes of pathogens and can cross-react with allogeneicantigen and mediate graft rejection. T helper 17(Th17) cells are a pro-inflammatory CD4+ lineage that provides immunity to pathogens and are pathogenic in autoimmune disease. We found that T helper 1 (Th1)and Th17 memory compartments contained a similar frequency of divided cells following allogeneic stimulation.Compared to Th1 cells, Th17 memory cells expressed significantly higher levels of the coinhibitory molecule CTLA-4. Stimulation in the presence of belatacept inhibited Th1 responses but augmented Th17 cells due to greater sensitivity to coinhibition by CTLA-4. Th17 cells from renal transplant recipients were resistant to ex vivo CD28/CTLA-4 blockade with belatacept, and an elevated frequency of Th17 memory cells was associated with acute rejection during belatacept therapy. These data highlight important differences in costimulatory and coinhibitory requirements of CD4+ memory subsets, and demonstrate that the heterogeneity of pathogen-derived memory has implications for immunomodulation strategies.

Prospects for therapeutic tolerance in humans

PURPOSE OF REVIEW

To provide an overview of recent advances and future possibilities for therapeutic tolerance.

RECENT FINDINGS

Allograft survival despite complete immunosuppressant withdrawal has been demonstrated in selected renal-transplant recipients with haematopoietic chimerism. Early clinical trials of mesenchymal stromal cell therapy have shown promising results in several autoimmune diseases. Regulatory T cells show potential benefit in graft versus host disease, although challenges to ex-vivo expansion remain. Targeted modulation of T-cell function in vivo with monoclonal antibodies has shown beneficial effects in phase II/III trials of multiple sclerosis (alemtuzumab) and type I diabetes mellitus (teplizumab, otelixizumab). Emerging data from animal models suggest an important role for the commensal microbiome in the maintenance and disruption of immune tolerance with parallels in human studies.

SUMMARY

After years of slow progress, recent research has reduced the translational gap between animal models and clinical therapeutic tolerance. Early detection of autoimmunity, potentially at preclinical stages, offers a window of opportunity for tolerogenic therapy. Reliable biomarkers of tolerance are urgently needed to provide objective measurements of the effectiveness of tolerogenic therapies, and to allow intelligent immunosuppressant withdrawal in patients whose autoimmune disease is stable.

VIDEO ABSTRACT AVAILABLE

See the Video Supplementary Digital Content 1 (http://links.lww.com/COR/A8).

Systemic lupus erythematosus: a therapeutic challenge for the XXI century

Despite significant advances in our understanding of the pathogenesis of systemic lupus erythematosus (SLE), there are only a few drugs approved by the regulatory agencies across the world for the treatment of these patients; in fact, many of the compounds subjected to clinical trials have failed in achieving their primary endpoints. Current therapeutic options include antimalarials which should be used in all SLE patients unless they are strongly contraindicated, glucocorticoids which should be used at the lowest possible dose and for the shortest possible time, and immunosuppressive drugs which should be used judiciously, mainly in patients with severe organ involvements or receiving high doses of steroids to control their disease. Despite improvement on the survival of SLE patients, damage accrual has not varied over the last few decades, reflecting a gap between these therapeutic options and the expectations of these patients and their treating physicians. Biologic compounds can be used in some refractory cases. However, their cost is of great concern for both the patients and the health system. Cost is of special importance in low-income countries, because low-income SLE patients tend to experience a more severe disease having an overall worse prognosis which is compounded by their limited access to the health system. Although a treatment to target based on defined molecular pathways for specific disease subsets is appealing, this is not yet a reality. This review addressed current therapeutic options for SLE patients and the state of the art of investigational drugs targeting pathogenic pathways identified in these patients.

Automated detection of off-label drug use

Off-label drug use, defined as use of a drug in a manner that deviates from its approved use defined by the drug's FDA label, is problematic because such uses have not been evaluated for safety and efficacy. Studies estimate that 21% of prescriptions are off-label, and only 27% of those have evidence of safety and efficacy. We describe a data-mining approach for systematically identifying off-label usages using features derived from free text clinical notes and features extracted from two databases on known usage (Medi-Span and DrugBank). We trained a highly accurate predictive model that detects novel off-label uses among 1,602 unique drugs and 1,472 unique indications. We validated 403 predicted uses across independent data sources. Finally, we prioritize well-supported novel usages for further investigation on the basis of drug safety and cost.

In-/off-label use of biologic therapy in systemic lupus erythematosus

Current therapies for systemic lupus erythematosus (SLE) include corticosteroids as a persistent mainstay and traditional immunosuppressants which are given according to disease severity, organ involvement and patient status. No treatment entails certain efficacy devoid of mild-to-moderate adverse effects. Nowadays, novel therapies are being developed aiming to target specific molecules involved in SLE development and progression which show variable effectiveness and safety. Biologic agents considered for SLE comprise monoclonal antibodies (chimeric, humanized or fully human) as well as fusion molecules or antibody fragments mostly consisting of B cell-targeted therapies beside anti-cytokines as well as T cell-targeted therapies. Encouraging evidence on biologics is mostly provided by case series or uncontrolled studies; conversely, larger randomized controlled clinical trials have frequently missed their primary endpoints with the exception of BLISS-52 and BLISS-76 trials. Actually, apart from belimumab, biologics are employed in clinical practice as off-label treatments for lupus and results are often promising, depending on specific SLE features, dose regimens and individual responsiveness.

Lupus clinical development: will belimumab's approval catalyse a new paradigm for SLE drug development?

INTRODUCTION

Systemic lupus erythematosus (SLE) is a diverse autoimmune disease affecting many different organ systems. Although disease manifestations are varied across the lupus population, the widespread presence of autoantibodies indicates that SLE immunopathology involves B-cell dysregulation. Belimumab, a human anti-B-cell activating factor (BLyS) monoclonal antibody, was invented by Human Genome Sciences and co-developed with GlaxoSmithKline and became, in 2011, the first new therapy approved for SLE patients in over 50 years.

AREAS COVERED

Belimumab approval represents a milestone as a new treatment for a subset of SLE patients and also a window onto the continued unmet need for many patients suffering from this diverse disease. This paper analyses the drugs and clinical trials of industry-sponsored development programs to profile the current SLE landscape and to consider how belimumab is shaping the future of SLE drug development.

EXPERT OPINION

Our analysis demonstrates that the belimumab clinical program created a model for improvements in study designs that is reflected in ongoing clinical trials sponsored by a broad range of companies. Additional BLyS inhibitors, with distinctive targeting characteristics, are now in late stage development. A broad range of drugs with other mechanisms of action are also under investigation in Phase II - III trials, some of which are focused on the underserved lupus nephritis population.

Biologics in SLE: towards new approaches

In recent years the use of biologic therapies in the management of systemic lupus erythematosus (SLE) has increased, and a number of clinical trials have highlighted both the potential and the pitfalls in the development of such agents. Many investigators reported that the off-label use of rituximab seemed promising in patients with refractory disease, but randomised trials with this agent failed. Likewise, the theoretical appeal of the co-stimulation blocker abatacept could not be confirmed in two clinical trials. Various considerations and post hoc analyses nonetheless suggest that these two biologics might have a role in the treatment of SLE. The anti-B-lymphocyte stimulator (anti-Blys) antibody belimumab demonstrated efficacy and safety in two large randomised trials and became the first approved biologic for lupus. Use in clinical practice has increased slowly, in part, due to uncertainty over which patients should be treated with this agent and in what stage of the disease. Finally, several other biologic agents are currently in advanced stages of clinical development for SLE. The overall picture that emerges is one of optimism that advances in SLE therapy will be realised through the targeted use of an increasing number of biologics.

Current management of lupus nephritis

Despite decades of clinical research aimed at finding the most appropriate immunosuppressive regime, lupus nephritis (LN) remains one of the major disease manifestations of systemic lupus erythematosus (SLE) with a great impact on survival and quality of life. We start this review by defining the disease burden, the real-world challenges and the poor prognostic factors. We then discuss the current anti-inflammatory, cytotoxic and biologic therapies, with special emphasis on the need for optimal global care.

Recent developments in the treatment of patients with systemic lupus erythematosus: focusing on biologic therapies

INTRODUCTION

Major trials hoping to obtain optimal disease control in systemic lupus erythematosus (SLE) are ongoing. Given its complex aetiology and pathogenesis, it is not surprising that multiple therapeutic targets have emerged and that none are uniformly successful.

AREAS COVERED

In this review, we highlight the recent, more significant studies focusing on the use of biologic therapies. There has been great emphasis on the role of B cells in SLE and many uncontrolled studies have encouraged the use of rituximab (an anti-CD20 monoclonal). Disappointingly, two major trials, EXPLORER and LUNAR did not confirm its utility, although doubts have been expressed on their trial design, and other trials using this drug are commencing. In contrast, belimumab, which blocks a B-cell activating factor, did meet its end points in two major randomised controlled clinical trials and has been approved for use in SLE by both the FDA and the European Medicines Agency. Encouraging, albeit preliminary, results with epratuzumab (which blocks CD22) have also been reported.

EXPERT OPINION

In addition to targeting B cells, other approaches including biologics, which modulate T-cell function and block interleukin-6 and interferon-α, have been explored. Finally, we review the recent developments in the use of conventional drugs, such as cyclophosphamide and mycophenolate.

Targeting co-stimulatory pathways: transplantation and autoimmunity

The myriad of co-stimulatory signals expressed, or induced, upon T-cell activation suggests that these signalling pathways shape the character and magnitude of the resulting autoreactive or alloreactive T-cell responses during autoimmunity or transplantation, respectively. Reducing pathological T-cell responses by targeting T-cell co-stimulatory pathways has met with therapeutic success in many instances, but challenges remain. In this Review, we discuss the T-cell co-stimulatory molecules that are known to have critical roles during T-cell activation, expansion, and differentiation. We also outline the functional importance of T-cell co-stimulatory molecules in transplantation, tolerance and autoimmunity, and we describe how therapeutic blockade of these pathways might be harnessed to manipulate the immune response to prevent or attenuate pathological immune responses. Ultimately, understanding the interplay between individual co-stimulatory and co-inhibitory pathways engaged during T-cell activation and differentiation will lead to rational and targeted therapeutic interventions to manipulate T-cell responses and improve clinical outcomes.

Immunomodulatory drugs: oral and systemic adverse effects

OBJECTIVE

The main objectives are to present the different adverse effects of the immunomodulatory drugs that can impair the quality of life of the immunosuppressed patients and study the impact of immunomodulation on oral diseases. Immunomodulatory drugs have changed the treatment protocols of many diseases where immune functions play a central role, such as rheumatic diseases. Their effect on oral health has not been systematically investigated, however.

STUDY DESIGN

We review current data on the new immunomodulatory drugs from the oral health perspective based on open literature search of the topic.

RESULTS

These target specific drugs appear to have less drug interactions than earlier immunomodulating medicines but have nevertheless potential side effects such as activating latent infections. There are some data showing that the new immunomodulatory drugs may also have a role in the treatment of certain oral diseases such as lichen planus or ameliorating symptoms in Sjögren's syndrome, but the results have not been overly promising.

CONCLUSION

In general, data are sparse of the effect of these new drugs vs. oral diseases and there are no properly powered randomized controlled trials published on this topic.

Immune checkpoint receptors in regulating immune reactivity in rheumatic disease

Immune checkpoint regulators are critical modulators of the immune system, allowing the initiation of a productive immune response and preventing the onset of autoimmunity. Co-inhibitory and co-stimulatory immune checkpoint receptors are required for full T-cell activation and effector functions such as the production of cytokines. In autoimmune rheumatic diseases, impaired tolerance leads to the development of diseases such as rheumatoid arthritis, systemic lupus erythematosus, and Sjogren's syndrome. Targeting the pathways of the inhibitory immune checkpoint molecules CD152 (cytotoxic T lymphocyte antigen-4) and CD279 (programmed death-1) in cancer shows robust anti-tumor responses and tumor regression. This observation suggests that, in autoimmune diseases, the converse strategy of engaging these molecules may alleviate inflammation owing to the success of abatacept (CD152-Ig) in rheumatoid arthritis patients. We review the preclinical and clinical developments in targeting immune checkpoint regulators in rheumatic disease.

Efficacy of abatacept for arthritis in patients with an overlap syndrome between rheumatoid arthritis and systemic lupus erythematosus

Introduction. This study aimed to investigate the efficacy of abatacept for arthritis in patients with rhupus, an overlap syndrome between rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Methods. Patients who fulfilled both the 2010 ACR/EULAR criteria for RA classification and the 1997 ACR revised criteria for classification of SLE and received abatacept treatment for arthritis were retrospectively studied. Results. Six rhupus patients who fulfilled the inclusion criteria above were identified. All patients had active arthritis despite receiving antirheumatic drugs including methotrexate when abatacept was initiated. Clinical Disease Activity Index (CDAI) significantly decreased between baseline and 12 weeks (P = 0.028) and remained low through 24 weeks. All patients achieved either a good or moderate response according to the EULAR response criteria at 24 weeks. Health Assessment Questionnaire-Disability Index (HAQ-DI) also significantly decreased between baseline and 24 weeks (P = 0.043). In addition, the levels of immunoglobulin G and anti-DNA antibody significantly decreased between baseline and 24 weeks (P = 0.028 and P = 0.043, resp.). Conclusions. Treatment with abatacept is likely to be efficacious in patients with rhupus whose arthritis is refractory to methotrexate. In addition, abatacept may have a moderate effect on abnormal antibody production in rhupus patients.

[Established medications : new areas of application]

During the last 10 years several new medications from hemato-oncology and transplantation medicine have been transferred to rheumatology. Additionally, medications which are approved for rheumatoid arthritis were increasingly also studied and used for other systemic inflammatory rheumatic diseases. This is especially the case for rituximab and mycophenolate and to a lesser extent also for leflunomide, tumor necrosis factor (TNF) antagonists, tocilizumab and abatacept. Recently, rituximab was approved for severe granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) after the publication of two prospective randomized trials in 2010. The situation concerning rituximab is much more problematic for systemic lupus erythematosus (SLE) where randomized placebo-controlled trials exist but unfortunately did not meet the primary endpoint requirements (too many highly effective additional forms of treatment in both arms and unsuitable endpoints), although data from registries suggest efficacy especially in cases resistant to treatment. In the case of mycophenolate (MPS) the problem with SLE is totally different. All prospective trials met the endpoints and in one trial MPS was even superior to azathioprine for treatment of lupus nephritis (LN) which led to the recommendation of MPS for induction and maintenance in LN by EULAR and EDTRA as well as more recently by the ACR. However, MPS still is not approved for SLE or LN. The present manuscript gives an overview of existing data for selected connective tissue diseases and vasculitides (for which at least larger retrospective case series or registry data exist) being treated with medications approved for other indications.