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

Treatment of systemic lupus erythematosus: new advances in targeted therapy

Treatment for systemic lupus erythematosus (SLE) has traditionally been restricted to broad-based immunosuppression, with glucocorticoids being central to care. Recent insights into lupus pathogenesis promise new, selective therapies with more favorable side effect profiles. The best example of this is belimumab, which targets the B cell cytokine BLyS and has now received Food and Drug Administration (FDA) approval for its use in SLE. Strategies targeting other cytokines, such as interleukin 6 (IL-6) and interferon (IFN)-α, are also on the horizon. Blockade of costimulatory interactions between immune cells offers another opportunity for therapeutic intervention, as do small molecule inhibitors that interfere with cell signaling pathways. We review here the current strategies for SLE treatment, with particular focus on therapies now in active pharmaceutical development. We will also discuss new understandings in lupus pathogenesis that may lead to future advances in therapy.

BAFF and innate immunity: new therapeutic targets for systemic lupus erythematosus

Recently, the B cell has emerged as a cornerstone of systemic lupus erythematosus (SLE) pathogenesis. This has been highlighted by studies of the cytokine B-cell-activating factor of the tumour necrosis factor (TNF) family (BAFF), a crucial factor regulating B-cell maturation, survival and function. Overexpression of BAFF in mice leads to the development of an SLE-like disease, independent of T cells but instead relying on innate immunity mechanisms. Moreover, BAFF has been shown to be elevated in the serum of patients suffering from autoimmune conditions, especially SLE, and may correlate with disease activity. These findings challenge the previous notion that T:B-cell collaboration is the sole driver of SLE. In recent years, controlled trials have for the first time tested targeted therapeutics for SLE. However, agents designed to target B cells failed to meet primary endpoints in clinical trials in SLE, suggesting that a more complex role for B cells in SLE awaited elucidation. By contrast, on 9 March 2011, the US Food and Drug Administration approved belimumab, a fully human anti-BAFF monoclonal antibody, as a new B-cell-specific treatment for SLE. This article will review over 10 years of research on the BAFF system, key findings that led to this recent positive clinical outcome and propose a model potentially explaining why this B-cell-specific therapy has yielded positive results in clinical trials. We will also review promising therapies presently in clinical trials targeting innate immunity, which are likely to revolutionize SLE management towards a personalized and targeted therapy approach.

[What's new in internal medicine: emerging treatments for systemic lupus erythematosus]

Today corticosteroids plus hydroxychloroquine are the cornerstone in the treatment of Systemic Lupus Erythematosus (SLE). In severe cases, particularly in proliferative glomerulonephritis, cyclophosphamide or mycofenolate mofetil are used in induction and mycofenolate mofetil or azathioprine are used to maintain the remission. Corticosteroid sparing is an important goal. New and future treatments of SLE focus on B and T cells down regulation and co-stimulation, cytokine inhibition, and open the concept of immune vaccination. However, positive phase III randomized studies in SLE remain rare. Rituximab (a chimeric monoclonal anti-CD 20 antibody) was the first promising biologic agent showing interesting results in large case series but 2 phases III randomised studies didn't reach their primary objective. This probably emphasizes the limit of the current tools used for the evaluation of the disease and point out the design of the studies using high dose of corticosteroids, immunosuppressive drugs and the use of rituximab as add on treatment and are not face to face with conventional treatment. Abatacept (CTLA4-Ig) also failed to meet its primary end point in a randomised controlled trial in non-nephritis SLE. A post-hoc analysis suggests however that abatacept may be beneficial in lupus patients with arthritis however, it will probably never be approved for that indication. Belimumab (a human monoclonal antibody to BLyS) is the first biologic agent which reached its primary end point in 2 different randomised controlled trials using a new index for the evaluation of the activity of the diseases taking into account the physicians judgement (SLE responder index). Lots of phase I/II studies are currently ongoing particular targeting on interferon alpha, interleukin 6, B cell CD22 and C5 complement component.

Measuring outcomes in systemic lupus erythematosus clinical trials

The recent approval of the biologic therapy, belimumab, for treatment of systemic lupus erythematosus (SLE) by the US FDA has shifted the developmental landscape of therapeutics for this autoimmune disease. Promising therapies are currently in development for the treatment of SLE, with trials designed to emphasize clinically relevant end points. This article will discuss outcome measures that have been utilized including disease activity indices, definitions of flare, measures of damage, global assessments of disease activity and measures of health-related quality of life. Application of these outcome measures in recent trials are highlighted as illustrative examples. Contributions to the recent success of randomized controlled trials in SLE have included use of evidence-based responder indices, clear definitions of treatment failure, predefined management strategies for use of immunosuppressive agents and corticosteroids, sufficient sample sizes and efforts to identify responsive patient populations. Each completed study in SLE promises to better inform trial design and offer further opportunities for success in a field with a continuing unmet therapeutic need.

Current state of evidence on 'off-label' therapeutic options for systemic lupus erythematosus, including biological immunosuppressive agents, in Germany, Austria and Switzerland--a consensus report

Systemic lupus erythematosus (SLE) can be a severe and potentially life-threatening disease that often represents a therapeutic challenge because of its heterogeneous organ manifestations. Only glucocorticoids, chloroquine and hydroxychloroquine, azathioprine, cyclophosphamide and very recently belimumab have been approved for SLE therapy in Germany, Austria and Switzerland. Dependence on glucocorticoids and resistance to the approved therapeutic agents, as well as substantial toxicity, are frequent. Therefore, treatment considerations will include 'off-label' use of medication approved for other indications. In this consensus approach, an effort has been undertaken to delineate the limits of the current evidence on therapeutic options for SLE organ disease, and to agree on common practice. This has been based on the best available evidence obtained by a rigorous literature review and the authors' own experience with available drugs derived under very similar health care conditions. Preparation of this consensus document included an initial meeting to agree upon the core agenda, a systematic literature review with subsequent formulation of a consensus and determination of the evidence level followed by collecting the level of agreement from the panel members. In addition to overarching principles, the panel have focused on the treatment of major SLE organ manifestations (lupus nephritis, arthritis, lung disease, neuropsychiatric and haematological manifestations, antiphospholipid syndrome and serositis). This consensus report is intended to support clinicians involved in the care of patients with difficult courses of SLE not responding to standard therapies by providing up-to-date information on the best available evidence.

Mechanisms of B cell autoimmunity in SLE

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that is known to be associated with polyclonal B-cell hyperreactivity. The underlying causes of the diffuse B-cell over-reactivity are unclear, but potential candidates include (a) intrinsic hyper-reactivity leading to polyclonal B-cell activation with disturbed activation thresholds and ineffective negative selection; (b) lack of immunoregulatory functions; (c) secondary effects of an overactive inflammatory environment, such as overactive germinal center and ectopic follicular activity; and/or (d) disturbed cytokine production by non-B immune cells. These mechanisms are not mutually exclusive and may operate to varying extents and at varying times in SLE. Phenotypic and molecular studies as well as the results of recent clinical trials have begun to provide new insights to address these possibilities. Of importance, new information has made it possible to distinguish between the contribution played by abnormalities in central checkpoints that could lead to a pre-immune repertoire enriched in autoreactive B cells, on the one hand, and the possibility that autoimmunity arises in the periphery from somatic hypermutation and abnormal selection during T cell-dependent B-cell responses on the other. There is an intriguing possibility that apoptotic material bound to the surface of follicular dendritic cells positively selects autoreactive B cells that arise from non-autoreactive B-cell precursors as a result of somatic hypermutation and thereby promotes the peripheral emergence of autoimmunity.

Treatment of mild, moderate, and severe lupus erythematosus: focus on new therapies

Despite large-scale efforts devoted to the conduct of clinical trials in systemic lupus erythematosus (SLE), no new therapy has been approved for treatment of this disease in more than 50 years. Increased understanding of the immunologic mechanisms underlying SLE has led to the development of a variety of biologic agents that target specific aspects of the adaptive and innate arms of the immune system, including B cells, T cells, dendritic cells, and various cytokines. One of these agents, belimumab, was the subject of two positive phase 3 trials in nonrenal lupus that have given us hope that a new therapy for SLE may be finally within our grasp. In addition to these newer therapies, recent studies of standard-of-care medications such as mycophenolate mofetil and hydroxychloroquine have better defined the efficacy and safety of these agents for the treatment of lupus nephritis and nonrenal lupus. This article provides a discussion of several novel biologic agents at different stages of development for the treatment of SLE, as well as an analysis of newer data on agents that have been used in the treatment of SLE for many years.

Clinical assessment and management of cytopenias in lupus patients

Anemia, leukopenia, and/or thrombocytopenia can occur as a result of non-immune- and immune-mediated mechanisms in patients with systemic lupus erythematosus. Although the differential diagnosis of these cytopenias is broad and warrants a thorough evaluation, lupus disease activity and medications are common etiologic factors. Corticosteroids are the mainstay of initial treatment for immune-mediated hemolytic anemia and severe thrombocytopenia; immunosuppressive agents such as mycophenolate mofetil or azathioprine are often added for their steroid-sparing effects. Rituximab and intravenous immunoglobulin can be considered for refractory cytopenias based on a large body of anecdotal evidence and case series. Newer biologic agents such as belimumab or epratuzumab have yet to be studied specifically in systemic lupus erythematosus-mediated hematologic disorders.

Intrinsic and extrinsic control of peripheral T-cell tolerance by costimulatory molecules of the CD28/ B7 family

Positive and negative costimulation by members of the CD28 family is critical for the development of productive immune responses against foreign pathogens and their proper termination to prevent inflammation-induced tissue damage. In addition, costimulatory signals are critical for the establishment and maintenance of peripheral tolerance. This paradigm has been established in many animal models and has led to the development of immunotherapies targeting costimulation pathways for the treatment of cancer, autoimmune disease, and allograft rejection. During the last decade, the complexity of the biology of costimulatory pathways has greatly increased due to the realization that costimulation does not affect only effector T cells but also influences regulatory T cells and antigen-presenting cells. Thus, costimulation controls T-cell tolerance through both intrinsic and extrinsic pathways. In this review, we discuss the influence of costimulation on intrinsic and extrinsic pathways of peripheral tolerance, with emphasis on members of the CD28 family, CD28, cytotoxic T-lymphocyte antigen-4 (CTLA-4), and programmed death-1 (PD-1), as well as the downstream cytokine interleukin-1 (IL-2).

Epidemiology and management of refractory lupus nephritis

Although the survival of patients with lupus nephritis (LN) has improved considerably in recent years, refractory LN appears in a substantial proportion of patients and, therefore, treatment of LN remains a real challenge today. We will use the term "refractory" LN, for those cases with none or partial response to first-line therapies. In this sense, numerous epidemiological factors, including racial, socioeconomic, histological and serological parameters, may influence treatment response and, therefore, may have an impact on the outcome of renal involvement. Initial conventional therapy will depend somewhat on these epidemiological factors. If this initial therapy fails, fortunately today we have alternative therapies that include the multitarget therapy and the use of biologics. Published evidence about these therapies is presented in this review. Important terms in the management of LN, such as the definition of complete response, partial response, sustained response and renal flare as well as the discrimination of different types of flare, are also discussed here according to the European consensus statement on the terminology used in the management of lupus glomerulonephritis.

The genetics of systemic lupus erythematosus and implications for targeted therapy

Observations of familial aggregation (λs=8-29) and a 40% identical twin concordance rate prompted recent work towards a comprehensive genetic analysis of systemic lupus erythematosus (SLE). Since 2007, the number of genetic effects known to be associated with human lupus has increased by fivefold, underscoring the complexity of inheritance that probably contributes to this disease. Approximately 35 genes associated with lupus have either been replicated in multiple samples or are near the threshold for genome-wide significance (p > 5 x 10⁻⁸). Some are rare variants that convincingly contribute to lupus only in specific subgroups. Strong associations have been found with a large haplotype block in the human leucocyte antigen region, with Fcγ receptors, and with genes coding for complement components, in which a single gene deletion may cause SLE in rare familial cases and copy number variation is more common in the larger population of SLE patients. Examples of newly discovered genes include ITGAM, STAT4 and MECP2/IRAK1. Ongoing studies to build models in which combinations of associated genes might contribute to specific disease manifestations should contribute to improved understanding of disease pathology. In addition, pharmacogenomic components of ongoing clinical trials are likely to provide insights into fundamental disease pathology as well as contributing to informed patient selection for targeted treatments and biomarkers to guide dosing and gauge responsiveness. Besides these potentially valuable new insights into the pathophysiology of an enigmatic, potentially deadly, and, as yet, unsolved disease, genetic studies are likely to suggest novel molecular targets for strategic development of safer and more effective therapeutics.

Targeted therapies in systemic lupus erythematosus: successes, failures and future

PURPOSE

The author's goal is to review recent phase III clinical trials in patients with systemic lupus erythematosus (SLE), with emphasis on outcomes and on mechanisms by which the experimental drugs/biological agents suppress autoimmunity.

METHODS

Prospective, randomised, controlled clinical trials in SLE published in the past 3 years identified in a PubMed search were reviewed, as well as abstracts describing similar but currently unpublished clinical trials presented at international meetings 2008-10.

CONCLUSIONS

Two interventions have been proved in large multicentre prospective trials to be useful in the management of SLE: mycophenolate mofetil (equivalent to cyclophosphamide with a similar safety profile) and anti-BLyS (Benlysta), which was superior to placebo when added to background immunosuppression and did not appear to increase toxicity. The anti-BLyS trial outcome measure was an anchored composite index that required reduction of disease activity measure by the systemic lupus erythematosus disease activity index. Other trials that failed or the results of which are pending are also discussed.

Advances in drug therapy for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder that afflicts 500,000 people in the United States. There has not been a new SLE drug approved in the United States since 1958. However, a guidance document issued by the Food and Drug Administration in 2005 provided a roadmap for investigators which spawned numerous ongoing clinical trials. Among these, Belimumab, a monoclonal antibody to soluble B lymphocyte stimulator, met its primary endpoints in two large trials and will probably obtain FDA approval soon. Other promising agents targeting a variety of mechanisms of action are currently in development. This minireview highlights the latest therapies under investigation in SLE and gives an overview of the pathways that are specifically being targeted.

Immunotherapy of systemic sclerosis

Scleroderma is a multisystem autoimmune disease characterized by an abnormal immune activation associated with the development of underlying vascular and fibrotic disease manifestations. This article highlights the current use of drugs targeting the immune system in scleroderma. Nonselective immunosuppression, and in particular cyclophosphamide, remains the main treatment for progressing skin involvement and active interstitial lung disease. Mycophenolate mofetil is a promising alternative to cyclophosphamide. The use of cyclosporine has been limited by modest efficacy and serious renal toxicity. Newer T-cell (sirolimus and alefacept) and B-cell (rituximab)-targeted therapies have provided some encouraging results in small pilot studies. Hematopoietic stem cell transplantation can be effective for severe fibrotic skin disease, but toxicity remains a concern. Clinical efficacy and safety of antifibrotic treatments (e.g., imatinib) await confirmation. Newer biological agents targeting key molecular or cellular effectors in scleroderma pathogenesis are now available for clinical testing.