Treatment of systemic lupus erythematosus patients with the BAFF antagonist "peptibody" blisibimod (AMG 623/A-623): results from randomized, double-blind phase 1a and phase 1b trials

Past and present discovery of the BAFF/APRIL system - A bibliometric study from 1999 to 2023

Cytokines from the Tumour Necrosis Factor (TNF) family are important regulators of both physiological and pathological processes. The discovery of novel TNF ligands and receptors, BAFF and APRIL, have opened up new possibilities for scientists to explore the effect of these cytokines on the human immune system. The role of BAFF/APRIL system in B lymphocytes is particularly important for survival and maintenance of homeostasis. Aberrant expression of the system is associated with various immunological disorders. Hence, this study provides a comprehensive overview of the past and present BAFF/APRIL system research development in a bibliometric perspective. To our best knowledge, this is the first ever bibliometric analysis conducted focusing on the BAFF/APRIL system. A total of 1055 relevant documents were retrieved from WoSCC. Microsoft Excel, VOSviewer, and Biblioshiny of R studio were bibliometric tools used to analyse the scientific literature. From 1999, the annual publications showed an upward trend, with Journal of Immunology being the most productive journal. USA leads the race for BAFF/APRIL system research developments. Pascal Schneider, a senior researcher affiliated with University of Lausanne, Switzerland was recognised as the most productive author and institution in the BAFF/APRIL system research field. The research focus transitioned from focusing on the role of the system in B cell biology, to immunological disorders and finally to development of BAFF/APRIL targeting drugs. Despite several studies elucidating briefly the pathway mechanism of BAFF/APRIL system in B-cell selection, substantial research on the mechanism of action in disease models and T cell activation and development of immunomodulating drugs from natural origins remains largely unexplored. Therefore, future research focusing on these areas are crucial for the deeper understanding of the system in disease manifestations and progression allowing a better treatment management for various immunological disorders.

Anti-B-Cell-Activating Factor (BAFF) Therapy: A Novel Addition to Autoimmune Disease Management and Potential for Immunomodulatory Therapy in Warm Autoimmune Hemolytic Anemia

Although rituximab is not specifically approved for the treatment of warm autoimmune hemolytic anemia (WAIHA), the First International Consensus Group recommends considering its use as part of the initial therapy for patients with severe disease and as a second-line therapy for primary WAIHA. Some patients do not respond to rituximab, and relapses are common. These relapses are associated with elevated B-cell-activating factor (BAFF) levels and the presence of quiescent long-lived plasma cells (LLPCs) in the spleen. A new group of immunomodulatory drugs, B-cell-activating factor inhibitors (BAFF-i), demonstrated efficacy in multiple autoimmune diseases and have the potential to improve WAIHA treatment outcomes by targeting B-cells and LLPCs. This article reviews the role of BAFF in autoimmune disorders and the currently available literature on the use of BAFF-directed therapies in various immunologic disorders, including WAIHA. Collectively, the clinical data thus far shows robust potential for targeting BAFF in WAIHA therapy.

A Quantitative Prediction Method for the Human Pharmacokinetics of Fc-Fusion Proteins

BACKGROUND AND OBJECTIVE

Fc fusion is an effective strategy for extending the half-lives of therapeutic proteins. This study aimed to evaluate the applicability of a human pharmacokinetics prediction method for Fc-fusion proteins by extending on reported methods for monoclonal antibodies (mAbs).

METHODS

To predict human pharmacokinetic profiles following intravenous (IV) dosing, the pharmacokinetic data for 11 Fc-fusion proteins in monkeys were analysed by two approaches: a species-invariant time method with a range of allometric exponents in clearance (CL, 0.7-1.0) and a two-compartment model reported for mAbs. The pharmacokinetic profiles following subcutaneous (SC) dosing were predicted by simple dose normalisation from monkeys or using the geometric means of the absorption rate constant (Ka) and bioavailability (BA) for mAbs or Fc-fusion proteins in humans and compared.

RESULTS

In the case of IV administration, the area under the curve could be predicted for more than 85% of Fc-fusion proteins within a twofold difference from the observed value using the species-invariant time method (scaling exponent for CL, 0.95). For SC dosing, incorporating the geometric means of absorption parameters for both mAbs (BA 68.2%, Ka 0.287 day-1) and Fc-fusion proteins (BA 63.0%, Ka 0.209 day-1) in humans provided better accuracy than simple normalisation from monkeys.

CONCLUSION

We have successfully predicted the human pharmacokinetic profiles of Fc-fusion proteins for both IV and SC administration within twofold of the observed value from monkey pharmacokinetic data by extending on reported methods for mAbs. This method will facilitate drug discovery and development of Fc-fusion proteins.

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

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

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

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

A randomized, phase II study of sequential belimumab and rituximab in primary Sjögren's syndrome

BACKGROUNDPrimary Sjögren's syndrome (pSS) is characterized by B cell hyperactivity and elevated B-lymphocyte stimulator (BLyS). Anti-BLyS treatment (e.g., belimumab) increases peripheral memory B cells; decreases naive, activated, and plasma B cell subsets; and increases stringency on B cell selection during reconstitution. Anti-CD20 therapeutics (e.g., rituximab) bind and deplete CD20-expressing B cells in circulation but are less effective in depleting tissue-resident CD20+ B cells. Combined, these 2 mechanisms may achieve synergistic effects.METHODSThis 68-week, phase II, double-blind study (GSK study 201842) randomized 86 adult patients with active pSS to 1 of 4 arms: placebo, s.c. belimumab, i.v. rituximab, or sequential belimumab + rituximab.RESULTSOverall, 60 patients completed treatment and follow-up until week 68. The incidence of adverse events (AEs) and drug-related AEs was similar across groups. Infections/infestations were the most common AEs, and no serious infections of special interest occurred. Near-complete depletion of minor salivary gland CD20+ B cells and a greater and more sustained depletion of peripheral CD19+ B cells were observed with belimumab + rituximab versus monotherapies. With belimumab + rituximab, reconstitution of peripheral B cells occurred, but it was delayed compared with rituximab. At week 68, mean (± standard error) total EULAR Sjögren's syndrome disease activity index scores decreased from 11.0 (1.17) at baseline to 5.0 (1.27) for belimumab + rituximab and 10.4 (1.36) to 8.6 (1.57) for placebo.CONCLUSIONThe safety profile of belimumab + rituximab in pSS was consistent with the monotherapies. Belimumab + rituximab induced enhanced salivary gland B cell depletion relative to the monotherapies, potentially leading to improved clinical outcomes.TRIAL REGISTRATIONClinicalTrials.gov NCT02631538.FUNDINGFunding was provided by GSK.

Reductions in circulating B cell subsets and immunoglobulin G levels with long-term belimumab treatment in patients with SLE

Objective

To examine the long-term changes in circulating B cell subsets and IgG levels at 5+ years of continuous belimumab treatment and their correlations with efficacy and safety measures.

Methods

This was a post hoc analysis of a continuation study (BEL112233; NCT00724867) of eligible US patients who completed the 76-week BLISS-76 Study (BEL110751; NCT00410384), with up to eight calendar-years of follow-up and median (IQR) belimumab exposure of 310 (209, 364) weeks. From week 76, patients initially randomised to intravenous belimumab 1 mg/kg or 10 mg/kg every 4 weeks in BLISS-76 continued to receive the same dose in the continuation study, while those initially randomised to placebo received belimumab 10 mg/kg intravenous every 4 weeks during continuation. All patients continued to receive standard SLE therapy. Biomarker data were collected, and the effects on baseline and early changes (weeks 0–24 after starting belimumab) from baseline in biomarkers on SLE Responder Index (SRI-4) and infection rate were evaluated.

Results

Of the 819 patients from BLISS-76, 268 self-selecting patients entered BEL112233. Compared with baseline, B cell subset counts decreased by 40%–99% after 312 weeks (6 years), and serum IgG levels decreased by 28% after 284 weeks. Higher baseline naïve B cell counts were associated with greater SRI-4 response rates (p<0.05), whereas higher baseline SLE subset plasma and short-lived plasma B cell counts were associated with lower SRI-4 response rates (p<0.05). Elevated baseline IgG levels were associated with increased infection rates over the treatment period (p<0.05), and early greater decreases in IgG levels were associated with higher SRI-4 response rates (p<0.05).

Conclusions

Belimumab treatment up to 312 weeks (6 years) resulted in substantial decreases in several circulating B cell subsets and IgG levels. Higher baseline naïve B cell counts and IgG levels were associated with improved SRI-4 response and increased infection rates, respectively.

Review article: targeting the B cell activation system in autoimmune hepatitis

BACKGROUND

The B cell activation system, consisting of B cell activating factor and a proliferation-inducing ligand, may have pathogenic effects in autoimmune hepatitis.

AIMS

To describe the biological actions of the B cell activation system, indicate its possible role in autoimmune diseases, and evaluate its prospects as a therapeutic target in autoimmune hepatitis METHODS: English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed.

RESULTS

The B cell activating factor is crucial for the maturation and survival of B cells, and it can co-stimulate T cell activation, proliferation, and survival. It can also modulate the immune response by inducing interleukin 10 production by regulatory B cells. A proliferation-inducing ligand modulates and diversifies the antibody response by inducing class-switch recombination in B cells. It can also increase the proliferation, survival, and antigen activation of T cells. These immune stimulatory actions can be modulated by inducing proliferation of regulatory T cells. The B cell activation system has been implicated in diverse autoimmune diseases, and therapeutic blockade is a management strategy now being evaluated in autoimmune hepatitis.

CONCLUSIONS

The B cell activation system has profound effects on B and T cell function in autoimmune diseases. Blockade therapy is being actively evaluated in autoimmune hepatitis. Clarification of the critical pathogenic components of the B cell activation system will improve the targeting, efficacy, and safety of blockade therapy in this disease.

B Cell Aberrance in Lupus: the Ringleader and the Solution

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease with high heterogeneity but the common characterization of numerous autoantibodies and systemic inflammation which lead to the damage of multiple organs. Aberrance of B cells plays a pivotal role in the immunopathogenesis of SLE via both antibody-dependent and antibody-independent manners. Escape of autoreactive B cells from the central and peripheral tolerance checkpoints, over-activation of B cells and their excessive cytokines release which drive T cells and dendritic cells stimulation, and dysregulated surface molecules, as well as intracellular signal pathways involved in B cell biology, are all contributing to B cell aberrance and participating in the pathogenesis of SLE. Based on that rationale, targeting aberrance of B cells and relevant molecules and pathways is expected to be a promising strategy for lupus control. Multiple approaches targeting B cells through different mechanisms have been attempted, including B-cell depletion via monoclonal antibodies against B-cell-specific molecules, blockade of B-cell survival and activation factors, suppressing T-B crosstalk by interrupting costimulatory molecules and inhibiting intracellular activation signaling cascade by targeting pathway molecules in B cells. Though most attempts ended in failure, the efficacy of B-cell targeting has been encouraged by the FDA approval of belimumab that blocks B cell-activating factor (BAFF) and the recommended use of anti-CD20 as a remedial therapy in refractory lupus. Still, quantities of clinical trials targeting B cells or relevant molecules are ongoing and some of them have displayed promising preliminary results. Additionally, advances in multi-omics studies help deepen our understandings of B cell biology in lupus and may promote the discovery of novel potential therapeutic targets. The combination of real-world data with basic research achievements may pave the road to conquering lupus.

A Comprehensive Review of Biological Agents for Lupus: Beyond Single Target

Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multiple immune cells. Due to its complex pathogenesis, the effectiveness of traditional treatment methods is limited. Many patients have developed resistance to conventional treatment or are not sensitive to steroid and immunosuppressant therapy, and so emerging therapeutic antibodies have become an alternative and have been shown to work well in many patients with moderate and severe SLE. This review summarizes the biological agents that are in the preclinical and clinical trial study of SLE. In addition to the various monoclonal antibodies that have been studied for a long time, such as belimumab and rituximab, we focused on another treatment for SLE, bispecific antibodies (BsAbs) such as tibulizumab, which simultaneously targets multiple pathogenic cytokines or pathways. Although the application of BsAbs in cancer has been intensively studied, their application in autoimmune diseases is still in the infant stage. This unique combined mechanism of action may provide a novel therapeutic strategy for SLE.

Targeting co-stimulatory molecules in autoimmune disease

Therapeutic targeting of immune checkpoints has garnered significant attention in the area of cancer immunotherapy, in which efforts have focused in particular on cytotoxic T lymphocyte antigen 4 (CTLA4) and PD1, both of which are members of the CD28 family. In autoimmunity, these same pathways can be targeted to opposite effect: to curb the over-exuberant immune response. The CTLA4 checkpoint serves as an exemplar, whereby CTLA4 activity is blocked by antibodies in cancer immunotherapy and augmented by the provision of soluble CTLA4 in autoimmunity. Here, we review the targeting of co-stimulatory molecules in autoimmune diseases, focusing in particular on agents directed at members of the CD28 or tumour necrosis factor receptor families. We present the state of the art in co-stimulatory blockade approaches, including rational combinations of immune inhibitory agents, and discuss the future opportunities and challenges in this field.

Therapeutic peptides for the treatment of systemic lupus erythematosus: a place in therapy

INTRODUCTION

Studies in vitro and in vivo have identified several peptides that are potentially useful in treating systemic lupus erythematosus (SLE). The rationale for their use lies in the cost-effective production, high potency, target selectivity, low toxicity, and a peculiar mechanism of action that is mainly based on the induction of immune tolerance. Three therapeutic peptides have entered clinical development, but they have yielded disappointing results. However, some subsets of patients, such as those with the positivity of anti-dsDNA antibodies, appear more likely to respond to these medications.

AREAS COVERED

This review evaluates the potential use of therapeutic peptides for SLE and gives an opinion on how they may offer advantages for SLE treatment.

EXPERT OPINION

Given their acceptable safety profile, therapeutic peptides could be added to agents traditionally used to treat SLE and this may offer a synergistic and drug-sparing effect, especially in selected patient populations. Moreover, they could temporarily be utilized to manage SLE flares, or be administered as a vaccine in subjects at risk. Efforts to ameliorate bioavailability, increase the half-life and prevent immunogenicity are ongoing. The formulation of hybrid compounds, like peptibodies or peptidomimetic small molecules, is expected to yield renewed treatments with a better pharmacologic profile and increased efficacy.

DNA Damage and Deficiencies in the Mechanisms of Its Repair: Implications in the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a perplexing and potentially severe disease, the pathogenesis of which is yet to be understood. SLE is considered to be a multifactorial disease, in which genetic factors, immune dysregulation, and environmental factors, such as ultraviolet radiation, are involved. Recently, the description of novel genes conferring susceptibility to develop SLE even in their own (monogenic lupus) has raised the interest in DNA dynamics since many of these genes are linked to DNA repair. Damage to DNA induces an inflammatory response and eventually triggers an immune response, including those targeting self-antigens. We review the evidence that indicates that patients with SLE present higher levels of DNA damage than normal subjects do and that several proteins involved in the preservation of the genomic stability show polymorphisms, some of which increase the risk for SLE development. Also, the experience from animal models reinforces the connection between DNA damage and defective repair in the development of SLE-like disease including characteristic features such as anti-DNA antibodies and nephritis. Defining the role of DNA damage response in SLE pathogenesis might be strategic in the quest for novel therapies.

Recent advances in the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease presenting highly heterogeneous clinical manifestations and multi-systemic involvement. Patients are susceptible to relapse- and remission, thus making management challenging. Moreover, a considerable number of side effects may occur with conventional therapies; therefore, there is clearly a need for new therapeutic strategies. Since the pathogenesis of SLE is highly complex, it is far from being fully understood. However, greater understanding of the pathways and of the cellular and molecular mediators involved in SLE is being achieved. Emerging evidence has allowed the development of new biological therapeutic options targeting crucial molecular mediators involved in the pathogenesis of SLE. This literature review analyzes the availability of biological and target-directed treatments, phase II and III trials, and new therapies that are being developed for the treatment of SLE.

Toward Small-Molecule Inhibition of Protein-Protein Interactions: General Aspects and Recent Progress in Targeting Costimulatory and Coinhibitory (Immune Checkpoint) Interactions

Protein-Protein Interactions (PPIs) that are part of the costimulatory and coinhibitory (immune checkpoint) signaling are critical for adequate T cell response and are important therapeutic targets for immunomodulation. Biologics targeting them have already achieved considerable clinical success in the treatment of autoimmune diseases or transplant recipients (e.g., abatacept, belatacept, and belimumab) as well as cancer (e.g., ipilimumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab). In view of such progress, there have been only relatively limited efforts toward developing small-molecule PPI inhibitors (SMPPIIs) targeting these cosignaling interactions, possibly because they, as all other PPIs, are difficult to target by small molecules and were not considered druggable. Nevertheless, substantial progress has been achieved during the last decade. SMPPIIs proving the feasibility of such approaches have been identified through various strategies for a number of cosignaling interactions including CD40-CD40L, OX40-OX40L, BAFFR-BAFF, CD80-CD28, and PD-1-PD-L1s. Here, after an overview of the general aspects and challenges of SMPPII-focused drug discovery, we review them briefly together with relevant structural, immune-signaling, physicochemical, and medicinal chemistry aspects. While so far only a few of these SMPPIIs have shown activity in animal models (DRI-C21045 for CD40-D40L, KR33426 for BAFFR-BAFF) or reached clinical development (RhuDex for CD80-CD28, CA-170 for PD-1-PD-L1), there is proof-of-principle evidence for the feasibility of such approaches in immunomodulation. They can result in products that are easier to develop/ manufacture and are less likely to be immunogenic or encounter postmarket safety events than corresponding biologics, and, contrary to them, can even become orally bioavailable.

Targeting BAFF and APRIL in systemic lupus erythematosus and other antibody-associated diseases

The B cell-stimulating molecules, BAFF (B cell activating factor) and APRIL (a proliferation-inducing ligand), are critical factors in the maintenance of the B cell pool and humoral immunity. In addition, BAFF and APRIL are involved in the pathogenesis of a number of human autoimmune diseases, with elevated levels of these cytokines detected in the sera of patients with systemic lupus erythematosus (SLE), IgA nephropathy, Sjögren's syndrome, and rheumatoid arthritis. As such, both molecules are rational targets for new therapies in B cell-driven autoimmune diseases, and several inhibitors of BAFF or BAFF and APRIL together have been investigated in clinical trials. These include the BAFF/APRIL dual inhibitor, atacicept, and the BAFF inhibitor, belimumab, which is approved as an add-on therapy for patients with active SLE. Post hoc analyses of these trials indicate that baseline serum levels of BAFF and BAFF/APRIL correlate with treatment response to belimumab and atacicept, respectively, suggesting a role for the two molecules as predictive biomarkers. It will, however, be important to refine future testing to identify active forms of BAFF and APRIL in the circulation, as well as to distinguish between homotrimer and heteromer configurations. In this review, we discuss the rationale for dual BAFF/APRIL inhibition versus single BAFF inhibition in autoimmune disease, by focusing on the similarities and differences between the physiological and pathogenic roles of the two molecules. A summary of the preclinical and clinical data currently available is also presented.

[Lupus nephropathy: Insight in new treatments]

Systemic lupus erythematosus is a chronic autoimmune disease. Both acquired and innate immune systems are involved in the development of this systemic disease. Lupus nephritis usually is the most serious manifestation of systemic lupus erythematosus, with significant morbidity and mortality. The physiopathological development of the renal involvement of lupus has been increasingly elucidated over the years and various target therapies have recently been developed. After some physiopathological reminders, we discuss the conventional treatment of lupus nephritis as well as the various therapeutic advances, in particular the contribution and the place of the new target therapies in the treatment of the lupus nephritis.

Update on Biologic Therapies for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic multisystemic autoimmune disease driven by genetic, hormonal, and environmental factors. Despite the advances in diagnostic and therapeutic approaches in the last decades, SLE still leads to significant morbidity and increased mortality. Although a cure for SLE is still unknown, treatment is required to control acute disease exacerbation episodes (flares), decrease the frequency and severity of subsequent lupus flares, address comorbidities, and prevent end-organ damage. While conventional SLE pharmacotherapy may exhibit suboptimal efficacy and substantial toxicity, a growing knowledge of the disease pathogenesis enabled the research on novel therapeutic agents directed at specific disease-related targets. In this paper, we review the recent progress in the clinical investigation of biologic agents targeting B cells, T cells, cytokines, innate immunity, and other immunologic or inflammatory pathways. Although many investigational agents exhibited insufficient efficacy or inadequate safety in clinical trials, one of them, belimumab, fulfilled the efficacy and safety regulatory requirements and was approved for the treatment of SLE in Europe and the USA, which confirms that, despite all difficulties, advances in this field are possible.

From mechanism to therapies in systemic lupus erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is a disabling and deadly disease. Development of novel therapies for SLE has historically been limited by incomplete understanding of immune dysregulation. Recent advances in lupus pathogenesis, however, have led to the adoption or development of new therapeutics, including the first Food and Drug Administration-approved drug in 50 years.

RECENT FINDINGS

Multiple cytokines (interferon, B lymphocyte stimulator, IL-6, and IL-17), signaling pathways (Bruton's Tyrosine Kinase, Janus kinase/signal transducer and activator of transcription), and immune cells are dysregulated in SLE. In this review, we cover seminal discoveries that demonstrate how this dysregulation is integral to SLE pathogenesis and the novel therapeutics currently under development or in clinical trials. In addition, early work suggests metabolic derangements are another target for disease modification. Finally, molecular profiling has led to improved patient stratification in the heterogeneous SLE population, which may improve clinical trial outcomes and therapeutic selection.

SUMMARY

Recent advances in the treatment of SLE have directly resulted from improved understanding of this complicated disease. Rheumatologists may have a variety of novel agents and more precise targeting of select lupus populations in the coming years.

Update on clinical trials in systemic lupus erythematosus

PURPOSE OF REVIEW

With advancement in our understanding of pathogenic mechanisms in systemic lupus erythematosus (SLE), there is tremendous enthusiasm in examining drugs, old and new, to improve outcomes. This review highlights recent trials' successes and impasses that have come to fore.

RECENT FINDINGS

Among B-cell therapies, belimumab continues its run of successes with sustained safety and tolerability documented in a long-term extension as well as the likely approval of a subcutaneous formulation in the near future. With greater antibody-dependent cytotoxicity and less immunogenicity, there is hope for obinituzumab to succeed where its anti-CD 20 predecessors have failed. Drugs targeting type I interferons - sifalimumab and anifrolumab - have been efficacious albeit with an increase in incidence of Herpes zoster infections. There is also renewed interest in evaluating the efficacy of calcineurin inhibitors, specifically tacrolimus in the induction and maintenance of lupus nephritis. Introspection into clinical trial designs have highlighted the effects of entry criteria, end points, background medications and geographical differences on study outcomes.

SUMMARY

There are at least 50 drugs and targets being evaluated in SLE. In addition to developing new drugs to treat lupus, future trials have to focus on more effective study designs to improve chances of trial success.

Systemic lupus erythematosus biomarkers: the challenging quest

SLE, a multisystem heterogeneous disease, is characterized by production of antibodies to cellular components, with activation of both the innate and the adaptive immune system. Decades of investigation of blood biomarkers has resulted in incremental improvements in the understanding of SLE. Owing to the heterogeneity of immune dysregulation, no single biomarker has emerged as a surrogate for disease activity or prediction of disease. Beyond identification of surrogate biomarkers, a multitude of clinical trials have sought to inhibit elevated SLE biomarkers for therapeutic benefit. Armed with new -omics technologies, the necessary yet daunting quest to identify better surrogate biomarkers and successful therapeutics for SLE continues with tenacity.

Targeted B cell therapies in the treatment of adult and pediatric systemic lupus erythematosus

Belimumab (Benlysta) is a fully-humanized monoclonal antibody that inhibits B-lymphocyte stimulator (also known as B cell activating factor) and was approved by the U.S. Federal Drug Administration and European Medicines Evaluation Agency for treatment in adults with autoantibody-positive systemic lupus erythematosus (SLE). Rituximab (Rituxan) is a chimeric anti-CD20 monoclonal antibody targeting B lymphocytes. This review discusses the key findings of the phase III trials in adults with SLE and of real-world use of belimumab and rituximab in the care of both adult and pediatric SLE patients. It highlights the safety profile of belimumab and rituximab and gives insight into the consideration of these therapies for specific SLE disease states. It concludes with a discussion of the current clinical trials investigating B cell therapies in specific SLE disease states and a look to the future, with ongoing clinical trials.

Efficacy and Safety of Subcutaneous Belimumab in Systemic Lupus Erythematosus: A Fifty-Two-Week Randomized, Double-Blind, Placebo-Controlled Study

Objective

To assess the efficacy and safety of subcutaneous (SC) belimumab in patients with systemic lupus erythematosus (SLE).

Methods

Patients with moderate‐to‐severe SLE (score of ≥8 on the Safety of Estrogens in Lupus Erythematosus National Assessment [SELENA] version of the SLE Disease Activity Index [SLEDAI]) were randomized 2:1 to receive weekly SC belimumab 200 mg or placebo by prefilled syringe in addition to standard SLE therapy for 52 weeks. The primary end point was the SLE Responder Index (SRI4) at week 52. Secondary end points were reduction in the corticosteroid dosage and time to severe flare. Safety was assessed according to the adverse events (AEs) reported and the laboratory test results.

Results

Of 839 patients randomized, 836 (556 in the belimumab group and 280 in the placebo group) received treatment. A total of 159 patients withdrew before the end of the study. At entry, mean SELENA–SLEDAI scores were 10.5 in the belimumab group and 10.3 in the placebo group. More patients who received belimumab were SRI4 responders than those who received placebo (61.4% versus 48.4%; odds ratio [OR] 1.68 [95% confidence interval (95% CI) 1.25–2.25]; P = 0.0006). In the belimumab group, both time to and risk of severe flare were improved (median 171.0 days versus 118.0 days; hazard ratio 0.51 [95% CI 0.35–0.74]; P = 0.0004), and more patients were able to reduce their corticosteroid dosage by ≥25% (to ≤7.5 mg/day) during weeks 40–52 (18.2% versus 11.9%; OR 1.65 [95% CI 0.95–2.84]; P = 0.0732), compared with placebo. AE incidence was comparable between treatment groups; serious AEs were reported by 10.8% of patients taking belimumab and 15.7% of those taking placebo. A worsening of IgG hypoglobulinemia by ≥2 grades occurred in 0.9% of patients taking belimumab and 1.4% of those taking placebo.

Conclusion

In patients with moderate‐to‐severe SLE, weekly SC doses of belimumab 200 mg plus standard SLE therapy significantly improved their SRI4 response, decreased severe disease flares as compared with placebo, and had a safety profile similar to placebo plus standard SLE therapy.

An update on diet and nutritional factors in systemic lupus erythematosus management

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease characterised by multiple organ involvement and a large number of complications. SLE management remains complicated owing to the biological heterogeneity between patients and the lack of safe and specific targeted therapies. There is evidence that dietary factors can contribute to the geoepidemiology of autoimmune diseases such as SLE. Thus, diet therapy could be a promising approach in SLE owing to both its potential prophylactic effects, without the side effects of classical pharmacology, and its contribution to reducing co-morbidities and improving quality of life in patients with SLE. However, the question arises as to whether nutrients could ameliorate or exacerbate SLE and how they could modulate inflammation and immune function at a molecular level. The present review summarises preclinical and clinical experiences to provide the reader with an update of the positive and negative aspects of macro- and micronutrients and other nutritional factors, including dietary phenols, on SLE, focusing on the mechanisms of action involved.

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.

Clinical Pharmacokinetics and Pharmacodynamics of Biologic Therapeutics for Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with potentially severe clinical manifestation that mainly affects women of child-bearing age. Patients who do not respond to standard-of-care therapies, such as corticosteroids and immunosuppressants, require biologic therapeutics that specifically target a single or multiple SLE pathogenesis pathways. This review summarizes the clinical pharmacokinetic and pharmacodynamic characteristics of biologic agents that are approved, used off-label, or in the active pipeline of drug development for SLE patients. Depending on the type of target, the interacting biologics may exhibit linear (non-specific) or non-linear (target-mediated) disposition profiles, with terminal half-lives varying from approximately 1 week to 1 month. Biologics given by subcutaneous administration, which offers dosing flexibility over intravenous administration, demonstrated a relatively slow absorption with a time to maximum concentration of approximately 1 day to 2 weeks and a variable bioavailability of 30-82 %. The population pharmacokinetics of monoclonal antibodies were best described by a two-compartment model with central clearance and steady-state volume of distribution ranging from 0.176 to 0.215 L/day and 3.60-5.29 L, respectively. The between-subject variability in pharmacokinetic parameters were moderate (20-79 %) and could be partially explained by body size. The development of linked pharmacokinetic-pharmacodynamic models incorporating SLE disease biomarkers are an attractive strategy for use in dosing regimen simulation and optimization. The relationship between efficacy/adverse events and biologic concentration should be evaluated to improve clinical trial outcomes, especially for biologics in the advanced phase of drug development. New strategies, such as model-based precision dosing dashboards, could be utilized to incorporate information collected from therapeutic drug monitoring into pharmacokinetic/pharmacodynamic models to enable individualized dosing in real time.

Pharmacokinetics, Pharmacodynamics and Preliminary Observations for Clinical Activity and Safety of Multiple Doses of Human Mouse Chimeric Anti-CD22 Monoclonal Antibody (SM03) in Chinese Patients with Systemic Lupus Erythematosus

BACKGROUND AND OBJECTIVES

SM03 is a novel recombinant, human/mouse chimeric immunoglobulin G1 monoclonal antibody directed against the CD22 antigen on human B lymphocytes. This was the first study to investigate the pharmacokinetics, pharmacodynamics, immunogenicity, safety and clinical activity of SM03 in patients with systemic lupus erythematosus (SLE).

METHODS

This study was an open, multiple-centre, parallel-group, multiple-ascending-dose, phase I study in 29 SLE patients. Pharmacokinetic assessment was conducted in 22 of these patients. Eligible patients received multiple intravenous infusions of SM03 for 4 weeks (240 mg/m², 600 or 900 mg, once weekly) and were monitored over an 84-day observation period for pharmacokinetics, pharmacodynamics, immunogenicity, safety and clinical response.

RESULTS

After multiple-dose SM03, the maximal serum concentration of SM03 was reached within 3-7 h. The mean elimination half-life was 15 days. The average accumulation ratios of the area under the time-concentration curve and the maximum concentration after the fourth administration of SM03 were 2.0 and 1.5. CD19⁺ B-lymphocyte counts were decreased. Infections were the most common adverse events. No drug-related serious adverse events were reported. The therapeutic benefit of SM03 was observed mainly in patients with moderate-to-severe disease activity.

CONCLUSION

Pharmacokinetic exposure increased in a lower-than-dose-proportional manner up to 900 mg. SM03 was well tolerated at doses ranging from 240 mg/m² to 900 mg, with no new safety signals identified. SM03 has potential efficacy in Chinese patients with SLE.

Blisibimod for treatment of systemic lupus erythematosus: with trials you become wiser

INTRODUCTION

Blisibimod is a potent and selective inhibitor of B cell activating factor (BAFF), a mediator of differentiation, maturation and survival of B cells. It has a unique tetravalent, 'peptibody' structure and resulting high potency, and is currently in clinical evaluation for the treatment of SLE. The importance of BAFF in the pathogenesis of systemic lupus erythematosus (SLE) is under intense investigation. The anti BAFF monoclonal antibody belimumab was approved by the FDA for the treatment of SLE.

AREAS COVERED

The general properties of blisibimod are reviewed including pharmacokinetic and pharmacodynamic properties in patients with SLE, efficacy and safety in the phase 2 PEARL-SC and open-label extension trials, and the focus in the ongoing phase 3 trial (CHABLIS-SC1) on the hypothesized 'responder' population. In addition, the rationale for evaluating blisibimod in patients with IgA nephropathy, a common nephritic disease for which there is no approved therapy, is presented.

EXPERT OPINION

Blisibimod's unique tetravalent, peptibody structure and resulting high potency, and the deliberate focus of the Phase 3 clinical development program on the 'responder populations' identified in completed trials in SLE raise the possibility that blisibimod will become an important medication for treatment of SLE and IgA nephropathy.

Present and future of biologic drugs in primary Sjögren's syndrome

INTRODUCTION

Primary Sjögren's (pSS) syndrome is a chronic, autoimmune, and systemic disease characterized by xerostomia, xerophthalmia, muscle pain and fatigue. The disease may be complicated by a systemic involvement, such as a pulmonary fibrosis or the development of lymphoma which severely worsens the prognosis. Actually, there are no recommendations for the management of pSS. However, recent advances in the understanding of its pathogenesis have uncovered some pathways that have potential as therapeutic targets. Areas covered: In this review, the authors present the biologic drugs potentially valuable to the treatment of pSS in light of its physiopathology with a 'bird's eye' view of future prospects. The authors took into account relevant studies published from 2004 to 2016. Expert opinion: Biological treatment in pSS is a promising opportunity to potentially control disease activity and prevent its complication. Currently, inhibition of B-cell and IL-17 pathways seem to be the most promising avenues. New achievements in the knowledge of pSS pathophysiology are necessary in order to try to simultaneously predict the predominant pathogenic pathway, the kind of patients at major risk to develop a more severe disease, and the appropriate biological therapy to use.

Overview of pathophysiology and treatment of human lupus nephritis

PURPOSE OF REVIEW

Despite recent developments and treatment successes, the outcome, and prognosis of patients with lupus nephritis (LuN) have not greatly changed since the 1980s. This review covers the application of new concepts to the understanding of renal inflammation and the study of new pharmacologic agents to improve patient outcomes.

RECENT FINDINGS

Studies have shown that the presence of anti-vimentin antibodies and T follicular helper cells in patient biopsies is associated with more severe interstitial inflammation, which has been tied to faster disease progression and onset of end-stage renal disease. Additionally, data regarding the role of serum IgE antidouble-stranded DNA antibodies in LuN by means of mediating IFN1 production by plasmacytoid dendritic cells are highlighted. Finally, a thorough review of completed and currently open clinical trials of therapeutic agents is provided.

SUMMARY

Current management of LuN is guided almost exclusively by glomerular involvement. Based on the data provided in this review, we argue that renal tubulointerstitial inflammation is no less important and represents an overlooked feature in the current clinical approach to patients. Tubulointerstitial inflammation is driven by both adaptive and innate immune mechanisms that are still poorly understood. Studying these pathogenic processes promises to reveal new therapeutic opportunities for those LuN patients with the worst prognosis.

VIDEO ABSTRACT

Alternate video abstract introduction (see Video, Supplemental Digital Content 1, with introduction by two of the authors - VL and KT). Abstract Video: http://links.lww.com/COR/A35.

Recent advances in the biologic therapy of lupus: the 10 most important areas to look for common pitfalls in clinical trials

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting different organs. The improved knowledge of the disease's pathogenesis has contributed to the emergence of immune targets and new biologic drugs directed at them. Although rheumatologists continue to use off-label biologics in SLE resistant to other immunosuppressants, only belimumab has been approved as a biological therapy since 2011.

AREAS COVERED

In this review, an overview is provided on: 1) the classification of the biologic drugs in clinical trials and of those under research; 2) the results of clinical trials of biologic therapy with an interpretation of pitfalls and syntheses of potential approaches to overcome these pitfalls and, 3) the commonly used disease activity metrics and composite indices for assessing response to drugs.

EXPERT OPINION

Some drugs that have failed in previous drug trials have shown to be efficacious in the treatment of lupus in observational studies. Moreover, the post-hoc analyses of the data of negative drug trials have shown that results of the same trials could be altered with the modification of some pitfalls. For future clinical trials, the consideration of these pitfalls is crucial when designing clinical trials. This could potentially enhance the approval of novel drugs for SLE.

Therapeutic options for cutaneous lupus erythematosus: recent advances and future prospects

INTRODUCTION

Treatment and prevention are of critical importance in patients with cutaneous lupus erythematosus (CLE), as the disease can have a devastating effect on patient well-being and quality of life.

AREAS COVERED

We conducted a selective search of the PubMed database for articles published between December 2010 and November 2015. This review encompasses both non-pharmaceutical (photoprotection, smoking cessation, drug withdrawal, and vitamin D replacement) and pharmaceutical (topicals, antimalarials, immunosuppressives, biologics, etc.) interventions used in the treatment of CLE. Expert Commentary: Recent work has expanded our understanding of established therapies as well as introduced new treatments for consideration, though existing medications still prove inadequate for a subset of patients. Changes in trial design may help to alleviate this issue.