Anifrolumab for systemic lupus erythematosus: A clinical study of Japanese patients in Kanazawa University Hospital

We investigated the effectiveness of anifrolumab in treating systemic lupus erythematosus (SLE). We treated seven patients with SLE (age range, 31-68 years; median age, 48 years); one male and six females) with anifrolumab between January 2022 and February 2023 at Kanazawa University Hospital. The period between the onset and initiation of anifrolumab treatment was 60-276 months (median, 234 months), and the SLE disease activity index-2000 (SLEDAI-2 K) before treatment was 2-6 months (median, 3 months). Five patients experienced skin rashes or alopecia, and their cutaneous lupus erythematosus disease area and severity index (CLASI) activity scores were 2-9 (median, 4). Six patients continued treatment with anifrolumab, but one did not because of uncontrolled pleurisy and pericarditis. Our results demonstrated that anifrolumab was effective in treating SLE and reducing both SLEDAI-2 K and CLASI activity scores (median decrease, 100%). Furthermore, the oral corticosteroid dosage could be reduced in all patients who were able to continue treatment. Our findings indicate that anifrolumab is effective not only for reducing disease and eruption activities, but also facilitates tapering of corticosteroid dosage.

Glucocorticoid-free remission in patients with SLE in the era of biologics: Immune complex disease is likely to benefit from current medications

OBJECTIVES

In addition to various immunosuppressive agents, belimumab and anifrolumab became available in Japan. We aimed to investigate glucocorticoid-free clinical remission in a single-centre retrospective cohort in October 2023.

METHODS

Our cohort included patients with SLE who needed to start or increase glucocorticoids for disease activity and were followed up for more than 1 year. We investigated the rate of achievement of clinical remission off corticosteroids (CR off C), defined as no clinical score on the SLEDAI-2K without glucocorticoids, baseline predictors of CR off C, medications used when CR off C was achieved, and flare rates following CR off C.

RESULTS

Out of the 60 patients followed for an average of 5.4 (±2.6) years, 17 (28.3%) achieved CR off C in 3.6 (±1.2) years after enrolment. Use of belimumab and anifrolumab accounted for eight (47.1%) of the achievers. Among the baseline data, male sex, recent enrolment, high glucocorticoid dose, and detection of immune complex (IC) significantly predicted CR off C, while lupus nephritis (LN) and a low C3 level tended to predict it. In the multivariate analysis, IC detection was the only predictor of CR off C. Clinical flares were observed in 5.9% of the achievers during a median 1.2 years after achievement of CR off C.

CONCLUSION

In the era of biologics, CR off C was achieved in 28.3% of the patient cohort requiring the start or increase of glucocorticoids for disease activity, with a relatively low rate of flares, suggesting that glucocorticoid-free clinical remission is an achievable target in SLE. IC disease, represented by male sex or nephritis, is likely to benefit from currently available medications.

An update on clinical trials for cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) comprises dermatologic manifestations that may occur independently or with systemic lupus erythematosus (SLE). Despite advancements in refining CLE classification, establishing precise subtype criteria remains challenging due to overlapping presentations and difficulty in distinguishing morphology. Current treatments encompass preventive measures, topical therapies, and systemic approaches. Hydroxychloroquine and glucocorticoids are the sole US Food and Drug Administration (FDA)-approved medications for CLE, with numerous off-label treatments available. However, these treatments are often not covered by insurance, imposing a significant financial burden on patients. The exclusion of most CLE patients, particularly those without concurrent SLE, from trials designed for SLE has resulted in a lack of targeted treatments for CLE. To develop effective CLE treatments, validated outcome measures for tracking patient responsiveness are essential. The Cutaneous Lupus Erythematosus Disease Area and Severity Index is widely utilized for its reliability, validity, and ability to differentiate between skin activity and damage. In contrast, the FDA mandates the use of the Investigator's Global Assessment, a five-point Likert scale related to lesion characteristics, for skin-related therapeutic trials. It requires the disease to resolve or almost completely resolve to demonstrate improvement, which can be difficult when there is residual erythema or incomplete clearance that is meaningfully improved from a patient perspective. Various classes of skin lupus medications target diverse pathways, allowing tailored treatment based on the patient's lupus inflammatory profile, resulting in improved outcomes. Promising targeted therapeutic drugs include anifrolumab (anti-type 1 interferon), deucravacitinib (allosteric tyrosine kinase 2 inhibitor), litifilimab (plasmacytoid dendritic cell-directed therapy), iberdomide (cereblon-targeting ligand), and belimumab (B-cell directed therapy). Despite the significant impact of CLE on quality of life, therapeutic options remain inadequate. While promising treatments for cutaneous lupus are emerging, it is crucial to underscore the urgency for skin-focused treatment outcomes and the implementation of validated measures to assess therapeutic effectiveness in clinical trials.

Microsimulation model of the cost-effectiveness of anifrolumab compared to belimumab in the United Arab Emirates

INTRODUCTION

SLE imposes a significant morbidity and mortality as well as a substantial burden on the healthcare system. The model aimed to measure the cost-effectiveness of anifrolumab implementation against belimumab as an add-on-therapy to the standard of care (SoC) over a lifetime horizon for Emirati patients.

METHODOLOGY

A microsimulation model was used to assess the cost-effectiveness of anifrolumab against belimumab (IV/SC) as an add-on therapy to SoC in a hypothetical cohort of adult Emirati patients with systemic lupus erythematosus (SLE) over a lifetime horizon. The clinical data was captured from published clinical trials as; TULIP-1, TULIP-2, BLISS-52, BLISS-76 and BLISS-SC. Health utility scores were constructed according to a linear regression model from the pooled data of the two TULIP Phase III trials of anifrolumab. Our model captures direct SLE-related medical costs from the Dubai Health Authority. Sensitivity analyses were conducted to assess model uncertainty.

RESULTS

Using BICLA as a response criterion in the Johns Hopkins cohort, anifrolumab was found to be more effective than belimumab (IV/SC; the incremental discounted QALY of anifrolumab against belimumab was 0.42). The incremental cost-effectiveness ratio (ICER) of anifrolumab against belimumab IV and belimumab SC were AED 466,371 ($209,135) and AED 252,612 ($113,279), respectively, these ICERs are below the cost-effectiveness threshold in the United Arab Emirates (UAE) (three times gross domestic product capita; AED 592,278). In the Toronto lupus cohort, the ICER of anifrolumab against belimumab IV and belimumab SC were AED 491,403 ($220,360) and AED 276,642 ($124,055), respectively (anifrolumab was a cost-effective option vs. belimumab IV and belimumab SC).

CONCLUSION

The addition of anifrolumab to SoC is a cost-effective option versus belimumab for the treatment of adult patients with active, autoantibody-positive SLE, despite being allocated to SoC. Cost-effectiveness was demonstrated by a reduction in complications and organ damage, which reflected costs and outcomes.

Treatment With Voclosporin and Anifrolumab in a Patient With Lupus Nephritis and Refractory Discoid Lupus Erythematosus: A Case Report and Literature Review

Systemic lupus erythematosus (SLE) is a complex heterogeneous disease with multiple clinical manifestations. Recently, two medications, anifrolumab and voclosporin, have been approved for the treatment of adults with SLE and lupus nephritis (LN), respectively. We present the case of an elderly woman with LN and refractory discoid lupus erythematosus (DLE), who was treated successfully with a combination of voclosporin and anifrolumab without major infections.

Relationships between Type 1 interferon signatures and clinical features of the new-onset lupus patients in Japan

OBJECTIVES

The objective of the study is to investigate the relationships between Type 1 interferon (T1-IFN) signatures and clinical characteristics of lupus patients.

METHODS

We examined 49 new-onset lupus patients who were diagnosed between 1999 and 2017. The patients treated with >10 mg of prednisolone or hydroxychloroquine were excluded from this study. Serum T1-IFN signatures were revealed by a functional reporter assay and standardized by recombinant IFN-α. Patient backgrounds, clinical findings, and treatments were retrospectively extracted from their electrical medical records. Clinical data were also available, including SLE Disease Activity Index of SLE patients on admission.

RESULTS

T1-IFN signatures of lupus patients closely correlated with lupus disease activities, such as SLE Disease Activity Index-2K, white blood cell, C3 levels, and the titre of double-strand DNA antibody. We found fever and acute lupus dermatitis closely associated with T1-IFN signature.

CONCLUSIONS

In lupus patients, fever and acute lupus dermatitis are good indicators of a strong T1-IFN signature.

The development of litifilimab (BIIB 059) for cutaneous and systemic lupus erythematosus

This review describes the litifilimab (BIIB 059) development program to date for systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE). Plasmacytoid dendritic cells (pDCs), major producers of type I interferons (IFN-I), play a key role in SLE pathogenesis. Litifilimab, a humanized monoclonal antibody, binds to BDCA2, a protein uniquely expressed on pDCs. The consequence of BDCA2 ligation is the inhibition of IFN-I as well as IFN-III, cytokine and chemokine production. Phase I and II LILAC trial parts A and B achieved primary end points in SLE and CLE patients, confirming the importance of pDCs and IFN-I in SLE and CLE. Litifilimab is currently being evaluated in phase III trials in both SLE and CLE.

Anifrolumab for Moderate and Severe Muco-Cutaneous Lupus Erythematosus: A Monocentric Experience and Review of the Current Literature

Refractory cutaneous manifestations constitute a significant unmet need in patients with cutaneous lupus (CLE), even in the setting of systemic lupus erythematosus (SLE) with otherwise good control of inflammatory manifestations. Anifrolumab, an anti-interferon I receptor monoclonal antibody has recently been approved for serologically positive SLE with or without CLE, but real-life efficacy and safety data are currently limited. In addition, relatively limited evidence exists about the spectrum of cutaneous manifestations potentially benefitting from anifrolumab treatment and about the optimal clinimetrics to monitor treatment efficacy. While summarising current evidence on the topic in the literature, we report on four patients with SLE and refractory CLE who were successfully treated with anifrolumab. We also describe the potential usefulness and complementarity of the cutaneous lupus activity investigator's global assessment (CLA-IGA) in assessing cutaneous activity in patients treated with anifrolumab.

Case Report: Response of cutaneous lupus lesions in SLE to interferon receptor blockade parallels reduction of interferon score in blood

Cutaneous lupus erythematosus (CLE), the main manifestation of systemic lupus erythematosus (SLE), is driven by type I interferons (IFNs) and often only partially responds to conventional therapies. Treatment of seven SLE patients with the monoclonal antibody anifrolumab induced fast and sustained remission of previously refractory CLE lesions, beginning within the first weeks of treatment. Decline in CLASI-A score was paralleled by a reduction in IFN score determined by mRNA expression of seven IFN-stimulated genes (ISGs) in blood. These data suggest that a subset of ISGs could be a valuable biomarker in CLE.

The long-term safety and tolerability of anifrolumab for patients with systemic lupus erythematosus in Japan: TULIP-LTE subgroup analysis

OBJECTIVES

Evaluate the long-term safety and tolerability of anifrolumab 300 mg, alongside standard therapy, in patients from Japan with systemic lupus erythematosus (SLE) in the TULIP-LTE trial (NCT02794285).

METHODS

TULIP-LTE was a 3-year, randomized, double-blind, placebo-controlled long-term extension (LTE) of the TULIP trials. The primary safety outcome included serious adverse events (SAEs) and AEs of special interest (AESIs) during the LTE period. Exploratory efficacy outcomes included SLE Disease Activity Index 2000 (SLEDAI-2K) scores and glucocorticoid use. We performed a post hoc subgroup analysis of patients who enrolled in Japan.

RESULTS

Exposure-adjusted incidence rates of SAEs during the LTE and follow-up for patients receiving anifrolumab 300 mg (n=21) were 8.7 per 100 patient-years; AESIs included influenza (6.9) and herpes zoster (3.5). One of three patients receiving placebo had an SAE (13.9). One patient per group discontinued due to an AE. There were no deaths. During the TULIP+LTE period, patients receiving anifrolumab 300 mg (n=24) had sustained reduction from baseline in mean SLEDAI-2K scores and cumulative glucocorticoid dosage.

CONCLUSIONS

Anifrolumab 300 mg showed a favourable benefit-risk profile for the long-term treatment of adult patients with moderate to severe SLE from Japan, with safety, tolerability, and efficacy profiles consistent with the overall population.

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

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

Role of Anifrolumab in Refractory Cutaneous Manifestations of Lupus Erythematosus: A Case Series and Literature Review

Lupus erythematosus (LE) is an autoimmune disease that presents either as a systemic (SLE) or an isolated skin disease (CLE). Currently, there is no FDA-approved medication specifically for CLE, and is treated with the same approach as SLE. We present two refractory cases of SLE with severe cutaneous manifestations unresponsive to the first-line therapy treated with anifrolumab. First, a 39-year-old Caucasian female with a known history of SLE with severe subacute CLE presented to the clinic for her refractory cutaneous symptoms. Her current regimen was hydroxychloroquine (HCQ), mycophenolate mofetil (MMF), and s/c belimumab with no improvement. Belimumab was discontinued, and she was started on anifrolumab with significant improvement. Another, a 28-year-old female with no known medical history was referred to a rheumatology clinic for elevated anti-nuclear antibody (ANA) and ribonucleoprotein (RNP) titers. She was diagnosed with SLE, and was treated with HCQ, belimumab, and MMF but failed to produce a reasonably good outcome. Hence belimumab was discontinued and anifrolumab was added instead with significant cutaneous improvement. The treatment spectrum for SLE is wide, which includes antimalarial (HCQ), oral corticosteroids (OCS), and immunosuppressants (Methotrexate-MTX, MMF, azathioprine-AZT). Anifrolumab, a type 1 IFNα receptor subunit 1 (IFNAR1) inhibitor, has been recently approved by the FDA for moderate to severe SLE while on standard therapy in August 2021. Early use of anifrolumab in moderate to severe cutaneous manifestations of SLE or CLE may result in significant improvement in patients.

The efficacy and safety of anifrolumab in Japanese patients with systemic lupus erythematosus: TULIP-2 subanalysis

OBJECTIVES

Evaluate the efficacy and safety of anifrolumab in the subpopulation of Japanese patients with systemic lupus erythematosus (SLE) in phase 3 TULIP-2 trial.

METHODS

TULIP-2 was a 52-week randomized placebo-controlled trial (N = 362) that evaluated efficacy and safety of anifrolumab 300 mg IV every 4 weeks vs. placebo in patients with moderate to severe SLE who were receiving standard therapy. We performed a post hoc analysis of the primary and key secondary endpoints, and safety, of TULIP-2 in the Japanese subpopulation.

RESULTS

In the Japanese subpopulation (anifrolumab, n = 24; placebo, n = 19), the proportion of patients who achieved a British Isles Lupus Assessment Group-based Composite Lupus Assessment response at Week 52 (primary endpoint) was greater in the anifrolumab group vs. placebo [50.0% (12/24) vs. 15.8% (3/19); treatment difference: 34.2%, 95% confidence interval 6.9, 61.5; nominal p = .014]. Improvement in skin activity and flare rates (key secondary endpoints) were favourable for anifrolumab vs. placebo. Consistent with the overall population, anifrolumab had an acceptable safety and tolerability profile.

CONCLUSIONS

The efficacy and safety of anifrolumab 300 mg in Japanese patients with SLE was consistent with the demonstrated clinical profile of anifrolumab for the overall TULIP-2 population.

La gestione del trattamento del paziente con diagnosi di Lupus Eritematoso Sistemico: un’analisi di consenso Delphi

Background:

Systemic lupus erythematosus (SLE) is associated with clinical burden for the patient and organ damage. The development of therapies for SLE has been constrained by clinical and biologic heterogeneity. These represent challenges in clinical trial design and endpoint selection.

Objective:

To identify the most relevant descriptors for efficacy, endpoints, disease activity, organ damage, quality of life (QoL), and Patient Reported Outcome Measures (PROMs) in the treatment of SLE.

Methods:

A Delphi study was conducted using a national expert panel of clinicians in the treatment of SLE. A steering committee composed of 3 opinion leaders with deep expertise in SLE treatment was defined. The steering committee analyzed and appraised the evidence, designed the Delphi study, defined the statements, and analyzed the expert panel responses. A 2-round Delphi survey was conducted. Participants were asked to rate the statements using a five-point Likert scale.

Results:

Nine experts participated in the Delphi survey. After the two rounds, the consensus was reached on 18 of the 23 statements: 2 statements were included in the “efficacy” domain, 2 in the “glucocorticoid-sparing” domain, 2 in the “endpoint evaluation” domain, 4 in the “score” domain, 1 in the “disease activity” domain, 1 in the “organ damage” domain, 1 in the “QoL” domain, 2 in the “PROMs” domain, 1 in the “AIFA monitoring” domain and 2 in the “extra” domain. No statements reached consensus within the “onset” domain.

Conclusion:

In this Delphi study, 18 statements across 11 domains were agreed upon for the treatment of SLE.

An update on the management of refractory cutaneous lupus erythematosus

Management of cutaneous lupus erythematosus (CLE) involves a combination of preventive measures, topical and systemic drugs, fairly similar for the different subtypes. Although guidelines exist, to date, no specific drugs have been specifically licensed for CLE. Antimalarials remain the first-line systemic treatment, but many patients do not respond, making refractory lupus a challenge for clinicians. The choice of alternative medication should be based on effectiveness, safety and cost. Most of the available drugs for CLE have been adapted from systemic lupus erythematosus (SLE) treatment but the existing literature is limited to small studies and evidence often lacks. As knowledge of pathogenesis of both CLE and SLE is improving, promising new therapies are emerging. In this review, we discuss the available medications, focusing on the novelties under development for CLE.

Rapid Response of Refractory Systemic Lupus Erythematosus Skin Manifestations to Anifrolumab-A Case-Based Review of Clinical Trial Data Suggesting a Domain-Based Therapeutic Approach

Systemic lupus erythematosus (SLE) is a clinically heterogeneous autoimmune disease, and organ manifestations, such as lupus nephritis (LN) or skin disease, may be refractory to standard treatment. Therefore, new agents are required to allow for a more personalized therapeutic approach. Recently, several new therapies have been approved internationally, including voclosporine for LN and anifrolumab for moderately to severely active SLE. Here, we report a case of SLE with a predominant and refractory cutaneous manifestation despite combination treatment with glucocorticoids, hydroxychloroquine, mycophenolate mofetil, and belimumab, which had been present for more than 12 months. Belimumab was switched to anifrolumab, and the patient responded quickly after two infusions (eight weeks) with a reduction in the Cutaneous Lupus Assessment and Severity Index (CLASI) from 17 to 7. In addition, we review the available clinical trial data for anifrolumab with a focus on cutaneous outcomes. Based on phase II and III clinical trials investigating the intravenous administration, a consistent CLASI improvement was observed at 12 weeks. Interestingly, in a phase II trial of subcutaneous anifrolumab application, CLASI response was not different from placebo at 12 weeks but numerically different at 24 and 52 weeks, respectively. Thus, anifrolumab emerges as an attractive new therapeutic option suggesting a possible domain-based approach.

Relationship of anifrolumab pharmacokinetics with efficacy and safety in patients with systemic lupus erythematosus

OBJECTIVES

To characterize the relationship of anifrolumab pharmacokinetics with efficacy and safety in patients with moderate to severe SLE despite standard therapy, using pooled data from two phase 3 trials.

METHODS

TULIP-1 and TULIP-2 were randomized, placebo-controlled, 52-week trials of intravenous anifrolumab (every 4 weeks for 48 weeks). For the exposure-response analysis, BILAG-based Composite Lupus Assessment (BICLA) or SLE Responder Index [SRI(4)] response rates at week 52 in each quartile/tertile of average anifrolumab serum concentration (Cave) were compared for anifrolumab and placebo in all-comers, patients who completed treatment, and IFN gene signature (IFNGS)-high patients who completed treatment, using average marginal effect logistic regression. Relationships between exposure and key safety events were assessed graphically.

RESULTS

Of patients in TULIP-1/TULIP-2 who received anifrolumab (150 mg, n = 91; 300 mg, n = 356) or placebo (n = 366), 574 completed treatment, of whom 470 were IFNGS high. In the exposure-efficacy analyses, BICLA and SRI(4) treatment differences favouring anifrolumab 300 mg vs placebo were observed across Cave subgroups and all analysis populations. Logistic regression identified Cave as a significant covariate for predicted BICLA response, as higher anifrolumab Cave predicted greater efficacy. There was no evidence of exposure-driven incidence of key safety events through week 52 in patients receiving anifrolumab 150 or 300 mg.

CONCLUSION

While higher Cave predicted greater efficacy, consistent positive benefit favouring anifrolumab 300 mg vs placebo was observed in BICLA and SRI(4) responses across Cave subgroups in the TULIP trials. There was no evidence of exposure-driven safety events.

CLINICALTRIAL.GOV NUMBERS

NCT02446912, NCT02446899.

The Relationship between Anifrolumab Pharmacokinetics, Pharmacodynamics, and Efficacy in Patients With Moderate to Severe Systemic Lupus Erythematosus

This study aimed to elucidate the pharmacokinetic/pharmacodynamic and pharmacodynamic/efficacy relationships of anifrolumab, a type I interferon receptor antibody, in patients with moderate to severe systemic lupus erythematosus. Data were pooled from the randomized, 52‐week, placebo‐controlled TULIP‐1 and TULIP‐2 trials of intravenous anifrolumab (150 mg/300 mg, every 4 weeks for 48 weeks). Pharmacodynamic neutralization was measured with a 21‐gene type I interferon gene signature (21‐IFNGS) in patients with high IFNGS. The pharmacokinetic/pharmacodynamic relationship was analyzed graphically and modeled with a nonlinear mixed‐effects model. British Isles Lupus Assessment Group–based Composite Lupus Assessment (BICLA) response rates were compared across 21‐IFNGS neutralization quartiles. Overall, 819 patients received ≥1 dose of anifrolumab or placebo, of whom 676 were IFNGS high. Over 52 weeks, higher average anifrolumab serum concentrations were associated with increased median 21‐IFNGS neutralization, which was rapid and sustained with anifrolumab 300 mg (>80%, weeks 12‐52), lower and delayed with anifrolumab 150 mg (>50%, week 52), and minimal with placebo. The proportion of patients with week 24 anifrolumab trough concentration exceeding the IC₈₀ (3.88 μg/mL) was greater with anifrolumab 300 mg vs anifrolumab 150 mg (≈83% vs ≈27%), owing to the higher estimated median trough concentration (15.6 vs 0.2 μg/mL). BICLA response rates increased with 21‐IFNGS neutralization; more patients had a BICLA response in the highest vs lowest neutralization quartiles at week 52 (58.1% vs 37.6%). In conclusion, anifrolumab 300 mg every 4 weeks rapidly, substantially, and sustainably neutralized the 21‐IFNGS and was associated with clinical efficacy, supporting this dosing regimen in patients with systemic lupus erythematosus.

Type I Interferons in Systemic Lupus Erythematosus: A Journey from Bench to Bedside

Dysregulation of type I interferons (IFNs) has been implicated in the pathogenesis of systemic lupus erythematosus (SLE) since the late 1970s. The majority of SLE patients demonstrate evidence of type I IFN pathway activation; however, studies attempting to address the relationship between type I IFN signature and SLE disease activity have yielded conflicting results. In addition to type I IFNs, type II and III IFNs may overlap and also contribute to the IFN signature. Different genetic backgrounds lead to overproduction of type I IFNs in SLE and contribute to the breakdown of peripheral tolerance by activation of antigen-presenting myeloid dendritic cells, thus triggering the expansion and differentiation of autoreactive lymphocytes. The consequence of the continuous stimulation of the immune system is manifested in different organ systems typical of SLE (e.g., mucocutaneous and cardiovascular involvement). After the discovery of the type I IFN signature, a number of different strategies have been developed to downregulate the IFN system in SLE patients, finally leading to the successful trial of anifrolumab, the second biologic to be approved for the treatment of SLE in 10 years. In this review, we will discuss the bench to bedside translation of the type I IFN pathway and put forward some issues that remain unresolved when selecting SLE patients for treatment with biologics targeting type I IFNs.

What is new in the treatment of Systemic Lupus Erythematosus?

Systemic lupus erythematosus treatment is targeted to achieve remission or low disease activity and protection from disease flares. A number of immunosupresive drugs in combination with glucocorticoids are used for this purpose and there is an increased possibility of the use of biologic treatment, especially of belimumab. Calcineurin inhibitor voclosporin is a novelty in lupus nephritis treatment. Another novelty is anifrolumab, a biologic drug which inhibits the activity of type I interferons. An integral part of care is the prevention of late disease complications, especially cardiovascular risk management.

Advances in Lupus Nephritis Pathogenesis: From Bench to Bedside

Systemic lupus erythematosus (SLE) is the prototype of autoimmune disorders caused by a loss of tolerance to endogenous nuclear antigens triggering an aberrant autoimmune response targeting various tissues. Lupus nephritis (LN), a major cause of morbidity and mortality in patients with SLE, affects up to 60% of patients. The recent insights into the genetic and molecular basis of SLE and LN paved the way for newer therapies to be developed for these patients. Apart from the traditional B-cell-centered view of this disease pathogenesis, acknowledging that multiple extrarenal and intrarenal pathways contribute to kidney-specific autoimmunity and injury may help refine the individual therapeutic and prognostic characterization of such patients. Accordingly, the formerly induction-maintenance treatment strategy was recently challenged with the exciting results obtained from the trials that evaluated add-on therapy with voclosporin, belimumab, or Obinutuzumab. The scope of this review is to provide an insight into the current knowledge of LN pathogenesis and future therapeutic strategies.

Anifrolumab in systemic lupus erythematosus: current knowledge and future considerations

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is potentially life-threatening and can affect any organ. The complex pathogenesis and heterogeneity of the disease, among other factors, present significant challenges in developing new therapies. Knowledge gained over many years has implicated type I interferon (IFN) in the pathogenesis of SLE and anti-IFN therapies hold promise as a much-needed future treatment for SLE. Anifrolumab, a human monoclonal antibody against the type I IFN receptor, has recently been evaluated in two Phase III clinical trials for the treatment of moderate-to-severe SLE. Here, we review the clinical efficacy and safety of anifrolumab and discuss the potential challenges in determining the optimal SLE patient subgroup for treatment.

Spotlight on anifrolumab and its potential for the treatment of moderate-to-severe systemic lupus erythematosus: evidence to date

Previous reports have described the appearance of systemic lupus erythematosus (SLE) cases following interferon-α (IFN-α) therapy, IFN-regulated gene expression is significantly increased in SLE, and an association between SLE and gene variants belonging to IFN downstream pathways has been shown. Based on this, targeting of IFN and of their signaling pathways has appeared to be interesting developments within the field of SLE therapy. Different specific type I IFN antagonists have been studied in clinical trials and some of those have already reached Phase III. A potential approach would be to target IFN receptors rather than IFN themselves. Anifrolumab (previously MEDI-546) is a fully human monoclonal antibody (Ab) that binds to subunit 1 of the type I IFN receptor (IFNAR1), blocking the action of different type I IFNs (IFN-α, IFN-β and IFN-ω). This drug has been assessed in 11 clinical studies: 9 in SLE, 1 in systemic sclerosis and 1 in rheumatoid arthritis. In SLE, clinical development reached Phase I for 1 study and Phases II and III for 5 and 3 trials, respectively. The Phase IIb, randomized control trial (RCT), double-blind, placebo-controlled study of adults with moderate-to-severe SLE (MUSE trial) showed positive results on the composite primary endpoint SRI-4. Greater efficacy was seen in patients with high baseline IFN gene signature compared with those with low baseline IFN gene signature. Anifrolumab also demonstrated promising results on cutaneous and arthritic manifestations, especially among patients with a high IFN gene signature. The pivotal Treatment of Uncontrolled Lupus via the Interferon IFN Pathway (TULIP 1 and 2 studies are now completed. In August 2018, the promoter announced that the TULIP 1 Phase III trial did not reach its primary endpoint. The release of the completed but not yet published Phase II studies and of the TULIP pivotal trials results will further inform us on the actual therapeutic potential of anifrolumab.

Lupus Low Disease Activity State (LLDAS) attainment discriminates responders in a systemic lupus erythematosus trial: post-hoc analysis of the Phase IIb MUSE trial of anifrolumab

Objectives

In a post-hoc analysis, we aimed to validate the Lupus Low Disease Activity State (LLDAS) definition as an endpoint in an systemic lupus erythematosus (SLE) Phase IIb randomised controlled trial (RCT) (MUSE [NCT01438489]) and then utilize LLDAS to discriminate between anifrolumab and placebo.

Methods

Patients received intravenous placebo (n=102) or anifrolumab (300 mg, n=99; 1,000 mg, n=104) Q4W plus standard of care for 48 weeks. LLDAS attainment (SLE Disease Activity Index 2000 ≤4 without major organ activity, no new disease activity, Physician’s Global Assessment ≤1, prednisolone ≤7.5 mg/d and standard immunosuppressant dosage tolerance) was assessed. Associations with endpoints and LLDAS attainment differences between treatments were explored.

Results

LLDAS attainment at Week 52 was associated with SLE Responder Index 4 (SRI[4]) and British Isles Lupus Assessment Group–based Composite Lupus Assessment (BICLA) (74/85[87%] and 62/84[74%] were also SRI[4] and BICLA responders, respectively; both nominal p<0.001). Only 74/159 (47%) of SRI(4) and 62/121 (51%) of BICLA responders reached LLDAS.

Anifrolumab-treated patients achieved earlier LLDAS, and more spent at least half their observed time in LLDAS (OR vs. placebo; 300 mg: 3.04, 95% CI 1.34 to 6.92, nominal p=0.008; 1,000 mg: 2.17, 95% CI 0.93 to 5.03, nominal p=0.072) vs placebo-treated patients. At Week 52, 17/102 (17%), 39/99 (39%) and 29/104 (28%) of patients on placebo, anifrolumab 300 and 1,000 mg, respectively, attained LLDAS (OR vs. placebo; 300 mg: 3.41, 95% CI 1.73 to 6.76, p<0.001; 1,000 mg: 2.03, 95% CI 1.01 to 4.07, nominal p=0.046).

Conclusions

LLDAS attainment represents a clinically meaningful SLE outcome measure, and anifrolumab is associated with more patients who met LLDAS criteria versus placebo. These data support LLDAS as an SLE RCT endpoint.

Trial registration number

NCT1438489; Post-results.

Molecular basis for antagonistic activity of anifrolumab, an anti-interferon-α receptor 1 antibody

Anifrolumab (anifrolumab) is an antagonist human monoclonal antibody that targets interferon α receptor 1 (IFNAR1). Anifrolumab has been developed to treat autoimmune diseases and is currently in clinical trials. To decipher the molecular basis of its mechanism of action, we engaged in multiple epitope mapping approaches to determine how it interacts with IFNAR1 and antagonizes the receptor. We identified the epitope of anifrolumab using enzymatic fragmentation, phage-peptide library panning and mutagenesis approaches. Our studies revealed that anifrolumab recognizes the SD3 subdomain of IFNAR1 with the critical residue R²⁷⁹. Further, we solved the crystal structure of anifrolumab Fab to a resolution of 2.3 Å. Guided by our epitope mapping studies, we then used in silico protein docking of the anifrolumab Fab crystal structure to IFNAR1 and characterized the corresponding mode of binding. We find that anifrolumab sterically inhibits the binding of IFN ligands to IFNAR1, thus blocking the formation of the ternary IFN/IFNAR1/IFNAR2 signaling complex. This report provides the molecular basis for the mechanism of action of anifrolumab and may provide insights toward designing antibody therapies against IFNAR1.