Safety profile of anifrolumab in patients with active SLE: an integrated analysis of phase II and III trials

Targeting Interferon Signalling in Systemic Lupus Erythematosus: Lessons Learned

The development of new medicines for systemic lupus erythematosus (SLE) has not addressed unmet clinical need, with only three drugs receiving regulatory approval for SLE in the last 60 years, one of which was specifically licensed for lupus nephritis. In the last 20 years it has become clear that activation of type 1 interferons (IFN) is reproducibly detected in the majority of SLE patients, and the actions of IFN in the immune system and on target tissues is consistent with a pathogenic role in SLE. These findings led to considerable drug discovery activity, first with agents directly targeting IFN family cytokines, with results that were encouraging but underwhelming. In contrast, targeting the type I IFN receptor with the monoclonal antibody anifrolumab, thereby blocking all IFN family members, was effective in a phase II clinical trial. This led to a pair of phase III trials, one of which was negative and the other positive, reflecting the difficulty of obtaining outcomes from trials in this complex disease. Nonetheless, the balance of evidence resulted in approval of anifrolumab in multiple jurisdictions from 2021 onwards. Multiple approaches to targeting the type 1 IFN pathway have subsequently had positive phase II clinical trials, including antibodies targeting cells that produce IFN, and small molecules targeting the receptor kinase TYK2, required for IFN signalling. Despite multiple hurdles, it is clear that IFN targeting in SLE is here to stay. The story of IFN-targeting therapy in SLE has lessons for drug development overall in this disease.

TYK2: an emerging therapeutic target in rheumatic disease

Tyrosine kinase 2 (TYK2) is a member of the JAK kinase family of intracellular signalling molecules. By participating in signalling pathways downstream of type I interferons, IL-12, IL-23 and IL-10, TYK2 elicits a distinct set of immune events to JAK1, JAK2 and JAK3. TYK2 polymorphisms have been associated with susceptibility to various rheumatic diseases including systemic lupus erythematosus and dermatomyositis. In vitro and animal studies substantiate these findings, highlighting a role for TYK2 in diseases currently managed by antagonists of cytokines that signal through TYK2. Various inhibitors of TYK2 have now been studied in human disease, and one of these inhibitors, deucravacitinib, has now been approved for the treatment of psoriasis. Phase II trials of deucravacitinib have also reported positive results in the treatment of psoriatic arthritis and systemic lupus erythematosus, with a preliminary safety profile that seems to differ from that of the JAK1, JAK2 and JAK3 inhibitors. Two other inhibitors of TYK2, brepocitinib and ropsacitinib, are also in earlier stages of clinical trials. Overall, TYK2 inhibitors hold promise for the treatment of a distinct spectrum of autoimmune diseases and could potentially have a safety profile that differs from other JAK inhibitors.

Safety, Tolerability, Pharmacokinetics, and Immunogenicity of the Anti-IFNAR1 Monoclonal Antibody QX006N: A First-in-Human Single Ascending Dose Study in Healthy Chinese Volunteers

BACKGROUND AND OBJECTIVE

QX006N is a novel, humanized, IgG4κ monoclonal antibody targeting IFNAR1, developed for the treatment of systemic lupus erythematosus. This study aims to investigate the pharmacokinetics, safety, tolerability, and immunogenicity of QX006N when administered intravenously to healthy Chinese individuals.

METHODS

A double-blind, randomized, placebo-controlled, single-ascending-dose, phase I clinical trial was conducted comprising five cohorts (n = 10 per cohort, except n = 5 for the first cohort). Subjects in each cohort were randomly assigned in a 4:1 ratio to receive a single intravenous infusion of QX006N (0.3 mg/kg, 1.0 mg/kg, 3.0 mg/kg, 6.0 mg/kg, or 10.0 mg/kg) or placebo for 30 minutes. Tolerability assessments included adverse events, vital signs, 12-lead electrocardiogram, physical examination, and clinical laboratory tests. The serum concentration of QX006N was measured using the enzyme-linked immunosorbent assay method, and the anti-drug antibodies were detected using the electrochemiluminescence assay method.

RESULTS

QX006N demonstrated a favorable safety and tolerability profile throughout the study. All treatment-emergent adverse events were of Grade 1-2 (CTCAE Version 5.0), and no serious adverse events, deaths, or drug discontinuations because of treatment-emergent adverse events were observed. All drug-related treatment-emergent adverse events showed no clear dose-related trends. Following an intravenous infusion of QX006N at doses that ranged from 0.3 mg/kg to 10 mg/kg, the half-life increased from 24.7 to 208 hours in a dose-dependent manner, while clearance decreased from 0.0828 to 0.0065 L/h. The maximum concentration exhibited nearly dose-proportional increases, and the area under the curve displayed a more than dose-proportional increment with non-linear pharmacokinetic characteristics. The incidence of anti-drug antibodies was observed to increase over time for doses that ranged from 1.0 mg/kg to 10.0 mg/kg of QX006N, reaching its peak at day 57 (range 62.50-87.50%). Conversely, the incidence of anti-drug antibodies in the QX006N 0.3-mg/kg and placebo cohorts remained low.

CONCLUSIONS

QX006N demonstrated acceptable safety, tolerability, and pharmacokinetic characteristics in healthy subjects when administered as a single intravenous infusion at doses that ranged from 0.3 mg/kg to 10.0 mg/kg. Based on the pharmacokinetic and safety outcomes, a recommended effective dose of 300 mg is proposed for future phase Ib studies.

CLINICAL TRIAL REGISTRATION

This study has been registered at http://www.chinadrugtrials.org.cn/ under identifier CTR20212834.

Vaccination updates and special considerations for systemic lupus erythematosus patients

PURPOSE OF REVIEW

We review the latest guidelines and note special considerations for systemic lupus erythematosus (SLE) patients when approaching vaccination against SARS-CoV-2, influenza, pneumococcus, herpes zoster, and potentially respiratory syncytial virus (RSV) vaccine in the future.

RECENT FINDINGS

SLE patients have unique infectious risks due to newer treatments and the nature of the disease itself. It is important to balance the benefit of additional protective immunity from updated vaccines against the possible risk of disease activity exacerbations.

SUMMARY

It is important to continuously evaluate the safety and immunogenicity of updated vaccines specifically for SLE patients. Additionally, the newly approved RSV vaccine should be considered for this population to reduce severe respiratory illness.

Human autoantibodies neutralizing type I IFNs: From 1981 to 2023

Human autoantibodies (auto-Abs) neutralizing type I IFNs were first discovered in a woman with disseminated shingles and were described by Ion Gresser from 1981 to 1984. They have since been found in patients with diverse conditions and are even used as a diagnostic criterion in patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1). However, their apparent lack of association with viral diseases, including shingles, led to wide acceptance of the conclusion that they had no pathological consequences. This perception began to change in 2020, when they were found to underlie about 15% of cases of critical COVID-19 pneumonia. They have since been shown to underlie other severe viral diseases, including 5%, 20%, and 40% of cases of critical influenza pneumonia, critical MERS pneumonia, and West Nile virus encephalitis, respectively. They also seem to be associated with shingles in various settings. These auto-Abs are present in all age groups of the general population, but their frequency increases with age to reach at least 5% in the elderly. We estimate that at least 100 million people worldwide carry auto-Abs neutralizing type I IFNs. Here, we briefly review the history of the study of these auto-Abs, focusing particularly on their known causes and consequences.

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: first biologic approved in the EU not restricted to patients with a high degree of disease activity for the treatment of moderate to severe systemic lupus erythematosus

INTRODUCTION

Type 1 interferons (IFNs) play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE) and various type I IFNs targeting therapeutic approaches have been developed. Anifrolumab, a monoclonal antibody that binds to the subunit 1 of the type I IFN receptor, has acquired considerable interest and has entered different clinical human trials willing to evaluate its efficacy and safety.

AREAS COVERED

This review summarizes the data obtained in phases 1, 2, and 3 clinical trials of anifrolumab for SLE patients. A focus is made on data of clinical efficacy and safety obtained in MUSE, TULIP-1 and TULIP-2 trials.

EXPERT OPINION/COMMENTARY

Anifrolumab is a promising therapeutic option for patients with SLE, currently authorized for moderate-to-severe SLE. Extensive real-world use is now going to generate data required to gain experience on the type of patients who benefit the most from the drug, and the exact positioning of anifrolumab in the therapeutic plan.

Emerging immunotherapeutic strategies for cutaneous lupus erythematosus: an overview of recent phase 2 and 3 clinical trials

INTRODUCTION

Cutaneous lupus erythematosus (CLE) is an autoimmune disease that is clinically heterogenous and may occur with or without the presence of systemic lupus erythematosus (SLE). While existing on a spectrum, CLE and SLE present differences in their underlying pathogenesis and therapeutic responses. No new therapies have been approved in recent decades by the U.S. Food and Drug Administration for CLE, although frequently refractory to conventional therapies. There is an unmet need to develop effective drugs for CLE as it significantly impacts patients' quality of life and may leave irreversible disfiguring damage.

AREAS COVERED

This review provides an update on the latest phase 2 and 3 clinical trials performed in CLE or SLE using skin-specific outcome measures. Emergent therapies are presented alongside their mechanism of action as recent translational studies have permitted identification of critical targets among immune cells and/or pathways involved in CLE.

EXPERT OPINION

While the recent literature has few trials for CLE, drugs targeting type I interferon, its downstream signaling and plasmacytoid dendritic cells have shown promising results. Further research is required to develop long-awaited effective therapies, and this review highlights the importance of implementing trials dedicated to CLE to fill the current gap in CLE therapeutics.

Advances in the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe multisystem autoimmune disease that can cause injury in almost every body system. While considered a classic example of autoimmunity, it is still relatively poorly understood. Treatment with immunosuppressive agents is challenging, as many agents are relatively non-specific, and the underlying disease is characterized by unpredictable flares and remissions. This State of The Art Review provides a comprehensive current summary of systemic lupus erythematosus based on recent literature. In basic and translational science, this summary includes the current state of genetics, epigenetics, differences by ancestry, and updates about the molecular and immunological pathogenesis of systemic lupus erythematosus. In clinical science, the summary includes updates in diagnosis and classification, clinical features and subphenotypes, and current guidelines and strategies for treatment. The paper also provides a comprehensive review of the large number of recent clinical trials in systemic lupus erythematosus. Current knowns and unknowns are presented, and potential directions for the future are suggested. Improved knowledge of immunological pathogenesis and the molecular differences that exist between patients should help to personalize treatment, minimize side effects, and achieve better outcomes in this difficult disease.

Anifrolumab in lupus nephritis: results from second-year extension of a randomised phase II trial

OBJECTIVE

To characterise the safety and efficacy of anifrolumab in active lupus nephritis (LN) through year 2 of the phase II randomised, double-blind Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP)-LN trial (NCT02547922) of 2 anifrolumab dosing regimens versus placebo.

METHODS

Patients received intravenous anifrolumab 900 mg for the first 3 doses followed by 300 mg anifrolumab (intensified regimen (IR)), 300 mg anifrolumab (basic regimen (BR)) or placebo every 4 weeks throughout. To continue into Year 2, patients must have achieved at least partial renal response and a glucocorticoid tapering target.

RESULTS

Of 147 randomised patients, 101 completed Year 1 study treatment; of these, 75 (74%) continued into Year 2 (anifrolumab IR: n=29, BR: n=23 and placebo: n=23). During Year 2, 72% of patients reported ≥1 adverse event (AE); serious AEs were reported in 6.9%, 8.7% and 8.7% of patients (anifrolumab IR, BR and placebo, respectively); 3 patients discontinued treatment due to an AE (anifrolumab IR: n=2 and placebo: n=1) and herpes zoster was reported in 2 patients (anifrolumab IR: n=1 and BR: n=1). The study was ongoing at the start of the pandemic, but no COVID-19 cases were reported. Of the 145 patients receiving treatment, more patients on the IR attained complete renal response at Week 104 compared with those on BR or placebo (27.3% vs 18.6% and 17.8%) and simultaneously achieved sustained glucocorticoid tapering (IR: 25.0%; BR: 18.6% and placebo: 17.8%). The improvements in estimated glomerular filtration rate were numerically larger in both anifrolumab groups versus placebo.

CONCLUSIONS

The safety and tolerability profile through Year 2 of TULIP-LN was generally consistent with Year 1, with promising efficacy results for the anifrolumab IR regimen. Collectively, the results support further investigation of an anifrolumab intensified dosing regimen in larger populations of patients with active proliferative LN.

TRIAL REGISTRATION NUMBER

NCT02547922.

Preclinical characterization of the Toll-like receptor 7/8 antagonist MHV370 for lupus therapy

Genetic and in vivo evidence suggests that aberrant recognition of RNA-containing autoantigens by Toll-like receptors (TLRs) 7 and 8 drives autoimmune diseases. Here we report on the preclinical characterization of MHV370, a selective oral TLR7/8 inhibitor. In vitro, MHV370 inhibits TLR7/8-dependent production of cytokines in human and mouse cells, notably interferon-α, a clinically validated driver of autoimmune diseases. Moreover, MHV370 abrogates B cell, plasmacytoid dendritic cell, monocyte, and neutrophil responses downstream of TLR7/8. In vivo, prophylactic or therapeutic administration of MHV370 blocks secretion of TLR7 responses, including cytokine secretion, B cell activation, and gene expression of, e.g., interferon-stimulated genes. In the NZB/W F1 mouse model of lupus, MHV370 halts disease. Unlike hydroxychloroquine, MHV370 potently blocks interferon responses triggered by specific immune complexes from systemic lupus erythematosus patient sera, suggesting differentiation from clinical standard of care. These data support advancement of MHV370 to an ongoing phase 2 clinical trial.

Clinical Pharmacokinetics, Pharmacodynamics, and Immunogenicity of Anifrolumab

The type I interferon (IFN) signaling pathway is implicated in the pathogenesis of systemic lupus erythematosus (SLE). Anifrolumab is a monoclonal antibody that targets the type I IFN receptor subunit 1. Anifrolumab is approved in several countries for patients with moderate to severe SLE receiving standard therapy. The approved dosing regimen of anifrolumab is a 300-mg dose administered intravenously every 4 weeks; this was initially based on the results of the Phase 2b MUSE and further confirmed in the Phase 3 TULIP-1 and TULIP-2 trials, in which anifrolumab 300-mg treatment was associated with clinically meaningful improvements in disease activity with an acceptable safety profile. There have been several published analyses of the pharmacokinetic and pharmacodynamic profile of anifrolumab, including a population-pharmacokinetic analysis of 5 clinical studies of healthy volunteers and patients with SLE, in which body weight and type I IFN gene expression were significant covariates identified for anifrolumab exposure and clearance. Additionally, the pooled Phase 3 SLE population has been used to evaluate how serum exposure may be related to clinical responses, safety risks, and pharmacodynamic effects of the 21-gene type I IFN gene signature (21-IFNGS). The relevance of 21-IFNGS with regard to clinical efficacy outcomes has also been analyzed. Herein, the clinical pharmacokinetics, pharmacodynamics, and immunogenicity of anifrolumab as well as results of population-pharmacokinetics and exposure-response analyses are reviewed.

Cutaneous Lupus Erythematosus: An Update on Pathogenesis and Future Therapeutic Directions

Lupus erythematosus comprises a spectrum of autoimmune diseases that may affect various organs (systemic lupus erythematosus [SLE]) or the skin only (cutaneous lupus erythematosus [CLE]). Typical combinations of clinical, histological and serological findings define clinical subtypes of CLE, yet there is high interindividual variation. Skin lesions arise in the course of triggers such as ultraviolet (UV) light exposure, smoking or drugs; keratinocytes, cytotoxic T cells and plasmacytoid dendritic cells (pDCs) establish a self-perpetuating interplay between the innate and adaptive immune system that is pivotal for the pathogenesis of CLE. Therefore, treatment relies on avoidance of triggers and UV protection, topical therapies (glucocorticosteroids, calcineurin inhibitors) and rather unspecific immunosuppressive or immunomodulatory drugs. Yet, the advent of licensed targeted therapies for SLE might also open new perspectives in the management of CLE. The heterogeneity of CLE might be attributable to individual variables and we speculate that the prevailing inflammatory signature defined by either T cells, B cells, pDCs, a strong lesional type I interferon (IFN) response, or combinations of the above might be suitable to predict therapeutic response to targeted treatment. Therefore, pretherapeutic histological assessment of the inflammatory infiltrate could stratify patients with refractory CLE for T-cell-directed therapies (e.g. dapirolizumab pegol), B-cell-directed therapies (e.g. belimumab), pDC-directed therapies (e.g. litifilimab) or IFN-directed therapies (e.g. anifrolumab). Moreover, Janus kinase (JAK) and spleen tyrosine kinase (SYK) inhibitors might broaden the therapeutic armamentarium in the near future. A close interdisciplinary exchange with rheumatologists and nephrologists is mandatory for optimal treatment of lupus patients to define the best therapeutic strategy.

Lupus low disease activity state attainment in the phase 3 TULIP trials of anifrolumab in active systemic lupus erythematosus

OBJECTIVES

In patients with systemic lupus erythematosus (SLE), lupus low disease activity state (LLDAS) attainment is associated with improved outcomes. We investigated LLDAS attainment in anifrolumab-treated patients.

METHODS

We performed post hoc analysis of pooled Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP-1) (NCT02446912) and TULIP-2 (NCT02446899) anifrolumab phase 3 trial data in patients with moderate to severe SLE receiving standard therapy. LLDAS was defined as: SLE Disease Activity Index 2000 ≤4 without major organ activity, no new disease activity, Physician's Global Assessment ≤1, prednisone ≤7.5 mg/day and no non-standard immunosuppressant dosing. Time to first LLDAS attainment was compared between groups using Cox regression modelling; responses were compared using logistic regression.

RESULTS

Agnostic to treatment, 205/819 (25.0%) patients attained LLDAS at week 52; 186/205 (90.7%) were also British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA)-responders. Among BICLA-responders at week 52, 186/318 (58.5%) attained LLDAS; 203/380 (53.4%) SLE Responder Index-4 (SRI(4)) responders attained LLDAS. Improvements from baseline in patient global assessment scores at week 52 were threefold greater in LLDAS-attainers. At week 52, 30.0% of anifrolumab-treated patients and 19.6% of placebo were in LLDAS (OR 1.8, 95% CI 1.3 to 2.5, p=0.0011). Compared with placebo, anifrolumab treatment was associated with earlier LLDAS attainment (time to first LLDAS, HR 1.76, 95% CI 1.35 to 2.30, p<0.0001), increased cumulative time in LLDAS (p<0.0001) and higher likelihood of sustained LLDAS (p<0.001). Anifrolumab treatment was also associated with higher rates of Definition of Remission in SLE remission at week 52 (15.3% vs 7.6%; OR 2.2, 95% CI 1.4 to 3.6, p=0.0013).

CONCLUSIONS

LLDAS attainment was highly associated with, but more stringent than, BICLA and SRI(4) responses. Compared with placebo, anifrolumab treatment was associated with earlier, more frequent, and more prolonged and sustained LLDAS.

TRIAL REGISTRATION NUMBERS

NCT02446912 and NCT02446899.

New biologics and targeted therapies in systemic lupus: From new molecular targets to new indications. A systematic review

INTRODUCTION

Despite available therapies, persistently active and corticosteroid-dependent Systemic Lupus Erythematosus (SLE) represent a significant therapeutic challenge. The purpose of this systematic review was to provide an updated view of targeted therapies currently in clinical development in SLE, with a special focus on the most promising ones.

METHODS

We performed a systematic review of targeted therapies in clinical development in SLE in clinicaltrials.gov (search date: 28th of August 2022). Targeted therapies (defined as drugs specifically designed to block certain molecules, receptors, or pathways involved in the development of SLE) were extracted. For each investigational drug, we considered only the study at the most advanced stage of clinical development.

RESULTS

The systematic review yielded a total of 92 targeted therapies (58 biological DMARDs [bDMARDs] and 34 targeted synthetic [ts]DMARDs) assessed in a total of 203 clinical trials. The candidate drugs reached phase I (n=20), Ia/IIb (n=6), phase II (n=51), phase II/III (n=1), phase III (n=13) and phase IV (n=1). These trials were reported as recruiting (n=31), active but not recruiting (n=8), not yet recruiting (n=4), enrolling by invitation (n=2), completed (n=31), prematurely terminated (n=12) and withdrawn in 1 (status unknown in 3). The main investigational drugs for SLE target inflammatory cytokines, chemokines or their receptors (n=19), intracellular signaling pathways (n=18), B cells (n=14) or plasma cells (n=7),T/B cells co-stimulation molecules (n=10), complement molecules (n=5),T lymphocytes (n=2), plasmacytoid dendritic cells (n=2), as well as various other immune targets (n=15).

CONCLUSION

The pipeline of investigational drugs in SLE is highly diversified and will hopefully enable more optimal Treat-To-Target with the goal of disease modification. Companion biomarkers will be needed to better characterized SLE heterogeneity and optimize treatment selection at the individual-patient level.

A Randomized, Placebo-Controlled Phase III Extension Trial of the Long-Term Safety and Tolerability of Anifrolumab in Active Systemic Lupus Erythematosus

OBJECTIVE

To explore long-term safety and tolerability of anifrolumab 300 mg compared with placebo in patients with systemic lupus erythematosus (SLE) who completed a Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP) trial and enrolled in the placebo-controlled 3-year long-term extension (LTE) study (ClinicalTrials.gov identifier: NCT02794285).

METHODS

In the blinded LTE study, patients continued anifrolumab 300 mg, switched from anifrolumab 150 mg to 300 mg, or were re-randomized from placebo to receive either anifrolumab 300 mg or to continue placebo, administered every 4 weeks. Primary comparisons in the LTE study were between patients who received anifrolumab 300 mg or placebo throughout the TULIP and LTE studies. For rare safety events, comparisons included patients who received any anifrolumab dose during TULIP or LTE. When exposure differed, exposure-adjusted incidence rates (EAIRs) per 100 patient-years were calculated.

RESULTS

In the LTE study, EAIRs of serious adverse events (SAEs) were 8.5 with anifrolumab compared with 11.2 with placebo; likewise, EAIRs of AEs leading to treatment discontinuation were 2.5 versus 3.2, respectively. EAIRs of non-opportunistic serious infections were comparable between groups (3.7 with anifrolumab versus 3.6 with placebo). Exposure-adjusted event rates of COVID-related AEs, including asymptomatic infections, were 15.5 with anifrolumab compared with 9.8 with placebo. No COVID-related AEs occurred in fully vaccinated individuals. EAIRs of malignancy and major acute cardiovascular events were low and comparable between groups. Anifrolumab was associated with lower cumulative glucocorticoid use and greater mean improvement in the SLE Disease Activity Index 2000, compared with placebo.

CONCLUSION

This LTE study represents the longest placebo-controlled clinical trial performed in SLE to date. No new safety findings were identified in the LTE study, supporting the favorable benefit-risk profile of anifrolumab for patients with moderate-to-severe SLE receiving standard therapy.

Time to onset of clinical response to anifrolumab in patients with SLE: pooled data from the phase III TULIP-1 and TULIP-2 trials

OBJECTIVES

To evaluate the time course of clinical response following anifrolumab treatment in patients with SLE.

METHODS

A post hoc analysis was conducted using pooled data from phase III, randomised, 52-week, placebo-controlled, Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP)-1 and TULIP-2 trials of intravenous anifrolumab (every 4 weeks, 48 weeks) in patients with moderate-to-severe SLE receiving standard therapy. Anifrolumab 300 mg and placebo groups were compared for British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response over time, time to sustained BICLA response, SLE Responder Index ≥4 (SRI(4)) response over time, time to sustained Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A) response and change in glucocorticoid dosage over time. All p values for comparisons were nominal.

RESULTS

Of the 726 evaluated patients (anifrolumab 300 mg, n=360; placebo, n=366), a greater proportion attained a BICLA response in the anifrolumab versus the placebo group from Week 8 (p<0.001); treatment group differentiation was maintained at all subsequent visits to Week 52. Consistently, more patients achieved a BICLA response sustained to Week 52 in the anifrolumab versus placebo group (HR=1.73, 95% CI 1.37 to 2.20). More patients attained SRI(4) response with anifrolumab than placebo from Week 12 (p=0.005). As early as Week 8, more patients achieved CLASI-A skin response sustained to Week 52 with anifrolumab versus placebo (HR=1.72, 95% CI 1.17 to 2.55). Glucocorticoid dosage reductions from baseline were greater in anifrolumab-treated versus placebo-treated patients from Week 20 (p=0.010) through Week 52.

CONCLUSIONS

Anifrolumab treatment was associated with sustained improvements in overall SLE disease activity and skin responses versus placebo from Week 8, which likely led to greater glucocorticoid reductions in the anifrolumab versus placebo groups from Week 20. These findings provide insights to physicians and patients on when to expect potential clinical responses following anifrolumab treatment.

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.

[National consensus statement by the Austrian Societies for Rheumatology, Pulmonology, Infectiology, Dermatology and Gastroenterology regarding the management of latent tuberculosis and the associated utilization of biologic and targeted synthetic DMARDS (disease modifying antirheumatic drugs)]

This nationwide Austrian consensus statement summarizes the recommendations on the management of latent tuberculosis by treatment with biologic and targeted synthetic DMARDs. The essential questions with respect to screening and preventive treatment were discussed by experts from the disciplines of rheumatology, pneumology, infectious diseases, dermatology and gastroenterology, based on the available data, and then a joint consensus was formed by agreement. This involved a differentiated discussion on the various forms of treatment, and clear recommendations were formulated.

Evaluation of anifrolumab safety in systemic lupus erythematosus: A meta-analysis and systematic review

Objectives

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, and type I interferon plays an important role in its pathogenesis. Anifrolumab is a new strategy for the treatment of systemic lupus erythematosus. It could antagonize the activity of all type 1 interferons by binding with type I interferon receptor subunit 1. The aim of our study was to evaluate the safety of anifrolumab in patients with moderate to severe SLE (excluding patients with active severe lupus nephritis or central nervous system lupus).

Methods

Four databases (Embase, Cochrane, PubMed, Web of Science) were systematically searched from inception until December 2021 for randomized controlled trials (RCTs) evaluating the safety of anifrolumab versus placebo in SLE patients. Then, the incidence of adverse events in each study was aggregated using meta-analysis.

Results

A total of 1160 SLE patients from four RCTs were included in the analysis. Serious adverse events were less common in the anifrolumab group than in the placebo group (RR: 0.76, 95% CI: 0.59-0.98, p<0.03). The most common adverse events included upper respiratory tract infection (RR: 1.48, 95% CI: 1.13-1.94, P=0.004), nasopharyngitis (RR: 1.66, 95% CI: 1.25-2.20, P=0.0004), bronchitis (RR: 1.96, 95% CI: 1.32-2.92, P=0.0009), and herpes zoster (RR: 3.40, 95% CI: 1.90-6.07, P<0.0001).

Conclusion

Anifrolumab is considered a well-tolerated option for the treatment of SLE patients with good safety.

Systematic Review Registration

https://inplasy.com, identifier 202230054.

Biological drugs for systemic lupus erythematosus or active lupus nephritis and rates of infectious complications. Evidence from large clinical trials

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease that frequently affects the kidneys, known as lupus nephritis (LN). Such patients are treated with antimalarials, corticosteroids or immunosuppressive drugs, and more recently, target-specific biological drugs. Although efficacy of these therapies improved SLE-related outcomes, SLE remains associated with higher rates of infections. Here, we performed a comprehensive systemic review of infectious complications in clinical trials covering drug interventions for SLE or specifically for active LN. Our search in 15 online registries yielded a total of 1477 studies of which 14 matched our prespecified criteria. These covered the biological drugs anifrolumab, belimumab, and rituximab that were tested in patients with non-renal SLE and active LN.The available safety data from the SLE trials indicated that infectious complications such as herpes zoster, upper respiratory tract infection, nasopharyngitis, bronchitis, and urinary tract infection in patients receiving placebo were quite prevalent especially in the EXPLORER (rituximab) trial. Infections occurred mostly during the first year of LN therapy. Serious adverse events and infectious complications occurred more frequently in placebo-treated patients with active LN, especially in the BLISS-LN (belimumab) and LUNAR (rituximab) trials. Anifrolumab and rituximab increased the number of clinically relevant episodes of herpes zoster compared to belimumab in patients with active LN. Anifrolumab displayed a similar trend for influenza infections, which is consistent with the specific mechanisms-of-action of anifrolumab; highlighting drug-specific effects on infectious complications. In addition, standard-of-care therapy, e.g., MMF and immunosuppressants, as well as a longer SLE duration may also affect the incidence of serious adverse events and certain infectious complications in SLE patients with active LN.Infectious complications are common in SLE but even more common in patients with active LN, especially herpes zoster is strongly associated with active LN and anifrolumab therapy (OR 2.8, 95% CI 1.18 to 6.66, p = 0.018). Immunotherapy seems to impose unspecific and specific risks for infections. The latter may imply specific precautions such as preemptive vaccination and individual risk-benefit assessments.

Belimumab or anifrolumab for systemic lupus erythematosus? A risk-benefit assessment

Treatment of systemic lupus erythematosus (SLE) currently employs agents with relatively unselective immunosuppressive properties. However, two target-specific biological drugs have been approved: belimumab (anti-B-cell-activating factor/BAFF) and anifrolumab (anti-interferon alpha receptor-1/IFNAR1). Here, we performed a comparative risk-benefit assessment for both drugs based on the role of BAFF and IFNAR1 in host defense and the pathogenesis of SLE and by considering the available data on safety and efficacy. Due to differences in target expression sites, anti-IFNAR1, but not anti-BAFF, might elicit organ-specific effects, consistent with clinical efficacy data. The IFNAR1 is specifically involved in innate and adaptive antiviral immunity in most cells of the body. Consistent with this observation, the available safety data obtained from patients negatively selected for LN and neuropsychiatric SLE, primary immunodeficiencies, splenectomy and chronic HIV, HBV, HCV infections suggest an increased risk for some viral infections such as varicella zoster and perhaps influenza. In contrast, BAFF is mainly involved in adaptive immune responses in lymphoid tissues, thus anti-BAFF therapy modulates SLE activity and prevents SLE flares without interfering with local innate host defense mechanisms and should only marginally affect immune memory to previous pathogen exposures consistent with the available safety data from SLE patients without chronic HIV, HBV or HCV infections. When using belimumab and anifrolumab, careful patient stratification and specific precautions may minimize risks and maximize beneficial treatment effects for patients with SLE.

National consensus statement by the Austrian Societies for Rheumatology, Pulmonology, Infectiology, Dermatology and Gastroenterology regarding the management of latent tuberculosis and the associated utilization of biologic and targeted synthetic disease modifying antirheumatic drugs (DMARDs)

This publication provides a thorough analysis of the most relevant topics concerning the management of latent tuberculosis when using biologic and targeted synthetic Disease Modifying Antirheumatic Drugs (DMARDs) by a multidisciplinary, select committee of Austrian physicians. The committee includes members of the Austrian Societies for Rheumatology and Rehabilitation, Pulmonology, Infectiology, Dermatology and Gastroenterology. Consensus was reached on issues regarding screening and treatment of latent tuberculosis and includes separate recommendations for each biologic and targeted synthetic DMARD.

Lower disease activity but higher risk of severe COVID-19 and herpes zoster in patients with systemic lupus erythematosus with pre-existing autoantibodies neutralising IFN-α

OBJECTIVES

Type-I interferons (IFNs-I) have potent antiviral effects. IFNs-I are also overproduced in patients with systemic lupus erythematosus (SLE). Autoantibodies (AAbs) neutralising IFN-α, IFN-β and/or IFN-ω subtypes are strong determinants of hypoxemic COVID-19 pneumonia, but their impact on inflammation remains unknown.

METHODS

We retrospectively analysed a monocentric longitudinal cohort of 609 patients with SLE. Serum AAbs against IFN-α were quantified by ELISA and functionally assessed by abolishment of Madin-Darby bovine kidney cell protection by IFN-α2 against vesicular stomatitis virus challenge. Serum-neutralising activity against IFN-α2, IFN-β and IFN-ω was also determined with a reporter luciferase activity assay. SARS-CoV-2 antibody responses were measured against wild-type spike antigen, while serum-neutralising activity was assessed against the SARS-CoV-2 historical strain and variants of concerns.

RESULTS

Neutralising and non-neutralising anti-IFN-α antibodies are present at a frequency of 3.3% and 8.4%, respectively, in individuals with SLE. AAbs neutralising IFN-α, unlike non-neutralising AAbs, are associated with reduced IFN-α serum levels and a reduced likelihood to develop active disease. However, they predispose patients to an increased risk of herpes zoster and severe COVID-19 pneumonia. Severe COVID-19 pneumonia in patients with SLE is mostly associated with combined neutralisation of different IFNs-I. Finally, anti-IFN-α AAbs do not interfere with COVID-19 vaccine humoral immunogenicity.

CONCLUSION

The production of non-neutralising and neutralising anti-IFN-I antibodies in SLE is likely to be a consequence of SLE-associated high IFN-I serum levels, with a beneficial effect on disease activity, yet a greater viral risk. This finding reinforces the recommendations for vaccination against SARS-CoV-2 in SLE.

Indirect treatment comparison of anifrolumab efficacy versus belimumab in adults with systemic lupus erythematosus

Aim: Assess the comparative efficacy of anifrolumab 300 mg versus belimumab 10 mg/kg in adults with moderate-to-severe systemic lupus erythematosus (SLE) receiving standard therapy. Patients and methods: Population-adjusted simulated treatment comparisons (primary analyses) and matching-adjusted indirect comparisons (supporting analyses) were conducted using individual patient data from TULIP-1/TULIP-2 and summary-level data from BLISS-52/BLISS-76. Results: Compared with belimumab-treated patients, anifrolumab-treated patients were more than twice as likely to achieve a reduction of four or more points in SLE Disease Activity Index 2000 score (simulated treatment comparison odds ratio: 2.47; 95% CI: 1.16-5.25) and SLE Responder Index-4 response (odds ratio: 2.61; 95% CI: 1.22-5.58) at 52 weeks. Conclusion: Patients with moderate-to-severe SLE are more likely to achieve an improvement in disease activity with anifrolumab than with belimumab.

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.

Nonlinear Population Pharmacokinetics of Anifrolumab in Healthy Volunteers and Patients With Systemic Lupus Erythematosus

We characterized the population pharmacokinetics of anifrolumab, a type I interferon receptor–blocking antibody. Pharmacokinetic data were analyzed from the anifrolumab (intravenous [IV], every 4 weeks) arms from 5 clinical trials in patients with systemic lupus erythematosus (SLE) (n = 664) and healthy volunteers (n = 6). Population pharmacokinetic modeling was performed using a 2‐compartment model with parallel linear and nonlinear elimination pathways. The impact of covariates (demographics, interferon gene signature [IFNGS, high/low], disease characteristics, renal/hepatic function, SLE medications, and antidrug antibodies) on pharmacokinetics was evaluated. Time‐varying clearance (CL) was characterized using an empirical sigmoidal time‐dependent function. Anifrolumab exposure increased more than dose‐proportionally from 100 to 1000 mg IV every 4 weeks. Based on population pharmacokinetics modeling, the baseline median linear CL was 0.193 L/day in IFNGS‐high patients and 0.153 L/day in IFNGS‐low/healthy volunteers. After a year, median anifrolumab linear CL decreased by 8.4% from baseline. Body weight and IFNGS were significant pharmacokinetic covariates, whereas age, sex, race, disease activity, SLE medications, and presence of antidrug antibodies had no significant effect on anifrolumab pharmacokinetics. Anifrolumab at a concentration of 300 mg IV every 4 weeks was predicted to be below the lower limit of quantitation in 95% of patients ≈10 weeks after a single dose and ≈16 weeks after stopping dosing at steady state. To conclude, anifrolumab exhibited nonlinear pharmacokinetics and time‐varying linear CL; doses ≥300 mg IV every 4 weeks provided sustained anifrolumab concentrations. This study provides further evidence to support the use of anifrolumab 300 mg IV every 4 weeks in patients with moderate to severe SLE.

Human autoantibodies underlying infectious diseases

The vast interindividual clinical variability observed in any microbial infection—ranging from silent infection to lethal disease—is increasingly being explained by human genetic and immunological determinants. Autoantibodies neutralizing specific cytokines underlie the same infectious diseases as inborn errors of the corresponding cytokine or response pathway. Autoantibodies against type I IFNs underlie COVID-19 pneumonia and adverse reactions to the live attenuated yellow fever virus vaccine. Autoantibodies against type II IFN underlie severe disease caused by environmental or tuberculous mycobacteria, and other intra-macrophagic microbes. Autoantibodies against IL-17A/F and IL-6 are less common and underlie mucocutaneous candidiasis and staphylococcal diseases, respectively. Inborn errors of and autoantibodies against GM-CSF underlie pulmonary alveolar proteinosis; associated infections are less well characterized. In individual patients, autoantibodies against cytokines preexist infection with the pathogen concerned and underlie the infectious disease. Human antibody-driven autoimmunity can interfere with cytokines that are essential for protective immunity to specific infectious agents but that are otherwise redundant, thereby underlying specific infectious diseases.

Anifrolumab efficacy and safety by type I interferon gene signature and clinical subgroups in patients with SLE: post hoc analysis of pooled data from two phase III trials

Objectives

To characterise the efficacy and safety of anifrolumab in patients with systemic lupus erythematosus (SLE) according to interferon gene signature (IFNGS), demographic and clinical subgroups.

Methods

We performed post hoc analyses of pooled data from the 52-week phase III TULIP-1/TULIP-2 placebo-controlled trials of intravenous anifrolumab in moderate-to-severe SLE. Outcomes were assessed in predefined subgroups: IFNGS (high/low), age, sex, body mass index, race, geographic region, age of onset, glucocorticoid use, disease activity and serological markers.

Results

In pooled data, patients received anifrolumab 300 mg (360/726) or placebo (366/726); 82.6% were IFNGS-high. IFNGS-high patients had greater baseline disease activity and were more likely to have abnormal serological markers versus IFNGS-low patients. In the total population, a greater proportion of patients treated with anifrolumab versus placebo achieved British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response at week 52 (difference 16.6%; nominal p<0.001). BICLA response treatment differences with anifrolumab versus placebo were comparable to the total population across most predefined subgroups, including subgroups for baseline glucocorticoid dosage (<10/≥10 mg/day prednisone/equivalent) and for clinical disease activity (SLE Disease Activity Index 2000 score <10/≥10). Subgroups with larger treatment differences included IFNGS-high patients (18.2%), patients with abnormal baseline serological markers (23.1%) and Asian patients (29.2%). The safety profile of anifrolumab was similar across subgroups.

Conclusions

Overall, this study supports the consistent efficacy and safety of anifrolumab across a range of patients with moderate-to-severe SLE. In a few subgroups, small sample sizes limited conclusions from being drawn regarding the treatment benefit with anifrolumab.

Trial registration number

NCT02446912, NCT02446899.

T Cells, Interleukin-2 and Systemic Lupus Erythematosus—From Pathophysiology to Therapy

The phenotypic and functional complexities of T cells engender complicated and often confusing concepts as to how T cells ignite, accelerate and brake the inflammatory processes involved in systemic lupus erythematosus (SLE), let alone the plasticity of T cells that takes place under different immunological contexts. Nevertheless, being one of the prime survival factors of T cells, interleukin (IL)-2 plays a potentially critical role in many immunological scenarios during the pathophysiological process of SLE. Here, the pathophysiology of lupus T cells and current, as well as ongoing, therapeutic approaches of SLE that involve low-dose IL-2 administration will be highlighted. The mechanisms of IL-2 deficiency in SLE pathophysiology, the effects of low-dose IL-2 on T cells and restoration of lupus manifestations in murine SLE models, as well as the efficacy and safety of clinical trials that evaluated low-dose IL-2-containing regimens in patients with SLE will be discussed.

Causal cascade of direct and indirect effects of anifrolumab on patient-reported outcomes: structural equation modelling of two Phase 3 trials

OBJECTIVES

SLE significantly impairs health-related quality of life (HRQoL). In this post hoc analysis, structural equation modelling was used to examine the 'causal cascade' of interaction between anifrolumab, disease activity and patient-reported outcomes (PROs) in pooled data from the phase 3 TULIP-1 and TULIP-2 trials.

METHODS

Data were pooled from the TULIP-1 (n = 364) and TULIP-2 (n = 362) randomized, placebo-controlled, 52-week trials of intravenous anifrolumab (300 mg every 4 weeks for 48 weeks). We evaluated changes from baseline to week 24 and week 52 in four clinical (BICLA, BILAG-2004, SLEDAI-2K and changes in glucocorticoid dosage) and six PRO measures (SF-36, FACIT-F, EQ-5D, LupusQoL, PHQ-8 and pain NRS) in our hypothesized model of interactions.

RESULTS

Our hypothesized model had an acceptable fit to the pooled TULIP trial data. At week 24, significant paths revealed that when compared with placebo, anifrolumab treatment improved disease activity as measured by BICLA, BILAG-2004, SLEDAI-2K and changes to glucocorticoid dosage. In turn, these clinical measures reduced pain, which improved fatigue, physical functioning, mood/emotions and HRQoL. When the model incorporated number of glucocorticoid tapers as the measure of change in glucocorticoid dosage, treatment effects of anifrolumab on glucocorticoid tapers were not retained at week 52. However, at week 52 treatment indirectly improved HRQoL through its direct effects on BICLA.

CONCLUSIONS

Anifrolumab is associated with significant patient-reported improvements in aspects of HRQoL including pain, fatigue, mood and physical function. These benefits are from the direct effect of anifrolumab treatment on disease activity and reduction in glucocorticoid dosage.

Phase II randomised trial of type I interferon inhibitor anifrolumab in patients with active lupus nephritis

Objective

To assess the efficacy and safety of the type I interferon receptor antibody, anifrolumab, in patients with active, biopsy-proven, Class III/IV lupus nephritis.

Methods

This phase II double-blinded study randomised 147 patients (1:1:1) to receive monthly intravenous anifrolumab basic regimen (BR, 300 mg), intensified regimen (IR, 900 mg ×3, 300 mg thereafter) or placebo, alongside standard therapy (oral glucocorticoids, mycophenolate mofetil). The primary endpoint was change in baseline 24-hour urine protein–creatinine ratio (UPCR) at week (W) 52 for combined anifrolumab versus placebo groups. The secondary endpoint was complete renal response (CRR) at W52. Exploratory endpoints included more stringent CRR definitions and sustained glucocorticoid reductions (≤7.5 mg/day, W24–52). Safety was analysed descriptively.

Results

Patients received anifrolumab BR (n=45), IR (n=51), or placebo (n=49). At W52, 24-hour UPCR improved by 69% and 70% for combined anifrolumab and placebo groups, respectively (geometric mean ratio=1.03; 95% CI 0.62 to 1.71; p=0.905). Serum concentrations were higher with anifrolumab IR versus anifrolumab BR, which provided suboptimal exposure. Numerically more patients treated with anifrolumab IR vs placebo attained CRR (45.5% vs 31.1%), CRR with UPCR ≤0.5 mg/mg (40.9% vs 26.7%), CRR with inactive urinary sediment (40.9% vs 13.3%) and sustained glucocorticoid reductions (55.6% vs 33.3%). Incidence of herpes zoster was higher with combined anifrolumab vs placebo (16.7% vs 8.2%). Incidence of serious adverse events was similar across groups.

Conclusion

Although the primary endpoint was not met, anifrolumab IR was associated with numerical improvements over placebo across endpoints, including CRR, in patients with active lupus nephritis.

Trial registration number

NCT02547922.

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.

Anifrolumab: An Inhibitor of Type I Interferon for the Treatment of Patients with Systemic Lupus Erythematosus

Anifrolumab is the only US Food and Drug Administration-approved therapy for patients with systemic lupus erythematosus (SLE) that directly targets type I interferons (IFNs). The phase I study in scleroderma and phase II study in SLE served as a foundation for the phase III programme that included the TULIP-1 and TULIP-2 SLE trials. We review the biology of IFNs and the scientific rationale for developing an inhibitor of the type I IFN pathway. The focus then turns to the specific trials that led to regulatory approvals.

The interferon gene signature as a clinically relevant biomarker in autoimmune rheumatic disease

The interferon gene signature (IGS) is derived from the expression of interferon-regulated genes and is classically increased in response to type I interferon exposure. A raised whole blood IGS has increasingly been reported in rheumatic diseases as sequencing technology has advanced. Although its role remains unclear, we explore how a raised IGS can function as a clinically relevant biomarker, independent of whether it is a bystander effect or a key pathological process. For example, a raised IGS can act as a diagnostic biomarker when predicting rheumatoid arthritis in patients with arthralgia and anti-citrullinated protein antibodies, or predicting systemic lupus erythematous (SLE) in those with antinuclear antibodies; a theragnostic biomarker when predicting response for patients receiving disease modifying therapy, such as rituximab in rheumatoid arthritis; a biomarker of disease activity (early rheumatoid arthritis, dermatomyositis, systemic sclerosis, SLE); or finally a predictor of clinical characteristics, such as lupus nephritis in SLE or disease burden in primary Sjögren's syndrome. A high IGS does not uniformly predict worse clinical phenotypes across all diseases, as demonstrated by a reduced disease burden in primary Sjögren's syndrome, nor does it predict a universally poorer response to all therapies, as shown in rheumatoid arthritis. This dichotomy highlights both the complexity of type I interferon signalling in vivo and the current lack of standardisation when calculating the IGS. The IGS as a biomarker warrants further exploration, with beneficial clinical applications anticipated in multiple rheumatic diseases.

Anifrolumab: First Approval

Anifrolumab (anifrolumab-fnia; Saphnelo^™) is a monoclonal antibody antagonist of the type 1 interferon receptor (IFNAR). It is being developed by AstraZeneca (under license from Medarex, now Bristol-Myers Squibb) for the treatment of autoimmune disorders, including systemic lupus erythematosus (SLE) and lupus nephritis, the underlying pathogenesis of which involves type 1 interferon. In July 2021, intravenous anifrolumab was approved in the USA for the treatment of adult patients with moderate to severe SLE who are receiving standard therapy. Anifrolumab (intravenous or subcutaneous) continues to be assessed in clinical studies in SLE in various countries, and the intravenous formulation is under regulatory review in the EU and Japan. This article summarizes the milestones in the development of anifrolumab leading to this first approval for the treatment of moderate to severe SLE.

Clinical translation of immunomodulatory therapeutics

Immunomodulatory therapeutics represent a unique class of drug products that have tremendous potential to rebalance malfunctioning immune systems and are quickly becoming one of the fastest-growing areas in the pharmaceutical industry. For these drugs to become mainstream medicines, they must provide greater therapeutic benefit than the currently used treatments without causing severe toxicities. Immunomodulators, cell-based therapies, antibodies, and viral therapies have all achieved varying amounts of success in the treatment of cancers and/or autoimmune diseases. However, many challenges related to precision dosing, off-target effects, and manufacturing hurdles will need to be addressed before we see widespread adoption of these therapies in the clinic. This review provides a perspective on the progress of immunostimulatory and immunosuppressive therapies to date and discusses the opportunities and challenges for clinical translation of the next generation of immunomodulatory therapeutics.