Influence of Immunogenicity on the Efficacy of Long-Term Treatment with TNF α Blockers in Rheumatoid Arthritis and Spondyloarthritis Patients

No Correlation between Anti-drug Antibodies and Therapeutic Response in Tunisian Patients with Chronic Inflammatory Diseases Treated by TNF Blockers

INTRODUCTION

Tumor necrosis factor alpha (TNF alpha) blockers such as infliximab (IFX) and adalimumab (ADA) had significantly changed the course of inflammatory diseases such as rheumatoid arthritis (RA), spondyloarthritis (SpA) and Crohn's disease (CD). However, about 30% of patients do not respond to these treatments. This lack of response may be due to the formation of antibodies against these drugs (anti-drug antibodies: ADAbs). The aim of this study was to determine the prevalence of ADAbs against IFX and ADA, and the trough serum concentration of IFX and ADA in RA, SpA or CD patients and to assess their impact on the therapeutic response.

METHODS

A cross sectional, multi-centric study was conducted, including patients with RA, SpA or CD treated with IFX or ADA as a first biotherapy for at least 6 months. ADAbs and trough levels were measured by an Enzyme Linked Immunosorbent assay (ELISA).

RESULTS

197 patients were included (57 RA, 73 SpA and 67 CD). ADAbs were positive in 40% of cases for IFX and 25% for ADA. They were positive in 40% of SpA, 35% of RA, and 21% of CD. The presence of ADAbs was inversely correlated to the trough levels of IFX and ADA during RA (p = 0.01 and p < 0.0001), SpA (p < 0.01 and p < 0.0001) and CD (p = 0.001 and p = 0.04). For all pathologies, the presence of ADAbs was not correlated with disease activity. Concomitant methotrexate significantly reduced immunogenicity.

CONCLUSION

In our study, the presence of ADAb and low trough levels seem to not affect the therapeutic response in patients on TNF alpha antagonists. Other tracks more than immunogenicity should be investigated to explain the loss of response to these biotherapies.

High BMI is associated with lower TNF-α inhibitor serum trough levels and higher disease activity in patients with axial spondyloarthritis

BACKGROUND

TNF-α inhibitor (TNFi) serum trough levels have previously been found to be related to disease activity in axial spondyloarthritis (axSpA). However, most research regarding serum trough levels has been conducted in patients who only recently started TNFi therapy. Therefore, our objective was to explore TNFi serum trough level measurements in relation to disease activity and BMI in the total axSpA population in daily clinical practice, also including patients on long-term TNFi therapy.

METHODS

Consecutive patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were approached for a TNFi serum trough level measurement during their regular outpatient visit at the UMCG. Spearman's correlation coefficient was used to analyse the relation of serum trough levels with disease activity and BMI. Logistic regression was performed to analyse the relation between therapeutic drug levels and disease activity, corrected for potential confounders, including BMI.

RESULTS

Thirty-four patients on adalimumab and 21 patients on etanercept were included. Mean age was 45 ± 12 years, 47% were male, median BMI was 26.4 (IQR 23.9-32.5) and median treatment duration was 41 months (range 2-126). According to definitions of Sanquin, 47% of patients had therapeutic serum trough levels. No significant correlations were found between TNFi levels and disease activity (ASDAS-CRP: adalimumab: ρ = -0.16, p = 0.39; etanercept: ρ = -0.29, p = 0.20). TNFi levels were moderately correlated with BMI (adalimumab: ρ = -0.48, p = 0.004; etanercept: ρ = -0.50, p = 0.021). Patients with active disease (ASDAS ≥ 2.1) showed higher BMI than patients with inactive disease (median 29.7 vs. 24.6, p = 0.015). In multivariable regression analyses, BMI was identified as the only confounder for the relationship between therapeutic drug levels and ASDAS.

CONCLUSION

In this cross-sectional, observational study of axSpA patients mainly on long-term treatment with TNFi, higher BMI was significantly associated with lower adalimumab and etanercept serum trough levels and higher disease activity.

Anti-Drug Antibodies in the Biological Therapy of Autoimmune Rheumatic Diseases

Autoimmune rheumatic diseases are a cluster of heterogeneous disorders that share some clinical symptoms such as pain, tissue damage, immune deregulation, and the presence of inflammatory mediators. Biologic disease-modifying antirheumatic drugs are some of the most effective treatments for rheumatic diseases. However, their molecular and pharmacological complexity makes them potentially immunogenic and capable of inducing the development of anti-drug antibodies. TNF inhibitors appear to be the main contributors to immunogenicity because they are widely used, especially in rheumatoid arthritis. Immunogenicity response on these treatments is crucial since the appearance of ADAs has consequences in terms of safety and efficacy. Therefore, this review proposes an overview of the immunogenicity of biological agents used in autoimmune rheumatic diseases highlighting the prevalence of anti-drug antibodies.

EULAR points to consider for therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases

OBJECTIVE

To develop EULAR points-to-consider for therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases (RMDs).

METHODS

The points-to-consider were developed in accordance with EULAR standardised operation procedures by a multidisciplinary task force from eight European countries, based on a systematic literature review and expert consensus. Level of evidence and strength of the points-to-consider were determined, and mean levels of agreement among the task force were calculated using a 10-point rating scale.

RESULTS

Six overarching principles and 13 points-to-consider were formulated. The level of agreement among the task force for the overarching principles and points-to-consider ranged from 8.4 to 9.9.The overarching principles define TDM and its subtypes, and reinforce the underlying pharmacokinetic/pharmacodynamic principles, which are relevant to all biopharmaceutical classes. The points-to-consider highlight the clinical utility of the measurement and interpretation of biopharmaceutical blood concentrations and antidrug antibodies in specific clinical scenarios, including factors that influence these parameters. In general, proactive use of TDM is not recommended but reactive TDM could be considered in certain clinical situations. An important factor limiting wider adoption of TDM is the lack of both high quality trials addressing effectiveness and safety of TDM and robust economic evaluation in patients with RMDs. Future research should focus on providing this evidence, as well as on further understanding of pharmacokinetic and pharmacodynamic characteristics of biopharmaceuticals.

CONCLUSION

These points-to-consider are evidence-based and consensus-based statements for the use of TDM of biopharmaceuticals in inflammatory RMDs, addressing the clinical utility of TDM.

Anti-TNFα drug levels in patients with rheumatoid arthritis and spondyloarthritis

BACKGROUND AND OBJECTIVES

Knowledge of the levels of anti-TNFa drugs can modify treatment in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA).

OBJECTIVES

To compare the levels of anti-TNFa in patients with RA vs SpA, in different clinical situations.

MATERIALS AND METHODS

A retrospective, observational study was conducted. Levels of anti-TNFa and the presence of anti-drug antibodies were measured in consecutively selected patients, using the ELISA technique.

RESULTS

Fifty-three, 73 and 78 patients treated with infliximab, adalimumab and etanercept were studied, respectively. The median drug levels in patients using standard doses were infliximab 2.2 µg/mL (1.4-5.2), adalimumab 4.9 µg/mL (0.8-8.9) and etanercept 3.1 µg/mL (2.3-4.4). There were no differences in drug levels according to disease activity but we found differences in etanercept and infliximab levels according to DMARD use.

CONCLUSIONS

Levels of anti-TNFa drugs will change with DMARD treatment.

An Engineered Monovalent Anti-TNF-α Antibody with pH-Sensitive Binding Abrogates Immunogenicity in Mice following a Single Intravenous Dose

Therapeutic Abs directed toward TNF-α display significant immunogenicity in humans, frequently leading to lower serum concentrations of the Ab that are associated with lower treatment efficacy. The enhanced incidence of immunogenicity observed with this class of therapeutics may be mediated by the expression of TNF-α as a homotrimer, both as a soluble serum protein and as a membrane-associated protein (mTNF-α) on the surface of dendritic cells. The TNF-α homotrimer enables the formation of polyvalent Ab-TNF-α immune complexes (ICs) that enhance binding to FcR and neonatal FcR. Polyvalent ICs and Ab bound to mTNF-α on the surface of dendritic cells can internalize, traffic to the lysosomes, and be processed for presentation by MHC molecules. To diminish immunogenicity caused by trafficking of ICs and mTNF-α to the lysosomes, we engineered a monovalent format of adalimumab with pH-sensitive binding to TNF-α. The engineered variant, termed AF-M2637, did not cross-link TNF-α trimers and consequently formed small, nonprecipitating ICs only. AF-M2637 bound TNF-α with high affinity at pH 7.4 (EC50 = 1.1 nM) and displayed a significantly faster dissociation rate than adalimumab at pH 6.0. No immune response to AF-M2637 was detected in mice following a single i.v. dose. In contrast, rapid immunization was detected following the injection of a single i.v. dose of adalimumab, monovalent adalimumab, or the bivalent form of the pH-sensitive variant. These data suggest that ICs and mTNF-α both contribute to the immunogenicity of adalimumab in mice and provide a general strategy for engineering less immunogenic therapeutic TNF-α Abs.

Predicting Sustained Clinical Response to Rituximab in Moderate to Severe Systemic Manifestations of Primary Sjögren Syndrome

OBJECTIVE

To assess outcomes of repeat rituximab cycles and identify predictors of sustained clinical response in systemic manifestations of primary Sjögren syndrome (pSS).

METHODS

An observational study was conducted in 40 rituximab-treated patients with pSS. Clinical response was defined as a 3-point or more reduction in the European League Against Rheumatism (EULAR) Sjögren Disease Activity Index (ESSDAI) at 6 months from baseline. Peripheral blood B cells were measured using highly sensitive flow cytometry. Predictors of sustained response (within two rituximab cycles) were analyzed using penalized logistic regression.

RESULTS

Thirty-eight out of 40 patients had moderate to severe systemic disease (ESSDAI >5). Main domains were articular (73%), mucocutaneous (23%), hematological (20%), and nervous system (18%). Twenty-eight out of 40 (70%) patients were on concomitant immunosuppressants. One hundred sixty-nine rituximab cycles were administered with a total follow-up of 165 patient-years. In cycle 1 (C1), 29/40 (73%) achieved ESSDAI response. Of C1 responders, 23/29 received retreatment on clinical relapse, and 15/23 (65%) responded. Of the 8/23 patients who lost response, these were due to secondary non-depletion and non-response (2NDNR; 4/23 [17%] as we previously observed in systemic lupus erythematosus with antirituximab antibodies, inefficacy = 2/23, and other side effects = 2/23). Within two cycles, 13/40 (33%) discontinued therapy. In multivariable analysis, concomitant immunosuppressant (odds ratio 7.16 [95% confidence interval: 1.37-37.35]) and achieving complete B-cell depletion (9.78 [1.32-72.25]) in C1 increased odds of response to rituximab. At 5 years, 57% of patients continued on rituximab.

CONCLUSION

Our data suggest that patients with pSS should be co-prescribed immunosuppressant with rituximab, and treatment should aim to achieve complete depletion. About one in six patients develop 2NDNR in repeat cycles. Humanized or type 2 anti-CD20 antibodies may improve clinical response in extra-glandular pSS.

Therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal disease: a systematic literature review informing EULAR points to consider

The objectives of this review were to collect and summarise evidence on therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases and to inform the EULAR Task Force for the formulation of evidence-based points to consider. A systematic literature review (SLR) was performed, covering technical aspects and (clinical) utility of TDM, to answer 13 research questions. MEDLINE, Embase and Cochrane were searched until July 2020. American College of Rheumatology and EULAR abstracts were also considered for inclusion. Data were extracted in evidence tables and risk of bias assessment was performed. For the search on technical aspects, 678 records were identified, of which 22 papers were selected. For the clinical utility search, 3846 records were identified, of which 108 papers were included. Patient-related factors associated with biopharmaceutical blood concentrations included body weight, methotrexate comedication and disease activity. The identification of a target range was hampered by study variability, mainly disease activity measures and study type. Evidence was inconsistent for multiple clinical situations in which TDM is currently applied. However, for some particular scenarios, including prediction of future treatment response, non-response to treatment, tapering and hypersensitivity reactions, robust evidence was found. There is currently no evidence for routine use of proactive TDM, in part because published cost-effectiveness analyses do not incorporate the current landscape of biopharmaceutical costs and usage. This SLR yields evidence in favour of TDM of biopharmaceuticals in some clinical scenarios, but evidence is insufficient to support implementation of routine use of TDM.

Fine Comparison of the Efficacy and Safety Between GB242 and Infliximab in Patients with Rheumatoid Arthritis: A Phase III Study

INTRODUCTION

This phase III trial (NCT04178850) evaluated the efficacy, safety, and immunogenicity of GB242, an infliximab biosimilar, vs. infliximab (Remicade^®) reference product in patients with moderate-to-severe active rheumatoid arthritis (RA) combination with methotrexate (MTX) therapy.

METHODS

Patients were randomized in a 1:1 ratio to receive either GB242 or INF (3 mg/kg). Therapeutic equivalence of clinical response according to the American College of Rheumatology 20% (ACR20) response rate at week 30 was declared if the two-sided 95% CI for the treatment difference was within ± 14%. The comparison of GB242 with INF also included the proportion of patients achieving a week 30 ACR 50 response, ACR70 response, change in Disease Activity Score 28 (DAS28), as well as safety and immunogenicity.

RESULTS

A total of 570 subjects were randomized into GB242 (N = 285) or INF (N = 285) and 283 subjects in each group were analyzed. At week 30, the ACR20 was 62.54% for the GB242 group (95% CI 56.62-68.20%) and 56.89% for the INF group (95% CI 50.90-62.74%). The difference between the two groups was 5.65% with a 95% CI of - 2.48 to 13.74. ACR50 response was 37.12% for GB242 and 32.86% for INF at week 30. ACR70 response was 19.79% for GB242 and 16.96% for INF at week 30, respectively. The incidence of treatment-emergent adverse events was comparable (77.4% in GB242 vs. 80.2% in INF) and detection of antidrug antibodies (ADA) to infliximab up to week 30 (60.8% in GB242 vs. 59.4% in INF) was comparable.

CONCLUSIONS

GB242 demonstrated equivalent efficacy to INF at week 30. Moreover, GB242 was well tolerated, with a similar immunogenicity and safety profile comparable to INF.

Anti-TNFα Drug Levels in Patients with Rheumatoid Arthritis and Spondyloarthritis

BACKGROUND AND OBJECTIVES

Knowledge of the levels of anti-TNFα drugs can modify treatment in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA).

OBJECTIVES

To compare the levels of anti-TNFα in patients with RA vs SpA, in different clinical situations.

MATERIALS AND METHODS

A retrospective, observational study was conducted. Levels of anti-TNFα and the presence of anti-drug antibodies were measured in consecutively selected patients, using the ELISA technique.

RESULTS

Fifty-three, 73 and 78 patients treated with infliximab, adalimumab and etanercept were studied, respectively. The median drug levels in patients using standard doses were infliximab 2.2μg/ml (1.4-5.2), adalimumab 4.9μg/ml (0.8-8.9) and etanercept 3.1μg/ml (2.3-4.4). There were no differences in drug levels according to disease activity but we found differences in etanercept and infliximab levels according to DMARD use.

CONCLUSIONS

Levels of anti-TNFα drugs will change with DMARD treatment.

An update on serum biomarkers to assess axial spondyloarthritis and to guide treatment decision

Axial spondyloarthritis (axSpA) is a group of debilitating, chronic, rheumatic conditions characterized by inflammation and new bone formation, mainly involving the spine and the sacroiliac joints. The lack of biomarkers in axSpA is well known. Despite significant treatment advances in recent years thanks to the introduction of drugs with a new mode of action, such as new biologic and targeted synthetic disease-modifying antirheumatic drugs, no relevant improvement in the identification of disease biomarkers has been achieved. Common parameters, such as erythrocyte sedimentation rate and C-reactive protein, which are routinely used to measure systemic inflammation, are the sole markers available to date and are not adequate to assess disease activity in all patients. The aim of this study is to review the most promising serum biomarkers that may help treatment decision in axSpA via a proper assessment of disease activity and identification of negative prognostic factors.

Immunogenicity-unwanted immune responses to biological drugs - can we predict them?

INTRODUCTION

Biological agents (BAs) target molecules involved in disease mechanisms and have modified the natural history of several immune-mediated disorders. All BAs are immunogenic, resulting in the formation of antidrug antibodies (ADAs), which can neutralize drug activity leading to loss of response and potential relapse, or serious adverse events such as infusion hypersensitivity reactions. The production of ADAs is the result of a specific adaptive immune response in which T and B cells are involved.

AREAS COVERED

Factors conditioning the immunogenicity of BAs, including drug-, treatment- and patient-related factors are currently the subject of many studies. Among them, a lot of attention is dedicated to define the impact of BAs structure, the effect of targeting (soluble or membrane) molecules, the impact of interruption of therapy as well as the role of genetic (HLA and non-HLA) predisposing factors and disease activity.

EXPERT OPINION

Knowledge of factors capable of influencing the immunogenicity of BAs may help to understand, in a predictive manner and at the single patient level, the presence of risk factors influencing the production of ADAs and their impact on clinical outcomes.

Immunogenicity of Sarilumab Monotherapy in Patients with Rheumatoid Arthritis Who Were Inadequate Responders or Intolerant to Disease-Modifying Antirheumatic Drugs

INTRODUCTION

This open-label study evaluated the immunogenicity, safety, and efficacy of sarilumab monotherapy in patients with active, moderate-to-severe rheumatoid arthritis (RA) and inadequate response or intolerance to prior conventional synthetic disease-modifying antirheumatic drugs.

METHODS

Adults with RA (n = 132) were randomized to receive subcutaneous sarilumab (150 [n = 65] or 200 mg [n = 67]) every 2 weeks (q2w) for 24 weeks. Endpoints included incidence of antidrug antibodies (ADAs) at week 24, safety, and efficacy.

RESULTS

Persistent ADAs occurred in eight patients (12.3%) receiving sarilumab 150 mg q2w, seven of whom (10.8%) had neutralizing antibodies (NAbs), and in four patients (6.1%) receiving sarilumab 200 mg q2w, two of whom (3.0%) had NAbs; all exhibited low antibody titers. Infections and neutropenia were the most common adverse events (AEs). There were three serious AEs, no reports of anaphylaxis, and few hypersensitivity reactions (e.g., rash) with no notable differences in hypersensitivity reactions in ADA-positive patients relative to ADA-negative patients. Changes in absolute neutrophil count, alanine aminotransferase level, and platelet count were consistent with interleukin-6 signaling blockade and in agreement with previous observations. At week 24, overall American College of Rheumatology 20%/50%/70% improvement criteria responses were 73.8%/53.8%/29.2%, respectively, with sarilumab 150 mg q2w and 71.6%/50.7%/29.9% with sarilumab 200 mg q2w. No patients with an ADA-positive response showed loss of efficacy.

CONCLUSIONS

ADA titers were low and persistent ADAs and NAbs occurred relatively infrequently in both sarilumab dose groups. ADA did not meaningfully impact the safety or efficacy of either dose of sarilumab over 24 weeks.

TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT02121210.

FUNDING

Sanofi Genzyme and Regeneron Pharmaceuticals, Inc. Plain language summary available for this article.

Therapeutic drug monitoring of infliximab in spondyloarthritis. A review of the literature

Available evidence indicates that a therapeutic drug monitoring strategy leads to major cost savings related to the anti-tumour necrosis factor-α therapy in both inflammatory bowel disease and rheumatoid arthritis (RA) patients, with no negative impact on efficacy. However, although the systematic use of therapeutic drug monitoring could potentially be beneficial and economically acceptable to drug dose optimization, it is not justifiable for all drugs. Infliximab (IFX) is a chimeric monoclonal immunoglobulin G1 targeting tumour necrosis factor. It has been approved for the treatment of immuno-inflammatory diseases, including RA, ankylosing spondylitis, psoriatic arthritis, Crohn's disease and ulcerative colitis. IFX's pharmacokinetics is highly variable and influences clinical response in chronic inflammatory diseases. Clinical response increases with IFX trough concentrations in RA, ankylosing spondylitis, inflammatory bowel disease and psoriatic patients. Target concentrations predictive of good clinical response were proposed in RA, Crohn's disease and ulcerative colitis. The purpose of this article is to review the current literature surrounding IFX serum concentrations and their related parameters with disease activity in patients with spondyloarthritis. Gathering information about the efficacy of IFX in patients with spondyloarthritis and relating IFX serum concentrations to disease activity were the main goals of this study.

Drug safety and immunogenicity of tumour necrosis factor inhibitors: the story so far

TNF-α inhibitor (TNFi) therapies have transformed the treatment of several rheumatic musculoskeletal diseases. However, the majority of TNFi's are immunogenic and consequent anti-drug antibodies formation can impact on both treatment efficacy and safety. Several controversies exist in the area of immunogenicity of TNFis and drug safety. While anti-drug antibodies to TNFis have been described in association with infusion reactions; serious adverse events (AEs) such as thromboembolic events, lupus-like syndrome, paradoxical AEs, for example, vasculitis-like events and other autoimmune manifestations have also been reported. The expansion of the biologic armamentarium, new treatment strategies such as introduction/switching to biosimilars and cost-saving approaches such as TNFi tapering, may all have a potential impact on immunogenicity and clinical sequelae. In this review we evaluate how evolution of biologics relates to drug safety and immunogenicity, appraise relevant evidence from trials, spontaneous pharmacovigilance and observational studies and outline the areas of uncertainty that still exist.

Evaluation of in vitro Assays to Assess the Modulation of Dendritic Cells Functions by Therapeutic Antibodies and Aggregates

Therapeutic antibodies have the potential to induce immunogenicity leading to the development of anti-drug antibodies (ADA) that consequently may result in reduced serum drug concentrations, a loss of efficacy or potential hypersensitivity reactions. Among other factors, aggregated antibodies have been suggested to promote immunogenicity, thus enhancing ADA production. Dendritic cells (DC) are the most efficient antigen-presenting cell population and are crucial for the initiation of T cell responses and the subsequent generation of an adaptive immune response. This work focuses on the development of predictive in vitro assays that can monitor DC maturation, in order to determine whether drug products have direct DC stimulatory capabilities. To this end, four independent laboratories aligned a common protocol to differentiate human monocyte-derived DC (moDC) that were treated with either native or aggregated preparations of infliximab, natalizumab, adalimumab, or rituximab. These drug products were subjected to different forms of physical stress, heat and shear, resulting in aggregation and the formation of subvisible particles. Each partner developed and optimized assays to monitor diverse end-points of moDC maturation: measuring the upregulation of DC activation markers via flow cytometry, analyzing cytokine, and chemokine production via mRNA and protein quantification and identifying cell signaling pathways via quantification of protein phosphorylation. These study results indicated that infliximab, with the highest propensity to form aggregates when heat-stressed, induced a marked activation of moDC as measured by an increase in CD83 and CD86 surface expression, IL-1β, IL-6, IL-8, IL-12, TNFα, CCL3, and CCL4 transcript upregulation and release of respective proteins, and phosphorylation of the intracellular signaling proteins Syk, ERK1/2, and Akt. In contrast, natalizumab, which does not aggregate under these stress conditions, induced no DC activation in any assay system, whereas adalimumab or rituximab aggregates induced only slight parameter variation. Importantly, the data generated in the different assay systems by each partner site correlated and supported the use of these assays to monitor drug-intrinsic propensities to drive maturation of DC. This moDC assay is also a valuable tool as an in vitro model to assess the intracellular mechanisms that drive DC activation by aggregated therapeutic proteins.

Switching Between Biological Treatments in Psoriatic Arthritis: A Review of the Evidence

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy. Therapy with anti-tumor necrosis factor (TNF)-α agents represents the first therapeutic choice for moderate and severe forms; however, PsA patients can experience anti-TNFα failure, lack of efficacy, or adverse events. Several evidences exist on the effectiveness of switching among different TNFα inhibitors, and we reviewed the published data on the effectiveness of anti-TNFα first-, second- and third-line. Most of the studies report that the main reason for switching to a second anti-TNFα agent is represented by lack of efficacy (primary or secondary) and, more rarely, adverse events. Switchers receiving their second anti-TNFα agent have considerably poorer responses compared with non-switchers. Survival of anti-TNFα treatment appears to be superior in PsA patients when compared with rheumatoid arthritis patients. Switching from anti-TNF agents to ustekinumab or secukinumab or apremilast can represent a valid alternative therapeutic strategy.

Immunoassay methods used in clinical studies for the detection of anti-drug antibodies to adalimumab and infliximab

We examined the assay formats used to detect anti-drug antibodies (ADA) in clinical studies of the anti-tumour necrosis factor (TNF) monoclonal antibodies adalimumab and infliximab in chronic inflammatory disease and their potential impact on pharmacokinetic and clinical outcomes. Using findings of a recent systematic literature review of the immunogenicity of 11 biological/biosimilar agents, we conducted an ancillary qualitative review of a subset of randomized controlled trials and observational studies of the monoclonal antibodies against anti-TNF factor adalimumab and infliximab. Among studies of adalimumab and infliximab, the immunoassay method used to detect antibodies was reported in 91 of 111 (82%) and 154 of 206 (75%) adalimumab and infliximab studies, respectively. In most adalimumab and infliximab studies, an enzyme-linked immunosorbent assay or radioimmunoassay was used [85 of 91 (93%) and 134 of 154 (87%), respectively]. ADA incidence varied widely among assays and inflammatory diseases (adalimumab, 0-87%; infliximab, 0-79%). Pharmacokinetic and clinical outcomes were only reported for ADA-positive patients in 38 of 91 (42%) and 61 of 154 (40%) adalimumab and infliximab studies, respectively. Regardless of assay format or biological used, ADA formation was associated with lower serum concentrations, reduced efficacy and elevated rates of infusion-related reactions. Consistent with previous recommendations to improve interpretation of immunogenicity data for biologicals, greater consistency in reporting of assay methods and clinical consequences of ADA formation may prove useful. Additional standardization in immunogenicity testing and reporting, application of modern, robust assays that satisfy current regulatory expectations and implementation of international standards for marketed products may help to improve our understanding of the impact of immunogenicity to biologics.

Are Janus Kinase Inhibitors Superior over Classic Biologic Agents in RA Patients?

The Janus Kinases (JAKs) are a family of intracellular tyrosine kinases that provide transmission signals from cytokine, interferons, and many hormones receptors to the nucleus resulting in synthesis of many biologically active compounds and changing cell metabolism and function. That was theoretical background to synthetize the JAK inhibitors (Jakinibs). In recent years a substantial battery of evidence has been collected indicating the potential role of Jakinibs to interact with the specific elements of the immune system, therefore changing the inflammatory response. JAK kinase blockade offers a unique opportunity to block most of the key cytokines enabling the deep interaction into immune system functioning. Following discovery first Jakinibs were intensively studied in various forms of autoimmune diseases, including rheumatoid arthritis, and finally two Jakinibs tofacitinib and Baricitinib have been approved for the treatment of rheumatoid arthritis. Some clinical data indicated that under special circumstances Jakinibs may be even superior to biologics in the treatment of RA; however this suggestion should be verified in large clinical and observational studies.

The impact of immunogenicity of TNFα inhibitors in autoimmune inflammatory disease. A systematic review and meta-analysis

BACKGROUND

Monoclonal antibodies drugs directed against TNFα, TNFα inhibitors, are immunogenic, and consequent anti-drug antibodies (ADA) formation may decrease the functional drug concentration, resulting in a loss of response. We evaluated the impact of ADA on TNFα therapeutic response.

METHODS

We considered studies enrolling adult patients affected by autoimmune inflammatory disease in therapy with TNFα inhibitors. We collected data about study and population characteristics, treatment dosage, determination of ADA and adverse events (AE). We combined data in meta-analysis, calculating risk ratios (RR) for each study. p-Values<0.05 were considered as statistically significant. Methodological quality was evaluated. Analyses were performed with the STATA 11 and RevMan 5.3 softwares.

RESULTS

We included 34 studies enrolling 4273 patients. Of these, 794 (18.6%) developed ADA. Our analysis showed a significant reduction of response (RR 0.43, 95%CI 0.3-0.63) in patients with ADA respect to patients without, especially in patients treated with Infliximab (RR 0.37) or Adalimumab (RR 0.40). Furthermore, the administration of TNFα inhibitors produced a reaction at the infusion site in 17%, infection in 30% and serious AE in 5% of patients.

CONCLUSION

Detectable ADA significantly reduced TNFα inhibitors response. Drug administration can also cause injection site reaction and infections. Early detection of serum ADA levels may improve patients' management. Currently, there are many indications about the use of immunogenicity tests to guide the therapy, but information regarding how to implement it in clinical practice is needed.

Higher body mass index and anti-drug antibodies predict the discontinuation of anti-TNF agents in Korean patients with axial spondyloarthritis

OBJECTIVE

The development of anti-drug antibodies against tumor necrosis factor inhibitors is a likely explanation for the failure of TNF-inhibitors in patients with spondyloarthritis. Our study determined the existence and clinical implications of ADAbs in axial spondyloarthritis patients.

METHODS

According to the Assessment of SpondyloArthritis International Society classification criteria for axial spondyloarthritis, patients treated with adalimumab or infliximab were recruited consecutively. Serum samples were collected at enrollment to measure anti-drug antibodies and drug levels.

RESULTS

Of 100 patients, the mean duration of current TNF inhibitor use was 22.3±17.9 months. Anti-drug antibodies were detected in 5 of 72 adalimumab users compared to 5 of 28 infliximab users (6.9% vs. 17.9%). Anti-drug antibodies-positive patients had a significantly higher body mass index than anti-drug antibodies-negative patients among both adalimumab (28.4±5.9kg/m² vs. 24.3±2.9kg/m², respectively, p=0.01) and infliximab users (25.9±2.8kg/m² vs. 22.6±2.8kg/m², respectively, p=0.02). During the median 15-month follow-up period, drug discontinuation occurred more frequently in the anti-drug antibodies-positive group than the anti-drug antibodies-negative group (30.0% vs. 6.5%, respectively, p=0.04). In logistic regression, anti-drug antibodies positivity (OR=5.85, 95% CI 1.19-28.61, p=0.029) and body mass index (OR=4.35, 95% CI 1.01-18.69, p=0.048) were associated with a greater risk of stopping TNF inhibitor treatment.

CONCLUSIONS

Our result suggests that the presence of anti-drug antibodies against adalimumab and infliximab as well as a higher body mass index can predict subsequent drug discontinuation in axial spondyloarthritis patients.

Higher body mass index and anti-drug antibodies predict the discontinuation of anti-TNF agents in Korean patients with axial spondyloarthritis

OBJECTIVE

The development of anti-drug antibodies (ADAbs) against tumor necrosis factor (TNF) inhibitors is a likely explanation for the failure of TNF-inhibitors in patients with spondyloarthritis (SpA). Our study determined the existence and clinical implications of ADAbs in axial SpA patients.

METHODS

According to the Assessment of SpondyloArthritis International Society classification criteria for axial SpA, patients treated with adalimumab or infliximab were recruited consecutively. Serum samples were collected at enrollment to measure ADAb and drug levels.

RESULTS

Of 100 patients, the mean duration of current TNF inhibitor use was 22.3±17.9 months. ADAbs were detected in 5 of 72 adalimumab users compared to 5 of 28 infliximab users (6.9% vs. 17.9%). ADAb-positive patients had a significantly higher body mass index than ADAb-negative patients among both adalimumab (28.4±5.9kg/m2 vs. 24.3±2.9kg/m2, respectively, p=0.01) and infliximab users (25.9±2.8kg/m2 vs. 22.6±2.8kg/m2, respectively, p=0.02). During the median 15-month follow-up period, drug discontinuation occurred more frequently in the ADAb-positive group than the ADAb-negative group (30.0% vs. 6.5%, respectively, p=0.04). In logistic regression, ADAb positivity (OR=5.85, 95% CI 1.19-28.61, p=0.029) and BMI (OR=4.35, 95% CI 1.01-18.69, p=0.048) were associated with a greater risk of stopping TNF inhibitor treatment.

CONCLUSIONS

Our result suggests that the presence of ADAbs against adalimumab and infliximab as well as a higher BMI can predict subsequent drug discontinuation in axial SpA patients.

TNF-α Promoter Polymorphisms Predict the Response to Etanercept More Powerfully than that to Infliximab/Adalimumab in Spondyloarthritis

While previous studies have researched in association analyses between TNFα promoter polymorphisms and responses to TNF blockers in spondyloarthritis patients, their results were conflicting. Therefore, we aimed to determine whether TNFα promoter polymorphisms could predict response to TNF blockers and find the source of heterogeneity. Data were extracted and analyzed from published articles and combined with our unpublished data. We found that the greatest potential sources of heterogeneity in the results were gender ratio, disease type, continents, and TNF blockers. Then Stratification analysis showed that the TNFα -308 G allele and the -238 G allele predicted a good response to TNF blockers (OR = 2.64 [1.48-4.73]; 2.52 [1.46-4.37]). However, G alleles of TNFα -308 and -238 could predict the response to etanercept (OR = 4.02 [2.24-7.23]; 5.17 [2.29-11.67]) much more powerfully than the response to infiliximab/adalimumab (OR = 1.68 [1.02-2.78]; 1.28 [0.57-2.86]). TNFα -857 could not predict the response in either subgroup. Cumulative meta-analysis performed in ankylosing spondylitis patients presented the odds ratio decreased with stricter response criteria. In conclusion, TNFα -308 A/G and -238 A/G are more powerful to predict the response to Etanercept and it is dependent on the criteria of response.