Adalimumab serum levels and antidrug antibodies towards adalimumab in peripheral spondyloarthritis: no association with clinical response to treatment or with disease relapse upon treatment discontinuation

Adalimumab serum levels and anti-drug antibodies: associations to treatment response and drug survival in inflammatory joint diseases

OBJECTIVES

To explore associations between serum adalimumab level, treatment response and drug survival in order to identify optimal drug levels for therapeutic drug monitoring of adalimumab. Also, to assess the occurrence and risk factors of anti-drug antibody (ADAb) formation.

METHODS

Non-trough adalimumab and ADAb levels were measured by automated fluorescence assays in serum collected after 3 months of adalimumab treatment in patients with RA, PsA or axial SpA (axSpA) included in the observational NOR-DMARD study. Treatment response was evaluated after 3 months and drug survival was evaluated during long-term follow-up.

RESULTS

In 340 patients (97 RA, 69 PsA, 174 axSpA), the median adalimumab level was 7.3 mg/l (interquartile range 4.0-10.3). A total of 33 (10%) patients developed ADAbs. Findings were comparable across diagnoses. In RA and PsA, adalimumab levels ≥6.0 mg/l were associated with treatment response [odds ratio (OR) 2.2 (95% CI 1.0, 4.4)] and improved drug survival [hazard ratio 0.49 (95% CI 0.27, 0.80)]. In axSpA, a therapeutic level could not be identified, but higher adalimumab levels were associated with response. Factors associated with ADAb formation were previous bDMARD use, no methotrexate comedication and the use of adalimumab originator compared with GP2017.

CONCLUSION

Higher adalimumab levels were associated with a better response and improved drug survival for all diagnoses, with a suggested lower threshold of 6.0 mg/l for RA/PsA. This finding, the large variability in drug levels among patients receiving standard adalimumab dose and the high proportion of patients developing ADAbs encourages further investigations into the potential role of therapeutic drug monitoring of adalimumab.

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.

Tailored therapeutic decision of rheumatoid arthritis using proteomic strategies: how to start and when to stop?

Unpredictable treatment responses have been an obstacle for the successful management of rheumatoid arthritis. Although numerous serum proteins have been proposed, there is a lack of integrative survey to compare their relevance in predicting treatment outcomes in rheumatoid arthritis. Also, little is known about their applications in various treatment stages, such as dose modification, drug switching or withdrawal. Here we present an in-depth exploration of the potential usefulness of serum proteins in clinical decision-making and unveil the spectrum of immunopathology underlying responders to different drugs. Patients with robust autoimmunity and inflammation are more responsive to biological treatments and prone to relapse during treatment de-escalation. Moreover, the concentration changes of serum proteins at the beginning of the treatments possibly assist early recognition of treatment responders. With a better understanding of the relationship between the serum proteome and treatment responses, personalized medicine in rheumatoid arthritis will be more achievable in the near future.

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.

Therapeutic drug monitoring of biologics in inflammatory bowel disease: unmet needs and future perspectives

Therapeutic drug monitoring (TDM) has emerged as a useful tool for optimising the use of biologics, and in particular anti-tumour necrosis factor (anti-TNF) therapy, in inflammatory bowel disease (IBD). However, challenges remain and are hindering the widespread implementation of TDM in clinical practice. These barriers include identification of the optimal drug concentration to target, the lag time between sampling and results, and the proper interpretation of anti-drug antibody titres among different assays. Solutions to overcome these barriers include the harmonisation of TDM assays and the use of point-of-care testing. Other unmet needs include well designed prospective studies and randomised controlled trials focusing on proactive TDM, particularly during induction therapy. Future studies should also investigate the utility of TDM for biologics other than anti-TNF therapies in both IBD and other immune-mediated inflammatory diseases such as rheumatoid arthritis and psoriasis, and the use of pharmacokinetic modelling dashboards and pharmacogenetics towards individual personalised medicine.

Immunogenicity of subcutaneous TNF inhibitors and its clinical significance in real-life setting in patients with spondyloarthritis

Key messages

Considerable proportion of patients with SpA have been immunized to the subcutaneous anti-TNF drug they are using. Concomitant use of MTX protects from immunization, whereas SASP does not. Patients with SpA using subcutaneous anti-TNF drugs can benefit from monitoring of the drug trough levels.

Abstract

Immunization to biological drugs can lead to decreased efficacy and increased risk of adverse effects. The objective of this cross-sectional study was to assess the extent and significance of immunization to subcutaneous tumor necrosis factor (TNF) inhibitors in axial spondyloarthritis (axSpA) patients in real-life setting. A serum sample was taken 1–2 days before the next drug injection. Drug trough concentrations, anti-drug antibodies (ADAb) and TNF-blocking capacity were measured in 273 patients with axSpA using subcutaneous anti-TNF drugs. The clinical activity of SpA was assessed using the Bath AS Disease Activity Index (BASDAI) and the Maastricht AS Entheses Score (MASES). ADAb were found in 11% of the 273 patients: in 21/99 (21%) of patients who used adalimumab, in 0/83 (0%) of those who used etanercept, in 2/79 (3%) of those who used golimumab and in 6/12 (50%) of those who used certolizumab pegol. Use of methotrexate reduced the risk of formation of ADAb, whereas sulfasalazine did not. Presence of ADAb resulted in decreased drug concentration and reduced TNF-blocking capacity. However, low levels of ADAb had no effect on TNF-blocking capacity and did not correlate with disease activity. The drug trough levels were below the consensus target level in 36% of the patients. High BMI correlated with low drug trough concentration. Patients with low drug trough levels had higher disease activity. The presence of anti-drug antibodies was associated with reduced drug trough levels, and the patients with low drug trough levels had higher disease activity. The drug trough levels were below target level in significant proportion of patients and, thus, measuring the drug concentration and ADAb could help to optimize the treatment in SpA patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00296-021-04955-8.

Impact of immunogenicity on clinical efficacy and toxicity profile of biologic agents used for treatment of inflammatory arthritis in children compared to adults

The treatment of inflammatory arthritis has been revolutionised by the introduction of biologic treatments. Many biologic agents are currently licensed for use in both paediatric and adult patients with inflammatory arthritis and contribute to improved disease outcomes compared with the pre-biologic era. However, immunogenicity to biologic agents, characterised by an immune reaction leading to the production of anti-drug antibodies (ADAs), can negatively impact the therapeutic efficacy of biologic drugs and induce side effects to treatment. This review explores for the first time the impact of immunogenicity against all licensed biologic treatments currently used in inflammatory arthritis across age, and will examine any significant differences between ADA prevalence, titres and timing of development, as well as ADA impact on therapeutic drug levels, clinical efficacy and side effects between paediatric and adult patients. In addition, we will investigate factors associated with differences in immunogenicity across biologic agents used in inflammatory arthritis, and their potential therapeutic implications.

Drug Levels and Antibodies Against TNF-blockers in Spondyloarthritis and Rheumatoid Arthritis are Associated with the Activity but they do Not Predict it

BACKGROUND

Many patients may have resistance to TNF-blockers. These drugs may induce neutralizing antibodies. The determination of the drug levels of TNF-blockers and Anti-Drug Antibodies (ADAs) against TNF-blockers may help to make clinical decisions.

OBJECTIVES

The objective of this study was to associate and predict the drug levels of TNFblockers and ADAs in relation to disease activity in patients with Spondyloarthritis (SpA) and Rheumatoid Arthritis (RA).

METHODS

Cross-sectional study including patients fulfilling ASAS classification criteria for SpA and 2010 ACR-EULAR classification criteria for RA. These patients were treated with Adalimumab (ADA), Infliximab (IFX), and Etanercept (ETN). A bivariate analysis and the chi-square test were performed to evaluate the association of ADAs and drug levels with activity measures for SpA and RA. Five regression models analyzing drug levels, ADAs and disease activity measures using a multiple linear regression were performed in order to evaluate the prediction of ADAs and drug levels in relation to disease activity.

RESULTS

In SpA, IFX levels were associated with BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) (p=0.034). In RA, total drug levels were associated with DAS28-ESR (28 joint Disease activity Score-erythrocyte sedimentation rate), (p=0.008), DAS28-CRP (p=0.042), CDAI (Clinical Disease Activity Index) (p=0.047) and SDAI (Simple Disease activity index), (p=0.017). ADA levels had association with CDAI (p=0.002) and SDAI (p=0.002). IFX levels were associated with a DAS28-ESR (p=0.044), DAS28-CRP (p=0.022) and SDAI (p=0.022). ADAs were associated in SpA with BASDAI (p=0.027). Drug levels and ADAs did not predict disease activity in patients with SpA or RA.

CONCLUSION

ADAs and drug levels of anti-TNF are associated with disease activity measures in patients with SpA and RA. However, they cannot predict clinical activity in these conditions.

In vitro human helper T-cell assay to screen antibody drug candidates for immunogenicity

Monoclonal antibody (mAb) drugs offer a number of valuable treatments. Many newly developed mAb drugs include artificial modification of amino acid sequences from human origin, which may cause higher immunogenicity to induce anti-drug antibodies (ADA). If the immunogenicity of a new candidate can be understood in the nonclinical phase, clinical studies will be safer and the success rate of development improved. Empirically, in vitro immunogenicity assays with human cells have proved to be sufficiently sensitive to nonhuman proteins, but not to human/humanized mAb. To detect the weaker immunogenicity of human-based mAb, a more sensitive biomarker for in vitro assays is needed. The in vitro study here developed a proliferation assay (T_H cell assay) using flow cytometry analysis that can detect a slight increase in proliferating T_H cells. Samples from 218 donors treated with a low-immunogenic drug (etanercept) were measured to determine a positive threshold level. With this threshold, positive donor percentages among PBMC after treatment with higher-immunogenicity mAb drugs were noted, that is, 39.5% with humanized anti-human A33 antibody (hA33), 27.3% with abciximab, 25.9% with adalimumab, and 14.8% with infliximab. Biotherapeutics with low immunogenicity yielded values of 0% for basiliximab and 3.7% for etanercept. These data showed a good comparability with previously reported incidences of clinical ADA with the evaluated drugs. Calculations based on the data here showed that a T_H cell assay with 40 donors could provide statistically significant differences when comparing low- (etanercept) versus highly immunogenic mAb (except for infliximab). Based on the outcomes here, for screening purposes, a practical cutoff point of 3/20 positives with 20 donors was proposed to alert immunogenicity of mAb drug candidates.

Early Adalimumab and Anti-Adalimumab Antibody Levels for Prediction of Primary Nonresponse in Ankylosing Spondylitis Patients

This study aimed at exploring the concentration‐effect relationship of adalimumab and early adalimumab and anti‐adalimumab antibody (AAA) levels in predicting primary nonresponse in a real‐world pilot cohort of patients with ankylosing spondylitis. Thirty‐one patients were included. The Ankylosing Spondylitis Disease Activity Score improved with increasing adalimumab trough level at week 12 and reached a major improvement with levels between 8 and 12 μg/mL. Moreover, weeks 4 and 2 adalimumab levels below 4.28 and 3.37 μg/mL were predictive of primary nonresponse (area under the curve (AUC) = 0.89, 0.88; P = 0.0003, P = 0.034, respectively). Week 4 AAA signal‐to‐noise levels were significantly higher among primary nonresponders, and the cutoff for primary nonresponse prediction was above 5.31 (AUC = 0.81; P = 0.004). Adalimumab trough levels in a range of 8–12 μg/mL are optimum to reach major improvement, and lower adalimumab with higher AAA levels at the early stage (week 4) predict primary nonresponse by supporting proactive monitoring to optimize adalimumab therapy.

Therapeutic drug monitoring with biologic agents in immune mediated inflammatory diseases

: Most exposure-response relationship studies show a positive correlation between biologic drug concentrations and favorable therapeutic outcomes in IMID with higher drug concentrations typically associated with more objective outcomes. Clinically, reactive TDM rationalizes the management of PNR and SLR to anti-tumor necrosis factor therapy and is emerging as the new standard of care in IBD as it is also more cost-effective than empiric dose escalation. Preliminary data suggest that proactive TDM with the goal to achieve a threshold drug concentration is associated with better therapeutic outcomes when compared to empiric drug optimization and/or reactive TDM of infliximab and adalimumab in IBD. However, more data from well-designed prospective studies are needed to prove the benefit of TDM-based algorithms in real life clinical practice in IMID.

The value of contrast-enhanced ultrasonography to detect the sacroiliac joint for predicting relapse after discontinuation of anti-tumor necrosis factor therapy in patients with ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by high relapse. Therefore, the present study aimed to investigate the ultrasonographic features of contrast-enhanced ultrasonography (CEUS) in the sacroiliac joint (SIJ) in patients with AS in remission after discontinuation of anti-tumor necrosis factor (TNF) therapy, and also examined the role of CEUS in predicting relapse.

METHODS

In this prospective observational study, 130 SIJs in 65 patients with AS (according to modified New York criteria) satisfying Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease after discontinuation of anti-TNF therapy were investigated on color Doppler ultrasonography (CDUS) and CEUS. Vascularization and the resistive index (RI) of the SIJ were observed and measured. We defined no blood flow, high RI of arterial blood flow (RI ≥0.7), the reversed phase in the diastolic phase or venous blood flow in the bilateral SIJs, as negative CDUS/CEUS; meanwhile, low RI of arterial blood flow (RI <0.7) in the unilateral or bilateral SIJs was defined as positive CDUS/CEUS. All the patients were followed up for 52 weeks until relapse. Relapse was defined as an increase of two or more items in comparison with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) at the time of anti-TNF withdrawal.

RESULTS

After 52 weeks, 46 of the 65 patients (70.8%) had relapse. The mean time to relapse was 31.4 weeks (±8.4 weeks, range 20 to 52). After discontinuation of anti-TNF therapy, positive CEUS accounted for 61.5%; this was significantly more than positive CDUS (13.8%). The vascularization detected by CEUS for patients of relapse was significantly different from that of patients with remission (P<0.05). In addition, patients with negative CEUS had a longer duration of remission than the patients with positive CEUS (P=0.005). A Cox proportional hazards regression analysis found that the disease duration could also be regarded as a factor predictive of relapse in patients with AS.

CONCLUSIONS

The use of CEUS distinctly improved the detection of vascularization in the SIJ in patients with AS in remission after anti-TNF withdrawal. The presence of vascularization in the SIJ detected by CEUS at the time of anti-TNF withdrawal could yield a valuable predictor of relapse in patients with AS. A significant limit of this study is the lack of magnetic resonance imaging (MRI) as the standard reference.

Therapeutic drug monitoring of biologicals in rheumatoid arthritis: a disconnect between beliefs and facts

PURPOSE OF REVIEW

To give an overview of recently published articles covering therapeutic drug monitoring (TDM) of biological DMARDs (bDMARDs) in rheumatoid arthritis.

RECENT FINDINGS

In the last 18 months, two clinical studies and nine reviews were found after a systematic literature search. Most (narrative) reviews conclude that TDM should be used to improve biological treatment in rheumatoid arthritis patients, whereas most of the clinical studies (including 13 studies identified earlier) whenever scrutinized do not support this conclusion. This disconnect between sobering data from prediction studies and test-treatment diagnostic studies and optimistic TDM beliefs in reviews is caused by failure to recognize incorrect study designs, false positives because of lack of validation after explorative multiple testing, cherry picking of studies, and incorrect interpretation of test characteristics.

SUMMARY

Serum (anti)-drug level monitoring has been extensively studied in rheumatoid arthritis, but correctly designed and executed interventional prediction studies or test-treatment intervention studies are sparse and mostly negative. In contrast, many reviews advocate use of biological TDM in rheumatoid arthritis. On the basis of current evidence, therapeutic drug monitoring of biologicals cannot be recommended in the treatment of rheumatoid arthritis patients, although two clinical scenarios deserve further study.

Current Practice for Therapeutic Drug Monitoring of Biopharmaceuticals in Spondyloarthritis

Treatment of spondyloarthritis (SpA) has greatly improved in the biopharmaceutical era. These compounds, primarily tumor necrosis factor inhibitors, are effective, but some patients may show poor response, sometimes due to the presence of antidrug antibodies (ADAs). In some instances, clinicians may increase or taper the dose, depending on the clinical response. Besides the current clinical practice, a tailored strategy based on drug monitoring is emerging as a way to improve the use of these drugs. However, the relevance of this therapeutic drug monitoring of biopharmaceuticals for SpA is still unknown. In this literature review, we examined the most relevant articles dealing with the concentration-response relation, ADA detection, and pharmacokinetics in SpA treated with biopharmaceuticals. ADAs were associated with low or undetectable concentration of monoclonal antibodies. The relation between drug concentration and clinical response in SpA is debated, some studies showing an association and others not. Therefore, therapeutic drug monitoring of biopharmaceuticals for SpA requires a better understanding of the association among the pharmacokinetics, pharmacodynamics, and immunogenicity of these drugs.

Secukinumab Demonstrates Significantly Lower Immunogenicity Potential Compared to Ixekizumab

Introduction

Secukinumab, a fully human monoclonal antibody that selectively neutralizes IL-17A, has been shown to have significant efficacy in the treatment of moderate to severe plaque psoriasis (PsO) and psoriatic arthritis (PsA), demonstrating a rapid onset of action and sustained responses with a favorable safety profile. All biotherapeutics, including monoclonal antibodies (mAbs), can be immunogenic, leading to formation of anti-drug antibodies (ADAs) that can result in loss of response and adverse events such as hypersensitivity reactions. Thus, the immunogenicity potential of biotherapeutics is of particular interest for physicians. Of the 2842 patients receiving secukinumab across six phase 3 psoriasis clinical trials, only 0.4% developed treatment-emergent ADAs over 3 years of treatment. Direct comparison of clinical immunogenicity incidence rates is hampered by the nature of clinical immunogenicity assays, differences in study designs, patient populations, and treatment regimens.

Methods

We evaluated side-by-side in the same healthy donors two recently approved IL-17A selective antibodies, secukinumab and ixekizumab, along with adalimumab and ustekinumab, for their capacity to induce anti-drug related T cell responses in vitro and estimated their potential for developing ADAs in patients.

Results

We found that healthy donors show both significantly less frequent T cell responses and lower numbers of pre-existing T cells to secukinumab than to ixekizumab and adalimumab. Although there was a tendency for a lower response to ustekinumab, this difference was not significant.

Conclusion

In summary, this in vitro study confirms the significantly lower immunogenicity potential and provides an explanation for the lower clinical immunogenicity incidence found for secukinumab in comparison to other approved therapeutic antibodies used to treat plaque psoriasis.

Funding

Novartis Pharmaceuticals AG.

Electronic supplementary material

The online version of this article (10.1007/s13555-018-0220-y) contains supplementary material, which is available to authorized users.

Practical recommendations for the use of therapeutic drug monitoring of biopharmaceuticals in inflammatory diseases

Biopharmaceuticals directed against tumor necrosis factor-alpha, integrins, interleukins, interferons and their receptors have become key agents for the management of inflammatory diseases in the fields of gastroenterology, rheumatology, dermatology and neurology. However, response to these treatments is far from optimal. Therapeutic failure has been attributed in part to inadequate serum concentrations of the drug and the formation of antidrug antibodies (ADA). Therapeutic drug monitoring (TDM) based on drug concentrations and ADA represents a pharmacologically sound tool for guiding dosage adjustments to optimize exposure. Although becoming standard practice in tertiary care centers, the widespread accessibility and recognition of TDM is hindered by several hurdles, including a lack of education of health care providers on TDM. In this paper, the Monitoring of monoclonal Antibodies Group in Europe (MAGE) provides an introduction on the fundamental principles of the concept of TDM, aiming to educate clinicians and assist them in the process of implementing TDM of anti-inflammatory biopharmaceuticals.

Clinical utility of therapeutic drug monitoring in biological disease modifying anti-rheumatic drug treatment of rheumatic disorders: a systematic narrative review

INTRODUCTION

Biological Disease Modifying Anti-Rheumatic Drugs (bDMARDs) have improved the treatment outcomes of inflammatory rheumatic diseases including Rheumatoid Arthritis and spondyloarthropathies. Inter-individual variation exists in (maintenance of) response to bDMARDs. Therapeutic Drug Monitoring (TDM) of bDMARDs could potentially help in optimizing treatment for the individual patient. Areas covered: Evidence of clinical utility of TDM in bDMARD treatment is reviewed. Different clinical scenarios will be discussed, including: prediction of response after start of treatment, prediction of response to a next bDMARD in case of treatment failure of the first, prediction of successful dose reduction or discontinuation in case of low disease activity, prediction of response to dose-escalation in case of active disease and prediction of response to bDMARD in case of flare in disease activity. Expert opinion: The limited available evidence does often not report important outcomes for diagnostic studies, such as sensitivity and specificity. In most clinical relevant scenarios, predictive value of serum (anti-) drug levels is absent, therefore the use of TDM of bDMARDs cannot be advocated. Well-designed prospective studies should be done to further investigate the promising scenarios to determine the place of TDM in clinical practice.

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.

Secukinumab, a novel anti-IL-17A antibody, shows low immunogenicity potential in human in vitro assays comparable to other marketed biotherapeutics with low clinical immunogenicity

Secukinumab is a human monoclonal antibody that selectively targets interleukin-17A and has been demonstrated to be highly efficacious in the treatment of moderate to severe plaque psoriasis, starting at early time points, with a sustained effect and a favorable safety profile. Biotherapeutics--including monoclonal antibodies (mAbs)--can be immunogenic, leading to formation of anti-drug antibodies (ADAs) that can result in unwanted effects, including hypersensitivity reactions or compromised therapeutic efficacy. To gain insight into possible explanations for the clinically observed low immunogenicity of secukinumab, we evaluated its immunogenicity potential by applying 2 different in vitro assays: T-cell activation and major histocompatibility complex-associated peptide proteomics (MAPPs). For both assays, monocyte-derived dendritic cells (DCs) from healthy donors were exposed in vitro to biotherapeutic proteins. DCs naturally process proteins and present the derived peptides in the context of human leukocyte antigen (HLA)-class II. HLA-DR-associated biotherapeutic-derived peptides, representing potential T-cell epitopes, were identified in the MAPPs assay. In the T-cell assay, autologous CD4(+) T cells were co-cultured with secukinumab-exposed DCs and T-cell activation was measured by proliferation and interleukin-2 secretion. In the MAPPs analysis and T-cell activation assays, secukinumab consistently showed relatively low numbers of potential T-cell epitopes and low T-cell response rates, respectively, comparable to other biotherapeutics with known low clinical immunogenicity. In contrast, biotherapeutics with elevated clinical immunogenicity rates showed increased numbers of potential T-cell epitopes and increased T-cell response rates in T-cell activation assays, indicating an approximate correlation between in vitro assay results and clinical immunogenicity incidence.

Clinical utility of random anti-tumor necrosis factor drug-level testing and measurement of antidrug antibodies on the long-term treatment response in rheumatoid arthritis

Objective

To investigate whether antidrug antibodies and/or drug non‐trough levels predict the long‐term treatment response in a large cohort of patients with rheumatoid arthritis (RA) treated with adalimumab or etanercept and to identify factors influencing antidrug antibody and drug levels to optimize future treatment decisions.

Methods

A total of 331 patients from an observational prospective cohort were selected (160 patients treated with adalimumab and 171 treated with etanercept). Antidrug antibody levels were measured by radioimmunoassay, and drug levels were measured by enzyme‐linked immunosorbent assay in 835 serial serum samples obtained 3, 6, and 12 months after initiation of therapy. The association between antidrug antibodies and drug non‐trough levels and the treatment response (change in the Disease Activity Score in 28 joints) was evaluated.

Results

Among patients who completed 12 months of followup, antidrug antibodies were detected in 24.8% of those receiving adalimumab (31 of 125) and in none of those receiving etanercept. At 3 months, antidrug antibody formation and low adalimumab levels were significant predictors of no response according to the European League Against Rheumatism (EULAR) criteria at 12 months (area under the receiver operating characteristic curve 0.71 [95% confidence interval (95% CI) 0.57, 0.85]). Antidrug antibody–positive patients received lower median dosages of methotrexate compared with antidrug antibody–negative patients (15 mg/week versus 20 mg/week; P = 0.01) and had a longer disease duration (14.0 versus 7.7 years; P = 0.03). The adalimumab level was the best predictor of change in the DAS28 at 12 months, after adjustment for confounders (regression coefficient 0.060 [95% CI 0.015, 0.10], P = 0.009). Etanercept levels were associated with the EULAR response at 12 months (regression coefficient 0.088 [95% CI 0.019, 0.16], P = 0.012); however, this difference was not significant after adjustment. A body mass index of ≥30 kg/m² and poor adherence were associated with lower drug levels.

Conclusion

Pharmacologic testing in anti–tumor necrosis factor–treated patients is clinically useful even in the absence of trough levels. At 3 months, antidrug antibodies and low adalimumab levels are significant predictors of no response according to the EULAR criteria at 12 months.