An open-label pilot study of the effectiveness of adalimumab in patients with rheumatoid arthritis and previous infliximab treatment: relationship to reasons for failure and anti-infliximab antibody status

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.

Assessing Immunogenicity of Biologic Drugs in Inflammatory Joint Diseases: Progress Towards Personalized Medicine

Biologic drugs have greatly improved treatment outcomes of inflammatory joint diseases, but a substantial proportion of patients either do not respond to treatment or lose response over time. Drug immunogenicity, manifested as the formation of anti-drug antibodies (ADAb), constitute a significant clinical problem. Anti-drug antibodies influence the pharmacokinetics of the drug, are associated with reduced clinical efficacy, and an increased risk of adverse events such as infusion reactions. The prevalence of ADAb differs among drugs and diseases, and the detection of ADAb also depends on the assay format. Most data exist for the tumor necrosis factor-alpha inhibitors infliximab and adalimumab, with a frequency of ADAb that ranges from 10 to 60% across studies. Measurement of ADAb and serum drug concentrations, therapeutic drug monitoring, has been suggested as a strategy to optimize therapy with biologic drugs. Although the recent randomized clinical Norwegian Drug Monitoring (NOR-DRUM) trials show promise towards a personalized medicine prescribing approach by therapeutic drug monitoring, several challenges remain. A plethora of assay formats, with widely differing properties, is currently used for measuring ADAb. Comparing results between different assays and laboratories is difficult, which complicates the development of cut-offs necessary for guidelines and the implementation of ADAb measurements in clinical practice. With the possible exception of infliximab, limited data on clinical relevance and cost effectiveness exist to support therapeutic drug monitoring as a routine clinical strategy to monitor biologic drugs in inflammatory joint diseases. The aim of this review is to provide an overview of the characteristics and prevalence of ADAb, predisposing factors to ADAb formation, commonly used assessment methods, clinical consequences of ADAb, and the potential implications of ADAb assessments for everyday treatment of inflammatory joint diseases.

High Anti-Infliximab Antibody Titers Do Not Impact Response to Subsequent Adalimumab Treatment in Inflammatory Bowel Diseases

BACKGROUND

While the role of anti-drug antibodies in mediating loss of response to infliximab (IFX) is known, it is possible that there are different clinical implications for high compared to low titers of antibodies to infliximab (ATI). The impact of ATI titer on efficacy of subsequent anti-TNF treatment has not been established previously.

METHODS

This is a multicenter retrospective cohort study of individuals with IBD who discontinued infliximab due to development of ATI and were subsequently switched to adalimumab therapy. IFX anti-drug antibody titer level was measured using Mayo or Esoterix assays. We examined clinical and endoscopic response to adalimumab at 3 months, 12 months, and 2 years.

RESULTS

Our study included 90 patients (69 CD, 17 UC, 4 CD of the ileoanal pouch) with IBD. The median antibody titer levels for the Esoterix (208 u/mL) or Mayo clinic laboratory (236 u/mL) were similar (p > 0. 50). Patients with high ATI titers (median 824 u/ml, IQR 405-1250 u/ml) were as likely to respond to adalimumab as those with low titers (median 76u/ml, IQR 41-129 u/ml). At 3 months and 12 months, the rates of clinical response/remission to adalimumab therapy were 78% and 77%, respectively, among those with high ATI titers and 81% and 84% among those with low ATI titers (p = 0.81 and 0.62, respectively). In patients who initiated a different therapeutic mechanism after adalimumab, the response rates were similar to that observed with adalimumab.

CONCLUSIONS

The presence of high titers of anti-drug antibodies to IFX is not predictive of treatment failure with adalimumab.

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.

Cycling of tumor necrosis factor inhibitors versus switching to different mechanism of action therapy in rheumatoid arthritis patients with inadequate response to tumor necrosis factor inhibitors: a Bayesian network meta-analysis

Introduction:

For patients with rheumatoid arthritis (RA) with an inadequate response to tumor necrosis factor inhibitors (TNFi), main options include cycling onto a different TNFi or switching to a biologic/targeted synthetic disease-modifying antirheumatic drug with a different mechanism of action (MOA). This network meta-analysis (NMA) assessed comparative clinical efficacy of cycling versus switching.

Methods:

We conducted a literature search in MEDLINE, Embase, and Cochrane Library. Outcomes included proportion of patients with 20%, 50%, or 70% response to American College of Rheumatology criteria (ACR20/ACR50/ACR70 response), Disease Activity Score in 28 joints (DAS28) score below 2.6 or between 2.6 and 3.2, mean change in DAS28 score, mean reduction in and proportion of patients achieving a clinically meaningful reduction (⩾0.22) in Health Assessment Questionnaire score, number of serious adverse events (AEs), and withdrawals for any reason/due to AEs/lack of treatment efficacy. To account for the wide range of study populations and designs, we developed three models to conduct the NMA: fixed-effect, random-effects, and hierarchical Bayesian. PROSPERO ID: CRD42019122993.

Results:

We identified nine randomized controlled trials and 16 observational studies. The fixed-effect model suggested a 0.99 probability that switch was the better strategy for increasing odds of a clinically meaningful improvement in ACR50 [odds ratio (OR): 1.35 (95% credible interval (CI): 0.96–1.81)]. The fixed-effect model also suggested that switch was associated with lower rates of withdrawal for any reasons [OR: 0.53 (95% CI: 0.40–0.68)]. The random-effects and hierarchical Bayesian models suggested additional uncertainty as they considered more variability than the fixed-effect model.

Discussion:

Results suggest that switching to a drug with a different MOA is more effective and associated with lower rates of withdrawal than cycling to a different TNFi after failure of first-line TNFi. Further trials that directly compare cycling with switching are warranted to better assess comparative efficacy.

Plain language summary

Assessment of the effectiveness of different drug treatment strategies in patients with rheumatoid arthritis: an analysis of the published literature

False-positive semiquantitative immunochromatography assays for procalcitonin in three patients with rheumatoid arthritis-A case series

We report three rheumatoid arthritis (RA) patients with false-positive procalcitonin (PCT) based on semiquantitative immunochromatography assays without infection, but who had negative PCT assay results based on quantitative methods. Immunochromatography was useful for screening; however, other heterophilic antibodies rather than rheumatoid factor were possible to affect, especially in RA flare.

Structural optimization of a TNFR1-selective antagonistic TNFα mutant to create new-modality TNF-regulating biologics

Excessive activation of the proinflammatory cytokine tumor necrosis factor-α (TNFα) is a major cause of autoimmune diseases, including rheumatoid arthritis. TNFα induces immune responses via TNF receptor 1 (TNFR1) and TNFR2. Signaling via TNFR1 induces proinflammatory responses, whereas TNFR2 signaling is suggested to suppress the pathophysiology of inflammatory diseases. Therefore, selective inhibition of TNFR1 signaling and preservation of TNFR2 signaling activities may be beneficial for managing autoimmune diseases. To this end, we developed a TNFR1-selective, antagonistic TNFα mutant (R1antTNF). Here, we developed an R1antTNF derivative, scR1antTNF-Fc, which represents a single-chain form of trimeric R1antTNF with a human IgG-Fc domain. scR1antTNF-Fc had properties similar to those of R1antTNF, including TNFR1-selective binding avidity, TNFR1 antagonistic activity, and thermal stability, and had a significantly extended plasma t _1/2 in vivo In a murine rheumatoid arthritis model, scR1antTNF-Fc and 40-kDa PEG-scR1antTNF (a previously reported PEGylated form) delayed the onset of collagen-induced arthritis, suppressed arthritis progression in mice, and required a reduced frequency of administration. Interestingly, with these biologic treatments, we observed an increased ratio of regulatory T cells to conventional T cells in lymph nodes compared with etanercept, a commonly used TNF inhibitor. Therefore, scR1antTNF-Fc and 40-kDa PEG-scR1antTNF indirectly induced immunosuppression. These results suggest that selective TNFR1 inhibition benefits the management of autoimmune diseases and that R1antTNF derivatives hold promise as new-modality TNF-regulating biologics.

Fluctuations in serum levels of adalimumab and infliximab in patients on stable treatment for psoriasis

Many patients with psoriasis fail to respond to biologic drugs either initially or lose response over time, the latter having predominantly been linked to low circulating drug levels. We examined how serum drug levels varied over three treatment cycles of stable maintenance therapy with either adalimumab or infliximab among a total of 28 patients with psoriasis (22 men, mean age 48.6 years, mean treatment time 6.2 years) and whether there was an association with various patient-specific factors. The range for all concentrations was 1.1 to 24.3 μg/mL for adalimumab and 0.0 to 180.6 μg/mL for infliximab. There was a consistent inverse association between body mass index (BMI) and trough and maximum serum concentrations of adalimumab (P < .05 for all comparisons) and a positive, less consistent, association between age and maximum serum concentration of infliximab (P < .05 for both comparisons). Patient-specific factors, such as BMI and age, can help predict fluctuations in serum concentrations of biologics used for psoriasis.

What Is the Clinical Relevance of TNF Inhibitor Immunogenicity in the Management of Patients With Rheumatoid Arthritis?

Tumor necrosis factor-α inhibitors (TNFis) have revolutionized the management of rheumatoid arthritis (RA), however despite considerable progress, only a small proportion of patients maintain long-term clinical response. Selection of, and switching between, biologics is mainly empirical, experiential, and not evidence-based. Most biopharmaceutical proteins (BP) can induce an immune response against the foreign protein component. Immunogenicity and the development of anti-drug antibodies (ADAs) is considered one of the main reasons for loss of therapeutic efficacy (secondary failure). ADAs may neutralize and/or promote clearance of circulating BP with resultant low serum drug levels, loss of clinical response, poor drug survival and adverse events, such as infusion reactions. ADA identification is technically difficult and not standardized, making interpretation of immunogenicity data from published clinical studies challenging. Trough TNFi drug levels correlate with clinical outcomes, exhibiting a "concentration-response" relationship. Measurement of ADA and drug levels may improve patient care and improve cost-effectiveness of BP use. However, in the absence of clinically-validated, reliable assays and consensus guidelines, therapeutic drug monitoring (TDM) and immunogenicity testing have not been widely adopted in routine clinical practice in Rheumatology. Here we discuss the utility and relevance of TDM and immunogenicity testing of TNFis in RA (focusing on the most widely used TNFis globally, with the most available data, i.e., infliximab, adalimumab, and etanercept), the limitations of currently available assays and potential future immunopharmacological strategies to personalize disease management.

Long-Term Safety of Adalimumab in 29,967 Adult Patients From Global Clinical Trials Across Multiple Indications: An Updated Analysis

INTRODUCTION

The safety profile of adalimumab was previously reported in 23,458 patients across multiple indications. Here we report the long-term safety of adalimumab in adults with plaque psoriasis (Ps), hidradenitis suppurativa (HS), rheumatoid arthritis (RA), ankylosing spondylitis, psoriatic arthritis, non-radiographic axial spondyloarthritis, peripheral spondyloarthritis, Crohn's disease (CD), ulcerative colitis (UC), and non-infectious uveitis (UV).

METHODS

Safety data from 77 clinical trials were pooled. Safety assessments included adverse events (AEs) and serious AEs (SAEs) that occurred after the first study dose and within 70 days (5 half-lives) after the last study dose.

RESULTS

A total of 29,967 patients were included, representing 56,916 patient-years (PY) of exposure. The most frequently reported SAE of interest was infection (3.7/100 PY) with highest incidences in CD, RA, UV, and UC (3.5/100 PY-6.9/100 PY); serious infections in Ps (1.8/100 PY) and HS (2.8/100 PY) were lower. The observed number of deaths was below what would be expected in an age- and sex-adjusted population for most adalimumab-treated patients (including Ps). Lack of real-life data and limited long-term data (> 5 years) for most patients are limitations of this analysis.

CONCLUSION

The safety profile of adalimumab was consistent with previous findings and no new safety signals were observed.

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.

Immunogenicity of Biologics in Chronic Inflammatory Diseases: A Systematic Review

OBJECTIVES

A systematic review was conducted to explore the immunogenicity of biologic agents across inflammatory diseases and its potential impact on efficacy/safety.

METHODS

Literature searches were conducted through November 2016 to identify controlled and observational studies of biologics/biosimilars administered for treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), non-radiographic axial spondyloarthritis (nr-axSpA), psoriasis (Ps), Crohn's disease, and ulcerative colitis.

RESULTS

Of >21,000 screened publications, 443 were included. Anti-drug antibody (ADAb) rates varied widely among biologics across diseases (and are not directly comparable because of immunoassay heterogeneity); the highest overall rates were reported with infliximab (0-83%), adalimumab (0-54%), and infliximab biosimilar CT-P13 (21-52%), and the lowest with secukinumab (0-1%), ustekinumab (1-11%), etanercept (0-13%), and golimumab (0-19%). Most ADAbs were neutralizing, except those to abatacept and etanercept. ADAb+ versus ADAb- patients had lower rates of clinical response to adalimumab (RA, PsA, JIA, AS, Ps), golimumab (RA), infliximab (RA, PsA, AS, Ps), rituximab (RA), ustekinumab (Ps), and CT-P13 (RA, AS). Higher rates of infusion-related reactions were reported in infliximab- and CT-P13-treated ADAb+ patients. Background immunosuppressives/anti-proliferatives reduced biologic immunogenicity across diseases.

CONCLUSIONS

Based on reviewed reports, biologic/biosimilar immunogenicity differs among agents, with the highest rates observed with infliximab and adalimumab. As ADAb formation in biologic-/biosimilar-treated patients may increase the risk of lost response, the immunogenicity of these agents is an important (albeit not the only) consideration in the treatment decision-making process.

A randomised, single-blind, single-dose, three-arm, parallel-group study in healthy subjects to demonstrate pharmacokinetic equivalence of ABP 501 and adalimumab

OBJECTIVE

To demonstrate pharmacokinetic (PK) similarity of biosimilar candidate ABP 501 relative to adalimumab reference product from the USA and European Union (EU) and evaluate safety, tolerability and immunogenicity of ABP 501.

METHODS

Randomised, single-blind, single-dose, three-arm, parallel-group study; healthy subjects were randomised to receive ABP 501 (n=67), adalimumab (USA) (n=69) or adalimumab (EU) (n=67) 40 mg subcutaneously. Primary end points were area under the serum concentration-time curve from time 0 extrapolated to infinity (AUCinf) and the maximum observed concentration (Cmax). Secondary end points included safety and immunogenicity.

RESULTS

AUCinf and Cmax were similar across the three groups. Geometrical mean ratio (GMR) of AUCinf was 1.11 between ABP 501 and adalimumab (USA), and 1.04 between ABP 501 and adalimumab (EU). GMR of Cmax was 1.04 between ABP 501 and adalimumab (USA) and 0.96 between ABP 501 and adalimumab (EU). The 90% CIs for the GMRs of AUCinf and Cmax were within the prespecified standard PK equivalence criteria of 0.80 to 1.25. Treatment-related adverse events were mild to moderate and were reported for 35.8%, 24.6% and 41.8% of subjects in the ABP 501, adalimumab (USA) and adalimumab (EU) groups; incidence of antidrug antibodies (ADAbs) was similar among the study groups.

CONCLUSIONS

Results of this study demonstrated PK similarity of ABP 501 with adalimumab (USA) and adalimumab (EU) after a single 40-mg subcutaneous injection. No new safety signals with ABP 501 were identified. The safety and tolerability of ABP 501 was similar to the reference products, and similar ADAb rates were observed across the three groups.

TRIAL REGISTRATION NUMBER

EudraCT number 2012-000785-37; Results.

Immunogenicity of tocilizumab in patients with rheumatoid arthritis

OBJECTIVE

The immunogenicity of tocilizumab (TCZ) has been poorly studied. We assessed the immunogenicity of TCZ and serum TCZ trough levels in rheumatoid arthritis (RA) patients and the preexisting TCZ-specific CD4+ T cell repertoire in healthy controls.

METHODS

Anti-drug antibodies (ADAs) to TCZ and serum TCZ trough levels in RA patients were assessed at different times by ELISA. Frequencies of naive anti-TCZ CD4+ precursors were studied in healthy controls.

RESULTS

In total, 91 samples from 40 RA patients were analyzed: 21 patients within the first 6 months after treatment initiation and 19 during follow-up after a mean TCZ treatment duration of 21±13 months. None of the 91 samples showed persistent ADAs to TCZ. Only 3 RA patients showed transient and low titers of anti-TCZ ADAs. Serum TCZ trough levels were associated with neither patient characteristics (gender, body mass index) nor disease activity and were identical for patients with and without co-treatment with methotrexate. Three of 9 healthy donors showed preexisting TZC-specific CD4+ T cells at a low level.

CONCLUSION

Serum TCZ trough levels were not affected by patient characteristics. The occurrence of ADAs to TCZ was a rare event. Because healthy donors show the same frequency of naive TCZ-specific and infliximab-specific CD4+ T cell precursors, the low prevalence of ADAs to TCZ might result from interleukin-6 blockade.

Association of anti-Ro/SSA antibody with response to biologics in patients with rheumatoid arthritis

OBJECTIVE

To compare the effectiveness of three different biologics in anti-Ro/SSA antibody-positive and antibody-negative patients with rheumatoid arthritis (RA).

METHODS

The study subjects were 110 biologics naïve patients with RA who started treatment with biologics and examined for anti-Ro/SSA antibody between December 2003 and March 2014. For patients treated with intravenous infliximab (IFX), tocilizumab (TCZ), or abatacept (ABT), we compared the clinical characteristics and changes in composite disease activity index, such as DAS28, SDAI, and CDAI, for 12 months in anti-Ro/SSA antibody-positive and antibody-negative patients.

RESULTS

We examined 59 patients (nine were positive and 50 were negative for anti-Ro/SSA antibody) treated with IFX, 27 patients (5 positive and 22 negative) treated with TCZ, and 24 patients (13 positive and 11 negative) treated with ABT. For patients treated with IFX, parameters of disease activity did not change significantly from baseline in anti-Ro/SSA antibody-positive patients, whereas they improved in antibody-negative patients. On the other hand, treatment with TCZ and ABT significantly decreased disease activity, relative to baseline, in both anti-Ro/SSA antibody-positive and antibody-negative patients. Anti-Ro/SSA antibody-positive patients treated with IFX showed higher frequency of HACA and seroconversion of ANA, and lower serum TGF-β levels.

CONCLUSIONS

Positivity to anti-Ro/SSA in RA seems to confer resistance to IFX via production of HACA and ANA, and low serum TGF-β levels, but not to TCZ and ABT.

Safety, effectiveness, and pharmacokinetics of adalimumab in children with polyarticular juvenile idiopathic arthritis aged 2 to 4 years

The objective of this study was to assess the safety of adalimumab in patients aged 2 to <4 years old or ≥4 years old weighing <15 kg with moderately to severely active polyarticular juvenile idiopathic arthritis (JIA). Clinical effectiveness and pharmacokinetics (PK) of adalimumab were also evaluated. This was an international, multicenter, open-label, phase 3b study in 32 patients with active JIA that were treated with adalimumab 24 mg/m² (maximum = 20 mg/dose) every other week up to 120 weeks, with or without concomitant methotrexate. Adverse events (AEs) were summarized for completed visits. Efficacy endpoints included American College of Rheumatology pediatric (PedACR) 30/50/70/90 responses and JIA core components. Adalimumab serum trough concentrations were measured in a subset of patients. Among the patients, 88 % were female. Baseline mean age, weight, and JIA duration were 3 years, 13 kg, and 12 months, respectively; 39 % had elevated C-reactive protein. AE incidence rates included any AEs (29/32, 91 %), serious AEs (5/32, 16 %), infectious AEs (25/32, 78 %), and serious infections (3/32, 9 %). No deaths, malignancies, or opportunistic infections were reported. Growth was not adversely impacted. At week 96, 92 % of patients achieved PedACR30, and 77 % achieved PedACR70. Improvements in JIA core components were observed. Mean steady-state serum adalimumab trough concentrations were 7–8 μg/mL at weeks 12 and 24. Adalimumab was well tolerated in JIA patients aged 2 to <4 years old or ≥4 years old weighing <15 kg. The efficacy and PK of adalimumab were comparable to those seen in older JIA patients.

Use of Bayesian multivariate meta-analysis to estimate the HAQ for mapping onto the EQ-5D questionnaire in rheumatoid arthritis

BACKGROUND

In health technology assessment, decisions about reimbursement for new health technologies are largely based on effectiveness estimates. Sometimes, however, the target effectiveness estimates are not readily available. This may be because many alternative instruments measuring these outcomes are being used (and not all always reported) or an extended follow-up time of clinical trials is needed to evaluate long-term end points, leading to the limited data on the target clinical outcome. In the areas of highest priority in health care, decisions are required to be made on a short time scale. Therefore, alternative clinical outcomes, including surrogate end points, are increasingly being considered for use in evidence synthesis as part of economic evaluation.

OBJECTIVE

To illustrate the potential effect of reduced uncertainty around the clinical outcome on the utility when estimating it from a multivariate meta-analysis.

METHODS

Bayesian multivariate meta-analysis has been used to synthesize data on correlated outcomes in rheumatoid arthritis and to incorporate external data in the model in the form of informative prior distributions. Estimates of Health Assessment Questionnaire were then mapped onto the health-related quality-of-life measure EuroQol five-dimensional questionnaire, and the effect was compared with mapping the Health Assessment Questionnaire obtained from the univariate approach.

RESULTS

The use of multivariate meta-analysis can lead to reduced uncertainty around the effectiveness parameter and ultimately uncertainty around the utility.

CONCLUSIONS

By allowing all the relevant data to be incorporated in estimating clinical effectiveness outcomes, multivariate meta-analysis can improve the estimation of health utilities estimated through mapping methods. While reduced uncertainty may have an effect on decisions based on economic evaluation of new health technologies, the use of short-term surrogate end points can allow for early decisions. More research is needed to determine the circumstances under which uncertainty is reduced.

Immunogenicity of anti-TNFα therapy in psoriasis: a clinical issue?

INTRODUCTION

Immunogenicity of antitumor necrosis factor-alpha (TNFα) agents has been proven to play a significant role in the variability of clinical responses among patients with chronic inflammatory diseases. However, its clinical impact on the outcome of patients with psoriasis and psoriatic arthritis receiving anti-TNFα treatment is not yet fully clear. Despite the high rates of efficacy of anti-TNFα agents in psoriasis, a substantial proportion of patients remain who experience a primary or secondary failure or significant side effects, which are potentially ascribable to immunogenicity.

AREAS COVERED

Topics include immunologic response elicited by anti-TNFα agents, the impact of immunogenicity on treatment response to anti-TNFα and the role played by immunogenicity in the lack of efficacy of anti-TNFα agents (infliximab, adalimumab and etanercept) in psoriasis.

EXPERT OPINION

Based on data available in the literature and the clinical experience of the authors, this article suggests the optimal approach to drug monitoring and antidrug antibody assay and the most effective use of biologic immunotherapies in this setting. Immunogenicity should be taken into account in the adoption of therapeutic choices in psoriatic patients, such as anti-TNFα agent intensification, or switching to another anti-TNFα agent or a drug with a different mechanism of action.

The immunogenicity to the first anti-TNF therapy determines the outcome of switching to a second anti-TNF therapy in spondyloarthritis patients

Introduction

Anti-TNF drugs have proven to be effective against spondyloarthritis (SpA), although 30% of patients fail to respond or experience adverse events leading to treatment discontinuation. In rheumatoid arthritis, the presence of anti-drug antibodies (ADA) against the first TNF inhibitor influences the outcome after switching. Our aim was to assess whether the response to a second anti-TNF drug is related to the previous development of ADA to the first anti-TNF drug SpA patients.

Methods

Forty-two SpA patients began a second anti-TNF drug after failing to respond to the first anti-TNF therapy. Clinical activity was assessed by the Ankylosing Spondylitis Disease Activity Score (ASDAS) at baseline (at the beginning of the first and second anti-TNF therapy) and at 6 months after switching. The drug and ADA levels were measured by ELISA before each administration.

Results

All patients were treated with anti-TNF drugs and mainly due to inefficacy were switched to a second anti-TNF drug. Eleven of 42 (26.2%) developed ADA during the first biologic treatment. At baseline, no differences in ASDAS were found in patients with or without ADA to the first anti-TNF drug (3.52 ± 1.03 without ADA vs. 3.14 ± 0.95 with ADA, p = 0.399) and to the second anti-TNF drug (3.36 ± 0.94 without ADA vs. 3.09 ± 0.91 with ADA, p = 0.466). At 6 months after switching, patients with previous ADA had lower disease activity (1.62 ± 0.93 with ADA vs. 2.79 ± 1.01 without ADA, p = 0.002) and most patients without ADA had high disease activity state by the ASDAS (25 out of 31 (80.6%) without ADA vs. 3 out of 11 (27.3%) with ADA, p = 0.002).

Conclusions

In SpA the failure to respond to the first anti-TNF drug due to the presence of ADA predicts a better clinical response to a second anti-TNF drug.

Tight control applied to the biological therapy of rheumatoid arthritis

In the last decade, treatment strategies for rheumatoid arthritis (RA) have included the early use of disease-modifying anti-rheumatic drugs, since prompt suppression of disease activity is associated with a reduction in radiological damage. This strategy has now been incorporated into the broader concept of "tight control", defined as a treatment strategy tailored to each patient with RA, which aims to achieve a predefined level of low disease activity or remission within a certain period of time. To pursue this goal, tight control should include careful and continuous monitoring of disease activity, and early therapeutic adjustments or switches should be considered as necessary. It is noteworthy that the key role of tight control of RA has been stressed by the recent EULAR Guidelines. This review discusses the most recent evidence concerning the role of a tight control strategy in the treatment of RA, and on how this strategy should be pursued.

Immunogenicity and autoimmunity during anti-TNF therapy

The introduction of anti-tumour necrosis factor (TNF) agents for the treatment of rheumatoid arthritis (RA), Crohn's disease (CD) or spondyloarthritis (SpA) has revolutionised the therapeutic approach to patients with active disease failing to respond to conventional therapy. However, some of the patients treated with selective TNF inhibitors may develop autoantibodies, such as antinuclear antibodies (ANAs) and anti-double-stranded DNA (anti-dsDNA) antibodies. Furthermore, anti-phospholipid antibodies, which are mainly detected by means of anti-cardiolipin assays, have been found in RA patients receiving TNF blockers. There have also been a number of reports of the development of anti-drug antibodies, of which those against infliximab can interfere with the drug's pharmacokinetics (and therefore its effects), and may also cause acute and delayed infusion and injection site reactions. The onset of autoimmune diseases during biological treatment is rare, but it needs to be promptly recognised in order to plan appropriate patient management. The addition of an immunosuppressive drug can reduce the induction of anti-TNF antibodies.

Thresholds in disease activity for switching biologics in rheumatoid arthritis patients: experience from a large U.S. cohort

OBJECTIVE

To examine the threshold in disease activity associated with switching biologic treatment regimens in rheumatoid arthritis (RA) patients in real-world clinical practice.

METHODS

Using data from a prospective observational North American cohort of RA patients through December 30, 2009, patients who initiated a new anti-tumor necrosis factor α (anti-TNFα) agent with ≥6 months of followup were identified. Patients were classified as switchers or maintainers depending on whether they continued their anti-TNF treatment or switched (including discontinuation) within 12 months. Level of disease activity measured by the Clinical Disease Activity Index (CDAI) and Disease Activity Score in 28 joints (DAS28) at the time of the switch (corresponding followup visit for maintainers) was examined and random-effect multivariable logistic regression was used to adjust for covariates.

RESULTS

Mean age and RA duration among 1,549 eligible patients were 56.1 and 9.6 years, respectively, 80% were women, 62% were initiating their first biologic, and 30% were initiating their second biologic. At the time of the switch, the median DAS28 and CDAI score were 3.1 and 8.4 among maintainers and 4.0 and 15.2 among switchers, respectively. Maintainers also experienced a greater amount of reduction in disease activity compared with switchers (CDAI: -7.7 versus -2.3, DAS28: -1.1 versus -0.3). The threshold to switch decreased over calendar time, with the greatest amount of reduction observed among patients with moderate disease activity.

CONCLUSION

On average, physicians and patients were willing to continue biologic treatment for patients who were at or near low disease activity. The threshold to switch decreased over time, especially among partial responders.

Outcomes of switching anti-TNF drugs in rheumatoid arthritis--a study based on observational data from the Finnish Register of Biological Treatment (ROB-FIN)

The aim of this study was to assess, based on observational data from the Finnish Register of Biological Treatment, the outcomes of switching an initial tumor necrosis factor (TNF) blocker to another in the treatment of rheumatoid arthritis (RA). RA patients, who started biological therapy with a TNF blocker between May 1999 and April 2009 and who switched to another TNF blocker, were studied (n=479). The outcomes were assessed according to the reason for and type of the switch. Outcome assessments included American College of Rheumatology 50 responder index (ACR50) response at 3 months after the switch, treatment duration of the second TNF blocker, and swollen joint counts, CRP and DAS28 score at the 3 months, best and last observations of the first and second TNF blocker, respectively. In those who switched due to lack of effectiveness (LOE), the disease activity parameters fell significantly from baseline upon use of infliximab or adalimumab, but had increased prior to the switch. Switching to another TNF blocker (etanercept or adalimumab) restored the response initially achieved with the first TNF blocker. The disease activity parameters fell significantly from baseline upon use of etanercept, and were maintained but not further improved after switching to adalimumab. TNF blocker switching seemed to be most beneficial in secondary LOE (defined as loss of ACR50 response). In those who switched due to adverse events (AE) or other reasons, a similar degree of response as had been achieved with the first agent was also achieved and maintained with the second agent. The results suggest that a second TNF blocker can restore the response in cases of secondary LOE and maintain it after switching due to an AE.

Tumor necrosis factor alpha inhibitors as immunomodulatory antirejection agents after intestinal transplantation

We reported the successful administration of infliximab for late-onset OKT3-resistant rejection in two patients, who presented persistent ulcerative inflammation of the ileal graft after intestinal transplantation (ITX). Based on this experience, the present study demonstrated our long-term experience with infliximab for different types of rejection-related and inflammatory allograft alterations. Infliximab administration (5 mg/kg body weight (BW)) was initiated at a mean of 18.2 ± 14.1 months after transplantation. The number of administrations per patient averaged 8.4 ± 6.7. Repeat dosing was timed according to clinical signs and graft histology in addition to serum-levels of tumor necrosis factor alpha (TNFα), lipopolysaccharide binding protein (LBP) and C-reactive protein (CRP). Infliximab was successful in the following patients: patients with late-onset OKT3- and steroid-refractory rejection who presented persistent ulcerative alterations of the ileal graft (n = 5), patients with ulcerative ileitis/anastomositis, who did not show typical histological rejection signs (n = 2), and one patient with early-onset OKT3-resistant rejection. Infliximab was not successful in one patient with early-onset OKT3-resistant rejection that was accompanied by treatment-refractory humoral rejection. In conclusion, infliximab can expand therapeutic options for late-onset OKT3- and steroid-refractory rejection and chronic inflammatory graft alterations in intestinal allograft recipients.

Assessing response and loss of response to biological therapies in IBD

OBJECTIVES

The advent of biological therapies for inflammatory bowel disease (IBD) began in 1998 with the approval of infliximab for the treatment of refractory (to conventional agents) Crohn's disease (CD). Since then, the indications for anti-tumor necrosis factor-α (anti-TNFα) therapy have increased to include induction and maintenance of clinical responses and remissions for luminal and fistulizing CD, the treatment of children with CD, and the treatment of adults with ulcerative colitis. Additional utilities of biological therapies have included demonstrable mucosal healing, improvement in quality of life, reduction in surgeries and hospitalizations, and the treatment of extraintestinal manifestations of IBD including central and peripheral arthritis and pyoderma gangrenosum. Natalizumab has also been approved for the treatment of refractory Crohn's in patients who have failed conventional agents and anti-TNFα therapies. Unfortunately, despite the overall effectiveness of biological agents in a spectrum of indications for IBD, a significant proportion of patients do not respond or lose response over time. In this review, we intend to appraise the latest evolution in treatment strategies in IBD and to suggest an evidence-based approach and risk stratification while coping with cases of non-responders or loss of response to biological therapies.

METHODS

We conducted a literature search of English publications listed in the electronic databases of MEDLINE (source PUBMED) and constructed an analytical review based on definitions of response and loss of response, considering potential responsible mechanisms, clinical assessment tools, and finally recommending a practical approach for its prevention and management.

RESULTS

Favorable clinical outcome appears to be the consequence of sustained therapeutic drug levels, and the current literature supports a practice of dose adjustments. When immunogenicity develops to a single biological agent, response can be regained by introduction of an alternative biological agent of the same or different class. Efficacy is reduced with second-line agents either within or across classes compared with naive patients. In the absence of direct measurement of drug levels and anti-drug antibodies, clinical judgment is necessary to assess the mechanisms of loss of response, and more empiric decision making may be necessary to determine the choice of second-line biological agents. Optimal treatment strategies are still controversial.

CONCLUSIONS

It is essential to recognize the spectrum of mechanisms affecting response and loss of response to form a logical and efficient management algorithm, and, perhaps, it is time to incorporate the measurement of trough levels and anti-drug antibodies in the strategy of such an assessment. Prospective controlled trials are direly needed to investigate the optimal tailored management in individual patients who lose response.

Acute infusion reactions induced by monoclonal antibody therapy

This article reports recent evidence on epidemiological data concerning monoclonal antibody (mAb) infusion-related anaphylaxis, as well as recent data on the correlation between mAb immunogenicity and safety profiles. Pathogenic mechanisms of mAb-related adverse reactions including hypersensitivity, IgE- and non-IgE-mediated events and cytokine release syndrome are also highlighted. Finally, the role of serum anti-mAb antibodies as markers to monitor the safety of such therapeutical compounds are extensively evaluated. The anaphylaxis occurring during therapy with the anti-TNF-α mAb infliximab, largely used in immune-mediated diseases, has been taken as a paradigm.

The efficacy and safety of reinstitution of tocilizumab in patients with relapsed active rheumatoid arthritis after long-term withdrawal of tocilizumab: retreatment of patients with rheumatoid arthritis with novel anti-IL-6 receptor antibody after a long-term interval following SAMURAI: the RONIN study

We have evaluated the efficacy and safety of tocilizumab (TCZ) re-administration in patients with active rheumatoid arthritis (RA) who had previously received TCZ treatment for about 31 months. Four patients whose RA had been well-controlled with 8 mg/kg TCZ treatment every 4 weeks and had withdrawn from the treatment were enrolled. They resumed TCZ treatment after TCZ was authorized for RA treatment in Japan. Disease activity was assessed by the Disease Activity Score 28 using erythrocyte sedimentation rate (DAS28-ESR), and synovitis in the wrists and elbows was measured by ultrasonography at baseline and during follow-up. The mean DAS28-ESR was 6.32 before the first TCZ infusion. After fewer than 20 months of initial TCZ treatment, the mean DAS28-ESR decreased to 1.87. However, after withdrawal of TCZ treatment, the disease activity could not be sufficiently controlled with conventional disease-modifying antirheumatic drugs or biologic agents. The maximum interval between TCZ treatments was approximately 34 months. Following reinstatement of the TCZ treatment, within 12 months the mean DAS28-ESR improved from 5.21 to 2.87, with the synovitis in the wrists and elbow joints also showing great improvement. These findings demonstrate that TCZ retreatment in active RA patients who had relapsed after long-term discontinuation of TCZ treatment led to an improvement in the signs and symptoms of RA and in synovitis without any severe adverse events.

Evaluating the efficacy of sequential biologic therapies for rheumatoid arthritis patients with an inadequate response to tumor necrosis factor-α inhibitors

Introduction

The long-term treatment of rheumatoid arthritis (RA) most often involves a sequence of different therapies. The response to therapy, disease progression and detailed knowledge of the role of different therapies along treatment pathways are key aspects to help physicians identify the best treatment strategy. Thus, understanding the effectiveness of different therapeutic sequences is of particular importance in the evaluation of long-term RA treatment strategies. The objective of this study was to systematically review and quantitatively evaluate the relationship between the clinical response to biologic treatments and the number of previous treatments with tumor necrosis factor α (TNF-α) inhibitors.

Methods

A systematic search was undertaken to identify published, peer-reviewed articles that reported clinical outcomes of biologic treatment among RA patients with an inadequate response to TNF-α inhibitors. Data were systematically abstracted. Efficacy rates were estimated for groups of patients who differed in the number of prior TNF-α inhibitors used. End points included American College of Rheumatology (ACR)-, European League Against Rheumatism (EULAR)- and Disease Activity Score 28 (DAS28)-based response criteria.

Results

The literature search identified 41 publications, of which 28 reported biologic treatment outcomes for RA patients with prior exposure to TNF-α inhibitors. Seven publications reported outcomes obtained in randomized clinical trials, while the remaining consisted of observational studies. The likelihood of responding to a subsequent biologic treatment decreased as the number of previous treatments with TNF-α inhibitors increased for six of the seven response criteria examined.

Conclusions

For patients with prior exposure to TNF-α inhibitors, the likelihood of response to subsequent treatment with biologic agents declines with the increasing number of previous treatments with TNF-α inhibitors.

Adverse events during biological therapy – focusing on dermatological side-effects

Biological response modifiers, especially tumour necrosis factor inhibitors have been proved to be very effective in the treatment of various immune mediated rheumatological, gastroenterological and dermatological diseases in the last 15 years. With their increasing use, the incidence of their adverse effects are more precisely defined. The aim of this cohort study was to analyse the adverse effects occurred within the study period in patients receiving biological therapy for rheumatological and dermatological autoimmune diseases. Methods: 324 patients within a 3 years study period were treated with biological response modifiers (adalimumab: 92, etanercept: 107, infliximab: 125). The primary diagnoses were rheumotoid arthritis (n = 174), ankylosing spondylitis (n = 60), psoriatic arthritis (n = 11), and psoriasis vulgaris (79). Results: Hypersensitive reactions were observed in 11 of the patients (3.4%), 7 of which were serious and needed treatment termination. Infections constituted the majority of side effects, which were localised to skin in 10 (3.1%) and to respiratory tract in 9 (2.8%). However, most of these were mild or moderate reactions. Malignant skin tumour developed in 1 case (0.3%) only. Drug induced inflammatory disorders occurred in some cases: onset of new psoriasis was observed in 1 and flares of the existing disease were detected in additional three. Lichenoid exanthema developed in one. (n = 5, 1.5%) Conclusion: The use of TNF-α blockers may provoke a broad spectrum of dermatological side effects. Our results suggest that the majority of these are infectious and inflammatory disorders, the latter may relatively often appear as drug induced psoriasis. The occurrence of malignancies was very low in our series. Orv. Hetil., 2011, 152, 212–220.

Anti-infliximab antibody status and its relation to clinical response in psoriatic patients: A pilot study

Although the mechanisms underlying the loss of response to infliximab are not completely understood, the formation of antibodies to infliximab (ATI) are thought to play a role. The aim of this study was to investigate the presence of ATI in psoriatic patients and to evaluate its relationship to the clinical response. Fifteen patients with psoriasis were treated with infliximab (5 mg/kg) every 8 weeks after an initial three-dose induction treatment. An enzyme linked immunosorbent assay kit was used for analyzing the presence of ATI in sera. Effectiveness assessments included the change in Psoriasis Area and Severity Index (PASI) compared with study entry. Five (33.3%) patients developed ATI. While 5.9 +/- 3.2 infliximab infusions achieved a fall in the PASI score from a mean of 20.4 +/- 8.3 to 5.3 +/- 2.4 in ATI-negative patients, these values changed from 23.3 +/- 11 to 10 +/- 4.9 after 9 +/- 5.2 infusions in ATI-positive patients. Our results suggested that ATI measured in psoriatic patients are of clinical importance. Therefore, monitoring for the induction of ATI and rescue strategies should be developed to avoid or to maintain a delay in ATI development.

The effectiveness of anti-TNF-alpha therapies when used sequentially in rheumatoid arthritis patients: a systematic review and meta-analysis

Objectives. To systematically review and meta-analyse evidence on the effectiveness of the TNF-α inhibitors when used sequentially.

Methods. Systematic review of comparative and single-arm observational studies. Data were synthesized using random-effects meta-analysis. Treatment effects were estimated using four outcome measures from the included studies: European League Against Rheumatism (EULAR) and ACR20 response rates and mean improvement in disease activity score-28 (DAS-20) and HAQ. The effect of other factors was explored via meta-regression and sub-group analyses.

Results. Twenty studies comprising 2705 patients were included in the analysis. All studies were observational and most had no control group. Therefore, our primary analysis considered patient changes from baseline. The mean percentage of ACR20 responders was 60.8% (95% CI 53.8, 67.4), EULAR responders 70.5% (95% CI 63.7, 76.6), mean overall improvement in DAS-28 scores was 1.53 (95% CI 1.25, 1.80) and in HAQ scores was 0.25 (95% CI 0.11, 0.40). Four studies made comparisons with patients who received TNF-α inhibitors for the first time. Response rates associated with sequential TNF-α inhibitor treatment were lower than for first-time use.

Conclusions. Sequential TNF-α inhibitor use is likely to lead to treatment benefit in terms of the signs and symptoms of disease and physical function. There is also some evidence to suggest that the probability of achieving a response is lower, and the average magnitude of response is lower than the first use. Further evidence from randomized controlled trials is required to confirm and further quantify the role specific anti-TNF-α agents have when used sequentially.

Immunogenicity of Anti-TNF-alpha agents in autoimmune diseases

Prognosis of several autoimmune diseases, especially rheumatoid arthritis (RA), ankylosing spondylitis, Crohn's disease (CD), and psoriasis, usually refractory to conventional treatment improved considerably with the introduction of tumor necrosis factor alpha (TNF-alpha) antagonistic agents, which is now available (infliximab, etanercept, and adalimumab). However, a portion of patients persists with active disease, infusion reactions, and relapses even during current biological therapy. One of the reasons for this is the associated immunogenicity to these drugs. The incentive for induction of antibodies against anti-TNF-alpha agent depends mainly on its constitution. Chimerical drugs have a higher capacity of inducing immunogenicity compared to completely human drugs. Among the three anti-TNF-alpha agents, this phenomenon has been studied mainly in patients using infliximab, especially in RA and CD. The prevalence of anti-infliximab antibodies in RA varies from 12% to 44% and seems to be inversely proportional to the level of seric infliximab and therapeutic response. The use of etanercept was associated to the development of anti-etanercept antibodies in 0% to 18% of patients, without apparent effect on effectiveness or adverse events. Studies with RA and CD patients show prevalence of anti-adalimumab antibodies from 1% to 87%. Immunosuppressive drug addiction can reduce the induction of anti-TNF-alpha antibodies.