Marieke H. Otten

Factors Associated With Treatment Response to Etanercept in Juvenile Idiopathic Arthritis

CONTEXT Since the introduction of biologic therapies, the pharmacological treatment approach for juvenile idiopathic arthritis (JIA) has changed substantially, with achievement of inactive disease as a realistic goal. OBJECTIVE To determine the response to therapy after initiation of etanercept therapy among patients with JIA and to examine the association between baseline factors and response to etanercept treatment. DESIGN, SETTING, AND PATIENTS The Arthritis and Biologicals in Children Register, an ongoing prospective observational study since 1999, includes all Dutch JIA patients who used biologic agents. All biologically naive patients who started etanercept before October 2009 were included, with follow-up data to January 2011. Among the 262 patients, 185 (71%) were female, 46 (18%) had systemic-onset, and the median age at initiation of etanercept treatment was 12.4 years. MAIN OUTCOME MEASURES Excellent response (inactive disease or discontinuation earlier due to disease remission), intermediate response (more than 50% improvement from baseline, but no inactive disease), and poor response (less than 50% improvement from baseline or discontinuation earlier due to ineffectiveness or intolerance) evaluated 15 months after initiation of etanercept. RESULTS At 15 months after treatment initiation, 85 patients (32%) were considered excellent responders; 92 (36%), intermediate responders; and 85 (32%), poor responders. Compared with an intermediate or poor response, an excellent response was associated with lower baseline disability score (range, 0-3 points, with 0 being the best score; adjusted odds ratio [OR] per point increase, 0.49; 95% CI, 0.33-0.74); fewer disease-modifying antirheumatic drugs (DMARD) (including methotrexate) used before initiating etanercept (adjusted OR per DMARD used, 0.64; 95% CI, 0.43-0.95), and younger age at onset (adjusted OR per year increase, 0.92; 95% CI, 0.84-0.99). Compared with an intermediate or excellent response, a poor response was associated with systemic JIA (adjusted OR systemic vs nonsystemic categories, 2.92; 95% CI, 1.26-6.80), and female sex (adjusted OR female vs male, 2.16; 95% CI, 1.12-4.18). Within the first 15 months of etanercept treatment, 119 patients experienced 1 or more infectious, noninfectious, or serious adverse events, including 37 among those with an excellent response, 36 with an intermediate response, and 46 with a poor response. Within the first 15 months of treatment, 61 patients discontinued etanercept treatment, including 4 with an excellent response, 0 with an intermediate response, and 57 with a poor response. In a secondary analysis of 262 patients with a median follow-up of 35.6 months after initiation of etanercept, a range of 37% to 49% of patients reached inactive disease. The mean adherence to etanercept was 49.2 months (95% CI, 46.4-52.0) for patients with an excellent response after 15 months, 47.5 months (95% CI, 44.9-50.1) for patients with an intermediate response, and 17.4 months (95% CI, 13.6-21.2) for patients with a poor response. CONCLUSIONS Among patients with JIA who initiated treatment with etanercept, one-third achieved an excellent response, one-third an intermediate response, and one-third a poor response to therapy. Achievement of an excellent response was associated with low baseline disability scores, DMARDs used before initiating etanercept, and younger age at onset of JIA. Achievement of a poor treatment response was associated with systemic JIA and female sex.

The toll-like receptor 4 agonist MRP8/14 protein complex is a sensitive indicator for disease activity and predicts relapses in systemic-onset juvenile idiopathic arthritis

Background Analysis of myeloid-related protein 8 and 14 complex (MRP8/14) serum concentrations is a potential new tool to support the diagnosis of systemic-onset juvenile idiopathic arthritis (SJIA) in the presence of fever of unknown origin. Objective To test the ability of MRP8/14 serum concentrations to monitor disease activity in patients with SJIA and stratify patients at risk of relapse. Methods Serum concentrations of MRP8/14 in 52 patients with SJIA were determined by a sandwich ELISA. The monitoring of therapeutic regimens targeting interleukin 1 and tumour necrosis factor α, and methotrexate treatment was analysed and diagnostic power to predict flares was tested. Results MRP8/14 levels were clearly raised in active disease and decreased significantly in response to successful treatments. Serum concentrations of MRP8/14 increased significantly (p<0.001) (mean±95% CI 12.030±3.090 ng/ml) during disease flares compared with patients with inactive disease (864±86 ng/ml). During clinical remission MRP8/14 serum levels of >740 ng/ml predicted disease flares accurately (sensitivity 92%, specificity 88%). MRP8/14 levels correlated well with clinical disease activity, as assessed by physicians global assessment of disease activity (r=0.62), Childhood Health Assessment Questionnaire (r=0.56), active joint count (r=0.46) and with C-reactive protein (r=0.71) and erythrocyte sedimentation rate (r=0.72) (for all p<0.001). Conclusion MRP8/14 serum concentrations correlate closely with response to drug treatment and disease activity and therefore might be an additional measurement for monitoring anti-inflammatory treatment of individual patients with SJIA. MRP8/14 serum concentrations are the first predictive biomarker indicating subclinical disease activity and stratifying patients at risk of relapse during times of clinically inactive disease.

Diagnosis and management of juvenile idiopathic arthritis

#### Summary points Juvenile idiopathic arthritis is the most common cause of chronic arthritis in childhood; a review of 34 epidemiological studies showed that 0.07-4.01 per 1000 children worldwide are affected.w1 It is characterised by joint inflammation that often leads to joint destruction with physical disability and chronic pain that affects daily life.1 During the past decade, increased understanding of the disease has improved treatment, particularly through earlier diagnosis and new treatments that help to prevent long term damage to joints. Earlier this year, the British Society for Paediatric and Adolescent Rheumatology published standards of care for children and young people with juvenile idiopathic arthritis, which outlined the importance of involving different disciplines within healthcare.2 We review recent advances in the diagnosis and management of juvenile idiopathic arthritis, focusing on evidence from randomised controlled trials, cohort studies, systematic reviews, and current guidelines. #### Sources and selection criteria As well as using our personal reference collections, we searched Medline, Embase, and Cochrane Central for clinical studies and reviews using the keywords “juvenile idiopathic arthritis”, “juvenile rheumatoid arthritis”, “juvenile chronic arthritis”, “diagnosis”, “treatment”, “therapy”, “non-steroidal anti-inflammatory drugs”, “corticosteroids”, “disease modifying antirheumatic drugs”, “biologicals”, and “biologics.” We also reviewed guidelines from the British Society …

Tumor necrosis factor-blocking agents for children with enthesitis-related arthritis--data from the dutch arthritis and biologicals in children register, 1999-2010

Objective. To evaluate the effectiveness and safety of biological agents in children with enthesitis-related arthritis (ERA). Methods. All patients with ERA in whom a biological agent was initiated between 1999 and 2010 were selected from the Dutch Arthritis and Biologicals in Children (ABC) register. In this ongoing multicenter observational register, data on the course of the disease and medication use are retrieved prospectively at the start of the biological agent, after 3 months, and yearly thereafter. Inactive disease was assessed in accordance with the Wallace criteria. Results. Twenty-two patients with ERA started taking 1 or more biological agents: 20 took etanercept, 2 took adalimumab (1 switched from etanercept to adalimumab), and 2 took infliximab (1 switched from etanercept to infliximab). Characteristics: 77% were male, 77% had enthesitis, 68% were HLA-B27-positive. The median age of onset was 10.4 (IQR 9.4–12.0) years; median followup from the start of the biological agent was 1.2 (IQR 0.5–2.4) years. Intention-to-treat analysis shows that inactive disease was achieved in 7 of 22 patients (32%) after 3 months, 5 of 13 patients (38%) after 15 months, and 5 of 8 patients (63%) after 27 months of treatment. Two patients discontinued etanercept because of ineffectiveness, and switched to adalimumab (inactive disease achieved) or infliximab (decline in joints with arthritis after 3 months of treatment). One patient discontinued etanercept because of remission, but had flare and restarted treatment, with good clinical response. No serious adverse events occurred. Conclusion. Tumor necrosis factor (TNF)-blocking agents seem effective and safe for patients with ERA that was previously unresponsive to 1 or more DMARD. However, a sustained disease-free state could not be achieved, and none discontinued TNF-blocking agents successfully.

Efficacy of biological agents in juvenile idiopathic arthritis: a systematic review using indirect comparisons

Objective Over the past decade, the availability of biological agents for the treatment of juvenile idiopathic arthritis (JIA) has increased substantially. Because direct head-to-head trials comparing these agents are lacking, we indirectly compared their efficacy. Methods In a systematic review, all available efficacy data from randomised controlled trials performed in JIA with inclusion of biological agents were retrieved. Indirect between-drug comparisons (based on Buchers method) were conducted only if trials were comparable with regard to design and patients’ characteristics related to treatment outcome. Results We identified 11 randomised controlled trials. On the basis of the equality of the trials, six trials were grouped into two networks of evidence. Network 1 included withdrawal trials which evaluated etanercept, adalimumab and abatacept in polyarticular course JIA. Indirect comparisons identified no significant differences in short-term efficacy. Network 2 indirectly compared trials with a parallel study design investigating anakinra, tocilizumab and canakinumab in systemic JIA; no differences in comparative efficacy were identified. Although the two networks were constructed on the basis of comparability, small differences in trial design and case mix still existed. Conclusions Because of the small number of trials and the observed differences between trials, no definite conclusions could be drawn about the comparative effectiveness of the indirectly compared biological agents. Therefore, for now, the paediatric rheumatologist has to rely on observational data and safety, practical and financial arguments. Comparability of future trials needs to be improved, and head-to-head trials are required to decide on the best biological treatment for JIA.

Trends in prescription of biological agents and outcomes of juvenile idiopathic arthritis: results of the Dutch national Arthritis and Biologics in Children Register

Background Treatment of juvenile idiopathic arthritis (JIA) has changed dramatically since the introduction of biological agents in 1999. Objective To evaluate trends in prescription patterns of biological agents and the subsequent outcome of JIA. Methods The Arthritis and Biologics in Children register (multicentre prospective observational study) aimed to include all consecutive patients with JIA in the Netherlands who had started biological agents since 1999. Patients were divided according to year of introduction of first biological agent. Patient characteristics at introduction of the first biological agent and its effectiveness were analysed over 12 years. Results 335 patients with non-systemic JIA and 86 patients with systemic JIA started a biological agent between 1999 and 2010. Etanercept remained the most often prescribed biological agent for non-systemic JIA; anakinra became first choice for systemic JIA. The use of systemic glucocorticoids and synthetic disease-modifying antirheumatic drugs before biological agents decreased. During these 12 years of observation, biological agents were prescribed earlier in the disease course and to patients with lower baseline JADAS (Juvenile Arthritis Disease Activity Score) disease activity. All baseline disease activity parameters were lowered in patients with non-systemic JIA. In systemic JIA, prescription patterns changed towards very early introduction of biological agents (median 0.4 years of disease duration) in patients with a low number of joints with active arthritis and high erythrocyte sedimentation rates. These changes for both systemic and non-systemic JIA resulted in more patients with inactive disease after 3 and 15 months of treatment. Conclusions Biological agents are increasingly prescribed, earlier in the disease and in patients with JIA with lower disease activity. These changes are accompanied by better short-term disease outcomes.

Effectiveness and safety of a second and third biological agent after failing etanercept in juvenile idiopathic arthritis: results from the Dutch National ABC Register

Objective To evaluate the effectiveness and safety of switching to a second or third biological agent in juvenile idiopathic arthritis (JIA) after etanercept failure. Methods The Arthritis and Biologicals in Children Register aims to include all Dutch JIA patients who have used biological agents. Data on the disease course were used to estimate drug survival with Kaplan–Meier and calculate adverse event (AE) rates. Results Of 307 biologically naive JIA patients who started etanercept, 80 (26%) switched to a second and 22 (7%) to a third biological agent. During 1030 patient-years of follow-up after the introduction of etanercept, 49 switches to adalimumab, 28 infliximab, 17 anakinra, four abatacept and four trial drugs were evaluated. 84% (95% CI 80% to 88%) of patients who started etanercept as a first biological agent were, after 12 months, still on the drug, compared with 47% (95% CI 35% to 60%) who started a second and 51% (95% CI 26% to 76%) who started a third biological agent. Patients who switched because of primary ineffectiveness continued the second agent less often (32%, 95% CI 12% to 53%). After etanercept failure, drug continuation of adalimumab was similar to infliximab for patients with non-systemic JIA; anakinra was superior to a second TNF-blocker for systemic JIA. AE rates within first 12 months after initiation were comparable for each course and each biological agent. Conclusions Switching to another biological agent is common, especially for systemic JIA patients. A second (and third) agent was less effective than the first. The choice of second biological agent by the physician mainly depends on availability and JIA category.

Treatment choices of paediatric rheumatologists for juvenile idiopathic arthritis: etanercept or adalimumab?

OBJECTIVES To evaluate differences in baseline characteristics between etanercept- and adalimumab-treated JIA patients and to reveal factors that influence the choice between these TNF inhibitors, which are considered equally effective in the recent ACR recommendations for JIA treatment. METHODS Biologic-naïve JIA patients with active arthritis who started treatment with adalimumab or etanercept between March 2008 and December 2011 were selected from the Dutch Arthritis and Biologicals in Children register. Baseline characteristics were compared. Focus group interviews with paediatric rheumatologists were performed to evaluate factors determining treatment choices. RESULTS A total of 193 patients started treatment with etanercept and 21 with adalimumab. Adalimumab-treated patients had longer disease duration prior to the start of biologics (median 5.7 vs 2.0 years) and more often a history of uveitis (71% vs 4%). Etanercept-treated patients had more disability at baseline (median Childhood Health Assessment Questionnaire score 1.1 vs 0.4) and more active arthritis (median number of active joints 6 vs 4). The presence of uveitis was the most important factor directing the choice towards adalimumab. Factors specific for the paediatric population-such as painful adalimumab injections-as well as the physicians familiarity with the drug accounted for the preference for etanercept. CONCLUSION Although the two TNF inhibitors are considered equally effective, in daily practice etanercept is most often prescribed; adalimumab is mainly preferred when uveitis is present. In choosing the most suitable biologic treatment, paediatric rheumatologists take into account drug and patient factors, considering newly published data and cautiously implementing this into daily care.

Tumour necrosis factor (TNF)-blocking agents in juvenile psoriatic arthritis: Are they effective?

Objectives To evaluate the effectiveness of tumour necrosis factor (TNF) blockers in juvenile psoriatic arthritis (JPsA). Methods The study was a prospective ongoing multicentre, observational study of all Dutch juvenile idiopathic arthritis (JIA) patients using biologicals. The response of arthritis was assessed by American College of Rheumatology (ACR) paediatric response and Wallace inactive disease criteria. The response of psoriatic skin lesions was scored by a 5-point scale. Results Eighteen JPsA patients (72% female, median age onset 11.1 (range 3.3–14.6) years, 50% psoriatic skin lesions, 39% nail pitting, 22% dactylitis) were studied. The median follow-up time since starting anti-TNFα was 26 (range 3–62) months. Seventeen patients started on etanercept and one started on adalimumab. After 3 months of treatment 83% of the patients achieved ACR30 response, increasing to 100% after 15 months. Inactive disease reached in 67% after 39 months. There was no discontinuation because of inefficacy. Six patients discontinued treatment after a good clinical response. However, five patients flared and restarted treatment, all with a good response. During treatment four patients (two JPsA and two JIA patients with other subtypes) developed de novo psoriasis. In four of the nine patients the pre-existing psoriatic skin lesions improved. Conclusion Anti-TNFα therapy in JPsA seems effective in treating arthritis. However, in most patients the arthritis flared up after treatment discontinuation, emphasising the need to investigate optimal therapy duration. The psoriatic skin lesions did not respond well and four patients developed de novo psoriasis.

Anticarbamylated protein (anti-CarP) antibodies are present in sera of juvenile idiopathic arthritis (JIA) patients

In juvenile idiopathic arthritis (JIA) patients there is a lack of markers that predict severe disease. Although anticitrullinated protein antibodies (ACPA) have contributed substantially to the understanding of rheumatoid arthritis (RA),1 their detection in JIA has not been equally useful as incidence rates in JIA patients are low2 and merely confined to the polyarticular immunoglobulin (Ig)M-rheumatoid factor (RF)-positive category resembling RA. Recently, anticarbamylated protein (anti-CarP) antibodies were detected in 45% of RA patients and importantly also in 16%–20% ACPA-negative patients.3–5 Within the ACPA-negative patients, anti-CarP antibodies were associated with more severe radiographic progression.3 Since most JIA patients are ACPA-negative we investigated whether anti-CarP antibodies are present in the sera of JIA patients and how they are related to ACPA and IgM-RF. JIA patients from three Dutch sources were included: the BeSt for Kids trial (NTR 1574, a treatment strategy study) (n=33), a previously described cohort6 (n=48) and the Arthritis and Biologicals in Children (ABC) register7 (n=153). Healthy controls (n=107) (mean age/range 11/(2–20)) are stem-cell graft …