Increasing the etanercept dose in a treat-to-target approach in juvenile idiopathic arthritis: does it help to reach the target? A post-hoc analysis of the BeSt for Kids randomised clinical trial.

BACKGROUND: Etanercept has been studied in doses up to 0.8 mg/kg/week (max 50 mg/week) in juvenile idiopathic arthritis (JIA) patients. In clinical practice higher doses are used off-label, but evidence regarding the relation with outcomes is lacking. We describe the clinical course of JIA-patients receiving high-dose etanercept (1.6 mg/kg/week; max 50 mg/week) in the BeSt for Kids trial. METHODS: 92 patients with oligoarticular JIA, RF-negative polyarticular JIA or juvenile psoriatic arthritis were randomised across three treat-to-target arms: (1) sequential DMARD-monotherapy (sulfasalazine or methotrexate (MTX)), (2) combination-therapy MTX + 6 weeks prednisolone and (3) combination therapy MTX + etanercept. In any treatment-arm, patients could eventually escalate to high-dose etanercept alongside MTX 10mg/m2/week. RESULTS: 32 patients received high-dose etanercept (69% female, median age 6 years (IQR 4-10), median 10 months (7-16) from baseline). Median follow-up was 24.6 months. Most clinical parameters improved within 3 months after dose-increase: median JADAS10 from 7.2 to 2.8 (p = 0.008), VAS-physician from 12 to 4 (p = 0.022), VAS-patient/parent from 38.5 to 13 (p = 0.003), number of active joints from 2 to 0.5 (p = 0.12) and VAS-pain from 35.5 to 15 (p = 0.030). Functional impairments (CHAQ-score) improved more gradually and ESR remained stable. A comparable pattern was observed in 11 patients (73% girls, median age 8 (IQR 6-9)) who did not receive high-dose etanercept despite eligibility (comparison group). In both groups, 56% reached inactive disease at 6 months. No severe adverse events (SAEs) occurred after etanercept dose-increase. In the comparison group, 2 SAEs consisting of hospital admission occurred. Rates of non-severe AEs per subsequent patient year follow-up were 2.27 in the high-dose and 1.43 in the comparison group. CONCLUSIONS: Escalation to high-dose etanercept in JIA-patients who were treated to target was generally followed by meaningful clinical improvement. However, similar improvements were observed in a smaller comparison group who did not escalate to high-dose etanercept. No SAEs were seen after escalation to high-dose etanercept. The division into the high-dose and comparison groups was not randomised, which is a potential source of bias. We advocate larger, randomised studies of high versus regular dose etanercept to provide high level evidence on efficacy and safety. TRIAL REGISTRATION: Dutch Trial Register; NTR1574; 3 December 2008; https://onderzoekmetmensen.nl/en/trial/26585 .

Presentation of enthesitis-related arthritis and juvenile-onset spondyloarthritis: a cross-sectional study in a pediatric and adult clinic.

BACKGROUND: Juvenile idiopathic arthritis (JIA) comprises a whole spectrum of chronic arthritis starting before 16 years of age. The study aims to explore the clinical and demographic descriptors, treatment, and disease progression of enthesitis-related arthritis (ERA) in comparison with juvenile-onset spondyloarthritis (SpA). METHODS: Cross-sectional analysis of consecutive patients in two dedicated clinics, with a single visit and retrospective case-notes review. Arthritis, enthesitis and sacroiliitis were evaluated by scoring disease activity and damage. Continuous variables were reported by median, interquartile range; categorical variables were reported by the frequency comparison of the two groups. RESULTS: Thirty-three cases were included, being 23 (69.7%) with ERA. The median age at diagnosis was 12.5 y (SpA) vs. 9 y (ERA) (p < 0.01); the time from symptom onset to diagnosis was 5.5 y (SpA) vs. 1.5 y (ERA) (p < 0.03). In both groups, the predominant presentation was a single joint or < 5 lower limb joints and asymmetric involvement, with a high frequency of enthesitis. There was a higher frequency of mid-tarsal and ankle synovitis in the ERA group and hip involvement in those with SpA. The comparison of the frequency of spine symptoms at presentation, 30% SpA vs. 21.7% ERA (p = 0.7), was not significant, and radiographic progression to spinal involvement occurred in 43.5% of ERA patients. The median time for spinal progression and age at onset was 2.2 and 12 y for ERA, and 4 and 16.5 y for SpA, respectively. Activity and damage scores were not significantly different between the groups. Treatment comparison resulted in 91.3% of ERA and 100% SpA being treated, predominantly with NSAIDs in both groups, followed by DMARDs and biologics, with a higher frequency of biologics in SpA. CONCLUSION: The main differences were the late diagnoses of SpA, and the hip and spine involvement, with higher frequency of biologic treatment in juvenile-onset SpA compared to ERA.

Adherence to low-dose methotrexate in children with juvenile idiopathic arthritis using a sensitive methotrexate assay.

BACKGROUND: Low-dose weekly methotrexate (MTX) is the mainstay of treatment in juvenile idiopathic arthritis. Unfortunately, a substantial part of patients has insufficient efficacy of MTX. A potential cause of this inadequate response is suboptimal drug adherence. The aim of this study was to assess MTX adherence in juvenile idiopathic arthritis patients by quantification of MTX concentrations in plasma. Secondly, the association between MTX concentrations and either self-reported adherence issues, or concomitant use of biologics was examined. METHODS: This was a retrospective, observational study using plasma samples from juvenile idiopathic arthritis patients. An ultrasensitive liquid chromatography-tandem mass spectrometry method was developed for quantification of MTX and its metabolite 7-hydroxy-MTX in plasma. The determined MTX plasma concentrations in juvenile idiopathic arthritis patients were compared with corresponding adherence limits, categorising them as either adherent or possibly non-adherent to MTX therapy. RESULTS: Plasma samples of 43 patients with juvenile idiopathic arthritis were analysed. Adherence to MTX in this population was 88% shortly after initiation of MTX therapy and decreased to 77% after one year of treatment. Teenagers were more at risk for non-adherence (p = 0.002). We could not find an association between MTX adherence with either self-reported adherence issues, nor with the use of concomitant biological treatment (p = 1.00 and p = 0.27, respectively; Fisher's Exact). CONCLUSIONS: Quantification of MTX in plasma is a feasible and objective method to assess adherence in patients using low-dose weekly MTX. In clinical practice, the use of this method could be a helpful tool for physicians to refute or support suspicion of non-adherence to MTX therapy.

Relapses of juvenile idiopathic arthritis in adulthood: A monocentric experience.

INTRODUCTION: Our aim was to describe a monocentric cohort of young adult patients with juvenile idiopathic arthritis (JIA), assessing the risk of relapse after transition to adult care. METHODS: We conducted a retrospective study and collected clinical, serological, and demographic data of young adult patients (18-30 years old) referred to the Transition Clinic of a single Italian centre between January 2020 and March 2023. Patients with systemic-onset JIA were excluded. Primary outcome was disease relapse, defined by Wallace criteria. Risk factors were analysed by Cox proportional hazards regression. RESULTS: Fifty patients with age 18-30 years old were enrolled in the study and followed for a median 30 months. The median disease duration at transition was 15 years. Twenty (40%) patients were on conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and 38 (76%) were on biological DMARDs through adulthood. Twenty-three patients relapsed after transitioning to adult care for a median 9-month follow-up (IQR 0-46.5). Most relapses involved the knees (69.6%). The univariate analysis identified monoarthritis (HR 4.67, CI 1.069-20.41, p value = 0.041) as the main risk factor for relapse within the first 36 months of follow-up. Early onset, ANA positivity, past and ongoing treatment with csDMARDs or bDMARDs, therapeutic withdrawal, and disease activity within 12 months before transition did not significantly influence the risk of relapse. CONCLUSION: In JIA patients, the risk of relapse after transitioning to adult care remains high, irrespective of disease subtype and treatment. The main risk factor for the early occurrence of articular activity is monoarticular involvement.

Comparative efficacy and safety of different drugs in patients with systemic juvenile idiopathic arthritis: A systematic review and network meta-analysis.

BACKGROUND: The goal of this study was to estimate the relative efficacy and safety of different biological agents (infliximab, canakinumab, baricitinib, anakinra, adalimumab, tofacitinib, tocilizumab, and rilonacept) compared with placebo for systemic juvenile idiopathic arthritis (JIA) patients, through a network meta-analysis. METHODS: Pubmed, Embase, and Cochrane Library were searched from database inception to July 2023 for randomized controlled trials comparing different biological agents (infliximab, canakinumab, baricitinib, anakinra, adalimumab, tofacitinib, tocilizumab, and rilonacept) or placebo directly or indirectly in JIA. Bayesian network meta-analyses were conducted. Data was extracted and analyzed by R with gemtc package. The treatment options were ranked using the surface under the cumulative ranking curve (SUCRA) value. RESULTS: We identified 10 randomized controlled trials and analyzed 898 participants. Canakinumab (odds ratio 55.0, 95% credible intervals 2.4-67.0) was more effective than the placebo, and the difference was statistically significant. However, there was no statistical significance between other drugs versus placebo in terms of the modified ACRpedi30 (P > .05). The SUCRA shows that canakinumab ranked first (SUCRA, 86.9%), anakinra ranked second (SUCRA, 77.7%), adalimumab ranked third (SUCRA, 61.9%), and placebo ranked the last (SUCRA, 6.3%). Nevertheless, there were no notable discrepancies in the occurrence of adverse events, hepatic-related adverse events, infectious adverse event, serious adverse events, and serious infection following treatment with canakinumab, anakinra, tocilizumab, rilonacept, or the placebo. Based on the clustergram of modified ACRpedi30 and adverse events, canakinumab is suggested for JIA according to the surface under SUCRAs considering the symptom and adverse events simultaneously. CONCLUSIONS: Among patients with JIA, canakinumab exhibited the highest likelihood of being the optimal treatment for achieving the modified ACRpedi30 response rate, and neither of the tested biological agents carried a significant risk of serious adverse events.

Validation of new medication use algorithms as proxies for worsening disease activity in patients with juvenile idiopathic arthritis.

PURPOSE: To facilitate claims-based research on populations with juvenile idiopathic arthritis (JIA), we sought to validate an algorithm of new medication use as a proxy for worsening JIA disease activity. METHODS: Using electronic health record data from three pediatric centers, we defined new JIA medication use as (re)initiation of disease-modifying antirheumatic drugs or glucocorticoids (oral or intra-articular). Data were collected from 201 randomly selected subjects with (101) or without (100) new medication use. We assessed the positive predictive value (PPV) and negative predictive value (NPV) based on a reference standard of documented worsening of JIA disease activity. The algorithm was refined to optimize test characteristics. RESULTS: Overall, the medication-based algorithm had suboptimal performance in representing worsening JIA disease activity (PPV 69.3%, NPV 77.1%). However, algorithm performance improved for definitions specifying longer times after JIA diagnosis (≥1-year post-diagnosis: PPV 82.9%, NPV 80.0%) or after initiation of prior JIA treatment (≥1-year post-treatment: PPV 89.7%, NPV 80.0%). CONCLUSION: An algorithm for new JIA medication use appears to be a reasonable proxy for worsening JIA disease activity, particularly when specifying new use ≥1 year since initiating a prior JIA medication. This algorithm will be valuable for conducting research on JIA populations within administrative claims databases.

Anti-tumor necrosis factor (aTNF) weaning strategy in juvenile idiopathic arthritis (JIA): does duration matter?

BACKGROUND: To compare outcomes of a short and long weaning strategy of anti-tumor necrosis factor (aTNF) in our prospective juvenile idiopathic arthritis (JIA) cohort. RESEARCH DESIGN AND METHODS: JIA patients on subcutaneous adalimumab with at least 6 months of follow-up were recruited (May 2010-Jan 2022). Once clinical remission on medication (CRM) was achieved, adalimumab was weaned according to two protocols-short (every 4-weekly for 6 months and stopped) and long (extending dosing interval by 2 weeks for three cycles until 12-weekly intervals and thereafter stopped) protocols. Outcomes assessed were flare rates, time to flare, and predictors. RESULTS: Of 110 JIA patients, 77 (83% male, 78% Chinese; 82% enthesitis-related arthritis) underwent aTNF weaning with 53% on short and 47% on long weaning protocol. The total flare rate during and after stopping aTNF was not different between the two groups. The time to flare after stopping aTNF was not different (p = 0.639). Positive anti-nuclear antibody increased flare risk during weaning in long weaning group (OR 7.0, 95%CI: 1.2-40.8). Positive HLA-B27 (OR 6.5, 95%CI: 1.1-30.4) increased flare risks after stopping aTNF. CONCLUSION: Duration of weaning aTNF may not minimize flare rate or delay time to flare after stopping treatment in JIA patients. Recapture rates for inactive disease at 6 months remained high for patients who flared after weaning or discontinuing medication.

JAK inhibitors in the treatment of adult patients with juvenile idiopathic arthritis: a retrospective monocentric experience.

OBJECTIVES: This study aims to evaluate the efficacy and safety of JAK inhibitors (JAKi) in a monocentric cohort of adult patients with juvenile idiopathic arthritis (JIA). METHODS: Patients attending a rheumatology transition clinic were retrospectively included in case of: i) JIA diagnosis according to current classification criteria (1); ii) age ≥18 years and iii) treatment with JAKi for at least 3 months. RESULTS: Seventeen adult patients with JIA were treated with JAKi (as first JAKi, 9 patients (52.9%) received tofacitinib and 8 (47.1%) baricitinib). At 3 months after JAKi initiation, 8 patients (47%) achieved a response and 4 patients (23.5%) achieved disease remission (3 patients with baricitinib and 1 with tofacitinib, 37.5% vs. 16.7%, p=0.294). None of those with systemic JIA and enthesitis-related arthritis obtained remission; the remission rate at 3 months was higher, although not significantly, in the oligoarticular subset compared to the polyarticular subset (37.5% vs. 20%). Patients with ≤1 active joint involvement at JAKi start had a higher remission rate (50% vs. 22.2%). Subjects who achieved remission on JAKi had a significantly lower pre-treatment DAS28-CRP compared to those with still active disease (p=0.010, Mann-Whitney U=4). A pre-treatment DAS28-CRP <3.76 predicted response to JAKi with 100% sensitivity and 84.6% specificity (p=0.023). The remission rate was lower among patients who had been treated with ≥2 biological drugs before JAKi start (9% vs. 66.7%; p=0.05). One patient in concomitant treatment with leflunomide developed severe arterial hypertension. CONCLUSIONS: JAKi may represent an effective and safe treatment option for adult JIA patients with low/moderate disease activity, particularly in case of oligoarticular involvement.

Efficacy and safety of canakinumab in systemic juvenile idiopathic arthritis, the first Chinese experience.

BACKGROUND: Systemic juvenile idiopathic arthritis (sJIA) is a severe form of juvenile arthritis that is characterized by chronic joint inflammation and systemic symptoms such as fever, rash, and organ involvement. Anti-IL-6 receptor monoclonal antibody tocilizumab is an effective treatment. However, some patients still experience persisting or recurrent symptoms and the real-world effectiveness of canakinumab in Chinese patients with sJIA has never been reported. Therefore, this study aimed to assess the efficacy and safety of canakinumab in Chinese patients with sJIA using real-world data. METHODS: We conducted a retrospective study on children with active sJIA. Clinical features, laboratory data, corticosteroid dosage, and adverse events (AEs) were collected at baseline and at 4, 8, 12, and 24 weeks after initiating canakinumab treatment. RESULTS: Seven female and four male patients were included in the study. All patients had previously been treated with tocilizumab and were administered canakinumab for 12.4 ± 3.4 months. Notably, significant improvements were observed in both clinical signs and symptoms as well as laboratory indicators. Four children under corticosteroid treatment were able to successfully discontinue their corticosteroid therapy: one at week 4, two at week 12, and one at week 24. Notably, there was a significant reduction in the number of tender and swollen joints (P = 0.0059) as well as the systemic juvenile arthritis disease activity score (P < 0.0001). The most common AE was infection, but no patients experienced serious AEs. No cases of macrophage activation syndrome or death were reported during the follow-up period. CONCLUSIONS: Canakinumab was found to be potentially efficacious and safe in Chinese patients with sJIA. No new AEs were observed with canakinumab treatment.

Long-term follow-up of 109 children with juvenile idiopathic oligoarthritis after first intra-articular corticosteroid injection.

BACKGROUND: To evaluate long-term outcomes and prognostic factors in patients with juvenile idiopathic arthritis (JIA), presenting as oligoarthritis, who received IAC as the first treatment for their disease. METHODS: We conducted retrospective study at the University Children's Hospital Ljubljana, Slovenia, from January 2015 to May 2023 in children with JIA, clinically presenting as oligoarthritis receiving intra-articular corticosteroid injection (IAC) as the initial treatment. Patient and treatment data were collected, and the outcomes were categorized into three groups based on the later need for therapy: no therapy needed, only additional IAC needed and systemic therapy needed. The last group was further divided based on the requirement of bDMARD. Log-rank (Mantel-Cox) survival analyses compared different outcome groups. RESULTS: We included 109 patients with JIA, presenting as oligoarthritis (63% female), who were first treated with IAC. The mean age at IAC was 8.0 years, with a 4.3-year follow-up. Notably, 38.5% of patients did not require additional therapy post-IAC, whereas 15.5% required only additional IAC. Systemic therapy, mainly methotrexate (MTX), was necessary for 45.9% of patients, initiated in average 7.8 months post-IAC. Biologic therapy was initiated in 22% in average 2.2 years post-IAC. Number of injected joints correlated with the need for biologics. At the last follow-up, 88.9% had inactive disease. ANA positivity (P = 0.049, chi square 3.89) and HLA B27 antigen presence (P = 0.050, chi square 3.85) were associated with the need for systemic therapy. A subgroup of children older than 8 years, ANA and HLA B27 negative required significantly less systemic (25.8%) and biologic therapy (9.6%) compared to other patients (p = 0.050, chi square 3.77). CONCLUSION: Almost 40% of children with oligoarticular JIA requiring IAC did not progress to chronic disease. Younger age, ANA positivity, and HLA B27 presence were predictive factors for systemic therapy, while the number of injected joints predicted the future need for biologic therapy.

Tumor-necrosis factor α-rich environment alters type-I interferon response to viral stimuli in patients with juvenile idiopathic arthritis by altering myeloid dendritic cell phenotype.

The balance between the tumor-necrosis factor α (TNFα) and type-I interferon (T1IFN) pathways is crucial for proper immune function. Dysregulation of either pathway can contribute to autoimmune diseases development. Even though TNFα blockade has shown promising results in various autoimmune diseases, the effect on the balance between TNFα and T1IFN is elusive. We used targeted anti-TNFα therapies in juvenile idiopathic arthritis (JIA) as an experimental approach to study the cross-regulation between TNFα and type-I IFN. We found that TNFα-rich environment affected viral defense through the attenuation of T1IFN responses and affected the phenotype and distribution of myeloid dendritic cells, which are engaged in early viral infections. Anti-TNFα therapy normalized the observed deviations in JIA patients. We hypothesize that the inadequate immune response caused by a high TNFα environment could be projected to more frequent or lengthy viral infections and possibly play a role in the process of JIA disease development.

Serum and salivary inflammatory biomarkers in juvenile idiopathic arthritis-an explorative cross-sectional study.

BACKGROUND: Biomarkers may be useful in monitoring disease activity in juvenile idiopathic arthritis (JIA). With new treatment options and treatment goals in JIA, there is an urgent need for more sensitive and responsive biomarkers. OBJECTIVE: We aimed to investigate the patterns of 92 inflammation-related biomarkers in serum and saliva in a group of Norwegian children and adolescents with JIA and controls and in active and inactive JIA. In addition, we explored whether treatment with tumor necrosis factor inhibitors (TNFi) affected the biomarker levels. METHODS: This explorative, cross-sectional study comprised a subset of children and adolescents with non-systemic JIA and matched controls from the Norwegian juvenile idiopathic arthritis study (NorJIA Study). The JIA group included individuals with clinically active or inactive JIA. Serum and unstimulated saliva were analyzed using a multiplex assay of 92 inflammation-related biomarkers. Welch's t-test and Mann-Whitney U-test were used to analyze the differences in biomarker levels between JIA and controls and between active and inactive disease. RESULTS: We included 42 participants with JIA and 30 controls, predominantly females, with a median age of 14 years. Of the 92 biomarkers, 87 were detected in serum, 73 in saliva, and 71 in both biofluids. A pronounced difference between serum and salivary biomarker patterns was found. Most biomarkers had higher levels in serum and lower levels in saliva in JIA versus controls, and in active versus inactive disease. In serum, TNF and S100A12 levels were notably higher in JIA and active disease. The TNF increase was less pronounced when excluding TNFi-treated individuals. In saliva, several biomarkers from the chemokine family were distinctly lower in the JIA group, and levels were even lower in active disease. CONCLUSION: In this explorative study, the serum and salivary biomarker patterns differed markedly, suggesting that saliva may not be a suitable substitute for serum when assessing systemic inflammation in JIA. Increased TNF levels in serum may not be a reliable biomarker for inflammatory activity in TNFi-treated children and adolescents with JIA. The lower levels of chemokines in saliva in JIA compared to controls and in active compared to inactive disease, warrant further investigation.

Disease activity trajectories from childhood to adulthood in the population-based Nordic juvenile idiopathic arthritis cohort.

OBJECTIVES: To identify long-term disease activity trajectories from childhood to adulthood by using the clinical Juvenile Arthritis Disease Activity Score (cJADAS10) in juvenile idiopathic arthritis (JIA). Second, to evaluate the contribution of the cJADAS10 components and explore characteristics associated with active disease at the 18-year follow-up. METHODS: Patients with onset of JIA in 1997-2000 were followed for 18 years in the population-based Nordic JIA cohort. We used a discrete mixture model for longitudinal clustering of the cJADAS10 and its components. We assessed factors potentially associated with higher scores on the patient's global assessment of well-being (PaGA) by hierarchical clustering and correlation analysis. RESULTS: Four disease activity trajectories were identified based on the cJADAS10 components among 427 patients. In trajectory-group 2, the PaGA and the physician's global assessment of disease activity (PhGA) increased significantly during the course, but not the active joint count. The increase in the PaGA was significantly higher than the increases in the PhGA and the active joint count (p<0.0001). A similar pattern was found among all the patients with active disease in the total cohort. Patients with higher PaGA scores had unfavourable scores on several other patient-reported outcomes. CONCLUSIONS: We have identified groups of patients based on long-term disease activity trajectories. In our study the PaGA was the most important driver of disease activity into adulthood assessed by cJADAS10. We need to better understand how our patients interpret global well-being and implement strategies to achieve inactive disease perceived both by the patient and the physician.

Treatment of non-systemic juvenile idiopathic arthritis.

In the past two decades, the treatment of juvenile idiopathic arthritis (JIA) has evolved markedly, owing to the availability of a growing number of novel, potent and relatively safe therapeutic agents and the shift of management strategies towards early achievement of disease remission. However, JIA encompasses a heterogeneous group of diseases that require distinct treatment approaches. Furthermore, some old drugs, such as methotrexate, sulfasalazine and intraarticular glucocorticoids, still maintain an important therapeutic role. In the past 5 years, information on the efficacy and safety of drug therapies for JIA has been further enriched through the accomplishment of several randomized controlled trials of newer biologic and synthetic targeted DMARDs. In addition, a more rational therapeutic approach has been fostered by the promulgation of therapeutic recommendations and guidelines. A multinational collaborative effort has led to the development of the recommendations for the treat-to-target strategy in JIA. There is currently increasing interest in establishing the optimal time and modality for discontinuation of treatment in children with JIA who achieve sustained clinical remission. The aim of this Review is to summarize the current evidence and discuss the therapeutic approaches to the management of non-systemic phenotypes of JIA, including oligoarthritis, polyarthritis, enthesitis-related arthritis and psoriatic arthritis.

Clinical Characteristics of Adolescents With Juvenile Idiopathic Arthritis Transitioning to Adult Rheumatology Care in Canada: Results From the CAPRI Registry.

OBJECTIVE: Using Canadian Alliance of Pediatric Rheumatology Investigators (CAPRI) juvenile idiopathic arthritis (JIA) registry data, we describe (1) clinical characteristics of patients with JIA transitioning to adult care, (2) prevalence of disease-related damage and complications, and (3) changes in disease activity during the final year prior to transfer. METHODS: Registry participants who turned 17 years between February 2017 and November 2021 were included. Clinical characteristics and patient-reported outcomes (PROs) at the last recorded pediatric rheumatology visit, and changes observed in the year prior to that visit were analyzed. Physicians completed an additional questionnaire characterizing cumulative disease-related damage and adverse events by age 17 years. RESULTS: At their last visit, 88 of 131 participants (67%) had inactive and 42 (32%) had active disease. Overall, 96 (73%) were on medications and 41 (31%) were on biologic disease-modifying antirheumatic drugs. Among 80 participants for whom the additional questionnaire was completed, 26% had clinically detected joint damage, 31% had joint damage on imaging, 14% had uveitis, and 7.5% had experienced at least 1 serious adverse event. During the final year, 44.2% of patients were in remission, 28.4% attained inactive disease, and 27.4% became or remained active. Mean scores of PROs were stable overall during that last year, but a minority reported marked worsening. CONCLUSION: A substantial proportion of youth with JIA transitioning to adult care in Canada had a high disease burden, which was reflected by their degree of disease activity, joint damage, or ongoing medication use. These results will inform pediatric and adult providers of anticipated needs during transition of care.

Tofacitinib pharmacokinetics in children and adolescents with juvenile idiopathic arthritis.

These analyses characterized tofacitinib pharmacokinetics (PKs) in children and adolescents with juvenile idiopathic arthritis (JIA). Data were pooled from phase I (NCT01513902), phase III (NCT02592434), and open-label, long-term extension (NCT01500551) studies of tofacitinib tablet/solution (weight-based doses administered twice daily [b.i.d.]) in patients with JIA aged 2 to less than 18 years. Population PK modeling used a nonlinear mixed-effects approach, with covariates identified using stepwise forward-inclusion backward-deletion procedures. Simulations were performed to derive dosing recommendations for children and adolescents with JIA. Two hundred forty-six pediatric patients were included in the population PK model. A one-compartment model with first-order elimination and absorption with body weight as a covariate for oral clearance and apparent volume of distribution sufficiently described the data. Oral solution was associated with comparable average concentration (Cavg) and slightly higher (113.9%) maximum concentration (Cmax) versus tablet, which was confirmed by a subsequent randomized, open-label, bioavailability study conducted in healthy adult participants (n = 12) by demonstrating adjusted geometric mean ratios (90% confidence interval) between oral solution and tablet of 1.04 (1.00-1.09) and 1.10 (1.00-1.21) for area under the curve extrapolated to infinity and Cmax, respectively (NCT04111614). A dosing regimen of 3.2 mg b.i.d. solution in patients 10 to less than 20 kg, 4 mg b.i.d. solution in patients 20 to less than 40 kg, and 5 mg b.i.d. tablet/solution in patients greater than or equal to 40 kg, irrespective of age, was proposed to achieve constant Cavg across weight groups. In summary, population PK characterization informed a simplified tofacitinib dosing regimen that has been implemented in pediatric patients with JIA.

Existing and Emerging Targeted Therapies in Juvenile Psoriatic Arthritis: Challenges and Unmet Needs.

Juvenile psoriatic arthritis (JPsA) is a heterogeneous type of non-systemic chronic inflammatory arthritis affecting children and young people. This review focuses on highlighting challenges in harmonising recommendations for the use of available therapies in JPsA, according to its distinct clinical phenotypes, and explores the similarities and differences between the disease classification and management across age. We further explore the emerging therapeutic landscape, summarising the recently completed clinical trials in JPsA, and ongoing studies in both JPsA and adults with psoriatic arthritis, highlighting unmet needs and barriers for translational research in JPsA. The novel therapeutic agents in clinical development in JPsA range from monoclonal antibodies targeting interleukin (IL)-17, IL-12/23 and IL-23 blockades to synthetic small molecules targeting Janus kinase and tyrosine kinase and phosphodiesterase-4 inhibition. In addition, there are head-to-head clinical trials comparing tumour necrosis factor-α blockade with both IL-17 and IL-23 inhibition. Most of these new therapies have been tested in adults with psoriatic arthritis and have advanced to the phase III stage of drug development or received license for use, suggesting promising signals for efficacy and potentially acceptable safety and tolerability for JPsA. Further translational research in JPsA is required to improve our understanding of the impact of age at onset on treatment efficacy, as well as to provide opportunities for better management of refractory disease and improved long-term outcomes in JPsA, for ultimate patient benefit.

Methotrexate for juvenile idiopathic arthritis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Methotrexate has broad immunomodulatory properties and is the most commonly used disease-modifying antirheumatic drug (DMARD). This is an update of a 2001 Cochrane review. It supports a living guideline for children and young people with JIA. OBJECTIVES: To assess the benefits and harms of methotrexate for children and young people with juvenile idiopathic arthritis. SEARCH METHODS: The Australian JIA Living Guideline Working Group created a registry of all randomised controlled trials (RCTs) of JIA by searching CENTRAL, MEDLINE, Embase, and trials registries. The date of the most recent search of online databases was 1 February 2023. SELECTION CRITERIA: We searched for RCTs that compared methotrexate with placebo, no treatment, or another DMARD (with or without concomitant therapies) in children and young people (aged up to 18 years) with JIA. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. The main comparison was methotrexate versus placebo. Our outcomes were treatment response, sustained clinically inactive disease, function, pain, participant global assessment of well-being, serious adverse events, and withdrawals due to adverse events. We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We identified three new trials in this update, bringing the total number of included RCTs to five (575 participants). Three trials evaluated oral methotrexate versus placebo, one evaluated methotrexate plus intra-articular glucocorticoid (IAGC) therapy versus IAGC therapy alone, and one evaluated methotrexate versus leflunomide. Doses of methotrexate ranged from 5 mg/m2/week to 15 mg/m2/week in four trials, and participants in the methotrexate group of the remaining trial received 0.5 mg/kg/week. Trial size varied from 31 to 226 participants. The average age of participants ranged from four to 10 years. Most participants were females and most had nonsystemic JIA. The study that evaluated methotrexate plus IAGC therapy versus IAGC therapy alone recruited children and young people with the oligoarticular disease subtype of JIA. Two placebo-controlled trials and the trial of methotrexate versus leflunomide were adequately randomised and blinded, and likely not susceptible to important biases. One placebo-controlled trial may have been susceptible to selection bias due to lack of adequate reporting of randomisation methods. The trial investigating the addition of methotrexate to IAGC therapy was susceptible to performance and detection biases. Methotrexate versus placebo Methotrexate compared with placebo may increase the number of children and young people who achieve treatment response up to six months (absolute difference of 163 more per 1000 people; risk ratio (RR) 1.67, 95% confidence interval (CI) 1.21 to 2.31; I2 = 0%; 3 trials, 328 participants; low-certainty evidence). However, methotrexate compared with placebo may have little or no effect on pain as measured on an increasing scale of 0 to 100 (mean difference (MD) -1.10 points, 95% CI -9.09 to 6.88; 1 trial, 114 participants), improvement in participant global assessment of well-being (absolute difference of 92 more per 1000 people; RR 1.23, 95% CI 0.88 to 1.72; 1 trial, 176 participants), occurrence of serious adverse events (absolute difference of 5 fewer per 1000 people; RR 0.63, 95% CI 0.04 to 8.97; 3 trials, 328 participants), and withdrawals due to adverse events (RR 3.46, 95% CI 0.60 to 19.79; 3 trials, 328 participants) up to six months. We could not estimate the absolute difference for withdrawals due to adverse events because there were no withdrawals in the placebo group. All outcomes were reported within six months of randomisation. We downgraded the certainty of the evidence to low for all outcomes due to indirectness (suboptimal dosing of methotrexate and diverse outcome measures) and imprecision (few participants and low event rates). No trials reported function or the number of participants with sustained clinically inactive disease. Serious adverse events included liver derangement, abdominal pain, and inadvertent overdose. Methotrexate plus intra-articular corticosteroid therapy versus intra-articular corticosteroid therapy alone Methotrexate plus IAGC therapy compared with IAGC therapy alone may have little or no effect on the probability of sustained clinically inactive disease or the rate of withdrawals due to adverse events up to 12 months in children and young people with the oligoarticular subtype of JIA (low-certainty evidence). We could not calculate the absolute difference in withdrawals due to adverse events because there were no withdrawals in the control group. We are uncertain if there is any difference between the interventions in the risk of severe adverse events, because none were reported. The study did not report treatment response, function, pain, or participant global assessment of well-being. Methotrexate versus an alternative disease-modifying antirheumatic drug Methotrexate compared with leflunomide may have little or no effect on the probability of treatment response or on function, participant global assessment of well-being, risk of serious adverse events, and rate of withdrawals due to adverse events up to four months. We downgraded the certainty of the evidence for all outcomes to low due to imprecision. The study did not report pain or sustained clinically inactive disease. AUTHORS' CONCLUSIONS: Oral methotrexate (5 mg/m2/week to 15 mg/m2/week) compared with placebo may increase the number of children and young people achieving treatment response but may have little or no effect on pain or participant global assessment of well-being. Oral methotrexate plus IAGC injections compared to IAGC injections alone may have little or no effect on the likelihood of sustained clinically inactive disease among children and young people with oligoarticular JIA. Similarly, methotrexate compared with leflunomide may have little or no effect on treatment response, function, and participant global assessment of well-being. Serious adverse events due to methotrexate appear to be rare. We will update this review as new evidence becomes available to inform the living guideline.