Disease modifying anti-rheumatic drugs in juvenile idiopathic arthritis: striving for individualized therapy

Costs of Hospital-Associated Care for Patients With Juvenile Idiopathic Arthritis in the Dutch Health Care System

OBJECTIVE

The aim of this study was to quantify costs of hospital-associated care for juvenile idiopathic arthritis (JIA), provide insights in patient-level variation in costs, and investigate costs over time from the moment of JIA diagnosis. Results were reported for all JIA patients in general and by subtype.  METHODS: This study was a single-center, retrospective analysis of prospective data from electronic medical records of children with JIA, ages 0-18 years, between April 1, 2011 and March 31, 2019. Patient characteristics (age, sex, JIA subtype) and hospital-based resource use (consultations, medication, radiology procedures, laboratory testing, surgeries, emergency department [ED] visits, hospital stays) were extracted and analyzed. Unit prices were obtained from Dutch reimbursement lists and pharmaceutical and hospital list prices.

RESULTS

The analysis included 691 patients. The mean total cost of hospital care was €3,784/patient/year, of which €2,103 (55.6%) was attributable to medication. Other costs involved pediatric rheumatologist visits (€633/patient/year [16.7%]), hospital stays (€439/patient/year [11.6%]), other within-hospital specialist visits (€324/patient/year [8.6%]), radiology procedures (€119/patient/year [3.1%]), laboratory tests (€114/patient/year [3.0%]), surgeries (€46/patient/year [1.2%]), and ED visits (€6/patient/year [0.2%]). Mean annual total costs varied between JIA subtypes and between individuals and were the highest for systemic JIA (€7,772/patient/year). Over the treatment course, costs were the highest in the first month after JIA diagnosis.

CONCLUSION

Hospital care costs of JIA vary substantially between individuals, between subtypes, and over the treatment course. The highest annual costs were for systemic JIA, primarily attributable to medication (i.e., biologics). Costs of other hospital-associated care were comparable regardless of subtype.

Pharmacological treatment patterns in patients with juvenile idiopathic arthritis in the Netherlands: a real-world data analysis

OBJECTIVE

To investigate medication prescription patterns among children with JIA, including duration, sequence and reasons for medication discontinuation.

METHODS

This study is a single-centre, retrospective analysis of prospective data from the electronic medical records of JIA patients receiving systemic therapy aged 0-18 years between 1 April 2011 and 31 March 2019. Patient characteristics (age, gender, JIA subtype) and medication prescriptions were extracted and analysed using descriptive statistics, Sankey diagrams and Kaplan-Meier survival methods.

RESULTS

Over a median of 4.2 years follow-up, the 20 different medicines analysed were prescribed as monotherapy (n = 15) or combination therapy (n = 48 unique combinations) among 236 patients. In non-systemic JIA, synthetic DMARDs were prescribed to almost all patients (99.5%), and always included MTX. In contrast, 43.9% of non-systemic JIA patients received a biologic DMARD (mostly adalimumab or etanercept), ranging from 30.9% for oligoarticular persistent ANA-positive JIA, to 90.9% for polyarticular RF-positive JIA. Among systemic JIA, 91.7% received a biologic DMARD (always including anakinra). When analysing medication prescriptions according to their class, 32.6% involved combination therapy. In 56.8% of patients, subsequent treatment lines were initiated after unsuccessful first-line treatment, resulting in 68 unique sequences. Remission was the most common reason for DMARD discontinuation (44.7%), followed by adverse events (28.9%) and ineffectiveness (22.1%).

CONCLUSION

This paper reveals the complexity of pharmacological treatment in JIA, as indicated by: the variety of mono- and combination therapies prescribed, substantial variation in medication prescriptions between subtypes, most patients receiving two or more treatment lines, and the large number of unique treatment sequences.

Metabolomic Profiling Identifies Exogenous and Microbiota-Derived Metabolites as Markers of Methotrexate Efficacy in Juvenile Idiopathic Arthritis

Variability in methotrexate (MTX) efficacy represents a barrier to early and effective disease control in the treatment of juvenile idiopathic arthritis (JIA). This work seeks to understand the impact of MTX on the plasma metabolome and to identify metabolic biomarkers of MTX efficacy in a prospective cohort of children with JIA. Plasma samples from a cohort of children with JIA (n = 30) collected prior to the initiation of MTX and after 3 months of therapy were analyzed using a semi-targeted global metabolomic platform detecting 673 metabolites across a diversity of biochemical classes. Disease activity was measured using the 71-joint count juvenile arthritis disease activity score (JADAS-71) and clinical response to MTX was based on achievement of ACR Pedi 70 response. Metabolomic analysis identified 50 metabolites from diverse biochemical classes that were altered following the initiation of MTX (p < 0.05) with 15 metabolites reaching a false-discovery rate adjusted p-value (q-value) of less than 0.05. Enrichment analysis identified a class-wide reduction in unsaturated triglycerides following initiation of MTX (q = 0.0009). Twelve of the identified metabolites were significantly associated with disease activity by JADAS-71. Reductions in three metabolites were found to be associated with clinical response by ACR Pedi 70 response criteria and represented several microbiota and exogenously derived metabolites including: dehydrocholic acid, biotin, and 4-picoline. These findings support diverse metabolic changes following initiation of MTX in children with JIA and identify metabolites associated with microbial metabolism and exogenous sources associated with MTX efficacy.

Methotrexate Disposition, Anti-Folate Activity, and Metabolomic Profiling to Identify Molecular Markers of Disease Activity and Drug Response in the Collagen-Induced Arthritis Mouse Model

Methotrexate (MTX) is widely used in the treatment of autoimmune arthritis but is limited by its unpredictable and variable response profile. Currently, no biomarkers exist to predict or monitor early therapeutic responses to MTX. Using a collagen-induced arthritis (CIA) mouse model, this study aimed to identify biochemical pathways and biomarkers associated with MTX efficacy in autoimmune arthritis. Following arthritis disease induction, DBA/1J mice were treated with subcutaneous MTX (20 mg/kg/week) and disease activity was assessed based on disease activity scores (DAS) and paw volume (PV) measurements. Red blood cell (RBC) and plasma samples were collected at the end of the study and were assessed for folate and MTX content. Plasma samples were analyzed by semitargeted global metabolomic profiling and analyzed by univariate and multivariate analysis. Treatment with MTX was associated with significant reductions in disease activity based on both DAS (p = 0.0006) and PV (p = 0.0006). MTX therapy resulted in significant reductions in 5-methyltetrahydrofolate (5mTHF) levels in plasma (p = 0.02) and RBCs (p = 0.001). Reductions in both RBC and plasma 5mTHF were associated with lower DAS (p = 0.0007, p = 0.01, respectively) and PV (p = 0.001, p = 0.005, respectively). Increases in RBC MTX were associated with lower DAS (p = 0.003) but not PV (p = 0.23). Metabolomic analysis identified N-methylisoleucine (NMI) and quinolone as metabolites significantly altered in disease mice, which were corrected towards healthy control levels in mice treated with MTX. Reductions in plasma NMI were associated with lower DAS (p = 0.0002) and PV (p = 9.5 × 10^-6). Increases in plasma quinolone were associated with lower DAS (p = 0.02) and PV (p = 0.01). Receiver-operating characteristic curve analysis identified plasma NMI (AUC = 1.00, p = 2.4 × 10^-8), RBC 5mTHF (AUC = 0.99, p = 2.4 × 10^-5), and plasma quinolone (AUC = 0.89, p = 0.01) as top discriminating metabolites of MTX treatment. Our data support a relationship between MTX efficacy and its effect on circulating folates and identified 5mTHF, NMI, and quinolone as potential therapeutic biomarkers of disease activity and MTX response in the CIA mouse model of autoimmune arthritis.

Plasma Metabolome Normalization in Rheumatoid Arthritis Following Initiation of Methotrexate and the Identification of Metabolic Biomarkers of Efficacy

Methotrexate (MTX) efficacy in the treatment of rheumatoid arthritis (RA) is variable and unpredictable, resulting in a need to identify biomarkers to guide drug therapy. This study evaluates changes in the plasma metabolome associated with response to MTX in RA with the goal of understanding the metabolic basis for MTX efficacy towards the identification of potential metabolic biomarkers of MTX response. Plasma samples were collected from healthy control subjects (n = 20), and RA patients initiating MTX therapy (n = 20, 15 mg/week) before and after 16 weeks of treatment. The samples were analyzed by a semi-targeted metabolomic analysis, and then analyzed by univariate and multivariate methods, as well as an enrichment analysis. An MTX response was defined as a clinically significant reduction in the disease activity score in 28 joints (DAS-28) of greater than 1.2; achievement of clinical remission, defined as a DAS-28 < 2.6, was also utilized as an additional measure of response. In this study, RA is associated with an altered plasma metabolome that is normalized following initiation of MTX therapy. Metabolite classes found to be altered in RA and corrected by MTX therapy were diverse and included triglycerides (p = 1.1 × 10⁻¹⁶), fatty acids (p = 8.0 × 10⁻¹²), and ceramides (p = 9.8 × 10⁻¹³). Stratification based on responses to MTX identified various metabolites differentially impacted in responders and non-responders including glucosylceramides (GlcCer), phosphatidylcholines (PC), sphingomyelins (SM), phosphatidylethanolamines (PE), choline, inosine, hypoxanthine, guanosine, nicotinamide, and itaconic acid (p < 0.05). In conclusion, RA is associated with significant alterations to the plasma metabolome displaying at least partial normalization following 16 weeks of MTX therapy. Changes in multiple metabolites were found to be associated with MTX efficacy, including metabolites involved in fatty acid/lipid, nucleotide, and energy metabolism.

Costs of medication use among patients with juvenile idiopathic arthritis in the Dutch healthcare system

Background: This study aims to quantify medication costs in juvenile idiopathic arthritis (JIA), based on subtype.Research design and methods: This study is a single-center, retrospective analysis of prospective data from electronic medical records of JIA patients, aged 0-18 years between 1 April 2011 and 31 March 2019. Patient characteristics (age, gender, subtype) and medication use were extracted. Medication use and costs were reported as: 1) mean total annual costs; 2) between-patient heterogeneity in these costs; 3) duration of medication use; and, 4) costs over the treatment course.Results: The analysis included 691 patients. Mean total medication costs were €2,103/patient/year, including €1,930/patient/year (91.8%) spent on biologicals. Costs varied considerably between subtypes, with polyarticular rheumatoid-factor positive and systemic JIA patients having the highest mean costs (€5,020/patient/year and €4,790/patient/year, respectively). Mean annual medication costs over the patient's treatment course ranged from <€1,000/year (71.1% of patients) to >€11,000/year (2.5% of patients). Etanercept and adalimumab were the most commonly used biologicals. Cost fluctuations over the treatment course were primarily attributable to biological use.Conclusions: Polyarticular rheumatoid-factor positive and systemic JIA patients had the highest mean total annual medication costs, primarily attributable to biologicals. Costs varied considerably between subtypes, individuals, and over the treatment course.

Juvenile idiopathic arthritis in a premature baby: rare case report

Juvenile idiopathic arthritis (JIA) is chronic arthritis in children and adolescents. It is clinically diagnosed, which includes children under the age of 16 with arthritis for at least six weeks. Cases younger than six months of age are extremely rare. Here we report a rare case in the literature about Juvenile idiopathic arthritis in a premature baby, presenting at 21 days of age. The diagnosis was made according to clinical symptoms, laboratory analyses and duration of disease.

Metabolomic Profiling to Identify Molecular Biomarkers of Cellular Response to Methotrexate In Vitro

Variation in methotrexate (MTX) efficacy represents a significant barrier to early and effective disease control in the treatment of autoimmune arthritis. We hypothesize that the utilization of metabolomic techniques will allow for an improved understanding of the biochemical basis for the pharmacological activity of MTX, and can promote the identification and evaluation of novel molecular biomarkers of MTX response. In this work, erythroblastoid cells were exposed to MTX at the physiologic concentration of 1,000 nM and analyzed using three metabolomic platforms to give a broad spectrum of cellular metabolites. MTX pharmacological activity, defined as cellular growth inhibition, was associated with an altered cellular metabolomic profile based on the analysis of 724 identified metabolites. By discriminant analysis, MTX treatment was associated with increases in ketoisovaleric acid, fructose, galactose, and 2-deoxycytidine, and corresponding reductions in 2-deoxyuridine, phosphatidylinositol 32:0, orotic acid, and inosine monophosphate. Inclusion of data from analysis of folate metabolism in combination with chemometric and metabolic network analysis demonstrated that MTX treatment is associated with dysregulated folate metabolism and nucleotide biosynthesis, which is in line with its known mechanism of action. However, MTX treatment was also associated with alterations in a diversity of metabolites, including intermediates of amino acid, carbohydrate, and lipid metabolism. Collectively, these findings support a robust metabolic response following exposure to physiologic concentrations of MTX. They also identify various metabolic intermediates that are associated with the pharmacological activity of MTX, and are, therefore, potential molecular biomarker candidates in future preclinical and clinical studies of MTX efficacy in autoimmune arthritis.

Methotrexate disposition, anti-folate activity and efficacy in the collagen-induced arthritis mouse model

Methotrexate (MTX) efficacy in autoimmune arthritis is variable and unpredictable resulting in the need for the identification of biomarkers to guide drug therapy. This study utilizes the collagen-induced arthritis mouse model to investigate erythrocyte MTX disposition and anti-folate activity as biochemical markers of efficacy in autoimmune arthritis. Following induction of arthritis, DBA/1J mice were treated with once-weekly subcutaneous MTX at varying doses over a period of 40 days. At the completion of the study tissue samples were analyzed for MTX and folate content and assessed for their relationship with MTX efficacy. MTX treatment resulted in a reduction in disease activity that was variable and dose-dependent. Erythrocyte accumulation of MTX and its polyglutamate metabolites were dose proportionate, however, polyglutamate metabolites represented a mean ± S.E.M. of 8.9 ± 0.4% of total erythrocyte MTX, which is markedly lower than previously observed in humans and failed to display any significant association with MTX efficacy. MTX treatment resulted in reductions in erythrocyte 5-methyl-tetrahydrofolate (5mTHF) levels that were similar to those previously observed in human studies. Disease induction was associated with a decrease in liver 5mTHF and increased formyl-tetrahydrofolate (fTHF) that was normalized in MTX treated mice. MTX efficacy was associated with reductions in erythrocyte 5mTHF (P = 0.04) and increases in liver 5mTHF (P = 0.0001). Together, these findings demonstrate a relationship between alterations in tissue folate levels and MTX efficacy, and supports erythrocyte levels of 5mTHF as a marker of MTX efficacy in autoimmune arthritis.

Cytokine Biomarkers of Disease Activity and Therapeutic Response after Initiating Methotrexate Therapy in Patients with Juvenile Idiopathic Arthritis

STUDY OBJECTIVE

To evaluate the relationship between plasma cytokine levels with disease activity and therapeutic response in patients with juvenile idiopathic arthritis (JIA) after initiating methotrexate (MTX) therapy.

DESIGN

Single-center observational prospective cohort study.

SETTING

Outpatient pediatric rheumatology clinic at a tertiary care academic pediatric hospital.

PATIENTS

The study included 61 patients diagnosed with JIA who started therapy with standard-dose MTX 15 mg/m² /week. At 3 months, treating physicians were given the option of maintaining the MTX dose, increasing the MTX dose, or adding etanercept (ETN), based on their clinical judgment.

MEASUREMENTS AND MAIN RESULTS

Patients were evaluated at baseline, 3 months (51 patients), and 6 months (35 patients). Plasma samples from each visit were analyzed for interleukin (IL)-1α, IL-1β, IL-1Ra, IL-6, and tumor necrosis factor-α (TNF-α). Cytokine concentrations were evaluated for relationships with disease activity using the 71-joint count Juvenile Arthritis Disease Activity Score (JADAS). Therapeutic response was assessed by changes in JADAS. Failure to respond to standard-dose MTX was defined as the need for the addition of ETN or a MTX dose increase at or before the 3-month visit. Increased disease severity at baseline was associated with increased IL-6 (p=0.01) and TNF-α (p=0.008) levels. Initiation of MTX was associated with reductions in IL-1α (p=0.009), IL-1β (p=0.01), IL-1Ra (p=0.007), and IL-6 (p=0.03) levels; however, reductions in JADAS were only associated with reductions in IL-6 (p=0.009) and TNF-α levels (p=0.02). Compared with responders, patients failing to respond to standard-dose MTX had increased TNF-α levels at baseline (p=0.02) and at 3 months (p=0.005). Reductions in JADAS by 6 months were observed following either the addition of ETN (p=0.009) or an increase in MTX dose (p=0.007), but the addition of ETN was associated with a median 7-fold increase in TNF-α levels (p=0.003) that corresponded with clinical response.

CONCLUSION

Plasma cytokine levels were responsive to MTX therapy in patients with JIA, but only TNF-α and IL-6 levels were consistently associated with disease activity and therapeutic response. Increased TNF-α levels at baseline were associated with failure to respond to standard-dose MTX and the need for more aggressive drug therapy. Initiation of ETN resulted in increased TNF-α levels that corresponded with therapeutic response, suggesting a potential clinical benefit of monitoring TNF-α levels as a pharmacodynamic marker of etanercept activity.