Tumor necrosis factor (TNF) inhibitors for juvenile idiopathic arthritis-associated uveitis

Population Pharmacokinetics of Adalimumab in Juvenile Idiopathic Arthritis Patients: A Retrospective Cohort Study Using Clinical Care Data

BACKGROUND AND OBJECTIVE

Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disorder that primarily affects the joints in children. Notably, it is known to co-occur with uveitis. Adalimumab, a monoclonal anti-TNF antibody, is effective in treating both conditions. A deeper understanding of the pharmacokinetics (PK) of adalimumab in JIA is crucial to advance in more personalized treatment approaches. The objective of this study is to evaluate the population PK profile of adalimumab in JIA and to explain causes for its variability.

MATERIALS AND METHODS

Adalimumab and antidrug antibody concentrations were retrospectively retrieved from the charts of patients with JIA. Initially, five literature-based population PK models of adalimumab were evaluated to assess their ability to describe the observed concentration-time profiles in the JIA cohort. These models included one specifically for the pediatric Crohn's disease population and four derived from studies in adult populations in healthy subjects and rheumatoid arthritis patients. Subsequently, a novel population PK model tailored to the JIA population was developed using NONMEM software. Monte Carlo simulations were then conducted utilizing the final PK model to visualize the concentration-time profile of adalimumab in patients with JIA and the impact of covariates.

RESULTS

A cohort of 50 patients with JIA with 78 available adalimumab samples was assessed. The mean age was 11.8 ± 3.9 years, with a median body weight of 49 kg (interquartile range 29.4-59.8 kg). All literature models adequately described the concentration-time profiles in JIA. The best model, which was developed in patients with rheumatoid arthritis during the maintenance phase of treatment, served as a basis for estimating clearance in JIA, resulting in a value of 0.37 L per day per 70 kg. Patient body weight, antidrug antibodies, methotrexate use, CRP level, and comorbidity of uveitis were found to have a significant impact on adalimumab clearance, and these reduced the inter-patient variability from 58.6 to 28.0%. On steady state in the simulated patient population, the mean trough level was 7.4 ± 5.5 mg/L. The two dosing regimens of 20 and 40 mg every other week, based on patients' body weight, resulted in comparable simulated overall drug exposure.

CONCLUSIONS

Five literature models effectively described adalimumab PK in this pediatric cohort, highlighting the potential for extrapolating existing models to the pediatric population. The new JIA model confirmed the effect of several known covariates and found a novel association for drug clearance with methotrexate use (lower) and uveitis (higher), which might have clinical relevance for personalized dosing in JIA.

Janus Kinase Inhibitors as a Third-Line Therapy for Refractory Endogenous Noninfectious Uveitis

PURPOSE

Janus kinase (JAK) inhibitors have recently been used to treat patients with biologic refractory noninfectious uveitis (NIU). This narrative review updates the current evidence relevant for their application in patients with refractory NIU.

METHODS

A literature search was performed for articles published until October 2023 in the PubMed, Scopus, and CENTRAL databases using the key terms "noninfectious uveitis" and "Janus kinase inhibitor" or "JAK inhibitor" without any exclusion criteria. Published articles were selected based on their clinical focus, relevance for ocular disease, time since publication and study design reflecting their scientific soundness with a critical appraisal of drug safety aspects.

RESULTS

Janus kinases are transmembrane signaling proteins. Their inhibition has shown therapeutic potential experimentally and in patients with multiple immune-mediated diseases, including NIU. JAK inhibitors differ from biological agents in that they inhibit not one specific but multiple cytokines. These agents can be ingested orally and seem superior to adalimumab for most indications. While there is no doubt regarding their efficacy in treating immune-mediated inflammatory diseases, reports regarding their safety are increasing, and the findings are generally confusing and contradictory. Since substantiated information about their specific safety profiles in patients with inflammatory eye disease is lacking, their position in the therapeutic algorithm for uveitis has yet to be determined.

CONCLUSIONS

In the absence of evidence from controlled clinical trials, JAK inhibitor therapy is still rendered experimental and currently considered only for sight-threatening uveitis. JAK inhibitors may be considered for specific NIU entities for which there is insufficient response or secondary loss of response to conventional or biologic disease-modifying drugs.

Treatment with Biologic Drugs in Pediatric Behçet's Disease: A Comprehensive Analysis of the Published Data

BACKGROUND AND OBJECTIVE

Behçet's disease (BD) is a variable vessel vasculitis. Biologic drugs are increasingly used in the treatment of BD. We aimed to analyze biologic drug use in the treatment of pediatric BD.

METHODS

MEDLINE/PubMed and Scopus databases were searched from the inception of these databases until 15 November 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only reports presenting data of pediatric patients with BD (BD diagnosis < 18 years of age) treated with biologic drugs were included. The demographic features, clinical characteristics, and data on treatment were extracted from the included papers.

RESULTS

We included 87 articles including 187 pediatric patients with BD treated with biologic drugs (215 biologic treatments). Tumor necrosis factor (TNF)-α inhibitors (176 treatments) were the most frequently used biologic drugs followed by interferons (21 treatments). Other reported biologic treatments were anti-interleukin-1 agents (n = 11), tocilizumab (n = 4), daclizumab (n = 2), and rituximab (n = 1). The most common indication for biologic drug use was ocular involvement (93 treatments) followed by multisystem active disease (29 treatments). Monoclonal TNF-α inhibitors, adalimumab and infliximab, were preferred over etanercept in ocular and gastrointestinal BD. The improvement rates with any TNF-α inhibitor, adalimumab, infliximab, etanercept, and interferons were 78.5%, 86.1%, 63.4%, 87.5%, and 70%; respectively. The organ-specific improvement rate with TNF-α inhibitors was 76.7% and 70% for ocular and gastrointestinal system involvement. Adverse events have been reported for TNF-α inhibitors, interferons, and rituximab. Six of these were severe [TNF-α inhibitors (n = 4); interferons (n = 2)].

CONCLUSIONS

The presented systematic literature search revealed that TNF-α inhibitors followed by interferons were the most frequently used biologic drugs in pediatric BD. Both group of biologic treatments appeared to be effective and have an acceptable safety profile in pediatric BD. However, controlled studies are required for analyzing indications for biologic treatments in pediatric BD.

Tumor necrosis factor (TNF) inhibitors for juvenile idiopathic arthritis-associated uveitis

BACKGROUND

Uveitis is the most common extra-articular manifestation of juvenile idiopathic arthritis (JIA) and a potentially sight-threatening condition characterized by intraocular inflammation. Current treatment for JIA-associated uveitis (JIA-U) is largely based on physician experience, observational evidence and consensus guidelines, resulting in considerable variations in practice.  OBJECTIVES: To evaluate the effectiveness and safety of tumor necrosis factor (TNF) inhibitors used for treatment of JIA-U.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We last searched the electronic databases on 3 February 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing TNF inhibitors with placebo in participants with a diagnosis of JIA and uveitis who were aged 2 to 18 years old.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology and graded the certainty of the body of evidence for seven outcomes using the GRADE classification.

MAIN RESULTS

We included three RCTs with 134 participants. One study conducted in the USA randomized participants to etanercept or placebo (N = 12). Two studies, one conducted in the UK (N = 90) and one in France (N = 32), randomized participants to adalimumab or placebo. All studies were at low risk of bias. Initial pooled estimates suggested that TNF-inhibitors may result in little to no difference on treatment success defined as 0 to trace cells on Standardization of Uveitis Nomenclature (SUN)-grading; or two-step decrease in activity based on SUN grading (estimated risk ratio (RR) 0.66; 95% confidence interval (CI) 0.21 to 2.10; 2 studies; 43 participants; low-certainty evidence) or treatment failure defined as a two-step increase in activity based on SUN grading (RR 0.31; 95% CI 0.01 to 7.15; 1 study; 31 participants; low-certainty evidence). Further analysis using the individual trial definitions of treatment response and failure suggested a positive treatment effect of TNF inhibitors; a RR of treatment success of 2.60 (95% CI 1.30 to 5.20; 3 studies; 124 participants; low-certainty evidence), and RR of treatment failure of 0.23 (95% CI 0.11 to 0.50; 3 studies; 133 participants). Almost all the evidence was on adalimumab and the evidence on etanercept was very limited.  For secondary outcomes, one study suggests that adalimumab may have little to no effect on risk of recurrence after induction of remission at three months (RR 2.50, 95% CI 0.31 to 20.45; 90 participants; very low-certainty evidence) and visual acuity, but the evidence is very uncertain; mean difference in longitudinal logMAR score change over six months was -0.01 (95% CI -0.06 to 0.03) and -0.02 (95% CI -0.07 to 0.03) using the best and worst logMAR measurement, respectively (low-certainty evidence). Low-certainty evidence from one study suggested that adalimumab treatment results in reduction of topical steroid doses at six months (hazard ratio 3.58; 95% CI 1.24 to 10.32; 74 participants who took one or more topical steroid per day at baseline). Adverse events, including injection site reactions and infections, were more common in the TNF inhibitor group. Serious adverse events were uncommon.

AUTHORS' CONCLUSIONS

Adalimumab appears to increase the likelihood of treatment success and decrease the likelihood of treatment failure when compared with placebo. The evidence was less conclusive about a positive treatment effect with etanercept. Adverse events from JIA-U trials are in keeping with the known side effect profile of TNF inhibitors. Standard validated JIA-U outcome measures are required to homogenize assessment and to allow for comparison and analysis of multiple datasets.