Biological Agent Switching in Patients With Juvenile Idiopathic Arthritis: A Tertiary Center Experience

OBJECTIVE

The purpose of this study is to investigate the causes and outcomes of switching biological agents in juvenile idiopathic arthritis (JIA) patients using biological agents and compare the characteristics of patients whose biological agents are switched and those whose are not.

METHODS

This medical records review study was conducted with 128 patients who were diagnosed with JIA at our clinic between January 2009 and January 2022 and were receiving biologic agents. Factors affecting the biologic agent switching were investigated.

RESULTS

The JIA subtype with the most frequent switching in biological agents was systemic JIA (n = 13, 40.6%). Systemic JIA was followed by rheumatoid factor-negative polyarticular JIA and persistent oligoarticular JIA with 5 patients (15.6%), extended oligoarticular JIA and enthesitis-related JIA with 3 patients (9.3%), rheumatoid factor-positive polyarticular JIA with 2 patients (6.2%), and undifferentiated JIA with 1 patient (3.1%). Among the patients, 32 (25%) patients had their biological agent switched once, and 5 (3.9%) had theirs switched twice. The most frequently used biological agent was etanercept (n = 76, 59.3%), whereas the most frequently observed cases of biological agent switching were from an anti-TNF agent to another anti-TNF agent (40.6%). The reason for switching was unresponsiveness to the agent in 22 patients (68.8%), adverse effects in 6 patients (18.7%), drug intolerance in 1 patient (3.1%), and other reasons in 3 patients (9.3%).

CONCLUSIONS

The most frequently used biological agent was etanercept; the most frequent cases of biological agents switching were from an anti-TNF agent to another anti-TNF agent.

Analysis of the Immunogenicity from Abatacept-Treated Pediatric Patients With Polyarticular-Course Juvenile Idiopathic Arthritis: Findings From Two Phase III Clinical Trials

Objective

The goal of this article is to present the analysis of anti‐abatacept antibody data from children with polyarticular‐course juvenile idiopathic arthritis (pJIA), treated with abatacept. The data are from 395 participants with pJIA from two abatacept registrational trials.

Methods

We analyzed immunogenicity data according to age groups, administration route (intravenous [IV] or subcutaneous [SC]), drug treatment interruption, and co‐medications (with or without methotrexate [MTX]) to assess impact on the incidence of anti‐abatacept antibodies.

Results

The overall immunogenicity incidences observed in both JIA trials ranged between 4.7% and 23.3%. There was a slightly higher immunogenicity incidence in the 2–5‐year‐old participants (15.2%) compared with 6–17‐year‐old participants (4.7%). In the study with SC dosing, the overall incidence on treatment was 2.3% (3% if co‐dosed with MTX), similar to the incidence for Period A of the IV study (similar duration of treatment as the SC study), which was 2.1% (1.4% if co‐dosed with MTX). In the IV study, the period following a 6‐month interruption in treatment had comparable immunogenicity incidences (22.9% with interruption vs. 18.2% without interruption, both co‐dosed with MTX and 0% for both not co‐dosed with MTX). In most cases, participants co‐dosed with MTX had higher immunogenicity incidences than those on abatacept alone.

Conclusion

Although some trends were noted in terms of incidence according to age and MTX co‐dosing, none where conclusive owing to differences in population size. Drug holiday had no impact on immunogenicity incidence once treatment was resumed, and incidences across SC and IV dosing were comparable. There was no impact of immunogenicity on pharmacokinetics, safety, and efficacy.

Approach to switching biologics in juvenile idiopathic arthritis: a real-life experience

The primary aim of the treatment of juvenile idiopathic arthritis (JIA) is complete remission and minimizing the development of complications. Though biologic agents (BAs) provide better disease control, data related to BA switching patterns in JIA patients are scarce. This study aimed to determine the BA switching patterns in JIA patients. The study included children with JIA that received ≥ 1 BAs. Disease activity was evaluated based on the juvenile arthritis disease activity score 71 (JADAS71). Demographic data, clinical and laboratory findings, BA switching patterns, and the rationales for BA switching were recorded. The study included 177 (82 female and 95 male) JIA patients that received ≥ 1 BAs. Mean age at diagnosis of JIA was 9.1 ± 4.9 years. BAs were prescribed a median of 14 months (range: 3-66 months) after diagnosis. Among the 177 patients, 31 (17.5%) required BA switching a median 10.5 months (range: 3-38 months) after initiation of the first BA. Among all the BAs that were switched to after administration of the first BA, tocilizumab was the most commonly switched (n = 15). The most common reason for BA switching was inadequate response (n = 29). BAs were switched 2 times in 5 patients and 3 times in 1 patient. When patients that switched BAs 1 time were compared to those that switched 2 and 3 times there were not any differences in terms of JIA types, whereas those that switched 2 and 3 times had a higher active joint count and JADAS71 score after 6 months of initiation of the first BA. As some of the JIA patients could not achieve remission despite using the prescribed BA, BA switching was required. Herein, we provide data on both BA switching patterns and requirements, which may improve the management of JIA patients.

Targeted pharmacologic immunomodulation for inborn errors of immunity

Inborn errors of immunity consist of over 400 known single gene disorders that may manifest with infection susceptibility, autoimmunity, autoinflammation, hypersensitivity and cancer predisposition. Most patients are treated symptomatically with immunoglobulin replacement, prophylactic antimicrobials or broad immunosuppression pertaining to their disease phenotype. Other than haematopoietic stem cell transplantation, the aforementioned treatments do little to alter disease morbidity or mortality. Further, many patients may not be transplant candidates. In this review, we describe monogenic disorders affecting leucocyte migration, disorders of immune synapse formation and dysregulation of immune cell signal transduction. We highlight the use of off-label small molecules and biologics mechanistically targeted to altered disease pathophysiology of such diseases.