# Use of biologic drugs in juvenile idiopathic arthritis patients followed in an adult rheumatology clinic: real-life data from the HUR-BIO biologic registry

## TL;DR

This study examines biologic drug use and outcomes in adult patients with juvenile idiopathic arthritis, finding that certain subgroups experience higher disease severity and treatment changes.

## Contribution

The study provides real-life data on biologic treatment patterns and outcomes in JIA patients transitioning to adult care, highlighting subgroup differences.

## Key findings

- Enthesitis-related arthritis and polyarthritis are the most common JIA subgroups in adult clinics.
- Secondary failure is the main reason for changing biologic treatments during follow-up.
- Polyarticular JIA is associated with higher disease severity and disability compared to other subgroups.

## Abstract

This study aimed to determine whether there are differences in biologic treatment and complications according to subgroups of juvenile idiopathic arthritis (JIA) patients in adulthood.

HUR-BIO (Hacettepe University Rheumatology Biologic Registry) has been a single-center biologic disease-modifying anti-rheumatic drug registry since 2005. Patients were selected from HUR-BIO who met the International League of Associations for Rheumatology classification criteria for juvenile idiopathic arthritis.

Enthesitis-related arthritis (82, 49.1%), rheumatoid factor (-) polyarthritis (39, 23.4%), and rheumatoid factor ( +) polyarthritis (26, 15.6%) were the most prevalent subgroups in 167 JIA patients. Etanercept (105, 62.9%), adalimumab (28, 16.8%), and infliximab (21, 12.6%) were the most prescribed first-line biologic drugs. Secondary failure was the most common reason for the treatment changes among 42 (43.3%) patients, followed by non-life-threatening side effects in 12 (12.4%) and primary failure in 11 (11.3%). Polyarticular JIA showed higher HAQ (p = 0.020) and DAS28-ESR (p < 0.001) before biologics and had a longer disease duration to initiation of biologic treatment than enthesitis-related arthritis (p < 0.001). Only one patient (1.2%) in the enthesitis-related arthritis group needed the hip prosthesis, while 12 patients (18.5%) in the polyarticular JIA group required the same procedure (p < 0.001).

In adult rheumatology departments, the most common JIAs present with ongoing disease are enthesitis-related arthritis and polyarthritis. Secondary failure was the main reason nearly half of the patients needed biologic changes during follow-up. The polyarticular group appears to have a higher disease severity and level of disability.
Key Points• The most of juvenile idiopathic arthritis patients in adult rheumatology clinics require biologics are enthesitis-related arthritis and polyarticular arthritis.• Approximately half of the patients require biologic changes during follow-up, most of these due to secondary failure.• Disease severity and disability appear to be higher in the polyarticular group, therefore treatment intensification may be considered.

Key Points

• The most of juvenile idiopathic arthritis patients in adult rheumatology clinics require biologics are enthesitis-related arthritis and polyarticular arthritis.

• Approximately half of the patients require biologic changes during follow-up, most of these due to secondary failure.

• Disease severity and disability appear to be higher in the polyarticular group, therefore treatment intensification may be considered.