Changes in systemic medication in children and adolescents with juvenile idiopathic arthritis: why, when and which patterns

OBJECTIVE: To investigate why, when and in which patterns decisions about changes in systemic medications were made in a cohort of juvenile idiopathic arthritis (JIA) patients.

METHODS: JIA patients starting first line systemic therapy were prospectively followed in a Dutch tertiary pediatric rheumatology center. Treatment lines were constructed for the included systemic therapies (systemic corticosteroids, conventional and biological disease modifying antirheumatic drugs (cDMARDs and bDMARDs)). Each change in systemic medication and its reason was registered. Main outcomes were frequencies and timing of change reasons, across treatment lines. A Sankey diagram was used to visualize flows between change reasons over treatment lines, cumulative incidences Fine-Gray models to illustrate the frequencies of the change reasons over time.

RESULTS: 551 patients were included of which 67.9% were female and oligoarticular JIA was the most common JIA diagnosis (41.9%). 1422 different systemic drug treatment lines were observed, with a median number of 2 (IQR 1-3) treatment lines per patient. Methotrexate was predominantly used as first treatment line (89.1%), while bDMARDs were mostly used as next treatment line (53.3%). JIA medication was mostly changed because of inefficacy (42.9%) in the first treatment line vs remission in the second treatment line (46.2%).

CONCLUSION: JIA medication is mostly changed because of inefficacy in the first treatment line (predominantly methotrexate) vs remission in the second treatment line (roughly half on bDMARDs). This indicates that bDMARDs may be a more effective treatment than methotrexate in part of the JIA population, advocating reconsideration of current JIA treatment guidelines.