Treatment to Target Using Recombinant Interleukin‐1 Receptor Antagonist as First‐Line Monotherapy in New‐Onset Systemic Juvenile Idiopathic Arthritis: Results From a Five‐Year Follow‐Up Study

Abstract

Objective Systemic juvenile idiopathic arthritis (JIA) is a multifactorial autoinflammatory disease with a historically poor prognosis. With current treatment regimens, approximately half of patients still experience active disease after 1 year of therapy. This study was undertaken to evaluate a treat‐to‐target approach using recombinant interleukin‐1 receptor antagonist (rIL‐1Ra; anakinra) as first‐line monotherapy to achieve early inactive disease and prevent damage. Methods In this single‐center, prospective study, patients with new‐onset systemic JIA with an unsatisfactory response to nonsteroidal antiinflammatory drugs received rIL‐1Ra monotherapy according to a treat‐to‐target strategy. Patients with an incomplete response to 2 mg/kg rIL‐1Ra subsequently received 4 mg/kg rIL‐1Ra or additional prednisolone, or switched to alternative therapy. For patients in whom inactive disease was achieved, rIL‐1Ra was tapered after 3 months and subsequently stopped. Results Forty‐two patients, including 12 who had no arthritis at disease onset, were followed up for a median of 5.8 years. The median time to achieve inactive disease was 33 days. At 1 year, 76% had inactive disease, and 52% had inactive disease while not receiving medication. High neutrophil counts at baseline and a complete response after 1 month of rIL‐1Ra were highly associated with inactive disease at 1 year. After 5 years of follow‐up, 96% of the patients included had inactive disease, and 75% had inactive disease while not receiving medication. Articular or extraarticular damage was reported in <5%, and only 33% of the patients received glucocorticoids. Treatment with rIL‐1Ra was equally effective in systemic JIA patients without arthritis at disease onset. Conclusion Treatment to target, starting with first‐line, short‐course monotherapy with rIL‐1Ra, is a highly efficacious strategy to induce and sustain inactive disease and to prevent disease‐ and glucocorticoid‐related damage in systemic JIA.