Clinicians can be confident about the long-term safety profile of the interleukin-1 receptor antagonist anakinra for systemic juvenile idiopathic arthritis, researchers say.

Although adverse events are common, the overall incidence gradually decreases over time, according to their study based on the observational Pharmachild registry of patients with systemic juvenile idiopathic arthritis (sJIA).

Furthermore, the Paediatric Rheumatology International Trials Organisation investigators stressed, there was no evidence that long-term anakinra treatment increased the risk of macrophage activation syndrome (MAS).

Writing in the Journal of Rheumatology, the team analysed data from 306 patients (median age eight) treated continuously with the immunomodulator for at least 12-24 months to identify the type and frequency of adverse events.