What was already known?

Biologic therapy is usually given to patients with juvenile idiopathic arthritis (JIA) after they have failed to respond or do not tolerate methotrexate. Patients with systemic JIA do not seem to respond well to tumour necrosis factor inhibitors (TNFi) and, because of their unique genetics and disease pathways, interleukin (IL)-1 and -6 inhibitors seem more appropriate to use.

From 2010 in the UK, the IL-1 inhibitor anakinra (currently unlicensed) and IL-6 inhibitor tocilizumab are the most common biologics used in patients with systemic JIA. The aim of this study was to investigate real-world short-term responses in children and young people with systemic JIA starting with tocilizumab or anakinra.

What was discovered?

The Biologics for Children with Rheumatic Diseases (BCRD) cohort study collects data on children and young people starting biologic therapy for JIA. Between 2010 and 2016, 76 patients with systemic JIA starting either tocilizumab or anakinra agreed to participate in the register; 54 starting tocilizumab and 22 starting anakinra.

Patients starting anakinra were more likely to be starting it as a first-line biologic, with consequently shorter disease duration, and more likely to have a history of macrophage activation syndrome (MAS).

After one year of treatment:

• 42% of patients were at least 90% better.
• 51% achieved minimal disease activity.
• 39% achieved clinically inactive disease.

However, there were no differences in response between patients on tocilizumab versus anakinra. There were no other clinical factors associated with achieving any of the three outcomes.

By one year, 89% of patients on tocilizumab were still on therapy compared with 59% of anakinra patients (p=0.002). One-third of the patients who stopped anakinra reported injection-related problems.

Why is this important?

This is the first study to show that, in the UK, approximately half of the patients with systemic JIA treated with tocilizumab or anakinra had minimal disease activity, and two-fifths either achieved a significant clinical short-term response or inactive disease by one year.

It is important to demonstrate that treatment response appeared to be similar between tocilizumab and anakinra treated patients. However, more patients seemed to stop anakinra, with one-third of those stopping anakinra reporting injection-related problems.

Publications

(Kearsley-Fleet L. et al. (2018). Short-term outcomes in patients with systemic juvenile idiopathic arthritis treated with either tocilizumab or anakinra. Rheumatology August 21 [Epub ahead of print]. PMID:30137641| DOI:10.1093/rheumatology/key262)

Related