Systemic Juvenile Idiopathic Arthritis (sJIA) is a rare disease, affecting 20-40 new patients in the Netherlands each year. SJIA is currently classified as a subtype of JIA, characterised by chronic arthritis as well as signs of systemic (auto-) inflammation.
Until recently, the cornerstone in the treatment of sJIA consisted of corticosteroids, often necessary in high doses during prolonged time. This resulted in significant side effects like growth retardation, hypertension etc.
Since 2005, understanding of the pathophysiology of sJIA has increased, showing the importance of IL-1 and IL-6 in the inflammatory cascade of this disease. These findings have resulted in the use of recombinant IL-1 receptor antagonist (rIL-1RA or anakinra), still an unregistered drug for this indication, as well as the registration of tocilizumab (anti-IL-6) in 2011 and Canakinumab (anti-IL-1) in 2013 for the indication sJIA.
However, Tocilizumab and Canakinumab are registered as 2nd line treatment, for children with unsatisfactory responses to corticosteroids. This means that patients with sJIA still suffer from major side effects of corticosteroids and ultimately many of these patients need to switch to anti-IL-1 or anti-IL-6 in the chronic phase of sJIA, when proven steroid dependent. As no known stop-strategies for these drugs are currently available, these patients face long-term immunosuppressive treatment at high costs and uncertain risks.
We recently performed a prospective cohort study, treating new-onset sJIA patients with r-IL-1RA as first line treatment in corticosteroid naïve sJIA patients. We showed high response rates and importantly, also tested a stop-strategy that associated succesful stopping with low levels of several biomarkers.
The current project proposal continues on our findings, aiming to develop a biomarker guided stop strategy for the use of rIL-1RA in sJIA: short and targeted therapy early in the disease course with a yet unregistered drug for sJIA.