Juvenile Idiopathic Arthritis (JIA) is one of the most common chronic diseases in childhood, leading to significant morbidity and long-term disability. JIA has similarities with adult Reumatoid Arthritis (RA) as they are both autoimmune diseases that primarily affect the joints. Nevertheless, critical differences exist not only in clinical phenotype, but also in genetic susceptibility and inheritance, prognosis, and treatment response. For these reasons JIA and RA can be considered separate disease entities. Yet, to date, treatment of JIA is still based on therapies developed for RA, which, given the differences between the two diseases is highly unlikely to be optimal.

New therapies, especially those based on blockade of specific inflammatory pathways have benefited patients with JIA in the short term and have significantly reduced disease morbidity and disability. However, the special vulnerability of children with JIA remains a source of serious concern for several compelling reasons:

Pharmaceutical companies do not spearhead the development of novel therapies for children, and none of the approved therapies are developed for children with JIA.

There is no safe and cost-effective cure for JIA forcing long-term treatment. Current treatment interferes in crucial pathways involved in cell growth and differentiation, which can be expected to have a significant impact especially on growing children

As a consequence of the above, children with JIA undergo lifelong treatment with serious consequences both for them (high risks of long-term side effects) and for society as a whole (high costs). The risk of long-term side effects in children was recently underlined by a FDA report showing an increased risk of cancer and other malignancies in children treated with TNF-blockers and by reports on a possible increased treatment-related occurrence of inflammatory bowel disease in children with JIA. Other yet largely unknown but expected long-term side effects include increased risks of cardiovascular complications and treatment-related loss of fertility.