Emerging drugs to treat juvenile idiopathic arthritis.

INTRODUCTION: Juvenile idiopathic arthritis (JIA) differs markedly from adult rheumatoid arthritis (RA). It is not a single disease, but an exclusion diagnosis that gathers together all forms of arthritis that begin before the age of 16 years, persist for > 6 weeks and are of unknown origin. This heterogeneous group of disorders has been classified on clinical and laboratory features to try to identify homogeneous, mutually exclusives categories. While some of them appear to represent rather homogenous entities others still seem to include heterogeneous conditions. AREAS COVERED: The advent of new biological treatments has dramatically changed both the observed responses to treatment and the expectations of therapies. The implementation of an adequate legislation as well as the presence of international research networks of pediatric rheumatology have contributed to foster the conduct of controlled clinical trials and the development of validated outcome measures. EXPERT OPINION: Despite these progresses, there are still many problems to be solved to provide a better treatment for those patients who fail to adequately respond to current therapies. Some of the new drugs that are under investigation for RA could also be suitable in the future for improving the treatment of JIA.