Abstract

Recently new classification criteria have been developed for axial spondyloarthritis (SpA) covering both patients who already show radiographic evidence of structrual damage in the sacroilac joints (or spine), termed radiographic axila SpA (or using the older term: ankylosing spondylitis (AS)) and patients in the earlier phase without radiographic evidence of structural damage in the bone, termed non-radiographic (nr) axial SpA. There is general agreement that these two stages represent a continuum of the same disease and that preferentially the term axial SpA should be used. Both EMA and FDA have raised questions about the natural course of the earlier stage (nr-axSpA), the potential rate of spontaneous remission and the possibilty of overtreatment with biologcs in these patients. However, the EMA has accepted that there was an unmet need for treatment with TNF-blockers of these patients if they fail conventional therapy, which resulted in an approval for TNF-blockers for nr-axSpA - in addition to patients with AS - in the EU, if they have objective signs of inflammation such as positive CRP and/or active bone inflammation on MRI, and many other countries but not the US. The EMA has demanded post-approval studies from the TNF-blocker companies investigating what happens if the drug is stopped (or the dosage reduced) in patients who are reaching remission. These studies are ongoing and will deliver sufficient informations whether overtreatment might occur in these patients. In contrast, the FDA is asking for further phase 3 trials which include a placebo-controlled phase over 12 months. Such a study design would be very difficult to be conducted in EU countries – withholding an effective drug up to 12 months from active patients. But the different apporaches used by the two agencies also reflect that European rheumatologists have been much more familiar over the last decades with this early phase of axSpA compared to US rheumatologists. It is hoped that the results of the ongoing trials - in Europe, US and other parts oft he world – will result in a worldwide acceptance of the axial SpA concept and of the need to offer adaequate treatment to all axial SpA patients in their active phase.