Spondyloarthritis: Inducing Drug-free Remission by Early TNF-alpha Blockade

The SPARTACUS study will explore the therapeutic efficacy of 2 different treatment strategies for patients suffering from peripheral Spondyloarthritis (pSpA), classified according to the "Assessment in SpondyloArthritis international Society" (ASAS) classification criteria; it will be set up as a 48-week, prospective, randomized, active-comparator controlled, double-blind, double-dummy, clinical trial with a two-fold clinical objective: * To compare a standard step-up approach using conventional synthetic Disease-Modifying Anti-Rheumatic Drugs (csDMARDs), such as methotrexate and/or sulphasalazine (the "csDMARD Step-Up"-strategy), with an early remission-induction treatment strategy that immediately introduces biological DMARDs (bDMARDs) as the first step in the treatment algorithm; in this group the Tumor Necrosis Factor inhibitor (TNFi) golimumab will be utilised (the "TNFi Induction"-strategy). * To define the window of opportunity within which temporary treatment with bDMARDs might be more effective, by stratifying patients according to symptom duration: patients with shorter symptom duration (\<3 months) versus those with more longstanding disease (between 3-12 months of symptom duration). The double-blind phase of the study will compare the 2 treatment strategies with regard to the proportion of patients that achieve a status of (sustained) clinical remission. Differences between patients with very early disease (\<3 months symptom duration) versus those with symptom duration between 3 and 12 months, will be evaluated. In patients that reach sustained clinical remission, all study treatments (both in the "csDMARD Step-up"-group and the "TNFi Induction"-group) will be stopped, and long-term, clinical follow-up of these patients will allow to explore the possibility of "drug-free remission"; also with regard to this objective, the difference in symptom duration will be evaluated.