Despite the huge progress made by the use of tumour necrosis factor (TNF) inhibitors in the treatment of rheumatoid arthritis (RA), there was still an unmet need for discovering and implementing new biologic therapies for RA patients who lost response or had side-effects to TNF inhibitors. The advances in molecular biology and understanding of the complex pathogenesis of RA enabled the identification of other pivotal molecules, whose blockage was associated with clinical benefits in RA. This chapter reviews the clinical efficacy, safety profile and cost-effectiveness of several biologic agents licensed for use in RA patients, which target different interleukins (IL), such as IL1 (anakinra) and IL6 (tocilizumab), or are associated with B cell depletion (rituximab), T cell co-stimulatory blockage (abatacept) and small molecule inhibition (tofacitinib). In addition, we discuss the national and international guidelines for use of these biologic agents in relation to the use of TNF inhibitors in patients with moderatesevere RA, providing examples of switching between various biologic therapies
