Biological therapy in rheumatoid arthritis : epidemiological studies

The landscape of RA treatment has unquestionably changed dramatically during the last decade. A deeper understanding of the pathophysiological and immunological mechanisms in RA, earlier and more aggressive treatment, and the development and introduction to daily clinical practice of a new class of antirheumatic drugs, the so-called biologic therapies, has contributed to this ‘revolution’. To date, nine biologic agents have been approved for the treatment for RA and more molecules with distinct mechanisms of action are currently being tested in laboratories and in clinical trials. In all cases, very good clinical efficacy and safety were documented in large, randomized, controlled clinical trials that led to regulatory approval. However, not all questions regarding the optimal use of these agents can be addressed in randomized trials. Observational studies based on registries can provide important information about the effectiveness and safety of biologics in real-life RA populations as well as better insight of different treatment strategies. Thus they are important ‘pieces of the puzzle’ and can help complete the picture of RA treatment. This thesis comprises of two parts: part I is based on four studies about several aspects of rituximab use in RA which are based on a large international cohort. The second part is based on four studies about the use of TNF inhibitors in RA (cycling, switching and discontinuation) which are based on local and national registers and a pilot clinical trial