The efficacy and safety of abatacept in rheumatoid arthritis.

Despite important progress in the treatment of rheumatoid arthritis in the last decade, even in the era of tumour necrosis factor (TNF) blockade there is a need for additional therapeutic options in many patients. In recent years three therapies with a distinct mode of action became available: rituximab, an anti-B cell therapy, tocilizumab, an anti IL-6 therapy, and abatacept, a costimulation blocker. Primary efficacy results of all three therapies are comparable at 6 months, nevertheless they have distinct efficacy and safety profiles. In the current review we focus on specific aspects of efficacy and safety of abatacept: increasing clinical and X-ray improvements over time, important and stable responses over several years, timing of response, improvements in patient-centered outcomes, and also long-term safety and easy administration with low rates of perfusion reactions. Currently, head to head comparisons between biologics are still lacking and registry data of drugs with a mode of action different to TNF blockade are still rare. In the meantime detailed analysis of all trials with a drug such as abatacept provides important information for the practicing rheumatologist.