[Rituximab and abatacept in rheumatoid arthritis]

Abatacept and rituximab are two biologic drugs approved in patients with rheumatoid arthritis who have an inadequate response or intolerance to other disease modifying antirheumatic drugs, including one or more tumor necrosis factor (TNF) inhibitors. The current indication for use is the only thing that both drugs have in common because they are different molecules (abatacept is a fusion molecule and rituximab a monoclonal antibody) with different mechanisms of action and different patterns of administration. Both treatments have shown their clinical efficacy, the stop of structural damage and medium term safety in randomized, double-blind clinical trials. In this paper we will review the structure and mechanisms of action of both drugs, presenting studies in which the efficacy and safety data are based and will finally postulate different controversial questions in the use of these drugs.