B-cell therapies in established rheumatoid arthritis.

B-cell depletion therapy based on rituximab is effective and relatively safe in established rheumatoid arthritis. Rituximab is licensed for the treatment of rheumatoid arthritis in combination with methotrexate and in patients who did not respond or cannot tolerate tumour necrosis factor antagonists. Sustained control of disease activity can be achieved by repeated courses of treatment. The optimal dose and schedule of retreatment are still not established. Nevertheless, data are now available that provide a good base for current clinical practice and a good starting point for further research. In general, rituximab has a good safety profile with most studies showing similar incidences of serious adverse events and infections to placebo. However, reasonable and well-funded doubts remain over the safety of long-term strategies of treatment of rheumatoid arthritis with rituximab, in particular, in relation to the risk of secondary hypogammaglobulinaemia and potential increased risk of infections.