[Inhibition of interleukin 6, a new therapeutic option in rheumatoid arthritis].

Tocilizumab (TCZ) is a humanized monoclonal antibody which targets the receptor for IL-6, developed by the Japanese pharmaceutical company Chugai and the swiss company Roche. In Japan it is already under use for Castleman's disease, rheumatoid arthritis (RA) and Juvenile Idiopathic Arthritis. The clinical development outside Japan is very extensive and has shown efficacy in possible RA scenarios; early RA (part of the AMBITION study), established, MTX-resistant RA (OPTION) and RA resistant to other DMARD (TOWARD), and anti-TNF-α resistant RA (RADIATE). Both monotherapy with TCZ (AMBITION) and associated to other background drugs. Radiological efficacy has also been proven (LITHE). So TCZ is probably the biologic therapy with the most extensive clinical development before marketing in the western hemisphere. In this review we will specifically deal with clinical and radiological efficacy, as wel as its safety profile.