[Etanercept].

Abstract

Etanercept (ETN) is a fusion protein of the receptor (CD120b) for tumor necrosis factor (TNF) and the Fc portion of IgG1. A phase III trail and the JESMR study, both performed in Japan, implicated the importance of concomitant methotrexate (MTX) use in the treatment of rheumatoid arthritis (RA). Further evidences, including the TEAR study and the PRESERVE study, supported the recent treatment strategy for RA, being divided into at least two phases: remission induction phase(step-up or initial combination) and its maintenance phase (step-down). Thus, optimization of RA treatment chiefly based on MTX and anti-TNF biological agents is in progress.