Abatacept is the only T cell co-stimulation modulator approved thus far for the treatment of moderate-to-severe rheumatoid arthritis (RA) and is licensed for use in patients with an inadequate response to methotrexate (MTX) and/or anti-tumor necrosis factor (anti-TNF) therapy. The upstream mechanism of action of abatacept leads to downstream effects in a variety of cell types associated with the production of autoantibodies and pro-inflammatory cytokines implicated in RA. Accumulating data also suggest effects on other cells involved in the pathogenesis of RA, including regulatory T cells and osteoclasts. Clinical trials have demonstrated that abatacept is an effective and well-tolerated treatment in RA. More recently, evidence from the Assessing Very Early Rheumatoid arthritis Treatment (AVERT) trial showed that complete drug-free remission following treatment with abatacept may be a possibility in some patients with early RA, indicating that the disease course could be altered by early intervention. Equivalent efficacy and onset of action of abatacept and anti-TNF therapy have also been demonstrated in patients with an inadequate response to MTX in the Abatacept versus adaliMumab comParison in bioLogic-naïvE rheumatoid arthritis subjects with background methotrexate (AMPLE) trial. Together, these findings support the use of abatacept in early and established RA.
Keywords: Abatacept; CTLA-4-Ig; Co-stimulation; Rheumatoid arthritis; T cell therapy.