Abatacept for the treatment of rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) is a complex disease in which different mechanisms are involved. Studies suggest a key role for aberrant pathways of T-cell activation in the initiation and perpetuation of disease. Abatacept is a fusion protein composed of the Fc region of the immunoglobulin G1 (IgG1) fused to the extracellular domain of cytotoxic T lymphocyte-associated antigen (CTLA4). It has the ability to modulate T-cell activation by interfering with co-stimulation of these cells, a necessary step to become activated. This suggests that abatacept may play a role in the progression and/or even the initiation of RA. Areas covered: a review of the different studies carried out during clinical development of abatacept was performed. Both formulations, intravenous (IV) and subcutaneous (SC), showed a similar and consistent efficacy and safety profile. Abatacept was effective both in RA patients not responding to methotrexate (MTX) and to tumor necrosis factor (TNF) inhibitors. Expert commentary: abatacept, with its unique mechanism of action, proved to be a useful therapeutic alternative in RA, also having an acceptable safety profile. Evidence points out that abatacept may be able to alter the RA disease course. Ongoing studies will clarify this issue.