Experience with subcutaneous abatacept for rheumatoid arthritis: an update for clinicians.

Abatacept is recommended by several expert consensus groups including the 2013 update of the EULAR recommendations for the pharmacologic management of rheumatoid arthritis (RA), as a potential choice for biologic therapy for patients with RA. Initially developed, studied, and approved as an intravenous (IV) formulation, abatacept is now also available as a subcutaneous (SC) injection. Having both options available makes abatacept a particularly versatile agent for the management of RA, greatly expanding the population of patients who could benefit from this treatment. This review provides a summary of the most important clinical trials that have investigated this molecule in both of its formulations, with a focus on the more recent trials evaluating the SC formulation, specifically the AMPLE study, the first major trial evaluating two biologic agents (abatacept and the tumor necrosis factor (TNF)-inhibitor adalimumab) in a head-to-head manner. In that study, SC abatacept was found to have an efficacy profile similar to that of SC adalimumab, both in combination with methotrexate.