Efficacy results from pivotal clinical trials with abatacept.

Rheumatoid arthritis (RA) is a prevalent systemic disease that causes significant joint dysfunction and disability. Dramatic improvements in the management of RA have been achieved with the use of biologic therapies aimed at cytokines, and B and T lymphocytes. Abatacept, a soluble receptor-IgG fusion protein that interferes with T-cell co-stimulation, has now been shown to improve symptoms, signs and function in RA, while also slowing radiographic progression. The degree of improvement in these measures is comparable to that seen with other biologic agents.Abatacept is effective in a range of RA patients that are encountered in clinical practice, namely methotrexate-inadequate responders, as well patients with inadequate responses to tumor necrosis factor inhibitors and patients with co-morbidities common in an aging population. When used for up to 2 years, abatacept appears to be safe and remains efficacious, although there is a trend toward increased infection rates when used in combination with other biologic therapies, as well as a trend toward more adverse events when used in a background of chronic obstructive pulmonary disease. Backed by these data, ongoing extensions of these trials, and additional new studies, abatacept represents the first co-stimulation modulator approved for RA, and is a welcome addition to the biologic therapies available for the management of this disease.