Critical appraisal of efficacy and safety of abatacept in the treatment of refractory rheumatoid arthritis.

Rheumatoid arthritis is a chronic, progressive, autoimmune disease that leads to significant disability and premature mortality. Various treatment options are available, but the foundation of treatment includes nonbiologic and biologic disease-modifying antirheumatic drugs. The incidence of patients with rheumatoid arthritis refractory to first-line agents is estimated to be at least 20%. Abatacept, a T cell costimulation modulator, is the first agent to interfere with full T cell activation by competing with CD28 for binding of CD80 and CD86, which results in decreased secretion of proinflammatory cytokines and autoantibody production. Current American College of Rheumatology treatment guidelines recommend abatacept for patients with at least moderate disease activity and a poor prognosis demonstrating an inadequate response to other agents. Several key Phase III trials have been conducted to evaluate the efficacy and safety of abatacept in patients with an inadequate response to methotrexate or anti-tumor necrosis factor alpha therapy. Response rates in all trials showed statistically significant improvements compared with placebo according to American College of Rheumatology criteria for disease improvement. The most common adverse event report in patients receiving abatacept was infection; however, the frequency of adverse events was similar to placebo. Abatacept is a safe and effective rheumatoid arthritis treatment for patients with an inadequate response to methotrexate or anti-tumor necrosis factor alpha therapy.