There have been considerable advances in the treatment of rheumatoid arthritis. However, many patients are found to be refractory to traditional disease-modifying antirheumatic drugs and the newer anti-cytokine therapies. Agents such as abatacept and rituximab now offer exciting new options for patients, including those who, until recently, had limited treatment options. Randomized, multinational, double-blind, placebo-controlled trials have assessed the efficacy and safety of abatacept in patients with active RA, who are methotrexate (MTX) and tumor necrosis factor (TNF) antagonist inadequate responders. Results from these trials have shown that abatacept provides significant clinical and health-related quality of life benefits in both MTX and TNF antagonist inadequate responders. Abatacept also slowed the progression of structural damage compared with placebo/ MTX alone. In addition to these clinical benefits, a fixed dose of abatacept has demonstrated a consistent safety and tolerability profile. Longer-term data will be necessary to confirm the observations seen to date.