Abatacept: a T-cell co-stimulation modulator for the treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a debilitating autoimmune disease that has traditionally been treated with disease-modifying anti-rheumatic drugs (DMARDs). In the European Union (EU), patients who fail to respond to traditional DMARDs may receive tumor necrosis factor-alpha (TNF-alpha) antagonists. However, approximately one-third of patients fail TNF-alpha antagonists due to adverse effects or lack of efficacy, and there are limited treatment options available to these patients. As knowledge of the underlying immunopathology of RA evolves, new strategies for inhibiting the inflammatory process have emerged. It is well known that activated T cells play a key role in orchestrating the immunopathological mechanisms of RA. Inhibiting the full activation of T cells is a rational strategy in the treatment of RA and represents a novel method of inhibiting disease activity, distinct from inflammatory cytokine blockade. Here, the safety and efficacy of abatacept, a selective T-cell co-stimulation modulator recently approved in the EU, is reviewed in patients with RA who have shown an inadequate response to TNF-alpha antagonists. In a randomized, placebo-controlled, double-blind, phase III trial of patients with an inadequate response to TNF-alpha antagonism, abatacept was effective in improving the signs and symptoms of RA, as well as patient-centered outcomes, such as fatigue, disability, and other mental and physical aspects of health-related quality of life. These improvements were sustained through 2 years during the open-label, long-term extension period. In this trial, abatacept demonstrated a safety and tolerability profile similar to placebo. Taken together, these data suggest that selective co-stimulation modulation with abatacept may be a viable option for patients who are refractory to both traditional therapies and TNF-alpha antagonists.