[Efficacy and safety of abatacept in patients with rheumatoid arthritis and no prior treatment with biologics].

Abatacept (ABA) is a recombinant human fusion protein that blocks co-stimulation signals on T lymphocytes, impeding their activation. Randomized and controlled trials examining efficacy and safety have been performed with ABA combined with methotrexate (MTX), vs MTX monotherapy and vs infliximab (IFB) combined with MTX in patients with Rheumatoid Arthritis and who are naïve to biologic therapy. ABA has shown to be more effective than MTX and at least as effective as IFB+MTX, in terms of activity and clinical remission, physical function and reduction in radiological progression. Safety data at 7 years have shown that the drug is comparable to MTX in monotherapy and safer than the IFB+MTX combination, although infections still constitute the main risk when using ABA. This review summarizes the safety and efficacy data of the AIM, ATTEST, Phase IIb IM101-100 and AGREE trials.