[A novel treatment option in rheumatoid arthritis: abatacept, a selective modulator of T-cell co-stimulation].

Abatacept is the first drug in a new class of disease-modifying anti-rheumatic drugs known as selective modulators of T-cell costimulation. The efficacy of abatacept in the treatment of rheumatoid arthritis (RA) has been shown in several clinical phase II and phase III trials, wherein abatacept was used in monotherapy, either in combination with methotrexate (MTX) after MTX-failure, in combination with MTX after failure of anti-TNF-alpha therapy or in combination with TNF-alpha blockers. In addition, the combination of abatacept/MTX was directly compared with infliximab/MTX. Current data on abatacept demonstrate an encouraging safety profile of this drug. The number of adverse events in patients on abatacept is comparable to that in patients treated with other biologics. Severe infections, however, are more common in abatacept-treated patients than in placebo-treated patients. Opportunistic infections are rare in patients with abatacept and the frequency of malignancies is not higher than expected in RA-patients. Additional studies are now warranted to get more information on rare adverse events and long-term unwanted effects.