ACR response rates with abatacept at 6 months in the ATTAIN study. *P = 0.003, **P < 0.001. Reproduced with permission from Genovese et al. N Engl J Med 2005, 353:1114–1123 . Copyright ©2005 Massachusetts Medical Society. All rights reserved. ACR, American College of Rheumatology; ATTAIN, Abatacept Trial in Treatment of Anti-TNF INadequate responders.