Safety and efficacy of the selective costimulation modulator abatacept in patients with rheumatoid arthritis receiving background methotrexate: a 5-year extended phase IIB study.
Westhovens R, Kremer JM, Moreland LW, Emery P, Russell AS, Li T, Aranda R, Becker JC, Qi K, Dougados M. Safety and efficacy of the selective costimulation modulator abatacept in patients with rheumatoid arthritis receiving background methotrexate: a 5-year extended phase IIB study. J Rheumatol. 2009 Apr; 36(4):736-42.