The purpose of this research study is to evaluate the safety of the study drug, tofacitinib (CP-690,550-10) at two doses (5mg and 10mg) compared to a tumor necrosis factor inhibitor (TNFi) drug (adalimumab in the US, Puerto Rico and Canada and etanercept in all other countries).

If you enroll in the study, you will be assigned by chance (like the flip of a coin) to receive either tofacitinib (5 mg twice daily or 10 mg twice daily) or a TNFi (adalimumab 40 mg injection every other week). Overall in the study subjects will have a 66% (2 in 3) chance of receiving tofacitinib and a 33% (1 in 3) chance of receiving a TNFi. Visits are outlined through Visit 22 (Month 60). However, the study may be extended beyond Month 60 or may be stopped earlier; your study team will keep you informed and tell you when you are scheduled for your next visit.