Pfizer Inc. (NYSE:PFE) today announced that the ORAL Sync Phase 3 study (A3921046) of tofacitinib (development code: CP-690,550), formerly known as tasocitinib, an investigational, novel, oral JAK inhibitor, being studied in moderate-to-severe rheumatoid arthritis (RA), met its primary endpoints by showing statistically significant changes versus placebo in reducing signs and symptoms of RA, as measured by ACR20 response rates at six months; in improving physical function, as measured by mean change in HAQ DI at three months; and in reaching DAS28-4(ESR) <2.6 at six months. The safety profile of tofacitinib was consistent with that seen previously in the clinical program, and no new safety signal was detected. A full analysis of efficacy and safety data will be submitted to a future scientific meeting.