Background:Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA).This study assessed the efficacy and safety of tofacitinib in Chinese patients with RA enrolled in Phase 3 and long-term extension (LTE) studies.Methods:ORAL Sync was a 1-year,randomized,placebo-controlled,Phase 3 trial.Patients received tofacitinib 5 or 10 mg twice daily (BID) or placebo advanced to tofacitinib 5 or 10 mg BID at 3 or 6 months.All patients remained on ≥1 background conventional synthetic disease-modifying antirheumatic drug.ORAL Sequel is an open-label LTE study (data-cut:March 2015;data collection andanalyses were ongoing,and study database was not locked at the time of analysis;study was closed in 2017).Efficacy outcomes:American College of Rheumatology (ACR) 20/50/70 response rates and Disease Activity Score in 28 joints using erythrocyte sedimentation rate (DAS28-4 [ESR]).Patient-and physician-reported outcomes:Health Assessment Questionnaire-Disability Index (HAQ-DI),Patient and Physician Global Assessment of Arthritis,and pain (visual analog scale).Safety was assessed throughout.Results:ORAL Sync included 218 patients;192 were subsequently enrolled into ORAL Sequel.In ORAL Sync,more patients achieved ACR20 (tofacitinib 5 mg BID,67.4％;10 mg BID,70.6％;placebo,34.1％) and DAS28-4 (ESR) ＜2.6 (tofacitinib 5 mg BID,7.1％;10 mg BID,13.1％;placebo,2.3％) with tofacitinib versus placebo at Month 6.Mean changes from baseline in HAQ-DI were greater with tofacitinib versus placebo at Month 6.In ORAL Sequel,efficacy was consistent to Month 48.Incidence rates for adverse events of special interest in tofacitinib-treated patients were similar to the global population.Conclusions:Tofacitinib significantly reduced signs/symptoms and improved physical function and quality of life in Chinese patients with moderate-to-severely active RA up to Month 48.The safety profile was consistent with the global population.Clinical Trial Identifier:NCT00856544 and NCT00413699.