ObjectiveTo report 5-year efficacy and safety of upadacitinib (UPA) in rheumatoid arthritis (RA) from the phase III long-term extension (LTE) of SELECT-NEXT.MethodsPatients on stable conventional synthetic disease-modifying antirheumatic drugs were randomized to UPA 15 mg once daily (QD), UPA 30 mg QD, or placebo for 12 weeks. Following this, placebo-randomized patients were switched to UPA 15 mg QD or UPA 30 mg QD in the LTE; UPA-randomized patients continued their original dose. Blinding remained until dose switching from UPA 30 mg QD to UPA 15 mg QD because of approval of UPA 15 mg QD; the earliest switch occurred at week 168. Efficacy (as observed) and treatment-emergent adverse events (TEAEs) are reported through 5 years.ResultsOverall, 611 (92%) randomized patients entered the LTE; 271 (44%) discontinued the study drug by 5 years, primarily because of adverse events (16%). Clinical outcomes improved or were maintained at 5 years; 51% and 43% of patients achieved Clinical Disease Activity Index remission and 75% and 66% achieved Disease Activity Score in 28 joints based on C-reactive protein < 2.6 among those initially randomized to UPA 15 mg QD and UPA 30 mg QD, respectively. Proportions of patients achieving ≥ 20%/50%/70% improvement in American College of Rheumatology criteria responses increased from week 60 through 5 years. Results were similar regardless of initial randomization to UPA or placebo. TEAEs, including TEAEs of special interest, were consistent with earlier analyses and other SELECT studies. Malignancies (excluding nonmelanoma skin cancer), major adverse cardiovascular events, and venous thromboembolic events were reported infrequently. No new safety signals were observed.ConclusionThe 5-year benefit-risk profile for UPA in RA remains favorable. (SELECT-NEXT; ClinicalTrials.gov:NCT02675426)