IntroductionEfficacy and safety of the Janus kinase (JAK) inhibitor upadacitinib (UPA) was evaluated in patients with psoriatic arthritis (PsA) through week 104 of the ongoing long-term extension of the phase 3 trial SELECT-PsA 1.MethodsExploratory analyses of all primary and secondary endpoints (non-responder imputation and as observed for binary endpoints; mixed-effect model repeated measures and as observed for continuous endpoints), and summary of treatment-emergent adverse events, in patients receiving UPA 15 mg (UPA15) or 30 mg (UPA30) once daily, or adalimumab 40 mg (ADA) every other week, through week 104 are reported.ResultsOf 1704 patients, 25.4% discontinued the study drug by week 104. Proportions of patients achieving ≥ 20%/50%/70% improvement in American College of Rheumatology criteria (ACR20/50/70), ≥ 75%/90%/100% improvement in Psoriasis Area and Severity Index (PASI75/90/100), or minimal disease activity (MDA) were maintained through week 104; greater responses by nominal P value were observed with UPA15 and UPA30 versus ADA for ACR20/50/70 and MDA. Mean change from baseline in modified total Sharp/van der Heijde Score (mTSS) was similar across groups and to week 56 results. The safety profile of UPA was generally comparable to ADA and not altered from week 56 data. Rates of serious infection, herpes zoster, anemia, neutropenia, lymphopenia, and elevated creatine phosphokinase remained numerically higher with UPA15 and/or UPA30 versus ADA. Rates of malignancies excluding non-melanoma skin cancer (NMSC), major adverse cardiovascular events, and venous thromboembolism were similar across groups; rates of NMSC were higher with UPA versus ADA. Two deaths were reported with UPA15, one with UPA30, and one with ADA.ConclusionsIn PsA patients, efficacy responses were similar or greater with UPA15 or UPA30 versus ADA through week 104, and inhibition of radiographic progression was maintained. No new safety risks were identified with exposure to UPA through 2 years (week 104).Clinical Trial RegistrationClinicalTrials.gov, NCT03104400.