IntroductionIn the phase 3 SELECT-PsA 1 study, treatment with upadacitinib (UPA), an oral Janus kinase (JAK) inhibitor, improved signs and symptoms of psoriatic arthritis (PsA) from weeks 12 through 152. We now report the long-term extension phase, evaluating safety and efficacy of upadacitinib versus adalimumab (ADA) up to week 260 (~ 5 years).MethodsData on treatment-emergent adverse events and all primary and secondary endpoints were collected through week 260 for patients who received a placebo or ≥ 1 dose of UPA at either 15 mg (UPA15) or 30 mg (UPA30) daily, or ADA 40 mg every other week. For non-radiographic binary endpoints, both observed data and non-responder imputation methods were used, whereas for radiographic binary endpoints, the observed data method was used. For continuous endpoints, observed data and mixed-effects model repeated-measures analyses were employed.ResultsA total of 1704 patients received at least one dose of study drug, with 983 (57.7%) completing 260 weeks of treatment. The safety profile of UPA through week 260 was consistent with data from weeks 104 and 152. UPA treatment was associated with higher rates of serious infections, herpes zoster, lymphopenia, creatine kinase elevation, and non-melanoma skin cancer compared with ADA treatment. The exposure-adjusted incidence rates for major adverse cardiovascular events (n/100 PY [95% CI]: UPA15, 0.4 [0.2, 0.8]; UPA30, 0.4 [0.1, 0.9]; ADA, 0.3 [0.1, 0.7]) and venous thromboembolism (UPA15, 0.2 [0.0, 0.5]; UPA30, 0.4 [0.1, 0.9]; ADA, 0.2 [0.0, 0.6]) were low and comparable across treatment groups. Efficacy improvements observed with UPA at weeks 56 and 104 were maintained through week 260 and were comparable to those achieved with ADA.ConclusionsThe safety profile of UPA over 5 years remained consistent with that observed at weeks 104 and 152, with no new signals identified.Trial RegistrationClinicalTrials.gov identifier, NCT03104400.