ABSTRACT
Background/Aims Upadacitinib (UPA), an oral Janus kinase (JAK) inhibitor, demonstrated efficacy and safety in patients (pts) with psoriatic arthritis (PsA) and prior inadequate response or intolerance to >=1 biologic disease modifying antirheumatic drug (bDMARD) at week (wk) 56 in the phase 3 SELECT-PsA 2 study. We aimed to evaluate the efficacy and safety of UPA at wk 104 from the ongoing long-term extension of SELECTPsA 2. Methods Pts were randomized to UPA 15mg (UPA15), UPA 30mg (UPA30), or placebo (PBO) for 24 wks;PBO pts were then switched to UPA15 or UPA30. For continuous UPA treatment groups, efficacy endpoints at wk 104 were analyzed using non-responder imputation (NRI) and as observed (AO) (binary endpoints) or mixed-effect model repeated measures (MMRM) and AO (continuous endpoints). Treatmentemergent adverse events (TEAEs) were summarized for pts who received >=1 dose of study drug using visit-based cut-off at wk 104. Results A total of 641 pts received >=1 dose of study drug. At wk 104, 38.4% of all patients had discontinued study drug, with the highest discontinuation observed in patients randomized to PBO at baseline (all PBO: 46.7%). The most common reasons for discontinuation were lack of efficacy (UPA15: 12.3%, UPA30: 8.7%, all PBO: 21.7%) and adverse event (UPA15: 10.9%, UPA30: 13.3%, all PBO: 12.7%). The proportion of UPA pts that achieved ACR20/50/70, MDA, PASI75/90/100, and resolution of dactylitis and enthesitis were generally similar, or further improved, with 104 wks of treatment vs 56 wks. Similarly, mean change from baseline in HAQ-DI, patient's assessment of pain, BASDAI, and ASDAS was improved with UPA treatment. At 104 wks of therapy, clinical responses were largely similar with UPA15 and UPA30. Generally, safety data at wk 104 were consistent with that reported at wk 56. Rates of serious infection, herpes zoster, hepatic disorder, anemia, neutropenia, lymphopenia, and CPK elevation remained numerically higher with UPA30 vs UPA15, while rates of malignancies, MACE, and VTE were similar for both UPA groups. One death was reported with UPA15 (unexplained due to lack of information;however, the patient had recently been diagnosed with ovarian cancer) and two with UPA30 (pancytopenia and COVID-19 pneumonia). Conclusion In PsA pts with prior inadequate response or intolerance to>=1 bDMARD, clinical responses were maintained with UPA15 and UPA30 up to two years of treatment. No new safety signals were identified in this long-term extension.