Targeting axial and peripheral psoriatic arthritis: a retrospective observational study on the clinical relevance of upadacitinib

Objective: To evaluate upadacitinib (UPA) effectiveness on axial and peripheral manifestations of PsA by assessing the proportion of patients achieving low disease activity (LDA) and inactive disease (ID) status for axial involvement, and MDA and DAPSA-defined remission/LDA for peripheral domain. Methods: This retrospective study included PsA patients from 27 Italian rheumatology centres. Demographic, clinical and outcome data were collected at baseline, 6 and 12 months. Kaplan-Meier curves assessed treatment persistence. Multivariate models identified predictors of discontinuation and outcomes. Results: Among the 425 patients, 282 (66.4%) had peripheral PsA and 143 (33.6%) mixed (peripheral and axial) PsA. The 12-month UPA survival rate was 75.1%, higher in peripheral than mixed PsA (P = 0.039). Fibromyalgia was the strongest predictor of discontinuation (aHR 1.72; 95% CI: 1.08-2.75; P = 0.022). At 12 months, 38.2% of patients achieved ASDAS-LDA and 20.6% reached ASDAS-ID (LUNDEX-adjusted rates were 29.4% and 15.8%, respectively). The crude 12-month MDA rate was 59.9% (47.4% after LUNDEX adjustment). Enthesitis resolved in 80.2% of patients (P < 0.001), and NSAIDs use decreased to 32.9% (P < 0.001). Overall, VAS pain decreased significantly from 71.4 to 40 (mean change -31.4; 95% CI: -42.5 to -33.6; P < 0.0001), with a 44% reduction, well above the minimal clinically important improvement. No major cardiovascular events were reported; most adverse events were mild, including gastrointestinal intolerance (19%), infections (9.5%) and elevated liver enzymes (14.2%). Conclusion: Our study confirms UPA effectiveness across PsA domains, with clinically meaningful improvements in axial involvement and pain.