PO:04:054 | Clinical efficacy and drug retention rate of upadacitinib in patients with axial spondyloarthritis: results from a single-center observational study

Simona Buonanno¹, Carla Gaggiano¹, Caterina Baldi¹, Marco Bardelli¹, Cristiana Barreca¹, Francesca Bellisai¹, Marta Fabbroni¹, Paolo Falsetti¹, Anna Paola Pata¹, Enrico Selvi¹, Jurgen Sota¹, Antonio Vitale¹, Luca Cantarini¹, Bruno Frediani¹, Stefano Gentileschi¹ | U.O.C. Reumatologia, Dipartimento di Scienze Mediche, Chirurgiche e Neuroscienze, Università di Siena, A.O.U. Senese, Italy

Background. This single-center study aimed to evaluate the clinical efficacy of upadacitinib (UPA) in patients with axial spondyloarthritis (axSpA) and to assess its long-term treatment persistence. A secondary objective was to identify potential predictors of treatment persistence with UPA.

Materials and Methods. All adult patients diagnosed with axSpA and treated with UPA for at least six months were included. Clinical data were retrospectively collected at baseline and after 3, 6, and 12 months of therapy. Outcome measures included changes in disease activity assessed by ASDAS-CRP and BASDAI, pain intensity evaluated using a visual analogue scale (VAS), and functional limitation measured with the BASFI. The UPA drug retention rate (DRR) at 18 months was estimated using Kaplan–Meier survival analysis, and the influence of potential modifying factors was assessed using the log-rank test.

Results. A total of 49 patients (35 F, 14 M) with a mean ± SD age at baseline of 50.3 ± 12.7 years were included. Median (IQR) baseline values were: ASDAS-CRP = 3.2 (1.2), BASDAI = 6.5 (3.2), BASFI = 4.1 (3.2), and VAS-pain = 7.0 (3.0). From month 3 onward, there was a statistically significant reduction in median ASDAS-CRP (p < 0.01), BASDAI (p < 0.01), BASFI (p = 0.047), ESR (p = 0.02), and VAS-pain (p < 0.01). At month 6, further decreases were observed in ESR (p < 0.01), ASDAS-CRP (p < 0.01), BASDAI (p < 0.01), and BASFI (p = 0.02). A significant improvement in BASFI (p < 0.01) was also recorded between months 6 and 12, while the other parameters reached a plateau (Fig. 1). At the last follow-up, 85.4% of patients remained on UPA therapy; seven patients had discontinued treatment (n = 1 primary inefficacy; n = 5 adverse events). The UPA DRR at 6, 12, and 18 months was 95.5%, 85%, and 81.3%, respectively (Fig. 2). Sex (p = 0.32), BMI (p = 0.07), radiographic SpA (p = 0.88), prior bDMARDs use (p = 0.54), and fibromyalgia (p = 0.08) did not significantly affect treatment persistence.

Conclusions. This study confirms the efficacy of upadacitinib in achieving a rapid reduction in disease activity and pain among patients with axSpA, with significant improvements detectable from month 3 and progressive enhancement of functional capacity up to month 12. The observed DRR indicates sustained long-term effectiveness and a favorable tolerability profile, which appear to be independent of sex, BMI, treatment line, or coexisting fibromyalgia.