Analysis of the Pharmacoutilization of Biological Drugs in Psoriatic Arthritis Patients: A Real-World Retrospective Study Among an Italian Population

Introduction: Real-world pharmacoutilization analysis of biological drugs in psoriatic arthritis (PsA) patients with the aim to evaluate biologic treatment patterns and pharmacoutilization among patients with PsA in Italy. Methods: A retrospective study was conducted using administrative databases of Italian Entities. PsA patients were included and diagnosed by hospitalization and/or an active exemption code. Two analyses were performed: a cross-sectional for treatment patterns in patients enrolled among 2017–2020, and a longitudinal study during 2015 to investigate the pharmacoutilization, in terms of persistence and monthly maintenance dosage of biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). Patients with or without b/tsDMARDs prescriptions before inclusion were defined as bioexperienced or naïve, respectively. An analysis on ixekizumab-treated patients (IXE patients) from the 2017-to study ending was performed. Results: PsA was diagnosed in 24,786 (2017), 27,221 (2018), 28,889 (2019), and 29,292 (2020) patients. Across 2017–2020, 31.1–40.5% of PsA patients were untreated with systemic medications, and 16.4–18.8% were under biological therapies. Among b/tsDMARD-treated patients, decreasing use of TNF-inhibitors (77.6–57.1%) and increasing IL-inhibitors (19.6–33.2%) was found across 2017–2020, respectively. Persistence to TNF-inhibitors and IL inhibitors as first-line ranged, respectively, 74.9–83.0% and 73.0–84.6%; specifically, 73.1–76.9% and 73.0–83.8% among bio-naïve, 83.3–90.0%, and 87.0% among bio-experienced. Among IXE-patients (N= 178), 55.6% were bio-naïve, while 21.9% previously used secukinumab, 12.9% adalimumab, 10.1% etanercept. During a 1-year follow-up, 6.8% of IXE patients switched therapy. Conclusions: This real-world study of PsA pharmacoutilization in Italy showed that more than one-third of patients were systemically untreated, and almost 20% were receiving biological medications. Among biological users, increasing use of IL-inhibitors and a decrease in TNF-inhibitors prescriptions over the years were found. A rather-high extent of persistency in treatment was observed. A focused analysis on IXE patients revealed over half of them to be bio-naïve, while around one-fourth were bio-experienced to IL inhibitors.