Apremilast retention rate in clinical practice: observations from an Italian multi-center study

Objective There are few real-world setting studies focused on apremilast effectiveness (i.e., retention rate) in psoriatic arthritis (PsA). The main aim of this retrospective observational study is the assessment of apremilast 3-year retention rate in real-world PsA patients. Moreover, the secondary objective is to report the reasons of apremilast discontinuation and the factors related to treatment persistence. Methods In fifteen Italian rheumatological referral centers, all PsA consecutive patients who received apremilast were enrolled Anamnestic data, treatment history, and PsA disease activity (DAPSA) at baseline were recorded. The Kaplan-Meier curve and the Cox analysis computed the apremilast retention rate and treatment persistence-related risk factors. A p-value <0.05 was considered statistically significant. Results The 356 enrolled patients (median age 60 [interquartile range IQR 52-67] yrs; male prevalence 42.7%) median observation period was 17 [IQR 7-34] months (7218 patients-months). The apremilast retention rate at 12, 24, and 36 months was, respectively, 85.6%, 73.6%, and 61.8%. The main discontinuation reasons were secondary inefficacy (34% of interruptions), gastro-intestinal intolerance (24%), and primary inefficacy (19%). Age and oligo-articular phenotype were related to treatment persistence (respectively hazard ratio 0.98 IQR 0.96-0.99; p = 0.048 and 0.54 IQR 0.31-0.95; p= 0.03). Conclusion Almost three-fifths of PsA patients receiving apremilast were still in treatment after 3 years. This study confirmed its effectiveness and safety profile. Apremilast appears as a good treatment choice in all oligo-articular PsA patients and in those ones burdened by relevant comorbidities.