Objectives: This study evaluates the cost of biologic treatments for psoriasis (PsO) patients in Greece, focusing on bio-naïve and bio-experienced populations.

Methods: This observational, retrospective, longitudinal cohort study analyzed national prescription data from January 1, 2015, to December 31, 2020. Eligible patients had at least 2-years of available follow-up since January 1, 2016. Patients were bio-naïve or bio-experienced based on their treatment history during 2015. Persistent patients remained on their index drug (without gaps >90-days) during the follow-up (one- or two-years), while discontinuers stopped index treatment and did not receive any treatment during the remaining follow-up period. Costs were evaluated over 1- and 2-year follow-up periods. The cost was the quantity of medication packages dispensed to the patient during the follow-up period, multiplied by the corresponding invoice price of the package. Cost comparisons were performed using Dunn's Pairwise Comparisons with Bonferroni adjustment following Kruskal-Wallis tests.

Results: Among 3,830 bio-naïve patients, the mean 1-year cost per patient was €8,404 (95% CI: €8,293 – €8,510). Certolizumab Pegol had the lowest mean cost, while Secukinumab had the highest. Swithers and persistent patients incurred the highest costs, averaging €9,467 (95% CI: €9,002 – €9,886) and €9,907 (95% CI: €9,627 – €10,203), respectively. For the 2-year follow-up, the mean cost increased to €13,899 (95% CI: €13,690 – €14,095). For the bio-experienced population (N=1,681), the mean 1-year cost was €7,253 (95% CI: €7,085 – €7,436). Etanercept had the lowest costs, with Secukinumab being the most expensive. During the 2-year follow-up persistent patients had the highest costs, reaching the €12,400 (95% CI: €12,106 – €12,722).

Conclusions: The study highlights significant variability in biologic treatment costs for PsO, influenced by drug, persistence, and prior treatment history. These findings underscore the importance of balancing clinical efficacy and economic impact in treatment decisions for PsO, ensuring effective care while managing healthcare resources efficiently.