OBJECTIVES: Psoriasis and psoriatic arthritis (PsA) are chronic inflammatory conditions treated with biologics such as TNF-α inhibitors, IL-12/23, IL-17 and IL-23. Spanish National Health System prioritizes anti-TNF drugs over interleukins. Aim was to assess budget impact of biologic medications on biologic-naïve patients with moderate-to-severe psoriasis or PsA in the Balearic Islands from the perspective of the Spanish National Health Service (SNS).

METHODS: Retrospective study on patients aged 18+ with moderate-severe psoriasis/PsA, naïve to biologicals, with at least 4 months of treatment, in six public hospitals in the Balearic Islands from January 2018 to December 2023. Recorded variables were sex, age, and diagnosis. Budget impact was assessed over three years, considering treatment persistence with each medication and potential second-line treatments. Annual cost calculations were based on the average number of pharmaceutical forms dispensed, treatment duration, and purchase costs as of May-2024.This was compared with a hypothetical scenario where all biologic-naïve patients had initiated with TNF-α inhibitors.

RESULTS: 986 patients were evaluated, being 54.5% male, and 73.7% diagnosed with psoriasis. Mean age was 53 years old (SD 13.39). 50,6% initiated treatment with TNF-α(adalimumab), 23,7% with IL-17 (secukinumab or ixekizumab), 20,6% with IL12/23(ustekinumab) and 4,9%(guselkumab). The 36-month persistence rates were: guselkumab(61%), ustekinumab(58%), secukinumab(52%), ixekizumab(50%), and adalimumab(48%). The log-rank test revealed no significant differences(p = 0.1) in persistence rates among the treatments.

CONCLUSIONS: This study highlights that, with no statistically significant differences in persistence, the best therapeutic strategy is to prioritize the use of TNF-α inhibitors as proposed by the SNS.