Treatment Switching and Drug Survival of Biologic Therapies in Psoriasis: A Real-World Italian Study Across Biologic Classes
Background/Objectives: Psoriasis is a chronic inflammatory skin disease leading to substantial
psycho-physical and social burden and reduced quality of life. Biologic agents
have transformed its therapeutic landscape. This real-world Italian study described the
pattern of treatment with biologic drugs in patients with psoriasis. Methods: A retrospective
observational study was conducted using administrative databases from Italian
Local Health Units, covering nearly 12 million individuals. The study included adults
with psoriasis identified from January 2015 to March 2025 by hospitalization, co-payment
exemption code, or topical anti-psoriatic prescriptions. Patients initiating a biologic drug
(anti-TNFα, anti-IL12/23, anti-IL17, and anti-IL23) were selected and further analyzed
in terms of treatment switching, drug survival, and healthcare resource utilization and
related costs within the first year after biologic initiation, and compared. Results: A total
of 10,270 biologic-naïve adult patients was included in the analysis (anti-TNFα N = 5078;
anti-IL12/23 N = 767; anti-IL17 N = 2574; anti-IL23 N = 1851). Most patients (95.0%) starting
an anti-IL23 agent did not switch. Compared with anti-TNFα, initiating an anti-IL23
inhibitor was associated with a significant reduced risk of switching (HR = 0.186; 95%CI:
0.144–0.240; p < 0.001). According to the cost analysis stratified by switching status, remaining
on the index biologic was associated with a lower economic burden. Although
differences between switchers vs. non-switchers among anti-IL23 users did not reach
statistical significance (€12,052 vs. €11,406, respectively, p = 0.132), data support the economic
advantage associated with greater treatment stability. Conclusions: Anti-IL23 agents
showed effective, durable first-line use with potential long-term clinical and economic
benefits in moderate-to-severe psoriasis.