Predictors of PASI90 response in patients with psoriasis treated with ınterleukin ınhibitors: observational cohort study.

Background: Psoriasis is a chronic multisystem disorder, and the inhibition of different cytokine pathways has been associated with different treatment responses.

Objective: To demonstrate independent predictors of PASI90 response in patients with psoriasis under biologic therapy and compare the effectiveness of different biologic classes METHODS: This cross-sectional study was conducted in a single tertiary center between January 2023 and May 2024 and included 623 patients (M/F: 320/303). PASI90 response was the primary end-point of the study, and PASI100 was the secondary end-point. Univariate and multivariate cox-regression analyses were used to identify predictors of PASI90. The efficacy of different biologic classes for achieving PASI90 and PASI100 responses was assessed using the Kaplan-Meier method.

Results: The age of disease onset (HR = 1.037, 95% CI [1.029‒1.044], p < 0.001) and being biologic-naïve (HR = 1.261, 95% CI [1.046‒1.521], p = 0.015) were identified as significant predictors of PASI90 response. IL23 inhibitors showed considerably superior efficacy in achieving PASI90 response than both TNF inhibitors (p = 0.042) and ustekinumab (p = 0.027). Also, IL17 inhibitors exhibited near-significantly higher effectiveness than TNF inhibitors (p = 0.090) and ustekinumab (p = 0.050). The performance of biologic classes was not substantially different in reaching PASI100 overall.

Study Limitations: The most important limitation of this study is the retrospective data collection.

Conclusion: Age of disease onset and being biologically naïve were positively associated with achieving PASI90 response, whereas ustekinumab use was negatively associated. Age of disease onset was the strongest predictor of PASI90. Also, IL23 and IL17 inhibition, especially IL23, appeared to provide a better therapeutic response.