A cohort study of guselkumab in the treatment of psoriasis refractory to previous biologic therapies: effectiveness, safety and adherence.

Background Guselkumab is indicated for moderate-to-severe plaque psoriasis. Data from real-life clinical practice regarding its use are scarce, especially concerning patients who relapse after previous biologic therapies. Aim This study aimed to evaluate the effectiveness, safety, and adherence to guselkumab in psoriasis refractory to biologic therapies. Method This real-life, retrospective study included patients who initiated guselkumab between February 2019 and October 2020. The main objective was to assess effectiveness, expressed as the psoriasis area and severity index (PASI) ≤5, ≤2 and 0, at the first follow-up medical visit. As secondary effectiveness outcomes, we assessed the body surface area (BSA) and dermatology life quality index (DLQI). We also evaluated adverse events and adherence (using the medication possession ratio [MPR]). Results The study included 35 patients who had previously received a median of two biologic drugs. The median basal PASI score (IQR) was 11 (7.3-15.9), decreasing to 0 (0-1.4) at first follow-up medical visit. At this point, 32 patients (94.1%) reached PASI ≤5, 28 (82.4%) PASI ≤2 and 19 (55.9%) PASI 0. We also found statistically significant improvements in PASI, BSA and DLQI at first follow-up (p<0.001). Three patients developed adverse events. Most patients (N=29, 85.3%) had an MPR ≥90%. The MPR was not associated with PASI score at first follow-up. Conclusion Our study supports evidence that guselkumab is an effective and safe drug in psoriasis refractory to biologic therapies. Adherence to treatment is not related to effectiveness, suggesting that, in some cases, the interval between doses could be increased.