Guselkumab Retention, Effectiveness, and Safety in Psoriasis: A 260‐Week Real‐World Multicenter Retrospective Study Exploring the Role of Concomitant PsA–IL PSO (Italian Landscape Psoriasis)

Introduction: Guselkumab is a monoclo- nal antibody targeting the p19 subunit of interleukin (IL)-23, approved for the treatment of moderate-to-severe plaque psoriasis and pso- riatic arthritis (PsA). While patients with pso- riasis often achieve high clinical response rates (Psoriasis Area and Severity Index [PASI] 90 and PASI 100), the presence of PsA may influence long-term outcomes. We conducted a 260-week, multicenter, retrospective study to compare the effectiveness, safety, and drug survival of guselkumab in patients with and without con- comitant PsA. Methods: A total of 1765 patients were enrolled, including 352 with a concomitant diagnosis of PsA and 1413 with isolated skin involvement. All patients were treated with guselkumab following the approved dosing schedule for moderate-to-severe plaque psoria- sis for at least 1 year. Treatment effectiveness was evaluated in terms of PASI 90, PASI 100, and absolute PASI ≤ 2 at weeks 16, 28, 52, 104, 156, 204, and 260. Guselkumab drug survival was assessed using the Kaplan–Meier method at the same time points. The safety profile was evaluated by analyzing adverse events recorded in medical charts at each follow-up visit. Results: Throughout the study period, response rates remained comparable between the two cohorts of patients, with a significant difference at 2 years of follow-up in terms of PASI 90 (80.51% versus 74.02%). Drug sur- vival overall remained stable and similar, with 79.5% (95% confidence interval (CI) 76.9–81.9) of patients without PsA and 78.5% (95% CI 72.9–83.1) of patients with PsA still receiving guselkumab treatment after 5 years. Conclusions: Our results confirm the long- term effectiveness, persistence, and favorable safety profile of guselkumab in patients with moderate-to-severe psoriasis, regardless of the presence of concomitant PsA.