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 monoclonal antibody targeting the p19 subunit of interleukin (IL)-23, approved for the treatment of moderate-to-severe plaque psoriasis and psoriatic arthritis (PsA). While patients with psoriasis 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 concomitant 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 psoriasis 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 survival 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.