Clinical Experience of Risankizumab in Patients With a History of Erythrodermic Psoriasis

ABSTRACT Erythrodermic psoriasis (EP) is a severe and challenging variant of psoriasis that often shows poor drug survival. While risankizumab, an IL‐23 inhibitor, has demonstrated efficacy in patients with moderate‐to‐severe plaque psoriasis, its effectiveness in patients with a history of EP is less explored. This study aimed to evaluate treatment response to risankizumab and identify potential predictors influencing the treatment response. In this single‐center, longitudinal retrospective study, we included 56 patients treated with risankizumab between August 1, 2016, and June 1, 2023, of whom 22 had a history of EP. Treatment response was assessed using the Psoriasis Area and Severity Index (PASI), and the impact of patient characteristics, including prior biologic exposure and HLA‐Cw genotypes, on treatment response was analysed using the Mann–Whitney U test. Throughout the 100‐week follow‐up, patients with a history of EP exhibited a poorer treatment response compared to those without such a history. Among patients with a history of EP, those with prior exposure to guselkumab and those treated with more than five biologics demonstrated a decreased response to risankizumab. Additionally, there was a non‐significant trend indicating that HLA‐Cw1–negative patients responded better to risankizumab. This case series indicated that risankizumab might be an effective and sustainable treatment option for most patients with a history of EP. However, prior exposure to multiple biologics, particularly those with a similar mode of action targeting IL‐23, may reduce its effectiveness. The potential association between HLA‐Cw1 genotype and treatment response warrants further investigation.