Prevalence of omalizumab-resistant chronic urticaria and real-world effectiveness of dupilumab in patients with omalizumab-refractory chronic urticaria: a single-centre experience.

Chronic urticaria (CU) is characterized by weals (hives) angio-oedema (or both) that last for ≥ 6 weeks, with chronic spontaneous urticaria (CSU) being the most common subtype. Patients with omalizumab-refractory CSU represent an unmet clinical need. In this study, we aimed to assess the prevalence and predictors of omalizumab failure in a large cohort of patients with CU and assess the effectiveness of dupilumab for omalizumab-refractory CU. Of 338 patients with CU, 33 received omalizumab; 69.7% (n = 23) were responders and 30.3% (n = 10) were nonresponders. Bivariate regression demonstrated that female sex [adjusted odds ratio (aOR) 1.53, 95% confidence interval (CI) 1.14-2.06], higher baseline weekly urticaria activity score (aOR 1.05, 95% CI 1.01-1.09) and older age (controlling for sex) (aOR 1.00, 95% CI 1.00-1.01) were associated with omalizumab failure. Of 10 patients with omalizumab-refractory CU, 3 were well controlled with ciclosporin (all children), whereas the 7 adults failed a mean [standard deviation (SD)] of 5.6 (2.6) treatments, including ciclosporin. All seven achieved a complete response with dupilumab, with time to response varying between 1 and 6 months. While our results suggest a favourable efficacy of dupilumab in patients with omalizumab-refractory CU, future confirmatory studies are required.