Treatment response to omalizumab in patients with refractory chronic spontaneous urticaria

Previous clinical trials have demonstrated the efficacy and safety of the anti-IgE monoclonal antibody omalizumab in chronic spontaneous urticaria (CSU) not responding to antihistamine treatment. The primary aim of our study was to describe the response patterns of patients with refractory CSU treated with omalizumab in a real-world clinical setting.

A retrospective analysis of medical records of 20 patients with refractory CSU was performed. Demographic, clinical, and laboratory features were retrieved and analyzed in correlation with treatment data.

Mean age of our patient population was 54.5 years, while the majority were females (15/20 cases, 75%). Mean disease duration prior to omalizumab administration was 21.8 months. All patients had a history of chronic urticaria, refractory to high antihistamine and corticosteroid treatment, and responded favorably to omalizumab after administration of 1-5 doses of omalizumab; complete response was observed in 17/20 patients (85%) and well-controlled disease in the remaining 3/20 patients (15%). In a subset of cases (6/20, 30%), best response to omalizumab was achieved after interval administration of a 9-day course of methylprednisolone (total dose of 188 mg). Late response to omalizumab (after three-month treatment) was significantly correlated (P = 0.026) with shorter disease duration before initiation of omalizumab.

In the present series, omalizumab, either alone or in combination with a short-term course of corticosteroids, was highly effective in resolution of refractory CSU. Furthermore, disease duration prior to omalizumab had a significant effect on timing of response.