Off-label use of biologics in urticarial vasculitis: a European retrospective cohort study.

Objectives: Urticarial vasculitis (UV) is characterized by atypical urticarial lesions and leukocytoclastic vasculitis, sometimes with extracutaneous manifestations. First-line treatment is based on colchicine, hydroxychloroquine, dapsone or low-dose glucocorticoids. In refractory forms, the use of biologics has been anecdotally described as potentially effective. We aimed to describe the efficacy and safety of biologics in patients with UV.

Methods: We conducted a retrospective European multicentre study including patients with hypocomplementemic or normocomplementemic UV who received at least one biologic, including anti-CD20, anti-IgE and/or IL1-targeted therapy, from 2008 to 2021. We analysed clinical and biological characteristics as well as efficacy and safety of the biologics.

Results: Forty-one patients receiving 52 therapeutic sequences were analysed, including rituximab in 23, IL1-targeted therapy in 16 and anti-IgE in 13 cases. UV was hypocomplementemic in 24 (59%) cases. Biologics were used in median in fifth line of treatment, in combination with glucocorticoids in 75%. After a median follow-up of 25 (IQR 12-43) months, the cutaneous response was complete in 40%, partial in 37% and inadequate in 23%. Glucocorticoid discontinuation was achieved in 34% of patients. Serious adverse events, mainly infectious, were observed in 7 (17%) patients.

Conclusion: Biologics are an effective and rather well-tolerated treatment option for UV that are refractory to conventional therapies.