Update on the Treatment of Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is a mast cell-mediated skin disease that presents with wheals, angioedema, or both for more than 6 weeks. Less than 10% of patients have complete control of their CSU (the main goal of CSU treatment) with second generation H1-antihistamines, the first-line treatment. About 70% of patients with antihistamine-refractory CSU do not reach complete control with omalizumab, the second-line treatment. Novel therapies are especially needed for patients with mast cell-activating immunoglobulin (Ig)G autoantibodies (autoimmune CSU) associated with nonresponse or late response to omalizumab. Furthermore, there is a lack of disease-modifying treatments that induce long-term CSU remission after drug withdrawal. Several emerging treatments can address these unmet needs including Bruton tyrosine kinase inhibitors, e.g., remibrutinib and rilzabrutinib; anti-KIT monoclonal antibodies, e.g., barzolvolimab; and anti-cytokine therapies, e.g., dupilumab. In clinical trials, 30-31%, 28-32%, and 38-51% of patients with CSU showed complete response to treatment with dupilumab (phase 3, week 24), remibrutinib (phase 3, week 24), and barzolvolimab (phase 2, week 12), respectively. The most common adverse events were injection site reactions for dupilumab (12%), respiratory tract infections (11%), headache (6%), and petechiae (4%) for remibrutinib and changes in hair color (14%), neutropenia / decreased neutrophil count (9%) and skin hypopigmentation (1%) for barzolvolimab. This review provides an update on the current state of development of treatments for CSU.