Predictors of delayed treatment-free remission with omalizumab in chronic spontaneous urticaria

Background: Reliable biomarkers that predict delayed treatment-free remission with omalizumab in chronic spontaneous urticaria (CSU) remain unclear. Objective: The objective was to identify independent predictors of delayed treatment-free remission with omalizumab by comparing patients who achieved treatment-free remission with ≤ 12 doses with those who required > 12 doses. Methods: This single-center retrospective study included 163 adult patients with antihistamine-refractory CSU who were treated with omalizumab (300 mg every 4 weeks) between January 2018 and October 2025. Treatment discontinuation was considered only after at least six consecutive doses and complete disease control, defined as a urticaria control test (UCT) score of 16 with no wheals or angioedema. Treatment-free remission was defined as a symptom-free period of at least 6 months without pharmacotherapy after discontinuation. Patients were classified as having early remission (≤12 doses) or delayed remission (>12 doses). Demographic, clinical, and laboratory variables were compared, and multivariable logistic regression was performed. Results: Of the 163 patients (median age, 41 years; 60.1% women), 99 (60.7%) had delayed remission and 64 (39.3%) had early remission. Delayed remission was associated with a higher prevalence of autoimmune disease in the delayed remission group than in the early remission group (27.3% versus 12.5%; p = 0.025) longer symptom duration before omalizumab initiation (p < 0.001), and higher baseline total immunoglobulin E (IgE) levels (p < 0.001). In multivariable analysis, longer pretreatment symptom duration (odds ratio [OR] 1.023 [95% confidence interval {CI}, 1.009-1.038]; p = 0.002) and autoimmune disease (OR 2.984 [95% CI, 1.130-7.882]; p = 0.027) independently predicted delayed remission, whereas the total IgE value did not (p = 0.070). Conclusion: Longer pretreatment symptom duration and coexisting autoimmune disease were the strongest independent predictors of delayed treatment-free remission with omalizumab in CSU.