Analysis of the Efficacy and Recurrence of Omalizumab Use in the Treatment of Chronic Spontaneous Urticaria and Chronic Inducible Urticaria

Introduction: Chronic urticaria (CU) is a common skin condition that can be divided into chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). Omalizumab is one treatment option for CU, but currently there are limited clinical studies of omalizumab's efficacy for treating CU in Chinese patients. This study sought to investigate the efficacy and safety of omalizumab treatment for CU patients in a Chinese patient population. Specifically, we aimed to compare the differential efficacy of omalizumab for CSU and CIndU patients and predict risk factors for recurrence. Methods: We completed a retrospective clinical data review of 130 CU patients who received omalizumab treatment from August 2020 to May 2022, with a maximum follow-up period of 18 months. Results: A total of 108 CSU patients and 22 CIndU patients were included in the study. After treatment with omalizumab, the response rate in the CSU group was higher than that in the CIndU group (93.5% vs. 68.2%), and CSU patients accounted for a higher proportion of responders and early responders (responders: 87.1% vs. 12.9%, p < 0.001; early responders: 95.7% vs. 4.3%, p = 0.001). Nonresponders had lower total immunoglobulin E (IgE) levels (75.0 vs. 167.5 IU/mL, p = 0.046) and a relatively shorter duration of treatment (1.0 vs. 3.0 months, p = 0.009) compared to responders. Early responders had shorter disease duration (1.0 vs. 3.0 years, p = 0.028), higher baseline UCT (4.0 vs. 2.0, p = 0.034), lower baseline DLQI (18.0 vs. 18.5, p = 0.026), and shorter total treatment time (2.0 vs. 4.0 months, p < 0.001) compared to late responders. All adverse events reported during treatment were mild. Seventy-four patients with CU discontinued the drug after achieving complete disease control, of which 26 (35.1%) relapsed for 2.0 months (interquartile range: 1.0-3.0 months). Compared with nonrelapsed patients, relapsed patients often had other allergic diseases (42.3% vs. 18.8%, p = 0.029), higher basal levels of total IgE (263.0 vs. 140.0 IU/mL, p = 0.033), and longer disease duration (4.2 vs. 1.0 years, p = 0.002). Relapsed patients could still achieve good disease control after restarting omalizumab therapy. Conclusion: Omalizumab was effective and safe for CSU and CIndU patients. Patients with CSU responded more quickly to omalizumab and showed a relatively better treatment effect. However, there was a possibility of relapse after discontinuation of omalizumab after complete control of CU, and in these cases, restarting omalizumab treatment after relapse was effective.