The Efficacy of Different Dosing Regimens of Omalizumab in children and adolescents with chronic spontaneous urticaria based on real-life data.

Introduction: Limited data are available regarding the effectiveness of different omalizumab dosing strategies in childhood chronic spontaneous urticaria (CSU). This study, aimed to investigate the efficacy of omalizumab initiated at different doses in children and adolescents with CSU based on real-life data.

Methods: This study was conducted at five academic medical centers in Turkey. Patient data were obtained from their file data. Omalizumab treatment was initiated at a dose of 150 mg every four weeks in 37 patients (60.7%) (Group 1) and 300 mg in 24 patients (39.3%) (Group 2).

Results: The mean age of patients was 14.4 ± 2.6 years (6.3¬-¬18 years), and female to male ratio was 2.2 (42/19). There was no difference between the mean initial UAS7 scores of Groups 1 and 2 (34 ± 8.8 and 34.6 ± 9.1, respectively) (p = 0.854). Groups 1 and 2 achieved an urticaria-free or well-controlled status at rates of 75.7% (n = 28) and 87.5% (n = 21), respectively, during the treatment period (p = 0.334). Group 2 achieved urticaria-free or well-controlled status in a shorter time than Group 1 (median: 1 month (1-3 months) and median: 2 months (1-4 months), respectively) (p = 0.036). The rate of patients who achieved urticaria-free status during the study period was 59.5% (n = 22) and 87.5% (n = 21) in Groups 1 and 2, respectively (p = 0.023). Seven patients in Group 1 (31.8%) and two patients in Group 2 (9.5%) experienced recurrence (p = 0.132). At the last evaluation, more patients in Group 2 (83.3%, n = 20) were urticaria-free than in Group 1 (48.6%, n = 18) (p = 0.008). A patient had an exacerbation of urticaria associated with omalizumab within the first 24 hours of the first dose, but this complication was not repeated. Other than dizziness in one patient, no different side effects were seen in our cohort of patients.

Conclusion: Omalizumab is an effective and reliable treatment option for childhood CSU. Urticaria-free or well-controlled status can be achieved in a shorter time by initiating treatment with a 300 mg/4 week regimen. Although this dose may need to be increased in most cases, control can be achieved with a dose of 150 mg/4 weeks in a significant number of patients.