D2.471 - Efficacy of omalizumab in the treatment of chronic spontaneous urticaria in children

The monoclonal anti-immunoglobulin E (IgE) antibody, omalizumab, was the first drug approved for use in patients with chronic spontaneous urticaria (CSU) who remain symptomatic despite H1 -antihistamine treatment. Omalizumab binds to free IgE, which lowers free IgE levels and causes FcεRI receptors on basophils and mast cells to be downregulated. 

At the University Children’s Clinic, during the period from January 2023 to January 2026, omalizumab was administered in the treatment of 11 patients aged 10–17 years. All patients had a previously established diagnosis of chronic spontaneous urticaria. Prior to the initiation of biologic therapy, treatment with H1-antihistamines had been administered for a minimum duration of 8 weeks at up to fourfold standard doses. At baseline, total serum IgE levels were measured, and disease activity was assessed using the standardized UAS7 (Urticaria Activity Score over 7 days). All patients had a baseline UAS7 score >16 prior to the initiation of omalizumab therapy. The dosing interval was 4 weeks, with the possibility of interval shortening to 2 weeks depending on the level of disease control achieved

After 6 months of omalizumab therapy, all patients demonstrated a reduction in UAS7 scores. Complete disease control (UAS7 = 0) was achieved in 54.5% of patients. Five patients (36.4%) required more than 12 doses of omalizumab to achieve adequate disease control. Total serum IgE levels ranged from 33 to 267 IU/mL. Elevated total serum IgE levels (>250 IU/mL) were observed in 27.3% of patients, all of whom achieved complete disease control following omalizumab therapy. Among patients with low total IgE levels, 40% required shortening of the dosing interval.

Omalizumab therapy proved effective in achieving disease control in patients with chronic spontaneous urticaria. Patients with lower IgE levels are more likely to be non-responders to omalizumab and therefore required updosing more often than the patients without