D2.475 - Treatment delay and likelihood of remission on omalizumab in chronic spontaneous urticaria: a real-world observational study

Omalizumab is effective in chronic spontaneous urticaria (CSU), yet predictors of its’ efficacy remain uncertain. We aimed to assess if earlier initiation of biologic therapy is associated with higher likelihood of remission in patients with CSU.

Single-center real-world cohort of CSU patients treated with omalizumab. We reviewed all patients treated in our tertiary allergy centre to find responders (achieving complete CSU remission after 6 months of treatment), and non-responders (requiring omalizumab therapy for ≥2 years, with relapses on biologic therapy suspension). Treatment delay was defined as time from CSU diagnosis to first omalizumab dose. Groups were compared using Mann–Whitney test and logistic regression to assess associations between delay and remission.

Twenty-four patients were included in the study (15 responders; 9 non-responders). Responders were qualified earlier for biologic therapy than non-responders (median delay 13.9 months [IQR 9.4–23.3] vs 26.0 months [24.0–182.1]; p=0.083). In univariate logistic regression, longer delay was associated with lower odds of remission (OR per 12-month delay 0.85; 95% CI 0.70–1.03; p=0.091). After adjustment for age, sex, baseline UAS7 and DLQI (n=23), the association remained directionally similar (adjusted OR per 12-month delay 0.87; 95% CI 0.71–1.05; p=0.143).

In this real-world CSU cohort, earlier qualification for omalizumab showed a consistent trend toward higher remission likelihood, independent of baseline clinical severity measures, but did not reach statistical significance. Larger datasets are warranted to test a potential “window of opportunity” for biologic initiation in CSU.