RT Journal Article T1 Biomarkers predicting the controller dose of omalizumab in patients with chronic spontaneous urticaria A1 Zubiaga- Fernandez, L. A1 Testera Montes, Almudena A1 Rondon, C. A1 Perez-Sanchez, N. A1 Gomez- Perez, F. A1 Vega-Chicote, J. M. A1 Bartra, Joan A1 Ferrer, M. A1 Eguiluz-Gracia, Ibón A1 Torres-Jaén, María Josefa K1 Alergia K1 Urticaria - Tratamiento AB BackgroundClinical trials showed the efficacy of 300 mg/4 weeks of omalizumab (OMA) during 6 months in patients with severe chronic spontaneous urticaria (CSU). Nevertheless, in real life, many patients require higher doses and/or longer treatment. This study assesses the real-life performance of OMA in severe CSU and identifies factors associated with the response.MethodsCSU patients eligible for OMA were recruited prospectively. Clinical data and a blood test were collected before OMA initiation. Urticaria Activity Score 7 (UAS7) was calculated at baseline and every 3 months during OMA treatment. CSU control was defined as UAS7 <7 points. This work was partially sponsored by OMA manufacturer.ResultsEighty-nine adults (19.1% males) with severe CSU were recruited. Median duration of CSU prior to OMA initiation was 2 years, and median severity by UAS7 at baseline was 24 points (range 10–42 points). OMA controlled 94.4% of patients, but 17.9% of responders required doses >300 mg/4 weeks. A blood basophil count >20 cells/μL (OR 13.33; 95% CI 3.32–52.63; p < .001) and the absence of hypothyroidism (OR 3.65; 95% CI 0.78–16.95; p = .099) were identified as predictive factors to achieve control with 300 mg/4 weeks. Twelve patients were able to stop OMA during the study (responders in remission, RR). RR had received OMA for a median of 29 months (12–53 months). Conversely, 32 patients had been on OMA for >29 months at the end of the study (active responders, AR). AR had received OMA for a median of 45 months (30–100 months). There were no significant differences in clinical or analytical factors between RR and AR patients.ConclusionsLow blood basophil count and the presence of hypothyroidism might serve as biomarkers for the controller dose of OMA in severe CSU patients. PB Wiley YR 2024 FD 2024-02-11 LK https://hdl.handle.net/10630/30407 UL https://hdl.handle.net/10630/30407 LA eng NO Zubiaga-Fernandez L, Testera-Montes A, Rondon C, et al. Biomarkers predicting the controller dose of omalizumab in patients with chronic spontaneous urticaria. Clin Exp Allergy. 2024;00:1-10. doi:10.1111/cea.14462 NO Funding for open Access charge: Universidad de Málaga / CBUA.Instituto de Salud Carlos III; Novartis Pharmaceuticals Corporation; Consejería de Salud y Bienestar Social, Junta de Andalucía DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 22 ene 2026