Abstract
Dupilumab is effective for chronic spontaneous urticaria (CSU), but its clinical benefit of switching to dupilumab in omalizumab-resistant CSU remains unclear. This prospective pilot study evaluated the effectiveness of dupilumab in 12 CSU patients whose Urticaria Control Test (UCT) scores remained <12 after receiving at least 4 doses of omalizumab. Patients were transitioned to dupilumab after inadequate response to omalizumab. UCT scores were assessed at baseline, and 1 and 4 months after starting dupilumab. Laboratory parameters including eosinophil and basophil counts, total IgE, C-reactive protein, and anti-thyroid peroxidase antibody levels were also evaluated. The mean UCT score at the initiation of dupilumab was 6.5 ± 2.2, improving to 8.4 ± 3.0 at 1 month (P = 0.016) and 8.1 ± 3.9 at 4 months (P = 0.045), compared to 4.9 ± 3.1 before omalizumab treatment. Three patients achieved UCT ≥12 after switching to dupilumab. No significant differences were found in clinical characteristics or laboratory markers between effective and ineffective groups. Interestingly, 3 patients who returned to omalizumab after inadequate response to dupilumab achieved UCT ≥12. Dupilumab may improve disease control in a subset of omalizumab-resistant CSU patients. Further studies are needed to identify which patients benefit most from switching therapies.