Effectiveness of transitioning from omalizumab to dupilumab in chronic spontaneous urticaria patients with inadequate response to omalizumab

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.