Effectiveness of omalizumab in chronic spontaneous urticaria assessed with patient‐reported outcomes: a prospective study

Abstract Aim To examine the effectiveness of omalizumab (anti‐IgE) on symptoms and disease‐related quality of life in chronic spontaneous urticaria ( CSU ) and to identify possible patient‐specific factors associated with response to omalizumab in patients with antihistamine refractory CSU . Methods Six months prospective trial of omalizumab 300 mg every 4 weeks among patients with CSU from a dermatological university department. The primary outcome was the urticaria activity score in the past week ( UAS 7) at 3 months. Results A total of 117 patients (39 men and 78 women) with a mean age of 42 years were included. The mean baseline UAS 7 score was 29.3 points ( SD = 10.8), which improved to 11.9 points ( SD = 12.9) at 3 months follow‐up, difference = 17.4 points (95% CI : 14.8–19.9), P < 0.0001. Other patient‐reported outcomes ( PRO s) also improved significantly during 3 months of treatment. No significant further improvement was seen between three and 6 months follow‐up. None of the following patient‐specific factors: sex, age, age of onset of CSU , symptom duration, presence of chronic inducible urticaria ( CINDU ), comorbidities, positive urticaria HR test, smoking, ethnicity, angio‐oedema, serum total IgE level, CRP , leucocytes, absolute neutrophil count or previous treatment with prednisolone or montelukast were significantly associated with response to omalizumab at 3 months, P > 0.05 for all comparisons. Previous treatment with traditional immunosuppressant drugs (azathioprine, cyclosporine or methotrexate) was associated with poorer treatment response to omalizumab at 3 months, P < 0.001. A strong correlation was seen between different patient‐reported outcomes ( PRO s) at baseline and 3 months follow‐up. Fifteen patients (12.8%) reported side‐effects of the treatment. Conclusion Omalizumab is a highly effective therapy for antihistamine refractory CSU with treatment effects similar to those observed in randomized controlled trials. Validated PRO s to assess disease activity, disease control and impairment of quality of life are valuable tools in the clinical management of CSU . Identification of patient‐specific predictors of effect and safety of omalizumab in CSU is still warranted.