The Effectiveness of Omalizumab Treatment in Real-Life is Lower in Patients with Chronic Urticaria Longer than 18 Months' Evolution and Prior Immunosuppressive Treatment

Abstract

Background: The efficacy of omalizumab in the treatment of chronic spontaneous urticaria has been demonstrated in phase iii clinical trials, but limited information is available regarding real-life effectiveness using the weekly Urticarial Activity Score (UAS7). The aim of the study was to assess clinical response (UAS7≤6) and complete response (UAS7=0) rates at weeks 12 and 24 in a real-life cohort and to identify possible predictors of response to omalizumab.

Methods: Clinical records of consecutive patients with moderate-to-severe chronic spontaneous urticaria (UAS≥16) treated with omalizumab at a university-affiliated reference dermatology department in Barcelona, Spain, from February 2014 to September 2017 were retrospectively reviewed. UAS7 values and patients' evolution were assessed according to a predefined protocol. Statistical analysis of data was done using SPSS 18 statistical package (SPSS 18 Inc., Chicago, IL, USA) software.

Results: Forty-eight patients were included in the study. All of them completed at least 24-weeks of treatment and follow-up. At week 12, clinical response rates (UAS7<6) were 70.8% and complete response rates (UAS7=0) were 47.9%. At week 24, clinical response rates were 64.6% and complete response rates were 52.1%.

Patients: with long-term urticaria (≥18 months' duration) were less likely to achieve a clinical response at week 12 (odds ratio: 0.25; 95% confidence interval 0.06-0.96). Previous immunosuppressive treatment tended to be associated with a lower probability of complete response at week 12 (odds ratio: 0.27 95% confidence interval: 0.07-1.02). H1-antihistamine treatment was associated with lower probability of response at week 24 (odds ratio: 0.1 95% 95% confidence interval: 0.01-0.88) CONCLUSIONS: The effectiveness and safety of omalizumab in real life are similar to efficacy and safety in clinical trials. Duration of disease, previous immunosuppressive therapy and requirement for concomitant H1-antihistamine treatment may be helpful in predicting response to omalizumab treatment.

Keywords: Chronic spontaneous urticaria; Omalizumab; Predicción; Prediction; Real life; Urticaria; Urticaria crónica espontánea; Vida real.