Real world evidence on treatment of chronic spontaneous urticaria with omalizumab: Preliminary data

Dear Editor Chronic spontaneous urticaria (CSU) is defined by the presence of pruritic wheals and/or angioedema for at least 6 weeks and does not appear to be induced by any external stimuli. The safety and efficacy of omalizumab for the treatment of CSU has been demonstrated in previous clinical trials and in our previous observations. Omalizumab has been approved for the treatment of CSU by the European Medical Agency (300 mg every 4 weeks) and by the U.S. Food and Drug Administration (150-300 mg every 4 weeks). This is a longitudinal observational study of patients with refractory CSU, attending our Department of Dermatology at A.R.N.A.S. Civico Hospital of Palermo (Italy), who underwent omalizumab therapy between January 2016 and June 2018 at a dose of 300 mg every 4 to 6 weeks. Diagnosis of CSU was made by an experienced dermatologist and was based on currently available guidelines. Inclusion criteria were: clinician-confirmed diagnosis of CSU; persistence or recurrence of symptoms for at least 4 weeks after up-dosing (up to 4-fold the approved dose) of second-generation non-sedating H1-antihistamines and administration of repeated courses of oral corticosteroids; and omalizumab administration. We considered the following variables: age at diagnosis, gender, disease duration (from symptom onset to omalizumab treatment), history of angioedema and clinically relevant comorbidities, laboratory data including antinuclear antibodies (ANA), response to omalizumab. and the total number of omalizumab doses administered. We followed 68 patients (42 women, 26 men) with CSU treated with omalizumab: 25 (36.8%) experienced angioedema, 18 (26.5%) had hypertension, 9 (13.2%) had Hashimoto's thyroiditis, and 7 (10.3%) had diabetes. Positive ANA was found in 17.6% of cases (n = 12). Median age at the start of this study was 51 years (Q1-Q3: 38.5-63). Other demographic and clinical variables are shown in Table 1. The median weekly urticaria activity score (UAS7) prior to omalizumab administration was 20 (Q1-Q3: 20-30; min-max range 16-42). The median number of injections was 5.5 (Q1-Q3: 3-8), during the treatment periods. Fast responders (UAS7 reduction >50% after 3 months of therapy) were 45 patients (84.9%) out of 53 that had completed the three-month follow-up. Twenty-seven patients (60.0%) out of 45 had a good-to-excellent clinical response at the six-month follow-up: no association between ANA positivities and disease activity was recognized by logistic regression analysis. This study showed that omalizumab is safe and effective in reducing symptoms in most patients affected by refractory CSU. It should be noted that this study has some limitations, such as the number of subjects included and the short follow-up period. However, we report only preliminary data. Further data are needed for inference about long-term outcomes and predictors of clinical response in a more representative sample of patients.