Effect of omalizumab on angioedema in H 1 ‐antihistamine‐resistant chronic spontaneous urticaria patients: results from X‐ ACT , a randomized controlled trial

Abstract

Background: Chronic spontaneous urticaria ( CSU ) severely impacts quality of life (QoL), especially in patients with wheals and angioedema. Omalizumab is approved as add‐on therapy for CSU patients; however, its effect on patients who are double‐positive for wheals and angioedema has not been systematically studied. Objective: The primary objective was to evaluate the efficacy of omalizumab vs placebo at week 28 using the Chronic Urticaria Quality of Life ( CU ‐Q2oL) questionnaire. Number of angioedema‐burdened days, time interval between successive angioedema episodes, disease activity, angioedema‐specific and overall QoL impairment were secondary objectives. Methods: X‐ ACT was a phase III , randomized, double‐blind study conducted in 24 centres (Germany), which selectively included CSU patients with angioedema and wheals. Patients were randomized (1 : 1) to omalizumab 300 mg or placebo (every 4 weeks up to week 24) (ClinicalTrials.gov number: NCT 01723072). Results: Of the 91 patients randomized to omalizumab ( n = 44) or placebo ( n = 47) at baseline, 68 completed the 28‐week treatment phase (omalizumab, 35; placebo, 33). Omalizumab was superior to placebo in improving CU ‐Q2oL scores at week 28 ( P < 0.001). There was a threefold improvement in angioedema‐burdened days/week with omalizumab (0.3) vs placebo (1.1). The median time to first recurrence of angioedema was 57–63 days with omalizumab and <5 days with placebo. Omalizumab significantly improved angioedema‐specific QoL ( P < 0.001). The adverse events reported are in line with the established safety profile of omalizumab. Conclusion: Omalizumab was an effective treatment option for patients with moderate‐to‐severe CSU symptoms and angioedema unresponsive to high doses of antihistamine treatment.