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

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: NCT01723072). 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.