Omalizumab in patients with chronic spontaneous urticaria nonresponsive to H1-antihistamine treatment: results of the phase IV open-label SUNRISE study

Abstract

Background: Omalizumab is approved as an add-on therapy for the treatment of chronic spontaneous urticaria (CSU) in patients with inadequate response to H1-antihistamine treatment. The urticaria control test (UCT) is a reliable, concise tool developed as an alternative to the 7-day urticaria activity score (UAS7) - the standard for CSU disease activity assessment.

Objectives: This prospective, open-label, phase IV study evaluated the efficacy and safety of omalizumab in French adult patients with CSU nonresponsive to H1-antihistamine treatment.

Materials and methods: Patients [n = 136; stratified 1 : 2 (with angio-oedema : without angioedema)] received omalizumab 300 mg subcutaneously every 4 weeks for 12 weeks. Study assessments included UCT, UAS7, angio-oedema activity score and d-dimer levels (exploratory objective).

Results: At Week 12, 74·6% of the patients achieved disease control [UCT score ≥ 12 (primary endpoint)] and 67·7% of patients showed well-controlled disease (UAS7 ≤ 6). There was a strong negative correlation between UCT score and UAS7 at Week 12 (Spearman's correlation coefficient -0·839). Mean plasma d-dimer concentration was elevated at baseline (1002·1 ng mL^-1 ) and decreased notably at Week 8 (455 ng mL^-1 ). Among the nine patients with a very high baseline d-dimer concentration (> 3000 ng mL^-1 ), eight were responders (UAS7 ≤ 6) at Week 12.

Conclusions: Omalizumab was efficacious in patients with CSU nonresponsive to H1-antihistamines. The UCT was a reliable tool for disease assessment and the scores correlated well with UAS7. This study does not support the usefulness of d-dimer to monitor long-term disease prognosis in adult urticaria; however, it may indicate patients who respond to omalizumab.