A Phase III Study to Evaluate the Efficacy and Safety of Xolair® (Omalizumab) in Chinese Patients With Chronic Spontaneous Urticaria (CSU) Who Remain Symptomatic Despite Antihistamine Treatment

This was a randomized, multicenteric, double-blinded, placebo-controlled, parallel-group study to evaluate the efficacy and safety of omalizumab as an add-on therapy for the treatment of patients of refractory CSU who remained symptomatic despite approved-dosed H1AH treatment. The study consisted of three distinct epochs over 24 weeks: Screening epoch (Day -28 to Day -1), Randomized treatment epoch (Day 1 to Week 12) and Post-treatment follow-up epoch (Week 12 to Week 20). Patients were randomized into three treatment groups (omalizumab 300 mg s.c. omalizumab 150 mg s.c. and placebo) in a 2:2:1 ratio, stratified by latent tuberculosis (TB) status at Baseline (Yes/No). On Day 1, eligible patients were randomly assigned to receive omalizumab (150 mg or 300 mg) or placebo by subcutaneous (s.c.) injection every 4 weeks (on Day 1, Week 4, and Week 8) during the 12-week double-blind randomized-treatment epoch. Patients visited the study center at 4-week intervals. Patients were instructed to stay on the same CSU H1AH treatment at stable dose that they were using during the pre-randomization period during the randomized treatment epoch. They were allowed to use diphenhydramine as rescue medication during all epochs. The last dose of the study drug during the randomized-treatment epoch was administered at Week 8 study visit, however, the last assessment was done at Week 12. After the completion of the 12-week randomized-treatment epoch, all patients entered an 8-week post-treatment follow-up epoch.