Study of Efficacy and Safety of Xolair® (Omalizumab) in Chinese Patients With Chronic Spontaneous Urticaria

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

The purpose of this study was to demonstrate the efficacy and safety of omalizumab, compared with placebo, as an add-on to H1 antihistamines (H1AH) therapy in adult patients suffering from Chronic Spontaneous Urticaria (CSU) who remained symptomatic despite H1AH therapy.

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.

Main Inclusion Criteria:

• Symptomatic CSU patients with CSU diagnosis for at least 6 months.
• Patients must have been on an approved dose of an H1AH for CSU for at least the 3 consecutive days immediately prior to the Day -14 screening visit
• Patients must have documented current use on the day of the initial screening visit

Main Exclusion Criteria

• Clearly defined underlying etiology for chronic urticarias other than CSU (main manifestation being physical urticaria)
• Other skin disease associated with itch Urticarial vasculitis, urticaria pigmentosa, erythema multiforme, mastocytosis, hereditary or acquired angioedema, lymphoma, leukemia, or generalized cancer