Conditions: Chronic Idiopathic Urticaria
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 319
Healthy volunteers: no

Brief summary:
The study is a global Phase III, multicenter, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of omalizumab administered subcutaneously as an add-on therapy for the treatment of adolescent and adult patients aged 12-75 who have been diagnosed with refractory CIU and who remain symptomatic despite standard-dose H1 antihistamine treatment.

Detailed description:
Type I Error Rate Control Plan

Primary Outcome Measure

In order to maintain an overall type I error rate of 0.05 (2-sided) across the 3 omalizumab dose levels, the testing of the primary Outcome Measure was conducted in the following hierarchical order. A p-value \< 0.05 is only considered statistically significant if statistical significance was claimed at the previous stage.

* Stage 1: Omalizumab 300-mg group vs. placebo
* Stage 2: Omalizumab 150-mg group vs. placebo
* Stage 3: Omalizumab 75-mg group vs. placebo

Secondary Outcome Measures

A hierarchical analysis of the following secondary Outcome Measures was performed for each dose found to be significant in the primary Outcome Measure. A p-value \< 0.05 is only considered statistically significant if statistical significance was claimed at the previous stage.

* Stage 1: Change from baseline to Week 12 in the urticaria activity score over 7 days (UAS7)
* Stage 2: Change from Baseline to Week 12 in the weekly number of hives score
* Stage 3: Time to minimally important difference (MID) response in the weekly itch severity score by Week 12
* Stage 4: Percentage of participants with a UAS7 score ≤ 6 at Week 12
* Stage 5: Percentage of weekly itch severity score MID responders at Week 12
* Stage 6: Change from Baseline to Week 12 in the weekly size of the largest hive score
* Stage 7: Change from Baseline in the overall dermatology life quality index (DLQI) score at Week 12
* Stage 8: Change from Baseline in the overall dermatology life quality index (DLQI) score at Week 12
* Stage 9: Percentage of complete responders (UAS7 = 0) at Week 12

Arms:
arm 1: Participants received placebo subcutaneously every 4 weeks during the 24 week treatment period. arm 2: Participants received omalizumab 75 mg subcutaneously every 4 weeks during the 24 week treatment period. arm 3: Participants received omalizumab 150 mg subcutaneously every 4 weeks during the 24 week treatment period. arm 4: Participants received omalizumab 300 mg subcutaneously every 4 weeks during the 24 week treatment period.

Interventions: intervention 1: Omalizumab intervention 2: Placebo
Intervention descriptions: intervention 1: Omalizumab was supplied as a lyophilized, sterile powder in a single-use vial. intervention 2: Placebo was supplied as a lyophilized, sterile powder in a single-use vial without study drug.

Protocol document: