XTEND-CIU (Xolair Treatment Efficacy of Longer Duration in Chronic Idiopathic Urticaria): A Phase IV, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Omalizumab Through 48 Weeks in Patients With Chronic Idiopathic Urticaria

Study start date: May 18, 2015

Inclusion Criteria: * Diagnosis of CIU refractory to H1 antihistamines at baseline * Presence of itch and hives for at least 8 consecutive weeks at any time prior to enrollment despite current use of H1 antihistamine treatment (up to four times the approved dose) during this time period * UAS7 score (range 0-42) ≥ 16 and itch component of UAS7 (range 0-21) ≥ 8 during 7 days prior to baseline * Participants must have been on a non-sedating H1 antihistamine treatment (up to four times the approved dose) for CIU for at least 3 consecutive days immediately prior to screening visit with continued current use on the day of the initial screening visit * CIU diagnosis for ≥ 6 months * Willing and able to complete a daily symptom eDiary for the duration of the study Exclusion Criteria: * Treatment with an investigational agent within 30 days of the initial screening visit * Body weight less than 20 kilograms * Clearly defined underlying etiology for chronic urticarias other than CIU * Evidence of a parasitic infection * Atopic dermatitis, bullous pemphigoid, dermatitis herpetiformis, senile pruritus or other skin disease associated with itch * Previous treatment with omalizumab within 1 year prior to the initial screening visit * Participants may not have taken during treatment period or have been taking within 30 days before the initial screening visit any of the following medications or treatments: regular (daily/every other day during 5 or more consecutive days) systemic corticosteroids, hydroxychloroquine, methotrexate, mycophenolate, cyclosporine, cyclophosphamide, intravenous immunoglobulin G or plasmapheresis * Regular (daily/every other day) oral doxepin use within 14 days prior to the initial screening visit * Pregnant or lactating women, or women intending to become pregnant during the study