OPTIMA: Efficacy of Optimized Re-treatment and Step-up Therapy With Omalizumab in Chronic Spontaneous Urticaria (CSU) Patients

Key Inclusion Criteria: * Men or women at least 18 years of age at time of screening. * Having a diagnosis of CSU and the presence of symptoms for ≥6 months prior to the screening visit. * Presence of itch and hives for ≥6 consecutive weeks at any time prior to the screening visit despite concurrent use of non-sedating H1-antihistamine treatment * Patient must have been on an approved dose of non-sedating H1-antihistamine for CSU, and no other concomitant CSU treatment, for at least the 7 consecutive days immediately prior to the randomization visit and must document current use on the day of the randomization visit. Key Exclusion Criteria: * Patients having a clearly defined underlying etiology for chronic urticaria other than CSU including the following urticarias: acute, solar, cholinergic, heat, cold, aquagenic, delayed pressure or contact * Patients with other skin disease associated with itch that could interfere with study outcomes and/or compromise the safety of the patient * Patients with evidence of parasitic infection * Patients with a history of malignancy of any organ system (other than localized basal cell carcinoma of the skin), treated or untreated, within the past 5 years, regardless of whether there is evidence of local recurrence or metastases. * Pregnant or nursing (lactating) women, * Women of child-bearing potential, unless they are using effective methods of contraception during dosing of study treatment. * Patients who are unable or unwilling to com…