A Study to Evaluate the Efficacy, Response Duration and Safety of Xolair (Omalizumab) in Patients With Chronic Idiopathic Urticaria (CIU)/Chronic Spontaneous Urticaria (CSU) Who Remain Symptomatic Despite Antihistamine Treatment (H1)

Exclusion Criteria

• •Treatment with an investigational agent within 30 days prior to screening.
• •Weight \< 20 kg (44 lbs).
• •Clearly defined underlying etiology for chronic urticarias other than CIU.
• •Evidence of parasitic infection.
• •Atopic dermatitis, bullous pemphigoid, dermatitis herpetiformis, senile pruritus, or other skin disease associated with itch.
• •Previous treatment with omalizumab within a year prior to screening.
• •Routine doses of the following medications within 30 days prior to screening: Systemic or cutaneous (topical) corticosteroids (prescription or over the counter), hydroxychloroquine, methotrexate, cyclosporine, or cyclophosphamide.
• •Intravenous (IV) immunoglobulin G (IVIG), or plasmapheresis within 30 days prior to screening.
• •Regular (daily/every other day) doxepin (oral) use within 6 weeks prior to screening.
• •Any H2 antihistamine use within 7 days prior to screening.
• •Any leukotriene receptor antagonist (LTRA) (montelukast or zafirlukast) within 7 days prior to screening.
• •Any H1 antihistamines at greater than approved doses within 3 days prior to screening.
• •Patients with current malignancy, history of malignancy, or currently under work-up for suspected malignancy except non-melanoma skin cancer that has been treated or excised and is considered resolved.
• •Hypersensitivity to omalizumab or any component of the formulation.
• •History of anaphylactic shock.
• •Presence of clinically significant cardiovascular, neurological, psychiatric, metabolic, or other pathological conditions that could interfere with the interpretation of the study results and or compromise the safety of the patients.
• •Evidence of current drug or alcohol abuse.
• •Nursing women or women of childbearing potential, unless they meet the following definition of post-menopausal: 12 months of natural amenorrhea or 6 months of spontaneous amenorrhea with serum follicle-stimulating hormone (FSH) levels \> 40 milli-international units per milliliter (mIU/mL) or 6 weeks post surgical bilateral oophorectomy (with or without hysterectomy) or hysterectomy or are using one or more of the following acceptable methods of contraception: surgical sterilization, hormonal contraception, and double-barrier methods.