Effect of Omalizumab (Xolair) on Basophils in Patients With Chronic Idiopathic Urticaria

The purpose of this study is to evaluate for changes in the proteins produced in white blood
cells (basophils) in patients with chronic hives who are treated with and respond to
omalizumab.

Inclusion Criteria:

- Chronic urticaria (hives) for more than 6 weeks.

- No improvement with standard doses of antihistamines (loratadine 10 mg daily,
desloratadine 5 mg daily, fexofenadine 180 mg daily, cetirizine 10 mg daily, or
levocetirizine 5 mg daily)

Exclusion Criteria:

- Taken any oral steroids for 1 month prior to beginning the study.

- Taken any other immunomodulatory drugs (sulfasalazine, hydroxychloroquine,
cyclosporine, methotrexate) for 1 month prior to beginning the study.

- Physical urticaria as a primary diagnosis.

- Known allergic precipitant of urticaria such as foods.

- Urticarial Vasculitis.

- Anemia.

- Asthma.

- Serum Immunoglobulin E (IgE) >700 IU/ml.

- Women of childbearing potential not using contraception method(s), as well as women
who are pregnant and/or breastfeeding.

- Known sensitivity to omalizumab or this class of drug.

- Use of any other investigational agent in the last 1 month.

- Untreated intercurrent illness.