Predicting the Clinical Response to Omalizumab With Anti-Immunoglobulin E (IgE) Ab Response or Syk Expression in Basophils

Inclusion Criteria: * Patients with moderate-to-severe asthma; male and females aged 18-75 who are symptomatic despite treatment with inhaled corticosteroids if they also had an asthma duration \> 1 year. * Positive blood testing to at least one common allergen (including must mite, D. F. and D. P., cockroach, dog or cat) * Serum IgE within the bounds of the dosing table (\>30 IU/ml to \< 700 IU/ml) * Reversibility of \> 12% within 30 minutes after administration of albuterol or history of reversibility in past or history of positive methacholine in past * Baseline Forced expiratory volume (FEV1) of \> 0% and \< 80% of predicted * Treatment with 400 to 800 ug day of beclomethasone dipropionate or its equivalent. * Patients must be willing to give written informed consent and be able to adhere to dose and visit schedules and meet trial requirements. * Patients will be excluded if they have prior sensitivity to omalizumab, and acute respiratory tract infection prior to or during the run-in period, or a need for regular B-agonist use. Exclusion Criteria: * Treatment with an investigational agent within 30 days of screening * Previously treated with omalizumab within a year prior to screening * Treatment 1 month prior to screening with: hydroxychloroquine, methotrexate, cyclosporine, cyclophosphamide, intravenous immunoglobulin G, and plasmapheresis * Clinically relevant laboratory anomalies at screening including individuals with reduced hematocrit (\<32%), White Blood Cell (WBC) count (2400/microliter), platelet count (\< 75000/microliter), and increased creatinine (\> 141.4 micromolar/L), or aminotransferase (AST) (\>100 IU/L). * Patients with current malignancy, history of malignancy, or currently under work-up for suspected malignancy, or bleeding disorder. * History of any medical condition that is unstable * Inability to comply with study and follow-up procedures * Patients may not take systemic corticosteroids within 2 weeks prior to screening\\ * Women of childbearing potential who are pregnant or nursing mothers, or who are of childbearing potential (post-menarche) and are not practicing an acceptable form of contraception ( as determined by the site investigator) * Individuals with body weight less than 30 kg or greater than 150 kg.