Patients with moderate to severe allergic asthma who are poorly adherent to inhaled corticosteroids (ICS) have persistent airway inflammation that results in excessive morbidity and sometimes death. Omalizumab (OMB), an anti-IgE monoclonal antibody decreases the release of mediators from mast cells, reduces the frequency of exacerbations and allows a reduction in ICS dose. However, there are no data on the effects of OMB on airway inflammation. Bronchoprovocation with adenosine 5' monophosphate (AMP) is a robust and sensitive non-invasive measure of allergic airway inflammation, but the effect of OMB on this surrogate marker has not been previously reported. Based upon the mechanisms of actions of OMB and AMP and the fact that OMB will be administered at 2-4 week intervals in the clinic (i.e., direct observed therapy), it is our hypothesis that treatment with this new agent will reduce airway responsiveness to AMP and compensate for poor adherence to ICS.