Open Label Study to Assess Safety and Immunogenicity of Omalizumab Liquid Formulation.

Inclusion Criteria: * Patients 12 years old or above with moderate to severe allergic asthma * Body weight greater than 30kg and less than 150 kg and total serum IgE level greater than 30 to less than 700 IU/ml * Diagnosis of allergic asthma greater than 1 year duration, according to the American Thoracic Society criteria (14) and at screening, a history consistent with clinical features of moderate to severe persistent asthma. * Positive skin prick test (diameter of wheel is greater than 3mm) to at least one perennial allergen within the previous one year to visit 1, to which the patient will be exposed on a regular basis (most days) for the duration of the study. * No clinically significant asthma exacerbations that required treatment with systemic corticosteroids during the four weeks immediately prior to screening visit (Visit 1) and during screening period (between Visit 1 and 2) * Demonstrated evidence of inadequate asthma symptom control, despite treatment with ICS according to clinical features of moderate to severe persistent asthma. Exclusion Criteria: * Previous exposure to omalizumab * Previous exposure to other humanized proteins or monoclonal antibodies * Known HAHA to other monoclonal antibodies * History of hypersensitivity to any of the study drugs or to drugs with similar chemical structures * Known hypersensitivity to any ingredients, including excipients of the study medication or drugs related to omalizumab (e.g. monoclonal antibodies, polyclonal gamma globulin) * Active lung disease other than allergic asthma (e.g. cystic fibrosis, bronchiectasis) * Elevated serum IgE levels for reasons other than allergy (e.g. parasite infections, hyperimmunoglobulin E syndrome, Wiskott-Aldrich Syndrome or allergic bronchopulmonary aspergillosis)