Efficacy and Safety Evaluation of Allergen Immunotherapy Co-Administered With Omalizumab, an Anti-IgE Monoclonal Antibody (ITN019AD)

Study start date: April 1, 2003

Inclusion Criteria * Able to comprehend and grant a witnessed, written informed consent prior to any study procedures. * Female participants of child bearing age must have a negative urine pregnancy test at Screening Visit and subsequent visits. In addition, female participants must be using a medically acceptable form of birth control. * History of seasonal allergic rhinitis for at least 2 years with symptoms during the ragweed pollen season requiring pharmacotherapy. * A positive skin test by prick method to ragweed pollen at the Screening Visit. A positive skin prick test will be defined as a ragweed pollen-induced wheal greater than 3 mm larger in diameter than diluent control (measurements will be made 15-20 minutes after application). * Must be capable of faithfully completing the diary and of attending regularly scheduled study visits. * Must intend to remain in the ragweed pollen area during the entire ragweed season. * Willing to avoid prohibited medications for the periods indicated in the protocol. * Participants must meet pretrial eligibility requirements for trial enrollment (acceptable medical history, physical examination results, normal electrocardiogram and acceptable laboratory test results). * Participants must have a baseline serum Immunoglobulin E (IgE) level greater than 10 and less than 700 IU/mL. Exclusion Criteria * weigh less than 30 kg or more than 120 kg. * pregnant or lactating. * history of severe anaphylactoid (non-IgE mediated) or anaphylactic reactions). * history of immunotherapy within the past 10 years, if received one full year of immunotherapy, or within the past 5 years if received less than one year of immunotherapy. * known hypersensitivity to trial rescue medication (fexofenadine HCl). * taking beta-adrenergic antagonists in any form. * taking allergic ophthalmologic medication. * clinically significant perennial rhinitis that would interfere in assessment of ragweed-induced seasonal allergic rhinitis symptoms. * Presence of a severely deviated nasal septum, septal perforation, structural nasal defect or large nasal polyps causing obstruction. * History of an upper respiratory or sinus infection requiring treatment with an antibiotic within 2 weeks prior to Screening Visit. * Documented evidence of acute or significant chronic sinusitis, as determined by the Investigator. * Asthma (either history of, abnormal spirometry, \[forced expiratory volume in 1 second (FEV1) less than 80% predicted\] or use of asthma medications). * Chronic or intermittent use of inhaled, oral, intra-muscular, or intra-venous corticosteroids; or chronic or intermittent use of topical corticosteroids within 4 weeks of Visit Screening Visit. * Chronic use of medications (e.g., tricyclic antidepressants) that would affect assessment of the effectiveness of the study medication. * Rhinitis medicamentosa. * History or presence of significant renal, hepatic, neurologic, cardiovascular, hematologic, metabolic, cerebrovascular, respiratory, gastrointestinal or other significant medical condition including, autoimmune or collagen vascular disorders, aside from organ-specific autoimmune disease limited to the thyroid that in the Investigator's opinion could interfere with the study or require medical treatment that would interfere with the study. * History of cancer other than basal cell carcinoma of the skin. * History within the past year of excessive alcohol intake or drug addiction. * Current smokers, greater than 10 pack year history, or participants who quit smoking less than one year prior to Screening. * Use of any prohibited concomitant medications during the washout period (i.e., before screening) and throughout the study period. * Participants currently undergoing immunotherapy. * Participants with clinically significant abnormality on 12-lead Electrocardiogram (ECG) on screening visit. * Treatment with an experimental, non-approved drug, or investigational drug within the past 30 days. * Participants with a history of noncompliance to medical regimens and participants who are considered potentially unreliable. * Previous treatment with a monoclonal antibody for any reason including anti-IgE in any form (e.g., omalizumab). * Participants with known hypersensitivity to trial drug ingredients (i.e., sucrose, histidine, polysorbate 20) or related drugs (i.e., monoclonal antibody; polyclonal gamma-globulin).