The Effect of Omalizumab on Responses to Cat Allergen Challenge

Inclusion Criteria

• Ability to understand and provide informed consent
• Male or Female (non-pregnant), age 18-50
• Females must be: Surgically sterile (hysterectomy, bilateral oophorectomy, bilateral tubal ligation), OR postmenopausal (at least 1 year since last menses), OR using a medically acceptable form of birth control throughout the duration of the study.
• Clinical history of seasonal or perennial allergic rhinitis for at least two years, with or without mild persistent asthma
• Positive puncture skin test greater than or equal to 5 mm diluent control
• Positive Immunocap to Fel d 1 > 0.35 kallikrein unit/L
• Positive intranasal cat allergen challenge as defined by > 5 sneezes or a tripling of measured nasal lavage mediators
• In vitro assay of basophil responsiveness to cat allergen with greater than 20% histamine release
• The use of antihistamines, cromolyn, leukotriene modifiers and other non-steroid (astelin and topical decongestants), nasal medications will be allowed, but they will be withheld for 5 days prior to each nasal allergen provocation session. Inhaled corticosteroids for mild asthma will be permissible.
• No known contraindications to therapy with omalizumab

Exclusion Criteria

• Asthma with forced expiratory volume at one second (FEV1) 141.4 micromolar/L, or aspartate aminotransferase (AST) > 100 IU/L
• Body weight less than 30 kg or greater than 150 kg will be excluded.
• Plans to become pregnant or breastfeed will be excluded from the study
• A perforated nasal septum, structural nasal defect, large nasal polyps causing obstruction, evidence of acute or chronic sinusitis
• A life expectancy less than 6 months
• A terminal illness as determined by the investigator
• A history of malignancy, anaphylaxis or bleeding disorder are also exclusion illnesses.
• Mental illness or history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements.
• Inability or unwillingness of a participant to give written informed consent or comply with study protocol
• Use of any investigational drugs within 8 weeks of participation
• Contraindications to omalizumab include patients with a previous hypersensitivity to omalizumab
• Recent recipient of any licensed or investigational live attenuated vaccine(s) within two months of study initiation such as flu mist.
• Prior use of omalizumab
• Frequent sinusitis (>2/ documented episodes per year) or active sinusitis within 2 weeks of enrollment
• Use of immunotherapy within the last 5 years