The Effects of Omalizumab (Anti-IgE) on the Late-phase Response to Nasal Allergen Challenge
Condition: Cat Allergy
MeSH terms: Hypersensitivity
Intervention: Omalizumab; Placebo
Intervention description: Injections subcutaneously (up to 3) every 2 or 4 wks based on the subjects weight and baseline total serum IgE level as approved for therapy in allergic asthma. Duration of therapy is approximately 14 wks.; Injections subcutaneously (up to 3) every 2 or 4 wks based on the subjects weight and baseline total serum IgE level as approved for therapy in allergic asthma. Duration of therapy is approximately 14 wks.
Intervention MeSH terms: Omalizumab
Phase: Phase 2
Study type: Interventional
Primary purpose: Basic Science
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Enrollment: 19.0
Sex: All
Minimum age: 18 Years
Maximum age: 50 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: cat allergy

Summary:

      This research is being done to study the effects of the drug omalizumab (Xolair) in people
      with cat allergies. The investigators will use omalizumab to study changes in the cells in
      the nose, cells in the blood and cells in the skin that cause allergies. The investigators
      will compare the changes in the nose to changes in the skin and blood cells.

      Objective: To test the hypothesis that treatment with omalizumab will decrease the nasal
      allergen challenge late-phase eosinophil count in nasal brushings at the time when blood
      basophils have become hypo-responsive to in vitro allergen exposure.
    

Eligibility criteria:

        Inclusion criteria:

          1. Male or female, ages 18-50

          2. Females must be surgically sterile or postmenopausal or using a specified acceptable
             form of birth control throughout the duration of the study. Females in certain
             categories (not sexually active, vasectomized partner) will be admitted at the
             discretion of the investigator on a case-by-case basis.

          3. Females must have a negative urine pregnancy test at Visit A and other visits
             specified in this protocol.

          4. Clinical history of perennial allergic rhinitis for at least two years, with or
             without seasonal allergic rhinitis, and with or without mild persistent asthma as
             define by the 2007 NAEPP guidelines.

          5. Allergic cat sensitization defined by a positive puncture skin test (mean wheal
             diameter 3 mm or more greater than diluent control), and a positive CAP-RAST to cat >
             0.35 kU/L.

          6. Positive intranasal cat allergen challenge defined by the induction of a total of ≥ 5
             sneezes at screening(criterion not applicable in the ancillary study).

          7. Baseline in vitro histamine release of peripheral blood basophils to cat allergen ≥7%.

          8. Peripheral blood basophils > two million per 100 ml of blood (criterion only
             applicable in the ancillary study)

        Exclusion Criteria:

          1. Asthma with baseline FEV1 < 80% predicted, and/or moderate to severe asthma
             classification per the 2007 NAEPP guidelines.

          2. Individuals with total serum IgE levels less than 30 IU/mL or greater than 700 IU/mL
             at the time of enrollment.

          3. Individuals with reduced hematocrit (< 32%), WBC count (2400/microliter), platelet
             count (< 75000/microliter), and increased creatinine (> 141.4 micromolar/L), or AST (>
             100 IU/L).

          4. Individuals with body weight less than 30 kg or greater than 150 kg.

          5. Pregnant females or females with plans to become pregnant or breastfeed during the
             duration of the study.

          6. Individuals with perforated nasal septum, structural nasal defects, large nasal polyps
             causing obstruction, evidence of acute or chronic sinusitis.

          7. History of malignancy, anaphylaxis or bleeding disorder.

          8. 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.

          9. Inability or unwillingness of a participant to give written informed consent or comply
             with study protocol.

         10. Use of any investigational drugs within 8 weeks of participation.

         11. Contraindications to omalizumab including patients with a previous hypersensitivity to
             omalizumab.

         12. Recent recipient of any licensed or investigational live attenuated vaccine(s) within
             two months of study initiation such as flu mist.

         13. Any prior use of omalizumab.

         14. Frequent episodes of acute sinusitis (>2 documented episodes per year) or active
             sinusitis within 2 weeks prior to enrollment

         15. Use of aeroallergen immunotherapy within 5 years prior to enrollment

         16. Current or within 4 weeks prior to enrollment use of nasal steroids, nasal cromolyn or
             oral steroids

         17. Past or current medical problems or findings from physical examination or laboratory
             testing that are not listed above, which, in the opinion of the investigator, may pose
             additional risks from participation in the study, may interfere with the participant's
             ability to comply with study requirements or may compromise the quality