• The primary efficacy endpoint (increase in airway neutrophils) will be assessed by comparison of the differences between sputum neutrophil influx after ozone (adjusted for post air challenge neutrophils) between omalizumab and placebo treated volunteers [ Time Frame: 16 weeks ] [ Designated as safety issue: No ]
  

• Differences in ozone induced changes in FEV1 and FVC between omalizumab and control groups [ Time Frame: 16 weeks ] [ Designated as safety issue: No ]
  
• Differences in mucociliary clearance and airway deposition between omalizumab and control groups [ Time Frame: 16 weeks ] [ Designated as safety issue: No ]
  
• Differences in ozone induced changes in sputum eosinophils between omalizumab and control groups [ Time Frame: 16 weeks ] [ Designated as safety issue: No ]
  

Week 0: Training and baseline studies day MCC (Dr. Bennett and MCC technician); blood draw for baseline studies, urine pregnancy test if applicable, treadmill training, spirometry, exercise testing with minute ventilation measurement, and sputum induction for baseline studies (SC)

Randomization of cohorts for study (SC):

1. Mild, mite sensitive asthmatics randomized to omalizumab
2. Mild mite sensitive asthmatics on placebo

Week 1: Visit for injection of omalizumab vs. placebo (injections carried out by CEMALB nurse; MD immediately available in facility) (see below for dosing of omalizumab); phlebotomy for baseline CBC with platelets; urine pregnancy test if applicable

Week 3: Visit for injection of omalizumab vs. placebo; urine pregnancy test if applicable

Week 5: Visit for injection of omalizumab vs. placebo (CEMALB nurse); urine pregnancy test if applicable

Week 7: Visit for injection of omalizumab vs. placebo; urine pregnancy test if applicable

Week 9: Visit for injection of omalizumab vs. placebo; urine pregnancy test if applicable

Week 11: Visit for injection of omalizumab vs. placebo, phlebotomy for CBC and platelets; urine pregnancy test if applicable

Randomization of chamber exposure order (for each cohort) (SC):

1. Clean, filtered air with mild exercise for 2 hours
2. 0.4 ppm O3 with mild exercise for 2 hours

Week 13: EXPOSURE PROCEDURES-SESSION 1

Day 1 (Pre-exposure):

1. Review medical history (30 min) (SC)
2. Pre-challenge spirometry (30 min) (SC)
3. Sputum induction (SC) for assessment of pre-challenge differential cell counts, CD11b, cell identification markers, samples for mucus and mediator assessments (30 min)
4. Phlebotomy for circulating cell surface markers, and for CBC and platelet count (30 min) (CEMALB nurse)
5. urine pregnancy test if applicable

Day 2 (Exposure to Air or 0.4 ppm Ozone for 2 hours):

1. Pre-challenge spirometry and symptom scoring (SC) and physical examination assessment (Investigator MD) (1 hr)
2. Begin 2 hours morning exposure/exercise protocol (15 minutes of mild exercise followed by15 minutes rest for total of 2 hrs, spirometry and minute ventilation 2 minutes after beginning each exercise session) (SC and Human Studies Facility exposure chamber staff) (see below for dosing of ozone)
3. Post-challenge spirometry and symptom scoring (SC)
4. Inhalation of 99mTc labeled particles and baseline imaging for MCC and C/P ratio (30 minutes) (Dr Bennett and MCC technician)
5. Gamma camera scintigraphy for assessment of MCC for 2 hours post inhalation (Dr Bennett and MCC technician). A lunch will be provided and subjects will have time to eat during part of this study day.
6. Methacholine challenge for NSBR (1 hr) (SC)
7. Administration of 2 puffs of albuterol
8. Sputum induction for assessment of post-challenge cell differential counts, CD11b, cell identification markers, samples for mucus and mediator assessments (30 min) (SC)
9. Phlebotomy for circulating cell surface markers (30 min) (CEMALB staff)
10. Overnight observation in GCRC if needed (for observation or treatment for adverse event as defined below under Safety Measures). (CEMALB nurse and Investigator MD)

Day 3 (followup gamma scan)

1. Return next morning for 30 min gamma camera scan. (Dr Bennett and MCC technician)
2. Symptom scoring and dismiss home (SC), Physical assessment

THREE WEEK WAITING PERIOD (+/- 1 WEEK)

Week 16: EXPOSURE PROCEDURES-SESSION 2

Similar to Session 1 except with opposite (air or ozone) exposure regimen.

Study Discontinuation Visit (5-10 days after last exposure) History, spirometry (SC), medical evaluation if needed (Investigator MD)

Dosages of ozone and omalizumab

Ozone:The 0.4 ppm ozone exposures will be conducted in an ozone exposure chamber. Each subject will be exposed to ozone for 2 hours. During exposures, subjects will perform four 15 minute bouts of moderate exercise (minute ventilation or VE = 30 40 L/min) on a treadmill, each separated by 15 minutes of seated rest. Minute ventilation is measured for 2-3 minutes after about 4 minutes of exercise during the first exercise period, and again at about 12 minutes of exercise. It is then measured at about 12 minutes into each exercise period.

Omalizumab: Dosing for omalizumab will be consistent with doses approved for use in moderate or severe allergic asthma. The only exception to its indicated use is that we will be examining its effect in mild (rather than moderate or severe) allergic asthmatics, a group we have recruited for ozone challenge. IgE within the following ranges and body weights for subcutaneous omalizumab dosing:

1. IgE ≥30-100 int. units/mL: 30-90 kg: 150 mg every 4 weeks
2. IgE >100-200 int. units/mL: 30-90 kg: 300 mg every 4 weeks
3. IgE >200-300 int. units/mL:30-60 kg: 300 mg every 4 weeks >60-90 kg: 225 mg every 2 weeks
4. IgE >300-400 int. units/mL:30-70 kg: 225 mg every 2 weeks>70-90 kg: 300 mg every 2 weeks
5. IgE >400-500 int. units/mL:30-70 kg: 300 mg every 2 weeks>70-90 kg: 375 mg every 2 weeks
6. IgE >500-600 int. units/mL:30-60 kg: 300 mg every 2 weeks>60-70 kg: 375 mg every 2 weeks>70 kg: Do not administer dose
7. IgE >600-700 int. units/mL:30-60 kg: 375 mg every 2 weeks

Subjects for whom the IgE level and weight indicate that no dose will be given will be excluded from the study.