Xolair Enhances Oral Desensitization in Peanut Allergic Patients

We hypothesize that pretreatment with anti-IgE mAb will greatly reduce the side effects and
allergic reactions that occur during oral desensitization to peanut and will enhance the
development of oral tolerance in patients with severe peanut allergy.

Inclusion Criteria:

1. Patients with severe peanut allergy, between the ages of 7-25 years, having a history
of significant clinical symptoms within 1 hr of peanut ingestion.

2. Total IgE >50 kU/L but <2,0000 kU/L.

3. Sensitivity to peanut will be documented by a positive skin prick test result and
RAST test to peanut, with 20 kU/L as a lower limit for eligibility.

4. Patients must also fail a double blind food challenge with peanut at a dose of 100 mg
or less (after a cumulative dose of 186 mg), with minimal or no reactions to the
placebo challenge.

5. All female subjects of childbearing potential will be required to provide a urine
sample for pregnancy testing that must be negative one week before being allowed to
participate in the study.

6. Subjects must be planning to remain in the study area during the trial.

7. Subjects and/or their parents must be trained on the proper use of the Epi-Pen to be
allowed to enroll in the study.

Exclusion Criteria:

Due to the risk of serious systemic anaphylactic reactions to peanut in this study, we
will exclude:

1. Patients with acute infections, autoimmune disease, severe cardiac disease, and those
who are treated with beta-adrenergic antagonistic drugs (beta-blockers, which
increase the risk of more serious symptoms of anaphylaxis).

2. Subjects having a history of severe anaphylaxis to peanut requiring intubation or
admission to an ICU, frequent urticaria, or history consistent with poorly controlled
persistent asthma.

3. Total IgE > 2,000 IU/mL.

4. Subjects with unstable angina, significant arrhythmia, uncontrolled hypertension,
chronic sinusitis, or other chronic or immunological diseases that in the mind of the
investigator might interfere with the evaluation or administration of the test drug
or pose additional risk to the subject e.g. gastrointestinal or gastroesophageal
disease, chronic infections, scleroderma, hepatic and gallbladder disease, chronic
non-allergic pulmonary disease.

5. Subject with an FEV1 or PEF less than 80% predicted with or without controller
medication (if able to perform the maneuver) at screening, the oral desensitization
visit, or food challenge visit.

6. Subjects who have received an experimental drug in the last 30 days prior to
admission into this study or who plan to use an experimental drug during the study,
who are current users of oral, intramuscular, or intravenous corticosteroids, or
tricyclic antidepressants, or who are using medication that could induce adverse
gastrointestinal reactions during the study.

7. Subjects refusing to sign the EpiPen Training Form.

8. Pregnant or breast-feeding females.

9. Subjects with severe food associated eczema, dermatitis herpetiformis, eosinophilic
esophagitis, eosinophilic enteritis, proctocolitis, food protein induced
enterocolitis syndrome (FPIES) or other gastrointestinal diseases. These
requirements are necessary to limit the study to patients with primarily IgE mediated
peanut allergy, and to exclude patients with peanut sensitivity mediated by
cellular/T cell (non-IgE mediated) mechanisms.