In this project, the investigators would like to learn if 24 weeks (about 5 and a half months) of omalizumab injections, given every 2 weeks, will be safe and effective for food allergic people who have a total immunoglobulin E (IgE) above the current FDA approved dosing regimen enabling a person to increase tolerance to the food(s) that the person is allergic to.

The investigators would also like to learn if participants who demonstrate increased tolerance to food after 24 weeks of omalizumab, can introduce the food into the diet utilizing an additional 8 weeks (about 2 months) of twice weekly omalizumab injections.

Inclusion Criteria:

• Age 1 to 55 years
• A positive prick skin test (PST) with a wheal ≥ 6 mm to at least one of the relevant foods (peanut, cashew, walnut, egg, milk, or wheat)
• Positive food-specific IgE (≥2.0 kilo units of allergen-specific IgE per liter (kUA/L)) to at least one of the study specific foods
• A weight / IgE level that would have excluded the participant from the OUTMATCH study based on the dosing table noted above
• Positive double-blind, placebo-controlled food challenge (DBPCFC) to one of the relevant foods at a cumulative dose of ≤144 mg (maximum tolerated dose ≤30 mg)

Exclusion Criteria:

• Clinically significant laboratory abnormalities at screening.
• Dose-limiting symptoms during the blinded food challenge to placebo during the screening DBPCFC.
• Poorly controlled or severe asthma/wheezing at screening
• History of severe anaphylaxis to participant-specific foods that will be used in this study, defined as neurological compromise or requiring intubation.
• Treatment with a burst of oral, intramuscular (IM), or intravenous (IV) steroids of more than two days for an indication other than asthma/wheezing within 30 days of screening.
• Currently receiving oral, IM, or IV corticosteroids, tricyclic antidepressants, or β-blockers.
• Past or current history of eosinophilic gastrointestinal disease within three years of screening.
• Past or current history of cancer, or currently being investigated for possible cancer.
• Past or current history of any food immunotherapy (e.g., oral immunotherapy (OIT), sublingual immunotherapy (SLIT), epicutaneous immunotherapy (EPIT) within 6 months of screening.
• Treatment with monoclonal antibody therapy, such as omalizumab, dupilumab, benralizumab, mepolizumab, reslizumab, tezepelumab, or other immunomodulatory therapy within 6 months of screening.
• Inability to discontinue antihistamines for minimum wash-out periods required for skin prick tests (SPTs) or oral food challenges (OFCs).
• Pregnant or breastfeeding, or intending to become pregnant during the study
• Evidence of clinically significant chronic disease.