Omalizumab to Accelerate a Symptom-driven Multi-food OIT

Participants will receive omalizumab 16 mg/kg monthly doses for 12 weeks, followed by omalizumab 8 mg/kg monthly for 4 weeks and then omalizumab 4 mg/kg monthly for 4 weeks, for a total of 20 weeks including a taper period.

Participants will receive omalizumab 8 mg/kg monthly doses for 12 weeks, followed by omalizumab 4 mg/kg monthly for 4 weeks and then omalizumab 2 mg/kg monthly for 4 weeks, for a total of 20 weeks including a taper period.

Participants will receive placebo for 8 weeks prior to the initiation of oral immunotherapy and 12 weeks after for a total of 20 weeks including a taper period.

Multi-food oral immunotherapy will be conducted to a mix of three foods. It will be started 8 weeks after study drug with an initial food escalation. Participants will undergo biweekly increase until they tolerate a maintenance dose of 1500 mg (500 mg per food) of food protein.