Study in Pediatric Subjects With Peanut Allergy to Evaluate Efficacy and Safety of Dupilumab as Adjunct to AR101 (Peanut Oral Immunotherapy)

Primary objective is to assess whether dupilumab as adjunct to AR101 compared to placebo improves desensitization at the completion of up-dosing, defined as an increase in the proportion of participants who pass a post up-dosing double-blind placebo-controlled food challenge (DBPCFC) at visit 16.

Secondary objectives are:

* To assess whether dupilumab as adjunct to AR101 compared to placebo improves desensitization at the completion of up-dosing, defined as an increase in the cumulative tolerated dose (log transformed) of peanut protein during a post up-dosing DBPCFC at visit 16
* To assess whether dupilumab as (indefinite \[continuously\]) adjunct to AR101 compared to placebo maintains desensitization, defined as an increase in the proportion of participants who pass a post maintenance DBPCFC at visit 22
* To assess whether dupilumab as (limited \[previously\]) adjunct to AR101 compared to placebo maintains desensitization, defined as an increase in the proportion of participants who pass a post maintenance DBPCFC at visit 22
* To evaluate the safety and tolerability of dupilumab as adjunct to AR101 compared to placebo
* To assess the effect of dupilumab (compared to placebo) as adjunct to AR101 on the change in peanut-specific Immunoglobulin E (sIgE), Immunoglobulin G (IgG), Immunoglobulin G4 (IgG4), and peanut-specific IgG4/IgE ratio
* To assess if dupilumab increases the tolerability of AR101 as measured by the daily symptoms (electronic diary \[e-diary\]) during the up-dosing phase


Eligibility Criteria:
Key Inclusion Criteria:

* Experience dose-limiting symptoms at or before the challenge dose of peanut protein on screening and not experiencing dose-limiting symptoms to placebo as defined in the protocol
* Serum Immunoglobulin E (IgE) to peanut of ≥10 kUA/L and/or a skin prick test (SPT) to peanut ≥8 mm compared to a negative control
* Participants/legal guardians must be trained on the proper use of the epinephrine autoinjector device to be allowed to enroll in the study
* Participants with other known food allergies must agree to eliminate these other food items from their diet so as not to confound the safety and efficacy data from the study

Key Exclusion Criteria:

* History of other chronic disease (other than asthma, Atopic Dermatitis (AD), or allergic rhinitis) requiring therapy (eg, heart disease, diabetes, hypertension) that would represent a risk to participant's health or safety in this study or ability to comply with study protocol
* History of frequent or recent severe, life-threatening episode of anaphylaxis or anaphylactic shock
* History of eosinophilic Gastrointestinal (GI) disease
* Asthma at time of enrollment with any of the following:

  * Forced Expiratory Volume 1 Second (FEV1) \<80% of predicted or ratio of FEV1 to forced vital capacity (FEV1/FVC) \<75% of predicted with or without controller medications
  * Inhaled corticosteroids (ICS) dosing of daily fluticasone (or equivalent ICS based on NHLBI dosing chart)
  * One hospitalization in the past year for asthma
  * Emergency room visit for asthma within 6 months prior to screening
* Use of systemic corticosteroids within 2 months prior to screening
* Use of other forms of allergen immunotherapy or immunomodulatory therapy within 3 months prior to screening
* Use of any agents known or likely to interact with epinephrine (eg, beta-blockers, angiotensin converting enzyme-inhibitors, tri-cyclic antidepressants, or other drugs), within 3 weeks prior to screening
* Allergy to oat (placebo in DBPCFC)

Note: Other protocol Inclusion/Exclusion Criteria apply