Grass Pollen Immunotherapy Plus Dupilumab for Tolerance Induction

Inclusion Criteria: * Participant must be able to understand and provide informed consent * A clinical history of grass pollen-induced allergic rhinoconjunctivitis for at least 2 years, with peak symptoms in May, June, or July * A clinical history of moderate to severe rhinoconjunctivitis symptoms for at least 2 years, interfering with usual daily activities or with sleep as defined according to the Allergic Rhinitis and Its Impact on Asthma (ARIA) classification of rhinitis * A clinical history of inadequately controlled rhinoconjunctivitis symptoms, despite treatment with antihistamines and/or nasal corticosteroids during the grass pollen season, for at least 2 years * Positive skin prick test response at screening, defined as wheal diameter ≥3 mm to Phleum pratense * Positive specific immunoglobulin E (IgE) at screening, defined as IgE class 2 (e.g., ≥ 0.7 kilounits per liter \[kU/L\]) against Phleum pratense * A woman of childbearing potential (WOCBP), regardless of birth control history, must: * have a negative serum pregnancy test at screening, * not be breast-feeding or lactating, and ---is required to consistently use one of the following highly effective methods of contraception throughout the study: * hormonal (e.g. oral, transdermal, intravaginal, implant, or injection), * intrauterine device (IUD) or system (IUS), * vasectomized partner, * bilateral tubal occlusion, or * sexual abstinence. Exclusion Criteria: * Inability or unwillingne…