Tezepelumab in Allergic Rhinitis and Asthma Study (TEZARS)

Overview

The goal of this clinical trial is to learn about how well tezepelumab (pronounced TEZ e PEL ue mab), a Health Canada-approved drug for severe asthma, works in participants with coexisting allergic asthma and allergic rhinitis (hayfever). The main questions it aims to answer are: * How well does the study drug work to reduce nasal symptoms following exposure to an allergen after 6 doses, and after 12 doses? * Does the study drug reduce chemicals found in the nose known to be involved in the allergic rhinitis response? Both allergic and non-allergic participants will be enrolled in the study. Non-allergic participants will: * Not be receiving the study drug. * Be exposed to allergen via the Nasal Allergen Challenge, which involves the administration of allergen extract directly to the nose. * Complete nasal symptom and quality of life questionnaires * Have nasal fluid and blood samples collected at various time points up to 24 hours following allergen exposure. * Visit the clinic 3 separate times: * At a screening visit to determine their eligibility to participate in the study * At the baseline Nasal Allergen Challenge visit * At the 24-hour post-Nasal Allergen Challenge follow-up visit Allergic participants will: * Receive one dose of tezepelumab every 1 month for 12 months. Tezepelumab will be administered as an injection into the fatty layer just beneath the skin on the stomach, arm, or thigh. * Be exposed to allergen via the Nasal Allergen Challenge, which involves the administration of allergen extract directly to the nose. * Complete nasal symptom and quality of life questionnaires * Have nasal fluid and blood samples collected at various time points up to 24 hours following allergen exposure. * Visit the clinic 17 separate times: * At a screening visit to determine their eligibility to participate in the study * At the baseline, 6-month, and 12-month Nasal Allergen Challenge visits * At each 24-hour post-Nasal Allergen Challenge follow-up visit * For each dose of the study drug The investigator will compare changes in nasal symptoms and allergic chemicals measured from nasal fluid and blood samples between non-allergic participants and allergic participants at baseline and at 6- and 12-months following the use of the study drug.

Tezepelumab is a novel monoclonal antibody that blocks thymic stromal lymphopoietin (TSLP), a molecule implicated in allergic disease. The purpose of this open-label, unblinded, exploratory mechanistic pilot study will be to evaluate the efficacy of tezepelumab (1 subcutaneous injection of 210mg given once every 4 weeks) in participants with moderate to severe allergic asthma and concomitant seasonal and perennial AR (SAR and/or PAR) over 12 months. The tezepelumab in allergic rhinitis and asthma study (TEZARS) is a single-centre study. The trial will enrol 14 non-pregnant/non-lactating female and/or male comorbid allergic rhinitis (AR) and allergic asthma participants ages 18 to 65 years old from the Kingston, Frontenac, Lennox and Addington regions. An additional 5 non-allergic participants will be enrolled to participate in the baseline Nasal Allergen Challenge (NAC) visit and then will exit the study. Comorbid AR and allergic asthma participants attend the baseline NAC, then receive one dose of tezepelumab every 1 month for 12 months. A 6-month post-treatment follow-up NAC will be conducted one month following the sixth dose. A 12-month post-treatment follow-up NAC will be conducted two weeks following the twelfth dose. At each NAC visit, symptom scores and quality of life questionnaires, in addition to nasal fluid and blood samples will be collected at various time points. The investigators hypothesize that tezepelumab will improve AR-related outcomes (TNSS; Peak Nasal Inspiratory Flow, PNIF; Rhinitis Control Assessment Test, RCAT) that are stimulated by NAC with seasonal and perennial allergens in our study population. Secondarily, the investigators hypothesize tezepelumab will decrease the release of allergic mediators (i.e., IL-1b, IL-3, IL-4, IL-5, IL-6, IL-8, IL-9 IL-10, IL-13, IL-18, MCP-1, TNFα, RANTES, eotaxin, tryptase, chymase) and alarmins (i.e., TSLP, IL-25, and IL-33) in the nose following NAC. A decrease in the gene expression of TSLP and mast cell mediators (tryptase and chymase) is also anticipated. Furthermore, the number of both nasal and peripheral eosinophils and total and specific immunoglobulin E (IgE) following NAC will decline after tezepelumab treatment. Five non-atopic controls will undergo baseline NAC to confirm the reliability of allergic mediator and alarmin methodologies. The investigators also hypothesize asthma-related outcomes (spirometry; Fractional Exhaled Nitric Oxide, FeNO; Asthma Control Questionnaire 5, ACQ5) will improve following treatment with tezepelumab. Finally, the NAC protocol in an asthmatic population will be assessed.