Evaluating the Effect of Benralizumab in Severe, Poorly-controlled Eosinophilic Asthma Using Inhaled Hyperpolarized 129-Xenon MRI

This is an open-label, single arm, pilot study in patients with severe, poorly-controlled eosinophilic asthma to quantify hyperpolarized 129-Xenon MRI ventilation defect percent (VDP) before and after benralizumab therapy administered every 4 weeks for the first three injections (subcutaneous injection). Male and female patients between 18 and 70 years of age will be screened (Enrolment, Visit 1) and those that satisfy all inclusion and exclusion criteria will undergo five additional two-hour study visits (Visit 2=Day 0/baseline, Visit 3=Day 14±2 days and Visit 4=Day 28±2 days, Visit 5=Day 56±2 days, Visit 6=112±2 days) which will involve spirometry, plethysmography for airways resistance (Raw) and lung volumes, forced oscillation technique (FOT), multiple breath nitrogen washout (MBNW) for the lung clearance index (LCI) and 129-Xenon MRI pre- and post-bronchodilator, with the exception of Visit 5, which will not include MRIs. At all visits fractional exhaled nitric oxide (FeNO) will be measured pre-bronchodilator. The Asthma Control Questionnaire (ACQ-6), the Asthma Quality of Life Questionnaire (AQLQ) and the St. George's Respiratory Questionnaire (SQRQ) will be completed at all visits except Visit 3. Sputum induction will be performed on Visits 2 and 4 to measure sputum eosinophils, and blood samples will be performed on Visits 1 and 4 to measure blood eosinophils. Participants that satisfy all inclusion and exclusion criteria will complete a total of six study visits. Upon study enrolment, all participants will be allocated to a benralizumab treatment arm (30 mg injection after completion of study assessments on Visit 2/Day 0, Visit 4/Day 28 and Visit 5/Day 56). After Visit 6/Day 112, all participants will be offered participation in the AstraZeneca Patient Support Program to receive benralizumab therapy on Day 112 and every 8 weeks thereafter.