Phase II Study to Evaluate the Effect of AZD4604 on Airway Inflammation and Biomarkers in Adults With Asthma

This is a multicentre, randomised, placebo-controlled, double-blind study to investigate the effect on airway inflammation and JAK1-associated signalling pathways of AZD4604, administered over a 4-week treatment period to adult patients with moderate-to-severe asthma. The study will recruit patients receiving treatment with medium-to-high dose inhaled corticosteroid-long-acting beta-agonist (ICS-LABA) at screening and having a history of at least one severe asthma exacerbation within the year prior to Visit 1 or have an Asthma control questionnaire-6 (ACQ-6) score ≥ 1.5 at Visit 1. Enrolled participants will be randomised into the study to either AZD4604 or placebo. Participants discontinuing the study before the completion of Visit 6a (including the second bronchoscopy) will be replaced. Participants will be randomised using an interactive response technology/randomisation and trial supply management system at a ratio of 2:1 to AZD4604 or placebo, respectively. Randomisation will be stratified based on fractional exhaled nitric oxide (FeNO) levels to ensure a similar proportion of participants with FeNO above and below 25 parts per billion (ppb) in the 2 treatment arms. The study will be conducted at approximately 28 sites in approximately 6 countries.