An Exploratory Study to Characterise Changes in Airway Inflammation, Symptoms, Lung Function and Reliever Use in Adult Asthma Patients

This is a randomised, active-comparator, open-label, parallel-group, multicentre phase IV exploratory study to characterise changes in airway inflammation, symptoms, lung function, and reliever use in asthma patients using SABA (salbutamol) or anti-inflammatory reliever (SYMBICORT®) as reliever medication in addition to SYMBICORT as daily asthma controller. Eligible patients diagnosed with asthma at least 6 months prior to the Screening Visit (Visit 1) and fulfilling all of the inclusion criteria and none of the exclusion criteria will continue into the Run-in Period. During the run-in period, patients will take their maintenance medication (ie, SYMBICORT \[100/6 or 200/6 μg, × 2 BID\]) and reliever salbutamol \[100 μg, PRN\]) using the connected inhalers. At Visit 2, patients will be assessed for randomisation criteria and, if met, will be randomised to receive either SYMBICORT as maintenance and reliever treatment or SYMBICORT as maintenance treatment and salbutamol as reliever treatment in a 1:1 ratio. Randomisation will be stratified by the patient's ongoing dose of ICS (low or medium) at study entry. This study will include a minimum of 3 site visits. Patients will be requested to come to the study site for 4 additional Event Visits (E1 to E4) at approximately 4-day intervals beginning after the first visit if they experience any one of the following 3 criteria: a) A severe exacerbation defined as use of systemic steroids for at least 3 days, emergency room visit, or inpatient hospitalisation due to asthma, b) Symptom worsening criteria based on CompEx evaluation - an asthma worsening identified by a combination of deteriorations in at least 2 variables (decrease in PEF of at least 15% compared with baseline, an increase of reliever medication of at least 1.5 occasions compared with baseline, or an increase in asthma symptoms of at least 1 compare with baseline or the absolute max score \[=3\]) at least 2 consecutive days, or c) A single day (in 24 hours) with 6 or more occasions of reliever medication use. The duration of participation in the study will be 26 to 28 weeks (maximum) for each individual patient, including a 2-week Run-in Period, followed by a 24-week randomised Treatment Period and an additional follow-up period if the Event Visits fall within the final 2 weeks of the Treatment Period. The study plans to randomise a minimum of 60 patients to a maximum of 80 patients to achieve at least 54 patients completing the study. The study will be conducted at no less than 2 sites in the United Kingdom (UK). The estimated study duration is approximately 30 months.