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

Inclusion Criteria

• Provision of signed and dated, written Informed Consent Form (ICF) prior to any study-related procedures, sampling, and analyses (at Visit 1).
• Patient must be ≥18 years of age at the time of signing the ICF.
• A physician diagnosis of asthma for a minimum ≥6 months prior to Visit 1.
• Use of ICS (low or medium dose)/LABA for asthma for ≥3 months prior to Visit 1.
• Episode of asthma symptom worsening requiring overuse of reliever (more than the standard for the individual patient) at least once during the last 30 days prior to Visit 1.
• The patient must be able to read speak, and understand local language; and be able to, in the Investigator's judgment, comply with the study protocol.
• Able to perform home FeNO and spirometry assessments and complete the asthma symptom diary on a regular basis during the conduct of the study.
• Male and/or female
• Negative pregnancy test (urine) for female patients of childbearing potential at Visit 1.
• For randomisation at Visit 2, patients should fulfil the following criteria:
• Symptoms requiring reliever medication use for a minimum of 2 to a maximum 8 days out of the last 10 days of the Run-in Period.
• At least 80% overall compliance rate for performing FeNO and spirometry assessments and completing the asthma symptom diary during the Run-in Period.

Exclusion Criteria

• Any significant disease or disorder, or evidence of drug/substance abuse which in the Investigator's opinion would pose a risk to patient safety, interfere with the conduct of study, have an impact on the study results, or make it undesirable for the patient to participate in the study.
• Any asthma worsening requiring change in asthma treatment other than the patient's prescribed reliever medication (SYMBICORT as Maintenance and Reliever Therapy [SMART] therapy, SABA, and/or short-acting anticholinergic agent) within 30 days prior to Visit 1.
• Medical history of life- threatening asthma including intubation and intensive care unit admission.
• Medical conditions (other than allergic rhinitis) or medications (other than ICS) that will influence FeNO, as judged by the Investigator.
• Concurrent respiratory disease: presence of a known pre-existing, clinically important lung condition other than asthma (eg, cystic fibrosis, idiopathic pulmonary fibrosis, pulmonary arterial hypertension).
• Acute upper or lower respiratory infections requiring antibiotics or antiviral medication within 30 days prior to the date informed consent is obtained (Visit 1) or during the screening/Run-in Period.
• A severe asthma exacerbation (defined by an exacerbation resulting in ≥3 days of oral corticosteroids [or one depot intramuscular injection of a glucocorticosteroid], an urgent care or emergency room visit that results in systemic corticosteroids, or an inpatient hospitalisation due to asthma) within 30 days prior to screening.
• Any disease state or procedure that may necessitate the use of oral/systemic corticosteroids during the Treatment Period, other than asthma.
• Malignancy: a current malignancy or previous history of cancer in remission for less than 12 months prior to Visit 1 (patients that had localised carcinoma of the skin which was resected for cure will not be excluded).
• Patients with a history/treatment of malignancy, and which in the Investigator's opinion could compromise the safety of the patient.
• Other concurrent medical conditions: patients who have known, pre-existing, clinically significant endocrine, autoimmune, metabolic, neurological, renal, gastrointestinal, hepatic, haematological or any other system abnormalities that are uncontrolled with standard treatment.
• Current smokers: previous smokers are allowed to be included provided that they stopped smoking >12 months prior to Visit 1 AND have a smoking history of ≤10 pack-years.
• Alcohol/substance abuse: a history (or suspected history) of alcohol misuse or substance abuse within 2 years prior t