Measuring Small-Airways Disease Improvement After Step-up to Extrafine TRIple or High-dose ICS/LABA in Patients Uncontrolled on Medium Dose ICS/LABA eXploring T2 Inflammation

All data related to the study will be recorded for each participating patient by the investigator in a separate, specially designed Case Report Form (CRF) at the start of the study. The CRF pages are specifically designed to capture the information required by the study protocol, and the investigator will enter these data into the corresponding fields, ensuring consistency with the information documented in the patient's medical record. All patients who sign the informed consent to participate in the study will be assigned a unique 5-digit identification number in the format of XX-XXX (first two digits represent the centre number and the last 3 digits the patient number), which will be recorded on all relevant study documents (CRF etc.). The patient's initials and full date of birth will not be recorded in the CRF to protect personal data, except in cases specifically permitted under the General Data Protection Regulation (GDPR). • At all 3 Visits, the following assessments will be performed to all patients: (1) Evaluation of asthma control (ACT, ACQ-5), (2) Blood Eosinophil Counts (BEC, cells/mL and %), (3) FeNO (FeNO+, MGC Diagnostics, at 50 mL/sec and at 100 and 150 mL/sec to measure alveolar NO as a marker of SAD), (4) Forced Oscillometry Technique (FOT, Resmon PRO Full V3), measuring peripheral resistance (difference between resistance at 5Hz and 19Hz, R5-19), frequency resonance (Fres), area of reactance (AX), and reactance (X5), (5) Simple spirometry, including forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced expiratory flow at 25-75% of FVC (FEF25-75%), (6) Static lung volumes by body plethysmography, including total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC), (7) At the optional Visit 4 at 52 weeks, we will collect the previous parameters and the number of exacerbations (OCS courses, emergency department visits, hospitalizations). eCRFs will be periodically reviewed by the principal investigator to minimize missing values. When NaN entries cannot be avoided, the amount, pattern, and assumed mechanism of missingness (missing completely at random, missing at random, or missing not at random) will be evaluated to determine the most appropriate statistical approach. Imputation methods may include mean or median imputation, random sample imputation, or multiple imputation, as appropriate.