VENTURI (VENTilation Using Respiratory Imaging)

The study will comprise of 5 visits. A screening visit (V1, Week -2), with baseline assessment. At the randomization visit (V2, Week 0), patients will be randomized in a 1:1 ratio to receive one of the following treatments for 8 weeks: * BDP/FF/G 100/6/12.5 mcg pMDI, two inhalations twice-daily * FluF/UMEC/VI 100/62.5/25 mcg DPI, one inhalation once-daily A subsequent visit will be performed at 8 weeks (V3), where participants will undergo spirometry, oscillometry, and imaging. Participants will then stop the assigned treatment and undergo a washout period of 4 weeks using an unrelated maintenance ICS/LABA combination inhaler. Following the washout period, at the next visit (V4, Week 12) participants will then be crossed over to the other treatment they did not receive at randomization. At the final visit (V5, Week 20), patients will once again undergo spirometry, oscillometry, and imaging. In the event of premature study discontinuation, an early termination (ET) visit will be conducted and the Investigator must fill in the "Study Termination" page in the eCRF, reporting the main reason for withdrawal. Participants who were previously screened and found ineligible due to transient or correctable conditions (e.g., recent exacerbation) may be considered for rescreening twice. Rescreening must be approved by the Principal Investigator and documented in the subject's screening log. Rescreening will follow the same procedures as the initial screening, including informed consent, unless otherwise specified in the protocol. The reason for rescreening and any changes in eligibility status must be clearly documented in the case report form (CRF) and source documents.