A Study to Evaluate the Effects of BGF and GFF on Specific Image Based Airway Volumes and Resistance in Subjects With Moderate to Severe COPD

Inclusion Criteria: Subject must be 40 years to ≤80 years of age inclusive, at the time of signing the informed consent form at Visit 1. * COPD Diagnosis: Subjects with an established clinical history of COPD * Screening clinical laboratory tests must be acceptable to the Investigator. * Screening ECG must be acceptable to the Investigator * Individual Compliance: Subjects must be willing to remain at the study center as required per protocol to complete all visit assessments * Patients should be on scheduled maintenance treatment with one or more inhaled bronchodilator therapies. Exclusion Criteria: * As judged by the investigator, any evidence of significant diseases other than COPD, i.e., disease or condition which, in the investigator's opinion makes it undesirable for the subject to participate in the trial. * Spirometry Performance: 1. Subjects who cannot perform acceptable spirometry, i.e., meet ATS/ERS acceptability criteria. 2. Repeatability: Subjects who cannot perform technically acceptable spirometry in accordance with ATS repeatability criteria * Cancer: Subjects who have cancer that has not been in complete remission for at least five years. * Substance Abuse: Subjects, who in the opinion of the Investigator, significantly abuse alcohol or drugs * Subjects who in the opinion of the investigator are unable to abstain from prohibited medications including LABA/LAMAs/ICS