The purpose of this study is to compare the effectiveness of inhaled bronchodilators delivered via nebulizers vs. dry powder inhalers (DPIs) in symptomatic participants with Chronic Obstructive Pulmonary Disease (COPD) who have airflow obstruction (FEV1/FVC ≤ 70%) and show significant air trapping (RV ≥ 120% of predicted).

The investigators hypothesize that, in patients with symptomatic COPD, therapy with a long-acting anti muscarinic agent/long-acting beta agonist (LAMA/LABA) combination administered by nebulizer will improve hyperinflation (increase in inspiratory capacity and reduction in residual volume) and reduce symptoms related to COPD to a greater extent than LAMA/LABA therapy given by a DPI.

The study aims to demonstrate the following:

1. Compare the values of inspiratory capacity (IC) and residual volume (RV) in patients receiving LAMA/LABA by DPI with those receiving LAMA/LABA by nebulizer
2. Compare patient reported outcomes (COPD Assessment Test (CAT score), Baseline/Transition Dyspnea Index (BDI/TDI) and the St. George Respiratory Questionnaire (SGRQ) in symptomatic patients with COPD receiving LAMA/LABA by DPI with those receiving LAMA/LABA by nebulizer

This is a prospective, randomized, parallel group, double dummy, phase four, 13-week clinical trial with 1:1 allocation comparing long-acting anti-muscarinic agent (LAMA; Umeclidinium 62.5 μg once daily) and long acting beta-agonist (LABA; Vilanterol 25 μg once daily) delivered by DPI (Group A), vs a nebulized LAMA/LABA combination (revefenacin 175 μg once daily and formoterol 20 μg twice daily) (Group B) among symptomatic subjects with stable COPD.

The study begins with a screening visit and run-in period. Patients who are eligible and willing to participate will sign informed consent. They will be trained on the use of the DPI and nebulizer, as well as completion of the daily diary (symptom and medication logs) and questionnaires (CAT, BDI/TDI, SGRQ). Vital signs and a physical examination will be performed, and inspiratory flow rate will be determined using the In-Check DIAL. Medications will be adjusted to ensure clinical stability prior to randomization.

Baseline Study Visit 2 occurs within one week of the screening visit. Prior to this visit, participants must not have taken study medication within 48 hours or rescue medication within 6 hours of pulmonary function testing; otherwise, the visit will be rescheduled. At this visit, medical history, current medications, and adverse events are reviewed. Compliance with the daily diary (symptom and medication logs) is assessed, and participants must demonstrate ≥80% completion to continue. Participants complete CAT, BDI, and SGRQ questionnaires, undergo physical examination and vital sign measurement, and perform baseline pulmonary function testing in a plethysmograph. Eligible participants are then randomized 1:1 to receive either active drugs via DPI (Group A) or nebulizer (Group B), with treatment assignments generated using permuted blocks. Group A receives Anoro Ellipta DPI plus nebulized Revefenacin and Formoterol placebos, while Group B receives nebulized Revefenacin and Formoterol plus placebo DPI. The nebulizer is always administered first, followed by the DPI; Time 0 is defined as the end of DPI administration. Post-dose, vital signs and pulmonary function tests are conducted at 1, 2, 4, and 6 hours. Participants also receive training on diary use, study drug/device administration, and medication compliance, and they begin the assigned treatment for 12 weeks with morning and evening doses as per group assignment.

Following Visit 2, patients will continue their assigned treatments twice daily for 12 weeks. Telephone follow-ups will occur at weeks 4 and 8 (Phone Visits 1 and 2) to monitor symptoms, adverse events, and medication adherence, with administration of additional questionnaires.

The final Study Visit 3 will take place at week 12 and will include repeat pulmonary function testing pre-dose and at 1, 2, 4, and 6 hours post-dose, symptom questionnaires, vital signs, and adverse event assessment. Throughout the study, patients will maintain daily symptom diaries, including CAT scores.

Inclusion Criteria:

1. Age > 40 years
2. Either sex
3. Current smoker or past cigarette smoking history of > 10 pack-years
4. Symptoms of COPD (cough, sputum production, shortness of breath)
5. Modified Medical Research Council Dyspnea Scale (mMRC) score ≥2 or CAT score ≥10 at Screening/Run-in visit
6. A PIFR > 30 at screening
7. FEV1/FVC ratio < 70% (within the past 12 months)
8. Residual volume (RV) ≥ 120% predicted (within the past 12 months

Exclusion Criteria:

1. Diagnosis of asthma (Verification via medical record and/or patient report)
2. Previously diagnosed atrial fibrillation with rapid ventricular response (heart rate > 110 bpm) or ventricular arrhythmia (ventricular tachycardia) (Verification via medical record and/or patient report)
3. Acute myocardial infarction within 12 weeks of patient study registration (Verification via medical record and/or patient report)
4. Acute exacerbation of congestive heart failure (Verification via medical record and/or patient report)
5. Acute exacerbation of COPD within 8 weeks (Verification via medical record and/or patient report)
6. Recent (within 8 weeks) h/o eye surgery (Verification via medical record and/or patient report)
7. Uncontrolled glaucoma (Verification via medical record and/or patient report)
8. Known diagnosis of liver cirrhosis (Verification via medical record and/or patient report)
9. Known diagnosis of chronic renal insufficiency (defined as a previous serum creatinine > 2.5 mg/dL - Verification via medical record and/or patient report)
10. Intolerance to any of the study drugs
11. Patients receiving long-term azithromycin
12. Planned surgery requiring hospital admission within 3 months
13. Currently enrolled in a pulmonary rehabilitation program
14. Inability to give informed consent
15. Pregnant or nursing women or women of childbearing potential not using a medically approved means of contraception (i.e., oral contraceptives, intrauterine devices, diaphragm, or subdermal implants)
16. Inability to understand instructions or comply with the study protocol
17. Participation in another investigational drug clinical trial within 30 days of patient study registration

Medical history can be confirmed by medical records and/or verbal confirmation from patients. However, Inclusion criteria 6 & 7 must be verified by a previous PFT report dated within 6 months of screening