A Phase 3 interventional study of Ensifentrine and Placebo in Pulmonary Disease, Chronic Obstructive, sponsored by Merck Sharp & Dohme LLC. Not yet recruiting. Open to participants aged 40 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-15.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 3, Interventional, and Treatment
The purpose of this study is to evaluate the efficacy and safety of ensifentrine (MK-5884) compared with placebo for the prevention of moderate and severe COPD exacerbation in adults with COPD and a history of exacerbations while receiving SOC treatment. The study will also evaluate the efficacy of ensifentrine compared with placebo in improving lung function, improving health related quality of life, and preventing severe exacerbations.
4,252 studies on the registry are indexed under Pulmonary Disease, Chronic Obstructive; 707 are open to participants now.
This study's planned enrollment of 2,136 is above the median of 70 across 3,008 interventional studies indexed under Pulmonary Disease, Chronic Obstructive.
Browse Pulmonary Disease, Chronic Obstructive studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,159 studies on the registry; 133 are open to participants now.
Of its 497 completed or terminated interventional studies of FDA-regulated products, 369 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:
Inclusion Criteria include but are not limited to:
Exclusion Criteria:
Exclusion criteria include but are not limited to:
Participants, who meet the criteria of being on standard of care (SOC) background treatment receive ensifentrine twice a day (bid) by oral inhalation via a standard jet nebulizer for up to 52 weeks.
Drug: Ensifentrine · Drug: Standard of Care (SOC)
Participants, who meet the criteria of being on SOC background treatment receive placebo bid by oral inhalation via a standard jet nebulizer for up to 52 weeks.
Other: Placebo · Drug: Standard of Care (SOC)
Delivered twice daily by oral inhalation via a standard jet nebulizer
Also known as: MK-5884, RPL554
Placebo matched to ensifentrine delivered twice daily by oral inhalation via a standard jet nebulizer
Background treatment of LAMA/LABA/ICS or LAMA/LABA (if ICS is not appropriate) administered per product approved label delivered by oral inhalation as part of standard of care
Annualized Rate of Adjudicated Moderate or Severe Chronic Obstructive Pulmonary Disease (COPD) Exacerbations
The annualized rate of moderate or severe exacerbations over 52 weeks will be reported.
Time frame: Up to 52 Weeks
Change From Baseline in Forced Expiratory Volume in One Second Area Under the Curve From 0-4 Hours (FEV1 AUC0-4h)
FEV1 measures the volume of air exhaled during the first second of a forced exhalation maneuver from the point of maximal inspiration. FEV1 AUC0-4h represents the bronchodilator response over the 4-hour period following administration of study intervention. Spirometry will be performed to determine the FEV1. Change from baseline in average FEV1 AUC0-4h on Week 12 will be reported.
Time frame: Baseline and Week 12
Change From Baseline in St. George's Respiratory Questionnaire (SGRQ) Total Score Responder Status
The SGRQ is a 50-item patient-reported outcome (PRO) questionnaire used to evaluate health-related quality of life (HRQOL) in patients with COPD. The questionnaire contains 3 domains: Symptoms (frequency and severity of respiratory symptoms), Activity (effect of disease on common daily physical activities), and Impacts (psychological effects of the disease). The recall period of the questionnaire is over the past 4 weeks. The total score ranges from 0 to 100, with lower scores indicating better health status. A clinically meaningful improvement in HRQOL, as measured by the SGRQ, is defined as a ≥4.0-point decrease in SGRQ total score. HRQOL, as measured by the percentage of SGRQ responders (≥4-point decrease) at Week 24 will be reported.
Time frame: Baseline and Week 24
Annualized Rate of Adjudicated Severe COPD Exacerbations
The annualized rate of adjudicated severe COPD exacerbations over 52 weeks will be reported.
Time frame: Up to 52 Weeks
Number of Participants with at Least One Adverse Event (AE)
An AE is any untoward medical occurrence in a subject, temporally associated with the use of the study medication, whether or not considered related to the study medication. Number of participants who experience at least one AE will be reported.
Time frame: Up to 53 weeks
Number of Participants who Discontinued Study Intervention Due to an Adverse Event
An AE is any untoward medical occurrence in a subject, temporally associated with the use of the study medication, whether or not considered related to the study medication. Number of participants who discontinue study intervention due to an AE will be reported.
Time frame: Up to 52 Weeks
No study locations are listed for this record.
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
Start is estimated for Oct 2026; primary completion for Apr 2029, 30 months later.
Of 91 industry-sponsored phase 3 interventional studies under Pulmonary Disease, Chronic Obstructive, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 43. This study's planned 30 months is above that.
Counting every sponsor, half of 119 studies reached it within 25 months; a quarter within 15 and three quarters within 44.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Ensifentrine
Pulmonary Disease, Chronic Obstructive →