Frespaciguat (MK-5475) INSIGNIA-PH-COPD: A Study of the Efficacy and Safety of Frespaciguat (an Inhaled sGC Stimulator) in Adults With PH-COPD

The key inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: * Has Group 3.1 pulmonary hypertension chronic obstructive pulmonary disease (PH-COPD) as defined by the Clinical Classification of Pulmonary Hypertension. * Has a right heart catheterization (RHC) at screening or historical RHC within 12 months before screening that meets hemodynamic criteria. * Has a physician diagnosis of obstructive lung disease on pulmonary function testing (PFT) performed at screening. * Has a WHO Functional Class assessment of Class II to IV. * If on supplemental oxygen, the regimen must be stable. * Has stable and optimized chronic, baseline COPD-specific therapy. * If on PDE5 inhibitor, has stable concomitant use (initiated at least 3 months prior to randomization and no change in drug or dosage for at least 3 months prior to randomization) and changes to PDE5 inhibitor dosing is not anticipated during the 24 week Base Period. * If on antihypertensives and/or a diuretic regimen has stable concomitant use. * If on anticoagulants has stable concomitant use. * Is of any sex/gender from 40 to 85 years of age inclusive. * Female is not pregnant or breastfeeding, and is not of childbearing potential or uses acceptable contraceptive method or abstains from sexual intercourse, or has a negative highly sensitive pregnancy test within 24 hours before the first dose of study intervention, or whose history and sexual activity has been reviewed by the investigator. Exclusion criteria: * Has Group 1 pulmonary arterial hypertension (PAH), Groups 2, 4 or 5 pulmonary hypertension (PH). * Has non-COPD related Group 3 PH. * Has evidence of untreated more than mild obstructive sleep apnea. * Has significant left heart disease. * Expects to receive a lung and/or heart transplant from screening through the end of the 24 week Base Period. * Has evidence of a resting oxygen saturation (SpO2) \< 88%. * Has experienced a moderate or severe COPD exacerbation within 2 months before randomization. * Has experienced right heart failure within 2 months before randomization. * Has uncontrolled tachyarrhythmia. * Has acute coronary syndrome, undergone coronary artery bypass graft, or percutaneous coronary intervention within 2 months before randomization. * Has evidence of significant chronic renal insufficiency. * Has evidence of chronic liver disease, portal hypertension, cirrhosis, or hepatic abnormalities. * Initiated a pulmonary rehabilitation program within 2 months before randomization. * Has impairments that limit the ability to perform 6MWT. * Has history of cancer. * Is a user of illicit drugs or has a recent history of drug/alcohol abuse or dependence. * Has used PAH-specific therapies within 2 months of randomization.