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 12months 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 priorto randomization and no change in drug or dosage for at least 3 months prior torandomization) and changes to PDE5 inhibitor dosing is not anticipated during the 24week 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 oruses acceptable contraceptive method or abstains from sexual intercourse, or has anegative highly sensitive pregnancy test within 24 hours before the first dose ofstudy intervention, or whose history and sexual activity has been reviewed by theinvestigator.

Exclusion criteria:

• Has Group 1 pulmonary arterial hypertension (PAH), Groups 2, 4 or 5 pulmonaryhypertension (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 ofthe 24 week Base Period.

• Has evidence of a resting oxygen saturation (SpO2) < 88%.

• Has experienced a moderate or severe COPD exacerbation within 2 months beforerandomization.

• Has experienced right heart failure within 2 months before randomization.

• Has uncontrolled tachyarrhythmia.

• Has acute coronary syndrome, undergone coronary artery bypass graft, or percutaneouscoronary intervention within 2 months before randomization.

• Has evidence of significant chronic renal insufficiency.

• Has evidence of chronic liver disease, portal hypertension, cirrhosis, or hepaticabnormalities.

• 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 ordependence.

• Has used PAH-specific therapies within 2 months of randomization.