• Provision of a signed and dated informed consent form

• Stated willingness to comply with all study procedures for the duration of the study

• Confirmed to have pulmonary hypertension (PH) due to chronic lung disease at screening

‣ Pulmonary hypertension is defined based on meeting all three of the following measured at rest during the RHC:

• Mean pulmonary artery pressure \>20 mmHg

∙ Pulmonary artery wedge pressure ≤15 mmHg

∙ Pulmonary vascular resistance \> 2 Wood units

⁃ Pulmonary hypertension is classified in Group 3: PH associated with lung diseases and/or hypoxia

• Medications approved for the treatment of pulmonary hypertension must be at a stable dose for at least 30 days

• Ability to take oral medication and be willing to adhere to the study intervention regimen

• For females of reproductive potential: agreement to use highly effective contraception during study participation and for an additional 4 weeks after the end of study participation.

• For males of reproductive potential: use of condoms or other methods to ensure effective contraception with a partner

• Agreement to adhere to Lifestyle Considerations (below) throughout the study duration o During this study, participants are asked to arrive in the clinic for study visits in the fasting state. Specifically, participants should abstain from any caloric intake for 6 hours before arrival for the study visit.