A Study to Learn About the Study Medicine (Called PF-07868489) in People With Pulmonary Arterial Hypertension Who Have Previously Participated in a Clinical Study With PF-07868489

The purpose of this study is to learn about the long-term safety, tolerability and effects of the study medicine (PF-07868489) for the possible treatment of PAH. PAH is a condition in which there is high blood pressure in the arteries that carry blood from the heart to the lungs. This high pressure makes it harder for the heart to pump blood through those lungs, potentially damaging the right side of the heart. This is an open-label study. Which means that both the healthcare providers and the study participants are aware of the medicine being given. This study is also an extension study with study medicine (PF-07868489). An extension study allows patients from an earlier clinical study (also called as qualifying study) to continue participating to assess long-term benefits and safety of the medicine.

This study is seeking participants who are: * aged 18 years or older at screening of the previous study and completed the required treatment duration with PF-07868469 and other assessments at the end of that study. * willing and able to abide with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. * do not have worsening or hospitalization for worsening PAH during the qualifying study. * not on placement for a surgery to replace any tissue or part of the body (transplant), and planned surgery for PAH. * do not have an ongoing major health issue in the qualifying study, which in the opinion of the study doctor could make the participant not qualify for this study. * not suffering from or in the past have suffered from hepato-pulmonary syndrome (liver-related lung problem). * not currently prescribed or taking medicines called as GLP-1 agonist.