Pulmonary Arterial Hypertension (PAH) is a condition where blood pressure in the lungs' arteries is too high. This study is looking at the long-term effects of a medicine called sotatercept for treating PAH. The medicine has shown improvements in patients' heart and lung function in earlier studies. This new study wants to see if the medicine is safe and works well over a longer time.

Key Points:

• The study is for adults who finished earlier sotatercept studies for PAH, and they must continue with their PAH treatments.
• Participants will have regular checkups to monitor safety and effectiveness, and they need to agree to use birth control if they can have children.
• Participants will not be allowed to join other drug or device studies while this study is ongoing.

To join, participants need to have completed previous sotatercept studies and agree to follow study rules. They must not have any serious ongoing health issues related to the medicine. Pregnant or breastfeeding women cannot participate. The study ensures that the medicine is safe and effective over a longer period. Participants will need to attend regular visits and follow the study plan closely.