A Clinical Study of Sotatercept (MK-7962) in People With Pulmonary Arterial Hypertension (MK-7962-038)

Researchers are looking for more ways to treat PAH. In PAH, the blood vessels in the lungs become thick and narrow, which makes it harder for blood to flow. This causes high blood pressure in the lungs and overworks the heart. PAH can make it hard to breathe and be active. Some standard (usual) treatments for PAH can treat symptoms of PAH but do not stop PAH from getting worse. Sotatercept is a study medicine designed to treat PAH. It is a targeted therapy, which is a treatment that works on certain proteins that play a role in causing PAH. This is a long-term follow-up (LTFU) study. People who took part in certain other studies testing sotatercept for PAH may be able to join this study. The goal of this study is to learn about the long-term safety of sotatercept and if people tolerate it when taken with standard PAH treatment over a longer period of time.

LTFU PAH sotatercept study MK-7962-004 (Obsolete Identifier: NCT04796337) has been incorporated into the current MK-7962-038 (NCT07218029) study for administrative reasons. The MK-7962-004 study is no longer enrolling participants and will be formally closed. Only those who participated in MK-7962-004 may be eligible to continue into MK-7962-038.

Inclusion Criteria: The main inclusion criteria include but are not limited to the following: * Has completed their current respective PAH sotatercept clinical study and its requirements, and must not have discontinued early * Is willing to adhere to the study visit schedule, and understands and will comply with all protocol requirements * Must have the ability to understand and provide documented informed consent Exclusion Criteria: The main exclusion criteria include but are not limited to the following: * Did not participate in a sotatercept PAH parent study * Missed more than the equivalent of 4 consecutive doses between the end of parent study and the start of this study. * Presence of an ongoing serious adverse event that occurred during a PAH sotatercept clinical study that is assessed to be possibly or probably related to sotatercept * Is a female who is pregnant or breastfeeding * Is or has an immediate family member who is investigational site or Sponsor staff directly involved with this study * Is currently enrolled in another investigational product study other than a sotatercept study * Is incapacitated