A Study of Sotatercept for the Treatment of Pulmonary Arterial Hypertension (MK-7962-003/A011-11)(STELLAR)

Exclusion Criteria

• •Diagnosis of pulmonary hypertension WHO Groups 2, 3, 4, or 5
• •Diagnosis of the following PAH Group 1 subtypes: human immunodeficiency virus (HIV)-associated PAH and PAH associated with portal hypertension. Exclusions in PAH Group I should also include schistosomiasis associate PAH and pulmonary veno occlusive disease
• •Hemoglobin (Hgb) at screening above gender-specific upper limit of normal (ULN), per local laboratory test
• •Baseline platelet count \< 50,000/mm\^3 (\< 50.0 x 109/L) at screening
• •Uncontrolled systemic hypertension as evidenced by sitting systolic blood pressure \> 160 mmHg or sitting diastolic blood pressure \> 100 mmHg during screening visit after a period of rest
• •Baseline systolic blood pressure \< 90 mmHg at screening
• •Pregnant or breastfeeding women
• •Any of the following clinical laboratory values at the screening visit:
• •* Estimated glomerular filtration rate (eGFR) \< 30 mL/min/m2 (as defined by the Modification of Diet in Renal Disease \[MDRD\] equation)
• •* Serum alanine aminotransferase, aspartate aminotransferase, or total bilirubin levels \> 3 × ULN (bilirubin criterion waived if there is a documented history of Gilbert's syndrome)
• •Currently enrolled in or have completed any other investigational product study within 30 days for small molecule drugs or within 5 half-lives for biologics prior to the date of signed informed consent
• •Prior exposure to sotatercept (ACE-011) or luspatercept (ACE 536) and/or excipients or known allergic reaction to either one
• •History of full pneumonectomy
• •Pulmonary function test (PFT) values of forced vital capacity (FVC) \< 60% predicted at the screening visit or within 6 months prior to the screening visit. If PFT is not available, a chest CT scan showing more than mild interstitial lung disease (ILD) at the screening visit or 1 year prior to it
• •Initiation of an exercise program for cardiopulmonary rehabilitation within 90 days prior to the screening visit or planned initiation during the study (participants who are stable in the maintenance phase of a program and who will continue for the duration of the study are eligible)
• •History of more than mild obstructive sleep apnea that is untreated
• •Known history of portal hypertension or chronic liver disease, including hepatitis B and/or hepatitis C (with evidence of recent infection and/or active virus replication), defined as mild to severe hepatic impairment (Child-Pugh Class A-C)
• •History of restrictive, constrictive or congestive cardiomyopathy
• •History of atrial septostomy within 180 days prior to the screening visit
• •Electrocardiogram (ECG) with Fridericia's corrected QT interval (QTcF) \> 500 ms during the screening period
• •Personal or family history of long QT syndrome (LQTS) or sudden cardiac death
• •Left ventricular ejection fraction \< 45% on historical echocardiogram within 6 months prior to the screening visit
• •Any symptomatic coronary disease events (prior myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft surgery, or cardiac anginal chest pain) within 6 months prior to the screening visit. Note: Anginal pain can be ignored as an exclusion criterion if coronary angiography shows no obstructions
• •Cerebrovascular accident within 3 months prior to the screening visit
• •Acutely decompensated heart failure within 30 days prior to the screening visit, as per investigator assessment
• •Significant (≥ 2+ regurgitation) mitral regurgitation or aortic regurgitation valvular disease
• •Received intravenous inotropes (e.g., dobutamine, dopamine, norepinephrine, vasopressin) within 30 days prior to the screening visit