Please assess the completion status of the following clinical trial:

Trial Title: A Study of Sotatercept for the Treatment of Pulmonary Arterial Hypertension (PAH)

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE2
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion Criteria:~1. Age ≥18 years~2. Documented diagnostic right heart catheterization (RHC) at any time prior to Screening confirming diagnosis of WHO diagnostic pulmonary hypertension Group I: PAH in any of the following subtypes:~   i. Idiopathic ii. Heritable PAH iii. Drug- or toxin-induced PAH iv. PAH associated with connective tissue disease v. PAH associated with simple, congenital systemic-to-pulmonary shunts at least 1 year following shunt repair~3. Symptomatic pulmonary hypertension classified as WHO functional class II or III~4. Screening RHC documenting a minimum PVR of ≥400 dyn·sec/cm5 (5 Wood units)~5. Pulmonary function tests (PFTs) within 6 months prior to Screening as follows:~   1. Total lung capacity (TLC) \>70% predicted; or if between 60 to 70% predicted, or not possible to be determined, confirmatory high-resolution computed tomography (CT) indicating no more than mild interstitial lung disease (ILD), per investigator interpretation, or~  2. Forced expiratory volume (first second) (FEV1)/ forced vital capacity (FVC) \>70% predicted~6. Ventilation-perfusion (VQ) scan (or, if unavailable a negative CT pulmonary angiogram \[CTPA\] result, or pulmonary angiography result), any time prior to Screening Visit or conducted during the Screening Period, with normal or low probability result),~7. No contraindication per investigator for RHC during the study~8. 6MWD ≥150 and ≤550 meters repeated twice at Screening and both values within 15% of each other, calculated from the highest value~9. PAH therapy at stable (per investigator) dose levels of SOC therapies~Exclusion Criteria:~1. Stopped receiving any pulmonary hypertension chronic general supportive therapy (e.g, diuretics, oxygen, anticoagulants, digoxin) within 60 days prior to study visit Cycle 1 Day 1 (C1D1)~2. Received intravenous inotropes (e.g., dobutamine, dopamine, norepinephrine, vasopressin) within 30 days prior to study visit C1D1~3. History of atrial septostomy within 180 days prior to Screening~4. History of more than mild obstructive sleep apnea that is untreated~5. 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)~6. History of human immunodeficiency virus infection-associated PAH~7. Prior exposure to sotatercept (ACE-011) or luspatercept (ACE-536)~8. Initiation of an exercise program for cardiopulmonary rehabilitation within 90 days prior to C1D1 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).~9. Uncontrolled systemic hypertension as evidenced by sitting systolic blood pressure (BP) \>160 mm Hg or sitting diastolic blood pressure \>100 mm Hg during Screening Visit after a period of rest~10. Systolic BP \<90 mmHg during Screening or at baseline~11. History of known pericardial constriction~12. Electrocardiogram (ECG) with Fridericia's corrected QT interval (QTcF) \>480 msec during Screening Period or C1D1~13. Personal or family history of long QTc syndrome or sudden cardiac death~14. Cerebrovascular accident within 3 months of C1D1~15. History of restrictive or congestive cardiomyopathy~16. Left ventricular ejection fraction (LVEF) \<45% on historical echocardiogram (ECHO) within 6 months prior to Screening Period (or done as a part of the Screening Period) or pulmonary capillary wedge pressure (PCWP) \>15 mmHg as determined in the Screening Period RHC.~17. Any current or prior history of symptomatic coronary disease (prior myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft surgery, or cardiac anginal chest pain)~18. Acutely decompensated heart failure within 30 days prior to study visit C1D1, as per investigator assessment~19. Significant (≥2+ regurgitation) mitral regurgitation (MR) or aortic regurgitation (AR) valvular disease~20. Any of the following clinical laboratory values during the Screening Period prior to C1D1:~    1. Baseline Hgb \>16.0 g/dL~   2. Serum alanine aminotransferase or aspartate aminotransferase levels \>3X upper limit of normal (ULN) or total bilirubin \>1.5X ULN within 28 days of C1D1~   3. Estimated glomerular filtration rate \<30 ml/min/1.73m2 (4-variable Modification of Diet in Renal Disease equation) within 28 days of C1D1 or required renal replacement therapy within 90 days~   4. WBC count \<4000/mm3~   5. Platelets \<100,000/μL~   6. Absolute neutrophil count \<1500/mm3~21. History of opportunistic infection (e.g., invasive candidiasis or pneumocystis pneumonia) within 6 months prior to Screening; serious local infection (e.g., cellulitis, abscess) or systemic infection (e.g., septicemia) within 3 months prior to Screening~22. History of severe allergic or anaphylactic reaction or hypersensitivity to recombinant proteins or excipients in the investigational product~23. Major surgery within 8 weeks prior to C1D1. Participants must have completely recovered from any previous surgery prior to C1D1.~24. Prior heart or heart-lung transplants or life expectancy of \<12 month~25. Pregnant or breastfeeding females~26. If on corticosteroids, and at any time in the last 30 days prior to the Screening Period: have been receiving doses of \>20 mg/day of prednisone (or equivalent) or on a new or changing dose of ≤20 mg/day; only participants receiving stable doses of ≤20 mg prednisone (or equivalent) in last 30 days prior to the Screening Period permitted in the study~27. History of active malignancy, with the exception of fully excised or treated basal cell carcinoma, cervical carcinoma in-situ, or ≤2 squamous cell carcinomas of the skin~28. History of clinically significant (as determined by the investigator) non-PAH related cardiac, endocrine, hematologic, hepatic, (auto)immune, metabolic, urologic, pulmonary, neurologic, neuromuscular, dermatologic, psychiatric, renal, and/or another disease that may limit participation in the study. Autoimmune diseases are excluded with the exception of those related to PAH etiologies included in this study.~29. Participation in another clinical trial involving intervention with another investigational drug, approved therapy for investigational use, or investigational device within 4 weeks prior to C1D1, or if the half-life of the previous product is known, within 5 times the half-life prior to C1D1, whichever is longer~30. Weight \>140 kg at Screening

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Placebo (Type: PLACEBO_COMPARATOR): Participants will receive placebo plus SOC by SC injection during the 24-week treatment period. Dosing will occur once every 3 weeks.
- Sotatercept 0.3 mg/kg (Type: EXPERIMENTAL): Participants will receive sotatercept 0.3 mg/kg plus SOC by SC injection during the 24-week treatment period. Per protocol, participants may have their doses titrated. Dosing will occur once every 3 weeks.
- Sotatercept 0.7 mg/kg (Type: EXPERIMENTAL): Participants will receive sotatercept 0.7 mg/kg plus SOC by SC injection during the 24-week treatment period. Per protocol, participants may have their doses titrated. Dosing will occur once every 3 weeks.

Based on this trial design, predict the completion outcome and termination type (if applicable).