Primary Outcome Measures: | |
1. |
Serum Trough Concentration (Ctrough) of Sotatercept [ Time Frame: Predose Day 1, Day 21, Day 42, Day 63, Day 84, Day105, Day 126, Day 147, Day 168, Day 189. Postdose Day 7, Day 14, Day 64, Day 69 and Day 76 ]
Ctrough was the lowest concentration of Sotatercept in serum just before the next dose. Blood samples will be collected at multiple time points to estimate the Ctrough of Sotatercept. |
2. |
Area Under the Curve at Steady State (AUCss) of Sotatercept [ Time Frame: Predose Day 1, Day 21, Day 42, Day 63, Day 84, Day105, Day 126, Day 147, Day 168, Day 189. Postdose Day 7, Day 14, Day 64, Day 69 and Day 76 ]
Blood samples will be collected at multiple time points to estimate the AUCss of Sotatercept. |
3. |
Area Under the Curve from 0 to 3 weeks (AUC0-3 weeks) of Sotatercept [ Time Frame: Predose Day 1, Day 7, Day 14, and Predose Day 21 ]
Blood samples will be collected at Predose Day 1, Day 7, Day 14, and Predose Day 21 to estimate the AUC0-3 weeks of Sotatercept. |
4. |
Percentage of Participants Who Experience at Least 1 Adverse Event (AE) [ Time Frame: Up to 24 weeks ]
An AE is any unfavourable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. The percentage of participants with 1 or more AEs will be assessed. |
5. |
Percentage of Participants Who Discontinue Study Drug Due to an AE [ Time Frame: Up to 24 weeks ]
An AE is any unfavourable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an adverse event. The percentage of participants who discontinued the study drug due to an AE regardless of study completion status will be assessed. |
6. |
Laboratory Parameter (Hematology): Concentration of Hemoglobin [ Time Frame: Up to 24 weeks ]
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The concentration of hemoglobin will be presented. |
7. |
Laboratory Parameter (Hematology): Hematocrit [ Time Frame: Up to 24 weeks ]
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The hematocrit will be presented. |
8. |
Laboratory Parameter (Hematology): Red Blood Cell (RBC) Count [ Time Frame: Up to 24 weeks ]
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The RBC count will be presented. |
9. |
Laboratory Parameter (Hematology): Reticulocyte Count [ Time Frame: Up to 24 weeks ]
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The reticulocyte count will be presented. |
10. |
Laboratory Parameter (Hematology): Platelet Count [ Time Frame: Up to 24 weeks ]
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The platelet count will be presented. |
11. |
Blood Pressure (BP) [ Time Frame: Up to 24 weeks ]
BP will be assessed while the participant was seated after a period of rest in a quiet setting with no distractions (eg, television and cell phones). |
12. |
Titer of Anti-drug Antibody (ADA) to Sotatercept [ Time Frame: Up to 24 weeks ]
ADA to Sotatercept will be assessed. |
Secondary Outcome Measures: | |
1. |
Mean Change from Baseline in 6-Minute Walk Distance (6MWD) (Cohorts 1 and 2) [ Time Frame: Baseline and Week 24 ]
6MWD will be assessed using the 6-minute walk test (6MWT). |
2. |
Mean Change from Baseline in Tricuspid Annular Plane Systolic Excursion (TAPSE) [ Time Frame: Baseline and Week 24 ]
A two-dimensional echocardiogram (ECHO) will be performed with the results interpreted by a blinded independent central review (BICR) at baseline and after 24 weeks of treatment. The change from baseline in TAPSE will be reported. |
3. |
Mean Change from Baseline in Pulmonary Artery Systolic Pressure (PASP) [ Time Frame: Baseline and Week 24 ]
A two-dimensional ECHO will be performed with the results interpreted by a BICR at baseline and after 24 weeks of treatment. The change from baseline in PASP will be reported. |
4. |
Mean Change from Baseline in Right Ventricular Fractional Area Change (RVFAC) [ Time Frame: Baseline and Week 24 ]
A two-dimensional ECHO will be performed with the results interpreted by a BICR at baseline and after 24 weeks of treatment. The change from baseline in RVFAC will be reported. |
5. |
Mean Change from Baseline in Eccentricity Index [ Time Frame: Baseline and Week 24 ]
A two-dimensional ECHO will be performed with the results interpreted by a BICR at baseline and after 24 weeks of treatment. The change from baseline in eccentricity index will be reported. |
6. |
Mean Change from Baseline in Right Ventricular (RV) Function (Cohort 1 Only) [ Time Frame: Baseline and Week 24 ]
Cardiac magnetic imaging (MRI) will be performed with the results interpreted by a BICR at baseline and after 24 weeks of treatment. The change from baseline in eccentricity index will be reported. |
7. |
Mean Change from Baseline on Cardiac Output (Cohort 1 Only) [ Time Frame: Baseline and Week 24 ]
Cardiac magnetic imaging (MRI) will be performed with the results interpreted by a BICR at baseline and after 24 weeks of treatment. The change from baseline in cardiac output will be reported. |
8. |
Mean Change from Baseline in Pulmonary Arterial Pressure (PAP) (Cohort 1 Only) [ Time Frame: Baseline and Week 24 ]
Cardiac magnetic imaging (MRI) will be performed with the results interpreted by a BICR at baseline and after 24 weeks of treatment. The change from baseline in PAP will be reported. |
9. |
Mean Change from Baseline in Pediatric Quality of Life (PedsQL) Generic Score [ Time Frame: Baseline and Week 24 ]
PedsQL Measurement Model is a modular approach to measuring health-related quality of life in healthy children and adolescents and those with acute and chronic health conditions. The change from baseline in the PedsQL generic core scale will be reported. |
10. |
Mean Change from Baseline in N-terminal Prohormone B-type Natriuretic Peptide (NT-proBNP) [ Time Frame: Baseline and Week 24 ]
The change from baseline in plasma NT-proBNP levels will be reported. |
11. |
Percentage of Participants Who Either Improved or Maintained Their World Health Organization Functional Class (WHO FC) [ Time Frame: Baseline and Week 24 ]
The severity of an individual's PAH symptoms will be graded using the WHO FC system. WHO functional classification for PAH range from Class I (no limitation in physical activity, no dyspnea with normal activity), Class II (slight limitation of physical activity), Class III (marked limitation of physical activity) and Class IV (cannot perform a physical activity without any symptoms, dyspnea at rest). The change from baseline in WHO FC will be classified into "Improved", "No change" and "Worsened". Improvement = reduction in FC, worsened = increase in FC and no change = no change in FC. |