The BDI was calculated by using a 10-point scale (0 = None, 10 = Maximum) and indicates the degree of breathlessness after completion of the 6-minute walk test. The BDI scale was assessed by each participant. Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. Observed data analysis (no imputation technique).

There are four grades for the WHO FC (Class I = none, Class IV = most severe). The WHO FC indicates the severity of Pulmonary Arterial Hypertension and is an adaptation of the New York Heart Association classification. It was assessed by the investigator. Observed data analysis (no imputation technique).

Time to clinical worsening was defined as the time from baseline to the first occurrence of death, lung transplantation, hospitalization for PAH treatment, atrial septostomy (a surgical procedure in which a small hole is made in the wall between the left and right atria of the heart), or study discontinuation due to change to other PAH treatment. Time to clinical worsening was measured as the number of participants who experienced these events up to 164.14 weeks.

mPAP is a measure of cardiopulmonary hemodynamics (echocardiography). Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. Observed data analysis (no imputation technique).

CO is a measure of cardiopulmonary hemodynamics (echocardiography). Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. Observed data analysis (no imputation technique).

Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. BNP is a surrogate marker of heart failure and was measured by a central laboratory. Observed data analysis (no imputation techniques).

Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, and 156 minus the baseline value. 6MWD was measured by a 6-minute walk test. This test measures the distance that a participant can walk in a period of 6 minutes. Imputation technique was last observation carried forward, which was used in an attempt to compensate for missing data. For each participant, missing values were replaced with the last observed value.

Full Analysis Set (FAS): All participants registered, with the exception of those who did not receive any dose of the investigational product and those who had no efficacy assessment after treatment.

The BDI was calculated by using a 10-point scale (0 = None, 10 = Maximum) and indicates the degree of breathlessness after completion of the 6-minute walk test. The BDI scale was assessed by each participant. Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. Observed data analysis (no imputation technique).

FAS. Participants were followed for different lengths of time; thus, not all participants were analyzed at all study weeks.

There are four grades for the WHO FC (Class I = none, Class IV = most severe). The WHO FC indicates the severity of Pulmonary Arterial Hypertension and is an adaptation of the New York Heart Association classification. It was assessed by the investigator. Observed data analysis (no imputation technique).

FAS. Participants were followed for different lengths of time; thus, not all participants were analyzed at all study weeks.

Time to clinical worsening was defined as the time from baseline to the first occurrence of death, lung transplantation, hospitalization for PAH treatment, atrial septostomy (a surgical procedure in which a small hole is made in the wall between the left and right atria of the heart), or study discontinuation due to change to other PAH treatment. Time to clinical worsening was measured as the number of participants who experienced these events up to 164.14 weeks.

FAS

mPAP is a measure of cardiopulmonary hemodynamics (echocardiography). Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. Observed data analysis (no imputation technique).

FAS. Participants were followed for different lengths of time; thus, not all participants were analyzed at all study weeks.

CO is a measure of cardiopulmonary hemodynamics (echocardiography). Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. Observed data analysis (no imputation technique).

FAS. Participants were followed for different lengths of time; thus, not all participants were analyzed at all study weeks.

Change from baseline was calculated as each value at Weeks 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, and Withdrawal/Completion minus the baseline value. BNP is a surrogate marker of heart failure and was measured by a central laboratory. Observed data analysis (no imputation techniques).

FAS. Participants were followed for different lengths of time; thus, not all participants were analyzed at all study weeks.

The severity of adverse events was assessed by the investigator; events were assigned to one of the following categories: mild, an event that was easily tolerated by the participant, causing minimal discomfort and not interfering with everyday activities; moderate, an event that was sufficiently discomforting to interfere with normal everyday activities; and severe, an event that prevented normal everyday activities.

Safety Population