All subjects who received oral treprostinil in TDE-PH-311 were included in the Safety population. All AEs were captured from the time the ICF was signed. All AEs were followed until resolution (or return to normal or baseline values), until they were judged by the Investigator to no longer be clinically significant, or for up to 30 days if the AE extended beyond the final visit. All SAEs were followed until resolution, death, or the subject was lost to follow-up, even if they were ongoing more than 30 days after completion of the final visit. The overall summary of AEs includes the number of subjects with any AE, the number of subjects with any study drug-related AEs, the number of subjects with AEs leading to study drug withdrawal, the number of subjects with any serious AEs, the number of subjects with any severe AEs, and the number of subjects with any study drug-related severe/serious AEs. AEs were coded using the Medical Dictionary for Regulatory Activities.

All subjects who received oral treprostinil in TDE-PH-311 were included in the Safety population.

A summary of change from Baseline in 6MWD at Week 48 for the Safety Population is provided. The Safety Population is all subjects who received oral treprostinil in TDE-PH-311.

All participants are subjects who received oral treprostinil in TDE-PH-311. For post-Baseline visits, only subjects with measurements at Baseline and the corresponding visit are included. Baseline is defined as the last measurement prior to the first dose of oral treprostinil in TDE-PH-311.

Change in Borg Dyspnea Score from at Week 48 is provided for the Safety Population (all subjects who received oral treprostinil in TDE-PH-311).

The Borg Dyspnea Scale is a 0 to 10 rated numerical score used to measure dyspnea as reported by the patient during submaximal exercise and was administered during six-minute walk testing (6MWT), one of the most common and frequently used measures to assess disease severity in PAH. The numbers on the scale are as follows: 0 (no shortness of breath [SOB]), 0.5 (very very slight SOB), 1 (very slight SOB), 3 (moderate SOB), 4 (somewhat severe SOB), 5 (severe SOB), 7 (very severe SOB), 9 (very very severe SOB), 10 (maximal SOB).

Safety Population (all subjects who received oral treprostinil in TDE-PH-311). For post-Baseline visits, only subjects with measurements at Baseline and the corresponding visit are included. Baseline is defined as the last measurement prior to the first dose of oral treprostinil in TDE-PH-311.

Change from Baseline at Week 48 in WHO FC in the Safety Population (all subjects who received oral treprostinil in TDE-PH-311).

The World Health Organization functional classification (WHO-FC) is a clinician-rated assessment used widely to assess PAH severity and functioning.

Class I (least severe): Patients are without limitation of physical activity.

Class II: Patients are comfortable at rest. Ordinary physical activity causes undue dyspnea or fatigue, chest pain or near syncope.

Class III: Marked limitation of physical activity. They are comfortable at rest.

Class IV (most severe): Inability to carry out any physical activity without symptoms. These patients manifest signs of right heart failure.

Safety Population was analyzed. Baseline is defined as the last measurement prior to the first dose of oral treprostinil in TDE PH 311.

Change in N-terminal pro-brain natriuretic peptide from Baseline at Week 48 for the Safety Population (any subject who received oral treprostinil in TDE-PH-311)

Subjects in the Safety Population were analyzed. For post-Baseline visits, only subjects with measurements at Baseline and the corresponding visit are included. Baseline is defined as the last measurement prior to the first dose of oral treprostinil in TDE-PH-311.