This was an international, multicenter, open-label study designed to provide oral treprostinil for eligible subjects who participated in Studies TDE-PH-301, TDE-PH-302, TDE-PH-308, TDE-PH-202, TDE PH 203, and TDE-PH-205. Subjects randomly allocated to receive oral treprostinil in Studies TDE-PH-301, TDE-PH-302, or TDE-PH-308 and enrolled in this open-label study completed visits at Months 6, 12, 24, 36, and yearly visits thereafter. Subjects randomly allocated to receive placebo in Studies TDE-PH-301, TDE-PH-302, or TDE-PH-308 completed visits at Months 3, 6, 12, 24, 36, and yearly visits thereafter. Subjects that transitioned from Studies TDE-PH-202, TDE-PH-203, and TDE-PH-205 (that had an open-label study design) followed the regimen for subjects receiving oral treprostinil. A 6-Minute Walk Test (6MWT) and Borg dyspnea score were conducted at the visit which occurred 12 months after the subject's first exposure to oral treprostinil.~Adverse events (AEs) were reported continuously throughout the study; any AEs ongoing at the time of discharge from Studies TDE PH-301, TDE PH-302, TDE-PH-308, TDE-PH-202, TDE-PH-203, and TDE-PH-205 were recorded as AEs and marked as ongoing from previous study in the subject's electronic Case Report Form (eCRF). Study drug dosing and pulmonary arterial hypertension (PAH) concomitant medication usage were assessed at each scheduled study visit and recorded in the subject's eCRF.
This study provided/continued to provide oral treprostinil (UT-15C SR; treprostinil diethanolamine) to eligible subjects who participated in Studies TDE-PH-202, TDE-PH-203, TDE-PH-205, TDE-PH-301, TDE-PH-302, and TDE-PH-308. The study assessed the long term safety of oral treprostinil and the effect of continued treatment with oral treprostinil on exercise capacity after 1 year of treatment.