Oral Treprostinil in Subjects With Pulmonary Hypertension Associated With Heart Failure With Preserved Ejection Fraction

Study TDE-HF-301 was a multicenter, randomized, double-blind, placebo-controlled study designed to investigate the effect of oral treprostinil compared with placebo on exercise capacity in subjects with WHO Group 2 PH associated with HFpEF. Once randomized, subjects were dispensed study drug and took an initial dose (0.125 mg) at the study site on the day of randomization. Dosing of study drug continued at 0.125 mg 3 times daily (TID; every 6 to 8 hours) with food. Dose increases could occur in 0.125-mg increments every 72 hours at the discretion of the Investigator up to a maximum allowable dose of 6 mg TID. Subjects received oral treprostinil as 0.125, 0.25, 1.0, or 2.5 mg sustained-release osmotic tablets (maximum dose 6 mg TID) or matching placebo. Doses of study drug were to be increased in the absence of dose-limiting drug-related adverse events (AEs) to ensure that each subject received the optimal dose throughout the study. Subjects returned for visits at Weeks 6, 12, 18, and 24. Subjects who terminated study drug early were asked to complete all remaining study visits. The study had an adaptive design where the maximum allowable dose was 2 mg until the Data Monitoring Committee had confirmed a satisfactory safety profile. After this confirmation, the maximum allowable dose was increased to 4 mg TID. This occurred after 45 subjects had been enrolled. A subsequent Data Monitoring Committee meeting, which occurred after 75 subjects had been enrolled, increased the maximum allowable dose to 6 mg TID. Efficacy assessments consisted of 6-Minute Walk Distance (6MWD), blood collection for N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, clinical worsening, WHO Functional Class (FC), Borg dyspnea score, glycated hemoglobin (HbA1c), and Kansas City Cardiomyopathy Questionnaire (KCCQ). Safety assessments consisted of AEs, physical examinations, vital signs, 12-lead electrocardiograms (ECGs), echocardiograms (ECHOs), heart failure signs and symptoms, pregnancy testing, clinical laboratory tests, hospitalizations due to cardiopulmonary indication, and worsening heart failure as demonstrated by outpatient administration of intravenous (IV) diuretics. Subjects could have optionally provided samples for the evaluation of biomarkers and pharmacogenomics. Subjects that completed the 24-week treatment period on study drug were permitted to enter the open-label extension study (Study TDE-HF-302). The study was discontinued by the Sponsor on 14 October 2019 due to slow enrollment. As only a small portion of the anticipated total subjects had been enrolled, with many terminating early due to the study termination, there was a limited ability to explore the effect of oral treprostinil in this indication in this study.