A Dose Response Study of UT-15C SR in Patients With Exercise-Induced Pulmonary Hypertension

Prospective, randomized, parallel group study with two periods: a 10 week, dose titration period, followed by a 2 week, dose maintenance period in patients with exercise-induced PH. The study population will be randomized into Dose Group 1, Dose Group 2, or an Individual Maximum Tolerated Dose (iMTD) of UT-15C SR by Week 10 and maintained through Week 12. Patients may be either currently receiving an approved oral background therapy for their PH (phosphodiesterase-5 \[PDE-5\] inhibitor, OR endothelin receptor antagonist \[ERA\]) (no dual background therapy), or not currently receiving therapy for PH.