Addition of UT-15C SR to Pulmonary Arterial Hypertension Patients Currently Receiving Tyvaso®

This was a multi-center, open-label, safety and tolerability study in WHO Group 1 PAH subjects adding UT-15C SR to Tyvaso and PAH approved background therapy. This study had a 24-week evaluation period followed by a long term safety period. Six study visits occurred in the first 24 weeks of study; Screening, Baseline, Week 4, Week 8, Week 12, and Week 24 visits. Right heart catheterization occurred between 2-4 hours following the last Tyvaso dose at Baseline (prior to the administration of UT-15C SR) and Week 24.