Adults 18 to 75, any sex, with Pulmonary Arterial Hypertension. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Time to First Clinical Worsening EventPrimary· From randomization to approximately 4 years
Clinical worsening was assessed continuously from randomization until the subject's last study visit. Clinical worsening events were defined as death (all causes), hospitalizations due to worsening pulmonary arterial hypertension (PAH), initiation of an inhaled or infused prostacyclin (PGI2) for the treatment of worsening PAH, disease progression, or unsatisfactory long-term clinical response. All clinical worsening events reported by the study sites were reviewed by the Sponsor Medical Monitors. Once a clinical worsening event occurred, it was entered in the eCRF and a narrative was submitted
Group
Value
95% CI
UT-15C
60.58
± 42.93
Placebo
49.31
± 46.28
Change in 6-Minute Walk DistanceSecondary· From Baseline to Week 24
The intent of the 6-Minute Walk Test (6MWT) is to evaluate exercise capacity associated with carrying out activities of daily living. A baseline 6MWT was performed prior to initiation of study drug on the day of randomization. 6MWTs were conducted at Weeks 4, 8, 12, 24, and every 12 weeks thereafter. The change between Baseline and Week 24 is reported.
Baseline
Group
Value
95% CI
UT-15C
392.9
± 92.5
Placebo
398.5
± 100.00
Week 24
Group
Value
95% CI
UT-15C
395.4
± 120.0
Placebo
372.3
± 163.0
Change in Plasma N-Terminal Pro-brain Natriuretic Peptide (NT-proBNP) From Baseline to Week 24Secondary· From Baseline to Week 24
Plasma NT-proBNP concentration is a useful biomarker for the severity of PAH as it is associated with changes in right heart morphology and function. NT-proBNP sample collection occurred at Baseline (prior to starting study drug), Week 12, Week 24, the first Continued Visit, and every other Continued Visit thereafter (ie, Continued Visits 3, 5, 7, etc). NT-proBNP was also assessed at the Study Drug Termination Visit. The change between Baseline and Week 24 is reported.
Group
Value
95% CI
UT-15C
0.7859
± 1.05470
Placebo
1.1230
± 1.05439
Change in World Health Organization Functional Class (WHO FC) From Baseline to Week 48Secondary· Baseline to Week 48
The WHO FC for PAH was assessed at Baseline prior to starting study drug, at all subsequent scheduled study visits, and every time the 6MWT was performed for purposes of assessing clinical worsening status.
Group
Value
95% CI
UT-15C
46
Placebo
38
UT-15C
203
Placebo
170
UT-15C
66
Placebo
103
Adverse events — posted to ClinicalTrials.gov
Time frame: The study lasted 6 years; however, subjects remained in the study for various durations. The longest subject duration in the study was 5.1 years..
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
This is an international, multicenter, randomized, double-blind, placebo-controlled, event driven study in subjects with pulmonary arterial hypertension.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
Other recruiting trials for Pulmonary Arterial Hypertension
Currently open trials in the same condition.
NCT07391228 — Cognitive Alterations in Pulmonary Arterial Hypertension (PAH)
· active not recruiting
NCT06351345 — 129 Xenon Imaging in Patients Treated With Sotatercept
· Phase 2
· recruiting
NCT07217522 — Rutgers University Study of the Genetics of Pulmonary Hypertension
· recruiting
NCT07013149 — The Impact of ERA Switching on Risk Stratification in Pulmonary Arterial Hypertension
· recruiting
NCT06658522 — Right Ventricular Compensation With Sotatercept: A Prospective Single Arm Open Label Phase 4 Study to Evaluate the Effec
· Phase 4
· recruiting
Other United Therapeutics trials
Trials by the same sponsor.
NCT06388421 — DeciPHer-ILD: A Real-world Patient Registry in Group 3 Pulmonary Hypertension Associated With Interstitial Lung Disease
· recruiting
NCT05060315 — Evaluate Real-World Use of Next Generation Infusion Pumps to Administer Remodulin
· terminated
NCT05203510 — A Study of a Mean Pulmonary Artery Pressure-Targeted Approach With Early and Rapid Treprostinil Therapy to Reverse Right
· Phase 4
· active not recruiting
NCT05255991 — Multinational Study of Efficacy and Safety of Inhaled Treprostinil in Subjects With Idiopathic Pulmonary Fibrosis
· Phase 3
· completed
NCT04708782 — Study of Efficacy and Safety of Inhaled Treprostinil in Subjects With Idiopathic Pulmonary Fibrosis
· Phase 3
· completed
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by United Therapeutics
Last refreshed: 13 February 2020
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT01560624.