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FREEDOM - M: Oral Treprostinil as Monotherapy for the Treatment of Pulmonary Arterial Hypertension (PAH)

A 12-Week, International, Multicenter, Double-Blind, Randomized, Placebo-Controlled Comparison of the Efficacy and Safety of Oral UT-15C Sustained Release Tablets in Subjects With Pulmonary Arterial Hypertension

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00325403
Enrollment
349
Registered
2006-05-12
Start date
2006-10-31
Completion date
2011-04-30
Last updated
2024-01-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pulmonary Hypertension

Keywords

Pulmonary Arterial Hypertension

Brief summary

This study was an international, multicenter, randomized (2:1 active:placebo), double-blind, placebo-controlled study in subjects with PAH who were NOT currently receiving approved therapy for their PAH. Study visits occurred at 4 week intervals for 12 weeks (with an additional visit at Week 11) with the key measure of efficacy being the 6-minute walk test. Study procedures included routine blood tests, medical history, physical exams, disease evaluation, and exercise tests. Two optional substudies were also a part of FREEDOM-M at select centers - a hemodynamic substudy with a right heart catheterization at Baseline and Week 12 and a genetics and biomarkers substudy with blood samples collected at Baseline and Week 12. Patients who completed all assessments for 12 weeks were also eligible to enter an open-label, extension phase study (FREEDOM - EXT).

Interventions

Sustained release oral tablet, twice daily

OTHERPlacebo

Placebo oral tablet twice daily

Sponsors

United Therapeutics
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
12 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

* Between 12 and 75 years of age, inclusive. * Body weight at least 40 kg with a Body Mass Index \< 45 * PAH that is either idiopathic/heritable; associated with repaired congenital systemic-to-pulmonary shunts (repaired ≥ 5 years); associated with collagen vascular disease; associated with HIV. * Previous testing (e.g., right heart catheterization, echocardiography) consistent with the diagnosis of PAH. * Baseline 6-minute walk distance between 200 and 425 meters, inclusive. * Reliable and cooperative with protocol requirements.

Exclusion criteria

* Nursing or pregnant. * Currently receiving an endothelin receptor antagonist, a phosphodiesterase-5 inhibitor, or prostacyclin within 30 days of Baseline. * PAH due to conditions other than noted in the above inclusion criteria. * History of uncontrolled sleep apnea, renal insufficiency, anemia, left sided heart disease, uncontrolled systemic hypertension, or parenchymal lung disease. * Use of an investigational drug within 30 days of Baseline.

Design outcomes

Primary

MeasureTime frameDescription
Six Minute Walk Distance (6MWD)Baseline and Week 12Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 12, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). The six minute walk test was to be conducted 3 to 6 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 12. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Secondary

MeasureTime frameDescription
Clinical Worsening AssessmentBaseline and Week 12Definition of clinical worsening included patients who met at least one of the following criteria during the 12 weeks of the study: 1. Death (all causes excluding accident) 2. Transplantation or atrial septostomy 3. Clinical deterioration as defined by: 1. Hospitalization as a result of PAH, or 2. greater than or equal to 20% decrease in 6MWD from Baseline (or too ill to walk) and a decrease in WHO functional class And 3. Initiation of new PAH specific therapy (i.e., ERA, PDE5-I, prostacyclin)
World Health Organization Functional Classification for PAHBaseline and Week 12Class I: Patients with pulmonary hypertension but without resulting limitation of physical activity. Ordinary physical activity does not cause undue dyspnea or fatigue, chest pain, or near syncope. Class II: Patients with pulmonary hypertension resulting in slight limitation of physical activity. These patients are comfortable at rest, but ordinary physical activity causes undue dyspnea or fatigue, chest pain or near syncope. Class III: Patients with pulmonary hypertension resulting in marked limitation of physical activity. They are comfortable at rest. Ordinary activity causes undue dyspnea or fatigue, chest pain, or near syncope. Class IV: Patients with pulmonary hypertension with inability to carry out any physical activity without symptoms. These patients manifest signs of right heart failure. Dyspnea and/or fatigue may be present even at rest. Discomfort is increased by any physical activity.
Six Minute Walk Distance (6MWD)Baseline and Week 11Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 11, a time expected to correlate with trough treprostinil concentration. The six minute walk test was to be conducted 8 to 13 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 11. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.
Dyspnea-Fatigue IndexBaseline and Week 12The dyspnea-fatigue index has three components, each rated on a scale of 0 to 4, for the magnitude of the task that evokes dyspnea or fatigue, the magnitude of the pace (or effort) with which the task is performed and the associated functional impairment in general activities. The ratings for each component were added to form an aggregate score, which could range from 0, for the worst condition, to 12, for the best.
Symptoms of PAHBaseline and Week 12Defined symptoms of PAH including fatigue, dyspnea, edema, dizziness, syncope, chest pain, and orthopnea were assessed at Baseline prior to starting study drug and during the Treatment Phase at Week 12. Severity grade values (i.e., 0, 1, 2, or 3 in increasing severity) were assigned for each symptom.
Borg Dyspnea ScoreBaseline and Week 12The Borg dyspnea score is a 10-point scale rating the maximum level of dyspnea experienced during the 6-minute walk test. The Borg dyspnea score was assessed immediately following the 6-minute walk test. Scores ranged from 0 (for no shortness of breath) to 10 (for greatest shortness of breath ever experienced).

Countries

Austria, Belgium, Canada, China, France, India, Israel, Italy, Mexico, Netherlands, Poland, Puerto Rico, United States

Participant flow

Recruitment details

349 subjects participated in the study from 24 October 2006 to 29 April 2011 at 52 of 77 sites across the United States, Puerto Rico, Canada, Europe, Israel, India, Mexico, and China. The primary endpoint was analyzed using the primary analysis population which included 228 subjects who had access to 0.25 mg tablets at the time of randomization.

Participants by arm

ArmCount
Placebo
These subjects were randomly allocated to receive placebo twice daily and were included in the primary analysis population. Baseline measures are provided for the modified intention to treat (mITT) group, which includes subjects with access to 0.25 mg tablets at randomization (n=228).
77
UT-15C (Oral Treprostinil)
These subjects were randomly allocated to receive oral treprostinil twice daily and were included in the primary analysis population. Baseline measures are provided for the modified intention to treat (mITT) group, which includes subjects with access to 0.25 mg tablets at randomization (n=228).
151
Total228

Baseline characteristics

CharacteristicUT-15C (Oral Treprostinil)TotalPlacebo
Age, Categorical
<=18 years
9 Participants10 Participants1 Participants
Age, Categorical
>=65 years
1 Participants8 Participants7 Participants
Age, Categorical
Between 18 and 65 years
141 Participants210 Participants69 Participants
Age, Continuous37.8 years
STANDARD_DEVIATION 13.5
39.4 years
STANDARD_DEVIATION 13.7
42.5 years
STANDARD_DEVIATION 13.5
Baseline Six Minute Walk Distance331.3 meters
STANDARD_DEVIATION 64.9
330.0 meters
STANDARD_DEVIATION 66.8
327.6 meters
STANDARD_DEVIATION 70.7
PAH Etiology
Idiopathic or heritable PAH
114 participants170 participants56 participants
PAH Etiology
PAH associated w collagen vascular disease
26 participants43 participants17 participants
PAH Etiology
PAH associated w HIV infection
1 participants2 participants1 participants
PAH Etiology
PAH associated w repaired congenital heart defect
10 participants13 participants3 participants
Sex: Female, Male
Female
108 Participants166 Participants58 Participants
Sex: Female, Male
Male
43 Participants62 Participants19 Participants
WHO Functional Classification
WHO Class I
1 participants2 participants1 participants
WHO Functional Classification
WHO Class II
52 participants76 participants24 participants
WHO Functional Classification
WHO Class III
98 participants150 participants52 participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
6 / 779 / 151
other
Total, other adverse events
68 / 77138 / 151
serious
Total, serious adverse events
15 / 7727 / 151

Outcome results

Primary

Six Minute Walk Distance (6MWD)

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 12, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). The six minute walk test was to be conducted 3 to 6 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 12. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 12

Population: Analyses were conducted using the modified intention to treat (mITT) group, which includes subjects with access to 0.25 mg tablets at randomization (n=228). All alpha was spent on this subgroup, thereby maintaining an overall type I error rate of 0.05. For sensitivity purposes, efficacy analyses were also performed on all enrolled subjects (n=349).

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD)6MWD at Baseline339 meters
PlaceboSix Minute Walk Distance (6MWD)6MWD at Week 12343 meters
PlaceboSix Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 12-5 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Baseline350 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Week 12370 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 1225 meters
Comparison: Using an allocation ratio of 2:1 between oral treprostinil and placebo, a fixed sample size of approximately 195 subjects with access to 0.25 mg tablets at randomization would provide at least 90% power at a significance level of 0.01 (two-sided hypothesis) to detect a between-treatment difference in the change from Baseline to Week 12 in distance traversed during the 6-minute walk, assuming a true underlying treatment difference of 45 meters with a SD of 75 meters in both treatment groups.p-value: 0.012595% CI: [4, 41]ANCOVA
Secondary

Borg Dyspnea Score

The Borg dyspnea score is a 10-point scale rating the maximum level of dyspnea experienced during the 6-minute walk test. The Borg dyspnea score was assessed immediately following the 6-minute walk test. Scores ranged from 0 (for no shortness of breath) to 10 (for greatest shortness of breath ever experienced).

Time frame: Baseline and Week 12

ArmMeasureGroupValue (MEDIAN)
PlaceboBorg Dyspnea ScoreBorg dyspnea score at Baseline3 units on a scale
PlaceboBorg Dyspnea ScoreBorg dyspnea score at Week 123 units on a scale
PlaceboBorg Dyspnea ScoreChange in Borg dyspnea score from Baseline to Wk120 units on a scale
UT-15C (Oral Treprostinil)Borg Dyspnea ScoreBorg dyspnea score at Baseline3 units on a scale
UT-15C (Oral Treprostinil)Borg Dyspnea ScoreBorg dyspnea score at Week 123 units on a scale
UT-15C (Oral Treprostinil)Borg Dyspnea ScoreChange in Borg dyspnea score from Baseline to Wk120 units on a scale
p-value: 0.488795% CI: [-1, 0]Wilcoxon rank-sum test
Secondary

Clinical Worsening Assessment

Definition of clinical worsening included patients who met at least one of the following criteria during the 12 weeks of the study: 1. Death (all causes excluding accident) 2. Transplantation or atrial septostomy 3. Clinical deterioration as defined by: 1. Hospitalization as a result of PAH, or 2. greater than or equal to 20% decrease in 6MWD from Baseline (or too ill to walk) and a decrease in WHO functional class And 3. Initiation of new PAH specific therapy (i.e., ERA, PDE5-I, prostacyclin)

Time frame: Baseline and Week 12

ArmMeasureValue (NUMBER)
PlaceboClinical Worsening Assessment8 participants
UT-15C (Oral Treprostinil)Clinical Worsening Assessment15 participants
p-value: 1Fisher Exact
Secondary

Dyspnea-Fatigue Index

The dyspnea-fatigue index has three components, each rated on a scale of 0 to 4, for the magnitude of the task that evokes dyspnea or fatigue, the magnitude of the pace (or effort) with which the task is performed and the associated functional impairment in general activities. The ratings for each component were added to form an aggregate score, which could range from 0, for the worst condition, to 12, for the best.

Time frame: Baseline and Week 12

Population: Two subjects (one in the placebo arm and one in the oral treprostinil arm) from the primary analysis population (n=228) did not have a Baseline dyspnea-fatigue index score and were not included in this analysis.

ArmMeasureGroupValue (MEAN)Dispersion
PlaceboDyspnea-Fatigue IndexDyspnea-fatigue index at Baseline5.8 units on a scaleStandard Deviation 2.4
PlaceboDyspnea-Fatigue IndexDyspnea-fatigue index at Week 125.5 units on a scaleStandard Deviation 2.9
PlaceboDyspnea-Fatigue IndexChange in dyspnea-fatigue index from BL to Wk 12-0.3 units on a scaleStandard Deviation 2.5
UT-15C (Oral Treprostinil)Dyspnea-Fatigue IndexDyspnea-fatigue index at Baseline6.2 units on a scaleStandard Deviation 2.1
UT-15C (Oral Treprostinil)Dyspnea-Fatigue IndexDyspnea-fatigue index at Week 125.9 units on a scaleStandard Deviation 2.8
UT-15C (Oral Treprostinil)Dyspnea-Fatigue IndexChange in dyspnea-fatigue index from BL to Wk 12-0.3 units on a scaleStandard Deviation 2.4
p-value: 0.611695% CI: [0, 1]Wilcoxon sum-rank test
Secondary

Six Minute Walk Distance (6MWD)

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 4, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). The six minute walk test was to be conducted 3 to 6 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 4. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 4

Population: Analyses were conducted using the modified intention to treat (mITT), which includes subjects who had access to 0.25 mg tablets at randomization (n=228). All alpha was spent on this subgroup, thereby maintaining an overall type I error rate of 0.05. For sensitivity purposes, efficacy analyses were also performed on all enrolled subjects (n=349).

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD)6MWD at Baseline339 meters
PlaceboSix Minute Walk Distance (6MWD)6MWD at Week 4350 meters
PlaceboSix Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 40 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Baseline350 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Week 4360 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 47 meters
p-value: 0.051895% CI: [0, 24]ANCOVA
Secondary

Six Minute Walk Distance (6MWD)

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 11, a time expected to correlate with trough treprostinil concentration. The six minute walk test was to be conducted 8 to 13 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 11. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 11

Population: Analyses were conducted using the modified intention to treat (mITT) group, which includes subjects with access to 0.25 mg tablets at randomization (n=228). All alpha was spent on this subgroup, thereby maintaining an overall type I error rate of 0.05. For sensitivity purposes, efficacy analyses were also performed on all enrolled subjects (n=349).

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 110 meters
PlaceboSix Minute Walk Distance (6MWD)6MWD at Baseline339 meters
PlaceboSix Minute Walk Distance (6MWD)6MWD at Week 11335 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 118 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Baseline350 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Week 11350 meters
p-value: 0.065395% CI: [-2, 33]ANCOVA
Secondary

Six Minute Walk Distance (6MWD)

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 8, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). The six minute walk test was to be conducted 3 to 6 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 8. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 8

Population: Analyses were conducted using the modified intention to treat (mITT) group, which includes subjects with access to 0.25 mg tablets at randomization (n=228). All alpha was spent on this subgroup, thereby maintaining an overall type I error rate of 0.05. For sensitivity purposes, efficacy analyses were also performed on all enrolled subjects (n=349).

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD)6MWD at Baseline339 meters
PlaceboSix Minute Walk Distance (6MWD)6MWD at Week 8347 meters
PlaceboSix Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 80 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Baseline350 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)6MWD at Week 8355 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD)Change in 6MWD from Baseline to Week 817 meters
p-value: 0.030795% CI: [1, 33]ANCOVA
Secondary

Symptoms of PAH

Defined symptoms of PAH including fatigue, dyspnea, edema, dizziness, syncope, chest pain, and orthopnea were assessed at Baseline prior to starting study drug and during the Treatment Phase at Week 12. Severity grade values (i.e., 0, 1, 2, or 3 in increasing severity) were assigned for each symptom.

Time frame: Baseline and Week 12

ArmMeasureGroupValue (MEAN)Dispersion
PlaceboSymptoms of PAHChange in edema symptoms0.3 units on a scaleStandard Deviation 1
PlaceboSymptoms of PAHChange in syncope symptoms0.3 units on a scaleStandard Deviation 1
PlaceboSymptoms of PAHChange in dyspnea symptoms-0.1 units on a scaleStandard Deviation 0.9
PlaceboSymptoms of PAHChange in chest pain symptoms0.1 units on a scaleStandard Deviation 0.9
PlaceboSymptoms of PAHChange in dizziness symptoms0.0 units on a scaleStandard Deviation 1
PlaceboSymptoms of PAHChange in orthopnea symptoms0.2 units on a scaleStandard Deviation 0.9
PlaceboSymptoms of PAHChange in fatigue symptoms0.1 units on a scaleStandard Deviation 1
UT-15C (Oral Treprostinil)Symptoms of PAHChange in orthopnea symptoms0.2 units on a scaleStandard Deviation 1
UT-15C (Oral Treprostinil)Symptoms of PAHChange in fatigue symptoms0.0 units on a scaleStandard Deviation 1
UT-15C (Oral Treprostinil)Symptoms of PAHChange in dyspnea symptoms-0.2 units on a scaleStandard Deviation 0.9
UT-15C (Oral Treprostinil)Symptoms of PAHChange in edema symptoms0.2 units on a scaleStandard Deviation 1.1
UT-15C (Oral Treprostinil)Symptoms of PAHChange in dizziness symptoms0.3 units on a scaleStandard Deviation 1
UT-15C (Oral Treprostinil)Symptoms of PAHChange in syncope symptoms0.3 units on a scaleStandard Deviation 0.9
UT-15C (Oral Treprostinil)Symptoms of PAHChange in chest pain symptoms0.2 units on a scaleStandard Deviation 1
Secondary

World Health Organization Functional Classification for PAH

Class I: Patients with pulmonary hypertension but without resulting limitation of physical activity. Ordinary physical activity does not cause undue dyspnea or fatigue, chest pain, or near syncope. Class II: Patients with pulmonary hypertension resulting in slight limitation of physical activity. These patients are comfortable at rest, but ordinary physical activity causes undue dyspnea or fatigue, chest pain or near syncope. Class III: Patients with pulmonary hypertension resulting in marked limitation of physical activity. They are comfortable at rest. Ordinary activity causes undue dyspnea or fatigue, chest pain, or near syncope. Class IV: Patients with pulmonary hypertension with inability to carry out any physical activity without symptoms. These patients manifest signs of right heart failure. Dyspnea and/or fatigue may be present even at rest. Discomfort is increased by any physical activity.

Time frame: Baseline and Week 12

Population: Subjects with a WHO functional classification assessment at Week 12.

ArmMeasureGroupValue (NUMBER)
PlaceboWorld Health Organization Functional Classification for PAHWHO Class III38 participants
PlaceboWorld Health Organization Functional Classification for PAHWHO Class II29 participants
PlaceboWorld Health Organization Functional Classification for PAHWHO Class IV9 participants
PlaceboWorld Health Organization Functional Classification for PAHWHO Class I1 participants
UT-15C (Oral Treprostinil)World Health Organization Functional Classification for PAHWHO Class IV15 participants
UT-15C (Oral Treprostinil)World Health Organization Functional Classification for PAHWHO Class II59 participants
UT-15C (Oral Treprostinil)World Health Organization Functional Classification for PAHWHO Class III75 participants
UT-15C (Oral Treprostinil)World Health Organization Functional Classification for PAHWHO Class I2 participants
p-value: 0.73895% CI: [0, 0]Wilcoxon rank sum test
Post Hoc

Six Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAH

Exploratory efficacy analyses were to determine the effect of PAH etiology (idiopathic/heritable, associated with collagen vascular disease, and other etiologies) on treatment effect for change in 6MWD. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 12. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 12

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAH6MWD at Baseline332.5 meters
PlaceboSix Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAH6MWD at Week 12310.5 meters
PlaceboSix Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAHChange in 6MWD from BL to Wk 12-7.5 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAH6MWD at Baseline346 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAH6MWD at Week 12380 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) by PAH Etiology: Idiopathic or Heritable PAHChange in 6MWD from BL to Wk 1225 meters
p-value: 0.002495% CI: [10, 55]ANCOVA
Post Hoc

Six Minute Walk Distance (6MWD) for the Entire Study Population

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 4, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). This outcome measure was assessed using data from all subjects enrolled in the study, regardless of tablet strength availability at randomization. The six minute walk test was to be conducted 3 to 6 house after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 4. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 4

Population: This analysis was performed using data from all subjects enrolled in the study, regardless of tablet strength availability at randomization.

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline338.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 4339.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 4-4 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline347 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 4358 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 47 meters
p-value: 0.002595% CI: [3.9, 25]ANCOVA
Post Hoc

Six Minute Walk Distance (6MWD) for the Entire Study Population

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 11, a time expected to correlate with trough treprostinil concentration. This outcome measure was assessed using data from all subjects enrolled in the study, regardless of tablet strength availability at the time of randomization. The six minute walk test was to be conducted 8 to 13 hours after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 11. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 11

Population: This analysis was performed using data from all subjects enrolled in the study, regardless of tablet strength availability at randomization.

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline338.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 11326.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 11-2 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline347 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 11351 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 116 meters
p-value: 0.002595% CI: [3, 33]ANCOVA
Post Hoc

Six Minute Walk Distance (6MWD) for the Entire Study Population

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 8, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). This outcome measure was assessed using data from all subjects enrolled in the study, regardless of tablet strength availability at randomization. The six minute walk test was to be conducted 3 to 6 house after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 8. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 8

Population: This analysis was performed using data from all subjects enrolled in the study, regardless of tablet strength availability at randomization.

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline338.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 8339.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 81.0 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline347 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 8360 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 817.0 meters
p-value: 0.000895% CI: [7, 34]ANCOVA
Post Hoc

Six Minute Walk Distance (6MWD) for the Entire Study Population

Placebo corrected change in six minute walk distance (6MWD) from Baseline to Week 12, correlates with the historical clinical standard for assessing patient functional status in the treatment of PAH and is considered an objective measure of patient functional status by the American Thoracic Society (ATS). This outcome measure was assessed using data collected from all subjects enrolled in the study, regardless of tablet strength availability at randomization. The six minute walk test was to be conducted 3 to 6 house after the previous dose of study drug. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Wk 12. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference i

Time frame: Baseline and Week 12

Population: This analysis was performed using data from all subjects enrolled in the study, regardless of tablet strength availability at randomization.

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline338.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 12329.5 meters
PlaceboSix Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 120 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Baseline347 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study Population6MWD at Week 12370 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance (6MWD) for the Entire Study PopulationChange in 6MWD from Baseline to Week 1225 meters
p-value: 0.000195% CI: [10, 41]ANCOVA
Post Hoc

Six Minute Walk Distance by Baseline WHO Functional Classification III or IV

Exploratory efficacy analyses were to determine the effect of Baseline WHO functional class on treatment effect for change in 6MWD. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 12. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 12

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance by Baseline WHO Functional Classification III or IV6MWD at Baseline333.5 meters
PlaceboSix Minute Walk Distance by Baseline WHO Functional Classification III or IV6MWD at Week 12316.5 meters
PlaceboSix Minute Walk Distance by Baseline WHO Functional Classification III or IVChange in 6MWD from Baseline to Week 12-8.5 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance by Baseline WHO Functional Classification III or IV6MWD at Baseline330 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance by Baseline WHO Functional Classification III or IV6MWD at Week 12354 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance by Baseline WHO Functional Classification III or IVChange in 6MWD from Baseline to Week 1220.5 meters
p-value: 0.032695% CI: [1, 49]ANCOVA
Post Hoc

Six Minute Walk Distance by Baseline WHO Functional Classification: I or II

Exploratory efficacy analyses were to determine the effect of Baseline WHO functional class on treatment effect for change in 6MWD. The Hodges-Lehmann median difference between treatment groups was used to estimate the treatment effect on 6MWD from Baseline to Week 12. A rank-based methodology was used instead of parametric-based methodology to avoid statistical bias caused by extreme outliers resulting from the handling of data that are missing due to death or clinical worsening of PAH. It is a more robust estimator than the between-treatment difference in medians.

Time frame: Baseline and Week 12

ArmMeasureGroupValue (MEDIAN)
PlaceboSix Minute Walk Distance by Baseline WHO Functional Classification: I or II6MWD at Baseline370 meters
PlaceboSix Minute Walk Distance by Baseline WHO Functional Classification: I or II6MWD at Week 12379 meters
PlaceboSix Minute Walk Distance by Baseline WHO Functional Classification: I or IIChange in 6MWD from Baseline to Week 1218 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance by Baseline WHO Functional Classification: I or II6MWD at Baseline366 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance by Baseline WHO Functional Classification: I or II6MWD at Week 12391 meters
UT-15C (Oral Treprostinil)Six Minute Walk Distance by Baseline WHO Functional Classification: I or IIChange in 6MWD from Baseline to Week 1227 meters
p-value: 0.227595% CI: [-15, 47]ANCOVA

Source: ClinicalTrials.gov · Data processed: Mar 24, 2026