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

United Therapeutics349 enrolled

Overview

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).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

349

Conditions

Pulmonary Hypertension

Interventions

Eligibility

Sex: ALLMin age: 12 YearsMax age: 75 Years

Medical Language ↔ Plain English

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.

Locations (77)

University of Alabama-Birmingham

Birmingham, Alabama, United States

Arizona Pulmonary Specialist

Phoenix, Arizona, United States

Mayo Clinic Arizona

Phoenix, Arizona, United States

University of California, San Francisco-Fresno

Fresno, California, United States

West Los Angeles VA Healthcare Center

Los Angeles, California, United States

Outcomes

Primary Outcomes

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

Secondary Outcomes

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

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

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

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

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

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

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

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