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Safety and Efficacy of APD811 in Pulmonary Arterial Hypertension

A Randomized, Double-blind, Parallel-group, Placebo-controlled Phase 2 Trial of Ralinepag, an Oral IP Receptor Agonist, in Patients With Pulmonary Arterial Hypertension

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02279160
Enrollment
61
Registered
2014-10-30
Start date
2014-12-31
Completion date
2017-06-30
Last updated
2020-07-14

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

Conditions

Pulmonary Arterial Hypertension

Brief summary

The study was conducted as a placebo-controlled, randomized, 22-week double-blind study which included a dose titration period. An additional transition period occurred for those patients who elected to enroll into the open-label extension study, APD811-007. A total of 61 patients with PAH were enrolled.

Detailed description

Study APD811-003 was a 22-week, randomized, double-blind, parallel-group, placebo-controlled study in subjects with symptomatic WHO Group 1 PAH. The study consisted of a dose titration period of up to 9 weeks, a 13-week maintenance period, and a follow-up visit that was to occur approximately 3 weeks after the end of the maintenance period (Week 25). The transition period of 3 weeks (±1 week) was to occur for those subjects who elected to enroll into the open-label extension (OLE) Study APD811-007. Approximately 60 subjects with PAH were planned to be enrolled (61 actual). After screening, eligible subjects were randomized 2:1 to ralinepag (APD811) or to placebo. Randomization was stratified by baseline WHO/NYHA functional class (II versus III or IV). Subjects randomized to active therapy were given ralinepag at a starting dose of 0.01 mg BID. Subjects randomized to the placebo arm received matching placebo capsules to preserve the blind. Subjects were instructed to take the study drug (ralinepag or placebo) with food. Dosage was then uptitrated, as tolerated, over the course of the 9-week dose-titration period to a maximum dose of 0.3 mg BID. Although doses could be reduced based on tolerability, the final dosage reached was required to be stable during the 13-week treatment period prior to evaluation at Week 22. Subjects could receive concomitant oral disease-specific PAH therapy consisting of an ERA and/or an agent acting on the nitric oxide pathway, a PDE-5 inhibitor or a sGC stimulator, provided the dose had remained stable for at least 3 months prior to the start of screening. It was recommended that subjects continue the same dose and regimen of these medications for the duration of the study. With the exception of prostanoids, the use of other supporting therapies, which may affect PAH, was also permitted. During the study, assessments of efficacy were performed including PVR and other hemodynamic parameters as determined by RHC, the 6MWT, assessment of clinical worsening, BNP and NT-proBNP levels, WHO/NYHA functional class assessment of PAH. Safety assessments included standard evaluations of AEs, clinical laboratory values, vital signs, and ECG measurements. At the end of the maintenance period, subjects who did not choose to participate in the OLE study were to discontinue study drug (ralinepag or placebo). All subjects that chose to continue in the OLE study were to remain on study drug until the follow-up visit at Week 25. This visit served as the baseline visit for the OLE study if the subject was eligible and chose to participate.

Interventions

DRUGAPD811
DRUGPlacebo

Placebo

Sponsors

United Therapeutics
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

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

Inclusion criteria

* Males or females aged 18-75 years, inclusive * Symptomatic WHO Group 1 PAH classified by one of the following subgroups: * Idiopathic pulmonary arterial hypertension (IPAH); * Heritable pulmonary arterial hypertension (HPAH); * Drugs and toxins induced; * Associated pulmonary arterial hypertension (APAH); specifically connective tissue diseases, HIV infection and congenital heart disease. * Has had the diagnosis of PAH confirmed by cardiac catheterization * Has WHO/NYHA functional class II- IV symptomatology * Previously diagnosed with PAH and on stable oral disease-specific PAH therapy with either an ERA and/or an agent acting on the nitric oxide pathway, i.e. a PDE5 inhibitor or a soluble guanylate cyclase stimulator. Stable is defined as no change in dose within 3 months of the start of Screening and for the duration of the study * Has 6MWT distances of 100-500 m, and within 15% of each other on 2 consecutive tests done on different days at Screening * Has pulmonary function tests (PFTs) within 6 months prior to the start of Screening with no evidence of significant parenchymal lung disease * Has a ventilation-perfusion (V/Q) lung scan or pulmonary angiogram within 5 years prior to Screening and concomitant with or following diagnosis of PAH that shows no evidence of thromboembolic disease * If on vasodilators (including calcium channel blockers), digoxin, spironolactone, or L-Arginine supplementation; the patient must be on a stable dose for at least 1 month prior to the start of Screening

Exclusion criteria

* Newly diagnosed with PAH and on no disease-specific PAH therapy * Previous participation in any clinical study with an investigational drug, biologic, or device within 2 months prior to the Screening visit * Acutely decompensated heart failure within 1 month prior to start of Screening * Systolic blood pressure \<90 mm Hg at Screening * Evidence or history of left-sided heart disease and/or clinically significant cardiac disease * Use or chronic administration (defined as \>30 days) of a prostacyclin or prostacyclin analogue within 3 months of Screening * Any previous use of a prostacyclin or prostacyclin analogue that was stopped for safety or tolerability issues associated with pharmacology/mechanism of action * Other severe acute or chronic medical or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the patient inappropriate for entry into this study

Design outcomes

Primary

MeasureTime frameDescription
Change From Baseline in Pulmonary Vascular Resistance (PVR)Baseline and 22 WeeksMeasurements of PVR from right heart catheterization were obtained prior to Day 1 of the dose titration period and at the end of the maintenance period (Week 22), approximately 4 hours after the last dose of study drug.
Change From Baseline in 6-minute Walk Distance (6MWD) in Patients With PAHBaseline and 22 WeeksThe 6MWT was conducted according to the modified guidelines issued by the American Thoracic Society prior to Day 1 of the dose titration period and at the end of the maintenance period (Week 22).

Countries

Australia, Bulgaria, Czechia, Hungary, Poland, Romania, Serbia, Spain, United States

Participant flow

Participants by arm

ArmCount
APD811
Multiple dose titration to maximum tolerated dose. APD811
40
Placebo
Multiple dose titration to maximum tolerated dose. Placebo
21
Total61

Baseline characteristics

CharacteristicAPD811TotalPlacebo
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
1 Participants4 Participants3 Participants
Age, Categorical
Between 18 and 65 years
39 Participants57 Participants18 Participants
Age, Continuous46.5 years51 years60 years
Baseline 6MWD405 meters400 meters367 meters
Baseline Pulmonary Vascular Resistance704.6 dyn*sec/cm^-5575.7 dyn*sec/cm^-5479.7 dyn*sec/cm^-5
Baseline WHO/NYHA Functional Class
Class I
0 Participants0 Participants0 Participants
Baseline WHO/NYHA Functional Class
Class II
22 Participants34 Participants12 Participants
Baseline WHO/NYHA Functional Class
Class III
17 Participants26 Participants9 Participants
Baseline WHO/NYHA Functional Class
Class IV
1 Participants1 Participants0 Participants
BMI27.18 kg/m^227.13 kg/m^225.68 kg/m^2
Duration of PAH (Years)2.22 years2 years1.76 years
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants4 Participants2 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
38 Participants57 Participants19 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Height160.5 cm161 cm162 cm
PAH Classification
Associated PAH
11 Participants20 Participants9 Participants
PAH Classification
Drugs or Toxin Induced
4 Participants4 Participants0 Participants
PAH Classification
Heritable PAH
4 Participants5 Participants1 Participants
PAH Classification
Idiopathic PAH
21 Participants32 Participants11 Participants
PAH Treatment
Combination Therapy (ERA + PDE5-Inhibitor/sGCS)
26 Participants36 Participants10 Participants
PAH Treatment
Monotherapy (ERA or PDE5-Inhibitor)
14 Participants25 Participants11 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
1 Participants1 Participants0 Participants
Race (NIH/OMB)
Black or African American
1 Participants1 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants2 Participants2 Participants
Race (NIH/OMB)
White
38 Participants57 Participants19 Participants
Region of Enrollment
Australia
6 participants10 participants4 participants
Region of Enrollment
Bulgaria
2 participants2 participants0 participants
Region of Enrollment
Czechia
3 participants4 participants1 participants
Region of Enrollment
Hungary
0 participants3 participants3 participants
Region of Enrollment
Poland
1 participants4 participants3 participants
Region of Enrollment
Romania
3 participants6 participants3 participants
Region of Enrollment
Serbia
8 participants11 participants3 participants
Region of Enrollment
Spain
7 participants9 participants2 participants
Region of Enrollment
United States
10 participants12 participants2 participants
Sex: Female, Male
Female
33 Participants53 Participants20 Participants
Sex: Female, Male
Male
7 Participants8 Participants1 Participants
Weight73.5 kg72.5 kg68 kg

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 402 / 21
other
Total, other adverse events
40 / 4019 / 21
serious
Total, serious adverse events
4 / 406 / 21

Outcome results

Primary

Change From Baseline in 6-minute Walk Distance (6MWD) in Patients With PAH

The 6MWT was conducted according to the modified guidelines issued by the American Thoracic Society prior to Day 1 of the dose titration period and at the end of the maintenance period (Week 22).

Time frame: Baseline and 22 Weeks

Population: Modified Intent-to-Treat Population

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
APD811Change From Baseline in 6-minute Walk Distance (6MWD) in Patients With PAH36.2 metersStandard Error 11.79
PlaceboChange From Baseline in 6-minute Walk Distance (6MWD) in Patients With PAH29.4 metersStandard Error 16.16
p-value: 0.900295% CI: [-28, 30]Stratified Wilcoxon
Primary

Change From Baseline in Pulmonary Vascular Resistance (PVR)

Measurements of PVR from right heart catheterization were obtained prior to Day 1 of the dose titration period and at the end of the maintenance period (Week 22), approximately 4 hours after the last dose of study drug.

Time frame: Baseline and 22 Weeks

Population: Intent-to-Treat Population

ArmMeasureValue (GEOMETRIC_MEAN)Dispersion
APD811Change From Baseline in Pulmonary Vascular Resistance (PVR)514.6 dyn*sec/cm^5Standard Deviation 1.85
PlaceboChange From Baseline in Pulmonary Vascular Resistance (PVR)512.0 dyn*sec/cm^5Standard Deviation 1.62
p-value: 0.02295% CI: [0.575, 0.958]ANCOVA

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026