Completed

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Safety and Efficacy Study of Sitaxsentan Sodium (Thelin™) Treatment With an Open-Label Bosentan Arm in Patients With Pulmonary Arterial Hypertension (PAH)

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What is being tested

Data Collection

Who is being recruted

Pulmonary Arterial Hypertension+5

+ Cardiovascular Diseases

+ Hypertension

From 12 to 75 Years
See all eligibility criteria
How is the trial designed

Treatment Study

Phase 3
Interventional
Study Start: May 2003
See protocol details

Summary

Principal SponsorEncysive Pharmaceuticals
Last updated: January 14, 2026
Sourced from a government-validated database.Claim as a partner

Study start date: May 1, 2003

Actual date on which the first participant was enrolled.

The purpose of this study is to evaluate the safety and efficacy of Thelin™ (sitaxsentan sodium) as compared to placebo in the treatment of patients with PAH. A cohort of patients will be randomized to usual treatment with Tracleer® (bosentan) for observational comparisons of safety and efficacy.

Official TitleA Phase 3, Randomized, Double-Blind, Placebo-Controlled Safety and Efficacy Study of Sitaxsentan Sodium (Thelin™) Treatment With an Open-Label Bosentan Arm in Patients With Pulmonary Arterial Hypertension (PAH) 
NCT00080457
Principal SponsorEncysive Pharmaceuticals
Last updated: January 14, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details

240 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

Treatment Study

These studies test new ways to treat a disease, condition, or health issue. The goal is to see if a new drug, therapy, or approach works better or has fewer side effects than existing options.


Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria

Any sex

Biological sex of participants that are eligible to enroll.

From 12 to 75 Years

Range of ages for which participants are eligible to join.

Healthy volunteers not allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

Pulmonary Arterial HypertensionCardiovascular DiseasesHypertensionHypertension, PulmonaryLung DiseasesRespiratory Tract DiseasesVascular DiseasesFamilial Primary Pulmonary Hypertension

Criteria

Inclusion Criteria: * Have a current diagnosis of symptomatic PAH classified by one of the following: 1. primary pulmonary hypertension (PPH) - also known as idiopathic pulmonary arterial hypertension (IPAH); 2. PAH associated with connective tissue diseases; 3. PAH associated with one of the following congenital heart defects: 1. repaired ASD, VSD or PDA greater than one year post-operative 2. un-repaired secundum ASD (with resting oxygen saturation greater than 88 percent in room air measured by oximeter) * World Health Organization (WHO) functional class II, III, IV * Greater than 12 and less than 75 years of age * Women of childbearing potential must be using two forms of medically acceptable contraception (at least one barrier method) * Have a cardiac catheterization within 6 months before study entry that shows the following values: 1. mean pulmonary artery pressure (PAPm) greater than 25 mmHg (at rest), 2. pulmonary capillary wedge pressure (PCWP) or left ventricular-end diastolic pressure less than 15 mmHg, and 3. pulmonary vascular resistance (PVR) greater than 3 mmHg/L/min. Exclusion Criteria: * Portal hypertension or chronic liver disease * ALT or AST levels greater than 1.5 times the upper limit of normal at the Screening Visit * Contraindication to treatment with an endothelin receptor antagonist * Recent history of abusing alcohol or illicit drugs * Chronic renal insufficiency * Pregnant or breastfeeding * Atrial septostomy within 30 days before study entry * Previous failure on bosentan because of safety concerns of the lack of clinical response

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 1 location

Suspended

Encysive Pharmaceuticals

Houston, United StatesSee the location
CompletedOne Study Center