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Sitaxsentan Efficacy And Safety Trial With A Randomized Prospective Assessment Of Adding Sildenafil (SR-PAAS)

This study has been terminated.
(Safety Issue: The trial was prematurely terminated on Dec 9, 2010, due to safety concerns, specifically new emerging evidence of hepatic injury.)
Information provided by (Responsible Party):
Pfizer Identifier:
First received: November 20, 2008
Last updated: March 4, 2015
Last verified: March 2015
This protocol is for subjects with pulmonary arterial hypertension and is the first of 3 studies forming the Sitaxsentan efficacy and safety trial with Randomized Prospective Assessment of Adding Sildenafil (SR-PAAS) program.

Condition Intervention Phase
Pulmonary Arterial Hypertension Pulmonary Hypertension Drug: Sitaxsentan Drug: Placebo Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator)
Primary Purpose: Treatment
Official Title: A Phase 3, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Safety And Efficacy Study Of Sitaxsentan Sodium In Subjects With Pulmonary Arterial Hypertension

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Change From Baseline in Total Distance Walked During 6 Minute Walk Distance (6MWD) at Week 12 [ Time Frame: Baseline/Day 1 and Week 12 ]
    6 MWD was the distance that a participant could walk in 6 minutes. Participants were asked to perform the test at a pace that was comfortable to them, with as many breaks as they needed. Continuous pulse oximetry was conducted during the test for safety. Change is Week 12 results minus baseline results.

Secondary Outcome Measures:
  • Number of Participants With Change From Baseline in World Health Organization (WHO) Functional Classification at Weeks 4, 8 and 12 [ Time Frame: Baseline, Weeks 4, 8 and 12 or Early Termination (ET) ]
    WHO functional classification for PAH ranges from Class I (no limitation in physical activity, no dyspnea with normal activity) to Class IV (cannot perform a physical activity without any symptoms, dyspnea at rest). Improvement = reduction in functional class, deterioration = increase in functional class, no change = no change in functional class.

  • Time to Clinical Worsening (TTCW) [ Time Frame: Baseline, Weeks 4, 8 and 12 or ET ]
    TTCW defined as the number of days between first dose of study drug and the occurrence of a predefined clinical worsening event. Predefined clinical worsening events included: hospitalization for worsening PAH, on-study death, heart-lung or lung transplant, atrial septostomy or withdrawal due to the addition of any chronic medications for the treatment of worsening PAH.

Enrollment: 183
Study Start Date: December 2008
Study Completion Date: March 2011
Primary Completion Date: March 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Sitaxsentan
Drug: Sitaxsentan
Sitaxsentan = 100 mg tablet administered orally, once daily
Placebo Comparator: Sitaxsentan Placebo
Drug: Placebo
Sitaxsentan Placebo = 1 tablet administered orally, once daily
Other Name: Sitaxsentan Placebo


Ages Eligible for Study:   16 Years to 80 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Current diagnosis of symptomatic pulmonary arterial hypertension (PAH) classified by one of the following: idiopathic arterial hypertension (IPAH), primary pulmonary hypertension (PPH), familial pulmonary arterial hypertension (FPAH) or pulmonary arterial hypertension (PAH) associated with connective tissue diseases. Has WHO functional class III symptoms.

Exclusion Criteria:

  • Previous exposure to an endothelin receptor antagonist (ETRA) such as sitaxsentan, bosentan or ambrisentan.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00795639

  Show 85 Study Locations
Sponsors and Collaborators
Study Director: Pfizer Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Pfizer Identifier: NCT00795639     History of Changes
Other Study ID Numbers: B1321001
Study First Received: November 20, 2008
Results First Received: January 30, 2012
Last Updated: March 4, 2015

Keywords provided by Pfizer:
endothelin receptor antagonist

Additional relevant MeSH terms:
Hypertension, Pulmonary
Familial Primary Pulmonary Hypertension
Vascular Diseases
Cardiovascular Diseases
Lung Diseases
Respiratory Tract Diseases
Endothelin Receptor Antagonists
Molecular Mechanisms of Pharmacological Action processed this record on July 21, 2017