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Study Providing Monotherapy (Sitaxsentan) And Combination Therapy (Sitaxsentan+Sildenafil) To Subjects With Pulmonary Arterial Hypertension (PAH) To Assess Long-Term Safety

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: January 20, 2012
Last verified: April 2011
As sitaxsentan is the agent most highly selective for ETA (Endothelin Type A (receptor)), and does not significantly impact sildenafil pharmacokinetics the combination of most promise for pulmonary arterial hypertension (PAH) therapy is these two oral drugs administered in combination.

Condition Intervention Phase
Pulmonary Arterial Hypertension Pulmonary Hypertension Drug: Sitaxsentan Drug: Sitaxsentan and Sildenafil Phase 3

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A Phase 3, Multi-Center, Open Label Study To Evaluate The Long-Term Safety Of Monotherapy Sitaxsentan Sodium And Combination Therapy With Sitaxsentan Sodium And Sildenafil Citrate In Subjects With Pulmonary Arterial Hypertension

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Overall Survival [ Time Frame: Baseline and every 12 weeks up to Week 18 ]
    Overall survival is the duration from first dose to death. For participants who are lost to follow-up, survival was censored at the last date of follow-up.

Secondary Outcome Measures:
  • Change From Baseline in 6 Minute Walk Distance at Weeks 12 and 24 [ Time Frame: Baseline, Weeks 12 up to Early Termination (ET) (up to Week 18) ]
    The walk distance was the total distance walked during the 6-minute test. Change is distance walked at week x minus distance walked at baseline.

  • Number of Participants in Each World Health Organization (WHO) Functional Class of Pulmonary Arterial Hypertension (PAH) [ Time Frame: Baseline, Week 12 and ET (up to Week 18) ]
    The WHO functional classes of PAH range from Class 1 (no limitation in physical activity) to Class IV (can not perform a physical activity without any symptoms).

Enrollment: 3
Study Start Date: July 2010
Study Completion Date: January 2011
Primary Completion Date: January 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Sitaxsentan
Monotherapy arm
Drug: Sitaxsentan
Sitaxsentan = 100 mg tablet administered orally, once daily
Experimental: Sitaxsentan and Sildenafil
Combination treatment
Drug: Sitaxsentan and Sildenafil
Sitaxsentan = 100 mg tablet administered orally, once daily plus Sildenafil = 20 mg tablet administered orally, three times a day


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

Inclusion Criteria:

  • Previously enrolled in B1321001 for at least 4 weeks.
  • Previously enrolled in B1321003, discontinued from the study.
  • Completed the B1321003 study as planned.

Exclusion Criteria:

  • Treated with an investigational drug (other than sitaxsentan or sildenafil in either B1321001 or B1321003) or device that has not received regulatory approval within the 30 days prior to Baseline/Day 1 or during the study.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00796510

United States, California
Pfizer Investigational Site
Fountain Valley, California, United States, 92708
Pfizer Investigational Site
Cluj Napoca, Romania, 400 001
Pfizer Investigational Site
Kyiv, Ukraine
Sponsors and Collaborators
Study Director: Pfizer Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Pfizer Identifier: NCT00796510     History of Changes
Other Study ID Numbers: B1321002
Study First Received: November 20, 2008
Results First Received: December 9, 2011
Last Updated: January 20, 2012

Keywords provided by Pfizer:
endothelin receptor antagonist (ETRA)

Additional relevant MeSH terms:
Hypertension, Pulmonary
Familial Primary Pulmonary Hypertension
Vascular Diseases
Cardiovascular Diseases
Lung Diseases
Respiratory Tract Diseases
Endothelin Receptor Antagonists
Sildenafil Citrate
Molecular Mechanisms of Pharmacological Action
Vasodilator Agents
Phosphodiesterase 5 Inhibitors
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Urological Agents processed this record on June 23, 2017