Assess the Efficacy and Safety of Sildenafil When Added to Bosentan in the Treatment of Pulmonary Arterial Hypertension

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00323297
Recruitment Status : Completed
First Posted : May 9, 2006
Results First Posted : November 19, 2013
Last Update Posted : November 4, 2014
Information provided by (Responsible Party):

Brief Summary:
To assess the efficacy and safety of sildenafil when added to patients with PAH who are taking bosentan as all or part of their background therapy.

Condition or disease Intervention/treatment Phase
Pulmonary Arterial Hypertension Drug: Bosentan Other: Placebo Drug: Sildenafil Citrate Phase 4

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 105 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Multinational, Multicentre, Randomized, Double-blind Study To Assess The Efficacy And Safety Of Oral Sildenafil 20mg Tid Or Placebo When Added To Bosentan In The Treatment Of Subjects, Aged 18 Years And Above, With Pulmonary Arterial Hypertension (Pah)
Study Start Date : September 2006
Actual Primary Completion Date : August 2013
Actual Study Completion Date : August 2013

Arm Intervention/treatment
Placebo Comparator: placebo Drug: Bosentan
Bosentan + Placebo for 12 weeks of the study (double blind), then 12 months open label phase (bosentan + sildenafil)

Other: Placebo
Bosentan + Placebo for 12 weeks of the study (double blind), then 12 months open label phase (bosentan + sildenafil)

Experimental: Active Drug: Bosentan
Bosentan + Sildenafil for 12 weeks of the study (double blind), then 12 months open label phase

Drug: Sildenafil Citrate
Bosentan + Sildenafil for 12 weeks of the study (double blind), then 12 months open label phase

Primary Outcome Measures :
  1. Change From Baseline in the Total Distance Walked During 6 Minute Walk Time (6MWT) at Week 12 [ Time Frame: Week 12 ]
    6MWT is 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.

Secondary Outcome Measures :
  1. Number of Participants With Change From Baseline in World Health Organization (WHO) Functional Class in Participants With PAH at Week 12 LOCF [ Time Frame: Week 12 ]
    WHO functional classification for PAH range from Class I (no limitation in physical activity, no dyspnea with normal activity) to Class IV (can not 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.

  2. Clinical Worsening Events [ Time Frame: Week 12 ]

    No survival analysis was carried out for the study due to very few events of clinical worsening. Hence, we present a summary of clinical worsening events instead.

    Events of clinical worsening were categorized as (A). Death, (B). Heart/lung transplantation, (C). Hospitalization due to pulmonary arterial hypertension (PAH), and (D). Clinical deterioration of PAH requiring additional therapy.

  3. Change From Baseline in Borg Dyspnea Score at Week 12 [ Time Frame: Week 12 ]

    Borg dyspnea scale is a 10-point scale where following scores stands for severity of dyspnea: 0 (no breathlessness at all); 0.5 (very very slight [just noticeable]);

    1. (very slight);
    2. (slight breathlessness);
    3. (moderate); 4 (some what severe);

    5 (severe breathlessness); 7 (very severe breathlessness); 9 (very very severe [almost maximum]); and 10 (maximum).

  4. One Year Survival Probability From the Start of Sildenafil Treatment. [ Time Frame: One year from the time of starting sildenafil ]
    The survival probability of all participants up to 1-year post start of Sildenafil treatment; for participants who were randomized to Sildenafil, this was the week 52 from randomization, and for participants who were originally randomized to Placebo group, this was the Week 64 from Baseline (Week 52 from Week 12, when the first dose of Sildenafil was administered to these participants). Those participants who discontinued from the study prior to 1 year after start of sildenafil were considered as censored at the time of discontinuation and those who discontinued from the study post 1-year after start of sildenafil were considered as censored at the time of 1-year post start of sildenafil.

  5. One Year Survival From the Start of Sildenafil Treatment. [ Time Frame: One year from the time of starting sildenafil ]
    The survival status of all participants who discontinued from the study, including those participants who discontinued during the double-blind phase, was to be assessed at one year post their Week 12 visit/ End of treatment visit.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Subjects aged 18 and over above with PAH and for which bosentan therapy is indicated according to national license
  • Subjects with a mean pulmonary artery pressure of >25mmHg and a pulmonary artery wedge pressure of <15mmHg at rest via right heart catheterization within 3 years prior to randomization.
  • Subjects whose baseline 6 Minute Walk Test distance is >100m and < 450m.

Exclusion Criteria:

  • PAH secondary to any aetiology including congenital heart disease other than those specified in the inclusion criteria
  • Subjects whose 6 Minute Walk Test may be limited by conditions other than PAH related dyspnoea or fatigue eg. claudication from vascular insufficiency or arthritis.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00323297

  Hide Study Locations
United States, California
West Los Angeles VA Healthcare, Pulmonary Hypertension Program
Los Angeles, California, United States, 90073
United States, Michigan
Henry Ford Hospital
Detroit, Michigan, United States, 48202
United States, Pennsylvania
Allegheny General Hospital
Pittsburgh, Pennsylvania, United States, 15212
United States, Texas
Baylor College of Medicine
Houston, Texas, United States, 77030
The Methodist Hospital
Houston, Texas, United States, 77030
Diagnostics Research Group
San Antonio, Texas, United States, 78229
Australia, New South Wales
St. Vincents Hospital
Darlinghurst, New South Wales, Australia, 2010
Australia, Queensland
The Prince Charles Hospital
Chermside, Queensland, Australia, 4032
Czech Republic
Vseobecna fakultni nemocnice v Praze
Praha 2, Czech Republic, 128 08
Institut klinicke a experimentalni mediciny, Klinika kardiologie
Praha 4, Czech Republic, 140 21
Clinique des Maladies Respiratoires
Lille, France, 59037
Hopital Claude Huriez
Lille, France, 59037
Hopital Adules Brabois
Vandoeuvre Les Nancy, France, 54511
Unfallkrankenhaus Berlin, Klinik fuer Innere Medizin
Berlin, Germany, 12683
II. Medizinische Klinik, Kardiologie, Angiologie und Pneumologie
Coburg, Germany, 96450
Universitaetsklinikum Essen, Zentrum fuer Innere Medizin, Klinik fuer Kardiologie
Essen, Germany, 45122
Universitaetsklinikum Giessen und Marburg GmbH, Standort Giessen
Giessen, Germany, 35392
Medizinische Hochschule Hannover
Hannover, Germany, 30625
Universitaetsklinikum des Saarlandes, Innere Medizin V
Homburg, Germany, 66421
Medizinische Klinik und Poliklinik I, Universitaetsklinikum Leipzig
Leipzig, Germany, 04103
Med. Klinik u. Poliklinik I der LMU Muenchen, Klinikum Grosshadern
Muenchen, Germany, 81377
Praxis fuer Innere Medizin, Kardiologie und Angiologie
Nuernberg, Germany, 90402
Missionsaerztliche Klinik Wuerzburg, Gemeinnuetzige Gesellschaft mbH
Wuerzburg, Germany, 97067
Attikon Hospital
Haidari, Athens, Greece, 12462
Rambam Medical Center
Haifa, Israel, 31096
Rabin Medical Centre
Petach Tikva, Israel, 49100
Cardiologia, Azienda Ospedaliera Monaldi, Seconda Università di Napoli
Napoli, Italy, 80131
Unita' di Ipertensione Polmonare, Dipartimento di Scienze Respiratorie e Cardiovascolari
Roma, Italy, 00161
Department of Surgery, National Taiwan University Hospital
Taipei, Taiwan, 100
United Kingdom
Papworth Everard, Cambridgeshire, United Kingdom, CB23 3RE
Sponsors and Collaborators
Study Director: Pfizer Call Center Pfizer

Additional Information:
Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Pfizer Identifier: NCT00323297     History of Changes
Other Study ID Numbers: A1481243
2006-001464-23 ( EudraCT Number )
PATHWAYS ( Other Identifier: Alias Study Number )
First Posted: May 9, 2006    Key Record Dates
Results First Posted: November 19, 2013
Last Update Posted: November 4, 2014
Last Verified: October 2014

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