Assess the Efficacy and Safety of Sildenafil When Added to Bosentan in the Treatment of Pulmonary Arterial Hypertension
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ClinicalTrials.gov Identifier: NCT00323297 |
Recruitment Status :
Completed
First Posted : May 9, 2006
Results First Posted : November 19, 2013
Last Update Posted : February 1, 2021
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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 |
- 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.
- 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.
- 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.
- 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]);
- (very slight);
- (slight breathlessness);
- (moderate); 4 (some what severe);
5 (severe breathlessness); 7 (very severe breathlessness); 9 (very very severe [almost maximum]); and 10 (maximum).
- 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.
- 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.

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 ClinicalTrials.gov identifier (NCT number): NCT00323297

Study Director: | Pfizer CT.gov Call Center | Pfizer |
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Pfizer's Upjohn has merged with Mylan to form Viatris Inc. |
ClinicalTrials.gov Identifier: | NCT00323297 |
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: | February 1, 2021 |
Last Verified: | January 2021 |
Pulmonary Arterial Hypertension Familial Primary Pulmonary Hypertension Hypertension Vascular Diseases Cardiovascular Diseases Hypertension, Pulmonary Lung Diseases Respiratory Tract Diseases Bosentan |
Sildenafil Citrate Molecular Mechanisms of Pharmacological Action Vasodilator Agents Phosphodiesterase 5 Inhibitors Phosphodiesterase Inhibitors Enzyme Inhibitors Urological Agents Antihypertensive Agents Endothelin Receptor Antagonists |