Assess the Efficacy and Safety of Sildenafil When Added to Bosentan in the Treatment of Pulmonary Arterial Hypertension
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.
Pulmonary Arterial Hypertension
Drug: Sildenafil Citrate
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, 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)|
- Change From Baseline in the Total Distance Walked During 6 Minute Walk Time (6MWT) at Week 12 [ Time Frame: Week 12 ] [ Designated as safety issue: No ]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 ] [ Designated as safety issue: No ]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 ] [ Designated as safety issue: No ]
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 ] [ Designated as safety issue: No ]
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 ] [ Designated as safety issue: Yes ]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 ] [ Designated as safety issue: Yes ]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.
|Study Start Date:||September 2006|
|Study Completion Date:||August 2013|
|Primary Completion Date:||August 2013 (Final data collection date for primary outcome measure)|
|Placebo Comparator: placebo||
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)
Bosentan + Sildenafil for 12 weeks of the study (double blind), then 12 months open label phaseDrug: Sildenafil Citrate
Bosentan + Sildenafil for 12 weeks of the study (double blind), then 12 months open label phase
Please refer to this study by its ClinicalTrials.gov identifier: NCT00323297
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|Study Director:||Pfizer CT.gov Call Center||Pfizer|