E.1 Medical condition or disease under investigation |
E.1.1 | Medical condition(s) being investigated |
Pulmonary Arterial Hypertension PAH . |
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MedDRA Classification |
E.1.2 Medical condition or disease under investigation |
E.1.2 | Version | 6.1 |
E.1.2 | Level | PT |
E.1.2 | Classification code | 10037400 |
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E.1.3 | Condition being studied is a rare disease | Yes |
E.2 Objective of the trial |
E.2.1 | Main objective of the trial |
To assess the effect on exercise capacity as measured by the 6 Minute Walk Test after 12 weeks of treatment of sildenafil 20mg Three Times a Day TID or placebo, when added to subjects with PAH who are stabilized on bosentan therapy. |
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E.2.2 | Secondary objectives of the trial |
To assess the safety and tolerability of sildenafil 20mg TID or placebo, when added to subjects with PAH who are currently treated with bosentan, after 12 weeks of treatment. To assess the safety and tolerability of the open label treatment of sildenafil 20mg TID and bosentan therapy in subjects with PAH after 12 months of treatment. To assess the effect on other clinical outcome measures clinical worsening, Borg dyspnoea score and PAH functional class after 12 weeks of treatment of sildenafil 20mg TID or placebo when added to bosentan therapy in subjects with PAH. To determine the population pharmacokinetic parameters of sildenafil and bosentan and to investigate potential pharmacokinetic interactions between the two compounds in the target patient population. To investigate the Pharmacokinetic/Pharmacodynamic PK/PD relationship between sildenafil and bosentan exposure on the 6-Minute Walk Test. |
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E.2.3 | Trial contains a sub-study | Information not present in EudraCT |
E.3 | Principal inclusion criteria |
. Subjects aged 18 and above at the time of the screening visit who have any of the following types of pulmonary arterial hypertension and functional class, and for which bosentan therapy is indicated according to national license Idiopathic Primary Pulmonary Arterial Hypertension PAH . Pulmonary Hypertension secondary to Scleroderma. Subjects with WHO functional class III prior to initiation of bosentan therapy Subjects must have been treated continually with a stable dose of bosentan 62.5mg bid or 125mg bid for a minimum of three months prior to randomization. . Subject with a mean pulmonary artery pressure / 25 mmHg and a pulmonary capillary wedge pressure of 15 mmHg at rest, via right heart catheterization within 12 months prior to randomization. . Subjects whose baseline 6-Minute Walk Test distance is / 100m and / 400m. . who have given written informed consent to participate in the study before being screened for the study. . All women of childbearing potential must use adequate contraception i.e. hormonal in conjunction with intrauterine device or barrier methods with spermicide throughout the study and for the duration of their bosentan therapy or must be celibate or their partner must have had vasectomy. The screening serum pregnancy test must be negative. Women who have been surgically sterilized or are at least two years postmenopausal may be enrolled and do not need to use birth control. |
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E.4 | Principal exclusion criteria |
. PAH secondary to any aetiology including congenital heart disease other than those specified in the inclusion criteria. .With the exception of bosentan therapy, subjects who are currently receiving any forms of chronic treatment for PAH such as any formulations of prostacyclin, PDE-5 inhibitors, other endothelin-receptor antagonists, nitrates or nitric oxide donors e.g. arginine supplements including nicorandil in any form or any potent CYP3A4 inhibitors e.g. Cyclosporin A and Glibenclamide . Note Acute vasodilator response testing with any short acting vasodilators such as prostacyclin or inhaled NO during right heart catherization is permitted. . Subjects with significant i.e. 2 valvular disease other than tricuspid regurgitation or pulmonary regurgitation. Subjects with previous surgical replacement of a valve may be eligible for entry into the study after consultation with a Pfizer study clinician provided the following conditions are satisfied That there was no evidence of PAH secondary to valvular disease prior to surgery. The prosthetic valve is functioning normally on echocardiography. The valve replacement occurred at least one year prior to randomization. .Subjects with acutely decompensated heart failure within 30 days prior to randomization. . Subjects with LV Ejection Fraction of 45 or LV shortening fraction of 0.2 within three months prior to randomization. . Subjects who have had a myocardial infarction or stroke within 6 months prior to randomization. . Subjects who have had a change of dose or class of standard background therapy used for treatment of PAH i.e. oxygen, calcium channel blockers, digoxin, diuretics used for the treatment of PAH within 30 days prior to randomization. Note a change in the dose or oral anticoagulant therapy within this timeframe to maintain the INR within the therapeutic range is acceptable. . Subjects with congenital heart disease unless they fulfill inclusion 4.1.1 , pulmonary hypertension due to thromboembolism, HIV or schistosomiasis. . Subjects who have undergone atrial septostomy within six months prior to randomization. . Subjects with uncontrolled brady- or tachyarrhythmias, placement of pacemakers or implantable defibrillators 60 days prior to randomization. . Subjects whose 6 Minute Walk Test distance may be limited by conditions other than PAH related dyspnoea or fatigue e.g. claudication from vascular insufficiency or arthritis. .Pregnant or lactating women. .Subjects with a history or pulmonary embolism verified by ventilation/perfusion scan, angiogram or spiral chest CT scan. .Subjects with hypotension defined as systolic arterial pressure 90 mm Hg after sitting for 5 minutes at either screening or baseline. .Subjects with known hereditary degenerative retinal disorders such as retinitis pigmentosa or history of non-arteritic ischemic optic neuropathy NAION . .Subjects with history of chronic lung diseases / restrictive lung disease e.g. COPD or scleroderma with impairment of lung function as defined by TLC 60 and/or FEV1 / 80 predicted within 30 days or randomization. . Subjects who have previously failed on bosentan or sildenafil therapy defined as those subjects who had no evidence of clinical improvement whilst on the medicines, and no worsening in symptoms or clinical status, on discontinuation of the medicines . |
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E.5 End points |
E.5.1 | Primary end point(s) |
The change from baseline in the total distance walked during the 6-Minute Walk Test at Week 12 of the study. |
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E.6 and E.7 Scope of the trial |
E.6 | Scope of the trial |
E.6.1 | Diagnosis | No |
E.6.2 | Prophylaxis | No |
E.6.3 | Therapy | No |
E.6.4 | Safety | Yes |
E.6.5 | Efficacy | Yes |
E.6.6 | Pharmacokinetic | Yes |
E.6.7 | Pharmacodynamic | Yes |
E.6.8 | Bioequivalence | Information not present in EudraCT |
E.6.9 | Dose response | No |
E.6.10 | Pharmacogenetic | Information not present in EudraCT |
E.6.11 | Pharmacogenomic | No |
E.6.12 | Pharmacoeconomic | No |
E.6.13 | Others | Information not present in EudraCT |
E.7 | Trial type and phase |
E.7.1 | Human pharmacology (Phase I) | No |
E.7.1.1 | First administration to humans | No |
E.7.1.2 | Bioequivalence study | No |
E.7.1.3 | Other | No |
E.7.1.3.1 | Other trial type description | |
E.7.2 | Therapeutic exploratory (Phase II) | No |
E.7.3 | Therapeutic confirmatory (Phase III) | No |
E.7.4 | Therapeutic use (Phase IV) | Yes |
E.8 Design of the trial |
E.8.1 | Controlled | Yes |
E.8.1.1 | Randomised | Yes |
E.8.1.2 | Open | No |
E.8.1.3 | Single blind | No |
E.8.1.4 | Double blind | Yes |
E.8.1.5 | Parallel group | Yes |
E.8.1.6 | Cross over | No |
E.8.1.7 | Other | No |
E.8.2 | Comparator of controlled trial |
E.8.2.1 | Other medicinal product(s) | No |
E.8.2.2 | Placebo | Yes |
E.8.2.3 | Other | No |
E.8.3 |
The trial involves single site in the Member State concerned
| No |
E.8.4 | The trial involves multiple sites in the Member State concerned | Yes |
E.8.5 | The trial involves multiple Member States | Yes |
E.8.6 Trial involving sites outside the EEA |
E.8.6.1 | Trial being conducted both within and outside the EEA | Yes |
E.8.6.2 | Trial being conducted completely outside of the EEA | Information not present in EudraCT |
E.8.6.3 | If E.8.6.1 or E.8.6.2 are Yes, specify the regions in which trial sites are planned |
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E.8.7 | Trial has a data monitoring committee | Information not present in EudraCT |
E.8.8 |
Definition of the end of the trial and justification where it is not the last
visit of the last subject undergoing the trial
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E.8.9 Initial estimate of the duration of the trial |
E.8.9.1 | In the Member State concerned years | 1 |
E.8.9.1 | In the Member State concerned months | 6 |
E.8.9.1 | In the Member State concerned days | |
E.8.9.2 | In all countries concerned by the trial years | 1 |
E.8.9.2 | In all countries concerned by the trial months | 6 |