To Assess The Efficacy and Safety Of Oral Sildenafil in the Treatment of Pulmonary Arterial Hypertension.

Official Title: “A Multinational, Multicentre, Randomized, Parallel Group, Double-Blind Study To Assess The Efficacy and Safety Of 1 mg, 5 mg and 20 mg TID of Oral Sildenafil in the Treatment of Subjects Aged 18 Years and Over With Pulmonary Arterial Hypertension (PAH)”

To demonstrate a dose response for 1 mg, 5 mg and 20 mg TID oral sildenafil for the treatment of subjects with PAH.

Intervention(s) in this Clinical Trial

• Drug: Sildenafil citrate
  • oral, 20 mg, tid
• Drug: Sildenafil citrate
  • oral 1 mg, tid
• Drug: Sildenafil citrate
  • oral 5 mg, tid
• Drug: Sildenafil citrate
  • oral 20 mg, tid

Arms, Groups and Cohorts in this Clinical Trial

• Experimental: Sildenafil High dose
• Experimental: Sildenafil Low dose
• Experimental: Sildenafil medium dose
• Experimental: Sildenafil - Open label Phase
  • Open label extension from week 12 to week 24.

Primary Measures

• Change From Baseline in the Total Distance Walked During 6MWT at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No

Secondary Measures

• Change From Baseline in mPAP at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No
• Time to Clinical Worsening
  • Time Frame: Baseline through Week 12
    Safety Issue?: No
• Number of Participants With Change From Baseline in PAH Criteria for Functional Capacity and Therapeutic Class at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No
• Change From Baseline in BNP at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No
• Change From Baseline in Pro-BNP at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No
• Change From Baseline in TAPSE Measurement at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No
• Change From Baseline in BORG Dyspnoea Score at Week 12
  • Time Frame: Baseline and Week 12
    Safety Issue?: No

Inclusion Criteria:

• Subjects with PAH (i.e. IPAH or secondary to connective tissue disease or with surgical repair of ASD, VSD, PDA, aorto-pulmonary window) whose baseline six minute walk test distance is >/= 100 m and </= 450 m.
• Subjects with a mean pulmonary artery pressure of >/= 25 mmHg and a pulmonary artery wedge pressure of </= 15 mmHg at rest via right heart catheterization performed within 12 weeks prior to randomization.

Exclusion Criteria:

• Subjects whose 6 Minute Walk Distance may be limited by conditions other than PAH related dyspnoea or fatigue, e.g. claudication from vascular insufficiency or significant arthritis.
• Subjects who are currently receiving any forms of chronic treatment for PAH such as prostacyclin, PDE-5 inhibitors, endothelin-receptor antagonists, nitrates or nitric oxide donors (e.g. arginine supplement, nicorandil) in any form, protease inhibitors such as ritonavir and saquinavir, ketoconazole, itraconazole, and alpha blockers.
• Subjects previously receiving any of these drugs must have stopped use for a period of at least 1 month prior to screening, except in the case of bosentan or prostacyclin (3 months).

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Investigator: Pfizer Industry

Overall Clinical Trial Officials and Contacts

Pfizer CT.gov Call Center Study Director Pfizer  

Information obtained from ClinicalTrials.gov on February 12, 2012

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00430716

Study ID Number: A1481244

ClinicalTrials.gov Identifier: NCT00430716

Health Authority: United States: Food and Drug Administration

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