search
Back to results

A Long Term Extension Study Evaluating Safety Of Sildenafil Citrate When Used To Treat Pulmonary Arterial Hypertension (PAH) In Children

Primary Purpose

Pulmonary Arterial Hypertension

Status
Completed
Phase
Phase 3
Locations
International
Study Type
Interventional
Intervention
Sildenafil citrate
Sildenafil citrate
Sildenafil citrate
Sponsored by
Pfizer's Upjohn has merged with Mylan to form Viatris Inc.
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Pulmonary Arterial Hypertension focused on measuring children

Eligibility Criteria

1 Year - 17 Years (Child)All SexesDoes not accept healthy volunteers

Inclusion Criteria: Patients must complete the 16 Week double-blind efficacy study A1481131. Exclusion Criteria: Any patient who did not complete Study A1481131.

Sites / Locations

  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site
  • Pfizer Investigational Site

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm Type

Experimental

Experimental

Experimental

Arm Label

Sildenafil high dose

Sildenafil Low dose

Sildenafil medium dose

Arm Description

As per Protocol Amendment 8 (Aug 2011), all doses in the high dose treatment group were discontinued. Subjects who were receiving these doses and continued in the study were requested to down titrate.

As per Protocol Amendment 8 (August 2011), the dose 40 mg TID in the medium dose treatment group was discontinued. Subjects who were receiving this dose and continued in the study were requested to down titrate.

Outcomes

Primary Outcome Measures

Number of Participants Reporting at Least One Adverse Event
Safety was measured according to standard adverse event collection as described in the adverse event section of the results. Complete tables of the adverse events according to the A1481156 treatment groups are provided in the reported adverse event section.
Number of Participants Reporting Treatment-related Adverse Events
Safety was measured according to standard adverse event collection as described in the adverse event section of the results.
Number of Participants Reporting at Least One Serious Adverse Event
Safety was measured according to standard adverse event collection as described in the adverse event section of the results. Complete tables of the serious adverse events according to the A1481156 treatment groups are provided in the reported adverse event section.
Number of Participants Reporting Treatment-related Serious Adverse Events
All serious adverse events regardless of treatment group or suspected relationship to study drug were reported. Investigators were to provide independent determination of possible causality of any serious adverse event.
Number of Deaths Reported in the Study Prior to the Data Monitoring Committee (DMC) Recommendation of Dose Down Titration
Deaths were reported immediately independent of the circumstances or suspected cause at any time during the study through the last follow-up visit or 30 days after the last administration of study drug, whichever comes later.
Number of Deaths Reported During This Study
Deaths were reported immediately independent of the circumstances or suspected cause at any time during the study through the last follow-up visit or 30 days after the last administration of study drug, whichever comes later.
Discontinuation Due to Intolerability
Participant who experienced drug-related intolerance, the participant's dose was reduced by 50%. If, after a dose reduction, the participant continued to appear intolerant, they were discontinued from study treatment.
Downtitration in Dose Due to Intolerability.
Based on review of the survival data, DMC concluded that the high dose of sildenafil was associated with a harmful effect on survival when compared to the low dose. The DMC also expressed concern as to the potential dose-response relationship between increasing dose and mortality. Therefore, on 04 August 2011, the DMC recommended discontinuation of the 40 mg and 80 mg three times a day (TID) doses, as well as the 20 mg TID dose in children with body weight ≤20 kg. The protocol was amended per DMC recommendations.
Number of Participants With Deterioration Post Baseline in Visual Acuity Safety Tests
Visual Acuity is measured either using the reduced Snellen test or via Teller cards, and was assessed in the left and right eyes separately. There were 9 lines on the reduced Snellen chart which were coded as 6/60, 6/36, 6/24, 6/18, 6/12, 6/9, 6/6, 6/5, 6/4 (where 6/60 was the easiest to read and 6/4 was the most difficult to read). If a participant experienced a visual adverse event the investigator was asked to perform additional ocular assessments either at the visit when the participant reported the visual adverse event or at an unplanned visit.
Number of Participants With Deterioration Post Baseline in Color Vision Monitoring Safety Tests.
Colour vision was measured where appropriate via the Farnsworth-Munsell D-15 Hue test. This test was performed in both eyes simultaneously or just in a single specific eye. If using a single eye the same eye was used throughout the study. In case of young participants an age-and-ability-appropriate evaluation such as the Ishihara Test for Unlettered Persons were conducted.
Pediatric Cognitive Development Status at Week 16.
Participant's cognitive development status was assessed at A1481156 baseline (Week 16 in A1481131; NCT00159913) using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's cognitive development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Pediatric Cognitive Development Status at Week 52.
Participant's cognitive development status was assessed at Week 52 using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's cognitive development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Pediatric Motor Development Status at Week 16.
Participant's motor development status was assessed at A1481156 baseline (Week 16 in A1481131; NCT00159913) using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's motor development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Pediatric Motor Development Status at Week 52
Participant's motor development status was assessed at Week 52 using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's motor development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.

Secondary Outcome Measures

Peak Volume of Oxygen (VO2) Consumed at Year 1 Using a Bicycle Ergometry Cardiopulmonary Exercise Test (CPX)
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to determine the peak volume of VO2 consumed. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant
Percentage Change From Baseline in Percent Predicted Peak VO2 at Year 1.
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the percent predicted peak VO2 at Week 16 and Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Percent Change From Baseline in Time to Maximum VO2 at Year 1
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to determine the time to maximum VO2. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Percent Change From Baseline in Respiratory Exchange Ratio at Year 1
This is the ratio of carbon dioxide (CO2) produced to O2 consumed [VCO2/VO2]. Exercise Tolerance Test was performed on developmentally able participants to determine the respiratory exchange ratio on week 16 and Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913).
Percent Change From Start of Sildenafil in Total Ventilation (VE) to Year 1
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to determine the total ventilation. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Percentage Change From Baseline in End Tidal Oxygen (O2) at Year 1.
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the End Tidal O2 at Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Percentage Change From Baseline in End Tidal Carbon Dioxide (CO2) at Year 1.
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the End Tidal CO2 at Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Percentage Change From Baseline in Anaerobic Threshold at Year 1.
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the anaerobic threshold at Week 16 and Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Summary of Shift in Changes From Start of Sildenafil in World Health Organization Pulmonary Hypertension (WHO PH) Functional Class by A1481156 Treatment Group at Year 1.
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarized at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 baseline at Years 1, 2, 3 and 4 were evaluated.
Summary of Shift in Changes From Start of Sildenafil in WHO PH Functional Class by A1481156 Treatment Group at Year 2.
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarised at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 baseline at Years 1, 2, 3 and 4 were evaluated.
Summary of Shift in Changes From Start of Sildenafil in WHO PH Functional Class by A1481156 Treatment Group at Year 3.
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarised at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 (NCT00159913) baseline at Years 1, 2, 3 and 4 were evaluated.
Summary of Shift in Changes From Start of Sildenafil in WHO PH Functional Class by A1481156 Treatment Group at Year 4.
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarised at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 baseline at Years 1, 2, 3 and 4 were evaluated.
Additions From Baseline in Background Therapy up to the End of Study
This was defined as an addition or discontinuation in the class(es) of drugs used as background medication (e.g., anticoagulants, oxygen, diuretics, calcium channel blockers, and digoxin) compared to baseline of Study A1481131 (NCT00159913).
Change From Baseline in Child Health Questionnaire-Parent Form (CHQ-PF28) as Assessed by the Psychosocial Scale at Year 1.
CHQ: 50-item, 15 subscale parent or legal guardian assessed instrument of child's physical, emotional, social well-being, and relative burden of disease on the parents; rated on Likert-type scale: range 0 to 100; higher scores indicate a more positive health status. Global indicators for Physical Health and Psychosocial Health are weighted composites derived from subscale items using scoring algorithms (transformed scores); range 0 to 100: higher scores indicate more positive health status.
Change From Baseline in Child Health Questionnaire-Parent Form (CHQ-PF28) as Assessed by the Physical Scale at Year 1.
CHQ: 50-item, 15 subscale parent or legal guardian assessed instrument of child's physical, emotional, social well-being, and relative burden of disease on the parents; rated on Likert-type scale: range 0 to 100; higher scores indicate a more positive health status. Global indicators for Physical Health and Psychosocial Health are weighted composites derived from subscale items using scoring algorithms (transformed scores); range 0 to 100: higher scores indicate more positive health status.
Participant (Parent) Global Assessment at Year 1
The participant (parent) global assessment of disease severity was assessed at Year 1 in this extension study. The number and percentage of participants markedly improved, moderately improved, mild improvement, no change, slightly worse, moderately worse, markedly worse were evaluated. Participants who withdrew from study treatment after at least 10 weeks of treatment were requested to perform the global assessments.
Physician Global Assessment at Year 1
The physician global assessment of disease severity was assessed at Year 1 in this extension study. The number and percentage of participants with markedly improved, moderately improved, mild improvement, no change, slightly worse, moderately worse, markedly worse were evaluated. Participants who withdrew from study treatment after at least 10 weeks of treatment were requested to perform the global assessments.

Full Information

First Posted
September 8, 2005
Last Updated
January 28, 2021
Sponsor
Pfizer's Upjohn has merged with Mylan to form Viatris Inc.
search

1. Study Identification

Unique Protocol Identification Number
NCT00159874
Brief Title
A Long Term Extension Study Evaluating Safety Of Sildenafil Citrate When Used To Treat Pulmonary Arterial Hypertension (PAH) In Children
Official Title
A Multicenter, Long-Term Extension Study to Assess Safety of Oral Sildenafil Citrate In The Treatment Of Subjects Who Have Completed Study A1481131
Study Type
Interventional

2. Study Status

Record Verification Date
January 2021
Overall Recruitment Status
Completed
Study Start Date
January 2004 (undefined)
Primary Completion Date
December 2012 (Actual)
Study Completion Date
December 2012 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Pfizer's Upjohn has merged with Mylan to form Viatris Inc.

4. Oversight

Data Monitoring Committee
Yes

5. Study Description

Brief Summary
Active treatment, dose-blinded extension study evaluating the safety and long term efficacy of sildenafil citrate in children with PAH.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Pulmonary Arterial Hypertension
Keywords
children

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 3
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
234 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Sildenafil high dose
Arm Type
Experimental
Arm Description
As per Protocol Amendment 8 (Aug 2011), all doses in the high dose treatment group were discontinued. Subjects who were receiving these doses and continued in the study were requested to down titrate.
Arm Title
Sildenafil Low dose
Arm Type
Experimental
Arm Title
Sildenafil medium dose
Arm Type
Experimental
Arm Description
As per Protocol Amendment 8 (August 2011), the dose 40 mg TID in the medium dose treatment group was discontinued. Subjects who were receiving this dose and continued in the study were requested to down titrate.
Intervention Type
Drug
Intervention Name(s)
Sildenafil citrate
Intervention Description
Oral, subjects with body weight ≥8 - 20 kg: 20 mg 3 times a day (tid) subjects with body weight >20 - 45 kg: 40 mg 3 times a day (tid) subjects with body weight >45 kg: 80 mg 3 times a day (tid)
Intervention Type
Drug
Intervention Name(s)
Sildenafil citrate
Intervention Description
Oral,10 mg 3 times a day (tid), only subjects with body weight >20 kg
Intervention Type
Drug
Intervention Name(s)
Sildenafil citrate
Intervention Description
Oral, subjects with body weight ≥8 - 20 kg: 10 mg 3 times a day (tid); subjects with body weight >20 - 45 kg: 20 mg 3 times a day (tid); subjects with body weight >45 kg: 40 mg 3 times a day (tid)
Primary Outcome Measure Information:
Title
Number of Participants Reporting at Least One Adverse Event
Description
Safety was measured according to standard adverse event collection as described in the adverse event section of the results. Complete tables of the adverse events according to the A1481156 treatment groups are provided in the reported adverse event section.
Time Frame
Up to Follow-Up visit (30 to 40 days after study completion or treatment discontinuation)
Title
Number of Participants Reporting Treatment-related Adverse Events
Description
Safety was measured according to standard adverse event collection as described in the adverse event section of the results.
Time Frame
Up to Follow-Up visit (30 to 40 days after study completion or treatment discontinuation)
Title
Number of Participants Reporting at Least One Serious Adverse Event
Description
Safety was measured according to standard adverse event collection as described in the adverse event section of the results. Complete tables of the serious adverse events according to the A1481156 treatment groups are provided in the reported adverse event section.
Time Frame
Up to Follow-Up visit (30 to 40 days after study completion or treatment discontinuation)
Title
Number of Participants Reporting Treatment-related Serious Adverse Events
Description
All serious adverse events regardless of treatment group or suspected relationship to study drug were reported. Investigators were to provide independent determination of possible causality of any serious adverse event.
Time Frame
Up to Follow-Up visit (30 to 40 days after study completion or treatment discontinuation)
Title
Number of Deaths Reported in the Study Prior to the Data Monitoring Committee (DMC) Recommendation of Dose Down Titration
Description
Deaths were reported immediately independent of the circumstances or suspected cause at any time during the study through the last follow-up visit or 30 days after the last administration of study drug, whichever comes later.
Time Frame
Pre-DMC Recommendation dose down titration (04 August 2011)
Title
Number of Deaths Reported During This Study
Description
Deaths were reported immediately independent of the circumstances or suspected cause at any time during the study through the last follow-up visit or 30 days after the last administration of study drug, whichever comes later.
Time Frame
Last follow-up visit or 30 days after the last administration of study drug
Title
Discontinuation Due to Intolerability
Description
Participant who experienced drug-related intolerance, the participant's dose was reduced by 50%. If, after a dose reduction, the participant continued to appear intolerant, they were discontinued from study treatment.
Time Frame
Throughout the treatment duration (median treatment duration 1689 to 1744 days)
Title
Downtitration in Dose Due to Intolerability.
Description
Based on review of the survival data, DMC concluded that the high dose of sildenafil was associated with a harmful effect on survival when compared to the low dose. The DMC also expressed concern as to the potential dose-response relationship between increasing dose and mortality. Therefore, on 04 August 2011, the DMC recommended discontinuation of the 40 mg and 80 mg three times a day (TID) doses, as well as the 20 mg TID dose in children with body weight ≤20 kg. The protocol was amended per DMC recommendations.
Time Frame
Pre-DMC recomendation (04 August 2011)
Title
Number of Participants With Deterioration Post Baseline in Visual Acuity Safety Tests
Description
Visual Acuity is measured either using the reduced Snellen test or via Teller cards, and was assessed in the left and right eyes separately. There were 9 lines on the reduced Snellen chart which were coded as 6/60, 6/36, 6/24, 6/18, 6/12, 6/9, 6/6, 6/5, 6/4 (where 6/60 was the easiest to read and 6/4 was the most difficult to read). If a participant experienced a visual adverse event the investigator was asked to perform additional ocular assessments either at the visit when the participant reported the visual adverse event or at an unplanned visit.
Time Frame
Week 36
Title
Number of Participants With Deterioration Post Baseline in Color Vision Monitoring Safety Tests.
Description
Colour vision was measured where appropriate via the Farnsworth-Munsell D-15 Hue test. This test was performed in both eyes simultaneously or just in a single specific eye. If using a single eye the same eye was used throughout the study. In case of young participants an age-and-ability-appropriate evaluation such as the Ishihara Test for Unlettered Persons were conducted.
Time Frame
Week 36
Title
Pediatric Cognitive Development Status at Week 16.
Description
Participant's cognitive development status was assessed at A1481156 baseline (Week 16 in A1481131; NCT00159913) using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's cognitive development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Time Frame
Week 16
Title
Pediatric Cognitive Development Status at Week 52.
Description
Participant's cognitive development status was assessed at Week 52 using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's cognitive development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Time Frame
Week 52
Title
Pediatric Motor Development Status at Week 16.
Description
Participant's motor development status was assessed at A1481156 baseline (Week 16 in A1481131; NCT00159913) using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's motor development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Time Frame
Week 16
Title
Pediatric Motor Development Status at Week 52
Description
Participant's motor development status was assessed at Week 52 using the physician assessment questions. Assessment question (i.e., compared to other children the participant's age group is this participant's motor development limited?) included the following criteria : severely limited, moderately limited, mildly limited and not limited.
Time Frame
Week 52
Secondary Outcome Measure Information:
Title
Peak Volume of Oxygen (VO2) Consumed at Year 1 Using a Bicycle Ergometry Cardiopulmonary Exercise Test (CPX)
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to determine the peak volume of VO2 consumed. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant
Time Frame
1 year
Title
Percentage Change From Baseline in Percent Predicted Peak VO2 at Year 1.
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the percent predicted peak VO2 at Week 16 and Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Time Frame
Baseline, Year 1
Title
Percent Change From Baseline in Time to Maximum VO2 at Year 1
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to determine the time to maximum VO2. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Time Frame
Baseline, Year 1
Title
Percent Change From Baseline in Respiratory Exchange Ratio at Year 1
Description
This is the ratio of carbon dioxide (CO2) produced to O2 consumed [VCO2/VO2]. Exercise Tolerance Test was performed on developmentally able participants to determine the respiratory exchange ratio on week 16 and Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913).
Time Frame
Baseline, Year 1
Title
Percent Change From Start of Sildenafil in Total Ventilation (VE) to Year 1
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to determine the total ventilation. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Time Frame
Year 1
Title
Percentage Change From Baseline in End Tidal Oxygen (O2) at Year 1.
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the End Tidal O2 at Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Time Frame
Baseline, Year 1
Title
Percentage Change From Baseline in End Tidal Carbon Dioxide (CO2) at Year 1.
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the End Tidal CO2 at Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Time Frame
Baseline, Year 1
Title
Percentage Change From Baseline in Anaerobic Threshold at Year 1.
Description
Exercise Tolerance Test (CPX test) was performed on developmentally able participants to measure the anaerobic threshold at Week 16 and Year 1. Participants were assumed to be developmentally able if they had a CPX exercise assessment at any visit during study A1481131 (NCT00159913). The CPX tests were performed as close to trough plasma levels of sildenafil as possible, i.e., prior to dosing and at least 4 hours after the previous dose. If participants were able to perform the CPX test in Study A1481131 (NCT00159913), they were expected to be able to perform the exercise paradigm in the extension study (A1481156) unless their clinical condition had deteriorated and the investigator considered this was unsafe for the participant.
Time Frame
Baseline, Year 1
Title
Summary of Shift in Changes From Start of Sildenafil in World Health Organization Pulmonary Hypertension (WHO PH) Functional Class by A1481156 Treatment Group at Year 1.
Description
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarized at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 baseline at Years 1, 2, 3 and 4 were evaluated.
Time Frame
Baseline, Year 1
Title
Summary of Shift in Changes From Start of Sildenafil in WHO PH Functional Class by A1481156 Treatment Group at Year 2.
Description
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarised at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 baseline at Years 1, 2, 3 and 4 were evaluated.
Time Frame
Baseline, Year 2
Title
Summary of Shift in Changes From Start of Sildenafil in WHO PH Functional Class by A1481156 Treatment Group at Year 3.
Description
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarised at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 (NCT00159913) baseline at Years 1, 2, 3 and 4 were evaluated.
Time Frame
Baseline, Year 3
Title
Summary of Shift in Changes From Start of Sildenafil in WHO PH Functional Class by A1481156 Treatment Group at Year 4.
Description
The WHO PH functional classification was as follows: Class I : Participants with PH but without resulting limitation of physical activity. Class II : Participants with PH resulting in slight limitation of physical activity. Class III : Participants with PH resulting in marked limitation of physical activity. Class IV : Participants with PH with inability to carry out any physical activity without symptoms. Changes from baseline in functional class were summarised at Years 1, 2, 3, and 4. Numbers of participants improving by 3 classes, improving by 2 classes, improving by 1 class, not changing, worsening by 1 class, worsening by 2 classes or worsening by 3 classes from A1481131 baseline at Years 1, 2, 3 and 4 were evaluated.
Time Frame
Baseline, Year 4
Title
Additions From Baseline in Background Therapy up to the End of Study
Description
This was defined as an addition or discontinuation in the class(es) of drugs used as background medication (e.g., anticoagulants, oxygen, diuretics, calcium channel blockers, and digoxin) compared to baseline of Study A1481131 (NCT00159913).
Time Frame
Up to the end of study
Title
Change From Baseline in Child Health Questionnaire-Parent Form (CHQ-PF28) as Assessed by the Psychosocial Scale at Year 1.
Description
CHQ: 50-item, 15 subscale parent or legal guardian assessed instrument of child's physical, emotional, social well-being, and relative burden of disease on the parents; rated on Likert-type scale: range 0 to 100; higher scores indicate a more positive health status. Global indicators for Physical Health and Psychosocial Health are weighted composites derived from subscale items using scoring algorithms (transformed scores); range 0 to 100: higher scores indicate more positive health status.
Time Frame
Baseline, Year 1
Title
Change From Baseline in Child Health Questionnaire-Parent Form (CHQ-PF28) as Assessed by the Physical Scale at Year 1.
Description
CHQ: 50-item, 15 subscale parent or legal guardian assessed instrument of child's physical, emotional, social well-being, and relative burden of disease on the parents; rated on Likert-type scale: range 0 to 100; higher scores indicate a more positive health status. Global indicators for Physical Health and Psychosocial Health are weighted composites derived from subscale items using scoring algorithms (transformed scores); range 0 to 100: higher scores indicate more positive health status.
Time Frame
Baseline, Year 1
Title
Participant (Parent) Global Assessment at Year 1
Description
The participant (parent) global assessment of disease severity was assessed at Year 1 in this extension study. The number and percentage of participants markedly improved, moderately improved, mild improvement, no change, slightly worse, moderately worse, markedly worse were evaluated. Participants who withdrew from study treatment after at least 10 weeks of treatment were requested to perform the global assessments.
Time Frame
Year 1
Title
Physician Global Assessment at Year 1
Description
The physician global assessment of disease severity was assessed at Year 1 in this extension study. The number and percentage of participants with markedly improved, moderately improved, mild improvement, no change, slightly worse, moderately worse, markedly worse were evaluated. Participants who withdrew from study treatment after at least 10 weeks of treatment were requested to perform the global assessments.
Time Frame
Year 1

10. Eligibility

Sex
All
Minimum Age & Unit of Time
1 Year
Maximum Age & Unit of Time
17 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Patients must complete the 16 Week double-blind efficacy study A1481131. Exclusion Criteria: Any patient who did not complete Study A1481131.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Pfizer CT.gov Call Center
Organizational Affiliation
Pfizer
Official's Role
Study Director
Facility Information:
Facility Name
Pfizer Investigational Site
City
Palo Alto
State/Province
California
ZIP/Postal Code
34304
Country
United States
Facility Name
Pfizer Investigational Site
City
Palo Alto
State/Province
California
ZIP/Postal Code
94305
Country
United States
Facility Name
Pfizer Investigational Site
City
Stanford
State/Province
California
ZIP/Postal Code
94305
Country
United States
Facility Name
Pfizer Investigational Site
City
Aurora
State/Province
Colorado
ZIP/Postal Code
80045
Country
United States
Facility Name
Pfizer Investigational Site
City
Boston
State/Province
Massachusetts
ZIP/Postal Code
02115
Country
United States
Facility Name
Pfizer Investigational Site
City
Ann Arbor
State/Province
Michigan
ZIP/Postal Code
48109
Country
United States
Facility Name
Pfizer Investigational Site
City
Saint Louis
State/Province
Missouri
ZIP/Postal Code
63110
Country
United States
Facility Name
Pfizer Investigational Site
City
New York
State/Province
New York
ZIP/Postal Code
10032
Country
United States
Facility Name
Pfizer Investigational Site
City
Columbus
State/Province
Ohio
ZIP/Postal Code
43205
Country
United States
Facility Name
Pfizer Investigational Site
City
Charleston
State/Province
South Carolina
ZIP/Postal Code
29425
Country
United States
Facility Name
Pfizer Investigational Site
City
Seattle
State/Province
Washington
ZIP/Postal Code
98105
Country
United States
Facility Name
Pfizer Investigational Site
City
Sao Paulo
State/Province
SP
ZIP/Postal Code
04012-909
Country
Brazil
Facility Name
Pfizer Investigational Site
City
São Paulo
State/Province
SP
ZIP/Postal Code
04023-062
Country
Brazil
Facility Name
Pfizer Investigational Site
City
Puente Alto
State/Province
Santiago
Country
Chile
Facility Name
Pfizer Investigational Site
City
Medellin
State/Province
Antioquia
Country
Colombia
Facility Name
Pfizer Investigational Site
City
Bogota
State/Province
Cundinamarca
Country
Colombia
Facility Name
Pfizer Investigational Site
City
Guatemala
Country
Guatemala
Facility Name
Pfizer Investigational Site
City
Budapest
ZIP/Postal Code
1083
Country
Hungary
Facility Name
Pfizer Investigational Site
City
Budapest
ZIP/Postal Code
1096
Country
Hungary
Facility Name
Pfizer Investigational Site
City
Szeged
ZIP/Postal Code
6720
Country
Hungary
Facility Name
Pfizer Investigational Site
City
Hyderabad
State/Province
Andhra Pradesh
ZIP/Postal Code
500 001
Country
India
Facility Name
Pfizer Investigational Site
City
Hyderabad
State/Province
Andhra Pradesh
ZIP/Postal Code
500 073
Country
India
Facility Name
Pfizer Investigational Site
City
Kochi
State/Province
Kerala
ZIP/Postal Code
682 041
Country
India
Facility Name
Pfizer Investigational Site
City
Bologna
ZIP/Postal Code
40138
Country
Italy
Facility Name
Pfizer Investigational Site
City
Tokyo
Country
Japan
Facility Name
Pfizer Investigational Site
City
Penang
ZIP/Postal Code
10050
Country
Malaysia
Facility Name
Pfizer Investigational Site
City
Penang
ZIP/Postal Code
10900
Country
Malaysia
Facility Name
Pfizer Investigational Site
City
Penang
ZIP/Postal Code
11600
Country
Malaysia
Facility Name
Pfizer Investigational Site
City
Mexico
State/Province
DF
ZIP/Postal Code
14080
Country
Mexico
Facility Name
Pfizer Investigational Site
City
Krakow
ZIP/Postal Code
30-663
Country
Poland
Facility Name
Pfizer Investigational Site
City
Ruda Slaska
ZIP/Postal Code
41-703
Country
Poland
Facility Name
Pfizer Investigational Site
City
Warszawa
ZIP/Postal Code
04-730
Country
Poland
Facility Name
Pfizer Investigational Site
City
Zabrze
ZIP/Postal Code
41-800
Country
Poland
Facility Name
Pfizer Investigational Site
City
Moscow
ZIP/Postal Code
115478
Country
Russian Federation
Facility Name
Pfizer Investigational Site
City
Moscow
ZIP/Postal Code
125412
Country
Russian Federation
Facility Name
Pfizer Investigational Site
City
Lund
ZIP/Postal Code
221 85
Country
Sweden
Facility Name
Pfizer Investigational Site
City
Kaohsiung
ZIP/Postal Code
81346
Country
Taiwan
Facility Name
Pfizer Investigational Site
City
Taipei
ZIP/Postal Code
100
Country
Taiwan
Facility Name
Pfizer Investigational Site
City
Taipei
ZIP/Postal Code
11217
Country
Taiwan

12. IPD Sharing Statement

Citations:
PubMed Identifier
31908813
Citation
Russell S, Beghetti M, Oudiz R, Balagtas C, Zhang M, Ivy D. Effects of oral sildenafil on exercise capacity in children with pulmonary arterial hypertension: a randomised trial. Open Heart. 2019 Dec 3;6(2):e001149. doi: 10.1136/openhrt-2019-001149. eCollection 2019.
Results Reference
derived
PubMed Identifier
31538282
Citation
Chanu P, Gao X, Bruno R, Claret L, Harnisch L. A modeling and simulation-based assessment of the impact of confounding factors on the readout of a sildenafil survival trial in pulmonary arterial hypertension. J Pharmacokinet Pharmacodyn. 2019 Oct;46(5):499-509. doi: 10.1007/s10928-019-09654-3. Epub 2019 Sep 20.
Results Reference
derived
PubMed Identifier
24637559
Citation
Barst RJ, Beghetti M, Pulido T, Layton G, Konourina I, Zhang M, Ivy DD; STARTS-2 Investigators. STARTS-2: long-term survival with oral sildenafil monotherapy in treatment-naive pediatric pulmonary arterial hypertension. Circulation. 2014 May 13;129(19):1914-23. doi: 10.1161/CIRCULATIONAHA.113.005698. Epub 2014 Mar 17.
Results Reference
derived
Links:
URL
https://trialinfoemail.pfizer.com/pages/landing.aspx?StudyID=A1481156&StudyName=A%20Long%20Term%20Extension%20Study%20Evaluating%20Safety%20Of%20Sildenafil%20Citrate%20When%20Used%20To%20Treat%20Pulmonary%20Arterial%20Hypertension%20%28PAH%29%20In%20Chil
Description
To obtain contact information for a study center near you, click here.

Learn more about this trial

A Long Term Extension Study Evaluating Safety Of Sildenafil Citrate When Used To Treat Pulmonary Arterial Hypertension (PAH) In Children

We'll reach out to this number within 24 hrs