A Pharmacokinetics Study for Pediatric Participants With Pulmonary Arterial Hypertension

Inclusion Criteria:

• Currently have a diagnosis of PAH that is either:

  • idiopathic (including hereditary), related to collagen vascular disease, related to anorexigen use, associated with surgical repair, of at least 6 month duration, of a congenital systemic to pulmonary shunt (for example, atrial septal defect, ventricular septal defect, patent ductus arteriosus).
• Have a history of the diagnosis of PAH established by a resting mean pulmonary artery pressure ≥25 mm Hg, pulmonary artery wedge pressure ≤15 mm Hg, and a pulmonary vascular resistance (PVR) ≥3 Wood units via right heart catheterization. In the event that a pulmonary artery wedge pressure is unable to be obtained during right heart catheterization, participants with a left ventricular end diastolic pressure <15 mm Hg, with normal left heart function, and absence of mitral stenosis on echocardiography can be eligible for enrollment
• Have a World Health Organization (WHO) functional class value of I, II or III at the time of enrollment

Exclusion Criteria:

• Have pulmonary hypertension related to conditions other than specified above, including but not limited to chronic thromboembolic disease, portal pulmonary hypertension, left-sided heart disease or lung disease and hypoxia

• History of left-sided heart disease, including any of the following:

  • clinically significant (pulmonary artery occlusion pressure [PAOP] 15 to 18 mm Hg) aortic or mitral valve disease (that is, aortic stenosis, aortic insufficiency, mitral stenosis, moderate or greater mitral regurgitation)
  • pericardial constriction
  • restrictive or congestive cardiomyopathy
  • left ventricular ejection fraction <40% by multigated radionucleotide angiogram (MUGA), angiography, or echocardiography
  • left ventricular shortening fraction <22% by echocardiography
  • life-threatening cardiac arrhythmias
  • symptomatic coronary artery disease within 5 years of study entry as determined by the physician
• History of atrial septostomy or Potts Shunt within 3 months before administration of study drug
• Unrepaired congenital heart disease