Safety Study Extension of Iloprost Power 15 in Pulmonary Arterial Hypertension

Inclusion Criteria: 1. Signed informed consent prior to initiation of any study mandated procedure, 2. Patients with symptomatic idiopathic or familial pulmonary arterial hypertension in NYHA functional class II to IV who have completed study AC-063A301, 3. Women of childbearing potential must have a negative urine pregnancy test and must use an adequate method of contraception during the study and for 28 days after discontinuation of the study drug. Exclusion Criteria: 1. Pulmonary arterial hypertension related to any condition other than those specified in the inclusion criteria, 2. Pulmonary arterial hypertension associated with significant venous or capillary involvement (Pulmonary capillary wedge pressure (PCWP) \> 15 mmHg), known pulmonary veno-occlusive disease, or pulmonary capillary hemangiomatosis, 3. Moderate to severe obstructive lung disease: forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) \< 70% and FEV1 \< 65% of predicted value after bronchodilator administration, 4. Moderate to severe restrictive lung disease: total lung capacity (TLC) \< 60% of predicted value, 5. Pregnant or breast-feeding women, 6. Systemic hypertension (systolic blood pressure \> 160 mmHg or diastolic blood pressure \> 100 mmHg on repeated measurement), 7. Systolic blood pressure \< 95 mmHg, 8. Moderate to severe hepatic impairment, i.e., Child-Pugh Class B or C, 9. Chronic renal insufficiency defined by serum creatinine \> 2.5 mg/dL (221 μmol/L) or ongoing dialysis, 10. Clinically relevant bleeding disorder or active bleeding, 11. Known hypersensitivity to iloprost or any of its excipients.