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 inNYHA 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 usean adequate method of contraception during the study and for 28 days afterdiscontinuation of the study drug.

Exclusion Criteria:

1. Pulmonary arterial hypertension related to any condition other than those specified inthe inclusion criteria,

2. Pulmonary arterial hypertension associated with significant venous or capillaryinvolvement (Pulmonary capillary wedge pressure (PCWP) > 15 mmHg), known pulmonaryveno-occlusive disease, or pulmonary capillary hemangiomatosis,

3. Moderate to severe obstructive lung disease: forced expiratory volume in 1second/forced vital capacity (FEV1/FVC) < 70% and FEV1 < 65% of predicted value afterbronchodilator administration,

4. Moderate to severe restrictive lung disease: total lung capacity (TLC) < 60% ofpredicted 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) orongoing dialysis,

10. Clinically relevant bleeding disorder or active bleeding,

11. Known hypersensitivity to iloprost or any of its excipients.