- Subjects aged 16 and over, and classified as having pulmonary arterial hypertension
- Subjects who meet the following conditions on right heart catheterization at screening
or baseline: mean pulmonary arterial pressure of ≥ 25mmHg and pulmonary capillary
wedge pressure of ≤ 15mmHg at rest
- Subjects whose baseline 6-Minute Walk test distance is >100 m and
- Significant Hepatic and/or renal disorder
- Subjects with known hereditary degenerative retinal disorders (such as retinitis
pigmentosa) or history of non-arteritic ischemic optic neuropathy (NAION)
- Subjects who are currently receiving nitrates or nitric oxide donors in any form,
ritonavir, ketoconazole and itraconazole