Inability meet enrollment in study population.

The EAGLE study is a Phase 3, open-label, multi-center, two-part, single-arm study of GeNOsyl(R) delivery system(s) to evaluate if inhaled nitric oxide-induced vasodilation predicts successful wean from parenteral prostacyclin (PGI) in subjects with World Health Organization (WHO) Group 1 pulmonary arterial hypertension (PAH) undergoing a medically necessary right heart catheterization (RHC). All subjects enrolled in the study will undergo an attempt to wean from parenteral PGI per standard of care.

This study will be divided into 2 parts: a Pilot Phase followed by Pivotal Phase.

• The Pilot Phase will enroll up to 20 subjects. The information derived from the Pilot Phase will evaluate safety, and assess the vasoreactivity test response rate.
• Approximately 150 subjects will be enrolled in the Pivotal Phase of the study, to gather further data on weaned successes from parenteral PGI. The Investigator and study staff involved with the wean and patient management will be blinded in this phase of the study to the vasoreactivity results.

Inclusion Criteria:

• The subject or subject's legally authorized representative signs and dates an Institutional Review Board (IRB) approved informed consent form prior to the initiation of any study-related activities.
• The subject has been diagnosed with PAH (WHO Group 1) and is WHO Functional Class I or II at Screening.
• The subject has documented continuous PGI use for ≥ 1 year from Screening, without a significant interruption (i.e., ≤ 2 day interruption) and without a failed complete wean attempt.
• The subject is a candidate for weaning off parenteral PGI therapy (per Investigator judgment and standard of care).

Exclusion Criteria

• The subject has a hypersensitivity or allergy to ingredients of inhaled nitric oxide or other clinically significant allergies (clinical significance per Investigator judgment).
• The subject has a PCWP or left ventricular end diastolic pressure (LVEDP) ≥15 mmHg at Baseline.
• The subject has participated in an investigational product or device study within the 30 days prior to Screening.