The purpose of this study is to determine the safety and maximum tolerated dose of inhaled NX1011 for the treatment of pulmonary arterial hypertension (PAH).

Inclusion Criteria:

• Patient must either:

  • meet the PAH diagnostic criteria at Screening (based on a documented history of diagnosis as outlined in the American College of Chest Physicians [ACCP] 2004 Evidence-Based Clinical Practices Guidelines)15; or
  • have elevated pulmonary pressure with a suspected PAH diagnosis based on a clinical referral at Screening for a RHC.

• Patient must have PAH as defined by a mean pulmonary artery pressure (PAP) > 25 mmHg.

• Patient must have symptoms of pulmonary hypertension (PH) according to the World Health Organization (WHO) Functional Classification of Pulmonary Hypertension Class II through IV.

• Patient must consent to, be able to tolerate, and have adequate venous and arterial access for Swan-Ganz catheterization (SGC) and an arterial line.

Exclusion Criteria:

• Clinically significant right-to-left intracardiac shunts based on Doppler echocardiography with bubble study.

• History of pulmonary veno-occlusive disease or clinically significant aortic or mitral stenosis.

• History of sustained ventricular tachycardia (VT-S) or ventricular fibrillation (VF) and cardiac arrest, or presence of atrial fibrillation.

• Active cardiac disease meeting the following criteria:

  • Patient with elevated pulmonary capillary wedge pressures (PCWPs) > 25 mmHg.
  • Patient with a history of myocardial infarction or coronary intervention within the last 60 days.
  • Patient with a history of pacemaker, cardiac defibrillator, or biventricular pacemaker insertion within 4 weeks of Baseline.
  • Patient who cannot be withdrawn from nitrate therapy.