Two-Part Dose-Confirming Study of Pulsed Inhaled Nitric Oxide in Subjects With WHO Group 3 Pulmonary Hypertension Associated With COPD

This two-part study is designed to confirm the dose of inhaled nitric oxide (NO), administered through an investigational pulsed delivery device (INOpulse® DS-C) that results in decreased pulmonary arterial systolic pressure (PASP) without significantly affecting systemic oxygenation. In Part A, 80 subjects will be randomized to 1of 4 treatment groups in a 1:1:1:1 ratio (with 20 subjects in each treatment group). Subjects assigned to an iNO group will receive pulsed iNO at a dose of 0.003 mg/kg IBW/hr, 0.010 mg/kg IBW/hr, or 0.015 mg/kg IBW/hr, with a set pulse width (PW) of 260 milliseconds (ms). Part A subjects assigned to the placebo group will receive nitrogen (N2) at a randomly assigned device setting of 0.003, 0.010 or 0.015 mg/kg IBW/hr with a set PW of 260 ms. Subjects who were randomized in Part A are permitted to participate in Part B of the study. Subjects will need to be re-screened and re-randomized for Part B participation. In Part B, 60 subjects will be randomized to 1 of 3 treatment groups in a 1:1:1 ratio (with 20 subjects in each treatment group). Subjects assigned to an iNO group will receive pulsed iNO at either 0.030 mg/kg IBW/hr or 0.075 mg/kg IBW/hr, with a set PW of 260 ms. Part B subjects assigned to placebo will receive N2 at a randomly assigned device setting of 0.030 mg/kg IBW/hr or 0.075 mg/kg IBW/hr with a set PW of 260 ms. Part B will use a skewed block randomization scheme with 10 blocks of 6 subjects as follows: * Blocks 1-3: 3 subjects at 0.030 mg/kg IBW/hr, 1 subject at 0.075 mg/kg IBW/hr, and 2 subjects randomly assigned to placebo either 0.030 or 0.075 mg/kg IBW/hr * Blocks 4-7: 2 subjects at 0.030 mg/kg IBW/hr, 2 subjects at 0.075 mg/kg IBW/hr, and 2 subjects randomly assigned to placebo either 0.030 or 0.075 mg/kg IBW/hr * Blocks 8-10: 1 subject at 0.030 mg/kg IBW/hr, 3 subjects at 0.075 mg/kg IBW/hr, and 2 subjects randomly assigned to placebo either 0.030 or 0.075 mg/kg IBW/hr