An Open-Label ProSpective MultiCENTer Study to Evaluate Safety and Tolerability of Dry Powder Inhaled Treprostinil in PH

Cohort A Key Inclusion Criteria: 1. Males or Females between 18 years to 80 years of age. 2. Has a confirmed diagnosis of WHO Group 3 PH-ILD based on CT chest imaging performed, which demonstrates evidence of diffuse parenchymal lung disease and FEV1/FVC (absolute values) ≥ 70% and are required to have evidence of pulmonary hypertension (PH) as demonstrated from right heart catheterization (RHC) with the following hemodynamic parameters. 1. i) Pulmonary vascular resistance (PVR) ≥ 3 Wood Units (WU) and ii) Pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg and iii) A mean pulmonary arterial pressure (mPAP) of ≥ 30 mmHg. OR 2. An exploratory subset of subjects with ILD: i) Pulmonary vascular resistance (PVR) ≥ 3 Wood Units (WU) and ii) Pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg and iii) A mean pulmonary arterial pressure (mPAP) of ≥ 21 mmHg. 3. 6-minute walk distance of ≥ 125 meters Cohort A Key Exclusion Criteria: A Subject is not eligible for inclusion in the study if any of the following criteria apply: 1. PH in the Updated WHO Classification Groups 1, 2, 4, or 5. 2. History of hemodynamically significant left-sided heart disease. 3. Exacerbation of underlying lung disease or active pulmonary or upper respiratory infections. 4. Initiation of pulmonary rehabilitation. Cohort B Key Inclusion Criteria 1. Male or Females between 18 years to 75 years of age at Screening. 2. Has a diagnosis of WHO Group 3 PH-ILD confirmed with CT chest imaging performed at the screening visit, which demonstrates evidence of diffuse parenchymal lung disease and FEV1/FVC (absolute values) ≥70%. Subjects are required to have evidence of pulmonary hypertension (PH) as demonstrated from right heart catheterization (RHC) with the following documented parameters: 1. Pulmonary vascular resistance (PVR) ≥3 Wood Units (WU) and 2. Pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg and 3. A mean pulmonary arterial pressure (mPAP) of ≥ 25 mmHg 3. Subjects must be on protocol specified dose of inhaled treprostinil QID not at treatment goal, and able to transition from their prescribed dose of inhaled Treprostinil therapy to LIQ861. 4. 6-minute walk distance of ≥ 200 meters Cohort B Key Exclusion Criteria 1. PH in the Updated WHO Classification Groups 1, 2, 4, or 5. 2. Inability to titrate inhaled treprostinil above 5 breaths (Tyvaso®) or above 16 mcg Tyvaso DPI®. 3. History of Bronchospasm with Tyvaso or Tyvaso DPI. 4. History of persistent moderate asthma or severe asthma. 5. History of hemodynamically significant left-sided heart disease. 6. Exacerbation of underlying lung disease or active pulmonary or upper respiratory infections.