Acute Interstitial Pneumonia Clinical Trials

• Adults aged 18 years or older

• Diagnosis of fibrotic ILD based on high-resolution computed tomography imaging, including but not limited to:

‣ Idiopathic interstitial pneumonia, including idiopathic pulmonary fibrosis

⁃ Autoimmune ILD

⁃ Chronic hypersensitivity pneumonitis

⁃ Nonspecific interstitial pneumonia

⁃ Occupational lung disease

⁃ Combined pulmonary fibrosis and emphysema with fibrosis greater than the extent of emphysema on lung imaging as determined by the Investigator

• For patients to be eligible for Cohorts 1 to 3: RHC confirmed PH (mean pulmonary artery pressure \>20 mmHg, pulmonary artery wedge pressure

• ≤15 mmHg, pulmonary vascular resistance \>2 WU).

• For patients to be eligible for Cohort 1, they must not be receiving inhaled treprostinil at Baseline.

• For patients to be eligible for Cohort 2, they must have initiated

∙ Tyvaso/Tyvaso DPI at 1 of the following time points:

• Baseline

• ≤90 days prior to Baseline 6. For patients to be eligible for Cohort 3, they must be receiving Tyvaso/Tyvaso DPI at Baseline and for \>90 days prior to Baseline. 7. For patients to be eligible for Cohort 4: Prior RHC not meeting the definition of PH as described in Inclusion Criterion 3 but has a pulmonary artery wedge pressure ≤15 mmHg. 8. Co-enrollment in other observational or interventional studies is permitted. 9. Patient is willing and able to provide informed consent and complete surveys/questionnaires in English or Spanish.