A Study to Assess the Efficacy and Safety of Treprostinil Palmitil Inhalation Powder (TPIP) in Participants With Progressive Pulmonary Fibrosis (PPF)

Inclusion criteria

• Radiologic evidence of pulmonary fibrosis of >10% extent on high-resolution computed tomography (HRCT) in the previous 12 months.
• Diagnosis of interstitial lung disease (ILD) (other than idiopathic pulmonary fibrosis [IPF]) that fulfills at least 1 of the following criteria for progression within 24 months of screening despite standard treatment of ILD, as assessed by the Investigator:

• Clinically significant decline in % predicted Forced Vital Capacity (FVC) based on ≥10% relative decline
• Decline in % predicted FVC based on ≥5% to <10% relative decline combined with worsening of respiratory symptoms
• Decline in % predicted FVC based on ≥5% to <10% relative decline combined with an increasing extent of fibrotic changes on chest imaging
• Worsening of respiratory symptoms and increasing extent of fibrotic changes on chest imaging
• Forced Vital Capacity ≥45% predicted at Screening.
• Diffusing Capacity of the Lungs for Carbon Monoxide (DLCO) ≥25% of predicted normal corrected for hemoglobin at Screening.
• Participants may be either:

• On stable therapy (defined as no dose changes in the prior 12 weeks) with an approved antifibrotic agent (eg, nintedanib or nerandomilast) for at least 12 weeks prior to Screening and during the screening period and are planning to stay on this background treatment throughout the study. Combination therapy with more than 1 approved antifibrotic agent is not allowed. Or
• Not on treatment with an approved antifibrotic agent (eg, nintedanib or nerandomilast) for at least 8 weeks prior to Screening and during the screening period (ie, either antifibrotic-treatment-naïve or previously discontinued) and do not plan to start or restart antifibrotic treatment during the study.
• If treated with rituximab, must be on it for at least 6 months before Screening and in the Investigator's clinical opinion must be refractory to the current regimen. If treated with other immunosuppressive agents (eg, mycophenolate, methotrexate, azathioprine, oral corticosteroids), need to be on treatment for at least 12 weeks before Screening and in the investigator's clinical opinion must be refractory to the current regimen.

Exclusion criteria

• Prebronchodilator Forced Expiratory Volume in 1 second (FEV1)/Forced Vital Capacity (FVC) <0.7 and less than the age-adjusted lower limit of normal at Screening.
• Diagnosis of idiopathic pulmonary fibrosis (IPF).
• Diagnosis of combined pulmonary fibrosis and emphysema.
• Extent of emphysema greater than fibrosis on HRCT within 1 year prior to Screening or during the screening period confirmed by central overread.
• Acute ILD exacerbation within 90 days prior to Screening or during the screening period (investigator-determined). If hospitalized for a respiratory indication, participants must have been discharged more than 90 days prior to Screening to be eligible.
• Acute respiratory infection (eg, COVID-19, influenza, pneumonia) within 30 days prior to Screening or during the Screening period.
• Acute pulmonary embolism within 90 days prior to Screening.
• Prior TPIP exposure or participation in other clinical trials involving the study drug, TPIP.
• Known hypersensitivity or contraindication to treprostinil or TPIP or TPIP formulation excipients (eg, mannitol, leucine).
• History of clinically significant pulmonary hypertension (PH) (ie, pulmonary hypertension requiring medical treatment) or the participant has received any PH-approved therapy, including prostacyclin analogs (eg, beraprost, epoprostenol, iloprost, or treprostinil; except for acute vasoreactivity testing), prostacyclin receptor (IP receptor) agonists (eg, selexipag), endothelin receptor antagonists (eg, ambrisentan, bosentan, or macitentan), activin signaling inhibitors (eg, sotatercept), phosphodiesterase type 5 inhibitors (PDE5-Is; eg, sildenafil, tadalafil), or soluble guanylate cyclase stimulators (eg, riociguat) within 60 days prior to Screening or during the screening period. As needed use of a PDE5-I for erectile dysfunction is permitted, provided that no doses are taken within 48 hours prior to any study-related efficacy assessments.
• Any physical limitation that would impair the participant's use of the inhaler device or ability to participate in spirometry and/or DLCO assessment.

Note: Other protocol-defined inclusion/exclusion criteria may apply.