This is a Ph 2, randomized, double-blind, placebo-controlled global multicenter study to evaluate the efficacy, safety, tolerability, and pharmacokinetics (PK) of PIPE-791 in participants with a diagnosis of Idiopathic Pulmonary Fibrosis (IPF) with or without background treatment.

This is a Ph 2, randomized, double-blind, placebo-controlled global multicenter study to evaluate the efficacy, safety, tolerability, and PK of PIPE-791 in participants with a diagnosis of Idiopathic Pulmonary Fibrosis with or without background treatment. The treatment period is 26 weeks and full study duration is up to 36 weeks including Screening and Follow-Up. Approximately 324 participants will be enrolled into one of three treatment arms, PIPE-791 Dose A, PIPE-791 Dose B, or placebo.

Key Inclusion Criteria:

• Male or female ≥ 40 years of age at the time of Randomization.
• A diagnosis of IPF within 7 years prior to Screening, based on the 2022 ATS/ERS/JRS/ALAT practice guideline as confirmed by the Investigator, and a centrally read screening HRCT consistent with usual interstitial pneumonia (UIP) or probable UIP.
• Percent predicted (pp) FVC ≥ 40% on Screening spirometry.
• Participants may enter the study whether or not they are receiving background nintedanib or pirfenidone therapy approved for the treatment of IPF, but not both concurrently.

Key Exclusion Criteria:

• Those with a history of interstitial lung disease (ILD) other than IPF are not eligible.
• Those with pulmonary arterial hypertension (PAH) requiring multi-drug therapy are not eligible.
• Those who have experienced an IPF exacerbation within 6 weeks of Screening, or during Screening, are not eligible.
• Those with an estimated glomerular filtration rate (eGFR) ≤ 30 ml/min/1.73 m2 (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] formula) (Inker 2021) or who have Child-Pugh Class B or C hepatic impairment are not eligible.
• Female participants must not be of childbearing potential.

Additional inclusion and exclusion criteria apply.