Evaluation of Efficacy and Safety of PLN-74809 in Patients With Idiopathic Pulmonary Fibrosis

Inclusion Criteria:

   - Diagnosis of IPF based upon the Fleischner Society guidelines within 3 years from
   Screening (Part A) or based on ATS/ERS/JRS/ALAT 2018 guidelines within 5 years from
   Screening (Part B, C & D)

   - FVC % of predicted ≥45%

   - DLco (hemoglobin-adjusted) ≥30%

   - Participants receiving treatment for IPF with nintedanib or pirfenidone are allowed,
   if on a stable dose for at least 3 months

Exclusion Criteria:

   - Currently receiving or planning to initiate treatment for IPF (fibrosis) with agents
   not approved for that indication by the FDA

   - Forced expiratory volume during the first seconds of the forced breath (FEV1)/FVC
   ratio <0.7 at Screening

   - Clinical evidence of active infection, including but not limited to bronchitis,
   pneumonia, sinusitis that can affect FVC measurement or IPF progression

   - Known acute IPF exacerbation or suspicion by the Investigator of such, within 6 months
   of Screening

   - Smoking of any kind within 3 months of Screening