Study Evaluating INS018_055 Administered Orally to Subjects With Idiopathic Pulmonary Fibrosis

Inclusion Criteria:

1. Male or female patients aged ≥40 years based on the date of the written informed consent form
2. Diagnosis of IPF as defined by American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Latin American Thoracic Association guidelines
3. In a stable condition and suitable for study participation based on the results of medical history, physical examination, vital signs, 12-lead ECG, and laboratory evaluation
4. Meeting all of the following criteria during the screening period:

   1. FVC ≥40% predicted normal
   2. DLCO corrected for Hgb ≥25% and \<80% predicted normal
   3. Forced Expiratory Volume in the first second/FVC (FEV1/FVC) ratio \>0.7 based on pre-bronchodilator value

Exclusion Criteria:

1. Acute IPF exacerbation within 4 months prior to Visit 1 and/or Day 1, as determined by the investigator
2. Patients who are unwilling to refrain from smoking within 3 months prior to screening and until the end of the study
3. Female patients who are pregnant or nursing
4. Abnormal ECG findings