Study Evaluating INS018_055 Administered Orally to Subjects With Idiopathic Pulmonary Fibrosis (IPF)

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. Subjects with background pirfenidone or nintedanib may be enrolled if their regimen of antifibrotic therapy has been stable for \> 8 weeks prior to Visit 1 5. Meeting all of the following criteria during the screening period: 1. FVC ≥40% predicted of normal 2. DLCO corrected for Hgb ≥25% and \<80% predicted of 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 during the screening period, 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 Other protocol inclusion and exclusion criteria may apply.