This Study Tests Different Doses of BI 1015550 in Patients With Idiopathic Pulmonary Fibrosis (IPF). The Study Tests How BI 1015550 is Taken up by the Body and How Well it is Tolerated.

Inclusion Criteria: * Signed and dated written informed consent prior to admission to the study in accordance with ICH Harmonised Tripartite Guideline for Good Clinical Practice (ICH-GCP) and local legislation * Male or female patients aged ≥40 years at visit 1. * A clinical diagnosis of IPF based on ATS/ERS/JRS/ALAT 2011 guideline within the previous 5 years as confirmed by the investigator based on chest high-resolution computed tomography (HRCT) scan taken within 12 months of visit 1 and confirmed by central review prior to visit 2. * Forced Vital Capacity (FVC) ≥50% of predicted normal at visit 1 * Diffusion capacity of the lung for carbon monoxide (DLCO) (corrected for haemoglobin \[Hb\] \[Visit 1\]): \> 30% of predicted normal at visit 1 Exclusion Criteria: * Patients with a significant disease or condition other than IPF which in the opinion of the investigator, may put the patient at risk because of participation, interfere with study procedures, or cause concern regarding the patient's ability to participate in the study. * Any laboratory value outside the reference range that the investigator considers to be of clinical relevance * Surgery of the GI tract that could interfere with PK of the trial medication (except appendectomy) * Diseases of the central nervous system (including but not limited to any kind of seizures or stroke), and other relevant neurological or psychiatric disorders including but not limited to mood disorders. * Evidence of active infection (…