A Study in Healthy Men to Test How BI 1815368 is Processed in the Body

The main objectives are: * To assess mass balance by determining the extent of recovery of total \[¹⁴C\]-radioactivity in urine and faeces after a single oral dose administration of BI 1815368 (C-14) (test treatment T) in healthy male trial participants. * To investigate the absolute bioavailability of BI 1815368 using a single, concomitant intravenous micro-dose administration of BI 1815368 (C13) (reference treatment R). * To provide plasma, urine, and faecal samples

Inclusion Criteria: 1. Healthy male trial participant as determined by the investigator, as based on a complete medical history including a physical examination, vital signs (blood pressure (BP), pulse rate (PR)), 12-lead electrocardiogram (ECG), and clinical laboratory tests 2. Age of 18 to 55 years (inclusive) at screening 3. Body mass index (BMI) of 18.5 to 29.9 kg / m2 (inclusive) at screening 4. Signed and dated written informed consent in accordance with ICH-GCP and local legislation prior to any trial-related procedure Exclusion Criteria: 1. Any finding in the medical examination (including BP, PR or ECG) deviating from normal and assessed as assessed by the investigator 2. Repeated measurement of systolic blood pressure outside the range of 90 to 140 mmHg, diastolic blood pressure outside the range of 50 to 90 mmHg, or pulse rate outside the range of 45 to 90 bpm 3. Any laboratory value outside the reference range as judged by the investigator 4. Any evidence of a concomitant disease considered clinically relevant by the investigator Further exclusion criteria apply.