A Study in Healthy Men to Test How Fluconazole Influences the Amount of BI 425809 in the Blood

Inclusion Criteria: * Healthy male subjects according to the assessment of 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 * Age of 18 to 55 years (inclusive) * Body mass index (BMI) of 18.5 to 29.9 Kilograms/Square Meter (kg/m2) (inclusive) * Signed and dated written informed consent prior to admission to the study, in accordance with Good Clinical Practice (GCP) and local legislation Exclusion Criteria: * Any finding in the medical examination (including blood pressure (BP), pulse rate (PR) or Electrocardiogram (ECG)) deviating from normal and assessed as clinically relevant by the investigator * Repeated measurement of systolic blood pressure outside the range of 90 to 140 millimetres of mercury (mmHg), diastolic blood pressure outside the range of 50 to 90 mmHg, or pulse rate outside the range of 45 to 90 beats per minute (bpm) * Any laboratory value outside the reference range that the investigator considers to be of clinical relevance * Any evidence of a concomitant disease assessed as clinically relevant by the investigator * Relevant gastrointestinal, hepatic, renal, respiratory, cardiovascular, metabolic, immunological or hormonal disorders * Cholecystectomy or other surgery of the gastrointestinal tract that could interfere with the pharmacokinetics of the trial medication (except appendectomy or simple hernia repair) * Diseases of the central nervous system (including but not limited to any kind of seizures or stroke), and other relevant neurological or psychiatric disorders * History of relevant orthostatic hypotension, fainting spells, or blackouts Further exclusion criteria apply.