A Study in Healthy Men to Measure the Amount of BI 425809 in the Blood When Taken as a Tablet

Inclusion Criteria: * Healthy male subjects according to the assessment of the investigator, 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 65 years (incl.) * Body mass index (BMI) of 18.5 to 29.9 kg/m2 (incl.) * Signed and dated written informed consent prior to admission to the study in accordance with Good Clinical Practice (GCP) and local legislation * Subjects who are sexually active must use, with their partner, highly effective contraception from the time of administration of trial medication until 4 months after administration of trial medication. Adequate methods are: * Condoms plus use of hormonal contraception by the female partner that started at least 2 months prior to administration of trial medication (e.g., implants, injectables, combined oral or vaginal contraceptives, intrauterine device) or * Condoms plus surgical sterilization (vasectomy at least 1 year prior to enrolment) or * Condoms plus surgically sterilised partner (including hysterectomy) or * Condoms plus intrauterine device or * Condoms plus partner of non-childbearing potential (including homosexual men) Subjects are required to use condoms to prevent unintended exposure of the partner to the study drug via seminal fluid. * Alternatively, true abstinence is acceptable when it is in line with the subject's preferred and usual lifestyl…