A Study in Healthy Men and Women to Test Which Effects Donepezil and BI 425809 Have on Each Other

Inclusion Criteria: * Healthy male or female 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 50 years (inclusive) * Body Mass Index (BMI) of 18.5 to 29.9 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 * Male subjects, or female subjects who meet any of the following criteria from the first administration of trial medication until 30 days after trial completion: * Use of adequate contraception that does not contain hormones, i.e. non-hormonal intrauterine device plus condom * Sexually abstinent * A vasectomised sexual partner (vasectomy at least 1 year prior to enrolment) * Surgically sterilised (including hysterectomy) * Postmenopausal, defined as at least 1 year of spontaneous amenorrhea (in questionable cases a blood sample with levels of FSH above 40 U/L and estradiol below 30 ng/L is confirmatory) 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 mmHg, diastolic blood pressure outside the range of 50 to 90 mmHg, or pulse rate outside the range of 50 to 90 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 * 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 * Chronic or relevant acute infections * History of relevant allergy or hypersensitivity (including allergy to the trial medication or its excipients) * Use of drugs within 30 days of planned administration of trial medication that might reasonably influence the results of the trial (including drugs that cause QT/QTc interval prolongation) * Intake of an investigational drug in another clinical trial within 60 days of planned administration of investigational drug in the current trial, or concurrent participation in another clinical trial in which investigational drug is administered * Smoker (more than 10 cigarettes or 3 cigars or 3 pipes per day) * Inability to refrain from smoking on specified trial days * Alcohol abuse (consumption of more than 20 g per day for females and 30 g per day for males) * Drug abuse or positive drug screening * Blood donation of more than 100 mL within 30 days of planned administration of trial medication or intended blood donation during the trial * Intention to perform excessive physical activities within one week prior to the administration of trial medication or during the trial * Inability to comply with the dietary regimen of the trial site * A marked baseline prolongation of QT/QTc interval (such as QTc intervals that are repeatedly greater than 450 ms in males or repeatedly greater than 470 ms in females) or any other relevant Electrocardiogram (ECG) finding at screening * A history of additional risk factors for Torsade de Pointes (such as heart failure, hypokalaemia, or family history of Long QT Syndrome) * Subject is assessed as unsuitable for inclusion by the investigator, for instance, because the subject is not considered able to understand and comply with study requirements, or has a condition that would not allow safe participation in the study * Further exclusion criteria apply