The main objective of this trial is to investigate the effect of rifampicin on the pharmacokinetics of BI 894416.

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 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

Exclusion criteria:

• Any finding in the medical examination (including Blood pressure (BP), Pulse rate (PR) or Electrocardiogram (ECG) and including the neurological examination) 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 45 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 (unless the subject quit smoking for at least 3 months prior to first planned administration of trial medication)
• Alcohol abuse (consumption of more than 24 g per day)
• 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) or any other relevant 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
• History of relevant neurological disorder affecting the peripheral or central nervous system (this includes, but is not limited to: stroke, epilepsy, inflammatory or atrophic diseases affecting the nervous system, cluster headache or any cancer of the nervous system). Febrile seizures in childhood or adolescence, recovered carpal tunnel syndrome, recovered uncomplicated meningitis, recovered herpes zoster, tension headache, occasional benign tics (e.g. due to stress) or minor par- or dysesthesia (e.g. as a side effect of prior blood withdrawal) do not constitute a history of relevant neurological disorder.
• History of immunological disease except allergy not relevant to the trial (such as mild hay fever or dust mite allergy) and except asthma in childhood or adolescence
• History of cancer (other than successfully treated basal cell carcinoma)
• Liver enzymes (ALT, AST, gGT, AP) above upper limit of normal at the screening examination
• Within 10 days prior to administration of trial medication, use of any drug that could reasonably inhibit platelet aggregation or coagulation (e.g., acetylsalicylic acid)
• Male subjects with Woman of child bearing potential (WOCBP) partner who are unwilling to use male contraception (condom or sexual abstinence) from time point of first administration of trial medication until 30 days after the last administration of trial medication

Clinical studies sponsored by Boehringer Ingelheim, phases I to IV, interventional and non-interventional, are in scope for sharing of the raw clinical study data and clinical study documents, except for the following exclusions:

1. studies in products where Boehringer Ingelheim is not the license holder; 2. studies regarding pharmaceutical formulations and associated analytical methods, and studies pertinent to pharmacokinetics using human biomaterials; 3. studies conducted in a single center or targeting rare diseases (because of limitations with anonymization). For more details refer to: https://www.mystudywindow.com/msw/datatransparency

Treated set (TS): The treated set included all participants who were treated with at least 1 dose of trial drug.

BI 894416 (Reference): From treatment with BI 894416 in treatment period 1 until first treatment with rifampicin in treatment period 2, up to 3 days. Rifampicin: From first treatment with rifampicin in treatment period 2 until treatment with BI 894416 in treatment period 2, up to 7 days. BI 894416 + Rifampicin (Test): From treatment with BI 894416 in treatment period 2 until the individual paricipant's end of trial, up to 15 days.

The treated set included all participants who were treated with at least 1 dose of trial drug. The treated set was used for safety analyses.