The purpose of this study is to investigate how quickly and to what extent ACT-246475 is absorbed, distributed, metabolized (broken down) and eliminated from the body. ACT-246475 will be labeled with 14-Carbon (14C) and, in this way can be traced in blood, urine, and feces. This study will also investigate how safe is ACT-246475 and how well it is tolerated when administered to healthy male volunteers.

Main Inclusion Criteria:

• Signed informed consent in the local language prior to any studymandated procedure,
• Healthy male subjects aged between 45 and 65 years (inclusive) at screening,
• No clinically significant findings on the physical examination at screening,
• Body mass index of 18.0-28.0 kg/m2 (inclusive) at screening,
• Systolic blood pressure (BP) 100-140 mmHg, diastolic BP 50-90 mmHg, and pulse rate 45-90 bpm (inclusive), measured on either arm, after 5 min in the supine position at screening,
• 12-lead electrocardiogram (ECG) without clinically relevant abnormalities, measured after 5 min in the supine position at screening,
• Values of closure time tested with the Platelet Function Analyzer equipment, for both cartridges of collagen/epinephrine and collagen/adenosine diphosphate below the upper limit of normal range at screening.

Main Exclusion Criteria:

• Known hypersensitivity to ACT-246475 or drugs of the same class, or any excipients of the ACT-246475 formulation,
• History or clinical evidence of any disease and/or existence of any surgical or medical condition, which might interfere with the absorption, distribution, metabolism or excretion of the study treatment (appendectomy and herniotomy allowed, cholecystectomy not allowed),
• Family or personal history of prolonged bleeding (e.g., after surgical intervention) or bleeding disorders (e.g., thrombocytopenia, clotting disturbances), intracranial vascular diseases, stroke, reasonable suspicion of vascular malformations, or peptic ulcers,
• Platelet count < 120 x10^9 L-1 at screening,
• Previous exposure to ACT-246475,
• Participation in another study with a radiation burden of > 0.1 mSv and ≤ 1.0 mSv in a period of 1 year prior to screening; a radiation burden of > 1 mSv and ≤ 2.0 mSv in a period of 2 years prior to screening, etc. (add 1 year per 1 mSv),
• Exposure to radiation for diagnostic reasons (except dental X-rays and plain X-rays of thorax and bony skeleton [excluding spinal column]), during work or during participation in a clinical study, in the period of 1 year prior to screening,
• Any circumstances or conditions, which, in the opinion of the investigator, may affect full participation in the study or compliance with the protocol.