The purpose of this study is to evaluate the effect of clopidogrel on the pharmacokinetics of selexipag and its active metabolite (ACT-333679) in healthy male adults (by determining the blood concentrations of selexipag and its metabolite). Also, the safety of selexipag when administered alone or with clopidogrel will be assessed.
Inclusion Criteria: * Signed informed consent in the local language prior to any study-mandated procedure. * Healty male subjects aged between 18 and 45 years (inclusive) at screening. * Body mass index from 18.0 to 28.0 kg/m2 (inclusive) at screening. * Systolic blood pressure (SBP) 100-145 mmHg, diastolic blood pressure (DBP) 50-90 mmHg, and pulse rate 45-90 bpm (inclusive). Exclusion Criteria: * Any contraindication included in the SmPC of selexipag or clopidogrel treatment. * 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 treatments. * History or clinical evidence of any disorder of hemostasis, hemorrhagic diathesis, nose or gingival bleeding, hemophilia, thrombotic thrombocytopenic purpura, presence of any lesions with a propensity to bleed (particularly gastrointestinal and intraocular), history of bleeding complications after surgical procedures such as tooth extraction * Previous history of stroke, fainting, collapse, syncope, orthostatic hypotension,vasovagal reactions, head injury. * Excessive caffeine consumption * Nicotine consumption within 3 months prior to screening, and inability to refrain from nicotine consumption during the course of the study * Previous treatment with any prescribed medications (including vaccines) or over the counter (OTC) medications (including herbal medicines such as St John's Wort, homeopathic preparations, vitamins, and minerals) within 2 weeks prior to first selexipag administration. * Subjects with rare hereditary problems of galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption. * Any circumstances or conditions, which, in the opinion of the investigator, may affect the subject's full participation in the study or compliance with the protocol.