A study in healthy male subjects to investigate whether administration of rifampicin can affect the fate in the body (amount and time of presence in the blood) of clazosentan

Inclusion Criteria:

• Signed informed consent in a language understandable to the subject prior to any study-mandated procedure.
• Healthy male subjects aged between 18 and 65 years (inclusive) at Screening.
• Body mass index (BMI) of 18.0 to 30.0 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), measured on the same arm, after 5 min in the supine position at Screening and on Day -1 of the first Period.
• Healthy on the basis of physical examination, cardiovascular assessments and laboratory tests.

Study-specific criteria

- Acceptance for the duration of the study and for 3 months thereafter to use a condom and not to procreate.

Exclusion Criteria:

• Previous exposure to clazosentan.
• Previous exposure to rifampicin within 3 months prior to Screening.
• Known hypersensitivity to clazosentan or rifampicin or treatments of the same class, or any of their excipients.
• Known hypersensitivity or allergy to natural rubber latex.
• Participation in a clinical study involving study treatment administration within 3 months prior to Screening or in more than 4 clinical studies within 1 year prior to Screening.
• History or clinical evidence of alcoholism or drug abuse within the 3-year period prior to Screening.
• Positive results for hepatitis B surface antigen or hepatitis C virus antibody at Screening.
• Positive results from the HIV serology at Screening.
• Any circumstances or conditions, which, in the opinion of the investigator, may affect full participation in the study or compliance with the protocol.