A Study in Healthy Subjects to Investigate Whether Administration of Clazosentan Can Affect Normal Heart Function

Randomized, Double-blind (for Clazosentan), Placebo- and Moxifloxacincontrolled, 3-way Cross-over Phase 1 Study to Assess the Effect of Two Intravenous Doses of Clazosentan on the QTc Interval Duration in Healthy Subjects

The study will investigate whether administration of clazosentan can affect normal heart function in healthy subjects

Inclusion Criteria:

General criteria

• Signed informed consent prior to any study-mandated procedure
• Body mass index of 18.0-30.0 kg/m2 (inclusive) at Screening
• Systolic blood pressure 100-145 mmHg, diastolic blood pressure 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
• 12-lead ECG: QT interval corrected using Fridericia's formula (QTcF) <450 ms for male subjects and < 470 ms for female subjects, QRS interval < 110 ms, PR interval ≤ 200 ms, and heart rate (HR) ≤ 90 bpm without clinically relevant abnormalities using a 12-lead ECG measured after 5 min in the supine position at Screening and on Day -1 of the first Period

Study-specific criteria

• Women of non-childbearing potential
• Male subjects must accept to use a condom and not to procreate for the duration of the study and for 3 months thereafter

Exclusion Criteria:

General criteria

• Previous exposure to clazosentan or to moxifloxacin within 3 months prior to Screening
• Known hypersensitivity to any of clazosentan excipients or to moxifloxacin or any of its excipients
• Any contraindication to moxifloxacin treatment
• Acute, ongoing, recurrent, or chronic systemic disease able to interfere with the evaluation of the study
• Previous history of fainting, collapse, syncope, orthostatic hypotension, or vasovagal reactions if considered clinically significant by the investigator
• Veins unsuitable for i.v. puncture on either arm (e.g., veins that are difficult to locate, access, or puncture, veins with a tendency to rupture during or after puncture)
• 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
• Any circumstances or conditions, which, in the opinion of the investigator, may affect full participation in the study or compliance with the protocol

Study-specific criteria

• History or presence of rhythm disorders (e.g., sinoatrial heart block, sick-sinus syndrome, second- or third-degree atrioventricular block, long QT syndrome, symptomatic bradycardia, atrial flutter, or atrial fibrillation)