A Clinical Study to Investigate the Potential Interactions Between Food and ACT-541468 and Between ACT-541468 and Midazolam

A Single-center, Open-label Study to Investigate the Food Effect on the Pharmacokinetics of ACT-541468 and the Effect of Single- and Multiple-dose ACT-541468 on the Pharmacokinetics of Midazolam and Its Metabolite 1-Hydroxymidazolam in Healthy Male Subjects

The main objectives of this phase 1 trial are to evaluate the effect of food on the pharmacokinetics (i.e. how long and how much a compound is present in the blood) of ACT-541468 and to evaluate whether ACT-541468 can affect the pharmacokinetics of midazolam, a CYP3A4 substrate.

Food effect will be assessed by comparing the pharmacokinetic (PK) parameters of a single dose of ACT-541468 under fasted (Treatment B) and fed (Treatment C) conditions.

Potential CYP3A4 inhibiting / inducing effects of ACT-541468 will be assessed by comparing the PK parameters of midazolam alone (Treatment A) and midazolam given with a single dose of ACT-541468 (Treatment B) or with multiple doses of ACT-541468 (Treatment D).

Inclusion Criteria:

• Signed informed consent form
• Male subjects aged from 18 to 45 years (inclusive) at screening
• Body mass index (BMI) from 18.0 to 30.0 kg/m2 (inclusive) at screening
• Healthy on the basis of physical examination, cardiovascular assessments and laboratory tests

Exclusion Criteria:

• Any contraindication to the study treatments
• History or clinical evidence of any disease or medical / surgical condition or treatment, which may put the subject at risk of participation in the study or may interfere with the absorption, distribution, metabolism or excretion of the study treatments
• History of narcolepsy or cataplexy or modified Swiss narcolepsy scale total score < 0
• 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