Study to Assess the Long Term Safety and Tolerability of ACT-541468 in Adult and Elderly Subjects Suffering From Difficulties to Sleep

Inclusion Criteria:

- Signed informed consent prior to any study-mandated procedure (Visit 1).

- Having completed the DB study treatment and the run-out period of ID-078A301 or
ID‒078A302 (Visit 1).

- For woman of childbearing potential, the following is required:

- Negative urine pregnancy test (EOT of ID-078A301 or ID-078A302 studies)

- Agreement to use the contraception scheme as required by the protocol from Visit
1 up to at least 30 days after EODBT.

Exclusion Criteria:

- Unstable medical condition, significant medical disorder or acute illness, C-SSRS©,
ECG, hematology or biochemistry test results in ID-078A301 and ID-078A302, which in
the opinion of the investigator could affect the subject's safety or interfere with
the study assessments (Visit 1).

- For female subjects: lactating or planning to become pregnant during the duration of
the study (Visit 1).

- Positive urine drug test (for benzodiazepines, barbiturates, cannabinoids, opiates,
amphetamines, or cocaine) or presence of alcohol in exhaled breath as detected by
breathalyzer test (EOT of ID-078A301 or ID-078A302 studies if same day as Visit 1 or
Visit 1 if within 7 days after EOT).