A Clinical Study to Examine the Drug-drug Interactions Between ACT-541468 and Citalopram in Healthy Male and Female Subjects

Study Overview
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Brief Summary
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A clinical study to examine the drug-drug interactions between ACT-541468 and citalopram in healthy male and female subjects

Official Title
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A Single-center, Single-blind, Randomized, Placebo-controlled, Sequential Design Phase 1 Study With the Inclusion of Two Double-blind Nested Crossover Parts to Investigate the Drug-drug Interactions Between ACT-541468 and Citalopram in Healthy Male and Female Subjects

Conditions
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Healthy

Intervention / Treatment
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* Drug: ACT541468
* Drug: ACT541468 placebo
* Drug: Citalopram


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Signed informed consent prior to any study-mandated procedure. Healthy male and female subjects aged between 24 and 55 years (inclusive) at Screening. Body mass index of 18.5 to 29.9 kg/m2 (inclusive) at Screening. Women of childbearing potential must have a negative serum pregnancy test at Screening and a negative urine pregnancy test on Day -1. They must consistently and correctly use a highly effective method of contraception, be sexually inactive, or have a vasectomized partner. Women of non-childbearing potential (i.e., postmenopausal, with previous bilateral salpingectomy, bilateral salpingo oophorectomy or hysterectomy, or with premature ovarian failure, XY genotype, Turner syndrome, uterine agenesis). Healthy on the basis of physical examination, cardiovascular assessments, and clinical laboratory tests. Exclusion Criteria: Pregnant or lactating women. Any circumstances or conditions, which, in the opinion of the investigator, may affect full participation in the study or compliance with the protocol. Modified Swiss Narcolepsy Scale total score < 0 at Screening or history of narcolepsy or cataplexy. Any contraindication to citalopram or any other selective serotonin reuptake inhibitor. History of cardiovascular disease (e.g., congenital long QT syndrome, arrhythmia). Relevant history of a suicide attempt or suicidal behavior. Personal or family history of psychiatric disorder(s). Individuals of Asian descent. History or clinical evidence of alcoholism or drug abuse within the 3-year period prior to Screening. Excessive caffeine consumption, defined as ≥ 800 mg per day at screening. 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 or 5 terminal half-lives (t½; whichever is longer) prior to first study treatment administration. Ongoing, recurrent, or chronic hypokalemia or hypomagnesemia.

Ages Eligible for Study
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Minimum Age: 24 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Single-center, single-blind, randomized, placebo-controlled, sequential design Phase 1 study with the inclusion of two double-blind nested crossover parts
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Treatment A and B<br>On Day 1 and Day 2, subjects will EITHER receive: a single dose of 50 mg ACT-541468 (Treatment A) on Day 1 and a single dose of ACT- 541468 placebo (Treatment B) on Day 2 OR a single dose of ACT-541468 placebo (Treatment B) on Day 1 and a single dose of 50 mg ACT-541468 (Treatment A) on Day 2. | Drug: ACT541468<br>* 50 mg; film-coated tablet for oral use<br>Drug: ACT541468 placebo<br>* film-coated tablet for oral use<br>|
| Other: Treatment C, D, E, and F<br>From Day 3 to Day 10, subjects will on each day receive: • a single dose of 20 mg citalopram and EITHER a single dose of ACT-541468 placebo OR a single dose of 50 mg ACT-541468. | Drug: ACT541468<br>* 50 mg; film-coated tablet for oral use<br>Drug: ACT541468 placebo<br>* film-coated tablet for oral use<br>Drug: Citalopram<br>* 20 mg; tablet tor oral use; for single- or repeated dosing<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline for Saccadic Peak Velocity (degrees/sec) to assess sedation |  | From pre-dose to 8 hours after dosing on Day 1, Day 2, Day 3, Day 9, and Day 10 |