Taking people in BelgiumPhase 3
A Phase 3 Efficacy and Safety Study of HBS-301 in Participants With Narcolepsy
Key facts
- Who runs it
- Harmony Biosciences Management, Inc.
- Where
- Edegem, Gent, Leuven, and Liège, BelgiumSee the 4 sitesAlso in 7 other countries, 71 sites
- Trial code
- Status
- Recruiting
- Phase
- Phase 3
- People taking part
- 258 people, planned
- Started
- 4 Jun 2026
- Expected to end
- Nov 2027
- Type of study
- Interventional, 3 groupsOne group gets a placebo (a dummy treatment), for comparison.
- Treatments tested
- HBS-301
- Placebo
- Record updated
- 27 August 2026
Who can take part
- Age
- 18 years and older
- Sex
- Women and men
- Healthy volunteers
- Cannot take part
The registry criteria, word for word
Show all 10 criteriaShow less
Who can take part
- Has a current documented diagnosis of NT1 or NT2 per the International Classification of Sleep Disorders, Third Edition (ICSD-3) or the ICSD-3 Text Revision (ICSD-3-TR) within the last 10 years
- Has EDS
- If taking a permitted chronic concomitant medication or supplement, including nonprohibited antidepressants or wake-promoting agents, must be on a stable dose for at least 3 months prior to Screening and agree to continue at that stable dose for the Double-blind Treatment Period of the study. As needed (PRN) use of any treatment that could affect daytime sleepiness (including but not limited to oxybates, stimulants, modafinil, and armodafinil) is not permitted
Who cannot take part
- Has a history of pitolisant use within 5 half-lives prior to Screening
- Has a primary diagnosis of psychiatric illness, including depression, that is not well controlled (i.e., symptoms and medications have not been stable for at least 3 months prior to Screening)
- Has hypersomnia due to another medical disorder
- Has any history of bipolar disorder or psychosis
- Has acute or chronic liver disease or a history of moderate or severe hepatic impairment
- Has a body surface area-corrected estimated glomerular filtration rate (eGFR) <60 mL/min
- Has a known history of long QT syndrome or serious abnormality of the electrocardiogram (ECG)
Where in Belgium
Also in 7 other countries, 71 sites
- Universitair Ziekenhuis AntwerpenEdegem, BelgiumTaking people
- Universitair Ziekenhuis GentGent, BelgiumTaking people
- UZ LeuvenLeuven, BelgiumTaking people
- Centre Hospitalier Regional de la CitadelleLiège, BelgiumTaking people
About the trial
What the trial wants to find out
This is a Phase 3, multicenter, randomized, double-blind, parallel-group, placebo-controlled clinical study to assess the efficacy and safety of HBS-301 in treating excessive daytime sleepiness (EDS), cataplexy, sleepiness/wakefulness, and fatigue in adult participants (ages ≥18 years) with narcolepsy.
The 3 groups in the trial
- Double-Blind Treatment Period HBS-301Treatment being tested
HBS-301 tablets administered once daily in the morning upon wakening
Treatment: HBS-301
- Double-blind Treatment Period PlaceboPlacebo, for comparison
Matching placebo tablets administered once daily in the morning upon wakening
Treatment: Placebo
- Open-Label Extension Period HBS-301Treatment being tested
HBS-301 tablets administered once daily in the morning upon wakening
Treatment: HBS-301
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
- Official title
- A Phase 3, Randomized, Double-blind, Placebo-Controlled, Efficacy and Safety Study of HBS-301 in Participants With Narcolepsy Followed by an Open-label Extension
- Record updated
- 27 August 2026