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Phase 3 Study of HBS-301 for Narcolepsy

This study is testing a drug called HBS-301 to see if it can help adults with narcolepsy who experience excessive daytime sleepiness (EDS), cataplexy (sudden muscle weakness), and fatigue. You might be able to join if you are 18 or older, have a narcolepsy diagnosis from the last 10 years, and experience EDS. The main goal is to see how much HBS-301 improves your sleepiness compared to a placebo (an inactive pill), as measured by a sleepiness scale over 8 weeks. The study is currently unclear about its recruitment status.

Study design
This is a Phase 3, randomized, double-blind study, meaning some participants will receive HBS-301 and others a placebo, and neither you nor your doctor will know which you are getting. About 258 adults with narcolepsy are expected to participate.
What's involved
You would participate in a screening period, followed by an 8-week treatment period where you would take either HBS-301 or a placebo tablet. There is also an optional longer treatment period of 1 year.
Compensation
Not stated in the trial record.
Follow-up
After the main treatment period, there will be 30 days of safety follow-up.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07675135

A Phase 3 Efficacy and Safety Study of HBS-301 in Participants With Narcolepsy

Recruiting
PHASE3Ages 18+InterventionalTreatment
Harmony Biosciences Management, Inc.
~258 participants
Updated 2026-08-27 on ClinicalTrials.gov
What's tested:HBS-301Placebo

At a glance

Recruiting sites
29 of 53 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Change in severity of EDS as measured by the Epworth Sleepiness Scale (ESS)
Measured over Baseline to end of Double-Blind Treatment Period (8 weeks)

Conditions

EDS
Cataplexy
Fatigue
Narcolepsy

Explore related trials

Narcolepsy

Where it's being run

53 sites across 26 states
Texas6
California5
Georgia4
Pennsylvania4
Michigan3
North Carolina3
South Carolina3
Alabama2

Study leadership

  • David Seiden, MD · STUDY_DIRECTOR · Harmony Biosciences Management, Inc.

Who to contact

Michelle Manuel
[email protected]
847-903-4610
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

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.

Exclusion

Has hypersomnia due to another medical disorder.
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 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).

What this trial measures

  • Change in severity of EDS as measured by the Epworth Sleepiness Scale (ESS)Baseline to end of Double-Blind Treatment Period (8 weeks)

    The ESS is an 8-item, 4-point rating scale.