Idiopathic HypersomniaPhase 3NCT07500090
A Phase 3 Efficacy and Safety Study of HBS-301 in Participants With Idiopathic Hypersomnia (IH)
A Phase 3 study testing HBS-301 tablet in people with Idiopathic Hypersomnia, run by Harmony Biosciences Management, Inc. at 42 sites in 2 countries.
Trial summary
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 adult participants (ages ≥18 years) with idiopathic hypersomnia (IH). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Idiopathic Hypersomnia
- What is being tested?
- HBS-301 tablet
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 248 participants
- Where
- 42 sitesin 2 countries
- Study dates
- 16 Mar 2026to Oct 2028
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Has a current documented diagnosis of IH per the International Classification of Sleep Disorders, Third Edition (ICSD-3) or Text Revision (ICSD-3-TR) criteria with confirmatory polysomnogram (PSG) with multiple sleep latency test (MSLT; and if applicable, a 24-hour PSG report or an actigraphy report with sleep log) on file that led to the diagnosis and was completed within the last 10 years.
- Has EDS.
- Has moderate to very severe symptoms of IH.
- 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 use of any treatment that could affect daytime sleepiness (including but not limited to stimulants, modafinil, and armodafinil) used on an as-needed basis is not permitted.
Who cannot join
- 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.
- Has a history of moderate or severe hepatic impairment.
- Has a body surface area (BSA)-corrected estimated glomerular filtration rate (eGFR) <60 mL/min.
- Has a known history of long QT syndrome or any significant history of a serious abnormality of the electrocardiogram (ECG).
Trial locations and contacts
42 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
42 sites in 2 countries
United States40 sites, 40 recruiting
- Recruiting
Abington Neurological Associates
Abington, Pennsylvania, 19001
Rachel Grossman, 215-957-9250, rachelgrossman.ana@gmail.com
John Khoury
- Recruiting
Neurology Care
Ardmore, Oklahoma, 73401
Maaz Ghani, mghani@sunbeamresearch.com
Baha Abu-Esheh
- Recruiting
NeuroTrials Research Inc.
Atlanta, Georgia, 30328
Shriya Parekh, 404-851-9934, sparekh@neurotrials.com
Dennis Lacey, MD
- Recruiting
Aayus Research
Austin, Texas, 78731
Maria-Fernanda Gamero, 803-606-2052, Maria@aayus.com
Bhavim Desai
- Recruiting
Sleep Disorders Center of Alabama
Birmingham, Alabama, 35213
Joseph Wright, 205-599-1020, jwright@sleepalabama.com
Robert Doekel
- Recruiting
Alpine Clinical Research Center, Inc.
Boulder, Colorado, 80301
Frederica Bresciani, 601-520-1333, fika@alpineresearch.com
John Harsh
- Recruiting
Neuroscience Research Center, LLC
Canton, Ohio, 44718
Kellie McCabe, 330-244-2542, kelliem@neurocarecenter.com
Ryan Drake
- Recruiting
Lowcountry Lung and Critical Care, PA
Charleston, South Carolina, 29406
Courtney Arnold, 843-572-8545, carnold@lowcountrylung.com
Thomas Kaelin
- Recruiting
St. Luke's Hospital, Sleep Medicine and Research Center
Chesterfield, Missouri, 63017
Kimberly Allen-Bowzer, 314-205-6011, SLHSleepResearch@stlukes-stl.com
Michael McLeland, PhD
- Recruiting
Intrepid Research
Cincinnati, Ohio, 45245
Tiffany Schira, 513-977-8891, tschira@intrepidresearch.md
Bruce Corser
- Recruiting
Delta Waves LLC
Colorado Springs, Colorado, 80918
Emma Gallagher, 719-262-9283, egallagher@deltawaves.org
Jonathan Olin
- Recruiting
Bogan Sleep Consultants, LLC
Columbia, South Carolina, 29201
Lorraine Potts, 803-251-3093, Lorraine.Potts@bogansleep.com
Richard Bogan
- Recruiting
Southwest Family Medicine Associates
Dallas, Texas, 75235
Safia Shaikh, 493-893-1242, sshaikh@swmedicalgroup.com
Chrisette Dharma
- Recruiting
Infinity Medical Research Inc.
East Providence, Rhode Island, 02914
Patricia Mello, 508-998-3041, pmello@infinitymedicalresearch.com
Curtis Mello
- Recruiting
Fort Wayne Neurological Center
Fort Wayne, Indiana, 46804
Patti Case, 704-659-0090, pcase@iuhealth.org
James Stevens
- Recruiting
Clinical Research of Gastonia
Gastonia, North Carolina, 28054
Melissa Lanham, 704-675-7144, mlanham@crgastonia.com
Madeline Gibson, 704-675-7144, mgibson@crgastonia.com
- Recruiting
Stern Research Partners, LLC
Huntersville, North Carolina, 28078
Felix Kurniawan, 704-659-0090 ext. 1012, felix@arsmnc.com
Thomas Stern, MD
- Recruiting
Sleep Practitioners, LLC
Macon, Georgia, 31210
Noelle Williams, 478-745-5779, nwilliams@sleeppractitioners.com
Charles Wells
- Recruiting
University of Washington
Madison, Wisconsin, 53792
Ahmad Allen, 608-232-3333, aallen45@wisc.edu
David Plante
- Recruiting
Metroplex Pulmonary and Sleep Center
McKinney, Texas, 75069
Rupa Krishna, 972-838-1892, rkrishna@mpsleepcenter.com
Shahrukh Kureishy
- Recruiting
PharmDev Research Institute, LLC
Miami, Florida, 33176
Rolando Rodriguez, 305-420-5636, rrodriguez@pharmadevresearch.com
Edward Mezerhane, MD
- Recruiting
West Virginia University
Morgantown, West Virginia, 26506
Lauren Chase, 304-598-4000
Mouhannad Azzouz
- Recruiting
David Kudrow, MD
Morrisville, North Carolina, 27560
Victoria Taylor, 984-377-3737, HarmonyIHPEC@science37.com
David Kudrow
- Recruiting
K2 Medical Research
Nashville, Tennessee, 37204
Francesca McKay, 615-208-5252, francesca.mckay@k2med.com
Joshua Lennon, MD
- Recruiting
Phoenix Medical Group LLC
Peoria, Arizona, 85381
Daniel Kasenovich, 623-583-6542, dkasenovich@phxresearch.com
Robert Orr
- Recruiting
Stanford Center for Sleep Medicine
Redwood City, California, 94063
Sara Lomba, 650-799-1565, slomba@stanford.edu
Oliver Sum-Ping, MD
- Recruiting
Southeast Lung Associates Research
Rincon, Georgia, 31326
Lisa Rodnicki, 912-826-3927, lisa.rodnicki@centricityresearch.com
Maria Mascolo
- Recruiting
Sleep Therapy and Research Center
San Antonio, Texas, 30328
Erin Marshall, 210-614-6000, marshall.erin@sleeptrc.com
Nagwa Lamaie
- Recruiting
HAS Research
San Antonio, Texas, 78240
Kimberly Rosales, 210-614-7711, kimberly.rosales@hasresearch.com
Hernan A Salazar, DO
- Recruiting
Trial Site Solutions
San Ramon, California, 04583
Phil Strauss, 925-415-5353, phil@sleepmds.com
Haramandeep Singh
- Recruiting
Santa Monica Clinical Trials
Santa Monica, California, 90404
Samantha Montanez, 310-586-0843, smontanez@smclinicaltrials.com
Daniel Norman, MD
- Recruiting
Revive Research Institute
Southfield, Michigan, 48975
Abhishek Dhillon, 248-564-1485, adhillon@rev-research.com
Syed Muhammad Talib Rizvi Raza, MD
- Recruiting
Washington State University Sleep and Performance Center
Spokane, Washington, 99210
Olivia Brooks, 509-358-7754, Olivia.brooks@wsu.edu
Devon Hansen
- Recruiting
Clinical Neuropsychology Services
Sterling Heights, Michigan, 48314
Jessica Austin, 586-254-0707, austinj@sleepandattentiondisorders.com
Shaffi Kanjwal
- Recruiting
Clinical Research Institute Stockbridge
Stockbridge, Georgia, 30281
Beverly Jenkins, 678-782-5358, bjenkins@clinicalresearchinstitute.us
Phillip Nowlin
- Recruiting
Tricoastal Narcolepsy and Sleep Disorders Center
Sugar Land, Texas, 77478
Natalia Dubok, 832-210-3850, research@tricoastalsleep.com
Gerry Meskill
- Recruiting
Suburban Research Associates
West Chester, Pennsylvania, 19380
Carol McDevitt, 610-891-9024, cmcdevitt@suburbanresearch.com
Omer Abdullah, MD
- Recruiting
TPMG Clinical Research
Williamsburg, Virginia, 23188
Gabrielle Land, 757-707-3503, gabrielle.land@tpmgpc.com
Richard Parisi
- Recruiting
Central Florida Pediatric Sleep Disorders Institute (Florida Pediatric Research Institute, LLC)
Winter Park, Florida, 32789
Heidi Patenube, 407-898-2767, heidi@ajayhealthcare.com
Akinyemi Ajayi
- Recruiting
Berks Schuylkill Respiratory Specialists
Wyomissing, Pennsylvania, 19610
Lisa Hill, 610-685-5864, lhill@lungmd.net
Alec Platt, MD
Canada2 sites, 2 recruiting
- Recruiting
AMNDX Inc
Markham, Ontario, M5S 3A3
Urszula Lamoureux, 416-435-6244, urszula@amndx.ca
Alan Lowe
- Recruiting
Jodha Tishon Inc
Toronto, Ontario, M5S 3A3
Naheed Hossain, (416) 551-8296, aheedkhossain@jodhatishon.com
Colin Shapiro
About this study
Official title: A Phase 3, Randomized, Double-blind, Placebo-Controlled, Efficacy and Safety Study of HBS-301 in Participants With Idiopathic Hypersomnia (IH) Followed by an Open-label Extension
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 adult participants (ages ≥18 years) with idiopathic hypersomnia (IH).
Read the detailed description
Approximately 248 participants are planned for randomization in the study. The study will consist of a Screening/Baseline Period (up to 28 days), a Double-blind Treatment Period (8 weeks), an optional Open-label Extension (OLE) Period (1 year), and 30 days of safety follow-up.
- Conditions
- Idiopathic Hypersomnia
- Being tested
- HBS-301 tablet, Placebo
- Keywords
- pitolisant, HBS-301, idiopathic hypersomnia, excessive daytime sleepiness, sleep inertia, fatigue
- Medical subject headings
- Idiopathic Hypersomnia, Disorders of Excessive Somnolence, Fatigue
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HBS-301 tabletDrug
Also called pitolisant delayed-release
HBS-301 tablet
PlaceboDrug
Placebo tablet
| Study group | Role | What they receive |
|---|---|---|
| Double-Blind Treatment Period HBS-301 | Experimental | HBS-301 tablets administered once daily in the morning upon wakening Receives: Drug: HBS-301 tablet |
| Double-blind Treatment Period Placebo | Placebo comparator | Matching placebo tablets administered once daily in the morning upon wakening Receives: Drug: Placebo |
| Open-label Extension Period HBS-301 | Experimental | HBS-301 tablets administered once daily in the morning upon wakening Receives: Drug: HBS-301 tablet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in severity of EDS as measured by the Epworth Sleepiness Scale (ESS)
The ESS is an 8-item, 4-point rating scale.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Secondary outcomes (19)
Change in severity of IH symptoms as measured by the Idiopathic Hypersomnia Severity Scale (IHSS)
The IHSS is a 14-item questionnaire designed to measure IH symptoms.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in sleep inertia as measured by the Sleep Inertia Questionnaire (SIQ)
The SIQ is a 22-item questionnaire that measures aspects of night and day sleep symptoms and the sleep inertia related to each.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in fatigue as measured by the Patient-Reported Outcomes Measurement Information System Fatigue Short Form 7a
The PROMIS-Fatigue-SF-7a is a 7-question, 5-point scale used to assess fatigue.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in severity of EDS as measured by the Epworth Sleepiness Scale
The ESS is an 8-item, 4-point rating scale.
Measured: Baseline through Week 1 and Week 2 of the Titration Period (1 week and 2 weeks)
Change in severity of IH symptoms as measured by the IHSS
The ESS is an 8-item, 4-point rating scale.
Measured: Baseline through Week 1 and Week 2 of the Titration Period (1 week and 2 weeks)
Change in severity of EDS as measured by the Clinical Global Impression of Severity (EDS)
The Clinical Global Impression of Severity (EDS) is a 5-item observer-rated scale that gauges the severity of a participant's EDS symptoms.
Measured: Baseline to end of Double-blind Treatment Period (8 weeks)
Change in severity of EDS as measured by the Patient Global Impression of Severity (EDS)
The Patient Global Impression of Severity (EDS) is a participant-reported assessment that gauges the severity of a participant's EDS symptoms.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Improvement in severity of EDS as measured by the Patient Global Impression of Change (EDS)
The Patient Global Impression of Change (EDS) is a participant-reported outcome used to evaluate the effectiveness of a treatment on their EDS symptoms.
Measured: End of the Double-blind Treatment Period (8 weeks)
Change in severity of IH symptoms as measured by the Clinical Global Impression of Severity (IH)
The Clinical Global Impression of Severity (IH) is a 3-item observer-rated scale used to track IH symptom changes.
Measured: Baseline to end of Double-blind Treatment Period (8 weeks)
Change in severity of IH symptoms as measured by the Patient Global Impression of Severity (IH)
The Patient Global Impression of Severity (IH) is a participant-reported assessment that gauges the severity of a participant's IH symptoms.
Measured: Baseline to end of Double-blind Treatment Period (8 weeks)
Improvement in severity of IH symptoms as measured by the Patient Global Impression of Change (IH)
The Patient Global Impression of Change (IH) is a participant-reported outcome used to evaluate the effectiveness of a treatment on their IH symptoms.
Measured: Baseline to end of Double-blind Treatment Period (8 weeks)
Change in severity of sleep inertia as measured by the Patient Global Impression of Severity (Sleep Inertia)
The Patient Global Impression of Severity (Sleep Inertia) is a participant-reported assessment that gauges the severity of a participant's sleep inertia symptoms.
Measured: Baseline to end of Double-blind Treatment Period (8 weeks)
Improvement in severity of sleep inertia as measured by the Patient Global Impression of Change (Sleep Inertia)
The Patient Global Impression of Change (Sleep Inertia) is a participant-reported outcome used to evaluate the effectiveness of a treatment on their sleep inertia symptoms.
Measured: End of the Double-blind Treatment Period (8 weeks)
Change in severity of fatigue as measured by the Patient Global Impression of Severity (Fatigue)
The Patient Global Impression of Severity (Fatigue) is a participant-reported assessment that gauges the severity of a participant's fatigue symptoms.
Measured: Baseline of the end of the Double-blind Treatment Period (8 weeks)
Improvement in severity of fatigue as measured by the Patient Global Impression of Change (Fatigue)
The Patient Global Impression of Change (Fatigue) is a participant-reported outcome used to evaluate the effectiveness of a treatment on their fatigue symptoms.
Measured: End of the Double-blind Treatment Period (8 weeks)
Change in cognitive complaints as measured by the British Columbia Cognitive Complaints Inventory
The British Columbia Cognitive Complaints Inventory is a participant-reported, 6-item, 4-point scale that assesses perceived cognitive difficulties.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in health-related quality of life as measured by the Short Form Health Survey-36 physical and mental component summaries
The Short Form-36 includes 36 questions across 8 health domains to measure a participant's functional health and well-being.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in work productivity as measured by the Work Productivity and Activity Impairment: Idiopathic Hypersomnia Work Productivity loss score
The Work Productivity and Activity Impairment: Idiopathic Hypersomnia questionnaire is a 6-item scale used to measure impairments over 7 days.
Measured: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Incidence of treatment-emergent adverse events
A treatment-emergent adverse event is any adverse event reported after the first dose of study drug and up to 30 days after final dose of study drug, or any worsening of a pre-existing condition reported after first dose of study drug and up to 30 days after final dose of study drug.
Measured: Throughout study (16 months including OLE)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Mar 2026
- Study start16 Mar 2026
- Primary completionOct 2027 (estimated)
- Study completionOct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Idiopathic HypersomniaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 248 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Harmony Biosciences Management, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- David Seiden, MD, Study director, Harmony Biosciences Management, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07500090
- Sponsor's protocol ID
- HBS-301-CL-302
- Other IDs
- 2025-523822-42-00, 2025
- Status last verified
- Sep 2026
- First submitted
- 21 Mar 2026
- Last updated
- 14 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Randomized, Double-blind, Placebo-Controlled, Efficacy and Safety Study of HBS-301 in Participants With Idiopathic Hypersomnia (IH) Followed by an Open-label Extension
- ClinicalTrials.gov ID
- NCT07500090
- Acronym / sponsor ID
- HBS-301-CL-302
- Conditions
- Idiopathic Hypersomnia
- Keywords
- pitolisant, HBS-301, idiopathic hypersomnia, excessive daytime sleepiness, sleep inertia, fatigue
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 248 participants (estimated)
- Lead sponsor
- Harmony Biosciences Management, Inc.Industry (pharma, biotech, devices)
- Study start
- 16 Mar 2026 (actual)
- Primary completion
- Oct 2027 (estimated)
- Study completion
- Oct 2028 (estimated)
- First posted
- 30 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 adult participants (ages ≥18 years) with idiopathic hypersomnia (IH).
Detailed description
Approximately 248 participants are planned for randomization in the study. The study will consist of a Screening/Baseline Period (up to 28 days), a Double-blind Treatment Period (8 weeks), an optional Open-label Extension (OLE) Period (1 year), and 30 days of safety follow-up.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Double-Blind Treatment Period HBS-301 | Experimental | Drug: HBS-301 tabletHBS-301 tablets administered once daily in the morning upon wakening |
| Double-blind Treatment Period Placebo | Placebo comparator | Drug: PlaceboMatching placebo tablets administered once daily in the morning upon wakening |
| Open-label Extension Period HBS-301 | Experimental | Drug: HBS-301 tabletHBS-301 tablets administered once daily in the morning upon wakening |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Has a current documented diagnosis of IH per the International Classification of Sleep Disorders, Third Edition (ICSD-3) or Text Revision (ICSD-3-TR) criteria with confirmatory polysomnogram (PSG) with multiple sleep latency test (MSLT; and if applicable, a 24-hour PSG report or an actigraphy report with sleep log) on file that led to the diagnosis and was completed within the last 10 years.
- Has EDS.
- Has moderate to very severe symptoms of IH.
- 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 use of any treatment that could affect daytime sleepiness (including but not limited to stimulants, modafinil, and armodafinil) used on an as-needed basis is not permitted.
Key exclusion criteria (6 listed)
- 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.
- Has a history of moderate or severe hepatic impairment.
- Has a body surface area (BSA)-corrected estimated glomerular filtration rate (eGFR) <60 mL/min.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| HBS-301 tabletAlso: pitolisant delayed-releaseHBS-301 tablet | Drug | Double-Blind Treatment Period HBS-301, Open-label Extension Period HBS-301 |
| PlaceboPlacebo tablet | Drug | Double-blind Treatment Period Placebo |
Primary outcome
Change in severity of EDS as measured by the Epworth Sleepiness Scale (ESS)
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
The ESS is an 8-item, 4-point rating scale.
19 secondary outcomes
Change in severity of IH symptoms as measured by the Idiopathic Hypersomnia Severity Scale (IHSS)
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in sleep inertia as measured by the Sleep Inertia Questionnaire (SIQ)
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in fatigue as measured by the Patient-Reported Outcomes Measurement Information System Fatigue Short Form 7a
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in severity of EDS as measured by the Epworth Sleepiness Scale
Time frame: Baseline through Week 1 and Week 2 of the Titration Period (1 week and 2 weeks)
Change in severity of IH symptoms as measured by the IHSS
Time frame: Baseline through Week 1 and Week 2 of the Titration Period (1 week and 2 weeks)
Change in severity of EDS as measured by the Clinical Global Impression of Severity (EDS)
Time frame: Baseline to end of Double-blind Treatment Period (8 weeks)
Change in severity of EDS as measured by the Patient Global Impression of Severity (EDS)
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Improvement in severity of EDS as measured by the Patient Global Impression of Change (EDS)
Time frame: End of the Double-blind Treatment Period (8 weeks)
Change in severity of IH symptoms as measured by the Clinical Global Impression of Severity (IH)
Time frame: Baseline to end of Double-blind Treatment Period (8 weeks)
Change in severity of IH symptoms as measured by the Patient Global Impression of Severity (IH)
Time frame: Baseline to end of Double-blind Treatment Period (8 weeks)
Improvement in severity of IH symptoms as measured by the Patient Global Impression of Change (IH)
Time frame: Baseline to end of Double-blind Treatment Period (8 weeks)
Change in severity of sleep inertia as measured by the Patient Global Impression of Severity (Sleep Inertia)
Time frame: Baseline to end of Double-blind Treatment Period (8 weeks)
Improvement in severity of sleep inertia as measured by the Patient Global Impression of Change (Sleep Inertia)
Time frame: End of the Double-blind Treatment Period (8 weeks)
Change in severity of fatigue as measured by the Patient Global Impression of Severity (Fatigue)
Time frame: Baseline of the end of the Double-blind Treatment Period (8 weeks)
Improvement in severity of fatigue as measured by the Patient Global Impression of Change (Fatigue)
Time frame: End of the Double-blind Treatment Period (8 weeks)
Change in cognitive complaints as measured by the British Columbia Cognitive Complaints Inventory
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in health-related quality of life as measured by the Short Form Health Survey-36 physical and mental component summaries
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Change in work productivity as measured by the Work Productivity and Activity Impairment: Idiopathic Hypersomnia Work Productivity loss score
Time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)
Incidence of treatment-emergent adverse events
Time frame: Throughout study (16 months including OLE)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Idiopathic Hypersomnia
RecruitingPhase 2/3
A Study of TAK-360 in People With Narcolepsy or Idiopathic Hypersomnia
Idiopathic Hypersomnia, Narcolepsy Type 1
RecruitingObservational study
Rare Disease Patient Registry & Natural History Study - Coordination of Rare Diseases at Sanford
Rare Disorders, Undiagnosed Disorders
RecruitingPhase 2/3
A Long-Term Study of ALKS 2680 in Subjects With Narcolepsy and Idiopathic Hypersomnia
Narcolepsy Type 1, Narcolepsy Type 2
RecruitingPhase 3
A Study Evaluating the Efficacy and Safety of Xywav Expanded Dosing vs Placebo in Participants With Narcolepsy or IH
Narcolepsy, Idiopathic Hypersomnia
Active, not recruitingPhase 2
A Study to Evaluate the Safety and Effectiveness of ALKS 2680 in Subjects With Idiopathic Hypersomnia
Idiopathic Hypersomnia
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David Seiden, MD study director
Harmony Biosciences Management, Inc.
42 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing HBS-301 tablet in people with Idiopathic Hypersomnia, run by Harmony Biosciences Management, Inc. at 42 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 42 sites in United States, Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Katie Wilmsen (443-309-5556, clinicaltrials@harmonybiosciences.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in severity of EDS as measured by the Epworth Sleepiness Scale (ESS) (time frame: Baseline to the end of the Double-blind Treatment Period (8 weeks)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Sep 2026.