Prader-Willi SyndromePhase 3NCT07219485
A Study of Pitolisant in Participants With Prader-Willi Syndrome
A Phase 3 study testing Pitolisant in people with Prader-Willi Syndrome, run by Harmony Biosciences Management, Inc. at 1 site in United States.
Trial summary
The purpose of this study is to assess safety of pitolisant in eligible participants with Prader-Willi syndrome (PWS) who completed the End of Treatment (EOT) visit in a parent study (HBS-101-CL-002 [Open Label Extension (OLE)], HBS- 101-CL-004, or HBS-101-CL-312 OLE). Read more about this study
- Who is it for?
- Ages 7 years and older
- Conditions the study is for
- Prader-Willi Syndrome
- What is being tested?
- Pitolisant
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Aug 2025to Aug 2030
- 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 7 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Each participant must meet the following criteria to be enrolled in this study:
- Ability to provide voluntary, written informed consent (participant, if applicable, or parent[s]/legal guardian[s]) and, where applicable, voluntary, written assent (participant, as appropriate).
- Completion of an EOT visit in one of the following parent studies with pitolisant: HBS-101-CL-002 (OLE), HBS-101-CL-004, or HBS-101-CL-312 (OLE).
- Note: The parent study EOT visit may be completed after the participant completes screening for study HBS-101-CL-314 to allow for continuation of study drug between the 2 studies.
- A participant who is a female of childbearing potential (FCBP) must have a negative urine pregnancy test at the last in-person visit of the parent study prior to screening and must agree to remain abstinent or use an effective method of nonhormonal contraception to prevent pregnancy for the duration of the study and for 21 days after final dose of study drug. Participants using hormonal contraception must also use an alternative nonhormonal contraceptive method during treatment with pitolisant and for at least 21 days after discontinuing treatment. An FCBP is defined as a female who is post menarche, has an intact uterus and at least 1 ovary, and is <1 year postmenopausal.
- Male participants who are not azoospermic (vasectomized or due to a medical cause) must agree to use a barrier method of contraception for the duration of the study and for 21 days after the final dose of study drug.
- In the opinion of the Investigator, the participant/parent(s)/legal guardian(s) are capable of understanding and willing to comply with the requirements of the protocol and administration of oral study drug.
Who cannot join
- A participant who meets any of the following criteria will be excluded from enrollment in the study:
- Does not agree to discontinue any prohibited medication or substances listed in this protocol.
- Is planning to breastfeed over the course of the study. Lactating women must agree not to breastfeed for the duration of the study and for 7 days after final dose of study drug.
- Participation in an interventional research study with an investigational medication or device, other than pitolisant, for the duration of the study.
- Has a body surface area (BSA) corrected estimated glomerular filtration rate (eGFR) of <15 mL/minute.
- Has a history of severe hepatic impairment (Child-Pugh Class C).
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- Is receiving or is unable to discontinue a medication known to prolong the QT interval.
- Has a significant risk of committing suicide or suicidality based on history, routine psychiatric examination, Investigator's judgment, or an answer of "yes" to question 4 or 5 of the Columbia-Suicide Severity Rating Scale (C-SSRS), that was completed at the last visit in the parent study.
- Based on the judgment of the Investigator, is unsuitable for the study for any reason, including but not limited to unstable or uncontrolled medical conditions (including psychiatric and neurological conditions) or a medical condition that might interfere with the conduct of the study, confound interpretation of study results, pose a health risk to the participant, or compromise the integrity of the study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: An Open-Label Study to Evaluate Safety of Pitolisant in Participants With Prader-Willi Syndrome
The purpose of this study is to assess safety of pitolisant in eligible participants with Prader-Willi syndrome (PWS) who completed the End of Treatment (EOT) visit in a parent study (HBS-101-CL-002 [Open Label Extension (OLE)], HBS- 101-CL-004, or HBS-101-CL-312 OLE).
Read the detailed description
This is a Phase 3, open-label study evaluating the long-term safety of pitolisant in approximately 150 participants with Prader-Willi syndrome who have completed participation in qualifying parent studies (HBS-101-CL-002 [OLE], HBS-101-CL-004, or HBS-101-CL-312 [OLE]).
Safety assessments will be conducted every 6 months. This study is open to participants from the qualified parent studies who were enrolled at US sites only.
- Conditions
- Prader-Willi Syndrome
- Being tested
- Pitolisant
- Keywords
- Pitolisant, HBS-101, Prader-Willi syndrome, PWS
- Medical subject headings
- Prader-Willi Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PitolisantDrug
Also called HBS-101
- Pitolisant 4.45 mg tablets
- Pitolisant 17.8 mg tablets
| Study group | Role | What they receive |
|---|---|---|
| Pitolisant | Experimental | All participants receive pitolisant administered orally once daily in the morning upon awakening. Receives: Drug: Pitolisant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of participants reporting Treatment-Emergent Adverse Events (TEAEs)
A treatment-emergent adverse event (TEAE) is any adverse event reported during treatment with study drug in this study and up to 30 days after final dose of study drug, or any worsening of a pre-existing condition reported during treatment with study drug and up to 30 days after final dose of study drug.
Measured: From the end of the EOT visit of the parent study through 30 days after the final dose of study drug.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Oct 2025
- Study start20 Aug 2025
- Primary completionAug 2030 (estimated)
- Study completionAug 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prader-Willi SyndromeStudies 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
- Not applicable
- Intervention model
- Single group
- Model description
- All participants receive pitolisant
- Masking
- None (open label)
- Enrolment
- 150 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
- NCT07219485
- Sponsor's protocol ID
- HBS-101-CL-314
- Status last verified
- Mar 2026
- First submitted
- 20 Oct 2025
- Last updated
- 17 Mar 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 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label Study to Evaluate Safety of Pitolisant in Participants With Prader-Willi Syndrome
- ClinicalTrials.gov ID
- NCT07219485
- Acronym / sponsor ID
- HBS-101-CL-314
- Conditions
- Prader-Willi Syndrome
- Keywords
- Pitolisant, HBS-101, Prader-Willi syndrome, PWS
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Harmony Biosciences Management, Inc.Industry (pharma, biotech, devices)
- Study start
- 20 Aug 2025 (actual)
- Primary completion
- Aug 2030 (estimated)
- Study completion
- Aug 2030 (estimated)
- First posted
- 21 Oct 2025 (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.
The purpose of this study is to assess safety of pitolisant in eligible participants with Prader-Willi syndrome (PWS) who completed the End of Treatment (EOT) visit in a parent study (HBS-101-CL-002 [Open Label Extension (OLE)], HBS- 101-CL-004, or HBS-101-CL-312 OLE).
Detailed description
This is a Phase 3, open-label study evaluating the long-term safety of pitolisant in approximately 150 participants with Prader-Willi syndrome who have completed participation in qualifying parent studies (HBS-101-CL-002 [OLE], HBS-101-CL-004, or HBS-101-CL-312 [OLE]).
Safety assessments will be conducted every 6 months. This study is open to participants from the qualified parent studies who were enrolled at US sites only.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- All participants receive pitolisant
| Arm | Type | Receives |
|---|---|---|
| Pitolisant | Experimental | Drug: PitolisantAll participants receive pitolisant administered orally once daily in the morning upon awakening. |
Who may qualify
- Ages
- 7 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Ability to provide voluntary, written informed consent (participant, if applicable, or parent[s]/legal guardian[s]) and, where applicable, voluntary, written assent (participant, as appropriate).
- Completion of an EOT visit in one of the following parent studies with pitolisant: HBS-101-CL-002 (OLE), HBS-101-CL-004, or HBS-101-CL-312 (OLE).
- Note: The parent study EOT visit may be completed after the participant completes screening for study HBS-101-CL-314 to allow for continuation of study drug between the 2 studies.
- A participant who is a female of childbearing potential (FCBP) must have a negative urine pregnancy test at the last in-person visit of the parent study prior to screening and must agree to remain abstinent or use an effective method of nonhormonal contraception to prevent pregnancy for the duration of the study and for 21 days after final dose of study drug. Participants using hormonal contraception must also use an alternative nonhormonal contraceptive method during treatment with pitolisant and for at least 21 days after discontinuing treatment. An FCBP is defined as a female who is post menarche, has an intact uterus and at least 1 ovary, and is <1 year postmenopausal.
- Male participants who are not azoospermic (vasectomized or due to a medical cause) must agree to use a barrier method of contraception for the duration of the study and for 21 days after the final dose of study drug.
Key exclusion criteria (9 listed)
- A participant who meets any of the following criteria will be excluded from enrollment in the study:
- Does not agree to discontinue any prohibited medication or substances listed in this protocol.
- Is planning to breastfeed over the course of the study. Lactating women must agree not to breastfeed for the duration of the study and for 7 days after final dose of study drug.
- Participation in an interventional research study with an investigational medication or device, other than pitolisant, for the duration of the study.
- Has a body surface area (BSA) corrected estimated glomerular filtration rate (eGFR) of <15 mL/minute.
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 |
|---|---|---|
| PitolisantAlso: HBS-101* Pitolisant 4.45 mg tablets * Pitolisant 17.8 mg tablets | Drug | Pitolisant |
Primary outcome
Percentage of participants reporting Treatment-Emergent Adverse Events (TEAEs)
Time frame: From the end of the EOT visit of the parent study through 30 days after the final dose of study drug.
A treatment-emergent adverse event (TEAE) is any adverse event reported during treatment with study drug in this study and up to 30 days after final dose of study drug, or any worsening of a pre-existing condition reported during treatment with study drug and up to 30 days after final dose of study drug.
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 17 Mar 2026.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Pitolisant in people with Prader-Willi Syndrome, run by Harmony Biosciences Management, Inc. at 1 site in United States.
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 7 inclusion and 9 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: enrolling by invitation, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. 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. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of participants reporting Treatment-Emergent Adverse Events (TEAEs) (time frame: From the end of the EOT visit of the parent study through 30 days after the final dose of study drug.). 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 17 Mar 2026.