Who may be eligible for the A Study of Pitolisant in Participants With Prader-Willi Syndrome trial?

Inclusion Criteria: Each participant must meet the following criteria to be enrolled in this study: 1. 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). 2. 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. 3. 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. 4. 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. 5. 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. Exclusion Criteria: A participant who meets any of the following criteria will be excluded from enrollment in the study: 1. Does not agree to discontinue any prohibited medication or substances listed in this protocol. 2. 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. 3. Participation in an interventional research study with an investigational medication or device, other than pitolisant, for the duration of the study. 4. Has a body surface area (BSA) corrected estimated glomerular filtration rate (eGFR) of \<15 mL/minute. 5. Has a history of severe hepatic impairment (Child-Pugh Class C). 6. Is receiving or is unable to discontinue a medication known to prolong the QT interval. 7. 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. 8. 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.

ClinicalTrials.gov record NCT07219485

A Study of Pitolisant in Participants With Prader-Willi Syndrome

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

An Open-Label Study to Evaluate Safety of Pitolisant in Participants With Prader-Willi Syndrome

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusEnrolling by invitationThe study enrols only people the study team invites, for example patients already at a particular clinic. It is not open to the public.

Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.

PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.

Age7 years old and older

SexAll

LocationUnited States

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This Phase 3, open-label study follows people with Prader-Willi syndrome who completed certain parent studies to evaluate pitolisant taken once daily. About 150 participants will be followed, with safety checks about every 6 months. The study records adverse events during treatment and for a set period after the final dose.

What it is studying. The study is testing the long-term safety of daily oral pitolisant in people with Prader-Willi syndrome who finished qualifying parent studies. It looks for adverse events that occur while participants take the drug and shortly after stopping it.

What the researchers hope to learn. To collect data on the long-term safety of pitolisant in people with Prader-Willi syndrome. To measure how many participants report treatment-emergent adverse events during treatment and up to 30 days after the final dose.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

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).

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug: Pitolisant

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

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.

Exclusion criteria

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).
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.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

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.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants will take pitolisant tablets by mouth once daily in the morning and attend safety visits about every six months. They must follow pregnancy testing, contraception, and breastfeeding rules and stop any prohibited medications as required. The study team will monitor safety from entry (after the parent‑study EOT) through 30 days after the final dose. Specific tests or procedures are determined by the study team during safety visits.

How the study is structured. Open-label, single-group Phase 3 trial in which all enrolled participants receive pitolisant by mouth once daily. Participants are followed over time for safety, with assessments approximately every six months. There is no placebo or comparison group.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

The registry says participants are enrolled by invitation. Who decides who is invited, and how?
The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on Prader-Willi syndrome

Clinical trials19 trials listed for Prader-Willi syndromeEvery trial the registry lists for Prader-Willi syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Prader-Willi syndrome researchLatest monthly update: September 2026. Includes: Hunger symptoms. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: Aug 20, 2025
Primary completion: August 2030 (estimated)
Study completion: August 2030 (estimated)
Target enrollment: 150 participants (estimated)
Last updated on registry: Mar 17, 2026
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: Harmony Biosciences Management, Inc.

Participating sites (1)

Science 37
Morrisville, North Carolina, 27560 · United States

Terms used on this page · explanations by MedicalUpdates.ai

Open Label: No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
written informed consent: The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
legal guardian: A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
assent: A child's or dependent adult's agreement to take part, given alongside the formal consent of a parent or legal representative.
study drug: A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
childbearing potential: Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
prior to screening: The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
enrollment: The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
prohibited medication: A medicine that participants may not use during the study, usually because it could interfere with the study treatment or its measurement.
estimated glomerular filtration rate: A blood-test estimate of how well the kidneys are filtering. Lower numbers mean reduced kidney function; many studies set a minimum value.
Inclusion Criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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