A Study of Pitolisant in Participants With Prader-Willi Syndrome

NCT07219485 | Enrolling By Invitation Phase 3 FDA Drug

• 1 other identifier: HBS-101-CL-314
• Study Type: interventional
• Target: 150
• Locations: 1 country
• Sites: 1

Brief 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).

Conditions

Prader-Willi Syndrome

Keywords

Pitolisant; HBS-101; Prader-Willi syndrome; PWS

Outcome Measures

Primary Outcomes (1)

• 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.

  From the end of the EOT visit of the parent study through 30 days after the final dose of study drug.

Study Arms (1)

Pitolisant

EXPERIMENTAL

All participants receive pitolisant administered orally once daily in the morning upon awakening.

Drug: Pitolisant

Interventions

Pitolisant DRUG

* Pitolisant 4.45 mg tablets * Pitolisant 17.8 mg tablets

Also known as: HBS-101

Pitolisant

Eligibility Criteria

• Age: 7 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Harmony Biosciences Management, Inc.: lead

Study Sites (1)

Science 37

Morrisville, North Carolina, 27560, United States

Location

MeSH Terms

Conditions

Prader-Willi Syndrome

Interventions

pitolisant

Condition Hierarchy (Ancestors)

Intellectual Disability; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Abnormalities, Multiple; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Chromosome Disorders; Genetic Diseases, Inborn; Imprinting Disorders; Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases

Study Officials

• David Seiden, MD

  Harmony Biosciences Management, Inc.

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: All participants receive pitolisant

Study Record Dates

• First Submitted: October 20, 2025
• First Posted: October 21, 2025
• Study Start: August 20, 2025
• Primary Completion (Estimated): August 1, 2030
• Study Completion (Estimated): August 1, 2030
• Last Updated: March 17, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)