Clinical trial Recruiting at 52 sites Phase 3 Interventional Ages 6 and up

Evaluating pitolisant for excessive daytime sleepiness in Prader-Willi syndrome

Official title: A Phase 3, Randomized, Double-Blind, Placebo-controlled, Efficacy and Safety Study of Pitolisant Followed by an Open-Label Extension in Patients With Prader-Willi Syndrome

Run by Harmony Biosciences Management, Inc. · NCT06366464 · Data updated 2026-11-12

This study is testing if a medication called pitolisant can help reduce excessive daytime sleepiness in people aged 6 and older with Prader-Willi syndrome.

Quick facts

PhasePhase 3
Study typeInterventional
Ages6 Years and up
SexAll
Enrollment134 (estimated)
SponsorHarmony Biosciences Management, Inc.
Industry-sponsored
Locations57 sites (Los Angeles, California and 56 other locations)
StatusRecruiting
StartedMay 28, 2024
Main results expectedApril 2027
Study endsApril 2028
Registry record updatedAugust 25, 2026
Trial IDNCT06366464 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are individuals aged 6 and older with a genetically confirmed diagnosis of Prader-Willi syndrome and excessive daytime sleepiness.

Probably not a fit

Patients with uncontrolled sleep apnea or hypersomnia due to other medical disorders may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This Phase 3 clinical study investigates the efficacy and safety of pitolisant in treating excessive daytime sleepiness in patients aged 6 and older with Prader-Willi syndrome. The study is randomized, double-blind, and placebo-controlled, involving multiple centers globally. Participants will undergo a screening period followed by a treatment phase where they will receive either pitolisant or a placebo. Secondary objectives include assessing the drug's impact on behavioral issues such as irritability and hyperphagia.

Why it matters

Potential benefit: If successful, this treatment could significantly improve daytime alertness and overall quality of life for patients with Prader-Willi syndrome.

How similar studies have gone: While this approach is novel for Prader-Willi syndrome, similar studies have shown promise in treating excessive daytime sleepiness in other conditions.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Genetically confirmed diagnosis of PWS
* Excessive daytime sleepiness
* Has a consistent parent/caregiver (preferably the same person throughout the study) who is willing and able to complete the required study assessments.
* In the opinion of the Investigator, the patient/parent(s)/caregiver(s)/legal guardian(s) are capable of understanding and complying with the requirements of the protocol and administration of oral study drug.

Exclusion Criteria:

* Has a diagnosis of sleep apnea (OSA, CSA) that is not adequately controlled
* Has a diagnosis of hypersomnia due to another sleep/medical disorder
* Participation in an interventional research study involving another investigational medication, device, or behavioral treatment within 30 days or 5 half-lives (whichever is longer) of the investigational medication prior to Screening

Where it's running

  • Santa Monica Clinical Trials
    Los Angeles, California, United States
    Recruiting
  • Center of Excellence in Diabetes and Endocrinology
    Sacramento, California, United States
    Recruiting
  • Rady Children's Hospital - Scan Diego
    San Diego, California, United States
    Recruiting
  • Colorado Children's Hospital
    Aurora, Colorado, United States
    Recruiting
  • Nemours Children's Hospital
    Wilmington, Delaware, United States
    Recruiting
  • Emory University School of Medicine
    Atlanta, Georgia, United States
    Recruiting
Show 44 more locations
  • Ann And Robert H Lurie Children's Hospital of Chicago
    Chicago, Illinois, United States
    Recruiting
  • Riley Children's Hospital
    Indianapolis, Indiana, United States
    Recruiting
  • Johns Hopkins University Hospital
    Baltimore, Maryland, United States
    Recruiting
  • Johns Hopkins Hospital
    Baltimore, Maryland, United States
    Recruiting
  • Mayo Clinic-PPDS
    Rochester, Minnesota, United States
    Recruiting
  • Maimonides Medical Center
    Brooklyn, New York, United States
    Recruiting
  • Montefiore Medical Center
    The Bronx, New York, United States
    Recruiting
  • Science 37 (at-home option)
    Morrisville, North Carolina, United States
    Recruiting
  • Science 37
    Morrisville, North Carolina, United States
    Recruiting
  • Center for Human Genetics
    Cleveland, Ohio, United States
    Recruiting
  • Texas Children's Hospital
    Houston, Texas, United States
    Recruiting
  • Road Runner Research
    San Antonio, Texas, United States
    Recruiting
  • Childrens Hospital of Wisconsin
    Milwaukee, Wisconsin, United States
    Recruiting
  • Queensland Children's Hospital
    Brisbane, Queensland, Australia
    Recruiting
  • Royal Prince Alfred Hospital
    Camperdown, Australia
    Recruiting
  • Sydney Children's Hospital
    Randwick, Australia
    Recruiting
  • Children's Hospital at Westmead
    Westmead, Australia
    Recruiting
  • UZ Brussels
    Jette, Belgium
    Recruiting
  • AMNDX Inc.
    Thornhill, Ontario, Canada
    Recruiting
  • Aarhus University Hospital
    Aarhus, Denmark
    Recruiting
  • Rigshospitalet
    Copenhagen, Denmark
    Recruiting
  • CHU d'Angers
    Angers, France
    Recruiting
  • CHU de Toulouse-Hôpital Des Enfants
    Toulouse, France
    Recruiting
  • University Hospital Essen
    Essen, Germany
    Recruiting
  • University of Florence
    Florence, Tuscany, Italy
    Recruiting
  • Azienda Ospedaliero Universitaria A Meyer
    Florence, Italy
    Recruiting
  • Istituto G Gaslini Ospedale Pediatrico IRCCS - INCIPIT - PIN
    Genova, Italy
    Recruiting
  • Ospedale San Raffaele S.r.l. - PPDS
    Milan, Italy
    Recruiting
  • Azienda Ospedale Università Padova - Dipartimento Salute della Donna e del Bambino - INCIPIT - PIN
    Padova, Italy
    Recruiting
  • Ospedale Pediatrico Bambino Gesù IRCCS
    Roma, Italy
    Recruiting
  • IRCCS Materno Infantile Burlo Garofolo - INCIPIT - PIN
    Trieste, Italy
    Recruiting
  • Samodzielny Publiczny Szpital Kliniczny
    Szczecin, Poland
    Recruiting
  • Uniwersytecki Szpital Kliniczny im. Jana Mikulicza-Radeckiego we Wroclawiu-Chalubinskiego 2-2a
    Wroclaw, Poland
    Recruiting
  • Institutul National de Endocrinologie C. I. Parhon
    Bucharest, Romania
    Recruiting
  • Institutul National de Endocrinologie C. I. Parhon
    Bucharest, Romania
    Recruiting
  • National Clinical Center for Children Neurorehabilitation "Dr. Nicolae Robanescu"
    Bucharest, Romania
    Recruiting
  • Louis Turcanu Emergency Clinical Hospital for Children
    Timișoara, Romania
    Recruiting
  • Corporacio Sanitaria Parc Tauli, Sabadell
    Barcelona, Spain
    Recruiting
  • Hospital Sant Joan de Deu
    Barcelona, Spain
    Recruiting
  • Hospital Universitario 12 de Octubre
    Madrid, Spain
    Recruiting
  • Universitario Virgen de la Victoria
    Málaga, Spain
    Recruiting
  • Karolinska Universitetssjukhuset Solna
    Solna, Sweden
    Recruiting
  • Fulbourn Hospital
    Cambridge, England, United Kingdom
    Recruiting
  • Hull Royal Infirmary
    Hull, England, United Kingdom
    Recruiting

+7 more sites. See ClinicalTrials.gov for the full list.

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.