A Long-Term Safety Study of PTC923 in Participants With Phenylketonuria

NCT ID: NCT05166161

Last Updated: 2025-05-08

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE3

Total Enrollment

200 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-02-14

Study Completion Date

2026-04-30

Brief Summary

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The main purpose of this study is to evaluate the long-term safety of PTC923 in participants with phenylketonuria, and to evaluate the changes from baseline in dietary phenylalanine (Phe)/protein consumption.

Detailed Description

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Eligible participants are:

Feeder participants: those who have completed a Phase 3 PTC Therapeutics (PTC) sponsored feeder study.

Non-feeder controlled participants: those who have not completed a feeder study and have blood Phe levels \<360 μmol/L at study entry.

Non-feeder uncontrolled participants: those who have not completed a feeder study and have blood Phe levels ≥360 μmol/L at study entry.

Conditions

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Phenylketonuria

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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PTC923

Participants will receive PTC923 7.5 mg/kg (participants 0 to \<6 months of age), 15 mg/kg (participants 6 to \<12 months of age), 30 mg/kg (participants 12 months to \<2 years of age), or 60 mg/kg (participants ≥2 years of age) orally once daily for a minimum of 12 months or until participant experiences lack of efficacy, adverse events (AEs) that lead to discontinuation, withdraws from treatment, or PTC923 is authorized and commercially available in the specific country.

Group Type EXPERIMENTAL

PTC923

Intervention Type DRUG

PTC923 powder for oral use will be suspended in water or apple juice prior to administration.

Interventions

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PTC923

PTC923 powder for oral use will be suspended in water or apple juice prior to administration.

Intervention Type DRUG

Other Intervention Names

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Sepiapterin

Eligibility Criteria

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Inclusion Criteria

* Clinical diagnosis of PKU with hyperphenylalaninemia (HPA) documented by past medical history of at least 2 blood Phe measurements ≥600 μmol/L.
* Women of childbearing potential must have a negative pregnancy test at screening and agree to abstinence or the use of at least one highly effective form of contraception for the duration of the study, and for up to 90 days after the last dose of the study drug.
* Males who are sexually active with women of childbearing potential who have not had a vasectomy must agree to use a barrier method of birth control during the study and for up to 90 days after the last dose of study drug. Males must also refrain from sperm donations during this time period.
* Willing to continue current diet unchanged while participating in the study (unless specifically instructed to change diet during the study by the investigator).

Exclusion Criteria

* Inability to tolerate oral medication.
* A female who is pregnant or breastfeeding, or considering pregnancy.
* Serious neuropsychiatric illness (for example, major depression) not currently under medical control, that in the opinion of the investigator or PTC, would interfere with the participant's ability to participate in the study or increase the risk of participation for that participant.
* Past medical history and/or evidence of renal impairment and/or condition including moderate/severe renal insufficiency (glomerular filtration rate \[GFR\] \<60 milliliters \[mL\]/minute \[min\] min as estimated most recently during qualifying participation in a feeder study) and/or under care of a nephrologist.
* Any other condition that in the opinion of the investigator or PTC, would interfere with the participant's ability to participate in the study or increase the risk of participation for that participant.
* Requirement for concomitant treatment with any drug known to inhibit folate synthesis (for example, methotrexate).
* Concomitant treatment with tetrahydrobiopterin (BH4) supplementation (for example, sapropterin dihydrochloride, KUVAN) or pegvaliase-pqpz (PALYNZIQ).

Additional criteria for non-feeder participants who did not participate in a feeder study:

* Gastrointestinal disease (such as irritable bowel syndrome, inflammatory bowel disease, chronic gastritis, and peptic ulcer disease, etc) that could affect the absorption of study drug.
* History of gastric surgery, including Roux-en-Y gastric bypass surgery or an antrectomy with vagotomy, or gastrectomy.
* History of allergies or adverse reactions to synthetic BH4 or sepiapterin.
* Any clinically significant laboratory abnormality as determined by the investigator.
* Any abnormal physical examination and/or laboratory findings indicative of signs or symptoms of renal disease, including calculated GFR \<60 milliliters (mL)/minute/1.73 square meter (m\^2).

Confirmed diagnosis of a primary BH4 deficiency as evidenced by biallelic pathogenic mutations in 6-pyruvoyltetrahydropterin synthase, recessive GTP cyclohydrolase I, sepiapterin reductase, quinoid dihydropteridine reductase, or pterin-4-alphacarbinolamine dehydratase genes.
Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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PTC Therapeutics

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Children's Hospital Colorado

Aurora, Colorado, United States

Site Status RECRUITING

UF College of Medicine, Department of Pediatrics Division of Genetics and Metabolism

Gainesville, Florida, United States

Site Status RECRUITING

Indiana University School of Medicine Department of Medical and Molecular Genetics

Indianapolis, Indiana, United States

Site Status RECRUITING

Boston Children's Hospital

Boston, Massachusetts, United States

Site Status ACTIVE_NOT_RECRUITING

Icahn School of Medicine at Mount Sinai (ISMMS)

New York, New York, United States

Site Status RECRUITING

UPMC Children's Hospital of Pittsburgh

Pittsburgh, Pennsylvania, United States

Site Status RECRUITING

University of Utah

Salt Lake City, Utah, United States

Site Status RECRUITING

Westmead Hospital

Westmead, New South Wales, Australia

Site Status RECRUITING

PARC Clinical Research

Adelaide, South Australia, Australia

Site Status RECRUITING

Royal Children's Hospital

Parkville, Victoria, Australia

Site Status RECRUITING

Hospital de clinicas de Porto Alegre

Porto Alegre, Rio Grande do Sul, Brazil

Site Status RECRUITING

Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo

Ribeirão Preto, São Paulo, Brazil

Site Status RECRUITING

Metabolics and Genetics in Calgary (MAGIC) Clinic, Ltd.

Calgary, Alberta, Canada

Site Status RECRUITING

McMaster Children's Hospital Hamilton Health Sciences

Hamilton, Ontario, Canada

Site Status RECRUITING

The Hospital for Sick Children University of Toronto Adult Clinic: The Fred A Litwin Family Centre in Genetic Medicine University Health Network & Mt. Sinai Hospital

Toronto, Ontario, Canada

Site Status RECRUITING

Fakultní nemocnice Královské Vinohrady Klinika dětí a dorostu Ambulance pro léčbu PKU a HPA

Prague, , Czechia

Site Status RECRUITING

Copenhagen University Hospital, Rigshospitalet

Copenhagen, , Denmark

Site Status RECRUITING

Hôpital Necker-Enfants Malades - Centre de Référence des Maladies Héréditaires du Métabolisme

Paris, , France

Site Status RECRUITING

Medical Genetics and Laboratory Diagnostics Center

Tbilisi, , Georgia

Site Status RECRUITING

University Children's Hospital Hamburg Eppendorf (Kinder-UKE) Klinik für Kinder- und Jugendmedizin (Kinder-UKE)

Hamburg, , Germany

Site Status RECRUITING

Universitätsklinikum Heidelberg / Zentrum für Kinder- und Jugendmedizin / Sektion für Neuropädiatrie & Stoffwechselmedizin

Heidelberg, , Germany

Site Status RECRUITING

Universitätsklinikum Münster

Münster, , Germany

Site Status RECRUITING

Azienda Ospedaliera-Universita Padova

Padua, Veneto, Italy

Site Status RECRUITING

Department of Human Neuroscience, Child and Adolescent Neuropsychiatry, Policlinico Umberto I

Rome, , Italy

Site Status RECRUITING

PTC Clinical Site 1

Multiple Locations, , Japan

Site Status RECRUITING

PTC Clinical Site 2

Multiple Locations, , Japan

Site Status RECRUITING

PTC Clinical Site 3

Multiple Locations, , Japan

Site Status RECRUITING

PanAmerican Clinical Research

Guadalajara, Jalisco, Mexico

Site Status RECRUITING

UMCG Beatrix Children's Hospital

Groningen, , Netherlands

Site Status RECRUITING

Pomorski Uniwersytet Medyczny w Szczecinie Centrum Wsparcia Badań Klinicznych

Szczecin, , Poland

Site Status RECRUITING

CENTRO HOSPITALAR UNIVERSITÁRIO LISBOA NORTE Hospital de Santa Maria,

Lisbon, Estremadura, Portugal

Site Status RECRUITING

CENTRO HOSPITALAR UNIVERSITÁRIO LISBOA NORTE Hospital de Santa Maria

Lisbon, Estremadura, Portugal

Site Status RECRUITING

Centro Hospitalar Universitário Do Porto, Epe

Porto, , Portugal

Site Status RECRUITING

Univerzitetni klinicni center Ljubljana

Ljubljana, , Slovenia

Site Status RECRUITING

Hospital Sant Joan de Déu

Barcelona, Esplugues de Llobregat, Spain

Site Status RECRUITING

Hospital Universitario Ramón y Cajal

Madrid, , Spain

Site Status RECRUITING

Hospital Universitario Virgen del Rocío

Seville, , Spain

Site Status RECRUITING

Hacettepe University Medical Faculty

Altındağ, Ankara, Turkey (Türkiye)

Site Status RECRUITING

Gazi Üniversitesi Tıp Fakültesi

Yenimahalle, Ankara, Turkey (Türkiye)

Site Status RECRUITING

İstanbul Üniversitesi Cerrahpaşa Tıp Fakültesi

Fatih, Istanbul, Turkey (Türkiye)

Site Status RECRUITING

Ege University Faculty of Medicine Children Hospital

Bornova, İzmir, Turkey (Türkiye)

Site Status RECRUITING

Çukurova Üniversitesi Tıp Fakültesi Balcalı Hastanesi

Adana, , Turkey (Türkiye)

Site Status RECRUITING

Birmingham Children's Hospital NHS Foundation Trust

Birmingham, , United Kingdom

Site Status RECRUITING

UNIVERSITY HOSPITALS BIRMINGHAM NHS Foundation Trust

Birmingham, , United Kingdom

Site Status RECRUITING

Great Ormond Street Hospital

London, , United Kingdom

Site Status RECRUITING

Countries

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United States Australia Brazil Canada Czechia Denmark France Georgia Germany Italy Japan Mexico Netherlands Poland Portugal Slovenia Spain Turkey (Türkiye) United Kingdom

Central Contacts

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Patient Advocacy

Role: CONTACT

1-866-562-4620

Other Identifiers

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2021-000497-28

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

2023-509229-31-00

Identifier Type: OTHER

Identifier Source: secondary_id

PTC923-MD-004-PKU

Identifier Type: -

Identifier Source: org_study_id

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