A Study About Antibody Levels and Biomarkers in the Blood in People With Late-onset Pompe Disease

Last updated: May 2, 2025
Sponsor: Astellas Gene Therapies
Overall Status: Active - Recruiting

Phase

N/A

Condition

Pompe Disease

Treatment

No Intervention

Clinical Study ID

NCT06150820
AT845-02
  • Ages 16-69
  • All Genders

Study Summary

Pompe disease is a genetic condition which causes muscle weakness over time. People with Pompe disease have a faulty gene that makes an enzyme called acid alpha-glucosidase (or GAA). This enzyme breaks down a type of sugar called glycogen. Without this enzyme, there is a build-up of glycogen in the cells of the body. This causes muscle weakness and other symptoms. Pompe disease can happen at any age, but in late-onset Pompe disease, symptoms generally start from 12 months old onwards.

The standard treatment for people with Pompe disease is to receive regular infusions of the GAA enzyme. This is known as enzyme replacement therapy. However, people can build up antibodies against the GAA enzyme over time.

Gene therapy is used to treat conditions caused by a faulty gene. It works by replacing the faulty gene with a working gene inside the cells of the body. The working gene is delivered into the cells using certain viruses as carriers (vectors). Viruses are often used as carriers as they can easily get inside cells. The genetic material of the original virus is replaced with the working gene, so only the working gene gets inside the cells. A common virus used as a carrier in gene therapy is the adeno-associated virus (or AAV). This is like an adenovirus, which causes the common cold.

The original type of AAV does not cause any harm to humans. However, people that have previously been infected with the original type of AAV may have built up antibodies against AAV. These antibodies may stop the AAV carrier with the working gene getting inside the cells.

Researchers want to learn more about antibody levels against AAV and the GAA enzyme in people with late-onset Pompe disease. They also want to learn about other substances in the blood that provide more information about late-onset Pompe disease. These are known as biomarkers.

In this study, older teenagers and adults with late-onset Pompe disease will take part. They will not have had gene therapy using AAV. There will be 2 groups - those who have never had enzyme replacement therapy, and those who have had enzyme replacement therapy for 6 months or more. No study treatment will be given during the study, but blood and urine samples will be taken for testing.

The main aims of the study are to check antibody levels against AAV8 (a type of AAV) in people with late-onset Pompe disease who had not received any treatment using AAV, to check antibody levels against the GAA enzyme in people previously treated with GAA as part of enzyme replacement therapy, to check levels of biomarkers for Pompe disease, and to check for medical problems.

In the study, people will visit the study clinic several times. Some visits may be in the person's home. The first visit is to check if they can take part. Those who can take part will have a medical examination, and have their vital signs checked. Vital signs include blood pressure, heart rate, breathing rate and temperature. Blood samples will be taken to check antibody levels against the GAA enzyme and against AAV8. Blood and urine samples will also be taken to check for biomarkers for Pompe disease. Blood and urine samples will be taken about every 4 months for up to 2 years.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Participant has a documented clinical diagnosis of LOPD.

  • Participant is enzyme replacement therapy ERT-naïve (ERT-N) or if the participant iscurrently taking an approved ERT treatment or is participating in anERT-interventional study, the ERT must have been received for at least 6 months ormore (ERT-experienced [ERT-E]).

  • Participant is willing and able to comply with study visits and procedures.

  • Participant agrees to not start participating in any other clinical study involvingan investigational study treatment, including ERT, while participating in thisstudy.

Exclusion

Exclusion Criteria:

  • Participant previously received an AAV-related product (any serotype).

  • Participant is currently participating in a Pompe-related interventional study (other than ERT-interventional studies) or has received gene or cell therapy.

  • Participant requires any invasive or noninvasive ventilation support while awake andupright (non-invasive support while sleeping with either continuous positive airwaypressure (CPAP) or bilevel positive airway pressure (BiPAP) is acceptable foreligibility).

  • Participant is unable to ambulate (assistive devices [e.g., cane or walker] areacceptable for eligibility).

  • Participants who have received any ERT for less than 6 months as of the Baselinevisit are not eligible.

Study Design

Total Participants: 100
Treatment Group(s): 1
Primary Treatment: No Intervention
Phase:
Study Start date:
February 01, 2024
Estimated Completion Date:
May 31, 2027

Study Description

No investigational drug will be administered to participants in this study. Blood and urine will be collected as part of the study. The duration of the study is approximately 2 years, participants may withdraw at any time.

Connect with a study center

  • AU61003

    Adelaide,
    Australia

    Active - Recruiting

  • AU61001

    Herston,
    Australia

    Active - Recruiting

  • BR55002

    Porto Alegre,
    Brazil

    Site Not Available

  • CN15003

    Edmonton,
    Canada

    Active - Recruiting

  • CA15001

    Montreal,
    Canada

    Active - Recruiting

  • FR33006

    Angers,
    France

    Active - Recruiting

  • FR33009

    Garches,
    France

    Active - Recruiting

  • FR33005

    Lille,
    France

    Active - Recruiting

  • FR33007

    Limoges,
    France

    Active - Recruiting

  • FR33002

    Marseille,
    France

    Active - Recruiting

  • FR33003

    Nantes,
    France

    Active - Recruiting

  • FR33004

    Nice Cedex 3,
    France

    Active - Recruiting

  • FR33001

    Strasbourg,
    France

    Active - Recruiting

  • FR33007

    Strasbourg,
    France

    Active - Recruiting

  • DT49005

    Bonn,
    Germany

    Active - Recruiting

  • DT49004

    Essen,
    Germany

    Active - Recruiting

  • DT49003

    Hochheim,
    Germany

    Active - Recruiting

  • DT49006

    Münster,
    Germany

    Active - Recruiting

  • IT39002

    Firenze,
    Italy

    Site Not Available

  • IT39005

    Gussago,
    Italy

    Active - Recruiting

  • IT39012

    Messina,
    Italy

    Active - Recruiting

  • IT39009

    Milano,
    Italy

    Active - Recruiting

  • IT39011

    Milano,
    Italy

    Active - Recruiting

  • IT39008

    Pavia,
    Italy

    Active - Recruiting

  • IT39006

    Pisa,
    Italy

    Active - Recruiting

  • IT39004

    Roma,
    Italy

    Active - Recruiting

  • National Center of Neurology and Psychiatry

    Kodaira-Shi,
    Japan

    Active - Recruiting

  • Tokyo Women's Medical University Hospital

    Shinjuku-Ku,
    Japan

    Active - Recruiting

  • ES34003

    Albacete,
    Spain

    Active - Recruiting

  • ES34004

    Barcelona,
    Spain

    Site Not Available

  • ES34006

    Barcelona,
    Spain

    Site Not Available

  • ES34007

    L'hospitalet de Llobregat,
    Spain

    Active - Recruiting

  • ES34001

    Madrid,
    Spain

    Active - Recruiting

  • ES34005

    Madrid,
    Spain

    Active - Recruiting

  • Hospital Universitario 12 de Octubre

    Madrid,
    Spain

    Active - Recruiting

  • ES34009

    San Sebastian,
    Spain

    Site Not Available

  • ES34002

    Valencia,
    Spain

    Active - Recruiting

  • Hospital Universitari i Politecnic La Fe de Valencia

    Valencia,
    Spain

    Active - Recruiting

  • National Taiwan University Hospital

    Taipei, Province Of China
    Taiwan

    Active - Recruiting

  • TW88601

    Taipei,
    Taiwan

    Active - Recruiting

  • TW88602

    Taipei,
    Taiwan

    Active - Recruiting

  • TW88603

    Taoyuan City,
    Taiwan

    Site Not Available

  • UK44003

    Cambridge,
    United Kingdom

    Active - Recruiting

  • UK44001

    Newcastle upon Tyne,
    United Kingdom

    Active - Recruiting

  • UK44004

    Salford,
    United Kingdom

    Active - Recruiting

  • University of California Irvine

    Irvine, California 92868
    United States

    Active - Recruiting

  • Emory Clinic

    Atlanta, Georgia 30322
    United States

    Active - Recruiting

  • University of Kansas Medical Center

    Kansas City, Kansas 66160
    United States

    Active - Recruiting

  • University of Michigan

    Ann Arbor, Michigan 48109
    United States

    Active - Recruiting

  • Children's Hospitals and Clinics of Minnesota

    Minneapolis, Minnesota 55404
    United States

    Site Not Available

  • Hackensack University Medical Center

    Hackensack, New Jersey 07601
    United States

    Active - Recruiting

  • University of Cincinnati

    Cincinnati, Ohio 45221
    United States

    Active - Recruiting

  • University of Pennsylvania

    Philadelphia, Pennsylvania 19104
    United States

    Active - Recruiting

  • University of Pittsburgh Medical Center

    Pittsburgh, Pennsylvania 15213
    United States

    Active - Recruiting

  • Lysosomal and Rare Diseases Research and Treatment Center, Inc.

    Fairfax, Virginia 22030
    United States

    Active - Recruiting

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