NCT06581146 · Astellas Gene Therapies
A Study to Check Liver Health in Boys With XLMTM, a Serious Genetic Muscle Condition
(EXCEL)
What this study is about
XLMTM (X-linked myotubular myopathy) is a serious genetic muscle condition. It is caused by changes in the MTM1 gene which stops or slows down normal muscle development, causing severe muscle weakness. There is currently no cure for XLMTM. Ongoing care is needed to manage symptoms and prevent further medical problems from this condition.
View original scientific description
XLMTM (X-linked myotubular myopathy) is a serious genetic muscle condition. It is caused by changes in the MTM1 gene which stops or slows down normal muscle development, causing severe muscle weakness. There is currently no cure for XLMTM. Ongoing care is needed to manage symptoms and prevent further medical problems from this condition. Recent research shows that individuals with XLMTM often have reduced bile flow which can affect liver and gallbladder health. Bile is a liquid made in the liver that helps digest fat. Ongoing liver health checks may help with the routine care of people with XLMTM. There is a need to understand liver problems that develop in individuals with XLMTM over time. The main aim of the study is to learn how many boys with XLMTM have new cases of liver problems during the study. This study is about collecting information only. This is known as an observational study. The individual's doctor decides on treatment, not the study sponsor (Astellas). In this study, boys under 18 diagnosed with XLMTM will be followed for about 1 year. The health of their liver and gallbladder will be checked about every 6 weeks. This can be done at home, if preferred. A scan called a Fibroscan (also known as transient elastography) will check for signs of scarring in the liver (fibrosis) and the build-up of lipids. It is suggested that each boy will have a Fibroscan when they start the study and another scan when they complete the study. This study will help understand liver, gallbladder, and bile duct issues in individuals with XLMTM over time. The goal is to improve their care and provide information to use in future clinical studies.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participant has a diagnosis of XLMTM resulting from a genetically confirmed mutation in the MTM1 gene based on genetic test reports.
- Participant requires some mechanical ventilatory support (e.g., ranging from 24 hours per day full-time mechanical ventilation, to non-invasive support such as continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) during sleeping hours)
- Participant (as applicable) and/or parent(s)/carer is willing to comply with the recommended schedule of assessments.
Exclusion criteria
- Participant is currently enrolled in an interventional study designed to treat XLMTM.
Where
- Chicago, Illinois
- Boston, Massachusetts
- Cincinnati, Ohio
- Philadelphia, Pennsylvania
- Pittsburgh, Pennsylvania
- Salt Lake City, Utah
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 29, 2026 · Source of record for eligibility and locations