X-Linked Myotubular MyopathyEXCELNCT06581146
A Study to Check Liver Health in Boys With XLMTM, a Serious Genetic Muscle Condition
An observational study of X-Linked Myotubular Myopathy, run by Astellas Gene Therapies at 11 sites in 3 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages Up to 17 years, men only
- Conditions the study is for
- X-Linked Myotubular Myopathy
- How many people
- 50 participants
- Where
- 11 sitesin 3 countries
- Study dates
- 19 May 2025to 31 Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 17 years
- Men only
- No healthy volunteers
- Child
Study population: Approximately 50 male participants < 18 years of age with genetically confirmed XLMTM will be enrolled at specialist sites.
Who may be able to join
- 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.
Who cannot join
- Participant is currently enrolled in an interventional study designed to treat XLMTM.
Trial locations and contacts
11 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
11 sites in 3 countries
United States7 sites, 7 recruiting
- Recruiting
Boston Children's Hospital
Boston, Massachusetts, 02115
- Recruiting
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611
- Recruiting
Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio, 45229
- Recruiting
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
- Recruiting
UPMC Children's Hospital of Pittsburgh
Pittsburgh, Pennsylvania, 15224
- Recruiting
University of Utah
Salt Lake City, Utah, 84112
- Recruiting
UCLA Neurological Services
Santa Monica, California, 90401-2072
United Kingdom3 sites, 3 recruiting
- Recruiting
Site GB44006
Leeds
- Recruiting
Site GB44003
London
- Recruiting
Site GB44005
Oxford
About this study
Official title: A Non-interventional, Epidemiologic Study of XLMTM and Clinical Expression in the Liver
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.
Read more
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.
- Conditions
- X-Linked Myotubular Myopathy
- Being tested
- No Intervention
- Keywords
- XLMTM, Hepatobiliary
- Medical subject headings
- Myopathies, Structural, Congenital
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No InterventionOther
No investigational drug will be administered to participants in this study.
| Study group | Role | What they receive |
|---|---|---|
| Participants with XLMTM | Pediatric and adolescent participants with XLMTM. Receives: Other: No Intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence rate of cholestasis
Calculated as the number of new cases of cholestasis over 48 weeks divided by total duration of follow-up for enrolled participants.
Measured: Up to Week 48
Point prevalence of cholestasis
Point prevalence of cholestasis is defined as the proportion of participants who have had at least 1 case of cholestasis prior to Day 1 (baseline).
Measured: Day 1
Prevalence of cholestasis
Prevalence of cholestasis is defined as the proportion of participants who have had at least 1 case of cholestasis within 1 year of Day 1 (baseline).
Measured: Up to 1 year
Secondary outcomes (9)
Genetic variants of MTM1
The association between genetic variants of MTM1 and cholestasis will be evaluated.
Measured: Up to Week 48
Risk of cholestasis temporarily associated with environmental modifiers
Medication use, immunization history, infectious disease history and dietary habits will be collected.
Measured: Up to Week 48
Hospitalizations
Frequency and reason for hospitalizations will be collected.
Measured: Up to Week 48
Duration of Hospitalizations
Duration of hospitalization visits will be collected.
Measured: Up to Week 48
Emergency room visits
Frequency and reason for visit will be collected.
Measured: Up to Week 48
Hepatology specialist visits
Frequency and reason for visit will be collected.
Measured: Up to Week 48
Scheduled/unscheduled office visits
Frequency and reason for visit will be collected.
Measured: Up to Week 48
Non-study-specified home healthcare visits
Frequency and reason for visit will be collected.
Measured: Up to Week 48
Surgeries/procedures
Frequency and type will be collected.
Measured: Up to Week 48
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Sep 2024
- Study start19 May 2025
- Primary completion31 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for X-Linked Myotubular MyopathyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Astellas Gene Therapies
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Astellas Gene Therapies
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06581146
- Sponsor's protocol ID
- 1600-MA-3536
- Acronym
- EXCEL
- Status last verified
- Sep 2026
- First submitted
- 19 Aug 2024
- Last updated
- 30 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Access to anonymized individual participant level data will not be provided for this trial. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Non-interventional, Epidemiologic Study of XLMTM and Clinical Expression in the Liver
- ClinicalTrials.gov ID
- NCT06581146
- Acronym / sponsor ID
- EXCEL / 1600-MA-3536
- Conditions
- X-Linked Myotubular Myopathy
- Keywords
- XLMTM, Hepatobiliary
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Astellas Gene TherapiesIndustry (pharma, biotech, devices)
- Study start
- 19 May 2025 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 3 Sep 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Participants with XLMTM | – | Other: No InterventionPediatric and adolescent participants with XLMTM. |
Who may qualify
- Ages
- Up to 17 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- Approximately 50 male participants < 18 years of age with genetically confirmed XLMTM will be enrolled at specialist sites.
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (1 listed)
- Participant is currently enrolled in an interventional study designed to treat XLMTM.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No InterventionNo investigational drug will be administered to participants in this study. | Other | Participants with XLMTM |
Primary outcome
Incidence rate of cholestasis
Time frame: Up to Week 48
Calculated as the number of new cases of cholestasis over 48 weeks divided by total duration of follow-up for enrolled participants.
Point prevalence of cholestasis
Time frame: Day 1
Point prevalence of cholestasis is defined as the proportion of participants who have had at least 1 case of cholestasis prior to Day 1 (baseline).
Prevalence of cholestasis
Time frame: Up to 1 year
Prevalence of cholestasis is defined as the proportion of participants who have had at least 1 case of cholestasis within 1 year of Day 1 (baseline).
9 secondary outcomes
Genetic variants of MTM1
Time frame: Up to Week 48
Risk of cholestasis temporarily associated with environmental modifiers
Time frame: Up to Week 48
Hospitalizations
Time frame: Up to Week 48
Duration of Hospitalizations
Time frame: Up to Week 48
Emergency room visits
Time frame: Up to Week 48
Hepatology specialist visits
Time frame: Up to Week 48
Scheduled/unscheduled office visits
Time frame: Up to Week 48
Non-study-specified home healthcare visits
Time frame: Up to Week 48
Surgeries/procedures
Time frame: Up to Week 48
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Sep 2026.
- Individual participant dataSharing planned: No. Access to anonymized individual participant level data will not be provided for this trial. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.
Related trials for X-Linked Myotubular Myopathy
Not yet recruitingPhase 1/2
A Long-term Follow-up Study in Male Participants With X-linked Myotubular Myopathy Treated With ASP2957
X-linked Myotubular Myopathy
RecruitingPhase 1/2
Study of ASP2957 in Male Participants With X-linked Myotubular Myopathy Who Need Ventilators
X-Linked Myotubular Myopathy
Active, not recruitingPhase 2/3
A Study of AT132 in Young Children With X-Linked Myotubular Myopathy (XLMTM)
X-Linked Myotubular Myopathy
Recruiting
Assessments in Patients With Muscular Pathology and in Control Subjects : The ActiLiège Next Study
Duchenne Muscular Dystrophy, Fascioscapulohumeral Muscular Dystrophy
RecruitingObservational study
Myotubular and Centronuclear Myopathy Patient Registry
Myotubular Myopathy, Myotubular Myopathy 1
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Medical Director study director
Astellas Gene Therapies
11 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of X-Linked Myotubular Myopathy, run by Astellas Gene Therapies at 11 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 30 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 11 sites in United States, United Kingdom, Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Astellas Gene Therapies (800-888-7704, Astellas.registration@astellas.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence rate of cholestasis (time frame: Up to Week 48). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2026.