Optimal care for XLMTM should be provided by an integrated, multidisciplinary team with a neuromuscular specialist at the helm.1,2
Patients with XLMTM require intensive long-term medical care. Interventions primarily offer supportive care similar to that for managing other congenital myopathies.2 Currently, there are no treatments for XLMTM, and neither respiratory nor motor function improves over time with the current standard of care.7-10
Urgent and immediate requirements for severe XLMTM:
Patients with XLMTM, regardless of severity, require extensive, lifelong at-home support and assistance with daily activities.1,2, 11, 12 Clinicians can help educate caregivers on how to perform these duties at home, where to find equipment, and ways to connect with other organizations for resources and support.
At-home care can entail:
Significant pharyngeal or respiratory muscle weakness results in reduced effectiveness of cough for patients with XLMTM.13 Patients have difficulties sufficiently clearing mucus secretions, thereby increasing their risk of infection or aspiration pneumonia.
Routine management—often multiple times per hour or more frequently if respiratory illness is present—includes use of:1
Caregiver support groups are a good source of information and tips for navigating daily care outside the clinical setting. For more resources, visit our dedicated For Caregivers section.
Ongoing research and natural history studies
Registries and epidemiologic studies are underway to better understand the features and disease course of XLMTM in affected male and female patients. Examples include:
We’re here to help clinicians navigate the XLMTM diagnostic and treatment journey.
For inquiries from US healthcare professionals, please contact Astellas Medical Affairs at medinfo.us@astellas.com.
1. Wang CH, Dowling JJ, North K, et al. Consensus statement on standard of care for congenital myopathies. J Child Neurol. 2012;27(3):363-382. doi:10.1177/0883073812436605 2. Dowling JJ, Lawlor MW, Das S. X-linked myotubular myopathy. In: Adam MP, Bick S, Mirzaa GM, et al., eds. GeneReviews® [Internet]. Updated August 23, 2018. Accessed November 17, 2025. https://www.ncbi.nlm.nih.gov/books/NBK1432/ 3. D'Amico A, Longo A, Fattori F, et al. Hepatobiliary disease in XLMTM: a common comorbidity with potential impact on treatment strategies. Orphanet J Rare Dis. 2021;16(1):425. doi: 10.1186/s13023-021-02055-1 4. Shieh PB, Kuntz NL, Dowling JJ, et al. Safety and efficacy of gene replacement therapy for X-linked myotubular myopathy (ASPIRO): a multinational, open-label dose-escalation trial. Lancet Neurol. 2023;22(12):1125-1139. doi: 10.1016/S1474-4422(23)00313-7 5. Beggs A, Haslekorn T, Dhawan A, et al. 49P Epidemiologic study of XL-MTM and clinical expression in the liver (EXCEL): study design of an observational, patient-centric study. Neuromuscul Disord. 2024;43(Suppl 1):104441.247. doi:10.1016/j.nmd.2024.07.256 6. Myotubular Trust Fact sheet: https://myotubulartrust.org/managing-your-liver/ 7. Amburgey K, Tsuchiya E, de Chastonay S, et al. A natural history study of X-linked myotubular myopathy. Neurology. 2017;89(13):1355-1364. doi:10.1212/WNL.0000000000004415 8. Annoussamy M, Lilien C. Gidaro T, et al. X-linked myotubular myopathy: A prospective international natural history study. Neurology. 2019;92(16):e1852-e1867. doi:10.1212/WNL.0000000000007319 9. Graham RJ, Muntoni F, Hughes I, et al. Mortality and respiratory support in X-linked myotubular myopathy: a RECENSUS retrospective analysis. Arch Dis Child. 2020;105(4):332-338. doi:10.1136/archdischild-2019-317910 10. Dowling JJ, Müller-Felber W, Smith BK, et al. INCEPTUS natural history, run-in study for gene replacement clinical trial in X-linked myotubular myopathy. J Neuromuscul Dis. 2022;9(4):503-516. doi:10.3233/JND-210781 11. Graham RJ, Darras BT, Haselkorn T, et al. Real-world analysis of healthcare resource utilization by patients with X-linked myotubular myopathy (XLMTM) in the United States. Orphanet J Rare Dis. 2023;18(1):138. doi: 10.1186/s13023-023-02733-2 12. Lawlor MW, Dowling JJ. X-linked myotubular myopathy. Neuromuscul Disord. 2021;31(10).1004-1012. doi:10.1016/j.nmd.2021.08.003 13. Smith BK, Goddard M, Childers MK. Respiratory assessment in centronuclear myopathies. Muscle Nerve. 2014;50(3):315-326. doi:10.1002/mus.24249 14. Martin C, Servais L. X-linked myotubular myopathy: an untreated treatable disease. Expert Opin Biol Ther. 2025;25(4):379-394. doi: 10.1080/14712598.2025.2473430 15. Study of ASP2957 in male participants with X-linked myotubular myopathy who need ventilators; NCT07052929. Clinicaltrials.gov. Updated October 8, 2025. https://clinicaltrials.gov/study/NCT07052929. Accessed January 5, 2026 16. Ganguli A, Gentyala R, Graham R, et al. 74P Design of a phase 1/2 study assessing the safety and preliminary efficacy of ASP2957 gene therapy for X-linked myotubular myopathy (XLMTM). Neuromuscul Disord. 2025;53(Suppl):105855. doi: 10.1016/j.nmd.2025.105855 17. A study to check liver health in boys with XLMTM, a serious genetic muscle condition (EXCEL); NCT06581146. Clinicaltrials.gov. Updated December 2, 2025. https://clinicaltrials.gov/study/NCT06581146. Accessed January 5, 2026.