Dystrophie musculaire de Duchenne

Vue d’ensemble

Duchenne muscular dystrophy (DMD) is a severe, inherited condition caused by disease-causing changes in the DMD gene, which normally makes dystrophin, a protein that helps protect muscle fibers during contraction. Without sufficient functional dystrophin, skeletal muscle, heart muscle, and breathing muscles are progressively damaged. DMD usually affects males because the gene is on the X chromosome, although some female carriers can have symptoms. Early signs commonly include delayed motor milestones, frequent falls, difficulty rising from the floor, and worsening weakness; many people lose independent walking during adolescence and later face serious heart and respiratory complications. Modern multidisciplinary care has improved survival, but DMD remains life-limiting. Dystrophinopathies Duchenne Muscular Dystrophy

Current care combines corticosteroids, physical therapy and contracture prevention, mobility and orthopedic support, regular heart and lung monitoring, and treatment for cardiomyopathy and respiratory insufficiency. Mutation-specific exon-skipping medicines and newer disease-modifying drugs can help some groups, while givinostat is approved in the United States for people aged six years and older regardless of their DMD variant; none of these treatments fully restores normal dystrophin throughout the body or constitutes a cure. Dystrophinopathies FDA approval of givinostat

Scope of Recent Research (2020–present)

Research since 2020 has been exceptionally active, spanning viral gene transfer, improved RNA medicines, permanent gene editing, muscle regeneration, and better outcome measures for clinical trials. The central question is no longer whether dystrophin can be restored at all, but whether enough functional protein can be delivered safely and durably to skeletal muscle, heart, and diaphragm in people of different ages and disease stages. A treatment that reliably halts or reverses DMD remains out of reach, but the field has moved from laboratory proof-of-concept to approved gene transfer and multiple early- and late-stage clinical programs. AAV gene therapy in EMBARK PBGENE-DMD FUNCTION-DMD trial SGT-003 IMPACT DUCHENNE trial

Avancées majeures et thérapies émergentes

La progression la plus significative récente a été le transfert génique systémique utilisant un virus adéno-associé (AAV), utilisé comme véhicule de délivrance. Delandistrogene moxeparvovec (Elevidys) délivre un gène “micro-dystrophine” raccourci mais conçu, car le gène DMD complet est trop volumineux pour l’emballage AAV standard. Dans l’étude EMBARK de phase 3 chez des garçons ambulatoires âgés de quatre à moins de huit ans, le traitement a produit une expression de micro-dystrophine mais n’a pas amélioré de manière significative le critère fonctionnel principal à 52 semaines par rapport au placebo; plusieurs mesures motrices temporisées ont néanmoins été favorables numériquement au traitement. [AAV gene therapy in EMBARK] En novembre 2025, la FDA a révisé l’étiquette d’Elevidys pour limiter son indication aux patients ambulatoires âgés de quatre ans et plus après des rapports d’insuffisance hépatique aiguë fatale chez des patients non ambulatoires; l’étiquette porte désormais un avertissement encadré pour les lésions hépatiques graves et l’insuffisance hépatique aiguë. [FDA Elevidys safety communication]

RNA-based exon skipping remains an important, though mutation-specific, strategy. Antisense oligonucleotides are short synthetic strands of genetic material designed to make the cell skip a selected exon while processing DMD RNA, potentially restoring the genetic reading frame and allowing production of a shorter dystrophin. This approach does not repair DNA and generally requires repeated dosing, but newer antibody-oligonucleotide conjugates aim to bring more drug into muscle. Dyne Therapeutics’ phase 1/2 DELIVER trial is evaluating DYNE-251 for people with mutations amenable to exon 51 skipping; initial reported data showed muscle exposure, exon skipping, and dystrophin production, although larger and longer studies are needed to establish clinical benefit. DYNE-251 DELIVER initial data Dystrophinopathies

Gene editing is the most direct potential route toward a one-time, mutation-correcting treatment. CRISPR-based approaches seek to cut, remove, reframe, or alter selected parts of the defective DMD gene so that muscle can make dystrophin itself. A 2024 study used adenine base editing—a form of editing that changes a single DNA letter without making a double-strand DNA break—to alter splicing around human dystrophin exon 50 in a humanized DMD mouse model. Systemic AAV delivery restored dystrophin in skeletal muscle, heart, and diaphragm and improved muscle performance in those mice; however, this remains preclinical evidence, not evidence of safety or efficacy in people. Adenine base editing in a humanized DMD mouse

Other approaches attempt to preserve or rebuild muscle rather than directly replace dystrophin. Givinostat, a histone deacetylase inhibitor, is intended to reduce disease-related inflammation and muscle loss; in its pivotal 18-month trial, participants receiving standard corticosteroids plus givinostat declined less on a four-stair-climb measure than those receiving placebo. FDA approval of givinostat Cell-based programs, including deramiocel, aim to deliver cells or cell-derived biological signals that may support cardiac and skeletal muscle function, but they are best understood as regenerative or disease-modifying strategies rather than genetic cures. HOPE-3 deramiocel trial

Essais cliniques et approches expérimentales

The completed phase 3 EMBARK trial of Sarepta’s delandistrogene moxeparvovec randomized 125 ambulatory boys to a one-time intravenous gene therapy infusion or placebo. At week 52, the trial missed its primary functional endpoint, but it demonstrated micro-dystrophin expression and showed numerical advantages on some timed measures; because the primary endpoint was not statistically significant, the secondary findings cannot establish definitive clinical benefit on their own. AAV gene therapy in EMBARK Continued postmarketing monitoring is especially important because the FDA has required a prospective observational safety study in 200 treated patients following the serious liver-injury signal. FDA Elevidys safety communication

Several notable experimental programs illustrate the breadth of the current pipeline. Capricor’s HOPE-3 is a randomized phase 3 study of deramiocel in ambulatory and non-ambulatory people with impaired skeletal-muscle function. HOPE-3 deramiocel trial Precision BioSciences’ FUNCTION-DMD is a phase 1/2a study of PBGENE-DMD, an in vivo gene-editing approach intended for mutations that may be treated by excising exons 45–55, with dystrophin expression in skeletal muscle among its biological activity outcomes. PBGENE-DMD FUNCTION-DMD trial Solid Biosciences’ IMPACT DUCHENNE is a phase 3 randomized, placebo-controlled study of the investigational micro-dystrophin gene therapy SGT-003 in ambulant males with DMD. SGT-003 IMPACT DUCHENNE trial

Méthodologies et approches scientifiques

DMD researchers combine patient-derived muscle cells, induced pluripotent stem-cell models, engineered three-dimensional muscle systems, mouse models, and larger-animal studies to test whether a candidate therapy restores dystrophin and improves muscle function before it reaches people. Humanized mouse models are increasingly valuable because they allow investigators to test editing guides directed at human DMD sequences rather than relying only on the different mouse gene sequence. Adenine base editing in a humanized DMD mouse

Clinical studies measure dystrophin or micro-dystrophin in muscle biopsies, blood markers of muscle injury such as creatine kinase, cardiac and lung measurements, and functional outcomes including the North Star Ambulatory Assessment, time to rise from the floor, timed walking or running tests, and wearable-device measures of real-world stride velocity. These tools are needed because DMD changes gradually and because a biological increase in dystrophin does not automatically prove a meaningful long-term functional benefit. AAV gene therapy in EMBARK

Leading Institutions and Funding

The field is driven by academic neuromuscular centers and gene-editing laboratories, alongside companies including Sarepta Therapeutics, Roche, Solid Biosciences, Precision BioSciences, Dyne Therapeutics, and Capricor Therapeutics. Patient organizations—particularly Parent Project Muscular Dystrophy (PPMD), Muscular Dystrophy Association, CureDuchenne, and Duchenne UK—help fund translational work, recruit trial participants, maintain registries, and connect investigators with affected families. [PPMD research program] [MDA research grants]

Government support includes the U.S. Department of Defense Duchenne Muscular Dystrophy Research Program, whose fiscal-year 2025 Clinical/Translational Research Awards allowed up to $910,000 over three years for Funding Level 1 projects and up to $1.75 million over four years for Funding Level 2 projects. DoD DMD Research Program funding table As an example of philanthropic investment in early clinical translation, PPMD and Duchenne UK jointly awarded $500,000 in 2024 to support a University of Minnesota phase 1 study of myogenic progenitor cells for DMD. PPMD and Duchenne UK cell-therapy award

Strengths, Limitations, and Challenges

The strongest recent progress is that researchers can now deliver dystrophin-related genetic payloads body-wide, measure protein expression in muscle, and run increasingly rigorous randomized trials. The major limitation is that micro-dystrophin is not full-length dystrophin, and the pivotal EMBARK study did not meet its primary endpoint despite favorable signals in some secondary timed outcomes. AAV gene therapy in EMBARK Exon-skipping therapies are limited to particular mutations and require repeat treatment, while gene-editing systems must overcome mutation diversity, efficient whole-body delivery, immune reactions, off-target changes, and uncertainty about durability. DYNE-251 DELIVER initial data Adenine base editing in a humanized DMD mouse

Safety and equitable access are equally consequential challenges. Systemic AAV gene therapies can trigger liver toxicity and immune complications, and the Elevidys experience shows that risks may differ between ambulatory and non-ambulatory populations. FDA Elevidys safety communication Trials must also demonstrate benefits that matter to patients over years—not merely higher dystrophin levels or short-term changes in a single functional test—and must include older, non-ambulatory, cardiac, and respiratory populations that have often been underrepresented in early development. DoD DMD Research Program funding table

Outlook and Future Directions

A true cure for DMD would likely need safe, durable restoration of adequate dystrophin in the full range of affected muscles, ideally early enough to prevent irreversible fibrosis and muscle loss. The next milestones are longer-term outcomes and safety follow-up for micro-dystrophin therapies, confirmation that next-generation RNA conjugates produce clinically meaningful benefit, first-in-human results from permanent gene-editing programs, and validation of treatments that also protect heart and respiratory muscle. The recent progress is substantial, but the evidence as of August 8, 2026 supports cautious optimism rather than a claim that DMD has been cured. AAV gene therapy in EMBARK PBGENE-DMD FUNCTION-DMD trial Adenine base editing in a humanized DMD mouse

References

• Dystrophinopathies — GeneReviews®, 2023.
• Duchenne Muscular Dystrophy — StatPearls, 2023.
• FDA approval of givinostat — U.S. Food and Drug Administration, 2024.
• FDA Elevidys safety communication — U.S. Food and Drug Administration, 2025.
• AAV gene therapy in EMBARK — Nature Medicine, 2024.
• DYNE-251 DELIVER initial data — Neuromuscular Disorders, 2024.
• Adenine base editing in a humanized DMD mouse — Nature Communications, 2024.
• HOPE-3 deramiocel trial — ClinicalTrials.gov, 2026.
• PBGENE-DMD FUNCTION-DMD trial — ClinicalTrials.gov, 2026.
• SGT-003 IMPACT DUCHENNE trial — ClinicalTrials.gov, 2026.
• PPMD research program — Parent Project Muscular Dystrophy, 2026.
• MDA research grants — Muscular Dystrophy Association, 2026.
• DoD DMD Research Program funding table — Congressionally Directed Medical Research Programs, 2025.
• PPMD and Duchenne UK cell-therapy award — Parent Project Muscular Dystrophy and Duchenne UK, 2024.