December 26, 2025
Duchenne muscular dystrophy (DMD) is a rare genetic disease affecting fewer than 20,000 patients in the United States. For decades, treatment options were limited to corticosteroids and supportive care aimed at slowing disease progression rather than modifying its course. This paradigm is now shifting. Advances in gene therapy, oligonucleotide delivery, and cell-based approaches have ushered in a new wave of disease-modifying therapies that aim to alter the underlying biology of DMD.
Sarepta’s Elevidys became the first FDA-approved gene therapy for DMD, marking a regulatory and scientific milestone. While its path has included safety-related pauses and label limitations, Elevidys redefined what is achievable in DMD and opened the door for a broad pipeline of next-generation approaches now moving through clinical development.
Emerging Therapies in Duchenne Muscular Dystrophy
The table below summarizes key approved and investigational DMD therapies, including modality, clinical phase, and recent updates, based on US regulatory context.
| Company | Medicine | Modality | Phase or Status | Key Updates |
| Sarepta Therapeutics | Elevidys (delandistrogene moxeparvovec-rokl) | Gene therapy | FDA approved June 2023 | Approved for non-ambulatory patients aged 4 years and older in June 2023 and for ambulatory patients aged 4 years and older in June 2024; FDA requested a hold in July 2025 after safety concerns; ambulatory use reinstated while non-ambulatory indication remains paused |
| Solid Biosciences | SGT-003 | Gene therapy | Phase 1 and 2 active, recruiting | Fifteen participants dosed as of August 2025 in the INSPIRE DUCHENNE trial; FDA meeting planned for Q4 2025 |
| Regenxbio | RGX-202 | Gene therapy | Phase 1, 2, and 3 active, recruiting | Interim data published May 2025; Phase 3 enrollment ongoing; BLA submission expected mid-2026 via accelerated approval |
| Insmed | INS1201 | Gene therapy | Phase 1 active, recruiting | ASCEND Phase 1 trial initiated May 2025; first patient dosed July 2025; intrathecal delivery designed to reduce systemic AAV exposure |
| Dyne Therapeutics | DYNE-251 | Targeted exon-skipping therapy, exon 51 | Phase 1 and 2 active, not recruiting | Long-term data from DELIVER trial released March 2025; FDA Breakthrough Therapy Designation granted August 2025; BLA submission expected early 2026 |
| Avidity Biosciences | Del-zota (AOC 1044) | Targeted exon-skipping therapy, exon 44 | Phase 1 and 2 completed, open-label extension active | One-year data from EXPLORE44 released September 2025; FDA Breakthrough Therapy Designation granted July 2025; BLA submission expected by year-end 2025 |
| BioMarin | BMN-351 | Targeted exon-skipping therapy, exon 51 | Phase 1 and 2 active, recruiting | Trial initiated January 2024; initial data expected by year-end 2025 |
| Capricor Therapeutics | CAP-1002 | Cell therapy | Phase 3 active, not recruiting | Three-year HOPE-2 data released October 2024; FDA issued CRL in July 2025 requesting additional efficacy and CMC data; BLA resubmission expected late 2025 |
| ReveraGen and Santhera | Agamree (vamorolone) | Disease-modifying small molecule steroid | FDA approved October 2023 | Approved for patients aged 2 years and older; commercial launch initiated Q1 2024; Health Canada approval granted October 2025 |
| ITF Therapeutics | Duvyzat (givinostat) | Disease-modifying small molecule, HDAC inhibitor | FDA approved March 2024 | Approved as the first nonsteroidal therapy for DMD in patients aged 6 years and older; US launch initiated mid-2024 |
Note: Phase and approval status reflect the US market and FDA actions and may differ in other regions.
Gene Therapy: From Proof of Concept to Iteration
Elevidys established gene therapy as a viable modality in DMD but also highlighted challenges related to safety, dosing, and durability. Building on this foundation, next-generation programs from Solid Biosciences and Regenxbio are using engineered AAV capsids designed to improve muscle tropism and reduce liver exposure. These approaches aim to address delivery limitations observed with first-generation vectors.
Insmed’s INS1201 represents a differentiated strategy through intrathecal delivery into the cerebrospinal fluid, enabling substantially lower vector doses. This route of administration may mitigate systemic safety concerns that have constrained broader use of high-dose intravenous AAV therapies.
Targeted Exon Skipping with Improved Delivery
Second-generation exon-skipping programs are attempting to overcome the limited tissue uptake of earlier phosphorodiamidate morpholino oligonucleotide therapies. Dyne and Avidity both employ antibody-oligonucleotide conjugates to enhance delivery to muscle tissue. While these therapies are inherently mutation-specific and therefore applicable to defined patient subsets, recent data and Breakthrough Therapy Designations suggest a more favorable efficacy profile than earlier exon-skipping drugs.
Cell Therapy and Small Molecule Approaches
Capricor’s CAP-1002 takes a cell-based approach using allogeneic cardiosphere-derived cells intended to reduce inflammation and support muscle repair through paracrine signaling. Despite receiving a Complete Response Letter, the program remains active with a BLA resubmission expected in 2025.
In parallel, disease-modifying small molecules have expanded treatment options. Agamree and Duvyzat provide oral alternatives that address inflammation and epigenetic regulation, complementing gene and oligonucleotide-based strategies.
Takeaway
Duchenne muscular dystrophy is undergoing its most significant therapeutic transformation in decades. While Elevidys marked a historic first, the broader pipeline reflects a shift toward iterative innovation across gene therapy, targeted exon skipping, cell therapy, and small molecules. Clinical and regulatory milestones expected in 2025 and 2026 will be critical in determining which approaches can deliver durable, scalable benefit and how disease-modifying strategies ultimately integrate into standard DMD care.
