Aperture

Neuromuscular · Rare

Duchenne muscular dystrophy

Updated August 2026 · DMD (dystrophin, Xp21)

Thesis

Duchenne is no longer an empty rare-disease market. It is a crowded, mutation-stratified franchise where the first gene therapy has been safety-reset, exon skippers remain modest, and the residual unmet need has shifted from 'any dystrophin' to 'meaningful, durable function in non-ambulatory and cardiac disease.' The next dollar of Corp Dev value sits in next-gen transfer, oligonucleotide delivery, and cardiomyopathy — not in another weekly IV skipper.

7MM prevalent

~32,000

DelveInsight 2025; US ~17,500

Birth incidence

1 / 5,000

Live male births

Market (7MM, 2025)

~$4.0B

Growing ~11% CAGR into the 2030s

Approved DMD-specific

8

US; steroids + 4 skippers + GT + HDAC

Elevidys treated

>1,000

Clinical + US commercial through Nov 2025

Residual unmet

High

Non-ambulatory, cardiac, magnitude

So-what for Corp Dev

  1. 01Elevidys is now labelled only for ambulatory patients ≥4, with a boxed warning for fatal acute liver failure after two non-ambulatory deaths (FDA, Nov 2025). The first-mover GT is a commercial product with a structurally capped ceiling.
  2. 02Addressable demand is mutation- and stage-gated. A 'DMD patient' is not a 'GT patient.' Model the funnel or you will double-count.
  3. 032026 readouts (RGX-202 pivotal, Avidity del-zota BLA, Capricor deramiocel resubmission) can reorder the franchise. Any diligence that treats the pipeline as static is already wrong.
  4. 04Unmet need has not closed. Non-ambulatory boys, cardiac decline, and families who will not take AAV risk are the white space.

Residual unmet need

  • Non-ambulatory and older patients

    Elevidys indication withdrawn for non-ambulatory DMD after fatal ALF. No approved GT remains for the majority of prevalent patients who have already lost ambulation.

  • Cardiac disease

    Cardiomyopathy, not skeletal weakness, is now the dominant cause of death. Skeletal-focused micro-dystrophin constructs have not solved the heart. Deramiocel is the near-term test of a cardiac-specific thesis.

  • Magnitude of benefit

    Exon skippers produce low single-digit % dystrophin and accelerated approvals on a biomarker. EMBARK missed NSAA. Families and payers now ask for function, not Western blots.

  • Safety of systemic AAV

    High-dose AAV + advanced disease = liver risk. Seroprevalence, redosing impossibility, and the boxed warning permanently change informed consent and centre selection.

Marketed share (dir.)

  • Prednisone / prednisolone38%
  • Emflaza22%
  • Duvyzat14%
  • Agamree12%
  • Exondys 515%
Algorithm

Late pipeline

  • RGX-202

    REGENXBIO · Phase 3 · Gene therapy

  • del-zota (AOC 1044)

    Avidity → Novartis (announced) · Filed / review · ASO / exon skip

  • Deramiocel (CAP-1002)

    Capricor · Filed / review · Cell therapy

Full pipeline

Asset dives

Public case study. Figures are Aperture synthesis from labels, FDA communications, PPMD, registries and sell-side models — not a sponsored report.