Before 2016, clinicians treating Duchenne muscular dystrophy (DMD) had only corticosteroids to slow functional decline — nothing that addressed the root cause. That changed dramatically over the next decade, as the FDA approved eight disease-targeted therapies spanning multiple mechanisms and patient populations, transforming DMD from an untreatable condition into one with a growing therapeutic toolkit.

The approvals began with eteplirsen (2016), the first exon-skipping therapy, followed by deflazacort (2017), a corticosteroid approved for all DMD genotypes. Three more exon-skipping agents — golodirsen, viltolarsen, and casimersen — expanded mutation-specific options through 2021. The landmark 2023–2024 period brought delandistrogene moxeparvovec (Elevidys), the field's first gene therapy; vamorolone, a dissociative steroid designed to reduce side effects; and givinostat, the first nonsteroidal option for all DMD variants.

Key Takeaways:

• Eteplirsen raised dystrophin from 0.16% to 0.93% of normal by week 180, though clinical benefit wasn't established at the time of approval
• Deflazacort 0.9 mg/kg/day outperformed prednisone in muscle strength preservation from weeks 12–52
• Givinostat slowed stair-climb decline by ~58% vs. placebo (1.25 vs. 3.03 seconds) and reduced muscle fat infiltration by ~30%
• Elevidys' expanded approval came despite its confirmatory EMBARK trial missing its primary NSAA endpoint at 52 weeks

Why it matters: Each approval has expanded the share of DMD patients with targeted treatment options, and together they signal a meaningful shift toward precision, mechanism-based care for a disease that once offered little hope beyond supportive therapy.