To evaluate whether nmDMD patients receiving ataluren + standard of care (SoC; corticosteroids/palliative therapies) experienced a delay in loss of ambulation (LoA) and a slower decline in pulmonary function compared with a matched cohort of patients receiving SoC in the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG DNHS).

Duchenne muscular dystrophy (DMD) is a fatal rare, X-linked disease characterized by progressive muscle weakness. Approximately 10–15% of DMD cases are caused by a nonsense mutation (nmDMD) in the dystrophin gene, resulting in the absence of functional dystrophin. Ataluren (10, 10, 20 mg/kg [morning, midday, and evening]) targets the underlying cause of nmDMD, enabling the formation of full-length, dystrophin.

Study 019 was a phase 3, long-term (~4.5 years) safety study that enrolled nmDMD patients from prior ataluren clinical trials (NCT01557400) (N=94). 

Age at LoA was delayed by ~2.5 years in nmDMD patients receiving ataluren in Study 019 compared with CINRG DNHS patients (median ages: Study 019, 15.5 years; CINRG DNHS, 13.0 years; p=0.0079 [each n=60]). In non-ambulatory patients, ataluren was associated with a delay in decline to predicted FVC <60% by ~2.5 years (median ages: Study 019, 18.1 years; CINRG DNHS, 15.5 years; p=0.0376 [each n=45]) and a trend in delay in decline to predicted FVC <50% by ~1 year.

Ataluren + SoC delays LoA and may delay pulmonary function decline in nmDMD patients compared with DMD patients receiving SoC, although longer follow-up will be required to more fully assess this latter outcome.