P.390Pulmonary function in patients with Duchenne muscular dystrophy from the STRIDE registry and the CINRG natural history study: a matched cohort analysis

This analysis aimed to investigate if patients with nonsense mutation Duchenne muscular dystrophy (nmDMD) receiving ataluren plus standard of care (Strategic Targeting of Registries and International Database of Excellence [STRIDE] [NCT02369731]) experienced a lesser decline in pulmonary function compared with patients with DMD receiving standard of care alone. STRIDE is an ongoing, multicenter, observational registry designed to provide data on ataluren use in patients with nmDMD in routine clinical practice. Propensity score matching was performed to identify patient cohorts from STRIDE and CINRG who were comparable in established predictors of disease progression: age at onset of first symptom; duration of deflazacort use; and duration of other corticosteroid use. The majority of patients from CINRG were included in this analysis; however, patients from CINRG who received any other mutation-specific investigational drug for DMD were excluded. The proportion of patients in each cohort with a predicted forced vital capacity (FVC) < 50% or FVC < 1 L was determined. The mean (standard deviation) age at onset of first symptom in the STRIDE and CINRG cohorts (n=187 in each cohort) was 2.7 (1.8) and 2.9 (1.6) years, respectively. The majority of patients (STRIDE vs CINRG) received corticosteroids for ≥12 months (56.7% vs 55.1%), with a similar proportion receiving deflazacort (24.6% vs 23.5%) or other corticosteroids (34.8% vs 34.8%). In the STRIDE cohort, 2.1% (3/140) of patients had a predicted FVC < 50% compared with 32.5% (37/114) of patients in the CINRG cohort. No patients (0/131) in the STRIDE cohort had an FVC < 1 L compared with 24.3% (33/136) in the CINRG cohort. These data suggest that in routine clinical practice, treatment with ataluren in addition to standard of care slows disease progression in patients with nmDMD.