Pulmonary function in Duchenne muscular dystrophy patients from the STRIDE Registry and CINRG Natural History Study: a matched cohort analysis

Objectives: We investigated if nonsense mutation Duchenne muscular dystrophy (nmDMD) patients receiving ataluren plus standard of care (SoC) in the STRIDE Registry (NCT02369731) experienced a lesser decline in pulmonary function versus DMD patients receiving SoC alone in the CINRG Duchenne Natural History Study (NCT00468832).

Methods: STRIDE is an ongoing, multicenter, observational registry providing data on ataluren use in nmDMD patients in routine clinical practice (data extracted, January 31, 2021). Propensity score matching identified STRIDE and CINRG patient cohorts (N=241) comparable in established predictors of disease progression: age at first symptoms, age at initiation of corticosteroid use, duration of deflazacort use, and duration of other corticosteroid use. CINRG patients who had received DMD investigational drugs were excluded. Kaplan–Meier analyses estimated ages at %-predicted forced vital capacity (FVC) <60% and <30%.

Results: Mean (SD) ages at onset of first symptoms (STRIDE vs CINRG; N=241 per cohort) were 2.7 (1.7) and 2.8 (1.5) years, respectively. Most patients (STRIDE vs CINRG) received corticosteroids for ≥12 months (79.7% per cohort); a similar proportion received deflazacort (43.6% vs 45.2%) or other corticosteroids (41.5% vs 43.2%). Median (95% CI) ages at %-predicted FVC <60% (STRIDE vs CINRG) were 17.6 (16.2, non-estimable) and 15.8 (15.1, 16.5) years, respectively (p=0.0051). Median (95% CI) ages at %-predicted FVC <30% were non-estimable for STRIDE patients (0.5% [1/192] of patients reached %-predicted FVC <30%) and 25.4 (20.6, 29.4) years for CINRG patients (p=0.0085).

Conclusion: These interim registry data suggest that ataluren plus SoC in routine clinical practice slows nmDMD disease progression.