P197 Pulmonary function in patients with Duchenne muscular dystrophy from the STRIDE registry and CINRG natural history study: a matched cohort analysis

We investigated if nonsense mutation Duchenne muscular dystrophy (nmDMD) patients receiving ataluren plus standard of care (SoC) in the Strategic Targeting of Registries and International Database of Excellence (STRIDE) Registry (NCT02369731) experienced a slower decline in pulmonary function versus DMD patients receiving SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Natural History Study (NCT00468832). STRIDE is an ongoing, multicenter, observational registry providing data on ataluren use in nmDMD patients in routine clinical practice since 2015. Data were extracted on January 31, 2023. STRIDE (N=277) and CINRG (N=398) patient cohorts were propensity-score matched 1:1 according to 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. Patients from CINRG who had received investigational drugs for DMD were excluded. Kaplan–Meier analyses were used to estimate ages at %-predicted forced vital capacity (FVC) <60% and 50%. The mean (SD) ages at onset of first symptoms (STRIDE vs CINRG; N=277 per cohort) were 2.8 (1.7) and 2.9 (1.5) years, respectively. Most patients (STRIDE vs CINRG) received corticosteroids for ≥12 months (88.8% vs 89.2%), with a similar proportion receiving deflazacort (52.0% vs 47.7%) or other corticosteroids (44.8% vs 48.4%). Median (95% confidence interval [CI]) ages at %-predicted FVC <60% (STRIDE vs CINRG) were 17.7 (16.9, 19.9) and 15.6 (15.1, 16.4) years, respectively (HR [95% CI] 0.630 [0.440, 0.903]; p=0.0086). Median (95%) CI) ages at %-predicted FVC <50% (STRIDE vs CINRG) were 19.2 (17.8, not estimable) and 17.7 (16.5, 18.6) years, respectively (HR [95% CI] 0.630 [0.426, 0.932]; p=0.0206). These real-world, multi-country data suggest that treatment with ataluren and SoC in routine clinical practice slows disease progression in pulmonary function in nmDMD patients. We investigated if nonsense mutation Duchenne muscular dystrophy (nmDMD) patients receiving ataluren plus standard of care (SoC) in the Strategic Targeting of Registries and International Database of Excellence (STRIDE) Registry (NCT02369731) experienced a slower decline in pulmonary function versus DMD patients receiving SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Natural History Study (NCT00468832). STRIDE is an ongoing, multicenter, observational registry providing data on ataluren use in nmDMD patients in routine clinical practice since 2015. Data were extracted on January 31, 2023. STRIDE (N=277) and CINRG (N=398) patient cohorts were propensity-score matched 1:1 according to 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. Patients from CINRG who had received investigational drugs for DMD were excluded. Kaplan–Meier analyses were used to estimate ages at %-predicted forced vital capacity (FVC) <60% and 50%. The mean (SD) ages at onset of first symptoms (STRIDE vs CINRG; N=277 per cohort) were 2.8 (1.7) and 2.9 (1.5) years, respectively. Most patients (STRIDE vs CINRG) received corticosteroids for ≥12 months (88.8% vs 89.2%), with a similar proportion receiving deflazacort (52.0% vs 47.7%) or other corticosteroids (44.8% vs 48.4%). Median (95% confidence interval [CI]) ages at %-predicted FVC <60% (STRIDE vs CINRG) were 17.7 (16.9, 19.9) and 15.6 (15.1, 16.4) years, respectively (HR [95% CI] 0.630 [0.440, 0.903]; p=0.0086). Median (95%) CI) ages at %-predicted FVC <50% (STRIDE vs CINRG) were 19.2 (17.8, not estimable) and 17.7 (16.5, 18.6) years, respectively (HR [95% CI] 0.630 [0.426, 0.932]; p=0.0206). These real-world, multi-country data suggest that treatment with ataluren and SoC in routine clinical practice slows disease progression in pulmonary function in nmDMD patients.