Age at loss of ambulation in patients with DMD from the STRIDE Registry and the CINRG Natural History Study: a matched cohort analysis



Poster Number: 97


Pannie Trifillis, PTC Therapeutics Inc., South Plainfield, NJ, USA, Eugenio Mercuri, Paediatric Neurology and Centro Clinico Nemo, Catholic University and Policlinico Gemelli, Fondazion, Francesco Muntoni, MD, Great Ormond Street Institute of Child Health, London, UK, Filippo Buccella, Parent Project APS, Rome, Italy, Isabelle Desguerre, Hôpital Necker – Enfants Malades, Paris, France, Janbernd Kirschner, MD, Medical Center-University of Freiburg; University Hospital Bonn, Faculty of Medicine, Andres Nascimento-Osorio, MD, Hospital Sant Joan de Déu, Unidad de Patología Neuromuscular, Universidad de Barcelona, Spain, Már Tuliniums, MD, Department of Pediatrics, Gothenburg University, Queen Silvia Children’s Hospital, Sweden, Shelley Johnson, DBA, MBA, PTC Therapeutics Inc., South Plainfield, NJ, USA, Christian Werner, PhD, PTC Therapeutics Germany GmbH, Frankfurt, Germany, Allan Kristensen, PhD, PTC Therapeutics Inc., South Plainfield, NJ, USA, Joel Jiang, PhD, PTC Therapeutics Inc., South Plainfield, NJ, USA, James Li, PTC Therapeutics Inc., South Plainfield, NJ, USA, Rich Able, PhD, PTC Therapeutics, Claudio L. Santos, MD, MBA, PTC Therapeutics Inc., South Plainfield, NJ, USA, Craig McDonald, MD, UC Davis Health

Background: Strategic Targeting of Registries and International Database of Excellence (STRIDE) Registry (NCT02369731) is an ongoing, multicenter, observational registry providing data on ataluren use in nonsense mutation Duchenne muscular dystrophy (nmDMD) patients in routine clinical practice.

Objective: We examined if nmDMD patients receiving ataluren plus standard of care (SoC) in STRIDE Registry (NCT02369731) experienced a delay in age at loss of ambulation (LOA) versus DMD patients receiving SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (NCT00468832).

Methods: Data were extracted on 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. Patients from CINRG who had received investigational drugs for DMD were excluded. Kaplan–Meier analyses were used to estimate age at LOA.

Results: The mean (standard deviation) ages at first symptoms in the STRIDE and CINRG cohorts (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), with a similar proportion receiving deflazacort (43.6% vs 45.2%) or other corticosteroids (41.5% vs 43.2%). In the STRIDE cohort, 24.9% (60/241) of patients lost ambulation compared with 52.7% (127/241) of patients in the CINRG cohort. The median (95% confidence interval) ages at LOA (STRIDE vs CINRG) were 17.9 (14.4, non-estimable) and 12.5 (11.6, 13.5) years, respectively. Kaplan–Meier analyses showed that ataluren plus SoC delayed age at LOA compared with SoC alone (p<0.0001).

Conclusions: These interim registry data show that treatment with ataluren and SoC in routine clinical practice slows disease progression in nmDMD patients.