Observational study of changes to glucocorticosteroid prescribing patterns in duchenne muscular dystrophy in the UK over the last decade.

Background: Glucocorticosteroids (GC) are standard-of-care treatment for most boys with duchenne muscular dystrophy (DMD). GC use has changed over time with evolving evidence, and we describe GC patterns, dosing and side-effects in the UK over 11 years.

Method: NorthStar data from 2012 to 2022 were analysed to understand GC type, regime and starting age. GC dose with age, patterns of GC switching and side-effect profiles by type and regime were also analysed. Participants attributed to 'other' regimes were queried and details were included.

Results: Data on GC usage were available for 1117 boys, across 6905 observations, with 74% of boys GC treated. Prednisolone was the most common regime in the period (65% of assessments) but deflazacort prescription has increased (17% in 2012 and 43% in 2022). Daily regimes were more common (66% of assessments), and the incidence of intermittent (10 days on/10 days off) regimes has declined (46% in 2012 and 26% in 2022). Older participants were more commonly on less than recommended doses, and this was more common in those on deflazacort or daily regimes. Gastrointestinal symptoms and cushingoid features were more common in those on deflazacort than prednisolone, while increased appetite, cushingoid features, gastrointestinal symptoms and insomnia were more common in those on daily than intermittent regimes.

Conclusions: The use of deflazacort and daily regimes has steadily increased across the UK North Star Network in the last decade. This study provides one of the largest up-to-date real-world set of data of evolution in prescription patterns and the occurrence of side-effects in different groups of GC-treated DMD.