INTRODUCTION: Duchenne muscular dystrophy (DMD) leads to progressive muscle degeneration and premature death caused by absence of dystrophin. Mostly, deletions in the DMD gene disrupt the dystrophin open-reading frame. Exon-skipping therapies use antisense oligonucleotides to restore the open-reading frame for generation of a shortened dystrophin containing essential functional domains. Viltolarsen is an FDA-approved, weekly infusion for patients with DMD amenable to exon 53 skipping. Maintaining treatment persistence is necessary to slow disease progression and manage functional decline. Treatment persistence with viltolarsen is high in clinical studies, but there are limited real-world data. Here, treatment persistence was estimated over 1-, 2-, and 3-year periods using a US open-claims dataset (Veeva Compass Patient).
METHODS: The longitudinal, non-interventional, retrospective cohort analysis included male patients ≤30 years old with a confirmed DMD diagnosis and anonymized open viltolarsen claims (09/01/2020 and 09/11/2024). Data from patients with viltolarsen claims for a minimum of two distinct calendar dates were included. For 3-year persistence (Group 1), patients’ first claims started before 03/01/2021. For 2-year persistence (Group 2), claims started on or after 03/01/2021 and before 02/28/2022. For 1-year persistence (Group 3), claims started after 03/01/2022 and before 02/28/2023. Persistence was defined as the first prescription fill to failure, loss-to-follow-up, or end of study period, allowing for ≤61 days between claims.
RESULTS: Overall, 94 patients (mean age: 13.4±6.4 years) were identified. Five patients failed between the first and second claim and were excluded from the main analysis. Persistence to viltolarsen was 81% in Group 1 (n=12; 3-year persistence); 81% in Group 2 (n=41; 2-year persistence); and 86% in Group 3 (n=36; 1-year persistence).
CONCLUSION: High treatment persistence is important to slow progression and manage functional decline in DMD. High real-world persistence to viltolarsen was sustained through 3 years, suggesting strong patient and caregiver commitment to continuing weekly viltolarsen infusions.