Viltolarsen

Funato M, et al. Brain and Development, 2025, 47(1), 104297.

Viltolarsen, an exon 53-skipping antisense oligonucleotide, has emerged as a targeted therapy for Duchenne muscular dystrophy (DMD). By enabling the production of truncated yet functional dystrophin, viltolarsen offers therapeutic potential for DMD patients with amenable genetic mutations.
A retrospective analysis evaluated the long-term efficacy and safety of viltolarsen in patients aged 6-19 years with DMD. Five patients received weekly viltolarsen treatment for over three years, while age- and time-matched controls did not receive viltolarsen or underwent intermittent therapy. Results demonstrated notable benefits: three patients maintained motor function, and one ambulatory patient exhibited significantly slower motor decline compared to controls, 89% of whom experienced marked motor deterioration.
Adverse events were minimal and manageable. One patient experienced localized swelling due to extravasation, and another developed axillary lymph node enlargement from frequent intravenous infusions. Importantly, no patients discontinued therapy, underscoring the tolerability of viltolarsen.
This study highlights the importance of consistent, once-weekly viltolarsen administration in preserving motor function and slowing disease progression. It also emphasizes the treatment's safety profile and potential as a long-term therapeutic option for DMD. However, larger-scale studies with extended follow-up periods are necessary to further validate these findings and optimize treatment protocols.