A drug targeting exon 53 skipping of the DMD gene authorised in the United States and Japan, viltolarsen was evaluated for 48 weeks (80mg/kg/week) in 10 walking and 10 non-walking DMD patients aged 8 and over, in the Galactica53 trial. The results compared with those of untreated DMD patients from an external cohort showed that :
- Forced vital capacity was maintained or improved; it exceeded the 50% threshold for almost all patients in both groups (9 out of 10 in both cases). The average improvement was 8.3% in walking patients (+1.2% in controls) and 1.6% in non-walkers (-3.2% in controls).
- In seven out of 10 non-walkers, coughing capacity remained above 160 L/min, and in three of these patients, treatment enabled coughing capacity to rise to this threshold. Six out of 10 walking patients also maintained this threshold. The average gain in coughing capacity was 22.6 L/min in walking patients (+1.8 in controls) and 56.7 L/min in non-walkers (+15.1 L/min in controls).
- The upper limb motor score (PUL scale) was unchanged in both groups.
