Title: "Safety, pulmonary function, and motor function in ambulatory and nonambulatory participants with Duchenne muscular dystrophy treated with viltolarsen"
Abstract:
Introduction: Pulmonary decline is concerning in Duchenne muscular dystrophy (DMD). Viltolarsen is indicated for the treatment of DMD patients amenable to exon 53 skipping. Previously, viltolarsen demonstrated increased dystrophin production, stabilized motor function, and was well tolerated; pulmonary and upper limb function were not evaluated.
Objectives: Evaluate safety and pulmonary and motor function in DMD participants treated with viltolarsen.
Methods: Phase 2, 48-week study of ambulatory (n=10) and nonambulatory (n=10) DMD participants aged ≥8 years treated with viltolarsen 80 mg/kg/week (NCT04956289). LS mean change from baseline ±SE in percent predicted forced vital capacity (FVC%p) and peak cough flow (PCF) in participants receiving viltolarsen were compared with CINRG Duchenne Natural History Study (DNHS control, N=48), matched for multiple variables. Performance of Upper Limb (PUL) 2.0 was evaluated.
Results: Baseline characteristics were well-matched between viltolarsen and DNHS cohorts. Nineteen viltolarsen participants reported treatment-emergent adverse events (AEs); 4 treatment-related. No serious AEs were reported. None discontinued. FVC%p for ambulatory and nonambulatory participants was higher at Week 49 for viltolarsen versus DNHS control (ambulatory: 8.3±3.3% vs. 1.2±2.1%, respectively, and nonambulatory: 1.6±3.0% vs 3.2±2.0%, respectively). PCF for ambulatory and nonambulatory participants was higher for viltolarsen versus DNHS control at Week 49. PUL 2.0 scores were stable with treatment.
Conclusions: Safety of viltolarsen is consistent with previous trials. This is the first study of viltolarsen evaluating pulmonary and upper limb function and includes ambulant and nonambulant participants. These results suggest benefit of viltolarsen on respiratory and motor function for boys and older males with DMD amenable to exon 53 skipping.
