Background : Long-term glucocorticoids remain standard of care for patients with Duchenne muscular dystrophy (DMD), but are associated with adverse effects on growth, body composition, and bone health. Vamorolone is a dissociative steroid designed to preserve anti-inflammatory efficacy while reducing glucocorticoid-related side effects. Real-world data describing growth, bone health, and functional outcomes with vamorolone remain limited.
Objectives: To describe growth velocity (GV), body mass index (BMI), bone health, and functional outcomes in boys with DMD treated with vamorolone in clinical practice.
Methods: Case series of patients with DMD who transitioned to vamorolone. Longitudinal data were collected at least 0.5 years before and after vamorolone initiation, including anthropometrics, DXA-derived measures, spine imaging, fracture history, and functional outcomes (North Star Ambulatory Assessment, NSAA and 10-meter walk/run). Annualized GV and BMI change were calculated. Non-parametric testing was used for comparison.
Results: Seven ambulatory boys were included, and treated with vamorolone at a median age of 6.0 years (range 4.6–14.6) following prior prednisone/deflazacort for 0.5–5.6 years. Vamorolone exposure ranged from 0.5 to 1.1 years. Pre-vamorolone GV ranged from 2.3 to 5.2 cm/y, increasing to 6.5–7.9 cm/y post-vamorolone, showing significant improvement (Wilcoxon signed-rank test, p=0.0156). Findings unchanged when post-pubertal patient excluded (p=0.0312).
BMI change was heterogeneous; change ranged from –0.23 to +6.7 kg/m²/y pre and –1.9 to +5.6 kg/m²/y post-vamorolone, with 4 patients demonstrating reduction. Lumbar spine DXA z-scores ranged from –2.5 to –0.1 pre and –2.2 to +0.9 post-vamorolone, with change ranging from –0.6 to +1.4 (p=1), with the highest change on a boy receiving bisphosphonates (p=0.5 after exclusion). Spine imaging (N=3) remained stable, without new fractures. Changes in functional outcomes (N=4, ages 4.6-8.3 years) were heterogenous, from improvement to worsening of decline, not statistically significant, with no change in analysis after excluding a patient post gene therapy (GT).
Conclusions: Vamorolone was associated with significantly improved growth, stabilization of BMI trajectories, preserved bone health. These findings highlight the need for larger,longitudinal real-world studies.
Limitations: small sample, variable follow-up, potential confounding from prior corticosteroid use, bisphosphonates, GT.