Moderate-term dimethyl fumarate treatment reduces pathology of dystrophic skeletal and cardiac muscle in a mouse model

In Duchenne muscular dystrophy (DMD), corticosteroids significantly slow disease progression and have been used as a standard of care tool for more than 30 years. However, corticosteroids also impart side effects severe enough to preclude use in some patients. There remains an unmet need for new therapeutics that target the flow-on pathogenic mechanisms of DMD with a more favourable side-effect profile. We have previously demonstrated that short-term treatment with dual-purpose anti-inflammatory, anti-oxidative dimethyl fumarate (DMF), a drug with indication and established safety data in Multiple Sclerosis, more selectively modulates Duchenne ( mdx ) immunology than the frequently used corticosteroid, prednisone (PRED). Here, we assess the effect of moderate-term DMF treatment over 5 weeks in the typically mild mdx mouse model that we aggravated using exercise. We show that like PRED, DMF maintains anti-inflammatory action but with additional anti-fibrotic and anti-lipogenic effects on muscle with moderate-term use. This study supports our previous work highlighting DMF as a possible repurposing candidate for DMD, especially for patients who cannot tolerate chronic corticosteroid treatment.