Development of Quantitative Muscle Imaging as a Biomarker of Disease Endpoints in Myotonic Dystrophy

Myotonic dystrophy (dystrophia myotonica; DM), the most prevalent form of muscular dystrophy in adults, is characterized by progressive myopathy, myotonia, and multi-systemic involvement. DM causes severe disability and profoundly affects the patient's quality of life. Currently, no effective treatments are available that alter the course of the disease, but ongoing clinical trials are underway.

Past and current clinical trials in DM1 have relied on muscle biopsies to evaluate pathology and measure drug activity. However, this method is invasive and inefficient for long-term monitoring. What is lacking are non-invasive imaging biomarkers capable of providing comparable data, which would enhance trial planning, accelerating drug development while reducing morbidity and costs. Non-invasive muscle imaging, particularly through Quantitative Magnetic Resonance Imaging (qMRI), is essential to better understand how DM affects muscle structure. Moreover, the relationships between Magnetic Resonance Imaging (MRI) measures, disease severity, and Ribonucleic Acid (RNA) splicing outcomes from muscle tissues in the same DM patients are not yet known. As MRI has been relatively unstudied in DM, there needs to be a comprehensive baseline characterization of muscle structure and its relationship to clinical endpoints and RNA-associated disease processes. This will help evaluate the potential of qMRI as a biomarker of disease severity in DM.