According to an article from Marisa Wexler in Muscular Dystrophy News, promising study data is available from the Phase 1 ARCH study. Within the study, researchers evaluated EDG-5506, an experimental treatment for individuals with Becker muscular dystrophy. 

Developer Edgewise Therapeutics explains that EDG-5506, which is orally administered:

reduces stress by selectively targeting the muscle motor protein myosin that regulates contraction of fast skeletal muscle fibers. The tissue specificity of EDG-5506 means that the function of other muscles such as slow skeletal, smooth and cardiac muscle are not affected.

EDG-5506 is being developed as a potential option for people with Becker muscular dystrophy, Duchenne muscular dystrophy, and, in the future, limb-girdle muscular dystrophy and metabolic myopathies. 

Within the ARCH trial, researchers treated 12 men with Becker muscular dystrophy. Of these men, seven had participated in another trial which highlighted the ability of the therapy to reduce muscle damage. Participants received 10mg EDG-5506 nightly for the first two months, 15mg for the next two months, and 20mg thereafter. Findings from the study show:

• Within two months following treatment, muscle damage markers (specifically fast skeletal muscle troponin I and creatine kinase) were reduced (by 68% and 30% respectively). After four months, reductions were 74% and 29% respectively. 
• EDG-5506 is safe and relatively well-tolerated. While some adverse reactions have occurred, these are mostly fatigue and tiredness, dizziness, and/or headaches. 
• Motor and muscle function improved or stabilized in a majority of patients. 

Moving forward, EDG-5506 will continue being evaluated in a series of clinical trials. Upcoming are the Phase 2 CANYON trial and the Phase 2 LYNX trial.

Becker Muscular Dystrophy (BMD): An Overview

There are nine main forms of muscular dystrophy; Becker muscular dystrophy (BMD) falls under this umbrella. While Becker muscular dystrophy is similar to Duchenne muscular dystrophy, BMD often has a later onset and slower progression. BMD is characterized by progressive muscle weakness and loss affecting the cardiac and skeletal muscles. As BMD follows an X-linked recessive pattern of inheritance, it primarily affects males, although females can sometimes be affected. Symptom onset normally occurs between ages 5-15. These symptoms can include:

• Progressive muscle weakness which often begins in the legs and pelvis
• Cardiomyopathy
• Fatigue
• Problems with balance and coordination
• Muscle weakness and contractures
• Difficulty with walking or climbing
• Frequent tripping and falling
• Scoliosis
• Cognitive impairment