The 2023 Annual Meeting of the Myotonic Dystrophy Foundation took place from September 7-9 this year. During the meeting, stakeholders gathered in the nation’s capital to discuss research, trends, and practices to best support this community. Clinical-stage biopharmaceutical company AMO Pharma Limited (“AMO” or “AMO Pharma”) shared that results from the Phase 3 REACH-CDM trial would be reviewed on the last day of the Meeting. The REACH-CDM trial is evaluating a new drug called AMO-02 (tideglusib) for people living with congenital myotonic dystrophy type 1 (congenital DM1 or CDM1).

56 participants between ages six to 16 enrolled in the study. Participants received either AMO-02 or a placebo. AMO-02 is an investigational therapy that disrupts the pathogenic (disease-causing) RNA repeat. The treatment also inhibits glycogen synthase kinase 3 beta (GSK3ß), which is shown to be higher in people with DM1 (as well as muscle biopsies and animal models).

Within the study, researchers examined the safety and efficacy of AMO-02. It also looked at its impact on the people with DM1. Did the treatment improve their ability to walk and run? How did AMO-02 improve cognition or adaptive function? Did this treatment alter bone density? After examining the data, the researchers found that AMO-02 had generally positive responses and helped improve patient health and function. In particular, AMO-02 was shown to improve cognition and muscle strength. The treatment was also safe and well-tolerated. Trial participants were given the option to continue into the Open-Label Extension (OLE), which just 2% of people turned down. Only 15% of people discontinued treatment following the OLE. Moving forward, AMO plans to continue developing this therapy, as well as evaluate it for adults with this condition.

The Details of Myotonic Dystrophy type 1 (DM1)

Congenital myotonic dystrophy type 1 is also known as Steinert disease. DM1 was first described in medical literature in 1909. It exists under the greater umbrella of muscular dystrophies. DM1 is considered either classic or congenital. DPMK gene mutations cause DM1. In the classic form, affected individuals experience muscle weakness and wasting, cataracts before age 50, and abnormal electrical heart impulses. The congenital form is considered to be severe and often comes with poorer outcomes. It can cause early mortality or severe complications throughout life. Symptoms may, but do not always, include:

• Severe muscle weakness
• Hypotonia (“floppy” or poor muscle tone)
• Learning or behavioral disabilities
• Muscle weakness affecting both sides of the face
• Gastroparesis
• Failure to thrive
• Nausea
• Cardiac abnormalities
• Breathing problems and/or respiratory failure
• Visual issues such as poor visual acuity, astigmatism, farsightedness, cataracts, or blurry vision
• Clubfoot