Currently, there are no approved treatment options for myotonic dystrophy type 1 (DM1), a progressive neuromuscular disease. As the disease progresses, affected individuals experience muscle weakness, respiratory distress, and cardiac issues, leading to a lower quality of life and, in many cases, eventual death. Finding a treatment option could potentially alleviate or slow the progression of symptoms. Additionally, it could pave the way for further research and development of therapies for other forms of muscular dystrophy and related genetic disorders.
Biopharmaceutical company Avidity Biosciences, Inc. (“Avidity”) recognizes the importance of drug development in the DM1 space and is committed to providing support and relief for this community. The company’s investigational therapy delpacibart etedesiran (AOC 1001) reduces DMPK levels. DMPK is a disease-related mRNA. In DM1, DMPK levels are highest in skeletal, cardiac, and smooth muscle. Through using a monoclonal antibody that targets DMPK mRNA, this therapy reduces the levels, which Avidity believes can reduce or relieve symptoms relating to myotonic dystrophy type 1.
Recognizing the benefits of AOC 1001, as well as its promising results in the Phase 2 MARINA-OLE clinical study, the FDA recently granted the drug with Breakthrough Therapy designation. This designation provides expedites drug review and development in therapies designed to treat a serious condition where the drug might show substantial improvement over existing available therapies. AOC 1001 has also received Orphan Drug and Fast Track designations in the United States.
The ongoing MARINA-OLE study is evaluating how safe and well-tolerated AOC 1001 is. Initial data suggests that it slows, or even reverses, disease progression. We look forward to seeing the results of the study.
Additionally, Avidity plans to begin the Phase 3 HARBOR trial in 2024 to identify whether AOC 1001 is effective in improving muscle and hand grip strength, as well as several other endpoints.
What is Myotonic Dystrophy type 1 (DM1)?
DM1 is one subtype of myotonic dystrophy and also the most common form of adult-onset muscular dystrophy. This rare disease, characterized by progressive muscle weakness and wasting, results from an abnormally expanded section on chromosome 19. DM1 is typically more severe than DM2, with muscle weakness often affecting the hands, neck, face, and lower legs. People with myotonic dystrophy type 1 may show signs of:
- Voluntary muscle weakness
- Cataracts
- Myotonia (being unable to relax muscles at will)
- Labor and pregnancy complications
- Dysphagia (difficulty swallowing) due to gastrointestinal tract weakness
- Constipation
- Difficulty breathing caused by respiratory muscle weakness
- Diabetes mellitus
- Gallstones
- Slurred speech
- Abnormal heart rhythm due to cardiac muscle weakness
- Learning disabilities and/or cognitive impairment
- Apathy
These signs often appear in someone’s twenties or thirties, though they can appear at other points in one’s life.
