Currently, there are no therapeutic options available for patients with myotonic dystrophy type 1 (DM1). However, that may soon change. According to Marketwatch, the FDA recently granted Fast Track designation to AOC 1001, an investigational therapy for DM1.
AOC 1001
So what exactly is AOC 1001? This investigational treatment, developed by biopharmaceutical company Avidity Biosciences, Inc. (“Avidity”), was developed using Avidity’s proprietary AOC platform. The therapy uses a monoclonal antibody which binds to the transferrin receptor 1 (TfR1). Additionally, the treatment includes siRNA which targets DMPK. DM1 is caused by an abnormally expanded section on the DMPK gene; when read by cells, the cells produce abnormally long and toxic DMPK messenger RNA (mRNA). AOC 1001 works to reduce this and stop the processes which drive DM1 progression.
Preclinical studies highlighted the therapy’s benefit in reducing DMPK throughout a variety of muscles. It was also seen as relatively safe and well-tolerated. Moving forward, Avidity will be evaluating AOC 1001 for DM1 in a Phase 1/2 clinical trial.
Recently, the FDA granted Fast Track designation to AOC 1001. This designation is granted to drugs or biologics which fulfill unmet medical needs within certain realms, or which treat rare and serious conditions. Once a therapy receives Fast Track designation, the drug developer is also granted an expedited review process. Outside of this status, AOC 1001 also earned Orphan Drug designation in Europe and the United States.
Myotonic Dystrophy
Myotonic dystrophy is a rare disease that is characterized by progressively worsening muscle weakness and atrophy. As described above, an abnormally expanded section on DMPK causes myotonic dystrophy type 1 (DM1), while type 2 (DM2) results from an abnormally expanded section on ZNF9. Typically, DM2 is milder than type 1. Another difference is that DM1 affects the face, neck, hands, and lower legs, while DM2 often affects the neck, elbows, hips, and shoulders. Symptoms include:
- Myotonia (prolonged muscle contractions)
- Difficulty relaxing muscles after use
- Excessive sleepiness
- Cataracts
- Gastrointestinal muscle weakness, manifesting in constipation, gallstones, or difficulty swallowing
- Fatigue
- Heart muscle weakness and abnormal heart rhythm
- Difficulty breathing
- Learning disabilities and cognitive impairment
- Abnormal uterine muscles, leading to pregnancy and labor complications
- Problems with speech, hearing, and vision
Learn more about myotonic dystrophy here.
