Practical NeurologyFDA Grants Orphan Drug Designation to Exon 44 Skipping AOC for Duchenne Muscular Dystrophy

The decision marks a milestone in DMD treatment.

The FDA has granted orphan drug designation to AOC 1044, an antibody oligonucleotide conjugate (AOC) developed by Avidity Biosciences, for treating Duchenne muscular dystrophy (DMD) patients with mutations amenable to exon 44 skipping therapy. This comes on the heels of the FDA’s Fast Track Designation for the drug in April 2023, signaling a promising future for this novel treatment.

Key Points:

• AOC 1044 is currently being evaluated in a phase 1/2 clinical trial called EXPLORE44 (NCT05670730), which is actively recruiting participants.
• The trial is a randomized, placebo-controlled, double-blind study divided into two cohorts: a healthy control group and a DMD group amenable to exon 44 skipping therapy.
• The primary outcome focuses on the incidence of treatment-emergent adverse events (TEAEs), with secondary outcomes measuring pharmacokinetics in plasma, urine, and skeletal muscle tissue, as well as changes in dystrophin protein levels.

Additional Points:

• DMD is an incurable disease with an average life expectancy of 26 years, characterized by progressive muscle weakness in skeletal, cardiac, and respiratory muscles.
• The FDA’s orphan drug designation aims to expedite the clinical development and evaluation of drugs for rare diseases.
• Results from the first part of the EXPLORE44 study are expected by the end of 2023.

More on Rare Diseases in Neurology