Avidity Biosciences provides regulatory update on dystrophy candidate AOC 1001

Avidity Biosciences provided an update on the Phase 1/2 MARINA trial of AOC 1001 in adults with myotonic dystrophy type 1 – DM1 -, an underrecognized, progressive and often fatal neuromuscular disease with no approved treatment options. In September 2022, the FDA placed a partial clinical hold on new participant enrollment in the Phase 1/2 MARINA clinical trial after reviewing information provided by Avidity related to a serious adverse event reported in a single participant in the 4 mg/kg cohort of the MARINA study. The event was classified by the investigator as drug related. After an extensive investigation, Avidity cannot identify a plausible biological link to any component of AOC 1001, the AOC platform, the transferrin receptor delivery mechanism or reduction of DMPK. In December 2022, the company announced positive data from a preliminary assessment of the Phase 1/2 MARINA study of AOC 1001 demonstrating the first-ever successful targeted delivery of RNA to skeletal muscle, DMPK reduction and splicing improvements, with early signs of clinical activity with improvement in myotonia after just one or two doses of AOC 1001. The top-line data from MARINA will be presented in an oral presentation on April 27, 2023 at the 75th American Academy of Neurology Annual Meeting in Boston. Data supports that the targeted dose range is between 2 mg/kg and 4 mg/kg. Therefore, Avidity will not move forward with the 8 mg/kg dose of AOC 1001. Avidity remains on track to share a first look at the data from the MARINA-OLE study at the end of 2023.