Avidity Biosciences Announces Positive Topline Data from Myotonic Dystrophy Trial

Avidity Biosciences, a biopharmaceutical company committed to delivering a new class of RNA therapeutics called Antibody Oligonucleotide Conjugates (AOCs™), today announced positive topline data from the Phase 1/2 MARINA™ clinical trial of AOC 1001 for the treatment of myotonic dystrophy type 1 (DM1) demonstrating functional improvement, DMPK reduction, splicing improvements and a favorable safety and tolerability profile. The AOC 1001 topline data were highlighted in an oral presentation at the 75th American Academy of Neurology (AAN) Annual Meeting in Boston, Mass. AOC 1001, Avidity’s lead clinical program utilizing its AOC platform, is designed to address the root cause of DM1, an underrecognized, progressive and often fatal neuromuscular disease with no approved therapies.

“The AOC 1001 topline data demonstrated directional improvement across a variety of functional assessments in patients with DM1, including myotonia and muscle strength in a six-month period. This result is more than we could have anticipated in such a short time. These AOC 1001 data are remarkable and could make a real impact for people living with DM1,” said Nicholas E. Johnson, M.D., M.Sci., FAAN, associate professor and vice chair of research in the Department of Neurology at Virginia Commonwealth University, and lead investigator in the MARINA trial. “We know from the natural history study that these improvements do not happen without intervention. The AOC 1001 data are very encouraging for people with DM1 who need treatment options that can improve their ability to do necessary, everyday tasks that can be incredibly challenging when living with this disease.”

The Phase 1/2 MARINA trial is a randomized, double-blind, placebo-controlled study designed to evaluate the safety and tolerability of single and multiple ascending doses of AOC 1001 administered intravenously in adults with DM1. Topline data were assessed from a 3:1 randomized study with 38 participants, who were administered one dose of 1 mg/kg AOC 1001, three doses of either 2 mg/kg AOC 1001 or 4 mg/kg of AOC 1001 (reflected as siRNA dose), or placebo.

“The topline data from the MARINA trial reinforce our belief in the potential for AOC 1001 to be an effective treatment for people living with the devastating impact of DM1. Data from MARINA exceeded our expectations and delivered a robust data package to support advancement into a pivotal study. We are focused on designing the quickest path to bring AOC 1001 to patients and look forward to discussions with the FDA,” said Sarah Boyce, president and chief executive officer at Avidity. “Our vision is to profoundly improve people’s lives by revolutionizing the delivery of RNA therapeutics. These AOC 1001 data further demonstrate the broad and disruptive potential of our proprietary AOC platform to address targets and diseases previously unreachable with existing RNA therapies. We look forward to advancing all three of our clinical development programs while we continue to expand our pipeline in skeletal muscle, cardiology, immunology and other diseases.”

Avidity continues to work with the U.S. Food and Drug Administration (FDA) regarding the partial clinical hold on new participant enrollment in the AOC 1001 program. The company continues to dose the participants at both 2 mg/kg and 4 mg/kg of AOC 1001 in the MARINA open-label extension (MARINA-OLE™) study to evaluate the long-term safety and tolerability of AOC 1001 in participants with DM1 who were previously enrolled in the Phase 1/2 MARINA trial. Avidity remains on track to share a first look at the data from the MARINA-OLE study at the end of 2023.