FDA Lifts Partial Clinical Hold on Avidity's Delpacibart Etedesiran

SAN DIEGO, Oct. 3, 2024 — Avidity Biosciences, Inc., a biopharmaceutical company listed on Nasdaq under the ticker RNA, has announced that the U.S. Food and Drug Administration (FDA) has lifted the partial clinical hold on delpacibart etedesiran (del-desiran/AOC 1001). This investigational treatment targets myotonic dystrophy type 1 (DM1), a severe neuromuscular disease for which there are currently no approved therapies.

Del-desiran is currently under investigation in the Phase 3 HARBOR™ trial involving DM1 patients. DM1 is a progressive and often life-threatening disease that impacts skeletal and cardiac muscles, leading to a variety of symptoms such as myotonia, muscle weakness, respiratory complications, fatigue, and cardiac issues. The disease is caused by a triplet-repeat in the DMPK gene, leading to a toxic gain of function mRNA, and it is characterized by significant variability in severity and age of onset. Despite its impact, there are no approved treatments for DM1 at this time.

Del-desiran, the lead product candidate from Avidity's Antibody Oligonucleotide Conjugates (AOC) platform, is specifically designed to reduce levels of the disease-related mRNA called DMPK. The treatment combines a proprietary monoclonal antibody targeting the transferrin receptor 1 (TfR1) with siRNA that targets DMPK mRNA. The global Phase 3 HARBOR™ trial and the ongoing MARINA-OLE™ trial are currently evaluating this treatment. Long-term data from the MARINA-OLE™ trial has shown promise, indicating a reversal of disease progression in DM1 patients across various measures such as hand function, muscle strength, and daily activities, as compared to natural history data from the END-DM1 study.

The investigational drug has garnered significant regulatory attention, receiving Breakthrough Therapy, Orphan Drug, and Fast Track designations from the FDA, as well as Orphan designation from the European Medicines Agency (EMA).

Avidity Biosciences, headquartered in San Diego, is pioneering a new class of RNA therapeutics known as AOCs. These therapeutics aim to combine the targeted approach of monoclonal antibodies with the precision of oligonucleotide therapies, allowing for the treatment of diseases previously inaccessible with standard RNA therapies. The company's innovative platform has demonstrated successful targeted delivery of RNA into muscle cells, positioning them at the forefront of RNA therapeutic development for rare muscle diseases such as DM1, Duchenne muscular dystrophy (DMD), and facioscapulohumeral muscular dystrophy (FSHD). Avidity is also expanding its therapeutic pipeline to include programs in cardiology and immunology through both internal research and strategic partnerships.

Avidity's mission is to significantly improve patient outcomes by advancing a groundbreaking class of RNA therapeutics. The company's commitment to innovation is underscored by its ongoing clinical trials and expanding pipeline aimed at addressing unmet medical needs across various disease areas.