What's Happening?
Avidity Biosciences has announced the publication of results from its Phase 1/2 MARINA trial in The New England Journal of Medicine, highlighting the potential of delpacibart etedesiran (del-desiran) in treating myotonic dystrophy type 1 (DM1). The trial demonstrated
that del-desiran effectively delivered siRNA to muscle tissue, resulting in a mean reduction of approximately 40% in DMPK mRNA levels. This reduction is significant as it addresses the genetic root cause of DM1, a progressive neuromuscular disease. The study also reported improvements in muscle function, strength, and mobility, alongside acceptable safety and tolerability profiles. The trial involved 38 participants and was designed to evaluate the safety and efficacy of del-desiran administered intravenously. The results are promising for DM1 patients, who currently have no approved disease-modifying therapies.
Why It's Important?
The findings from the MARINA trial are significant as they offer hope for a new treatment option for DM1, a condition that currently lacks effective therapies. DM1 is a hereditary disease that leads to progressive muscle weakening and other systemic issues, severely impacting patients' quality of life. The successful reduction of toxic DMPK mRNA levels by del-desiran could potentially transform the treatment landscape for DM1, providing a targeted approach to managing the disease. This development is crucial for the thousands of individuals and families affected by DM1 in the U.S., as it could lead to the first globally approved drug for this condition. The trial's positive outcomes also reinforce the potential of Avidity's Antibody Oligonucleotide Conjugates (AOCs) platform in addressing other rare muscle diseases.
What's Next?
Avidity Biosciences is advancing to a global Phase 3 HARBOR trial to further assess del-desiran's efficacy and safety in a larger cohort of DM1 patients. This trial, which has completed enrollment, will provide more comprehensive data on the drug's impact on key functional aspects of DM1. The results from this trial are expected in the second half of 2026. If successful, del-desiran could become the first approved treatment for DM1, offering a new therapeutic avenue for patients. Avidity is also exploring the potential of its AOC platform in other rare muscle diseases, which could expand the impact of this innovative approach in the field of RNA therapeutics.
