Avidity Biosciences Granted Orphan Drug Designation in Japan for Myotonic Dystrophy Type 1 Therapy
Wednesday, April 09, 2025
Avidity Biosciences has received Orphan Drug designation in Japan from the Ministry of Health, Labour and Welfare (MHLW) for its lead investigational treatment, delpacibart etedesiran (also known as del-desiran), for myotonic dystrophy type 1 (DM1).
Del-desiran is also being evaluated in the ongoing Phase 2 MARINA-OLE™ study, which includes patients previously enrolled in the MARINA Phase 1/2 trial.
Del-desiran works by targeting DMPK mRNA, the genetic cause of DM1. It combines a monoclonal antibody that binds to transferrin receptor 1 with a small interfering RNA (siRNA) designed to reduce DMPK levels.
DM1 is a complex inherited condition caused by a genetic mutation in the DMPK gene. It affects skeletal and cardiac muscles and presents a wide range of symptoms such as muscle weakness, myotonia, respiratory difficulties, fatigue, heart issues, gastrointestinal problems, and cognitive or behavioural impairments.
The disease varies in severity and onset, and remains without an approved treatment.
This marks the first time a DM1 therapy has been granted such status in Japan.
Del-desiran is being developed to target the root cause of DM1, a serious, progressive, and often life-threatening neuromuscular condition for which no approved therapies currently exist.
The treatment is based on Avidity’s Antibody Oligonucleotide Conjugates (AOCs™) platform, and has already received Breakthrough Therapy, Orphan Drug, and Fast Track designations from the US FDA, as well as Orphan designation from the European Medicines Agency (EMA).
The Japanese Orphan Drug designation is reserved for treatments addressing rare diseases affecting fewer than 50,000 patients in the country and which meet criteria related to medical need and lack of approved alternatives.
Avidity plans to complete enrolment in the Phase 3 HARBOR study by mid-2025 and intends to submit marketing applications in the United States, European Union, and Japan starting in 2026.
Source: prnewswire.com
