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Avidity Biosciences: Receives FDA Rare Pediatric Disease Designation for AOC 1044 for Treatment of DMD in People with Mutations Amenable to Exon 44 Skipping

February 22, 2024

Avidity Biosciences, Inc. (Nasdaq: RNA), announced that the U.S. Food and Drug Administration (FDA) has granted Rare Pediatric Disease designation to AOC 1044, the company’s investigational therapy for the treatment of Duchenne muscular dystrophy (DMD) in people living with mutations amenable to exon 44 skipping (DMD44).

AOC 1044 is being assessed in the Phase 1/2 EXPLORE44™ trial for people living with DMD44 and is the first of multiple AOCs the company is developing for DMD. In addition to receiving Rare Pediatric Disease Designation, AOC 1044 has been granted Orphan Designation by the FDA and the European Medicines Agency (EMA), and Fast Track Designation by the FDA. Currently, there are no therapies approved targeting exon 44.

“We are pleased that the FDA has granted Rare Pediatric Disease designation to AOC 1044, adding to the Orphan Drug and Fast Track designations already granted. The effects of DMD44 are devastating, with symptoms often starting in childhood. These designations by the FDA underscore the urgent need for innovative treatments and validate the potential of AOC 1044 to address the unmet need of people living with Duchenne muscular dystrophy.”

Steve Hughes, M.D., chief medical officer at Avidity.

The EXPLORE44 trial is a randomized, placebo-controlled, double-blind, Phase 1/2 clinical trial to evaluate AOC 1044 in healthy volunteers and participants with DMD mutations amenable to exon 44 skipping (DMD44). Note: Currently clinical trials are only being conducted in the United States. EXPLORE44 is expected to enroll approximately 40 healthy volunteers and 24 participants with DMD44, ages seven to 27 years old. The EXPLORE44 trial will assess exon skipping and dystrophin protein levels in participants with DMD44. Participants with DMD44 will have the option to enroll into an extension study.

For more information about the EXPLORE44 trial, visit the EXPLORE44 study website or visit and search for NCT05670730.

About AOC 1044

AOC 1044 is currently in Phase 1/2 development as part of the EXPLORE44™ trial for the treatment of DMD mutations amenable to exon 44 skipping. Data from the Phase 1/2 EXPLORE44 trial showed that AOC 1044 delivered unprecedented concentrations of PMO in skeletal muscle with up to 50-times greater concentrations of PMO in skeletal muscle following a single dose compared to peptide conjugated PMOs in healthy volunteers. AOC 1044 was well tolerated, demonstrated statistically significant exon 44 skipping compared to placebo of up to 1.5% in healthy volunteers after a single dose of 10 mg/kg AOC 1044 and increased exon skipping in all participants. Avidity plans to provide a first look at AOC 1044 data in people living with DMD44 in 2H 2024.

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