Avidity Biosciences, Inc. (Nasdaq: RNA), a biopharmaceutical company committed to delivering a new class of RNA therapeutics called Antibody Oligonucleotide Conjugates (AOCs™), today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to AOC 1044 for the treatment of Duchenne muscular dystrophy (DMD) in people with mutations amenable to exon 44 skipping (DMD44). DMD is a rare genetic condition that is characterized by progressive muscle damage and weakness due to the loss of dystrophin protein that typically starts in males at a very young age. AOC 1044 is being assessed in the Phase 1/2 EXPLORE44™ clinical trial for people living with DMD44 and is the first of multiple AOCs the company is developing for DMD. Avidity plans to share results from the healthy volunteer portion of the EXPLORE44 trial in the second half of 2023.

It is very encouraging to receive FDA Fast Track designation as it further validates the potential of AOC 1044 to target the underlying cause of DMD44 and the importance of bringing people living with this devastating disease an effective treatment option. This recognition also means that now all three of our clinical-stage programs have Fast Track status, further reinforcing our efforts to make a profound difference in people's lives," said Steve Hughes, M.D., chief medical officer at Avidity. "We will continue to work closely with the FDA as we advance AOC 1044 and look forward to the anticipated data readout from the healthy volunteer portion of our Phase 1/2 EXPLORE44 clinical trial later this year."

Avidity's proprietary AOCs are designed to combine the specificity of monoclonal antibodies (mAbs) with the precision of oligonucleotide therapies to target the root causes of diseases previously untreatable with RNA therapeutics. In the case of DMD, the disease is caused by a genetic mutation that prevents the body from producing the dystrophin protein, which protects muscle cells from injury during contraction. The lack of functional dystrophin leads to stress and tears of muscle cell membranes, resulting in muscle cell death and progressive loss of muscle function. AOC 1044 is designed to deliver phosphorodiamidate morpholino oligomers (PMOs) to skeletal muscle and heart tissue. The PMOs circumvent the mutation by causing exon 44 of the dystrophin gene to be skipped, which enables production of functional dystrophin protein.

The EXPLORE44™ Phase 1/2 Trial of AOC 1044
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). EXPLORE44 will evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamic effects of single and multiple ascending doses of AOC 1044 administered intravenously. 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.