AOC 1001 Earns Orphan Drug Status for DM1 in Europe

Margarida Maia, PhD avatar

by Margarida Maia, PhD |

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AOC 1001

The European Commission (EC) has granted orphan designation to AOC 1001, Avidity Biosciences’ investigational therapy for myotonic dystrophy type 1 (DM1).

This designation is given to investigational therapies that have the potential to treat rare, life-threatening, or very serious diseases that affect less than five in 10,000 patients in the European Union. Orphan designation confers certain benefits to companies, including fee reductions, clinical protocol advice, and 10 years of protetion from competition following regulatory approval.

The decision by the EC follows the U.S. Food and Drug Administration (FDA) also granting orphan drug designation to AOC 1001 earlier this year.

AOC 1001 belongs to a new class of RNA therapies called antibody oligonucleotide conjugates (AOCs).

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“We are pleased that both the EC and the FDA have granted AOC 1001 Orphan Designation, further validating AOCs as a powerful new class of drugs that can bring benefit to people suffering from untreated and undertreated diseases,” Sarah Boyce, president and CEO of Avidity, said in a press release. 

DM1 is caused by an abnormal expansion in the DMPK gene that results in an abnormally long messenger RNA (mRNA), which is a type of molecule that carries the genetic instructions needed to make proteins. This abnormally long mRNA forms clumps and is toxic to cells.

A potential therapeutic strategy for DM1 involves the use of a small interfering RNA (siRNA). A siRNA is a short RNA molecule that binds to a target mRNA so that it then can be destroyed by the cell.

As siRNA molecules alone generally cannot get into living cells, AOC 1001 makes use of an antibody that attaches to the transferrin receptor 1 (TfR1), a protein that sits on the surface of cells. This induces a process through which the siRNA can be imported into cells to act on its target mRNA.

“AOC 1001 is designed to address the root cause of DM1 and has the potential to be a first-in-class treatment for people living with this debilitating rare disease,” Boyce said.

Cell and animal studies have shown that AOC 1001 may deliver siRNAs efficiently to muscle cells and reduce the levels of the DMPK mRNA.

Earlier this month, the FDA gave Avidity a green light to start a Phase 1/2 clinical trial, called MARINA, that will primarily evaluate the safety and tolerability of different doses of AOC 1001 in adult DM1 patients. Measures of mobility and muscle strength, as well as whether AOC 1001 can decrease the levels of DMPK mRNA, also will be assessed.