The US Food and Drug Administration has granted orphan drug designation to Amsterdam Molecular Therapeutics for AMT-080, a gene therapy for the treatment of Duchenne muscular dystrophy.

A study showed that the gene therapy successfully restored dystrophin activity in affected human cells obtained from patients with Duchenne muscular dystrophy.

The company plans to start the clinical trials of AMT-080 by the end of 2012.

Duchenne muscular dystrophy is a neuromuscular disorder in which the production of functional dystrophin protein is blocked, resulting progressive muscle degeneration and death in young adulthood.

Orphan drug designation is granted to drugs that treat rare diseases affecting less than 200,000 people in the US.