The European Medicines Agency (EMA) has given American pharma company PTC Therapeutics the go-ahead on their drug ataluren, commonly referred to as Translarna. After initially agreeing not to pass the drug in January, the EMA has since reviewed its decision in favour of Translarna.

The drug targets nonsense mutations (nm) that result in forms of diseases including cystic fibrosis (CF) and Duchenne muscular dystrophy (DMD). Diagnosis of nonsense mutation CF (nmCF) and nonsense mutation DMD (nmDMD) occurs through a genetic test that screens particularly for genetic disorders with underlying nonsense mutations.

Nonsense mutations create premature stop signals in the translation of certain proteins, causing them to form incompletely rather than functionally. In the case of nmDMD, ataluren interacts with the ribosome unit responsible for translation of the protein dystrophin, which is found in muscles and is responsible in protecting muscles from injury.

The drug allows the ribosome to read past these nonsense premature stop signals, allowing the formation of full-length, fully-functioning protein dystrophin.

NmDMD occurs in 10-15 percent of the total DMD population, causing muscle damage and eventually total muscle loss of function in patients. Children aged five and older who are still able to walk are to gain the most from the use of ataluren.

Due to its specific targeting of nonsense mutations, the drug has potential to be highly successful in the treatment of nonsense mutation genetic disorders, potentially without unwarranted, dangerous side-effects thus far.

The orally-administered drug will be the only therapy of its kind on the market in the near future. Both the EMA as well as the U.S. Food and Drug Administration (FDA) have pushed for the product’s approval as it has been developed for the sole purpose of treating very specific, and rare medical conditions, hence designating it an ‘orphan drug’.

“Most of those diagnosed with Duchenne muscular dystrophy, usually before the age of five, will use a powered wheelchair before they are 12, will not have the muscle strength to pick up a glass of water by the age of 20 and will not live to see their 30th birthday.” said Robert Meadowcroft, chief executive of the Muscular Dystrophy Campaign.

The campaign is urging the approval for the drug for use in the UK by spring 2015.