PTC Therapeutics has withdrawn its new approval application for Translarna (ataluren) for the treatment of Duchenne muscular dystrophy (DMD) caused by a nonsense mutation following negative feedback from the US Food and Drug Administration (FDA).[1] The FDA said the data submitted in the application "highly likely do not meet its standard of "substantial evidence of efficacy" required for drug approval.[1][3] Translarna has been in development for more than two decades, and this withdrawn application represents another major setback in its development in the US.[1][3] The drug was already rejected in the US in 2016 and again in 2017, when the FDA demanded additional studies to prove its effectiveness.[1] In Europe, Translarna received conditional approval in 2014, but the European Commission issued a negative opinion on its renewal in 2024.[1] The drug remains available in the UK through the National Health Service.[1] Approximately 130 DMD patients in the US have been treated long-term with Translarna, some for more than ten years.[2]