PTC pulls file for Duchenne therapy on FDA feedback
PTC Therapeutics' CEO, Matthew Klein.
PTC Therapeutics has abandoned its latest attempt to secure FDA approval for Duchenne muscular dystrophy (DMD) treatment Translarna, after the FDA said it was unlikely to approve the drug based on the submitted data.
In a statement, PTC's chief executive, Matthew Klein, said the company had decided to pull the filing for Translarna (ataluren) as a treatment for nonsense mutation DMD after the FDA said it was "unlikely to meet the agency's threshold of substantial evidence of effectiveness."
The latest setback looks like it could finally spell the end for Translarna in the US, after around a decade of attempts by PTC to bring it to market there. Its first attempt resulted in a refusal-to-file (RTF) letter in 2016, which was successfully appealed, but nevertheless followed by a rejection by the FDA in 2017.
After years of discussion and debate with the regulator, and various additional clinical trials, PTC resubmitted Translarna in 2024.
The drug was approved in Europe in 2014, but in 2024, the European Commission decided not to renew its conditional marketing authorisation after multiple reviews of its safety and efficacy.
"We have worked tirelessly for over two decades to develop a safe and effective therapy for boys and young men affected by nonsense mutation DMD in the US, and are disappointed that FDA approval cannot be achieved," said Klein.
In a letter to the DMD community in the US, PTC said "differences in data interpretation" between the company and the FDA could not be resolved, adding that it would be deciding in the next few weeks what the implications would be on the supply of ataluren for those currently receiving therapy.
"We understand that this outcome is devastating for the [patient] community, the families who have participated in clinical trials for almost 20 years, and the families who continue to wait for a treatment option that addresses the underlying cause of nonsense mutation Duchenne muscular dystrophy."
In its third-quarter 2025 results, PTC reported sales of around $50 million for Translarna, down from $72 million a year earlier. The company's other DMD therapy – steroid-based Emflaza (deflazacort) – is also in decline after losing patent protection.
PTC will now have to focus its attention on the rollout of Sephience (sepiapterin), its new treatment for people living with the rare disorder phenylketonuria (PKU), in the US and Europe. Third-quarter 2025 sales were around $20 million.
Its pipeline also includes Novartis-partnered votoplam for Huntington's disease – which generated mid-stage data last year – and vatiquinone for Friedreich's ataxia, which was turned down by the FDA in 2025 with a request for more efficacy data.
