PTC Therapeutics Withdraws FDA Application for Duchenne Drug Translarna After Decade-Long Effort

PTC Therapeutics announced February 12, 2026 that it has withdrawn the New Drug Application resubmission for Translarna (ataluren) for the treatment of nonsense mutation Duchenne muscular dystrophy following U.S. Food and Drug Administration feedback on the application review. The FDA shared that based on its review to date, the data in the NDA submission are unlikely to meet the Agency's threshold of substantial evidence of effectiveness to support approval of Translarna.

The withdrawal ends more than a decade of efforts by the Warren, N.J.-based company to secure FDA approval for the drug. According to the company, there were differences in the interpretation of the data submitted for the drug and these differences cannot be resolved. In a letter to the U.S. Duchenne community, PTC stated: "Despite the evidence of safety and effectiveness demonstrated across several clinical studies, FDA has shared that they view the data as insufficient to meet their threshold for approval."

The chief executive officer stated: "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 U.S. and are disappointed that FDA approval cannot be achieved."

Translarna is a protein restoration therapy designed to enable the formation of a functioning protein in patients with genetic disorders caused by a nonsense mutation. This oral small molecule is intended to enable a cell's protein-making machinery to read through the premature stop signal, enabling formation of functioning dystrophin.

The drug's clinical development faced significant challenges. Translarna failed in Phase 2 testing. Nevertheless, PTC advanced Translarna to Phase 3. In 2015, PTC announced the drug failed this placebo-controlled study. Still, the company pressed forward with an FDA submission based on "the totality of the data." The FDA turned down PTC's submission in 2017 and has rebuffed the drugmaker's subsequent efforts to seek approval.

Translarna had better regulatory success in Europe initially. In 2014, European regulators granted the drug conditional marketing authorization, which requires annual renewal until there is sufficient data to support a standard marketing authorization. In 2023 and 2024, PTC disputed a negative opinion by the European Commission's Committee on Medicinal Products for Human Use, which had concluded the drug's benefit was not confirmed and authorization should not be renewed. Last March, the commission finally adopted the opinion and declined renewal.

Even though Translarna has not been commercially available in the U.S., a limited number of patients have had access to this drug under the FDA's expanded access program. The company stated that in the coming weeks, it will determine the next steps for the remaining supply of the drug for those currently receiving it.

Translarna is one of two PTC drugs for Duchenne. The company also markets Emflaza, which is approved in the U.S. but not in Europe. The way Emflaza works in Duchenne is not understood but this drug is a corticosteroid that reduces inflammation. Translarna and Emflaza are PTC's top products, together accounting for $315.6 million in revenue through the first three quarters of 2025. Translarna will provide marginal revenue from the remaining markets where the drug is still available and Emflaza has already lost market exclusivity.

The next highest contributor to PTC's revenue is a new product, Sephience. Last summer, this drug was approved first in Europe and then the U.S. as a treatment for the rare metabolic disease phenylketonuria. Sephience accounted for $19.5 million in revenue in the third quarter of 2025. Kebilidi (Upstaza in Europe), a gene therapy approved in 2024 as a treatment for an ultra-rare enzyme deficiency, accounted for $15.7 million in revenue in the first nine months of 2025.

As for PTC's pipeline, the company is still trying to find a path forward for vatiquinone, a drug developed for the rare neuromuscular disorder Friedreich's ataxia. The FDA issued a complete response letter for this drug last August. PTC had submitted a new drug application despite the small molecule's failure in Phase 3 testing.

Duchenne muscular dystrophy primarily affects males and is a rare and fatal genetic disorder that results in progressive muscle weakness from early childhood and leads to premature death in the mid-20s due to heart and respiratory failure. It is a progressive muscle disorder caused by the lack of functional dystrophin protein. Dystrophin is critical to the structural stability of all muscles, including skeletal, diaphragm, and heart muscles. Patients with Duchenne can lose the ability to walk (loss of ambulation) as early as 10 years old, followed by loss of the use of their arms. Duchenne patients subsequently experience life-threatening lung complications, requiring the need for ventilation support, and heart complications in their late teens and 20s.