For greater than a decade, PTC Therapeutics has been going backwards and forwards with the FDA to discover a path ahead for a Duchenne muscular dystrophy drug with spotty monitor file in medical testing. That effort has come to an finish.
PTC has withdrawn its utility searching for regulatory approval for the drug ataluren, model identify Translarna, the corporate introduced after Thursday’s market shut. Based on PTC, the regulator mentioned that based mostly on its evaluation up to now, the information within the submission are unlikely to indicate sufficient efficacy to assist regulatory approval. The uncommon illness drug developer elaborated a bit extra in a letter to the U.S. Duchenne neighborhood, saying there have been variations within the interpretation of the information submitted for the drug and these variations can’t be resolved.
“Regardless of the proof of security and effectiveness demonstrated throughout a number of medical research, FDA has shared that they view the information as inadequate to fulfill their threshold for approval,” the letter mentioned. “Accordingly, PTC has made the tough determination to withdraw the resubmission of the New Drug Utility for ataluren.”
The progressive muscle weak point of Duchenne stems from an inherited lack of dystrophin, a protein key to muscle perform. A so-called non-sense mutation within the gene that codes for dystrophin prematurely stops manufacturing of the protein, resulting in a shortened and non-functional model. Translarna, which was internally found by PTC, was developed as a protein restoration remedy. This oral small molecule is meant to allow a cell’s protein-making equipment to learn by way of the untimely cease sign, enabling formation of functioning dystrophin. At the least, that’s the way it’s alleged to work.
Translarna failed in Part 2 testing. Nonetheless, PTC superior Translarna to Part 3. In 2015, PTC introduced the drug failed this placebo-controlled research. Nonetheless, the corporate pressed ahead with an FDA submission based mostly on “the totality of the information.” The FDA turned down PTC’s submission in 2017 and has rebuffed the drugmaker’s subsequent efforts to hunt approval.
For some time, Translarna had higher luck in Europe. In 2014, European regulators granted the drug conditional advertising and marketing authorization, which requires annual renewal till there’s enough information to assist a normal advertising and marketing authorization. In 2023 and 2024, PTC disputed a unfavourable opinion by the European Fee’s Committee on Medicinal Merchandise for Human Use, which had concluded the drug’s profit was not confirmed and authorization shouldn’t be renewed. Final March, the fee lastly adopted the opinion and declined renewal.
Though Translarna has not been commercially out there within the U.S., a restricted variety of sufferers have had entry to this drug underneath the FDA’s expanded entry program. PTC’s letter mentioned that within the coming weeks, the corporate will decide the subsequent steps for the remaining provide of the drug for these presently receiving it.
Translarna is one among two PTC medication for Duchenne. The corporate additionally markets Emflaza, which is accredited within the U.S. however not in Europe. The way in which Emflaza works in Duchenne is just not understood however this drug is a corticosteroid that reduces irritation. Translarna and PTC are PTC’s high merchandise, collectively accounting for $315.6 million in income by way of the primary three quarters of 2025. However PTC faces monetary challenges forward. Translarna will present marginal income from the remaining markets the place the drug remains to be out there and Emflaza has already misplaced market exclusivity.
The subsequent highest contributor to PTC’s income is a brand new product, Sephience. Final summer season, this drug was accredited first in Europe after which the U.S. as a therapy for the uncommon metabolic illness phenylketonuria. Sephience accounted for $19.5 million in income within the third quarter of 2025. Kebilidi (Upstaza in Europe), a gene remedy accredited in 2024 as a therapy for an ultra-rare enzyme deficiency, accounted for $15.7 million in income within the first 9 months of 2025.
As for PTC’s pipeline, the corporate remains to be looking for a path ahead for vatiquinone, a drug developed for the uncommon neuromuscular dysfunction Friedreich’s ataxia. The FDA issued a whole response letter for this drug final August. PTC had submitted a brand new drug utility regardless of the small molecule’s failure in Part 3 testing.
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