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 report in scientific testing. That effort has come to an finish.
PTC has withdrawn its software looking for regulatory approval for the drug ataluren, model identify Translarna, the corporate introduced after Thursday’s market shut. In line with PTC, the regulator mentioned that primarily based on its overview thus far, the information within the submission are unlikely to point out sufficient efficacy to assist regulatory approval. The uncommon illness drug developer elaborated a bit extra in a letter to the U.S. Duchenne neighborhoodsaying 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 scientific 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 nonsense 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. No less than, that’s the way it’s purported to work.
Translarna failed in Section 2 testing. However, PTC superior Translarna to Section 3. In 2015, PTC introduced the drug failed this placebo-controlled research. Nonetheless, the corporate pressed ahead with an FDA submission primarily based 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 may be ample knowledge to assist a typical advertising and marketing authorization. In 2023 and 2024, PTC disputed a destructive 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.
Although Translarna has not been commercially accessible 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 certainly one of two PTC medicine for Duchenne. The corporate additionally markets Emflaza, which is authorized within the U.S. however not in Europe. The way in which Emflaza works in Duchenne shouldn’t be understood however this drug is a corticosteroid that reduces irritation. Translarna and PTC are PTC’s prime 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 continues to be accessible 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 authorized 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 authorized 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 continues to be looking for a path ahead for vatiquinone, a drug developed for the uncommon neuromuscular dysfunction Friedreich’s ataxia. The FDA issued a full response letter for this drug final August. PTC had submitted a brand new drug software regardless of the small molecule’s failure in Section 3 testing.
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