PTC Therapeutics (NASDAQ:PTCT) saw its share price decline about 4% in after-hours trading on Thursday after the company disclosed it had withdrawn its resubmission of a New Drug Application (NDA) for Translarna, intended to treat nonsense mutation Duchenne muscular dystrophy (DMD).
The decision to pull the filing came after the U.S. Food and Drug Administration provided feedback indicating that the data included in the NDA resubmission were "unlikely to meet the Agency’s threshold of substantial evidence of effectiveness to support approval" for the medicine.
In a company statement, PTC’s chief executive reflected on the setback and the long-running effort to develop the treatment. The statement said:
"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," said Matthew B. Klein, M.D., Chief Executive Officer of PTC Therapeutics.
Translarna is described by the company as a protein restoration therapy. It is designed to allow the production of functioning protein in patients whose genetic disorder is caused by a nonsense mutation. The clinical mechanism cited for DMD is that such mutations can prematurely stop the synthesis of essential proteins, including dystrophin, which is critical in Duchenne muscular dystrophy.
Withdrawing the NDA resubmission marks a significant interruption to PTC’s plans to obtain U.S. approval for Translarna after years of development work on the compound. The company framed the move as a response to the FDA's assessment of the evidence provided in the application materials.
The announcement and the attendant market reaction highlight immediate investor sensitivity in the biotechnology and pharmaceutical sectors when regulatory reviews signal that submitted clinical data may not meet approval standards. The company has not indicated further regulatory steps in the announcement summarizing the withdrawal.
Context and implications: The withdrawal closes the current regulatory pathway for Translarna in the U.S. based on the resubmitted NDA, and will require PTC to reassess any future approach in light of the FDA's stated evaluation of the submitted evidence.