Global biopharma leader Ascendis Pharma's bid to bring its groundbreaking treatment for children with achondroplasia to the US has hit a temporary roadblock.  

The FDA has classified recent submissions as a major amendment, pushing the approval to its New Drug Application (NDA) for TransCon CNP (navepegritide), a treatment for children with achondroplasia, back three months to February 28, 2026. 

“We have responded to all outstanding requests from the FDA, including the request for a revised protocol for the post-marketing study, which we received as the lone item for discussion at our late-cycle meeting,” said Jan Mikkelsen, President and CEO of Ascendis Pharma.  

“We are committed to working diligently with the FDA to finalize elements of the post-marketing requirement, with the goal of bringing this innovative therapy to patients in the U.S. as soon as possible.” 

The delay comes as Ascendis Pharma and the FDA continue discussions on post-marketing requirements, a key step before potential U.S. approval of the therapy, which aims to address the growth challenges faced by children with achondroplasia.