Ascendis shares two-year YUVIWEL data at ISDS 2026

Ascendis Pharma has announced that two-year data from the pivotal ApproaCH Trial of navepegritide (TransCon CNP) in children with achondroplasia will be presented as an oral at the International Skeletal Dysplasia Society meeting in Toronto from 26 to 29 August 2026. The presentation, given by Carlos Bacino of Baylor College of Medicine and Texas Children's Hospital, covers the open-label extension of the study through Week 104.

The dataset is the first substantial long-term readout since the US Food and Drug Administration approved navepegritide under the brand name YUVIWEL in February 2026 for paediatric patients aged two and over with achondroplasia with open epiphyses. The FDA approval makes YUVIWEL the first approved CNP-based prodrug for the condition in the United States.

Clinical profile

Aimee Shu, chief medical officer at Ascendis Pharma, said the long-term data "reinforces the benefits seen in clinical trials of once-weekly TransCon CNP, which have ranged from durable improvements in height to improvements in lower-extremity alignment, body proportionality, spinal canal dimensions, muscle function, and physical functioning, with a safety and tolerability profile similar to placebo and a low rate of injection site reactions."

The accompanying poster at ISDS addresses the methodology for estimating injection site reaction risk when indirect treatment comparison is not considered suitable, a practically important statistical issue for payer submissions in a competitive rare-disease market.

Achondroplasia, caused by a gain-of-function variant in fibroblast growth factor receptor 3 (FGFR3), is estimated to affect more than 250,000 people worldwide. Beyond the well-recognised skeletal phenotype, FGFR3 overactivation in non-bone tissues produces neurological, cardiorespiratory, and muscular complications that accumulate across childhood and into adulthood. Ascendis frames YUVIWEL's mechanism, continuous CNP receptor engagement that dampens aberrant FGFR3 signalling, as addressing this broader systemic burden.

Regulatory outlook and competitive context

European approval remains outstanding. Ascendis's Marketing Authorisation Application for YUVIWEL is under review by the European Medicines Agency, with a decision anticipated in the fourth quarter of 2026. A positive opinion would open access to one of the larger commercial markets for rare skeletal dysplasias and would follow a regulatory path comparable to that already established by the FDA.

The achondroplasia treatment landscape has become more competitive over the past three years. BioMarin's vosoritide, approved in both the United States and Europe as a daily subcutaneous injection, was the first targeted therapy to reach the market in this indication. YUVIWEL's once-weekly dosing and the breadth of endpoints covered in the ApproaCH Trial are positioned by Ascendis as differentiators, though head-to-head data against vosoritide have not been disclosed. Payers and health technology assessment bodies are likely to scrutinise comparative evidence closely before granting broad reimbursement, particularly given the chronic and paediatric nature of treatment.

Investors will be watching the ISDS oral presentation for the underlying growth velocity and safety numbers at two years, which will inform both the EMA assessment and early commercial uptake in the United States following February's approval.