Leg bowing in children with achondroplasia is not a cosmetic concern. Severe genu varum drives chronic pain, restricts mobility, and frequently ends in orthopedic surgery, which makes the radiographic signal from the ApproaCH trial’s Week 104 data worth close attention. In the subgroup of children who entered the trial with a baseline tibial-femoral angle at or above 5 degrees, those who received TransCon CNP throughout the full two years saw a mean TFA reduction of 3.8 degrees. Those who crossed over from placebo at Week 52 and had the most severe baseline bowing (mean TFA 18.2 degrees) achieved that same 3.8-degree reduction in just the 52-week open-label extension period. The trajectory did not plateau at one year; it kept moving.
The trial design is worth parsing. ApproaCH enrolled 84 children aged 2 to 11 in a randomized, double-blind, placebo-controlled structure for the first 52 weeks, then rolled all participants into an open-label extension through Week 104. That late-switcher cohort is analytically useful: their placebo period allowed TFA to drift upward slightly before treatment began, so the subsequent correction in a single year offers something close to an internal comparison. Meanwhile, children on active drug since the start showed that TFA Z-scores continued declining from 3.62 at baseline to 2.96 at Week 104, suggesting the drug is moving lower-limb alignment progressively rather than establishing an early correction and stalling. Fibula-to-tibia length ratio stayed stable across the extension, indicating the growth occurring in the lower leg remained proportional rather than segmentally distorted.
The safety read at two years remains clean. Injection-site reactions were all mild, no symptomatic hypotension occurred, and bone age did not accelerate, a concern that follows any growth-modulating therapy in a pediatric population. No child discontinued treatment due to adverse events. YUVIWEL (navepegritide) received FDA accelerated approval on February 27, 2026, with the indication centered on increasing linear growth, so these radiographic alignment data sit outside the approved label claim but directly address the surgical burden families actually face.
Ascendis is presenting these findings at ICCBH 2026 while the European Medicines Agency reviews YUVIWEL’s marketing authorisation application, with a decision anticipated in Q4 2026. The EMA review is the immediate pressure point. European regulators will be looking at the totality of the clinical package, and two-year radiographic data showing persistent correction of a complication that leads to surgery strengthens that package in ways that annualized growth velocity alone cannot. Track whether EMA requests additional skeletal outcomes data or accepts the current dossier as filed, because that determination sets the scope of the European label and, by extension, how payers across those markets define the therapeutic benefit they are willing to reimburse.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
