Positive 52-Week Phase 2 Data for TransCon CNP/hGH in Achondroplasia

On April 8, 2026, Ascendis Pharma announced positive new 52-week data from its Phase 2 COACH Trial evaluating the combination of once-weekly TransCon CNP and once-weekly TransCon hGH in children with achondroplasia. The data demonstrated that the combination therapy accelerated benefits beyond linear growth, showing substantial improvements in arm span, spinal canal dimensions, and lower limb alignment. Specifically, treatment-naïve and previously treated children showed mean ACH-specific arm span Z-score improvements of +1.02 and +0.66, respectively. Additionally, improvements in interpedicular distance (IPD) were observed, suggesting a potential reduction in nerve compression. The combination therapy also enhanced the straightening of legs, with a mean change in tibial femoral angle (TFA) Z-score of -0.86 in treatment-naïve patients compared to -0.47 for monotherapy. All participants completed 52 weeks of treatment and remain on therapy, with no new safety concerns or acceleration of bone age reported. These results suggest the combination therapy could be a differentiated treatment for short stature in growth hormone-sufficient settings.