Three-dimensional craniofacial imaging in children with achondroplasia treated with vosoritide.

Purpose: Achondroplasia is the most common form of disproportionate short-stature skeletal dysplasia. Constitutively activated FGFR3 signaling disrupts endochondral ossification, affecting long bone growth, as well as the craniofacial skeleton and skull base. This results in the distinctive craniofacial features of achondroplasia, such as midface hypoplasia and nasal bridge depression. Vosoritide is a precision medicine that acts through the C-type natriuretic peptide pathway to counteract overactive FGFR3 signaling, including its inhibitory effects on chondrocyte differentiation and proliferation. The aim of this study was to investigate the potential effects of vosoritide treatment on the craniofacial skeleton in achondroplasia. Methods: We used longitudinal 3D facial surface imaging in children aged 5 to 10 years receiving vosoritide to test for differences in face shape over the course of treatment. We used nonlinear registration to standardize a dense measurement of all facial meshes. Finally, we defined the achondroplasia phenotype by scoring participant faces based on their shape similarity to the distinctive facial presentation of achondroplasia. Results: We measured the change in achondroplasia score for all participants recruited in this study. Using a linear mixed model approach to account for individual differences, we detected a small but significant reduction in the achondroplasia phenotype score over the course of vosoritide treatment. Conclusion: Our findings indicate that vosoritide treatment leads to a measurable improvement in facial phenotype in achondroplasia, highlighting its potential utility beyond enhancing linear growth. We discuss the role of pathway-disrupting medications, such as vosoritide, in addressing the broader spectrum of medical issues experienced by children with achondroplasia.