Real-world Outcome of Vosoritide Treatment in Children With Achondroplasia: A 12-month Retrospective Observational Study

Abstract Context Vosoritide is the first approved targeted therapy for achondroplasia (ACH) based on increased annualized growth velocity in clinical trials. The aim of our project was an assessment of the real-world setting and treatment with vosoritide. Design This was a 12-month, retrospective observational study on an inception cohort of 34 patients with ACH treated with vosoritide. Patients and Methods Thirty-four patients with ACH (22 males; aged 2.8 to 15.3 years at treatment initiation) who received vosoritide treatment for at least 12 months at a specialized clinic for skeletal dysplasia in childhood were included in the analysis. Auxological measurements at baseline and after 12 months of therapy were converted into disease-specific (ACH) and general population Centers for Disease Control and Prevention (CDC) z-scores. Physical function assessed by a 6-minute walk test was converted into z-scores and compared to an unaffected reference cohort. Results After 12 months of treatment, both ACH and CDC height z-scores showed significant increases, with mean changes (mean ± SD) of 0.52 ± 0.35 and 0.38 ± 0.44, respectively (both P .0001). The annualized growth velocity exceeded reference values for untreated children with ACH. No significant changes were observed in body mass index, upper to lower body segment ratio (sitting height/height), or head circumference. The 6-minute walking distance improved, with z-scores increasing from −2.00 ± 1.12 to −1.39 ± 1.23 (P = .0215). Conclusion In a real-world setting, children with ACH showed significant improvements in growth and physical function after 12 months of treatment with vosoritide.