Vosoritide for Short Stature in Turner Syndrome

Turner syndrome (TS) is characterized by a missing whole or part of the second sex chromosome in a phenotypic female, resulting in short stature due to haploinsufficiency of the short-stature homeobox-containing (SHOX) gene. Growth hormone (GH) is an approved therapy for this condition, although not associated with GH deficiency, and benefits are modest. Vosoritide, a C-type natriuretic peptide (CNP) analog, targets chondrocytes within the growth plate leading to increased cell proliferation and hypertrophy. We hypothesize that patients with TS and short stature will respond to vosoritide treatment leading to increased growth velocity. This study will enroll pre-pubertal girls with TS who are either naïve to GH or have had a poor response to GH therapy. All subjects will be treated with vosoritide for 12 months and will be assessed for safety monitoring and improvement in height outcomes. Annualized growth velocity (AGV) on vosoritide will be compared to AGV in the 6-18 months prior to initiation of vosoritide based on historical data available in the medical record. Subjects with a positive response to therapy will be given the option to continue in the extension phase of the study during which they will continue to receive vosoritide until growth cessation.