Safe and persistent growth-promoting effects of vosoritide in children with achondroplasia: 2-year results from an open-label, phase 3 extension study

Genet Med. 2021 Dec;23(12):2443-2447. doi: 10.1038/s41436-021-01287-7. Epub 2021 Aug 2.


Purpose: Achondroplasia is caused by pathogenic variants in the fibroblast growth factor receptor 3 gene that lead to impaired endochondral ossification. Vosoritide, an analog of C-type natriuretic peptide, stimulates endochondral bone growth and is in development for the treatment of achondroplasia. This phase 3 extension study was conducted to document the efficacy and safety of continuous, daily vosoritide treatment in children with achondroplasia, and the two-year results are reported.

Methods: After completing at least six months of a baseline observational growth study, and 52 weeks in a double-blind, placebo-controlled study, participants were eligible to continue treatment in an open-label extension study, where all participants received vosoritide at a dose of 15.0 μg/kg/day.

Results: In children randomized to vosoritide, annualized growth velocity increased from 4.26 cm/year at baseline to 5.39 cm/year at 52 weeks and 5.52 cm/year at week 104. In children who crossed over from placebo to vosoritide in the extension study, annualized growth velocity increased from 3.81 cm/year at week 52 to 5.43 cm/year at week 104. No new adverse effects of vosoritide were detected.

Conclusion: Vosoritide treatment has safe and persistent growth-promoting effects in children with achondroplasia treated daily for two years.

Publication types

  • Clinical Trial, Phase III
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Achondroplasia* / drug therapy
  • Achondroplasia* / genetics
  • Child
  • Double-Blind Method
  • Humans
  • Natriuretic Peptide, C-Type* / analogs & derivatives
  • Natriuretic Peptide, C-Type* / therapeutic use
  • Treatment Outcome


  • Natriuretic Peptide, C-Type
  • vosoritide