The Food and Drug Administration (FDA) has granted accelerated approval to Voxzogo (vosoritide) injection, a C-type natriuretic peptide analogue, to increase linear growth in patients 5 years of age and older with achondroplasia and open epiphyses.

The approval was based on data from a multicenter, randomized, double-blind, placebo-controlled, phase 3 study (ClinicalTrials.gov Identifier: NCT03197766) that evaluated the efficacy and safety of vosoritide in 121 children aged 5 to 14.9 years with genetically-confirmed achondroplasia. Patients were randomly assigned 1:1 to receive vosoritide subcutaneously once daily or placebo for 52 weeks. The primary endpoint was the change from baseline in mean annualized growth velocity.

Findings demonstrated that treatment with vosoritide met the primary endpoint resulting in a placebo-adjusted increase from baseline in growth velocity of 1.57cm/year (95% CI, 1.22-1.93; P <.0001). The results were reported to be consistent across all predefined subgroups analyzed including sex, age group, Tanner stage, baseline height Z-score, and baseline annualized growth velocity. 

Upon completion of the 52-week phase 3 study, patients were eligible to enroll into an open-label extension study (ClinicalTrials.gov Identifier: NCT03424018). Among the patients who had 2 years of follow-up since randomization, the improvement in annualized growth velocity was maintained.


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“Achondroplasia is a lifelong genetic condition resulting from the disordered skeletal architecture caused by impaired endochondral bone growth throughout childhood,” said Lynda Polgreen, MD, an investigator in clinical trials for Voxzogo and an Investigator at The Lundquist Institute at Harbor-UCLA Associate Professor at David Geffen School of Medicine, UCLA. “This approval is an important milestone representing the first time that physicians will be able to offer a therapy targeted at the root cause of the condition for families of children with achondroplasia aged 5 and older.”

The most common adverse reactions (less than 10%) observed with vosoritide were injection site erythema, injection site swelling, vomiting, injection site urticaria, arthralgia, decreased blood pressure, and gastroenteritis. To reduce the risk of low blood pressure, it is recommended that patients be well hydrated and have adequate food intake prior to treatment administration.

Voxzogo is supplied as a 0.4mg, 0.56mg, or 1.2mg lyophilized powder in single-dose vials for reconstitution. The product is expected to be available by mid- to late- December 2021.

References

  1. BioMarin receives FDA approval for Voxzogo (vosoritide) for injection, indicated to increase linear growth in children with achondroplasia aged 5 and up with open growth plates. News release. BioMarin Pharmaceutical Inc. Accessed November 19, 2021. https://www.prnewswire.com/news-releases/biomarin-receives-fda-approval-for-voxzogo-vosoritide-for-injection-indicated-to-increase-linear-growth-in-children-with-achondroplasia-aged-5-and-up-with-open-growth-plates-301429145.htm
  2. FDA approves first drug to improve growth in children with most common form of dwarfism. News release. US Food and Drug Administration. Accessed November 19, 2021. https://www.prnewswire.com/news-releases/fda-approves-first-drug-to-improve-growth-in-children-with-most-common-form-of-dwarfism-301429137.html.
  3. Voxzogo. Package Insert. BioMarin Pharmaceutical Inc.; 2021. Accessed November 19, 2021. https://pages.bmrn.com/rs/424-CBN-212/images/prescribing_information.pdf.