FDA Approves BioMarin’s Voxzogo for Young Children with Dwarfism

Pictured: FDA sign at its office in Washington, DC

Pictured: FDA sign at its office in Washington, DC

JHVEPhoto/Getty Images

The label for the achondroplasia drug, which promotes endochondral bone growth, now covers children under five years of age with the rare genetic disease causing the most common form of dwarfism.

Pictured: FDA sign outside its headquarters, DC/iStock, JHVEPhoto

The FDA on Friday approved BioMarin Pharmaceutical’s supplemental New Drug Application for its achondroplasia drug Voxzogo (vosoritide), authorizing its use in children under five years of age with open growth plates.

Voxzogo is the only approved therapy for children with achondroplasia, a rare and genetic disease that causes the most common form of dwarfism. Friday’s approval makes the drug available to younger children and allows patients and physicians to initiate treatment earlier, potentially leading to a much greater effect.

Even with the expanded label, Voxzogo remains under accelerated approval, initially granted in November 2021 for pediatric patients aged five and above, based on its strong and positive effects on annualized growth velocity. The therapy’s continued approval may be dependent on additional confirmatory studies that verify its clinical benefit in this indication.

Achondroplasia is characterized by the slow formation of bone tissue, resulting in the hallmark disproportionately short stature among patients. The condition is due to a gain-of-function mutation in the FGFR3 gene, a negative regulator of bone growth.

Voxzogo is an analog of the C-type natriuretic peptide and works as a positive regulator of a signaling pathway downstream of FGFR3, promoting endochondral bone growth.

To support its label expansion, BioMarin provided data from a Phase II trial that administered Voxzogo in pediatric patients aged five years and younger. The study demonstrated that the drug had a similar efficacy and safety profile in the younger and older patient subpopulations.

Last month, at the 2023 Meeting of the European Society for Pediatric Endocrinology, BioMarin presented data from a Phase II open-label study, demonstrating additional long-term benefit data for Voxzogo. Over a four-year period, children aged two years and older treated with BioMarin’s drug saw mean height gain of 6.3 to 7.8 centimeters compared to untreated patients, while patients who started treatment under the age of two years grew taller by 3.5 to 3.9 centimeters.

BioMarin intends to use this open-label study, as well as other ongoing trials, to fulfill its post-marketing requirement under the FDA’s accelerated approval pathway, according to the company.

Voxzogo’s label expansion comes just months after BioMarin won the FDA’s approval for its hemophilia A gene therapy roxaparvovec-rvox, carrying the brand name Roctavian. The one-time, single-dose infusion is the first authorized gene therapy for hemophilia A.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. He can be reached at tristan@tristanmanalac.com or tristan.manalac@biospace.com.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.