FDA Approves First Treatment for Children with Achondroplasia

FDA recently approved Voxzogo injection for children five years of age and older with achondroplasia and open epiphyses. 

Achondroplasia is the most common form of dwarfism. Individuals living with achondroplasia have a genetic mutation that causes a specific growth regulation gene, fibroblast growth factor receptor 3, to become overly active. This overactive gene prevents normal bone growth. 

Voxzogo, a C-type natriuretic peptide (CNP) analog, represents a new class of therapy. The drug is a positive regulator of the signaling pathway downstream of FGFR3 that promotes endochondral bone growth.

Voxzogo is the first FDA-approved treatment for children with achondroplasia.

“Today’s approval fulfills an unmet medical need for more than 10,000 children in the United States and underscores the FDA’s commitment to help make new therapies available for rare diseases,” Theresa Kehoe, MD, director of the division of general endocrinology in the FDA’s Center for Drug Evaluation and Research, said in the announcement.

“With this action, children with short stature due to achondroplasia have a treatment option that targets the underlying cause of their short stature,” Kehoe continued. 

FDA based its decision on a double-blind, placebo-controlled Phase 3 study, which enrolled 121 participants five years and older to receive Voxzogo or placebo. 

Researchers measured participants’ annualized growth velocity at the end of the year. Patients who received the drug grew an average of 1.57 centimeters taller than those who received a placebo. 

The most common side effects of Voxzogo included injection site reactions, vomiting, and decreased blood pressure. With this approval, FDA also issued a Rare Pediatric Disease Priority Review Voucher (PRV).

Continued approval is contingent upon verification of clinical benefit in confirmatory studies, with the company intending to use the ongoing open-label extension studies to fulfill this post-marketing requirement.

Voxzogo is expected to become available in the US by next month. BioMarin will begin promoting Voxzogo immediately. 

“We thank the FDA for recognizing its value as the first therapeutic treatment option for children with achondroplasia,” Jean-Jacques Bienaimé, chairman and chief executive officer of BioMarin, said in a press release.

“We extend our gratitude to the community, clinical investigators and the children and their families, who participated and continue to participate in our comprehensive clinical research program as we continue to investigate the full potential of vosoritide,” Bienaimé continued.