FDA Approves First Drug for a Form of Dwarfism

The FDA has granted accelerated approval to BioMarin Pharmaceutical’s Voxzogo (vosoritide) injection to improve growth in children five years of age and older with achondroplasia, the most common form of dwarfism. People with achondroplasia have a genetic mutation that causes fibroblast growth factor receptor 3 to be overly active, which prevents normal bone growth.

Voxzogo works by binding to a specific receptor called natriuretic peptide receptor-B that reduces the growth regulation gene’s activity and stimulates bone growth.

Continued approval for this indication is contingent upon confirmatory studies. BioMarin is conducting ongoing open-label extension studies.

Lynda Polgreen, M.D.

“Achondroplasia is a lifelong genetic condition resulting from the disordered skeletal architecture caused by impaired endochondral bone growth throughout childhood,” Lynda Polgreen, M.D., 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, said in a statement. “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 five and older.”

The approval was based on the outcomes of a global phase 3 study evaluating the efficacy and safety of Voxzogo and the open-label extension of this phase 3 study. The study enrolled 121 children aged 5 to 14.9 years of age with achondroplasia. At 52 weeks, the mean improvement in annualized growth velocity (AGV) was 1.40 cm/year for the Voxzogo treated patients compared with -0.17 cm/year for those in the placebo arm.

In terms of safety, transient decreases in blood pressure have been observed with Voxzogo. The most common adverse reactions were injection site reactions, vomiting, joint pain, decreased blood pressure, gastroenteritis, diarrhea, dizziness, ear pain, influenza, fatigue, seasonal allergy, and dry skin.

The European Commission approved Voxzogo in August 2021, and regulatory reviews are under way in Japan, Brazil, and Australia.

Voxzogo is expected to be available in the United States by mid- to late-December.