Rare Daily Staff

The Japanese Ministry of Health, Labor and Welfare granted marketing approval to BioMarin Pharmaceutical’s Voxzogo for injection, indicated for the treatment of achondroplasia in children of all ages, whose growth plates are not closed.

Achondroplasia, the most common form of skeletal dysplasia leading to disproportionate short stature, is characterized by slowing of endochondral bone growth, which results in disproportionate short stature and disordered architecture in the long bones, spine, face, and base of the skull.  This condition is caused by a gain of function mutation in the fibroblast growth factor receptor 3 gene (FGFR3), a negative regulator of bone growth. More than 80 percent of children with achondroplasia have parents of average stature and have the condition as the result of a spontaneous change in the gene. Around 25 percent of individuals living with achondroplasia have open growth plates. The worldwide incidence rate of achondroplasia is about one in 25,000 live births.

 Voxzogo (vosoritide), a modified C-type natriuretic peptide (CNP), directly targets the underlying pathophysiology of achondroplasia by down regulating fibroblast growth factor receptor 3 (FGFR3) signaling and consequently promoting endochondral bone formation.

“We are delighted to offer children in Japan of all ages with achondroplasia access to a treatment option that addresses the underlying genetic mechanism of the condition,” said Jean-Jacques Bienaimé, chairman and CEO of BioMarin. “CNP was discovered as a natural regulator of bone growth in Japan in 1990 so we are especially proud to be able to offer a therapeutic choice there.”

Japan accounts for approximately half of the 1,500-patient opportunity in the Asia Pacific region. The MHLW in Japan based its decision on the outcomes of a global phase 3 randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of Voxzogo and the long-term extension of this phase 3 study as well as data from patients participating in a phase 2 randomized, double-blind, placebo-controlled clinical trial evaluating the safety and efficacy of Voxzogo in infants and young children with achondroplasia, age 0 to < 60 months.

The most common adverse reactions, occurring in greater than or equal to 5 percent of patients treated with Voxzogo and at a percentage greater than placebo in the phase 3 study are injection site reactions (including redness, itching, swelling, bruising, rash, hives, pain), vomiting, joint pain, decreased blood pressure, gastroenteritis, diarrhea, dizziness, ear pain, influenza, fatigue, seasonal allergy, and dry skin.

In 2021, Voxzogo received approvals in the United States, Europe, and Brazil. In the United States, Voxzogo is used to increase linear growth in children with achondroplasia who are 5 years of age and older with open growth plates (epiphyses). It is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials.

Photo: Jean-Jacques Bienaimé, chairman and CEO of BioMarin

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