Source: FDA label
| Molecular formula | C176H290N56O51S3 |
|---|---|
| Molecular weight | 4103 g/mol |
| Registered trials | 18 |
| PubChem CID | 119058036 |
| Brand names | VOXZOGO 0.4mg, VOXZOGO 0.56mg, VOXZOGO 1.2mg |
Mechanism of Action
12.1 Mechanism of Action In patients with achondroplasia, endochondral bone growth is negatively regulated due to a gain of function mutation in fibroblast growth factor receptor 3 ( FGFR3 ). Binding of vosoritide to natriuretic peptide receptor-B (NPR-B) antagonizes FGFR3 downstream signaling by inhibiting the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the mitogen-activated protein kinase (MAPK) pathway at the level of rapidly accelerating fibrosarcoma serine/threonine protein k
Parents of children with achondroplasia often ask whether any treatment can support bone growth during childhood. Vosoritide, sold as VOXZOGO, is one such option, and understanding how it works and what it has been studied for can help frame conversations with a care team.
Key takeaways
- Vosoritide (VOXZOGO) is approved to increase linear growth in pediatric patients with achondroplasia who still have open growth plates.
- It works by acting on a growth signaling pathway that is disrupted by the genetic mutation underlying achondroplasia.
- The approval is an accelerated approval based on annualized growth velocity, with confirmatory trials pending.
- More than a dozen clinical trials have studied vosoritide, including extensions into related growth conditions.
- Reported side effects in available data relate to product handling and prescribing rather than a specific physical reaction.
What Vosoritide Is
Vosoritide is a C type natriuretic peptide (CNP) analog, a lab-made version of a peptide the body uses to help regulate bone growth. In achondroplasia, a mutation in the FGFR3 gene overactively suppresses bone growth signaling. Vosoritide binds to a receptor called NPR-B and interferes with that overactive signaling pathway, allowing growth plate activity to proceed more normally.
What Vosoritide Is Approved For
VOXZOGO is indicated to increase linear growth in pediatric patients with achondroplasia who still have open epiphyses, meaning their growth plates have not yet closed. It is marketed in three dosage strengths: VOXZOGO 0.4mg, 0.56mg, and 1.2mg. The indication carries accelerated approval status, based on improvement in annualized growth velocity, and continued approval may depend on results from confirmatory trials. The label does not carry a boxed warning.
What the Evidence Shows
Vosoritide has been studied across 18 registered clinical trials. Ongoing work includes a long-term extension study evaluating vosoritide in children with hypochondroplasia, currently enrolling by invitation. A separate Phase 2/3 trial is recruiting to compare an investigational compound against vosoritide in children with achondroplasia, and another study is assessing vosoritide for growth deficits in MPS IVA and VI.
Reported Side Effects
Reports submitted to the FDA's adverse event system for vosoritide have centered on dose calculation errors, product preparation errors, and product prescribing errors, each reported once in the available data. These figures reflect raw report counts, not confirmed incidence or proven causation. The pattern points toward handling and administration processes rather than a specific bodily side effect signal in this dataset.
FAQ
What is vosoritide used for?
Vosoritide, sold under the brand name VOXZOGO, is approved to increase linear growth in children with achondroplasia who still have open growth plates. It works by targeting a growth signaling pathway affected by the genetic cause of achondroplasia. The approval was granted on an accelerated basis pending confirmatory trial results.
How does vosoritide work?
Vosoritide is a C type natriuretic peptide analog that binds to the NPR-B receptor. This action counters overactive signaling from a mutated FGFR3 gene, which normally suppresses bone growth in people with achondroplasia. By interfering with that suppression, vosoritide supports more typical growth plate activity.
Is vosoritide FDA approved?
Yes, vosoritide is FDA approved under the brand name VOXZOGO. The approval covers pediatric patients with achondroplasia who have open epiphyses. It was granted through the accelerated approval pathway based on improvements in annualized growth velocity.
Does vosoritide carry a boxed warning?
No, the current VOXZOGO label does not include a boxed warning.
What side effects have been reported with vosoritide?
Available adverse event reports for vosoritide list dose calculation errors, product preparation errors, and product prescribing errors, each with a single report. These are raw report counts rather than confirmed side effects or proof of a causal link. The reports point more toward handling and prescribing issues than a specific physical reaction.
This page is an editorial information resource. It does not sell, prescribe, or recommend any medication.
Content is editorial information, not medical advice. Talk to your doctor before any treatment decision.
Sources: FDA label (DailyMed) for VOXZOGO FDA FAERS adverse event reports ClinicalTrials.gov PubChem CID 119058036
Updated 2026-09-19