Vosoritide
Vosoritide (Voxzogo), C-type natriuretic peptide analogue
Written by Aaron CuhaReviewed Sep 2026
Also known as: Voxzogo, BMN 111, CNP analogue
A C-type natriuretic peptide analogue approved for achondroplasia on a randomised phase 3. It increases growth velocity by roughly 1.6 cm a year, and nobody knows the effect on final adult height.
Overview
Vosoritide is the clearest example on this site of a peptide designed from a precise understanding of a single mutation. Achondroplasia is caused by a gain-of-function mutation in FGFR3 that over-suppresses growth plate cartilage. C-type natriuretic peptide signals through a different receptor that antagonises that same pathway downstream. So supplying a stabilised analogue of it counteracts the mutation at the point where it acts.
The randomised phase 3 in children showed increased annualised growth velocity, and it was approved on that basis.
The honest limitation is important and is why this page reads the way it does. The trial measured growth velocity over a year, not final adult height, and those are different outcomes. A child who grows faster for a year has not necessarily ended up taller as an adult.
Mechanism of action
A 39-amino-acid analogue of C-type natriuretic peptide, modified to resist degradation by neutral endopeptidase, which destroys the native peptide within minutes. It binds natriuretic peptide receptor B, raising cyclic GMP and activating protein kinase G, which inhibits the RAF and MEK and ERK cascade at the level of RAF-1. In achondroplasia, an activating FGFR3 mutation drives that same MAPK cascade too hard and suppresses chondrocyte proliferation in the growth plate. So vosoritide works by braking the pathway the mutation over-accelerates, which is antagonism downstream of the defect rather than correction of it.
Human evidence
A randomised double-blind placebo-controlled phase 3 with a positive growth velocity result, plus extension data. No final adult height outcome.
- Randomised, double-blind, placebo-controlled, multicentre phase 3 in children with achondroplasia and open epiphyses.
- Annualised growth velocity increased against placebo, which is the basis of the approval.
- Requires a daily subcutaneous injection in children, which is a real adherence burden over the years of treatment involved.
- Injection site reactions and transient decreases in blood pressure are the expected adverse effects, the latter following directly from natriuretic peptide receptor activation.
- Final adult height was not the trial endpoint and remains unestablished.
What this does not tell you: Growth velocity over one year is a surrogate for the outcome families care about, which is adult height and function. Faster growth for a period can reflect a shifted trajectory or an earlier one, and distinguishing those requires following children to skeletal maturity. It is also worth saying that achondroplasia is not a disease in the view of many people who have it, and that the medical complications worth treating, such as foramen magnum stenosis and sleep apnoea, are not the same thing as height.
Reading the research record
This is a good page to read next to the growth hormone secretagogues elsewhere on this site, because it shows what a precisely targeted peptide looks like. The mutation is known, the pathway is known, the counteracting receptor is known, and the drug was engineered to hit it. That is a different category of evidence from a peptide sold because it raises a hormone that declines with age.
The surrogate endpoint problem still applies, and it applies here as strongly as anywhere. Growth velocity is not adult height, and the site's position is that an approved drug on a surrogate endpoint is an approved drug on a surrogate endpoint.
The evidence, charted
Fig. 1 · evidence composition
1of 1 citation (100%) is in people
Every citation cited here is Human work; no other study type is cited on this page. This count is of our own citation list and understates any literature larger than the sources we cite.
Fig. 2 · evidence over time
Every citation here was published in 2020.
Too few distinct publication years on this page to plot as a timeline. The newest citation on file is from 2020, more than five years ago; the published record may have gone quiet.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four jurisdictions shown. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Key studies & citations
- Human2020
Once-daily, subcutaneous vosoritide therapy in children with achondroplasia: a randomised, double-blind, phase 3, placebo-controlled, multicentre trial
The pivotal randomised double-blind placebo-controlled phase 3 in children with achondroplasia, showing increased annualised growth velocity on daily subcutaneous vosoritide. This is the trial the approval rests on, and its endpoint is growth velocity rather than final adult height.
The Lancet
Frequently asked questions
Does vosoritide make children with achondroplasia taller as adults?
Unknown. The randomised phase 3 measured annualised growth velocity over a year and found it increased, and that is what the approval rests on. Final adult height requires following children to skeletal maturity and was not established at approval.
How does it work when the problem is a genetic mutation?
It does not fix the mutation. The FGFR3 mutation over-activates a growth-suppressing signalling cascade, and C-type natriuretic peptide signalling inhibits that same cascade further downstream. So the drug pushes back against the mutation's effect rather than correcting its cause.
Why does it need a daily injection?
Because its half-life is roughly 20 to 30 minutes even after engineering for resistance to the enzyme that destroys the natural peptide. That is a substantial practical burden when the patient is a child and treatment runs for years.