Is vosoritide FDA-approved, and what does the research show?

What is vosoritide?

Vosoritide is a prescription drug, sold as Voxzogo, that increases growth in height in children with achondroplasia ¹. FDA calls achondroplasia "the most common form of dwarfism" and describes it as "a genetic condition that causes severely short stature and disproportionate growth" ². The average adult with the condition is about four feet tall, FDA says ².

The drug is a peptide, a short chain of amino acids, which are the building blocks of proteins ¹. It is an analog, an altered copy, of human C-type natriuretic peptide (CNP), which the label calls "a positive regulator" of bone growth ¹. Vosoritide has 39 amino acids: 37 from the human CNP sequence and two added at one end ¹. The label says the added pair is there "to convey resistance" to neutral endopeptidase, an enzyme that breaks peptides down ¹. The drug is made in bacteria by recombinant DNA technology, a way of having cells build a chosen protein ¹.

Is vosoritide FDA-approved?

Yes, for one use, by prescription. FDA approved Voxzogo (vosoritide) on November 19, 2021, under new drug application (NDA) 214938, held by BioMarin ³. Its marketing status is "Prescription" as of November 9, 2026, the date of the Drugs@FDA record's data ³.

The label says Voxzogo is "indicated to increase linear growth in pediatric patients with achondroplasia with open epiphyses" ¹. Linear growth is growth in height, and epiphyses are the growth plates of the bones ¹, ². FDA explains that open growth plates mean "these children still have the potential to grow" ². The label tells prescribers to stop the drug permanently "upon confirmation of no further growth potential, indicated by closure of epiphyses" ¹. The label names no other use, and none in adults ¹.

This is an accelerated approval. FDA describes that pathway as one that "allows for earlier approval of drugs that treat serious conditions and fill an unmet medical need, based on a surrogate or intermediate clinical endpoint" ². An endpoint is the result a trial measures, and here it was "an improvement in annualized growth velocity," the speed of growth in height over a year ¹. The label adds that continued approval "may be contingent upon verification and description of clinical benefit in confirmatory trial(s)" ¹.

FDA said in 2021 that a condition of the approval was a post-marketing study "that will assess final adult height" ². In 2023 FDA replaced that requirement with a final-adult-height trial in children whose growth plates are open, its final report due August 2026 ⁶.

The 2021 approval covered children "five years of age and older" ². The label revised in November 2024 sets no lower age limit ¹. Drugs@FDA records an efficacy supplement, a later filing with new evidence about a drug's use, approved on October 20, 2023 ³. FDA's letter for that supplement says it expanded use "from pediatric patients who are 5 years of age and older to include all pediatric patients" ⁶.

See the FDA status of every peptide, updated weekly.

How does vosoritide work?

In achondroplasia, the label says, bone growth "is negatively regulated due to a gain of function mutation in fibroblast growth factor receptor 3 (FGFR3)" ¹. A gain-of-function mutation is a genetic change that makes a gene's product more active than it should be. FDA's plainer version is that the mutation makes this growth-regulating gene "overly active, which prevents normal bone growth" ².

Vosoritide binds a different receptor, a protein that receives a chemical signal, called natriuretic peptide receptor-B (NPR-B) ¹. That binding, the label says, "antagonizes FGFR3 downstream signaling": it dampens the chain of signals FGFR3 sends inside the cell ¹. As a result the drug "promotes chondrocyte proliferation and differentiation," the multiplying and maturing of cartilage cells ¹. FDA's summary is that the drug "reduces the growth regulation gene's activity and stimulates bone growth" ².

The label reports two measurements in children with achondroplasia ¹. After a dose, cyclic GMP in the urine, a marker of the receptor's activity, rose within the first four hours and was highest at two hours ¹. Daily treatment also raised a blood marker of growth-plate activity, collagen type X marker, which the label says "remains elevated beyond 24 months" ¹. The drug itself clears quickly ¹. Its mean half-life, the time for half of it to leave the blood, ranged from 21.0 to 27.9 minutes in 58 children studied over 52 weeks ¹.

What does the research show?

The larger of the two randomized trials is the one the label calls Study 1 ¹. It was a phase 3 trial, the large stage that precedes an approval, run at 24 sites in seven countries ⁴, ¹. It was randomized, double-blind and placebo-controlled ¹. Chance decided who received the drug and who received a dummy injection, and neither families nor investigators knew which ⁴.

The trial enrolled 121 children with genetically confirmed achondroplasia, aged 5.1 to 14.9 years ¹. Its entry criteria included an age of 5 to under 18 years and six months in a baseline growth study ⁴. Sixty were assigned to vosoritide and 61 to placebo, injected under the skin once a day for 52 weeks ¹. Trained caregivers gave the injections at home ⁴. Children with recent or planned limb-lengthening surgery were excluded ¹.

The main measure was annualized growth velocity, the speed of growth in height in centimeters a year ¹. Before treatment the mean was 4.26 centimeters a year in the vosoritide group and 4.06 in the placebo group ¹. After 52 weeks it had risen by 1.40 centimeters a year in the vosoritide group and fallen by 0.17 in the placebo group ¹.

The difference was 1.57 centimeters a year, with a 95 percent confidence interval of 1.22 to 1.93 ⁴, ¹. A confidence interval is the range in which the true difference probably lies, and this one sat well clear of zero ¹. The p value, the probability of a gap at least this large if the drug did nothing, was below 0.0001 ¹.

At the start, the children's mean height standard deviation score was -5.13 ¹. That score counts how far a child's height sits from the average, in standard deviations. Over the year it changed by -0.02 in the placebo group and by 0.26 in the vosoritide group ¹. The difference was 0.28, with a 95 percent confidence interval of 0.17 to 0.39 ¹.

The ratio of upper to lower body length, a measure of body proportion, changed by -0.02 with placebo and -0.03 with vosoritide ¹. The p value for that difference was 0.5, so chance alone could readily produce it ¹.

Two children in the vosoritide group left before week 52, and 119 completed the trial ⁴, ¹. Afterward, 58 children first assigned to vosoritide entered an open-label extension, in which everyone receives the drug and there is no placebo group ¹. Among those followed for two years from randomization, the label says, "the improvement in AGV was maintained," AGV being annualized growth velocity ¹. The trial's authors wrote, in a paper in the Lancet issue dated September 5, 2020: "It is not known whether final adult height will be increased, or what the harms of long-term therapy might be" ⁴. BioMarin Pharmaceutical, the maker, funded the trial ⁴, ¹.

Studied in people younger than 5: a phase 2 trial, an earlier and smaller stage, was published online on November 18, 2023 ⁵. It ran in 16 hospitals across Australia, Japan, the United Kingdom and the United States ⁵. It recruited 75 children aged 3 to 59 months with genetically confirmed achondroplasia ⁵. Eleven were "sentinels," who received vosoritide to set the dose for their age group ⁵. Of the rest, 32 were randomized to vosoritide and 32 to placebo, by daily injection for 52 weeks ⁵.

The efficacy measure in that trial was the change in height Z score, another name for the standard deviation score ⁵. Among the 64 randomized children, the change was 0.25 higher in the vosoritide group than in the placebo group ⁵. The 95 percent confidence interval ran from -0.02 to 0.53, which includes zero, the value that would mean no difference ⁵. The authors described the result as a "gain in the change in height Z score from baseline" ⁵. BioMarin funded this trial as well ⁵.

The label reports no result for body weight ¹. It says scores for weight and for body mass index (BMI), weight relative to height, were collected for at least six months before randomization, and reports no result for either ¹. Every clinical study in the label is of children with achondroplasia ¹. The label adds that long-term carcinogenicity studies, tests of whether a drug can cause cancer, "have not been performed" ¹. No clinical study of drug interactions has been conducted, it says ¹.

What are the side effects?

Under "Contraindications," the label says "None" ¹. Its one warning is headed "Risk of Low Blood Pressure" ¹. In the main trial, 8 of 60 children on vosoritide (13 percent) had a transient fall in blood pressure, against 3 of 61 on placebo (5 percent) ¹. In the vosoritide group the falls began a median of 31 minutes after the injection and resolved within a median of 31 minutes ¹. Two of the 60 had an episode with symptoms, vomiting or dizziness or both, against none of the 61 on placebo ¹.

The label notes that children with "significant cardiac or vascular disease" and patients on blood-pressure medicines were excluded from the trials ¹. It tells prescribers to "instruct patients to be well hydrated and have adequate food intake prior to administration" ¹.

Injection-site reactions were the most common effect, and they were common with placebo too ¹. They occurred in 51 of 60 children on vosoritide (85 percent) and 50 of 61 on placebo (82 percent) ¹. The number of events differed more: 6,983 with vosoritide and 1,776 with placebo, or 120.4 against 29.2 per person per year ¹. Two children in the vosoritide group stopped treatment because of "pain and anxiety with injections" ¹.

Several other reactions were more frequent with vosoritide than with placebo in that trial ¹. Swelling at the injection site affected 62 percent against 36 percent, and hives there 25 percent against 10 percent ¹. Vomiting affected 27 percent against 20 percent, and joint pain 15 percent against 7 percent ¹. A rise in alkaline phosphatase, an enzyme measured in blood tests, was seen in 17 percent against 7 percent ¹.

In the published report, 59 of 60 children on vosoritide and 60 of 61 on placebo had at least one adverse event ⁴. No serious adverse event was judged related to treatment, and no child died ⁴.

For children younger than 5, the label reports Study 2, in which 64 were randomized and 11 treated open-label; injection-site reactions (86 percent) and rash (28 percent) were most common ¹. It calls the overall safety profile "similar to that seen in older pediatric patients" ¹. The report of the trial in children aged 3 to 59 months counted 204.5 adverse events per patient per year with vosoritide and 73.6 with placebo ⁵. Most were transient reactions at the injection site ⁵.

Serious adverse events in that trial occurred in 3 of 43 children given vosoritide (7 percent), the 11 sentinels included, and 6 of 32 on placebo (19 percent) ⁵, ⁷. One child in the vosoritide group died, and the report lists sudden infant death syndrome among that group's serious events ⁵. The trial's registry record, posted by BioMarin, lists the death as "sudden infant death syndrome, not related" ⁷.

Since approval, abnormal hair growth (hypertrichosis) has been reported, at a frequency the label says is not always possible to estimate reliably ¹. Antibodies against the drug were found in 46 of 131 treated children aged 5 and older (35 percent) ¹. None of those antibodies neutralized the drug, and the label reports no link with injection-site reactions, or with growth at month 12 ¹.

The label says Voxzogo "is not recommended for patients with eGFR < 60 mL/min/1.73 m2," eGFR being an estimate of how well the kidneys filter ¹. It has "no available data" on use in pregnancy and no information on whether the drug passes into human milk ¹.

In sport

Vosoritide is not named on the 2026 Prohibited List of WADA, the World Anti-Doping Agency ⁸. Section S2 is headed "Peptide hormones, growth factors, related substances, and mimetics" ⁸. Its growth-factor part, S2.3, names several growth factors and then adds "other growth factors or growth factor modulators affecting muscle, tendon or ligament protein synthesis/degradation, vascularisation, energy utilization, regenerative capacity or fibre type switching" ⁸.

What JumpstartMD offers

JumpstartMD does not prescribe vosoritide. Our peptide library covers it so you have the facts on its FDA status and the evidence, current as of November 10, 2026.

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Compounded medications are not FDA-approved, and FDA does not review their safety, effectiveness, or quality before they are marketed. A licensed clinician decides after an evaluation whether a peptide is appropriate for you, and not every patient will qualify.