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Active, not recruitingNCT04554940Updated Mar 13, 2026

A Clinical Trial to Evaluate Safety of Vosoritide in At-risk Infants With Achondroplasia

A Phase 2 interventional study of vosoritide in Achondroplasia, sponsored by BioMarin Pharmaceutical. Active, not recruiting at 3 sites in 2 countries. Open to participants aged 0 Months to 12 Months. Per ClinicalTrials.gov, last updated 2026-03-13.

Sponsored by BioMarin Pharmaceutical · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
20
Allocation
Randomized
Ages
0 Months to 12 Months
Sex
All
01

Study summary

Study 111-209 is a Phase 2 randomized, open-label clinical trial of BMN 111 in infants and young children with a diagnosis of Achondroplasia at a heightened risk of requiring cervicomedullary decompression surgery

02

Conditions studied

  • Achondroplasia

Keywords

  • Dwarfism
  • Bone Diseases
  • Bone Diseases, Developmental ACH
  • Natriuretic Peptide, C-Type
  • Musculoskeletal Diseases
03

In context

Achondroplasia

47 studies on the registry are indexed under Achondroplasia; 13 are open to participants now.

This study's enrollment of 20 is below the median of 74 across 28 interventional studies indexed under Achondroplasia.

Browse Achondroplasia studies →

Lead sponsor

BioMarin Pharmaceutical is the lead sponsor of 112 studies on the registry; 13 are open to participants now.

Of its 17 completed or terminated interventional studies of FDA-regulated products, 12 (71%) have results posted.

Browse BioMarin Pharmaceutical studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
0 Months to 12 Months
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Parent(s) or guardian(s) willing and able to provide signed after the nature of the study has been explained and prior to performance of any research related procedure.
  • Have ACH, documented by genetic testing.
  • Are willing and able to perform all study procedures as physically possible.
  • Age 0 to ≤ 12 months, at study entry (Day 1). Given that any potential impact of vosoritide therapy on the foramen magnum is dependent on treating as early as possible and as long as possible while the synchondroses at the base of the skull are still open. For subjects > 6 months of age at enrollment, a discussion between the investigator and the Medical Monitor should occur with the goal of limiting the number of subjects in the range of > 6 months to ≤ 12 months of age.
  • Parent(s) or caregiver(s) are willing to administer daily injections to the subject and complete the required training.
  • Have evidence of CMC that "may" require surgical intervention

Exclusion criteria

Exclusion Criteria:

  • Have hypochondroplasia or short-stature condition other than achondroplasia (eg, trisomy 21, pseudoachondroplasia, etc).
  • Have CMC that either does not require surgical intervention (for example foramen magnum narrowing with preservation of the cerebrospinal fluid space) or does require immediate surgical intervention .
  • Have any of the following: Untreated congenital hypothyroidism or maternal history of hyperthyroidism, Insulin-requiring neonatal diabetes mellitus, inflammatory disease, Inflammatory bowel disease, Autonomic neuropathy.
  • Have a history of any of the following:Renal insufficiency, Chronic anemia,Baseline systolic blood pressure below age and gender specified normal range or recurrent symptomatic hypotension (defined as episodes of low blood pressure generally accompanied by symptoms eg, pallor, cyanosis, irritability, poor feeding) and Cardiac or vascular disease.
  • Have a finding or arrhythmia that indicates abnormal cardiac function or conduction or -F ≥ 450 msec on screening .
  • Have been treated with growth hormone, insulin-like growth factor 1, or anabolic steroids in the 6 months prior to Screening, or long-term treatment (> 3 months) at any time.
  • Have ever had prior cervicomedullary decompression surgery.
  • Have had a fracture of the long bones or spine within 6 months prior to Screening.
Terms in these criteria, in plain language(5)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
20 participants (actual)

Study arms

  • Experimental
    Vosoritide + Standard of Care

    Standard of Care treatment for cervicomedullary compression and once daily subcutaneous injection of recommended dose of vosoritide based on weight-band dosing.

    Biological: vosoritide

  • No intervention
    Standard of Care Alone

    Institutional standard of care monitoring and treatment for cervicomedullary compression

Interventions

  • Biologicalvosoritide

    Subcutaneous injection of recommended dose of BMN 111 based on weight-band dosing once daily.

06

What researchers measure

Primary outcomes

  1. Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]

    Time frame: Through Week 260

Secondary outcomes

  1. Evaluate the effect of Vosoritide on total foramen magnum volume (in cm3) by MRI volumetric measurement software

    Time frame: Through Week 260

07

Study locations

3 sites
08

References and documents

Publications

  • Savarirayan R, Irving M, Maixner W, Thompson D, Offiah AC, Connolly DJ, Raghavan A, Powell J, Kronhardt M, Jeha G, Ghani S, Fisheleva E, Day JR. Rationale, design, and methods of a randomized, controlled, open-label clinical trial with open-label extension to investigate the safety of vosoritide in infants, and young children with achondroplasia at risk of requiring cervicomedullary decompression surgery. Sci Prog. 2021 Jan-Mar;104(1):368504211003782. doi: 10.1177/00368504211003782. PubMed 33761804 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 13, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04554940
Lead sponsor
BioMarin Pharmaceutical
Responsible party
Sponsor
First posted
Sep 18, 2020
Start date
Oct 10, 2020
Primary completion
Dec 2027 (estimated)
Completion
Dec 2027 (estimated)
Last update
Mar 13, 2026

Study contacts

Medical Director, MD
study director · BioMarin Pharmaceutical

Oversight

FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.

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Discussion

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