AuthorisedPhase II and Phase III (Integrated)Interventional

A Multicenter, Randomized, Operationally Seamless Phase 2/3 Study to Evaluate the Efficacy and Safety of BMN 333 versus Vosoritide in Children with Achondroplasia

This research study is comparing two treatments, BMN 333 and Voxzogo, for children who have achondroplasia. Achondroplasia is a condition that affects how bones grow, leading to shorter stature. The main goal of the study is to see how much these medicines help children grow taller over 52 weeks, and to find out if they are safe to use. Voxzogo is already an approved medicine, and BMN 333 is a newer treatment being investigated. By comparing them, researchers hope to understand which treatment might be more effective and better tolerated for children with this condition. This study is split into two parts: an early phase to get initial information and a later, larger phase to confirm the findings.

At a glance

Status

Authorised

Phase

Phase II and Phase III (Integrated)

Sponsor

Biomarin Pharmaceutical Inc.

Enrolment target

Start

05 May 2026

Achondroplasia

What is this study about?

This study is investigating new and existing medicines for children with achondroplasia. Achondroplasia is a genetic condition that affects bone growth, leading to shorter arms and legs, and a shorter stature overall. The scientists are looking at two medicines: BMN 333, which is a new medicine they are testing, and Voxzogo, which is a medicine already available and approved for use.

The main aim of this study is to compare these two medicines. Researchers want to see how much each medicine helps children grow taller over a 52-week period. They will measure growth carefully to understand if either treatment makes a noticeable difference. Another very important part of the study is to check for side effects and make sure the medicines are safe for children to use. They will be looking at things like hospital visits, any serious reactions, and overall health.

By doing this study, the researchers hope to find better and safer ways to help children with achondroplasia grow. The information gathered from this research could ultimately lead to new or improved treatments becoming available.

Key takeaways

This study compares two treatments for achondroplasia: a new medicine (BMN 333) and an approved one (Voxzogo).
The main goals are to see how much children grow and if the medicines are safe over 52 weeks.
Participation involves regular injections and clinic visits for health checks and tests.
There's a chance your child could get either treatment.
You can withdraw your child from the study at any time.

Who may be eligible?

This study is open to children of all ages, both boys and girls, who have achondroplasia. The researchers will look at each child's health closely to make sure they are suitable and that taking part is safe for them.

There will be specific health checks and tests to confirm a child can join the study. These checks are important to ensure the study is conducted safely and that the results are as accurate as possible. Your child's doctor or the study team will be able to tell you if your child meets all the necessary requirements to participate.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Does my child have achondroplasia?
Is my child currently healthy enough to take part in a study?
Am I able to commit to regular clinic visits for my child?
Am I comfortable with my child receiving injections and having various medical tests?

Answer every question to see your result.

What does participation involve?

If your child takes part in this study, they would receive either the new medicine (BMN 333) or the approved medicine (Voxzogo) through injections. These injections would be given regularly over 52 weeks (about a year). Throughout this time, your child would have several visits to the clinic.

During these visits, the study team would carefully check your child's health. This would involve taking measurements like their standing height, as well as blood tests, urine tests, and checks of their heart (ECG). They would also have X-rays and scans to look at their bones. These checks are vital to see how the medicine is affecting your child's growth and to monitor for any side effects. After the 52 weeks of treatment, there might be follow-up visits to continue monitoring your child's health. The total time your child is involved in the study would include these treatment and follow-up periods.

Potential risks and benefits

Taking part in a study like this could potentially offer your child access to a new treatment (BMN 333) that might help with growth. Even if they receive the approved treatment (Voxzogo), they would be closely monitored by a specialist team. However, there are also potential risks. Both medicines can have side effects, which the study team will explain in detail. Injections can sometimes cause discomfort or bruising. All tests and procedures have a small risk as well. You have the right to withdraw your child from the study at any time, for any reason, without it affecting their regular medical care.

Locations (3)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
Poland
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Unverified
Italy
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Unverified
Romania

Common questions

What is achondroplasia?

Achondroplasia is a condition that affects how bones grow, leading to shorter arms, legs, and overall height.

What are BMN 333 and Voxzogo?

BMN 333 is a new medicine being tested, and Voxzogo is an approved medicine, both for treating achondroplasia.

How will the medicines be given?

Both medicines are given as injections, likely under the skin.

How long will the study last?

The main treatment part of the study lasts for 52 weeks (about a year), with follow-up appointments after that.

Will my child definitely get the new medicine?

No, this study is comparing two medicines, so your child could receive either the new medicine (BMN 333) or the approved medicine (Voxzogo).