A Phase 2 Study of Vosoritide in Children With Idiopathic Short Stature

What Was Tested

This registered phase 2 trial tested Vosoritide.

It had five arms (groups): one (experimental), one (experimental), one (experimental), Placebo (placebo comparator) and Human Growth Hormone (active comparator).

The registry classes the interventions as drug.

More on the Plan

Participants randomized to the hGH group will receive open-label hGH for a minimum of 4 years.

A Treatment Completion visit will occur approximately 4 weeks after the last administration of investigational product.

Participants who discontinue study treatment after ≥13 weeks of exposure may remain in the study and complete follow-up assessments per the protocol schedule (including annual and periodic assessments through End of Study).

If a participant discontinues treatment and declines further participation, they will be asked to return for a final Treatment Completion and End of Study visit approximately 4 weeks after the last injection.

Who Took Part

The registry lists 100 planned participants were the target.

It was open to people of any sex aged from 3 years up to 11 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Previous treatment with a growth promoting agent.

The full record lists 4 inclusion and 0 exclusion criteria.

How the Study Was Run

Design: randomized, parallel-group and quadruple-blind.

Because people in this Vosoritide study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Groups ran in parallel: each of the participants stayed in one arm throughout.

Blinding on both sides kept the participants and researchers unaware of who received Vosoritide.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2024-10-21 with completion listed for 2026-06.

It ran at 47 sites in United States (35), France (4), Italy (3), South Korea (3), Australia (1) and Germany (1).

Its stated primary purpose is treatment.

What Was Measured

Researchers chose this as the main measure: Change from baseline in Annualized Growth Velocity (AGV) (time frame: At 6 months). Change from baseline in height (time frame: At 4 years). Change from baseline in height Z-score (time frame: At 4 years).

It also tracked 18 secondary outcomes, for example Incidence of treatment-emergent adverse events, Change from baseline in Height Z-score (average stature reference), Change from baseline in height, Change from baseline in height Z score, Change from baseline at prespecified timepoints in urine cyclic guanine monophosphate (cGMP) and Change from baseline at pre-specified timepoints in serum collagen X marker (CXM).

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Vosoritide in 100 people.

It is still recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Vosoritide compound page, all human trials.