BioMarin's VOXZOGO hits growth-velocity target in hypochondroplasia trial
The CANOPY-HCH-3 Phase 3 study showed a 2.33 cm/yr growth-velocity gain over placebo, setting up an FDA sNDA filing planned for the third quarter of 2026.
Executive Summary
- BioMarin's pivotal hypochondroplasia trial cleared its primary growth-velocity endpoint against placebo, with the improvement carrying over into height, height Z-score, and arm span.
- The company is moving directly from that readout into a U.S. regulatory filing, positioning vosoritide for a second approved indication beyond its existing achondroplasia label.
- Vosoritide is the only NPR-B-targeted therapy to reach Phase 3 testing in hypochondroplasia, with the nearest peer programs still in earlier-phase testing in the related achondroplasia population.
- Because vosoritide's growth-promoting effect is already established in achondroplasia, the filing tests whether regulators accept replication of that established effect in a related, smaller-studied skeletal dysplasia.
The readout
BioMarin announced on May 20, 2026 that CANOPY-HCH-3, a global Phase 3 study of 80 children ages 3 to 17 with hypochondroplasia, showed a statistically significant improvement in annualized growth velocity (AGV) at Week 52 versus placebo, with a least-squares mean difference of 2.33 cm/yr (p<0.0001). The trial also hit key secondary endpoints: standing height (p<0.0001), height Z-score (p<0.0001), and arm span (p=0.004), a prespecified secondary endpoint the company called a measure linked to functional independence. Andrew Dauber, the lead study investigator and chief of endocrinology at Children's National Hospital, called the results "a milestone we have hoped for after so many years without treatment options". BioMarinBioMarin Announces Positive Phase 3 Pivotal Study Results for VOXZOGO® (vosoritide) in Children with HypochondroplasiaMay 20, 2026
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
The design
CANOPY-HCH-3 (Study 111-303, registered as NCT06455059) is a randomized, double-blind, placebo-controlled trial run across nine countries including the United States, Japan, and several European sites. The trial is registered as Active, not recruiting, with a primary completion date of August 1, 2026, and its enrollment held at its 80-patient target with no change in size. BioMarin reported that VOXZOGO's safety findings in the study were consistent with its established profile in achondroplasia, with no new safety signals identified. NCT06455059+1Interventional Study of Vosoritide for the Treatment of Children With HypochondroplasiaNCT06455059BioMarin Announces Positive Phase 3 Pivotal Study Results for VOXZOGO® (vosoritide) in Children with HypochondroplasiaMay 20, 2026
What comes next
BioMarin said the supplemental New Drug Application to the FDA is planned for the third quarter of 2026, to be followed by submissions to the European Medicines Agency and other regional health authorities. The company has guided to that Q3-2026 filing window consistently since the May readout. Full trial results are expected to be presented at a medical meeting beyond the topline release. BioMarinBioMarin Announces Positive Phase 3 Pivotal Study Results for VOXZOGO® (vosoritide) in Children with HypochondroplasiaMay 20, 2026
The competitive frame
Vosoritide already holds an approved profile in achondroplasia through BioMarin's other Phase 3 vosoritide programs, and CANOPY-HCH-3 extends that same NPR-B-activating mechanism into hypochondroplasia, a related but distinct skeletal dysplasia. Among industry trials in hypochondroplasia, vosoritide is the only program to reach Phase 3; the nearest indication peer, QED Therapeutics' infigratinib, an FGFR1 inhibitor with a different mechanism, remains in Phase 2/3 testing. Within the NPR-B activator class more broadly, Ascendis Pharma's navepegritide and BioMarin's own BMN 333 are advancing in the related achondroplasia population, meaning a positive hypochondroplasia filing carries readthrough for how regulators and investigators view NPR-B activation across skeletal dysplasias more broadly. NCT06455059Interventional Study of Vosoritide for the Treatment of Children With HypochondroplasiaNCT06455059
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.