Phase 3 trial shows vosoritide improves growth in children with hypochondroplasia

BioMarin Pharmaceutical announced positive phase 3 results for vosoritide (VOXZOGO) in children with hypochondroplasia, reporting statistically significant improvements in growth outcomes compared with placebo after 52 weeks of treatment.¹

According to the company, the global CANOPY-HCH-3 trial (NCT07126262) met its primary endpoint, demonstrating a statistically significant increase in annualized growth velocity (AGV) among children treated with vosoritide. The least squares mean difference compared with placebo was +2.33 cm/year (P < .0001). Investigators also reported statistically significant improvements in standing height and height Z-score compared with placebo after 1 year of treatment.^1,2

Additional findings showed significant improvements in arm span, a prespecified secondary endpoint, with investigators noting that the outcome may have implications for independence and daily functioning in children with hypochondroplasia.

“As someone who treats children with hypochondroplasia, I find these positive results tremendously encouraging. Seeing these improvements in growth is a milestone we have hoped for after so many years without treatment options,” said Andrew Dauber, MD, lead study investigator and chief of endocrinology at Children’s National Hospital in Washington, DC. “These data suggest we may be approaching a new era in how we care for children with hypochondroplasia.”

What is hypochondroplasia?

Hypochondroplasia is a rare genetic skeletal dysplasia characterized by impaired bone growth that leads to disproportionate short stature and skeletal differences involving the long bones, spine, and other parts of the skeleton. Clinical manifestations may affect physical functioning and quality of life and can include neurologic and otolaryngologic complications. The condition is often identified during toddlerhood or early school age based on clinical and radiologic findings.

Currently, no therapies are approved by the FDA or the European Medicines Agency specifically for hypochondroplasia.

How could vosoritide change treatment for hypochondroplasia?

“For the first time, a pivotal phase 3 study in hypochondroplasia has demonstrated impressive gains in growth, including improvements in arm span, highlighting VOXZOGO's potential to fundamentally change the treatment landscape for this condition,” said Greg Friberg, MD, executive vice president and chief research and development officer at BioMarin. “We are incredibly pleased with these results, which exceeded our expectations for this study, and we are deeply grateful to the families and investigators who made this outcome possible. We look forward to sharing these data with regulatory authorities and the broader community as we work to bring this medicine to children living with hypochondroplasia around the world.”

The CANOPY-HCH-3 study enrolled 80 children aged 3 to 17 years in a randomized, double-blind, placebo-controlled design conducted across multiple centers globally. In addition to AGV, secondary endpoints included standing height, arm span, upper-to-lower body segment ratio, health-related quality of life, safety, and tolerability assessments. Participants will continue in a long-term extension study.

BioMarin reported that the safety profile observed in children with hypochondroplasia was consistent with the established experience of vosoritide in achondroplasia, with no new safety signals identified during the study.

When could FDA submission for vosoritide in hypochondroplasia occur?

Vosoritide is currently approved in the United States, Japan, Australia, and Europe for increasing linear growth in children with achondroplasia who have open growth plates. In the United States, the therapy received accelerated approval based on improvements in annualized growth velocity.

BioMarin stated that a supplemental New Drug Application for hypochondroplasia is planned for submission to the FDA during the third quarter of 2026, with additional regulatory submissions planned for Europe and other regions

References

1. BioMarin Pharmaceutical. BioMarin Announces Positive Phase 3 Pivotal Study Results for VOXZOGO® (vosoritide) in Children with Hypochondroplasia. BioMarin Pharmaceutical.. May 20, 2026. Accessed May 20, 2026. https://investors.biomarin.com/news/news-details/2026/BioMarin-Announces-Positive-Phase-3-Pivotal-Study-Results-for-VOXZOGO-vosoritide-in-Children-with-Hypochondroplasia/default.aspx
2. BioMarin Pharmaceutical Clinical Trials. A Study of Vosoritide Versus Placebo in Children With Hypochondroplasia Aged 0 to < 36 Months. BioMarin Pharmaceutical. 2026. Accessed May 20, 2026. https://clinicaltrials.biomarin.com/clinical-trial/a-study-of-vosoritide-versus-placebo-in-children-with-hypochondroplasia-aged-0-to-36-months/