VOXZOGO (vosoritide) significantly improved growth velocity, height and arm span in children with hypochondroplasia in the Phase 3 CANOPY-HCH-3 trial.
Written By: Charvi Kalal, Pharm D
Reviewed By: Pharmacally Editorial Team
BioMarin announced new data from its Phase 3 CANOPY-HCH-3 study evaluating VOXZOGO (vosoritide) in children with hypochondroplasia. Published in NEJM Evidence and presented at the ESPE 2026 Annual Meeting, the results showed statistically significant improvements in annualized growth velocity (AGV), standing height, height Z-score, and arm span after 52 weeks of treatment. The safety profile was consistent with previous experience with VOXZOGO in achondroplasia.
A Targeted Therapy for Hypochondroplasia
Hypochondroplasia is a rare genetic skeletal dysplasia, primarily associated with activating variants in FGFR3 that impair endochondral bone growth and cause disproportionate short stature and other skeletal abnormalities. Unlike achondroplasia, hypochondroplasia currently has no FDA- or EMA-approved disease-directed treatment.
VOXZOGO is a C-type natriuretic peptide analog that acts through natriuretic peptide receptor-B signaling to counteract excessive FGFR3 signaling and promote endochondral bone growth. BioMarin estimates that approximately 14,000 children with hypochondroplasia across its global markets could potentially be candidates for treatment.
Phase 2 Evidence Supported Phase 3 Development
CANOPY-HCH-3 builds on an earlier Phase 2, single-arm, open-label study of vosoritide in children with hypochondroplasia. Among 26 enrolled children, 24 received treatment for 12 months following a six-month observation period. Annualized growth velocity increased by 1.81 cm/year, while height standard deviation score increased by 0.36 SD. No treatment-related serious adverse events were reported, supporting further evaluation in a randomized Phase 3 trial.
CANOPY-HCH-3 Results
CANOPY-HCH-3 was a global, randomized, double-blind, placebo-controlled Phase 3 study in children aged 3 to under 18 years with hypochondroplasia. The trial randomized 81 children to once-daily subcutaneous vosoritide or placebo for 52 weeks. The primary endpoint was change from baseline in AGV compared with placebo.
VOXZOGO met the primary endpoint, producing a least-squares mean difference in AGV of 2.33 cm/year versus placebo (p<0.0001).
Statistically significant improvements were also observed in:
- Standing height: +2.35 cm (p<0.0001)
- Height Z-score: +0.39 SD (p<0.0001)
- Arm span: +1.03 cm (p=0.0082)
Upper-to-lower body segment ratio and health-related quality of life were also assessed as prespecified outcomes. Although numerical findings favored vosoritide, these outcomes did not reach statistical significance under the hierarchical testing procedure.
Safety and Regulatory Status
The safety profile was consistent with established vosoritide experience in achondroplasia, with most adverse events mild and no treatment-related serious adverse events identified. Known risks include transient hypotension, injection-site reactions, increased alkaline phosphatase, vomiting, joint pain, and abdominal pain. Adequate food and fluid intake before dosing is recommended to reduce blood-pressure-related symptoms.
Following the positive Phase 3 results, BioMarin submitted an sNDA to the FDA seeking approval of VOXZOGO for hypochondroplasia and plans submissions to the EMA and other regional regulators. VOXZOGO is not currently approved for hypochondroplasia.
Separately, BioMarin has an achondroplasia-related supplemental application under FDA review with a February 28, 2027 target action date. This regulatory application is separate from the newly submitted hypochondroplasia application.
Potential Clinical Impact
If approved, VOXZOGO would become the first targeted therapy specifically indicated for hypochondroplasia. The CANOPY-HCH-3 findings provide randomized evidence of improved growth velocity and several measures of linear growth. However, because the primary treatment period was 52 weeks, longer-term follow-up will be needed to determine whether these gains translate into sustained improvements in final adult height, body proportionality, functional outcomes, quality of life, and long-term safety.
References
BioMarin Pharmaceutical Inc. BioMarin Announces Positive Results of Phase 3 VOXZOGO (vosoritide) Study in Hypochondroplasia Published in NEJM Evidence. September 9, 2026.
About the Writer
Charvi Kalal (LinkedIn) is a Pharm.D intern and aspiring medical writer with hands-on experience in medical writing, clinical research, pharmacovigilance, and clinical pharmacy. She has experience in medical content writing through CliMed, along with exposure to ADR monitoring, prescription analysis, patient counselling, literature review, and research documentation. Her research focuses on ADR monitoring and reporting in breast cancer patients receiving targeted therapy. With certifications in GCP, biomedical research, scientific writing, and clinical research, she is passionate about transforming scientific evidence into accurate, engaging, and accessible healthcare content.