BioMarin Pharmaceutical has announced positive pivotal Phase 3 results for VOXZOGO (vosoritide) in children with hypochondroplasia, the most common skeletal dysplasia after achondroplasia, for which there are currently no approved pharmacological treatments.

In the CANOPY-HCH-3 study, VOXZOGO met its primary endpoint, improving annualised growth velocity by 2.33 centimetres per year compared to placebo at week 52. The result is clinically meaningful in a population where impaired linear growth leads to disproportionate short stature and a range of orthopaedic complications throughout childhood and into adulthood.

Vosoritide is a C-type natriuretic peptide (CNP) analogue that works by inhibiting the FGFR3 signalling pathway, the same pathway dysregulated in both achondroplasia and hypochondroplasia. VOXZOGO is already FDA-approved and EMA-approved for achondroplasia; if the hypochondroplasia indication secures approval, it would substantially expand the addressable patient population for the drug.

Hypochondroplasia affects approximately 1 in 15,000 to 1 in 40,000 live births globally. Despite sharing overlapping molecular pathology with achondroplasia, hypochondroplasia has historically received less clinical research attention due to its more variable phenotypic presentation and the challenges of phenotypic stratification in clinical trial design.

The CANOPY-HCH-3 data will support regulatory submissions to the FDA and EMA. BioMarin has not yet announced a submission timeline. The result reinforces CNP-analogue biology as a durable therapeutic approach for FGFR3-related skeletal dysplasias and highlights the growing appetite among developers for label expansions that leverage existing safety profiles and manufacturing infrastructure to serve additional rare disease populations.