BioMarin's vosoritide meets primary endpoint in Phase III hypochondroplasia trial

BioMarin Pharmaceutical (Nasdaq: BMRN) [reported](https://www.prnewswire.com/news-releases/biomarin-announces-positive-phase-3-pivotal-study-results-for-voxzogo-vosoritide-in-children-with-hypochondroplasia-302778176.html) that vosoritide (Voxzogo) met its primary endpoint in the Phase III CANOPY-HCH-3 study in children with hypochondroplasia, producing a 2.33 cm/yr improvement in annualized growth velocity versus placebo — the first pivotal trial to demonstrate a statistically significant growth benefit in this condition, which currently has no approved pharmacotherapy. [CANOPY-HCH-3](https://app.allsci.com/clinical-trial/ASC-CT-0000000179371-1.0-1745776457) is a Phase III, randomized, double-blind, placebo-controlled, multicenter study enrolling 80 children aged 3 to 17 with hypochondroplasia in a 1:1 ratio. The primary endpoint was change from baseline in annualized growth velocity at 52 weeks. The primary endpoint was met with a least-squares mean difference in annualized growth velocity of +2.33 cm/yr compared to placebo at week 52, which BioMarin described as highly statistically significant (p-value not fully disclosed in the press release). Arm span, a prespecified key secondary endpoint and a measure linked to functional independence in daily activities, also improved significantly versus placebo (p\=0.004). Statistically significant increases in standing height and height Z-score were additionally reported, though full numerical data for these and other secondary endpoints — including upper-to-lower body segment ratio and health-related quality of life — are pending presentation at a forthcoming medical meeting. The safety profile was consistent with vosoritide's established record in achondroplasia, with no new safety signals identified. Known effects include injection site reactions, transient reductions in blood pressure, elevated alkaline phosphatase, and gastrointestinal symptoms. ## The trial context Hypochondroplasia is a rare skeletal dysplasia caused by mutations in the fibroblast growth factor receptor 3 (FGFR3) gene, the same receptor implicated in achondroplasia, though the clinical presentation is generally milder and more variable. Unlike achondroplasia, hypochondroplasia has received comparatively limited clinical trial attention, and no drug has been approved by the US FDA or the European Medicines Agency for its treatment. [Vosoritide ](https://app.allsci.com/drugs/ASC-DR-0000000011323-1.0-1757706147)is a C-type natriuretic peptide (CNP) analog that activates natriuretic peptide receptor-B (NPR-B/NPR2), increasing intracellular cGMP signaling in growth-plate chondrocytes to promote endochondral bone growth. The mechanistic rationale for extending the drug into hypochondroplasia follows directly from the shared FGFR3 biology: both conditions involve dysregulated FGFR3 signaling that suppresses the CNP/NPR-B pathway in the growth plate. The 2.33 cm/yr AGV improvement observed in CANOPY-HCH-3 is notable in this context, as it suggests the CNP-axis intervention translates across FGFR3-related dysplasias beyond achondroplasia. BioMarin's position in this space reflects the broader competitive dynamics shaping the CNP-analog class. In achondroplasia, vosoritide faces a direct challenge from Ascendis Pharma's TransCon CNP (navepegritide), a pegylated long-acting CNP prodrug also targeting NPR-B, which reported positive Phase III ACHieve trial data in 2024 showing statistically significant annualized growth velocity improvements. Navepegritide's once-weekly dosing profile contrasts with vosoritide's daily subcutaneous injection, a distinction that could carry commercial weight in the achondroplasia market where BioMarin holds first-mover status following its [2021 US FDA approval.](https://app.allsci.com/article/ASC-PB-0000469275888-1.0-1774251161) In hypochondroplasia specifically, however, the competitive field is less developed. No approved therapy exists, and CANOPY-HCH-3 appears to be the first completed Phase III randomized controlled trial in the condition. BridgeBio's infigratinib, an oral FGFR inhibitor with mechanistic relevance to FGFR3-driven dysplasias, has been evaluated in achondroplasia but data in hypochondroplasia are not established from the available information. BioMarin plans to submit a supplemental New Drug Application to the US FDA in Q3 2026, followed by submissions to the EMA and other regional health authorities. The company submitted an sNDA for full approval of vosoritide in achondroplasia in April 2026 — converting from accelerated approval granted on the basis of AGV improvement — and expects notification of sNDA acceptance by Q3 2026. The hypochondroplasia submission would represent a separate indication expansion. The regulatory submission timeline positions a potential US FDA decision on the hypochondroplasia indication in 2027, assuming standard review timelines, though BioMarin has not disclosed a specific target action date. *** This article was generated with AI assistance and reviewed and edited by the AllSci editorial team Explore more at AllSci News: [https://allsci.com/news/](https://allsci.com/news/) --- Spot something wrong? [Report an issue with this article](https://newsgen-prod.reframedata.com/feedback/vosoritide-hypochondroplasia-trial-biomarins)