Carlos E Prada | Search PubMed

PubMed2026

A Phase 3 Trial of Vosoritide in Children with Hypochondroplasia.

BACKGROUND: Hypochondroplasia, a fibroblast growth factor receptor 3 (FGFR3)-related skeletal condition characterized by disproportionate short stature and a spectrum of clinical features, has no available targeted therapies. Vosoritide, a C-type natriuretic peptide analogue approved for the treatment of achondroplasia, is being investigated for hypochondroplasia. METHODS: In this phase 3, multicenter trial, children with hypochondroplasia who were 3 to less than 18 years of age were randomly assigned to receive once-daily subcutaneous injections of vosoritide or placebo for 52 weeks per weight-band dosing regimen. The primary end point was change from baseline in annualized growth velocity at week 52 versus placebo. Confirmatory statistical testing using hierarchical procedures to control for type I error at the one-sided 0.025 significance level (equivalent to the two-sided 0.05 level) was performed for the primary and six key secondary efficacy end points. The safety and side effect profile of vosoritide versus placebo was assessed. RESULTS: A total of 81 participants were randomly assigned to receive vosoritide (n=41) or placebo (n=40). At week 52, the least squares mean (LSM) change from baseline in annualized growth velocity was 1.95 cm/year with vosoritide versus -0.39 cm/year with placebo (LSM difference of 2.33 cm/year; 95% confidence interval, 1.85-2.82 cm/year; two-sided P<0.0001). Most participants in the vosoritide group (87.8%) and the placebo group (72.5%) experienced at least one adverse event (AE). There were no reports of grade 3 or higher AEs, AEs leading to treatment discontinuation, or deaths. CONCLUSIONS: One year of vosoritide treatment significantly increased linear growth in children with hypochondroplasia. (Funded by BioMarin Pharmaceutical; ClinicalTrials.gov number, NCT06455059.).

Journal Article↗

PubMed2026

Clinical and Functional Characterization of Gain-of-Function ABL1 Variants Expands the Phenotypic Spectrum of CHDSKM.

Germline gain-of-function (GOF) variants in ABL1 cause congenital heart defects and skeletal malformations syndrome (CHDSKM), a multisystem developmental disorder characterized by congenital heart disease, skeletal abnormalities, dysmorphic features, and variable developmental delay. More recently, biallelic loss-of-function variants and ABL haploinsufficiency have been associated with distinct phenotypes, expanding the allelic spectrum of ABL1-related disorders. We report three individuals with ABL1 variants. A female infant with tetralogy of Fallot, critical pulmonary stenosis, covered omphalocele, and a lethal outcome was found by rapid trio genome sequencing to harbor a de novo likely pathogenic ABL1 variant, NM_007313.2:c.354G>T p.(Trp118Cys). We also provide updated clinical follow-up of a previously reported individual and describe a third individual, both carrying the recurrent p.(Tyr245Cys) variant. Functional studies were performed and support a GOF mechanism. Similar activation was observed for Tyr245Cys despite the differences in clinical severity. Our findings expand the phenotypic spectrum of ABL1-related CHDSKM to include severe conotruncal heart disease and covered omphalocele. The comparison of two biochemically activating ABL1 variants demonstrates substantial clinical variability despite a shared molecular mechanism. Furthermore, the overlap between ventral body wall abnormalities in GOF disease and omphalocele associated with ABL1 haploinsufficiency suggests that precise regulation of ABL1 signaling is critical for normal ventral body wall formation.

ABL1↗